Obesity-focused prehabilitation strategies in ventral hernia: Cohort study

This was a retrospective cohort study conducted at the Abdominal Wall Surgery Unit of Vall d'Hebron University Hospital, accredited by the Spanish Association of Surgeons [15]. The study adhered to the principles outlined in the Declaration of Helsinki and followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) [16] and Reporting of Studies Conducted Using Observational Routinely Collected Health Data (RECORD) [17] guidelines. Data from patients who visited for ventral hernia with obesity between April 2018 and April 2023 were retrospectively gathered from a prospectively maintained database. This retrospective study was based on anonymized data collected during routine clinical practice and, in accordance with local regulations, did not require approval by a research ethics committee.

The inclusion criteria were as follows: 1) aged ≥ 18 years and 2) patients who visited the specialized abdominal wall surgery unit for ventral hernia with a BMI ≥ 30 kg/m². The exclusion criteria were as follows: 1) patients who visited other nonspecialized abdominal wall surgery units of the hospital for ventral hernia; 2) patients with a BMI ≥ 30 kg/m² and had other hernias, such as inguinal femoral hernias; 3) patients with severe comorbidities, such as metastatic cancer or advanced cirrhosis, which are expected to limit survival to less than two years; and 4) pregnant patients.

In our unit, preoperative risk factors are routinely evaluated during the initial consultation, and a special emphasis is placed on obesity as a modifiable factor to improve surgical outcomes. Patients without significant risk factors, such as obesity, were considered suitable for elective surgery. Patients with a BMI ≥ 30 kg/m² were enrolled in a weight loss program to optimize their condition prior to surgery. Surgery was postponed until adequate weight loss was achieved.

The management of patients with ventral hernia and obesity followed a structured institutional optimization pathway based on BMI thresholds and clinical criteria, in accordance with current evidence-based guidelines [12, 18]. This protocol standardized the use of dietary counseling, pharmacotherapy, or bariatric surgery as weight-loss interventions, and included regular follow-up visits every three months to monitor weight, BMI, symptoms, and adherence. For patients with a BMI between 30 and 35 kg/m², dietary counseling was provided, with an emphasis on changing eating habits and engaging in regular physical activity. Additionally, the risks of obesity, both in general terms and specifically in relation to ventral hernia surgery, were thoroughly explained, and weight loss goals were established. These patients were also advised to visit their primary care physician for the optimization and management of any comorbid conditions, such as hypertension or diabetes. The objective was to achieve a BMI as close as possible to 30 kg/m², with sustained weight loss before proceeding with elective hernia repair [18]. However, eligibility was assessed on an individualized basis, considering patient characteristics, hernia complexity, and symptom severity. Patients with a BMI ≥ 35 kg/m² were referred to a comprehensive obesity treatment unit within the hospital. There, a multidisciplinary team composed of endocrinologists, nutritionists, psychologists, and metabolic surgeons assessed the patients to determine the most appropriate intervention, which could include dietary modifications, pharmacotherapy, or bariatric surgery, depending on the patient’s age, comorbidities, and personal preferences. For patients with BMI ≥ 40 kg/m² or BMI ≥ 35 kg/m² with significant obesity-related comorbidities, bariatric surgery was generally recommended, provided they met the necessary clinical and psychological criteria. Contraindications included severe cardiovascular disease, uncontrolled psychiatric disorders, active substance abuse, and the inability to adhere to postoperative dietary and lifestyle modifications. Patients deemed unsuitable for surgery were managed with dietary counseling and/or pharmacotherapy as alternative weight-loss strategies. These patients were required to achieve substantial and sustained weight loss before elective hernia repair was considered. For all patients, surgery was generally postponed until meaningful weight reduction was achieved, but exceptions were made for those with recurrent bowel obstruction, where delaying repair posed a higher risk. All patients were followed every three months, during which weight, BMI, and hernia symptoms were monitored. Emergency visits due to incarceration were also recorded, and the importance of adhering to the weight loss goals was reinforced.

For descriptive analysis, patients were grouped according to the recommended intervention within the structured pathway: (1) dietary and behavioral counseling, (2) pharmacological treatment for obesity, or (3) bariatric surgery. Each patient was assigned to a single group based on the initial weight-loss strategy recommended by the clinical team, following institutional protocols and considering patient preferences. Grouping was mutually exclusive for analysis purposes, and patients were not reassigned between strategies during follow-up. As this process involved shared decision-making, baseline characteristics such as age, BMI, and comorbidity burden differed across groups. In each group, the percentage of weight loss and percentage of BMI reduction, adherence to the weight loss protocol, incidence of urgent ventral hernia surgery, and rate of elective hernia surgery were documented. Surgical outcomes were also reported for patients who underwent hernia repair, including a descriptive comparison with non-obese patients treated during the same period.

Patient demographic and clinical variables were collected at the initial presentation. These included age, sex, and BMI at both the initial consultation and the final follow-up. The American Society of Anesthesiologists (ASA) classification was recorded, along with the presence of comorbidities. The comorbidities documented included cardiovascular disease, chronic obstructive pulmonary disease (COPD), diabetes, anticoagulant therapy, nephropathy, and active smoking. For patients who underwent ventral hernia surgery, additional data were gathered, including the patient’s age and BMI at surgery.

Hernia-related data included symptoms, defect size, complexity, and recurrence status. Hernia complexity was defined according to established criteria, including defect > 10 cm, loss of domain ≥ 20%, recurrent hernia, multiple defects, history of surgical site infections, need for component separation, wound class III–IV, skin grafts, and prior intraperitoneal mesh removal [19]. The type of hernia was classified into specific subtypes: umbilical, midline, trocar site, parastomal, combined, lateral, and suprapubic hernias. The recurrence of the hernia was also noted.

The operative records of patients who underwent ventral hernia repair were reviewed. Patients were classified into one of two groups on the basis of their adherence to preoperative weight loss recommendations: 1) patients who met the preoperative weight loss target and 2) patients who did not meet the preoperative weight loss goal but underwent surgery due to symptom severity. These two groups were compared to a control cohort of nonobese patients who underwent ventral hernia repair in our unit during the same period.

Patients were treated with an open, laparoscopic, or robotic approach. The choice of approach was at the discretion of the surgeon on the basis of his or her preference and patient characteristics. In general, techniques involving preperitoneal/retromuscular mesh placement are the preferred approach in our unit, in accordance with clinical guidelines for the treatment of ventral hernias [18, 20]. The decision regarding mesh placement (retromuscular, onlay, inlay or intraperitoneal) was based on patient-specific factors, including hernia size, location, previous surgical history, and surgeon preference, following clinical guidelines.

Additional operative variables included operative time, defined as the time from incision to the placement of the dressing, and whether component separation techniques were employed for hernia repair. Component separation was performed in cases where primary fascial closure was not feasible without excessive tension, particularly in patients with large defects, loss of domain, or recurrent hernias [20].

Postoperative variables included complications (within 90 days postoperatively), length of hospital stay (in days), and hernia recurrence. Postoperative complications included hematoma, seroma, wound infection, and surgical site ocurrences (SSO) [21]. The complications were classified according to the Clavien-Dindo grading system [22].

Hernia recurrence was assessed using a combination of clinical follow-up and patient-reported outcomes. Medical records were reviewed for any intervention due to hernia recurrence, either through surgical reintervention or diagnosis during physical examinations. Additionally, the Ventral Hernia Recurrence Inventory (VHRI) [23], a validated questionnaire specifically designed for ventral hernia patients [24], was used during telephone follow-ups to screen for recurrence. Any patient with a positive response on the VHRI was advised to schedule an in-person visit for physical examination. For patients who were lost to telephone follow-up, their last recorded in-person postoperative visit was used as the final follow-up date.

A total of 175 obese patients with ventral hernias were included in the study, of whom 148 (84.6%) underwent dietary counseling, 15 (8.6%) received pharmacotherapy, and 12 (6.8%) underwent bariatric surgery. The groups differed significantly in age distribution (P < 0.001): bariatric surgery patients were the youngest (mean 46 years, SD: 7.9), followed by the pharmacotherapy group (mean 57.5 years, SD: 10.7), while dietary counseling patients were the oldest (mean 61 years, SD: 12.6). No significant differences were observed in sex distribution (P = 0.592), comorbidities (P = 0.876), or hernia complexity (P = 0.364) (Table 1).

Significant differences were found in initial weight and BMI between the groups (P < 0.001). Bariatric surgery patients had the highest initial weight (116.9 kg) and BMI (42.8 kg/m²), followed by the pharmacotherapy group (99.1 kg, 37.9 kg/m²) and the dietary counseling group (95.0 kg, 35.5 kg/m²).

Bariatric surgery resulted in the greatest weight reduction, with a mean loss of 20.7% (SD: 15.5), compared with 4.6% (SD: 6.0) in the dietary counseling group and 4.4% (SD: 3.5) in the pharmacotherapy group (P < 0.001). BMI reduction followed a similar trend. Specifically, the BMI of the bariatric surgery group decreased from 42.8 kg/m² to 33.9 kg/m² (21.7% reduction). The BMI of the dietary counseling group decreased from 35.5 kg/m² to 33.9 kg/m² (5% reduction), and that of the pharmacotherapy group decreased from 37.9 kg/m² to 36.9 kg/m² (5.1% reduction) (Table 1).

The proportion of patients proceeding to elective hernia repair was significantly higher in the bariatric surgery group (83%) than in the dietary counseling (44%) and pharmacotherapy groups (13%) (P = 0.001). The dietary counseling group had the highest dropout rate (21%), followed by the pharmacotherapy group (13%), while no patients dropped out in the bariatric surgery group (P = 0.173). During the preoperative period, seven adverse events (4%) were recorded, all within the dietary counseling group. These included five emergency surgeries due to acute hernia incarceration and two cases of skin complications requiring specific treatment and follow-up (Table 1).

A total of 165 patients underwent ventral hernia repair, including 92 nonobese patients, 52 with preoperative weight loss, and 21 without weight loss. There were no significant differences in age (mean 61.7 ± 13.5 years, P = 0.566) or sex distribution across the groups. However, BMI remained significantly higher in the no-weight-loss group (34.5 ± 5.5 kg/m²) compared with the weight-loss group (29.8 ± 2.6 kg/m²) and nonobese patients (26.4 ± 2.4 kg/m²) (P < 0.001) (Table 2).

The weight-loss group had a higher prevalence of recurrent hernias (23%) and larger mean defect widths (6.1 ± 4.1 cm) compared with nonobese patients (11%, 5.4 ± 3.9 cm) and the no-weight-loss group (10%, 3.9 ± 2.2 cm). Although most patients had at least one comorbidity (86%), multiple comorbidities were slightly more common in the weight-loss group (42%) than in nonobese patients (38%) and those without weight loss (24%), though these differences were not statistically significant (Table 2).

Postoperative complications were significantly higher in the weight-loss (37%, IC 95%: 23.5%–49.6%) and no-weight-loss (33%, IC 95%: 13.2%–53.5%) groups compared to nonobese patients (16%, IC 95%: 8.8%–23.9%) (P = 0.016). The most common complication was SSO, affecting 33% of patients in both the weight-loss and no-weight-loss groups, compared with 10% in nonobese patients (P = 0.001). Hematomas were more frequent in the weight-loss (12%) and no-weight-loss (14%) groups (P = 0.031), while surgical wound infections occurred exclusively in the weight-loss group (8%) (P = 0.012) (Table 2).