For Ventral Hernia Repair, Biologic Onlay Improves Outcomes

Caroline Helwick

October 31, 2011

October 31, 2011 (San Francisco, California) — Recurrences after ventral hernia repair can be reduced significantly through the use of a component separation of parts augmented with onlay biologics, reported surgeons from the University of Pittsburgh, Pennsylvania, at the American College of Surgeons 97th Clinical Congress.

"We found a significant reduction in the hernia recurrence rate following repair using component separation of parts (SOP) augmented with biologics, and this was most striking among smokers, for whom the use of biologics reduced the risk of recurrence by 41%," said Jignesh V. Unadkat, MD, lead author of the study.

There are 250,000 ventral hernia repairs each year in the United States, and recurrence rates are high: 54% after primary repair, 25% after synthetic mesh repair, and 22% after components separation.

"There is a need for new repair strategies," Dr. Unadkat asserted. Augmentation of fascial repairs with biologic tissue has demonstrated improved biomechanical strength due to host tissue deposition and ingrowth," he noted.

"We hypothesized that the use of various onlay biologics along with SOP will reduce the hernia recurrence rate following ventral hernia repair," he said.

The researchers evaluated all patients at their center having hernia repair with SOP using a biologic membrane (acellular dermal matrix) overlay (n = 218). A retrospective classically treated cohort having SOP without biologics served as controls. Patients were followed at 1, 3, 6, and 12 months, then annually thereafter for hernia recurrence, up to approximately 4 years.

The demographic characteristics of the treatment groups were similar. Almost half the patients had previous hernia repairs, approximately one quarter smoked, and average body mass index was 33 kg/m2.

Reduced Recurrences With Biologic Overlay

Patients having hernia repair with SOP and a biologic overlay were significantly less likely to experience a recurrence within 3 to 4 years: 4.4% vs 18.6% of the controls (P = .001). There was a numeric trend toward longer time to recurrence as well: 13.1 months vs 9.3 months (P = .481).

Seromas were observed in 5.0% of the SOP/biologics group and 1.7% of the SOP group (P = .321), but wound complications were increased in the SOP/biologics cohort: 25.2% vs 8.5% (P = .005). Thromboembolism rates were similar at 3.9% and 3.4%, respectively (P = .639), Dr. Unadkat reported.

Operative data was similar, with "contaminated surgery" noted for 6.8% of the SOP controls and 10.1% of the SOP/biologics group (P = .859). Hospital stay was lengthened somewhat in the SOP/biologics group: 7 days vs 4.6 days for the control group (P = .067).

No preference was seen for one biologic over another, among Alloderm (LifeCell), Allomax (Davol), Permacol (Covidien), Strattice (LifeCell), and Xenmatrix (Davol). "We found no difference in the kind of biologic used," he said.

Greatest Predictors of Recurrence Were Biologic Overlay and Smoking

A multivariate analysis revealed 2 significant predictors of hernia recurrence. Smoking was associated with an odds ratio of 3.5 (P = .016), whereas use of a biologic overlay carried an odds ratio of 0.23, indicating a 77% reduced risk (P = .003), he reported.

"Smoking more than triples the risk of hernia recurrence," he noted.

Presence of diabetes mellitus, chronic obstructive pulmonary disease, steroids, or previous surgery were not significantly associated with increased risk for recurrence.

"We looked at the interaction between biologics and smoking and found that the biologic was especially protective against recurrence in smokers," he said.

For smokers, the odds ratio of recurrence without the use of a biologic was 3.464, but the use of a biologic reduced the risk, lowering the odds ratio to 2.084. This amounted to a risk reduction of 41%.

David M. Young, MD, professor of plastic surgery at the University of California School of Medicine in San Francisco, commented, "This is a very important paper looking at a complicated topic."

"In our own center, we grapple with the use of biologic mesh versus traditional synthetic mesh, simply for financial reasons. It’s incredibly more expensive to use most of these biologics," he said. Dr. Young pointed out that the use of overlays has been shown to reduce recurrences, but what has not been done and should be, he said, is a comparison of traditional Prolene mesh with a biologic mesh. "This would show if the biologic is really better, or maybe worse," he suggested.

Dr. Unadkat responded to the issue of cost by noting that his group uses about 1 cm of biologic on either side of the scar, "which significantly reduces the amount of biologic we need... It does not have to be a big chunk. You can use multiple pieces and stack them together. The way the biologic works it not to hold the edges together but to enhance the scar."

Dr. Unadkat and Dr. Young have disclosed no relevant financial relationships.

American College of Surgeons (ACS) 97th Clinical Congress. Presented October 26, 2011.


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