Clostridial myonecrosis of the abdominal wall. Resection and prosthetic replacement

Elective colonic operation and prosthetic repair of incisional hernia: does contamination contraindicate abdominal wall prosthesis use?

BACKGROUND

Wound infection and sepsis leading to incisional hernia development are common after emergency colonic operations. Later on, while being operated on to correct an incisional hernia, most of these patients will need colonic resection or bowel continuity reestablishment. Simultaneous treatment of incisional hernias in patients with colostomy or colonic disease remains a difficult challenge, considering the reluctance of most surgeons to treat both conditions at the same time, especially when prosthetic repair is needed.

STUDY DESIGN

The aim of this study was to analyze the short-term results of patients undergoing colonic resection or bowel continuity reestablishment and simultaneous incisional hernia repair with an onlay polypropylene mesh technique. Over a period of 6 years, 20 patients were operated on for colonic problems associated with incisional hernias, including 8 Hartmanns' colostomies, 6 colostomies or ileostomies with colonic mucous fistulas, 3 postoperative colocutaneous fistulas, a paracolostomic hernia, a Chagas' megacolon, and a pseudotumoral diverticulitis. A "rule of three" statistical analysis was used to estimate the maximum risk of adverse effects, concerning mesh-related morbidity, after 1- and 2-year followup.

RESULTS

A major complication occurred in a patient who developed an anastomotic leakage and secondary wound infection; the patient was treated with parenteral nutrition and antibiotics. Other complications included a minor wound infection, a seroma, and a chronic sinus. One patient died from postoperative problems unrelated to the surgical technique. The occurrence of postoperative wound infection did not prevent mesh incorporation. Followup ranging from 1 to 7 years detected no hernia recurrences; 13 patients were followed for 2 years or more. Our results suggest that risk of mesh-related morbidity does not exceed 15.8% (3 of 19) within the first year and 23.1% (3 of 13) for 2 years followup, with 95% confidence.

CONCLUSIONS

We concluded that prosthetic repair of incisional hernias associated with simultaneous colonic operations was possible, allowing abdominal wall anatomy reestablishment. There is no reason to believe that abdominal wall prostheses must be avoided in contaminated operations when an adequate surgical technique is used.

Emergency abdominal wall reconstruction with polypropylene mesh: short-term benefits versus long-term complications

The acute replacement of full-thickness abdominal wall has been facilitated by polypropylene mesh (Marlex) (PPM), allowing debridement of nonviable tissue and restoration of abdominal wall integrity without tension. However, no substantial long-term follow-up has been reported on the definitive wound coverage after the use of PPM in open wounds. Since 1976, we have placed PPM in 31 patients; 25 for infectious complication, three for massive bowel distension preventing abdominal closure, and three for shotgun wounds with extensive tissue loss. In 29 of 31 patients, the mesh was placed in heavily contaminated wounds; extensive fasciitis was present in 23 patients and 21 had intra-abdominal abscesses. Following mesh placement, 23 reoperations were required for continuing complications. No patients eviscerated, despite these multiple procedures. Polypropylene mesh was highly effective in restoring abdominal wall continuity. Despite advantages when PPM was used, significant long-term problems developed. Seven patients died from their primary illness in the postoperative period. Nine wounds were closed by granulation and subsequent split-thickness skin grafts. All nine developed mesh extrusion and/or enteric fistulae. Nine wounds healed by secondary intention, six developed enteric fistulae or continuing mesh extrusion. Full-thickness flap coverage after granulation provided the best means of wound closure. Polypropylene mesh had significant early advantages for providing abdominal wall integrity even in the presence of severe infection. However, long-term problems were common when wounds were closed to skin grafts or secondary intention. If the mesh cannot be completely removed, strong consideration should be given to myocutaneous flaps for coverage after the primary illness has resolved.

Management of acute full-thickness losses of the abdominal wall

Over a 20-year interval, 167 patients sustained acute full-thickness abdominal wall loss due to necrotizing infection (124 patients), destructive trauma (32 patients), or en bloc tumor excision (11 patients). Polymicrobial infection or contamination was present in all but five of the patients. Of 13 patients managed by debridement and primary closure under tension, abdominal wall dehiscence occurred in each. Only two patients survived, the 11 deaths being caused by wound sepsis, evisceration, and/or bowel fistula. Debridement and gauze packing of a small defect was used in 15 patients; the single death resulted from recurrence of infectious gangrene. Pedicled flap closure, with or without a fascial prosthesis beneath, led to survival in nine of the 12 patients so-treated; yet flap necrosis from infection was a significant complication in seven patients who survived. The majority of patients (124) were managed by debridements, insertions of a fascial prostheses (prolene in 101 patients, marlex in 23 patients), and alternate day dressing changes, until the wound could be closed by skin grafts placed directly on granulations over the mesh or the bowel itself after the mesh had been removed. Sepsis and/or intestinal fistulas accounted for 25 of the 27 deaths. Major principles to evolve from this experience were: 1) insertion of a synthetic prosthesis to bridge any sizeable defect in abdominal wall rather than closure under tension or via a primarily mobilized flap; 2) use of end bowel stomas rather than exteriorized loops or primary anastomoses in the face of active infection, significant contamination, and/or massive contusion; and 3) delay in final reconstruction until all intestinal vents and fistulas have been closed by prior operation.