Advanced Endovascular Approaches in the Management of Challenging Proximal Aortic Neck Anatomy: Traditional Endografts and the Snorkel Technique

The acute impact of baseline renal function and contrast medium volume/estimated glomerular filtration rate ratio on reduced renal function following endovascular abdominal aortic aneurysm repair

OBJECTIVE

The aim of this study was to determine the acute impact of baseline serum creatinine, estimated glomerular filtration rate (eGFR), and contrast medium volume (CMV) on the incidence of reduced renal function (RRF) after endovascular abdominal aortic aneurysm repair (EVAR). We aimed to determine if the CMV/eGFR ratio was a predictor of RRF.

METHODS

This study is a retrospective review of EVAR patients in the Society for Vascular Surgery/Vascular Quality Initiative (SVS/VQI) from January 2015 to August 2020. Reduced renal function was defined as > 0.3 mg/dl (26.5 μmol/L), 50% increase from baseline, and temporary or permanent dialysis. Receiver operator characteristic (ROC) curve analyses were conducted for serum creatinine, eGFR, contrast volume, fluid volume, and CMV/eGFR ratio. Two data sets (training and test) were developed followed by multivariate analyses.

RESULTS

SVS/VQI data for EVAR contained 38,701 records, of which 30,539 were divided into training (n = 18,283; 60%) and test (n = 12,256; 40%) data sets. RRF rate for the training set was 3.6% (n = 667) and 3.4% (n = 420) for the test data. RRF patients included more females (29.4 vs 19.0%, p < 0.001), were older in age (75.6 + 8.4 vs 73.3 + 8.7 years), had more congestive heart failure (22.3 vs 12.2%, p < 0.001), and more COPD (42.0 vs 34.2%, p < 0.001). An ROC analysis revealed that eGRF, creatinine, contrast, intravenous fluid, and contrast medium volume (CMV)/eGFR ratio were all significantly (p < 0.05) correlated with RRF. The eGFR and CMV/eGFR ratio had the largest area under the curve, (0.26) and (0.65), respectively, while fluid had the lowest (0.54). Negative predictive values were 93.7 (CMV/eGFR), 93.9 (creatinine), 94.2 (eGFR), 92.8 (contrast), and 92.6 (intravenous fluid). Multivariate analysis of the training data set resulted in the CMV/eGFR ratio as an independent predictor of RRF (odds ratio, OR: 1.9 with 95% CI: 1.6, 2.2, p < 0.015). For the test data, the CMV/eGFR ratio was an independent predictor of RRF (OR: 1.8, CI: 1.4 to 2.2, p < 0.001) as well as several other variables.

CONCLUSION

RRF after EVAR is a dreaded and potentially devastating complication. Baseline serum creatinine, eGFR, contrast medium volume, and the ratio (CMV/eGFR) were all significantly associated with RRF. The optimal cut-off value for the CMV/eGFR ratio, ≤ 2, provides an easy-to-use equation to provide a suggested contrast target based on initial renal function with caution applied for high-risk patients.

Endovascular interventions in main renal artery pathologies: an overview and update

Renal arteries are involved in a wide spectrum of pathologies including atherosclerosis, fibromuscular dysplasia, Takayasu arteritis, aneurysms, and aortic type B dissections extending into main renal arteries. They manifest as renovascular hypertension, renal ischemia, and cardiovascular dysfunction. The location of the renal arteries in relation to the abdominal aortic aneurysm is a critical determinant of interventional options and long-term prognosis. This article provides a comprehensive review of the role of interventional radiologists in transcatheter interventions in various pathologies involving the main renal arteries with analysis of epidemiology, pathophysiology, newer interventional techniques, and management options.

Funnel technique for wide infrarenal aneurysm neck with Lifetech Ankura™ Stent Graft System

Background

In this study, we present our mid-term results in patients undergoing treatment with the funnel technique and describe technical issues for this bailout technique in extra-wide infrarenal necks.

Methods

Between January 2018 and June 2020, a total of seven male, symptomatic patients (median: 74.5 years; range, 64 to 84 years) who had comorbidities and were in the American Society for Anesthesiologists Class IV and treated by the funnel technique in an endovascular fashion were included. Pre- and post-procedural data of the patients, early mortality and technical success rates were evaluated.

Results

There was no early mortality. Technical success rate was 100%. There was no type I or III endoleaks at the completion angiography. All patients were discharged without any problem on the second or third day of the procedure. The median follow-up was 13 (range, 6 to 28) months. The aneurysm sac shrinkage was achieved in all patients over six months of follow up. During the follow-up period, no proximal endoleak or infrarenal aortic neck diameter enlargement was found.

Conclusion

Based on our limited experience, the funnel technique may be considered more than a bailout procedure under special circumstances.

Is Mini-Invasive Surgery an Alternative for the Treatment of Juxtarenal Aortic Aneurysms?

INTRODUCTION

Aim of our study is to evaluate the outcomes of mini-laparotomy, suprarenal cross-clamping, and enhanced recovery after elective open surgical repair for juxta-renal abdominal aortic aneurysms (JAAA) in a tertiary referral center.

METHODS

Data of all consecutive patients with abdominal aortic aneurysms (AAA) electively treated with left sub-costal mini-laparotomy requiring infrarenal or suprarenal cross-clamping between 2013 and 2018 were retrospectively collected. Patients were divided into two groups: infra-renal cross-clamping (group A) and JAAA requiring supra-renal cross-clamping (group B). Early and mid-term mortality, postoperative renal dysfunction according to RIFLE criteria and factors affecting postoperative outcome were analysed.

RESULTS

Four hundred one patients, 356 (88.8%) men, mean age 70.8 yrs, underwent open surgical repair (OSR), 343 (85.5%) AAA in group A, 58 (14.5%) JAAA in group B. Mean diameter of the aneurysms was 54 ± 11.4 mm vs. 52 ± 9 mm and mean time of intervention 154.9 ± 56.3 min vs. 180.1 ± 65.7 min respectively. Total clamp time was 72.27 ± 31.4 vs. 75 ± 33.1 and suprarenal clamp time in group B 27.82 ± 14.1 min. Mean hospital length of stay was 5.1 ± 2.8 vs. 5.37 ± 3.4 days respectively. At 30 days, 3 (0.9%) patients died in group A and no one in group B; at 24 months 7 (2%) deaths in group A and 4 (6.9%) in group B. Preoperative, postoperative and discharge serum creatinine mean value, in group B, were 1.07 ± 0.32, 1.31 ± 0.36 and 1.83 ± 1.24 respectively. Based on RIFLE criteria for renal function, we observed Risk in 14.2% and Injury in 12.7% of patients after suprarenal cross clamping.

CONCLUSIONS

Our results show that mini-invasive open repair for JAAA with a suprarenal cross-clamping can be performed with acceptable morbidity and mortality rates similar to traditional surgical approach without significant modifications of renal functions.

Preoperative Neck Angulation is Associated with Aneurysm Sac Growth Due to Persistent Type Ia Endoleak after Endovascular Abdominal Aortic Aneurysm Repair

Objective: This study aims to determine how instructions for use affect the occurrence of aneurysm sac growth and endoleaks after an endovascular aneurysm repair (EVAR).

Materials and Methods: We reviewed 302 patients who underwent EVAR for abdominal aortic aneurysm between 2007 and 2013, and we were able to enroll 159 patients (74% men, mean age 78±7 years) with adequate data (mean follow-up; 48±20 months).

Results: The angle of the proximal landing zone (LZ) (hazard ratio: 1.02, 95% confidence interval: 1.00–1.03, p=0.01) was recognized as an independent risk factor of sac growth (≥5 mm). The receiver operating characteristics curve (area under the curve: 0.72) showed a cutoff value of 47° of the minimum angle of the proximal LZ to predict sac growth. Freedom rates for persistent type Ia endoleaks were also found to be lower in the angulated group than those in the other groups (p=0.0095, log-rank).

Conclusion: The angle of the proximal LZ was identified as an independent risk factor for sac growth post-EVAR. The incidence of persistent type Ia endoleaks was significantly higher in the angulated group.

Fenestrated Endovascular Aneurysm Repair versus Snorkel Endovascular Aneurysm Repair: Competing yet Complementary Strategies

Juxtarenal/pararenal aortic aneurysms and type IV thoracoabdominal aneurysms pose particular technical challenges for endovascular repair as they involve the visceral segment in addition to insufficient infrarenal neck for the use of standard endovascular aneurysm repair (EVAR) devices. To overcome these challenges, complex EVAR techniques have been developed to extend the proximal landing zone cephalad with maintaining perfusion to vital aortic branches, thereby broadening the applicability of endografting from the infrarenal to the suprarenal aorta. Complex EVAR can be divided into two broad categories: fenestrated endovascular aneurysm repair (FEVAR) and snorkel EVAR. FEVAR is a valid procedure with the standardized procedure, although it remains as a relatively complex procedure with a learning curve. Given time constraints for the custom fenestrated graft, snorkel EVAR may be an alternative for complex repairs in symptomatic or ruptured patients for whom custom-made endografts may not be immediately available. This article discusses these two most commonly used complex EVAR strategies.