Obesity is a significant risk factor for the development of a large hiatus hernia. [
1] In morbidly obese individuals, 37% will have a hiatus hernia of any size and 4.4% have a moderate to large-sized hernia. [
2] As the prevalence of obesity has more than doubled worldwide since 1990, the presentation of a large hiatus hernia in obese individuals is becoming more common. [
3] In Australia, it is estimated that nearly one in three adults are obese, meaning surgeons are increasingly facing the challenge of operating on larger patients. [
4] However, surgeons may be reluctant to offer antireflux surgery to obese patients for several reasons. These concerns include access challenges, increased perioperative morbidity and mortality risks, concern about an increased risk of hiatus hernia recurrence and ongoing reflux symptoms, and the potential need to add a bariatric procedure at the time of hiatus hernia repair or at a later date. [
5‐
11]
Surgery for large hiatus hernia is more complex than for reflux in patients with a small hernia. It requires greater thoracic dissection to reduce the hernia contents back into the abdomen, and the greater the percentage of intrathoracic stomach, the higher the risk of postoperative morbidity and ongoing reflux. [
19,
20] Currently, there is minimal data available to inform the outcomes for large hiatus hernia repair in obese and morbidly obese patients. Furthermore, the literature is confused by the lack of a universally accepted definition for a “large” hiatus hernia. Definitions include hernia containing more than 30% or 50% of the stomach, hernias measuring more than ≥ 7 cm in length, crural defects ≥ 5 cm in diameter, and crural defects surface area of ≥ 10 cm.
2. [
21‐
27]
In this study, we assessed a large cohort of patients who underwent elective repair of large hiatus hernias defined as containing at least 50% of the stomach to determine and compare safety and early clinical outcomes in non-obese, obese, and morbidly obese patient groups. We hypothesised that large hiatus hernia repair in obese and morbidly obese patients would be associated with a higher rate of perioperative morbidity and early hernia and symptom recurrence compared to non-obese patients.
Materials and methods
Data source and participants characteristics
A retrospective analysis was conducted of data from a prospective database which contained perioperative and outcome data for patients who underwent surgery for a large hiatus hernia between January 2000 and December 2023 at Flinders Medical Centre, Royal Adelaide Hospital and associated private hospitals in Adelaide, South Australia. Patients were included in this study if they had an elective operation for a large hiatus hernia identified by preoperative endoscopy, oral contrast X-ray study or CT, and subsequently confirmed at the time of surgery. Large hiatus hernia was defined as a hernia containing at least 50% of the stomach. This definition was chosen as it has been used elsewhere, it is conservative and does not include any patients with hernias that would be considered less than large in any classification system, and size can be confirmed on cross-sectional imaging and at laparoscopy. [
19] Only patients for whom their BMI at surgery was known were included. Patients were excluded if BMI data were not available, they were underweight (BMI < 18.5 kg/m
2), underwent emergency or revisional surgery, or had concomitant bariatric surgery in addition to the hiatus hernia repair. Patients who had surgery before January 2000 were also excluded to ensure any learning curve bias for laparoscopic repair was avoided as by then all consultant surgeons had then performed at least 40 previous operations. [
28] All operations were either performed or assisted by a consultant upper gastrointestinal surgeon.
Patients underwent preoperative endoscopy to assess for esophagitis, Barrett’s oesophagus, Cameron’s ulcers, and hernia size and to exclude underlying malignancy. Contrast swallow radiology (CT or X-ray) was usually performed to assess hernia size and type. Esophageal manometry and 24-h pH studies were performed at the surgeon’s discretion when patients were being considered for surgery for reflux. When undergoing surgery for mechanical problems, but not reflux, an anterior partial fundoplication was routinely performed and these tests were usually not required. Prior to surgery, patients also underwent routine blood tests within 2 weeks prior to surgery and any clinically significant anaemia was corrected with iron infusion.
Surgical procedure
A standardised surgical approach was performed across all sites and has been described previously. [
29] The steps included complete hiatal sac dissection, reduction of the entire sac, stomach, and lower 2–3 cm of distal oesophagus back into the abdominal cavity, tension-free sutured repair of the widened esophageal hiatus with posterior and supplemental anterior stitches as required, and a fundoplication to anchor the stomach below the diaphragm and control reflux. The type of fundoplication was tailored to the clinical presentation. A Nissen or anterior 180 degree partial fundoplication was constructed when reflux control was a significant component of the presentation, whereas an anterior 90
0 partial wrap was often used as a gastropexy to minimise the risk of post-fundoplication side effects when patients presented with mechanical issues from the large hiatus hernia, but not reflux. Hiatal mesh reinforcement was rarely performed. The majority of cases where mesh reinforcement was performed were part of a randomised controlled trial comparing sutured versus absorbable versus non-absorbable mesh repair or in the lead in phase to that trial. [
30] Beyond the trial, mesh was seldom used.
A contrast swallow was routinely performed on the day after surgery to ensure repair integrity and, if there were any radiological concerns, early laparoscopic re-exploration was undertaken. Later investigations were only performed in symptomatic patients. An early hernia recurrence was defined as occurring during the patient’s admission for the initial operation, and usually identified in the context of a routine day one postoperative contrast swallow X-ray study. A late hernia recurrence and reoperation was defined as occurring after discharge, but within 24 months following the original surgery. Hernia recurrences were classified as small (≤ 2 cm), medium (> 2 cm but < 5 cm), or large (≥5 cm) based on contrast swallow X-rays or endoscopy assessment.
Perioperative outcomes
Patients were categorised into 3 groups based on BMI: non-obese (BMI < 30 kg/m2), obese (BMI 30–34.9 kg/m2), and morbidly obese (BMI ≥ 35 kg/m2). Perioperative outcomes that were measured include length of stay, all complication, major complication (defined as Clavien–Dindo ≥ 3a), early reoperation, and 30-day and 90-day mortality rates. Late symptomatic hernia recurrence and reoperations were also determined.
Patient follow-up and symptom outcomes
Patients prospectively completed a structured questionnaire preoperatively, at 3, 6, and 12 months postoperatively and annually thereafter. The questionnaire included a yes/no section regarding the presence or absence of various symptoms: Heartburn, regurgitation, dysphagia, nausea and vomiting, shortness of breath, and nocturnal cough. Heartburn, regurgitation, dysphagia severity scores, and overall satisfaction scores were also determined (measured on a visual analogue scales 0–10). A yes/no question was also asked to determine if patients believed their original decision to undergo surgery was correct. We compared preoperative and 12-month postoperative time points. To maximise follow-up, if 12-month data were not available, but 2-year data were available, then this was substituted. If 2-year data were also missing, then 6-month followed by 3-month data were substituted in that order.
Statistical analysis
Categorical data were analysed using Fisher’s exact or Pearson’s chi-square test. Continuous variables were compared using ANOVA or independent sample t tests. Multivariable-adjusted models were then performed to adjust for potential confounders of age and sex to determine the association of outcomes with BMI. Generalised linear models with gamma distribution were employed to determine differences for length of stay; logistic regression models were applied to determine the risk for complications, mortality, hernia recurrence, and reoperation rates. Any missing data points were not included in the analysis.
A p value < 0.05 was considered significant for all baseline variables and multivariable regression analyses. Statistical analysis was performed using IBMs Statistical Package for the Social Sciences (SPSS; version 19 for Apple Macintosh).
This study has been reported in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines to ensure transparency and completeness in the reporting of observational research. Ethics approval was provided by the Southern Adelaide Clinical Research Ethics Committee (approval numbers: 145.23, 110.16, 12.14, 10.056).
Discussion
Contrary to our hypothesis, our study demonstrated that large hiatus hernia repair in obese and morbidly obese patients is a safe and effective treatment option, with comparable outcomes to non-obese patients. We found no differences in operative time, laparoscopic conversion to open rates, or length of stay. All adverse events (intraoperative and postoperative complications, early return to theatre, and mortality rates) were acceptably low and similar across all groups. Despite some literature suggesting that a symptomatic recurrent hiatus hernia is significantly greater in obese patients, we found no such differences. [
9] Furthermore, all groups experienced a significant improvement in heartburn, regurgitation, and dysphagia severity, as well as high overall satisfaction scores.
We found that obese and morbidly obese patients were more likely to be younger and female. Han et al., also reported both these findings in their study. [
31] This is likely due to selection bias, as surgeons are less inclined to operate on patients who are both elderly and obese. The discrepancy in gender is an interesting finding and possibly relates to different fat distribution patterns. Obese males are more likely to have increased visceral fat. [
32‐
34] Increased visceral adiposity has been shown to increase operating time, blood loss, and perioperative morbidity during laparoscopic surgery. [
35,
36] Furthermore, excessive visceral fat is strongly associated with significant comorbidities including insulin resistance and coronary artery disease. [
37,
38] As such, surgeons may be less inclined to operate on obese males than females due to both technical- and health-related concerns, although the surgeons contributing to this study did not consciously avoid operating on men.
Our study found that whilst heartburn was the most common reason for surgery, there were no significant differences between obese and non-obese patients. Interestingly, anaemia was a frequent preoperative finding, and this was highest in the morbidly obese group (41.7%). Carrott et al. also found that preoperative anaemia is a common finding in patients with a large hiatus hernia (45.6%) that resolved in 71% of patients following surgical repair. [
39] There is also a strong association between obesity and anaemia, which likely reflects the higher rate seen in this demographic. [
40] Despite similar rates of heartburn, obese patients were less likely to demonstrate macroscopic esophagitis. Kim et al. suggest that central obesity is also associated with non-erosive esophagitis. [
41]
Prior to our study, Han et al. published the largest study to assess the impact of BMI on large hiatal hernia repair. Of the 884 patients included, 725 (86.3%) had an intrathoracic stomach of 50% or more and 45 patients (5.1%) underwent an emergency procedure. They demonstrated similar findings that increasing BMI was not associated with increased perioperative blood loss, length of stay, major complications, 90-day mortality, or early recurrence. However, their study had several limitations. The cohort was split across six categories based on BMI (underweight, normal weight, pre-obesity, and obesity class 1, 2, and 3) for comparison. Obesity class II had 76 (8.6%) patients and class III had just 27 (3.1%) patients. These groups may be underpowered to detect any significant differences. Furthermore only 24.8% of patients included in their study underwent a standard minimally invasive approach, and this reduced to 7.8% for the obesity class 3 group. Finally, symptom outcomes were not measured to determine treatment success. [
31]
Our study expands on previous work by reporting a larger cohort of patients. We used stricter criteria by only including patients with a large hiatus hernia (≥50% intrathoracic stomach). We also excluded patients that underwent emergency surgery or were underweight (BMI ≤ 18.5 kg/m.
2) as they have been shown to independently increase perioperative morbidity and mortality. [
42]
However, our study does have several limitations. It is retrospective analysis of a prospectively collected audit and outcome data, and it is non-randomised. Baseline demographics were not homogeneous as obese and morbidly obese patients were more likely to be younger, female, and have diabetes. This is significant as being older and male sex can be associated with poorer surgical outcomes. [
42] As such, a multivariable regression analysis was performed to minimise the effect of these confounders. There were missing datapoints for some patients. However, this is somewhat mitigated by the large sample size. Also, follow-up investigations were limited to symptomatic patients and were performed at surgeon discretion. Thus, asymptomatic recurrences are not all identified, and the true number of recurrent hiatus hernias is likely not captured. However, the clinically important symptomatic hernias and those requiring further surgery were all identified.
The role of bariatric surgery with large hiatus hernia repair is controversial. Traditionally, sleeve gastrectomy has been avoided due to concerns it would worsen gastroesophageal reflux. A systematic review of simultaneous sleeve gastrectomy with hiatus hernia review in obese patients found that it was safe and generally effective, but prevalence of post-operative gastroesophageal reflux was 29.7%. [
43] The majority of the 18 included studies were small volume case series that were retrospective in nature. Hiatus hernia size is also either small to moderate in size or not mentioned at all. Roux-en-Y gastric bypass is considered the gold standard for morbidly obese patients with significant reflux symptoms. [
44] However, its role in managing a large hiatus hernia is largely unknown. Kollman et al. identified 12 patients over a 10-year period who underwent simultaneous large hiatal hernia (> 5 cm) repair with Roux-en-Y gastric bypass. They found that whilst operating time was longer compared to Roux-en-Y gastric bypass alone, major complications, reoperations, and length of stay did not differ. [
45] Other studies have demonstrated similar safety outcomes. [
46,
47] DuCoin et al. compared large hiatus hernia repair with and without gastric bypass. Of the 16 / 40 patients that underwent antireflux gastric bypass, they found no statistical differences in reflux resolution or hiatus hernia recurrence. [
11] However, surgeons may be apprehensive to combine large hiatus repair with gastric bypass for several reasons. These include longer operative time, increased surgical risks (e.g. stomal ulcers, anastomotic leak, and internal hernia), and a risk of intrathoracic pouch migration which may worsen reflux symptoms in the longer term. [
48]
Surgeons may still recommend short-term preoperative weight loss prior to large hiatus hernia repair to overcome some of the technical challenges encountered by operating on obese patients. As central adiposity increases, port access, positioning, and excessive torque may occur. [
49,
50] Furthermore, increased intra-abdominal fat and an enlarged steatotic left liver lobe can obscure the hiatus. [
51]
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