Search

Bypass grafting to vessels beyond the popliteal bifurcation is an established method for treating severe limb ischaemia. Failure rate is high, however, especially when prosthetic vascular substitutes have to be used. When left in situ, saphenous vein can be used down to much smaller diameters than would be possible with reversed vein. With this method, vein utilization of around 90% can be achieved with respective increases in patency and limb salvage. Our early results with 26 in situ grafts are presented. In two cases the presence of a suitable tributary of the saphenous vein allowed a 'bifurcated' or 'femorotibial' graft to be performed. All patients (17 males, nine females) were admitted with limb threatening ischaemia. Mean ankle pressure index was 0.29 (s.d. = 0.09), range 0.18-0.53. Average graft intra-operative flow rate measured 96 ml/min. Twenty grafts remain patent while six grafts have failed. In three of these failures, performed early in the series, the graft could not be made to function at the time of surgery. The mean postoperative ankle pressure index was 0.87 (s.d. = 0.19). Cumulative patency rate at 24 months is 74%. This rises to 83% if the three 'on table' failures are excluded. Five amputations were required; four as a result of graft failure and one despite a functioning graft. Four grafts clotted within 24 h but have remained patent following immediate thrombectomy. One patient required ligation of an arteriovenous fistula on the third postoperative day.

Increases in whole blood coagulability in patients undergoing abdominal surgery have been measured with the thrombelastograph. A continuous, low dose intravenous infusion of heparin has been administered in the operative period in an attempt to control these coagulability increases without increasing the risk of haemorrhage. A preliminary sub-cutaneous dose of heparin followed by a continuous infusion throughout the operation and for two hours afterwards effectively prevented the expected coagulability increase and resulted in reduction of early deep venous thrombosis incidence from 9/20 in controls to 1/19 in treated patients (p less than 0.05). The infusion has also been used in conjunction with a pre-operative test to predict the risk of deep venous thrombosis. Of 20 patients examined, 11 were designated as high risk and received an intra-operative heparin infusion and 9 predicted low risk patients received no specific prophylaxis. No venous thrombosis occurred in any patient within 48 hours of surgery.

In vitro dilution of blood with normal saline produces an increase in coagulability which can be accurately measured by the thrombelastograph. The degree to which the coagulability of an individual patient's blood is increased by such dilution appears to be directly related to that patient's risk of developing a postoperative deep venous thrombosis. In a small group of patients undergoing major abdominal surgery, a preoperative test based on the coagulability increase after in vitro saline dilution successfully predicted all those who subsequently developed a postoperative deep venous thrombosis on 125I-fibrinogen scanning.

Serum thiocyanate has shown itself to be useful in distinguishing smokers from non-smokers. Our anti-smoking attitude resulted in 12 out of 32 smokers stopping smoking during the trial. Further, our evidence suggests that a patient who says he has given up smoking entirely can probably be believed, but a claim to have reduced smoking may be less reliable.

A method is described for assessing stenosis in the aorto-iliac arterial segment using a hand-held variable capacitance pressure transducer to take objective measurements from the common femoral pulse. The aorto-iliac segments were studied in 51 arteriopaths and the common femoral pulse rise time derived. The patients also underwent an independent clinical examination. The rise time results from 88 common femoral pulses were compared with subsequent arteriographic assessment of the aorto-iliac segments, and in 67 cases with direct intra-arterial pressure measurements from the common femoral artery. A highly significant correlation coefficient was found between the common femoral pulse rise time and the degree of aorto-iliac stenosis on the arteriogram (r = 0.80). Similarly, there was good correlation between pulse rise time and the direct common femoral/radial pressure ratios (r = -0.82). The results were analysed in terms of sensitivity, specificity and diagnostic accuracy for determining greater or less than 50% stenosis on the arteriogram. Using a pulse rise time of 200 ms a sensitivity of 97%, specificity of 93% and diagnostic accuracy of 94% were obtained. This was significantly better than clinical examination which gave a diagnostic accuracy of 83% (X2 = 5.57, P less than 0.02). The results suggest that this non-invasive method of objective pulse assessment gives superior accuracy for diagnosing aorto-iliac stenotic disease. The ease of use and relative simplicity of the apparatus are advantages over more complex non-invasive techniques employing microprocessors in the analysis of blood velocity.

A treadmill exercise test is used in many vascular laboratories to measure the claudication time and the total walking time of patients with intermittent claudication. Three hundred and nine consecutive outpatients in the peripheral arterial disease clinic were assessed on the treadmill. Fifty-nine were unable to walk on it at all, and of the remaining 250 patients, 68 (27%) could manage five minutes of treadmill exercise, and 87 (35%) patients stopped for reasons other than intermittent claudication. Only 95 (38%) stopped walking within five minutes as a result of intermittent claudication. Fifty of these 95 patients were retested approximately 10 days later and the mean change from day 1 to day 2 in the claudication time and in the total walking time was calculated to establish the normal range. From these results, if a treadmill is to be used to infer any improvement, we calculate that the claudication time must increase by at least 63 seconds and the total walking time by 93 seconds. Treadmill testing for the assessment of symptoms, if it is used at all, should be used in conjunction with objective methods of assessment.

An instrument for monitoring the blood flow in skin flaps by temperature measurement is described. This compares the temperature of the flap with adjacent normal skin. An experimental assessment of the technique is presented. Although many of the problems associated with absolute temperature measurement were eliminated, the reaction to circulatory change within a flap was slow. However, with further refinement, the principle may have a place in clinical practice, especially in replantation surgery.

A technique based on reflection spectrophotometry has been tested for use as a monitor of the cutaneous circulation in experimental skin flaps. A very rapid indication was given of either arterial or venous insufficiency in a previously healthy flap. Post-operative monitoring produced characteristic traces for successful and unsuccessful free flaps. The ability of this method to discriminate between a satisfactory flap, an arterial failure, and a venous failure was highly significant (P less than 0.001).

An experimental model is described for end-to-end and end-to-side anastomosis involving rabbit femoral vessels. In this experimental situation the ultimate test of patency is transection beyond the anastomosis. Against this the micro-electromagnetic flow probe has been evaluated using 17 rabbits and 24 procedures. Likewise the directional Doppler has been evaluated with 13 rabbits involving 22 procedures. The condition of the anastomosis could always be accurately assessed by the directional Doppler but not always by the electromagnetic flow probe.

Fifteen women with claudication and increased serum thyrotrophin (TSH) were treated with L-thyroxine (25-75 micrograms). These women were selected from a group of 80 consecutive women presenting with claudication, rest pain or gangrene. One year after their TSH was normal, their progress, serum lipids and lipoproteins were compared with the 58 women with normal levels of serum TSH; the remainder were already receiving thyroxine. Non-invasive assessment showed that three of the 15 (20%) women treated with thyroxine had progression of arterial disease, two in the legs and one in the legs and coronary arteries; two women showed improvement of ankle/brachial pressure indices. There was no accelerated angina, myocardial infarction, stroke or death in this group. Fifty-six of the 58 patients with normal levels of TSH were alive at follow-up and there was progression of distal disease in 24 (43%), coronary artery disease in 6 (11%), increasing carotid stenosis in four and two complained of transient ischaemic attacks. In this group, disease progression affected 32/56 (57%) of the women and this is significantly greater than in the thyroxine treated group chi 2 (P less than 0.05). Treatment with L-thyroxine caused a significant increase in HDL-cholesterol from 1.29 +/- 0.34 to 1.45 +/- 0.49 mmol/L (P less than 0.05) and a significant decrease in cholesterol from 8.0 +/- 1.3 to 7.2 +/- 1.1 mmol/L (P less than 0.01) and apolipoprotein B from 1.23 +/- 0.20 to 1.04 +/- 0.16 g/l (P less than 0.001). Significant changes in apolipoprotein B were observed after 3 months of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Both stenosis and aneurysmal dilatation are associated with atherosclerosis of the distal aorta. As part of an investigation into factors predisposing to aneurysmal dilatation we compared the levels of acute phase proteins in patients with stenosing and aneurysmal disease. Increased levels of acute phase proteins were found in patients with abdominal aortic aneurysms compared with patients with stenosing aortic disease. In 20 aneurysm patients the C-reactive protein was 56 +/- 10 mg/l, alpha 1-proteinase inhibitor 2.5 +/- 0.13 g/l and ceruloplasmin 0.41 +/- 0.01 g/l. In 20 patients with stenosing aortic disease the C-reactive protein was 28 +/- 8 mg/l, alpha 1-proteinase inhibitor 1.65 +/- 0.11 g/l and ceruloplasmin 0.35 +/- 0.03 g/l. These results argue for the participation of an inflammatory process in the aortic wall in the pathogenesis of all aneurysms.

One hundred forty-nine consecutive patients who had peripheral arterial disease (PAD) with clinically audible asymptomatic bruits were studied. Sixty-two of these patients were age- and sex-matched with 62 PAD patients in whom no bruits were detected. The PAD was demonstrated by angiography or by the 1-minute exercise test. Clinical assessment was performed every 6 months and oculoplethysmography and carotid phonoangiography (OPG/CPA) were performed every year. Angiography and reconstructive surgery were performed only if symptoms of transient ischemic attack (TIA) or stroke occurred. Life-table analysis revealed that over a 5.5-year follow-up, 32% of 211 PAD patients were expected to die. In the control study 45% of bruit patients and 32% of control patients were expected to die (no significant difference). Myocardial infarction accounted for 59% of deaths in the bruit group compared with 28% in the control group (no significant difference). TIA occurred more commonly in the bruit group (26.5%) than in the controls (6%) (p less than 0.02). However, stroke without warning occurred in 9% of bruit patients compared with 8% of controls (no significant difference). It is concluded that for asymptomatic carotid bruit it is safe to wait for the onset of symptoms before angiography and corrective reconstructive surgery.

A new jig is described which enables the technique for abdominal aortic aneurysm to be taught and practiced as it is performed by arterial surgeons at the present time. The aneurysm jig enables a plastic simulated aortic aneurysm to be opened as at operation to allow the inlaying of a Dacron tube sutured into place with continuous sutures.

A method is described for predicting the outcome of experimental free flaps at the time of surgery using a directional ultrasound Doppler flowmeter. Tests of both arterial and venous anastomoses have been developed. Provided that both anastomoses are individually assessed, the technique is 100% accurate and is recordable. Spectral analysis of truly directional Doppler signals has provided knowledge of the peripheral resistance within a flap.