Synthetic Mesh Prevents Hernias in Open Gastric Bypass

LODZ, Poland, Sept. 28 -- In open Roux-en-Y gastric bypass surgery, the use of polypropylene mesh to hold the incision closed prevents hernias and does not extend hospital stays, researchers here reported.

In a small, randomized trial including 74 extremely obese patients who had open gastric bypass, none of 36 given polypropylene mesh closures developed hernias, compared with eight of 38 (21%) who had standard sutures, according to an online report in the British Journal of Surgery.

About 25% of patients who have open gastric bypass surgery develop incisional hernias, which can lead to serious complications and re-hospitalization, said Janusz Strzelczyk, M.D., of the Medical University of Lodz, and colleagues.

In the study, the mean (sd) body mass and body mass index in the mesh group were 137.3 (24.5) kg and 46.2 (7.1) kg/m². In the non-mesh group these mean values were similar: 139.0 (24.9) kg and 46.8 (7.6) kg/m² respectively.

The mean duration of hospital stay was similar in the mesh and non-mesh groups (8.4 and 10.3 days respectively; P= 0.092).

Patients were followed for at least six months (range six to 38 months), checking for hernia, bleeding, or any other surgery-related complication. However, here were no serious complications in either group, while the rate of seromas and minor wound leakage was similar, 14% in the mesh group and 11% in the non-mesh group.

The same three surgeons operated on all the patients, the researchers said. In both groups, the wound was closed with a polypropylene suture, whereas in the mesh group, the surgeons inserted a polypropylene mesh in a sublay manner.

The researchers described the surgical procedures as follows:

• The bypass procedure was done following upper midline laparotomy. For the no-mesh patients, following insertion of a silicone drain the abdominal cavity was closed in a standard way.
• In the mesh group, the cavity was closed in a multi-layered manner. First, the peritoneum and the posterior rectal sheath were closed with continuous sutures.
• Then a polypropylene mesh, 8 cm wide and 2 cm longer than the fascia defect, was inserted between the rectus muscle and its posterior sheath, and anchored with interrupted polypropylene sutures.
• Next the anterior rectal sheath was closed, and an additional drain was inserted between the mesh and the rectus muscles.
• Finally, the skin was closed with a continuous subcutaneous absorbable suture in both groups.

Gastric bypass is the most often performed bariatric procedure, and despite the increasing popularity and safety of a laparoscopic approach, for a variety of reasons many morbidly obese patients are still offered open procedures, Dr. Strzelczyk said.

Postoperative hernia following a bariatric procedure is more common than in other groups of surgical patients, and is one of the most common reasons for hospitalization in the years following bypass surgery. Thus the mesh findings are important, Dr. Strzelczyk said, adding that because the procedure did not prolong hospital stay, it is also economically viable.

Although polypropylene mesh has become a "gold standard" in the treatment of postoperative hernia, this study, the surgeons wrote, as far as they know, is the first reported randomized trial of prophylactic polypropylene mesh for wound closure in bariatric surgery.

As obesity is deemed a modern epidemic, they said, "it is expected that bariatric surgery will be increasingly performed in general hospitals, not just in specialized centers."

However, they noted, their study had some important limitations. Because the number of patients in both groups was small, rarely occurring complications may have been missed.

Also the patients were informed before the operation of the results of randomization and thus had an opportunity to withdraw from the study. However, it was decided that not telling them of prospective mesh use would be unethical. For obvious reasons, the surgeons were not blinded either.

"The results of the present trial strongly suggest that using polypropylene mesh in wound closure in open bariatric surgery fully prevents hernia development, regardless of the extent of obesity," the researchers said. Therefore, they concluded, "surgeons treating obesity with gastric bypass operations should consider using this procedure more often."