Great Debates: Do BMI Cut-offs for Surgical Candidacy Do More Harm than Good in Patients With Ventral Hernia

Abstract

Obesity is a well-established risk factor for perioperative morbidity and recurrence in patients undergoing ventral hernia repair (VHR). To mitigate poor outcomes, body mass index (BMI) is increasingly used as a preoperative optimization metric, with some surgeons only offering elective VHR to patients of a predetermined BMI threshold (cutoff). While substantial evidence supports improved outcomes for lower BMI patients, the options for VHR are extremely nuanced with multiple techniques, mesh, and even surgical approach (open, laparoscopic, and robotic). Consequently, using BMI as a binary decision-making tool remains controversial. This narrative summarizes the existing literature on BMI thresholds and outcomes following VHR. We examine the relationship between BMI and postoperative complications, recurrence, and quality of life for open and minimally invasive VHR. We also review evidence regarding BMI-based deferral strategies, emergency repair risk, and health disparities and discuss the role of preoperative optimization within a broader risk assessment framework.

Key Takeaways

• Patients with higher BMIs have increased morbidity and recurrence after ventral hernia repair, though no single BMI cutoff reliably predicts poor outcomes or surgical failure.

• BMI thresholds are derived largely from historic open repair data and may not apply to modern techniques.

• Contemporary surgical approaches may mitigate strict obesity-associated risk, calling into question the indiscriminate application of BMI cutoffs and suggesting a more nuanced approach to patient selection.

Introduction

The prevalence of ventral hernias is rising, congruent with the increasing number of abdominal operations performed annually and the global epidemic of obesity.^1–3 As a result, ventral hernias represent a growing burden to both patients and healthcare systems. Approximately 350 000 ventral hernia repairs are performed each year in the United States alone.^2,4 Obesity is a well-established risk factor for ventral hernia formation driven by increased intra-abdominal pressure, impaired wound healing, and associated metabolic comorbidities.^5-9 Obesity is also associated with higher rates of surgical site occurrences, postoperative recurrence, and prolonged recovery, complicating operative decision-making.^10,11 Technical challenges related to tissue quality, defect size, and altered anatomy—particularly in recurrent hernias—are common.^12,13

Body mass index (BMI) has become ubiquitous to preoperative planning in ventral hernia repair (VHR). In many healthcare systems, BMI thresholds, most commonly BMIs above 35 or 40 kg/m², are viewed as contraindications to elective VHR.^6,7,9,13 While BMI offers simplicity and ease of use, it functions as a surrogate marker rather than a direct predictor of hernia-specific risk, and its widespread adoption may obscure important clinical nuances. BMI cutoffs may lead to unintended consequences, including delays in definitive treatment, increased emergency presentations, and the exacerbation of existing health disparities. Patients with high BMI frequently experience more severe hernia-related symptoms such as chronic pain, reduced mobility, and limited daily activities, all of which negatively affect quality of life.^14,15 Beyond physical impairment, ventral hernias may contribute to social anxiety and psychological distress, further compounding their overall impact on patient well-being. This debate reviews the current evidence surrounding the use of BMI thresholds, both their benefits and limitations, in patient selection for VHR.

The Case for Using BMI Thresholds in VHR

Postoperative Complications in High BMI

Patients with a high BMI are at a significantly increased risk for multiple postoperative complications compared to individuals of normal BMI. Obesity is consistently associated with a higher incidence of surgical site infections (SSI). Winfield et al demonstrated that patients with obesity can have an odds ratio of 1.8 to 2.5 for development of SSI and other wound-related complications after abdominal surgery. ¹¹ This is thought to be a result of poor vascularization of excess adipose tissue, impaired oxygen delivery, and metabolic factors associated with obesity, such as diabetes, impairing wound healing. Additionally, venous thromboembolism, including pulmonary embolism, deep vein thrombosis, and mesenteric thrombosis, occurs 2 to 3 times more frequently in patients with obesity secondary to inflammatory changes, venous stasis, sleep apnea, and reduced mobility during the postoperative period. ¹⁶ Obese patients also tend to have longer operative times, greater blood loss intraoperatively, and delayed wound healing or dehiscence, which further increases the risk of complications and prolonged recovery.^10,17 Collectively, these factors contribute to the overall higher morbidity after surgery in higher BMI classes, highlighting the importance of patient-tailored perioperative decision-making and risk-reduction strategies for patients in this population.

Obesity and Ventral Hernia Recurrence Following Repair

Obesity is a well-established risk factor for recurrence following VHR through a combination of mechanical, physiological, and surgical aspects. Excess body weight leads to chronically elevated intra-abdominal pressure which subsequently places continual stress on the reconstructed abdominal wall, thereby increasing the risk of suture or mesh disruption with time.^18,19 Liu et al, and Cook et al, identified specific BMI cutoffs above which the rate of recurrence significantly increases. BMI >33.67-35.3 kg/m² was found to be a critical threshold where recurrence rates rise.^6,19 In the study by Liu et al, 75% of patients with a BMI >35.3 kg/m² had a postoperative course complicated by recurrence, while only 25.8% of those with a BMI <35.3 kg/m² had a recurrence. ⁶ This study also looked at multiple additional risk factors, including hernia incarceration, urgent repair, mesh placement and type, smoking status, and diabetes; however only a BMI >35.3 kg/m² was noted to be a significant factor for hernia recurrence. ⁶ In the study by Cook et al, hernias greater than 4 cm were assessed; 83% were open hernia repairs while 16.9% of the study patients underwent a minimally invasive ventral hernia repair. ¹⁹ The overall recurrence rate was 14.4% with 65.2% of the patients having a BMI >33.67 kg/m², which was found to be statistically significant, along with a history of cirrhosis and urgent or emergent repair. Patients with a BMI >33.67 kg/m² also were noted to have an increased risk of recurrence for up to 6 years following VHR. ²⁰ Sauerland et al, found that in a prospective cohort of 160 patients, those with a BMI of 33 kg/m² and 38 kg/m² had an increased risk of recurrence by 2.6 and 4.2 times, respectively when compared to patients with a BMI of 23 kg/m². ⁵ Additionally, in a retrospective cohort looking at over 35 000 patients, Bhardwaj et al, found that BMI was noted to be one of the 5 most important variables associated with recurrence following VHR using mesh, with a hazard ratio of 1.5 and 2 in patients having a BMI of 44 kg/m² and 55 kg/m², respectively. ²⁰

Pernar et al, found that there was nearly 3 times increased risk of postoperative complications in patients with a BMI >40 kg/m² compared to those with normal BMI. ²¹ Moreover, Owei et al, demonstrated that patients with a BMI >40 kg/m² had twice the risk of postoperative complications, including pneumonia, pulmonary embolism, acute renal failure, and urinary tract infection, with the odd ratio increased with higher BMI classes. ²² Classes II and III obesity have higher rates of seromas, SSI, and wound dehiscence, likely due to poor perfusion of adipose tissue which lowers oxygen tension and impairs oxygen delivery resulting in delayed wound healing. These complications are all significantly associated with hernia recurrence.^20,23 In the study by Holihan et al, it was found that SSI was a significant predictor of hernia recurrence as well as need for reoperation, with an odds ratio of 2.03 and 4.57, respectively. ²⁴ Additionally, obesity can lead to increased size and number of fascial defects, compromise fascial integrity, as well as limit surgical exposure due to increased subcutaneous tissue density and difficult fascial exposure. These surgical factors can complicate mesh placement and reduce the effectiveness of fixation, particularly in larger or complex hernias.^20,25,26 Together, these factors result in higher recurrence rates after VHR in patients with obesity and thus emphasize the importance of preoperative optimization of BMI to improve surgical outcomes.

Hernia Recurrence Rates Increase With Time

Hernia recurrence is often reported using the rate of representation and reoperation; however, this likely underestimates the true burden of disease, particularly in higher-risk populations such as those with obesity. A study by Helgstrand et al demonstrated that reoperation as a surrogate outcome for recurrence following VHR could underestimate the overall risk of hernia recurrence by approximately 4 to 5 times. ²⁷ Another study by Singal et al, has suggested that the majority of hernia recurrences occur within 2 years of VHR—a risk further amplified in patients with higher BMI secondary to increased intra-abdominal pressure and impaired wound healing.^18,19,28 In the study by Bhardwaj et al including over 35 000 patients, the rate of recurrence increased over time, with rates at 5 years postoperatively reaching 44.9% following a mesh-based repair and 73.7% after repairs with no mesh. ²⁰ This suggests that hernia is a chronic disease and optimizing modifiable risk factors, such as elevated BMI, may aid in reducing long-term disease burden.

Technical Challenges of Recurrent Hernia Repair

Over the years, numerous different surgical techniques were developed for VHR; however, an important tenant of hernia repair remains the same across all techniques—a tension free durable repair. ⁴ Importantly, elevated BMI plays a central role in undermining this principle. As discussed above, patients with a higher BMI are more likely to develop hernia recurrence resulting in a cascade effect of poorer outcomes in the future. Using a multicenter database looking at 794 patients, Holihan et al, demonstrated that there is a 37.5% recurrent rate with primary ventral hernia repair, 66.4% recurrence rate with first-time incisional repair, 67.5% with second time incisional hernia repair and as high as 73.3% with third-time or greater repairs over the course of 140 months. ²⁴ This study also determined that patients with a previous ventral hernia repair had increased prevalence of SSI, operative duration, recurrence, and subsequent need for additional procedures despite controlling for open or laparoscopic repair, mesh presence, type and location, skin flaps, myofascial release and comorbidities. ²⁴ Similarly, Bhardwaj et al demonstrated that patients who developed recurrence following VHR were more likely to have undergone prior hernia repair compared to those who did not experience recurrence. These patients also had higher rates of 30-day SSIs, reoperations, and readmissions. ²⁰ This pattern reflects the compounding effects of prior interventions, which are further amplified in patients with higher BMIs, who already face increased risks of wound complications and impaired healing. Collectively, these findings underscore the importance of preoperative optimization, including weight loss, to achieve a durable initial repair and avoid the added morbidity, technical challenges, and poorer outcomes associated with recurrent hernias.

Adhesions, altered anatomy and prior mesh all increase technical difficulty and the risk of seroma, SSI, enterotomy, mesh infection, need for reoperation—complications that not only increase morbidity but also can predispose patients to hernia recurrence and need for reoperation.^12,14 Additionally, each successive repair becomes more complex causing significantly longer operative times, nearly double the need for use of component separation techniques (39.5% vs 19.2%) and other adjunctive abdominal wall reconstruction procedures. ²⁹ This progressive escalation in morbidity and complexity highlights the importance of preventing hernia recurrence by modifying the risk factor of obesity which is strongly associated with both operative complications and recurrence.

Quality of Life in the Setting of Recurrent Ventral Hernias

Patients with elevated BMI and ventral hernia frequently experience more severe symptoms including chronic pain, reduced mobility, and limitations in daily activities, all of which negatively affect quality of life. ¹⁴ BMI not only influences symptom burden but also shapes patient expectations and postoperative outcomes. Patel et al, demonstrated that delaying ventral hernia repair for surgical optimization has led to patient frustration due to a perceived lack of shared decision-making, decreased emotional and social well-being, and overall uncertainty about the future. ¹⁴ However, Ciomperlik et al, found that patients with recurrence were more likely to have both lower baseline and follow-up quality of life compared to those without recurrence. ³⁰ This is particularly important in patients with obesity given their significantly higher rates of recurrence (hazard ratio 1.5 at BMI 44 kg/m² and 2.0 at BMI 55 kg/m²). ²⁰ These data suggest that patients with higher BMI—who often experience the greatest symptom burden and strongest desire for ventral hernia repair—are also those at the highest risk of recurrence and, consequently, potentially worse postoperative quality of life, creating a challenging and self-perpetuating cycle. ²⁰ Langbach et al assessed outcomes of ventral hernia repairs compared to a non-surgical group. Overall, surgical repair reduced chronic pain and physical impairment, leading to improved long-term quality of life. However, hernia recurrence and persistent pain diminished these benefits and were associated with moderate impairment. ³¹ These findings underscore that BMI is a critical driver of both preoperative symptom burden as well as postoperative outcomes, reinforcing the importance of individualized, patient-centered decision-making.

The Case Against Using BMI Thresholds in VHR

BMI Is Simply One of the Factors in a Multifactorial Risk Profile

Several studies emphasize that postoperative outcomes following VHR are influenced by a constellation of patient, hernia, and system-level factors. Novitsky et al demonstrated that hospital characteristics significantly affect outcomes independent of patient BMI. ³² Lindmark et al identified hernia characteristics, operative technique, and comorbid conditions as key predictors of complications, with BMI representing only one component of risk. ³³ Similarly, Giordano et al found that while higher BMI was associated with increased wound morbidity in patients undergoing abdominal wall reconstruction, it did not independently predict failure when controlling for other variables. ²³ A meta-analysis by Parker et al identified a total of 63 possible preoperative, intraoperative, and postoperative factors including BMI that all influenced postoperative complications and hernia recurrence. These findings underscore the limitations of relying on BMI alone to determine surgical candidacy for patients undergoing VHR. ³⁴

BMI and Surgical Risk: Gradients, Not Thresholds

Multiple studies have demonstrated an association between increasing BMI and postoperative morbidity following VHR. However, these studies consistently show risk gradients, not discrete thresholds. Park et al demonstrated higher SSI rates with increasing BMI following elective open VHR, particularly when combined with active smoking. ⁷ Importantly, the risk increased progressively rather than abruptly at any specific BMI cutoff. ⁷ Similar findings were reported by Owei et al, who observed higher wound complications with increasing BMI but identified no single threshold beyond which outcomes deteriorated catastrophically. ²² Pernar et al explicitly examined BMI thresholds for open VHR and found that proposed cutoffs varied depending on patient population and operative context, highlighting the lack of consensus surrounding any universal BMI threshold. ²¹ A recent systematic review and meta-analysis by Hajibandeh et al further reinforced that while obesity increases morbidity across general surgery procedures, the definition of “critical” BMI values remains inconsistent and procedure-dependent. ³⁵ Taken together, these data suggest that BMI functions as a continuous risk modifier rather than a binary determinant of surgical candidacy.

BMI Reflects Historic Open Repair Risk, Not Modern Hernia Surgery

A critical limitation of many studies defining BMI cutoffs is their focus on results in patients undergoing historic open VHR. As surgical technique evolves in both complex open abdominal wall reconstruction and minimally invasive surgery, the applicability of previously derived BMI thresholds becomes increasingly questionable. A recent study conducted at a mature hernia center evaluated their outcomes in patients undergoing open transversus abdominus release (TAR) for VHR. ³⁶ Patients with a BMI >35 kg/m², did have an increased risk of SSI, but had lower 1-year recurrences with similar durable 6-year results and improved quality of life scores compared to those with a BMI <35 kg/m². ³⁶

Overall, maturation of minimally invasive VHR has resulted in lower SSI rates, shorter hospital stays, and reduced morbidity across BMI classes. Large registry and cohort studies showed that MIS patients often have higher median BMIs yet experience lower complication rates than open repair patients.^37,38 Hallway et al recently demonstrated that surgical approach modifies the association between BMI and outcomes, with minimally invasive techniques mitigating obesity-associated surgical risk. ³⁷ In the ROVER meta-analysis, Capoccia et al found equivalent outcomes between robotic VHR and laparoscopic VHR with both techniques having improved SSI rates, mortality, and length of stay compared to open VHR. ³⁸ In regards to complex abdominal wall reconstruction and component separation, a recent study evaluated the impact of threshold BMI (BMI <35 kg/m² vs BMI >35 kg/m²) in outcomes for 128 patients undergoing robotic TAR. Despite the higher BMI >35 kg/m² group having larger and more recurrent hernias, no difference in recurrence was reported at 6 months. ³⁹ Similarly, Kudsi et al compared patients with a BMI >35 kg/m² to those with a BMI <35 kg/m² who underwent robotic VHR using various techniques, including Intraperitoneal Onlay Mesh (IPOM), Transabdominal Preperitoneal (TAPP), and retromuscular (RM) with/without TAR, showing no statistical difference between the 2 propensity-score matched groups in 90-day complications. ⁴⁰ These findings suggest that BMI cutoffs derived from open repair data may not be applicable to laparoscopic or robotic surgery.

Watchful Waiting and BMI-Based Deferral: A Dangerous Tradeoff

One of the most concerning consequences of BMI cutoffs is their contribution to prolonged watchful waiting. While deferral is often framed as “optimization,” evidence suggests that many patients never achieve the required weight loss to meet the BMI cutoff. In a randomized trial evaluating prehabilitation and weight loss prior to VHR, no significant difference was observed in long-term hernia-free or complication-free survival compared with standard counseling, despite increased delays and higher rates of emergency surgery in the prehabilitation group. ⁴¹ Large population-based analyses further demonstrated that patients with obesity are overrepresented among emergent ventral hernia repairs and that emergency surgery is associated with a doubling of complication rates compared with elective repair. ¹⁵ Thus, BMI-based deferral may paradoxically expose patients to higher-risk operations rather than protecting them from surgical morbidity.

BMI Cutoffs and Health Disparities

Rigid BMI cutoffs disproportionately affect women, Black patients, and individuals from socioeconomically distressed communities. Al-Mansour et al demonstrated that failure to meet preoperative optimization targets, including BMI thresholds, was significantly more common among these populations. ¹⁷

In safety-net hospitals, where access to structured weight loss programs and pharmacologic therapy is limited, BMI cutoffs function less as optimization tools and more as barriers to care. James et al showed that the majority of patients deferred for BMI optimization never underwent elective hernia repair, highlighting the real-world consequences of this preoperative management strategy. ¹³

Conclusion

Patients with obesity and ventral hernias represent a complex and heterogeneous population in whom operative decision-making requires multiple, careful considerations. Obesity is undeniably associated with increased risk of wound complications, venous thromboembolism, and hernia recurrence following VHR, all of which contribute to higher morbidity and threaten long-term durability. These risks justify heightened caution, deliberate perioperative optimization, and thoughtful operative planning. However, accumulating evidence suggests that BMI alone is an imprecise surrogate for hernia-specific risk and that rigid BMI cutoffs may oversimplify a multifactorial clinical problem. Additionally, currently utilized BMI thresholds were mostly derived from open repair data and may not reflect outcomes achieved with contemporary minimally invasive surgical techniques, many of which have been shown to mitigate obesity-associated risk. Finally, BMI-based deferral is associated with prolonged watchful waiting, increased emergency presentations, and disproportionate exclusion of vulnerable populations, without consistent evidence of improved long-term outcomes.^41,42

Advances in surgical techniques, particularly in minimally invasive abdominal wall reconstruction, along with improvements in perioperative care, have enabled experienced surgeons to achieve durable outcomes in carefully selected patients with obesity. Rather than serving as absolute contraindications, BMI thresholds should be viewed as one component of a broader risk assessment framework that incorporates hernia characteristics, comorbid disease burden, surgical approach, and patient-centered goals. A nuanced, individualized strategy, emphasizing optimization where feasible without indiscriminate deferral, offers the best opportunity to balance safety, durability, and equitable access to care in ventral hernia repair.