The Gore Viabahn balloon-expandable stent graft as a bridging stent in complex endovascular aortic procedures at 3 years performs better in fenestrations.

OBJECTIVE: Complex endovascular procedures are now recognized as the gold standard treatments for extensive aortic diseases. Bridging stents (covered stents used to couple the aortic graft to the visceral vessels) play a pivotal role, yet there is currently no dedicated device available on the market. The aim of the study was to evaluate the midterm performance of the Gore Viabahn balloon-expandable (VBX) stent graft as a bridging stent for target visceral vessels (TVVs). METHODS: Data from all consecutive patients who underwent a fenestrated and branched endovascular aortic repair and received the VBX stent graft as a bridging stent between July 2018 and September 2022 were prospectively collected and subsequently analyzed retrospectively. Primary end points included freedom from TVV instability and freedom from TVV-related reinterventions, both overall and in comparison between branched and fenestrated graft configurations. Secondary end points were overall survival, procedure and TVV-related (in an intent-to-treat basis) technical success, freedom from type IC/IIIC endoleak, and freedom from TVV patency loss. RESULTS: Sixty-three patients were treated with a fenestrated and branched endovascular aortic repair using the VBX stent graft as a bridging stent, of whom 47 (74.6%) presented an atherosclerotic aneurysm, 7 (11.1%) a post-dissecative aneurysm, and 9 (14.3%) an anastomotic pseudoaneursym or a type IA endoleak in a previous endovascular aortic repair. Included in the aortic repair were 231 of 243 (95.1%) total visceral vessels. The intraoperative requirement of 13 additional VBX stent grafts determined a TVV-related technical success of 94.4%. The mean follow-up was 26.1 ± 16.4 months. The estimated overall survival at 36 months was 73% ± 7.5%. The estimated rates at 36 months for freedom from type IC/IIIC endoleaks and TVV primary patency were 90.6% ± 3.9% and 99% ± 0.7%, respectively. The estimated rate at 36 months for freedom from TVV instability was 92.1% ± 3% and did not differ between branched and fenestrated configurations, whereas freedom from TVV-related reinterventions was 90.6% ± 3.1% and significantly in favor of fenestrations (69.4% vs 96.8%, P < .001). Multivariate analyses confirmed fenestrated configuration as a protective factor against TVV-related reinterventions (hazard ratio: 0.079; 95% confidence interval: 0.016-0.403). CONCLUSIONS: The VBX stent graft proves to be a reliable bridging stent for complex aortic procedures involving both fenestrated and branched endografts. Although immediate results are deemed satisfactory, they favor fenestrations regarding the need of reinterventions through 3 years. The success of the procedure heavily relies on a thorough understanding of the unique characteristics of this stent.

Fate of target visceral vessels in fenestrated and branched complex endovascular aortic repair.

OBJECTIVE: To assess branch vessel outcomes after endovascular repair of complex aortic aneurysms analyzing possible factors influencing early and long-term results. METHODS: The Italian Multicentre Fenestrated and Branched registry enrolled 596 consecutive patients treated with fenestrated and branched endografts for complex aortic disease from January 2008 to December 2019 by four Italian academic centers. The primary end points of the study were technical success (defined as target visceral vessel [TVV] patency and absence of bridging device-related endoleak at final intraoperative control), and freedom from TVV instability (defined as the combined results of type IC/IIIC endoleaks and patency loss) during follow-up. Secondary end points were overall survival and TVV-related reinterventions. RESULTS: We excluded 591 patients (3 patients with a surgical debranching and 2 patients who died before completion from the study cohort) were treated for a total of 1991 visceral vessels targeted by either a directional branch or a fenestration. The overall technical success rate was 98.4%. Failure was related to the use of an off-the-shelf (OTS) device (custom-made device vs OTS, HR, 0.220; P = .007) and a preoperative TVV stenosis of >50% (HR, 12.460; P < .001). The mean follow-up time was 25.1 months (interquartile range, 3-39 months). The overall estimated survival rates were 87%, 77.4%, and 67.8% at 1, 3, and 5 years, respectively (standard error [SE], 0.015, 0.022, and 0.032). During follow-up, TVV branch instability was observed in 91 vessels (5%): 48 type IC/IIIC endoleaks (2.6%) and 43 stenoses-thromboses (2.4%). The extent of aneurysm disease (thoracoabdominal aortic aneurysm [TAAA] types I-III vs TAAA type IV/juxtarenal aortic aneurysm/pararenal aortic aneurysm) was the only independent predictor for developing a TVV-related type IC/IIIC endoleak (HR, 3.899; 95% confidence interval [CI]:, 1.924-7.900; P < .001). Risk of patency loss was independently associated with branch configuration (HR, 8.883; P < .001; 95% CI, 3.750-21.043) and renal arteries (HR, 2.848; P = .030; 95% CI, 1.108-7.319). Estimated rates at 1, 3, and 5 years of freedom from TVV instability and freedom from TVV-related reintervention were 96.6%, 93.8%, and 90% (SE, 0.005, 0.007, and 0.014) and 97.4%, 95.0%, and 91.6% (SE, 0.004, 0.007, and 0.013), respectively. CONCLUSIONS: Intraoperative failure to bridge a TVV was associated with a preoperative TVV stenosis of >50% and the use of OTS devices. Midterm outcomes were satisfying, with an estimated 5-year freedom from TVV instability and reintervention of 90.0% and 91.6%, respectively. During follow-up, the larger extent of aneurysm disease was associated with an increased risk of TVV-related endoleaks, whereas a branch configuration and renal arteries were more prone to patency loss.

The risk of aneurysm rupture and target visceral vessel occlusion during the lead period of custom-made fenestrated/branched endograft.

OBJECTIVE: The objective of this study was to evaluate adverse events occurring during the lead period of custom-made fenestrated/branched endograft for juxtarenal/pararenal abdominal aortic aneurysm (j/p-AAA) and thoracoabdominal aortic aneurysm (TAAA). METHODS: Between 2008 and 2017, patients enrolled for custom-made fenestrated/branched endograft repair were prospectively collected. Anatomic, procedural, and postoperative data were retrospectively analyzed. Lead period was defined as the time between the endograft order to the manufacturer and implantation. Aneurysm diameter, target visceral vessel (TVV) severe stenosis (>75% of ostial lumen), and number of planned TVVs were evaluated at preoperative computed tomography angiography. Patency of TVVs was evaluated intraoperatively. Aneurysm rupture and TVV occlusion during the lead period were assessed. RESULTS: There were 141 custom-made fenestrated/branched endograft repairs planned. Of these, 133 patients (male, 87%; age, 73 ± 6 years) with complete available data were considered for the study. There were 75 (56%) j/p-AAAs and 58 (44%) TAAAs. The mean aneurysm diameter was 58 ± 6 mm (j/p-AAA, 56 ± 6 mm; TAAA, 67 ± 8 mm); 15 cases (11%) had >70-mm diameter. Planned TVVs were 431 (mean, 3 ± 1 TVVs/patient). The mean lead period was 89 ± 25 days, with five (3.8%) aneurysm ruptures (j/p-AAA, one; TAAA, four) occurring, two (1.5%) during manufacture and three (2.3%) with endograft available in the hospital (all three procedures were postponed because of cardiac or pulmonary comorbidities). In one TAAA rupture, the endograft was successfully implanted and the patient survived. Four of five ruptures had >70-mm diameter. On univariate analysis, chronic obstructive pulmonary disease (P = .01; odds ratio [OR], 2.6; 95% confidence interval [CI], 2.1-3.2) and aneurysm diameter >70 mm (P = .001; OR, 42; 95% CI, 4-411) were risk factors for aneurysm rupture during the lead period, with aneurysm diameter >70 mm being confirmed as an independent risk factor on multivariate analysis (P = .005; OR, 29.3; 95% CI, 2.8-308). Overall, eight endografts (6%) were not implanted (refusal, two; aneurysm rupture, four; death not related to aneurysm, two). In the remaining 125 patients (94%), 405 TVVs were planned. Of them, 46 (11%) had severe stenosis at preoperative computed tomography angiography. Twelve (3%) TVVs occluded in the lead period (renal arteries, five; celiac trunks, seven); six were recanalized and six were abandoned. Severe preoperative stenosis was a risk factor for TVV occlusion during the lead period (P = .000; OR, 1.3; 95% CI, 1.1-1.6). CONCLUSIONS: In our series, custom-made design required a mean lead period of 89 days, which was determined by both manufacturing time and clinical reasons. During this delay, there is a high risk of both rupture in aneurysms >70 mm and TVV occlusion in severely stenosed vessels. These factors should be considered in the indication for custom-made fenestrated/branched endograft repair.

Short- and Midterm Outcomes of Open Repair and Fenestrated Endografting of Pararenal Aortic Aneurysms in a Concurrent Propensity-Adjusted Comparison.

PURPOSE: To compare outcomes of patients treated for pararenal aortic aneurysms using fenestrated endovascular aneurysm repair (fEVAR) vs open surgical repair (OSR) in 3 high-volume centers. MATERIALS AND METHODS: A multicenter retrospective analysis was conducted of 200 pararenal abdominal aortic aneurysm patients electively treated with OSR (n=108) or fEVAR (n=92) from 1998 to 2015 at 3 tertiary institutions. Endpoints were 30-day morbidity and mortality, late reinterventions, visceral artery occlusion, and mortality. Analysis was conducted on the entire population and on a propensity score-matched population constructed on age, gender, coronary artery disease (CAD), and chronic renal failure. RESULTS: In the total cohort, fEVAR patients were significantly (p<0.001) older and had higher frequencies of CAD (p<0.001) and previous stroke (p=0.003). OSR patients had higher risk of perioperative morbidity (OR 2.5, 95% CI 1.09 to 5.71, p=0.033), specifically respiratory failure (OR 4.06, 95% CI 1.12 to 4.72, p=0.034). These findings were confirmed in the propensity-adjusted analysis, where cardiac complications were also higher after OSR (OR 12.8, 95% CI 0.07 to 0.21, p=0.02). No difference in perioperative mortality (2.2% in fEVAR vs 1.9% in OSR) was identified. Mean follow-up was 50 months (range 0-119). Four-year results showed higher survival (91.2% vs 69.3%, p=0.02) and freedom from reintervention (95.6% vs 77.8%, p=0.01) after OSR in the unmatched population, with a small but significant (p=0.021) difference in the risk of late visceral artery occlusion/stenosis after fEVAR. On propensity analysis, no differences in late survival were found between groups. CONCLUSION: fEVAR and OSR may afford similar early and midterm survival rates. Higher risks of perioperative systemic complications after OSR are counterbalanced by higher risks of late visceral vessel patency issues and need for reintervention after fEVAR. Both procedures are safe and effective in the long term in experienced centers, where patient evaluation should drive the treatment strategy.

Advanced Technical Considerations for Implanting the t-Branch Off-the-Shelf Multibranched Stent-Graft to Treat Thoracoabdominal Aneurysms.

PURPOSE: To demonstrate different techniques and device modifications that can expand the anatomic suitability of the off-the-shelf multibranched t-Branch for treatment of thoracoabdominal aortic aneurysm. TECHNIQUE: The t-Branch device is not customized for specific patient anatomy, and the most frequent limitations to its use are an inadequate sealing zone and renal artery anatomy. Experience with this device has prompted the development of several techniques that can be employed to maximize the suitability of this stent-graft. Advice is offered on modification of the device to minimize the risk of paraplegia or better match patient anatomy. Maneuvers are explained to ease delivery through tortuous anatomy or existing stent-grafts, catheterize visceral target vessels, select a bridging stent, reduce ischemia time in the limbs, and alter the configuration of the branches. CONCLUSION: Employing adjunctive maneuvers can increase the anatomic suitability of the t-Branch; in our experience, these techniques have increased the applicability to more than 80% of all elective and urgent thoracoabdominal aortic aneurysm cases.

Renal Artery Orientation Influences the Renal Outcome in Endovascular Thoraco-abdominal Aortic Aneurysm Repair.

OBJECTIVE: To evaluate the impact of renal artery (RA) anatomy on the renal outcome of fenestrated-branched endografts (FB-EVAR) for thoraco-abdominal aortic aneurysms (TAAA). METHODS: Between 2010 and 2016, all patients undergoing FB-EVAR for TAAA were prospectively collected. Anatomical, procedural, and post-operative data were retrospectively analysed. RA anatomy was assessed on volume rendering, multi planar and centre line reconstructions by dedicated software (3Mensio). RA diameter, length, ostial stenosis/calcification, orientation and aortic angles of the para-visceral aorta were evaluated. RA orientation was classified in four types: A (horizontal), B (upward), C (downward), D (downward + upward). RA revascularisation by fenestrations or branches was considered. Inability to cannulate and stent RA (RA loss), early RA occlusion (within three months), and composite RA events (one among RA loss, intra-operative RA lesion, RA related re-interventions, RA occlusion) were assessed. RESULTS: Seventy-three patients (male 77%; age 73 ± 6 years) with 39 (53%) type I, II, III and 34 (47%) type IV TAAA, underwent FB-EVAR, for a total of 128 RAs. The mean RA diameter and length were 6 ± 1 mm and 43 ± 12 mm, respectively. Type A, B, C, and D orientations were 51 (40%), 18 (14%), 48 (36%), and 11 (10%) RAs, respectively. Angulation of para-visceral aorta >45° was present in 14 cases (19%). Ostial stenosis and calcifications were detected in 20 (16%) and 16 (13%) RAs, respectively. Branches and fenestrations were used in 43 (34%) and 85 (66%) RAs, respectively. There were four (3%) intra-operative RA lesions (2 ruptures, 2 dissections). Ten (8%) RAs were lost intra-operatively because of the inability to cannulating and stenting. On univariable analysis, type B RA orientation (p = .001; OR 13.2; 95% CI 3.2-53.6), para-visceral aortic angle > 45° (p = .02; OR 4.9; 95% CI 1.3-18.5) and branches (p = .003; OR 9.0; 95% CI 1.9-46.9) were risk factors for intra-operative RA loss; type C RA orientation was a protective factor (p = .02; OR 0.1; 95% CI 0.01-0.9). On multivariable analysis, type B RA orientation (p = .03; OR 5.9; 95% CI 1.1-31.1) and branches (p = .03; OR 7.3; 95% CI 1.1-47.9) were independent risk factors for intra-operative RA loss. Fourteen patients suffered post-operative renal function worsening (> 30% of the baseline). The mean follow up was 19 ± 12 months. Four (3%) early RA occlusions occurred in three patients (2 single kidney patients required permanent haemodialysis). Type D RA orientation (p = .00; RR 17.8; 8.6-37.0) and branches (p = .004; RR 3.2; 2.4-4.1) were risk factors for early RA occlusion on univariable analysis. Five patients (7%) required early RA related re-interventions (recanalisation + relining 3; stent graft extension 1; parenchymal embolisation 1). No late RA occlusion or re-interventions were reported during follow up. Composite RA events occurred in 17 (13%) cases. Type B (p = .05; OR 3.9; 95% CI 1.1-15.7) or D (p = .006; OR 10.9; 95% CI 2.3-50.8) RA orientations and branches (p = .006; OR 5.7; 95% CI 1.6-20.3) were independent predictors of composite RA events on multivariable analysis. CONCLUSION: Renal artery orientation significantly affects the early RA outcome of FB-EVAR for TAAA. Intra-operative RA loss is predicted by type B RA orientation and branches, while early RA occlusion is predicted by type D orientation and branches. The present data suggest that in TAAA, fenestrations should be the first choice for renal revascularisation in type B and D RA orientations.

Role of imaging in visceral vascular emergencies.

Differential diagnosis in non-traumatic acute abdomen is broad and unrelated diseases may simulate each other from a clinical perspective. Despite the fact that they are not as common, acute abdominal pain due to diseases related to visceral vessels may be life-threating if not detected and treated promptly. Thrombosis, dissection, and aneurysm in the abdominal visceral arteries or thrombosis in visceral veins may cause acute abdominal pain. Imaging with appropriate protocoling plays a fundamental role in both early diagnosis and determination of the treatment approach in these cases where early treatment can be life-saving. Computed tomography (CT) appears to be the most effective modality for the diagnosis as it provides high detail images in a very short time. Patient cooperation is also a less concern as compared to magnetic resonance imaging (MRI). As the imaging findings may sometimes be really subtle, diagnosis may be difficult especially to inexperienced imagers. Correct protocoling is also very critical to detect arterial abnormalities as visceral arterial abnormalities may not be detectable in portal phase only abdominal CT scans. In this article, we aimed to increase awareness among imaging specialists to these not very common causes of acute abdomen.