Biomedical subjects
D J Tibbs
Publications and source records attributed to D J Tibbs.
Varicocele and varicose veins compared. A basis for logical surgery.
In the past only large symptomatic varicoceles were treated surgically, but this has changed now that they are believed to be a cause for infertility. Ten patients have been studied using the Doppler flowmeter and phlebography to compare varicoceles and varicose veins in the legs and to decide whether or not the same principles apply in their surgical treatment. These studies have confirmed a similar mechanism of retrograde flow from above a pumping mechanism to below it. Surgery must aim at effective and complete interruption of the source of the downflow. This requires ligation of the testicular vein either at sufficiently high level to insure that it is above any major branches or that these are included in the ligation. There is no danger of causing venous obstruction because a varicocele would not develop without the existence of a massive alternative venous outlet.
Reliability of tests of venous function.
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Intermittent claudication: factors determining outcome.
Two groups of patients were followed up for four to eight years after first referral or admission to hospital for intermittent claudication (IC) in a study of the natural history of the disease and of factors determining its outcome. In one series of 60 patients, those who stopped or reduced smoking after referral had a much improved prognosis. Thus even after the diagnosis of IC it is extremely important that patients should be encouraged to stop smoking, since this correctable factor appears to be of greater importance in determining outcome than other medical risk factors for the disease that are less amenable to treatment. In the second study, 160 patients were followed up for eight years after first hospital admission. They had a total of 480 hospital admissions and had spent 11 190 days in hospital; their life expectancy after the age of 60 was about half that of the general population. Age, coronary artery disease, cerebrovascular disease, and diabetes were associated with an adverse outcome.
Logarithmic time--a new dimension in organ preservation.
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Origin of arterial prosthesis lining from circulating blood cells.
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Technique of arterial embolectomy.
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Influence of the type of anastomosis: end-to-side anastomosis versus end-to-end.
The by-pass technique of arterial reconstruction has some theoretical disadvantages, particularly, unnecessary abandoning of useful main arteries, undesirable flow patterns and the possible descent of debris from the by-passed portion of artery. An oblique end-to-end technique can avoid these undesirable features and also avoid the creation of an over-sized vessel at the site of end-to-side anastomosis. It is suggested that the least procedure compatible with success should be used in arterial reconstruction in the lower limb and an ascending range of options open to the surgeon is given.
The intriguing problem of varicose veins.
New methods of investigation have given a fresh understanding of varicose veins. Aspects of this are described based on findings in patients investigated by Doppler flowmetry, functional phlebography and photoplethysmography. All observations refer to the upright position where various forms of failure in pumping blood upwards against gravity may arise. Simple varicose veins conduct flow from above a pumping mechanism to the low pressure area beneath it. Thus, saphenous incompetence allows downflow from the groin to below the musculovenous pumps of the calf and the foot. It is this reversed flow that creates tortuosity in the branch veins and sacculation beneath leaking saphenous valves. Perforator incompetence is often incidental and a concealed saphenous incompetence, without varicosites, is easily overlooked. Functional phlebography has shown that many patients with varicose veins also have inadequate deep vein valves so that the pumping mechanisms are soon overwhelmed and this may explain why some develop ulceration and others do not. Complex patterns of flow in superficial veins have been demonstrated, for example: strong collateral upflow past deformed deep veins whilst other veins allow spillage downwards: crossover incompetence with flow to the opposite limb and down its incompetent saphenous vein. The special investigations can accurately predict the outcome of surgery and are an important addition to successful management.