Endovascular Abdominal Aortic Aneurysm Repair Using the AneuRx® Stent Graft: Impact of Excluding Accessory Renal Arteries

Clinical and Radiological Outcomes of Accessory Renal Artery Exclusion during Endovascular Repair of Abdominal Aortic Aneurysms

BACKGROUND

Accessory renal arteries (ARAs) frequently coexist with abdominal aortic aneurysms (AAA) and can influence treatment. This study aimed to retrospectively analyze the ARA's exclusion effect on patients undergoing standard endovascular aneurysm repair for AAA.

METHODS

The study focused on medium- and long-term outcomes, including type II endoleak, aneurysmal sac changes, mortality, reoperation rates, renal function, and infarction post-operatively.

RESULTS

76 patients treated with EVAR for AAA were included. One hundred and two ARAs were identified: 69 originated from the neck, 30 from the sac, and 3 from the iliac arteries. The ARA treatment was embolization in 15 patients and coverage in 72. Technical success was 100%. One-month post-operative computed tomography angiography (CTA) revealed that 76 ARAs (74.51%) were excluded. Thirty-day complications included renal deterioration in 7 patients (9.21%) and a blood pressure increase in 15 (19.73%). During follow-up, 16 patients (21.05%) died, with three aneurysm-related deaths (3.94%). ARA-related type II endoleak (T2EL) was significantly associated with the ARA's origin in the aneurysmatic sac. Despite reinterventions were not significantly linked to any factor, post-operative renal infarction was correlated with an ARA diameter greater than 3 mm and ARA embolization.

CONCLUSION

ARAs can influence EVAR outcomes, with anatomical and procedural factors associated with T2EL and renal infarction. Further studies are needed to optimize the management of ARAs during EVAR.

Clinical effect of accessory renal artery coverage after endovascular repair of aneurysms in abdominal and thoracoabdominal aorta

BACKGROUND

The aim of our systematic review and meta-analysis was to assess the effect of accessory renal artery (ARA) coverage on renal function in terms of acute kidney injury (AKI), renal infarction, chronic renal failure (CRF), and mortality in patients undergoing standard endovascular aortic aneurysm repair (EVAR) or endovascular repair of complex aneurysms.

METHODS

An electronic search of the English language medical literature from 2000 to September 2020 was conducted using the MEDLINE, EMBASE, and Cochrane databases with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) method for studies reporting on ARA management in patients undergoing endovascular repair of aneurysms in the abdominal and thoracoabdominal aorta. The patients were divided into two groups: group 1, patients with ARA coverage; and group 2, patients without an ARA or without coverage of the ARA. Each group included two arms, one of patients who had undergone standard EVAR and one of patients who had undergone endovascular treatment of a complex aortic aneurysm. The GRADE (grading of recommendations assessment, development, evaluation) approach was used to evaluate the quality of evidence and summary of the findings. The primary outcomes included the incidence of AKI, renal infarction, CRF, and mortality.

RESULTS

Ten retrospective, nonrandomized, control studies were included in the systematic review reporting on 1014 patients (302 with a covered ARA vs 712 without an ARA or without ARA coverage). In six studies, the mean diameter of the covered ARA was <4 mm (range, 2.7-3.4 mm). The mean follow-up was 22.74 months (range, 1-42 months). In the standard EVAR subgroup, the risk of AKI (odds ratio [OR], 0.72; 95% confidence interval [CI], 0.21-2.51; I² = 0%] in the early period, and CRF (OR, 4.44; 95% CI, 0.46-42.61; I² = 87%) and death (OR, 0.91; 95% CI, 0.36-2.31; I² = 0%) during follow-up were similar between groups 1 and 2. Only the risk of renal infarction was greater in group 1 than in group 2 (OR, 93.3; 95% CI, 1.48-5869; I² = 92%). In the complex aneurysm repair subgroup, the risk of AKI (OR, 1.85; 95% CI, 0.61-5.64; I² = 42%) in early period and CRF (OR, 1.64; 95% CI, 0.88-3.07; I² = not applicable) and death (OR, 3.63; 95% CI, 0.14-96.29; I² = 56%) during follow-up were similar between groups 1 and 2. Only the risk of renal infarction was greater for group 1 compared with group 2 (OR, 8.58; 95% CI, 4.59-16.04; I² = 0%).

CONCLUSIONS

ARA (<4 mm) coverage in patients undergoing standard EVAR or endovascular repair of complex aneurysms is associated with an increased risk of renal infarction. However, we found no clinical effects of ARA coverage on renal function or mortality in early postoperative and follow-up period. Preservation of an ARA >4 mm should be considered.

Impact of Accessory Renal Artery Coverage on Renal Function during Endovascular Aortic Aneurysm Repair

BACKGROUND

Long-term outcomes of accessory renal artery (ARA) coverage after endovascular aneurysm repair (EVAR) are unknown. We analyzed the impact of ARA coverage on renal function long-term.

METHODS

This retrospective, monocentric study included patients treated by EVAR between 2008 and 2016. Patients with at least one ARA covered with EVAR (ARA group) were compared with patients with no covered ARA (control group). Renal function was determined by estimating the glomerular filtration rate (eGFR) and graded according to chronic kidney disease (CKD) classification stages.

RESULTS

A total of 184 patients were included (ARA group, n = 25; control group, n = 159). Renal risk factors were similar in the 2 groups. Mean (±standard deviation) duration of follow-up was 41.6 ± 25.8 months. Preoperative eGFR (mL/min/1.73 m²) was 68.9 ± 17.8 in the ARA group and 72.5 ± 17.4 in the control group (P = 0.33), with a similar decline in the 2 groups during follow-up (-6.52 ± 11.6 ARA group vs. -6.43 ± 13.8 control group; P = 0.97). At the end of the study, 8 ARA patients and 56 controls had deteriorated by one CKD stage (32% vs. 35.2%, respectively; P = 0.75). Rate of renal infarction was significantly higher in the ARA group (96% vs. 1.9%; P < 0.0001). In multivariate analysis, suprarenal fixation was identified as a risk factor for a decline in renal function (odds ratio = 2.01 [95% confidence interval: 1.05-3.84]; P = 0.04).

CONCLUSIONS

ARA coverage after EVAR does not appear to affect renal function long-term. Suprarenal fixation led to a greater decline in renal function.

Outcomes of Small Renal Artery Targets in Patients Treated by Fenestrated-Branched Endovascular Aortic Repair

OBJECTIVE

The aim was to evaluate renal related outcomes in patients who had incorporation of a small (<4.0 mm) renal artery (RA) during fenestrated-branched endovascular aortic repair (F-BEVAR).

METHODS

A total of 215 consecutive patients enrolled in a prospective F-BEVAR trial were reviewed. Computed tomography angiography centreline of flow reconstruction was used to measure mean RA diameter. Patients who had at least one <4.0 mm main or accessory RA incorporated by fenestration or directional branch (study group) were compared with patients who had incorporation of two ≥5.0 mm RAs (control group). Endpoints were technical success of RA incorporation, RA rupture and kidney loss, primary and secondary RA patency, RA branch instability and re-interventions, and renal function deterioration.

RESULTS

Twenty-four patients with 28 <4.0 mm RAs (16 accessory and 12 main RAs) were compared with 144 patients with 288 ≥5.0 mm incorporated RAs. Study group patients were significantly younger than controls (72 ± 8 vs. 75 ± 8 years, p = .04) and more often females (46% vs. 21%, p = .018); there were no differences in cardiovascular risk factors and aneurysm extent. Technical success was 92% for <4.0 mm and 99% for ≥5.0 mm RA incorporation (p = .05). Inadvertent RA rupture occurred in three patients in the study group (13%) and in one (1%) in the control group (p = .009) resulting in kidney loss in two study group patients (8%) and one (1%) control group patient (p = .05). At one year, primary patency was 79 ± 9% vs. 94 ± 1% (p < .001) and secondary patency was 84 ± 8% vs. 97 ± 1% (p < .001) for study vs. control group; freedom from branch instability was 79 ± 9% vs. 93 ± 2% (p = .005), respectively. There were no differences in re-intervention rates and renal function deterioration between the groups. The mean follow up time was 21 ± 14 months.

CONCLUSION

Incorporation of <4.0 mm RAs during F-BEVAR is associated with lower technical success, higher risk of arterial disruption and kidney loss, and lower patency rates at one year.

Coverage of Accessory Renal Arteries During Endovascular Aortic Aneurysm Repair: What Are the Consequences and the Implications for Clinical Practice?

An accessory renal artery (ARA) represents an anatomic variation which can challenge endovascular aortic aneurysm repair (EVAR). The aim of this review was to summarize the current knowledge on postoperative outcomes following ARA coverage during EVAR. We performed a systematic literature review. The MEDLINE database was searched on September 2017, and 8 relevant studies were included. The frequency of ARA in patients undergoing EVAR varied between 9.5% and 16.2%, and the frequency of ARA coverage varied between 5.2% and 9.4%. Four reports did not observe any significant changes on postoperative renal function, whereas 1 study reported an early transient increase in creatinine after ARA coverage. The occurrence of renal infarct varied from 20% to 84%. Five studies did not observe endoleaks related to ARA coverage, whereas one reported the occurrence of type II endoleaks in 3 of 18 patients who had ARA coverage. No significant change in blood pressure, mortality, and mean length of hospital stay was observed. The ARA coverage can potentially have renal and vascular consequences, but none of them were critical. Further studies may be useful to identify preoperative criteria that may help to choose the most appropriate surgical approach before ARA coverage.

Preservation of the accessory renal arteries after endovascular repair of common iliac artery aneurysm using kissing stent grafts

Exclusion of the accessory renal arteries (ARAs) is required during endovascular aneurysm repair if they arise from the sealing zone or aneurysm sac. Here, we report a case of successful endovascular treatment for a common iliac artery aneurysm located close to the aortic bifurcation and associated with nephrotic syndrome in a 51-year-old man. The bilateral ARAs were successfully preserved using kissing stent grafts. During surgery, the proximal ends of endografts inserted from the bilateral femoral arteries were adjusted so that they met at the same level in the aorta, and simultaneous balloon dilatation was performed. This method can be a useful treatment option for common iliac aneurysms in cases with large ARAs.

Can an accessory renal artery be safely covered during endovascular aortic aneurysm repair?

A best evidence topic was constructed according to a structured protocol. The question addressed was whether coverage of an accessory renal artery (ARA) in patients undergoing endovascular aortic aneurysm repair (EVAR) is associated with increased risk of renal impairment. Altogether, 106 papers were located using the reported searches, of which 5 represented the best evidence to answer the question. The authors, journal, date and country of publication, study type, patient group studied, relevant outcomes parameters and results of these papers are tabulated. Our best evidence analysis included 116 patients who had one or more ARA excluded during EVAR. Segmental renal infarction occurred in varying numbers of patients (ranging from 0 to 84%). The authors consistently demonstrate that loss of renal mass is not associated with functional renal impairment, expressed by various outcome parameters such as serum creatinine, glomerular filtration rate (GFR), renal failure requiring dialysis and worsening hypertension. Comparisons of groups of patient with covered or preserved ARAs by one of the selected studies showed no difference in any of these renal outcome parameters, apart from a significantly higher renal infarct volume in the former group (P < 0.001). Subgroup analysis of patients with pre-existing renal dysfunction (GFR < 60 ml/h/m(2)) showed no difference in GFR change when comparing covered with uncovered ARA patient cohorts. No type II endoleak related to the covered ARA was reported in any of these studies. In conclusion, current evidence supports the safety of coverage of ARAs located in the proximal fixation zone to achieve seal in EVAR.

Outcomes of accessory renal artery occlusion during endovascular aneurysm repair

OBJECTIVE

Accessory renal arteries are frequently encountered when patients are evaluated for endovascular abdominal aortic aneurysm repair (EVAR). Some have considered their presence a contraindication to EVAR in fear of endoleak and the end result of renal function. We sought to determine whether the coverage of accessory renal arteries during EVAR was associated with any adverse sequelae.

METHODS

Retrospective review of the medical records and computed tomographic scans of all patients undergoing EVAR (1998 to 2003) was performed. Note was made of the presence or absence of accessory renal arteries, hypertension, and renal function. Preoperative computed tomographic images were compared with postoperative images to determine the presence of renal infarction. A control group of 26 consecutive patients without accessory renal arteries was used for comparison of the results of EVAR.

RESULTS

EVAR was performed in 550 patients over the study interval. The mean follow-up was 16 months (range, 1-48 months). The average age was 74 years (range, 57-90 years). Thirty-five patients (6.6%; 32 male and 3 female) were documented to have accessory renal arteries; the average number of accessory arteries was 2 (range, 1-4). Bilateral accessory arteries were present in 13 patients: all but 1 patient (n = 34) had a left-sided accessory renal artery, and 23 had a right-sided accessory renal artery. EVAR was performed with a variety of endografts: AneuRx (n = 10), Talent (n = 7), PowerLink (n = 7), Zenith (n = 5), LifePath (n = 4), and Ancure (n = 2). There were no mortalities. Twelve endoleaks were documented: three type I, eight type II, and one type III. The accessory renal arteries were not implicated in any of the endoleaks, and none of these accessory vessels was embolized before or after EVAR. Seven patients (20%) had renal infarcts associated with EVAR that were noted on follow-up computed tomographic scans. The mean follow-up for patients with segmental infarction was 23 months (range, 8-48 months). Hypertensive status did not change in any patient in whom an accessory renal artery had been covered. The average serum creatinine was 1.08 mg/dL (range, 0.6-1.8 mg/dL) before EVAR in patients with accessory renal arteries covered by an endovascular graft and did not change significantly in response to EVAR. Serum creatinine increased almost twofold in two patients but spontaneously resolved in follow-up. The average preoperative creatinine clearance was 79 mL/min (range, 35-166 mL/min) in patients without an accessory renal artery and was 80 mL/min (range, 35-167 mL/min) after EVAR. The average preoperative creatinine clearance was 67 mL/min (range, 31-137 mL/min) in patients with an accessory renal artery and 68 mL/min (range, 45-83 mL/min) in patients with renal infarcts. None of the patients required temporary or permanent dialysis. There was no difference between control patients and patients with covered accessory renal arteries with respect to hypertensive status, presence of renal infarcts, serum creatinine, or creatinine clearance after EVAR.

CONCLUSIONS

Occlusion of accessory renal arteries is not associated with clinically significant signs or symptoms, even in patients with mild or moderate renal insufficiency. Sacrifice of accessory renal arteries most commonly does not lead to detectable renal infarction, either clinically or radiographically. When segmental infarction of the kidney does result, it seems to be well tolerated in this group of patients. Accessory renal arteries were not found to contribute to endoleaks and should not be prophylactically embolized.

The impact of aortic endografts on renal function

OBJECTIVE

To determine the impact on late postoperative renal function of suprarenal and infrarenal fixation of endografts used to treat infrarenal abdominal aortic aneurysm (AAA).

METHODS

Retrospective analysis of 277 patients treated from 2000 to 2003 with three different endografts at two clinical centers. Five patients on dialysis for preoperative chronic renal failure were excluded. Group IF of 135 patients treated with an infrarenal device (Medtronic AneuRx) was compared with group SF of 137 patients treated with a suprarenal device (106 Cook Zenith and 31 Medtronic Talent). Renal function was evaluated by calculating preoperative and latest postoperative creatinine clearance (CrCl) using the Cockcroft formula. Patients who developed a >20% decrease in CrCl were considered to have significantly impaired renal function.

RESULTS

There were no significant differences in patient age, sex, aneurysm size, preoperative risk factors, dose of intra- and postoperative contrast, or baseline CrCl (IF: 69.3 mL/min, SF: 71.7 mL/min, P = .4). Follow-up time of 12.2 months was the same in both groups. CrCl decreased significantly during the follow-up period in both groups (IF: 69.3 mL/min to 61.7 mL/min, P < .01; SF: 71.7 mL/min to 64.9 mL/min, P < .03). Postoperative CrCl (IF: 61.7 mL/min, SF: 64.9 mL/min, P = .3), and the rate of CrCl decrease during the follow-up period (IF: -10.9%, SF: -9.5%, P = .2) was not different between the two groups. The number of patients with a >20% decrease in CrCl was not different between the two groups (IF: n = 35 [25.9%], SF: n = 41 [29.9%], P = .46). However, the magnitude of decrease in CrCl in patients with renal impairment was greater in patients treated with suprarenal fixation endografts (SF: -39%) compared with those treated with infrarenal endografts (IF: -31%, P = .005). This greater degree of renal impairment was not due to identifiable differences in preoperative risk factors, age, or baseline CrCl. No patients in these series required dialysis.

CONCLUSIONS

Regardless the type of endograft used, there is a 10% decrease in CrCl in the first year after endovascular aneurysm repair. Suprarenal fixation does not seem to increase the likelihood of postoperative renal impairment. Decline in renal function over time after endovascular aortic repair is probably due to multiple factors, and measures known to be effective in protecting kidneys should be considered for these patients. Long-term follow-up with measurement of CrCl, along with renal imaging and regular blood pressure measurements, should be performed to detect possible late renal dysfunction. Prospective studies comparing suprarenal versus infrarenal fixation are needed to confirm those results.