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HPV na Prática Clínica

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Authored by Nejd F Alsikafi, MD, Staff Physician, Department of Surgery, Section of Urology, University of Chicago

Coauthored by Dimitri Kuznetsov, MD, Staff Physician, Department of Surgery, Section of Urology, University of Chicago; Glenn Gerber, MD, Director of Endourology, Director of Resident and Student Education, Associate Professor, Department of Surgery, Division of Urology, University of Chicago Pritzker School of Medicine

Injury to the ureter is one of the most serious complications of gynecologic surgery. Less common than injuries to the bladder or rectum, ureteral injuries are far more serious and troublesome and often are associated with a high morbidity, the formation of ureterovaginal fistulas, and the potential loss of kidney function, especially when recognized postoperatively. For these reasons, injuries to the urinary tract, particularly the ureter, are the most common cause for legal action against gynecologic surgeons.

Despite the close anatomical association between the female reproductive organs and the ureter, injury to the ureter is relatively uncommon. Nevertheless, when a ureteral injury does occur, quick recognition of the problem and a working knowledge of its location and treatment are essential in providing patients with optimal medical care. The purpose of this chapter is to elucidate how and why ureteral injuries occur and to review their surgical and nonsurgical treatments.

History of the Procedure: Berard (1841) and Simon (1869) reported the earliest recorded repairs of ureteral injuries in gynecologic surgery. While the exact details of this procedure are unknown, the ureter and its course were understood poorly. In the early 1900s, Dr John Sampson, then a young faculty member at Johns Hopkins University, conducted the first systematic study of the ureter. During the next 100 years, as the surgical management for gynecologic disease progressed, many contributions were made to the understanding of the etiology, prevention, diagnosis, and treatment of iatrogenic ureteral injuries.

Problem: A significant ureteral injury is defined as any recognized or unrecognized iatrogenic trauma to the ureter that prevents it from functioning properly or effectively. The injury may lead to acute ureteral obstruction (eg, a ureter that is inadvertently ligated) or discontinuity (ie, inadvertent ureteral resection). If an injury to the ureter has occurred and is unrecognized, it may lead to chronic ureteral obstruction (ie, crush injury, ischemia) or the formation of fistulas.

Frequency: The frequency of ureteral injury following gynecologic surgery is approximately 1%, with a higher percentage of injuries occurring during abdominal hysterectomies and partial vaginectomies. Patients who have received pelvic radiation or who have advanced pelvic cancers requiring extensive surgical procedures are more likely to experience a ureteral injury.
The rate of ureteral injuries in laparoscopic procedures varies. While some physicians report that laparoscopic procedures have an equivalent rate of ureteral stricture formation secondary to ureteral injury, other authors argue that the rates for ureteral strictures are significantly higher. More research is necessary before a definitive statement can be made regarding the rates of ureteral injury in laparoscopy.

Etiology: The 6 most common mechanisms of operative ureteral injury are as follows:

• Crushing from misapplication of a clamp
  
• Ligation with a suture
  
• Transsection (partial or complete)
  
• Angulation of the ureter with secondary obstruction
  
• Ischemia from ureteral stripping or electrocoagulation
  
• Resection of a segment of ureter

Any combination of these injuries may occur.
Several predisposing factors have been identified in iatrogenic urologic injury. These factors include uterus size larger than 12 weeks' gestation, ovarian cysts 4 cm or larger, endometriosis, pelvic inflammatory disease, prior intra-abdominal operation, radiation therapy, advanced state of malignancy, and anatomical anomalies of the urinary tract. Ureteral injuries can be either expected or unexpected, and they may be the result of carelessness or due to a technically challenging procedure.

Pathophysiology: The pathophysiology of ureteral injury depends upon many factors, including the type of injury and when the injury is identified. A number of consequences may occur after ureteral injury, including spontaneous resolution and healing of the injured ureter, hydronephrosis, ureteral necrosis with urinary extravasation, ureteral stricture formation, and uremia.

Spontaneous resolution and healing
If the injury to the ureter is minor, easily reversible, and noticed immediately, the ureter may heal completely and without consequence. Inadvertent ligation of the ureter is an example of such an injury. If this injury is noticed in a timely fashion, the suture can be cut off the ureter without significant injury.

Hydronephrosis
If complete ligation of the ureter occurs, the urine from the ipsilateral kidney is prevented from draining into the bladder, leading to hydronephrosis and progressive deterioration of ipsilateral renal function. These events may occur with or without symptoms. If the urine in this obstructed system becomes infected, the patient will almost certainly become septic with pyonephrosis.

Ureteral necrosis with urinary extravasation
In complete unrecognized ligation of the ureter, a section of the ureteral wall necroses because of pressure-induced ischemia. The ischemic segment of the ureter eventually weakens, leading to urinary extravasation into the periureteral tissues. If the urinary extravasation drains into the adjacent peritoneum, urinary ascites may develop. If the urinary ascites is infected, peritonitis may ensue. If the peritoneum has remained closed, a urinoma may form in the retroperitoneum.

Ureteral stricture
Ureteral stricture may occur when the adventitial layer of the ureter is stripped or electrocoagulated. When the adventitia, the outer layer of the ureter that contains the ureteral blood supply, is disturbed by either stripping or electrocoagulation, ischemia to a particular segment of ureter may result . Ischemic strictures of the ureter may develop subsequently, which leads to obstruction and hydronephrosis of the ipsilateral kidney.

Uremia
Uremia results when ureteral injury causes total urinary obstruction. This may result from bilateral ureteral injury or from a unilateral injury occurring in a solitarily functioning kidney. Anuria is the only immediate sign of imminent uremia. These cases require immediate intervention to preserve renal function.

Clinical: Iatrogenic ureteral injury from gynecologic surgery may present either intraoperatively or postoperatively. Intraoperative urologic consultation is obtained when the injury is recognized immediately; these patients are best treated with primary ureteral repair during the same operation. More than 70% of the time, unilateral ureteral injury is noticed postoperatively, when the patient may present with flank pain, prolonged ileus, fever, watery vaginal discharge, or elevated serum creatinine levels. In cases of bilateral ureteral injury, anuria is the first clinical sign.

The indications for evaluation of ureteral injury following gynecologic procedures include loin or costovertebral angle tenderness, unexplained fever, persistent abdominal distention, unexplained hematuria, escape of watery fluid through the vagina, appearance of lower abdominal or pelvic mass, and oliguria or elevated serum creatinine levels

Lab Studies:

• If the ureteral injury is noted intraoperatively, additional laboratory tests rarely, if ever, are needed. Imaging studies are of greater benefit.
  
• If ureteral injury is suspected postoperatively, laboratory tests, including a CBC with manual differential and an electrolyte panel with BUN and creatinine, are needed to assess for possible infection and renal dysfunction.
  
• In the event that a CT-guided aspiration of an abdominal or pelvic fluid collection has occurred, or if pelvic drain output is high through a surgically placed drain, a creatinine measurement of the fluid may be helpful in distinguishing whether the fluid is urine (ie, elevated creatinine level).

Imaging Studies:

• If the ureteral injury is noted intraoperatively and additional imaging is necessary to localize the lesion, the best imaging study is retrograde ureteropyelography. By placing a cystoscope in the bladder and cannulating the affected ureteral orifice with a ureteral catheter, dilute Cystografin is injected into the ureter under fluoroscopy or when taking a kidneys, ureters, bladder (KUB) image. If the dye is seen in the renal pelvis without any ureteral extravasation or significant narrowing along the ureter, the ureter is in continuity and may be managed conservatively, with either observation or stent placement.
  
• If ureteral injury is suspected postoperatively, imaging studies evaluating for hydronephrosis, ipsilateral renal function, and continuity of the ureter are necessary. These imaging studies may include an intravenous urogram (IVU), an abdominal and pelvic CT scan with IV contrast, a renal ultrasound, and/or retrograde ureteropyelography.
  
• While the IVU largely has fallen out of favor in the evaluation of stone disease, many urologists believe that an IVU is the best imaging study to evaluate for continuity of the ureter in cases of ureteral injury. Unlike a renal sonogram and a retrograde ureteropyelogram, the IVU assesses for function of the ipsilateral kidney and the drainage of the ureter in a series of sagittal images. Hydronephrosis, ureteral integrity, and any extravasation usually can be seen readily through an IVU.
  
• A CT scan also can assess for both function of the ipsilateral kidney and drainage of the ureter. Because CT images are a series of cross sections, visualizing ureteral integrity and continuity often is more difficult than with an IVU. CT scanning has the advantage of imaging for concomitant conditions at the same time.
  
• Renal ultrasound is perhaps the best noninvasive method to visualize the kidney and shows hydronephrosis with great sensitivity. Renal ultrasound does not assess for kidney function, nor does it assess the continuity of the ureter. Therefore, if renal ultrasonography is performed, retrograde ureteropyelography often is necessary to evaluate the course of the ureter.

Other Tests:

• If one is unsure whether a ureteral injury has occurred intraoperatively, IV administration of 10 mL of indigo carmine or methylene blue with 20 mg of furosemide may help to localize a ureteral injury. Extravasation of blue dye indicates ureteral discontinuity.
  
• Postoperatively, if any drainage is noted from the vagina, an attempt should be made to diagnose a ureterovaginal or vesicovaginal fistula. This may be accomplished with a bedside test. In this test, a tablet of oral Pyridium is administered. The bladder is instilled via a catheter with saline that is colored with methylene blue. A vaginal tampon is inserted. Since Pyridium turns the urine orange, if an orange liquid is observed on the end of the tampon, a presumptive diagnosis of a ureterovaginal fistula can be made. Alternatively, if the tampon absorbs a blue liquid, the diagnosis of vesicovaginal fistula can be made. However, since both types of fistulas may be present simultaneously, this test may not be completely reliable.

Diagnostic Procedures:

• If the patient is unsuitable for surgery because of sepsis or hemodynamic instability, urinary diversion in the form of a percutaneous nephrostomy tube placement should be performed. This allows decompression of an enclosed and potentially infected space and helps to treat a urinary source of sepsis.

Histologic Findings: Ureteral injury, very rarely, may be first diagnosed by identifying the ureter histologically in the pathologic specimen.

Medical therapy: No specific medical therapy is warranted for ureteral injury per se; however, potential concomitant conditions of ureteral injury (eg, infection, renal failure) should be treated medically.

Surgical therapy: Depending on the type, duration, and location of the ureteral injury, surgical treatment may range from simple removal of a ligature to ureteroneocystostomy. The most common surgical treatments for ureteral injury are simple removal of a ligature, ureteral stenting, ureteral resection and ureteroureterostomy, transureteroureterostomy, and ureteroneocystostomy.

Observation
If a clamp or ligature constricting the ureter is discovered, the clamp or ligature should be removed immediately, and the ureter should be examined. If ureteral peristalsis is preserved and it is believed that minimal damage has occurred, the ureter injury may be managed with observation.

Ureteral stenting with or without a ureterotomy
If tissue ischemia or a partial transection of the ureteral wall is suspected, a ureteral stent should be placed. The purpose of the stent, which typically is placed cystoscopically, is to act as a structural backbone onto which the healing ureter may mold. It also guarantees drainage of urine from the renal pelvis directly to the urinary bladder. It also can work as a gentle dilator since it moves slightly in an up-and-down motion, associated with breathing, as the kidney unit moves. The use of the stent is thought to minimize the rate of obstruction of a ureteral stricture in the injured area.
Alternatively, a ureterotomy may be made along the length of the injured or strictured section of ureter before placement of a stent. Davis described this technique in 1943 (the Davis intubated ureterotomy) in which a ureterotomy is made and left open over the stent. The ureter eventually heals to form a watertight closure over the stent. The stent is withdrawn 6 weeks after it is placed, as it is estimated that all ureteral healing has occurred by that time.
The principles of the Davis intubated ureterotomy have been extended to endoscopic treatments of ureteral strictures. Ureteroscopic endoureterotomy and Acucise endoureterotomy are 2 modalities that attempt to treat the segment of strictured ureter endoscopically by a longitudinal full-thickness ureteral incision, followed by a stent placement. The success of these procedures closely resembles the success of the open Davis intubated ureterotomy, which approaches 80% patency at 3 years.

Ureteral resection and ureteroureterostomy
If extensive ischemia or necrosis is the result of an injury, the ureter injury is best treated by excising the injured segment of the ureter and reestablishing continuity with the urinary system. If the ureteral injury occurred above the pelvic brim, the simplest reconstruction is a ureteroureterostomy, a procedure that is indicated for injuries to short segments of the ureter (ie, <2 cm), in which an anastomosis is performed between the 2 cut edges of the ureter.

Transureteroureterostomy
If ureteroureterostomy cannot be performed technically and the defect is too proximal in the ureter for a ureteroneocystostomy, a transureteroureterostomy may be performed. Absolute contraindications for transureteroureterostomy include urothelial cancer, contralateral reflux, pelvic irradiation, retroperitoneal fibrosis, or chronic pyelonephritis. Stone disease, which formerly was considered an absolute contraindication, is now considered a relative contraindication by some urologists, based on the current ability to prevent stone formation in over 90% of patients with medical therapy.

Ureteroneocystostomy
If the ureteral injury occurred below the pelvic brim, where visualization of the ureter is difficult and where the vesical pedicles overlie the ureter, ureteroureterostomy often is too difficult to perform. In these cases, 2 types of ureteroneocystostomy procedures are indicated, either a psoas hitch or a Boari flap, in which the bladder is mobilized to reach the easily identifiable ureter proximal to the injury. Boari flaps are contraindicated in patients with prior pelvic radiation, a history of bladder cancer, or any condition with a thick, hypertrophied bladder wall.

Preoperative details: If urologic consultation is indicated intraoperatively, the urologist dictates no specific preoperative preparation.
If a ureteral injury is identified after the patient is stabilized from the initial gynecologic operation, a discussion is conducted regarding the possible treatment options. Preoperative antibiotics that target urinary organisms should be administered. If patients are persistently febrile from a potentially infected and obstructed renal unit, percutaneous nephrostomy on the affected side may be indicated. Pertinent radiographic studies (eg, IVU, CT scan) may be used to help define the location of ureteral injury preoperatively.

Intraoperative details:
Ureteral stent placement with or without ureterotomy
After the perineum is prepared and draped in the standard sterile manner, and while the patient is sedated adequately or anesthetized, a cystoscope is inserted into the bladder.
After the bladder is examined and the ureteral orifices are identified, the ureteral orifice on the side of the injury is cannulated with a ureteral catheter. A dilute Cystografin-gentamicin mixture is injected slowly through the ureteral catheter under fluoroscopy, revealing the course of the ureter and identifying potential sites of injury.
A Teflon-coated guidewire is placed under fluoroscopic guidance through the ureteral catheter and up the ureter into the renal pelvis. A double-J stent is placed over the wire and is pushed so that its proximal J-hook is placed within the renal pelvis and its distal J-hook is within the bladder. Then, the wire is pulled, and the stent position is reaffirmed fluoroscopically. Proper length of the stent can be estimated from the measured length of the ureter on retrograde pyelography from the ureteral orifice to the ureteropelvic junction. Allowing for roughly 10% magnification from the x-ray, subtract 2-3 cm and select that length ureteral stent. If, after placement, the stent is not well positioned due to inadequate or surplus length, itis best to replace it with a stent of proper dimensions.
If an endoscopic ureterotomy is to be made, prior to placing the stent, a retrograde pyelogram is performed (as discussed above) to delineate the ureteral anatomy, and a Teflon-coated guidewire, acting as a safety wire, is positioned into the renal pelvis and out through the urethra.
With an ureteroscopic endoureterotomy, a rigid ureteroscope is then placed through the ureteral orifice and into the ureter lumen, until the ureteral lesion can be visualized. The ureteral stricture is then cut with a probe from a number of cutting modalities, including Holmium laser or electrocautery. A full-thickness incision through the ureteral wall is made until periureteral fat is visualized. Retrograde pyelography is performed; extravasation of contrast outside the ureter should be seen. A wide-caliber ureteral stent is then placed (usually 8F) in the fashion described above.
If an Acucise endoureterotomy is performed, the Acucise device is placed over the safety wire. Once position is confirmed via fluoroscopic guidance and the orientation of the cut is set, the Acucise balloon is inflated and electrocautery is instituted. The Acucise device is withdrawn, a retrograde pyelogram is performed to confirm extravasation, and a wide-caliber ureteral stent is placed in the fashion described above.
The formal Davis intubated ureterotomy typically is performed intraoperatively only when urologic consultation is called for while the patient is open. In this case, the injured ureter is cut sharply in a longitudinal fashion. A stent then can be placed to the kidney and bladder through the ureteral incision.

Ureteroureterostomy
If the urologist is asked to evaluate the ureteral lesion intraoperatively, further dissection of the existing exposure often is necessary, because the lack of exposure is the most likely contributor to the injury. Additional blunt and sharp dissection often is necessary to adequately identify the ureter and its course.
If the ureteral injury is discovered after the initial gynecologic procedure, the urologist must decide whether to enter through the original incision and approach the ureter transperitoneally or to make a new incision and approach the ureter using a retroperitoneal approach. Either approach is acceptable, and each has distinct advantages and disadvantages.
If one decides to enter through a previous midline incision, intraperitoneal adhesions may complicate the dissection; however, this approach spares the patient an additional incision.
In contrast, if a modified Gibson incision is made to approach the ureter retroperitoneally, the dissection may be less challenging technically because it avoids the adhesions of the peritoneal cavity, but the patient is left with an additional incision.
Regardless of the approach, a Foley catheter is placed and the patient is prepared and draped in a sterile manner.
In the transperitoneal approach, an incision is made though the scar of the old incision. The dissection is extended down to the peritoneal cavity, and, once the small bowel and colon are identified, a vertical incision is made along the left side of the small bowel mesentery. Blunt dissection is performed in the retroperitoneum until the desired ureter is identified. If the inferior mesenteric artery limits the exposure, it can be divided without consequence. If the left lower ureter is the area of the injury, the sigmoid can be mobilized medially to gain adequate exposure.
In the retroperitoneal approach, after the incision is made, the external oblique, internal oblique, and transversus abdominus muscles are dissected in a muscle-splitting manner. Once the transversalis fascia is incised, take care not to enter the peritoneal cavity. The peritoneum and its contents are retracted medially, and the ureter is located in its extraperitoneal position.
The ureter most consistently is found at the bifurcation of the common iliac artery, but it often can be difficult to identify, especially when dilated. Steps that can differentiate the ureter from a blood vessel with a similar appearance include pinching the structure with forceps and watching for peristalsis. If peristalsis occurs, the ureter has been identified. Additionally, a fine needle can be placed into the lumen of the questionable structure. If urine is retrieved through aspiration, the ureter has been identified; if blood is aspirated, the structure is a blood vessel.
Once the ureter is identified and dissected from its surrounding tissues, the diseased segment is excised. Take particular care not to disrupt the adventitia of the ureter, because its blood supply is contained within this layer. If difficulty is encountered in identifying the diseased segment, retrograde ureteropyelography can be performed to aid in localizing the lesion. Another option is to place a ureteral catheter cystoscopically up to the lesion, then the ureteral catheter can be palpated during the ureteral dissection.
Stay sutures are placed in each end of the ureter, and the ureter is mobilized enough so that a tension-free anastomosis can be performed. Simple ureteroureterostomy typically is performed for ureteral lesions shorter than 2 cm. If the lesion is longer than 2 cm, or if it appears that the ureteral ends will not come together without tension, seek an alternative surgical approach. Options include further mobilization of the ureter, mobilization of the ipsilateral kidney, transureteroureterostomy, ureteroneocystostomy, ileal ureter interposition, or a combination of the above.
Once the ureter appears to have enough length to be anastomosed without tension, both ureteral ends are spatulated. Two 5-0 absorbable sutures are placed in through the apex of the spatulated side of one ureter and out through the nonspatulated side of the opposite ureter. Each suture is tied, and a running stitch is performed on one half of the ureter. The same steps are performed to complete the anastomosis on the opposite half of the anastomosis.
Before completion of the second half, a double-J ureteral stent is placed by first placing a 0.038-cm Teflon-coated guide wire caudally and passing a standard 7F double-J stent over the wire. The wire is pulled after the position of the distal portion of the stent is confirmed within the bladder. Next, a small hole is made within the stent, such that the wire can be passed cephalad, placed into the proximal tip of the stent, and come out of the created hole in the side of the stent. Once the position of the cephalad tip in the renal pelvis is confirmed, the wire is pulled, leaving a well-positioned stent.
After the anastomosis is completed, a Penrose drain or a Jackson-Pratt (JP) drain is placed in the retroperitoneum and is brought out through the skin. Omentum may be retrieved from a small incision in the posterior peritoneum and can be used to wrap the repair. Adjacent retroperitoneal fat may be used. The anterior abdominal fascia and skin are closed.

Transureteroureterostomy
A transureteroureterostomy is approached best via a midline incision and can be performed using both intraperitoneal and extraperitoneal approaches. A left-to-right intraperitoneal transureteroureterostomy is described.
After a Foley catheter is placed and the patient is prepared and draped in a sterile manner, a midline incision is made, and the peritoneal cavity is opened. The small bowel is packed medially, and the posterior peritoneum lateral to the sigmoid and descending colon is incised to expose the ureter. The ureter is dissected, preserving its adventitia. The diseased portion of the ureter is identified, and a clamp is placed on the ureter proximal to the diseased portion. The diseased portion of ureter is excised, a stay stitch is placed on the proximal segment of the ureter, and the distal stump is ligated. The proximal ureter is dissected for a length of approximately 9-12 cm, while the adventitial vessels are preserved.
Attention then is turned to exposing the right ureter. The ascending colon is retracted medially while an incision is made through the posterior peritoneum lateral to the colon. Blunt dissection aids in the identification of the ureter. Approximately 4-6 cm above the level of transection of the left ureter, the right ureter is exposed to make room for an anastomosis.
A retroperitoneal tunnel is created via blunt dissection, and the left ureter is pulled through the tunnel by the stay suture. When the left ureter is pulled through, taking care to not to wedge the ureter between the inferior mesenteric artery (IMA) and the aorta is important, because obstruction may result. Instead, the ureter should be passed either over or under the IMA and should not be angulated or under any tension. If the ureter is too short and a tension-free anastomosis can only be performed with the ureter firmly wedged between the IMA and the aorta, it is appropriate to consider ligation of the IMA. If this maneuver is not performed and the ureter is left firmly between the IMA and the aorta, a fibrous reaction of the ureter typically occurs, which causes an obstruction that must be treated later with a surgical procedure.
The tip of the left ureter is spatulated, and the medial wall of the right ureter is incised using a hook blade for a distance just longer than the diameter of the lumen of the left ureter. Using 4-0 or 5-0 absorbable suture material, a suture is placed at each end of the ureteral incision from the outside in. Each stitch is run over the course of one half of the anastomosis. Before finishing the second side of the anastomosis, a stent is placed along the entire right ureter using the technique described in ureteral stent placement. The 2 stitches are tied to each other.
After the anastomosis is completed, a Penrose drain or a JP drain is placed in the retroperitoneum and is brought out through the skin. Omentum or any adjacent retroperitoneal fat may be used to wrap the repair. The anterior abdominal fascia and skin are closed.

Psoas hitch
After a Foley catheter is placed and the patient is prepared and draped in a sterile manner, various incisions are acceptable, including a midline, a Pfannenstiel, or a suprapubic V-shaped incision. A midline incision is preferred if the patient has a preexisting midline scar from a previous gynecologic operation. If entering the peritoneal cavity can be avoided, this incision is preferred.
The peritoneal reflection is dissected off the bladder. Some advocate saline installation in the subperitoneal connective tissue as a way of facilitating this portion of the dissection. If a peritoneal defect is encountered, it can be closed with a running chromic suture. Once the peritoneum is dissected off the bladder, the peritoneum can be reflected medially.
Attention then is turned to dissection and excision of the diseased ureteral segment. The diseased portion of the ureter is identified, and a clamp is placed on the ureter proximal to it. A diseased portion of ureter is excised, a stay stitch is placed on the proximal segment of the ureter, and the distal stump is ligated.
The superior pedicle of the bladder is ligated on the ipsilateral side, and the bladder wall is incised transversely, a little more than halfway around the bladder, in an oblique manner across the middle of its anterior wall at the level of its maximum diameter. When this horizontal incision is closed vertically, the effect of the incision is the elongation of the anterior wall of the bladder so that the apex of the bladder can be positioned and fixed above the iliac vessels.
After the bladder incision is made, 2 fingers are placed into the bladder to elevate it to the level of the proximal end of the ureter. If the bladder does not reach the proximal ureter, several steps can be performed for additional length. These steps include extending the bladder wall incision laterally to obtain further length, or the peritoneum and connective tissue from the pelvic and lateral walls may be dissected from the contralateral side of the bladder. This dissection may require ligation and division of the superior vesical pedicle on the contralateral side.
Once adequate mobilization of the bladder has occurred, the bladder is held against the tendinous portion of the psoas minor muscle without tension. Prolene sutures (2-0) are sutured into the bladder wall and to the tendon to fix the bladder in place.
With the bladder open, attention is turned to the ureteral reimplant. An incision is made in the bladder mucosa at the proposed site of the new ureteral orifice. A submucosal dissection occurs approximately 3 cm from the incision site so that a tunnel is created. Lahey scissors may be used to facilitate this dissection. After achieving a 3-cm tunnel length, the scissors are inverted and the tips are pushed through the bladder wall. An 8F feeding tube is passed over the scissor blades, and the stay suture on the proximal tip of the ureter is tied to the other end of the catheter so that traction on the catheter draws the ureter into the bladder. The ureteral tip is trimmed obliquely, and 4-6 absorbable sutures (4-0) are used to fix the ureter to the bladder mucosa. The ureteral adventitia is tacked to the extravesical bladder wall with several 4-0 absorbable sutures. A double-J ureteral stent may be placed at this time.
A nontunneled reimplant also is an acceptable choice in most adults if ureteral length is insufficient. The end of the ureter can be reflected back after making a small longitudinal incision from the tip proximally about 1.5 cm. This will make the end of the ureter into a nonrefluxing nipple, which is useful when there is inadequate length for an antirefluxing submucosal tunnel.
After completing the reimplant, 2 fingers are placed within the bladder, while 5 or 6 absorbable sutures (2-0) are placed within the bladder muscle, the psoas muscle, and the psoas minor tendon, paying specific attention not to suture the genitofemoral nerve. Alternatively, sutures also may take deep bites in the muscle itself. The bladder is closed with a 3-0 running absorbable suture on the mucosa and a running 2-0 suture incorporating the bladder muscle and adventitial layers. A Penrose drain or a JP drain is placed in the retroperitoneum next to the bladder closure. The anterior abdominal fascia and the skin then are closed.

Boari flap
After preparing and draping the patient, a midline or Pfannenstiel incision is made. Once the transversalis fascia is incised, the ureter may be approached either transperitoneally or retroperitoneally. In the transperitoneal approach, the peritoneal cavity is entered, the sigmoid or cecum is reflected medially, the posterior peritoneum is incised, and the ureter is identified. In the retroperitoneal approach, care is taken not to enter the peritoneal cavity, the peritoneum is mobilized medially, and the ureter is identified and exposed. A stay stitch is placed in healthy ureter tissue just proximal to the injury. The remaining end of the ureter is tied off.
The peritoneum is then dissected from the wall of the bladder. This dissection may be facilitated with hydrodissection, in which saline is injected subperitoneally, separating the peritoneal layer from the muscle layers of the bladder.
The necessary length of the bladder flap (ie, the distance between the posterior wall of the bladder and the end of the healthy proximal ureter) is measured with umbilical tape, the bladder is one half full of saline, and the length and shape of the bladder flap are planned. To measure accurately on the dome of the bladder, several stay stitches are placed at the base of the proposed bladder flap and at the apex. The bladder flap should be planned with a large base, because the base will contain the blood supply for the flap. The length of the bladder flap (ie, the distance between the base and apex) should equal the distance between the posterior wall of the bladder and the end of the healthy proximal ureter. The width of the apex should be at least 3 times the diameter of the ureter to prevent constriction after the flap is tubularized. Avoid scarred areas of the bladder.
After proper planning, an outline of the flap is made in the bladder wall with coagulating current, and the bladder flap is remeasured. If the measurements are satisfactory, the bladder flap is cut via cutting current, and the concomitant bleeding vessels are coagulated .
After the bladder flap is turned superiorly, Lahey scissors are used to prepare a ureteral tunnel. The tunnel should be at least 3 cm long and is created by placing the Lahey scissors submucosally at the apex of the flap, tunneling the appropriate distance and coming out through the mucosa. Submucosal injection of saline may aid in this dissection. An 8F feeding tube is pulled through the tunnel by the scissors and the stay suture on the proximal ureter is tied to the feeding tube after the ureteral end is spatulated. The feeding tube is pulled toward the bladder, followed by the ureter. The stay suture is cut after the ureter has traveled completely through the tunnel.
The bladder flap is sutured to the psoas tendon of the psoas minor with a few 2-0 absorbable sutures. These sutures fix the flap in place to prevent tension on the ureteral anastomosis.
The ureter is anastomosed to the bladder mucosa with several 4-0 absorbable sutures. A few of the sutures should include the muscle layer of the bladder to fix the ureter into place. An 8F feeding tube is passed up the ureter into the renal pelvis and out through the bladder and body wall.
Before closing the bladder, a large suprapubic tube is placed, ie, either a 22-24F Malecot or Foley. Then, the bladder is closed by approximating the bladder mucosa with a 3-0 absorbable running suture followed by a second row of running sutures, which approximates the muscularis and adventitial layers. A few absorbable sutures (5-0) can be placed to approximate the distal end of the flap to the adventitia of the ureter. If a transperitoneal approach is used, close the peritoneum and then place a Penrose or a JP drain retroperitoneally adjacent to the bladder closure. The anterior abdominal fascia and skin are closed.

Postoperative details:
Ureteral stent
After recovering from anesthesia, and when the patient is in suitable condition, the patient may be discharged with instructions to return to the clinic in 14-21 days, when the stent will be removed. The patient is discharged with 3 days of antibiotics (eg, Bactrim, nitrofurantoin, Cipro) and oral analgesics for potential bouts of discomfort from the stent.

Ureteroureterostomy, transureteroureterostomy, psoas hitch, and Boari flap
Patients who underwent a transperitoneal approach are kept on a regimen of nothing by mouth (NPO) for the first day after surgery. Subsequently, signs of bowel function are monitored routinely. Once bowel sounds are present, the diet is advanced to clear liquids, and when the patient passes flatus, a regular diet is instituted.
Patients who undergo a retroperitoneal approach are started on clear liquids on the first day after surgery unless they are nauseous. Their diets also are advanced when they have passed flatus.
All patients receive a patient-controlled anesthetic (PCA) pump postoperatively unless they had an epidural catheter placed intraoperatively, then they are given an epidural pump. Oral analgesics are administered after patients tolerate a regular diet.
All patients receive a 24-hour course of IV antibiotics to prevent wound infections.
Patients are encouraged to ambulate on the first day after surgery. Once the pain is controlled with oral analgesics and patients are tolerating a regular diet, they are eligible for discharge, with or without their drains. If drains are not removed in the hospital, set appointments to assess patients and their drains in the clinic.

Follow-up care: In patients who do not require a cystotomy, the Foley catheter or suprapubic tube is left to drain the bladder until the drain output from the Penrose or JP drain is less than 30 cc per day. If this is achieved, the Foley catheter can be removed or the suprapubic tube can be clamped, and the output from the Penrose or JP drain is monitored. If no drainage occurs, the drain can be removed. If drainage increases from the previous level, the Foley catheter is replaced, or the suprapubic tube is unclamped. After several days, the same sequence of events occurs to determine whether the ureter has healed completely. If a stent or feeding tube is used, it can be removed 7-10 days after surgery.
In patients requiring a cystotomy, the Foley catheter or suprapubic tube is left in place for 7-10 days after surgery, at which time a cystogram usually is performed. If no extravasation is observed during the cystogram, the Foley catheter or suprapubic tube can be removed. At the same time, the outputs from the Penrose or JP drain are monitored. If no drainage occurs, the drain can be removed. If drain output increases from the previous level, the Foley catheter is replaced. After several days, the same sequence of events occurs to determine whether the ureter has healed completely. If a stent is used, the stent is removed 10-14 days after surgery.

Complications

Excess drainage
The most common postoperative complication is excess drainage from the Penrose or JP drain. This may indicate the presence of a significant urine leak, either at the ureteral anastomosis or at the bladder closure.
Often, if the peritoneum is not closed or is closed incompletely, peritoneal fluid leaks from the drain, which may confound the situation. Although intraoperative efforts are made to avoid this situation, if one needs to differentiate a urine leak from peritoneal fluid, the fluid may be tested for the creatinine level. If the creatinine level is significantly greater than the serum creatinine measurement, a urine leak is suspected. If the fluid creatinine level is identical to the serum creatinine measurement, the fluid is transudative in nature and likely is peritoneal fluid.
The treatment for most cases of excess drainage is observation. Most often, the drainage tapers with time as the ureteral or bladder wall heals and seals the urine from the drain.
Persistent, long-term output from drain occurs occasionally and implies obstruction either at or beyond the anastomotic site. The most common causes of obstruction are a lack of bladder decompression, stricture at the anastomotic site, or technical error.

Urinary tract infections
Urinary tract infections (UTIs) may occur immediately postoperatively, especially after the removal of an indwelling stent. UTIs are easily treated with oral antibiotics.
Ureteral obstruction or reflux
The most common complications of tunneled ureteroneocystostomy are ureteral obstruction or reflux.
Immediately postoperative obstruction can be a result of either edema of the ureter or technical errors (eg, constricting ureteral tunnel, ureteral angulation during fixation of the bladder). If obstruction occurs later in the postoperative course, a ureteral stricture must be considered. Ureteral strictures typically occur at the distal segment of the ureter and most often are due to ischemia. These strictures can be refractory to endoscopic management; when this is the case, repeat ureteroneocystostomy may be considered.
If the ureteral tunnel is too short, reflux can occur. Unless systemic adverse effects from the reflux occur (eg, recurrent bouts of pyelonephritis, worsening renal function), reflux typically is managed conservatively with observation.

Boari flap complications
Complications specific to Boari flaps include ischemia of the flap, reduced lumen size of the flap secondary to thickened bladder wall, and reflux.
Because the blood supply of the Boari flap emanates from its base, the presence of any devascularization injury of the bladder base may cause flap ischemia and eventual necrosis.
The most common cause of flap ischemia is previous pelvic radiation; for this reason, Boari flaps are contraindicated in patients who have received radiation therapy.
Another possible cause of complications is that the bladder base that was created is too narrow, resulting in an inadequate blood supply to the distal end of the flap.
Yet another complication is that the bladder wall is too thick to form an adequate lumen for the implanted ureter. This situation should be assessed intraoperatively, and, if found, a Boari flap should not be performed

Prognosis

Few recent studies address the outcome and prognosis of ureteral injury, but older studies show that all of the surgical treatments mentioned are effective in treating ureteral injury.
Ureteral stents have been shown repeatedly to act as an excellent scaffolding mechanism when a partial ureteral distraction has occurred, with excellent long-term patency rates. In fact, the Davis intubated ureterotomy, which is the basis for current endourologic treatment of ureteral stricture disease, is aimed at incising a full-thickness portion of ureteral wall, followed by ureteral stent placement. As the ureter heals around the stent, the ureteral lumen is larger when compared to the size of the pretreated ureteral lumen.
The urologic literature comprehensively documents the data regarding the efficacy of ureteroureterostomy in the treatment of ureteral injury. Initial studies regarding ureteroureterostomy focused on the operative technique and asked what type of anastomosis was superior. End-to-end, side-to-side, end-to-side, spatulated, unspatulated, watertight, and loose approximation anastomoses were attempted. These efforts led to broad acceptance of spatulated watertight anastomoses, with or without stents, as the best ureteral reconstruction technique with regard to long-term outcome.
The literature also demonstrates the long-term efficacy of transureteroureterostomy. Hodges et al reported that of 100 patients accrued over a 25-year period who had been treated with transureteroureterostomy for various conditions, including ureteral stricture and intraoperative ureteral injury, 77 patients had no complications postoperatively. Of the 23 patients with complications, 5 patients had acute pyelonephritis, 3 patients had tumor blockage at the anastomotic site, 2 patients had IMA syndrome, and 2 patients had subsequent reflux of the normal ureter. In this study, 97% of patients had normal bilateral kidneys after a follow-up period of 1-23 years.
In a recent study by Mathews et al, the psoas hitch reimplantation was shown to be a successful technique for reestablishing ureteral continuity after distal ureteral injury. In their study of 20 patients who underwent psoas hitch reimplantation for various conditions, 13 patients had iatrogenic injuries during surgery, and 17 patients (85%) required no further intervention for urological problems and retained normal renal function after an average follow-up period of 6 years (range: 1-14 years). The authors conclude that psoas hitch reimplantation is an excellent treatment option for distal ureteral injuries.
In 1975, Konigsberg, et al reported on a series of patients; 15 of 21 patients studied had fair or excellent results for an average of 27 months after Boari flap reconstruction. Of the patients who had poor results, 2 patients had previous pelvic radiation, 2 patients had bladder carcinoma that recurred in the flap, and 2 patients had a flap that was not fixed to the psoas muscle. With the benefit of modern indications for the use of Boari flaps, fewer poor results have occurred, although increased risk exists for bladder necrosis, given the dissection needed to create the flap. As a result of this risk and other technical considerations, many urologists opt for the psoas hitch reimplant as their first choice in ureteral reconstruction after a distal ureteral injury.

Future

The future of distal ureteral injuries is exciting, and the use of new technology may change the management of distal ureteral injuries entirely. Recently, with the introduction of subintestinal submucosa (SIS) to be used as a tissue scaffold, a new modality to treat ureteral injuries has emerged. While no current studies are being performed using SIS for the treatment of distal ureteral injuries, the placement of SIS may serve as a healing bridge between 2 injured ureteral ends. Although SIS will not drastically affect the management of short ureteral injuries or strictures, it may be useful in treating longer ureteral defects

• Carlton CE, Scott R, Guthrie AG: The initial management of ureteral injuries: a report of 78 cases. J Urol 1971 Mar; 105(3): 335-40[Medline].
  
• Davis, D M: Intubated ureterotomy:a new operation for ureteral and ureteropelvic strictures . Surg Gynecol Obstet 1943; 76: 851.
  
• Gill H, Broderick GA: Urologic complications of gynecologic surgery. Vol 13. AUA Update Series; 1994: 254-9.
  
• Harkki-Siren P, Sjoberg J, Tiitinen A: Urinary tract injuries after hysterectomy. Obstet Gynecol 1998 Jul; 92(1): 113-8[Medline].
  
• Hinman F Jr: Ureteral repair and the splint. J Urol 1957; 78: 376.
  
• Hinman F Jr: Bladder flap repair. In: Atlas of Urologic Surgery. 2nd ed. 1998: 822-5.
  
• Hinman F Jr: Psoas hitch procedure. In: Atlas of Urologic Surgery. 2nd ed. 1998: 818-21.
  
• Hinman F Jr: Ureteroureterostomy. In: Atlas of Urologic Surgery. 2nd ed. 1998: 834-6.
  
• Hinman F Jr: Transureteroureterostomy. In: Atlas of Urologic Surgery. 2nd ed. 1998: 38-9.
  
• Hodges CV, Barry JM, Fuchs EF, et al: Transureteroureterostomy: 25-year experience with 100 patients. J Urol 1980 Jun; 123(6): 834-8[Medline].
  
• Konigsberg H, Blunt KJ, Muecke EC: Use of Boari flap in lower ureteral injuries. Urology 1975 Jun; 5(6): 751-5[Medline].
  
• Koo HP, Bloom DA: Lower ureteral reconstruction. Urol Clin North Am 1999 Feb; 26(1): 167-73, x[Medline].
  
• Leslie S: Selecting ureteral stent length. Personal communication 2001.
  
• Mariotti G, Natale F, Trucchi A, et al: Ureteral injuries during gynecologic procedures. Minerva Urol Nefrol 1997 Jun; 49(2): 95-8[Medline].
  
• Mathews R, Marshall FF: Versatility of the adult psoas hitch ureteral reimplantation. J Urol 1997 Dec; 158(6): 2078-82[Medline].
  
• Nakada SY, Pearle MS, Clayman RV: Acucise endopyelotomy: evolution of a less-invasive technology. J Endourol 1996 Apr; 10(2): 133-9[Medline].
  
• Saidi MH, Sadler RK, Vancaillie TG, et al: Diagnosis and management of serious urinary complications after major operative laparoscopy. Obstet Gynecol 1996 Feb; 87(2): 272-6[Medline].
  
• Sieben DM, Howerton L, Amin M, et al: The role of ureteral stenting in the management of surgical injury of the ureter. J Urol 1978 Mar; 119(3): 330-1[Medline].
  
• Soong Y, Lim PH: Urological injuries in gynaecological practice--when is the optimal time for repair? Singapore Med J 1997 Nov; 38(11): 475-8[Medline].
  
• Tamussino KF, Lang PF, Breinl E: Ureteral complications with operative gynecologic laparoscopy. Am J Obstet Gynecol 1998 May; 178(5): 967-70[Medline].
  
• Thompson JD: Operative injuries to the ureter: prevention, recognition, and management. In: Te Linde's Operative Gynecology. 8th ed. 1997: 1135-73.
  Wolf JS Jr, Elashry OM, Clayman RV: Long-term results of endoureterotomy for benign ureteral and ureteroenteric strictures. J Urol 1997 Sep; 158(3 Pt 1): 759-64[Medline].

Ureteroscopy

Authored by Michael Grasso, MD, Chairman, Saint Vincents Medical Center, Manhattan, New York, Professor and Vice Chairman, Department of Urology, New York Medical College
Ureteroscopy is defined as upper urinary tract endoscopy performed most commonly with an endoscope passed through the urethra, bladder, and then directly into the upper urinary tract. Indications for ureteroscopy have broadened from diagnostic endoscopy to a variety of minimally invasive therapies.
Endoscopic lithotripsy, treatment of upper urinary tract urothelial malignancies, incising strictures, and repairing ureteropelvic junction obstructions all are current treatments facilitated by contemporary ureteroscopic techniques. With this progression of ureteroscopic procedures from diagnostic to now complex therapeutic interventions, one would expect a proportional increase in the rate and severity of complications. However, with improved instrumentation and an evolution of surgical technique, the complication rate from ureteropyeloscopy actually has decreased significantly.

History of the Procedure: The progression from cystoscopy to upper urinary tract endoscopy was natural, with pediatric cystoscopes being employed as the first rigid rod-lens ureteroscopes. Relatively large rod-lens endoscopes, averaging 12F (3F = 1 mm) in diameter, combined with ultrasonic and electrohydraulic lithotripsy probes became the first commonly accepted ureteroscopic equipment combination used to treat distal ureteral calculi.
Ureteroscopic treatment of calculi and, in particular, distal ureteral stones was the first common application of upper urinary tract endoscopy. It was obvious early in this evolution that smaller and more precise instrumentation was less traumatic to normal tissues. Rigid ureteroscopes progressed from rod-lens imaging to fiberoptic imaging with outer-diameter miniaturization. Where the narrow and delicate distal ureter once required vigorous balloon dilation for ureteroscopic access, the fiberoptic-based rigid endoscopes were small enough by 1989 (averaging 7F in diameter) to frequently be placed in the distal ureter under direct vision. The small rigid ureteroscopes combined with both laser and pneumatic lithotriptors currently are employed to treat distal ureteral calculi in both university and community settings.
Flexible ureteroscopy was an attractive alternative to rigid ureteroscopy in that the more proximal ureter and intrarenal collecting system was theoretically more easily accessible to this type of instrument. The application of flexible ureteroscopy was first reported by Marshall in 1964. A 9F fiberscope manufactured by American Cystoscope Makers (Pelham Manor, NY) was passed into the ureter to visualize an impacted ureteral calculus. These first flexible ureteroscopes were not capable of being directed and did not have a working channel, thus permitting only the most primitive diagnostic maneuvers. The subsequent addition of a cystoscopically placed guide tube facilitated placement of the first flexible ureteroscopes. In addition, irrigant then could be passed through the guide tube to displace the ureteral mucosa and debris from the distal endoscopic lens.
In the early 1980s, Bagley, Huffman, and Lyon began work at the University of Chicago to develop an improved flexible fiberoptic ureteropyeloscope. Three major design changes improved the potential of the flexible ureteroscope. First, the addition of a working channel allowed irrigant and endoscopic accessories to be passed directly through the endoscope and not through an operating sheath. Second, active tip deflection allowed the endoscope to be directed or steered to areas of interest. Finally, by altering the stiffness (ie, based on durometer measurements) of the endoscope shaft, the actively deflecting portion could be combined with passive buckling of the endoscope (ie, secondary deflection), which helped facilitate lower-pole intrarenal access.
The first steerable, actively deflectable, flexible ureteropyeloscopes employed relatively large fiberoptic bundles for imaging and illumination. The addition of the working channel and a cable-and-pulley system used for active tip deflection required on outer diameter of 3.6 mm. By the late 1980s, optical fiber miniaturization and improved geometrical pixel packing produced a smaller fiberoptic bundle and thus, a smaller-diameter endoscope. Flexible ureteroscope specifications in 1990 included a 10F outer diameter, a standard 3.6F working channel, and unidirectional active tip deflection. Working sheaths were abandoned for direct guidewire endoscope placement, but intramural ureteral dilation often was required for placement of the flexible ureteroscope into the upper urinary tract. These endoscopes were employed to inspect the entire intrarenal collecting system and became part of the standard evaluation of filling defects of the upper urinary tract defined using contrast imaging studies.
Currently, rigid and flexible ureteroscopes average 7.5F in tip diameter and are passed atraumatically into the upper urinary tract without intramural dilation. These endoscopes are employed to treat a variety of upper urinary tract disorders, including stones, urothelial malignancies, stricture disease, and bleeding lesions. The addition of laser energy applied through optical quartz fibers passed through the working channel of the endoscope has helped facilitate these treatments. Specific treatments are discussed further in subsequent sections of this article.

Problem: Ureteroscopy is used as a diagnostic tool in situations such as investigating abnormal imaging findings, assessing obstruction or unilateral essential hematuria, or localizing the source of positive urinary cytology results.
Therapeutic uses of ureteroscopy have broadened to include a variety of minimally invasive therapies. Endoscopic lithotripsy (treating stones), treatment of upper urinary tract urothelial malignancies, incising strictures, and repairing ureteropelvic junction obstructions all are current treatments facilitated by contemporary ureteroscopic techniques.

Frequency: Ureteroscopy is a common procedure performed by urologists. The most common indication is to treat upper urinary tract calculi that are either unsuitable for extracorporeal shockwave lithotripsy or are refractory to that form of treatment. Other common indications include evaluation of an abnormal lesion noted on findings from less invasive imaging tools (eg, intravenous pyelography [IVP], MRI, CT scan) or localizing a source of positive urine culture results or cytology results. Thus, ureteroscopy often is an essential part of a diagnostic algorithm and also can be employed therapeutically to treat the underlying disorder.

Indications

Diagnostic indications for ureteropyeloscopy are as follows:

• Abnormal imaging findings - Filling defect
  
• Obstruction - Determination of etiology
  
• Unilateral essential hematuria
  
• Localizing source of positive urinary cytology results, culture results, or other test results

Therapeutic indications for ureteropyeloscopy are as follows:

• Endoscopic lithotripsy
  
• Retrograde endopyelotomy
  
• Incision of ureteral strictures
  
• Improvement of calyceal drainage
  
• Treatment of calyceal diverticular lesions
  
• Treatment of malignant urothelial tumors
  
• Treatment of benign tumors and bleeding lesions

Relevant Anatomy: The segments of the ureter in which calculi can become lodged also are natural barriers for the ureteroscope. Note first that the intramural ureter is the narrowest segment and can prohibit endoscope passage. Guidewires often are passed into the ureteral orifice cystoscopically and then directed into the renal pelvis with fluoroscopic assistance. These "safety" guidewires straighten the ureter and facilitate both the dilation of obstructed segments with balloon or graduated dilators and the placement of internal stents used after many therapeutic procedures.
Historically, the intramural ureter required balloon dilation for endoscope access. Currently, the small-diameter semirigid ureteroscopes often are less than 7.5F in tip diameter, while their shaft is graduated. This allows for tip access, and, when advanced, the intramural segment also is modestly dilated (ie, dilation under direct vision). As the fiberoptic-based rigid ureteroscope continues proximally past the ureteral orifice, it then is inhibited by the natural curvature of the ureter as it crosses the iliac vessels, psoas muscle, and the ureteropelvic junction. If the ureter is dilated, the rigid endoscope may be safely passed proximally. If not, then conversion to an actively deflectable, flexible endoscope is indicated.
Flexible ureteroscopes are passed into the upper urinary tract over a guidewire. Some authors have espoused the use of a 12F or 14F operating sheath to facilitate placement of this instrument. In a recent study of 1000 consecutive flexible ureteroscopic procedures using 7.5F instruments, this was not required. The flexible ureteroscope is a particularly useful instrument, especially when a rigid endoscope cannot be placed safely into the more proximal ureter or if intrarenal inspection is required. In these cases, active and passive endoscope tip deflection is essential to permit complete inspection of the calyces.
Lower-pole intrarenal access performed with a flexible ureteroscope often is difficult and requires both active and passive flexible ureteroscope deflections. To place the tip of the endoscope into the lower pole, the instrument first must be actively deflected and then advanced so as to allow the shaft below to buckle. This maneuver, termed secondary deflection, is required in 60% of flexible ureteroscopies if a complete inspection is to be attained.

Contraindications:

Few contraindications exist for diagnostic ureteroscopy. Untreated urinary tract infection or endoscopy without appropriate antibiotic coverage is a relative contraindication. Uncorrected bleeding diathesis is also a relative contraindication.
Contraindications for therapeutic ureteroscopy (eg, lithotripsy, endopyelotomy, tumor therapy) are more numerous and can mirror those associated with the corresponding more invasive open surgical intervention. In general, the major contraindications are related to untreated infections and uncorrected bleeding diathesis prior to therapeutic endoscopy.

Surgical therapy: Ureteroscopy can be divided into diagnostic endoscopy and therapeutic treatments.
Diagnostic endoscopy is performed with the most minimal trauma to the upper urinary tract. Most frequently, a small-diameter rigid ureteroscope is passed up the ureter as far as technically feasible to inspect and map this portion of the collecting system. A guidewire then is placed only to the area that already has been inspected, and a flexible instrument then is passed over it in a monorail fashion, under fluoroscopic guidance, to complete the mapping. The flexible ureteroscope is passed from calyx to calyx, and, frequently, dilute contrast material is injected through the working channel of the endoscope to help ensure the entire collecting system is inspected.
Therapeutic ureteroscopy is performed to treat stones, urothelial tumors, and stricture disease. In each case, an energy source is delivered through the working channel of the endoscope to fragment, ablate, and/or incise the lesion in question. Additional accessories also can be passed through the working channel of the endoscope to remove stone fragments or to obtain a tumor biopsy sample.

Preoperative details: Prior to performing a ureteroscopic examination, the surgeon must have the appropriate instrumentation available. This includes endoscopes, accessories, appropriate energy sources, and fluoroscopy.
Rigid ureteroscope specifications include the following:

• Tip diameter - 4.5-9.5F (6.9F most common)
  
• Optics - Fiberoptic bundles
  
• Working channels - One, 2, or 3 (2-channel preferred)
  
• Accessory length - Average 40 cm

Flexible ureteroscope specifications include the following:

• Tip diameter - 6.9-9.8F (7.5F most common)
  
• Optics - Fiberoptic bundles
  
• Working channel - Single, 3.6F
  
• Access - Guidewire (0.035 in nitinol or 0.038 in stainless steel)
  
• Accessory length - Average 100 cm

Energy sources include the following:

• Holmium:YAG (ie, yttrium-aluminum-garnet) laser
  
• Neodymium:YAG laser
  
• Electrocautery
  
• Electrohydraulic lithotripsy
  
• Mechanical impactor (ie, Lithoclast)

Prophylaxis is as follows:

• All patients receive a dose of a broad-spectrum parenteral antibiotic preoperatively.
  
• Most frequently, a first-generation cephalosporin is administered, unless prior culture results or anaphylaxis dictates otherwise.

Intraoperative details: When therapeutic ureteroscopy is performed, a safety guidewire is essential. This allows for multiple passes of the instrument while maintaining access to the upper urinary tract. An example would be treating a distal ureteral stone, for which a rigid ureteroscope is passed up the ureter beside the safety guidewire and laser energy is delivered through a small quartz fiber to fragment the stone. An accessory such as a wire prong grasper or nitinol basket then can be employed to extract fragments with multiple passes of the endoscope.
In the case of the flexible ureteroscope, 2 guidewires are required initially. The first is a safety guidewire, while the second is employed to facilitate endoscope placement. For example, this working guidewire can be replaced with a dual-lumen catheter after a stone fragment or biopsy specimen is extracted.
If electrocautery is to be employed, special attention to the guidewire choice helps prevent an intraoperative complication. If a standard stainless steel guidewire is employed, electrical current may inadvertently arc to the wire during an incision and cause excessive ureteral coagulation with subsequent fibrosis. This can be prevented by using an insulated guidewire such as a Teflon-sheathed nitinol guidewire (eg, Zebra wire, Boston Scientific, Natick, Mass).

Postoperative details: At the completion of a ureteroscopy, internal ureteral stents commonly are placed to help facilitate healing and ensure drainage, particularly if vigorous therapeutic maneuvers were performed. However, simple diagnostic ureteroscopy without ureteral dilation does not require postoperative ureteral stenting.
Internal ureteral stents are associated with lower urinary tract symptomatology, which includes urinary frequency, urgency, and mild-to-moderate hematuria, which is transient. Removal of ureteral stents is performed after a period of healing that can range from a few days to 6-8 weeks, depending on the complexity of the treatment. Stents are removed most commonly in the office with either an attached nylon suture left through the urethra postoperatively or cystoscopically.
Most ureteroscopic procedures are performed as day-surgery, outpatient procedures. Patients are discharged on oral quinolone-based antibiotics, analgesics, and, occasionally, on anticholinergic medication to decrease symptoms associated with the ureteral stent.

Follow-up care: Most patients are seen 1-2 weeks after the ureteroscopic procedure for stent removal and surgical follow-up. If endoscopic lithotripsy was performed, appropriate imaging consisting of either plain radiographs or sonography can be obtained to define residual stone burdens.
Subsequent imaging is required weeks to months after the procedure depending on the underlying disease process. If, for example, a ureteral stricture is incised ureteroscopically, serial follow-up imaging studies defining drainage and renal function (eg, IVP, nuclear medicine renal scan) should be performed periodically in the first year to ensure an acceptable surgical outcome

Minor intraoperative complications
Minor ureteroscopic complications are those that have no long-term deleterious effects and, if treated promptly, cause only minimal or transient postoperative problems. Table 1 lists chronologically 4 studies spanning the 10-year evaluation of ureteroscopic equipment and technique. In the initial series from the Mayo Clinic, large-diameter endoscopes were employed, while in the last series, the smallest-diameter ureteropyeloscopes were used, with a noticeable decrease in complication rates.
In general, the minor complication rate from ureteropyeloscopy was decreased based on refined technique, experience of the operators, and prompt treatment or prevention of intraoperative problems. Prophylactic parenteral antibiotics, careful guidewire placement, minimization of excessive ureteral dilation, and postoperative ureteral stenting all impacted on the rate of postoperative problems. This, combined with better surgical training and improved instrumentation, resulted in this very positive trend.

Major intraoperative complications
Major intraoperative problems include excessive trauma to tissues, leading to large wall perforations, avulsions, or foreign body (eg, stone) migration into the ureteral wall. The major complication rate has decreased markedly and occurs in approximately 1% of all ureteroscopic procedures. As with the minor problems, major problems occur less frequently for basically the same reasons. However, when they do occur, treatment is more complex.
In addition to major intraoperative problems, other complications that occur during upper urinary tract endoscopy may begin as minor events and, if left untreated or if addressed incorrectly, can progress to a more serious problem.
Major ureteral wall perforations also can be the product of a heavy-handed endoscopist and improper application of a semirigid ureteroscope. The forceful positioning of a semirigid ureteroscope above the iliac vessels, particularly in young male patients, is associated with a significant risk of ureteral wall trauma unless the collecting system is hydronephrotic or has been stented prior to endoscopy.
Ureteral wall tears may lead to stone migration through the tear. Subsequently, this may lead to a stone granuloma or ureteral wall stricture. In addition, large tears can lead to ureteral avulsion if the offending maneuver is repeated at the same sitting (eg, large ureteral wall perforation with subsequent vigorous attempts at accessing a calculus). In these settings, stopping the procedure and stenting the ureter, to return days later to perform subsequent maneuvers in a staged fashion after a period of healing, is wiser.
When a minor problem is encountered during ureteroscopy, taking appropriate measures to prevent progression is essential. Additionally, the inappropriate application of endoscopes, lithotrities, and accessories also can lead to surgical misadventure. An example would be basketing a relatively large renal stone with a retrograde-placed ureteroscope and attempting extraction.
A basic concern is that if the stone was too large to pass, how does engagement in a basket and applying tension along the long axis of the ureter have merit? Surgeons can find themselves in a tenuous situation in which extraction is impossible; stone disengagement is difficult; and, with a single endoscope working channel, simultaneous placement of an endoscopic lithotrite is difficult to impossible. Excessive tension on the ureter leads to an avulsion with disastrous complications that could be preventable if the mindset was stone fragmentation rather than extraction.
If ureteral avulsion occurs in the distal segment, repair is based on the standard open surgical techniques of ureteral reimplantation. Ureteroneocystostomy can be performed for most distal ureteral avulsions, with a psoas bladder hitch employed, if necessary, to create a tension-free anastomosis. A Boari bladder wall flap can increase the proximal extent of the repair to the middle third of the ureter. These repairs are performed most commonly over a ureteral catheter with perianastomotic drainage. This can be performed acutely at the time of the injury or in a staged fashion after proximal percutaneous drainage is obtained at the time of the injury.
The most proximal ureteral avulsions require the most complex surgical repairs. If a proximal ureteral avulsion is encountered intraoperatively and the majority of the ureter is intact, primary repair over a ureteral catheter can be performed. Unfortunately, in this setting, the majority of the ureter most often is devitalized, leading to an extremely morbid complication. If the entire devitalized ureteral segment is brought into the bladder, it is of no value in subsequent repair. Percutaneous renal drainage should be obtained immediately at the time of this type of ureteral injury. Subsequent therapy is based on either bowel interposition (ie, ileal ureter) or renal autotransplantation to a pelvic position. Both procedures are complex and have their own inherent risks, and, as such, the patient must be counseled appropriately.
Table 1. Comparison of Complication Rates Associated With Ureteroscopy, Emphasizing the Noticeable Decrease in the Major Complication Rate With Greater Experience and Endoscope Miniaturization

The outcome of a ureteroscopic procedure is based on the underlying disorder and whether a diagnostic or therapeutic endoscopy was performed. In diagnostic ureteroscopy, finding the source of bleeding or defining the nature of a filling defect most frequently is the end point.
Therapeutic ureteroscopy for the treatment of upper urinary tract calculi should resolve ureteral obstruction and decrease the stone burden. Endoscopic treatment of stricture disease also should improve drainage. Thus, ureteroscopy is a surgical platform from which a variety of disease processes can be treated, each with their own specific postoperative expectations and outcomes.
The following tables show success rates of ureteroscopic lithotripsy.
Table 2. New York University Experience With Ureteroscopic Treatment of Ureteral Calculi Employing the Holmium:YAG Laser

Future

Miniaturization of ureteroscopic instrumentation will continue, with smaller fiberoptics, improved accessories, and new energy sources. As the instrumentation becomes smaller and more refined, it also will become more delicate. Thus, manufacturers are challenged to develop new, smaller equipment that will survive the rigors of surgical therapy.
Today, a rigid ureteroscope may require repair after 3-6 months of vigorous use. This is in contrast to small flexible ureteroscopes, which may survive only approximately 20 cases. The lifespan-limiting factor for these instruments is the trauma of sterilization. The future should hold a more resilient flexible ureteroscope that requires infrequent repairs while still facilitating the most complex endoscopic procedures

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