Application of endograft to treat thoracic aortic pathologies: A single center experience

PurposeTo evaluate our experience of thoracic endoluminal graft (ELG) repair of various thoracic aortic pathologies using a commercially available device approved by the Food and Drug Administration. Our patient population includes patients eligible for open surgical repair and those with prohibitive surgical risk.MethodsFrom March 1998 to March 2006, endovascular stent repair of the thoracic aorta was performed on 406 patients with 324 patients (median age 72; 200 male) receiving the Gore Excluder endograft. Patient demographics, procedural characteristics, complications, including endoleak, spinal cord ischemia, and mortality, were retrospectively reviewed during follow-up. All patients were followed with chest computer tomography at 6 months and yearly. Statistical analysis was performed utilizing the SPSS Windows 11.0 program. Logistic regression (univariate) analysis used to identify risk factors for paraplegia; analysis of variance (ANOVA) for endoleak distribution; and χ2 used to analyze variables. Survival analysis was done using SAS version 9.1 (SAS Institute, Cary, NC).ResultsThree hundred twenty-four patients were treated with Gore Excluder graft between March 1998 and March 2006. One hundred fifty-seven patients (48.5%) had atherosclerotic aneurysms, 82 (25.3%) had dissections type B (DTB), 34 (10.5%) had penetrating ulcers (PU), 26 (8.0%) with pseudoaneurysms (PSA), 11 (3.4%) had transections (MVAT), 9 (2.8%) aorto-bronchial fistulas (AoBF), 4 (1.2%) embolization, and 1 (0.3%) aorto-esophageal fistula (AoEF). Preoperative aneurysm sac size in TAA ranged from 5 to 12 centimeters, average size 6.3 cm. Sac shrinkage occurred in 65% (102 of 157) of patients. Average postoperative sac size of 5.4 cm in a mean follow-up of 20.4 months. One hundred cases (31.5%) were nonelective; 49 (15.1%) were ruptures. Overall complication was 22.7%, 14.2% (46) in elective cases and 8.5% (28) in nonelective cases. Paraplegia occurred in five (1.5%) patients and paresis in three (0.9%); two of the latter improved and one resolved completely prior to discharge. Incidence of paraplegia was statistically significant (P value < .05) with retroperitoneal approach, perioperative blood loss greater than 1000 cc, and aortic coverage greater than 40 cm. Early endoleaks included 18 (5.5%) type I, four (1.2%) type II, and two (0.6%) type III. Thirty-day mortality was 5.5% (18 related deaths, including three intraoperative deaths). A log rank test did not find statistical differences in actuarial survival with 30-day related mortality between TAA and other pathologies (P = .29) or between DTB and other pathologies (P = .97). Late mortality was 9.6% with 31 unrelated deaths. Follow-up ranged between 1 month and 70 months, average 17 months.ConclusionsEndoluminal grafting is a feasible alternative to open surgical repair for thoracic aortic pathologies. After more than 300 cases, 30-day morbidity and mortality compares favorably with open repair. Paraplegia remains low as a complication and increases in incidence with retroperitoneal approach, increased perioperative blood loss, and increased aortic coverage

A multicenter clinical trial of endovascular stent graft repair of acute catastrophes of the descending thoracic aorta

OBJECTIVE: Thoracic endovascular aortic repair (TEVAR) is applicable to a spectrum of thoracic aortic pathology with half of the procedures performed world-wide for indications other than degenerative aneurysm of the descending thoracic aorta (DTA). This multicenter, prospective study queried perioperative and one-year results of TEVAR using the commercially available GORE TAG device, in the treatment of acute complicated Type B dissection (cTBD), traumatic aortic tear (TT), and ruptured degenerative aneurysm (RDA) of the DTA. METHODS: This prospective, non-randomized, literature controlled study included 59 patients; cTBD, n = 19; RDA, n = 20; TT, n = 20. The primary end-point was the composite of death and total paraplegia in subjects at <or= 30 days post-treatment compared with a cohort from current literature. Secondary end-points included adverse events related to device, procedural and systemic complications, and one-year survival. RESULTS: All 59 patients had successful endoprosthesis deployment. Fifteen of 19 (79%) patients in the cTBD group had either rupture or malperfusion syndromes at presentation. Combined 30-day mortality/paraplegia rate was 13.6% (8/59), with seven (11.9%) deaths (cTBD [3], RDA [3] and TT [1]) and 1 (TT, 1.7%) case of paraplegia. The primary end-point for the TEVAR cohort was significantly lower (P = .008) when compared with a composite literature control of 800 patients (combined 30-day mortality/paraplegia of 29.6%). Thirty-day complications of any nature occurred in 48 (81%) patients; 11 (18.6%) were device related, and 43 (73%) experienced one or more systemic adverse events. Six (10%) patients required additional TEVAR implantations and 3 (5%) patients (one in each pathology group) required conversion to open surgery. Seventeen (29%) patients had endoleaks of any kind or degree through 30 days; cTBD (7), TT (2), RDA (8). Nine patients (15.3%) had perioperative strokes with two resultant deaths. During mean follow-up time of 409 +/- 309 days, an additional 12 patients died, one patient required open conversion (cTBD), and two patients had major device related events. Actuarial survival at one year was 66% (range, 52%-77%) for the entire cohort; (cTBD) 79% (range, 53%-92%), (TT) 79% (range, 53%-92%) and (RDA) 37% (range, 16%-59%). On regression analysis, age at treatment (1.05 [range, 1.01-1.09]; P = .008) and chronic obstructive pulmonary disease (COPD) (4.3 [range, 1.3-14.4]; P = .02) were predictive of death at one year. CONCLUSION: This study confirmed treatment advantages for TEVAR for thoracic aortic catastrophes when compared with literature-based results of open repair. One-year treatment results indicate a low incidence of graft-related complications. TEVAR is the preferred initial treatment for the DTA catastrophes studied herein

Results of the ANCHOR prospective, multicenter registry of EndoAnchors for type Ia endoleaks and endograft migration in patients with challenging anatomy

ObjectiveProximal attachment site complications continue to occur after endovascular repair of abdominal aortic aneurysms (EVAR), specifically type Ia endoleak and endograft migration. EndoAnchors (Aptus Endosystems, Sunnyvale, Calif) were designed to enhance endograft proximal fixation and sealing, and the current study was undertaken to evaluate the potential benefit of this treatment.MethodsDuring the 23-month period ending in December 2013, 319 subjects were enrolled at 43 sites in the United States and Europe. EndoAnchors were implanted in 242 patients (75.9%) at the time of an initial EVAR procedure (primary arm) and in 77 patients with an existing endograft and proximal aortic neck complications (revision arm). Technical success was defined as deployment of the desired number of EndoAnchors, adequate penetration of the vessel wall, and absence of EndoAnchor fracture. Procedural success was defined as technical success without a type Ia endoleak at completion angiography. Values are expressed as mean ± standard deviation and interquartile range.ResultsThe 238 male (74.6%) and 81 female (25.4%) subjects had a mean age of 74.1 ± 8.2 years. Aneurysms averaged 58 ± 13 (51-63) mm in diameter at the time of EndoAnchor implantation (core laboratory measurements). The proximal aortic neck averaged 16 ± 13 (7-23) mm in length (42.7% <10 mm and 42.7% conical) and 27 ± 4 mm (25-30 mm) in diameter; infrarenal neck angulation was 24 ± 15 (13-34) degrees. The number of EndoAnchors deployed was 5.8 ± 2.1 (4-7). Technical success was achieved in 303 patients (95.0%) and procedural success in 279 patients (87.5%), 217 of 240 (89.7%) and 62 of 77 (80.5%) in the primary and revision arms, respectively. There were 29 residual type Ia endoleaks (9.1%) at the end of the procedure. During mean follow-up of 9.3 ± 4.7 months, 301 patients (94.4%) were free from secondary procedures. Among the 18 secondary procedures, eight were performed for residual type Ia endoleaks and the others were unrelated to EndoAnchors. There were no open surgical conversions, there were no aneurysm-related deaths, and no aneurysm ruptured during follow-up.ConclusionsUse of EndoAnchors to treat existing and acute type Ia endoleaks and endograft migration was successful in most cases. Prophylactic use of EndoAnchors in patients with hostile aortic neck anatomy appears promising, but definitive conclusions must await longer term follow-up data

Code of practice on the operation and maintenance of H T motors at wind tunnel centre

This document describes the performance of the high tension13; motors, which drive the centrifugal compressors, at the Wind13; Tunnel Centre Belur. These compressors are the vital equipment to supply compressed air to various wind tunnel facilities. These motors are in continuous use for the past 25 years, during which period the motors have under gone various preventive and breakdown maintenance operations including servicing and overhauling of liquid rheostat starter. Some of the breakdown maintenance operations were carried out under the supervision of M7s BHEL Engineers. Both the preventive and breakdown maintenance works carried out are being detailed in this report

Have we gone too far? Endovascular stent-graft repair of aortobronchial fistulas

ObjectiveAlthough endovascular repair of the descending thoracic aorta has emerged as a viable treatment option, little is known about its potential to treat patients diagnosed with aortobronchial fistulas. We reviewed our comprehensive thoracic endografting experience with regard to the endovascular management and subsequent outcome of patients with aortobronchial fistulas to assess whether endoluminal graft repair is a realistic option.MethodsBetween February 2000 and November 2005, 255 patients were successfully treated with an endoluminal graft to the descending thoracic aorta. Indications for intervention included: atherosclerotic aneurysms (109/255, 42.7%), acute and chronic dissections (75/255, 29.4%), miscellaneous (34/255, 13.3%), penetrating aortic ulcers (30/255, 11.8%), and aortobronchial fistulas (7/255, 2.7%).ResultsAverage patient age was 73.4 ± 10.1 years, with 4 male patients (4/7, 57.1%) and 3 female patients (3/7, 42.9%). All patients presented with hemoptysis, with 1 patient (1/7, 14.3%) requiring preoperative blood transfusion. Three patients (3/7, 42.9%) were diagnosed with atherosclerotic aneurysms, 3 patients (3/7, 42.9%) had pseudoaneurysms associated with prior open surgical repair, and 1 patient (1/7, 14.3%) had a prior endoluminal graft placed for a traumatic aortic transection. No standard postoperative antibiotic regimen was followed. There were no endoleaks, no incidences of paraplegia, and no endoluminal graft infections. Survival was 100% (7/7) at both 30 days and 1 year, and all patients are currently alive. Follow-up computed tomography was available for all 7 patients, with an average follow-up of 42.6 ± 28.5 months.ConclusionsEndovascular management of aortobronchial fistulas appears to be safe and well tolerated, even in surgically high-risk patients, with minimal risk of prosthesis infection. Long-term surveillance and continued investigation are warranted

Treatment of type II endoleaks associated with left subclavian artery coverage during thoracic aortic stent grafting

ObjectiveIncreasing experience with thoracic aortic stent grafts has led to a more aggressive approach to thoracic aortic pathologies in the distal aortic arch and proximal descending thoracic aorta. To increase the length of the proximal landing zone, it is sometimes necessary to cover the left subclavian artery with the thoracic stent-graft, introducing the risk of retrograde filling of the excluded aorta from the left subclavian artery. It is currently unclear how best to manage these patients to prevent persistent risk of aneurysm expansion or rupture. We report our experience with a minimally invasive endovascular repair of the covered left subclavian artery.MethodsWe reviewed prospectively gathered data on all investigational device exemption-approved patients undergoing thoracic aortic stent grafting at the Arizona Heart Institute from 2000 to 2006 (n = 289 patients). Patients had surveillance with a contrast-enhanced computed tomography scan on the first postoperative day and during follow-up at 1, 6, and 12 months.ResultsA total of 289 patients received thoracic stent grafts during the study: Medtronic Talent (Medtronic, Minneapolis, Minn) (n = 25) or Gore TAG (WL Gore & Associates Inc, Flagstaff, Ariz) (n = 261). The left subclavian artery was covered in 23% of patients (n = 66), of whom 17% had preoperative carotid-subclavian bypass (n = 11/66). Among patients with left subclavian artery coverage, the 30-day mortality was 6.1% (n = 4), procedure-related strokes developed in 3 patients (n = 3, 4.6%), and the incidence of left arm claudication was 7.6% (n = 5), necessitating postoperative carotid-subclavian bypass in 2 patients. Twelve patients (18%) had a type I (n = 6) or II (n = 7) endoleak. Coverage of the left subclavian artery accounted for 71% of the type II endoleaks (n = 5), whereas patent intercostals accounted for the rest (n = 2). Type II endoleaks associated with left subclavian artery coverage were successfully treated by retrograde coil embolization from the left brachial artery (n = 3) or left subclavian artery ligation (n = 1).ConclusionCoverage of the left subclavian artery during thoracic aortic stent grafting is associated with a low incidence of arm complications and type II endoleaks. All type II endoleaks were successfully treated by retrograde coil embolization or ligation of the left subclavian artery. Successful treatment of endoleaks may reduce the risk of aneurysm expansion or rupture