Results of a prospective multicenter study on port-access coronary bypass grafting.

BACKGROUND: We reviewed the initial patient series of three institutions performing large volume port-access (PA) coronary artery bypass grafting (CABG) to evaluate the efficacy of this new procedure. METHODS: From October 1996 until June 1998, 302 consecutive patients underwent isolated CABG using the PA approach. Patients (mean age 60.7 years) were predominantly male (77.5%) and received a mean of 2.3 distal anastomoses; few were New York Heart Association class III or IV (15.9%). The distribution of the number of grafts was: 76 (25.2%) single, 110 (36.4%) double, 73 (24.2%) triple, and 43 (14.2%) four or more bypass grafts. The Society of Thoracic Surgeons (STS) Database data collection form was used prospectively by all three institutions to define patient risk factors and record outcomes. RESULTS: Total 30-day hospital mortality was 0.99% compared to the STS-database-model-predicted risk of 1.2%. Complication rates for the PA CABG patients compared with risk-matched morbidity rates from the STS data for CABG alone were: reoperation for bleeding, 3.3% versus 1.9%; ventilatory support more than 1 day, 1.7% versus 3.8%; stroke, 1.7% versus 1.2%; and perioperative transmural myocardial infarction 0% versus 1.3%. CONCLUSIONS: The STS CABG risk-adjusted model demonstrates that the 30-day mortality for patients undergoing PA CABG is lower than predicted for traditional CABG patients (confidence intervals not available). Likewise, the morbidity was low, with minimal ventilatory support, pulmonary complications, and atrial fibrillation. The port-access technique is an acceptable strategy for multivessel bypass grafting.

Port-access coronary artery bypass grafting: technique and comparative results.

BACKGROUND: Interest in minimally invasive coronary artery bypass grafting (CABG) continues to grow, and the techniques evolve. Our study examines the technical strategies of port-access (PA) CABG and compares results between PA CABG and conventional CABG. METHODS: Two hundred and twenty-nine consecutive patients underwent PA CABG from December 1996 through July 1998. Postoperative complications were compared with a matched cohort of conventional access patients. Operative technique and times were reviewed in the PA group. RESULTS: The average Society of Thoracic Surgeons (STS) risk assessment was 1.3 in both groups. Observed mortality was 0.9%. Complications of stroke, perioperative myocardial infarction, and atrial fibrillation were not significantly different between the two groups. Reoperation for bleeding was more likely in the PA group, while infections were more likely in the sternotomy group (p < 0.05). Transfusion requirements and postoperative length of stay were lower in the PA group (p < 0.05). CONCLUSIONS: Early results were similar between these two low-risk cohort groups. These findings support continued careful use of port-access revascularization in low-risk patients. Close follow-up of outcomes is essential to define the appropriateness of port-access techniques in patients requiring surgical revascularization.

First report of the Port Access International Registry.

BACKGROUND: For minimally invasive cardiac operations to be widely applicable, the risks must be equivalent to those of standard open-chest operations. This study analyzed the outcomes of patients recorded in the multicenter Port Access (PA) International Registry to establish operative risks. METHODS: Data were analyzed for intent to treat in 583 patients who underwent PA coronary artery bypass grafting (CABG), 184 who underwent PA mitral valve replacement, and 137 who underwent PA mitral valve repair at 121 centers. RESULTS: Port Access was attempted in 1,063 patients and completed in 1,004 (94%). The operative mortality rate was 1% for PA CABG, 3.3% for PA mitral valve replacement, and 1.5% for PA mitral valve repair. Perioperative morbidity was low in all categories: stroke = 1.1% to 3.6%, myocardial infarction = 0 to 1%, primary procedure reoperation = 0 to 0.7%, renal failure = 0.2% to 0.7%, multiorgan failure = 0 to 0.5%, and atrial fibrillation = 5% to 7.3%. CONCLUSIONS: Data on 1,063 patients from 121 centers demonstrate that PA CABG and PA mitral valve operations can be performed safely, with morbidity and mortality rates similar to those associated with open-chest operations. Further studies are indicated to establish the long-term efficacy of this method and to analyze its effect on recovery time.

Alteration of the traditional extracorporeal bypass circuit to accommodate port-access minimally invasive cardiac procedures using endovascular based cardiopulmonary bypass.

Port-Access minimally invasive cardiac surgery systems (Heartport, Inc., Redwood City, CA, U.S.A.) enable surgeons to perform many procedures including valve surgery and complete coronary artery revascularization of all surfaces of the heart through small anterior thoracotomies. The endovascular based EndoCPB (Heartport, Inc.) cardiopulmonary bypass system uses a modified extracorporeal circuit to afford the same level of myocardial protection through cardioplegic cardiac arrest and bypass as is provided in traditional open chest surgery. We describe the changes required to convert a conventional CPB pump circuit to perform Port-Access procedures and make recommendations based on clinical experience to facilitate establishing a Port-Access surgical team and interpreting EndoCPB pressure and flow data. Specific emphasis is placed on the expanded role of the perfusionist in these cases.

Port-access cardiac surgery protocols and early outcomes.

As a new cardiac surgical procedure, port-access holds promise to significantly impact the surgical approaches for treatment of CAD. Supporting collaborative practice protocols contributes to early extubation, rapid in-hospital recovery, and shortened LOS. Discharge protocols address postoperative concerns. Early results suggest that patient recovery is shorter than the time for conventional procedures; patients are able to return to an active lifestyle that is beneficial to families, patients, and employers.

Port-Access coronary artery bypass grafting: technical strategies for multivessel complete revascularization.

Complete coronary artery revascularization results in improved symptom-free survival. Standard cardiac revascularization uses cardiac arrest for microvascular anastomoses. The Port-Access system allows multiple coronary anastomoses in an arrested blood-free field. The technique of Port-Access coronary artery bypass grafting has evolved from one based on internal mammary artery inflow to one based on aortic inflow. Proximal aortic anastomoses enables the surgeon to revascularize more targets more reliably. Procedural time is shortened with the use of these new techniques and familiarity with the EndoCPB endovascular cardiopulmonary bypass system. Port-Access revascularization results in short-term acceptable results, patient satisfaction, and decreased hospitalization.

Removal of an infected right atrial mass in a patient with sickle cell disease.

The use of indwelling central catheters for hyperalimentation, chemotherapy, and long-term venous access is increasing. We report the successful removal of an infected right atrial mass associated with the use of a central catheter in an adult with sickle cell disease. The clinical options for the treatment of infected atrial thrombus as well as the challenge of performing cardiopulmonary bypass in patients with sickle cell disease are briefly discussed.

Ambulatory intraaortic balloon counterpulsation.

A technique is described for the retroperitoneal placement of a balloon pump that preserves patient mobility. This technique may be superior to standard femoral placement when prolonged support is required for cardiac transplant candidates awaiting donor organs.

Myocardial contractility in a canine model of the brain-dead organ donor.

OBJECTIVE: To test the hypothesis that the induction and maintenance of brain death leads to a decrease in myocardial contractility. DESIGN: Prospective, randomized, controlled trial. SETTING: Laboratory at a large, university-affiliated medical center. SUBJECTS: Sixteen adult, male, mongrel dogs weighing 15 to 25 kg. INTERVENTIONS: Myocardial contractile performance was evaluated after the induction of either brain death (n = 8), sham brain death (n = 4), or an operative procedure serving as a time control (n = 4). Brain death was induced by increasing and maintaining intracranial pressure above arterial systolic pressure. Contractile performance was determined with sonomicrometers arrayed to measure wall thickness in the anterior and posterolateral left ventricle. Brief aortic constrictions enabled derivation of the end-systolic pressure-thickness relationship, a relatively load-insensitive index of contractility. MEASUREMENTS AND MAIN RESULTS: No statistically significant hemodynamic differences were detected between the sham and time control groups. The brain-dead group displayed marked hemodynamic deterioration; 4 hrs after brain death was induced, mean arterial blood pressure, cardiac index, and the peak positive first derivative of left ventricular pressure were 63%, 35%, and 53% lower, respectively, than those values in the two control groups. However, the slope of the end systolic pressure-thickness relationship remained at 92 +/- 12% of baseline levels 4 hrs after brain death was induced and was not significantly different from the two control groups. CONCLUSIONS: The hemodynamic deterioration after the induction of brain death could not be attributed to a decrease of myocardial contractility as measured by the end systolic pressure-thickness relationship.

The effect of intramyocardial pH on functional recovery in neonatal hearts receiving St. Thomas' Hospital cardioplegic solution during global ischemia.

The experiments in the present study were designed to address two issues: Is it possible to manipulate intramyocardial pH in neonatal hearts with different buffers in cardioplegic solution and, if so, do differences in intramyocardial pH during ischemia influence functional recovery? Isolated working hearts from 7- to 10-day-old rabbits underwent 60 minutes of cardioplegic arrest at 37 degrees C with cardioplegic washouts at the onset of ischemia and at 30 minutes. Hearts were reperfused with oxygenated physiologic saline solution (pH = 7.4), returned to the working mode for 30 minutes, and hemodynamic measurements were obtained to compare with baseline values. Intramyocardial pH was held constant during the ischemic interval by infusing cardioplegic solution containing different buffers: histidine (pK 6.0 at 37 degrees C), bicarbonate (pK 6.4), or tromethamine (pK 8.1). The intramyocardial pH was measured continuously with a Khuri glass electrode system (Vascular Technology, Inc., North Chelmsford, Mass.). Cardioplegic solutions buffered to pH values of 6.0 (histidine), 7.4 (bicarbonate), and 8.0 (tromethamine) were associated with ischemic intramyocardial pH values of 6.3 +/- 0.03, 7.02 +/- 0.05, and 7.88 +/- 0.06, respectively. Functional recovery was best in the acidic (histidine) and worst in the basic (tromethamine) groups. Recoveries of developed pressure, the rate of rise of pressure over time, and aortic flow were significantly better for each parameter in the bicarbonate-treated compared with the tromethamine-treated hearts (p less than 0.005). Recovery in the histidine group, however, was superior to that in both the bicarbonate-treated and the tromethamine-treated hearts (p less than 0.005). Regression analysis demonstrated that a significant inverse relationship existed between functional recovery and intramyocardial pH, supporting the conclusions that intramyocardial pH is an important determinant of functional recovery in the neonatal heart and that acidic conditions during normothermic ischemia optimize preservation of myocardial function.

Acadesine (AICA-riboside) improves postischemic cardiac recovery.

To test if acadesine (5-aminoimidazole-4-carboxamide riboside), a purine precursor, has cardioprotective effects, 16 dogs were placed on total cardiopulmonary bypass and subjected to global myocardial ischemia. Hemodynamic recovery was compared between a control (n = 8) group receiving standard cardioplegia and an acadesine (n = 8) group pretreated with intravenous acadesine (2.5 mg.kg-1.min-1 for 5 minutes, then 0.5 mg.kg-1.min-1) before ischemia, during ischemia, and until 10 minutes after removal of the aortic cross-clamp. Additionally, in the acadesine group the cardioplegia also contained 20 mumol/L acadesine. While the dogs were on cardiopulmonary bypass, global warm myocardial ischemia was induced by aortic cross-clamping for 5 minutes under normothermic conditions to simulate an angioplasty accident. Five minutes after aortic cross-clamping, hypothermic cardioplegia (30 mL/kg) was administered. The left anterior descending coronary artery was occluded before the first infusion of cardioplegia to simulate poor cardioplegia delivery that can occur during an emergency coronary artery bypass procedure after an angioplasty accident. The left anterior descending artery occlusion was released, and additional cardioplegia (15 mL/kg) infusions were made every 30 minutes thereafter during 120 minutes of cardioplegic ischemia. Thirty minutes after reperfusion, all animals in both groups were weaned from bypass and recovery data were obtained to compare with baseline preischemic values. There were no significant differences in heart rate, left atrial pressure, or systemic vascular resistance between groups after weaning from bypass. Peak developed pressure recovered to 79% +/- 19% (mean +/- standard deviation) of baseline in the acadesine group compared with 56% +/- 22% in the control group (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Repair of tetralogy of Fallot in infancy. Effect of pulmonary artery size on outcome.

The possible influence of small pulmonary artery size on the results following complete repair of tetralogy of Fallot has not been investigated in patients less than 1 year of age. We, therefore, reviewed our recent experience with infant repair to assess this. Between January 87 and October 90, repair was performed in 58 infants less than 1 year old (median, 6 months) with tetralogy of Fallot and pulmonary stenosis (n = 53) or pulmonary atresia without important aortopulmonary collaterals (n = 5). The McGoon ratio (diameter of the right pulmonary artery at the prebranching point plus that of the left divided by the diameter of the aorta at the diaphragm) by cineangiography (n = 48) was between 1.2 and 1.5 in 15 patients, 1.6 and 2.0 in 20, and greater than 2.0 in 13. Transannular patching was performed in 19 of the patients with pulmonary stenosis (36%). Muscle resection was avoided in 29 infants and was minimal in the remaining 29. A weak correlation, with considerable scatter, was found between the McGoon ratio and postrepair right ventricular/left ventricular pressure measured in the operating room (r = 0.4), and the relations were similar to those previously reported for children. Right ventricular/left ventricular pressure was 0.55 +/- 0.03 in infants with McGoon ratios of 1.2-1.5, 0.46 +/- 0.03 with ratios of 1.6-2.0, and 0.47 +/- 0.03 with ratios greater than 2.0 (p = 0.01). There were no hospital deaths, and the 3-year survivorship was 94%. Two infants underwent successful reoperation for residual right ventricular outflow tract obstruction. All other patients are free of significant hemodynamic residua.(ABSTRACT TRUNCATED AT 250 WORDS)

Early postoperative morbidity after surgical treatment of thyroid carcinoma.

The long-term results after operations for malignant thyroid conditions are well known. Less well known are figures on early postoperative morbidity and mortality after resection of malignant thyroid lesions and data on patient satisfaction with the surgical incision. The data presented in this study show that postoperative mortality (0%) and morbidity (2% incidence of recurrent laryngeal nerve damage; 13% temporary and 1% permanent hypocalcemia) rates are extremely low in this group of patients, who express a high degree of satisfaction with the cosmetic aspects of the operation.