Renal function changes after snorkel/chimney repair of juxtarenal aneurysms

Results of the Italian Collaborators for Evar Registry on Acute Kidney Injury After Elective Endovascular Aortic Repair of Infrarenal Abdominal Aortic Aneurysm

OBJECTIVES

To analyze the incidence and predictive factors of postoperative acute kidney injury (AKI) after elective standard endovascular aortic repair (EVAR) in a large recent, multicenter cohort.

MATERIALS AND METHODS

This is a multicenter, retrospective, financially unsupported physician-initiated observational cohort study. Between January 2018 and March 2021, only patients treated with elective standard EVAR for infrarenal non-infected abdominal aortic aneurysm were analyzed. Patients already on hemodialysis (HD) were excluded. AKI was defined as an increase in serum creatinine (sCr) ≥0.3 mg/dL within 48 hours or an increase in sCr to ≥1.5 times baseline known or presumed to have occurred within 7 days, or a urine volume of <0.5 mL/kg/h for 6 hours. Primary outcomes of interest were AKI incidence at 30 days and freedom from HD at 1-year follow-up. Secondary outcomes were freedom from severe postoperative complication, and freedom from aorta-related mortality (ARM) at 1 year.

RESULTS

The final cohort analyzed 526 (29.8%). There were 489 (93%) males and 37 (7%) females: the median age was 76 years (interquartile range [IQR], 71-81). Chronic kidney disease (CKD) was present in 86 (16.3%) patients. Early mortality was observed in 8 (1.5%) patients, none was aorta-related. Complication rate was 17.1% (n=89). AKI was observed in 17 (3.2%). Renal replacement therapy was needed in 4 (0.8%). HD was transitory in 2 cases and definitive in 1. Binary logistic regression analysis identified CKD (odds ratio [OR]: 4.68, 95% confidence interval [CI]: 2.10-10.45, p<0.001), and the presence of renal artery stenosis (OR: 3.80, 95% CI: 1.35-10.66, p=0.011) to be associated with an increased risk of postoperative AKI. Estimated freedom from ARM was 94.9% at 1 year. Estimated freedom from HD rate at 1 year was 94%: This was significantly different between patients with preoperative CKD and those who did not have preoperative CKD (log-rank, p=0.042).

CONCLUSION

AKI after elective standard EVAR still occurs but with an acceptably low incidence rate. Preoperative CKD is the most important predictor for postoperative AKI, which was not associated with the need for HD at 1-year follow-up but with a higher propensity of mortality.

CLINICAL IMPACT

This "real world" experience confirm that EVAR performed with standard contrats agent protocol remains safe for acute kidney injury development. Therefore, only patients presenting with preoperative borderline or ascertained chronic kidney disease will take the most advantage from the use of carbon dioxide contrast.

Transrenal Endovascular Aneurysm Repair-A Novel Approach for Abdominal Aortic Aneurysms with Difficult Neck Anatomy

BACKGROUND

The endovascular approach to treating ruptured or symptomatic abdominal aortic aneurysms (AAAs) with difficult neck anatomy still poses a major challenge. This study proposes and evaluates the outcomes of a novel technique, Transrenal Endovascular Aneurysm Repair (Tr-EVAR) which utilizes the top ring 'valley' and 'peak' configuration of the Anaconda stent graft to achieve proximal seal in AAAs with an unfavourable neck.

METHODS

All patients treated with Tr-EVAR over a period of 10 years were identified retrospectively. Demographic, clinical and outcome data were collected, and survival analysis was performed. The time-to-event was analyzed using Kaplan-Meier curves for complication-free survival, reintervention-free survival, and overall survival.

RESULTS

During the study period, 36 patients ruptured, symptomatic or large AAAs having unfavorable necks and not fit for open repair underwent Tr-EVAR. Two patients died in the first 30 days postprocedure (5.6%). The overall survival at 1 year, 3 years and 5 years were 86%, 72% and 54% respectively with a mean overall survival of 74.0 months (SE 7.8, 95% confidence interval 58.7-89.3) which was comparable to chimney endovascular aneurysm repair (EVAR). The complication-free survival and reintervention-free survival at 1 year, 3 years, and 5 years were 75%, 61%, 42%, 78%, 64%, and 45%, respectively.

CONCLUSIONS

Tr-EVAR can be considered as an off-the-shelf solution for urgent cases not fit for open repair with unfavourable neck features for standard EVAR. Careful patient selection and planning have generated acceptable immediate, midterm and long-term results comparable to those presented by chimney EVAR in the literature.

A novel pre-operative risk assessment tool to identify patients at risk of contrast associated acute kidney injury after endovascular abdominal aortic aneurysm repair

OBJECTIVES

Contrast-associated acute kidney injury (CA-AKI) after endovascular abdominal aortic aneurysm repair (EVAR) is associated with mortality and morbidity. Risk stratification remains a vital component of preoperative evaluation. We sought to generate and validate a pre-procedure CA-AKI risk stratification tool for elective EVAR patients.

METHODS

We queried the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2) database for elective EVAR patients and excluded those on dialysis, with a history of renal transplant, death during procedure, and without creatinine measures. Association with CA-AKI (rise in creatinine > 0.5 mg/dL) was tested using mixed effects logistic regression. Variables associated with CA-AKI were used to generate a predictive model via a single classification tree. The variables selected by the classification tree were then validated by fitting a mixed effects logistic regression model into the Vascular Quality Initiative (VQI) dataset.

RESULTS

Our derivation cohort included 7,043 patients, 3.5% of whom developed CA-AKI. After multivariate analysis, age (OR 1.021, 95% CI 1.004-1.040), female sex (OR 1.393, CI 1.012-1.916), GFR < 30 ml/min (OR 5.068, CI 3.255-7.891), current smoking (OR 1.942, CI 1.067-3.535), COPD (OR 1.402, CI 1.066-1.843), maximum AAA diameter (OR 1.018, CI 1.006-1.029), and presence of iliac artery aneurysm (OR 1.352, CI 1.007-1.816) were associated with increased odds of CA-AKI. Our risk prediction calculator demonstrated that patients with a GFR <30 ml/min, females, and patients with a maximum AAA diameter of > 6.9 cm are at higher risk of CA-AKI after EVAR. Using the VQI dataset (N = 62,986), we found that GFR <30 ml/min (OR 4.668, CI 4.007-5.85), female sex (OR 1.352, CI 1.213-1.507), and maximum AAA diameter > 6.9 cm (OR 1.824, CI 1.212-1.506) were associated with increased risk of CA-AKI after EVAR.

CONCLUSIONS

Herein, we present a simple and novel risk assessment tool that can be used pre-operatively to identify patients at risk of CA-AKI after EVAR. Patients with a GFR < 30 ml/min, maximum AAA diameter > 6.9 cm, and females who are undergoing EVAR may be at risk for CA-AKI after EVAR. Prospective studies are needed to determine the efficacy of our model.

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.

Selection criterion for endovascular aortic repair in those with chronic kidney disease

OBJECTIVE

Endovascular aortic repair (EVAR) is the preferred method of repair for abdominal aortic aneurysms (AAAs). However, patients with advanced chronic kidney disease (CKD) are a high-risk group, and it is unknown which patients with CKD benefit from EVAR vs continued surveillance. The purpose of this study was to identify which patients with advanced CKD may benefit from EVAR.

METHODS

The Vascular Quality Initiative Database was utilized to identify elective EVARs for AAAs. Patients were excluded if they underwent urgent or emergent repairs. CKD stages were categorized based on preoperative estimated glomular filtration rate (eGFR) and dialysis status. Predicted 1-year mortality of untreated AAAs was calculated by modifying a validated comorbidity score that predicts 1-year mortality (Gagne Index) without repair. The primary outcome was actual 1-year mortality, which was compared with the predicted 1-year mortality without repair.

RESULTS

A total of 34,926 patient met study criteria. There were differences in Gagne Indices among the varying classes of CKD. Patients with CKD 4 and CKD 5 had the highest 1-year mortality rates, followed by CKD 3b, which was significantly higher than those with CKD 1 and CKD 2. Patients with CKD 4 had no differences between actual 1-year mortality with EVAR and predicted 1-year survival without EVAR across all AAA sizes. Those with CKD 5 had worse actual 1-year survival with EVAR than predicted 1-year survival without EVAR for AAAs <5.5 cm. Patients with CKD 5 only experienced an actual mortality benefit with EVAR compared with predicted 1-year mortality without EVAR for AAAs ≥7.0 cm.

CONCLUSION

The current data suggest that patients with CKD 3b, 4, and 5 represent a high-risk group who may not benefit from elective EVAR utilizing traditional size criteria. Patients with CKD 4 and 5 with AAAs <5.5 cm do not benefit from elective EVAR. In patients with CKD 5, elective EVAR may need to be reserved for AAAs ≥7.0 cm unless there are other concerning anatomic characteristics.

Endovascular repair of abdominal and thoracoabdominal aneurysms using chimneys and periscopes is associated with poor outcomes

OBJECTIVE

Chimneys and periscopes are often used to treat pararenal or thoracoabdominal aneurysms de novo or after failed open or endovascular repair. We sought to describe our institutional experience, given their limited success and questionable long-term outcomes.

METHODS

We retrospectively reviewed the electronic records for patients treated with chimneys/periscopes from 1997 through 2020. Baseline characteristics, procedural details, periprocedural complications, reinterventions, and midterm outcomes were collected.

RESULTS

Fifty-eight patients (86 vessels) were treated; the median follow-up was 32 months (range, 0.03-104 months). There were 36% (n = 21) juxta-renal, 2% (n = 1) para-visceral, and 21% (n = 12) thoracoabdominal aneurysms, and 41% (n = 24) had pararenal failure of prior endovascular aneurysm repair (n = 17) or open repair (n = 7). Stent configuration for the majority of the 86 vessels (n = 80; 93%) treated were chimney configuration (n = 6 periscopes; 7%). The most common stent graft utilized was Viabahn, and 8.1% (n = 7) were reinforced with a bare metal stent. Although the majority of the cases were elective, 36.2% (n = 21) of the cases were urgent/emergent. At the conclusion of the initial procedure, 16 of 58 patients had an endoleak (gutter, 50% [8/16]; type Ia, 25% [4/16]; and type II, 25% [4/16]). On follow-up, 14 of 58 patients developed one or more endoleaks, with the most common endoleaks being a gutter endoleak (35% [7/20]). Other endoleaks observed included 30% (6/20) type III, 15% (3/20) type Ia, 15% (3/20) type Ib, and 5% (1/20) type II. Eleven of 58 patients underwent interventions for one or more endoleak (gutter, 33% [5/15]; type Ib, 20% [3/15]; type II, 7% [1/15]; and type III, 40% [6/15]). Twelve of 58 patients returned to the operating room for one or more procedures during the index hospitalization (five laparotomies, three dialysis access, three acute limb ischemia, and four chimney/periscope interventions). Ten of 58 patients underwent angioplasty/stenting for chimney/periscope compression or occlusion during the follow-up period. Survival was 61.3% at 1 year by Kaplan-Meier analysis (75% for elective, 37% for urgent/emergent) (aneurysm-related death, 22%). Cox hazard modeling showed that aneurysm diameter (hazard ratio, 1.03; 95% confidence interval, 1.004-1.05; P = .02) and urgent/emergent interventions (hazard ratio, 3.6; 95% confidence interval, 1.33-9.74; P = .01) were predictors of mortality.

CONCLUSIONS

Endovascular repair of aortic aneurysms with chimneys/periscopes is associated with poor outcomes, including limited technical success and aneurysm exclusion, as well as high morbidity and mortality, with a high rate of reinterventions both in the immediate postoperative period and on follow-up. They should be used only when other surgical or endovascular options are not possible.

Patient-specific computational flow modelling for assessing hemodynamic changes following fenestrated endovascular aneurysm repair

Objective

This study aimed to develop an accessible patient-specific computational flow modelling pipeline for evaluating the hemodynamic performance of fenestrated endovascular aneurysm repair (fEVAR), with the hypothesis that computational flow modelling can detect aortic branch hemodynamic changes associated with fEVAR graft implantation.

Methods

Patients who underwent fEVAR for juxtarenal aortic aneurysms with the Cook ZFEN were retrospectively selected. Using open-source SimVascular software, preoperative and postoperative visceral aortic anatomy was manually segmented from computed tomography angiograms. Three-dimensional geometric models were then discretized into tetrahedral finite element meshes. Patient-specific pulsatile in-flow conditions were derived from known supraceliac aortic flow waveforms and adjusted for patient body surface area, average resting heart rate, and blood pressure. Outlet boundary conditions consisted of three-element Windkessel models approximated from physiologic flow splits. Rigid wall flow simulations were then performed on preoperative and postoperative models with the same inflow and outflow conditions. We used SimVascular's incompressible Navier-Stokes solver to perform blood flow simulations on a cluster using 72 cores.

Results

Preoperative and postoperative flow simulations were performed for 10 patients undergoing fEVAR with a total of 30 target vessels (20 renal stents, 10 mesenteric scallops). Postoperative models required a higher mean number of mesh elements to reach mesh convergence (3.2 ± 1.8 × 10⁶ vs 2.6 ± 1.1 × 10⁶; P = .005) with a longer mean computational time (10.3 ± 6.3 hours vs 7.8 ± 3.5 hours; P = .04) compared with preoperative models. fEVAR was associated with small but statistically significant increases in mean peak proximal aortic arterial pressure (140.3 ± 11.0 mm Hg vs 136.9 ± 8.7 mm Hg; P = .02) and peak renal artery pressure (131.6 ± 14.8 mm Hg vs 128.9 ± 11.8 mm Hg; P = .04) compared with preoperative simulations. No differences were observed in peak pressure in the celiac, superior mesenteric, or distal aortic arteries (P = .17-.96). When measuring blood flow, the only observed difference was an increase in peak renal flow rate after fEVAR (17.5 ± 3.8 mL/s vs 16.9 ± 3.5 mL/s; P = .04). fEVAR was not associated with changes in the mean pressure or the mean flow rate in the celiac, superior mesenteric, or renal arteries (P = .06-.98). Stenting of the renal arteries did not induce significant changes time-averaged wall shear stress in the proximal renal artery (23.4 ± 8.1 dynes/cm² vs 23.2 ± 8.4 dynes/cm²; P = .98) or distal renal artery (32.7 ± 13.9 dynes/cm² vs 29.6 ± 11.8 dynes/cm²; P = .23). In addition, computational visualization of cross-sectional velocity profiles revealed low flow disturbances associated with protrusion of renal graft fabric into the aortic lumen.

Conclusions

In a pilot study involving a selective cohort of patients who underwent uncomplicated fEVAR, patient-specific flow modelling was a feasible method for assessing the hemodynamic performance of various two-vessel fenestrated device configurations and revealed subtle differences in computationally derived peak branch pressure and blood flow rates. Structural changes in aortic flow geometry after fEVAR do not seem to affect computationally estimated renovisceral branch perfusion or wall shear stress adversely. Additional studies with invasive angiography or phase contrast magnetic resonance imaging are required to clinically validate these findings. (JVS–Vascular Science 2021;2:53-69.)

Clinical Relevance

Using a computational flow modelling for assessing the hemodynamic performance of fenestrated endovascular aneurysm repair (fEVAR), this real-world, patient-specific study included 10 participants and found that structural changes in aortic flow geometry after fEVAR did not seem to adversely impact estimated renal or visceral branch perfusion metrics (eg, peak and mean arterial pressure and flow rates) or wall shear stress. These findings overall support the ongoing clinical use of commercially available fEVAR devices for repair of juxtarenal aortic aneurysms, and provides a computational framework for future evaluation of fEVAR configurations in a preoperative or postoperative settings.

The bio-sonographic index. A novel modality for early detection of acute kidney injury after complex vascular surgery. A protocol for an exploratory prospective study

Objective

Acute kidney injury (AKI) is a common complication of complex aortic surgery with high mortality, morbidity and health care expense. The current definition of AKI does not allow for structural characterization of the kidneys and utilizes functional indices with substantial limitations leading to delayed diagnosis and ineffective interventions. The aim of this study is to develop a method of early detection of structural renal abnormalities that can precede and predict the occurrence of AKI in this population. We propose a novel combined index of ultrasonography (shear wave elastography), biomarkers of renal stress (urinary insulin growth factor binding protein-7, IGFBP-7 and inhibitor of tissue metalloproteinase-2, TIMP-2) and renal injury markers (urinary neutrophil gelatinase-associated lipocalin -NGAL)- the bio-sonographic index (BSI).

Methods

A prospective observational study at a tertiary referral center will be performed enrolling 80 patients undergoing elective open and endovascular repair of the visceral aorta. The BSI will be evaluated at baseline, and at 6 and 24 hours after the procedure. The primary outcome is the occurrence of AKI according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria. Each patient will be his/her own control. A reference group of 15 healthy volunteers who are not undergoing interventions will be enrolled to test the feasibility of and to refine the novel SWE protocol. The BSI will be tested for its predictability of the occurrence of AKI. Comparisons will be made between individual and combined components of the BSI and traditional markers used in the KDIGO definition; serum creatinine and urine output in terms of baseline status of the kidney. Correlations will be made between the BSI and conventional indices of AKI and exploratory analyses will be conducted to identify individual disease patterns using the BSI.

Discussion

We hypothesize that the BSI will be a sensitive index of early structural abnormalities that precede and predict the occurrence of AKI as defined by KDIGO in complex vascular surgery.

Trial registration

ClinicalTrials.gov NCT04144894. Registered 1/6/2020.

Renal Artery Outcomes After Open Repair of Suprarenal or Type IV Thoraco-abdominal Aortic Aneurysms

OBJECTIVE

The aim of this study was to evaluate the mid and long term patency of elective renal artery reconstructions during open surgical repair of suprarenal aortic aneurysms (SRAA) and type 4 thoraco-abdominal aortic aneurysms (T4AAA).

METHODS

This retrospective, single centre study included all consecutive patients who underwent surgery for SRAA or T4AAA between January 2009 and December 2019 at Toulouse University Hospital. All patients underwent strict pre-operative planning with computed tomography angiography (CTA) and 3D reconstruction of the aortic aneurysm, visceral and renal artery anatomy to choose the most appropriate surgical technique for each case. Primary patency, primary assisted patency, and rates of re-intervention were calculated using the Kaplan-Meier method.

RESULTS

In total, 103 patients, having undergone 159 renal artery revascularisation procedures, were enrolled in the study. Fifty-five patients presented with a type T4AAA and 48 patients with a SRAA. In hospital mortality was 2.9%. In association with aortic surgery, 100 direct re-implantation (62.8%), 48 retrograde bypasses (30.1%), and 11 anterograde bypasses (6.9%) of the renal arteries were performed. Median follow up was 45.9 ± 36 months. Renal artery primary patency rates were 99.4%, 96.4%, and 93.1% at one, three, and five years, respectively. Assisted primary patency rates were 99.4%, 97.7%, and 97.7% at one, three, and five years, respectively, with five cases of renal stenosis > 70% successfully treated by renal stenting. No significant difference in patency was found regarding the type of renal revascularisation.

CONCLUSION

This retrospective study suggests that the mid term patency of elective open renal artery reconstruction during SRAA and type T4AAA surgery preceded by pre-operative planning with 3D-CTA reconstruction, yields excellent outcomes whatever the technique used.

Reporting standards for endovascular aortic repair of aneurysms involving the renal-mesenteric arteries

Endovascular aortic aneurysm repair of complex aortic aneurysms requires incorporation of side branches using specially designed aortic stent grafts with fenestrations, directional branches, or parallel stent grafts. These techniques have been increasingly used and reported in the literature. The purpose of this document is to clarify and to update terminology, classification systems, measurement techniques, and end point definitions that are recommended for reports dealing with endovascular repair of complex abdominal and thoracoabdominal aortic aneurysms involving the renal and mesenteric arteries.

Renal Dysfunction Following Elective Endovascular Aortic Aneurysm Repair

Abdominal aortic aneurysm (AAA) is a degenerative disease of the aortic wall with potentially fatal complications. Open repair (OR) was considered the gold standard, until the emergence of endovascular aneurysm repair (EVAR), which is less invasive and equally (if not more) effective. As the popularity of endovascular procedures grows, related complications become more evident, with kidney damage being one of them. Although acute kidney injury (AKI) following EVAR is relatively common, its true incidence is still uncertain. Also, there is insufficient data concerning long-term renal outcomes after EVAR, especially with repeated contrast agent exposure. Despite the lack of firm evidence on the effectiveness of individual strategies, it is evident that prevention of AKI following EVAR requires a multifactorial approach. This review focuses on recent findings based on human studies regarding the current evidence of renal impairment after EVAR, its quantification and strategies for its prevention.

Acute Renal Failure/Acute Kidney Injury (AKI) Associated with Endovascular Procedures

AKI is one of the most common yet underdiagnosed postoperative complications that can occur after any type of surgery. Contrast-induced nephropathy (CIN) is still poorly defined and due to a wide range of confounding individual variables, its risk is difficult to determine. CIN mainly affects patients with underlying chronic kidney disease, diabetes, sepsis, heart failure, acute coronary syndrome and cardiogenic shock. Further research is necessary to better understand pathophysiology of contrast-induced AKI and consequent implementation of effective prevention and therapeutic strategies. Although many therapies have been tested to avoid CIN, the only potent preventative strategy involves aggressive fluid administration and reduction of contrast volume. Regardless of surgical technique—open or endovascular—perioperative AKI is associated with significant morbidity, mortality and cost. Endovascular procedures always require administration of a contrast media, which may cause acute tubular necrosis or renal vascular embolization leading to renal ischemia and as a consequence, contribute to increased number of post-operative AKIs.

Fenestrated-branched endovascular aortic repair in patients with chronic kidney disease

OBJECTIVE

Renal function impairment is a common complication after open repair of complex abdominal aortic aneurysms and thoracoabdominal aortic aneurysms (TAAAs). The purpose of this study was to assess renal perioperative outcomes and renal function deterioration after fenestrated-branched endovascular aneurysm repair (F/BEVAR) in patients with chronic kidney disease (CKD).

METHODS

The study included 186 patients who underwent F/BEVAR between 2013 and 2018 for suprarenal, juxtarenal, and type I to type IV TAAAs. Glomerular filtration rate (GFR) was calculated using the Modification of Diet in Renal Disease (MDRD) study equation. Postoperative acute kidney injury (AKI) and CKD were defined using RIFLE criteria (Risk, Injury, Failure, Loss, and End-stage renal disease) and CKD staging system (stage ≥3, GFR <60 mL/min/1.73 m²), respectively. For those without baseline CKD, renal decline was defined as a drop in GFR <60 mL/min/1.73 m² (ie, progression to CKD stage 3 or higher). For patients with baseline renal dysfunction, GFR decline ≥20% or progression in CKD stage (ie, from stage 3 to stage 4) was considered renal decline.

RESULTS

CKD was present in 83 patients (44.6%). Postoperative AKI was diagnosed in 27 patients (14.5%); 13 (48.1%) had history of CKD and 14 (51.9%) had adequate renal function preoperatively (P = .8). None of these patients required permanent renal replacement therapy. Intraoperative technical success was 100%. Overall 30-day mortality was 1.1%. There was no difference in 30-day mortality in patients with (1.2%) and without (1.0%) CKD (P = .5). During a median follow-up time of 12 months (interquartile range, 6-23 months), renal decline was observed in 21 patients (25.3%) with previous CKD and in 11 patients (10.6%) without CKD (P = .01). Among patients with previous CKD, 18 patients (9%) progressed from stage 3 CKD to stage 4. In patients with progression in CKD stage, two (5%) had renal stent stenosis requiring restenting. Among patients with renal decline, 13 had juxtarenal aneurysms (21.3%), 27 had suprarenal aneurysms (44.3%), and 21 had TAAAs (34.3%; P = .4). Subset analysis of patients who developed AKI in the immediate postoperative period found that patients with a history of CKD were less likely to experience freedom from renal decline.

CONCLUSIONS

F/BEVAR is an effective and safe procedure for patients with complex abdominal aortic aneurysms and TAAAs, even among patients with CKD. The frequency of AKI was not affected by pre-existing CKD. Midterm outcomes demonstrated that progression of CKD was more frequent among patients with pre-existing CKD, but permanent renal replacement therapy was not required. Anatomic extent of aneurysms did not affect CKD progression. CKD patients are susceptible to renal decline over time if they experience AKI in the postoperative period. Therefore, preventing AKI in the postoperative period should be regarded as a priority. Long-term effects of CKD after F/BEVAR remain to be elucidated.

The removal of all proximal aneurysmal aortic tissue does not affect anastomotic degeneration after open juxtarenal aortic aneurysm repair

OBJECTIVE

For the open treatment of juxtarenal aortic aneurysms (JRAAs), some argue for the removal of all proximal aneurysmal aortic tissue to prevent future degeneration, whereas others deem it unnecessary. This study sought to compare perioperative and long-term outcomes of two different approaches to treatment of JRAAs.

METHODS

Patients who underwent open JRAA repair from 2007 to 2015 at our institution were reviewed and stratified by operative technique: plication of the aneurysm cuff with graft sewn up to the renal arteries (PLI) vs a beveled anastomosis with left renal artery bypass (LRB). Patients who underwent additional mesenteric bypasses were excluded. Primary outcomes included death, anastomotic degeneration, and decline in renal function. Univariate and Kaplan-Meier analyses were performed.

RESULTS

There were 199 patients identified, 56% PLI (n = 112) and 44% LRB (n = 87). The majority were male (68%), white (89%), and smokers (58%). Mean age was 71.5 ± 8.5 years. LRB patients were more likely to have chronic kidney disease (29% vs 13%; P = .01) and larger juxtarenal diameters (median, 25 mm vs 28 mm; P = .001). LRB patients had longer postoperative length of stay (median, 8 days vs 7 days; P = .003) and longer operative times (median, 4.7 hours vs 3.7 hours; P < .001). Overall 30-day mortality was 2% (n = 4), with no difference between cohorts. There were no differences in perioperative complications except for the development of acute kidney injury, which was more common in LRB patients (47% vs 23%; P < .001). During 3-year follow-up, there was no difference in anastomotic aneurysmal degeneration or sac growth. In the long term, LRB patients were more likely to develop an occluded left renal artery (20% vs 0%; P = .004) and right renal artery stenosis (29% vs 3%; P = .002). However, neither group was more likely to have a decline in renal function (PLI, 23%; LRB, 25%; P = .84). There was no difference in 5-year mortality (P = .72).

CONCLUSIONS

The more complex technique involving LRB was not protective against long-term anastomotic degeneration, decline in renal function, or mortality. In addition, LRB led to longer length of stay and operative times, with increased risk of perioperative acute kidney injury. In an era when fewer open aortic repairs are being performed, it is reasonable to consider the PLI technique in the treatment of JRAAs, particularly in patients with baseline chronic kidney disease.

Impact of Renal Artery Stent-Graft Placement on Renal Function in Chronic Aortic Dissection

PURPOSE

To evaluate the effect of renal stent-graft placement on kidney function and size alternation in chronic aortic dissection.

MATERIALS AND METHODS

Twenty-five consecutive patients with chronic aortic dissection after thoracic endovascular aortic repair who underwent renal stent-graft placement between January 2015 and December 2016 were retrospectively reviewed. Forty-three patients with chronic aortic dissection who received thoracic endovascular aortic repair in the same period were reviewed as a control group for kidney volume comparison.

RESULTS

Twenty-five stent-grafts were deployed over 25 renal arteries. Overall renal function was assessed by the slope of the regression line constructed from the plots of creatinine clearance versus time within 2 years after the procedure (-0.2810 vs -0.3146 mL/min^-1/mo^-1, P = .868), kidney volume at 12 months (129.4 ± 40.9 vs 137.0 ± 44.2 cm², P = .193) and effective renal plasma flow at 6 months (106.3 ± 46.9 vs 124.4 ± 55.5 mL/min, P = .050) and was not significantly deteriorated. Seven treated patients (87.5%) with a renal artery supplied by a false lumen had a decrease in kidney volume, as did 14 patients (56%) in the control group (P = .206). Three patients with a dissected renal artery (75%) in the stent-graft group had an increase in kidney volume compared with 1 patient (11.1%) in the control group (P = .052).

CONCLUSIONS

Occlusion of the re-entry tear by a stent-graft in the renal artery remains a safe strategy to promote false lumen thrombosis. The stent-graft poses a potential risk of reducing the kidney volume in kidneys supplied by the false lumen but may provide a positive effect in kidney volume with a concomitant dissected renal artery in chronic aortic dissection.

Advanced Techniques for Treating Juxtarenal and Pararenal Abdominal Aortic Aneurysms: Chimneys, Periscopes, Sandwiches and Other Methods

The complex aortic anatomy of patients who present with juxtarenal and pararenal abdominal aortic aneurysms requires advanced techniques to ensure adequate coverage and complete exclusion of the aneurysm. Parallel stent grafting is one option for endovascular repair of complex aneurysms. Using chimneys, periscopes, or snorkels, it is possible to extend the length of the proximal seal zone and maintain perfusion to branch vessels. Because readily available stent grafts and covered stents are used, this technique is highly adaptable to each patient's unique anatomical challenges. However, the complexity of these procedures requires careful preoperative planning, excellent intraoperative imaging capabilities, a thorough understanding of technique, and anticipation of potential procedural pitfalls and complications. We present our experience with chimney/snorkel and sandwich techniques as a reliable and effective treatment strategy for complex aortic aneurysm repair.

Epidemiology, outcomes, and management of acute kidney injury in the vascular surgery patient

OBJECTIVE

Conventional clinical wisdom has often been nihilistic regarding the prevention and management of acute kidney injury (AKI), despite its being a frequent and morbid complication associated with both increased mortality and cost. Recent developments have shown that AKI is not inevitable and that changes in management of patients can reduce both the incidence and morbidity of perioperative AKI. The purpose of this narrative review was to review the epidemiology and outcomes of AKI in patients undergoing vascular surgery using current consensus definitions, to discuss some of the novel emerging risk stratification and prevention techniques relevant to the vascular surgery patient, and to describe a standardized perioperative pathway for the prevention of AKI after vascular surgery.

METHODS

We performed a critical review of the literature on AKI in the vascular surgery patient using the PubMed and MEDLINE databases and Google Scholar through September 2017 using web-based search engines. We also searched the guidelines and publications available online from the organizations Kidney Disease: Improving Global Outcomes and the Acute Dialysis Quality Initiative. The search terms used included acute kidney injury, AKI, epidemiology, outcomes, prevention, therapy, and treatment.

RESULTS

The reported epidemiology and outcomes associated with AKI have been evolving since the publication of consensus criteria that allow accurate identification of mild and moderate AKI. The incidence of AKI after major vascular surgery using current criteria is as high as 49%, although there are significant differences, depending on the type of procedure performed. Many tools have become available to assess and to stratify the risk for AKI and to use that information to prevent AKI in the surgical patient. We describe a standardized clinical assessment and management pathway for vascular surgery patients, incorporating current risk assessment and preventive strategies to prevent AKI and to decrease its complications. Patients without any risk factors can be managed in a perioperative fast-track pathway. Those patients with positive risk factors are tested for kidney stress using the urinary biomarker TIMP-2•IGFBP7, and care is then stratified according to the result. Management follows current Kidney Disease: Improving Global Outcomes guidelines.

CONCLUSIONS

AKI is a common postoperative complication among vascular surgery patients and has a significant impact on morbidity, mortality, and cost. Preoperative risk assessment and optimal perioperative management guided by that risk assessment can minimize the consequences associated with postoperative AKI. Adherence to a standardized perioperative pathway designed to reduce risk of AKI after major vascular surgery offers a promising clinical approach to mitigate the incidence and severity of this challenging clinical problem.

Impact of aortic wall thrombus on late changes in renal function among patients treated by fenestrated-branched endografts

OBJECTIVE

Renal function deterioration is an important determinant of mortality in patients treated for complex aortic aneurysms. We have previously determined that catheter and guidewire manipulation in diseased aortas during fenestrated-branched endovascular aneurysm repair (F-BEVAR) is associated with risk of renal function deterioration. The aim of this study was to describe the impact of atherothrombotic aortic wall thrombus (AWT) on renal function deterioration among patients treated by F-BEVAR for pararenal and extent IV thoracoabdominal aortic aneurysms.

METHODS

Clinical data of 212 patients treated for complex aortic aneurysms with F-BEVAR were entered into a prospectively maintained database (2007-2015). AWT was evaluated by computed tomography angiography using volumetric measurements in nonaneurysmal aortic segments. AWT was classified as mild, moderate, or severe using objective assessment of the number of affected segments, thrombus type, thickness, area, and circumference. Acute kidney injury (AKI) was defined using Risk, Injury, Failure, Loss of kidney function, and End-stage renal disease (RIFLE) criteria, and renal function deterioration was defined by a decline in estimated glomerular filtration rate (eGFR) >30% from baseline. Patient survival and renal outcomes were assessed at dismissal, at 6 to 8 weeks, at 6 months, and annually, including AKI, serum creatinine concentration, eGFR, chronic kidney disease stage, need for renal replacement therapy, and presence of kidney infarction.

RESULTS

There were 169 male (80%) and 43 female (20%) patients with a mean age of 75 ± 7 years. Aneurysm extent was pararenal in 157 patients and extent IV thoracoabdominal aortic aneurysm in 55 patients. A total of 700 renal-mesenteric arteries were incorporated (3.1 ± 1 vessels/patient). AWT was classified as mild in 98 patients (46%), moderate in 75 (35%), and severe in 39 (19%). At 30 days, 45 patients (21%) developed AKI. Decline in eGFR and kidney infarction were associated with higher AWT volume index and severe AWT classification (P < .05). There was no association of AWT with 30-day mortality, which was 0.5% for the entire cohort. Mean follow-up was 29 ± 23 months. Freedom from renal function deterioration was 73% ± 6% for mild, 81% ± 6% for moderate, and 66% ± 8% for severe AWT patients at 3 years (P = .012) and 46% ± 9% and 82% ± 4% for those with or without AKI after the initial procedure (P < .001). Overall, 41 patients (19%) had progression of chronic kidney disease stage, but none of the patients required renal replacement therapy. Survival was 73% ± 5% for mild, 72% ± 6% for moderate, and 69% ± 10% for severe AWT patients at 3 years (P = .67).

CONCLUSIONS

AWT is a significant predictor of AKI and continued decline in renal function after the initial F-BEVAR procedure. Longer follow-up time is needed to determine the actual impact of AWT on survival.

Outcomes of Chimney and/or Periscope Techniques in the Endovascular Management of Complex Aortic Pathologies

Background:

The chimney/periscope technique has been used to address complex aortic pathologies. This study aimed to report the outcomes and experiences of chimney and/or periscope grafts (CPGs) used in the endovascular management of complex aortic pathologies.

Methods:

Twenty-two patients with complex aortic pathologies were retrospectively studied from January 2013 to August 2016 in two vascular centers of teaching hospitals. All patients were diagnosed using computed tomography angiography (CTA). The patients were followed up at postoperative 1, 3, 6, and 12 months and yearly thereafter with X-ray, ultrasound, and/or CTA.

Results:

Twenty-two cases (17 males; mean age 60.7 ± 16.3 years) with complex aortic pathologies were analyzed. Nineteen patients underwent CPGs only, and the other three cases underwent the simultaneous implantation of chimney/periscope and fenestrated/scallop grafts. Twenty-six arteries were managed with forty CPGs during the procedures. Complete angiographies revealed two Type I endoleaks, one Type III endoleak, and one Type IV endoleak. Other intraoperative complications included brachial thrombosis, external iliac artery rupture, and left renal stenosis. The 30-day mortality was 0. The mean follow-up was 26.1 ± 10.1 months with a range of 2–39 months. During the follow-up, two Type I endoleaks and one Type IV endoleak were observed. One right renal stent occlusion occurred in the 5^th month and turned patent after reintervention. Three patients died during the follow-up, one due to an aneurysm rupture as a Type I endoleak, and two due to myocardial infarction. The instant technical success was 96%. The primary and secondary patencies were 92% and 96%, respectively. The overall survival rates were 95%, 84%, and 84% at 12, 24, and 36 months, respectively. Stent migration was not observed in any patient.

Conclusions:

Chimney/periscope techniques could be used to tackle complex aortic pathologies, but the indications must be strictly controlled, and additional experiences are required.

Concurrent renal artery stent during endovascular infrarenal aortic aneurysm repair confers higher risk for 30-day acute renal failure

OBJECTIVE

Concurrent renal artery angioplasty and stenting (RAAS) during endovascular aneurysm repair (EVAR) of infrarenal abdominal aortic aneurysm (AAA) has been practiced in an attempt to maintain renal perfusion. The aim of this study was to identify the current practice of RAAS during EVAR and its effect on perioperative renal outcome.

METHODS

Patients with infrarenal AAA were identified from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP, 2011-2014) database. Baseline characteristics of patients with concurrent RAAS during EVAR were compared with those of patients who underwent EVAR only. Bivariate and multivariable logistic regression analyses controlling for patients' demographics, comorbidities, and operative factors were used to evaluate the predictors of 30-day acute renal failure (ARF). Sensitivity analysis was done to evaluate the role of RAAS in patients with prior kidney disease.

RESULTS

Overall, 6183 patients underwent EVAR for infrarenal AAA during the study period. Of them, 281 patients had RAAS during EVAR (4.5%). The median age of the patients was 74 years; 81.7% of the cohort was male, but a higher proportion of female patients received EVAR + RAAS compared with patients who underwent EVAR only (26.3% vs 17.9%; P < .001). There was no difference between groups in terms of comorbidities, being on dialysis, or functional status, yet the EVAR + RAAS group had a higher proportion of patients with glomerular filtration rate <60 mL/min/1.73 m2 (45.2% vs 37.2%; P = .011). RAAS was associated with significantly higher odds for development of ARF (adjusted odds ratio [aOR], 4.27; 95% confidence interval [CI], 2.06-8.84; P < .001). Other highly predictive factors of 30-day ARF were glomerular filtration rate <60 (aOR, 2.92; 95% CI, 1.47-5.78; P = .002), emergency status (aOR, 2.97; 95% CI, 1.21-7.27; P = .017), and ruptured AAA as the indication for EVAR (aOR, 4.74; 95% CI, 1.80-12.50; P = .002). Patients with prior kidney disease who had EVAR + RAAS demonstrated a 12-fold higher odds for 30-day ARF (aOR, 12.37; 95% CI, 4.66-32.89; P < .001).

CONCLUSIONS

Concurrent RAAS was found to be a significant determinant of adverse renal outcomes after EVAR for infrarenal AAA. This effect was present even after controlling for patients' risk factors that might contribute to postoperative ARF.

Perioperative outcome of endovascular repair for complex abdominal aortic aneurysms

BACKGROUND

As endovascular aneurysm repair (EVAR) continues to advance, eligibility of patients with anatomically complex abdominal aortic aneurysms (AAAs) for EVAR is increasing. However, whether complex EVAR is associated with favorable outcome over conventional open repair and how outcomes compare with infrarenal EVAR remains unclear. This study examined perioperative outcomes of patients undergoing complex EVAR, focusing on differences with complex open repair and standard infrarenal EVAR.

METHODS

We identified all patients undergoing nonruptured complex EVAR, complex open repair, and infrarenal EVAR in the American College of Surgeons National Surgical Quality Improvement Program Targeted Vascular Module. Aneurysms were considered complex if the proximal extent was juxtarenal or suprarenal or when the Zenith Fenestrated endograft (Cook Medical, Bloomington, Ind) was used. Independent risks were established using multivariable logistic regression analysis.

RESULTS

Included were 4584 patients, with 411 (9.0%) undergoing complex EVAR, 395 (8.6%) undergoing complex open repair, and 3778 (82.4%) undergoing infrarenal EVAR. Perioperative mortality was 3.4% after complex EVAR, 6.6% after open repair (P = .038), and 1.5% after infrarenal EVAR (P = .005). Postoperative acute kidney injuries occurred in 2.3% of complex EVAR patients, in 9.5% of those undergoing complex open repair (P < .001), and in 0.9% of infrarenal EVAR patients (P = .007). Compared with complex EVAR, complex open repair was an independent predictor of 30-day mortality (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.1-4.4), renal function deterioration (OR, 4.8; 95% CI, 2.2-10.5), and any complication (OR, 3.7; 95% CI, 2.5-5.5). When complex vs infrarenal EVAR were compared, infrarenal EVAR was associated with favorable 30-day mortality (OR, 0.5; 95% CI, 0.2-0.9), and renal outcome (OR, 0.4; 95% CI, 0.2-0.9).

CONCLUSIONS

In this study assessing the perioperative outcomes of patients undergoing repair for anatomically complex AAAs, complex EVAR had fewer complications than complex open repair but carried a higher risk of adverse outcomes than infrarenal EVAR. Further research is warranted to determine whether the benefits of EVAR compared with open repair for complex AAA treatment are maintained during long-term follow-up.

Monocentric Evaluation of Chimney Versus Fenestrated Endovascular Aortic Repair for Juxtarenal Abdominal Aortic Aneurysm

BACKGROUND

With approval of on-label fenestrated (F-) endovascular aortic repair (EVAR), concerns regarding long-term patency and endoleaks (ELs) after chimney graft (CG)-EVAR were raised. To add supportive data on the value of this technique, we chose to report the midterm results of CG-EVAR in a single center with standardized methods and to compare them to F-EVAR.

METHODS

A retrospective analysis of prospectively gathered data from January 2010 to January 2015 was conducted, and patients with excessive comorbidities for open repair treated by CG-EVAR or F-EVAR were included.

RESULTS

Ninety patients were treated by F-EVAR (88 men, 198 targets vessels) and 31 by CG-EVAR (26 men, 39 targets vessels, 12.9% treated in emergency; P = 0.001). Mean age was significantly higher in the CG group (71.3 ± 8.2 years in the FG group vs. 75.3 ± 6.6; P = 0.02), and there were significantly more patients suffering from preoperative chronic kidney disease (CKD) (13 [14.4%] treated by F-EVAR vs. 12 [38.7%]; P = 0.009). Target vessels were successfully reconstructed in 99.0% (196/198 target vessels) vs. 97.4% (38/39 target vessels) of cases (P = 0.3). In-hospital mortality was significantly higher after CG-EVAR (3.3% vs. 16.1%; P = 0.03). Incidence of acute kidney injury and CKD did not differ significantly between both groups. At 12 and 24 months, overall survival was 91.4% after F-EVAR vs. 82.1% and 81.8% vs. 69.0% (P = 0.4), estimated freedom from aneurysm related reintervention was 93.3% vs. 82.1% and 84.9% vs. 82.1% (P = 0.6), and target vessel's primary patency rate was 97.5% vs. 89.9% (P = 0.06), respectively. Freedom from type I EL's survival was significantly higher after F-EVAR at 12 and 24 months (100% vs. 89.0% and 97.7% vs. 89.0%; P = 0.01), but aneurysm maximum transverse diameter decrease did not differ significantly.

CONCLUSIONS

There are potential advantages to CG-EVAR with off-the-shelf availability, versatility, and low-profile devices. In this series, patients treated by CG-EVAR showed promising and durable midterm results compared with F-EVAR. CG-EVAR and F-EVAR should not be apprehended as opposed strategies but more as complementary ones, while the best indications for CG-EVAR are clarified.

Comparison of perioperative outcomes in endovascular versus open repair for juxtarenal and pararenal aortic aneurysms: A propensity-matched analysis

Objective

Endoluminal aortic aneurysm repair is suitable within certain anatomic specifications. This study aims to compare 30-day outcomes of endovascular versus open repairs for juxtarenal and pararenal aortic aneurysms (JAA/PAAs).

Methods

The ACS-NSQIP database was queried from 2012 to 2015 for JAA/PAA repairs. Procedures characterized as emergent were included in the study; however, failed prior repairs and ruptured aneurysms were excluded. The preoperative and perioperative patient characteristics, operative techniques, and outcome variables were compared between the open aortic repair and the endovascular aortic repair groups. Propensity scoring was performed to clinically match open aortic repair and endovascular aortic repair groups on preoperative risk and select perioperative factors that differed significantly in the unmatched groups. Outcome comparisons were then performed between matched groups.

Results

A total of 1005 (789 JAAs and 216 PAAs) aneurysm repairs were included in the study. Of these, there were 395 endovascular aortic repairs and 610 open aortic repairs. Propensity scoring created a matched group of 263 endovascular aortic repair and 263 open aortic repair patients. There was no statistically significant difference in 30-day mortality rates between matched endovascular aortic repair and open aortic repair patients (2.7% vs. 5.7%). The endovascular aortic repair group had a shorter ICU length of stay and overall hospital stay. The 30-day morbidity significantly favored endovascular aortic repair over open aortic repair (16% vs. 35%, p < 0.001). The main drivers of morbidity for endovascular aortic repair versus open aortic repair included return to the OR (6.8% vs. 15%, p < 0.001), rate of cardiac or respiratory failure (7.6% vs. 21%, p = 0.001), rate of renal insufficiency or failure (3.8% vs. 9.9%, p = 0.009), and rate of pneumonia (1.5% vs. 6.8%, p = 0.004).

Conclusions

There is no difference in mortality rates between endovascular aortic repair versus open aortic repair when repairing JAAs/PAAs. There is a significant difference in overall morbidity, and ICU and hospital length of stay favoring endovascular aortic repair over open aortic repair. This supports the expanded applicability and efficacy of endovascular repair for complex aneurysms.

Renal dysfunction and the associated decrease in survival after elective endovascular aneurysm repair

OBJECTIVE

The reported frequency of renal dysfunction after elective endovascular aneurysm repair (EVAR) varies widely in current surgical literature. Published research establishes pre-existing end-stage renal disease as a poor prognostic indicator. We intend to quantify the mortality effect associated with renal morbidity developed postoperatively and to identify modifiable risk factors.

METHODS

All elective EVAR patients with preoperative and postoperative renal function data captured by the Vascular Quality Initiative between January 2003 and December 2014 were examined. The primary study end point was long-term mortality. Preoperative, intraoperative, and postoperative parameters were analyzed to estimate mortality stratified by renal outcome and to describe independent risk factors associated with post-EVAR renal dysfunction.

RESULTS

This study included 14,475 elective EVAR patients, of whom 96.8% developed no post-EVAR renal dysfunction, 2.9% developed acute kidney injury, and 0.4% developed a new hemodialysis requirement. Estimated 5-year survival was significantly different between groups, 77.5% vs 53.5%, respectively, for the no dysfunction and acute kidney injury groups, whereas the new hemodialysis group demonstrated 22.8% 3-year estimated survival (P < .05). New-onset postoperative congestive heart failure (odds ratio [OR], 3.50; 95% confidence interval [CI], 1.18-10.38), return to the operating room (OR, 3.26; 95% CI, 1.49-7.13), and postoperative vasopressor requirement (OR, 2.68; 95% CI, 1.40-5.12) predicted post-EVAR renal dysfunction, whereas a preoperative estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 was protective (OR, 0.33; 95% CI, 0.21-0.53). Volume of contrast material administered during elective EVAR varies 10-fold among surgeons in the Vascular Quality Initiative database, but the average volume administered to patients is statistically similar, regardless of preoperative eGFR. Multivariable logistic regression demonstrated nonsignificant correlation between contrast material volume and postoperative renal dysfunction.

CONCLUSIONS

Any renal dysfunction developing after elective EVAR is associated with decreased estimated long-term survival. Protecting renal function with a rational dosing metric for contrast material linked to preoperative eGFR may better guide treatment.

Outcome of visceral chimney grafts after urgent endovascular repair of complex aortic lesions

OBJECTIVE

Endovascular abdominal aortic repair requires an adequate sealing zone. The chimney graft (CG) technique may be the only option for urgent high-risk patients who are unfit for open repair and have no adequate sealing zone. This single-center experience provides long-term results of CGs with endovascular repair for urgent and complex aortic lesions.

METHODS

Between July 2006 and October 2012, 51 patients (16 women) with a median age of 77 years (interquartile range, 72-81 years), were treated urgently (within 24 hours [61%]) or semiurgently (within 3 days [39%]) with endovascular aortic repair and visceral CGs (n = 73). Median follow-up was 2.3 years (interquartile range, 0.8-5.0 years) for the whole cohort, 3 years for 30-day survivors, and 4.8 years for patients who are still alive.

RESULTS

Five patients (10%) died within 30 days. All of them had a sacrificed kidney. All-cause mortality was 57% (n = 29), but the chimney- and procedure-related mortality was 6% (n = 3) and 16% (n = 8), respectively. Chimney-related death was due to bleeding, infection, renal failure, and multiple organ failure. There were two postoperative ruptures; both were fatal although not related to the treated disease. The primary and secondary long-term CG patencies were 89% (65 of 73) and 93% (68 of 73), respectively. Primary type I endoleak (EL-I) occurred in 10% (5 of 51) of the patients, and only one patient had recurrent EL-I (2%; 1 of 51). No secondary endoleak was observed. Chimney-related reintervention was required in 16% (8 of 51) of the patients because of EL-I (n = 3), visceral ischemia (n = 4), and bleeding (n = 2). The reinterventions included stenting (n = 5), embolization (n = 3), and laparotomy (n = 2). Thirty-one visceral branches were sacrificed (9 celiac trunks, 9 right, and 13 left renal arteries). Among the 30-day survivors, 8 of 17 patients (47%) with a sacrificed kidney required permanent dialysis; of these, seven underwent an urgent index operation. The aneurysm sac shrank in 63% (29 of 46) of cases.

CONCLUSIONS

The 6% chimney-related mortality and 93% long-term patency seem promising in urgent, complex aortic lesions of a high-risk population and may justify a continued yet restrictive applicability of this technique. Most endoleaks could be sealed endovascularly. However, sacrifice of a kidney in this elderly cohort was associated with permanent dialysis in 47% of patients.

Fenestrated endovascular repair of abdominal aortic aneurysms: a less invasive option for the treatment of juxtarenal aortic aneurysms

Endovascular aortic aneurysm repair has become the predominant surgical therapy for abdominal aortic aneurysms. Whereas anatomical limitations had become the major contraindication to endovascular treatment, fenestrated stent grafts were developed to overcome such obstacles. Fenestrated endovascular aortic aneurysm repair now provides an additional treatment option for patients felt to be unsuitable for an invasive open repair whose anatomy is not compatible with more traditional stent grafts. We review the evolution of fenestrated endovascular aortic aneurysm repair and compare its safety and efficacy to other endovascular options.

Fenestrated and Chimney Technique for Juxtarenal Aortic Aneurysm: A Systematic Review and Pooled Data Analysis

Juxtarenal aortic aneurysms (JAA) account for approximately 15% of abdominal aortic aneurysms. Fenestrated endovascular aneurysm repair (FEVAR) and chimney endovascular aneurysm repair (CH-EVAR) are both effective methods to treat JAAs, but the comparative effectiveness of these treatment modalities is unclear. We searched the PubMed, Medline, Embase, and Cochrane databases to identify English language articles published between January 2005 and September 2013 on management of JAA with fenestrated and chimney techniques to conduct a systematic review to compare outcomes of patients with juxtarenal aortic aneurysm (JAA) treated with the two techniques. We compared nine F-EVAR cohort studies including 542 JAA patients and 8 CH-EVAR cohorts with 158 JAA patients regarding techniques success rates, 30-day mortality, late mortality, endoleak events and secondary intervention rates. The results of this systematic review indicate that both fenestrated and chimney techniques are attractive options for JAAs treatment with encouraging early and mid-term outcomes.

Endovascular treatment of complex aortic aneurysms: prevalence of acute kidney injury and effect on long-term renal function

Objectives

To analyse predictors for short- and long-term renal function changes after fenestrated and branched endovascular aortic repair (EVAR).

Methods

A total of 157 patients underwent fenestrated and branched EVAR. Procedural intra-arterial iodinated contrast volume was documented. Serum creatinine and estimated glomerular filtration rate (eGFR) at baseline, during 48 h following EVAR, at discharge and latest moment of follow-up were recorded. Development of post-EVAR acute kidney injury (AKI; according to AKIN criteria), and potential risk factors for renal failure were recorded. Multivariate regression analyses were used to identify independent risk factors for AKI and eGFR decrease during follow-up.

Results

Forty-three patients (28 %) developed post-EVAR AKI. Long procedure time and occlusion of accessory renal arteries were independent risk factors for development of AKI. (odds ratio (OR) 1.005 per minute, 95 % CI 1.001–1.01; p = 0.025 and OR 3.02, 95 % CI 1.19–8.16; p = 0.029). Post-EVAR AKI was associated with a significantly increased risk for eGFR decrease at discharge and latest follow-up (hazard ratio (HR) 3.47, 95 % CI 1.63–7.36, p = 0.001 and HR 3.01, 95 % CI 1.56–5.80; p = 0.001). Iodinated contrast volume was not an independent risk factor for AKI or eGFR decrease during follow-up.

Conclusion

Development of post-EVAR AKI is an independent risk factor for long-term renal function decrease.

Key Points

• Longer procedure time is associated with an increased risk for AKI.

• Renal perfusion defects on angiography are associated with increased risk for AKI.

• Post-EVAR AKI is associated with higher probability for long-term eGFR decrease.

• Iodinated contrast volume is not an independent risk factor for AKI.

• Iodinated contrast volume is not an independent risk factor for long-term eGFR decrease.

Chimney Grafts in Aortic Stent Grafting: Hazardous or Useful Technique? Systematic Review of Current Data

BACKGROUND

The chimney graft (CG) technique was introduced to rescue accidentally covered aortic branches during aortic endovascular repair. It extends the sealing zone. There is concern about "gutter" type I endoleak (EL-I) and about the durability of CGs. The aim of the present report was to analyze the rapidly increasing existing data.

METHODS

A search was performed (PRISMA criteria) for all studies of visceral and thoracic/arch chimney grafts. Technical and clinical details and outcome were assessed.

RESULTS

The present review includes 831 patients who underwent EVAR/TEVAR (endovascular aneurysm repair/thoracic endovascular aneurysm repair) with one or more chimney, periscope, or sandwich grafts. For aortic visceral vessels 517 patients received 911 visceral CGs and 314 patients received 364 arch CGs. Most procedures (81% visceral and 69% arch CGs) were elective. Thirty day mortality was 4% for both groups. The rate of early EL-I was 13% (visceral CGs) and 11% (arch CGs). Most EL-I were handled conservatively (observation: 70% for visceral CG and 45% for arch CG). Early CG patency was high (97-99%) and remained high during follow up (median 17 months). Late (after 30 days) EL-I was reported in nine visceral (2%) and 12 arch (4%) CG cases. Few other late complications were reported, but those losing a kidney at the initial repair seemed to have a high risk of requiring permanent hemodialysis.

CONCLUSION

Increasing amounts of data support the benefit of visceral and arch chimney graft techniques. In particular, the low early mortality and complication rates and high long-term patency seem advantageous; however, the majority of cases have been treated electively, and there is a high risk of bias in all studies. Mid- to long-term data suggest few late complications, except in cases where one renal artery was sacrificed. The CG technique is valuable for complex urgent patients and needs further documentation for other patient groups.

Impact of Renal Artery Angulation on Procedure Efficiency During Fenestrated and Snorkel/Chimney Endovascular Aneurysm Repair

Purpose: To determine the impact of renal artery angulation on time to successful renal artery cannulation and procedure efficiency during fenestrated and snorkel/chimney endovascular aneurysm repair (EVAR). Methods: The imaging and procedure logs of 77 patients (mean age 74.2 years; 63 men) who underwent complex EVAR (24 fenestrated, 53 snorkel/chimney) from 2009 to 2013 were reviewed. Renal artery angulation was measured on preoperative computed tomographic angiography scans. Time to renal artery cannulation was retrieved from the EVAR procedure logs and compared to preoperative renal artery angulation and other metrics of procedure efficiency (eg, procedure time, fluoroscopy time, blood loss, etc). In all, 111 renal arteries were available for renal artery angulation measurement (39 fenestrated, 72 snorkel/chimney); 22 renal cannulations were inappropriate for the comparative analyses due to concomitant visceral artery stenting (n=15), combined procedures (n=6), or unsuccessful cannulation (n=1). Results: For patients undergoing fenestrated EVAR, mean renal artery angulation was -28°±21° (range +37° to -60°), not significantly different (p=0.66) from patients receiving snorkel/chimney grafts (mean -30°±19°, range +22° to -65°). Comparative analysis using median renal artery angulation (−30° for both groups) demonstrated that renal artery cannulation during fenestrated EVAR was performed significantly faster in arteries with less downward (≥ −30°) angulation (16.0 vs 32.8 minutes, p=0.04), whereas cannulation in snorkel/chimneys was faster in arteries with greater downward (< −30°) angulation (10.9 vs 17.3 minutes, p=0.05). Fenestrated EVAR cases involving less downward (≥ −30°) renal artery angulation were also associated with shorter overall procedure time (187.7 vs 246.2 minutes, p=0.01) and decreased fluoroscopy time (70.3 vs 98.2 minutes, p=0.04). Immediate renal function decline, procedural complications, and postoperative issues were not associated with renal artery angulation. Conclusion: Procedural efficiency may be optimized by considering renal artery angulation as one of several objective variables used in the selection of an appropriate endovascular strategy. The fenestrated approach is more efficient with less downward angulation to the renal arteries, while the snorkel/chimney strategy is facilitated by more downward renal artery angulation.