The Medtronic Vascular Talent Thoracic Stent Graft System (TTSG) has highly favorable preliminary outcomes in a high risk/non-surgical population of patients with heterogeneous thoracic aortic pathology, who would have been historically managed with "watchful waiting", concluded Dr Ronald Fairman and fellow investigators from the latest research from the VALOR Trial presented at the SVS annual meeting. Fairman, of the University of Pennsylvania, presented preliminary results from the high risk/non-surgical arm of the VALOR Trial in his presentation 'Preliminary Results of the Medtronic's Vascular Thoracic Stent Graft System for Patients With Thoracic Aortic Disease'.
Fairman and fellow investigators also concluded that procedural success was high, while operative mortality, stroke incidence, and paraplegia/paraparesis rates were particularly low. Long-term follow-up would be required to demonstrate durability and prevention of aneurysm-related mortality, they said.
The objective of this study was to evaluate the safety and efficacy of the TTSG for patients with thoracic aortic disease who were high risk for open surgery and/or non-surgical candidates. The proximal and distal aortic non-aneurysmal neck diameter requirement was within the range of 18-42mm. The study was a prospective, non-randomized, multi-center, consecutive, observational trial with a safety primary endpoint of all cause mortality. The efficacy primary endpoint was the proportion of patients with successful aneurysm treatment.
The secondary 30-day endpoints evaluated the percentage of patients who experienced successful deployment and delivery of the stent graft, death, paraplegia/paraparesis, secondary procedures due to endoleak, and one or more major adverse clinical events (MACE). Endpoints beyond 30 days included secondary procedures, open conversion, device migration, loss of patency, rupture, endoleaks, and one or more MACE. Supplementary clinical utility measures were also recorded. Standard follow-up interval examinations were prescribed at one month, six months, one year, and annually thereafter. There were no external controls. Outcomes were summarized by descriptive statistics.
Of the 137 patients treated, 59% were male and the mean age was 75 years. Thoracic aortic pathology treated included fusiform or saccular TAA (75%), dissecting TAA (4%), pseudoaneurysm (7%), traumatic injury (6%), and complicated acute Type B dissection (4%). Mean maximum aneurysm diameter at treatment was 63mm and mean aneurysm length was 108mm. Procedural success was 98%. The 30-day all cause mortality was 7.3% and the eight month mid-term mortality was 25%. The paraplegia/paraparesis rate was less than 1% at one month. Fourteen per cent of the procedures required a conduit for access. The one-month endoleak rate was 9% and the eight month rate was 6%. The 30-day stroke incidence was 7.3%. There were no cases of aneurysm rupture, one case of open conversion at the time of initial implant, two cases of device migration and no loss of graft patency. The mid-term secondary procedure rate was 7%. Clinical utility measures included mean duration of procedure (2.9 hours), volume of contrast used (167cc), estimated blood loss (360cc), and hospital length of stay (9.9 days).
Fairman also presented on 'Preliminary results of the phase 1 evaluation of the trivascular AAA stent-graft system in the treatment of abdominal aortic aneurysm'.
He and fellow investigators concluded that the trivascular AAA stent-graft system had the potential of expanding bifurcated endovascular AAA repair to include, for the first time, patients who harbor small access vessels, small calcified aortic bifurcations, and complicated aortic neck anatomy.
The objective of the study was to evaluate the safety and efficacy of the device for elective treatment of patients with abdominal aortic aneurysms (AAA).
The trivascular stent-graft is a novel bifurcated device mounted on a 16.5 F delivery system with three nitinol stents that expand to engage the vessel walls. The seal is produced through a network of cuffs and ring-shaped ribs along the trunk and legs that are filled with a liquid biopolymer that rapidly solidifies during the deployment procedure.
The prospective, observational study had two primary endpoints: absence of device related adverse events within one month of the endovascular procedure and absence of Types I, III, and IV endoleaks at one-month follow-up. The secondary endpoint was technical success in introducing the delivery system with deployment of the stent-graft in the desired location in the absence of device-related surgical conversion and intra-operative mortality. Primary follow-up evaluations are performed at one month, six months, one year, and annually thereafter. There were no external controls and patient outcomes were summarized by descriptive statistics.
Seventy-eight patients were treated worldwide; 43 inside and 35 outside the US. Seventy-three patients completed one-month follow-up, 62 completed six months, and 29 completed 12 months. Eighty-two per cent of the patients were male. Seventy-five per cent of the aneurysms were over 5cm in diameter and the mean diameter was 5.4 cm ±7. The majority of the patients had anatomic features that precluded treatment with any other endovascular device. These patients had small access vessels, small calcified aortic bifurcations, and/or complicated proximal aortic neck features.
There were no Types III, or IV endoleaks. There were two type I endoleaks. Device-related adverse events included: stent graft migration (zero), secondary procedures for threatened or loss of limb patency (five) unintentional hypogastric occlusion (three), and aneurysm rupture (zero). There was one technical failure without conversion due to an access problem.
Twelve patients (16%) had adjunctive stents placed in the endoprosthesis at the primary procedure.
One patient required surgical conversion due to endograft infection that created an aorto-enteric fistula. There were no aneurysm-related deaths nor were there any instances of aneurysm enlargement during follow-up.
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