Ureteral Trauma Treatment & Management

Management of ureteral injuries is dictated by the location, type, extent, timing of presentation, medical history, overall status of the patient, including associated injuries, and prognosis.

Ureteral injuries in patients who are too unstable to tolerate surgery should be repaired in a staged fashion or, extremely rarely, with nephrectomy. If a staged repair is chosen, the damaged ureter is initially tied off with long silk ties to aid in visualization of the ureter during the second stage of the repair. The kidney is drained percutaneously, preferably in the immediate postoperative period by the surgeon, or later by the interventional radiologist. Some surgeons have placed an 8F feeding tube into the ureter and exteriorized it until the repair can be completed.

Although nephrectomy is rarely necessary, it may be indicated in cases of severe collateral and irreparable injury to the ipsilateral kidney or a severe panureteral injury, although even the most devastating ureteral injuries can usually be repaired with reconstruction.

Understanding the vascular anatomy of the ureter is crucial in planning and effecting ureteral repair. Recall that the ureteric arteries and arterioles travel longitudinally in the adventitia, with the abdominal ureter receiving branches medially from the renal, aortic, gonadal, and lumbar arteries, while the pelvic ureter is perfused by branches laterally from the iliac artery and its branches. Following the principles of ureteral repair can prevent complications such as urinary leakage leading to patient debility, nephrectomy, and, in, rare cases, death.

• Carefully mobilize the ureter to preserve the adventitia (blood supply).
• Judiciously débride the nonviable tissue until the edges bleed.
• Spatulate the edges and repair with 5-0 absorbable suture under magnification.
• Anastomosis should be watertight and tension-free over an internal stent.
• The repair must be isolated from infection, retroperitoneal fibrosis, and cancer.
• The omentum or retroperitoneal fat can be used to cover the repair; this decreases the risk of fibrosis and increases the blood supply to the repair region. (Wrapping the repair reportedly also allows the ureter to remain unscarred and to resume normal peristalsis).
• The retroperitoneum should be drained with a gravity drain.

The choice of repair will be guided by several factors: hemodynamic stability of the patient, location and length of the injury, function of the contralateral kidney, and severity of associated injuries. Surgical decision making is also influenced by any prior history of urothelial carcinoma, radiation exposure, or retroperitoneal fibrosis.

Contusion

Although a contusion may be considered a minor injury, it can result in a stricture if left untreated. Extensive areas of contusion may even result in ureteral necrosis secondary to microvascular damage. Minor injuries can be treated with internal ureteral stenting, while severe or large areas of contusion should be excised and ureteroureterostomy performed.

Partial transection

Partial ureteral transections can be repaired with primary closure. This procedure should not be performed in victims of gunshot wounds. Instead, the injured segment should be resected, with 2-cm margins, and the edges reapproximated, as described above. For nonballistic injuries, the defect may be closed primarily in the Heineke-Mikulicz fashion (ie, closing the longitudinal laceration transversely in order to avoid narrowing of the lumen).

Upper ureteral injuries

Approximately 39% of ureteral injuries occur in the upper ureter. The mid ureter and distal ureter account for the remaining 31% and 30%, respectively. Location of injury and vascular integrity of the ureter dictates the choice of repair. Upper ureteral injuries can frequently be repaired with ureteroureterostomy. However, if additional length is required for a tension-free anastomosis, mobilization of the kidney may be of benefit. The kidney should be completely mobilized and rotated medially and inferiorly on its vascular pedicle, with the lower pole sutured to the psoas muscle. This maneuver may provide an additional 5-8 cm of length.

• Ureteroureterostomy

  • Ureteroureterostomy involves an end-to-end repair of ureteral defects smaller than 3 cm (see image below). This is mostly performed in the upper and mid ureter. The damaged segment of the ureter is mobilized and excised, and the ureteral ends are spatulated and approximated over an internal stent to achieve a water-tight anastomosis. To minimize handling of the ureter, holding sutures may be placed on both free ends. The reapproximation of the ureters may be performed in either a running or interrupted fashion with 5-0 absorbable suture with equal efficacy. Ureteroureterostomy in ureteral trauma.
  • This procedure yields a success rate of approximately 90%. Short-term complications include urinary leakage (10%-24% of patients), abscess, and fistula. Long-term complications (eg, ureteral stenosis) are less common (5%-12% of patients). Urinary leakage from a retroperitoneal drain can be managed expectantly; drainage following ureteral repair lasts an average of 12 days.
• Ureteropyelostomy: In the event of a ureteral avulsion from the renal pelvis or a very proximal ureteral injury, the ureter may be anastomosed directly into the renal pelvis.
• Ureterocalicostomy: If the renal pelvis or ureteropelvic junction is damaged beyond repair, ureterocalicostomy may be performed. In this procedure, the ureteral stump is sewn end-to-side into an exposed renal calyx.

Midureteral injuries

• Transureteroureterostomy

  • Transureteroureterostomy can be performed to manage an extensive defect that involves the mid or upper ureter if the length for anastomosis to the bladder is insufficient. This involves bringing the injured ureter across the midline to the recipient ureter in an end-to-side anastomosis (see image below). This is achieved by tunneling the donor ureter through the sigmoid colon mesentery superior to the inferior mesenteric artery to avoid kinking. With minimal mobilization of the recipient ureter, a small elliptical opening is created, and the donor ureter is spatulated to perform an end-to-side anastomosis. A feeding tube or double-J stent should be placed from the donor kidney, across the anastomosis, and down to the bladder. This procedure yields a high success rate (97%). Transureteroureterostomy in ureteral trauma.
  • Contraindications to transureteroureterostomy include a short donor ureter or a diseased recipient ureter. Relative contraindications include a history of urothelial cancer or calculi, pelvic or abdominal irradiation, retroperitoneal fibrosis, and ureteral injury caused during aortoiliac bypass surgery. Postoperatively, intubation of the injured ureter with ureteroscopy can be daunting. Importantly, this procedure risks injury to the uninjured ureter and thus should be performed only when other alternatives are unfavorable.

Lower ureteral injuries

• Ureteroneocystostomy

  • Injuries to the lower ureter are usually associated with disruption of its blood supply from the iliac vessels. Therefore, these injuries are best repaired with ureteroneocystostomy. Numerous techniques are available for this repair. The principles of repair include debridement and spatulation of the ureter, tunneling in the bladder wall toward the bladder neck in a 3:1 ratio of tunnel length to diameter of ureter. This tunnel is best placed superior and medial to the native ureteral orifice, where the bladder wall is less mobile, to avoid kinking of the ureter. The repair should be stented and a suprapubic tube and urethral Foley catheter placed. This repair can bridge defects up to 5 cm.
  • Whether the repair is antirefluxing depends on the age of the patient and the severity of associated injuries. In adults, antirefluxing and refluxing procedures are associated with the same rates of renal function preservation and risk of stenosis. In adults with normal bladders, unobstructed infravesical pathways, and no urinary tract infection, reflux does not impair renal function. Various types of reimplantation procedures have been described; such a discussion is beyond the scope of this review. The reimplant may be intravesical or extravesical, depending on surgeon preference.
• Vesicopsoas hitch

  • This is the treatment of choice for lower ureteral injuries that cannot be successfully repaired with ureteroneocystostomy alone (see image below). This procedure involves mobilizing the bladder and pulling it superiorly and laterally by fixing it to the psoas tendon with an absorbable suture. This technique can be used to bridge a 6- to 8-cm defect. Both the genitofemoral nerve located on the surface of the muscle and the femoral nerve deep to the muscle may be injured during this repair. In order to achieve additional length, the urachus, obliterated umbilical artery, and contralateral superior vesical artery may be divided. Ureteral anastomosis is performed medial to the hitch. Postoperative stenting for approximately 10-14 days is recommended, and an open anastomosis should be demonstrated radiographically prior to stent removal. This procedure yields a success rate of 95%. Psoas hitch in ureteral trauma.
  • Complications include ureteral obstruction, urinary leakage, and voiding difficulties. Relative contraindications include small-capacity bladders and bladder outlet obstruction.
• Boari bladder flap

  • For injuries too long to be bridged with the psoas hitch procedure alone, a Boari flap can be created to provide an additional 12-15 cm of length (see image below). In this procedure, a pedicle of bladder is swung cephalad and tubularized to bridge the gap to the injured ureter. The base of the flap should be at least 4 cm to avoid ischemia. It can be developed obliquely across the anterior bladder or as a spiral flap to help gain additional length. The flap can be fixed to the psoas tendon superiorly with the ureter anastomosed to the flap, which is then rolled anteriorly into a tube and closed in 2 layers. The procedure is time-consuming and is likely not useful in the acute setting. Boari flap procedure in ureteral trauma.
  • Complications include bladder pedicle ischemia with resultant necrosis, possible stricture formation, and urinary leakage. Relative contraindications include small contracted bladders, neurogenic bladder, and transitional cell carcinoma.

Other surgical options

Options for elective repair include autotransplantation or an ileal ureter.

• Autotransplantation

  • Autotransplantation involves relocating the ipsilateral native kidney to the pelvis; the renal artery and vein are then anastomosed to the iliac vessels, and the healthy ureter or renal pelvis is anastomosed to the bladder.
  • Autotransplantation offers the best results in patients younger than 60 years without any underlying aortoiliac atherosclerosis or renal disease. This may also be considered in patients with retroperitoneal fibrosis and may be useful in those with a poorly functioning or absent contralateral kidney. Autotransplantation has been associated with a loss of 8% of renal units. The authors believe that autotransplantation is less desirable than ileal ureter for massive ureteral loss.
• Ileal interposition

  • As with autotransplantation, ileal interposition (ie, the creation of a ureteral conduit from ileum) is inappropriate in the acute setting (see image below). When performed in the elective setting, it yields a high success rate (81%). However, this type of repair has several contraindications, including a serum creatinine level greater than 2 mg/dL, neurogenic bladder, bladder outlet obstruction, inflammatory disease, radiation enteritis, and hepatic dysfunction. Complete ureteral replacement utilizing ileum in ureteral trauma.
  • Metabolic complications are rare in patients with good renal function and an isoperistaltic ileal segment. In patients with high-pressure bladders, dilatation of the ileal segment may lead to urinary stasis and consequent metabolic disturbances such as hyperchloremic hypokalemic metabolic acidosis. However, the segment of ileum and transit time are usually short enough to prevent metabolic complications. Bacteriuria is common but is usually clinically insignificant as long as the bladder is being adequately drained and mucus buildup secondary to the secretion from ileal mucosa is minimized.
• Urinary diversion

  • Urinary diversion in the form of a stent and/or nephrostomy tube should be considered, when indicated. A stent aligns the area of anastomosis, prevents extravasation, prevents obstruction from edema, and provides a scaffolding around which the ureter may heal. Studies of ureteral healing have demonstrated that the mucosa has healed by 3 weeks and muscular continuity is established by 7 weeks.^[16] Thus, many recommend that a stent remain in place for 6-8 weeks after a repair. Stents come in various diameters (4-8F) and lengths. The size of stent chosen depends on the diameter and length of the ureter. The height of the patient is often used to estimate the ureteral length, although this is not always accurate. A stent should fit in the ureter smoothly, without compressing the ureteral wall, which would compromise ureteral blood supply.
  • The appropriate stent length can be gauged from an IVP or RPG (length corrected for 10% magnification plus 1 cm) or from the patient's height and sex. The average male usually requires a 26-cm stent, while the average female requires a 24-cm stent. The type of stent must also be considered. Stents are made of different materials that have different effects on the ureter and differing biocompatibility. All stents cause epithelial erosion and ulceration. Experimental studies have shown that C-Flex (Concept Polymer Technologies; Clearwater, FL), which is a proprietary styrene/ethylene/butylene copolymer, causes less epithelial reaction and has excellent biocompatibility. Firm or hard stents may be more appropriate in patients in whom fibrosis and extrinsic compression may become an issue.
  • Percutaneous nephrostomy may be used for more proximal diversion if the repair is tenuous or if healing may be delayed. However, complete proximal diversion should be avoided because the flow of urine down the ureter often is needed to help promote ureteral healing. Prolonged diversion may result in a dry anastomosis that may scar. The advantage of a percutaneous nephrostomy is that it can be clamped prior to removal to assess for symptoms of persistent obstruction, and antegrade nephrostography can be performed to assess the integrity of the repair. If persistent extravasation or poor healing is evident, the nephrostomy tract that has already been created can be used to place an indwelling ureteral stent if it has not been placed previously. In the author's institution, antegrade nephrostography is routinely performed to assess the integrity of the repair. Then, the tube is clamped for several hours to ensure the patient does not develop flank pain. It is then removed.
• Retrograde ureteral stent placement: An endoscopic approach with retrograde ureteral stent placement may be effective in certain iatrogenic injuries and injuries secondary to external violence. If the patient is stable, this is often the first line of treatment. If retrograde placement is unsuccessful, a percutaneous nephrostomy tube may be placed to acutely decompress the system and to potentially attempt antegrade placement of a stent.

Damage control

Patients with ureteral injury secondary to external violence often have multiple associated injuries, and the patient is often critically ill. In patients with acidosis (pH < 7.25), hypothermia (35°C), and coagulopathy, avoiding a prolonged reconstructive procedure is often prudent.

Patients who are in shock and/or have peritoneal contamination may be at a higher risk for complications following repair. Tissue hypoxia and gross contamination play an important role in the pathogenesis of strictures, urinomas, fistulas, and even death.

An abbreviated laparotomy and planned reoperation is becoming a preferred form of management in hemodynamically unstable patients with trauma. The damage-control approach involves evaluating the extent of the ureteral injury and expeditiously performing a stented cutaneous ureterostomy. Some surgeons have even placed an 8F feeding tube in the ureter and exteriorized it until the second operation. The patient can then be taken to the intensive care unit for resuscitation and definitive repair can be planned for the second-look laparotomy.

An alternative technique is to ligate the ureter, leaving long silk ties to aid in visualization at the time of the second operation. A percutaneous nephrostomy is placed by the surgeon intraoperatively or by the interventional radiologist postoperatively. This damage-control approach also allows the ureter to be reexamined at the planned reoperation.

Although nephrectomy is rarely necessary, it may be indicated in cases of severe collateral and irreparable injury to the ipsilateral kidney or a severe panureteral injury, although even the most devastating ureteral injuries can usually be repaired with reconstruction.

Delayed diagnosis

The diagnosis of ureteral injuries caused iatrogenically and those due to penetrating trauma is often delayed. In fact, 8%-57% of all ureteral injuries are recognized late. Such patients may present with signs and symptoms of fever, sepsis, flank pain, paralytic ileus, azotemia, and anuria. Abdominal CT scanning is a useful diagnostic tool to identify the site of injury and any associated abscess or fluid collection. Excretory urography and an RPG are also excellent first studies to help delineate the injury.

The interval from injury to recognition is important and should guide management. If the injury is diagnosed within the first 7 days without a concomitant significant infection, surgical exploration and repair may be performed. Attempting repair after 10-14 days may be difficult secondary to a marked inflammatory response. In addition, the presence of an abscess, urinoma, or fistula should delay any attempt at a definitive operative repair.

In patients in whom recognition of a ureteral injury is delayed, an initial endourologic approach may be appropriate. Patients with sepsis may benefit from urinary diversion via a percutaneous nephrostomy tube or retrograde ureteral catheter. Associated fluid collections can also be drained percutaneously.

Occasionally, diversion of the urine stream with a nephrostomy or stent is the only intervention needed. Ureters without strictures heal in most patients. However, if a stricture does develop, it can be managed endoscopically with balloon dilation or endoureterotomy. Open ureteral repair can be deferred for 1-3 months while infection and inflammation subside. Despite concerns of inflammation that may be encountered during early exploration, several studies have reported early open repair with low morbidity, a low complication rate, and equally good results.^[5]

Managing a ureteral injury during a vascular graft procedure is controversial and can be approached via nephrectomy (if the patient has a functioning contralateral kidney) or a primary ureteroureterostomy with isolation of the repair with omentum. While a nephrectomy may be advocated to prevent postoperative urine leakage around the prosthetic vascular graft, it may come at a cost. The mortality rate associated with renal failure during routine aortic aneurysmectomy is 3% (and up to 12% in patients with a ruptured aneurysm). Conversely, if the risk associated with ureteral repair is minimal, the vascular surgeon should complete the graft anastomosis before addressing the ureteral injury. Studies have demonstrated that primary ureteral repair without nephrectomy is feasible and does not unduly jeopardize the vascular graft if the urine is not infected preoperatively.^[17]

The repair should be observed regularly for the first year to evaluate for signs of obstruction or loss of renal function. This may include IVP to delineate the anatomy and serial renal ultrasonography to evaluate for hydronephrosis.

To evaluate renal function more objectively, nuclear scanning may be helpful.

In patients with an ileal ureter, serum chemistry studies are helpful to monitor serum creatinine and metabolic derangements.

Clearly, the frequency and duration of follow-up depends on the clinical setting and the long-term stricture rates associated with each procedure.

Procedures used to repair traumatically injured ureters carry a complication rate of 25%, and the specific types of complications possible depend on the type of reconstruction performed.

The most common acute complication is prolonged urinary leakage from the anastomosis. This can manifest as urinoma, abscess, or peritonitis and can be prevented by intraoperative placement of a drain in the retroperitoneum, thereby allowing both the drainage of urine and early recognition of urinary leakage from the anastomosis. If a high volume of fluid drains, the fluid should be checked for creatinine. The delayed recognition of undrained urinary leakage has been associated with sepsis, a more complicated reconstruction, and increased hospital stay.

Other complications common to all repairs may include stricture, hydronephrosis, abscess, fistula formation, and infection. The key is to diagnose the problem early and to treat accordingly.

Hydronephrosis that develops following injury repair may be managed by simply replacing a stent or dilating the strictured segment. However, management of each complication depends on the time of diagnosis and presentation. Most complications can be managed with endoscopy or reoperation.

Ileal ureter substitution may be complicated by stone formation, renal failure, infection, stricture, calculi, pyelonephritis, and associated metabolic derangements.

After ureteral repair during aortic surgery, vascular grafts can become infected, requiring vascular and urinary diversion to eradicate. The best method of treating this dreaded complication is prevention, which usually means performing a ureteral repair with omental interposition. Nephrectomy may still need to be performed if initial repairs are unsuccessful.

Complications related to prolonged stent placement and nephrostomy tubes include migration, infection, encrustation, pain, and loss of renal function.

See Surgical therapy for detailed discussions of the outcomes of each procedure.

Prevention

Ureters tend to be injured during difficult open surgery or endoscopic procedures. Some injuries may be unavoidable, and the goal is to minimize such injuries. Preoperative imaging is not indicated in all cases but may be of benefit in high-risk patients. Careful identification of the ureters and their course helps avoid injury. Lasix and hydration facilitate visualization of the ureter. The ureter is often injured during attempts at bleeding control. Adequate exposure and hemostasis, when possible, also help prevent injury.

Some have advocated the prophylactic placement of ureteral catheters or stents. Advocates of this practice argue that they help the surgeon palpate the ureter and may be of particular help in laparoscopic procedures. The stents may help in recognizing an injury intraoperatively. Of particular use in laparoscopy are lighted stents, which illuminate and help identify the ureter, thereby reducing the risk of iatrogenic injury.^{[18, 19]}

Opponents of this practice argue that, in the presence of inflammation, the stents still may not be palpable and that the presence of the stent actually may alter the course of the ureter, placing it at risk. Complication rates associated with ureteral stent placement are 1%. Anuria secondary to bilateral ureteral edema may occur. Some also argue that ureteral stimulation may cause renal cortical vasoconstriction, leading to decreased filtration and anuria. Additionally, placement of ureteral catheters significantly adds to the cost of the procedure.

However, the prophylactic placement of stents may be useful. Nonetheless, some studies have failed to demonstrate a reduction in iatrogenic injuries. Otherwise, placement is safe and associated with few complications. It does not prevent injury but may aid in the diagnosis and treatment of an injury.