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.

Non-traumatic lateral abdominal wall hernia.

A rare lateral abdominal wall hernia is described in an adult patient. This was diagnosed in a patient with a prominent right lateral abdominal wall deformity. The patient had been experiencing pain that increased progressively in severity over time. A computerized tomography (CT) scan of the abdomen revealed the location of the lateral abdominal wall defect. The hernia defect was through the transversus abdominis and the internal oblique, with the inferior aspect of the 11th rib forming part of the superior border of the defect. A 4-cm bony spur from the inferior aspect of the rib formed part of the lateral margin of the defect. The hernia sac was contained within a space underneath the external oblique muscle. The association of the hernia defect with a bony spur was highly suggestive of a congenital etiology. The hernia was successfully repaired laparoscopically with Parietex mesh (Sofradim, Lyons, France), and the patient had resolution of the symptoms on discharge and follow-up visits.