By Christina Frangou

Parastomal reinforcement with a biologic mesh failed to reduce the incidence of hernia formation in a large, prospective, randomized study.

The study, which was presented at the 2013 annual meeting of the American Society of Colon and Rectal Surgeons, demonstrated no difference in hernia occurrence or quality of life when Strattice reconstructive tissue matrix (LifeCell) was placed in the rectus sheath in patients undergoing surgery for permanent abdominal wall ostomy.

“Reinforcement of stomas with Strattice was safe but did not statistically reduce the incidence of parastomal hernia formation,” said lead author David E. Beck, MD, professor and chair of colon and rectal surgery, Oschner Clinic, New Orleans.

Experts caution that the study results were confounded by a lower-than-average incidence of parastomal hernia formation among patients without mesh reinforcement. More investigations are needed before biologic mesh can be ruled out as beneficial in this population.

“The real shock of this study is that there weren’t more hernias in the control group. You can’t say from this that there’s no benefit to reinforcement with a biologic. You can say, however, that we need more studies and need this study to be followed longer,” said Peter W. Marcello, MD, chair of colon and rectal surgery at the Lahey Clinic Medical Center, Burlington, Mass. Dr. Marcello was not involved in the study.

Patients who do not have mesh reinforcement during surgery for a permanent abdominal wall ostomy are typically expected to have about a 30% chance of hernia occurrence, based on previously reported studies. In this study, only 12% of patients without mesh reinforcement developed a hernia within two years of surgery. This rate was almost identical to the 11% hernia occurrence in patients who had tissue reinforcement with a biologic mesh.

The study was conducted at 22 centers throughout the United States. In all, 113 patients who were expected to have a stoma for more than one year were prospectively randomized to undergo standard end stomal construction or placement of a 6 cm × 6 cm square of Strattice tissue matrix reinforcement at the time of stomal construction.

The mesh was inserted through the stomal skin opening and placed in the space between the posterior sheath/peritoneum and rectus muscle. Patients were evaluated at three, six, 12 and 24 months for parastomal hernia occurrence by clinical exam. They also were asked to complete the Stomal Quality of Life questionnaire. Clinical suspicions were confirmed with an abdominal computed tomography scan.

At the 24-month follow-up, there were no differences in adverse events, stoma-related adverse events or deaths between the two groups of patients. Scores on quality of life were also similar.

The investigators are conducting subgroup analyses. Follow-up studies could explain the low hernia occurrence rate among patients without mesh reinforcement, Dr. Beck said.

“Potential reasons might include inclusions of ileostomies versus colostomies; use of laparoscopy; the fact that all cases were elective; [and] all were placed in the rectus sheath and were performed by experienced surgeons.”

Dr. Beck said he believed that high-risk patients, such as those with colostomies, people with weaker abdominal walls or those who engage in heavy lifting or manual labor, benefit from mesh reinforcement. Although biologics are expensive, he said the benefits justify the cost for some patients.

Dr. Marcello said the results should not be construed as parastomal hernias rarely occurring after a stoma. “Parastomal hernias are still a major concern for us, and remain the leading surgical complication after a stoma construction. Despite the encouraging results in the control group of this study, we believe that longer follow-up of this study and future studies will determine the role of prophylactic mesh in the prevention of parastomal hernias.”

“Long-term avoidance of this specific complication—one that is very hard to treat—would dramatically improve the quality of life of the ostomy patient,” Dr. Marcello added.

Dr. Beck disclosed that he received research funding and honoraria from LifeCell, the maker of Strattice. He also received support for research, honoraria and consulting fees from Helsin, Ethicon and Pacira. Dr. Marcello disclosed that he has been a consultant for Baxter and Covidien.