Frank J. Criado

Pivotal results of the Medtronic Vascular Talent Thoracic Stent Graft System: the VALOR trial.

OBJECTIVE This report summarizes the 30-day and 12-month results of endovascular treatment using the Medtronic Vascular Talent Thoracic Stent Graft System (Medtronic Vascular, Santa Rosa, Calif) for patients with thoracic aortic aneurysms (TAA) who are considered candidates for open surgical repair. METHODS The study was a prospective, nonrandomized, multicenter, pivotal trial conducted at 38 sites. Enrollment occurred between December 2003 and June 2005. Standard follow-up interval examinations were prescribed at 1 month, 6 months, 1 year, and annually thereafter. These endovascular results were compared with retrospective open surgical data from three centers of excellence. RESULTS The Evaluation of the Medtronic Vascular Talent Thoracic Stent Graft System for the Treatment of Thoracic Aortic Aneurysms (VALOR) trial enrolled 195 patients, and 189 were identified as retrospective open surgical subjects. Compared with the open surgery group, the VALOR test group had similar age and sex distributions, but had a smaller TAA size. Patients received a mean number of 2.7 +/- 1.3 stent graft components. The diameters of 25% of the proximal stent graft components implanted were <26 mm or >40 mm. Left subclavian artery revascularization was performed before the initial stent graft procedure in 5.2% of patients. Iliac conduits were used in 21.1% of patients. In 33.5% of patients, the bare spring segment of the most proximally implanted device was in zones 1 or 2 of the aortic arch. In 194 patients (99.5%), vessel access and stent graft deployment were successful at the intended site. The 30-day VALOR results included perioperative mortality, 2.1%; major adverse advents, 41%; incidence of paraplegia, 1.5%; paraparesis, 7.2%; and stroke, 3.6%. The 12-month VALOR results included all-cause mortality, 16.1%; aneurysm-related mortality, 3.1%; conversion to open surgery, 0.5%; target aneurysm rupture, 0.5%; stent graft migration >10 mm, 3.9%; endoleak (12.2%), stent graft patency, 100%; stable or decreasing aneurysm diameter, 91.5%; and loss of stent graft integrity, four patients. No deployment-related events or perforation of the aorta by a graft component occurred. The Talent Thoracic Stent Graft showed statistically superior performance with respect to acute procedural outcomes (P < .001), 30-day major adverse events (41% vs 84.4%, P < .001), perioperative mortality (2% vs 8%, P < .01), and 12-month aneurysm-related mortality (3.1% vs 11.6%, P < .002) vs open surgery. CONCLUSIONS The pivotal VALOR 12-month trial results demonstrate that the Medtronic Talent Thoracic Stent Graft System is a safe and effective endovascular therapy as an alternative to open surgery in patients with TAA who were considered candidates for open surgical repair.

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.

A Percutaneous Technique for Preservation of Arch Branch Patency during Thoracic Endovascular Aortic Repair (TEVAR): Retrograde Catheterization and Stenting

Purpose: To report a percutaneous endovascular technique to deal with stent-graft encroachment and coverage (partial or total) of the origin of the left common carotid artery (CCA) or the left subclavian artery during thoracic endovascular aortic repair. Technique: Percutaneous retrograde puncture of the left CCA was accomplished with guidewire advancement into the ascending aorta and insertion of a 6-F sheath. Balloon angioplasty and deployment of a stent across the origin of the left CCA successfully recanalized the vessel and restored normal antegrade flow and pressure. It was reasoned that the stent would maintain vessel patency by focally displacing the endograft device, preventing partial or total coverage (and obstruction) of the arch branch origin. This technique has been used successfully in 8 patients, 6 involving the left CCA and 2 the left subclavian artery. Two of the patients were lost to follow-up after 6 and 12 months. The other 6 patients have been followed from 10 to 32 months; the stented vessels have remained patent in all. Conclusion: While the “interposition” of a bare metal stent between a thoracic endograft and the aortic wall is theoretically unappealing and potentially detrimental, as the direct interaction between the devices might undermine the integrity of one or both, we have not seen such problems in this limited clinical experience.

Carotid artery stenting with emboli protection surveillance study: thirty-day results of the CASES-PMS study.

Objective: This study examined whether physicians with varying carotid stent experience would obtain safety and efficacy outcomes as good as those from the pivotal SAPPHIRE trial following participation in a comprehensive carotid stent training program. Background: This study was performed as a condition of approval study for the PRECISE® Nitinol Stent and the ANGIOGUARD™ XP Emboli Capture Guidewire. Methods: Patients at high surgical risk who were either symptomatic with ≥50% stenosis or asymptomatic with ≥80% stenosis of the common or internal carotid artery received carotid artery stenting with distal emboli protection using the PRECISE Nitinol Stent and the ANGIOGUARD XP Emboli Capture Guidewire. Physicians were qualified based on either prior experience in carotid stenting with the ANGIOGUARD XP Emboli Capture Guidewire or following participation in a formal training program. The primary endpoint of major adverse events (MAE) at 30 days (death, myocardial infarction (MI), or stroke) was tested for noninferiority compared with an objective performance criterion (OPC) of 6.3% established from the stent cohort of the SAPPHIRE trial. Results: The 30‐day MAE rate was 5.0%, meeting the criteria for noninferiority to the prespecified OPC (95% CI [3.9%, 6.2%] P < 0.001). Asymptomatic patients (N = 1,158, 78.2%) had similar outcomes to the overall results (MAE 4.7%). Outcomes were similar across levels of physician experience, carotid stent volume, geographic location, presence/absence of training program. Conclusions: Utilizing a comprehensive training program, carotid artery stenting by operators with differing experience in a variety of practice settings yielded safety and efficacy outcomes similar to those reported in the SAPPHIRE trial.

Report on the results of thoracic endovascular aortic repair for acute, complicated, type B aortic dissection at 30 days and 1 year from a multidisciplinary subcommittee of the Society for Vascular Surgery Outcomes Committee

OBJECTIVE This study analyzed 1-year outcome after thoracic endovascular aortic repair (TEVAR) in patients with complicated type B aortic dissection (cTBAoD) who had rupture or malperfusion and symptom onset ≤14 days (acute), 15 to 30 days (subacute), and 31 to 90 days (chronic) until required intervention. The main focus of this report is primarily on the acute cohort. METHODS Clinical data were systematically collected from five physician-sponsored investigational device exemption (IDE) clinical trials between 2000 and 2008 using standardized definitions and forms. Adverse events were reported early (≤30 days) and late (>30 days) by body system. Major adverse events included death, stroke, myocardial infarction, renal failure, respiratory failure, paralysis, and bowel ischemia. RESULTS There were 99 cTBAoD patients: 85 were acute, 11 were subacute, and 3 were chronic. Among the acute patients, 31.8% had rupture and 71.8% had malperfusion, including 55.7% lower extremity, 36.1% renal, 19.7% visceral, 8.2% other, and 3.3% spinal cord (patients may have more than one source). Rupture and malperfusion were both reported for three acute patients. Additional findings for the acute cohort included pain (76.5%), hypertension (43.5%), and bleeding (8.2%); comorbidities included hypertension (83.5%), current/past smoking history (69.8%), and diabetes (12.9%). The main focus of this analysis was the acute cohort (n = 85). Age averaged 59 years (72.9% male). Early adverse events included pulmonary (36.5%), vascular (28.2%), renal (25.9%), and neurologic (23.5%). Early major adverse events occurred in 37.6% of patients, including death (10.6%), stroke (9.4%), renal failure (9.4%), and paralysis (9.4%); late adverse events included vascular (15.8%), cardiac (10.5%), gastrointestinal (6.6%), and hemorrhage (5.3%). The point-estimate mortality rate was 10.8 (95% confidence interval [CI], 4.1-17.5) at 30 days and 29.4 (95% CI, 18.4-40.4) at 1 year, when 34 patients remained at risk. CONCLUSIONS Emergency TEVAR for patients with cTBAoD (malperfusion or rupture) provided acceptable mortality and morbidity results out to 1 year. Manufacturers can use this 30-day mortality point-estimate of 10.8 (95% CI, 4.1-17.5) for the acute cohort to establish a performance goal for use in single-arm commercial IDE trials if the Food and Drug Administration and other regulatory bodies concur.

The treatment of focal aortic arch branch lesions with Palmaz stents

PURPOSE The purpose of this study was to evaluate the safety and effectiveness of Palmaz stents as a less morbid alternative to traditional surgery for focal aortic arch branch lesions. METHODS Twenty-two patients with symptoms and a mean age of 61.3 years were treated from July 1991 to May 1995 with 26 stents at the following locations: 8 innominate artery, 5 left common carotid artery, 1 right common carotid artery, and 12 left subclavian. Procedures were carried out in an operating room with patients receiving either local anesthetic in 12 cases or general anesthetic in 10. Surgical exposure of either the cervical common carotid or brachial artery allowed precautionary distal clamping before retrograde stent deployment to prevent atheroembolization. RESULTS Initial success was possible in 92.3% (24 of 26) of cases. There were no strokes or deaths. During a mean follow-up period of 27 months, 22 of 26 (85%) vessels have remained patent and the patients symptom free. CONCLUSION Focal aortic branch lesions can be effectively and safely treated with Palmaz stents.

Perigraft air, fever, and leukocytosis after endovascular repair of abdominal aortic aneurysms.

BACKGROUND The postimplantation syndrome of fever and leukocytosis after endovascular repair of infrarenal aortic aneurysms has not been previously characterized and its etiology is not known. METHODS We studied the first 12 patients who underwent successful endovascular repair of infrarenal aortic aneurysms with Dacron-covered stent-grafts, as part of an ongoing phase II clinical trial. Sepsis syndrome evaluations (physical examination, urinalysis, chest radiograph, urine cultures, and blood cultures) were performed for all patients with postoperative temperature (T) greater than 101.4 degrees F. Computed tomography scans of the abdomen were performed, as part of the clinical protocol, on postoperative days 2 and 30. RESULTS Fever (T > 101.4 degrees F) was seen in 8 of 12 (67%) patients (P < 05). An additional 2 of 12 (17%) patients had low-grade fevers (100.3 degrees F, 100.6 degrees F). Only 2 of 12 (17%) patients remained afebrile postoperatively. Leukocytosis with counts over 11,000 white blood cells (WBC)/dL was observed in 7 of 12 (58%) patients (P < 05). Sepsis evaluations failed to identify any source of infection in 11 of 12 (97%) patients. Computed tomography scan evidence of perigraft air was noted in 8 of 12 (67%) patients. All patients were afebrile, had normal white blood cell counts, and were discharged within 1 week postoperatively. There has been no evidence of graft infection after 1 to 6 months of follow-up. CONCLUSIONS Fever and leukocytosis after stent-graft repair of aortic aneurysms does not represent evidence of systemic or graft infection and is not clearly related to nonspecific causes of postoperative fever and leukocytosis. Moreover, the finding of early postoperative perigraft air is not necessarily an indication of graft infection even when concurrently present with fever and leukocytosis.

Endoluminal Aortic Aneurysm Repair Using a Balloon-Expandable Stent-Graft Device: A Progress Report

We describe our experience with endoluminal repair of abdominal aortic aneurysms using the stent-graft device. Twenty-four patients underwent 25 procedures in the 27-month period ending December 31, 1992. Twenty-one of the patients were considered high-risk candidates for conventional surgical repair. The endoluminal stented grafts were aortoaortic in 16 procedures and unilateral aortoiliac in eight. One patient underwent a second procedure consisting of an ilioiliac graft to repair a separate common iliac artery aneurysm. Technical problems were primarily related to retrograde transluminal access across the iliac arteries, tortuous aneurysms, and misjudgments as to measurement of length. One patient died and another required secondary deployment of a distal stent at 4 months; subsequent aneurysm expansion mandated surgical replacement at 18 months. It is clear that this device and methodology will have to undergo further refinement before the technique is acceptable for wider clinical application. Current experience, however, is encouraging. Aneurysm exclusion with an endoluminal prosthesis is likely to become an important therapeutic alternative over the next several years.

Endovascular grafting in patients with short proximal necks: an analysis of short-term results.

OBJECTIVES To evaluate the safety of endovascular graft placement in patients with short proximal aneurysm necks, and assess factors contributing to endoleak formation. METHODS 55 patients were enrolled over a two year period from five centers following the placement of a Talent endograft with a suprarenal stent. Preoperative and 30-day post-implant CT scans were retrospectively analyzed in a blinded fashion by two physicians. Aortic measurements were obtained, the amount of thrombus was subjectively graded, and any extravasation of contrast into the aneurysm sac defined an endoleak. The data were analyzed using a t-test. Analyses compared patients with proximal necks<10mm (SN), n=13) to those with longer necks (LN, n=42), and then contrasted patients with endoleaks (n=12), to those without (n=43). RESULTS Endoleak rates were identical in the SN and LN groups (21 and 23%). Maximal aneurysm size was larger in the SN group (63 vs 56 mm, P<0.05). Endoleaks were more frequently noted in larger aneurysms (P<0.05), but not related to SN (P=0.6). There was no correlation between endoleaks and the amount of thrombus, aneurysm length, proximal neck diameter or other morphologic characteristics. One of 12 endoleaks resulted from a problem with proximal fixation, nine were due to perfusing vessels, and two were undefined. The proximal neck diameter increased (0.9 mm) over the 30 days (P<0.005). CONCLUSIONS Short-term proximal fixation can be achieved in proximal necks measuring less than 10mm. The narrow margin of acceptable seal mandates careful follow-up. Larger aneurysms were associated with an increased incidence of endoleaks. SNs were associated with larger aneurysms, but not with an increased incidence of endoleaks. Proximal neck dilation was noted, but likely relates to the placement of an oversized endograft during this brief period of observation.

Evolving indications for and early results of carotid artery stenting

BACKGROUND While carotid endarterectomy continues to be the gold standard of treatment for most patients with significant carotid artery disease, there are cases where lesion or anatomy-related factors create situations less than ideal for conventional surgery. Other therapeutic modalities, such as endoluminal stenting, may represent reasonable options for such patients. METHODS Thirty-three patients with 70% or greater internal carotid artery lesions were treated by endovascular stent placement from July 1994 through June 1996. Indications included transient ischemic attacks in 20 and previous stroke in 4; and 9 were asymptomatic. RESULT Stents were placed successfully in all instances. Mortality and stroke rates were zero. All patients remained asymptomatic during follow-up (mean 8 months), and stent patency by duplex ultrasound has been 100%. A single instance of intrastent restenosis has been observed. CONCLUSIONS Endoluminal stenting is an investigational technique of unproven efficacy and long-term durability. Yet it appears technically feasible, and possibly reasonable, as an alternate option for cases unfavorable for standard surgery.