title: Microbiology of infected acellular dermal matrix (AlloDerm) in patients requiring complex abdominal closure after emergency surgery.
abstract: BACKGROUND
  Acellular dermal matrix (AlloDerm) has recently been introduced as an option for complex abdominal closure for patients with loss of abdominal wall domain secondary to intra-abdominal sepsis or necrotizing fasciitis. AlloDerm has been touted as a promoter of neovascularization and collagen deposition. Currently, the rate of AlloDerm infection in contaminated cases is unknown. Our objective was to determine if the organisms cultured during source control would infect AlloDerm.
  
  
  METHODS
  The medical records of patients who required complex abdominal closure with AlloDerm in a tertiary-care hospital were reviewed from January to December, 2005. For each patient demographic, the reason for urgent surgery, American Society of Anesthesiologists (ASA) class, Acute Physiology and Chronic Health Evaluation (APACHE) II score, serum albumin concentration, culture results of purulent fluid obtained during surgery, and culture results of biopsies of infected-appearing AlloDerm (change of color, delayed granulation, odor) were collected. Data are presented as mean +/- standard error of the mean.
  
  
  RESULTS
  Seventeen patients required the use of AlloDerm for tension-free closure of the abdominal wall after surgery for source control in necrotizing fasciitis (13%) or intra-abdominal sepsis (87%). The mean age was 61 +/- 2 years; 73% of the patients were Caucasian, the remainder being African American. The mean APACHE II score was 23.7 +/- 2.0, and the median ASA class was 3. The mean preoperative albumin concentration was 2.27 +/- 0.26 g/dL. Most (76%) of the patients had a wound vacuum-assisted closure system placed over the AlloDerm. Four patients (24%) were noted to have an infection of the AlloDerm graft at 24 +/- 10 days postoperatively. The cultures obtained at operation and from infected AlloDerm show similar organisms (Pseudomonas in two, Escherichia coli and methicillin-resistant Staphylococcus aureus in one each). Infected AlloDerm was coated with silver sulfadiazene and moistened dressings, and all four patients had complete resolution of the AlloDerm infection with an adequate bed of granulation tissue, allowing skin grafting.
  
  
  CONCLUSIONS
  Patients with contaminated abdomens who require complex closure with AlloDerm are at risk of developing infection of their graft material with organisms similar to those present at the time of surgery. Once culture results are obtained, topical antimicrobials with activity against the cultured organisms may be employed as part of the AlloDerm dressings to prevent infection and promote healing.
authors.affiliation: Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Michael E. DeBakey Veteran Affairs Medical Center, Houston, Texas 77030, USA. sawad@bcm.tmc.edu
authors.forename: Samir S
authors.initials: SS
authors.lastname: Awad
authors.forename: Raghuram K
authors.initials: RK
authors.lastname: Rao
authors.forename: David H
authors.initials: DH
authors.lastname: Berger
authors.forename: Daniel
authors.initials: D
authors.lastname: Albo
authors.forename: Charles F
authors.initials: CF
authors.lastname: Bellows
mesh_terms: D000005:Abdomen / Q000601:surgery*; D000891:Anti-Infective Agents, Local / Q000627:therapeutic use; D019072:Antibiotic Prophylaxis; D015331:Cohort Studies; D003094:Collagen / Q000009:adverse effects*; D019115:Fasciitis, Necrotizing / Q000601:surgery; D016905:Gram-Negative Bacterial Infections / Q000209:etiology / Q000517:prevention & control; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus; D008875:Middle Aged; D012189:Retrospective Studies; D018805:Sepsis / Q000601:surgery; D012837:Silver Sulfadiazine / Q000627:therapeutic use; D017768:Skin, Artificial / Q000009:adverse effects*; D013203:Staphylococcal Infections / Q000209:etiology / Q000517:prevention & control; D013530:Surgical Wound Infection / Q000382:microbiology* / Q000517:prevention & control
chemical_list: C440568:Alloderm; D000891:Anti-Infective Agents, Local; D003094:Collagen; D012837:Silver Sulfadiazine