Management of Ventral Hernia in Obese Patients: Before or After Bariatric Surgery?

Abstract

Obesity is a known risk factor for ventral hernias and their recurrences. The timing of ventral hernia repair in obese patients who are candidates for bariatric surgery is still a debatable topic. To this date, there is no consensus, neither for the timing nor for the surgical repair technic. In this chapter, we will review briefly what was already discussed about this dilemma and explore our experience with our retrospective study. If asymptomatic, the ventral hernia should be repaired after bariatric surgery when there is stabilization of the weight loss. Laparoscopic approach is recommended to allow an exploration of the trocars sites and a second look after obesity surgery. An algorithm for ventral hernia management in obese patients is proposed.

1. Introduction

Obesity is a risk factor increasing the occurrence of primary and secondary ventral hernia; as well as the risk of complications when operating hernia, especially the risk of recurrence. On the other hand, when ventral hernia becomes symptomatic in obese patients with incarceration or strangulation, there is an increased risk of major complications or delayed diagnosis because obese patients can have little or no major clinical symptoms. Concerning bariatric surgery, hernia of the abdominal wall can make the operation more complicated while increasing also the operative time.

In order to manage ventral hernia in the bariatric population while having the lowest risk, it is mandatory to choose the best time to operate a hernia during the management of the obesity of this group. After studying 47 ventral hernias diagnosed during the preparation of 643 patients for their bariatric surgery and after a review of the literature that is relatively poor concerning this subject, we concluded that many factors are to consider during the management of ventral hernia in bariatric population; but, in general, if asymptomatic, ventral hernia should be repaired after bariatric surgery when here is the stabilization of the weight loss; and laparoscopic approach is recommended to allow an exploration of the trocars sites and a second look after obesity surgery.

2. Ventral hernia repair in obese patients

There are many techniques for ventral hernia repair and many approaches. Whether to combine it or not with bariatric surgery, the repair is most of the time inevitable. Since obesity is a risk factor for an increased incidence and recurrences of ventral hernia, the timing of repair is essential to balance out between a late repair with an increased risk of hernia-related complication, an early repair with its increased risk of recurrence, and a concomitant repair with higher morbidity.

2.1 Definition of obesity

To be able to discuss bariatric surgery we need to start by defining obesity. Even though this is a common pathology, the medical expert failed to define obesity properly in the 10th edition of the International Classification of Diseases relating it to its definition of “excess of calories” which was considered as a demeaning description. However, they managed to change that in the 11th edition and defined this chronic pathology as [1]:

“Abnormal or excessive fat store secondary to different causes including energy imbalance, drugs, and genetic disorders.”

According to the WHO, 4 million deaths per year resulted in 2017 from being obese or overweight. Its prevalence has increased globally, especially for children and adolescents. In 2016, more than 650,000,000 adults over 18 years old were obese (WHO). Globally, this preventable and treatable disease kills more than malnutrition. Moreover, this disease is no longer a high-income region problem with rates increasing even in the urban areas of low- and middle-income countries therefore it is now considered a global epidemic.

BMI or body mass index approximates the total body fat and it is equivalent to the weight divided by the square of the height in meters [2, 3].

This index is easy to calculate and consistent. It can correlate to the total fatness in the body but is not an accurate measure of body fat. For instance, muscular patients who are overweight will have a lower degree of adiposity compared to the same patients in the same category. Older adults will have a lower percentage of muscles and a higher percentage of fat in the same BMI category [3].

This Index is used to group patients into mainly 4 categories: Underweight (<18.5 kg/m²), normal range (18.5 to 24.9 kg/m²), overweight (25 to 29.9 kg/m²), and obese (≥30 kg/m²).

2.2 Abdominal wall hernia: definition, incidence, risk factor, classifications, and prognosis

2.2.1 Definition and incidence

An abnormal protrusion of abdominal contents through a weakness in the anterior abdominal wall is referred to as a ventral hernia. Abdominal wall hernias are quite prevalent, with a prevalence of 1.7% for people of all ages and 4% for people over the age of 45. It is estimated that more than 20 million hernias are treated annually throughout the world. About 75% of abdominal wall hernias are inguinal hernias, which have a lifetime risk of 27% in men and 3% in women. Inguinal hernias are the most prevalent type of ventral hernias. Umbilical, paraumbilical, epigastric, incisional, and rarer hernias including Spigelian and traumatic hernias are further forms of ventral hernias. In the postoperative setting, patients have approximately 10% risk of developing hernia following a midline laparotomy, 5% following a transverse muscle splitting incision, and less than 1% following laparoscopic repair.

2.2.2 Classification and risk factors

Ventral hernias can be mainly classified as primary or secondary: umbilical, epigastric, and hypogastric hernias are classified as primary while secondary ventral hernias occur following surgery, and are referred to as incisional hernias.

Inguinal and femoral groin hernias are not included in the classification of anterior abdominal wall hernias as primary or incisional hernias used by the European Hernia Society. The midline umbilical and epigastric hernias, as well as lateral spigelian hernias, are subclasses of primary hernias (or “ventral” hernias). Parastomal hernias are a specific type of ventral hernia with a variety of treatment options, despite the fact that they are incisional by definition. Before this consensus definition, the literature on abdominal wall hernias had been hindered by inconsistent nomenclature, and despite distinct etiology, epidemiology, and surgical outcomes, incisional and primary ventral hernias continue to be combined in studies [4]. Congenital or acquired causes of ventral hernias can be distinguished with acquired hernias being more frequent, and frequently brought on by previous surgery, trauma, or repetitive stress on vulnerable areas of the abdominal wall.

A big contributing cause of acquired ventral hernias is obesity, which weakens the abdomen’s fascia by stretching it.

In a study published in 2021 and entitled “Abdominal Wall Hernias: An Epidemiological Profile and Surgical Experience from a Rural Medical College in Central India,” predisposing factors in a majority of the patients were:

• Chronic cough (55%)

• Prostatic problems (23%)

• Chronic constipation (20%)

• Previous surgeries (10%)

• Obesity (1.2%)

• Ascites (1.1%)

• Multiparity (6.1%)

• Transabdominal gynecological surgeries (4.0%)

• Excessive crying (25% of the pediatric population)

• Chronic respiratory infections (23% of the pediatric population) [5]

2.2.3 Prognosis

The type, size, and potential for reducing risk factors that contribute to the development of a hernia are only a few of the variables that affect the prognosis of a certain hernia. The prognosis is usually favorable with prompt diagnosis and treatment. However, if the hernia is not identified or if problems develop while treating the condition, morbidity may result.

An incarcerated, obstructed, or even strangulated intestine with a poor blood supply is a potential hernia consequence. Missing this could lead to peritonitis and bowel perforation, both of which are potentially fatal. Therefore, surgical intervention is necessary to stop additional complications such as sepsis and perforation.

It is crucial to remember that surgery to repair a hernia can put the patient at risk for adhesions or infection. Hernias can also recur in the same place even after surgical correction [6].

Medical illiteracy, financial constraints, and societal inhibitions might cause delayed presentations and higher postoperative morbidity and mortality in rural parts of developing nations. To guarantee that early diagnosis and the finest procedures are available to various social strata, efforts must be made to conduct area-wise surveys, educate the populace, and reduce costs [7].

2.3 Indications for bariatric surgery

Bariatric surgery includes several procedures to target weight loss. They may target intestinal absorption or restrict the meal volume or do both. Before proceeding with any bariatric procedure, a multidisciplinary team will evaluate the patient’s nutritional status, psychological state, and lifestyle. Like any surgical procedure, it comes with multiple post-operative morbidities and mortality risk.

Bariatric surgery is indicated when [3]:

• BMI > 40

• 35 < BMI < 39.9 with an obesity-related comorbidity (Table 1: HTA DM GI reflux osteoarthritis.)

• BMI > 30 with an uncontrollable DM II or dysmetabolic syndrome X.

More than 300,000 procedures were performed in 2011 [3]. In the USA, 2000000 patients had a bariatric procedure between 1993 and 2016. Within that period, the evolution of bariatric surgery started, and there was a switch from open procedures to laparoscopic procedures. Due to technological advances and the escalation of the surgical experience, the postoperative morbidity and mortality rates decreased by around 10% from 1998 to 2016 (11.7–0.04). It is debatable whether these procedures should be offered before the start of the subordinate health impairments or limited to those who already suffer from comorbidities. However, all agree that these procedures should not be considered cosmetic interventions [8].

2.4 Review of different approaches to bariatric surgery

Currently, we have four common bariatric procedures that work on reducing the gastric space and or limiting the intestinal length:

• Gastric banding reduces food intake. It consists of banding the upper part of the stomach and connecting it to a subcutaneous port. Filling this port with saline will control the stricture of this band. This reversible and minimal invasive technique had its side effects like vomiting and solid food intolerance.

• Sleeve gastrectomy [3, 8] popularity has increased because of its feasibility and satisfying results. It consists of removing the lateral part of the stomach and fundus keeping just a small portion of the lesser curve and the antrum. It reduces the stomach’s capacity by almost 90% and preserves the pylorus and the totality of the intestines. It is simple to perform laparoscopically and eliminates the risk of many postoperative complications. Since the intestines are intact the risk of internal herniations is totally absent.

• Gastric bypass is a popular alternative developed 40 years ago that maintained its popularity since Wittgrove managed to perform this procedure laparoscopically [3, 8]. In the long run, this procedure can generate life-threatening complications such as ulcers or internal hernias and many nutritional deficiencies. The Roux en Y gastric bypass consists of creating a small gastric pouch by resecting the stomach horizontally than vertically. Then two anastomoses are made a gastro jejunal and a jejuno-jejunal anastomosis to create two limbs a biliary and an alimentary limb. The omega loop bypass or mini bypass consists of creating a mini gastric pouch and then a gastrojejunal anastomosis at the 200 cm mark from the Treitz angle.

• The duodenal switch was created by Hess [8] and it combines a gastric sleeve with a small bowel bypass. The sleeve gastrectomy is performed then the duodenum is transected away from the pylorus. The small bowel at 2.5 to 3 m from the ileocecal valve is transected then a 1.5 m alimentary limb is generated anastomosed to the gastric end of the duodenum. The distal part of the duodenum drains with the biliopancreatic secrection into the alimentary limb at 1.5 to 1 m from the ileocecal valve. Up to 70% of the small bowels are isolated in this procedure from the foodstream [8]. This results in a more significant reduction of fat absorption compared to other techniques, which leads to a more durable weight loss. By preserving the pylorus, this technique allows patients to eat with a lower risk of dumping [8]. Fat-soluble vitamins are required postoperatively. Since this technique is difficult to perform laparoscopically, its use is limited.

Other bariatric techniques include:

Gastric plication is a technique that resembles the gastric sleeve however without any resection. It reduces gastric volume with easier reversibility however this technique is more difficult, and it remains under investigation [8].

All these techniques should be performed, unless major contraindications, by laparoscopic approach which reduces the postoperative pain, respiratory complication, the formation of large hernia, decreases the hosiptal stay and improves esthetic outcomes.

2.5 Indications for ventral hernia repair

Among all surgical issues, abdominal wall hernias are among the most frequent. Inguinal hernia repairs account for over 770,000 of the nearly 1 million abdominal wall hernia operations performed annually in the United States. [9].

Through a thorough clinical examination and review of the patient’s medical history, abdominal wall hernia can be accurately diagnosed. However, in challenging or complex cases, imaging modalities, such as CT scan, ultrasound, and MRI, can be helpful. According to one study, a clinical examination has a sensitivity of 75% and a specificity of 96% for hernia diagnosis.

Ventral hernia repair is generally indicated for a variety of reasons, but the most prevalent ones include symptom relief, cosmetic improvement, and averting morbidities, such as pain, incarceration, enlargement, and skin changes, that are linked to the defect. In low- and moderate-risk individuals, elective surgery enhances the functional status and quality of life associated with hernias, but emergency repair increases morbidity and death. Older age, female sex, and umbilical hernia defects measuring from 2 to 7 cm or incisional hernia defects measuring up to 7 cm were significant risk factors for urgent repair. For incisional and umbilical hernias, watchful waiting is safe, but it causes substantial crossover rates (11–33%) and a significantly higher incidence of intraoperative perforations, fistulas, and mortality for emergency surgery. Older patients with incisional hernias typically have poorer outcomes following incisional hernia surgery. Advanced age was a significant risk factor for both umbilical hernias and ventral/incisional hernias requiring emergency repair; and an independent risk factor for poor early outcomes (readmission, reoperation, or death within 30 days). In patients with modifiable risk factors, watchful waiting is advised for medical improvement [10].

It is advised that symptomatic hernias be surgically addressed. The laparoscopic approach (standard or robotic method) should ideally be used especially for defects with a diameter of less than 15 cm.

2.6 Review of different approaches to ventral hernia

Surgery is the most typical treatment for ventral hernias. Hernias that are asymptomatic can be treated on an elective basis, while those that are strangulated need to be operated on right away. Incarceration without strangling is not a surgical emergency. Binder, truss, or corset use for non-surgical management of abdominal wall hernias is not thought to be successful. However, if a patient is not a good surgical candidate, this might be their only option.

Hernias have been repaired using a variety of surgical methods over the years. The use of a mesh with 3 to 5 cm of overlap, careful management of the mesh, limiting surgical site infections, and adopting an approach with the closure of the fascia if possible are further considerations, with a tension-free closure being the most crucial. The most straightforward strategy is a primary open repair without mesh, which should normally only be used for fascia abnormalities smaller than 2 cm. There are various alternatives for an open repair with mesh, including the kind of mesh and the placement of the mesh [6].

When compared to open techniques, laparoscopic ventral hernia repair consistently shows lower overall complication rates, shorter hospital stays, and quicker return to work. The majority of the current literature demonstrates that the recurrence rates are marginally lower in laparoscopic repair, despite the fact that this relationship has not always been statistically significant. Laparoscopy has drawbacks, including a larger risk of visceral harm and greater technical difficulty. Due to more surgical freedom, robotic ventral hernia procedures have also gained popularity. From a technological perspective, closing the fascial defect robotically is far simpler than trying to do it using traditional laparoscopic tools. Due to the possibility of maintaining smaller incisions, the advantages of laparoscopy are maintained. At present moment, no landmark trials have shown that robotic surgery is superior to laparoscopy; instead, it is often more expensive and requires longer operating durations.

2.6.1 The rives-stoppa repair

The retrorectus dissection plane is used in the Rives-Stoppa repair, which was first reported in the 1980s. This procedure is quite durable while preventing the development of subcutaneous flaps. The procedure allows for additional mobilization by releasing the posterior rectus sheath from the rectus muscles. This is normally done by dissecting bluntly toward the semilunar line while incising the posterior rectus sheath within 0.5 cm of its medial border. Then, the mesh is frequently positioned anterior to the posterior fascial plane, in a retromuscular manner [11].

Additionally, the abdominal wall musculature is preserved during this procedure, which is important for a successful abdominal wall reconstruction because it preserves both its functional and anatomical integrity. The restricted lateral dissection performed in this procedure, however, limits its use despite its stellar track record. The Rives-Stoppa repair, however, is inherently inappropriate in some circumstances. These include nonmidline ventral hernias lateral to the linea semilunaris, insufficient medial advancement of the posterior rectus sheath and musculature, and insufficient retrorectus space required for mesh placement. These restrictions have led to the development of new operating procedures.

2.6.2 Transversus abdominis release combined with posterior component separation

The transversus abdominis release has been useful in correcting nonmidline, complicated faults that the Rives-Stoppa repair is unable to fix. In this method, mesh overlap and lateral mobilization are added to the Rives-Stoppa repair’s retrorectus dissection plane. The posterior rectus sheath is incised, exposing the underlying transversus abdominis muscle, typically 0.5 cm medial to the semilunar line. After that, the underlying fascia is separated from the muscle plane, if necessary as far laterally as the psoas muscle [11].

2.6.3 Anterior component separation

A dissection anterior to the rectus muscles is used for anterior component separation. The external oblique fascia, which is located just lateral to the lateral aspect of the rectus muscles, is severed during the procedure to create a subcutaneous plane. If tension-free approximation is not initially achieved, further dissection to the anterior axillary line’s margin can be done. This procedure allows for efficient midline repair while allowing for significant medial mobilization of the abdominal wall muscles [11].

3. Discussing literature about the management of hernias in obese patients

Obesity is in fact a risk factor for the occurrence and the recurrence of ventral hernias. Many hernia repair techniques failed to treat hernias in obese patients [12]. Obesity is also a risk factor for increased wound infections, increased intra-abdominal pressure, and slow healing [13]. The incidence of recurrence can reach 35%, however, laparoscopic intraperitoneal onlay mesh repair can reduce this rate to 12% [13]. Weight loss can contribute to the reduction of hernia recurrences, however, recurrences may occur faster than reaching the optimal weight loss [12, 13]. Moreover, significant weight loss means a higher risk of internal hernias and need for re-intervention. Therefore, weight loss can compromise the efficacy of an early hernia repair.

There are no guidelines for the type or timing of hernia repairs however many retrospective studies discussed these issues.

A small study done on 23 patients who had a concomitant bariatric surgery with a laparoscopic intraperitoneal onlay mesh repair showed a low rate of recurrence over 3 years of follow-up [13]. This suggested that concomitant onlay mesh repair is a good alternative to delayed repair. However, the sample size was small and 4 patients had seromas postoperatively which is 7% more risk compared to the maximal incidence of seromas cited in the literature [13, 14].

A French nationwide retrospective study conducted between 2007 and 2018 concluded that hernia repair before bariatric surgery should be avoided to avoid the higher risk of reoperation that is associated with it [15]. Operating hernias before bariatric surgery had the highest recurrence rates compared to hernia repair postbariatric surgery or concomitant to bariatric surgery [15, 16].

Hernias suture repairs concomitant to bariatric surgery did not have a high recurrence rate due to the fact that usually suture repairs are indicated for smaller hernias that are less likely to reoccur [15]. A retrospective analysis of a UK-based sample of bariatric patients showed that the reoccurrence rate of concomitant repair is sufficiently low to suggest it for non-diabetic patients who are at a higher risk of infections [17].

The biggest dilemma resides in the fact that bariatric surgery with ventral hernia is challenging but obesity is a risk factor for recurrences [18]. Also, hernia repair during bariatric surgery is technically more difficult and can increase morbidity without annulling the risk of recurrences [18]. Since bariatric surgery is considered as clean contaminated, synthetic meshes offer better results in hernia repair but put patients at risk of infections [18].

Finally, a very diplomatic answer was given by Sait MS and Al. when questioning the timing of hernia repair in morbidly obese patients [19]. As suggested in their review, a case-by-case decision should be used since out of the 179 articles reported and the 5 main articles used to answer the questions, conflicting results dominated the research. The only common fact was that hernias should be repaired to avoid occlusion, synthetic mesh usage does not increase site infection in case of concomitant repair, and that randomized controlled trials are needed to reach a consensus [19].

4. Our study sample presentation and results

4.1 Objective

The objective of the study is to determine the best moment to operate a ventral hernia in obese patients during the management of their obesity.

4.2 Materials and methods

A retrospective study was conducted over the past 4 years. About 643 patients treated for morbid obesity were included: a ventral hernia (primary and incisional) was noted at the first consultation in 47 patients. All patients were asymptomatic. The mean time from the first consultation to bariatric surgery is 9 months. Thirty five patients were operated on 1 year after bariatric surgery called the “after bariatric surgery group,” five patients were operated on before bariatric surgery, four patients were in an emergency pattern for incarcerated or strangulated hernia, and three ventral hernia closed without mesh during bariatric surgery; this was “before bariatric surgery group.” The laparoscopic approach was used in 30 patients. Tension-free technique was used in 42 patients.

4.3 Results

Technically, it was easier to operate on patients after the weight loss.

Wound infection, hematoma, and pulmonary infection were seen in five patients, and there was no significant difference between the two groups concerning post-operative complications. No mortality was seen.

After at least 1 year of follow-up, one recurrence (2.8%) was noted in the “after bariatric surgery group” and seven recurrences (50%) in the “before bariatric surgery group.” One recurrence of the 7 was noted after 2 months of the primary repair and the others occurred after the weight loss. Two asymptomatic trocars site hernias were repaired at the same time when laparoscopic approach was used.

5. Conclusion

There is a need for a large prospective study to evaluate the perfect timing with the optimal repair technique to have a golden standard solution for ventral hernias repair and obesity surgery dilemma.

According to the algorithm, we propose that, if asymptomatic, the ventral hernia should be repaired after bariatric surgery when there is stabilization of the weight loss usually after the first year. Laparoscopic approach is recommended because it allows an exploration of the trocars sites and a second look after obesity surgery.

Conflict of interest

The authors declare no conflict of interest.