A 37-year-old woman comes to the emergency department for abdominal pain, nausea, and vomiting. A week ago, the patient underwent a laparoscopic hysterectomy for severe endometriosis, and she went home the next morning. For the past 2 days, the patient has had increasing diffuse abdominal pain and bloating, and she now has nausea and vomiting. She is voiding normally and passing flatus but has noticed increased vaginal discharge. The patient has no medical conditions, and her only other surgeries were 2 cesarean deliveries in her 20s. Temperature is 38 C (100.4 F), blood pressure is 128/72 mm Hg, and pulse is 88/min. The abdomen is moderately distended but soft and nontender. The laparoscopic incisions are intact and without palpable masses or defects. On pelvic examination, there is watery vaginal discharge and the vaginal cuff appears closed. Laboratory results are as follows.
| Complete blood count | |
| Hemoglobin | 12.2 g/dL |
| Platelets | 150,000/mm3 |
| Leukocytes | 10,000/mm3 |
| Serum chemistry | |
| Sodium | 136 mEq/L |
| Potassium | 3.6 mEq/L |
| Creatinine | 0.8 mg/dL |
Urinalysis is normal. Abdominal ultrasound reveals a large amount of intraabdominal fluid with no internal echoes. Which of the following is the most likely diagnosis in this patient?
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This postoperative patient's abdominal distension and large amount of intraabdominal fluid is likely due to uroperitoneum (ie, urine within the peritoneal cavity). In patients who have undergone gynecologic surgery (eg, hysterectomy), particularly those with distorted pelvic anatomy (eg, endometriosis, prior surgery), the most likely cause is from a unilateral ureteral laceration. The ureter is vulnerable to injury during gynecologic procedures due to its proximity to the ovarian vessels (in the infundibulopelvic/suspensory ligament) and uterine vessels (near the cervix).
Most ureteral injuries are identified during surgery but missed cases can present up to 2 weeks postoperatively as the damaged ureter drains urine directly into the abdomen, resulting in a large volume of intraabdominal fluid and subsequent abdominal distension (eg, diffuse pain, bloating). As the urine continuously fills the abdomen, it can overflow through the vagina (which is sutured but not fully healed) and cause a watery vaginal discharge. The caustic effects of the urine may cause signs of peritoneal inflammation (eg, fever, nausea, abdominal pain). Patients with a unilateral ureteral injury often have regular voiding and normal serum creatinine and urinalysis because the contralateral kidney and ureter continue to function normally. Diagnosis is typically with CT urography and treatment is surgical repair.
(Choice A) Hemoperitoneum can cause abdominal pain and accumulation of intraabdominal fluid (eg, blood) postoperatively; however, this patient's blood pressure, pulse, and hemoglobin are normal, making this diagnosis unlikely.
(Choice B) Intraabdominal abscess can present postoperatively with fever and abdominopelvic pain; however, patients typically also have high fever, leukocytosis, and abdominal tenderness.
(Choice C) Small bowel obstruction (SBO) is relatively common after intraabdominal surgery; it can cause nausea, vomiting, abdominal pain, and distension because the bowel becomes dilated and inflamed proximal to the obstruction site. SBO is not associated with increased vaginal discharge, and the diagnosis is less likely in this patient who is passing flatus.
(Choice E) Vaginal cuff dehiscence may present after hysterectomy with increased watery vaginal discharge (from peritoneal fluid leaking through the defect). This patient's vaginal cuff appears closed.
Educational objective:
Ureteral injury can occur during gynecologic surgery due to the proximity of the ureter to the ovarian and uterine vessels. Patients with unilateral ureteral laceration develop a large volume of intraabdominal fluid (uroperitoneum), but typically have normal voiding, serum creatinine levels, and urinalysis due to the functioning contralateral kidney and ureter.