Is release of the posterior lamella enough? A cadaveric exploration of posterior component separation techniques

Background: As posterior component separation techniques continue to gain popularity there is uncertainty regarding the degree of fascial advancement afforded by the various techniques. Our study seeks to compare the degree anterior rectus sheath translation seen in full transversus abdominus release compared to simple release of the posterior lamella of the rectus sheath.

Methods: Ten hemi-abdomens in five fresh cadavers were dissected. One hemi-abdomen underwent external oblique release. The contralateral hemi-abdomen underwent retrorectus dissection and initial release of the internal lamella of the internal oblique, followed by full transversus abdominus release. A 4 kg weight was suspended from the fascia and excursion was measured after 1) external oblique separation, 2) posterior lamella of the internal oblique separation, and 3) transversus abdominis separation.

Results: Average unilateral hemifascial translation after release of the external oblique provided an average unilateral hemi-fascial translation of 3.38 cm (+/- 0.69). Release of the posterior lamella of the internal oblique provided 3.98 cm (+/- 0.94). After transversus release the average translation increased to 4.31 cm (+/- 0.89).

Conclusions: In this cadaveric study, the majority (92%) of fascial advancement afforded by posterior component separation was achieved by an intermediate step in the transversus abdominus release operation: division of the posterior lamella of the internal oblique.