Surgical management of an iatrogenic ureteral injury

INTRODUCTION — 

Over 80 percent of ureteral injuries are iatrogenic [1-3]. Ureteral injuries can occur during open, laparoscopic, or robotic intra-abdominal, vaginal, and endourologic procedures that are performed by urologists, general and colorectal surgeons, and gynecologists [4-7].

The surgical management of iatrogenic ureteral injuries, whether identified early or late, is discussed here. Ureteral injuries following specifically trauma and gynecologic or colorectal procedures are reviewed elsewhere:

●(See "Overview of traumatic and iatrogenic ureteral injury".)

●(See "Urinary tract injury in gynecologic surgery: Identification and management".)

●(See "Management of intra-abdominal, pelvic, and genitourinary complications of colorectal surgery", section on 'Ureteral injury'.)

RECOGNITION AND PREPARATION — 

Seventy to eighty-five percent of all ureteral injuries are not identified intraoperatively but rather in the postoperative period [1,5,6,8,9]. The general principles of recognizing an iatrogenic injury to the ureter are the same, regardless of the indications of the operative procedure. These are reviewed in other topics. (See "Overview of traumatic and iatrogenic ureteral injury", section on 'Clinical presentations' and "Urinary tract injury in gynecologic surgery: Identification and management", section on 'Postoperative evaluation and diagnosis'.)

Prior to initiating the repair, the surgeon should:

●Review the preoperative imaging of the urinary tract (if performed) and extensiveness of the injury, including contralateral ureteral and bladder injury. The surgeon should determine if both kidneys are functioning.

●For an injury recognized intraoperatively, indigo carmine or methylene blue can be administered intravenously to aid in evaluating the integrity of the ureters. Alternatively, the dyes can be instilled via a urethral catheter to help identify or confirm bladder injuries.

●A consultation with a skilled urologist is necessary if the operating surgeon is inexperienced with primary or advanced repair and stenting of a ureter.

●If a patient has received antibiotic prophylaxis for the procedure, additional antibiotics are not administered for a ureteral injury repair [10]. Antimicrobial prophylaxis for genitourinary surgery, gynecologic and obstetric surgery, and colon and rectal surgery is provided in the accompanying tables (table 1).

●If a patient has not received prophylactic antibiotics or is undergoing delayed ureteral repair, we administer antimicrobial agents (cephalosporins, gentamicin, or fluoroquinolones) to cover enteric gram-negative bacilli that comprise most urinary tract pathogens.

GENERAL APPROACH — 

Surgical management of an intragenic ureteral injury depends on the severity and location of the injury and the timing of the diagnosis (algorithm 1).

Severity of injury — Ureteral injuries are classified from grade I to V according to the American Association for the Surgery of Trauma (AAST) injury scale (table 2).

●Minor injuries (grade I [contusion or hematoma] and grade II [<50 percent disruption]) can be managed endoscopically with insertion of a ureteral stent [11]. If the contusion is substantial, or if the blood supply is in question, the injured section of the ureter should be debrided to healthy tissue and a surgical repair performed.

●Major injuries (grade III [>50 percent disruption] or grade IV/V [complete disruption]) require surgical repair. The techniques of surgical repair depend on the type, location, and grade of the injury and will be discussed in detail below. (See 'Surgical repair' below.)

In the rare case that the ureter is inadvertently ligated in continuity, the suture should be removed and the ureter observed for viability. If compromise is observed, the injured ureter should be resected and a surgical repair performed [12]. A ligation injury recognized postoperatively will likely require surgical repair.

Timing of diagnosis — Ureteral injuries recognized immediately or early postoperatively may undergo immediate repair. Injuries that are recognized late, however, should undergo proximal urinary diversion and deferred repair due to the ongoing inflammatory reaction and risk of anastomotic failure [13].

●Intraoperative recognition – Iatrogenic ureteral injuries recognized during the operation should be repaired in that setting [14].

●Postoperative recognition – The approach for patients with a postoperative recognition of a ureteral injury is controversial [12]. Some advocate for stent placement as the first line of therapy while others perform a primary repair as soon as possible. The American Urological Association (AUA) urotrauma guidelines advocate immediate repair of ureteral injuries that are <7 days old [15], whereas the British guidelines advocate delaying repair for injuries that are >14 days old [16]. The decision should be individualized according to local practice and clinical scenario [13].

If the injury is recognized late or there are complications (eg, abscess, urinary infection, urinary fistula) that would interfere with ureteral healing, proximal urinary diversion is performed, and a delayed repair can be performed after three to six months. (See 'Urinary diversion' below.)

SURGICAL TECHNIQUES — 

Surgical techniques that have been used to manage iatrogenic ureteral injuries can be broadly classified into three categories: endourologic repair (eg, stenting), surgical repair (eg, ureteroureterostomy), and urinary diversion (eg, nephrostomy tube). The choice depends on urologist preference and the type, location, and grade of injury. (See 'Severity of injury' above.)

Endourologic repair — Advances in endourologic technique and equipment may provide a minimally invasive approach to select iatrogenic ureteral injuries.

●For minor injuries such as contusion and partial disruption, minimally invasive techniques (endoscopic or radiologic), such as retrograde or anterograde stent placement, should be attempted as a first-line treatment [10,16]. If stenting is successful, then a retrograde study at six weeks should be performed to ensure normal integrity and caliber of the ureter at the site of injury. In cases where there is ongoing leak or a stricture has developed, surgical repair and reconstruction are required [10,17].

●For patients with a delayed diagnosis, retrograde stenting may not be successful. Anterograde stenting after nephrostomy tube placement may be attempted [18,19]. If anterograde stenting is not successful either, the nephrostomy tube can be used to divert the urine before delayed surgical repair in three to six months [10] .

●In higher-grade injuries such as complete transection [20,21] and ligation [22], successful endoscopic treatment has also been reported, but not all authorities consider it feasible [10]. Surgical repair is ultimately required for most patients.

Surgical repair — For all ureteral injuries that require surgical repair, we suggest an ureteroureterostomy when it can be performed without tension. Ureteroureterostomy is typically performed over a stent. Surgical principles include:

●Debridement to viable tissue

●Wide spatulation

●Tension-free anastomosis

●Watertight closure with stent placement

●Periureteral drainage

When more extensive damage (eg, multifocal, extended defect) is present that would preclude a primary anastomosis, an advanced surgical repair, such as a flap procedure, ureteral substitution, autotransplantation, or nephrectomy, may be required [23].

The following sections describe the repair of an injured ureter based on the location of the injury (eg, lower, middle, and upper ureter) (figure 1 and figure 2 and algorithm 2).

Lower ureter — Approximately 90 percent of the trauma to the ureter occurs in the lower portion, which extends from the inferior border of the sacroiliac joint to the ureterovesical junction (figure 3 and figure 4) [1].

Transection injuries are repaired by a primary ureteroureterostomy, ureteral implant, or psoas hitch, depending on the severity of the injury and approximation to the ureterovesical junction (figure 5).

Ureteroureterostomy — If the ureteral injury is approximately 3 to 4 cm proximal to the ureterovesical junction, a primary ureteral anastomosis is performed.

The following general principles are applied when performing an ureteroureterostomy [11,12,16]:

●Mobilize the ureter to obtain adequate length for repair without devascularization.

●The edges of both the proximal and distal ureteral segments are resected to ensure that viable tissue is being anastomosed.

●Both ends of the ureter are spatulated and the anastomosis is performed using interrupted, absorbable sutures (figure 6).

●The anastomosis must be tension free.

●A stent is routinely utilized (picture 1 and image 1). It can be inserted by immediate cystoscopy or by a cystotomy.

●The site of the anastomosis is drained.

●The retroperitoneum is closed over the anastomosis. If not technically feasible, the anastomosis is isolated by using an omental flap.

Ureteroneocystostomy — When the ureteral injury is within the distal 2 cm from the ureterovesical junction, a primary ureteral repair is difficult. In these settings, a ureteroneocystostomy (ureteral reimplant) is usually preferred. There are several techniques described, such as the Leadbetter-Politano and extravesical approaches [24-27].

●Leadbetter-Politano is an intravesical technique that involves creating a submucosal tunnel to create a "flap valve" and prevent reflux [28]. The ureter enters the bladder superiorly for a distance of 2 to 3 cm, is tunneled under the mucosa, and is anastomosed directly to the bladder mucosa with interrupted absorbable sutures.

●Extravesical approaches, such as the Lich-Gregoire, involve incision of the detrusor muscle to create a trough for the ureter, followed by mucosal anastomosis and subsequent closure of the trough to create an antirefluxing mechanism [29].

In our practice, we prefer the nonrefluxing Leadbetter-Politano technique, in which the ureter is reattached to the bladder in a medial and superior position to the original insertion site, particularly for women of childbearing age. Whether to stent the reimplanted ureter is determined by the surgeon. We use a stent if the ureter has been extensively mobilized prior to the reimplantation. However, all ureteral reimplantations should be drained.

Psoas hitch ureteral reimplantation — The psoas hitch ureteral reimplantation is the best approach when a primary ureteroureterostomy or ureteroneocystostomy cannot be performed without tension [27,30-34].

The following general principles are applied when performing a psoas hitch procedure (figure 7) [33,35-38]:

●Mobilization of the bladder on the superior contralateral sides of the injury facilitates a tension-free anastomosis.

●The cystotomy is performed on the anterior wall of the bladder, away from the dome. This enables mobilization of the bladder, as well as placement of the anchoring stitches in the psoas tendon.

●The bladder is anchored to the psoas tendon with nonabsorbable stitches. Inserting the surgeon's fingers into the bladder dome facilitates placement.

●When anchoring the bladder to the psoas tendon, avoid injury or entrapment of the genitofemoral nerve (superficial) and the femoral nerve (deep). The bladder is hitched prior to reimplementation.

●The ureter is then reimplanted. Some have advocated a tunneled reimplant such as Leadbetter-Politano technique; however, a refluxing spatulated anastomosis can be performed [33].

●The cystostomy is closed with an absorbable suture.

●A urethral catheter is left in place; a suprapubic tube is usually not necessary unless the surgeon anticipates bloody urine that could result in an obstructed urethral catheter.

●The reimplantation site is drained.

Middle ureter — Approximately 7 percent of all ureteral injuries occur in the middle third of the ureter, which extends from the upper border to the lower border of the sacroiliac joint [1].

The optimal repair for a midureteral transection is a ureteroureterostomy (see 'Ureteroureterostomy' above). For more extensive injuries, or for when an anastomosis cannot be performed without tension, a transureteroureterostomy or a Boari flap is used. A transureteroureterostomy should not be performed in a patient with a history of renal stones or a nonfunctioning contralateral kidney.

Boari flap — The Boari flap is the optimal, but complex, approach for repair of an extensive midureteral injury (figure 8) [27,39-44]. This approach is best for a planned, delayed repair.

The following general principles are applied when performing a Boari flap [1,38]:

●Similar to the technique for a psoas hitch, the bladder must be thoroughly mobilized and hitched.

●Before the flap is created, the bladder should be distended with saline, and the flap carefully planned with a sterile marker. Prior to Boari reconstruction, an adequate capacity should be ensured (>300 cc) and patients should be counseled about the possible change in voiding patterns.

●A rectangular flap is created on the anterior surface of the bladder. The most critical maneuver is to preserve blood supply to the flap. Hence, the base must be at least 4 cm wide (wider for longer flaps), and the superior vesical artery must be preserved.

●The flap is sutured to the psoas tendon with nonabsorbable sutures. (See 'Psoas hitch ureteral reimplantation' above.)

●The ureter is tunneled through the proximal portion of the flap, and a neo-orifice is created.

●The bladder flap is tubularized with running absorbable sutures.

●The distal ureter is anastomosed to the flap using a running absorbable suture.

●The anastomosis is stented.

●The anastomotic site is drained.

●An indwelling urethral catheter drains the bladder.

●A suprapubic tube is used if the surgeon anticipates a large amount of bloody urine.

Transureteroureterostomy — A transureteroureterostomy, which is rarely used, utilizes an anastomosis between ureters, where the injured ureter crosses the midline to meet the contralateral ureter (figure 9) [11,31,35,45-48]. Indications include a planned, delayed repair in the setting of a small fibrotic bladder, pelvic abscess, or when there is an extensive lower ureteral defect. Contraindications include prior pelvic radiation, reflux, and a history of stone disease.

The following general principles are applied when performing a transureteroureterostomy [49]:

●Both the donor and recipient ureters are mobilized to prepare for a tension-free anastomosis.

●The recipient ureter should never be angulated to reach the donor ureter.

●The donor ureter is spatulated, and then stay sutures are placed in the recipient ureter.

●The ureteroureterostomy is performed between the stay sutures using running 4-0 chromic suture with the knot on the outside on the posterior wall. Interrupted sutures are used on the anterior wall.

●Typically, the anastomosis is unstented.

●The anastomotic site is always drained.

Upper ureter — Injuries to the upper ureter, which extends from the ureteropelvic junction to the upper border of the sacroiliac joint, occur in only 2 percent of all ureteral injuries [1]. The optimal procedure for repair of an upper ureteral injury is a ureteroureterostomy or ureteropyelostomy, if sufficient length can be mobilized for a primary repair without tension. This can be facilitated by mobilization of the kidney with fixation to the psoas tendon (nephropexy) to provide for a tension-free anastomosis. Mobilization of the left kidney can provide up to 4 cm of length, but mobilization of the right kidney does not add much length to the right ureter, as the right kidney is limited by a short right renal vein. The general principles are described in a preceding section. (See 'Ureteroureterostomy' above.)

When sufficient length cannot be mobilized for ureteroureterostomy, the options include an ileal or appendiceal interposition graft, anastomosing the ureter to the kidney (ureterocalicostomy), autotransplantation, or a nephrectomy. In most settings of an upper ureteral injury, the Boari flap is technically unfeasible.

Ileal or appendiceal interposition graft — The use of ileal or appendiceal interposition graft for extensive upper ureteral injuries has been described [1,31,41,50-54]. However, this approach is rarely considered as a first-line procedure [55,56].

As with autotransplantation, bowel interposition should be considered only when simpler alternatives are not practical. We prefer to use the ileum if the patient has had a preoperative bowel preparation (although not an absolute prerequisite) and in emergency settings. The techniques used for creation of an ileal ureter are similar to those used in an ileal conduit. The proximal and distal ureteral segments are fully mobilized, and the ureteral-ileal anastomosis is performed with absorbable sutures. No stents are utilized, and the anastomosis site is drained.

Ureterocalicostomy — Ureterocalicostomy is a procedure that implants the ureter into the lower calyx of the renal pelvis. It was first described in 1948 to prevent nephrectomy in patients who are not candidates for other reconstructions [57]. Minimally invasive techniques of ureterocalicostomy have since been developed [58,59].

Autotransplantation — Autotransplantation of the kidney, which involves moving the injured ureter and ipsilateral kidney to an ectopic site (eg, iliac fossa), is a complex procedure and should not be undertaken if other options exist (figure 10) [41,60-65]. It is usually considered when the contralateral kidney is absent or poorly functioning. The kidney is harvested with maximal vessel length for anastomoses to the iliac artery and vein. The upper ureter or renal pelvis can be directly anastomosed to the bladder.

Nephrectomy — A nephrectomy should only be used in rare settings. When a normal contralateral kidney is present, a simple nephrectomy can be considered as an expeditious option to an extensive upper ureteral injury or when ureteral injury occurs during procedures using prosthetic grafts [11,35,66]. Nephrectomy eliminates the risk of ureteral leak from an anastomosis and, as an independent procedure, is associated with low mortality [67].

Urinary diversion — Urinary diversion can be performed if the ureteral injury is not amenable to primary repair for delayed recognition of injury or clinical instability. It can also be used if the primary repair at any level is under tension. In the setting of an abscess or fistula and delayed recognition, this is an acceptable option until a primary repair can be performed. Options for urinary drainage include:

●Placement of a nephrostomy tube. (See "Percutaneous nephrostomy tubes".)

●Placement of a stent into the ureter with externalization of the stent as a conduit.

●The ureter can be externalized through a separate incision and sutured to the skin, akin to a "stoma."

Percutaneous nephrostomy is preferred, as the latter two options can only be performed when a ureteral injury is recognized intraoperatively and both are associated with complications (dislodgment of externalized ureteral stent, stenosis of percutaneous ureterostomy).

Delayed ureteral reconstruction can be performed once the patient has stabilized in three to six months [10].

ROLE OF MINIMALLY INVASIVE REPAIR — 

Laparoscopic ureteral repair is technically feasible and is an alternative to open repair for delayed diagnosis of a ureteral injury [19,68]. When performed laparoscopically, ureteroureterostomy and ureteroneocystostomy anastomoses are technically easier to perform than an implantation; a Boari flap is challenging but feasible [43,69]. Robotic-assisted laparoscopy for ureteral reimplantation and repair is another minimally invasive approach that can be performed efficaciously when performed by skilled surgeons [70,71].

Most cases and series involve ureteroneocystostomy with psoas hitch ureteral implantation either by an extravesical [72] or intravesical [73] or extravesical cystoscopy-assisted [74] techniques. The latter two approaches create a submucosal tunnel and allow for nonreflux reimplantation of the ureter. There is limited experience with robotic-assisted approaches for ureteroneocystostomy [75,76].

POSTOPERATIVE CARE AND FOLLOW-UP — 

The postoperative management for a patient with a ureteral injury includes [16]:

●Obtain computed tomography (CT) urogram six weeks after surgery to confirm no anastomotic leak. Internal stents are removed only after no leak is demonstrated.

●Repeat CT urogram at three to six months to ensure that the ureter is draining well and to evaluate for a ureteric or anastomotic stricture.

●We do not use prophylactic antibiotics, even with prolonged use of an indwelling catheter. (See "Catheter-associated urinary tract infection in adults", section on 'Prevention'.)

POSTOPERATIVE COMPLICATIONS — 

Most patients with immediate recognition of the injury have few complications.

●Urinary leakage occurs in approximately 10 to 24 percent of ureteroureterostomy repairs for injury, including early and delayed recognition [11]. Most urinary leaks that occur in the early postoperative period can be managed successfully with continued drainage. If an unstented ureter is leaking, either a stent or nephrostomy tube can usually successfully manage the problem.

●Less common acute complications include abscess and fistula formation. Abscesses should be drained, either percutaneously or by an open procedure, depending upon technical expertise and amenability of the abscess to percutaneous drainage.

LONG-TERM OUTCOMES — 

Long-term outcome data are limited to small series and case reports [19,36,55,56,68,77-79]. Long-term results are excellent if the diagnosis and repair is performed at the time of injury [11,12]. A delay in diagnosis worsens the prognosis because of infection, hydronephrosis, abscess, and fistula formation [80]. It may also negatively impact oncologic outcomes by delaying adjuvant chemotherapy [81].

●Ureteral strictures, which occur in 10 percent of ureteroureterostomy repairs, typically are a late complication of ureteral injury [11]. In most cases, they can be managed endoscopically with balloon dilation. If endoscopic management fails, then open repair may be necessary.

●Ureteral reflux is expected in patients in whom an antirefluxing type of reimplantation is not performed. In the adult, reflux generally does not lead to long-term problems with infection or pyelonephritis, and renal deterioration is uncommon. Obstruction at the site of reimplantation is uncommon (<5 percent) and may necessitate dilation or open repair with redo reimplantation.

●Fistula formation is very uncommon (<1 percent of repairs), especially if the repair is stented and drained. Ureteric fistulas are typically caused by distal obstruction.

SOCIETY GUIDELINE LINKS — 

Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Genitourinary tract trauma in adults".)

SUMMARY AND RECOMMENDATIONS

●Management of iatrogenic ureteral injuries – The management of ureteral injury depends on the severity of injury and time of recognition (algorithm 1):

•Minor injuries – For ureteral contusion, hematoma, or <50 percent disruption, we suggest endoscopic stenting rather than upfront surgical repair (Grade 2C). Successfully stented patients should undergo retrograde study in six weeks to rule out ongoing leak or stricture. Patients require surgical repair if endoscopic stenting is not successful. (See 'Endourologic repair' above.)

•Major injuries – For >50 percent disruption or ligation injuries, surgical repair is required, the timing of which depends on how early the injury is recognized (see 'Timing of diagnosis' above):

-For injuries recognized intraoperatively or in the early postoperative period (≤7 to 14 days), we suggest immediate surgical repair (Grade 2C). (See 'Surgical repair' above.)

-For injuries recognized late in the postoperative period (>7 to 14 days), we suggest urinary diversion and delayed repair in three to six months (Grade 2C). (See 'Urinary diversion' above.)

●Surgical techniques – Surgical techniques of ureteral injury repair are primarily chosen by anatomical locations of the injury.

•Preferred surgical technique – For all iatrogenic ureteral injuries, ureteroureterostomy is the optimal approach if it can be performed. Surgical principles include:

-Debridement to viable tissue

-Wide spatulation

-Tension-free anastomosis

-Watertight closure with stent placement

-Periureteral drainage

•Alternative surgical techniques – When more extensive damage (eg, multifocal, extended defect) is present that would preclude a primary anastomosis, an advanced surgical repair, such as a flap procedure, ureteral substitution, autotransplantation, or nephrectomy, may be required depending on the location of the injury (algorithm 2) (see 'Surgical repair' above):

-Lower ureteral injuries – A ureteroneocystostomy is usually performed when the injury is within 2 cm of the ureterovesical junction. When a ureteroneocystostomy is not feasible, we perform a psoas hitch implantation repair. (See 'Lower ureter' above.)

-Middle ureteral injuries – A transureteroureterostomy or a Boari flap is usually performed for middle ureteral injures. A transureteroureterostomy cannot be performed in a patient with a history of renal stones or a nonfunctioning contralateral kidney. (See 'Middle ureter' above.).

-Upper ureteral injuries – For upper ureteral injuries with insufficient proximal ureter for a tension-free anastomosis, options include appendiceal or ileal interposition graft, ureterocalicostomy, autotransplant, or a nephrectomy. The choice is up to surgeon preference. (See 'Upper ureter' above.)

ACKNOWLEDGMENTS — 

The UpToDate editorial staff acknowledges Kevin R Loughlin, MD, MBA, and Colleen Feltmate, MD, who contributed to earlier versions of this topic review.