Etiology and management outcomes of adult mechanical bowel obstruction in Nigeria: A systematic review and meta-analysis.

BACKGROUND: Adult mechanical bowel obstruction (AMBO) has been previously reported to be majorly caused by hernias in developing countries. In Nigeria, however, there has been a recent change in pattern with adhesions now being the leading cause. The aim of this systematic review is to examine the changing pattern of the causes, and outcomes of patients managed for AMBO in Nigeria.

METHODS: Relevant keywords relating to AMBO were used to conduct a search on PubMed, Web of Science, Google Scholar, and AJOL. The search returned 507 articles, which were subjected to title, abstract, and full text screenings, according to the inclusion and exclusion criteria. This generated 10 articles which were included in the final qualitative synthesis.

RESULTS: The total sample size across the 10 studies was 1033. Adhesions, hernias, and intra-abdominal tumors, responsible for 46.25%, 26.31%, and 12.23% of cases respectively, were the major causes of AMBO in Nigeria. 65.6% of cases were managed operatively and 34.4% were managed conservatively. The meta-analysis revealed high morbidity and mortality rates of 31% (95% CI: 17; 44, 5) and 11% (95% CI: 6; 15, 5), respectively, among adult patients managed for mechanical bowel obstruction in Nigeria.

CONCLUSIONS: Adhesion, which results predominantly from appendicectomy is the most common cause of AMBO in Nigeria. This is unlike former reports where hernia was the most common cause. Morbidity results majorly from wound infection, recurrent adhesions, and postoperative enterocutaneous fistula. The mortality rate is similar to reports from various West African studies, and it is significantly influenced by surgical intervention time.