Point-of-care sonographic diagnosis of maternal small bowel obstruction during pregnancy.

Abstract

The incidence of bowel obstruction in pregnancy is approximately 1 in 17 000 deliveries and is not increased in comparison to the non-pregnant population1. Approximately 50% of cases result from postsurgical adhesions, including those associated with Cesarean delivery1, 2. Small bowel obstruction is considered a catastrophic complication of pregnancy with a reported overall risk of fetal loss of 17% and a maternal mortality rate of 2%2. Sonography has been demonstrated to be superior to plain radiography in the assessment of non-pregnant patients with suspected small bowel obstruction3, however, diagnosis is considered more difficult during pregnancy2. Here we describe two cases of maternal small bowel obstruction diagnosed during pregnancy by point-of-care transabdominal ultrasound. A 30-year-old primiparous woman presented at 27 weeks' gestation, complaining of abdominal discomfort, nausea, vomiting and obstipation. Her medical history included right salpingectomy for a tubal pregnancy. Transabdominal ultrasound examination was performed and the fetus was considered appropriate in size for gestational age (AGA). Markedly dilated loops of maternal small bowel containing fluid and edematous bowel wall were observed (Figure 1). Prominent ‘to and fro’ peristalsis was visualized in the small bowel and free fluid was noted in the cul-de-sac. Maternal small bowel obstruction was suspected and was confirmed by computed tomography. Following unsuccessful conservative treatment, laparotomy was performed and a mechanical obstruction due to adhesions was identified and released. On the third postoperative day, the patient delivered precipitously a 1260-g infant. Both mother and infant were well at the time of writing. A 26-year-old primiparous woman presented at 34 weeks' gestation with worsening abdominal discomfort, nausea, vomiting and obstipation. Her medical history included laparoscopic cholecystectomy and right ovarian cystectomy. Serum levels of aspartate aminotransferase and alanine aminotransferase were elevated at 113 U/L and 175 U/L, respectively. Qualitative urine dipstick analysis revealed proteinuria of 2+ and ketonuria of 4+. Transabdominal ultrasound examination showed the fetus to be AGA. Sonography of the maternal upper abdomen revealed numerous dilated loops of small bowel, edematous small bowel walls (Figure 2), marked ‘to and fro’ peristalsis and free fluid in the peritoneal cavity. Small bowel obstruction was suspected and was confirmed by magnetic resonance imaging. The patient received 4 L of intravenous fluids and concurrently manifested hypertension, leading to a suspected diagnosis of pre-eclampsia. Following failed conservative treatment of the bowel obstruction, she was scheduled for exploratory laparotomy. Prior to surgery, elevated blood pressure of 170/110 mmHg confirmed severe pre-eclampsia. The patient requested and underwent Cesarean delivery of an infant weighing 2260 g. Following repair of the uterine incision, an internal hernia with an incarcerated segment (hyperemic, edematous, with punctate lesions and prenecrotic appearance) of small bowel, located within previous surgical adhesions, was released. Both mother and infant did well. Abdominal ultrasound performed at the patient's bedside (‘point of care’) for the diagnosis of small bowel obstruction is a recent application in the emergency room4. Specific sonographic findings associated with small bowel obstruction include diameter of the small bowel > 25 mm, small bowel wall edema, ‘to and fro’ peristalsis, intra-abdominal fluid and the presence of a sonographic transition point (defined as the location between dilated small bowel proximal to the obstruction and decompressed small bowel distal to the obstruction)5. In both our cases, all of these sonographic signs of small bowel obstruction, other than depiction of the transition point, were present despite the gravid uterus. In both patients, the transition/obstruction points that were confirmed at surgery were posterior to the gravid uterus, thus were obscured to transabdominal sonographic assessment. A systematic search (PubMed, MEDLINE) of articles published between 1966 and 2016 in English medical literature, utilizing the search terms ‘pregnancy’, ‘small bowel obstruction’, ‘mechanical ileus’, and ‘point-of-care sonography’, indicates that the diagnosis of small bowel obstruction during pregnancy utilizing point-of-care sonography has not been reported previously. Our cases suggest that point-of-care sonography, now advocated for patients with suspected small bowel obstruction, may also be beneficial in pregnant patients at relatively advanced gestational ages. D. M. Sherer*†, M. Dalloul†, A. Schwartzman‡, A. Strasburger§, R. A. Farrell†, H. Zinn¶ and O. Abulafia§ †Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, State University of New York (SUNY), Downstate Medical Center, 450 Clarkson Avenue, Box 24, Brooklyn, NY, USA; ‡Department of Surgery, State University of New York (SUNY), Downstate Medical Center, Brooklyn, NY, USA; §Department of Obstetrics and Gynecology, Division of Gynecological Oncology, State University of New York (SUNY), Downstate Medical Center,Brooklyn, NY, USA; ¶Department of Radiology, State University of New York (SUNY), Downstate Medical Center,Brooklyn, NY, USA *Correspondence. (e-mail: [email protected])