Exclusion of accessory renal arteries during endovascular repair of abdominal aortic aneurysms

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.

Concomitant large renal cancer and abdominal aortic aneurysm. An original multidisciplinar approach to solve both pathologies saving residual kidney

A 65-year-old male patient presented a large mass of the left kidney and a concomitant saccular abdominal aortic aneurysm (AAA) of the infrarenal aorta. Due to the particular vascularization of the right kidney in order to allow an endovascular Aneurysm Repair (EVAR), a hybrid staged repair was planned. Through a median laparotomy, a left radical nephrectomy and an ilio-renal bypass were performed, thus creating the anatomical feasibility for subsequent EVAR. Two days later the AAA was excluded by positioning of an abdominal straight stent graft. This original surgical strategy showed to be effective and reduced invasiveness of traditional approach.

The preservation of accessory renal arteries should be considered the treatment of choice in complex endovascular aortic repair

OBJECTIVE

To evaluate renal function and renal parenchymal length changes secondary to the coverage or preservation of accessory renal arteries (ARA) in complex aortic repair.

METHODS

Single-center retrospective study identifying all patients undergoing fenestrated or branched endovascular aortic repair (f-b EVAR) who present ARA. Two groups were created, a preserved ARA group, with incorporation of the vessel as a dedicated fenestration or branch in the endograft plan, and a non-preserved ARA group, without incorporation of them. Early >30% decline of glomerular filtration rate (GFR), kidney infarcts and endoleaks (EL) were evaluated. Mid-term results with freedom from kidney shrinkage (defined as length decrease > 10%) at follow-up, freedom from GFR decrease >30% or need for postoperative dialysis at follow-up were also analyzed. Primary assisted patency of incorporated ARA was calculated.

RESULTS

From 2011-2020, 145 patients undergoing complex aortic repair presented with an ARA. After excluding ruptured aneurysms, 33 patients had the ARA preserved with their incorporation into the stentgraft (preserved ARA group), and 99 did not have preservation of them (not-preserved ARA group). There were no statistical differences in demographics or type of aneurysm. Patients in the ARA-preserved group had more ARA (median of 2 per patient vs 1 in the non-preserved ARA group, p 0,01) and bigger ARA (median 4 vs 3 mm in the non-preserved ARA group, p 0,001).Early postoperative worsening >30% of GFR (23 vs 6%, p 0,03) as well as postoperative renal infarction (57% vs 6%, p 0,001) and ARA-related EL (20 vs 0%, p 0,01) were statistically higher for the not-preserved ARA group.Mid-term kidney length showed significant shrinkage in the not-preserved ARA group compared to the ARA preserved group (9,7 vs 0%, p 0,001). Freedom from >30% GFR decline at 2 years was significantly higher for the preserved ARA group (83% vs 47%, p 0,01).Two-years primary assisted patency of incorporated ARA was 94%.

CONCLUSIONS

In complex aortic repair incorporation of ARA is feasible, with low complications and good primary assisted patency at 2 years. It leads to less postoperative early renal dysfunction as well as higher freedom for mid-term renal disfunction and kidney shrinkage.

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.

Endovascular stent graft repair with chimney technique of an abdominal aortic aneurysm with concomitant horseshoe kidney

A 68-year-old male patient was referred to our clinic for treatment of an infrarenal abdominal aortic aneurysm. Computed tomography angiography revealed a horseshoe kidney overlying the aneurysm. The patient had an accessory renal artery arising from the anterior aspect of the aneurysm. Endovascular aneurysm repair was performed and the accessory renal artery could be revascularized successfully by chimney technique without any morbidity. Postoperative computed tomography angiography revealed complete exclusion of the aneurysm with no endoleak and a patent chimney graft.

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.

Spontaneous Accessory Renal Artery Aneurysm Rupture in a Patient With Neurofibromatosis Type 1: A Case Report

True renal artery aneurysms are rare. Ruptured aneurysms are even rarer but can have devastating consequences. Renal artery aneurysms most commonly occur in patients with hypertension, atherosclerosis, or fibromuscular dysplasia. Treatment options can range from embolization to nephrectomy. We describe an interesting case of spontaneous accessory renal artery aneurysm rupture in a 44-year-old female with neurofibromatosis type 1 (NF1) who otherwise had no medical problems. She was successfully treated with selective coil embolization, recovered without complications, and maintained preoperative renal function.

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.

Iliorenal periscope graft to maintain blood flow to accessory renal artery

Parallel endografts such as "chimney" and "periscope" are being increasingly used to maintain blood flow to visceral and supra-aortic branches in patients with different aortic disorders. We present a new technique, "iliorenal periscope graft", in a patient with abdominal aortic aneurysm undergoing endovascular aortic repair. In this case, left accessory renal artery flows were provided by an iliorenal periscope graft that extends from the left accessory renal artery to the right common iliac artery in a retrograde fashion.

How Many Patients with Infrarenal Aneurysms are Candidates for Endovascular Repair? The Northern California Experience

Purpose:

To determine how many patients with abdominal aortic aneurysms (AAA) meet the anatomical selection criteria for AneuRx stent-graft repair in community hospitals of Northern California.

Methods:

The records were reviewed of 220 AAA patients (171 men, 49 women) who were considered for endovascular repair by the treating vascular surgeon at 28 community hospitals in Northern California between January and October 2001. Contrast computed tomographic angiography (CTA) and selective arteriography were performed at each institution and reviewed by a centralized, independent image-reading center. Selection criteria determined by the manufacturer and published in the indications for use were applied to each set of imaging studies. The number of patients who met inclusion criteria were recorded, as were the anatomical characteristics of each aneurysm.

Results:

The mean aneurysm size in the 220 patients was 55.3±0.7 mm. Among these patients, 122 (55%) were judged to be candidates for endovascular repair and 98 (45%) were considered ineligible. The primary anatomical reason for ineligibility was a short infrarenal neck in 43 (44%) patients, followed by a large proximal neck diameter (25, 25%), iliac aneurysms (10, 10%), extremely tortuous or calcified neck (7, 7%), iliac occlusion (6, 6%), and small distal aortic bifurcation and accessory renal arteries (5, 5%). Four (4%) patients were classified as non-candidates due to poor quality imaging. There was no difference in aneurysm diameter (54.0±0.8 versus 57.1±1.2 mm, p=NS) or age (72.2±1.2 versus 74.6±2.2 years, p=NS) between candidates and non-candidates. However, proportionally more men (60%) than women (39%) were eligible for endovascular repair with the AneuRx stent-graft (p<0.05). All 122 patients who were considered candidates for endovascular repair were treated, with successful stent-graft placement achieved in 121 (99%).

Conclusions:

Fifty-five percent of patients considered for endovascular AAA repair in community hospitals in Northern California met the anatomical selection criteria for the AneuRx stent-graft. Men appeared to be twice as likely to meet the eligibility requirements as women. Unfavorable infrarenal neck anatomy was the primary exclusion criterion for endovascular repair in this community setting.

A Novel Chimney Approach for Management of Horseshoe Kidney During EVAR

INTRODUCTION

Abdominal aortic aneurysms (AAAs) with coexisting horseshoe kidney (HSK) can be difficult to repair, with variable blood supply from the aorta and iliac/mesenteric vessels. Endovascular aneurysm repair (EVAR) has become a popular, less invasive approach to aneurysm care, and a chimney approach to EVAR (ChEVAR) has expanded its use to more complex anatomy. It is mandatory to maintain adequate perfusion to the HSK and visceral branches as part of the treatment of an AAA.

REPORT

A 61-year-old male with an HSK was incidentally found to have an infrarenal AAA that measured 6 cm on a non-contrast computed tomography (CT) scan performed originally for a urologic complaint. A diagnostic angiogram was performed to define arterial anatomy and he was found to have a large inferior mesenteric artery (IMA) arising 1 cm above the level of the aneurysm. ChEVAR was performed to preserve the IMA and flow to the HSK with a completion angiogram revealing patent renal arteries, IMA, and no evidence of an endoleak. Follow-up CT imaging demonstrated a Type II endoleak that resolved upon partial nephrectomy for a right-sided transitional cell carcinoma with resection of the arterial blood supply feeding the Type II endoleak.

DISCUSSION

IMA preservation via ChEVAR is technically feasible and was crucial to preserve blood supply via the IMA to the HSK. Partial nephrectomy treated the transitional cell carcinoma and resolved the Type II endoleak requiring no additional endovascular intervention. A unique treatment course demonstrated the benefits of less invasive interventions when repairing AAA with an HSK.

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.

Tratamento endovascular de aneurisma de aorta abdominal em paciente com rim em ferradura: relato de caso

O rim em ferradura é uma das anomalias urológicas congênitas mais comuns e está presente em cerca de 0,12% dos pacientes com aneurisma de aorta abdominal. O reparo cirúrgico convencional está associado a dificuldades técnicas que provavelmente aumentam a morbidade e a mortalidade, mas que podem ser evitadas com o tratamento endovascular. Relatamos um caso de um paciente de 64 anos com rim em ferradura e aneurisma de aorta abdominal, que foi submetido ao reparo endovascular do aneurisma com sucesso.

A unique case of a type II endoleak after EVAR caused by patent inferior mesenteric and accessory renal arteries

Type II endoleaks have been viewed as the Achilles' heel of endovascular repair of abdominal aortic aneurysms. This report describes a unique etiology to this common challenge and our approach to endovascular repair.

Horseshoe kidney and inflammatory abdominal aortic aneurysm: a case report and literature review

The combined presence of an inflammatory abdominal aortic aneurysm and a horseshoe kidney is a rare event with only one reported case in previously published data. We present a case of a horseshoe kidney with a concomitant 6-cm inflammatory abdominal aortic aneurysm and a 3.6-cm right iliac artery aneurysm repaired through a transperitoneal approach with aortoiliac reconstruction.

Abdominal Aortic Aneurysm with Coexistent Horseshoe Kidney

Surgical repair of an abdominal aortic aneurysm (AAA) concomitant with a horseshoe kidney (HSK) may be technically demanding because of the complex anomalies of the kidney and of its collecting system and arteries, the greater risk of HSK-related complications, and the often unexpected intraoperative finding of HSK itself. We reviewed a database of more than 500 patients with AAA observed in our surgical department from 1994 to the time of writing. Five patients had AAA concomitant with HSK. Two of these patients did not undergo surgery because of the small dimension of the aneurysm or because of their poor health. The other three underwent successful repair of AAA with different techniques; namely, an aortobifemoral bypass via a thoracoabdominal retroperitoneal incision in one, a straight graft via an emergency median laparotomy in one, and an endovascular repair followed by open surgery 4 years later for endotension in one. Abnormal minor renal arteries were deliberately occluded and only one of these caused a minor renal infarct, but without functional impairment. These data and a review of the literature indicate that HSK should not preclude repair of coexistent AAA, as imaging procedures provide the information necessary to plan the best approach for each patient. Up-to-date surgical procedures, a posteriori retroperitoneal approach or endovascular repair, and deliberate occlusion of the minor renal arteries appear feasible and safe as they avoid most of the anatomical problems and provide results equivalent to those of uncomplicated aortic surgery.

Intentional Coverage of a Main Renal Artery During Endovascular Juxtarenal Aortic Aneurysm Repair in Symptomatic High-Risk Patients

PURPOSE

To describe the efficacy and morbidity of intentionally covering a main renal artery during symptomatic juxtarenal endovascular aneurysm repair (EVAR).

CASE REPORTS

Two patients with symptomatic juxtarenal abdominal aortic aneurysm (AAA) were felt to be at prohibitive risk for open repair. Each underwent EVAR with intentional coverage of 1 main renal artery to achieve adequate proximal hemostatic seal. One patient died at 24 months; the second is symptom-free at 10 months. Both aneurysms initially decreased in diameter. Both patients had increased serum creatinine and required increased therapy for hypertension, but neither required hemodialysis. Renal volume decreased 48.7% and 68.0%, respectively.

CONCLUSION

Intentional coverage of a main renal artery during EVAR for a symptomatic juxtarenal aneurysm resulted in effective short-term AAA repair with no need for dialysis. Despite the increased requirement for antihypertensive medications and the observed decline in renal function, this technique provides an option for treatment of this difficult patient subset.

Clinical Significance of Type II Endoleak after Endovascular Repair of Abdominal Aortic Aneurysm

Type II endoleaks after endovascular repair of abdominal aortic aneurysm (EVAR) are a result of retrograde flow from arterial branches (e.g., lumbar and inferior mesenteric) refilling the aneurysm sac, which has been excluded by the stent graft. Controversy continues with regard to the clinical significance and treatment of type II endoleaks. To develop recommendations for management, we analyzed outcome data from 10 EVAR trials completed over the last 5 years involving a total of 2,617 cases. The incidence of type II endoleak at discharge or 30 days was 6-17%, at 6 months 4.5-8%, and at 1 year 1-5%. Successful resolution of endoleak following secondary interventions was observed in 11-100% of cases. There were 10 conversions to open repair and no ruptures related to type II endoleak. In patients observed for 12 months with computed tomography and/or ultrasound, approximately one-half of type II endoleaks disappeared spontaneously. In the absence of a type I endoleak, our analysis of the current literature suggests that intervention for type II endoleak should be undertaken for abdominal aortic aneurysm sac enlargement occurring after 6 months, persistence for >12 months without abdominal aortic aneurysm sac enlargement, or an aneurysm sac pressure >20% of systolic blood pressure; translumbar aneurysm sac thrombosis and intra-arterial feeding vessel occlusion appear to be prudent management options.

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.

The Management of Abdominal Aortic Aneurysms in Patients with Concurrent Renal Impairment

INTRODUCTION

Patients with concurrent renal impairment and abdominal aortic aneurysms present a significant challenge in terms of pre-operative, intra-operative and post-operative management. This aim of this review was to determine the risks of surgery in this patient group and determine whether any clear management strategies exist to enhance their clinical management.

METHODS

Systematic review of published literature giving details of the outcome of open or endovascular abdominal aortic aneurysm repair in patients with pre-operative renal impairment. Papers concerning the management of post-operative acute renal failure in patients with normal pre-operative renal function has not been included.

RESULTS

There is little data regarding patients with end-stage renal failure and AAA although these patients appear to have a high peri-operative mortality rate. In contrast, those with renal impairment do not have a significantly higher mortality rate than those with normal renal function, rather they have a higher risk of complications associated with surgery and may require more intensive post-operative organ system support than normal patients. Many have a transient deterioration in renal function in the immediate peri-operative period that will resolve. In the case of patients with ruptured AAA, it is not clear whether pre-operative renal impairment affects mortality.

Transrenal fixation of aortic stent-grafts: current status and future directions

Aortic stent-graft repair has been widely used in clinical practice for more than a decade, achieving satisfactory results compared to open surgical techniques. Transrenal fixation of stent-grafts is designed to obtain secure fixation of the proximal end of the stent-graft to avoid graft migration and to prevent type I endoleak. Unlike infrarenal deployment of stent-grafts, transrenal fixation takes advantage of the relative stability of the suprarenal aorta as a landing zone for the uncovered struts of the proximal stent. These transostial wires have sparked concern about the patency of the renal arteries, interference with renal blood flow, and effects on renal function. Although short to midterm results with suprarenal stent-grafts have not shown significant changes in renal function, long-term effects of this technique are still not fully understood. This review will explore the current status of transrenal fixation of aortic stent-grafts, potential risks of stent struts relative to the renal ostium, alternative methods to preserve blood flow to the renal arteries, and future directions or developments in stent-graft design to prevent myointimal proliferation around the stent struts.

Endovascular aneurysm repair: treatment of choice for abdominal aortic aneurysm coincident with horseshoe kidney? three case reports and review of literature

There is still controversy as to which surgical method is the most suitable for repair of abdominal aortic aneurysm with concomitant horseshoe kidney (AAA-HSK). We report three cases of AAA-HSK treated with endovascular aneurysm repair. In one of these patients we sacrificed the accessory renal artery by applying coils before the operation. Renal infarction, hypertension, or elevated serum creatinine level was not observed in any of our patients. If the blood supply to the kidneys is taken into consideration, endovascular aneurysm repair is our preferred surgical method for repair of AAA-HSK when anatomic conditions are suitable for stent-graft application and kidney function is normal.

Suprarenal fixation of endograft in abdominal aortic aneurysm treatment: focus on renal function

OBJECTIVE

The objective of this work was to evaluate any variation of renal function detected by renal scintigraphy after the suprarenal fixation of endografts for abdominal aortic aneurysm (AAA) repair.

SUMMARY BACKGROUND DATA

In the few articles that have considered this problem, renal function was evaluated only by biochemical tests, which are inadequate in demonstrating small changes in renal function and in appreciating the worsening of a single kidney's function.

METHODS

Between April 1999 and May 2002, 47 patients with an inappropriate infrarenal proximal neck had a suprarenal fixation for AAA. To assess renal function, a technetium-99m diethylene triamine penta-acetic acid (TC-DTPA) perfusion scintigraphy was performed preoperatively on the third postoperative day and at 6, 12 months, and then yearly thereafter. Worsening of renal function was defined as a decrease of glomerular filtration rate (GFR) > or =20% (detected with Gates method). Serum creatinine level was tested preoperatively and at the first and third postoperative day.

RESULTS

Endograft deployment was technically successful in 44 patients (93.6%); clinical perioperative success was obtained in 46 patients (97.8%). In 12 patients (25.5%), a permanent reduction of the GFR was observed using postoperative TC-DTPA perfusion scintigraphy. By 99m TC-DTPA perfusion scintigraphy, a permanent reduction of GFR was observed postoperatively in 12 patients. A slight GFR reduction (<20%) was present in 7 (14.9%) patients, due to the planned occlusion of accessory renal arteries. A more significant GFR reduction (>20%) was present unexpectedly in 5 (10.6%) patients, in 3 of these a single kidney was involved, in 5 both with an increase of the serum creatinine level >20%.

CONCLUSIONS

Suprarenal fixation of endografts in AAA treatment is a safe procedure with good early and midterm procedural results and a risk of GFR impairment (>20%) of 10.6%.

The Renal Impact of Aortic Stent-Grafting in Patients with a Horseshoe Kidney

Aortic stent grafting may be an alternative to surgery for patients with an abdominal aortic aneurysm and coexistent horseshoe kidney but is not without difficulties. This study examines the renal consequences of aortic stent grafting in such patients. This is a retrospective review of patients with horseshoe kidney in whom aortic stent grafting was performed between December 1995 and August 2000. Follow-up occurred within the EUROSTAR protocol and included measurement of serum creatinine. Of 130 patients in whom aortic stent grafting was performed, 4 had coexistent horseshoe kidney. In all patients the aneurysm was successfully excluded with the occlusion of between one and four anomalous renal arteries. At follow-up, no clinically significant renal impairment was detected. Endovascular aneurysm repair is an attractive option for patients with a horseshoe kidney and normal preoperative creatinine levels.

Congenital familial vascular anomalies: a study of patients with an anomalous inferior vena cava, and of their first-degree relatives

With magnetic resonance angiography and computed tomography, congenital anomalies of the inferior vena cava are diagnosed more frequently than they used to be. Accessory renal arteries identified by magnetic resonance angiography in a patient with an anomalous inferior vena cava indicated a combination of arterial and venous abnormalities. The study was initiated to screen consecutive patients with an anomalous inferior vena cava for concomitant abdominal and pelvic arterial abnormalities, and their first-degree relatives for congenital vascular anomalies. Magnetic resonance angiography identified in 2 of 5 patients with an anomalous inferior vena cava concomitant accessory renal arteries and in 5 of 11 first-degree relatives major abdominal vascular anomalies including accessory renal arteries, accessory renal veins, and anomalies of the hepatic artery. None of the relatives showed abnormalities of the inferior vena cava. The familial occurrence of vascular anomalies strongly suggests an underlying pathogenetic component in affected family members. In patients with a congenital anomaly of the inferior vena cava, concomitant arterial abnormalities should be considered. First-degree relatives may be at risk for congenital vascular anomalies.

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

The aim of this study was to evaluate clinical sequelae of accessory renal artery exclusion during endo-AAA repair. Medical records and pre- and postoperative CT scans were reviewed from 114 AAA patients treated with the AneuRx stent graft between 1996-2001. Thirty-seven accessory renal arteries were identified in 32/114 patients (28%) with 19/32 patients having infrarenally located accessory renal arteries. In group I (11 patients), the stent graft excluded 11 accessory renal arteries. In group II (8 patients), eight accessory renal arteries were not excluded. Average infrarenal neck length was 24.9 mm in group I vs. 30.7 mm in group II (p = 0.07). The average length of device seal was similar in both groups (19.4 vs. 18.5 mm, p = 0.67). There were no perioperative deaths, significant postoperative hypertension, rise in serum creatinine, or postoperative renal infarctions in either group. Three of eight patients (38%) in the non-excluded group developed type I proximal endoleaks whereas none in the excluded patient group did (p = 0.06). Accessory renal arteries may be safely excluded during endovascular AAA repair and may result in a more secure proximal device fixation.

Does transrenal fixation of aortic endografts impair renal function?

OBJECTIVES

Transrenal fixation (TFX) of aortic endografts is thought to increase the risk for renal infarction and impaired renal function. We studied the late effects of TFX on renal function and perfusion.

METHODS

Of 189 patients with commercial aortic endografts, which we inserted between 1995 and 2002, we reviewed data for 130 patients (112 men, 18 women) with available creatinine (Cr) concentration and contrast enhanced computed tomography (CT) scans preoperatively and 1 to 97 months after the procedure. Of the 130 patients, 69 patients had TFX and 61 patients had infrarenal fixation (IFX). Both groups were physiologically comparable. Average age was 76 +/- 8 years for patients with TFX and 75 +/- 8 years for patients with IFX. Presence of renal infarct or renal artery occlusion was determined by nephrograms on serial contrast-enhanced CT scans.

RESULTS

Mean follow-up was 17 +/- 16 months (range, 1-54 months) for TFX and 21 +/- 21 months (range, 1-97 months) for IFX. Mean serum Cr concentration increased significantly during long-term follow-up in both groups (TFX, 1.3 +/- 0.5 mg/dL to 1.5 +/- 0.8 mg/dL, P <.01; IFX, 1.3 +/- 0.7 mg/dL to 1.4 +/- 0.8 mg/dL, P <.03). Creatinine clearance (CrCl) similarly decreased over long-term follow-up in both groups (TFX, 53.3 +/- 17.7 mL/min/1.73 m(2) to 47.9 +/- 16.2 mL/min/1.73 m(2), P <.01; IFX, 58.1 +/- 22.7 mL/min/1.73 m(2) to 53.1 +/- 23.4 mL/min/1.73 m(2), P <.02). There were no significant differences in the increase in Cr concentration (P =.19) or decrease in CrCl (P =.68) between TFX and IFX groups. Small renal infarcts were noted in four patients (5.8%) in the TFX group and one patient (1.6%) in the IFX group. No increase in Cr concentration or decrease in CrCl was noted in any patient with a renal infarct. Postoperative renal dysfunction developed in 7 of 69 patients (10.1%) in the TFX group and 7 of 61 patients (11.5%) in the IFX group. There were no statistically significant differences between groups with respect to number of patients with new renal infarcts (P =.37) or postoperative renal dysfunction (P =.81).

CONCLUSION

There is a slight increase in serum Cr concentration and decrease in CrCl after aortic endografting. However, there was no significant difference in these changes between patients with TFX and IFX. Although TFX may produce a higher incidence of small renal infarcts, these do not impair renal function. Thus our midterm results suggest that TFX can be performed safely, with no greater change in renal function than observed after IFX.