Smoking, ignorance, and peripheral vascular disease.

The effect of the surgeon's advice to give up smoking was studied in a group of 43 patients with peripheral vascular disease (PVD), using blood carboxyhemoglobin levels to detect deception. Only seven of 40 patients (17.5%) actually stopped smoking, but the remainder appeared fairly honest in reporting their continued habits. Few patients were aware of the possible harmful effect of smoking on the peripheral arteries. The 43 patients with PVD who smoked had significantly higher carboxyhemoglobin levels than a group of 25 smokers without PVD although their cigarette consumption was the same. This suggests that carboxyhemoglobin levels may provide a better indication of the risk of smoking than overall cigarette consumption alone in the development of PVD.

Oxygen tension of the skin of ischemic legs.

Using a Kontron Roche Transcutaneous Oxygen Monitor, we measured oxygen tension on the skin of the legs at three sites in patients with peripheral vascular disease and group of controls. Significant decreases in oxygen tension occurred in the patient groups, which correlated well with ankle systolic pressure, with differences between those with claudication and those with rest pain. These results suggest that in limbs with claudication, significant skin hypoxia may exist during rest in spite of reportedly normal skin and muscle blood flow. The progressive decrease in skin oxygen tension down a limb with occlusive vascular disease may play a significant role in skin healing.

Characterisation of carotid artery disease: comparison of duplex scanning with histology.

The ability of duplex scanning to characterise the component tissue of atheromatous lesions of the internal carotid artery and to detect ulceration has been examined in a histological study of 42 carotid endarterectomy specimens. The results suggest that the only component of atheromatous lesions of the internal carotid artery which can be characterised from the B-scan is calcification. The presence of ulceration, intraluminal and intramural thrombus, fibrous intimal thickening and necrosis are not related to the echogenic appearance of internal carotid stenoses and may not be detected reliably. B-mode imaging alone cannot reliably grade greater than 50% internal carotid stenoses, but when this is combined with pulsed Doppler in the technique of duplex scanning, accurate results may be obtained.

Glycosylated haemoglobin in non-diabetic peripheral vascular disease.

Glycosylated haemoglobin (Hb A1c) was measured in 20 patients with severe peripheral vascular disease (P.V.D.) and 12 controls. Levels were significantly higher in those with P.V.D. and this may be due to mild carbohydrate intolerance frequently exhibited by this group of patients.

The Southampton teaching triad: an audit of operative surgical instruction.

Clinical audit and regular morbidity and mortality meetings are required of all units involved in surgical training. Agreed standards of training are under discussion in the face of new examinations and have not at present been formally evaluated. In order to quantify the level of operative surgery instruction in this unit, a prospective 'Teaching Audit' has been undertaken, using an extension of the existing surgical audit. Results, which are presented as a standardised diagram, reflect the relationship between trainer and trainee. Problems, such as missed teaching opportunities, were identified. The method can be applied to any specialty, and may be useful in planning teaching resources and surgical training programmes.

Local audit in vascular surgery.

A 2-year audit of the Southampton Vascular Unit showed marked discrepancies in workload from nationally accepted figures. All forms of reconstructive surgery except emergency aortic aneurysm grafting were performed more frequently than expected. The vascular population is elderly and at high risk from major surgery. Mortality was appreciable in all major vascular procedures and usually cardiac or renal related. The elderly population and resulting workload is likely to increase in the near future. The role of local audit in vascular surgery is emphasised.

Below knee femoropopliteal bypass in severe ischaemia: results using EXS Dacron and human umbilical vein.

This paper reports our preliminary experience using EXS Dacron for infrageniculate femoropopliteal grafts in elderly patients, the majority (78%) suffering critical ischaemia. A comparison is made with human umbilical vein grafts (HUV). Ninety patients (mean age 69 years) with 92 grafts (42 EXS, 50 HUV) were followed up using ultrasound imaging to detect patency (median follow up 26 weeks (range 1-292)). Two and one year cumulative survivals were 57% and 80% for EXS Dacron and 39% and 48% for HUV respectively. Early failure of HUV grafts accounted for most but not all of the difference in survival (P = 0.0012, Wilcoxon Breslow). Graft kinking was not seen in EXS grafts and in only 2 HUV. Poor calf vessel run off was related to early graft occlusion (P = 0.01; Savage, Mantel Cox). This preliminary experience with EXS Dacron is encouraging and suggests the need for a formal randomised study.

Varicose vein surgery using a pneumatic tourniquet: reduced blood loss and improved cosmesis.

A prospective controlled randomised study has been performed of 100 consecutive patients undergoing varicose vein surgery. One group underwent saphenofemoral flush ligation and multiple lower leg avulsions with the leg exsanguinated with a Rhys-Davies cuff, and ischaemia maintained with a pneumatic tourniquet. The other group underwent identical surgery but with a 30 degree head down tilt only. Blood loss was significantly less (13.5 +/- 12 ml vs 133 +/- 78 ml; P less than 0.01) and postoperative cosmesis was significantly improved in patients in the tourniquet group. Operating time was similar (27 +/- 11 min vs 30 +/- 13 min) in the two groups.

Resistance to benzimidazole anthelmintics in equine strongyles. 2. Evidence of side-resistance, and susceptibility of benzimidazole-resistant strongyles to non-benzimidazole compounds.

The susceptibility of a known thiabendazole-resistant population of small strongyles to anthelmintics of both benzimidazole and non-benzimidazole groups, was determined. In the first study, 42 horses infected with thiabendazole-resistant small strongyles were allocated to 6 groups. Treatment groups received one of the following anthelmintics: mebendazole, febantel, febantel plus trichlorphon, morantel tartrate, or a combination of thiabendazole, piperazine and trichlorphon. Morantel tartrate and the thiabendazole/piperazine/trichlorphon combination produced highly significant (p less than 0.001) reductions in faecal strongyle egg counts 20 days post-treatment. Mebendazole, febantel and febantel plus trichlorphon failed to reduce strongyle egg counts significantly. Larval culture and differentiation indicated that in all cases of anthelmintic failure, small strongyles of the sub-family Cyathostominae were involved. Eighteen horses from groups in which treatment had failed were re-allocated to 3 groups. Treatment with either morantel tartrate or haloxon was highly efficient in reducing faecal strongyle egg counts. In the final study, fifty-four horses, infected with benzimidazole-resistant small strongyles were allocated to 10 groups. On day zero, each treatment group received one of the following anthelmintics: thiabendazole, cambendazole, mebendazole, oxibendazole, piperazine, thiabendazole/piperazine, cambendazole/piperazine, mebendazole/piperazine or oxibendazole/piperazine. Oxibendazole, piperazine and the benzimidazole/piperazine combinations produced highly significant reductions in faecal strongyle egg counts 20 days post-treatment (p less than 0.001). When administered alone, benzimidazole anthelmintics failed to reduce strongyle egg counts significantly, with the exception of oxibendazole. Larval culture and differentiation indicated that in all cases of anthelmintic failure, the species involved were small strongyles of subfamily Cyathostominae. There was no significant increase in benzimidazole resistance level (based on in vitro assay) as a result of drug treatment, over one generation.

Resistance to benzimidazole anthelmintics in equine strongyles. 1. Frequency, geographical distribution and relationship between occurrence, animal husbandry procedures and anthelmintic usage.

A survey was conducted to determine whether benzimidazole resistant populations of equine strongyles are present in New South Wales and north central Victoria; what is their frequency and geographical distribution; which species are involved; and whether different methods of parasite control could be related to the occurrence and frequency of anthelmintic resistant populations. Resistant populations of strongyles were found over wide areas of New South Wales and in north central Victoria. There was no relationship between geographical location and the occurrence of benzimidazole resistance. The species involved were small strongyles of the sub-family Cyathostominae. There was a direct correlation between the occurrence of resistance (including the level at which it is present) and the frequency of use of benzimidazole anthelmintics. Examination of management practices showed that resistance is not an important problem on farms where different chemical classes of anthelmintics were used in a slow rotation programme; combination anthelmintic therapy (for example, benzimidazole/piperazine/organophosphates) was used and anthelmintic treatment was given at intervals of not less than 16 weeks. Tentative suggestions are made for the control of small strongyles in the light of an emerging resistance problem.