Ventral Hernia Repair in Obese Patients: Risks and Benefits

New York—As much as 60% of the 350,000 patients who undergo ventral hernia repair every year meet the criteria for obesity. Despite the frequency with which surgeons see such patients, there is little consensus on how to treat them: Laparoscopic or open? Primary repair or mesh-enforced? Concomitant with bariatric surgery or delayed?

“We see a lot of obese patients with ventral hernias, and most of the time we don’t know what to do,” said Pablo Omelanczuk, MD, the director of the Mendoza Obesity and Surgery Center, in Argentina.

“With a body mass index (BMI) of more than 50, the risk of any complication in any kind of surgery is more than 20%; you always have to think of the risks and benefits of doing a repair in these patients.”

At the 2019 Controversies, Problems and Techniques in Surgery meeting, Dr. Omelanczuk described the link between obesity and hernia formation, the risks of surgery in this patient population, and an algorithm for guiding treatment in bariatric patients with ventral hernias.

Obesity and Ventral Hernia Risk: A Matter of Biology?

The correlation between obesity and ventral hernia has long been known, but the understanding behind what drives this correlation has become more sophisticated in recent years. It is not only a mechanical problem.

A 2015 paper evaluating biopsies from the rectus sheath of bariatric and nonbariatric patients found a decrease of both type I and type III collagen in the former, possibly due to changes in messenger RNA (J Surg Res 2015;195[2]:475-480).

“The same thing has been found with elastin,” Dr. Omelanczuk said. “These alterations in connective tissue can be causes of the tissue pathology of the hernia.”

Obesity also has an impact on OR resources. In a database evaluation of nearly 190,000 patients undergoing 14 types of procedures, the authors noted a stepwise increase in procedure time by BMI category for all procedures. Nonoperative OR time also was drawn out (World J Surg 2018;42[10]:3125-3133).

“Obese patients require additional time for any kind of surgery,” Dr. Omelanczuk said, noting that of the three types of procedures most affected by obesity, ventral hernia repair was No. 1, followed by laminectomy and hysterectomy.

Risks of Surgery in Obese Patients

Although there is a range of outcomes reported in the literature, obesity is generally associated with a higher risk for recurrence, complications and infection; longer procedural time; and greater length of stay in patients undergoing hernia repair. Patients with metabolic syndrome (MetS) may be at an especially high risk for poorer outcomes.

A review of 39,118 patients with or without MetS undergoing ventral hernia repair found the former more likely to have an ASA physical status of III or higher, more likely to require emergency surgery, required longer operative times, had a longer length of stay, and had more complications related to the wound (Surg Obes Relat Dis 2018;14[2]:206-213).

“They also had more readmissions, more reoperations and a higher risk of death,” Dr. Omelanczuk said.

Not surprisingly, he takes MetS into consideration while making treatment decisions when bariatric patients present with a ventral hernia in need of repair, and there are a lot of treatment decisions to consider.

Hernia Repair in Bariatric Patients

“When we find an unexpected ventral hernia during bariatric surgery, or when we already know the patient has a ventral hernia, we can do nothing and leave the omentum in place; we can close the defect laparoscopically with no mesh according to the size of the defect; we can repair the hernia with a synthetic mesh, close the defect with a biological mesh, or close the defect with a bioabsorbable mesh,” Dr. Omelanczuk said.

The algorithm that he and his colleagues use considers both patient and hernia characteristics (body habitus, hernia size and location, weight, body wall thickness) and the presence or absence of hernia-related symptoms.

“If the patient has favorable anatomy (gynecoid body habitus, centrally located hernia <8 cm, a BMI under 50, body wall thickness <4 cm) and is symptomatic, we can do a laparoscopic ventral hernia repair (LVHR) first and delay the bariatric surgery; if the patient is asymptomatic, we can do the LVHR and bariatric procedure at the same time.”

If the patient has unfavorable anatomy (android body habitus, peripherally located hernia >8 cm, body wall thickness >4 cm) and is symptomatic, they try nonsurgical weight loss before LVHR followed by bariatric surgery, reversing the order of procedures if the patient is asymptomatic.

“We always prefer to do the bariatric surgery first, then repair the hernia,” Dr. Omelanczuk said.

Emanuele Lo Menzo, MD, PhD, the director of the Department of Clinical Research and an associate professor of surgery at Cleveland Clinic Florida, in Weston, also prefers to do hernia repair after patients have lost some weight after bariatric surgery.

“But if the hernia needs to be taken down at the time of the bariatric operation, it should be fixed. Whether primarily or with mesh depends on the size of the hernia and location, and whether synthetic or biologic mesh is used depends on the amount of contamination.”

The type of bariatric procedure being performed may influence mesh decision. Although both Roux-en-Y gastric bypass and sleeve gastrectomy are considered clean–contaminated cases, this may not be entirely true for sleeve gastrectomy.

“There is evidence, including from our group, that certain procedures, such as the sleeve gastrectomy, do not seem to have contamination,” Dr. Lo Menzo said. “We’ve found there is no bacterial contamination in the abdominal cavity, as opposed to a gastric bypass.”