The earliest description of these musculofascial flaps dates back to the nineteenth century. These techniques were described by Guillouid in 1892, Chrobak in 1892, Gersuny in 1893, and Noble in 1895 [44]. Alfonso Albanese [42] from Argentina is credited with the first ever description of the technique that involved dividing the external oblique muscle vertically to enable the closure at midline by suturing together the rectus abdominis muscles in 1951. However in 1990, the technique was modified and refined by Ramirez et al. from Johns Hopkins University Hospital and was described as “components separation” [43]. This technique utilizes the medial advancement of bilateral, innervated, bipedicled, rectus abdominis-transversus abdominis-internal oblique muscle flap complexes to close ventral abdominal wall defects. In their landmark study, Ramirez and cowork­ers utilized human cadavers to demonstrate that the external oblique muscle can be separated from the internal oblique in an avascular plane by incising the external oblique fascia with an incision just lateral to the linea semilunaris [43]. Similarly, the rectus abdominis muscle with its overlying fascia can be separated from the posterior rectus sheath. This separation of the anatomic components allows significant mobilization for approximately 10, 20, and 8 cm in the upper, middle, and lower thirds of the abdomen, respectively.

I prefer, as do most surgeons, to reinforce the hernia repair with a mesh graft following component separation to help reduce recurrence; however, a randomized controlled trial comparing component separation with and without mesh repair found similar recurrence rates between the two approaches [49]. Redundant skin flaps are excised and finally, the undermined skin edges are approximated in layers

The dissection of this segment should start as cranially as you can. At the point of transition of posterior lamina of the internal oblique fascia you will be able to see the medial aspect of the transversus abdominus muscle (TAM). The muscle fibers and fascia of TAM can be separated from the underlying thin posterior transversus abdominis fascia and peritoneum with a right angle clamp. But, this separation requires a careful dissection under the muscle fibers of TAM. One has to be careful not to enter peritoneum, but if this does occur, one must make sure to identify and close with absorb­able suture. Transection of TAM can be done in a number of ways but I agree with these authors the transection of the TAM should start as far cranially as possible where these muscle fibers are prominent and progressing caudally aids markedly this part of the component separation [53]. This extraperitoneal space now can be extended laterally and cau­dally in order to make space for the prosthesis. This dissec­tion is facilitated greatly with a sweeping move of your hand. I prefer that this space extend to the costal margin and join the central tendon of the diaphragm in the midline. Once the space is created to your satisfaction, the posterior rectus sheaths are approximated with running absorbable suture. Fixation of the mesh superiorly, inferiorly and laterally with sutures, will help you with positioning the mesh appropri­ately. A number of techniques can be used to place the rest of the sutures. I prefer to use a Carter-Thomason suture passer, but other suture passers are just as good to fix the mesh to the anterior abdominal wall.

The benefits of PCS with TAR have been demonstrated with the superiority when compared with ACS by 50% decrease in wound morbidity with the posterior approach [54]. Most large series report significant lower morbidity with the PCS approach. Moreover, this technique has been suggested for patients who previously have ACS but have recurrence of hernia [55].