The impact of non-invasive manual and ultrasonographic reduction for incarcerated obturator hernia: a retrospective cohort study and systematic review.

Purpose: Non-invasive reduction in patients with incarcerated obturator hernias is an emergency surgery alternative. There are two non-invasive reduction types: manual and ultrasonographic (ultrasound-guided and ultrasound-assisted reduction). However, the impact of ultrasound guidance on manual reduction has not been adequately evaluated. We aimed to compare non-invasive ultrasound reduction with manual reduction in patients with incarcerated obturator hernias.

Methods: We searched MEDLINE, Cochrane Central Library, Embase, Ichushi Web, ClinicalTrial.gov, and ICTRP for relevant studies. The primary outcomes were success and bowel resection rates. We performed a subgroup analysis between ultrasound-guided and ultrasound-assisted reductions. This study was registered in PROSPERO (CRD 42,024,498,295).

Results: We included six studies (112 patients, including 12 from our cohort). The success rate was 78% (69 of 88 cases) with ultrasonographic reduction and 33% (8 of 24 cases) with manual reduction. The success rate was higher with ultrasonographic than with manual reduction. Subgroup analysis revealed no significant difference between ultrasonography-assisted (76%) and ultrasonography-guided (80%) reductions (p = 0.60). Non-invasive reductions were predominantly successful within 72 h of onset, although durations extended up to 216 h in one case. Among the successful reduction cases, emergency surgery and bowel resection were necessary in two cases after 72 h from onset. Bowel resection was required in 48% (12 of 25), where the non-invasive reduction was unsuccessful within 72 h of confirmed onset.

Conclusions: Ultrasonographic reduction can be a primary treatment option for patients with obturator hernias within 72 h of onset by emergency physicians and surgeons on call. Future prospective studies are needed to evaluate ultrasonographic reduction's impact.