Repair Of Juxtarenal Aortic Aneurysms Research Articles

Systematic Review and Meta-analysis of Fenestrated and Chimney/Snorkel Techniques for Endovascular Repair of Juxtarenal Aortic Aneurysms.

Comparative effectiveness of fenestrated endovascular aneurysm repair (FEVAR) and chimney graft endovascular aneurysm repair (ChEVAR) for juxtarenal aortic aneurysms (JAAs) remains unclear. Our objective was to identify and analyze the current body of evidence comparing the effectiveness of both techniques for JAA. We performed a systematic review and meta-analysis comparing the effectiveness of FEVAR and ChEVAR for JAA repair. We searched MEDLINE, EMBASE, and Cochrane Register for Controlled Trials from January 1, 1990, for randomized and non-randomized studies assessing outcomes of FEVAR and ChEVAR for JAA repair. Screening, data extraction, risk of bias assessment, and GRADE (Grading of Recommendations, Assessments, Development, and Evaluations) certainty of evidence were performed in duplicate. Data were pooled statistically where possible. Nine retrospective cohort studies comparing the use of FEVAR and ChEVAR for juxtarenal aneurysm were included for meta-analysis. The FEVAR and ChEVAR arms of the meta-analysis consisted of 726 participants and 518 participants, respectively. There were 598 (86.8%) and 332 (81.6%) men in each arm. The mean diameter was larger in the ChEVAR arm (59 mm vs 52.5 mm). Both techniques had similar rates of postoperative 30-day mortality, 3.38% (8/237) versus 3.52% (8/227), acute kidney injury, 16.76% (31/185) versus 17.31% (18/104), and major adverse cardiac events, 7.30% (46/630) versus 6.60% (22/333). The meta-analysis supported the use of FEVAR for most outcomes, with significant advantage for technical success (odds ratio [OR]: 3.24, 95% CI: 1.24-8.42) and avoidance of type 1 endoleak (OR: 5.76, 95% CI: 1.94-17.08), but a disadvantage for spinal cord ischemia (OR: 10.21, 95% CI: 1.21-86.11), which had a very low number of events. The quality of evidence was "moderate" for most outcomes. Both endovascular techniques had good safety profiles. The evidence does not support superiority of either FEVAR or ChEVAR for JAA. While lack of equipoise has hampered the design of randomised trials of open versus endovascular repair of juxtarenal aortic aneurysms, concern about the durability of endovascular repair highlights the need for stronger evidence of the comparative efficacy of endovascular techniques. This review performed meta-analysis and evidence appraisal of recent data from large observational studies comparing fenestrated and chimney techniques, using a comprehensive outcome set. Superiority of either intervention could not be established due to differences in participants' baseline risk in each study arm. However, data suggests that both techniques are safe and suitable for use when indicated.

Urgent Juxtarenal Aortic Aneurysm Repair With Modified Off-the-shelf Endograft to Preserve Intercostal Arteries and Branch Incorporation by Transfemoral Access.

To demonstrate the feasibility of the modification to preserve intercostal arteries of the t-Branch Endograft (Cook Medical, Bloomington, IN) in an urgent setting, associated with a less invasive approach for branch incorporation from percutaneous femoral access with steerable sheaths. A 73-year-old female patient presented at our institution with intense abdominal pain. Angiotomography showed a 50-mm juxtarenal aortic aneurysm, with no signs of rupture. Urgent endovascular repair was indicated due to abdominal symptom with an off-the-shelf multi-branched endograft. To limit descending thoracic aortic coverage, we performed t-Branch modification to preserve intercostal arteries and minimize the risk of spinal cord injury, associated with a percutaneous transfemoral approach and branch incorporation with steerable sheaths to avoid the risks associated with a superior axillary or brachial access. Control angiotomography showed adequate aneurysm sac exclusion with patency of all four visceral vessels. t-Branch-modified endograft to limit aortic coverage is an alternative option in urgent cases to diminish the risk of spinal cord injury, and association of steerable sheaths with branch incorporation is leading complex aortic repairs to an even less invasive procedure. This paper highlights the possibility of performing complex endovascular aortic repair in an urgent setting with modification of an off-the-shelf multi branched endograft limiting intercostal arteries coverage, thereby diminishing the risk of spinal cord ischemia. This technical innovation provides an alternative for clinicians when treating large, rapidly expanding, or symptomatic juxtarenal, pararenal, paravisceral or type 4 thoracoabdominal aortic aneurysms that could not wait for a custom-made device and do not need extensive thoracic aortic coverage that an off-the-shelf device provides. In summary, expand the possibilities of an endovascular repair of complex aortic aneurysms.

Comparison of Fenestrated Stentgrafts and Open Repair for Juxtarenal Aortic Aneurysms Using a Propensity Score Matching

The purpose of this study was to compare postoperative morbi-mortality and medium-term follow-up of fenestrated stent grafting and open repair (OR) for patients with juxtarenal aortic aneurysms (JRAAs). All consecutive patients who underwent custom-made fenestrated endovascular aortic repair (FEVAR) or OR for complex abdominal aortic aneurysm between 2005 and 2017 in 2 tertiary centers were scrutinized. Patients with JRAA constituted the study group. Suprarenal and thoracoabdominal aortic aneurysms were excluded. The groups were made comparable through the use of a propensity score matching. 277 patients with JRAAs were included, 102 (36.8%) in the FEVAR group and 175 (63.2%) in the OR group, respectively. After propensity score matching, 54 FEVAR patients (52.9%) and 103 OR patients (58.9%) were included for analysis. In-hospital mortality rates were 1.9% (n=1) in the FEVAR group versus 6.9% (n=7) in the OR group (P=0.483). Postoperative complications were less common in the FEVAR group (14.8% vs. 30.7%; P=0.033). Mean follow-up was 42.1months in the FEVAR group and 40months in the OR group. Overall mortality rates at 12 and 36months were 11.5% and 24.5% in the FEVAR group versus 9.1 % (P=0.691) and 11.6% (P=0.067) in the OR group. Late reinterventions were more frequent in the FEVAR group (11.3% vs. 2.9%; P=0.047). However, freedom from reintervention rates were not significantly different at 12months (FEVAR: 86% vs. OR: 90%; P=0.560) and 36months (FEVAR: 86% vs. OR: 88.4%, P=0.690). In the FEVAR group, persistent endoleak during follow-up was identified in 11.3% of cases. In the present study, there was no statistical difference in terms of mortality in-hospital at 12 or 36months between FEVAR and OR groups for JRAA. FEVAR for JRAA was associated with a significant reduction of overall postoperative major complications compared with OR. There were significantly more late reinterventions in the FEVAR group.

Postoperative Renal Complications Adversely Impact Late Survival Following Open Juxtarenal Aortic Aneurysm Repair

Preoperative renal function is a predictor of morbidity and mortality after the repair of juxtarenal aortic aneurysms. However, the impact of postoperative renal failure on late outcomes after repair are poorly understood. Therefore, our objective was to assess the impact of postoperative renal dysfunction on long-term outcomes after juxtarenal aortic aneurysm repair. We identified all open repairs of juxtarenal aortic aneurysms in the Vascular Quality Initiative from 2011 to 2018 with linkage to Medicare claims data. Juxtarenal aortic aneurysm repair was defined as the placement of proximal clamp above at least one renal artery during open repair. Postoperative renal function was categorized as stable renal function, acute kidney injury (AKI; ≥0.5 mg/dL serum creatinine increase) or new renal replacement therapy (RRT). Kaplan-Meier estimates and Cox regression were used to identify the effect of AKI or RRT on 5-year mortality, rupture, and reintervention. Of 1643 open repairs, 29% experienced postoperative AKI, and 6.5% required RRT. Renal visceral ischemia time >25 minutes was higher in the AKI and RRT cohorts (stable: 52% vs AKI 65% vs RRT 67%; P < .001). Postoperative mortality was higher with increasing severity of postoperative renal dysfunction (2.5% vs 9.5% vs 31%; P < .001). Increasing renal dysfunction severity was also associated with higher risk of 5-year mortality (14% vs 25% vs 57%; AKI: adjusted hazard ratio [aHR], 1.7 [1.3-2.4]; P < .001/RRT: aHR, 4.6 [3.1-7.0]; P < .001) (Fig). In addition, RRT was associated with higher risk of late rupture (3.1% vs 6.8% vs 10%; AKI: aHR, 1.1 [0.3-3.7]; P < .788/RRT: aHR, 5.5 [1.2-25]; P < .026) and late reintervention (15% vs 20% vs 55%; AKI: aHR, 1.4 [0.9-2.2]; P = .114/RRT: aHR, 3.4 [1.7-7.0]; P = .001). Postoperative renal dysfunction adversely impacts late mortality, rupture, and reintervention. In addition increasing severity of postoperative renal dysfunction has a dose-dependent effect on perioperative and late outcomes after repair. Preoperative and intraoperative care should be taken to prevent renal complications after repair. Furthermore, these patients may benefit from closer follow-up after repair.

Midterm Results of Supraceliac vs Infraceliac Sealing for Fenestrated Endovascular Aortic Repair of Juxtarenal Aortic Aneurysms

The complexity of fenestrated endovascular aortic repair (FEVAR) for juxtarenal abdominal aortic aneurysms has increased over time including a more proximal sealing zone despite a similar disease extent. Prior studies demonstrated that supraceliac sealing is associated with higher perioperative morbidity, although mortality seems to be similar. Durability of sealing at a supra celiac level vs an infraceliac level remains unknown. The aim of our study was to examine outcomes of FEVAR for juxtarenal abdominal aortic aneurysms comparing a supraceliac vs an infraceliac sealing zone. We included patients undergoing elective juxtarenal FEVAR from 2008 to 2021 at two large hospitals in the Netherlands. The definition of a supraceliac sealing zone was incorporation of the celiac trunk by either a scallop or fenestration. The primary outcome was 5-year aneurysm-related procedures. Secondary outcomes included perioperative complications, 5-year mortality and 1-year aneurysm sac dynamics. These outcomes were analyzed using t tests, Kaplan-Meier methods, multivariable Cox regression analysis, and χ2 tests. One-year aneurysm sac dynamics were evaluated between the groups with imaging data (sac regression/stable sac/sac expansion, based upon 5% volume change compared with 30-day volume). Among 173 patients identified, 114 (66%) had a supraceliac and 59 (34%) had an infraceliac sealing zone. Patients with supraceliac sealing more often had prior EVAR (26.3% vs 12%; P = .045). Furthermore, supraceliac sealing had similar rates of perioperative complications and mortality. No differences were found in one-year aneurysm sac dynamics. Supraceliac sealing was associated with significantly lower risks of secondary aneurysm-related procedures at 5 years compared to use of infraceliac sealing (25% vs 45%; hazard ratio, 0.37; 95% confidence interval, 0.17-0.79; P = .012) (Figure). Finally, supraceliac sealing had similar risks of 5-year mortality compared with infraceliac sealing (hazard ratio, 0.93; 95% confidence interval, 0.49-1.74; P = .813). FEVAR with supraceliac sealing is more durable with less secondary aneurysm-related procedures as compared to infraceliac sealing for juxtarenal aneurysms. Future research has to examine whether supraceliac sealing should be the standard for juxtarenal aneurysms.

Outcome Analysis Comparing Asymptomatic Juxtarenal Aortic Aneurysms Treated with Custom-Manufactured Fenestrated-Branched Devices and the “Off-The-Shelf” Zenith p-Branch Device

Numerous endovascular options have been used for the repair of juxtarenal aortic aneurysms (JRAAs) over the last 15years. This study aims to compare the performance between the Zenith p-branch device and custom-manufactured fenestrated-branched devices (CMD) for the treatment of asymptomatic JRAA. A single-center retrospective analysis of prospectively collected data was performed. Patients with a diagnosis of JRAA submitted to endovascular repair between July 2012 and November 2021 were included in the study, being divided into 2 groups: CMD and Zenith p-branch. The following variables were analyzed: preoperative information: demographics, comorbidities, and maximum aneurysm diameter; procedural data: contrast volume, fluoroscopy time, radiation dose, estimated blood loss, and technical success; and postoperative data: 30-day mortality, duration of intensive care unit and hospital stay, major adverse events, secondary interventions, target vessel instability, and long-term survival. From a total of 373 physician-sponsored investigational device exemption (Cook Medical devices) cases performed at our institution, 102 patients presented the diagnosis of JRAA. Of these, 14 patients were treated with the p-branch device (13.7%) and 88 (86.3%) with a CMD. Both groups presented similar demographic composition and maximum aneurysm diameter. All devices were successfully deployed, with no type I or III endoleaks observed at procedure completion. The contrast volume (P=0.023) and radiation dose (P=0.001) were significantly higher in the p-branch group. No significant difference was observed between the groups for the remaining intraoperative data. No paraplegia or ischemic colitis has been observed during the first 30days after the surgical procedures. There was no 30-day mortality in either group. One major cardiac adverse event was registered in the CMD group. Early outcomes were similar in both groups. No significant difference was found between the groups with respect to the presence of type I or III endoleaks during the follow-up. From a total of 313 target vessels stented in the CMD group (mean of 3.55 per patient) and 56 in the p-branch group (mean of 4 per patient), 4.79% and 5.35% presented instability, respectively, with no difference observed between the groups (P=0.743). Secondary interventions were required in 36.4% of the CMD cases and 50% of the p-branch group, but this was not statistically different (P=0.382). In the p-branch cohort, 2 of 7 reinterventions (28.5%) were target vessel-related and in the CMD group, 10 of 32 secondary interventions (31.2%) were target vessel-related. Comparable perioperative outcomes were obtained when appropriately selected patients were treated with either the off-the-shelf p-branch or CMD for JRAA. The long-term target vessel instability does not appear impacted by the presence of pivot fenestrations in comparison to other target vessel configurations. Given these outcomes, delay in CMD production time should be considered when treating patients with large juxtarenal aneurysms.

Outcomes in octogenarians after thoracoabdominal and juxtarenal aortic aneurysm repair using fenestrated-branched devices justifies treatment

ObjectiveTo compare outcomes between octogenarians and nonoctogenarians undergoing thoracoabdominal aortic aneurysm repair and juxtarenal aortic aneurysm repair using branched and/or fenestrated endovascular devices (F/BEVAR) and compare octogenarian survival to population survival statistics from Ontario, Canada. MethodsPatients who underwent F/BEVAR at a single institution between 2007 and 2020 were retrospectively reviewed with a median follow-up of 3.3 years (interquartile range, 1.6-5.3). The median survival of an average 84-year-old Ontarian from Canada, adjusted for a male:female ratio of 4:1, was retrieved from publicly available Statistics Canada data. ResultsIn total, 68 octogenarians (25.8%) and 196 nonoctogenarians (74.2%) were included (mean age, 83.5 ± 3.0 vs 71.9 ± 5.8 years; P ≤ .001). The maximum aneurysm size was significantly larger in octogenarians (68.9 ± 11.4 mm vs 65.4 ± 10.0 mm; P = .017). No differences in the number of thoracoabdominal aortic aneurysm repairs (29.4% vs 38.3%; P = .19) or operative technical success (92.6% vs 85.7%; P = .136) were observed between the two cohorts. Postoperatively, no significant differences in overall in-hospital mortality (7.3% vs 5.1%; P = .49), elective in-hospital mortality (6.1% vs 4.4%; P = .49), stroke (1.5% vs 3.6%; P = .384), or spinal cord ischemia (2.9% vs 9.2%; P = .094) were seen between octogenarians and nonoctogenarians. There was no difference in survival at 4 years between the two cohorts (62.9% vs 71.1%; P = .22), however, survival at 6 years was significantly lower for octogenarians (44.5% vs 64.1%; hazard ratio, 1.96; P = .02). The cumulative rate of reintervention (44.1% vs 41.3%; P = .84) and freedom from branch instability (67.6% vs 73.5%; P = .33) at 6 years were not different between the two groups. When comparing octogenarians who survived to discharge from index hospitalization after F/BEVAR with 84-year-old Ontarians unmatched for comorbidities, a survival difference of 4.8% and 11.1% was noted at 4 and 6 years, respectively. ConclusionsF/BEVAR in octogenarians is associated with no differences in technical success or postoperative adverse outcomes when compared with their younger counterparts. Octogenarians had increased mortality after 4 years and their survival at 4 years was comparable with that of an 84-year-old Ontarian. F/BEVAR was safe and effective in octogenarians deemed fit for intervention. Further research into preoperative patient selection and improving perioperative outcomes is needed.

Late Survival Is Affected by Renal Complication Following Endovascular Aortic Aneurysm Repair for Juxtarenal Aortic Aneurysm

Preoperative renal function is a predictor of morbidity and mortality after endovascular repair of juxtarenal aortic aneurysms. However, the impact of postoperative renal complication on outcomes after repair are poorly understood. Therefore, our objective was to assess the impact of postoperative renal dysfunction on midterm outcomes following endovascular repair of juxtarenal aortic aneurysms.

Renal Complications Following Juxtarenal Aortic Aneurysm Repair Affect Late Survival and Repair Durability

Renal complications following open and endovascular repair of juxtarenal aortic aneurysms are associated with increased postoperative mortality and morbidity. Our objective was to assess the effect of postoperative renal complications on late outcomes following juxtarenal aortic aneurysm repair.

Long-term outcomes after fenestrated endovascular aortic repair for juxtarenal aortic aneurysms

ObjectiveFenestrated endovascular aortic aneurysm repair (FEVAR) for juxtarenal aortic aneurysm (jAAA) disease is safe and effective with good short- and mid-term outcomes. The durability issues have mainly focused on the proximal and distal seal and target vessel (TV) instability, and long-term data are scarce. In previous studies, we have reported the short-term outcomes after FEVAR and compared our early and late experience and the long-term results for the early cohort. In the present report, we have provided the long-term outcomes for our late experience cohort who had undergone FEVAR at the Vascular Center (Skåne University Hospital, Malmö, Sweden). MethodsConsecutive patients who had undergone FEVAR for jAAAs from 2007 to 2011 were included in the present study. Data were collected retrospectively from the medical and imaging records. The follow-up protocol consisted of a clinical examination 1 month postoperatively and computed tomography angiography combined with plain abdominal radiography at 1 and 12 months and annually thereafter. The primary endpoints were TV instability, reinterventions, and survival. Changes in the aneurysm diameter and renal function and the incidence and type of endoleaks were also analyzed. ResultsA total of 94 patients were included in the present study. The median follow-up time was 89 months (range, 0-152 months). A total of 280 fenestrations or scallops were used, of which 205 were stented. Technical success was 89.4%. Primary TV patency was 94% ± 1% at 1 year, 90% ± 2% at 3 years, and 89% ± 2% at 5 years. Of the 94 patients, 37 (39.4%) had required a total of 70 reinterventions. The mean time to the first reintervention was 21 ± 3.97 months. Five patients (5.3%) had died of aneurysm-related causes. Overall survival was 95.7% ± 2.1% at 1 year, 87.1% ± 3.5% at 3 years, and 71.0% ± 4.7% at 5 years. A stable or decreasing aortic diameter after treatment was seen in 91% of the cases. The mean glomerular filtration rate had decreased from 59.2 ± 14.9 mL/min/1.73 m2 preoperatively to 50.0 ± 18.6 mL/min/1.73 m2 at the end of follow-up. ConclusionsThe results of the present study have shown that the long-term results after treatment of jAAAs with FEVAR remain good and the treatment is safe and effective. Although the need for reintervention remained high, long-term renal function and survival support the use of FEVAR as a valid treatment option for jAAA disease.

Outcomes Justify the Use of Branched and Fenestrated Endovascular Devices for Aortic Aneurysm Repair in Octogenarians

We compared the outcomes between patients aged ≥80 years and patients aged <80 years undergoing thoracoabdominal and juxtarenal aortic aneurysm repair using branched and/or fenestrated endovascular devices (B/FEVAR).

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

ObjectiveThis 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. MethodsPatients 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. ResultsPreoperative 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. ConclusionsIn 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 RelevanceUsing 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 Impact of Suprarenal Cross-Clamping on Kidney Function in Patients Undergoing Retroperitoneal Abdominal Aortic Aneurysm Repair following an Enhanced Recovery Protocol

The retroperitoneal approach (RP) is a well-established procedure for juxtarenal and infrarenal (IR) abdominal aortic aneurysm (AAA) repair when an endovascular option is not available. The aim of this study is to compare the effect of suprarenal (SR) and IR aortic clamping on postoperative renal function following an Enhanced Recovery Protocol (ERP). Since there are no defined guidelines within aortic surgery, we focused our attention on the role of fluid and vasopressor administration in the development of postoperative acute kidney injury (AKI). This is a single-center retrospective cohort study on 140 RP aortic aneurysm repair patients operated between 2009 and 2019. Patients were divided in 2 groups: 24 had SR clamping and 116 IR clamping. Since 2009, at our institution all patients have followed an Enchanced Recovery Program which has been implemented as standard care for patients undergoing open AAA repair. The 2 groups were well matched for baseline characteristics, preoperative renal function, and comorbidity. There was an increased need for intraoperative fluids (P=0.015), and vasopressors (P=0.002) in the SR group compared to the IR group. Patients in the SR group showed a higher trend of postoperative AKI as opposed to the control group (37.5% vs. 19.8%), although this event was not statistically significant (P=0.106). Acute Kidney Injury Network stage III requiring temporary dialysis occurred in only 3 patients who all belonged to the IR group. Conversely, stage I and II with a 2- or 3-fold increase in postoperative creatinine were more frequent in the SR group. However, these normalized before discharge in all cases. To the best of our knowledge, none of the above required permanent dialysis. The results from this study show that SR clamping during RP juxtarenal aortic aneurysm repair does not have an adverse effect on postoperative renal function in the short term. However, patients undergoing SR clamping require greater fluid and vasopressor usage, in contrast with the restrictive fluid therapy established by traditional protocols. This could be an important benchmark for future implementation of ERPs in vascular surgery, especially in open procedures requiring visceral clamping.

Patient-Specific Computational Flow Modelling for Assessing Hemodynamic Changes Following Fenestrated Endovascular Aneurysm Repair

Abstract 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;▪:1-17.) 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.

Long-term Results of Renal Artery Patency in Physician-modified Endografts for Juxtarenal Aneurysms

Renal artery stents are commonly placed in physician-modified fenestrated endografts for juxtarenal aortic aneurysms, but long-term outcomes of these stents is unknown. The purpose of this study was to identify the long-term outcome of stented renal arteries in patients who undergo a physician-modified endovascular graft (PMEG) for repair of juxtarenal aortic aneurysms. Data were prospectively collected on patients treated with PMEG from August 2011 to September 2019 in a prospective, consecutively enrolling investigational device exemption clinical trial (NCT #01538056). Anatomic criteria, including native renal artery stenosis and angulation, were systematically measured using preoperative computed tomography. The primary outcome of renal artery reintervention after PMEG was assessed with Kaplan-Meier survival estimation. Cox proportional hazard models were used to predict renal artery reintervention after PMEG, adjusting for preoperative demographic and patient risk factors, antiplatelet use prestent and poststent placement, and evidence of preoperative stenosis by duplex criteria. We studied 141 patients who underwent PMEG during the study period, representing 282 renal arteries. During the study period, 246 out of 282 (87%) renal arteries were stented. Inability to cannulate the renal artery as the most common cause (n = 9) of inability to stent the artery. However in 25% (n = 9) of these situations, the renal artery was preserved and in 25% (n = 9) an effective proximal seal zone was obtained without renal stenting. Preoperative ostial stenosis was present in 23% (n = 62) of renal arteries by diameter reduction and 22% (n = 58) by duplex criteria. Over a follow-up period of 5 years, 15 renal arteries in 13 patients required reintervention, for an overall reintervention rate of 6.1%. All stented renal arteries remained patent. Median follow-up was 2 years (interquartile range, 0.5-4 years). The most common cause for reintervention during the first 6 months was failure to cannulate during the initial PMEG (15%, n = 2). In-stent restenosis was the reason for reinterventions for 30% (n = 4). Long-term follow-up revealed stent separation (15%, n = 2) and type IIIc endoleak (15%, n = 2) as the most common cause for reintervention. The predicted reintervention free survival of the renal artery at 5 years is 90% (95% confidence interval, 82%-95%) (Figure). Using a Cox proportional hazard model, no significant anatomic or patient-based predictors of reintervention were identified. Renal artery stents placed during physician-modified endografts show excellent long-term durability with a low rate of reintervention. No preoperative renal artery measurements are predictive of either renal stent patency or reintervention.

Open repair of juxtarenal aortic aneurysms: 10-years of experience in a single center

Open repair of juxtarenal aortic aneurysms: 10-years of experience in a single center

Cold Renal Perfusion During Simulation of Juxtarenal Aortic Aneurysm Repair Reduces Systemic Oxidative Stress and Sigmoid Damage in Rats

Juxtarenal aortic surgery induces renal ischaemia reperfusion, which contributes to systemic inflammatory tissue injury and remote organ damage. Renal cooling during suprarenal cross clamping has been shown to reduce renal damage. It is hypothesised that renal cooling during suprarenal cross clamping also has systemic effects and could decrease damage to other organs, like the sigmoid colon. Open juxtarenal aortic aneurysm repair was simulated in 28 male Wistar rats with suprarenal cross clamping for 45 min, followed by 20 min of infrarenal aortic clamping. Four groups were created: sham, no, warm (37 °C saline), and cold (4 °C saline) renal perfusion during suprarenal cross clamping. Primary outcomes were renal damage and sigmoid damage. To assess renal damage, procedure completion serum creatinine rises were measured. Peri-operative microcirculatory flow ratios were determined in the sigmoid using laser Doppler flux. Semi-quantitative immunofluorescence microscopy was used to measure alterations in systemic inflammation parameters, including reactive oxygen species (ROS) production in circulating leukocytes and leukocyte infiltration in the sigmoid. Sigmoid damage was assessed using digestive enzyme (intestinal fatty acid binding protein - I-FABP) leakage, a marker of intestinal integrity. Suprarenal cross clamping caused deterioration of all systemic parameters. Only cold renal perfusion protected against serum creatinine rise: 0.45 mg/dL without renal perfusion, 0.33 mg/dL, and 0.14 mg/dL (p = .009) with warm and cold perfusion, respectively. Microcirculation in the sigmoid was attenuated with warm (p = .002) and cold renal perfusion (p = .002). A smaller increase of ROS production (p = .034) was seen only after cold perfusion, while leukocyte infiltration in the sigmoid colon decreased after warm (p = .006) and cold perfusion (p = .018). Finally, digestive enzyme leakage increased more without (1.5AU) than with warm (1.3AU; p = .007) and cold renal perfusion (1.2AU; p = .002). Renal ischaemia/reperfusion injury after suprarenal cross clamping decreased microcirculatory flow, increased systemic ROS production, leukocyte infiltration, and I-FABP leakage in the sigmoid colon. Cold renal perfusion was superior to warm perfusion and reduced renal damage and had beneficial systemic effects, reducing sigmoid damage in this experimental study.

Comparison of Fenestrated Stentgrafts and Open Repair for Juxtarenal Aortic Aneurysms Using A Propensity Score Matching

Introduction: The purpose of this study is to compare the short- and mid-term results of fenestrated stentgrafts (FEVAR) and open repair (OR) for juxtarenal aortic aneurysms (JRAA). Methods: This cohort study was conducted in two tertiary centers between 2005 and 2017. Preoperative CT scans of patients who underwent FEVAR for complex abdominal AAA in both centers were reviewed by two experienced surgeons to select JRAA and exclude suprarenal and thoracoabdominal aneurysms. JRAA were defined as requiring suprarenal cross clamping but infrarenal proximal suture if treated by OR. Patients with JRAA treated by FEVAR were compared to patients with JRAA treated by OR using a propensity score matching. Propensity score was calculated on age, sex, smoking, diabetes, obesity, coronary artery disease, heart/renal/respiratory failure, ASA score, history of aortic surgery, aneurysm diameter and center. Results: Of 277 patients with JRAA, 102 (36,8%) received FEVAR and 175 (63,2%) received OR. Before propensity score matching, 30-day, in-hospital, 12 months and 36 months mortality rates were 5,9% / 5,9% / 17,5% / 27,8% (n= 6/n=6/n=17/n=27) in the FEVAR group and 1,7%/4%/6,5%/9,4% (n=3/n=7/n=11/n=16) in the OR group, respectively. After propensity score matching, 102 FEVAR patients (66,7%) and 51 OR patients (33,3%) were included in the analysis. 30-day and in-hospital mortality rates were 5.9% (N = 6) in the FEVAR group vs. 3,9% (N=2) / 7,8% (N=4) in the OR group (p=0,61 / p=0,64). The median follow-up period was 40 months (range: 0,2-112) in the FEVAR group and 41 months (range: 1-149) in the OR group. During follow-up, overall mortality at 12 months was similar in both groups (FEVAR: 17,7% vs. OR: 12 %, p = 0,31). At 36 months, there was a non-significant trend towards higher overall mortality rates in the FEVAR group (27,1% vs. 14,0%, p = 0,07). FEVAR- patients experienced significantly fewer moderate to severe complications (FEVAR group: n=19, 18,8%; OR group: n=21, 41,2%, Odd Ratio = 0,32; 95% CI: 0.15-0.71; p = 0,05), especially renal (18,0% vs. 26,0%; p = 0,005) and respiratory (4,9% vs. 17,7%; p = 0,029). In total, twenty-five patients required reintervention (16,4%), with no difference between the two groups (FEVAR: 16,7% vs. OR: 15,7%, p = 0,88). In the FEVAR group, two aortic ruptures occurred during follow-up. Persistent endoleak was observed in 17 patients (16,7%) in the FEVAR group (3 type IA, 13 type II and 1 unclassified). Conclusion: This comparative study did not show a significant difference in mid-term mortality, although a trend towards higher mortality rates was observed at 36 months in the FEVAR group. Moderate to severe complications, especially renal and respiratory, were more frequent in the OR group. Propensity score matching mainly selected the most fragile patients in the OR group. This study highlights the need for a randomized study to compare FEVAR and OR for juxtarenal AAA. Disclosure: Frederic Cochennec is a proctor for Cook MEdical

Patient-Specific Computational Analysis of the Impact of Fenestrated and Chimney Endovascular Aortic Repair on Haemodynamics in Renal Arteries

Introduction: Fenestrated and chimney endovascular aortic repair with renal artery vascularization enables minimally invasive repair of juxtarenal aortic aneurysms. However, there are concerns regarding postoperative kidney function. The aim was to analyze the hemodynamic impact of fenestrations and chimneys on renal arteries (RA) in 2 patient-specific series of computer models using Computational Fluid Dynamics (CFD) simulations. Methods: We included 2 patients who had juxta-renal abdominal endovascular aortic repair (EVAR): 1 fenestrated-EVAR (F-EVAR) and 1 chimney-EVAR (Ch-EVAR). For each patient, 3 models were built from CT-scan in the software CRIMSON: preoperative, real postoperative and virtual postoperative models. The virtual model was an alternative scenario with replacement of renal fenestrated stentgrafts with renal chimneys in the first patient, and vice versa in the second patient. Patient-specific boundary conditions remained constant in all models for each patient. CFD analysis of hemodynamics was performed using CRIMSON. Pressure, flow, velocity, time-averaged wall shear stress (TAWSS) and platelet activation potential (PLAP) were compared in all models. Results: Aortic and RA flows were constant in preoperative and postoperative models for each patient. Peak velocity was higher in postoperative models compared to preoperative ones in both patients. Higher vortices were observed in both F-EVAR models and lower vortices in both Ch-EVAR. Flow recirculation zones were located below and above the aortic protruding proximal part of the renal stentgraft in both F-EVAR. Aortic inlet systolic pressures were higher in F-EVAR compared to preoperative and Ch-EVAR models. Renal systolic pressures were higher in both F-EVAR compared to Ch-EVAR. Renal mean pressure was the lowest in Ch-EVAR. TAWSS was lower in F-EVAR RA compared to Ch-EVAR in both patients. TAWSS was the highest in both Ch-EVAR. Both Ch-EVAR seem to carry higher risk of thrombosis in RA as the PLAP increase relative to the preoperative model was the highest at Ch-EVAR RA, around 40 %-increase in Ch-EVAR versus 20% in F-EVAR. Conclusion: Complex EVAR resulted in aortorenal flow disturbances that potentially contribute to renal stent-graft complications during follow-up. This intra-individual numerical comparison of the hemodynamic impact of complex EVAR on RA showed that Ch-EVAR carried the highest risk of RA thrombosis. F-EVAR increased renal and inlet pressures exposing the vascular wall to remodeling and wall thickening. Preoperative planning of endovascular repair could help physician to make the best choice between different treatment but further studies with more patient specific computational analysis of hemodynamics need to be performed. Disclosure: Nothing to disclose

Early and Mid-Term Outcomes of Open Repair, Fenestrated Stent Graft and Chimney Graft in Juxtarenal Abdominal Aortic Aneurysms

Introduction - Juxtarenal abdominal aortic aneurysm (JAAA) is defined as an infrarenal AAA that is adjacent to or involving the lower margin of the renal artery origins1. Recently, promising results have been reported in peer reviewed journals after fenestrated and chimney graft approaches to repair of JAAA2,3. Open repair, fenestrated endovascular aneurysm repair (FEVAR) and chimney endovascular aneurysm repair (Ch-EVAR) are effective methods to treat this condition, but the comparative effectiveness of these treatment modalities is unclear4. Upon completion of a hybrid vascular intervention room at our institution and careful planning and sizing, we started a prospective registry of all JAAA cases performed. Here we present our retrospectively analyzed results, including short and midterm follow-up results in patients with JAAA treated using either endovascular or open repair. Methods - We retrospectively reviewed patients with JAAA (n= 75) who underwent chimney grafts (Ch-EVAR, n = 23), fenestrated stent grafts (FEVAR, n = 20) or open repair (OR, n = 32) between January 2011 and December 2016 at a single institution. Our primary endpoint was peri-operative mortality. Secondary endpoints included renal function impairment, new-onset dialysis, procedural details and postoperative complications. Descriptive statistics are reported as mean ± standard deviation for continuous data and categorical data are presented as number and percentage. Kaplan-Meier analysis was used to estimate freedom from late re-intervention, primary patency of targeted vessel stent grafts and overall survival. Results - There were no statistically significant differences in baseline characteristics among the three groups. Perioperative mortality was not significantly different between groups: 4.3% (1/23) in the Ch-EVAR group, 0% in the FEVAR group and 3.1% (1/32) in the OR group(p = 0.532). Mean follow up time was 36.7 months. There were no statistically significant differences among the three groups in secondary endpoints, except for increased blood loss in the open repair group when compared to the endovascular groups. There were no statistically significant differences in overall survival among groups (p=0.282). Estimated targeted vessel stent patency at 1 and 4 years were 89.5% and 89.5% in the Ch-EVAR group and 93.8% and 93.8% in the FEVAR group, respectively. There were no statistically significant differences in estimated freedom from late re-intervention among groups (82.3% in the Ch-EVAR group, 77.2% in the FEVAR group and 96.4% in the OR group) Conclusion - We were unable to show a ststistically significant difference in outcomes among the treatment options for JAAA repair, which may be due to the size of our series. Nevertheless, our results show that after careful patient selection, we are able to offer our patients good results with fenestrated and chimney graft techniques that are comparable to open surgical procedures, but with a much faster recovery time. All three approaches (Ch-EVAR, FEVAR and open surgery) are effective treatment options for JAAA repair and have comparable short and mid-term outcomes in well-selected patients. Long term follow-up results are needed to determine the optimal management of JAAA. References·Jongkind V, Yeung KK, Akkersdijk GJ, Heidsieck D, Reitsma JB, Tangelder GJ, Wisselink W. Juxtarenal aortic aneurysm repair. J Vasc Surg. 2010;52:760-767·Verhoeven EL, Vourliotakis G, Bos WT, Tielliu IF, Zeebregts CJ, Prins TR, Bracale UM, van den Dungen JJ. Fenestrated stent grafting for short-necked and juxtarenal abdominal aortic aneurysm: An 8-year single-centre experience. Eur J Vasc Endovasc Surg. 2010;39:529-536·Donas KP, Torsello GB, Piccoli G, Pitoulias GA, Torsello GF, Bisdas T, Austermann M, Gasparini D. The protagoras study to evaluate the performance of the endurant stent graft for patients with pararenal pathologic processes treated by the chimney/snorkel endovascular technique. J Vasc Surg. 2016;63:1-7·Katsargyris A, Oikonomou K, Klonaris C, Topel I, Verhoeven EL. Comparison of outcomes with open, fenestrated, and chimney graft repair of juxtarenal aneurysms: Are we ready for a paradigm shift? J Endovasc Ther. 2013;20:159-169