Seven hundred and twenty one abdominal aortic aneurysms were treated between 1960 and 1985. Twenty one of these (2.9%) were complicated by the development of a spontaneous primary fistula, 16 (2.2%) into the vena cava or iliac veins and 5 (0.7%) into the duodenum. A correct preoperative diagnosis was made in only four instances, two aorto-caval and two aorto-duodenal fistulae. Hospital mortality was 44% for aorto-caval and 60% for aorto-duodenal fistulae. Despite the lack of a precise preoperative diagnosis in the majority of cases, the prognosis for aorto-caval fistula remained comparable to that for patients undergoing emergency surgery for uncomplicated ruptured aortic aneurysms. The mortality of spontaneous aorto-duodenal fistulae was appreciably higher and the aneurysmal contents of 4 out of these 5 cases had positive bacterial cultures.

INTRODUCTION T&/e/. Cause and site of knee injury ALTHOUGH severe knee trauma causing popliteal artery injury is uncommon in civilian practice, it does occur and these lesions tend to be more commonly associated with dislocations than fractures around the knee joint (Green and Allen, 1977). In this series of 23 cases, 8 limbs were eventually amputated as a result of three main factors occurring singly or in combination. These three factors were delay in the recognition of arterial injury, the presence of multiple limb fractures, or subsequent graft thrombosis and sepsis. Three additional patients had appreciable residual limb disabilities, Successful management depends on early recognition and rapid institution of appropriate treatment, since timely arterial reconstruction can and usually does prevent eventual limb amputation. The cause and site of knee injury is represented in Table I. Cause (no.)

The results of 329 consecutive autogenous vein grafts carried out between January 1962 and June 1973 have been reviewed. The 5- and 10-year mortality rates were 14.6 per cent and 18.7 per cent respectively. The corresponding patency rates were 70 per cent at 5 years and 34 per cent at 10 years, the lowest patency (27.8 per cent) occurring in below-knee anastomoses with grafts of 5 mm or less in diameter. As other have noted, the state of the popliteal--tibial run-off vessels had a considerable influence on long term patency rates. In severely ischaemic limbs, the limb salvage rate following this operation was 77 per cent. An analysis of symptoms, associated disease and complications is presented and discussed. No valid conclusions could be made regarding the effect of lumbar sympathectomy and postoperative anticoagulants on long term patency. This review has confirmed the findings of earlier studies that a satisfactory 5-year patency rate and a gratifying limb salvage rate can be achieved with an extremely low operative mortality rate of 0.37 per cent. Despite the presence of widespread atherosclerotic arterial disease, the 5-year mortality rate is 14.6 per cent, indicating that an attempt at reconstructive surgery is usually well worth while.

Achilles tenotomy was performed on 66 limbs in 60 patients with severe intermittent claudication and the results were assessed two years later. Early improvement occurred in half of them but decreased to 17% two years postoperatively. Sympathectomy did not influence the result. The postoperative morbidity was 14%, and 21% of limbs were subsequently amputated. The late mortality in the group studied was 8%.

The outcome of 185 consecutive autogenous vein bypass grafts for femoro-popliteal occlusions carried out between January 1962 and June 1968 has been reviewed. One patient died at operation and 21 late deaths have occurred since. The overall five-year patency was 61.5%, but was much lower when the popliteal-tibial runoff arteries were diseased. Distal anastomosis of the graft to the popliteal artery below the level of the knee joint also impaired the results, and if this was performed with a graft of minimal diameter less than 5 mm. sustained patency was obtained in only a quarter of the limbs. Nevertheless, where major amputation was imminent owing to advanced ischaemia three out of four limbs were salvaged.

Herpes Simplex Encephalitis-Evans et al. account of the sytemic use of idoxuridine in the treatment of a severe D.N.A.-virus infection, herpes simplex encephalitis.The place of idoxuridine in the chemotherapy of viral encephalitis, with or without corticosteroids, must await further trial; at least the facts of this case suggest that it may have antiviral action within the central nervous system.As the chemotherapy of virus disease.advances drugs are likely to be developed which are type-specific.Early identifica- tion of virus will be important.Brain biopsy, with the technique of Blackwood and Cumings (1959), is a safe and reliable procedure, but successful isolation of virus may depend on the speed with which material reaches the laboratory.ADDENDUM.-Since this report was submitted for publication Breeden et al. (1966) have described a case of herpes simplex encephalitis in a middle-aged man who recovered after treatment by cerebral decompression and a seven-day course of idoxuridine.1 , Our thanks are due to Professor W.