Incidence and risk factors for incisional hernia after open abdominal aortic aneurysm repair

Risk Factors for Development of Incisional Hernia After Aortic Aneurysm Repair: Secondary Analysis of the OVER Randomized Controlled Trial

OBJECTIVE

Since the risk of mortality from rupture is elevated, elective repair of abdominal aortic aneurysms (AAA) is often recommended. Currently, over 80% of elective repairs are carried out using an endovascular approach. While open repair has similar late survival and fewer reintervention outcomes when compared to endovascular repair, incisional hernia is a frequent complication with morbidity and cost implications. The Open Versus Endovascular Repair (OVER) trial was the largest randomized trial of endovascular versus open repair of abdominal aortic aneurysms in the United States. The purpose of this study was to determine risk factors associated with incisional hernia development following AAA repair via secondary analysis of the OVER data.

METHODS

This was a multi-site trial conducted within the Veterans Affairs healthcare system. Study participants (N=881) were enrolled from 2002-2008 and followed until 2011 with additional administrative data collection until 2016. Eligible patients had abdominal aortic aneurysms for which elective repair was planned and randomized 1:1 to either open or endovascular repair. Incisional hernia was a prespecified endpoint in the OVER protocol, specifically assessed at each protocol follow up visit. Technical details were extracted from each operative report, repair case report form(s), and adverse event form(s). Patient demographics, comorbid conditions, reported preoperative activity level, and operative details including initial approach, blood loss, and closure methods were analyzed using Bayesian hierarchical Weibull survival regression modeling.

RESULTS

Incisional hernias were recorded among 46 participants (5.2%). The average time to hernia diagnosis was 3.5 years. Of the 437 participants randomized to open treatment, 427 received an open repair including crossovers from endovascular treatment assignment. Transperitoneal repair was performed in 81%, running suture in 96%, and absorbable suture in 71% of cases. Randomization to endovascular repair was associated with reduced risk of hernia (HR 0.70, 95% CI 0.49-0.94). Higher activity level was associated with increased hernia risk (HR 1.39, 95% CI 1.06-1.84). Approach, suture closure techniques, BMI, diabetes, and smoking status were not associated with increased risk of hernia development.

CONCLUSIONS

Incisional hernia is a frequent complication associated with open repair of abdominal aortic aneurysm and commonly required reintervention. Endovascular repair was associated with reduced risk of hernia. Patients with increased activity experienced a higher incidence of hernia. However, no other modifiable patient, operative, or technical factors were found to be associated with hernia development.

Outcomes of elective and emergency surgical repair of incisional hernia: a comparative observational study

PURPOSE

Incisional hernia (IH) is a common complication following abdominal surgery. Surgical repair of IH is associated with the alleviation of symptoms and improvement of quality of life. Operative intervention can pose a significant burden to the patient and healthcare facilities. This study aims to describe and compare outcomes of elective and emergency surgical repair of IH.

METHODS

This study is a single-centre comparative retrospective study including patients who had repair of IH. Patients were divided into Group I (Emergency) and Group II (Elective), and a comparison was conducted between them.

RESULTS

Two hundred sixty-two patients were identified with a mean age of 61.8 ± 14.2 years, of which 152 (58%) were females. The mean BMI was 31.6 ± 7.2 kg/m2. More than 58% had at least one comorbidity. 169 (64.5%) patients had an elective repair, and 93 (35.5%) had an emergency repair. Patients undergoing emergency repair were significantly older and had higher BMI, p = 0.031 and p = 0.002, respectively. The significant complication rate (Clavien-Dindo III and IV) was 9.54%. 30 and 90-day mortality rates were 2.3% (n = 6) and 2.68% (n = 7), respectively. In the emergency group, the overall complications, 30-day and 90-day mortality rates were significantly higher than in the elective group, p ≤ 0.001, 0.002 and 0.001, respectively. Overall, 42 (16.1%) developed wound complications, 25 (9.6%) experienced a recurrence, and 41 (15.71%) were readmitted within 90 days, without significant differences between the two groups.

CONCLUSION

Patients who underwent emergency repair were significantly older and had a higher BMI than the elective cases. Emergency IH repair is associated with higher complication rates and mortality than elective repair.

Incisional Hernia: A Surgical Complication or Medical Disease?

Incisional hernia (IH) is a frequent complication following abdominal surgery. The development of IH could be more sophisticated than a simple anatomical failure of the abdominal wall. Reported IH incidence varies among studies. This review presented an overview of definitions, molecular basis, risk factors, incidence, clinical presentation, surgical techniques, postoperative care, cost, risk prediction tools, and proposed preventative measures. A literature search of PubMed was conducted to include high-quality studies on IH. The incidence of IH depends on the primary surgical pathology, incision site and extent, associated medical comorbidities, and risk factors. The review highlighted inherent and modifiable risk factors. The disorganisation of the extracellular matrix, defective fibroblast functions, and ratio variations of different collagen types are implicated in molecular mechanisms. Elective repair of IH alleviates symptoms, prevents complications, and improves the quality of life (QOL). Recent studies introduced risk prediction tools to implement preventative measures, including suture line reinforcement or prophylactic mesh application in high-risk groups. Elective repair improves QOL and prevents sinister outcomes associated with emergency IH repair. The watchful wait strategy should be reviewed, and options should be discussed thoroughly during patients' counselling. Risk stratification tools for predicting IH would help adopt prophylactic measures.