By Christina Frangou

Chicago—For the first time, a study has quantified the risks for incisional hernia formation from various general surgical procedures.

Research presented at the 2012 Clinical Congress of the American College of Surgeons showed that gastric/small bowel surgery, colon/appendix procedures and clean vascular surgery cases are associated with the highest incisional hernia risk requiring repair at rates of 5.16%, 4.65% and 4.05%, respectively, in a population of adult general surgery patients.

The finding confirms clinical suspicions long held by surgeons.

And now that the high-risk groups have been identified, surgeons may consider hernia prophylactic measures or abdominal wall surveillance in these patients, said lead author Benjamin K. Poulose, MD, MPH, assistant professor of general surgery, Vanderbilt University Medical Center, in Nashville.

“If we can identify patients at risk for hernia, perhaps we can initiate a program to prophylactically prevent hernias or identify their hernias at a much earlier course,” he said.

Previous research from this group has shown that each 1% reduction in hernia recurrence equates to $32 million in health care savings (Hernia 2012;16:179-183).

Dr. Poulose and his colleagues performed an observational cohort study of all adult patients who underwent elective operations in 2005 in four states, each representing a major census region in the United States: Nebraska, California, New York and Florida.

The data used in the study were collected by the Healthcare Cost and Utilization Project, a family of databases sponsored by the Agency for Healthcare Research and Quality. The project includes data from inpatient and outpatient procedures, paid for by different private and public payers.

The investigators looked at seven different procedure types: clean general surgery, clean vascular surgery, gastric/small bowel, colon/appendix, hepatopancreatobiliary (HPB), genitourinary/renal (GU) and gynecologic. Patients were followed for a minimum of two years after their initial operation, and ICD-9 codes were used to calculate rates of incisional hernia repair.

The data showed that 5,272 incisional hernia repairs were performed in the two years after surgery, which represented 3.99% of the 132,287 surgical procedures that met the study criteria.

Gynecologic surgery was associated with the lowest risk for incisional hernia formation requiring repair at 1.41%. The risk rose incrementally with other types of procedures: 2.77% for clean general surgery, 2.92% for HPB surgery and 3.07% for GU surgery. Three procedures posed above-average risk for incisional hernia repair: clean vascular, colon/appendix and gastric/small bowel surgeries.

“This is an important paper that attempts to get at the epidemiology and incidence of incisional hernia following surgical procedures,” said Mary Hawn, MD, professor and chief of gastrointestinal surgery, University of Alabama at Birmingham.

However, the study has significant limitations, she cautioned. The research likely underestimates the incidence of incisional hernia because only repair was measured. Moreover, the investigators were not able to assess which operations were performed with minimally invasive approaches, to determine whether these approaches are associated with reduced risk for subsequent incisional hernia repair.

Of the patients studied, 56% were women. They had a mean age of 56 years and a mean length of stay in hospital of 8.4 days. Two-thirds of the incisional hernia repairs were performed as inpatient procedures.

The researchers are continuing the study. They plan to follow these patients for an additional two years and will evaluate the effect of abdominal wall surveillance by serial clinical and/or radiographic evaluation in a prospective cohort of patients. The patients also may undergo hernia prophylaxis in the form of preemptive reinforcement of the abdominal wall before hernia formation.

“These strategies need further investigation as preventive measures in patients at high risk of hernia formation,” Dr. Poulose said.