Editing Management of Upper Urinary Tract Obstruction

== Ureteropelvic junction obstruction (UPJO) ==

* '''See Pediatrics Surgery of the Ureter Chapter Notes'''
* Most cases are congenital, but may only become clinically apparent much later in life
** Many newborns diagnosed with hydronephrosis are subsequently found to have UPJO
** '''UPJO in the neonates is most frequently found as a result of maternal-fetal ultrasound'''
* '''Causes'''
** '''Classified: congenital vs. acquired or intrinsic vs. extrinsic'''
*** '''Congenital UPJO usually results from intrinsic disease'''
** '''Congenital causes of UPJO (5): SHAVA'''
**# '''True ureteral Stricture'''
**# '''High insertion; found more frequently in the presence of renal ectopia or fusion anomalies'''
**# '''Aberrant vessels (controversy persists). Regardless, the presence of crossing vessels has a detrimental effect on the success rates of endopyelotomy'''
**# '''Kinks or Valves''' produced by infoldings of the ureteral mucosa and muscularis
**# '''Aperistaltic segment'''
** '''Acquired causes of UJPO (5): CRIIBS'''
**# '''Cancer'''
**# '''Vesicoureteral Reflux''' can lead to upper tract dilation with subsequent elongation, tortuosity, and kinking of the ureter
**# '''Post-Inflammatory or postoperative scarring or Ischemia'''
**# '''Benign lesion (e.g. fibroepithelial polyps)'''
**# '''Stones'''
* '''Diagnosis and evaluation of UPJO'''
** '''Imaging'''
*** Radiographic studies are performed to determine the anatomic site and functional significance of an apparent obstruction
*** '''Diuretic renography is commonly used''' for diagnosing both UPJ and ureteral obstruction because it provides quantitative data regarding differential renal function and obstruction, even in hydronephrotic renal units '''(see Pathophysiology of UUT Obstruction Chapter Notes for nuclear imaging details)'''
**** '''In general, kidneys with < 15% differential function are nonsalvageable in adults''' (Chapter 48 suggests <10%)'''.'''
***** '''If the potential for salvageability of function is still unclear, an internal stent or percutaneous nephrostomy may be placed for temporary relief of obstruction and renal function studies subsequently repeated'''
* '''Management of UPJO'''
** '''Options:'''
*** '''Observation'''
**** '''Careful observation with serial follow-up renal scans is appropriate if the patient is asymptomatic and the physiologic significance of the obstruction seems indeterminate'''
*** '''Intervention (4):'''
***# '''Decompression (stent or nephrostomy tube)'''
***# '''Endourological procedures (balloon dilation or endopyelotomy)'''
***# '''Pyeloplasty'''
***# '''Ureterocalycostomy'''
** '''Indications for interventions for UPJO (5): (similar to diversion for ureteric stone + HTN)'''
**# '''Symptoms associated with the obstruction'''
**# '''Stones'''
**# '''Infection'''
**# '''Renal dysfunction'''
**# '''Causal hypertension'''
** '''Endourologic management: balloon dilation, endopyelotomy'''
*** '''Advantages: less invasive, reduced hospital stays and postoperative recovery'''
*** '''Disadvantage: higher risk of failure than pyeloplasty'''. Furthermore, whereas open, laparoscopic, or robotic pyeloplasty can be applied to almost any anatomic variation of UPJO, consideration of any of the less invasive alternatives requires taking into account the degree of hydronephrosis, ipsilateral renal function, concomitant calculi, and possibly the presence of crossing vessels.
**** '''Moderate to severe hydronephrosis is most predictive of failure after percutaneous endopyelotomy'''
*** '''Transplantation complications are particularly suited to endoscopic (antegrade or retrograde) management'''
*** '''Approaches:'''
**** '''Retrograde balloon dilation alone'''
***** '''Long-term follow-up studies have shown a diminishing success rate over time'''
**** '''Endopyelotomy'''
***** '''Full-thickness lateral incision through the obstructing proximal ureter, from the ureteral lumen out to the peripelvic and periureteral fat'''
****** '''Rigorous anatomic studies have shown that the incision should usually be made laterally because this is the location devoid of crossing vessels'''
***** '''Contraindications to endopyelotomy (3):'''
*****# '''>2 cm of obstruction'''
*****# '''Active infection'''
*****# '''Untreated coagulopathy'''
***** '''Patients should be counseled that the success rate of any endourologic approach may be less than that of formal reconstruction.'''
****** Success rates approach 85-90% for percutaneous endopyelotomy.
***** Patients should also be counseled of the risk of bleeding requiring transfusion, urinary leak, drainage-related complications, and hydropneumothorax, particularly if upper pole access is used
***** Can be done with a percutaneous antegrade or retrograde ureteroscopic approach
****** The main advantage of retrograde ureteroscopic endopyelotomy is that it allows direct visualization of the UPJ and assurance of a properly situated, full-thickness endopyelotomy incision without the need for percutaneous access
***** Can be done with an endopyelotome, holmium laser or cutting balloon catheter
***** '''Little evidence for significant differences among endopyelotomy techniques.''' The differences lie in technical considerations and complications
***** '''Percutaneous endopyelotomy remains appropriate for patients with UPJO and concomitant pyelocalyceal stones, which can be managed simultaneously'''.
****** '''When a percutaneous endopyelotomy fails, several options exist including:'''
******* '''Retrograde endopyelotomy'''
******* '''Repeat percutaneous endopyelotomy'''
******* '''Laparoscopic, robotic, or open operative intervention'''
***** '''A stent is placed across the incision and is left to heal.''' There remains no consensus as to the optimal stent size or duration after endopyelotomy
***** Postoperative care:
****** Avoidance of strenuous activity for 8-10 days after the procedure is recommended
****** '''Once the stent is removed, that patient returns 1 month later for history and physical exam, urinalysis, and diuretic renography'''
****** '''For most adults, 2-3 year follow-up is justified''' because studies indicate that even at 36 months some late failures are identified, but relatively few are identified at 60 months
** '''Pyeloplasty'''
*** '''Principles of UPJ anastomosis (5):'''
***# '''Widely patent'''
***# '''Watertight'''
***# '''Without tension'''
***# '''Heal over a stent'''
***# '''Reconstructed UPJ should allow a funnel-shaped transition between the pelvis and the ureter that is in a position of dependent drainage'''
*** '''Absolute contraindications to pyeloplasty (3):'''
***# '''Uncorrected coagulopathy'''
***# '''Untreated UTI'''
***# '''Cardiopulmonary compromise unsuitable for surgery'''
*** '''Before definitive surgical management, drainage of a kidney with UPJO is recommended only for infection associated with the obstruction or renal dysfunction resulting from obstruction in a solitary kidney or bilateral disease [suggesting no stent in renal dysfunction from single side obstruction if contralateral kidney fine]'''
*** '''Transperitoneal laparoscopic approach is the most widely used method''' owing to its associated large working space and familiar anatomy.
**** Retroperitoneal laparoscopic approach and anterior extraperitoneal approach rely on creation of a working space using manual or balloon dilation.
*** '''A dismembered Anderson-Hynes pyeloplasty, which is preferred by most surgeons, or one of the non-dismembered methods such as Y-V plasty and flap pyeloplasty (Culp) can be used'''
**** '''The Foley Y-V-plasty is designed for repair of a UPJ obstruction secondary to a high ureteral insertion.'''
**** Flap procedures are not appropriate in the setting of crossing vessels and when reduction of redundant renal pelvis is desired
*** '''Dismembered pyeloplasty'''
**** '''Preferred by most urologists because this procedure is almost universally applicable to different clinical scenarios'''
***** Can be used regardless of whether the ureteral insertion is high on the pelvis or already dependent.
***** Permits reduction of a redundant pelvis or straightening of a tortuous proximal ureter
***** '''Anterior or posterior transposition of the UPJ can be achieved when the obstruction is the result of accessory or aberrant lower pole vessels'''
****** In the presence of crossing aberrant or accessory lower pole renal vessels associated with UPJ obstruction, a dismembered pyeloplasty is the only method to allow transposition of the UPJ in relation to these vessels.
***** '''Unlike the flap techniques, only a dismembered pyeloplasty allows complete excision of the anatomically or functionally abnormal UPJ itself'''
**** '''A dismembered pyeloplasty is not well suited to UPJO associated with (2):'''
****# '''Lengthy or multiple proximal ureteral strictures'''
****# '''Small, relatively inaccessible intrarenal pelvis'''
**** '''If dismembered pyeloplasty is performed for the presence of crossing vessels, the renal pelvis is first transected circumferentially above the UPJ and the lateral aspect of the proximal ureter is spatulated.''' The renal pelvis and proximal ureter are then transposed to the opposite side of the crossing vessel and the ureteropelvic anastomosis is then completed with intracorporeal suturing techniques
*** '''The provision of external drainage from the site of surgical repair is absolutely necessary'''
**** '''This helps minimize the risk of urinoma formation leading to possible disruption of the suture line, scarring, or sepsis'''
*** '''The Foley catheter is usually removed 24 to 36 hours postoperatively, and the surgical drain is removed before hospital discharge if the drain output remains negligible.'''
**** '''If the drain output increases after the Foley catheter removal, the Foley catheter should be replaced for 7 days to eliminate urinary reflux along the stent in the treated ureter and decrease urinary extravasation at the ureteropelvic anastomosis.'''
*** '''The ureteral stent is typically removed 4-6 weeks later in an outpatient setting, and follow-up including the use of imaging studies such as diuretic renal scan is performed'''
**** '''Persistent urinary drainage after an unstented pyeloplasty is common, and will often require intervention.'''
***** '''When this is associated with a large blood clot, and likely edema at the anastomosis, the kidney will need early drainage until the bleeding resolves and edema improves.'''
****** '''In children, this is best managed with a nephrostomy tube, as stent placement in a young infant would likely result in stent occlusion from the renal pelvic blood clot.'''
***** '''In the majority of cases not associated with an occlusive blood clot, the leak will resolve spontaneously, so observation is the best approach in the early postoperative period in these patients.'''
***** '''If the leak is persistent and not associated with a consolidated clot, it would most likely resolve with retrograde stent placement.'''
*** '''Most failures from laparoscopic pyeloplasty occur in the first 2 years.'''
**** '''For patients who fail laparoscopic pyeloplasty, open surgery has been used as a salvage procedure. However, most patients can be well managed with endoscopic intervention'''
*** '''The spiral flap may be of significant value when both UPJO and a relatively long segment of proximal ureteral narrowing or stricture occur in the same setting'''
** '''Ureterocalicostomy'''
*** '''Indications (3):'''
***# '''UPJO or proximal ureteral stricture is associated with a relatively small intrarenal pelvis'''
***# '''To provide completely dependent drainage when the UPJ is associated with rotational anomalies such as horseshoe kidney'''
***# '''Salvage technique for failed pyeloplasty'''
** '''An open or laparoscopic approach can be recommended to any patient in whom primary endourologic management has failed, and an endourologic approach in whom an open or laparoscopic repair has failed'''

== Retrocaval ureter ==

* '''See Pediatrics Ureter Anomalies Chapter Notes'''

== Ureteral stricture disease ==

* '''Evaluation and treatment of ureteral strictures is essential to preserve renal function and rule out presence of malignancy'''
* '''Causes (9)'''
** '''Classification: benign vs. malignant'''
** '''Benign SIIRRII PUF'''
**# '''Stones'''
**# '''Instrumentation, endoscopic'''
**# '''Infection (tuberculosis)'''
**# '''Renal ablation injury'''
**# '''Radiation'''
**# '''Ischemia''' (trauma, surgical dissection)
**# '''Idiopathic'''
**# '''PeriUreteral Fibrosis caused by abdominal aortic aneurysm or endometriosis'''
**#* Endometeriosis
**#** Most patients with ureteral obstruction associated with endometriosis are asymptomatic
**#*** Signs and symptoms may occur cyclically and include flank pain, dysuria, urgency, hematuria and frequent urinary tract infections.
**#** Management
**#*** A trial of hormonal therapy using gonadotropin-releasing hormone agonists (Lupron) or medroxyprogesterone (Danazol) should be initiated for mild symptomatic obstruction when there is good preservation of renal function.
**#*** For more severe obstruction associated with significant periureteral fibrosis, surgical intervention to correct the obstruction, with or without hysterectomy and bilateral salpingo-oophorectomy, is advisable
*** '''Hysterectomy accounts for over 50% of iatrogenic ureteral injuries'''
**** Most likely areas where the ureter can be occluded during hysterectomy (2):
****# Level of the broad ligaments
****# At the vaginal cuff and bladder trigone
* '''Malignant'''
** '''Intrinsic: e.g. urothelial carcinoma'''
** '''Extrinsic: cervical cancer'''
* '''Diagnosis and Evaluation'''
** '''The renal unit should be assessed for function before starting treatment because endourologic therapies require 25% function of the ipsilateral moiety to have reasonable success rates''' (Figure 49-34 suggests 20%)
** '''The presence of obstruction on CT can identify ureteral stricture disease, but antegrade or retrograde pyelogram, CT urography, or diagnostic ureteroscopy is necessary to define the location and length of the ureteral stricture'''
* '''Management'''
** '''Options (3):'''
**# '''Decompression'''
**# '''Endourological procedures (balloon dilation or endoureterotomy)'''
**# '''Surgical repair'''
** '''Decompression'''
*** '''Ureteral stent placement'''
**** Effective acutely in treating most ureteral strictures, particularly intrinsic ureteral strictures.
**** '''Patients with extrinsic ureteral compression eventually require percutaneous drainage or surgical management'''
**** '''The use of tandem ureteral stent placement (two parallel stents) has been shown to be effective in benign and malignant extrinsic ureteral obstruction'''
**** '''Placement of a ureteral stent in an obstructed system will result in decreased ureteral contractility'''
*** No clear consensus regarding the benefits of metallic stents
** '''Endourologic approaches: balloon dilation or endoureterotomy'''
*** '''The best management for ureteral strictures < 2 cm with no previous intervention is an endoscopic approach'''
*** '''Contraindications (1):'''
***# '''Strictures >2cm''' because dilation alone is unlikely to be successful
*** '''Balloon dilation'''
**** After 10 minutes of tamponade, the balloon is deflated and withdrawn. An internal stent is passed over a guidewire still in place, which is left indwelling for 2-4 weeks.
**** '''Follow-up diuretic renography''' is usually performed ≈1 month after stent extraction and at 6- to 12-month intervals thereafter
**** Success rates range from 50-76%, long-term outcomes are unfavorable
**** '''Best results obtained in patients with iatrogenic, non-anastomotic strictures such as those secondary to ureteroscopic instrumentation'''. In that setting, a success rate of 85% was achieved compared with a rate of 50% for anastomotic strictures
*** '''Endoureterotomy'''
**** '''The position for the incision is chosen as a function of the level of the ureter involved. In general'''
***** '''Lower ureteral strictures are incised in an anteromedial direction to stay away from the iliac vessels'''
***** '''Upper ureteral strictures are incised laterally or posterolaterally'''
**** The incision itself can be performed using a cold knife, a cutting electrode, or a holmium laser
** '''Surgical repair'''
*** '''Ureteroureterostomy'''
**** So-called end-to-end repair
**** '''Bridges ureteral defect of 2-3cm'''
**** '''A short defect involving the upper ureter or mid-ureter, either in the form of stricture or as a consequence of recent injury, is most appropriate for ureteroureterostomy'''
***** '''Only short defects (2-3cm) should be managed by end-to-end ureteroureterostomy''' because tension on the anastomosis almost always leads to stricture formation
**** '''Conversely, a lower ureteral stricture is usually best managed by ureteroneocystostomy with or without a psoas hitch or Boari flap.'''
**** In an open surgical approach, the choice of surgical incision depends on the level of the ureteral stricture
**** '''Postoperative care'''
***** '''A surgical drain is placed, and a Foley catheter is usually left indwelling for 1 to 2 days. The surgical drain may be removed if there is minimal output for 24 to 48 hours.'''
****** If the surgical procedure is not performed entirely in a retroperitoneal manner, it is important to determine the nature of the fluid from the surgical drain by checking the creatinine level of the fluid. If there is no urinary extravasation, the drain can then be removed.
***** '''The double-J ureteral stent is usually removed 4-6 weeks postoperatively'''
**** The success rate for a tension-free, watertight ureteroureterostomy is > 90%
*** '''Ureterocalycostomy'''
**** '''Ureteral stump is sewn end-to-side into an exposed renal calyx'''
**** '''Rarely used; used where there is profound damage to the renal pelvis and UPJ'''
*** '''Ureteroneocystotomy'''
**** Ureteroneocystostomy without a psoas hitch or Boari flap in an adult is appropriate for injury or obstruction affecting the distal 3 to 4 cm of the ureter
**** '''Bridges ureteral defect of 4-5cm'''
**** '''After adequate proximal ureteral mobilization, direct ureteroneocystostomy is performed only if a tension-free anastomosis is possible. Otherwise, a psoas hitch or Boari flap should be used as an adjunct.'''
**** A direct, non-tunneled anastomosis may be performed if postoperative reflux is acceptable
***** In a retrospective review, '''no significant difference in the preservation of renal function or risk of stenosis was found between refluxing versus anti-refluxing procedures.''' '''However, it is unclear if a non-refluxing anastomosis increases the risk of pyelonephritis in an adult patient'''
*** '''Psoas hitch'''
**** An effective method to bridge a defect of the lower third of the ureter.
**** May be preferred over ureteroureterostomy in lower ureteral injuries because the tenuous ureteral blood supply might not survive transection. However, '''a ureteral defect extending proximal to the pelvic brim usually requires more than a psoas hitch alone'''
**** '''Femoral nerve is most likely to be injured during a psoas hitch'''
**** '''Bridges ureteral defect of 6-10cm'''
***** Can provide an additional 5 cm of length compared to simple ureteroneocystostomy
**** '''Contraindications (1):'''
***** '''A small, contracted bladder with limited mobility'''
**** '''With traction, the ipsilateral dome of the bladder should be able to reach the level proximal to the iliac vessels. Additional mobility can be achieved by dividing the contralateral superior vesical artery'''
**** '''The ipsilateral bladder dome is secured to the psoas minor tendon or the psoas major muscle using several absorbable sutures. Care should be taken to avoid injury to the genitofemoral nerve and the femoral nerve'''
**** '''Relative to the Boari flap, the advantages of psoas hitch include:'''
****# '''Increased technical simplicity'''
****# '''Decreased risk of vascular compromise'''
****# '''Decreased risk of voiding difficulties'''
**** '''Complications occur uncommonly but include urinary fistula, ureteral obstruction, nerve injury, bowel injury, iliac vein injury, and urosepsis'''
*** '''Boari flap'''
**** '''A pedicle of bladder is swung cephalad and tubularized to bridge the a 10-15-cm gap to the injured ureter''' [Campbell's table says 12-15cm but text says 10-15cm]; '''a spiraled bladder flap can reach the renal pelvis in some circumstances, especially on the right side'''. Care should be taken to ensure adequate vascular supply to the flap
**** '''A small bladder capacity is likely to be associated with difficult or inadequate Boari flap creation, warranting consideration of alternative methods in the preoperative surgical planning'''
**** '''The ratio of flap length to base width should be ≤ 3:1 to help minimize flap ischemia'''
*** '''Renal descensus'''
**** '''Renal mobilization can provide additional length to bridge a defect in the upper ureter or decrease tension on a ureteral repair'''
**** '''Bridges ureteral defect of 5-8cm'''
**** After entry to the Gerota fascia, the kidney is completely mobilized and rotated inferiorly and medially on its vascular pedicle. The lower pole of the kidney is then secured to the retroperitoneal muscle using several absorbable sutures. Up to 8 cm of additional length may be gained using this technique.
*** '''Transureterostomy'''
**** Transposing the injured ureter across the midline and anastomosing it end-to-side into the uninjured ureter
**** '''Most often performed as a secondary or delayed procedure'''
**** '''Absolute contraindications (1):'''
****# '''Insufficient length of the donor ureter to reach the contralateral recipient ureter'''
**** '''Relative contraindications (5):'''
****# '''History of nephrolithiasis'''
****# '''Urothelial malignancy'''
****# '''RPF'''
****# '''Chronic pyelonephritis'''
****# '''Abdominopelvic radiation'''
****#* '''Any disease process that may affect both ureters represents a relative contraindication'''
**** '''Reflux to the recipient ureter, if present, needs to be identified and corrected simultaneously. Therefore, a voiding cystogram should be performed preoperatively, in addition to any other imaging'''
**** '''A tunnel under the sigmoid colon mesentery is created proximal to the inferior mesenteric artery''' to avoid ureteral tethering by this vessel; the donor ureter is then brought through the tunnel to the recipient side.
**** The injured ureter becomes subsequently difficult to intubate or image with ureteroscopy through the bladder; ureteral access needs to be provided by a nephrostomy placed on the injured side.
**** Caution is required while performing this procedure because it involves surgery on the uninjured, contralateral ureter with the theoretical risk for converting unilateral ureteral injury into bilateral ureteral injury. '''Instead of transureteroureterostomy, ileal interposition or ureteroureterostomy with renal mobilization, if necessary, are preferred.'''
*** '''Ileal ureter substitution'''
**** '''Reconstruction of the ureter with urothelium-based tissue is most preferable because it is not absorptive and is resistant to the inflammatory and potentially carcinogenic effects of urine. Incorporation of other tissue is reserved for situations in which a defect cannot be bridged by other methods.'''
**** Delayed ureteral repairs, especially when a very long segment of ureter is destroyed, can be performed by creation of a '''ureteral conduit out of ileum''' in much the same way that an ileal conduit is constructed to drain the urine after cystectomy.; appendix and fallopian tube have been found to be unreliable ureteral substitutes.
**** '''When an isoperistaltic segment of ileum is directly anastomosed to the bladder, reflux and renal pelvic pressure increase are usually seen only during voiding.''' The retrograde transmission of intravesical pressure is dependent on the length of ileum segment used in interposition and the voiding pressure
**** '''Only 12% of patients with normal preoperative renal function developed significant metabolic problems postoperatively, and preoperative renal function was identified to be an important prognostic factor'''
**** '''Not recommended in the acute setting'''
**** '''Contraindications (4):'''
****# '''Baseline renal insufficiency (creatinine > 2 mg/dL)'''
****# '''Inflammatory bowel disease'''
****# '''Radiation enteritis'''
****# '''Bladder dysfunction or outlet obstruction'''
**** Before the surgical procedure, a full mechanical and antibiotic bowel preparation is often used
**** The length of the ureteral defect is measured, and an appropriate segment of distal ileum is chosen. The segment should be ≥15 cm away from the ileocecal valve
**** In the presence of a scarred or intrarenal pelvis, ileocalicostomy may be performed
**** Patients with worsening metabolic abnormalities associated with a progressively dilating ileal ureter should be evaluated for vesicourethral dysfunction.
**** '''Malignancy arising from an ileal ureter segment has been reported and it is recommended that regular endoscopic examination be performed starting at postoperative year 3 for early detection'''
*** '''Other interposition'''
**** '''Short segments of small or large bowel are formed into a long, thin tube (Monti procedure)'''
**** '''Appendix has also been used'''
*** '''Autotransplantation'''
**** Generally, '''considered when the contralateral kidney is absent or poorly functioning or when other methods for ureteral substitution or repair are not feasible'''
**** '''Final option before nephrectomy'''
**** '''Not recommended in the acute setting'''

== Ureteroenteric anastomotic stricture ==

* '''Rates of ureteroenteric anastomotic stricture after continent diversion is 3-25%, majority occur within the first 2 years'''
* '''Most patients with a long-term urinary conduit will have an element of chronic hydronephrosis that is not secondary to obstruction; obstruction suggested by a decrease in renal function or loss of reflux on a routine loopogram should prompt diuretic renography to quantitatively assess for functional obstruction'''
* '''Factors predicting stricture after ureteroenteric anastomosis:'''
*# Technique used for ureteral dissection
*# Segment of bowel used for the diversion
*# '''Type of anastomosis performed'''
*#* '''Risk of stricture is less in refluxing anastamoses compared to non-refluxing anastamoses and therefore the use of a reflexing anastamosis is preferred for continent reservoirs (note that there is no difference in risk of stricture for ureteroneocystotomy)'''
*# '''Side of anastomosis'''
*#* '''Higher incidence of stricture formation on the left'''
*#** When performing an ileal conduit, the left ureter is brought underneath the sigmoid mesentery just overlying the aorta. The additional length and dissection needed on the left and the possibility of angulation around the inferior mesenteric artery may lead to increased risk of stricture on the left side
* '''Management (see Figure in Campbell's)'''
** '''Antegrade endourologic management of ureteroenteric or ureterocolic strictures is preferred''', unlike the management of ureteral strictures
** '''Strictures > 2cm or on the left are less likely to succeed with endourologic management'''
*** Endourologic success rate for
**** Strictures > 1cm is 6% vs. 50% strictures < 1 cm
**** Left sided-stricture 19% vs. 41% on the right
***** No difference was noted in sidedness with open repair
** '''Although long-term patency of minimally invasive procedures for ureteroenteric strictures is in the range of 50%, such approaches are still used as the initial intervention''', reserving operative management for those patients in whom endourologic intervention fails and for patients with strictures > 1 cm
* '''When considering endoscopic incision of a left ureteroenteric stricture, the risk of hemorrhage is a consideration because the sigmoid mesentery can be in close proximity. This, taken with the lower success rates of all endoscopic approaches on the left side, supports serious consideration for primary repair when treating left ureteroenteric anastomotic strictures'''

===== Questions =====

# What are the causes of UPJO?
# What are the indications for intervention in UPJO?
# What are the options for intervention in UPJO?
# How long is a stent kept for following pyeloplasty?
# When should a ureterocalycostomy be considered?
# What are the contraindications to endopyelotomy?
# Persistence of which structure results in a retrocaval ureter?
# What are the causes of ureteral stricture disease?
# What are the management options for ureteral stricture disease?
# What are the contraindications to transureterostomy?
# What investigations are needed before considering transureteroureterostomy?
# What are the contraindications to ileal ureter substitution?
# What is the preferred approach (retrograde vs. antegrade) for the endoscopic management of ureteroenteric stricture?
# What are the risk factors for failure of endourological management of a ureteroenteric anastamostic stricture?

== Answers ==

# What are the causes of UPJO?
## Congenital '''SHAVA'''
### True ureteral '''S'''tricture
### '''H'''igh insertion; found more frequently in the presence of renal ectopia or fusion anomalies
### '''A'''berrant vessels (controversy persists). Regardless, the presence of crossing vessels has a detrimental effect on the success rates of endopyelotomy
### Kinks or '''V'''alves produced by infoldings of the ureteral mucosa and muscularis
### '''A'''peristaltic segment
## Acquired '''CRIBS'''
### Cancer
### Reflux
### Ischemia
### Benign tumour
### Stones
# What are the indications for intervention in UPJO?
## Symptoms
## Stones
## Renal insufficiency
## Infections
## Causal HTN
# What are the options for intervention in UPJO?
## Observation
## Diversion (stent or nephrostomy tube)
## Endoscopic (balloon dilation, endopyelotomy)
## Pyeloplasty
## Ureterocalycostomy
# How long is a stent kept for following pyeloplasty?
## 4-6 weeks
# When should a ureterocalycostomy be considered?
## Small renal pelvis
## Dependent drainage in malrotated/ectopic kidney
## Failed pyeloplasty
# What are the contraindications to endopyelotomy?
## Stricture > 2cm
## Active infection
## Uncontrolled coagulopathy
# Persistence of which structure results in a retrocaval ureter?
## Posterior cardinal vein
# What are the causes of ureteral stricture disease?
## Stones
## Instrumentation, endoscopic
## Infection (TB)
## Radiation
## Renal ablation injury
## Ischemia
## Idiopathic
## Periureteral fibrosis
# What are the management options for ureteral stricture disease?
## Diversion
## Endoscopic
## Surgical
### Ureteroureterostomy
### Ureteroneocystotomy
### Psoas hitch
### Boari flap
### Renal descensus
### Transureteroureterostomy
### Ileal ureter
### Autotransplant
# What are the contraindications to transureterostomy?
## Absolute: insufficient length of ureter
## Relative: history of stones, upper tract cancer, RPF, radiation, chronic pyelonephritis, any process that affects both ureters
# What investigations are needed before considering transureteroureterostomy?
## VCUG to rule out reflux
# What are the contraindications to ileal ureter substitution?
## Baseline renal insufficiency
## Bladder dysfunction or outlet obstruction
## Inflammatory bowel disease
## Radiation enteritis
# What is the preferred approach (retrograde vs. antegrade) for the endoscopic management of ureteroenteric stricture?
## Antegrade
# What are the risk factors for failure of endourological management of a ureteroenteric anastamostic stricture?
## Left sided stricture
## Stricture > 1cm

== References ==

* Wein AJ, Kavoussi LR, Partin AW, Peters CA (eds): CAMPBELL-WALSH UROLOGY, ed 11. Philadelphia, Elsevier, 2015, chap 49