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Biomedical subjects

D A Cooley

Publications and source records attributed to D A Cooley.

At least 37 records · Page 2Linked to original sources
PubMed1999

Aortic aneurysm operations: past, present, and future.

Effective methods to treat aortic aneurysms are now available, although these lesions still challenge the cardiovascular surgeon. Attempts at treatment began in earnest in the 1800s, with the introduction of indirect and direct methods of repair. A major breakthrough occurred in the late 1800s, when Dr Rudolph Matas devised a method for internal repair of aneurysms in which continuity of blood flow was restored by excising the diseased portion of the lesion and creating a tunnel through the remaining normal portion. Matas named this technique reconstructive endoaneurysmorrhaphy. Until that time, surgeons had treated aneurysms by ligating the parent vessel with a Hunterian ligature or introducing foreign material to promote coagulation. Ligating the aneurysm rendered the extremities vulnerable to ischemic damage, however, and results were unpredictable with the use of various foreign materials. Around the turn of the century, Carrel began experimenting with different techniques for vascular anastomoses. The work of these early pioneers formed the basis for much of the modern treatment of aneurysms of the thoracic aorta. My experience began in 1950, when I excised a large aortic aneurysm in one of Dr Alfred Blalock's patients. The patient survived and was cured. After that experience, I knew that aortic aneurysms could be treated successfully by aggressive surgical means. Treatment has changed, however, from the early emphasis on excising the lesion to the present practice of restoring circulatory continuity with a suitable graft, ie, endoaneurysmorrhaphy. The development of reliable synthetic grafts has been one of the most important advances in the treatment of aneurysms. The surgical technique used today depends on the anatomic location of the aneurysm, which can occur anywhere from the aortic annulus and aortic valve to the distal thoracic aorta and visceral vessels in the abdomen.

Aortic Aneurysm↗
PubMed1999

Transmyocardial laser revascularization in the patient with unmanageable unstable angina.

BACKGROUND: Transmyocardial laser revascularization (TMR) provides relief for patients with chronic angina, nonamenable to direct coronary revascularization. Unmanageable, unstable angina (UUA) defines a subset of patients with refractory angina who are at high risk for myocardial infarction and death. Patients were classified in the UUA group when they had been admitted to the critical care unit with unstable angina for 7 days with three failed attempts at weaning them off intravenous antianginal medications. METHODS: Seventy-six treated patients were analyzed to determine if TMR is a viable option for patients with unmanageable unstable angina. These patients were compared with 91 routine protocol patients (protocol group [PG]) undergoing TMR for chronic angina not amenable to standard revascularization. The procedure was performed through a left thoracotomy without cardiopulmonary bypass. These patients were followed for 12 months after the TMR procedure. Both unmanageable and chronic angina patients had a high incidence of at least one prior surgical revascularization (87% and 91%, respectively). RESULTS: Perioperative mortality (< or = 30 days post-TMR) was higher in the UUAG versus PG (16% vs 3%, p = 0.005). Late mortality, up to 1 year of follow-up, was similar (13% vs 11%, UUAG vs PG; p = 0.83). A majority of the adverse events in the UUAG occurred within the first 3 months post-TMR, and patients surviving this interval did well, with reduced angina of at least two classes occurring in 69%, 82%, and 82% of patients at 3, 6, and 12 months, respectively. The percent improvement in angina class from baseline was statistically significant at 3, 6, and 12 months. A comparable improvement in angina was found in the protocol group of patients. CONCLUSIONS: TMR carried a significantly higher risk in unmanageable, unstable angina than in patients with chronic angina. In the later follow-up intervals, however, both groups demonstrated similar and persistent improvement in their angina up to 12 months after the procedure. TMR may be considered in the therapy of patients with unmanageable, unstable angina who otherwise have no recourse to effective therapy in the control of their disabling angina.

Adult↗
PubMed1999

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 Marfan's 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 Marfan's 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.

Adolescent↗
PubMed1999

The history of surgery of the thoracic aorta.

Until the late 19th century, treatment of thoracic aortic aneurysms relied on ligation of the parent vessel or introduction of foreign materials to promote coagulation or fibrosis. A major breakthrough occurred in 1888, when Rudolph Matas reported an internal repair technique known as endoaneurysmorrhaphy. In this approach, the clot was excised from the aneurysmal sac, and the orifices of the arteries that entered the sac were sutured from within, reestablishing continuous blood flow. At the beginning of the 20th century, Alexis Carrel and Charles Guthrie began to lay the foundation for modern vascular anastomotic techniques. Although isolated successes were reported, optimal treatment of thoracic aortic disease awaited the development of reliable synthetic grafts in the 1950s and 1960s. During the past 15 years, the treatment goal has reverted to endoaneurysmorrhaphy, involving the use of a suitable graft to restore aortic continuity.

Aortic Dissection↗
PubMed1999

Lowering the hemoglobin threshold for transfusion in coronary artery bypass procedures: effect on patient outcome.

BACKGROUND: There is controversy regarding the application of transfusion triggers in cardiac surgery. The goal of this study was to determine if lowering the hemoglobin threshold for red cell (RBC) transfusion to 8 g per dL after coronary artery bypass graft surgery would reduce blood use without adversely affecting patient outcome. STUDY DESIGN AND METHODS: Consecutive patients (n = 428) undergoing elective primary coronary artery bypass graft surgery were randomly assigned to two groups: study patients (n = 212) received RBC transfusions in the postoperative period if the Hb level was < 8 g per dL or if predetermined clinical conditions required RBC support, and control patients (n = 216) were treated according to individual physician's orders (hemoglobin levels < 9 g/dL as the institutional guideline). Multiple demographic, procedure-related, transfusion, laboratory, and outcome data were analyzed. Questionnaires were administered for patient self-assessment of fatigue and anemia. RESULTS: Preoperative and operative clinical characteristics, as well as the intraoperative transfusion rate, were similar for both groups. There was a significant difference between the postoperative RBC transfusion rates in study (0.9 +/- 1.5 RBC units) and control (1.4 +/- 1.8 RBC units) groups (p = 0.005). There was no difference in clinical outcome, including morbidity and mortality rates, in the two groups; group scores for self-assessment of fatigue and anemia were also similar. CONCLUSIONS: A lower Hb threshold of 8 g per dL does not adversely affect patient outcome. Moreover, RBC resources can be saved without increased risk to the patient.

Aged↗
PubMed1999

Selective hypothermia in repair of aneurysms of the descending aorta.

Since 1991, we have used a simple, single-clamp technique with open distal anastomosis to repair aneurysms of the descending aorta. To enhance the results of the single-clamp technique in a recent high-risk patient, we used selective hypothermia, cooling primarily the tissues and organs supplied by the aorta and tributaries distal to the left subclavian artery. This preliminary report describes the technique and gives the rationale for its use.

Aged↗
PubMed1998

Concomitant occlusive disease of the coronary arteries and great vessels.

BACKGROUND: Although an increasing number of elderly and high-risk patients, including those with generalized atherosclerosis, are undergoing coronary revascularization, few reports exist regarding the management of patients who have both occlusive disease of the great vessels and coronary artery disease. METHODS: Between 1972 and 1996, 31 consecutive patients (mean age, 56.5 years; 74% men) with multivessel coronary artery disease and symptomatic occlusive disease of the great vessels (25 single-vessel, 80.6%; 6 multiple-vessel, 19.4%) had 40 great vessels reconstructed by transthoracic bypass (n = 17, 42.5%), transthoracic endarterectomy (n = 8, 20%), or extrathoracic bypass (n = 15, 37.5%). All patients had simultaneous coronary artery bypass grafting (mean, 2.6 grafts per patient), and 8 patients had 10 distal carotid bifurcation endarterectomies (6 staged, 4 simultaneous). RESULTS: The early primary patency rate was 100%, and symptoms resolved completely in all 31 patients. There was 1 in-hospital death (3.2%) in a patient who had a respiratory arrest 11 days after operation. Perioperative morbidity included two myocardial infarctions (6.5%) and one opposite-hemisphere, embolic stroke (3.2%). Long-term follow-up of the 30 survivors (167.4 patient-years; mean, 5.6 years per patient) documented 5- and 10-year actuarial survival rates of 88.6% and 60.4%, respectively, with a 100% late brachiocephalic primary patency rate. Ten-year actuarial rates of freedom from the following events were as follows: death, 60.4%; myocardial infarction, 82.5%; stroke, 90.9%; percutaneous transluminal coronary angioplasty or redo coronary artery bypass grafting, 95.2%; and vascular operation or amputation, 78.4%. CONCLUSIONS: Depending on the anatomic distribution of the disease, an integrated approach to great vessel reconstruction that incorporated transthoracic and extrathoracic approaches and techniques of endarterectomy and bypass resulted in few adverse outcomes and excellent long-term patency. Simultaneous revascularization of the great vessels and coronary arteries can produce immediate and long-term, symptom-free outcome with acceptably low operative risk.

Aged↗
PubMed1998

Transmyocardial laser revascularization in allograft coronary artery disease.

We used transmyocardial laser revascularization to treat accelerated cardiac allograft atherosclerosis in 2 patients. One patient received transmyocardial laser revascularization as sole therapy, the other as an adjunct to coronary artery bypass grafting. The systolic function improved in both patients, although the patient who had adjunctive transmyocardial laser revascularization died of systemic infection and renal failure on postoperative day 55. The second patient is alive and well 1 1/2 years after the laser procedure. We discuss 4 other patients who received transmyocardial laser revascularization treatment elsewhere in the United States. Transmyocardial laser revascularization has the potential to become important in the treatment of transplant atherosclerosis. Randomized clinical trials are warranted to assess the efficacy of transmyocardial laser revascularization in this setting.

Coronary Artery Bypass↗
PubMed1998

Minimally invasive valve surgery versus the conventional approach.

As a result of reports touting the effectiveness of minimally invasive valve operations, many cardiovascular surgeons and their patients are beginning to believe that smaller incisions are always better. According to its proponents, the minimally invasive approach results in less pain, a faster recovery, and a more satisfactory cosmetic result. Proponents also believe that the operation can be done safely and effectively at a lower cost than traditional surgical approaches. This may not be the case, however, and additional prospective studies must be done before firm conclusions can be drawn. For example, cardiopulmonary bypass, myocardial ischemia, and overall operative times are significantly longer (40% or more) for minimally invasive surgical procedures. Morbidity and mortality rates do not appear to be decreased, the length of hospital stay varies by only 1 or 2 days, and patients do not necessarily report less postoperative pain. When the conventional technique is used, the operation can be performed precisely and expeditiously. Should complications occur, the surgeon will have direct access to the heart. The cost of a conventional procedure should not be much more than that of a minimally invasive procedure, and in some instances it may even be less-particularly when the less invasive procedure significantly extends the operating room time or requires additional monitors or costly disposables.

Cardiac Surgical Procedures↗
PubMed1998

Postinfarction ventricular septal rupture.

Postinfarction ventricular septal rupture is an uncommon but serious complication of acute myocardial infarction. Although I have tried various methods for repairing postinfarction septal defects, I recently began to use an exclusion technique, which is an extension of the intracavitary repair method that I use to treat ventricular aneurysms. This exclusion technique yields satisfactory results (early mortality rate, 36.4%), even in patients in severe cardiogenic shock.

Animals↗
PubMed1998

Single-clamp repair of aneurysms of the descending thoracic aorta.

Ischemic injury of the spinal cord remains a serious threat during the surgical treatment of aneurysms of the descending and thoracoabdominal aorta. Time is the critical factor in preventing spinal cord injury. The author uses a single-clamp technique that is simple and limits distal dissection, heparin dosage, and cross-clamp time, thus reducing the risk of paraplegia.

Aortic Aneurysm, Thoracic↗
PubMed1998

Transmyocardial laser revascularization. Does it have a role in the treatment of ischemic heart disease?

Transmyocardial laser revascularization, with or without coronary artery bypass grafting, is an alternative modality for complete revascularization in selected patients with coronary artery disease. Arguably, this modality works by shunting left ventricular blood directly into the ischemic myocardium via laser-mediated transmural channels. In clinical trials, drilling of laser channels has been strongly correlated with long-term improvement of angina, but a causal relationship has not yet been documented. For now, the usefulness of transmyocardial laser revascularization and the nature of its mechanism remain controversial. Some researchers question the existence of myocardial sinusoids altogether. Others question the physiologic possibility of moving blood from the left ventricular cavity into the myocardium against a pressure gradient. Further questions concern the possible routes through which the additional blood gains access to the myocardium; the difficulty of objectively documenting improved myocardial perfusion after transmyocardial laser revascularization; and the nature of the mechanism responsible for the observed clinical benefit. This article examines the different aspects of this controversy and discusses the current status of transmyocardial laser revascularization, as well as possible future directions.

Cardiac Output↗
PubMed1998

Limited-access coronary artery bypass grafting. The Texas Heart Institute experience.

Limited-access coronary artery bypass grafting, without the aid of cardiopulmonary bypass, is being performed with increased frequency, but its indications are not well defined. To determine the outcome of, and indications for, this procedure, we analyzed our experience with limited-access coronary artery bypass grafting. Between February 1996 and June 1998, 84 patients underwent limited-access coronary artery bypass grafting at our institution. We retrospectively divided these patients into 2 groups: a high-risk group with complex disease and multiple comorbidities (n = 56), and a low-risk group with uncomplicated disease (n = 28). There were 2 perioperative deaths (2%), and both of them occurred in high-risk cases. Early and late complications included myocardial infarction (2 cases), recurrent angina necessitating revascularization (2 cases), and multisystem dysfunction (1 case). Compared with conventional bypass grafting, limited-access coronary artery bypass grafting offered a smaller skin incision, fewer arrhythmias, less blood loss, less need for inotropic drugs, shorter hospitalization, lower cost, and quicker recovery time. Limited-access coronary artery bypass grafting might have a role in treating high-risk patients who have complex disease and require single-vessel bypass. Anastomosis can be challenging, however, if the target coronary artery is small, calcific, or intramyocardial. Moreover, the long-term results are unknown. Therefore, nonselective use of limited-access coronary artery bypass grafting is unjustified.

Aged↗