The Valiant Captivia thoracic stent graft system (Medtronic) has demonstrated freedom from all-cause mortality of 79.4% and freedom from dissection-related mortality of 90% at three years in acute complicated type B aortic dissection treatment. Ali Azizzadeh, University of Texas Health Science Center, San Antonio, USA, presented the new clinical data in a late-breaking trial session at Vascular Interventional Advances 2016 (VIVA; 18–22 September, Las Vegas, USA).
“Evidence shows that patients with acute complicated type B aortic dissections can be safely and effectively treated with thoracic endovascular aortic repair (TEVAR),” said Azizzadeh. “The Valiant Captivia system continues to produce positive outcomes through three years in a very challenging patient population.”
Azizzadeh explained that TEVAR has become a first-line therapy for acute type B aortic dissection treatment thanks to its ability to reduce early morbidity and mortality when compared to open surgical repair. However, he noted that “longer follow-up is required to understand reintervention risk.”
The data that Azizzadeh presented were gathered on 50 patients in the Medtronic Valiant Captivia dissection investigational device exemption trial, conducted at 16 US sites. Average patient age was 57.2±12.9 years and 80% were male. The majority of patients (62%) were white, 22% were black and 12% were of Asian descent. Cardiac history was reported in 90% of patients. At onset, 88% if patients presented with back or chest pain, 86% with malperfusion (visceral ischaemia 40%, renal ischaemia 42%, lower limb 40% and spinal cord 6%), 36% with abdominal pain, 20% with rupture and 12% with paraparesis. Anti-hypertensives were administered to 84% of patients, while 16% required ionotropic support. Baseline mortality for patients such as these if they are not treated is approximately 50%, according to Azizzadeh.
Delivery and deployment was successful in all patients, with all primary entry tears covered and no misaligned deployment. At three years, freedom from all-cause mortality was 79.4%—“If you compare this to the baseline, where mortality would have been approximately 50%, these outcomes are remarkable,” Azizzadeh said. Freedom from dissection-related mortality was 90%, with only one dissection-related mortality occurring after day 30 post-index (a pneumonia-related death on day 87). There were no post-index procedure ruptures or conversions. Through the three years, three patients underwent secondary endovascular procedures (all extension endografts) related to dissection, and a further one (for a left subclavian artery plug) unrelated to dissection. The dissection treated extended to or past the aortic bifurcation for 71.4% of patients (n=35/49), 42% (n=21/50) had more than one visible re-entry tear and 28% (n=14/50) had three or more re-entry tears. True-lumen diameter over the stented region remained stable or increased in 92.3% of patients (n=24/26), false-lumen diameter remained stable or decreased in 69.2% of patients (18/26), and the false lumen was partially or completely thrombosed in 75% of patients (n=18/24)—this, Azizzadeh said, represents “favourable reverse remodelling over the stented segment”.
“These mid-term results of the Valiant Captivia stent graft in the treatment of acute complicated type B aortic dissection are encouraging,” Azizzadeh told the VIVA audience. “Now, long-term outcomes are needed to assess the durability of TEVAR for this indication.”
“This study, in addition to other studies, has resulted in a paradigm shift with regards to management of patients with acute complicated aortic dissection,” he continued. “Today, every patient with acute complicated aortic dissection gets a stent graft, but that was not the case 10 years ago.”