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Accumulated evidence indicates that fresh aortic valve homografts function longer than preserved grafts. Thus it becomes important to assess the viability of fresh homografts on a quantitative basis. Recently, we have used autoradiography in addition to tissue culture to determine the viability of fresh aortic and pulmonary valve homografts. The uptake of thymidine was gradually reduced to 50% after 18 days of preservation in a balanced salt solution with antibiotics and the uptake was reduced to 21% in 63 days. We think that a nutrient medium is necessary if longer viability is to be obtained.

The surgical approach to myocardial revascularization has been undertaken on the same basis as in peripheral vascular surgery. Aorta to coronary saphenous vein bypass has been found to be one of the best methods of providing immediate augmentation of coronary blood flow. Thirty-eight patients have been operated upon. The hospital mortality was 5.3% and the total mortality has been 13.2% in a follow-up extending one month to two years. Among the survivors, 90% had excellent initial results with complete disappearance of symptoms and marked improvement in exercise tolerance. The authors advocate the saphenous vein bypass as the procedure of choice for elective coronary revascularization.

We have analysed the bacteraemias occurring before discharge from hospital in patients subjected to open-heart surgery. The overall incidence was 2·7%. The predominant organisms at first were staphylococci and streptococci, but in the later years of the study almost all positive blood cultures were due to Gram-negative bacilli. Short-term prophylactic antibiotics were used throughout. Eleven of the 12 Gram-positive bacteraemias occurred after the period of antibiotic prophylaxis; eight of the patients had endocarditis and a further three had serious wound infections. Most of the 32 Gram-negative bacillaemias occurred while antibiotics were being given. Some were transient phenomena in well patients; others were associated with terminal states. Infection was a major cause of death in four patients, however, and two patients had endocarditis. Serratia, providence, hafnia, and citrobacter were all identified as well as the more usual escherichia, klebsiella, and pseudomonas. We discuss the possible origins and management of these bacteraemias.

Between April 1969 and December 1970, 201 patients underwent 262 valve replacements with frame-mounted autologous fascia lata valves in the aortic, mitral, and/or tricuspid positions at the National Heart Hospital. A single fascia lata valve was inserted in 146 patients and multi-valve replacement was performed in 55 instances. Hospital and late mortality are comparable with that following other procedures of heart valve replacement. One hundred and fifty-four patients with 193 fascia lata valves were available for follow-up. A retrospective analysis of this method of valve replacement has been undertaken to assess the suitability of fascia lata as a heart valve substitute as well as the clinical results achieved by this method of valve replacement.

A case of an acquired left ventricular-right atrial fistula complicating Starr-Edwards replacement of a non-calcific mitral valve is reported. Emphasis is placed on the diagnostic methods and the anatomical relationship of the mitral valve to the atrioventricular septum. Surgical repair is advocated as soon as this complication of mitral valve replacement is discovered.

A case of chronic aortic to pulmonary artery traumatic fistula is presented and the surgical repair is detailed. Closure through the aorta is recommended; this approach provides a dry operative field and avoids the need for dissection of adhesions around the fistulous tract. Fistulae of this type are not common and the pertinent literature is reviewed.

The surgical treatment of 14 patients with annulo-aortic ectasia and aortic valve regurgitation secondary to cystic medial necrosis is presented. Resection of the aneurysm and replacement with a tubular graft, and aortic valve replacement with a rigid prosthesis, are advocated for definitive treatment. Eighty-six per cent of the patients survive and are doing well six months to four and a half years after surgery.

Ten cases of serum hepatitis occurring after open-heart surgery at the National Heart Hospital, London are reported. The incidence seemed to be rising and was at least 2% before antigen-screened blood became available. Investigation of 135 patients for the presence of Australia antigen and antibody showed that five (3·7%) had responses to exposure to the infective agent. All were and remained clinically well, but such patients may constitute a source of infection. Since tested blood has been used no hepatitis cases have been recognized.

The present study was undertaken to find an antibiotic mixture which would rapidly and completely sterilize a heavily contaminated allograft heart valve without reducing its viability. Two different antibiotic combinations were used; formula A was used for 66 valves and formula B for 60 valves. Viability of the valves was assessed by autoradiography and tissue culture, and was found to be similar in both formulae. Formula B proved more effective; all valves were sterile after 24 hours9 exposure to the antibiotics and remained so thereafter. The period of viability was greatly extended when a nutrient medium was used to store the valves.