Denton A. Cooley

Transmyocardial laser revascularization: Results of a multicenter trial with transmyocardial laser revascularization used as sole therapy for end-stage coronary artery disease ☆ ☆☆ ★ ★★ ♢

BACKGROUND Transmyocardial laser revascularization was used as the sole therapy for patients with ischemic heart disease not amenable to percutaneous transluminal coronary angioplasty or coronary artery bypass grafting. This technique uses a carbon dioxide laser to create transmyocardial channels for direct perfusion of the ischemic heart. METHODS Since 1992, 200 patients, at eight hospitals in the United States, have undergone transmyocardial laser revascularization. The patients have a combined 1560 months of follow-up for an average of 10 +/- 3 months per patient. Their age was 63 +/- 10 years and their ejection fraction was 47% +/- 12%. Eighty-two percent had at least one previous bypass graft operation and 38% had a prior angioplasty. Preoperatively, the patients underwent nuclear single photon emission computed tomography perfusion scans to identify the extent and severity of their ischemia. These scans were repeated at 3, 6, and 12 months. Angina class, admissions for angina, and medications were recorded. RESULTS The perioperative mortality was 9%. Angina class decreased significantly from before treatment to 3, 6, and 12 months (p < 0.001). Likewise, there was a significant decrease in the number of perfusion defects in the treated left ventricular free wall. Concomitantly, there was a significant decrease in the number of admissions for angina in the year after the procedure when compared with the year before treatment (2.5 vs 0.5 admissions per patient-year). CONCLUSION These combined results indicate that transmyocardial laser revascularization provides angina relief, decreases hospital admissions, and improves perfusion in patients with severe coronary artery disease.

Congenital Malformations of the Coronary Arteries: The Texas Heart Institute Experience

Coronary artery anomalies, some of which are considered clinically insignificant, can be associated with other congenital heart defects, myocardial ischemia, and reduced life expectancy. We conducted a retrospective study to determine the efficacy of surgical treatment in 191 patients who had a total of 202 coronary artery anomalies, which were classified as anomalies of origin (88 patients), termination (93), or distribution (10). Of the 88 patients with anomalies of origin, 60 had a coronary artery arising from the pulmonary artery, 18 had a right coronary artery arising from the left anterior descending artery, and 10 had a coronary artery arising from the contralateral sinus of Valsalva. All patients with an anomaly of termination had a coronary arteriovenous fistula, and all patients with an anomaly of origin had a single coronary artery. The diagnostic and operative techniques for each of the defects are evaluated. Based on our experience, early diagnosis and surgical intervention can yield satisfactory results in patients with coronary artery anomalies, with most experiencing relief of symptoms. The operative procedures were associated with a low early and late mortality; in addition, few patients experienced complications.

Orthotopic cardiac prosthesis for two-staged cardiac replacement

Abstract Clinical experience with cardiac transplantation has evidenced the feasibility of cardiac replacement in man but has made apparent the need for a mechanical device that will provide circulation and sustain life in emergency conditions while a suitable allograft is obtained. The cardiac prosthesis used in a 47 year old man consisted of two reciprocating pumps constructed entirely of synthetic materials and activated pneumatically in the orthotopic position by a control console connected by tubes passed through the patients chest wall. The device supported the patients circulation for 64 hours while a donor for cardiac transplantation was obtained. Death of the recipient from Pseudomonas pneumonia occurred 32 hours after the allografting. The first successful prolonged use of a total mechanical substitute for the human heart is recorded.

Ischemic contracture of the heart: “Stone heart”

Open heart surgery using cardiopulmonary bypass has enjoyed an exciting 15 year history during which many technical modifications were made and baffling complications encountered. For the past 8 years we have routinely employed a simplified technique using simple intravenous solutions to “prime” the extracorporeal circuit, maintained the patient and his heart at normothermic levels and induced ischemic cardiac arrest to control or prevent myocardial injury during the period of bypass.1,2 Periods of induced ischemia have been tolerated by some patients for more than 2 hours without apparent myocardial damage. However, we have seen a relatively small number of patients who died in the operating room from an unusual type of myocardial failure. Rather than the poorly contracting, overdistended ventricle of myocardial failure, a small spastic heart, literally frozen in systole, develops. The ventricular chamber is decreased notably in volume because of the contracture, and even vigorous manual massage does not produce an adequate stroke volume. Changes in peripheral resistance, cardiotonic agents, electrolyte solutions, adrenergic. blocking and stimulating agents and assist devices have not altered its inevitable course. On palpation the heart is in a contracted state similar to the uterine contraction ring or the tetanic contraction of striated muscle as seen in the laboratory. This characteristic state is recognized readily at the time of surgery. Ultimately, cardiopulmonary bypass cannot be discontinued without the patient dying because of the maintained contractile state. We have named this irreversibly contracted ventricle the “stone heart.” Fortunately, the stone heart is rare. Of the 4,732 patients (1,407 for congenital lesions and 3,325 for acquired) who have undergone open heart surgery at the Texas Heart Institute during the 5 years from July 1966 to July 19’71, 51 patients (1 percent) died during operation from acute myocardial insufficiency. Of that group, less than a third (13 patients) experienced severe contracture of the heart and the criterion we recognize as stone heart. We have reviewed the clinical and patho-

Surgical Experience in Descending Thoracic Aneurysmectomy with and without Adjuncts to Avoid Ischemia

Over the past twelve years, surgical treatment of descending thoracic aneurysms has been performed in 360 patients. Three different operative strategies were employed during resection to provide distal aortic perfusion by temporary bypass (Group 1, 75 patients) or shunt (Group 2, 22 patients) or to simplify the operative procedure with aortic cross-clamping alone (Group 3, 263 patients). The surgical results were determined primarily by patient-related and disease-related variables. Advanced age (older than 70 years), atherosclerotic cause, and emergency operation significantly increased the risks of early mortality and morbidity. The incidence of death (11.7%), paraplegia (6.5%), or renal failure (6%) was not reduced by the use of adjunctive perfusion, and bleeding complications increased significantly in Groups 1 and 2. Spinal cord injury was increased significantly by emergency operations, cross-clamp times exceeding 30 minutes, and extensive aneurysms (p less than 0.05). The risk of renal failure was increased by advanced age and atherosclerotic cause (p less than 0.05). With an experienced surgical team, the primary risks of descending thoracic aneurysmectomy are not influenced by the method of adjunctive perfusion, but are determined by patient factors such as the nature and extent of the aneurysm.

Transmyocardial laser revascularization: Clinical experience with twelve-month follow-up

We are investigating a new technique for myocardial revascularization in which an 800 W carbon dioxide laser is used to drill 1 mm diameter channels into a beating heart after left thoracotomy. Clotting occludes the channels on the subepicardium, and in the long-term setting, blood from the left ventricular cavity flows through these channels to perfuse the ischemic subendocardium. To test the efficacy of this technique in a preliminary clinical trial, we used it as sole therapy for 21 consecutive patients. All patients had hibernating myocardium, reduced coronary flow reserve, or both, had distal diffuse coronary artery disease, and had angina refractory to normal therapy. Eight patients were excluded from follow-up because of death (n=5), rerevascularization (n=2), or diaphragmatic paralysis resulting in postoperative respiratory incapacity (n=1). In the remaining 13 patients available for follow-up, the mean angina class (Canadian Cardiovascular Society) was 3.7 +/- 0.4 before operation and 1.8 +/- 0.6 12 months after operation (p < 0.01). Mean resting left ventricular ejection fraction was 48% +/- 10% before operation and 50% +/- 8% at 12-month follow-up. At 12 months, resting mean subendocardial/subepicardial perfusion ratio had increased by 20% +/- 9% in septal regions treated by laser but decreased by 2% +/- 5% in untreated regions (n=11, p <.001). These results suggest that revascularization by this laser technique positively affects subregional myocardial perfusion and may result in clinical benefits for patients with reversible myocardial ischemia. Studies to date have not demonstrated significant changes in global and regional ventricular contractile function.

Sinus of Valsalva aneurysm or fistula: management and outcome.

BACKGROUND Few large or long-term series exist regarding the management of patients with sinus of Valsalva aneurysms or fistulas (SVAFs). METHODS Between 1956 and 1997, 129 patients presented with a ruptured (64 cases; 49.6%) or nonruptured (65 cases; 50.4%) SVAF. The patients included 88 men and 41 women, with a mean age of 39.1 years. Associated findings included a history of endocarditis (42 cases; 32.6%), a bicuspid aortic valve (21 cases; 16.3%), a ventricular septal defect (15 cases; 11.6%), and Marfans syndrome (12 cases; 9.3%). Operative procedures included simple plication (61 cases; 47.3%), patch repair (52 cases; 40.3%), aortic root replacement (16 cases; 12.4%), and aortic valve replacement/repair (75 cases; 58.1%). RESULTS There were five in-hospital deaths (3.9%): four due to preexisting sepsis and endocarditis and one that followed dehiscence of the repair in a patient with Marfans syndrome. Two patients (1.6%) had strokes during the early postoperative period. The survivors were followed up for 661.1 patient-years (5.3 years/patient). The following late complications occurred: prosthetic valve malfunction (5 cases; 3.9%), prosthetic valve endocarditis (3 cases; 2.3%), SVAF recurrence (2 cases; 1.6%), thrombosis (1 case; 0.8%), and anticoagulation-related bleeding (1 case; 0.8%). CONCLUSIONS Resection and repair of SVAF entails an acceptably low operative risk and yields long-term freedom from symptoms. Early, aggressive treatment is recommended to prevent endocarditis or lesional enlargement, which causes worse symptoms and necessitates more extensive repair.

Myocardial Revascularization With Laser Preliminary Findings

BACKGROUND We assessed the transmyocardial laser revascularization (TMLR) as sole therapy in patients with symptomatic coronary artery disease refractory to interventional or medical treatment. METHODS AND RESULTS Thirty-one patients were evaluated with positron emission tomography (PET), dobutamine echocardiography, 201Tl single-photon emission computed tomography (201Tl-SPECT), and multigated acquisition radionuclide ventriculography (MUGA). TMLR was performed in 21 patients who had demonstrable ischemia in viable myocardium. The mean Canadian Cardiovascular Society (CCS) angina class was 3.70 +/- 0.7 (4 patients with unstable angina). Untreated septal segments were used as controls. At 3 months, (n = 15 patients), the mean CCS angina class was to 2.43 +/- 0.9 (P < .05). On dobutamine echocardiography, the mean resting wall motion score index was improved by 16% in lased segments (P < .03 vs control), and mean LVEF at peak stress increased by 19% (P = NS vs baseline). On 201Tl-SPECT, perfusion of lased and nonlased segments did not change. On PET, the mean ratio of subendocardial to subepicardial perfusion (SEn/SEp) increased 14% over baseline (P < .001 vs control). At 6 months (n = 15 patients), the mean CCS angina class was 1.7 +/- 0.8 (P < .05). The mean resting wall motion score index was up by 13% in lased segments (P < .05 vs control). Resting LVEF was unchanged. Stress LVEF increased 21% (P = NS vs baseline). Myocardial perfusion remained unchanged by 201Tl-SPECT. On PET, 36% of the lased segments were better, and 25% were worse compared with baseline. The resting SEn/SEp by PET was up 21% (P < .001 vs control). All deaths (two perioperative and three late) occurred in patients with preoperative congestive heart failure. Two patients required repeat revascularization of new coronary lesions. CONCLUSIONS These results suggest that TMLR improves anginal status, relative endocardial perfusion, and cardiac function in patients who do not have preoperative congestive heart failure.

The effect of coronary bypass on the outcome of peripheral vascular operations in 1093 patients

One of the greatest risks in peripheral vascular operations is the presence of significant coronary artery disease. To assess the proper timing and demonstrate a possible protective effect of coronary artery bypass (CAB), 1093 patients who underwent one or more peripheral vascular operations in addition to CAB from 1976 through 1984 were analyzed. During that same period, 24,441 patients underwent CAB procedures, and 8530 patients underwent major vascular operations. Carotid endarterectomy (493 patients), abdominal aneurysm resection (130 patients), renal artery bypass (12 patients), aortofemoral bypass (77 patients), femoral-popliteal-tibial bypass (190 patients), and combined vascular procedures (191 patients) were included. The patients were divided into three groups according to severity of disease, which determined timing of the procedure. Group I (255 patients) underwent simultaneous CAB and peripheral vascular operation because of unstable coronary artery disease and severe vascular disease. The early mortality rate for group I was 4% (10 patients). Seven of the 10 deaths were cardiac. In group II, 279 patients had CAB and peripheral vascular operation during the same hospital admission with the same operative mortality rate (4%, 10 patients). Six deaths were from cardiac causes, three from neurologic causes, and one from hemorrhage. In group III, 559 patients underwent CAB first, then peripheral vascular operation during a separate hospital admission. There were no cardiac-related deaths and only one neurologic-related death (operative mortality rate, 0.2%). These data demonstrate the protective effect of CAB in patients who undergo elective vascular surgery. The increased risk in patients undergoing simultaneous or same admission procedures was related to the severity of the vascular and coronary artery disease and not to the combined operations. Operative complications were not increased by performing simultaneous or same admission procedures.

Resection of Aortic Arch Aneurysms: A Comparison of Hypothermic Techniques in 60 Patients

Hypothermic circulatory arrest has been used to facilitate resection of aneurysms of the aortic arch. During a five-year period, two methods of hypothermic arrest were compared in 60 patients. In Group 1, 20 patients underwent deep hypothermia (14 degrees to 18 degrees C) and circulatory arrest to allow repair of the transverse arch under optimal conditions. A hospital mortality of 50% occurred and was attributed to uncontrolled hemorrhage and cerebral or cardiac complications. In Group 2, modified techniques were employed in 40 patients and included moderate levels of hypothermia (22 degrees to 26 degrees C) and simplified operative methods, which reduced the duration of circulatory arrest and shortened the length of perfusion. Pretreatment of plasma-soaked Dacron grafts by autoclaving eliminated serious bleeding problems. A marked improvement in patient survival (90%) and reduction in postoperative complications were observed after adoption of these modifications. The improved results in the present series have reconfirmed our belief that this type of intervention is the preferred approach to aneurysms of the aortic arch.