Modified Minimally Invasive Component Separation

Published on 09/04/2015 by admin

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Last modified 22/04/2025

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Chapter 10 Modified Minimally Invasive Component Separation image

2 Preoperative Considerations

Surgeons must consider the risks of surgery and anesthesia, including cardiopulmonary comorbidities and other general health issues.

3 Operative Steps

image It is imperative to identify the semilunar line to ensure that the appropriate plane is entered for the component separation release. Palpation is used to identify the edge of the rectus muscle, lateral edge of the rectus sheath, and transition of oblique musculature to aponeurosis, which serve as landmarks (Fig. 10-2). The presence of a fat pad between the internal and external oblique aponeuroses is a good indication of being in the correct plane. The optimal location of the release of the external oblique muscle is through its aponeurosis medial to the muscle body and lateral to its insertion into the rectus sheath complex, that is, generally 1.5 cm lateral to the lateral edge of the rectus complex. The area is marked with a pen and incised with a scalpel or electrocautery for 1 cm in the craniocaudal direction (see Fig. 10-2). In the event that the incision enters the rectus sheath (revealing the rectus abdominis muscle), the incision is closed and a new incision is made more laterally.
image Blunt dissection between the internal and external oblique aponeuroses and muscle is performed through the 1-cm vertical incision in the external oblique aponeurosis. The surgeon uses a blunt-tip, metal Yankauer suction handle (not connected to suction) to start the dissection between the internal and external oblique aponeuroses inferiorly and superiorly to the initial external oblique aponeurosis incision (Fig. 10-3). This should slide easily just lateral to the rectus complex superiorly over the costal margin (shown) and inferiorly toward the pubis (not shown). This sweeping blunt dissection provides separation between the internal and external oblique aponeuroses for a safe separation of the external oblique aponeurosis in a minimally invasive fashion without inadvertent injury to the underlying internal oblique structure muscular aponeurosis. The surgeon then inserts the suction handle inferiorly between the internal and external oblique aponeuroses and positions the handle against the rectus abdominis muscle complex and uses the suction handle as a palpable guide to create vertical, 3-cm-wide, subcutaneous tunnels (Fig. 10-4, A). Using a narrow Deaver retractor and electrocautery, dissection over the external oblique aponeurosis release site is performed inferiorly and superiorly (see Fig. 10-4). The external oblique aponeurosis is then freed anteriorly and posteriorly and can be easily transected without injuring the overlying subcutaneous tissue or underlying oblique muscle or aponeurosis.
image The external oblique aponeurosis incision can be performed inferiorly and superiorly to the initial external oblique aponeurosis incision through the initial lateral tunnel incision. The blunt tip suction handle is again used as a guide to avoid inadvertently entering the rectus complex medially (Fig. 10-4, B). The surgeon uses scissors to release the inferior half of the external oblique aponeurosis, which extends towards the pubis. The same technique is applied superiorly to fully release the aponeurosis of the external abdominal oblique muscle; however, electrocautery becomes necessary as more muscle and less aponeurosis are present at and above the costal margin. The release is continued cranially to 8-12 cm cranial to the costal margin. Electrocautery for hemostasis and dissection is often required for the considerable interdigitation between the external oblique muscular aponeurosis and the underlying musculature at and above the costal margin. After the external oblique aponeurosis is completely released, the internal oblique muscle should be clearly visible.
image The defect’s condition and the surgeon’s preferences determine the type of implantable surgical mesh to be used. To avoid the consequences of adhesions, macroporous synthetic mesh should not be placed directly onto the intraperitoneal viscera. Instead, for simple defects, composite antiadhesive barrier mesh may be used. For complex defects, particularly defects with bacterial contamination, defects in which mesh may be placed directly over viscera, defects with a high risk of skin dehiscence with subsequent mesh exposure, and/or defects in patients at an increased risk for perioperative wound healing complications, bioprosthetic mesh is generally used. The procedure has been described by the author, Charles Butler, as the MICSIB (Minimally Invasive Component Separation with Inlay Bioprosthetic Mesh) technique when minimally invasive component separation is used with an inlay bioprosthetic mesh. The mesh is inset with at least 4-5 cms of overlap with the musculofascial edges to ensure a reliable repair. The surgeon cuts the mesh, orients it into the defect, and marks the midline of the mesh with a marker. The surgeon then resects any devitalized, attenuated, or severely scarred midline tissue. The surgeon marks the anticipated suture line on the mesh and the musculofascia to ensure that once the inset sutures have been placed and tied, the fascial edges meet at the midline without tension over the reinforcing mesh inlay if primary fascial closure is possible (reinforced repair). If bridging mesh is required, the surgeon marks the area of bridging and the anticipated positions of central suture lines where the true musculofascial edges are inset to the mesh.
image The surgeon then performs a circumferential, interrupted #1 polypropylene suture inlay inset through the full thickness of the musculofascia, through the mesh, and then back out through the musculofascia. In Figure 10-5 the separation of the internal and external oblique muscles laterally and the completed external oblique aponeurosis release are shown with the discontinued external oblique aponeurosis on both sides. The rectus complex on both sides is now able to be medialized toward the midline. Bioprosthetic mesh is being inset with interrupted monofilament sutures. Suture knots are oriented ventral to the musculofascia. The distance between the entry and exit of a suture through the fascia should be at least 1.5 cm to avoid suture pull-through and sutures should be placed at approximately 2-cm intervals on the musculofascia during the inset. The most superior suture is placed first, often through or around the xiphoid process, and the remainder of the costal margin inset is performed with all sutures placed on hemostats and left untied. Next, the most inferior suture is placed to provide midline orientation and establish the appropriate physiologic tension of the inlay mesh. The remaining sutures are then placed in the appropriate positions to enable primary fascial closure (reinforced repair) or placement of bridging mesh (bridged repair) as previously determined. The surgeon must identify the inferior epigastric vessels as they penetrate the rectus muscles to avoid inadvertently occluding them with a suture and thereby compromising the vascularity of the rectus complex and overlying skin.
image When complete primary fascial closure is planned, the surgeon reapproximates the fascial edges in the midline with either a running or interrupted long-term monofilament resorbable suture (Fig. 10-6). The vascularity of the rectus muscle is then assessed to ensure that it has not become congested or devascularized after inset placement. In areas where bridging is required and primary fascial reapproximation at the midline is not possible, the surgeon should use resorbable sutures to carefully tack the fascial edges to the surface of the mesh without injuring the underlying intraperitoneal structures (Fig. 10-7). To protect from inadvertent injury to intraperitoneal sutures while placing these central sutures, it is helpful to have left several peripheral inset sutures untied and placed on hemostats. A wide malleable retractor (not shown in Fig. 10-7) can be inserted through this area and placed just under the bioprosthetic mesh to protect the bowel during central inset suture placement. The few untied inset sutures are then tied.
image Generally, 3 to 5 interrupted 3-0 resorbable sutures are placed in a vertical line between drainage catheter channels to quilt the elevated skin flaps from Scarpa fascia to the musculofascial repair to eliminate dead space and reduce shear. Figure 10-8 shows a completed closure in three-dimensional cross section, indicating location of drainage catheters inset sutures, and quilting sutures. This technique has minimized the need for extensive skin flap elevation and preserved the rectus perforator vascularity to the overlying skin.

5 Pearls/Pitfalls