PALM BEACH, Fla. – Mesh type or position during an incisional hernia repair has little impact on the technical difficulty or patient morbidity of any subsequent abdominal operation, a large retrospective study has determined.
Dr. Mary T. Hawn
Therefore, surgeons performing an initial hernia repair should select what they believe is the optimal method, without undue concern about the potential effects on subsequent operations, Dr. Mary Hawn said at the annual meeting of the Southern Surgical Association.
"Subsequent abdominal operations are common, with nearly 25% of our study population undergoing one over a median 80-month follow-up period," said Dr. Hawn of the Birmingham Veterans Affairs Medical Center in Alabama. Of those subsequent procedures, nearly two-thirds involved treating a recurrent incisional hernia, either as the primary procedure or in combination with another procedure. "We found a limited effect of mesh type and position, so we recommend when doing an incisional hernia repair, don’t limit your technique due to concerns of complications of future operations."
Dr. Hawn and her colleagues presented the results of a large retrospective study, which included 1,444 patients at 16 Veterans Affairs medical centers. All patients underwent an elective incisional hernia repair during 1998-2002. The investigators identified subsequent abdominal operations and associated complications. They also noted intra- and postoperative variables, including the length of the subsequent operation, the need for an enterotomy or unplanned bowel resection, postoperative infections, return to the hospital or operating room, and mortality.
A quarter of the cohort (366) required a subsequent abdominal operation. Most of these (65%) were redo hernia repairs, complications from hernia repair, or another procedure combined with a hernia repair. The remainder were other abdominal procedures – including small bowel, colorectal, biliary, gastric, or duodenal – or esophageal, urologic, or gynecologic procedures.
Most subsequent procedures (77%) were elective. The remainder were emergent repairs, which were significantly more common in patients undergoing a redo hernia repair that had been done with absorbable or biologic mesh.
About one-third of the subsequent procedures (38%) showed extensive or difficult adhesions. The rate of enterotomy or unplanned bowel resection was 10%, as was the necessity of removing the initial repair mesh. The mean operating time was 126 minutes, and the postoperative length of stay averaged 5 days.
Postoperative morbidities included surgical site infections (6%), return to the OR within 30 days (9%), and hospital readmission within 30 days (13%). There were 16 deaths within 30 days of the admission.
The investigators found no significant associations between any characteristics of the initial hernia repair (mesh position or type) when difficult or extensive adhesions were involved. However, the need for mesh removal was significantly associated with both open and laparoscopic placement of expanded polytetrafluoroethylene (ePTFE) mesh (24% and 16%, respectively).
The rates of enterotomy or unplanned bowel resection did not differ significantly, regardless of mesh positions or types (ePTFE, polypropylene, or absorbable/biologic meshes). A multivariate analysis found that the most important factors influencing risk for enterotomy or bowel resection were older age (odds ratio 1.04) and previous incisional hernia repair, which was associated with more than a fourfold increased risk of enterotomy or bowel resection. Both associations were statistically significant.
Operative time was used as a surrogate for the difficulty of the operation. "We found that after adjusting for patient variables, those with an underlay or inlay polypropylene or biologic mesh had significantly longer operative times," during the subsequent surgery, Dr. Hawn said.
A multivariate analysis found that the mean operative times were 176 minutes for underlay mesh, 207 minutes for inlay mesh, and 143 minutes for onlay mesh. Absorbable/biologic meshes required a mean operating time of 190 minutes – significantly shorter than the time needed to place polypropylene or ePTFE mesh.
The indication for the subsequent operation also significantly affected operating time. A nonincisional hernia repair (mean 212 minutes) took significantly longer than either a redo of an incisional hernia repair (139 minutes) or a redo hernia repair plus another procedure (159 minutes).
Although Dr. Hawn did not provide specific data, she said that, compared to polypropylene, ePTFE mesh that had been applied in an open repair had a significantly higher explantation rate, a lower operative time, and a similar enterotomy rate. In laparoscopic repair, ePTFE had a lower rate of explantation than did polypropylene, but this finding could have been confounded because of the low number of patients whose index hernia was laparoscopically repaired.
"Also, the patients selected for laparoscopy during that initial operation probably had less of a chance of having had prior surgery, so less of a chance of adhesions," she said.