Component Separation By– Dr Richa Jain

Facts Incisional hernia occurs in 11 % to 18.7 % of patients, within 10 years after laparotomy Long term follow up shows that 40 % of patients with an incisional hernia eventually become symptomatic with incarceration and strangulation requiring emergency surgery.

Facts In longstanding hernia, a considerable amount of abdominal contents will loose its “abdominal domain” due to abdominal wall weakness and lateral retraction of the muscles. Morbidity of surgery is high and long term results are poor with recurrence rates varying from 32 – 63 % after 10 years of follow up.

Facts Treatment options can be divided into closing- and bridging techniques. Closing techniques pursue re-approximation of the fascial edges to reestablish the initial anatomic situation, while a bridging technique connects these fascial edges by using a non physiologic compound, replacing the abdominal wall at the muscular defect.

Facts Introduction of prosthetic material indeed lowered the recurrence rate of incisional hernia repair but was also accompanied by specific complications such as chronic pain, infection, seroma formation, fistulation, shrinkage of the mesh. Despite these drawbacks, mesh repair seems the easiest and therefore often preferred and generally applicable procedure.

CST In 1990 Oscar Ramirez introduced Components Separation Method (CSM): a non-mesh functional repair in which the external and internal oblique abdominal muscles are separated after exposure through a midline laparotomy. By exclusive incision of the external aponeurosis, a separation of the external and internal oblique muscles can be realised as far as the posterior axillary line.

CST Component separation should be considered in the following situations: 1.  Infected abdominal wall with or without mesh. 2.  Patients with hernias who are also having a colostomy reversed. 3.  Very large ventral hernias. 4.  Multiple defects. 5.  Multiple failed attempts at previous repairs. 6.  Treatment or prevention of the abdominal compartment syndrome (ACS).  7.  In those patients with Loss of Domain, component separation allows placement of a smaller piece of mesh, thereby minimizing eventration

The Technique Skin and subcutaneous tissue are mobilized and the aponeurosis of the external oblique muscle incised pararectally, about 1 cm lateral to the rectus muscle.

The Technique The external and internal oblique muscles can be separated by blunt dissection.

The Technique Additionally the rectus muscle can be separated from the posterior rectus Sheath, though it is believed to be of minor relevance, but it can contribute an additional 2 cm of medial advancement for each muscle complex

The Technique Taking the external oblique out of action can theoretically allow the internal and transverse oblique muscles to rotate medially around its centre of origin, thereby facilitating a more medial and caudal translation of the rectus muscle.

The Technique Position of the retromuscular, prefascial mesh after performing the CSM.

The Technique In patients with an enterostomy, the technique described cannot be followed, first, because the vascularization of the skin is endangered and, second, because no release of the posterior rectus sheath can be performed. As an alternative, transection of the external oblique aponeurosis is performed through a separate skin incision lateral aspect of the rectus abdominis muscle. Mobilization of the posterior sheath of the rectus abdominis muscle should not be performed in these cases.

The Technique

The Technique Publications on the results of the CSM

Modified Sandwich Technique The sandwich technique was originally described in 1988 by Guarneri et al,  isolates prosthetic mesh from the bowel to prevent adhesions by placing it between the peritoneum and abdominal wall.

Contd… A modification of this technique that combines components separation closure of the midline, to reconstitute the abdominal wall myofascial system, with a biologic underlay as well as onlay mesh to the midline repair. The underlay mesh may be placed intraperitoneally or retromuscularly, depending on preference.

MICSIB In traditional, open component separation, the surgeon accesses external oblique aponeurosis by elevating the skin flaps over the entire rectus abdominis muscle, thus separating the subcutaneous fat from the anterior rectus sheath and dissecting the rectus abdominis myocutaneous perforator. However, elevating the skin flaps results in subcutaneous dead space, which can lead to seromas and infections, and the reduced blood flow caused by cutting the perforator vessels inhibits wound healing.

MICSIB

MICSIB Minimally invasive component separation with inlay bioprosthetic mesh (MICSIB) uses tunnel incisions for external oblique aponeurosis release. It preserves both the rectus abdominis myocutaneous perforator vessels that supply the overlying skin and the connection between the subcutaneous fat and anterior rectus sheath, thereby reducing subcutaneous dead space and potentially improving overlying skin flap vascularity. Inlay bioprosthetic mesh reinforces the musculofascial repair.

MICSIB Traditional CST MI CST

Lap CST The search for an ideal procedure which has merits of CST while less complications of dissection culminated into development of laproscopic approach for CST.

Lap CST

Lap CST This Approach approach involves a small incision at the costal margin lateral to the rectus abdominis muscle. The external oblique is exposed and incised. After exposure of the internal oblique muscle, a potential space is created using a balloon dissector between the two oblique muscles to the level of the inguinal ligament. A second lateral abdominal wall port is placed that allows for release of the external oblique.

Bilateral anterior rectus sheath turnover flap Koshimoto S et al used anterior rectus sheath turnover flap for abdominal closure in patients with open abdomen. Anterior rectus sheath is incised about 5-6 cm lateral to midline bilaterally. Rectus sheath is dissected and freed from underlying rectus muscle. Free rectus sheath flaps are turned and sutured.

Contd…

Rectus Abdominis Myofascial Splitting Flap If a chronic wound is accompanied by infection, a great deal of time and effort are necessary for treatment because the normal wound healing mechanism could be hindered and the inflammatory reaction could be distorted

Contd… If chronic wound infection is treated by surgery using a myofascial splitting flap, bacterial clearance would be increased due to the ample blood supply from vessels distributed on the muscle pedicle, and also the chronic infected wound would be effectively controlled due to an increased metabolic turnover rate of the tissue 

Contd… A portion of the rectus abdominis muscle that could sufficiently cover the defect size is elevated along with the anterior muscle sheath, and then the elevated muscle is turned over toward the midline, by turning over the anterior rectus sheath along with the rectus abdominis muscle, a horizontal mattress suture was made.

Contd… On the bilateral ends of the overlapping part, an interrupted suture is made.

Contd… The skin and subcutaneous tissue are sutured after confirming circulation by visual inspection or Doppler.

Robotic Rives Stoppa With Bilateral Posterior Component Separation

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