Intestinal obstruction caused by a strangulating adnexa: a rare complication of ovarian sparing hysterectomy

Abstract

Intestinal obstruction caused by a remnant fallopian tube from previous hysterectomy is a rare entity that has been reported once in the literature. We report the case of a 61-year-old woman who presented with both small and large bowel obstructions caused by a strangulating remnant fallopian tube. She had an ovarian sparing hysterectomy 16 years ago and was diagnosed with antiphospholipid syndrome. Our case report will discuss the clinical presentation, imaging and outcome of the patient. It will also briefly tackle other rare causes of bowel obstruction.

Background

Intestinal obstructions following hysterectomies are usually caused by intra-abdominal adhesions or abdominal tumours.¹ To our knowledge, intestinal obstruction caused by a fallopian tube has been previously described once in the literature.² We present a case of intestinal obstruction that was caused by a strangulating remnant fallopian tube 16 years after ovarian sparing hysterectomy.

Case presentation

A 61-year-old woman with a history of hysterectomy and ovarian preservation 16 years ago presented to the emergency department for increasingly severe and diffuse abdominal pain which started 3 days before presentation. The patient had abdominal distention but was not constipated or vomiting. She also did not have fever or chills. Her medical history includes hypertension and antiphospholipid syndrome for which she was taking aspirin and warfarin. On examination, her vital signs were within normal limits, and her abdomen was distended, tympanic and diffusely tender with no other signs of peritonitis.

Investigations

Her laboratory profile showed a haemoglobin of 14.6 g/dL, a white cell count of 9,600 x 10^9/L, and an elevated international normalised ratio (INR) and partial thromboplastin time (4.5 and 52 s, respectively). Due to her history of antiphospholipid syndrome, CT angiography of the abdomen was ordered which ruled out mesenteric ischaemia; however, it showed large intestinal obstruction with narrowing and swirling at the level of transverse colon around a tubular structure that was suspected to be an adhesion band (figures 1 and 2).

Figure 1.

Transaxial image of CT angiography of the abdomen showing a dilated and enhanced wall of transverse colon (asterisk) followed by an area of narrowing and swirling around the fallopian tube (arrowhead), suggestive of obstruction with internal hernia. Also, a small bowel loop (arrow) was strangulated by the fallopian tube.

Figure 2.

Oblique reconstruction with the line of axis parallel to the migrated fallopian tube demonstrates the tubular structure representing the migrated right adnexa in the abdomen (arrow) looping around a small bowel segment (arrowhead) and adherent to the transverse colon (asterisk).

Differential diagnosis

At this point, our differential was partial intestinal obstruction possibly due to an adhesion band, internal hernia, mechanical obstruction or malignancy.

Treatment

The patient was admitted for monitoring, and was started on intravenous hydration, nothing by mouth and nasogastric decompression. She was not vomiting, and the nasogastric tube was draining minimal gastric secretion and was removed on the patient’s request. Warfarin was stopped immediately then bridged to heparin on the second day as INR was declining (2.2). On her third day of hospitalisation, the patient was not passing flatus and had worsening abdominal pain and persistent distention. Thus, the decision was made for laparoscopic exploration which revealed an inseparable, calcified and nodular tubular structure wrapping around a segment of obstructed terminal ileum. The tubular structure was identified as the right ovary and fallopian tube (figures 3 and 4). The ovary was stuck at the root of the mesentery causing a localised inflammatory reaction resulting in distortion of a segment of the transverse colon which was identified to be the reason of the colonic obstruction. The decision was made to convert to a midline minilaparotomy. The right ovary and fallopian tube were dissected of the root relieving the obstruction and a right salpingo-oophorectomy was performed. The left tube and ovary were inspected and were found to be normal.

Figure 3.

Operative image of the migrated right ovary and fallopian tube in the abdomen.

Figure 4.

Operative image of the right fallopian tube (grasper passing beneath it) wrapping around a small bowel segment.

Outcome and follow-up

The patient had a smooth postoperative course with no complications. Low molecular weight heparin was started on the first postoperative day then bridged to warfarin before discharge. The patient was discharged on the fourth postoperative day tolerating regular diet with normal bowel function. The histopathology showed an oedematous right fallopian tube with serosal fibrous adhesions and a normal ovary that were negative for malignancy. The patient did well on follow-up with no reported complications.

Discussion

Mechanical bowel obstruction, which is a potentially life-threatening condition, comprises 15% of emergency hospital admissions due to abdominal pain.³ Common causes of bowel obstruction include adhesions, hernias, tumours, volvulus and strictures.^{4 5} Rarer causes of obstruction include gallstone ileus, intussusception, foreign bodies, bezoars, parasitic infections, endometriosis, vitelline duct remnant, internal hernias, abdominal cocoon, ileal duplication cysts, superior mesenteric artery syndrome and iatrogenic.^5–14 Also, the senior author and surgeon (AH) had reported a rare case of small bowel obstruction caused by a Metamucil (psyllium-based bulk-forming laxative) bezoar.¹⁵ Moreover, Wang et al ¹⁶ had reported a case of small bowel obstruction and intestinal necrosis that was caused by multiple mesenteric thrombi of small vessels finally revealing a diagnosis of antiphospholipid syndrome. Due to this condition, our patient had a CT angiography of the abdomen at presentation instead of unenhanced plain CT scan. However, her condition is unlikely to be related to her history of antiphospholipid syndrome as her bowel did not show signs of ischaemia or necrosis on inspection and returned to normal function postoperatively.

In our case report, we present a unique and rare case of bowel obstruction, which is the second reported to be caused by a remnant fallopian tube. Tee et al ² were the first to report a case of large bowel obstruction, namely caecal volvulus twisting around a remnant fallopian tube from a previous remote hysterectomy. Similarly, our patient had both small and large bowel obstructions. The remnant fallopian tube wrapped around the small bowel segment causing small intestinal obstruction. Also, the inflammation surrounding the fallopian tube made it adhere and distort a segment of the transverse colon causing the obstruction noted on the CT scan.

Learning points.

• The diagnosis and management of intestinal obstruction in patients with previous abdominal surgery and hypercoagulable state can be challenging. Ruling out intestinal ischaemia is of utmost importance in the initial phase of the management.

• A remnant fallopian tube following ovarian sparing hysterectomy can be a rare cause of small and large bowel obstructions. It can also be associated with internal hernia and colonic volvulus.

• Other rare causes of intestinal obstruction include gallstone ileus, intussusception, foreign bodies, bezoars, parasitic infections, endometriosis, vitelline duct remnant and hypercoagulable state.

• Managing the anticoagulation and the timing of surgery is crucial to control intraoperative and postoperative risks of bleeding.