Introducer Design Concepts for an Epicardial Parallel Wire Robot.

BACKGROUND: Cardiac gene therapies lack effective delivery methods to the myocardium. While direct injection has demonstrated success over a small region, homogenous gene expression requires many injections over a large area. To address this need, we developed a minimally invasive flexible parallel wire robot for epicardial interventions. To accurately deploy it onto the beating heart, an introducer mechanism is required. METHODS: Two mechanisms are presented. Assessment of the robot's positioning, procedure time, and pericardium insertion forces are performed on an artificial beating heart. RESULTS: Successful positioning was demonstrated. The mean procedure time was 230 ± 7 seconds for mechanism I and 259 ± 4 seconds for mechanism II. The mean pericardium insertion force was 2.2 ± 0.4 N anteriorly and 3.1 ± 0.4 N posteriorly. CONCLUSION: Introducer mechanisms demonstrate feasibility in facilitating the robot's deployment on the epicardium. Pericardium insertion forces and procedure times are consistent and reasonable.

Coronary vessel detection methods for organ-mounted robots.

BACKGROUND: HeartLander is a tethered robot walker that utilizes suction to adhere to the beating heart. HeartLander can be used for minimally invasive administration of cardiac medications or ablation of tissue. In order to administer injections safely, HeartLander must avoid coronary vasculature. METHODS: Doppler ultrasound signals were recorded using a custom-made cardiac phantom and used to classify different coronary vessel properties. The classification was performed by two machine learning algorithms, the support vector machines and a deep convolutional neural network. These algorithms were then validated in animal trials. RESULTS: Accuracy of identifying vessels above turbulent flow reached greater than 92% in phantom trials and greater than 98% in animal trials. CONCLUSIONS: Through the use of two machine learning algorithms, HeartLander has shown the ability to identify different sized vasculature proximally above turbulent flow. These results indicate that it is feasible to use Doppler ultrasound to identify and avoid coronary vasculature during cardiac interventions using HeartLander.

Combined carotid endarterectomy and transcatheter aortic valve replacement: Technique and outcomes.

BACKGROUND: Stroke and transient ischemic attack after transcatheter aortic valve replacement results in significantly higher morbidity and mortality. Severe carotid artery disease may be a contributing factor to this increased risk. We report our technique and outcomes of combined carotid endarterectomy (CEA) with transcatheter aortic valve replacement (TAVR). METHODS: From March 2013 to November 2017 a total of 753 TAVRs were performed at our institution for symptomatic severe aortic stenosis. Of this group, 16 patients underwent concomitant TAVR and CEA. A retrospective review was performed to assess risk, outcomes, and short-term survival. RESULTS: Sixteen patients underwent concomitant CEA/TAVR procedures for severe carotid and severe aortic stenosis. The mean Society of Thoracic Surgeons (STS) Risk Score was 7.0 ± 4.7. All patients had severe carotid artery stenosis and aortic stenosis. Nine patients had a transfemoral TAVR approach and eight patients had a transapical TAVR approach. The mean length of stay was 6.4 ± 3.7 days. At 30 days there were no cerebrovascular events and no mortalities. CONCLUSIONS: The use of concomitant CEA and TAVR in patients with severe aortic stenosis and severe carotid stenosis can be done safely without increased risk of complications. This approach may reduce the risk of stroke associated with TAVR in appropriately selected patients.

Repair of left ventricular pseudoaneurysm with the triple patch technique (Empanada Patch).

Left ventricular pseudoaneurysm is a rare but serious complication of myocardial infarction that requires urgent intervention to avoid unpredictable fatal rupture. Surgical repair aims at excluding the aneurysmal area with a patch to preserve the left ventricular geometry. Here, we present a case of successful repair of inferobasal left ventricular pseudoaneurysm using a modified triple patch technique ('Empanada Patch').

Long-term follow-up assessment of a phase 1 trial of angiogenic gene therapy using direct intramyocardial administration of an adenoviral vector expressing the VEGF121 cDNA for the treatment of diffuse coronary artery disease.

On the basis of studies in experimental animals demonstrating that AdVEGF121, an E1(-)E3(-) serotype 5 adenovirus coding the 121 isoform of vascular endothelial growth factor (VEGF), could mediate the generation of new blood vessels and reverse coronary ischemia, a clinical study of direct myocardial administration of AdVEGF121 was initiated in patients with late-stage, diffuse coronary artery disease. This study provides long-term (median, 11.8 years) follow-up on these patients. From 1997 to 1999, AdVEGF121 was administered by direct myocardial injection to an area of reversible ischemia in 31 patients with severe coronary disease, either as an adjunct to conventional coronary artery bypass grafting (group A) or as minimally invasive sole (MIS) therapy, using a minithoracotomy (group B). There was no control group; the study participants served as the control subjects. The 5- and 10-year survival was 10 of 15 (67%) and 6 of 15 (40%) for the group A patients, and 11 of 16 (69%) and 5 of 16 (31%) for group B sole therapy patients, respectively. In comparison, maximal medical therapy in comparable groups in the literature have a 3- to 5-year survival rate of 52 to 59%. For the survivors, the angina score for group A was 3.4±0.5 at time 0 and 1.9±1.0 at last follow-up, and for group B it was 3.4±0.6 and 2.0±1.1, respectively. The incidences of malignancy and retinopathy were no greater than that expected for the age-matched general population. We conclude that adenovirus-mediated VEGF direct myocardial administration to patients with severe coronary artery disease is safe, and future larger trials are warranted to assess efficacy.