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

OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSION: Both endovascular techniques had good safety profiles. The evidence does not support superiority of either FEVAR or ChEVAR for JAA. CLINICAL IMPACT: 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.

Endovascular repair using parallel grafts to treat a suprarenal pancreatitis-related abdominal aortic pseudoaneurysm.

Arterial pseudoaneurysms represent an uncommon complication of acute pancreatic inflammation or chronic pancreatitis. We describe a contained rupture of a suprarenal abdominal aortic pseudoaneurysm. An aorto-uni-iliac stent-graft was adopted as the aortic main body and was combined with two chimneys and two periscope stents for celiac/superior mesenteric artery and renal arteries, respectively. The procedure was complicated by the entrapment of the celiac sheath into the barbs of the aortic stent-graft and the attempts to remove the sheath resulted in an upward migration of the stent-grafts. A bail-out endovascular procedure was used to reline the stent-grafts and the pseudoaneurysmal sac was embolized with coils.

Outcomes of Castor Single-Branched Stent Graft for Reconstruction of Multiple Supra-Aortic Branches in Aortic Arch Disease.

PURPOSE: To report the outcomes of a combination of Castor single-branched stent grafts with other techniques for the reconstruction of multiple supra-aortic branches in aortic arch disease. MATERIALS AND METHODS: Between December 2019 and December 2021, 20 patients with aortic arch disease underwent thoracic endovascular aortic repair (TEVAR) at our institution using a Castor single-branched stent graft combined with the fenestration, chimney, or bypass techniques. Thoracic endovascular aortic repair is indicated for complicated or acute type B aortic dissection (TBAD), nonruptured aneurysms with a maximum aneurysm diameter >5.5 cm or showing rapidly expanded, ruptured, or threatened aneurysms, and penetrating aortic ulcers (PAUs) with a maximal aortic diameter >5.5 cm or with PAUs >10 mm deep or >20 mm in diameter. Preoperative, intraoperative, and postoperative clinical data were recorded. RESULTS: The median age of the patients was 56 (range=52-69 years) years, and 19 patients were men. Seven patients underwent the Castor single-branched stent graft and left common carotid artery (LCCA) chimney technique, 8 patients underwent the Castor single-branched stent graft and fenestration technique, and 5 patients underwent the Castor single-branched stent graft and bypass technique. The technical success rate was 100%. Major adverse events included 2 endoleaks, 1 spinal cord ischemia, and 1 early-stage retrograde type A aortic dissection. No cerebral stroke-related complications were observed. The mortality rate was 10% (2/20 patients). One patient with thoracic aortic aneurysm (TAA) died because of a sudden decrease in oxygen saturation and blood pressure after surgery. Relatives declined autopsy, and the cause of death was not determined. Another patient died of a retrograde type A dissection after surgery. The median follow-up period was 6 months (range=3.5-12 months). During follow-up, 1 patient with type I endoleak underwent thoracotomy again after a year. The remaining patients recovered well. CONCLUSIONS: The combination of a Castor single-branched stent graft with fenestration, chimney, or bypass techniques may be an effective treatment for preserving multiple supra-aortic branches in aortic arch disease. CLINICAL IMPACT: This study introduced three methods of reconstruction of multiple supra-aortic branches using a Castor single-branched stent graft (Castor single-branched stent graft combined with fenestration, chimney, or bypass technique) and analysed their advantages and shortcomings to provide experience for the future treatment of aortic arch diseases.

Outcomes of Clampless Real Chimney Technique with Dacron Graft and Sleeve Banding of the Ascending Aorta for Total Debranching Endovascular Arch Repair.

BACKGROUND: Hybrid aortic arch repair with debranching of the supra-aortic vessels carries a high risk of cerebral infarction and fatal complications associated with side clamping of the ascending aorta. A previous study had reported the "real chimney" technique, a novel method for clamp-free total debranching thoracic endovascular aortic repair with the ascending aortic sleeve banding with dacron. In this study, we aim to build upon this foundation by presenting our experience with the early and midterm outcomes of this technique. METHODS: We retrospectively reviewed the medical records of 61 consecutive older adult patients with aortic arch pathologies and a high risk of open repair who underwent total debranching thoracic endovascular aortic repair using the real chimney technique at our institution between January 2014 and June 2022. This technique was used to anastomose the ascending aorta with the main trunk of the triple-branched prosthetic graft. RESULTS: The mean patient age was 75.1 years, and 54% of patients were transferred from medical facilities with cardiothoracic surgery departments. The comorbidities included chronic obstructive pulmonary disease (49.2%), chronic kidney disease (63.9%), coronary artery disease (27.9%), and history of stroke (31.1%). No 30-day mortality was observed. Complications included postoperative renal failure requiring permanent hemodialysis (4; 6.6%), stroke (modified Rankin scale score: ≥2 in 5; 8.2%), permanent paraplegia (1; 1.6%), and permanent paraparesis (4; 6.6%). The median follow-up period was 40.5±28.5 months. The postoperative survival rates at 5 years were 66.8%. No patients experienced complications associated with the aorta or anastomosis site; only 1 patient required an additional procedure for stenosis of the anastomosis site (midterm). An aneurysmal diameter reduction of ≥3 mm was observed in 37 cases (60.7%), and the mean aneurysmal diameter reduction was 5.3 mm. CONCLUSIONS: The postoperative outcome of total debranching thoracic endovascular aortic arch repair is not only acceptable but also promising, particularly in patients at high risk of open repair. CLINICAL IMPACT: Our novel real chimney technique for total debranching thoracic endovascular aortic repair of aortic arch pathologies in patients who were at a high-risk for open repair resulted in no 30-day mortality and no complications related to the aorta or the real chimney anastomosis site.The real chimney technique is effective for managing aortic arch pathologies and enables less invasive total debranching thoracic endovascular aortic arch repair without the need for extracorporeal circulation and clamping of the ascending aorta.

Management of an Isolated Left Vertebral Artery on the Arch During Zone 2 Landing Thoracic Endovascular Aortic Repair: A Multicentre Retrospective Study.

OBJECTIVE: To compare the early and midterm outcomes of three different strategies for an isolated left vertebral artery on the arch (LVoA) revascularisation during thoracic endovascular aortic repair (TEVAR) with a proximal zone 2 landing. METHODS: Between January 2016 and December 2021, 67 patients with LVoA and aortic arch pathologies who underwent zone 2 landing TEVAR at four medical centres were enrolled. These patients were divided into three groups for comparison: the novel chimney (group A, n = 28) with the right brachial-left brachial through and through (RLT) procedure; in vitro fenestration (group B, n = 24); and transposition (group C, n = 15). The flow direction and velocity of the LVoA was examined by Doppler ultrasound in the pre-, intra-, and post-operative periods. Primary outcomes were all cause mortality and new neurological symptoms. RESULTS: No deaths or new neurological symptoms occurred within 30 days. Early type Ia endoleak rates were 18% (n = 5), 17% (n = 4), and 0% in groups A, B, and C, respectively (p = .22). All patients had antegrade flow of the LVoA. The mean ± standard deviation duration of follow up was 63.6 ± 4.0 months. No deaths were observed during follow up. The rates of new neurological symptoms were 0%, 8%, and 33% in groups A, B, and C, respectively. The rates of midterm type Ia endoleak were 7%, 12%, and 0% in groups A, B, and C, respectively (p = .35). Bidirectional flow rates in the LVoA were 0%, 21%, and 27% in groups A, B, and C, respectively (p = .021). Two (8%) and three (20%) patients in groups B and C underwent a secondary procedure because of mild dizziness, but this was not necessary in group A (p = .058). CONCLUSION: The novel chimney technique of the RLT procedure may be feasible for patients with a LVoA requiring zone 2 anchoring. Accurate determination of the safety and feasibility of this novel technique requires larger sample sizes and longer follow up.

Early Results of a Novel Gutter-Free Chimney Stent-Graft System to Treat Aortic Arch Dissection: Single-Center Data from a Prospective Clinical Trial.

AIMS: Discuss the clinical value, technique characteristics, and early follow-up results of a newly designed gutter-free chimney stent-graft system for aortic arch pathology. METHODS AND RESULTS: About 13 patients with aortic arch dissection were enrolled in a clinical trial testing a novel gutter-free stent-graft between February 2019 and December 2020. All 13 patients were male, age 52.6±10.4 years. The implantation time was 14.0±6.9 minutes; total procedure time was 89.5±19.8 minutes. The volume of contrast was 79.6±7.2 ml. And 15 aortic stent-grafts were implanted, and all 13 patients had chimney branch stent-grafts implanted into the left subclavian artery (LSA). There were 3 (23.1%) cases of immediate type Ιa endoleak after thoracic endovascular aortic repair (TEVAR), and 7.7% type Ιa endoleaks occurred in delayed fashion. Survival at 2 years was 100%, and the 2-year patency of chimney stent-grafts was 100%. CONCLUSIONS: This study reports early success with good freedom from endoleak using a novel stent-graft designed for chimney TEVAR to treat aortic arch dissection. Postoperative survival and patency of the branch stent-grafts were excellent. Additional data from this multicenter clinical trial will be forthcoming.

Combined fenestrated/chimney thoracic endovascular repair for the treatment of blunt traumatic aortic injury: A case report.

Blunt traumatic thoracic aortic injury (BTAI) is an extremely serious medical condition with a high rate of associated mortality. Recent advances in techniques such as thoracic endovascular repair offer new opportunities to manage the critical BTAI patients in an efficacious yet less invasive manner. A 65 year-old-male suffered from multiple injuries after a fall, including BTAI in the aortic arch, which resulted in dissection of the descending thoracic-abdominal aorta and iliac artery, development of an intimal flap in the left common carotid artery, and dissection of the left subclavian artery. Based on the imaging information of this patient and our clinical experience, the combined treatment of fenestrated thoracic endovascular repair and a chimney technique was immediately planned to fully repair these dissections and moreover prevent further dissection of the branching vessels, additionally to ensure sufficient blood flow in the left subclavian artery and left common carotid artery. The intervention yielded satisfactory early outcomes. Follow-up assessment at six months reported no symptoms or complications associated with the stent-graft. Computed tomography angiography further confirmed adequate stent-graft coverage of the aortic injury.

Endovascular Hybrid Repair of True Ascending Aortic Aneurysms Using Double Graft Wrapping to Prepare a Landing Zone for Ascending Aortic Stent-Graft Placement: A Cohort Study.

Purpose: To describe a hybrid procedure that avoids cardiopulmonary bypass to treat patients with true ascending aortic aneurysms without a suitable proximal landing zone for endovascular repair. Material and Methods: Thirteen consecutive patients (mean age 75.9±6.5 years; 8 women) with true ascending aortic aneurysms were treated with the endovascular hybrid repair of true aortic aneurysms (EHTA) approach, which consists of a conventional sternotomy with double wrapping of the ascending aorta followed by staged stent-graft placement. Via sternotomy, a polypropylene mesh trimmed to downsize the aneurysm is placed around the dilated ascending aorta and sutured to the adventitia. A similarly trimmed polytetrafluoroethylene graft is placed loosely around the first wrap to avoid adhesions and secure the proximal landing zone. There is no need for cardiopulmonary bypass. A few days later, a standard thoracic stent-graft is deployed via either a transaxillary or transfemoral access; chimney or bypass grafts are used as needed to revascularize the supra-aortic vessels. Results: The ascending aortic diameter was reduced from a mean 5.7 cm (range 4.8-6.5) to 3.9 cm (range 3.2-4.3) after wrapping. The mean interval between surgery and stent-graft placement was 5 days. In this interval, 2 patients with significant reduction in the diameter of the ascending aorta elected to forego placement of a stent-graft. Of the 11 patients who underwent the full hybrid EHTA procedure, the ascending aortic stent-graft was combined with a chimney graft in the innominate artery in 4 cases. In 1 patient, a supra-aortic debranching procedure using a bifurcated Dacron graft to the innominate and left common carotid arteries was performed after wrapping with the polypropylene mesh. There was no mortality or neurological complication. A sternal wound infection required a prolonged hospital stay. At a mean follow-up of 13.8 months (range 3-24), there has been no death, type I endoleak, or sign of aneurysm enlargement on imaging. Conclusion: This technique permits complete endovascular exclusion of an ascending aortic aneurysm in a less invasive approach than standard open repair. Although this is only a small cohort of patients without long-term follow-up, it seems that this hybrid procedure is associated with low morbidity and mortality. It offers a beating-heart approach to treat true ascending aortic aneurysms in selected high-risk patients.

In Vitro Evaluation of Balloon-Expandable Chimney Grafts in the Renal Arteries Combined With the Endurant Endograft.

Purpose: To compare balloon-expandable covered stents (BECS) available for use as renal chimney grafts to the Advanta V12 approved for use with the Endurant endograft. Materials and Methods: A silicone model was manufactured based on preoperative computed tomography angiography (CTA) scans of a patient with a 7-cm juxtarenal aneurysm treated with an Endurant bifurcated endograft and an Advanta V12 covered stent for the 6-mm-diameter right renal artery. The model was placed in a flow box filled with a 37°C blood-mimicking solution equipped with a pulsatile pumping system (140/60 mm Hg). The tested BECS were the Advanta V12, the VBX, and the BeGraft+. A 36-mm-diameter Endurant II endograft with a 16-mm-diameter contralateral limb and a 6×59-mm BECS chimney graft were used in 9 consecutive tests (3 for each combination). After each implantation, the model was placed in the CT scanner, and 2 radiologists blinded to the test device independently measured the gutter areas and the patent chimney graft lumen at the level of the Endurant's suprarenal stent, at the level of the chimney's maximum curvature, and 10 mm inside the renal artery. The intraclass correlation coefficients (ICC) were calculated to assess interreader reliability. Results: The mean gutter areas were 19.3±7, 20.2±8, and 22.3±8 mm2 for the Advanta, VBX, and BeGraft+, respectively (all p>0.05). At the level of the aortic endograft's suprarenal stent struts, the mean diameter of the Advanta V12, VBX, and BeGraft+ were 4.46±0.3, 4.12±0.4, and 4.12±0.3 mm, respectively (all p>0.05). At the level of the maximum chimney graft angulation, the mean diameters were 3.77±0.3, 4.16±0.1, and 3.74±0.3 mm, respectively (all p>0.05). In the right renal artery, the mean diameters were 3.91±0.2, 4.05±0.9, and 4.3±0.4 mm, respectively (all p>0.05). The ICCs varied between 0.7 and 0.9, indicating good agreement between readers. Conclusion: These in vitro findings showed comparable results between the Advanta V12 and the available BECS used in conjunction with the Endurant endograft according to the instructions for use. Further clinical evaluation is needed to confirm these results.

Chimney Endovascular Aneurysm Repair Using Endurant Stent-Grafts With Bare Balloon-Expandable Stents for Patients With Juxtarenal Aortic Aneurysms.

PURPOSE: To evaluate the advantages of chimney endovascular aneurysm repair (chEVAR) using an Endurant stent-graft with uncovered balloon-expandable stents (BES) for patients with juxtarenal aortic aneurysms. MATERIALS AND METHODS: Twenty-two patients (mean age 78.5±9.0 years; 13 men) who underwent chEVAR using Endurant and uncovered BES between January 2014 and December 2017 were analyzed retrospectively. The maximum aneurysm diameter was 59.1±11.9 mm, and the proximal neck length was 5.2±2.9 mm. Of the 22 cases, 9 (40%) involved proximal neck angulation and 9 (40%) had a conical neck. Single and double chimneys were performed using BES in 19 and 3 cases, respectively. In 2 cases, an additional self-expanding covered stent was used inside the uncovered BES. RESULTS: The technical success was 91% (20/22) as 2 (9%) cases showed minor type Ia endoleak. No postoperative systemic complications or acute renal dysfunction (Acute Kidney Injury Network classification stage 2 or higher) were observed. The mean radiologic observation period was 16.1±9.6 months, and no aneurysm expansion (>5 mm) was observed during this time. The mean maximum aneurysm diameter decreased to 52.9±10.2 mm (p<0.001 vs preoperative), with an individual mean sac regression of 6.2±5.9 mm. Overall primary chimney stent patency was 100%. One of the 2 cases of intraoperative type Ia endoleak resolved at the 6-month imaging, and no new type Ia endoleaks developed in any cases at follow-up. No additional treatment- or aneurysm-related events were observed. CONCLUSION: Short-term outcomes of chEVAR using Endurant with uncovered BES have been favorable when covered stents were unavailable, and it can be useful for high-risk patients with juxtarenal aortic aneurysms.

Deployment of stent graft in an excessively higher position above the renal artery induces a flow channel to the aneurysm in chimney endovascular aortic aneurysm repair: an in vitro study.

We aimed to investigate the influences of the sealing length above the renal artery (RA) on gutter formation, non-apposed regions between the aortic wall, stent graft (SG), and chimney graft and incidence of flow channel to the aneurysm in chimney endovascular aortic aneurysm repair (Ch-EVAR) using a juxtarenal abdominal aortic aneurysm model. Neck diameter and length of the silicone model were 24 and 4 mm, respectively. In double Ch-EVAR configuration using Advanta V12, 12 combinations were tested three times with two sizes [28.5 (20%-oversize) and 31 (30%-oversize) mm] of Excluder SG, three sealing lengths above the RA (10, 20, and 30 mm), and two deployment positions (anatomical and cross-leg). Gutter area, non-apposed region, and flow channels to the aneurysm were analyzed using micro-computed tomography. Average gutter area and non-apposed region of 30%-oversize SG were significantly smaller than those of 20%-oversize SG (p = 0.05). Furthermore, the non-apposed region of 30%-oversize SG with a 30-mm sealing length was significantly larger than that of the other sealing lengths. For 20%-oversize SGs, flow channel to the aneurysm was observed, except for the anatomical deployment with the sealing length of 10 mm. For 30%-oversize SGs, flow channel was absent, except for the SG with a 30-mm sealing length in both deployment positions. These flow channels were frequently formed through a valley space, existing in the lower unibody above the two limbs. Our data indicated that the optimal sealing length should be chosen in consideration of the device design difference due to the device diameter in Ch-EVAR.

Thoracic Endovascular Aneurysm Sealing of a Complex Thoracoabdominal Aneurysm.

PURPOSE: To report bailout treatment of a thoracoabdominal aortic aneurysm using a single Nellix stent and parallel stents. CASE REPORT: A 74-year-old man with multiple comorbidities and a previous fenestrated Anaconda stent-graft for a 60-mm juxtarenal aneurysm was diagnosed with a type IV thoracoabdominal aneurysm on the 2-year computed tomography angiography (CTA) scans. The imaging showed >10-mm downward migration of the proximal Anaconda stent with a massive type Ia endoleak and aneurysmal evolution of the distal descending thoracic aorta; the superior mesenteric artery (SMA) and renal artery covered stents were patent and intact. Open conversion or a second custom-made endograft was not feasible. A plan was devised to use off-the-shelf materials, including the deployment of a single Nellix stent extending from the descending thoracic aorta into the stented area of the fenestrated endograft, with parallel chimney stent-grafts into the SMA and right renal artery; the left renal artery was treated with a bare stent in a periscope configuration. Transient paraparesis was resolved with cerebrospinal fluid drainage. At 6-month CTA, ongoing aneurysm exclusion with patent SMA and renal arteries was confirmed. CONCLUSION: Thoracic endovascular aneurysm sealing with visceral and renal stenting seems to be a feasible bailout alternative treatment for urgent, complex cases without reconstruction options.

Collected Transatlantic Experience From the PERICLES Registry: Use of Chimney Grafts to Treat Post-EVAR Type Ia Endoleaks Shows Good Midterm Results.

PURPOSE: The aim of this retrospective analysis was to evaluate the performance of the chimney (ch) technique in the treatment of type Ia endoleaks after standard endovascular aneurysm repair (EVAR). METHODS: Between January 2008 and December 2014, 517 chEVAR procedures were performed in 13 US and European vascular centers (PERICLES registry). Thirty-nine patients (mean age 76.9±7.1 years; 33 men) were treated for persistent type Ia endoleak and had computed tomography angiography or magnetic resonance angiography follow-up at >1 month. Endurant abdominal stent-grafts were used in the 20 cases. Single chimney graft placement was performed in 18 (46%) patients and multiple in 21 (54%). Overall, 70 visceral vessels were targeted for revascularization. RESULTS: Technical success was achieved in 35 (89.7%) cases; 3 persistent type Ia endoleaks and 1 chimney graft occlusion were detected within the first 30 days. Thirty-day mortality was 2.6%. Two other deaths (not aneurysm related) occurred during a mean follow-up of 21.9 months (0.23-71.3). Primary patency of the chimney grafts was 94.3% at 36 months. In a subgroup analysis comparing Endurant to other stent-grafts, no significant differences were observed regarding persistent endoleak [1/20 (5%) vs 2/19 (11%), p=0.6] or reintervention [1/20 (5%) vs 0/19 (0%)]. CONCLUSION: The present series demonstrates that chEVAR in the treatment of post-EVAR type Ia endoleaks has satisfactory results independent of the abdominal and chimney graft combinations. Midterm results show that chEVAR is an effective method for treating type Ia endoleaks.

[Thoracoabominal aortic aneurysms-endovascular options]. / Aneurysmen der thorakoabdominalen Aorta ­ endovaskuläre Therapieoptionen.

BACKGROUND: Thoracoabdominal aortic aneurysms (TAAA) are predominantly atherosclerotic related and are usually asymptomatic. Treatment is necessary from a size greater 6.5 cm, while patients with rapidly growing, compression of organ structures, aneurysm-related connecting tissue orders must be treated from a diameter of 6 cm. METHODS: Elective interventions may be performed with fenestrated and/or branched grafts. Another possibility is the chimney, sandwich or periscop technique for treating TAAA. Depending on the extension of the TAAA, implantation of tube grafts for the thoracic aorta or bifurcation grafts for the abdominal aorta is necessary. Symptomatic TAAA may be treated by implantation of a t-Branch® or using the chimney, sandwich or periscop technique. CONCLUSIONS: The preinterventional planning and sizing with the help of computed tomography (CT) scans for endovascular repair of TAAA, and the implantation of the grafts during the procedure are challenging; thus, a well-experienced interdisciplinary team of medical and nonmedical specialists is required.

Use of the Nellix Endovascular Aneurysm Sealing System in Combination With Parallel Grafts for the Treatment of a Symptomatic Type V Thoracoabdominal Aortic Aneurysm.

PURPOSE: To report endovascular treatment of a symptomatic type V thoracoabdominal aortic aneurysm (TAAA) using the combined techniques of endovascular aneurysm sealing and parallel stent-grafts. CASE REPORT: A 70-year-old man was referred with a symptomatic type V TAAA. The Nellix EndoVascular Aneurysm Sealing (EVAS) System was used in combination with 2 chimney grafts for the celiac artery (CA) and the superior mesenteric artery (SMA); one periscope graft perfused the right renal artery. Completion angiography showed exclusion of the aneurysm and patency of all 3 parallel grafts but occlusion of the left renal artery (LRA) due to unintentional coverage of its ostium by the Nellix endobags. Antegrade catheterization of the LRA failed, requiring implantation of an aortorenal vein bypass. The postoperative course was complicated by acute kidney injury. Imaging at 6 months showed sustained exclusion of the aneurysm, patency of the CA and SMA parallel grafts and left aortorenal bypass but occlusion of the right renal artery periscope graft. Serum creatinine at 6 months was 1.5 mg/dL. CONCLUSION: The combination of EVAS with parallel grafts for preservation of the visceral vessels may be a feasible technique to treat selected TAAAs in the acute setting when other options are not applicable.

Anatomical Suitability of the Zenith Off-the-Shelf (p-Branch) Endograft in Juxtarenal Aortic Aneurysms Previously Treated Using the Chimney Technique.

PURPOSE: To examine the suitability of the Zenith off-the-shelf (p-branch) endograft in patients with juxta- or pararenal abdominal aortic aneurysms (J/PRAA) previously treated with endovascular aneurysm repair incorporating the chimney technique (chEVAR). METHODS: Between January 2012 and December 2014, high-resolution computed tomography angiograms and clinical data from 50 patients (mean age 79 years; 45 men) with J/PRAAs treated with chEVAR were retrospectively reviewed. Primary anatomical suitability was evaluated according to the Investigational Device Exemption protocol for the Zenith p-branch endograft in a dedicated 3-dimensional vascular workstation. Secondary suitability was defined as any additional intervention needed to overcome adverse anatomical conditions at the access vessels. The Zenith p-branch endograft is available in 2 configurations (A and B), with the main difference being the distance between the superior mesenteric artery (SMA) and the renal fenestrations. RESULTS: The p-branch endograft showed a primary suitability of 54% (n=27). Each configuration was suitable in 18 (36%) patients. Main anatomical limitations were the clock position of the left renal artery (LRA; n=7, 14%), the distance between the SMA and LRA (A: n=16, 32%; B: n=16, 32%), and significantly narrowed or calcified iliac arteries. If additional interventions at the access vessels were employed, a secondary suitability of 64% (n=32) could be achieved. CONCLUSION: In this specific group of patients treated with chEVAR, the Zenith p-branch system would be suitable in about half of the patients, which could be raised to two-thirds with ancillary access vessel procedures. A prospective clinical study is warranted to evaluate these results.

Impact of renal arterial morphology on fluoroscopy time in chimney endovascular aneurysm repair.

Objectives To evaluate the impact of renal artery morphology on fluoroscopy time in chimney endovascular aneurysm repair. Methods Morphology of renal artery was retrospectively quantified in the preoperative CT angiography. Renal artery angulation, ostial diameter, severity of ostial stenosis, main renal artery length, and tortuosity were analyzed with a 3D workstation. The main measure outcome was fluoroscopic time as an indicator of complexity. Uni- and multivariate logistic regression analyses were performed to determine predictors of longer fluoroscopy. Secondary endpoints were amount of contrast medium, patency of renal artery, and type Ia endoleak. Results The enrolled 38 patients (mean age 75.0 years; 34 males) were stratified at the median of fluoroscopic time of 35.2 min (interquartile range, 21.5) and classified in group A ( n = 19) and group B ( n = 19) having a fluoroscopic time of 24.5 (interquartile range, 5.9) and 46.4 (interquartile range, 16.0) min, respectively. The severity of ostial stenosis (OsSte) was significantly different between group A and B of 26.3 ± 13.4% and 41.6 ± 18.0%, respectively; P < .01. ROC curve analysis revealed that 35.5% was an optimal cut-off for OsSte. The difference of renal angulation (RAng) (-22.5° and -2.0°; interquartile ranges 49 and 35; P = .13), and main renal artery length (33.4 ± 11.8 mm and 33.7 ± 14.3 mm; P = .94) were not significantly different. In multivariate analysis after dichotomizing OsSte and RAng, OsSte > 35.5% was identified as the only significant predictor for the longer fluoroscopy (HR: 4.33; 95% CI: 1.02-18.4, P = .04). As for the secondary endpoints, no significant differences were observed between the groups. No correlation between longer fluoroscopy and renal patency or type Ia endoleak was observed. Conclusion Severity of ostial stenosis seems to be a significant predictor for longer fluoroscopic time.

Complementary Role of Fenestrated/Branched Endografting and the Chimney Technique in the Treatment of Pararenal Aneurysms After Open Abdominal Aortic Repair.

PURPOSE: To evaluate the totally endovascular techniques for treating complex pararenal aortic aneurysms after open repair of abdominal aortic aneurysm. METHODS: This retrospective study involved 34 men (mean age 74 years) with pararenal aortic aneurysms (22 pseudoaneurysms and 12 para-anastomotic aneurysms) that developed a median 11 years (range 4-22) after the primary surgical reconstruction. The median infrarenal neck length was 2 mm (range 0-9). Total endovascular aneurysm repair (EVAR) included the use of fenestrated (f-EVAR; n=17), branched (b-EVAR; n=11), combined f-EVAR/b-EVAR (n=1), and chimney (ch-EVAR; n=4) grafts and the "sandwich" technique (n=1). The primary outcome was aneurysm shrinkage >5 mm at latest follow-up. Secondary outcomes were target vessel patency, 30-day mortality, late survival, absence of type I and III endoleak, clinical success, and reintervention rate. RESULTS: Technical success was 97% (n=33/34), while clinical success was achieved in 32 (94%) patients. The 30-day mortality was 3% (n=1/34). Mean follow-up was 23.2±16.6 months. One patient was lost to follow-up, and 1 patient underwent late open conversion for endograft infection. Six (18%) of the 33 surviving patients required a reintervention. Primary patency of the target aortic branches was 98% (109/111). Mean aneurysm diameter decreased from 64.1±10.2 to 56.7±16.9 mm (p<0.001) at latest follow-up. Midterm mortality was 12.1% (4/33). Estimated survival rates at 1 and 2 years were 93.9% and 90.9, respectively. CONCLUSION: Use of f-EVAR, b-EVAR, and ch-EVAR allows effective treatment of postsurgical pararenal aneurysms based on a clear algorithm and patient selection, highlighting the complementary character of these less invasive approaches.

Preservation of Clinically Relevant Accessory Renal Arteries in Infrarenal AAA Patients With Adequate Proximal Landing Zones Undergoing EVAR.

PURPOSE: To report techniques to preserve the flow to relevant accessory renal arteries (ARA) in patients undergoing infrarenal endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) with adequate landing zones. METHODS: ARAs that originate inferior to the lowest ipsilateral main renal artery, supply one-third of the renal parenchyma, and having a diameter >4 mm have significant clinical importance. Between May 2012 and January 2015, among 389 high-risk patients with infrarenal AAAs who underwent standard EVAR, 9 (2.3%) patients each presented with a coexistent clinically relevant ARA. Their perfusion was secured by placing covered stents in the target ARA, parallel and outside of the main abdominal, as chimney grafts. Evaluation of acute and chronic renal decline was based on the consensus definition of RIFLE criteria (risk, injury, failure, loss, and end-stage) and chronic kidney disease (CKD) staging system, respectively. RESULTS: The procedure was completed successfully in all cases. In the immediate postoperative period, no acute kidney injury was observed based on the RIFLE criteria. Eight of the 9 covered stents remained patent during a mean follow-up of 13.8 ± 6.2 months. A single covered stent occlusion was observed 30 days postoperatively with infarction of the caudal pole of the kidney. This patient developed renal function impairment based on the CKD staging system 12 months after the initial procedure. For the remaining 8 patients, improvement of one CKD stage (n=1) or no change (n=7) in the CKD stage was observed. CONCLUSION: In AAA patients unfit for surgical revascularization, EVAR is associated with a significant decline in renal function. For this reason, preservation of relevant coexistent ARAs using the chimney technique should be considered as an option.

Late Retrograde Migration of a Left Subclavian Artery Chimney Stent-Graft Into the Innominate Artery.

PURPOSE: To report an uncommon case of chimney stent-graft migration in the aortic arch. CASE REPORT: A 29-year-old man presented with chronic left arm hyposthenia after late displacement and thrombosis of a left subclavian artery (LSA) chimney graft that migrated retrogradely into the innominate artery 2 years after deployment. The self-expanding LSA chimney was placed during a redo procedure to repair a pseudoaneurysm and type I endoleak after an index emergency thoracic endovascular aortic repair for traumatic aortic rupture 1 year earlier. The patient was successfully treated in an elective procedure via a median sternotomy, with arch aortotomy under circulatory arrest to remove the proximal end of the thrombosed chimney graft from the ostium of the innominate trunk. Three months later, a left carotid-to-subclavian bypass was performed to restore flow to the left arm. CONCLUSION: Migration of the proximal end of an overly long chimney graft that moved freely in the aortic arch exposed the patient to a high risk of stroke and death. Because of the high-risk situation, open repair under circulatory arrest was elected to remove the proximal end of the chimney graft, with no major complications.