Obesity and Ventral Hernia Repair: Is There Success in Staging?

Introduction

Obesity is implicated in the development of many related comorbid diseases such as diabetes, hypertension, obstructive sleep apnea, and hyperlipidemia. In addition, this patient population is predisposed to particular anatomic pathology, with a higher incidence of defects such as abdominal wall hernias. It has been estimated that the prevalence of ventral hernias in the bariatric population approaches 8%.^1,2 Contributing factors are believed to be increased intraabdominal pressure (due to abdominal wall thickness and visceral adiposity), increased risk of developing incisional hernias (impaired wound healing, poor tissue vascularity, diabetes), and increased risk of recurrence after repair.^3–5 Not only do obese patients have higher rates of abdominal wall hernias, but they have also been found to have larger hernia defects compared with the lower body mass index (BMI) groups. ⁶ The larger size, poor wound healing, and propensity for recurrence increase the complexity of treatment in this population.

These factors pose a challenge for the surgical management of the obese patient with large ventral hernia. Some would argue that the success of the hernia repair increases with weight loss, for which metabolic and bariatric surgery has shown to be the most effective modality. ⁷ The choice for the surgeon, thus, becomes whether to repair the hernia at the time of bariatric surgery, or to plan for a staged repair at a lower BMI. Are we more successful when we wait?

Authors' Recommendations and Literature Review

For our obese patients with large ventral hernias, we prefer to perform a staged procedure, with hernia repair occurring after significant initial weight loss. We feel this approach increases the success of the repair and decreases the risk of wound complications, many of which could be severe in the event an open approach is utilized. We have experienced poor healing of the subcutaneous fat and dehiscence of the midline incision in obese patients after open repair. Such wounds often require months of wound vac therapy and risk spreading infection to the underlying mesh if one was utilized. We believe such complications carry a difficult recovery, one that would be compounded for a patient simultaneously recovering from bariatric surgery. However, many surgeons feel the threat is exaggerated, and a second surgery can be safely avoided by performing everything at one time. The question persists, can a consensus be developed regarding obesity and ventral hernia repair (VHR), or does the variability between patient and hernia size preclude a generalizable statement?

Concurrent VHR and Bariatric Surgery

Surgeons who advocate for simultaneous VHR at the time of bariatric surgery discuss the desire to avoid complications from the untreated hernia, such as bowel obstruction. ⁸ In a retrospective study of 85 patients, Eid et al. found a small bowel obstruction rate of 37.5% in patients undergoing Roux-en-Y gastric bypass (RYGB) with deferred VHR. ⁸ Indeed, we the authors believe that for smaller defects, a free hernia sac that has become unplugged of omentum does warrant consideration of repair at the time of bariatric surgery. Postoperative obstruction by the hernia can easily lead to complicating conditions for the bariatric procedure, such as anastomotic disruption or staple line leak. These complications can be devastating and likely outweigh the possible morbidity incurred by concurrent laparoscopic repair of the small ventral hernia. Another consideration for ventral hernia reduction and repair at the time of RYGB is to facilitate the completion of the procedure. Omental or small bowel contents contained in the hernia are likely to hinder the completion of such a procedure, where exposure and mobilization of small bowel is necessary. ¹

Concurrent VHR and Mesh Placement

For larger defects, some surgeons recommend simultaneous laparoscopic repair with intraperitoneal mesh placement at the time of bariatric surgery. ⁹ The benefits are a stronger and potentially definitive repair in a patient at high risk for recurrence. The caveat of this repair is the possible risk of mesh infection given the violation of hollow viscus during the procedure (clean/contaminated) or in the event there is a subsequent leak complication. Praveen Raj et al. describe no such increase in mesh complications in their series of 150 patients, and additionally, they noted a low <1% rate of recurrence. ⁹ In these patients, bariatric surgery was performed with concurrent intraperitoneal onlay mesh repair and no mesh infections developed. Interestingly, to that effect, a study performed by Cozacov et al. found that peritoneal fluid cultures after sleeve gastrectomy were negative in all 50 patients studied, suggesting a rather sterile environment for mesh placement despite the violation of hollow viscus. Of the 26 RYGB patients they sampled, however, 15% were found to have positive fluid cultures. ¹⁰ Still, several small studies found no issues with infection after synthetic mesh placement in RYGB with VHR patients.^11–13

Concurrent VHR with Laparoscopy

Much of the morbidity of VHR in the obese patient is avoided when performed laparoscopically. Several studies have shown successful concurrent laparoscopic VHR at the time of bariatric surgery without an increase in morbidity or mortality. ¹⁴ Most of these have been smaller studies limited by power. Arguing against concurrent repair, Moolla et al. performed a large analysis of the MBSAQIP registry, finding 4648 propensity-matched pairs of patients (years 2015–2017). The authors found that “30-day major complications were significantly higher in patients receiving VHR at the time of bariatric surgery, concurrent VHR was also associated with a greater incidence of readmission, reoperation, deep surgical site infection, and sepsis.” ¹⁵ In a similar registry study, analysis of the National Surgical Quality Improvement Program (NSQIP) database by Khorgami et al. also found unfavorable results in 1976 patients. Those patients undergoing a primary bariatric procedure and additional VHR had an increased risk of experiencing significant 30-day morbidity after surgery (composite adverse event outcome, 30-day return to the operating room, and 30-day unplanned hospital readmission). ²

Aside from the mixed results with concurrent laparoscopy, we must acknowledge that larger hernias are not always amenable to a laparoscopic repair at the time of bariatric surgery. Large chronic hernias may require meticulous dissection, lysis of adhesions, and separation of components, which not all surgeons would feel comfortable performing in a minimally invasive fashion. In a consensus statement published by the American Society for Metabolic and Bariatric Surgery and American Hernia Society, it is recommended that for “patients with severe obesity and large abdominal wall hernia not amenable to laparoscopic repair, a staged repair should be considered. To that extent, metabolic and bariatric surgery appears to provide a far more significant weight loss than other modalities and is likely to improve outcomes.” ¹⁶ Another expert consensus guideline published in Annals of Surgery even states that a BMI >50 kg/m² should be a contraindication for elective VHR. ¹⁷ Thus, an attempt at weight loss to mitigate this adjustable risk factor is warranted.

Bariatric Surgery with Staged Repair of Ventral Hernia

Conclusion

As the previous literature review shows, consensus on the repair of ventral hernias in the obese patient is subject to much discrepancy due to wide variability in both patient and hernia characteristics. Symptomatic hernias containing bowel at risk for strangulation should likely be fixed in an expedited manor before subsequent weight loss surgery. For smaller hernias discovered at the time of bariatric surgery, those having come unplugged of contents should be repaired laparoscopically during the same surgery to decrease the risk of small bowel obstruction. In the case of large and chronic ventral hernias in the obese patient, an open incision will likely be required. We thus recommend repair in a staged fashion, following significant weight loss after metabolic and bariatric surgery. This approach is likely to decrease the rate of all-cause morbidity, wound complications, and recurrence.