OBTURATOR HERNIA: AN UNUSUAL CAUSE OF INTESTINAL OBSTRUCTION

Abstract

To the Editor: A previously healthy 93-year-old Taiwanese woman was sent to our emergency room because of no stool passage and distended abdomen for a week. She denied any systemic diseases except moderate hearing impairment and lower back pain due to kyphoscoliosis and was able to live independently. One month before admission, she had increased frequency but less amount of bowel movement. Because of her worsening condition and general weakness, she had been unable to walk and had remained in bed for a week. On the suspicion of ileus and malnutrition, she was admitted to our geriatric ward. On physical examination, she appeared thin (body weight 33.8 kg, height 150 cm) but alert. Her vital signs were blood pressure 141/92 mmHg, pulse rate 100 beats per minute, respiratory rate 20 breaths per minute, and tympanic temperature 36.5°C. The most symptomatic pain was in her abdomen, which was soft but distended. Bowel sounds were hyperactive. There was no mass palpable except for the distended umbilical area or any tender point or rebounding pain. No pitting edema was noted over the bilateral lower extremities. A plain abdominal film showed dilatation of the small bowel and spondylosis and scoliosis of the spine. Computed tomography (CT) of the abdomen was arranged immediately and showed an obturator hernia with small bowel dilatation, favoring incarceration (Figure 1). Abdominal computed tomography showing a cystic lesion on the right obturator foramen (arrow). Unfortunately, after taking the contrast medium and finishing the CT, the patient suffered aspiration in the ward and became unconscious because of low oxygen saturation. Her family refused surgery and intubation because of old age and the high risk involved after an explanation by a general surgeon, and she died on the following day. An obturator hernia is a rare type of hernia and a rare cause of intestinal obstruction.1 Searching the English literature, only two articles were found that enrolled more than 30 cases.2, 3 The incidence was approximately two cases per year at the study hospital. It occurs most commonly in emaciated elderly women, with a mean age of 80, body weight of 35 kg, and height of 145 cm and in a female:male ratio of 76:3.2, 3 Loss of the protective peritoneal fat from aging or malnutrition increases space in the obturator canal and facilitates hernia formation.4, 5 In women, a wider pelvis and more-triangular obturator canal opening with a greater transverse diameter may increase the risk for developing an obturator hernia. Some concomitant conditions, such as chronic constipation, chronic obstructive pulmonary disease, ascites, kyphoscoliosis, and multiparity may also predispose patients to herniation because of increasing intraabdominal pressure and relaxing of the peritoneum.2-4, 6 The most common presentation of obturator hernia is intestinal obstruction, but this is nonspecific. The Howship-Romberg sign is pain extending down the inner surface of the thigh to the knee caused by hernial irritation of the anterior division of the obturator nerve.6 Studies have revealed a low rate (<50%) of demonstrating Howship-Romberg sign before definite diagnosis.1-3 Rapid evaluation and surgical intervention has reduced the morbidity and mortality from obturator hernias. A useful algorithm has been proposed for the management of a suspected obturator hernia.4 In patients with nonspecific intestinal obstruction, a CT scan is useful for the early diagnosis of an obturator hernia.3 A correct CT diagnosis of obturator hernia leads to selection of minimally invasive surgery of the inguinal approach combined with patch repair and decreases the intestinal resection rate and surgical mortality.3 The median interval from admission to operation has been reported as 2 days.1 Poor physical condition of patients might lead to a delay in diagnosis and treatment.1 The mortality rate is 6% to 16%.1-4 We felt deep regret that an incidental episode of aspiration made the family members hesitate in proceeding with clinical management. Even a lady as old as 102 can be successfully operated on and recuperated.7 Conflict of Interest: The authors have no financial or any other kind of personal conflicts with this letter. Author Contributions: Study concept and design: Hui-Wen Pai and Chia-Ming Chang. Acquisition of subjects and data: All authors. Analysis and interpretation of data: Hui-Wen Pai and Chia-Ming Chang. Preparation of manuscript: Hui-Wen Pai. Critical review and approval: All authors. Sponsor's Role: None.