Thomas Z. Lajos

Coronary artery bypass grafting without cardiopulmonary bypass--an attractive alternative in high risk patients.

OBJECTIVE This study compares preoperative risk factors, estimated, observed, and risk adjusted mortality, and postoperative complications in patients undergoing coronary artery bypass grafting. Patients were divided in two groups depending on operative method: Group A patients had coronary artery bypass grafting using cardiopulmonary bypass. In group B cardiopulmonary bypass was not utilized. Patients operated on between January 1 1995 and August 31 1996 were compared. Group A consisted of 1829 patients and Group B 172. METHODS Patients were selected to undergo coronary artery bypass grafting without the use of cardiopulmonary bypass either because the surgeon felt that there were contraindications to--or no need for the heart-lung machine. The decision to avoid the use of cardiopulmonary bypass was taken pre-operatively by the individual surgeon. Median sternotomy, formal left thoracotomy or left anterior small thoracotomy were used. The data was collected and validated by the hospitals professional data collectors. Data-analysis was performed using the NY-state database. RESULTS Previous heart surgery and extensively calcified ascending aorta were significantly more common in Group B as was estimated and observed mortality. This resulted in identical risk-adjusted mortality of 2.8%. When reoperations were reviewed separately risk adjusted mortality was lower in Group B (2.1 versus 3.1%) but this difference was not statistically significant. Cardiovascular-and other-complications were higher in group A patients. In reoperative patients this difference was significant (P = 0.05). The need for postoperative mechanical assistance was also reduced (Group A: 14.9% versus Group B: 1.3% P = 0.01). CONCLUSION We conclude that coronary artery bypass surgery can be done safely in selected patients without cardiopulmonary bypass. Mortality is unchanged and complications are less frequent. Cost and hospital utilization are decreased. The greatest benefit is observed in reoperations.

Elimination of cardiopulmonary bypass: a prime goal in reoperative coronary artery bypass surgery

OBJECTIVE The purpose of this study was to evaluate morbidity and mortality in reoperative coronary artery bypass surgery using the New York State database. METHODS Patients undergoing reoperative coronary artery bypass between January-1995 and December 1996 were included. Patients were operated using cardiopulmonary bypass (CPB group, n = 184) or without cardiopulmonary bypass (non-CPB group, n = 105) by surgeon preference. Groups were compared for preoperative risk factors, postoperative mortality and major complications. RESULTS Crude mortality was lower in the non-CPB group, despite a higher expected mortality, resulting in a risk-adjusted mortality of 1.3% versus 2.7% for the CPB group (NS). Of non-CPB patients, 91.4% were without complications, while only 72.1% of CPB patients (P < 0.0001) were complication-free. Major complications were significantly reduced in non-CPB patients compared to CPB patients: stroke 0% versus 3.8% (P < 0.04), cardiovascular complications 4.8% versus 15.8% (P < 0.005), other major complications 1.9% versus 10.4% (P < 0.007). Postoperative IABP support was needed in 1.9% of the non-CPB group patients and in 14.2% of the CPB group (P < 0.0007). CONCLUSIONS The main object of reoperative CABG is to relieve symptoms, since the survival benefit of the procedure has not been demonstrated. Performance of reoperative coronary artery bypass surgery without cardiopulmonary bypass significantly reduces morbidity. We conclude that cardiopulmonary bypass should be avoided whenever possible in reoperative coronary bypass surgery.

Left Thoracotomy Reoperation for Coronary Artery Disease

Abstract Twenty patients underwent reoperative coronary artery bypass grafting (CABG) through a left thoracotomy since 1971. This was their second CABG in 16 patients, third in three patients and fourth in one patient. Surgery was performed from 1 to 16 years following the initial procedure. Demographic data showed no significant variation from patients undergoing standard reoperative CAGB in this institution. Ejection fraction varied between 30% and 73%. Cardiopulmonary bypass technic has gradually developed since 1971, using the left femoral artery and vein. For venous cannulation a 50‐cm long catheter was positioned in the right atrium. Monitoring included pulmonary artery catheter with oximetry. Fibrillatory arrest of the heart was utilized with 18–33°C core cooling cardioplegia. The left internal mammary artery (6) and reverse saphenous veins (44) were used for an average of 2.5 grafts per patient. The proximal anastomosis was placed on the descending thoracic aorta or the left subclavian artery. There were two early and no late deaths. Sixteen patients were restudied before discharge from the hospital with an early graft patency rate of 98% (41/42). The left thoracotomy approach may be preferable in selected cases of redo CABG. The danger of damage to the heart and patent grafts is greatly reduced.

Pitfalls of undetected patent foramen ovale in off-pump cases

We describe pitfalls of a hitherto undetected patent foramen ovale during the conduct of an off-bypass coronary revascularization. Manipulation of the heart resulted in right-to-left shunt and severe desaturation requiring institution of cardiopulmonary bypass to close the patent foramen ovale and complete the revascularization.

Pulmonary resection combined with cardiac operations

Surgical management of patients with concomitant critical cardiac disease and resectable lung lesions is controversial. During a 7-year period (1982 to 1988), 21 patients underwent combined cardiac and pulmonary operations. Patients had cardiac symptoms only; the lung lesions were found on preoperative chest roentgenograms. The pathological diagnosis was established in only 2 of the patients before operation. All underwent concurrent pulmonary resection during cardiac operations requiring extracorporeal circulation. The pulmonary operations included 17 wedge resections and four lobectomies. The final diagnoses in 8 patients with stage I non-small cell lung cancer included epidermoid carcinoma (4), adenocarcinoma (3), and bronchoalveolar carcinoma (1). Postoperatively, 1 patient required a permanent pacemaker and 1 patient died. The actuarial survival at 5 years for all patients who underwent combined procedures was 95%. The 5-year survival for the 8 patients with lung cancer was 88% compared with 100% for those with benign pulmonary pathology (p = 0.172). This experience suggests that combining pulmonary resection with cardiac operations is safe and offers a favorable prognosis to a select group of patients.

Detection of creatine kinase BB isoenzyme in sera of patients undergoing aortocoronary bypass surgery

Creatine kinase BB isoenzyme (CK-BB) was detected intraoperatively in 22 of 25 patients undergoing aortocoronary bypass surgery, both in the coronary sinus and in the mixed venous blood. In a group of 10 patients in whom selective intracavitary profound hypothermic arrest was used, CK-BB values were lower than in another group of 10 patients, in whom controlled ventricular fibrillation with moderate total body hypothermia was instituted. This latter group also had higher levels of CK-MB. Patients who developed acute myocardial infarction immediately prior to or during the surgical intervention had the highest CK-BB values. This enzyme appeared as early as 15 minutes after the institution of cardiopulmonary bypass and disappeared within 6 hours. It is considered that part of the BB isoenzyme in serum of patients undergoing heart surgery is of myocardial origin.

Evaluation of Venous Bypass Grafts from Aorta to Coronary Artery by Inert Gas Desaturation and Direct Flowmeter Techniques

Blood flow through aorta-to-coronary artery bypass grafts has been measured selectively in 16 patients at or within 6 wk after operation. Inert gas desaturation curves were obtained from coronary venous blood samples after a 7-15 min infusion of dissolved H(2) directly into the graft. Samples were analyzed chromatographically and curves resolved to 1-3% of initial H(2) concentrations. Average flow per unit volume (F/V) was 67+/-21 (sd) ml/min per 100 g. Semilogarithmic plots showed F/V to be distributed heterogeneously in every case. In nine studies at operation, H(2) measurements of average F/V were combined with electromagnetic measurements of total flow to estimate revascularized tissue mass. Electromagnetic flows ranged from 25 to 170 ml/min and averaged 69 ml/min. Tissue mass ranged from 46 to 155 g and averaged 88 g. We conclude that bypass grafts provide nutritive flow to significant amounts of myocardium at and shortly after operation. However, nutritive flow is not distributed evenly throughout the revascularized segment. The majority of the segment has a F/V within the accepted range of normal but there remain areas in which F/V is reduced significantly. The combination of inert gas and electromagnetic techniques allows a revascularized area to be characterized in terms of total flow, F/V, and tissue mass.

Circumferential Intimal Tear Causing Obstruction of the Aortic Arch: An Unusual Complication of Aortic Dissection

A 66-year-old man was first seen because of occlusive disease of the aortic arch vessels secondary to a Type I aortic dissection. At operation, circumferential detachment of the intima was found with intussusception of this flap into the descending aorta causing obliteration of the arch vessels. There has been only one previous report of circumferential intimal intussusception complicating aortic dissection.

Evaluation of post-cardiopulmonary bypass Sonoclot signatures in patients taking nonsteroidal anti-inflammatory drugs.

Patients who take nonsteroidal anti-inflammatory drugs (NSAID) and who experience bleeding after cardiopulmonary bypass (CPB) are treated empirically with platelet transfusions because of the unavailability of rapid and accurate diagnostic clotting function tests. Therefore, a Sonoclot Analyzer (Sienco, Inc, Morrison, CO), which measures the change in the viscoelastic properties of recalcified whole blood, was used to assess platelet function in 51 patients undergoing CPB for cardiac surgery. Seventeen patients (group 1) taking NSAID were compared with 34 patients who were not taking NSAID (group 2). Blood samples were drawn for Sonoclot analysis before and after CPB. Chest tube drainage was measured for 24 hours postoperatively in both groups. Clot retraction, measured by the down slope on the Sonoclot signature, decreased significantly in group-1 patients, although values obtained for both groups were in the normal range. No difference was found between groups when Sonoclot signatures were compared, requirements for replacement of clotting factors or platelets, chest tube blood drainage, and unscheduled return to the operating room for bleeding. It is concluded that patients taking NSAID did not experience increased bleeding after cardiopulmonary bypass and that empiric platelet transfusion seemed unnecessary. In addition, the Sonoclot Analyzer seems to be a useful and sensitive instrument for rapidly assessing platelet function in the operating room.

Structural-functional correlates of reversible myocardial anoxia

Abstract Using the mammary artery-pedicle preparation, the structural-functional response of the canine myocardium to increasing periods of reversible normothermic anoxia was precisely defined. At 15 min there was complete return of structure and function. Sixty minutes of anoxia produced irreversible damage; 30 min resulted in changes that were largely reversible.