Predicting Features of Visceral Stent Failure in Fenestrated Endovascular Aortic Aneurysm Repair.

PURPOSE: Visceral stents in fenestrated endovascular aortic repair (FEVAR) have a significant risk of complications and carry a considerable burden of reinterventions. The aim of this study is to identify preoperative and intraoperative predictors of visceral stent failure. MATERIALS: A retrospective review of 75 consecutive FEVARs in a single center from 2013 to 2021 was undertaken. Data on mortality, stent failure, and reintervention pertaining to 226 visceral stents were collected. METHODS: Anatomical features including aortic neck angulation, aneurysm diameter, and angulation of target viscerals were obtained from preoperative computed tomography (CT) scans. Stent oversizing and intraprocedural complications were recorded. Postoperative CT scans were analyzed to determine the length of cover of target vessels. RESULTS: Only bridging stents through fenestrations to visceral vessels were considered; 28 (37%) cases had 4 visceral stents, 24 (32%) had 3, 19 (25%) had 2, 4 (5%) had 1. Thirty day mortality was 8%, a third of which was related to visceral stent complications. Intraprocedural complexity was documented during the cannulation of 8 (3.5%) target vessels, with a technical success rate of 98.7%. A significant endoleak or visceral stent failure was identified in 22 stents (9.8%) postoperatively, of which 7 (3%) had in-patient reintervention within 30 days. Further reinterventions at 1, 2, and 3 years were 12 (5.4%), 2 (1%), and 1 (0.4%), respectively. Most reinterventions were for renal stents (n=19, 86%). A smaller stent diameter and a shorter length of visceral stent were significant predictors of failure. No other anatomical feature or stent choice was found to be a significant predictor of failure. CONCLUSIONS: The modality of visceral stent failures varies, but renal stents with a smaller diameter and/or shorter length are more likely to fail over time. Their complications and reinterventions are common and carry a significant burden; therefore, close surveillance must be continued long term. CLINICAL IMPACT: With this work we share the methodology adopted at our centre to treat juxtarenal aneurysm with FEVAR. Thanks to this detailed review of anatomical and technical features we provide guidance for endovascular surgeons to face hostile aneurysm with peculiar visceral vessels anatomy. With our findings will also motivate industries in their attempt to produce improved technologies able to overcome issues identified in this paper.

Comparison between open repair with suprarenal clamping and fenestrated endovascular repair for unruptured juxtarenal abdominal aortic aneurysms.

BACKGROUND: Management of juxtarenal abdominal aortic aneurysms (JRAAA) remains challenging. Both open surgical and endovascular options are feasible, however, there is lack of level 1 evidence to support one modality over the other. Operative interventions frequently necessitate either open repair with a suprarenal clamp positioning (ORSRC) or complex endovascular repair (EVAR) with fenestrated (fEVAR) or parallel stent grafts (chEVAR). The aim of this study was to compare the renal function deterioration and mortality between ORSRC and fEVAR in patients who were operated on for unruptured JRAAA at a tertiary centre. METHODS: A retrospective review of prospectively collected data was performed on patients who underwent repair for unruptured JRAAA between March 2008 and October 2019. Analysis of short and mid-term outcomes after ORSRC (occlusion of the aorta above at least one of the main renal arteries) and fEVAR was conducted. Patients who underwent open repair of JRAAA with an infrarenal clamp were excluded. Procedural data as well as data regarding complications was noted. Acute kidney injury (AKI) and chronic kidney disease were defined using the KDIGO criteria (Kidney Disease: Improving Global Outcomes). Renal impairment data up to 1 year and mortality up to 5 years was recorded. RESULTS: During the study period, 162 patients who underwent JRAAA repair met the inclusion criteria (60.5% of them having ORSRC). Approximately, 85.8% of the population were males (80.6% in the open group compared to 93.7% in the endovascular group; P=0.019). The mean age for patients in the open group was 74.0 (SD=±5.5) years compared to 76.1 (SD=±7.2) years in the fEVAR group (P=0.035). More patients in the ORSRC group were symptomatic (18.4% versus 6.3% in the fEVAR group; P=0.028) and they also had larger aneurysms compared to the fEVAR group (66.9 (±12.7) mm versus 62.6 (±8.6) mm, respectively; P=0.021). In the ORSRC group, all patients required suprarenal clamping, with clamping above only one of the main renal arteries carried out in 43 patients (44.3%) of cases. At baseline, 37.0% and 44.5% of patients had CKD stage 3 or worse in ORSRC and fEVAR groups, respectively (P=0.759). Approximately 47.6% of patients having ORSRC had evidence of acute renal impairment on post-operative day 3 compared to 12.7% of those in the endovascular group (p<0.05). By 9-12 months, 54.6% of patients in the OR group had a CKD stage of 3 or worse, compared to 62.1% of patients in the fEVAR group (Pearson χ2, P=0.713). The median total length of stay (LOS) was 10 days for OR versus 6 days for fEVAR (p<0.05). Patients having fEVAR were more likely to require re-intervention (26.6% v/s 10.2%; P=0.006). Mortality at 30 days was 8.2% for ORSRC against 7.8% for complex EVAR (P=0.936). The corresponding figures at 1 and 5 years were 10.2% and 25.5% for ORSRC compared to 14.1% and 32.8% (P=0.456 and P=0.314, respectively). CONCLUSIONS: In the context of JRAAA, patients receiving fEVAR procedures tended to be older, with a smaller diameter aneurysm. Postoperatively, fEVAR was associated with shorter hospitalisation and less risk of AKI in the immediate post-operative course, but had a greater likelihood of requiring re-intervention over time. Both interventions had similar rate of renal function deterioration at 1 year and the five year mortality rate was comparable.

Outcomes of Sub-threshold Abdominal Aortic Aneurysms Undergoing Surveillance in Patients Aged 85 Years or Over.

OBJECTIVE: Despite an increasing elderly population there is limited evidence regarding the surveillance and management of small abdominal aortic aneurysms (AAAs) in octogenarians. This study investigated outcomes of patients aged ≥85 years undergoing AAA surveillance to identify whether discontinuation of surveillance might be safe. METHODS: This was a retrospective cohort study of all patients aged 85 years undergoing surveillance with a small (30-54 mm) AAA between January 2007 and November 2017. Patients were stratified depending on aneurysm diameter at index (<40 mm, 40-50 mm, > 50 mm). A threshold of 55 mm was used to decide intervention in all patients. Subsequent management of threshold aneurysms, aneurysm related and all cause mortality were also collected. RESULTS: One hundred and one patients were included (88 male, mean diameter at index 45 mm, median follow up 56.0 months). The majority of patients (72.3%) undergoing surveillance had not reached threshold at the end of follow up. Only one patient in the <40 mm group developed a threshold aneurysm, compared with five (11.6%) and 22 (75.9%) in the 40-50 mm and >50 mm groups, respectively (p < .0001). Of the 28 patients reaching threshold, eight (28.6%) underwent surgical repair (5 standard endovascular, one complex endovascular, and two open). Twenty-six (25.7%) patients died during follow up, with cardiorespiratory pathologies being the leading cause of death. Only three aneurysm related deaths were observed, including two fatal ruptures and one death following repair from an infected stent graft (all in the >50 mm index group). CONCLUSION: The present data suggests that discontinuation of aneurysm surveillance in patients aged 85 years with aneurysms < 40 mm might be safe. In patients with a larger aneurysm or those approaching threshold, early assessment of fitness for surgery may prevent unnecessary surveillance. The decision to treat aneurysms reaching threshold is complex but is appropriate in selected patients.

A Comparison of Manual and Three-Dimensional Modalities in Predicting Nellix Polymer Volume.

PURPOSE: Achieving an effective seal with the Nellix endovascular aneurysm system is dependent on filling the stent bags with an appropriate volume of polymer. Calculating this volume preoperatively is essential and can be performed manually or using three-dimensional (3D) software. The aim of this project was to compare the accuracy of these two methods relative to the actual polymer volume used. MATERIALS AND METHODS: Consecutive patients undergoing Nellix aneurysm repair were included in this retrospective study. Operation notes were analysed for the polymer volume used intra-operatively. Predicted volumes for all patients had been calculated on picture archiving and communication system (PACS) using a manual 'segmental cylinder' method. Computed tomography angiograms were then re-analysed using the Synapse 3D PACS update. The difference between groups was assessed using a paired t-test. RESULTS: Twenty-eight patients were included in the analysis; 26 men (92.9%) and 2 women (7.1%); median age 80.9 years (interquartile range, 72.5-84.5 years). The mean volume of polymer used was 103 mL. The mean manual-derived prediction was 100.1 mL (P=0.365) and 3D-derived prediction 110.2 mL (P<0.001). Manual prediction led to an average 2.8% underestimate of polymer volume whilst 3D prediction led to an average 7.0% overestimate. CONCLUSION: Calculating predicted polymer volume for the Nellix system is more accurate using a manual approach then the 3D alternative. Whilst this method is more time-consuming, there is no significant difference when compared to the actual volume used. Quicker 3D software predictions can be utilised, but their tendency to overestimate should be recognized and taken into account during planning.

Neoaortic Xenoprosthetic Grafts for Treatment of Mycotic Aneurysms and Infected Aortic Grafts.

BACKGROUND: There is no international consensus regarding the optimum management of infected aortae (mycotic aneurysms, infected aortic grafts). Neoaortoiliac reconstruction has advantages over extra-anatomical bypass grafting; however, the use of autologous vein is associated with venous hypertension and compartment syndrome, alternatively cadaveric homografts are associated with high rates of perianastomotic hemorrhage, limb occlusion, and pseudoaneurysm. Arterial repair using xenoprosthetic patches is associated with lower infection rates compared to the use of prosthetic material. The aim of this case series and literature review is to report the use of xenoprosthetic bovine biomaterial for neoaortic repair of mycotic aneurysmal disease and infected aortic grafts. METHODS: Patients with evidence of infected aortic grafts or mycotic aneurysms who were suitable for open aortic surgery were included. Following removal of the graft/excision of the aneurysmal sac, a 10 × 16 cm XenoSure Biologic Surgical Patch (LeMaitre, Germany) was rolled into a tube, or bifurcated tube graft, and secured with prolene sutures. Proximal and distal anastomoses were conducted as per standard aortic anastomoses. Patients were continued on long-term antibiotics and surveyed with computerized tomography at 1, 3, 6, and 12 months. RESULTS: Six patients underwent bovine aortic repair between 2013 and 2015: an infected Dacron aortobi-iliac graft causing iliac pseudoaneurysm, an infected Dacron aortic graft from open repair later relined with endovascular stent graft, a mycotic iliac aneurysm, and 3 mycotic aortic aneurysms. All were treated with bovine reconstructed aortic grafts or patches. Patients had a median age of 69.5 years (range 67-75), with perioperative and 30-day mortality of 0%. Median follow-up was 13 months (range 2-23). Postoperative contrast-enhanced computed tomography revealed no evidence of infection at the operative site in all patients. Freedom from reinfection and reintervention was 100%. CONCLUSIONS: Xenoprosthetic (bovine) neoaortic grafts are an alternative method to treat infected aortae with excellent short-term freedom from infection and reintervention. Optimum duration of postoperative antibiotic therapy remains undetermined. Further cases and longer follow-up are required to determine the true efficacy of this technique.

Endovascular abdominal aortic aneurysm sealing: A systematic review of early outcomes.

Objectives There has been a clear move towards endovascular repair of abdominal aortic aneurysms owing to better peri-operative outcomes compared with open surgical repair. However, follow-up has continued to reveal relatively high rates of endoleaks and re-interventions. Improvements in endovascular stent-grafts aim to decrease these complications. This systematic review aims to determine the early outcomes of abdominal aortic aneurysm sealing. Methods Standard PRISMA guidelines were followed. A literature search was performed with the aim to extract any publication related to the endovascular aneurysm sealing device. Results The total number of patients in this systematic review of 11 studies is 684, with a mean age of 73.2 years, and 587 (88.0%) males. The majority were undergoing elective procedures ( n = 606, 91.0%), the remainder as emergencies ( n = 30, 4.5% as ruptures, n = 30, 4.5% as symptomatic). Technical success rate including emergency cases was 99.1%. Thirty-day mortality rate was 2.6% ( n = 17) including all cases, and 1.0% ( n = 6) including elective cases only. Thirty -day endoleak detection rate was 4.7% ( n = 31) including all cases, and 4.8% ( n = 29) including elective cases only. Thirty-day aneurysm-related re-intervention rate was 5.7% ( n = 38) including all cases, and 4.6% ( n = 28) including elective cases only. There was no conversion to open surgery within 30 days post-op in the elective cases. There were three delayed conversions to open surgery within 30 days and one report of stent migration causing rupture in the emergency setting. Conclusions This novel endovascular aneurysm-sealing device for abdominal aortic aneurysm repair has shown respectable early outcomes. Good technical success rates, in both elective and emergency settings, low rates of all-type endoleaks and low re-intervention rates have all been demonstrated. It is proving to be a safe alternative to open and endovascular aneurysm repair; however, longer term follow-up results are needed to assess the safety and effectiveness of the device in the long term.

Outcomes of endovascular aneurysm repair with 2 different endograft systems with suprarenal fixation in patients with hostile infrarenal aortic anatomy.

OBJECTIVE: To evaluate 2 different aortic endograft systems with suprarenal fixation in patients with unfavorable neck morphology. METHODS: A prospective observational study assigning patients with abdominal aortic aneurysm with unfriendly neck anatomy treated with 2 different endograft systems (Endurant and Zenith) was conducted. The log-rank test was applied to investigate the differences in cumulative outcome parameters. RESULTS: Successful endograft implantation was achieved in all patients. Requirement for troubleshooting techniques was similar in the 2 groups (P = .156 and P = .081, respectively). In-hospital procedure-related morbidity occurred in 7 patients (Zenith vs Endurant, P = .690). Freedom from any type of endoleak and overall mortality did not differ significantly between the groups (log-rank test, P = .068 and P = .087). Reinterventions were more commonly required in the Zenith group (log-rank rest, P = .041), and were all nongraft/aneurysm-related. CONCLUSIONS: Similar performances of the Zenith and the Endurant endograft systems were demonstrated.

Reduction of ischemia-reperfusion injury in the rat kidney by FTY720, a synthetic derivative of sphingosine.

BACKGROUND: The current shortage of organ donors has led many centers to use marginal and nonheart-beating donors (NHBDs). Recent research has implicated the infiltration of lymphocytes as an important mediator of ischemia-reperfusion injury (IRI). FTY720 is an immunosuppressant that promotes lymphocyte sequestration into lymph nodes. The purpose of this study was to examine the potential for FTY720 to abrogate IRI when subjected to increasing ischemic times. METHODS: Male Sprague-Dawley rats underwent bilateral flank incision with removal of the right kidney and clamping of the left hilum. Groups were divided into ischemia times of 45, 55, and 65min; each group was further divided into a control group (IRI only), IRI+FTY720 (1 mg/kg/d), and IRI+cyclosporine (15 mg/kg/d), n=4 per group. RESULTS: Thre days after 45 min of ischemia, serum creatinine in the ischemia only (477+/-37 micromol/L) and cyclosporine groups (698+/-32 micromol/L) was significantly increased compared with the FTY720-treated animals (194+/-66 micromol/L). The beneficial effect of FTY720 was also observed at 55 and 65 min; indeed, FTY720-treated animals demonstrated signs of recovery from 65 min of ischemia whereas control and cyclosporine-treated animals required sacrifice between days 3 and 5. Treatment with FTY720 reduced renal damage assessed histologically and also reduced apoptosis and increased cell proliferation. CONCLUSION: Treatment with FTY720 reduced IRI and prevented unrecoverable acute renal failure after significant ischemic injury. This study suggests that FTY720 may help improve the quality of grafts from NHBD and marginal donors by abrogating the IRI insult.