Daniel G. Knauf

Mortality, Morbidity, and Cost-Accounting Related to Coronary Artery Bypass Graft Surgery in the Elderly

The purpose of this study was to document early mortality, perioperative complication rate, duration of hospitalization, and costs related to coronary artery bypass graft (CABG) surgery in the elderly. Arbitrarily, elderly patients were defined by age greater than or equal to 65 years; younger patients were less than or equal to 60 years old. A detailed list of specific perioperative complications was analyzed. Early (30-day) mortality was similar between groups, while 120-day mortality was higher among elderly compared with younger patients (7.6% versus 1.3%; p = 0.05). The number of elderly patients with 1 or more complications was also higher than among the younger patients (62% versus 43%; p = 0.05). When the incidences of atrial arrhythmias and transient psychoses were considered minor complications and excluded from consideration, the incidence of major complications was higher in the elderly: 41 major events among 76 younger surviving patients compared with 89 major complications in 61 older surviving patients (p = 0.001). Time spent in the intensive care unit and the duration of postoperative hospitalization were also greater in the elderly (p = 0.01 and p = 0.001, respectively). Finally, the elderly group incurred greater costs than the younger patients (p = 0.03). The likelihood of increased perioperative morbidity in elderly patients is documented in this study. Also, it appears that the increased frequency of complications in elderly patients is associated with a longer hospital stay and greater financial expense. Consequently, the careful preoperative evaluation of these patients, including cautious patient selection, assumes greater importance. After CABG procedures, the highly symptomatic elderly patient may experience dramatic relief of symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Pancoast tumor : radiation therapy alone versus preoperative radiation therapy and surgery

This is a retrospective analysis of 73 patients with non-oat cell carcinoma of the lung presenting as a Pancoast tumor. All patients were treated with curative intent between October 1964 and September 1987 (minimum follow-up 2 years). The treatment plan consisted of preoperative radiation therapy (usually 3000 cGy in 2 weeks or 4500 cGy in 5 weeks) in 41 patients and radiation therapy alone (usually 6500-7000 cGy in 6.5-8.0 weeks) in 32 patients. In general, radiation therapy alone was reserved for poor-prognosis patients (extensive disease or medical inoperability). Although 41 patients were initially scheduled to receive preoperative radiation therapy and surgery, the surgery was not performed in 12 cases (29%) because of patient refusal (4 patients), poor response to radiation therapy (4 patients), distant metastasis (2 patients), or debilitation (2 patients). Separate calculations were carried out for the patients who completed the surgery as planned (preoperative radiation therapy and surgery) and the entire group originally scheduled for combined-modality therapy. There was no significant difference in the absolute or cause-specific survival rates between treatment groups, but severe complications were significantly more common in patients receiving combined therapy.

Emergency Coronary Artery Bypass Graft Surgery for Threatened Acute Myocardial Infarction Related to Coronary Artery Catheterization

In 20 patients undergoing cardiac catheterization, usually involving balloon-catheter dilation or streptokinase infusion, catheter-induced coronary artery intimal damage resulted in severe chest pain, electrocardiographic evidence of obstruction or dissection of a major coronary artery. These patients were surgically revascularized within 8 hours after the onset of the acute chest pain syndrome. Our experience with pharmacological and catheter-related manipulations to improve coronary blood flow after the ischemic episode but before operation suggested that the additional time spent in the catheterization laboratory was worthwhile. The injured coronary artery was the left anterior descending in 10 patients, the right in 8, the left main in 1 patient, and an obtuse marginal branch of the circumflex in 1. The average number of grafts per patient was 2.5; only 6 patients had single bypass grafts. In 5 patients, intraaortic balloon pumping was used either preoperatively or postoperatively. Inotropic support was used postoperatively in 5 patients, and 7 patients received lidocaine for ventricular irritability. Abnormal elevation of the serum isoenzyme of creatine kinase (CK-MB) was seen in 8 patients, and new Q waves were noted in 4 patients; 3 of these 4 patients with new Q waves also had abnormal serum CK-MB levels. Global ejection fraction obtained by the equilibrium-gated blood pool scan postoperatively was 60 +/- 3%, which was similar to the 62 +/- 3% obtained from the contrast-determined ventriculogram done preoperatively prior to the catheter-related injury. There were no early or late deaths, but morbidity was much higher in the group who had emergency coronary artery bypass grafting (CABG) compared with those who had elective CABG.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term follow-up of transvenous cardiac pacing in children

Abstract Aggressive diagnosis and treatment, both medical and surgical, for congenital or acquired heart disease in children have resulted in an increased need for permanent cardiac pacing systems. However, frequent premature pacemaker revisions have been necessary for many reasons, including lead fractures, noncapture due to increasing threshold, and wound infection or skin breakdown over the pacemaker generator. 1–3 Most pacemaker systems in children have used epicardial leads because of concern for lead dislodgement or damage to intracardiac structures, large lead size relative to small venous access, and difficulty in implanting relatively large pacemaker generators in a suitable prepectoral location. Recent changes in design of pacemaker generators and leads have made use of transvenous systems more tenable even in younger children who require permanent cardiac pacing. 4 However, little information has been reported regarding long-term results of transvenous pacemakers in children.

Coronary Artery Bypass Graft Surgery: Clinical Comparison of Cold Blood Potassium Cardioplegia, Warm Cardioplegic Induction, and Secondary Cardioplegia

An analysis of myocardial protection was performed in 45 low-risk patients undergoing coronary bypass procedures who were divided into three equal groups with similar preoperative ejection fractions and coronary artery obstructions. Group 1 (N = 15) received cold blood cardioplegia, Group 2 received cold blood cardioplegia and secondary cardioplegia, and Group 3 received cold blood cardioplegia plus warm cardioplegic induction. The aortic cross-clamp time and the number of bypass grafts were similar among the groups. The following variables were measured serially: electrocardiographic changes, serum myocardial-specific isoenzyme of creatine kinase, cardiac output, left ventricular filling pressure, ejection fraction, and left ventricular wall motion. The three methods evaluated were all effective in protecting the myocardium during global myocardial ischemia. Patients who received secondary cardioplegia (Group 2) were more likely to exhibit spontaneous defibrillation (12/15) than those in Group 1 (5/15) or Group 3 (6/15) (p less than 0.05). However, measurements of left ventricular performance and evidence of perioperative myocardial infarction were similar among all three groups. These data suggest that a standard technique of cold potassium cardioplegia alone should be the method of choice in elective, low-risk coronary bypass operations rather than this technique in combination with either of the other two more costly and complex methods evaluated in this study.

Interatrial groove tear: An unusual complication of balloon atrial septostomy

SummaryThe authors present an unusual complication of the balloon atrial septostomy procedure performed in a neonate with D-transposition of the great arteries. Cardiac tamponade developed shortly after the balloon atrial septostomy procedure and the infant was found to have a tear in the superior aspect of the left atrium, parallel to the interatrial groove. The tear was successfully sutured and may have been caused by the greater pull-back force needed if the catheter balloon is maximally distended for the first pull-back.

Preliminary Experience with Intraoperative Transluminal Balloon-Catheter Dilation and Coronary Artery Bypass Grafting for the Treatment of Symptomatic Diffuse Coronary Artery Disease

Transluminal balloon-catheter dilation of coronary artery lesions has become increasingly common in the cardiac catheterization laboratory. We describe a method of intraoperative dilation that may improve surgical results when used in combination with coronary artery bypass graft (CABG) operations in patients with diffusely diseased coronary arteries. In 16 patients, long-segment intraoperative dilations were performed to enlarge luminal narrowings in 21 different regions. All of these patients had postoperative coronary angiography and left ventriculography so that we could objectively evaluate the coronary dilatations. There were no operative deaths or perioperative myocardial infarctions, and angina was relieved in all patients. Of the 21 dilated segments, 12 (57%) were unchanged, 2 (10%) became worse, and 7 (33%) were improved postoperatively. In addition, two new areas of intimal damage were detected in patients with unchanged postoperative liminal diameters. We conclude that further experience and longer follow-up are necessary before the efficacy of intraoperative coronary artery balloon-catheter dilation can be accurately determined.

The changing strategies in operation for transposition of the great vessels

Between July 3, 1985, and February 24, 1994, a total of 55 infants underwent arterial switch procedures for the repair of transposition of the great vessels. Thirty-five infants had an intact ventricular septum and 20 had ventricular septal defects. To date, there have been three late deaths, one in the group with an intact ventricular septum and two in the group with a ventricular septal defect. Early postoperative complications included atrial dysrhythmias, prolonged ventilation, inability to close the sternum, and tension on the coronary arteries. Follow-up echocardiographic data for 44 patients indicate that pulmonary artery gradients are a worrisome postoperative problem, especially in infants who have ventricular septal defects.

Coronary Artery Bypass Graft Surgery: Relative Efficacy of Initial Proximal versus Distal Anastomoses

Controversy exists concerning the most appropriate sequence of anastomoses in coronary artery bypass grafting (CABG) procedures. While the more commonly employed method of distal coronary anastomoses first has withstood a long clinical experience, a recent study and several cardiac surgical groups have suggested that construction of the proximal anastomoses first offers certain advantages. In 30 patients undergoing CABG, we performed a prospective, randomized trial comparing both techniques. Relative efficacy was assessed by hemodynamic, radionuclide, electrocardiographic, enzymatic, thermographic, and clinical evaluation. The length of cardiopulmonary bypass was longer in the group having the distal anastomoses done first. Myocardial temperature mapping was similar between groups. Hemodynamic changes, including cardiac output, ejection fraction, and regional wall motion, were nearly identical between the groups. The incidence of myocardial damage reflected by levels of myocardial-specific isoenzymes (serum CK-MB) and electrocardiographic changes was also similar. In conclusion, the sequence of anastomoses is not critical in routine CABG operations. However, we speculate that each technique may have certain advantages under different clinical circumstances found on occasion. Ideally, each method should be part of the coronary surgeons armamentarium.

Intraoperative balloon-catheter dilatation: University of Florida experience.

Thirty-four patients with stable angina underwent coronary artery bypass surgery with supplemental intraoperative coronary artery balloon-catheter dilatation. Coronary dilatation was performed on 35 vessels at 50 sites. The balloon catheter could not be passed through one stenotic site. Intimal dissection occurred at two sites, as noted on early postoperative angiographic studies, with resolution on follow-up studies. There was one perioperative myocardial infarction, 100% early relief of angina, and one operative death. Of 25 distal arterial narrowings studied early by angiography (mean, 10 days), 15 (60%) were unchanged, two (8%) were worse, and eight (32%) were improved. Discrete narrowings improved more than diffuse narrowings; in 46% of the former there was an increase in luminal diameter, in comparison to only 17% of the latter. During a maximal 34-month follow-up period, two patients developed recurrent angina and one died of congestive heart failure. Of 13 distal coronary narrowings studied late (mean, 1 year), six (46%) were unchanged, three (23%) were worse, and four (31%) were improved. Postoperative serial catheterization (early and late) of 10 distal narrowings revealed that nine were unchanged and one was worse. Adjunctive intraoperative coronary balloon-catheter dilatation can be performed safely with acceptable clinical results. The procedure may also allow more complete revascularization of the myocardium.