Publications

2003
Gianluca Bonanomi, Marco A Zenati, and David Schwartzman. 2003. “Left atrial appendectomy and maze.” J Am Coll Cardiol, 41, 1, Pp. 170; author reply 170-1.
Marco A Zenati, Gianluca Bonanomi, Albert K Chin, and David Schwartzman. 2003. “Left heart pacing lead implantation using subxiphoid videopericardioscopy.” J Cardiovasc Electrophysiol, 14, 9, Pp. 949-53.Abstract
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.
Gianluca Bonanomi, Keith Rebello, Kyle Lebouitz, Cameron Riviere, Elena Di Martino, David Vorp, and Marco A Zenati. 2003. “Microelectromechanical systems for endoscopic cardiac surgery.” J Thorac Cardiovasc Surg, 126, 3, Pp. 851-2.
Gianluca Bonanomi, David Schwartzman, David Francischelli, Kim Hebsgaard, and Marco A Zenati. 2003. “A new device for beating heart bipolar radiofrequency atrial ablation.” J Thorac Cardiovasc Surg, 126, 6, Pp. 1859-66.Abstract
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.
2002
Marco A Zenati, Larry Nichols, Gianluca Bonanomi, and Bartley P Griffith. 2002. “Experimental off-pump coronary bypass using a robotic telemanipulation system.” Comput Aided Surg, 7, 4, Pp. 248-53.Abstract
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.
Marco A Zenati, Gianluca Bonanomi, Dean Kostov, and Robert Lee. 2002. “Images in cardiovascular medicine. Fulminant Clostridium septicum aortitis.” Circulation, 105, 15, Pp. 1871.
Marco A Zenati, Gianluca Bonanomi, Dean Kostov, and Oleg Svanidze. 2002. “A new live animal training model for off-pump coronary bypass surgery.” Heart Surg Forum, 5, 2, Pp. 150-1.Abstract
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.
Karen EA Burns, Robert J Keenan, Wayne F Grgurich, Jan D Manzetti, and Marco A Zenati. 2002. “Outcomes of lung volume reduction surgery followed by lung transplantation: a matched cohort study.” Ann Thorac Surg, 73, 5, Pp. 1587-93.Abstract
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).
2001
MA Zenati. 2001. “Hybrid strategies in minimally invasive revascularization.” Heart Surg Forum, 4, 4, Pp. 328-30.
MA Zenati, J Paiste, JP Williams, G Strindberg, JP Dumouchel, and BP Griffith. 2001. “Minimally invasive coronary bypass without general endotracheal anesthesia.” Ann Thorac Surg, 72, 4, Pp. 1380-2.Abstract
This report describes the case of a 51-year-old man with myocardial ischemia resulting from in-stent restenosis of the left anterior descending coronary artery who underwent a minimally invasive direct coronary artery bypass using thoracic epidural analgesia while awake, without general endotracheal anesthesia.
J Paiste, RJ Bjerke, JP Williams, MA Zenati, and GE Nagy. 2001. “Minimally invasive direct coronary artery bypass surgery under high thoracic epidural.” Anesth Analg, 93, 6, Pp. 1486-8, table of contents.Abstract
IMPLICATIONS: This report describes the use of high-thoracic epidural anesthesia for a patient undergoing minimally invasive direct coronary artery bypass.
MA Zenati. 2001. “Robotic heart surgery.” Cardiol Rev, 9, 5, Pp. 287-94.Abstract
Advances in computer and robotic technology are transforming cardiac surgery, overcoming the limitations of conventional endoscopic tools. Using minimal access through 5 millimeter ports, computer-enhanced instruments provide superhuman dexterity through tremor filtration and motion scaling, and are capable of precise manipulation in confined body cavities. Using these technologies, endoscopic beating heart coronary bypass surgery as well as complex mitral valve repairs have been performed in the last few years. However, the current world experience with robotic heart surgery is mostly anecdotal, retrospective, and noncontrolled. Results of rigorous prospective randomized studies in the United States under Food and Drug Administration approved protocols, are awaited. The use of robotic telemanipulation technology for heart surgery is restricted in the United States to patients enrolled in clinical studies in a few elite centers. Further refinement in robotic and image-guided technology for cardiac surgery may further expand the use of computer enhanced instrumentation in the near future.
T Sakai, L. R Kormos, R. K Mccurry, J Ristich, G. B Hattler, M Zenati, and P. B Griffith. 2001. “Ten year experience of FK 506 for adult cardiac transplantation at a single institution.” J Heart Lung Transplant, 20, 2, Pp. 191-192.
1999
M Zenati, HA Cohen, and BP Griffith. 1999. “Alternative approach to multivessel coronary disease with integrated coronary revascularization.” J Thorac Cardiovasc Surg, 117, 3, Pp. 439-44; discussion 444-6.Abstract
OBJECTIVE: Integrated coronary revascularization combines minimally invasive coronary artery bypass grafting (MICABG) with left internal thoracic artery-left anterior descending artery grafting and percutaneous coronary intervention. We hypothesized that integrated coronary revascularization could result in successful revascularization in suitable patients with multivessel coronary artery disease. METHODS: Between September 1996 and January 1998, 31 consecutive patients underwent integrated coronary revascularization. Twenty-two were male; mean age was 69 years (46-86 years) and 42% were older than 75 years. Eight patients (26%) had a Parsonnet score greater than 20%. Left ventricular ejection fraction was 46.3% +/- 12%; 6 patients (19%) had a left ventricular ejection fraction less than 35%. RESULTS: The anastomosis time for MICABG with the internal thoracic artery was 14.6 +/- 5.2 minutes and the operating time was 105 +/- 20 minutes; 28 patients (90%) were extubated in the operating room. The internal thoracic artery anastomosis was patent in all 31 patients (100%). Percutaneous coronary intervention was performed before MICABG in 2 patients (7%), on the same day of MICABG in 16 patients (52%), on postoperative day 1 in 3 patients (9%), and on postoperative days 2 to 4 in 10 patients (32%). Postprocedure length of stay in the hospital was 2.7 +/- 1.0 days and 13 patients (42%) were discharged home on postoperative day 1 or 2. Three patients (9.6%) required repeat target vessel revascularization in the distribution of the previous percutaneous coronary intervention. All patients are alive without angina at a follow-up of 10.8 +/- 3.8 months. CONCLUSION: Our early results demonstrate that integrated coronary revascularization can be performed safely and effectively. Long-term results will be available from a prospective randomized trial now underway to compare integrated coronary revascularization with coronary artery bypass grafting for multivessel coronary artery disease.
HA Cohen and M Zenati. 1999. “Alternative Approaches to Coronary Revascularization.” Curr Interv Cardiol Rep, 1, 2, Pp. 138-146.
WE Katz, M Zenati, WA Mandarino, HA Cohen, and J Gorcsan. 1999. “Assessment of left internal mammary artery graft patency and flow reserve after minimally invasive direct coronary artery bypass.” Am J Cardiol, 84, 7, Pp. 795-801.Abstract
Despite its merits, minimally invasive direct coronary artery bypass surgery (MIDCAB) has been criticized for variable left internal mammary artery (LIMA) graft patency rates, prompting the frequent use of postoperative LIMA angiography. Noninvasive transthoracic Doppler interrogation of LIMA grafts has recently been shown to have utility for assessing patency and flow reserve after conventional bypass surgery, but data after MIDCAB has been limited. The objective of this study was to assess LIMA graft anatomy and physiology in 54 patients after MIDCAB using angiography and noninvasive LIMA Doppler imaging. The right internal mammary artery (RIMA) was studied as a control. LIMA flow reserve in response to adenosine was evaluated in a subgroup of 18 randomly chosen patients with patent grafts. LIMA angiographic patency was 93%. Forty-four patients (81%) had obtainable LIMA Doppler data. Patent grafts had a diastolic dominant flow pattern with a peak diastolic/systolic velocity ratio of 1.3 +/- 0.6 and a percent diastolic time-velocity integral (TVI) of 70 +/- 11%. These data were significantly different than the RIMA control values of 0.2 +/- 0.1 and 30 +/- 10%, respectively (p <0.05). Occluded grafts had absent flow or a systolic dominant pattern. Adenosine-induced increases in LIMA peak diastolic velocity from 48 +/- 20 to 105 +/-28 cm/s (p <0.05 vs baseline) and diastolic TVI from 21 +/- 10 to 37 +/- 19 cm (p <0.05 vs baseline), yielding adenosine/baseline ratios of 2.4 +/- 0.9 and 2.0 +/- 0.7, respectively, which was consistent with normal flow reserve. The diastolic flow velocity reserve response was inversely related to baseline diastolic flow (r = -0.69). In conclusion, MIDCAB can be associated with a high rate of LIMA potency and favorable physiologic Doppler flow patterns. Correlation of these findings to long-term patient outcome after MIDCAB is warranted.
M Zenati and HA Cohen. 1999. “Emerging new concepts of myocardial laser revascularization.” J Thorac Cardiovasc Surg, 118, 5, Pp. 977-8.
HA Cohen and M Zenati. 1999. “Integrated coronary revascularization.” J Invasive Cardiol, 11, 3, Pp. 184-90; discussion 190-1.
K Koncsol, K DeVoogd, M Hravnak, and M Zenati. 1999. “Minimally invasive coronary artery bypass grafting: a kinder cut.” Dimens Crit Care Nurs, 18, 2, Pp. 21-3.Abstract
Minimally invasive coronary artery bypass graft (CABG) surgery is a promising variation on traditional CABG, avoiding the risks of sternotomy and cardiopulmonary bypass. This article describes the procedure, patient-selection criteria, and postoperative care.
BG Hattler, BP Griffith, MA Zenati, JR Crew, M Mirhoseini, LH Cohn, SF Aranki, OH Frazier, DA Cooley, AM Lansing, KA Horvath, GP Fontana, KP Landolfo, JE Lowe, and SW Boyce. 1999. “Transmyocardial laser revascularization in the patient with unmanageable unstable angina.” Ann Thorac Surg, 68, 4, Pp. 1203-9.Abstract
BACKGROUND: Transmyocardial laser revascularization (TMR) provides relief for patients with chronic angina, nonamenable to direct coronary revascularization. Unmanageable, unstable angina (UUA) defines a subset of patients with refractory angina who are at high risk for myocardial infarction and death. Patients were classified in the UUA group when they had been admitted to the critical care unit with unstable angina for 7 days with three failed attempts at weaning them off intravenous antianginal medications. METHODS: Seventy-six treated patients were analyzed to determine if TMR is a viable option for patients with unmanageable unstable angina. These patients were compared with 91 routine protocol patients (protocol group [PG]) undergoing TMR for chronic angina not amenable to standard revascularization. The procedure was performed through a left thoracotomy without cardiopulmonary bypass. These patients were followed for 12 months after the TMR procedure. Both unmanageable and chronic angina patients had a high incidence of at least one prior surgical revascularization (87% and 91%, respectively). RESULTS: Perioperative mortality (< or = 30 days post-TMR) was higher in the UUAG versus PG (16% vs 3%, p = 0.005). Late mortality, up to 1 year of follow-up, was similar (13% vs 11%, UUAG vs PG; p = 0.83). A majority of the adverse events in the UUAG occurred within the first 3 months post-TMR, and patients surviving this interval did well, with reduced angina of at least two classes occurring in 69%, 82%, and 82% of patients at 3, 6, and 12 months, respectively. The percent improvement in angina class from baseline was statistically significant at 3, 6, and 12 months. A comparable improvement in angina was found in the protocol group of patients. CONCLUSIONS: TMR carried a significantly higher risk in unmanageable, unstable angina than in patients with chronic angina. In the later follow-up intervals, however, both groups demonstrated similar and persistent improvement in their angina up to 12 months after the procedure. TMR may be considered in the therapy of patients with unmanageable, unstable angina who otherwise have no recourse to effective therapy in the control of their disabling angina.

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