Management of post-traumatic non-iatrogenic lumbar/flank hernias: diagnosis and treatment options-systematic review, meta-analysis and management algorithm.

Background: Post-traumatic non-iatrogenic lumbar/flank hernias (LFH) represent a unique and important subset of abdominal wall hernias that can develop following either blunt or penetrating trauma to the abdomen. There is paucity of evidence guiding the management and identification of associated complications of this hernia type in the literature. We aim to pool available cases in the literature and summarize the diagnostic and management approaches of traumatic LFH.

Methods: PUBMED, EMBASE and Scopus databases were queried, and relevant articles were selected following PRISMA guideline for systematic reviews. Studies in English and with complete data on post-traumatic non-iatrogenic LFH, including case reports, were included.

Results: A total of 211 cases of post-traumatic non-iatrogenic lumbar/flank hernias (LFH) from 62 articles published between 1993 and 2023 were included, with mean age of 52.1 years (interquartile range IQR: 25.8-62.7 years). Most patients had CT-confirmed diagnosis (96.1%), had inferiorly located LFHs (86.8%), and fell into Type B Moreno-Egea class (74.6%). Flank pain was the commonest presenting complaint (13.4%) with flank hematoma present at presentation in 8.6% of the cohort. Post-traumatic non-iatrogenic LFHs were diagnosed at index hospitalization/presentation in 75.5% and repaired during the same admission in 48.2% of patients. Open repair with mesh was the most common method of repair (59.8%), followed by open repair without mesh in 28.7% and by minimally invasive laparoscopic approach in 11.5% cases. Overall recurrence rate (for all repair types) was 8% at mean follow up of 15.4 months (IQR: 12.5-25.0 months). Hernia defect size of ≥ 8 cm was 100% sensitive and 52.9% specific for the prediction of mesenteric injuries. Flank hematoma/seatbelt sign was 100% sensitive and 81.8% specific for the prediction of mesenteric injuries in traumatic LFHs.

Conclusions: Patients presenting with flank pain and flank hematoma following a blunt abdominal wall trauma should receive a thorough radiologic evaluation, particularly a CT scan, for post-traumatic non-iatrogenic LFHs. Complications such as mesenteric avulsion must be considered with high suspicion in patients whose hernia is associated with flank hematoma or with hernia diameter ≥ 8 cm. Long term follow-up after repair still requires further study. Open repair with extraperitoneal mesh reinforcement is the standard of care for hernias ≥ 8 cm repaired acutely or electively, and minimally invasive laparoscopic approach is typically utilized for hernias < 8 cm.