Transperitoneal versus retroperitoneal approach for elective open abdominal aortic aneurysm repair

Guidelines on the management of abdominal aortic aneurysms: updates from the Italian Society of Vascular and Endovascular Surgery (SICVE)

The objective of these Guidelines was to revise and update the previous 2016 Italian Guidelines on Abdominal Aortic Aneurysm Disease, in accordance with the National Guidelines System (SNLG), to guide every practitioner toward the most correct management pathway for this pathology. The methodology applied in this update was the GRADE-SIGN version methodology, following the instructions of the AGREE quality of reporting checklist as well. The first methodological step was the formulation of clinical questions structured according to the PICO (Population, Intervention, Comparison, Outcome) model according to which the Recommendations were issued. Then, systematic reviews of the Literature were carried out for each PICO question or for homogeneous groups of questions, followed by the selection of the articles and the assessment of the methodological quality for each of them using qualitative checklists. Finally, a Considered Judgment form was filled in for each clinical question, in which the features of the evidence as a whole are assessed to establish the transition from the level of evidence to the direction and strength of the recommendations. These guidelines outline the correct management of patients with abdominal aortic aneurysm in terms of screening and surveillance. Medical management and indication for surgery are discussed, as well as preoperative assessment regarding patients' background and surgical risk evaluation. Once the indication for surgery has been established, the options for traditional open and endovascular surgery are described and compared, focusing specifically on patients with ruptured abdominal aortic aneurysms as well. Finally, indications for early and late postoperative follow-up are explained. The most recent evidence in the Literature has been able to confirm and possibly modify the previous recommendations updating them, likewise to propose new recommendations on prospectively relevant topics.

AAA Revisited: A Comprehensive Review of Risk Factors, Management, and Hallmarks of Pathogenesis

Despite declining incidence and mortality rates in many countries, the abdominal aortic aneurysm (AAA) continues to represent a life-threatening cardiovascular condition with an overall prevalence of about 2-3% in the industrialized world. While the risk of AAA development is considerably higher for men of advanced age with a history of smoking, screening programs serve to detect the often asymptomatic condition and prevent aortic rupture with an associated death rate of up to 80%. This review summarizes the current knowledge on identified risk factors, the multifactorial process of pathogenesis, as well as the latest advances in medical treatment and surgical repair to provide a perspective for AAA management.

Comparative outcomes of open abdominal therapy after ruptured abdominal aortic aneurysm via open and endovascular approaches

BACKGROUND

Open abdomen therapy is sometimes a necessary lifesaving procedure after repair of ruptured abdominal aortic aneurysm (rAAA). OAT aims to prevent or treat abdominal compartment syndrome (ACS). This study aims to evaluate our experience with open abdomen therapy (OAT) after repair of ruptured abdominal aortic aneurysms (rAAAs).

DESIGN

Retrospective cohort study METHODS: Medical records were retrieved for ruptured abdominal aortic aneurysm patients who underwent open surgical repair (OS) or endovascular aneurysm repair (EVAR) between January 1, 2008 and December 12, 2015 from a single center. Univariate and multivariate analysis were performed with statistical significance.

RESULTS

The study included 171 patients. Thirty-three patients (19.3%) required OAT. A smaller percentage of patients required OAT after EVAR (9.8%) compared to OS (23.3%) (P = 0.05). Patients with OAT also had a significantly longer operation (257 vs. 202.7 minutes; P < 0.05), required more intra-operative fluids (15,700 vs. 8,050 mL; P < 0.05), had a longer hospital stay (20 vs. 8.5 days; P < 0.05), and had a higher peri-operative mortality rate (48.5% vs 25.4%; P < 0.05). On multivariate logistic regression analysis, a lower preoperative SBP (OR 0.9, P = 0.01) and history of hypertension (OR 0.3, P = 0.02) were protective against OAT, while longer operative duration increased the risk of OAT (OR: 1.27, P = 0.05). Mean duration of OAT prior to closure was 4.76 days. Comparing OS patients (transperitoneal and retroperitoneal) that underwent OAT closure, patients who had a retroperitoneal repair received less intra-operative fluids (13.79 vs. 19.11 L; P = 0.212), had earlier return of bowel function (10 vs. 16.9 days; P = 0.08), and a shorter hospital stay (19.9 vs. 32.2 days; P = 0.03).

CONCLUSIONS

OAT is a lifesaving procedure that is associated with higher morbidity and mortality following OS and EVAR for rAAA. Patients with longer operations and extensive fluid resuscitation are at higher risk for OAT following rAAAs. Preoperative permissive hypotension may be protective against OAT. OAT following the RP approach to rAAA is associated with earlier abdominal wall closure, earlier bowel recovery, and shorter hospital stay.

Retroperitoneal versus transperitoneal approach for elective open abdominal aortic aneurysm repair

BACKGROUND

There has been extensive debate in the surgical literature regarding the optimum surgical access approach to the infrarenal abdominal aorta during an operation to repair an abdominal aortic aneurysm. The published trials comparing retroperitoneal (RP) and transperitoneal (TP) aortic surgery show conflicting results. This is an update of the review first published in 2016.

OBJECTIVES

To assess the effectiveness and safety of the retroperitoneal versus transperitoneal approach for elective open abdominal aortic aneurysm repair on mortality, complications, hospital stay and blood loss.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and the ClinicalTrials.gov trials registers to 30 November 2020. The review authors searched the Chinese Biomedical Literature Database and handsearched reference lists of relevant articles to identify additional trials.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that assessed the RP approach versus the TP approach for elective open abdominal aortic aneurysm (AAA) repair. There were no restrictions on language or publication status.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data from the included trials. We resolved any disagreements through discussion with a third review author. Two review authors independently assessed the risk of bias in included trials with the Cochrane risk of bias tool. For dichotomous outcomes, we calculated the odds ratio (OR) with the corresponding 95% confidence interval (CI). For continuous data, we calculated a pooled estimate of treatment effect by calculating the mean difference (MD) and standard deviation (SD) with corresponding 95% CIs. We pooled data using a fixed-effect model, unless we identified heterogeneity, in which case we used a random-effects model. We used GRADE to assess the overall certainty of the evidence. We evaluated the outcomes of mortality, complications, intensive care unit (ICU) stay, hospital stay, blood loss, aortic cross-clamp time and operating time.

MAIN RESULTS

We identified no new studies from the updated searches. After reassessment, we included one study which had previously been excluded. Five RCTs with a combined total of 152 participants are included. The overall certainty of the evidence ranged from low to very low because of the low methodological quality of the included trials (unclear random sequence generation method and allocation concealment, and no blinding of outcome assessors), small sample sizes, small number of events, high heterogeneity and inconsistency between the included trials, no power calculations and relatively short follow-up. There was no evidence of a difference between the RP approach and the TP approach regarding mortality (odds ratio (OR) 0.32, 95% CI 0.01 to 8.25; 3 studies, 110 participants; very low-certainty evidence). Similarly, there was no evidence of a difference in complications such as hematoma (OR 0.90, 95% CI 0.13 to 6.48; 2 studies, 75 participants; very low-certainty evidence), abdominal wall hernia (OR 10.76, 95% CI 0.55 to 211.78; 1 study, 48 participants; very low-certainty evidence), or chronic wound pain (OR 2.20, 95% CI 0.36 to 13.34; 1 study, 48 participants; very low-certainty evidence) between the RP and TP approaches in participants undergoing elective open AAA repair. The RP approach may reduce ICU stay (mean difference (MD) -19.02 hours, 95% CI -30.83 to -7.21; 3 studies, 106 participants; low-certainty evidence); hospital stay (MD -3.30 days, 95% CI -4.85 to-1.75; 5 studies, 152 participants; low-certainty evidence); and blood loss (MD -504.87 mL, 95% CI -779.19 to -230.56; 4 studies, 129 participants; very low-certainty evidence). There was no evidence of a difference between the RP approach and the TP approach regarding aortic cross-clamp time (MD 0.69 min, 95% CI -7.23 to 8.60; 4 studies, 129 participants; very low-certainty evidence) or operating time (MD -15.94 min, 95% CI -34.76 to 2.88; 4 studies, 129 participants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

Very low-certainty evidence from five small RCTs showed no clear evidence of a difference between the RP approach and the TP approach for elective open AAA repair in terms of mortality, or for rates of complications including hematoma (very low-certainty evidence), abdominal wall hernia (very low-certainty evidence), or chronic wound pain (very low-certainty evidence). However, a shorter intensive care unit (ICU) stay and shorter hospital stay was probably indicated following the RP approach compared to the TP approach (both low-certainty evidence). A possible reduction in blood loss was also shown after the RP approach (very low-certainty evidence). There is no clear difference between the RP approach and TP approach in aortic cross-clamp time or operating time. Further well-designed, large-scale RCTs assessing the RP approach versus TP approach for elective open AAA repair are required.

Retroperitoneal Aortobifemoral Bypass by a Combination of Horseshoe Kidney and Aortoiliac Occlusive Disease with Stent Thrombosis

Bilateral aorto-profunda femoris bypass with Dacron bifurcation graft was performed by a patient with aortoiliac occlusive disease (AIOD) and horseshoe kidney (HSK) who had undergone stenting of the right common iliac artery and of the left superficial femoral artery with subsequent stent thrombosis as well as significant subrenal aortic stenosis. As endovascular treatment was not feasible and surgical treatment by means of transperitoneal incision would be associated with high risk of damage to the HSK, the operation was successfully accomplished through left pararectal retroperitoneal approach.

The Obesity-associated Risk in Open and Endovascular Repair of Abdominal Aortic Aneurysm

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The rising pandemic of obesity in modern society should direct attention to a more comprehensive approach to abdominal aortic aneurysm (AAA) treatment in the affected population. Although overweight patients are considered prone to increased surgical risk, studies on the subject did not confirm or specify the risks well enough.

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Associated comorbidities inevitably lead to a selection bias leaning towards endovascular abdominal aortic repair (EVAR), as a less invasive treatment option, which makes it hard to single out obesity as an independent risk factor. The increased technical difficulty often results in prolonged procedure times and increased blood loss. Several smaller studies and two analyses of national registries, including 7935 patients, highlighted the advantages of EVAR over open repair (OR) of abdominal aortic aneurysm, especially in morbidly obese population (relative risk reduction up to 47%). On the other hand, two other studies with 1374 patients combined, concluded that EVAR might not have an advantage over OR in obese patients (P = 0.52). Obesity is an established risk factor for wound infection after both EVAR and OR, which is associated with longer length of stay, subsequent major operations, and a higher rate of graft failure. Percutaneous EVAR technique could present a promising solution to reducing this complication.

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EVAR seems like a more feasible treatment option than OR for obese patients with AAA, due to lower overall morbidity and mortality rates, as well as reduced wound-related complication rates. However, there is a clear lack of high-quality evidence on the subject, thus future prospective trials are needed to confirm this advantage.

Prophylactic Mesh Reinforcement versus Sutured Closure to Prevent Incisional Hernias after Open Abdominal Aortic Aneurysm Repair via Midline Laparotomy: A Systematic Review and Meta-Analysis

OBJECTIVE/BACKGROUND

Incisional hernia is a frequent late complication after open abdominal aortic aneurysm (AAA) repair. We aimed to determine whether prophylactic mesh reinforcement of the abdominal wall at open AAA repair via midline laparotomy reduces the rate of incisional hernia compared to standard sutured closure.

METHODS

A systematic review and meta-analysis was carried out in accordance with the PRISMA statement (PROSPERO registration CRD42017072508). Randomised controlled trials (RCTs) comparing prophylactic mesh reinforcement with standard sutured closure were eligible for inclusion. MEDLINE, Embase, and the Cochrane Library were searched. A meta-analysis with a random effects model was carried out to estimate pooled risk ratios (RR) with 95% confidence intervals (CIs) for the incidence of, and re-operation rate for, incisional hernias. Assessments of methodological quality, quality of evidence, and strength of recommendations were done with the Cochrane Collaboration's tool for assessing risk of bias and the GRADE approach.

RESULTS

Four RCTs with a total of 388 patients were included in the meta-analysis. Pooled analysis showed that mesh reinforcement significantly reduced the risk of incisional hernia after AAA repair compared with standard sutured closure (RR 0.27, 95% CI 0.11-0.66). The pooled rate of re-operations was not different between groups (RR 0.23, 95% CI 0.11-1.05). Mesh reinforcement did not cause more intra-operative or post-operative complications than sutured closure. The risk of bias in studies was low and the quality of evidence was rated as moderate.

CONCLUSION

Prophylactic mesh reinforcement of the abdominal wall after open AAA repair via midline laparotomy significantly reduces the risk of incisional hernia. However, no significant difference in re-operation for incisional hernia was found.

Organ protection during aortic cross-clamping

Open surgical repair of an aortic aneurysm requires aortic cross-clamping, resulting in temporary ischemia of all organs and tissues supplied by the aorta distal to the clamp. Major complications of open aneurysm repair due to aortic cross-clamping include renal ischemia-reperfusion injury and postoperative colonic ischemia in case of supra- and infrarenal aortic aneurysm repair. Ischemia-reperfusion injury results in excessive production of reactive oxygen species and in oxidative stress, which can lead to multiple organ failure. Several perioperative protective strategies have been suggested to preserve renal function during aortic cross-clamping, such as pharmacotherapy and therapeutic hypothermia of the kidneys. In this chapter, we will briefly discuss the pathophysiology of ischemia-reperfusion injury and the preventative measures that can be taken to avoid abdominal organ injury. Finally, techniques to minimize the risk of complications during and after open aneurysm repair will be presented.