To close or not to close: morphologic changes associated with closure of the posterior rectus sheath after posterior component separation.

Abstract

Introduction: This study aims to evaluate morphologic changes of the rectus muscles after closure of the posterior rectus sheath (PRS) following component separation. There is no consensus on whether to close the PRS, and limited data exists on how closure affects the morphology and potential function of the abdominal wall musculature.

Methods: Retrospective review of all patients between 1/1/2016 and 12/31/2022 who underwent PRS release for ventral hernia repair performed by a single surgeon. During this period, some patients had reconstitution of the PRS while others had the posterior layer buttressed with peritoneum. Subjects were included if preoperative and postoperative cross-sectional imaging was available for review and excluded with: transversus abdominis muscle release, external oblique muscle release, open surgery, or complication of hematoma or seroma. Measurements of rectus muscle width and distance between semilunar lines were obtained at the level of the umbilicus, upper, middle, and lower abdomen. Statistical analysis performed using Student's t-test analysis on continuous variables. Significance defined as p = .050.

Results: Results include 90 patients divided into two arms: PRS buttressed versus PRS closed. Closed PRS was associated with significantly decreased percent difference in distance between semilunar lines in the middle (4% vs -5%, p = .001), umbilical (2% vs -4%, p = .031), and lower abdomen (2% vs -3%, p = .018) and rectus muscle width in the middle (Right: 20% vs 11%, p = .009; Left: 20% vs 6%, p ≤ .001), umbilical (Right: 20% vs 9%, p = .001; Left: 21% vs 10%, p = .002), and lower abdomen (Right: 8% vs 0%, p = .006; Left: 8% vs -1%, p = .006).

Conclusions: Release and decoupling of PRS results in increased width of rectus abdominis muscle in both cohorts although significantly larger change observed in PRS bridged. Reloading of the PRS brings the semilunar lines closer together as compared to preop measurements, the opposite is observed when leaving the PRS bridged with peritoneum.