The role of coronary artery disease in complications of abdominal aortic aneurysm surgery.

Coronary artery disease (CAD) is a major cause of morbidity and mortality after elective surgical repair of abdominal aortic aneurysm (AAA). The aim of this study was to determine the relationship between the extent of CAD observed in coronary angiograms (more than 50% stenosis) and the frequency of postoperative myocardial ischemic complications in a consecutive series of 84 patients who underwent elective AAA repair. Ninety-four percent of the patients with clinical evidence of CAD had significant disease as observed in coronary angiograms and eight patients had left main CAD. Seventy-two patients underwent AAA repair with a mortality rate of 1.4%; five patients had preliminary myocardial revascularization, and AAA surgery was not recommended for four patients because of severe cardiac disease. Postoperative myocardial ischemic complications occurred in 13.4% of the patients who had undergone surgery--almost exclusively in patients with clinical evidence of CAD. Both myocardial ischemia and preoperative intervention were more frequent in patients with double- or triple-vessel disease than in patients with less extensive disease. Patients with symptoms and with double- or triple-vessel CAD have a high risk of developing myocardial ischemia after AAA surgery. Preliminary myocardial revascularization may be beneficial in this group of patients.

The use of regional, low dose streptokinase in recently thrombosed arterial grafts.

Between August 1983 and January 1985, 20 patients aged 33-77 years, with occluded lower limb bypass grafts, were on 23 occasions treated with streptokinase via intra-arterial infusion. Streptokinase (5000 units/h) was effective in clearing occluded grafts in 15 patients on 16 occasions. The median duration of occlusion in these patients was 5 days and the median duration of streptokinase infusions was 24 h. Completion angiography following streptokinase thrombolysis revealed five graft stenoses and 12 outflow stenoses or occlusions. In two grafts no cause for graft failure could be identified. These results permitted the surgeon to make an accurate pre-operative assessment of the definitive therapy required to ensure graft patency.

Long term follow-up of patients following successful selective and non-selective portasystemic shunt surgery.

The long term morbidity and mortality of two consecutive groups of patients undergoing successful shunt surgery for bleeding oesophageal varices has been studied. Twenty-seven patients with a non-selective shunt in the form of a mesocaval Dacron 'H' graft and 21 patients with selective variceal decompression via a distal lienorenal shunt, all of whom had a patent shunt on discharge from hospital, were included in the study. Shunt associated encephalopathy was documented in 77% of the patients following mesocaval shunts and only 19% of patients following distal lienorenal surgery. Other postoperative morbidity was largely related to problems with the synthetic Dacron graft. Late shunt blockage, often resulting in recurrent variceal bleeding, was documented in 25% of these patients and shunt infection was responsible for complicating fatal disseminated sepsis in 18.5%. Long term survival, as assessed by life table analysis, following distal lienorenal shunt surgery was consistently better than that following mesocaval shunts. This was largely due to specific problems which could be directly related to the synthetic nature of the Dacron graft. It is concluded that the mesocaval Dacron interposition graft carries the potentially lethal long term complications of shunt blockage and infection rendering it unsuitable as a portasystemic shunt. Provided that successful surgery can be performed the distal lienorenal shunt may be a more appropriate alternative due to its reduced shunt related morbidity and, possibly, mortality.

Delayed-onset heparin-induced thrombocytopenia. A potentially malignant syndrome.

Delayed-onset thrombocytopenia developed in 12 patients while they were receiving either prophylactic or therapeutic heparin. Five of the patients had thrombocytopenia alone, and seven had thromboembolic complications which contributed to the death of one patient. These complications included deep venous thrombosis (four patients), pulmonary embolism (three patients), myocardial infarction (one patient), sagittal sinus thrombosis (one patient), and femoral artery occlusion (one patient). The diagnosis of heparin-induced thrombocytopenia was delayed for between one and 13 days after the initial complicating event. All patients had heparin-dependent platelet-aggregating factor in their plasma. The characteristics of the heparin-dependent platelet-aggregating reaction were the same in all patients, but the nadir of thrombocytopenia was lower in patients with delayed-onset heparin-induced thrombocytopenia and complicating thromboembolism. These findings highlight the necessity for early recognition of this syndrome and for the prompt withdrawal of heparin to prevent considerable patient morbidity.

The distal lienorenal shunt: perioperative experience with 30 patients.

During the past 51/2 years, thirty consecutive and unselected patients who bled from oesophageal varices underwent distal lienorenal shunt surgery. Eight deaths occurred in the immediate postoperative period. Three of nine emergency patients died because of continued bleeding and, of the five elective patients who died, four were largely the result of technical problems encountered at surgery. In the immediate postoperative period variceal bleeding recurred in five of eight emergency patients despite shunt patency. This did not occur in the elective group. Shunt blockage was relatively common compared to that following conventional porta-systemic shunt surgery; being documented in five of the 24 patients in whom patency was assessed. No clinical, biochemical or histological criteria were identified as predictors of outcome. In particular, the presence of preoperative ascites gave no indication of postoperative problems. However, if ascites developed in the immediate postoperative period, it was a major management problem in 50% of patients. In conclusion, the distal lienorenal shunt has a high perioperative mortality, is commonly complicated by shunt thrombosis and, in the emergency situation, often fails to control bleeding. The technical difficulties encountered at surgery appear largely responsible for the early morbidity and mortality.

Low dose heparin in the prevention of deep-vein thromboses in patients with acute myocardial infarction.

Patients with acute myocardial infarction of less than 48 hours duration were randomized into three groups. The "fully anticoagulated" group received heparin by intravenous infusion and warfarin sodium to maintain a whole blood clotting time of 30 to 90 minutes and a prothrombin index of 10% to 35%. The "low dose" heparin group received 500 units by intravenous infusion every 12 hours. The control group received no anticoagulants. The radioactive fibrinogen test was used to diagnose the presence of leg vein thromboses. The control group had an incidence of venous thrombosis of 29.7% compared with 13.9% in the low dose group and 11.3% in the fully anticoagulated group. Patients in the control group who had cardiac failure had a significantly higher incidence of venous thromboses (71.4%) when compared with patients not in failure (20.0%). In the two treatment groups no significant difference was observed in patients with and without cardiac failure. Patients with cardiac failure complicating an acute myocardial infarction have a high incidence of venous thromboses. Anticoagulants significantly reduce this incidence and low dose intravenous heparin is as efficacious as full anticoagulation.

The effect of prophylactic proteinase inhibitor therapy on post-traumatic pulmonary insufficiency and platelet counts.

In a prospective double blind clinical study of 70 patients with bony trauma and shock, 35 patients were allocated into each group receiving either a placebo or Aprotinin. In both groups there was a high incidence of pulmonary insufficiency and thrombocytopaenia. In the placebo group there was a higher incidence of pulmonary insufficiency, but not its severity, with greater volumes of blood transufsion and the most severe form occurred only after decompensated shock. Thrombocytopaenia showed a similar pattern in all patients from both groups falling to a mean minimum on the 2nd day and rising thereafter. In the placebo group counts were lower in those with decompensated shock, and the fall was more profound, rapid and earlier in patients developing severe pulmonary insufficiency. Counts of less than 100,000 on the first day were associated with a high probability of severe pulmonary insufficiency subsequently occurring and this finding was not associated with greater volumes of blood transfusion. In those patients receiving Aprotinin, the subsequent incidence of severity of pulmonary insufficiency was less and not associated with increased volumes of blood transfusion. The platelet counts were not lower in decompensated shock and there was a more rapid rise from the minimum level.

Arterial reconstruction extending below the popliteal bifurcation.

Results are reported for 172 anastomoses below the popliteal artery in patients almost exclusively suffering from severe distal ischaemia with an in-hospital mortality of 7.6 per cent. The patency rate in survivors was 83 per cent on discharge and 39 per cent at 3 years. There were 37 major amputations following 172 operations and 15 following 47 operations on diabetics. As most of the patients would have lost their limbs if arterial repair was not undertaken this constitutes a considerable salvage rate. Diabetes mellitus does not appear to influence the results infavourably, so patients suffering from this disease should be considered for operation.

Pulmonary embolism secondary to anomalies of deep venous system of the leg.

Two cases of recurrent pulmonary emboli secondary to thrombosis in anomalies of the deep veins of the lower limb are presented. In both cases the source of emboli was not evident clinically, and it was only after venography that the venous anomalies were discovered, both being confined to one limb and amenable to surgical intervention. Such anomalies have not previously been reported as sources of venous thromboembolism in adults. The importance of venography in establishing the source of pulmonary emboli, especially when recurrent, is stressed.

The mesocaval "H" graft: experience with 22 cases.

During the past 32 months, 22 consecutive unselected patients who had bled from oesophageal varices have undergone mesocaval "H" graft operations. There have been nine deaths, three in the early and six in the late postoperative periods. Two deaths were the result of bleeding complicating severe primary fibrinolysis and three were due to disseminated sepsis, one originating from an infected shunt. Continued alcohol intake may have contributed to five of the late deaths. Ten of the 19 patients who left hospital developed some degree of hepatic encephalopathy easily controlled by diet and medical therapy. However, in one case the development of grade IV coma necessitated ligation of the shunt to reverse the coma. Patency of the shunt was demonstrated in all but one patient. Recurrence of bleeding occurred only in this patient and the one in whom the shunt was ligated. Although the operation had a comparatively low operative mortality, the long-term mobidity and mortality were no better than those of the more conventional portacaval anastomosis.