Ureteral injury is rare (~1% of urologic injuries) but frequently iatrogenic and unrecognised at the time. This tab covers its causes, intraoperative detection, grading, and stability-based management.
Pathogenesis and Causes
Acute ureteral injury arises from iatrogenic injury (open, laparoscopic, or endoscopic surgery), external violence (high-speed blunt — massive force should raise suspicion), and penetrating stab/gunshot wounds.
- Iatrogenic — the commonest culprit is hysterectomy (54%), then colorectal surgery (14%), ovarian-tumour removal (8%), and transabdominal urethropexy (8%). Injuries during laparoscopy are less often recognised immediately than in open surgery (where ~1/3 are caught intraoperatively).
- Endoscopic — perform ureteroscopy over a wire in the renal pelvis. Complication risk rises with longer operative times, stone treatment, surgeon inexperience, and prior irradiation; persisting with basketing after a tear is a classic cause. When a perforation is identified, stop and place a stent.
- Other — ureteral manipulation in aortoiliac/aortofemoral bypass (12–20%) can cause hydronephrosis (usually benign; steroids if symptomatic). A gunshot blast contusion can cause delayed stricture or necrosis. Prophylactic preoperative stenting does NOT reduce injury risk in gynaecologic surgery (RCT), though it may aid intraoperative recognition.
Intraoperative Ureteral Assessment
Options to confirm ureteral integrity include direct inspection (opening the retroperitoneum), retrograde pyelography, and IV dye (methylene blue or indigo carmine) with cystoscopy to confirm absence of hematuria and the presence of bilateral ureteral jets (a poor predictor of injury).
- IV methylene blue is safe at <2 mg/kg but is a potent MAO inhibitor — contraindicated in pregnancy (teratogenic), with SSRIs/SNRIs (fatal serotonin toxicity), and in G6PD deficiency (methemoglobinemia, hemolysis). IV indigo carmine is contraindicated in pregnancy and can cause bronchospasm and hypotension.
- Ineffective methods: single-shot IVP, intraoperative hydration/diuretic, digital palpation, and grasping the ureter to evoke peristalsis (never rely on this).
Diagnosis and Evaluation
Hematuria is non-specific and significant injury can occur without it. Missed injury presents postoperatively with flank pain, fever, leukocytosis, ileus, abdominal distention, or a urinary fistula. In stable patients not going straight to laparotomy, obtain a contrast CT with 10-minute delayed films; findings suggesting injury are contrast extravasation, absent contrast distal to the injury, an ipsilateral delayed pyelogram, and ipsilateral hydronephrosis. Otherwise, inspect directly at laparotomy.
AAST Grading
- I — contusion or hematoma without devascularisation.
- II — laceration with <50% transection.
- III — laceration with ≥50% transection.
- IV — complete transection with <2 cm devascularisation.
- V — avulsion with >2 cm devascularisation.
Management
Management depends on hemodynamic stability:
- Stable — repair lacerations immediately, converting a longitudinal laceration into a transverse closure (Heineke-Mikulicz) to avoid narrowing.
- Unstable — temporary urinary drainage with delayed definitive repair: a ureteral stent alone, a short period of observation with reoperation at ~24 h, exteriorising the ureter, or tying off the ureter (with long silk for identification) plus percutaneous nephrostomy.
General principles of ureteral repair: mobilise widely while sparing the adventitia, debride minimally until the edges bleed (especially after gunshot), and create a spatulated, tension-free, stented, watertight anastomosis with fine absorbable monofilament (e.g. 5-0 PDS) and retroperitoneal drainage; retroperitonealise the repair, do not tunnel ureteroneocystostomies, and use omental interposition for complex/blast injuries. Repair choice follows the defect's level (see the Ureteric Stricture Disease topic):
- Above the iliac vessels — ureteroureterostomy, ureterocalicostomy, transureteroureterostomy, or interposition/autotransplant (not acutely); rarely acute nephrectomy.
- Below the iliac vessels — ureteroneocystostomy, psoas hitch, or Boari flap.
Special scenarios: a ureteral contusion is stented unless severe or gunshot-related (then resect to healthy, well-vascularised, spatulated ends). A delayed diagnosis is managed with a stent, escalating to nephrostomy if stenting fails — but immediate repair is indicated if detected within 72 h, if the injury is near a closed viscus (bowel/vagina), or if re-exploring anyway. A ureterovaginal fistula is first managed by stent (64–100% success). Follow-up after repair: remove the stent at 6 weeks (with a retrograde ureterogram), a Lasix renogram at 10 weeks, and renal US at 4 months.
Self-Test
1. What CT findings suggest a ureteral injury? Contrast extravasation, absent contrast distal to the injury, an ipsilateral delayed pyelogram, and ipsilateral hydronephrosis.
2. Which procedure carries the highest risk of ureteric injury? Hysterectomy.
3. What are the contraindications to IV methylene blue? Pregnancy, concurrent SSRIs/SNRIs, and G6PD deficiency.
4. What are the signs and symptoms of a missed ureteral injury? Flank pain, fever, leukocytosis, ileus, abdominal distention, and a urinary fistula.
5. How is an unstable patient with an intraoperatively found ureteral injury managed? Temporary drainage with delayed repair — ureteral ligation plus percutaneous nephrostomy, or an externalised catheter on the proximal ureteral end.
6. How is a gunshot-related ureteral contusion managed? Stenting, or resection and primary repair, depending on ureteral viability.
7. What are the surgical options for a penetrating ureteral injury by location? Above the iliac vessels — ureteroureterostomy over a stent (± psoas hitch/Boari); below the iliac vessels — ureteroneocystostomy or ureteroureterostomy over a stent.