Talent LPS AAA stent graft: results of a pivotal clinical trial

PURPOSE

We report results of a pivotal prospective clinical trial that compared standard surgical repair with endovascular exclusion of abdominal aortic aneurysm (AAA) with the Talent LPS stent graft system.

METHODS

Between March 24, 1999, and September 19, 2000, 240 patients with AAA who underwent stent graft placement and 126 patients who concurrently underwent surgery to treat AAA were enrolled at 17 centers in the United States. All patients were considered to be at low risk from aortic surgery. Patients who underwent endovascular repair received a bifurcated Talent LPS stent graft; surgical control subjects underwent standard operative techniques. Inclusion criteria were AAA larger than 4.0 cm in diameter, with proximal neck > 5 mm long and 14 to 32 mm in diameter, and a 15 mm landing zone in at least one common iliac artery. Access requirements included one external iliac artery of 7 mm caliber or larger. Preoperative anatomic evaluation included computed tomography and angiography. After stent-graft placement, evaluation involved plain radiography and computed tomography performed before discharge and at 1, 6, and 12 months and yearly thereafter.

RESULTS

There was no significant difference in early (<30 days) or late mortality between the two groups. Complications were slightly higher in the surgical cohort. The stent graft group did better in terms of procedure duration, requirement for general anesthesia and blood transfusion, and intensive care unit and hospital stay. There were three access or deployment failures. Immediate surgical conversion was necessary in only 1 patient, and late conversion in 5 additional patients. There were no aneurysm ruptures. Endoleak rate detected at CT (core laboratory validated) was 14% at 1 month, 12% at 6 months, and 10% at 12 months.

CONCLUSIONS

Compared with surgical control subjects, patients with AAA treated with the Talent LPS stent graft had fewer complications and the same low operative mortality. Likewise, endovascular repair performed better than surgery in the perioperative period, as measured with several key procedural indicators. Long-term follow-up of patients with the stent graft will be essential to assess durability of these early results.

Stent graft repair in the aortic arch and descending thoracic aorta: a 4-year experience

BACKGROUND

Thoracic aortic aneurysms (TAAs) and type B aortic dissections (ADs) are relatively frequent, serious conditions that are often managed nonoperatively because of perceived poor outcome of standard surgical reconstruction. Recently developed stent graft techniques represent a more attractive, less invasive option. We sought to determine the technical feasibility and safety of endovascular repair in the thoracic aorta with a retrospective review of our experience with such an approach.

METHODS

Forty-seven patients received thoracic stent graft implants during the 4-year period ending March 31, 2002. All patients signed an Institutional Review Board-approved informed consent. Thirty-one patients had TAAs, and 16 had ADs. Device design and implant strategy were on the basis of evaluation of morphology with angiography and computed tomographic scan. The procedures were done with fluoroscopic guidance, with local anesthesia in five cases, spinal anesthesia in 19 cases, and general anesthesia in 23 cases. Endovascular access was achieved with femoral cutdown in 41 cases and a temporary iliac conduit in six cases. A Talent patient-specific device, with 4-mm to 6-mm oversize, was used in all. Proximal endograft attachment was in the descending thoracic aorta in 16 cases, parasubclavian in 21 cases, and the suprasubclavian aorta in 10 cases. Eight patients had adjunctive cervical reconstruction to transpose or revascularize the left subclavian or left common carotid arteries, enabling more proximal endograft attachment in the aortic arch.

RESULTS

Access failure occurred in one patient (2.1%). One patient (2.1%) died within 30 days of access-related iliac artery rupture. Another death occurred at 60 days from a ruptured thoracoabdominal aneurysm with type I endoleak. No instances of paraplegia, stroke, or surgical conversion were seen. Five patients (TAA) were found to have endoleak on 30-day computed tomographic scan. Repair of type I endoleak was undertaken in three cases at 1, 4, and 6 months. Eight patients (17%) had adverse events within the first 30 days. Length of follow-up ranged from 1 to 44 months, with a mean of 18 months. Two patients were lost to follow-up, and one withdrew from the study. Four additional mortalities were observed, none related to the endograft or aortic pathology.

CONCLUSION

Stent graft repair of TAA and AD is feasible and can be achieved with technical success and relatively low rates of perioperative morbidity and mortality. The Talent customized design proved versatile in various morphologies. More information is needed on indications, clinical efficacy, and long-term results.

Technical strategies to expand stent-graft applicability in the aortic arch and proximal descending thoracic aorta

The endovascular repair of thoracic aortic pathology is on an evolutionary threshold, as advancing technologies and techniques combine to offer the interventionist expanded treatment opportunities. A variety of maneuvers are recommended to address the landing zone limitations to thoracic endografting imposed by the arch vessels: transostial bare stent placement, intentional occlusion of the arch vessel origin, vessel transposition, and bypass grafting. These adjunctive techniques can help us extend the option of a minimally invasive treatment to a greater number of patients with severe thoracic aortic lesions and comorbidities that place them at high risk for standard surgical intervention.

Carotid artery stenting in a vascular surgery practice

PURPOSE

We tested the clinical applicability, technical results, and morbidity of carotid angioplasty-stenting (CAS) in the treatment of severe stenosis of the internal carotid artery (ICA) in patients deemed to be high-risk candidates for carotid endarterectomy (CEA).

METHOD

After an initial series (1994-1997) of 52 interventions, we adopted the use of a transfemoral access technique and self-expanding stents in late 1997. From Dec 1, 1997, to Mar 31, 2001, 135 CAS procedures were performed on 132 patients with more than 70% (symptomatic) or more than 80% (asymptomatic) stenoses of the ICA. Sixty percent of the patients had no symptoms, and 40% of patients had symptoms. The interventional technique was standardized with the use of a 7F long interventional sheath, balloon pre-dilatation of the stenotic lesion, placement of a self-expanding stent (Wallstent in 12 patients and a SMART stent in 120 patients), and post-balloon dilatation when necessary. Brain protection devices were not used. Patients were given clopidogrel and aspirin before and after the procedure and heparin during the intervention.

RESULTS

All procedures except two were completed as planned, with access failure in three patients (2.2%). Residual in-stent stenosis of less than 20% was detected in 14 of 132 stented vessels (11%) and accepted as a satisfactory angiographic outcome. Neurologic complications included one patient with a single-episode transient ischemic attack (TIA; motor-sensory deficit of the hand) occurring 2 hours after CAS. One patient sustained a major stroke after thrombosis of the stented ICA, which occurred 3 days after the CAS procedure and 24 hours after open-heart surgery. A third patient sustained a minor stroke that began intraprocedurally after post-balloon dilatation of the stent, and a fourth patient had another minor stroke with transient aphasia (beginning during the procedure and resolving after 4 hours) and monoparesis of the hand, which resolved after 1 week. All stented vessels remained patent during the follow-up period (range, 2-41 months; mean, 16 plus minus 9 months), with four instances of hemodynamically significant in-stent restenosis. Re-intervention with balloon angioplasty was undertaken successfully at 4 months in one patient with restenosis. The periprocedural mortality rate was 0.

CONCLUSION

Carotid stenting can be performed with acceptable safety on carefully selected patients by using meticulous, standardized interventional techniques. It may offer a possibly superior therapeutic alternative for non-CEA candidates. Evolving technological improvements and brain protection devices are likely to enhance its role in the treatment of carotid artery disease in the future. Surgical endarterectomy remains the standard of care for most patients at the present time.

Update on the Talent aortic stent-graft: a preliminary report from United States phase I and II trials

PURPOSE

Phase I and phase II trials were conducted to determine the safety and efficacy of the Talent aortic stent-graft (Medtronic World Medical, Sunrise, Fla) in the treatment of infrarenal abdominal aortic aneurysms (AAA). This is a preliminary report of the technical results and 30-day clinical outcome of these trials.

METHODS

Multicenter prospective trials were conducted to test the Talent stent-graft in high-risk and low-risk patient populations with AAA, including phase I feasibility and phase II clinical trials. The low-risk study included concurrent surgical controls.

RESULTS

In the phase I trial, deployment success was achieved in 92% (23/25 patients), and initial technical success was 78% (18/23 implants without endoleak). The 30-day technical success rate was 96%, with six endoleaks that resolved spontaneously (without need for further intervention); and the 30-day mortality rate was 12% (3/25 patients). The phase II high-risk trial demonstrated a deployment success of 94% (119/127 patients) and an initial technical success of 86% (102/119 implants). The 30-day technical success rate was 96%, and the 30-day mortality rate was 1.5% (2/127 patients). The phase II low-risk trial included a first-generation and a second-generation Talent stent-graft. Deployment success rates were 97% and 99%, respectively, and technical success rates at 30 days were 97% and 96%, respectively. The 30-day mortality rate was 2% in the phase II low-risk first-generation device trial, and the adverse-event rate was 20%. Corresponding figures for the second-generation device were 0% and 1.8%, respectively.

CONCLUSION

The Talent stent-graft can be deployed successfully and achieves endovascular exclusion in a large proportion of patients with AAA. Morbidity and mortality rates are acceptable. One-year clinical results and the comparison with concurrent surgical control subjects remain to be evaluated.

Brachial artery catheterization to facilitate endovascular grafting of abdominal aortic aneurysm: safety and rationale

PURPOSE

Endovascular treatment of abdominal aortic aneurysms (AAAs) is a technically demanding procedure that is based on the complexity and multiplicity of steps and the guidewire and catheter manipulations required. Brachial artery catheterization is an adjunctive technique that can facilitate the placement of an endoluminal prosthesis.

METHODS

Brachial access was used during endoluminal AAA repair in 79 of 103 consecutive patients with a modular-design stent-graft prosthesis at two institutions.

RESULTS

Left brachial access facilitated (1) angiography to guide juxtarenal device deployment, (2) antegrade contralateral limb access, (3) device delivery through disadvantaged iliac arteries by means of a brachial femoral wire, (4) access to renal arteries when necessary, and (5) catheter exchanges and a reduction in fluoroscopic positional changes. Complications included one puncture-site pseudoaneurysm, seven hematomas, and 29 patients with extensive ecchymosis. The length of stay was not prolonged in any case. There were no embolic, oculocerebral, or ischemic upper extremity events.

CONCLUSIONS

Brachial artery catheterization, as an adjunctive technique to endoluminal AAA repair, offers noteworthy technical advantages with few, but self-limiting complications.

Relationship between preoperative patency of the inferior mesenteric artery and subsequent occurrence of type II endoleak in patients undergoing endovascular repair of abdominal aortic aneurysms

OBJECTIVES

The purpose of this study was (1) to find out whether preoperative inferior mesenteric artery (IMA) patency (on radiographic imaging) predicts IMA-related endoleaks after endovascular repair of infrarenal abdominal aortic aneurysms, (2) to determine feasibility of measuring aneurysm sac pressures in patients with endoleaks, and (3) to report early evidence of effective endovascular obliteration of IMA endoleaks.

METHODS

We studied 76 consecutive cases of infrarenal aortic aneurysms that were repaired with an endovascular approach (March 1998-April 1999).

RESULTS

There were 13 (17%) endoleaks persistent 30 days after the procedure. Eleven (85%) of these 13 were IMA-related endoleaks, which were documented with selective superior mesenteric artery angiography. The preoperative finding (on computed tomographic scan) of a patent IMA does not always predict an IMA-related endoleak, but results in a statistically and clinically significant higher ratio of patients with IMA-related endoleaks in the immediate postoperative period (24% versus 3%, P <.035). In eight of the 11 patients with persistent IMA-related endoleaks, measurement of intra-aneurysm sac pressures was possible, and six of these patients had systemic pressures within the excluded aneurysm sac. Nine (82%) of 11 IMA-related endoleaks were successfully obliterated by means of selective IMA embolization.

CONCLUSIONS

Many endoleaks are caused by a patent IMA, and this can result in persistence of systemic pressure within the aneurysm sac. The preoperative finding (on computed tomographic scan) of a patent IMA is a predictor of increased rates of IMA endoleaks, and IMA endoleaks can be successfully obliterated through endovascular procedures, after endovascular abdominal aortic aneurysm repair.

Safety of coil embolization of the internal iliac artery in endovascular grafting of abdominal aortic aneurysms

PURPOSE

During endovascular grafting of an abdominal aortic aneurysm (AAA), iliac limb extension to the external iliac artery may be indicated when the common iliac artery is ectatic or aneurysmal. Preliminary or concomitant coil embolization of the internal iliac artery (IIA) is thus necessary to prevent potential reflux and endoleak. We sought to determine the safety of hypogastric flow interruption in this setting.

METHODS

We retrospectively reviewed 156 patients who underwent stent-graft AAA repair at two institutions between February 1, 1998, and January 31, 1999. Coil embolization of one or both IIAs was undertaken when the diameter of the common iliac artery was more than 20 mm to enable limb endograft extension to the external iliac artery. Bilateral procedures were staged.

RESULTS

Thirty-nine (25%) of 156 patients were selected for coil embolization of one (n = 28) or both (n = 11) IIAs. The interventions were performed before (n = 31) or during (n = 8) the stent-graft procedure. Complications included groin hematomas in 3 patients, iliac artery dissection in 1, failure to catheterize the IIA in 2, and transient rise in the serum creatinine level in 3. One patient had erectile dysfunction, and five patients (13%) had buttock claudication after unilateral occlusion. Serious ischemic complications were not observed.

CONCLUSION

Coil embolization of one or both IIAs appears to be safe in the setting of endovascular grafting of AAA. Buttock claudication is a relatively significant problem and may limit applicability of this strategy to patients who are unfit for standard open repair.