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Background Infected false femoral aneurysm (IFFA) is a life-threatening complication of intravenous drug abuse and presents a difficult management problem for the vascular surgeon. Controversy exists regarding the best management. The choice lies between ligation and excision with immediate revascularization, and ligation and excision with observation; reconstruction is reserved for critical ischaemia. Methods After disappointing results with the former method it was decided to perform ligation and excision with observation as the initial treatment of IFFA. A 9-year experience of 28 patients treated at this hospital is reviewed. Results In 26 cases of primary ligation and excision of an IFFA there were no amputations and patients described claudication only in follow-up. In two cases of a second IFFA in the same limb, repeat ligation and excision resulted in one viable limb with claudication only and one above-knee amputation for non-viability. At 9-year follow-up (80 per cent complete), over 90 per cent of the patients were still drug abusers and therefore not suitable for revascularization. There were two deaths, both of which were drug related. Conclusion Ligation and excision of an IFFA is simple, effective and safe, and is the most appropriate method of dealing with these challenging patients.

There is accumulating evidence that thrombosis contributes to peripheral arterial disease, and that antithrombotic therapy should be considered at all symptomatic stages. In claudication, antiplatelet therapy is indicated in addition to lifestyle advice and sometimes surgery or angioplasty; the place of thrombolysis is unproven. In chronic critical limb ischaemia, prophylaxis of venous thromboembolism by low-dose heparin is indicated during hospitalisation, as is long-term antiplatelet therapy; local thrombolysis or systemic prostanoid infusions are increasingly used. In acute critical limb ischaemia, full dose heparinisation is followed by thromboembolectomy, local thrombolysis, angioplasty and surgery as appropriate. Antiplatelet therapy and/or anticoagulation are employed following such procedures, according to risk factors in the individual patient. Collaboration between vascular surgeons, radiologists and physicians is important in comprehensive patient care.

Answers on p 666. A 29 year old pregnant woman, at 35 weeks' gestation, was admitted with a three day history of a painful left thigh and calf which was exacerbated by walking. She also complained of paraesthesiae, muscle weakness, and coldness of the left foot which at times became cyanosed. These …

Seventy consecutive patients with infrainguinal bypass grafts entered a 1-year graft surveillance programme involving colour duplex scanning, direct graft insonation and computer-assisted impedance analysis. Graft patients with a positive duplex scan, high frequencies on graft insonation or an impedance value above 0.50 subsequently underwent arteriography. Sixteen patients were excluded before the initial surveillance visit. The 54 remaining patients with grafts (30 vein, 24 synthetic) underwent a total of 137 surveillance visits, with 21 grafts confirmed to be ‘at risk’. The sensitivity of an impedance value above 0.55 in identifying these grafts was 86 per cent, rising to 95 per cent when combined with graft insonation. Duplex scanning did not identify any abnormalities in 11 grafts that were either shown by arteriography to be ‘at risk’ or occluded before arteriography. Impedance measurement and graft insonation are simple screening techniques with a high sensitivity (when combined), which identify ‘at risk’ infrainguinal grafts. Positive graft insonation or an impedance value over 0.55 will identify all ‘at risk’ vein grafts while minimizing the number of unnecessary arteriograms.

Fifty-five consecutive patients, with colorectal metastases confined to the liver, underwent surgical placement of a hepatic artery catheter. At angiography, abnormal hepatic arterial anatomy was present in 33% of patients. In the majority of patients, the hepatic artery catheter was inserted in the conventional manner. In eleven patients with unusual arterial anatomy, a saphenous vein graft was used to create a conduit for the catheter. Satisfactory perfusion was obtained in all patients.

Eight cases of aortocaval fistula are described. In all of them operation was performed with repair of the fistula and replacement of the aneurysm by a prosthetic graft. In seven cases the cause was rupture of an atherosclerotic aneurysm but one case followed rupture of a re-entrant dissecting aortic aneurysm. A fistula is most easily recognized by the sensation of a palpable thrill over the aorta during operation together with systemic venous congestion and a high central venous pressure before aortic clamps are applied. Diagnosis of the fistula before surgery or its recognition during operation and before opening the aorta usually leads to a successful outcome.

Cutaneous blood flow in the foot was assessed by 125I iodoantipyrine clearance in patients with peripheral vascular disease. Three groups were studied: group (a) consisted of 10 controls, Group (b) of 10 patients who had arterial reconstruction, and Group (c) of 10 patients having lumbar sympathectomy. Skin blood flow remained constant in the control patients. In Group (b) arterial reconstruction increased skin blood flow from mean 4.3 ml/100g/min to a mean of 14.9 ml/100g/min (p less than 0.001). In group (c) skin blood flow did not significantly change from a mean preoperative value of 7.6 ml/100g/min to a mean postoperative value of 8.1 (ml/100g/min). These results suggest that lumbar sympathectomy does not affect nutritional blood flow.

Blood flow in the superficial liver tissue was measured by recording the clearance rate of the β emissions of 85 Kr following its injection into the portal vein. The flow values calculated from monoexponential clearance curves were compared to portal venous blood flow simultaneously recorded with a calibrated electromagnetic flow probe in six dogs whose hepatic artery had been ligated. The liver: blood partition coefficient of 85 Kr was measured in these dogs and was found to be 0.91. There was a close correlation ( r = 0.95) between the blood flow values obtained from the two techniques over a wide range of flow values. This shows that measurement of liver blood flow in the surface layers of the liver using the 85 Kr clearance method provides a true reflection of the blood flow in the liver tissue as a whole.

Recent reports by Starzl [T. E. Starzl], A. Francavilla, C. G. Halgrimson, F. R. Francavilla, K. A. Porter, T. H. Brown, and C. W. Putman, Surg. Gynecol. Obstet.137: 179, 1973; T. E. Starzl, K. A. Porter, N. Kashiwagi, I. Y. Lee, W. J. I. Russell, and C. W. Putnam, Surg. Gynecol. Obstet.140: 549, 1975] have described a splanchnic flow division experiment in the dog, in which portal blood from the upper gastrointestinal tract (including pancreas) was directed to the right lobes of the liver, while the left lobes received blood exclusively from the intestines via a vein graft. It was shown that the right lobes increased in weight, whereas the left lobes atrophied, and it was concluded that portal blood contains hepatotrophic factors of pancreatic origin. In the present experiments, the possible existence of differences in blood flow in the two hepatic segments was examined as an alternative explanation for the changes observed. Tissue perfusion was measured by 85Kr clearance in the right and left hepatic lobes of five dogs 60 days after splanchnic division, and it was found that there was no difference between the flows through the two segments, while changes in liver weight similar to those of the previous workers were seen. The results therefore confirm the observations of Starzl that the size of the liver depends on its portal circulation, and is mainly related to the quality of the blood that it supplies to the liver rather than on quantity of flow.

The placement of catheters for hepatic arterial perfusion in patients with metastatic hepatic disease and unusual vascular anatomy can be problematic. Many options have been previously described, none of them entirely satisfactory or without risk. We have described herein the use of a saphenous vein graft that is anastomosed to the aberrant hepatic artery as a versatile catheter conduit, which is quick, easy and safe to construct.

In a period of seven years, 120 revision operations were performed for complications occurring in 1,284 aortic bifurcation grafts. The reasons cited for operation were: graft limb occlusion or stenosis in 82 patients, false aneurysm in 28 and symptomatic disease distal to the graft in ten. Preferred operations were replacement of the graft and distal anastomosis for occlusion or complete reconstruction of the anastomosis with fresh graft material for a false aneurysm. The operative mortality rate was 1.6 per cent and three patients (2.5 per cent) underwent amputation after multiple procedures. This group of 120 patients with complications was compared with a random sample of 300 patients with aortic bifurcation grafts with no complications. In the group with complications, there were significantly fewer patients who underwent sympathectomy or profundaplasty and significantly more with an iliac rather than a femoral artery graft insertion. Those patients who had graft complications develop also had a significantly higher hematocrit level at the first procedure.

A method for the measurement of liver blood flow (LBF) in rats has been developed by recording the clearance of 85Kr from the liver after injection of a solution of the gas into the portal vein. This technique provides a measure of tissue perfusion at a cellular level. The animal preparation was maintained in a stable haemodynamic and respiratory state for up to 4-3 h by careful fluid and anaesthetic control. Stability of the model was reflected by relative constancy of the LBF measured throughout the experiment in all of the animals studied. The mean LBF determined in six rats was 2-41+/-(s.d.) 0-50 ml/g/min.

Previous animal studies of liver blood flow (LBF) with the radioactive inert gas clearance technique have shown that the clearance rate of gas after its injection into the hepatic artery (HA) is slower than following injection into the portal vein (PV). Separation of HA and PV blood in the hepatic sinusoids has been suggested as an explanation. In the present study, alternate bolus injections of 85 Kr were made into the PV and HA in two groups of dogs. In the first group, injection into the HA resulted in calculated LBF values 31% lower than those derived from PV injections. The second group was subjected to a dissection which isolated the liver from local recirculation of 85 Kr from HA to PV via collateral vessels. In this group, calculated LBF values were identical after PV and HA injections. This finding supports the concept that the hepatic parenchyma is perfused by mixed HA and PV blood.

Liver tissue perfusion can be measured by analysis of the clearance of the radioactive inert gases Xenon133 and Krypton85 from the liver. The technique commonly gives rise to multiexponential clearance curves which have previously been quoted as evidence of complex intrahepatic blood flow patterns. The clearance of 133Xe from the canine liver was studied in 17 dogs and by screening out extrahepatic radioactivity it was found that the true intrahepatic clearance is monoexponential. The slower components seen in the multiexponential curve recorded without screening represent 133Xe in tissue other than the liver and much of this activity was shown to originate from 133Xe which accumulates in the stomach and intestines. These findings simplify the interpretation of inert gas clearance curves in the measurement of liver blood flow and therefore encourage further application of the technique in both experimental and clinical situations.

The changes in liver haemodynamics following partial hepatectomy (PH) were studied using an 85Kr clearance technique to measure perfusion in the livers of rats before and after both PH and sham operations. Post-operative measurements were made for 8 h following operation and also at 21 and 35 h, when uptake of tritiated thymidine into DNA is maximal in regenerating rat liver. Sham operation did not influence hepatic perfusion, arterial pressure or portal pressure. PH induced an early increase in perfusion of 293% in spite of a decrease in arterial blood pressure during the initial 4 h. The increase in perfusion lasted at least 8 h, had returned to normal values by 35 h, and was not explained solely by an observed elevation of portal pressure of 50% which returned to normal 5 h postoperatively. The total volume flow to the liver remnant after PH, however, was essentially the same as the flow to the liver before operation.

The clearance from the surface of the liver of krypton 85 following its injection into the portal vein was measured in 10 patients. Six control patients (i.e. those not suffering from portal hypertension) averaged flow values of 142 ml per 100 g liver weight per min. A repeat flow estimation in these patients was not significantly different. Four patients with portal hypertension were studied. In 2 with congenital hepatic fibrosis the portal vein was temporarily occluded to allow prediction of the degree of hepatic perfusion likely to be achieved by the hepatic artery alone after portal deviation. The flow after portal venous clamping was unaffected in one of these cases but reduced by 45 per cent in the other. In a patient undergoing a Warren distal splenorenal shunt there was no change in flow after the procedure. If measurements are performed before and during temporary portal vein occlusion, an assessment of the flow reduction to be expected after a shunt procedure can be made. We suggest that a knowledge of liver tissue perfusion might influence the choice of operative procedure.