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Biomedical subjects

Thomas A Vassiliades

Publications and source records attributed to Thomas A Vassiliades.

At least 19 recordsLinked to original sources
PubMed2006

Integrated coronary revascularization with drug-eluting stents: immediate and seven-month outcome.

OBJECTIVE: We sought to demonstrate the safety and feasibility of an integrated coronary revascularization strategy that combines minimally invasive left internal thoracic artery to left anterior descending coronary artery anastomosis with drug-eluting stent implantation to non-left anterior descending coronary artery lesions. METHODS: Over 18 months, 47 consecutive patients with multivessel coronary artery disease underwent thoracoscopic harvesting of the left internal thoracic artery to graft the left anterior descending coronary artery. Anastomoses were constructed by hand, off-pump, and under direct vision through a 4-cm non-rib-spreading, muscle-sparing chest incision. Non-left anterior descending coronary artery lesions were then treated percutaneously using sirolimus- or paclitaxel-eluting stents. Angiographic follow-up was performed in all patients. RESULTS: Within the first 90 days of hospitalizations, there were no deaths, myocardial infarctions, neurologic events, or wound complications. Forty patients underwent left internal thoracic artery to left anterior descending coronary artery grafting, and 7 patients underwent left internal thoracic artery to left anterior descending coronary artery/diagonal sequential grafting for a total of 54 anastomoses. Angiographic patency scores were FitzGibbon A 96.2% (52/54) and FitzGibbon A + B 100% (54/54). A total of 65 drug-eluting stents were implanted in 61 non-left anterior descending coronary artery coronary lesions of which 49.1% (30/61) were type B2 or C lesions, including 5 left main lesions. Diabetes was present in 53.2% of patients (25/47). At a mean follow-up time of 7.0 +/- 4.8 months, the target lesion or vessel repeat revascularization rate was 6.6% (4/61) for drug-eluting stents and 1.9% (1/54) for left internal thoracic artery to left anterior descending coronary artery grafting. One anastomosis required balloon dilation, but no patients have required repeat coronary artery bypass grafting. CONCLUSIONS: Integrated coronary revascularization using drug-eluting stents is feasible and safe. There are sufficient data to justify a randomized comparison of integrated coronary revascularization with standard coronary artery bypass grafting.

Adult↗
PubMed2004

Multivessel, all-arterial, off-pump surgical revascularization without disruption of the thoracic skeleton.

PURPOSE: To evaluate the feasibility of performing multivessel off-pump surgical revascularization without manipulation of the thoracic cage. DESCRIPTION: The technique consists of bilateral thoracoscopic internal mammary artery harvesting followed by a nonrib-spreading, muscle-sparing opening in the soft tissue of the thorax. An endoscopic cardiac positioner and stabilizers exposes and steadies the target arteries beneath a small opening. Anastomoses are constructed off-pump through the natural width of the intercostal space without the need for rib spreading. EVALUATION: Fifty-two patients underwent all-arterial, off-pump revascularization through incisions avoiding manipulation of the thoracic skeleton. The mean number of grafts per patient was 2.2 +/- 0.4. Transit time flow measurements verified graft patency before closure in all cases. The mean operating time was 4.4 hours (range, 3.4 to 5.6). Hospital length of stay was 2.6 +/- 1.9 days. There was no early or late mortality. Postoperative angiography performed in 63.8% of the grafts (74 of 116) revealed an overall patency rate of 98.6%. CONCLUSIONS: A grafting approach that avoids any manipulation of the thoracic skeleton offers significant patient value and may not be limited to single-graft cases.

Aged↗
PubMed2003

Off-pump apicoaortic conduit insertion for high-risk patients with aortic stenosis.

OBJECTIVES: Recently, we implanted an apicoaortic conduit off-pump in three high-risk patients with severe aortic stenosis. METHODS: A muscle-coring device was utilized to create the apical outflow tract followed by insertion of a rigid apical connector. A valved conduit was then connected to the descending thoracic aorta and to the apical connector graft. RESULTS: A stentless porcine bioprosthesis was implanted in two patients and a stented valve in one. The left ventricular (LV)-aortic gradients were reduced from a mean of 66 to 28 mmHg. CONCLUSIONS: With modification of an existing technique, apicoaortic conduit insertion can be performed safely off-pump. This technique can be applied to complex forms of LV outflow obstruction and high-risk patients.

Animals↗
PubMed2003

Endoscopic-assisted atraumatic coronary artery bypass.

Minimally invasive operations designed to graft the left anterior descending coronary artery with the left internal mammary artery are either traumatic to the chest wall or technically difficult and expensive. This report describes a novel procedure that is less traumatic and simpler.

Coronary Artery Bypass↗
PubMed2003

Effects of obesity on outcomes in endoscopically assisted coronary artery bypass operations.

BACKGROUND: Obesity has been shown to be an independent risk factor for adverse outcomes and prolonged hospitalization following conventional coronary artery bypass (CAB). For this reason and because of increased technical challenges, obesity has been considered a relative contraindication for minimally invasive bypass. The purpose of this study was to determine if in fact severe or morbid obesity is an independent risk factor for patients undergoing minimally invasive CAB. METHODS: Outcome data of 350 consecutive endoscopic, atraumatic CAB procedures performed at our institution over a 4-year period were reviewed with respect to patient body mass index (BMI). All operations consisted of thoracoscopic left or right internal mammary artery (IMA) harvesting followed by off-pump grafting of the left anterior descending (with/without diagonal coronary artery) or right coronary artery via a 4-cm thoracotomy. Patients were divided into 4 groups: small (BMI = 24 kg/m2), normal to mild obesity (24 kg/m2 < BMI = 34 kg/m2), severe obesity (34 kg/m2 < BMI = 40 kg/m2), and morbid obesity (BMI >40 kg/m2). RESULTS: Although the BMI >34 kg/m2 groups had a higher incidence of hypertension, diabetes, and hypercholesterolemia, there was no statistical difference in operative risk between groups. Thirty-day mortality, conversion to sternotomy, transfusion rate, and wound, pulmonary, neurological, and myocardial complications were not significantly different between groups. The BMI >34 kg/m2 patients required longer IMA harvest times and total operating times, but the intensive care unit length of stay was not significantly different between groups. Hospital length of stay was longer for the BMI =24 kg/m2 group than for the BMI 18 to 34 kg/m2 group (P =.025). CONCLUSION: Despite increased technical difficulty caused by obesity, it is not an independent risk factor for patients undergoing minimally invasive CAB.

Analysis of Variance↗
PubMed2002

Hemodynamic collapse during off-pump coronary artery bypass grafting.

BACKGROUND: The causes of hemodynamic collapse during off-pump coronary artery bypass (OPCAB) remain scarcely defined. We present an analysis of 23 cases of sustained hemodynamic collapse during elective off-pump CABG. METHODS: During a 54-month period, we performed 1420 elective OPCAB procedures through a sternotomy, constituting 71.2% of the total CABG procedures performed. Twenty-three patients (1.6%) experienced hemodynamic collapse intra-operatively requiring immediate cardiopulmonary bypass. Preoperative characteristics, intraoperative data, and postoperative outcome were retrospectively reviewed in each patient. RESULTS: In all cases, improvements in intra-operative technique and/or judgment could be made retrospectively. Twenty (20/23) of these patients had an uneventful postoperative course and three (3/23) patients had an unstable course with two deaths. CONCLUSIONS: The causes of hemodynamic collapse during elective OPCAB were ischemic, mechanical, or a combination of both. A detailed review of our five and a half year experience has revealed a number of suggestions for improving the conduct of the operation.

Aged↗
PubMed2002

Hybrid robotic coronary artery surgery and angioplasty in multivessel coronary artery disease.

BACKGROUND: Complete surgical revascularization that includes left internal thoracic artery grafting to the left anterior descending coronary artery remains the gold standard of treatment for coronary artery disease. Not all patients are good candidates for sternotomy. Therefore, we sought to identify a strategy that would combine the long-term advantages of internal thoracic artery grafting to lessen surgical trauma while still allowing complete revascularization. METHODS: A total of 54 consecutive patients from four institutions underwent hybrid revascularization combining surgery and angioplasty. All internal thoracic artery grafts were endoscopically harvested with robotic assistance using either the Aesop or Zeus system, and all anastomoses were manually constructed through a 4- to 6-cm anterior thoracotomy incision. Angioplasty was carried out to achieve total revascularization to ungrafted vessels. RESULTS: There were no early or late deaths, myocardial infarctions, strokes, or wound infections. Of the patients, 37 (69%) were extubated in the operating room. Length of stay in the intensive care unit averaged 24.4 hours and hospital stay 3.45 days. In all, 16 patients (29.6%) required transfusion of packed red blood cells. Late complications included 1 patient with stent occlusion at 3 months and 2 patients with in-stent restenosis. Three patients were treated for postpericardiotomy syndrome. Mean follow-up was 11.7 months. Event-free was survival 87.1% and freedom from recurrent angina 98.3%. CONCLUSIONS: Hybrid endoscopic atraumatic internal thoracic artery to anterior descending coronary artery graft surgery combined with angioplasty is a reasonable revascularization strategy in multiple vessel coronary artery disease in selected patients. Longer follow-up and more patient data in a randomized study are needed to determine the patient cohort most likely to benefit from this approach.

Adult↗
PubMed2002

Coronary perfusion methods during off-pump coronary artery bypass: results of a randomized clinical trial.

BACKGROUND: Several techniques are being used to perform off-pump coronary artery bypass (OPCAB) grafting. This three-armed clinical trial was performed to determine whether one OPCAB method of coronary perfusion was superior over the others with respect to myocardial protection and performance. METHODS: Over the course of 11 months, 151 consecutive unselected patients underwent elective first-time OPCAB grafting by sternotomy performed by a single surgeon. Patients were prospectively randomized to receive one of three OPCAB coronary perfusion treatments: (1) no coronary perfusion (NCP), ie, OPCAB using no coronary perfusion during the distal anastomosis or graft perfusion after the distal anastomosis until all the proximal anastomoses were completed; (2) passive coronary perfusion (PCP), providing distal coronary perfusion during the anastomosis and immediate graft perfusion after the distal anastomosis by means of a passive cannula from the aorta; or (3) active coronary perfusion (ACP), providing assisted distal coronary perfusion and graft perfusion by means of an in-line pump (perfusion-assisted direct coronary artery bypass. Hemodynamic and biochemical data were recorded to disc continuously throughout the operation and postoperatively. RESULTS: With no statistically significant differences in the three treatment groups with respect to patient age, left ventricular systolic or diastolic function, and extent and distribution of coronary disease or grafts performed, cardiac performance postoperatively was superior in the active coronary perfusion group compared to the groups receiving either passive coronary perfusion or no coronary perfusion (p < 0.001). In addition, troponin I levels were lower in the coronary perfusion groups (PCP and ACP) (p = 0.023). CONCLUSIONS: Providing active coronary perfusion during the anastomosis and after each distal anastomosis by using an in-line pump resulted in superior myocardial protection and performance during OPCAB surgery when compared to either no coronary perfusion or passive coronary perfusion.

Aged↗
PubMed2002

The cardiopulmonary effects of single-lung ventilation and carbon dioxide insufflation during thoracoscopic internal mammary artery harvesting.

BACKGROUND: Thoracoscopic internal mammary artery harvesting has become an integral part of minimally invasive coronary artery bypass operations. The technique involves the use of single-lung ventilation and carbon dioxide insufflation to maximize exposure and facilitate rapid dissection. The hemodynamic and pulmonary effects of this technique have not been extensively studied. METHODS: Seventy-five consecutive patients undergoing a minimally invasive coronary artery bypass operation were prospectively studied intra-operatively. Sixty-six left and nine right thoracoscopic IMA harvests were performed in patients with ejection fractions ranging from 12 to 70%. Carbon dioxide insufflation was utilized in the range of 8 to 12mm Hg and the effects on cardiovascular and pulmonary performance were recorded to disk every sixty seconds. RESULTS: Carbon dioxide insufflation in combination with single-lung ventilation increases central venous pressure and pulmonary artery pressure. At higher levels of insufflation pressure, negative effects are seen on systemic blood pressure, cardiac output and left ventricular stroke work. These effects can be aggravated by hypovolemia and a poor preoperative left ventricular ejection fraction. CONCLUSIONS: Single-lung ventilation and carbon dioxide insufflation greatly enhances the technical ease of thoracoscopic internal mammary artery harvest. While safe in the majority of patients, CO2 insufflation should be used cautiously in hypovolemic patients and patients with poor left ventricular function.

Adult↗
PubMed2002

Technical aids to performing thoracoscopic robotically-assisted internal mammary artery harvesting.

OBJECTIVE: This report outlines the procedures and technical aids used for performing thoracoscopic internal mammary artery (IMA) harvesting in a series of 308 patients. METHODS: As a part of atraumatic coronary artery bypass (ACAB) operations, thoracoscopic IMA harvests (294 left, 14 right, and 12 bilateral) were performed in 308 consecutive patients. Single-lung ventilation and carbon dioxide insufflation were employed in all cases to facilitate exposure and dissection. A voice-activated robotic arm controlled the camera view, and harvesting was accomplished with the electrocautery on a low setting. RESULTS: Harvest time decreased from a mean of 58.4 minutes in the first fifty procedures to 29.4 minutes in the last fifty procedures. There were no significant complications as a result of this technique, and no patients required a conversion to sternotomy as a result of IMA injury. CONCLUSIONS: Thoracoscopic internal mammary artery harvesting is an essential basic skill for cardiac surgeons interested in performing minimally invasive and atraumatic coronary bypass procedures. Thoracoscopic IMA harvesting can be successfully performed with the use of the technical aids and procedures outlined in this report.

Humans↗
PubMed2002

CAPS--coronary-assisted perfusion system.

For the past 35 years the use of the extracorporeal bypass circuit has been a mainstay for coronary artery bypass grafting (CABG) in cardiac surgery arena. Since John Gibbon's early design, evolution of the pump has expanded rapidly with new techniques and engineering. The cardiopulmonary bypass (CPB) circuit has allowed cardiovascular surgeons to perform complete revascularization in a motionless and bloodless field. Presently, there is a new focus on CABGs because of new engineering designs of retractors and stabilizers, robotic techniques, and the monetary issues of cost and length of stay. Surgeons at our hospital perform 70% of CABG procedures off pump. We have developed a coronary-assisted perfusion system called CAPS. This is a simple shunt system that uses existing pump hardware to deliver arterial blood to the myocardium after the completion of the distal anastomosis. Flow is regulated by monitoring a pressure-sensing display either at systemic or suprasystemic pressure. Temperature of the blood is maintained with a Vanguard BCD heat exchanger (COBE Cardiovascular Inc., Arvada, CO) with a built-in temperature probe port. This system is capable of delivering optional agents for coronary vasodilatation, myocardial resuscitation, and performance through a connection to any standard medication infusion pump. The advantages of this system are that it is safe, requires no additional perfusion hardware, cost effective, easy to setup, has a low and rapid prime, has both inflow and outflow pressure monitoring sites, has heat a exchanger with temperature monitor, and has a drug additive port for pharmacologic infusion.

Cardiopulmonary Bypass↗