PubMed Health⌕ Search

Biomedical subjects

Marco A Zenati

Publications and source records attributed to Marco A Zenati.

12 recordsLinked to original sources
PubMed2006

Robotic implantation of a multichamber cardiac resynchronization therapy defibrillator.

Transvenous implantation of a cardiac resynchronization therapy defibrillator (CRT-D) may not be feasible due to anatomic constraints. One of the most notable advances in minimal-access heart surgery has been the introduction of robotic telemanipulation systems. We present a challenging case in which a CRT-D system was implanted using a robotic approach. Feasibility of such an approach expands the horizons for delivery of CRT-D therapy.

Defibrillators, Implantable↗
PubMed2004

Serial dobutamine stress echocardiography with Doppler assessment of the left internal thoracic artery graft after minimally invasive bypass for a patient with an orthotopic heart transplant.

Select patients who have undergone orthotopic heart transplantation with proximal left anterior disease may be candidates for minimally invasive direct coronary artery bypass surgery. Combining left internal thoracic artery transthoracic Doppler flow assessment with wall motion assessment during dobutamine stress echocardiography adds to the utility of this test by focusing attention on the graft's status as well as detecting ischemia due to cardiac allograft vasculopathy.

Aged↗
PubMed2004

Prototype epicardial crawling device for intrapericardial intervention on the beating heart.

The development and preliminary testing of a device for facilitating minimally invasive beating-heart intrapericardial interventions are described. We propose the concept of an endoscopic robotic device that adheres to the epicardium by suction and navigates by crawling like an inchworm to any position on the surface under the control of a surgeon. This approach obviates cardiac stabilization, lung deflation, differential lung ventilation, and reinsertion of laparoscopic tools for accessing different treatment sites, thus offering the possibility of reduced trauma to the patient. The device has a working channel through which various tools can be introduced for treatment. The current prototype demonstrated successful prehension, turning, and locomotion on beating hearts in a limited number of trials in a porcine model.

Animals↗
PubMed2003

A new device for beating heart bipolar radiofrequency atrial ablation.

OBJECTIVE: A technique for mimicking left atrial atriotomies using an ablation device that can be deployed without cardiopulmonary bypass has been developed. METHODS: In 12 healthy large (35-50 kg) adult pigs, maze-like ablation lesions were directly applied to the left atrial epicardium on the beating heart. The ablation device is irrigated, with a bipolar "hemostat" morphology, utilizing radiofrequency energy. Prior to and after ablation, left atrial electromechanical properties were measured during sinus rhythm in the latest 5 pigs using percutaneous endocardial catheter electromechanical mapping and intracardiac echocardiography. Pathologic analysis was performed acutely. RESULTS: All ablation lesions demonstrated conduction block along their entire course. Global left atrial conduction time (49.4 +/- 8.8 milliseconds before vs 58.8 +/- 9 milliseconds after) and pattern were not significantly altered. Although a significant amount (17.12% +/- 9%) of myocardium was either ablated or electrically isolated, ablation was not associated with significant alterations in global left atrial mechanics (left atrium ejection fraction 19% before vs 17% after; pulmonary vein peak flow velocity 1.22 m/s before vs 1.38 m/s after; peak mitral inflow velocity 2.34 m/s before vs 2.64 m/s after), mitral valve function, nor left ventricular function. There was no evidence of atrial thrombus formation. Transmurality was achieved in most lesions with no evidence of charring or barotrauma. CONCLUSIONS: Utilizing this ablation device, atrial lesions similar to the left component of the Maze procedure were deployed with uniform success in a beating heart without cardiopulmonary bypass or atriotomy and without adverse effects on left atrial electromechanics.

Animals↗
PubMed2003

Epicardium-based left atrial ablation: impact on electromechanical properties.

UNLABELLED: Epicardium-Based LA Ablation. INTRODUCTION: An important developmental task for surgical ablation of atrial fibrillation is simplification. A significant step would be the development of tools that create satisfactory ablation lesions without necessitating cardiopulmonary bypass or atriotomy. Optimally, these lesions would have no adverse impact on atrial electromechanical properties. METHODS AND RESULTS: We sought to characterize left atrial (LA) lesions created by a bipolar ablation device without cardiopulmonary bypass or atriotomy and to assess their impact on LA electromechanical properties. In each of five pigs, lesions were delivered to the epicardium of the beating heart, and encircled and connected right and left pulmonary vein vestibules and the atrial appendage. Before and after ablation, LA electromechanical properties were assessed using endocardial electromechanical mapping and intracardiac echocardiography. Postmortem histologic analysis also was performed. Each lesion was thrombus-free and barotrauma-free, histologically transmural, and a complete conduction barrier. Although a large aggregate area (24% +/- 6%) of LA myocardium was excluded, there was no significant change in global electromechanical properties. However, marked diminishment in appendage function was observed. CONCLUSION: Epicardium-based LA ablation in a beating heart could be achieved successfully without cardiopulmonary bypass or atriotomy. Although there was no adverse impact on global electromechanical properties, there was evidence of important regional diminishment.

Animals↗
PubMed2003

Left heart pacing lead implantation using subxiphoid videopericardioscopy.

INTRODUCTION: Recent clinical data support the utility of left heart pacing. The transvenous approach for left heart pacing lead implantation is imperfect. A direct epicardial approach may have advantages, but heretofore its utility has been limited because of the requirement for thoracotomy. We sought to examine the feasibility of a method for epicardial lead implantation that did not require thoracotomy. METHODS AND RESULTS: In five large swine, percutaneous access to the epicardium was achieved with subxiphoid videopericardioscopy, using a device that marries endoscopy with a port through which pacing leads could be introduced. In each animal, standard, active fixation pacing leads were implanted onto the left atrium and ventricle. The atrial lead was implanted at the base of the appendage. The ventricular lead was implanted on the anterior, lateral, and inferior walls. Continuous direct visualization of the epicardium provided guidance for lead localization and fixation, including avoidance of complications such as trauma to epicardial coronary vessels. Capture thresholds were uniformly low. Postmortem examination demonstrated anatomically accurate, uncomplicated lead fixation. CONCLUSION: Using subxiphoid videopericardioscopy, uncomplicated, anatomically accurate left heart epicardial pacing lead implantation can be achieved without thoracotomy.

Animals↗
PubMed2002

Experimental off-pump coronary bypass using a robotic telemanipulation system.

We hypothesized that a high-quality anastomosis between the left internal thoracic artery and the left anterior descending coronary artery could be constructed off-pump using a 4-degrees-of-freedom robotic telemanipulation system, endoscopic myocardial stabilization, and two-dimensional visualization. Nine swine were used. Three ports were created on the left chest for the endoscope and the two robotic arms, and another port was created on the right chest for the endostabilizer. Quality of anastomosis was assessed by angiography, analysis of flow, survival after proximal coronary ligation, and histopathology. All nine anastomoses were completed successfully in 22 +/- 3.6 minutes without the need for repair stitches. Left internal thoracic artery flow was 21.6 +/- 2.5 ml/min with diastolic dominant pattern. Eight animals (89%) survived for 60 minutes with the proximal left anterior descending coronary ligated. Angiographic patency was 100% with Fitzgibbon grade A in all. Histopathology of the anastomosis demonstrated minor changes in the integrity of the endothelium and the internal elastic lamina and absence of medial necrosis. We have demonstrated in our robotic off-pump coronary bypass model that a high-quality anastomosis can be constructed between the left internal thoracic artery and the left anterior descending coronary artery. These results support continued research towards robotic endoscopic off-pump CABG.

Anastomosis, Surgical↗
PubMed2002

Outcomes of lung volume reduction surgery followed by lung transplantation: a matched cohort study.

BACKGROUND: Lung volume reduction surgery (LVRS) has been demonstrated to provide symptomatic relief and to improve lung function in patients with end-stage emphysema. The goal of this study was to assess the additional morbidity associated with lung transplantation after LVRS for end-stage emphysema with regard to immediate postoperative outcomes, longitudinal spirometry, and survival rates compared to an age-, gender-, procedure-matched, and transplant time-matched cohort that had lung transplantation alone. METHODS: We compared the postoperative and long-term outcomes of a sequential procedure cohort to a matched cohort to assess the possible added post-transplant morbidity. RESULTS: Fifteen patients who underwent sequential LVRS (including 11 unilateral LVRS, 4 bilateral LVRS) and lung transplantation (ipsilateral in 7 and contralateral in 8) on average 28.1 +/- 17.2 months (median, 27.4 months; range, 3.7 to 61.7 months) later were assessed. No significant differences were noted in pretransplant demographics, post-transplant variables, longitudinal spirometric indices, or survival. A trend toward a lower pretransplant arterial carbon dioxide tension was apparent in the sequential procedure cohort. Group analysis revealed a significant increase in the number of patients requiring transfusion and in the total number of units transfused in patients undergoing ispsilateral transplantation after LVRS; a significant increase in the length of intensive care unit stay; and a trend toward an increase in the duration of hospital stay in patients undergoing lung transplantation within 18 months of LVRS. CONCLUSIONS: In appropriate candidates, LVRS bridged the time to transplantation by an average of 28.1 +/- 17.2 months (median, 27.4 months; range, 3.7 to 61.7 months) without significantly increasing post-transplant morbidity or mortality. Furthermore, bilateral LVRS bridged the time to transplantation to a greater extent than unilateral LVRS (34.9 +/- 29.8 months; median, 32.1 months versus 25.4 +/- 16.3 months; median, 22.3 months; p = 0.23).

Aged↗
PubMed2002

A new live animal training model for off-pump coronary bypass surgery.

Training models are needed to perform accurate off-pump coronary artery bypass (OPCAB) surgery and to test evolving new technologies like minimally invasive devices and robotics. We describe a simple, effective and reproducible live animal training model to perform multiple arterial anastomoses on the beating heart that would maximize the use of available resources for training purposes.

Anastomosis, Surgical↗