Biodegradable mesh may help prevent fistula after pancreatic surgery

Last Updated: 2016-11-03

By Joan Stephenson

NEW YORK (Reuters Health) - In patients undergoing distal pancreatectomy, wrapping the cut surface of the pancreas with a biodegradable mesh reduced the rate of clinically relevant pancreatic fistula, a small multicenter randomized trial shows.

"Polyglycolic acid (PGA) mesh decreases the rate of pancreatic leakage after distal pancreatectomy," senior author Dr. Sun-Whe Kim of Seoul National University College of Medicine in South Korea told Reuters Health by email.

Postoperative pancreatic fistula (POPF) is the most frequent and serious complication in patients undergoing distal pancreatectomy to treat such conditions as chronic pancreatitis, benign pancreatic cystadenoma, and pancreatic adenocarcinoma.

The International Study Group for Pancreatic Fistulas (ISGPF) defines POPF as an amylase concentration in drain fluid exceeding three times the upper normal serum concentration after postoperative day three. Studies have reported a frequency of POPF ranging from 13% to 64%.

Various methods of pancreatic stump closure have been investigated to reduce pancreatic leakage, including the use of fibrin glue, with inconsistent results, Dr. Kim said.

A total of 107 patients were enrolled at five centers between 2011 and 2014, with 49 randomized to the intervention group and 58 to the control group. All patients underwent distal transection of the pancreas with a stapling device; for patients in the intervention group only, surgeons applied fibrin glue to the remnant pancreatic stump and wrapped PGA mesh around it.

Ten patients were excluded for various reasons, leaving 97 evaluable patients ages 20 to 85 (44 in PGA mesh group and 53 in the control group).

The study's primary end point was the development of a clinically relevant POPF (grade B or C by the ISGPF grading system). After surgery, amylase concentrations in serum and drainage fluid were repeatedly measured; patients also underwent abdominal computed tomography (CT) five days and three months after surgery.

Overall, rates of POPF of any grade (A, B, or C) in the PGA mesh and control groups did not differ significantly (65.9% vs. 54.7%, respectively).

However, the rate of clinically relevant POPF was significantly lower among patients treated with the PGA mesh. Five in the PGA group and 15 in the control group had grade B or C POPF (11.4% vs. 28.3%, p=0.04), the researchers report in JAMA Surgery, online October 26.

"Application of PGA mesh may become a routine procedure to prevent POPF following distal pancreatectomy," they write.

The findings were comparable with those of three previous retrospective studies, Drs. Yen-Yi Juo and Joe Hines, of the David Geffen School of Medicine at the University of California, Los Angeles, note in an accompanying editorial.

However, because surgeons' practices vary in terms of obtaining amylase levels or abdominal CT, some "clinically significant" POPF reported in the study might not be detected in real-life practice, and "the applicability of these results remains unknown," they noted.

Despite this concern and "minor biases" in the study design, the editorialists said that use of PGA mesh "represents a possible solution to the main complication following pancreatic resection" and merits further investigation "considering the minimal associated risk."

The results "should be verified first by other groups before accepting it as a standard technique," Dr. Masafumi Nakamura of Kyushu University's Graduate School of Medical Sciences in Fukuoka, Japan, said in an email.

"The effect of PGA mesh is supposed to be a sealing effect on the pancreatic stump, which should influence every grade of pancreatic fistula," said Dr. Nakamura, who was not involved with the research. However, while the rate of clinically relevant (grades B and C) fistulas was lower among the PGA group, there was no difference between groups in terms of any grade of pancreatic fistula, he told Reuters Health.

Although the described reduction from 28% to 11% in the study "seems promising," the study has methodological flaws, said Dr. Werner Hartwig of Ludwig Maximilians-University Munich in Germany.

For example, although the researchers reported a 1:1 randomization, the group's sizes are not distributed evenly, he told Reuters Health by email.

"Most importantly, no intention-to-treat analysis has been provided, which would be of major relevance for a high-class" randomized trial, which means that the study's findings require confirmation in a future randomized trial, said Dr. Hartwig.

He also noted that another just-published randomized trial found that covering the pancreatic stump with autologous vascularized tissue, a teres ligament patch, reduced the incidence of pancreatic fistula following distal pancreatectomy (http://bit.ly/2f39ha3). A recent meta-analysis that he and colleagues conducted confirmed that this approach was effective, he said (http://bit.ly/2f6Kr9i).

"Therefore, the optimal technique . . . still needs to be established," Dr. Hartwig said.

He noted that because most distal pancreatectomies in many centers are performed laparoscopically, an optimal technique must be feasible for use in minimally invasive surgery.

The researchers reported no conflicts of interest.

SOURCE: http://bit.ly/2dYTYuk and http://bit.ly/2eUijGn

JAMA Surg 2016.