Evaluation of anterior versus posterior component separation for hernia repair in a cadaveric model

Background Component separation remains an integral step during ventral hernia repair. Although a multitude of techniques are described, anterior component separation (ACS) via external oblique release (EOR) and posterior component separation (PCS) via transversus abdominis muscle release (TAR) are commonly utilized. The extent of myofascial medialization after ACS or PCS has not been well elucidated. We conducted a comparative analysis of ACS versus PCS in an established cadaveric model. Methods Fifteen cadavers underwent both ACS via EOR and PCS via TAR. Following midline laparotomy (MLL), baseline myofascial elasticity was measured. Steps for ACS included creation of subcutaneous flaps (SQF), external oblique release (EOR), and retrorectus dissection (RRD). For PCS, steps included retrorectus dissection (RRD), transversus abdominis muscle division (TAD), and retromuscular dissection (RMD). Maximal advancement of anterior rectus fascia (ARF) was measured following application of tension to the fascia as a whole, and separately at upper, middle, and lower segments. Statistical analysis was performed with Mann–Whitney U test. Values are represented as average myofascial medialization in centimeters. Results Following MLL an average of 5.0 ± 0.9 cm (range 3.4–6.0 cm) of baseline medialization was obtained. Complete ACS provided 8.8 ± 1.2 cm (range 6.3–10.7 cm) of ARF advancement compared to 10.2 ± 1.7 cm (range 7.6–12.7 cm) with PCS, p = 0.046. In the upper and mid-abdomen, we noted increased ARF advancement with PCS versus ACS (8.1 ± 1.4 cm vs. 6.7 ± 1.2 cm and 11.4 ± 1.5 vs. 9.6 ± 1.4 cm, respectively, p = 0.01). Similar levels of ARF advancement were observed in the lower abdomen, 9.1 ± 1.7 cm versus 8.7 ± 1.8 cm, p = 0.535. Conclusions Component separation via both anterior and posterior approaches provide substantial myofascial advancement. In our model, we noted statistically greater anterior fascial medialization after PCS versus ACS as a whole, and especially in the upper and mid-abdomen. We advocate PCS as a reliable and possibly superior alternative for linea alba restoration for reconstructive repairs, especially for large defects in the upper and mid-abdomen. Graphic Abstract