A 41-year-old woman, presented to the clinic with a history of a mass in the lower abdomen that had progressively grown in size over the past 10 years. Additionally, she complained of having heavy menstrual bleeding for the past five months. However, due to her financial situation, she was unable to seek medical help until her church provided support. She had been married for 10 years and was sexually active with her husband, however, she had not been able to conceive.
She worked as a public servant and had no history of diabetes or hypertension. Moreover, her medical and family history did not reveal any relevant information either. Furthermore, she did not smoke or consume alcohol. However, she mentioned experiencing adverse reactions to chloroquine, amoxicillin, and clavulanic acid in the past. She had no history of any blood transfusions before.
On examination, doctors observed that she appeared pale. Her body temperature was 36.5 °C, her respiratory rate was 24 breaths per minute, her pulse rate was 84 beats per minute, her blood pressure was 130/90 mmHg, and her body mass index (BMI) was 20.3. Her packed cell volume was 24%, and urinalysis revealed the presence of significant pyuria. Electrolyte levels, urea and creatinine levels, and clotting profile were unremarkable.
An abdominal ultrasound showed multiple large fibroids in her uterus. The size of her uterus was that of 28- to 52-week gestation, and there were no abnormalities in other organs. The vaginal examination was also unremarkable. Based on these findings, doctors diagnosed her with a symptomatic uterine fibroid. After counselling, they prepared her for elective myomectomy, which is a surgical procedure to remove the fibroids. Doctors also prescribed her oral ciprofloxacin 500 mg twice daily for five days to treat a urinary tract infection. Before the surgery, she received three units of blood.
During the surgery, surgeons administered prophylactic antibiotics (200 mg ciprofloxacin and 500 mg metronidazole) intravenously. They performed the procedure under subarachnoid block anaesthesia. Moreover, the procedure was an exploratory laparotomy via a long incision in the midline above the umbilicus for adequate access. The surgical findings revealed a large uterus with multiple fibroid masses of varying sizes and adenomatous tissues. To minimize bleeding, they used a tourniquet and applied desmopressin diluted in normal saline to the uterus base. To prevent bowel adhesions, they covered the area on the posterior wall of the uterus with an omentum after myomectomy. She received two units of blood during the surgery.
Following the surgery, she developed a fever which the doctors suspected was due to a febrile blood transfusion reaction and malaria, as malaria was prevalent in the region. They sent investigations for malaria parasites, which were positive in her blood film. Doctors treated her with anti-malarial drugs, specifically intramuscular injections of artemether 80 mg twice daily for three days. They also prescribed her antihistamines, a single intravenous dose of promethazine (25 mg), and a single intravenous dose of hydrocortisone (200 mg). They discharged the patient from the hospital on the sixth postoperative day.
On the eighth post-operative day, she returned to the hospital with a profuse, purulent, and foul-smelling discharge from the site of the operation. Doctors drained 200 ml of pus and took a wound swab for further analysis. They removed all the stitches and initiated a wick-drain dressing. However, the wound culture did not show any bacterial growth after three days. On the 36th day after the operation, a blister formed in the area of the wound sinus, which later ruptured.
On the 46th postoperative day, doctors observed gangrenous tissue protruding from the open portion of the wound. Upon general examination, she appeared calm and not in distress. She was pale, and her body temperature was 36 °C. Her respiratory rate was 20 breaths per minute, her pulse rate was 86 beats per minute, and her blood pressure was 130/80 mmHg. Her packed cell volume was 28%, and her white blood cell count was 13,000 cells per millilitre.
Re-explorative Surgery: Omental Infarction
The doctors admitted the patient again. They administered three litres of 5% dextrose saline over a four-hour period. Additionally, the patient received intravenous antibiotic therapy with 2g ceftriaxone and 500 mg of metronidazole, along with a unit of blood transfusion.
During the re-exploration, they discovered that the wound had partially opened, and infarcted omental tissue was protruding from it. However, the pelvic organs, including the uterus, appeared normal. They removed the infarcted tissue, which left behind a cavity filled with pus. The extracted tissue was sent for histological examination. To clean the cavity, they performed a thorough saline lavage and left a drain in place. They closed the abdominal wound. They continued to administer broad-spectrum intravenous antibiotics after the surgery to prevent infection. However, on the third day following the reoperation, a surgical site wound infection occurred.
The following day, the patient started experiencing signs and symptoms of partial intestinal obstruction, which was confirmed by abdominal X-Ray. However, with conservative management, intravenous administration of 500ml of 5% dextrose saline every four hours, placement of a nasogastric tube, and the continuation of parenteral antibiotics; the obstruction resolved after four days. Finally, on the 11th day of readmission, the patient was discharged home. A follow-up visit with the doctors four months later revealed no complications.
Omental infarction is a rare condition, with only about 400 reported cases. It accounts for approximately 7% of all cases of acute abdomen seen in the emergency department.
There are two types of omental infarction: primary (idiopathic) and secondary. Idiopathic omental infarction (IOI) occurs due to factors such as the length of the omentum, the delicate blood supply, increased abdominal pressure, and increased peristalsis due to overeating. Obesity, middle age, male gender, local trauma, excessive straining and coughing, and sudden changes in posture are some of the precipitating factors for this. Omental pathologies like cysts, tumour invasion, malformations, and kinking of the omentum due to congenital abnormalities, can also contribute to this condition.
Secondary causes of omental infarction include strangulated inguinal hernia, intra-abdominal tumours, pelvic inflammatory disease, post-operative venous thrombosis, and arterial ligation, resulting from previous abdominal surgery. The use of the omentum for reconstruction in abdominal and pelvic surgeries is common due to its ability to form adhesions, promote neovascularization, and provide defence against infection.
Abdominal ultrasonography (USS) and computed tomography (CT) scan are used for pre-operative diagnosis of omental infarction. These can also help exclude other pathologies and reveal characteristic signs of twisted omentum. Laparoscopy can be used if the radiological diagnosis is inconclusive.
Conservative management is the first line of management. It should be confirmed and followed up with ultrasound or CT scans. If conservative measures fail, open omentectomy or laparoscopic excision of the infarcted omentum may be necessary. Surgery is indicated with severe pain, adhesions, intestinal obstruction, abscess formation, or persistent fever.