Think of the wall as a tube, or pressure generator that aids in balance, orientation in three-dimensional space, micturition, defecation, parturition, coughing, breathing, and phonation. Layers including skin, subcutaneous fat, fascia, muscle, pre peritoneal fat, and peritoneum.
In simpler terms, there are two layers: (a) cutaneous or superficial and (b) musculofascial or deep, insofar as reconstruction is concerned. Both must be recreated for optimal cosmetic result and protective function.
The abdominal wall is a complex structure that must be well-understood before reconstruction is pursued.
Individual results may vary
To understand reconstruction, we must first understand the anatomy. There are two rows of rectus abdominis muscles separated by tendinous inscriptions. Dissection can proceed only as far up and down as necessary. There are three leaflets of muscle that flank the rectus muscles.
As we have learned from advanced abdominal wall repair, only one or two layers of muscle are necessary to obtain functional competence. Therefore, when possible, the sparing of one or more of these layers may make the subsequent repair easier.
Restoration of function is our primary goal in abdominal wall reconstruction. Minimization of cosmetic deformity is but a secondary goal. The stability of a patient must be assured before reconstruction is planned. Devices that provide negative pressure therapy like the wound vac can aid the elimination of pathogens and effectively temporize definitive reconstruction indefinitely, decrease re-operation rate, and increase the rate of delayed primary fascial closure.
The requirement of specialized care for dressing changes, consumable supplies, a weak construct, and the nuisance of being ‘shackled’ by a negative-pressure source are significant limitations.
To reiterate, reconstruction must address two major items: protection of abdominal organs and soft tissue coverage. Protection of the viscera involves the peritoneum, rectus muscles, and the investing fasciae. Failure to successfully reconstruct this layer can lead to bulge, hernia, evisceration, and significant deformity. Functionally, the acts of defecation, micturition, parturition, coughing, and orientation in three-dimensional space are compromised.
A successful repair of this deep layer will maximize functional recovery as well as app clearance. Failure to obtain soft tissue coverage of the abdominal wall imposes undue risk on the underlying reconstruction and may lead to increased risk for infection, marginal malignancies, insensible fluid losses, pain, significant deformity, and reduced quality of life. Negative pressure therapy can provide temporary relief, and in some cases, definitive coverage by secondary healing.
Reconstruction of the deep layer of the abdominal wall is essential for protective and functional recovery after excision of necrotizing disease. The principles of abdominal wall reconstruction follow those discussed elsewhere in this textbook and loosely follow the reconstructive ladder referenced elsewhere in our specialty. Healing by secondary intention is not applicable.
Primary closure of a defect is desirable, but given the often extensive defects resulting from necrosectomy, this is unlikely without undue tension. Therefore, we rely on local advancement flaps, regional flaps, and free tissue transfer to obtain coverage. Although cadaveric homograft and autograft skin has been used for over a century, in the past decade, there has been a paradigm shift from using alloplastic (prosthetic) materials toward biologic grafts for reinforcing.