The number of heart valve replacement procedures has increased over the last four decades, with >200,000 done worldwide every year. Various valve substitutes are available, and are broadly divided into biological and mechanical prostheses. Choice is dictated by multiple factors, including longevity of the valve substitute as well as patient and surgeon preference. In general, mechanical valves are used in the younger age group and require lifelong anticoagulation. Biological valves are used in older age groups and have a limited lifespan compared to mechanical valves. The design of prosthetic heart valves continues to evolve, with improved haemodynamics, longevity and durability. Mortality and morbidity associated with heart valve surgery is low. Infrequent but major complications of valve replacement include haemorrhage, thromboembolism and infection.
In a consecutive series of 436 Indian Subcontinent Asians and 1,458 Caucasians undergoing primary isolated coronary artery bypass grafting, the mortality rate was twofold higher in Asians than in Caucasians, which resulted mainly from a mortality difference between men in the 2 groups. Diabetics had a higher mortality rate than nondiabetics. and diabetes, 2.5 times more frequent in Asians than in Caucasians, was an independent predictor of death only in Asians and may in part explain the mortality difference.
Arterial embolization of a malignant tumor is extremely rare. We report an unusual case of a young adult man who presented with acute lower limb ischemia and a mass in the right lung and left atrium. These clinical manifestations were the result of metastases and embolization from a germ cell tumor and were the first indication of malignancy in this patient. The importance of appropriate investigations in the subsequent treatment is stressed.
Background: Aprotinin is a serine protease inhibitor used extensively in cardiac operations to reduce postoperative bleeding. It has also been used in trials aimed at reducing the systemic inflammatory response to cardiopulmonary bypass. It remains unclear whether the anti-inflammatory action of aprotinin is related to its general ability to suppress leukocyte activation or whether aprotinin can exercise effects during the leukocyte-endothelial cell adhesion cascade. Methods: We used intravital microscopy to study the 3 main stages of the adhesion cascade (leukocyte rolling, firm adhesion, and extravasation) within the mesenteric microcirculation of rats. This in vivo technique allows leukocyte recruitment to be viewed directly through the transparent mesentery of anesthetized animals. Results: Aprotinin, given by continuous infusion at a clinically relevant dose, exerted no effect on the rolling or firm adhesion responses toward local chemoattractant N -formyl-methyl-leucyl-phenylalanine but significantly inhibited extravasation of leukocytes (73% at 40 minutes, P =.04) into surrounding tissues. In parallel in vitro experiments, aprotinin (used at 200, 800, and 1600 kIU/mL) dose dependently inhibited neutrophil transmigration through cultured endothelial cells in response to 3 different chemoattractants: N -formyl-methyl-leucyl-phenylalanine (P <.001 at 800 and 1600 kIU/mL), interleukin 8 (P <.05 at 200 kIU/mL and P <.001 at 800 and 1600 kIU/mL), and platelet-activating factor (P <.05 at 1600 kIU/mL). Conclusions: Our studies have therefore revealed a novel anti-inflammatory mechanism of aprotinin operating at the level of leukocyte extravasation. These findings may be relevant in the prevention of systemic inflammation after cardiopulmonary bypass through the use of protease inhibitors. (J Thorac Cardiovasc Surg 2000;120:361-9)
Cardiopulmonary bypass (CPB) has improved a great deal since its first applications in the early 1950s. If improvements are to be continued, a preclinical model of CPB for small animals is desirable, mainly because of convenience of equipment and low costs. We review the different models of CPB for rats that have been designed, discuss their characteristics and points where improvements may be made. We give suggestions and requirements for a new up-to-date model that could be a useful tool in continued research on the pathophysiology and therapeutic strategies of CPB.
J Thorac Cardiovasc Surg 1999;117:620-1
Cardiopulmonary bypass is often followed by pulmonary dysfunction as assessed by measuring the alveolar-arterial oxygenation gradient, intrapulmonary shunt, degree of pulmonary edema, pulmonary compliance, and pulmonary vascular resistance. It is also regarded as a risk factor for development of acute respiratory distress syndrome. On the other hand, cardiopulmonary bypass is associated with a whole body inflammatory response, which involves activation of complement, leukocytes, and endothelial cells with secretion of cytokines, proteases, arachidonic acid metabolites, and oxygen free radicals. Leukocyte adhesion to microvascular endothelium, leukocyte extravasation, and tissue damage are the final steps. Although the inflammatory response to cardiopulmonary bypass often remains at subclinical levels, it can also lead to major organ dysfunction and multiple organ failure. This review article summarizes the recent literature on the molecular and cellular mechanisms involved in the phenomenon of pulmonary dysfunction after cardiopulmonary bypass. It also summarizes reports on the prevalence and mortality of acute respiratory distress syndrome after cardiac surgery.
BACKGROUND:Despite early reports showing a high incidence of postoperative morbidity and mortality, coronary endarterectomy continues to be used as an adjunct to coronary artery bypass grafting, particularly in diffusely diseased coronary arteries. The changing nature of patients and improvements in modern cardiac surgery call for a reevaluation of the role of coronary endarterectomy.METHODS:Data from the 56 patients, who underwent coronary endarterectomy in our institution between January 1993 and August 1996, were reviewed retrospectively and compared with a control group of 56 patients matched for age, sex, LV function, and angina class. In the endarterectomy group, there were 47 men and nine women, with a mean age of 59.6 years. The mean follow-up time was 21 months. Indications for operation were angina in 45 (80.3%), angina with signs or symptoms of cardiac failure in 3 (5.4%), and prognosis in 8 (14.3%) asymptomatic patients.RESULTS:Fifty (89%) patients had one, four (7.2%) had two, and 2 (3.6%) patients had three coronary arteries endarterectomized. Of these 64 endarterectomies, 33 (51.5%) involved the right coronary artery, 20 (31.3%) the left anterior descending artery, and 11 (17.2%) branches of the circumflex artery. There were three (5.4%) nonfatal myocardial infarctions in the endarterectomy group, but none in the control group (p>0.05). Two patients (3.6%) in the endarterectomy group, but none in the control group, died within the first 30 days (p>0.05). Actuarial survival and incidence of recurrent angina were similar in the two groups.CONCLUSIONS:In current cardiac surgical practice, coronary endarterectomy displays satisfactory rates of postoperative morbidity and medium term results in selected groups of patients.
Objective: To assess the 30-day mortality, long-term survival and freedom from reoperation following surgery for prosthetic endocarditis (PVE). Method: A retrospective analysis of data from the UK Heart Valve Registry of 322 patients who had undergone single mechanical/bioprosthetic valve replacement for PVE between 1 January 1986 and 31 December 1996, The mean age was 54.9 +/- 12.8 years and 213 (66.1%) were males. There were 170 aortic and 152 mitral valve implantations. Eighty-five (26%) of the infected valves were bioprosthetic and 237 (74%) were mechanical. Of the new prostheses implanted 53 (17%) were bioprosthetic and 269 (83%) were mechanical. Of those with infected bioprostheses, 50 (15.2%) had mechanical valves at redo surgery, whilst 219 (68.3%) of infected mechanical prostheses were re-replaced by mechanical prostheses. The follow-up was 98% complete with a total of 1084.9 patient years. Results: The 30-day mortality was 63 (19.9%; 95%CI 15.9-24.7%). There were 85 late deaths. One, 5 and 10 year survival rates were 67.1% (61.6-72.0%), 55.0% (49.0-60.7%) and 37.6% (27.9-47.2%), respectively. Age was the only significant determinant of 30-day mortality (P = 0.04). Age (P = 0.001) and explanting of infected bioprosthesis and replacement by mechanical valve (P = 0.04) determined long-term survival (P = 0.001). The incidence of re-reoperation was 9.9%. Freedom from reoperation for PVE was 88.4, 87.3 and 87.3% at 1, 5 and 10 years, respectively. Explanting of bioprosthesis and replacement by mechanical valve (P < 0.001) and reoperation within 60 days of native valve replacement (P = 0.02) were determinants of reoperation for PVE. Freedom from death or reoperation was 61.1, 50.6 and 34.2% at 1, 5 and 10 years, respectively. Age (P = 0.003), explanting of bioprosthesis and replacement by mechanical valve (P = 0.002) and the period between prosthetic re-replacement (P = 0.04) determined freedom from death or reoperation. Conclusion: Operation for PVE carries a high 30-day mortality and reduced long-term survival. There is no evidence that type of prosthesis used for re-reoperation determines survival or freedom from re-reoperation. (C) 1998 Elsevier Science B.V. All rights reserved.
Background. Little is known of time-related outcome and comparative performance of biological and mechanical prostheses following tricuspid valve replacement (TVR).Methods. A retrospective UK Heart Valve Registry study (Jan 1, 1986 to June 30, 1997) identified 425 patients who underwent TVR. Two-hundred twenty-five (52.9%) received biological and 200 (47.1%) received mechanical valves. One-hundred sixty (38%), 158, and 76 had isolated, double, and triple valve replacements, respectively. The follow-up was 96% complete with a total of 1,585 patient-years.Results. Thirty-day mortality for TVR was 17.3% (73 deaths). One-, 5-, and 10-year survival rates were 72.2%, 59.9%, and 42.9%, respectively. Year of operation (p = 0.04), age (p = 0.04), and number of valves implanted (p = 0.03) predicted overall mortality. Age (p < 0.001) and year of operation (p = 0.002) predicted overall survival. Thirty-day mortality for biological and mechanical prostheses was 18.8% and 15.6%, respectively. One-, 5-, and 10-year survival rates were 70.5%, 61.5%, and 47.7% for biological and 74.0%, 57.9%, and 33.9% for mechanical prostheses, respectively. Freedom from reoperation at 1 and 10 years was 98.7% and 97.4%. Freedom from death or reoperation was 71.2% at 1 year and 41.9% at 10 years. None of the above outcomes was significantly different between the type of valve prostheses.Conclusions. TVR carries a high 30-day mortality and a poor longer term survival. No superiority could be identified for biological or mechanical prostheses in the tricuspid position for either survival or reoperation.
With the advent of antibiotics syphilis and its complications appear to have been declining as an important cause of cardiovascular disease. We describe a patient with an unusual aorto-pulmonary communication secondary to syphilitic aortitis. The case illustrates the difficulty in defining the anatomy of this rare association preoperatively. The reason for the rarity of this manifestation is discussed and finally doubt is cast upon the assumption that cardiovascular syphilis is of only historical interest.
current knowledge of the drug. The first four introductory chapters of the book provide a review of the current concepts behind the haemostatic insult and the inflammatory response to cardiopulmonary bypass. Written in a readily digestible manner the main criticism of this section is the failure to describe the important part played by tissue factor in the revised formulation of the model of coagulation. Some information of the pharmacokinetics of the drug are reviewed in chapters 5 and 6, which are followed by a delightful chapter documenting the developmental history of the drug. Next, evidence is presented for the possible mechanisms of the haemostatic effect of aprotinin in cardiac surgery. There appears to be no progression to our knowledge in relation to this mechanism beyond the hypothesis that the haemostatic effect is due either to an
The authors, Lewis and Graham, should be congratulated in producing this comprehensive and up-to-date overview of circulatory support. The book takes the form of contributions by experts in the various fields of this growing branch of cardiac surgery. Set up in sections, the introductory chapters give a history of circulatory support followed by an explanation of the physiology of ventricular assistance and of the problems of the biomaterial-blood interface. This is followed by sections on advanced respiratory support, cardiopulmonary bypass (which is limited), shortterm and medium-term support, long-term support, biological assistance and problems in general associated with circulatory support. In this context, given the title of the book, a minor criticism might be the size of the section on biological assistance. Given the developments in biological support, a title such as ’Circulatory Support’ may have been more appropriate. The chapters are in a most readable form, providing the reader with all the essential information. Of particular value is section 7, which deals with the practical points associated with mechanical circulatory support, particularly with regards to bleeding and to coagulation, cannulation infection and optimization of flow. This is not simply a book for those about to enter the field of circulatory support, but is strongly recommended to all practising cardiac surgeons.