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Biomedical subjects

W J Walker

Publications and source records attributed to W J Walker.

At least 19 recordsLinked to original sources
PubMed1992

Complications attributable to the formation of the track in patients undergoing percutaneous nephrolithotomy.

Reported complication rates of percutaneous nephrolithotomy vary considerably. In our own experience of 110 percutaneous nephrolithotomies performed by an experienced interventional radiologist, the complication rate for the entire procedure was 3.6%, and for the formation of the nephrostomy track 0.9%. This compares favourably with the reports from the major centres. Radiation dose to the operator was monitored and our results confirm that with meticulous attention to technique, dosages may be kept very low. We conclude that prior training in interventional techniques is a major factor in reducing both the morbidity associated with percutaneous nephrolithotomy and the radiation dose to the operator.

Adolescent↗
PubMed1990

Conservative management of asymptomatic popliteal aneurysm.

Historical review shows that the treatment of popliteal aneurysm has developed by trial and error and there is disagreement about the proper management of the symptomless patient. In 1981 a policy of conservative management for asymptomatic popliteal aneurysm was adopted in this unit. Since that time we have also managed nine patients with thrombosed popliteal aneurysms by arteriography and low-dose intra-arterial streptokinase. Six patients treated within 72 h of occlusion achieved significant (70-100 per cent) lysis, but streptokinase was ineffective in those treated 10 or more days after the thrombosis. Of the six patients with significant lysis, three were treated by elective reconstruction and two by anticoagulation. One patient who had significant lysis died. Vascular patency of all five successfully treated limbs was maintained and no limb loss occurred in those who presented late and failed to achieve significant lysis. These results reinforce the view that thrombolysis is the treatment of choice for thrombosed popliteal aneurysms. The low complication rate for asymptomatic popliteal aneurysms and the advent of safe, effective thrombolysis indicate that operation for symptomless popliteal aneurysm is no longer required.

Adult↗
PubMed1990

Ultrasound guided fine needle aspiration of ovarian cysts: diagnosis and treatment in pregnant and non-pregnant women.

Ovarian cysts are conventionally managed by laparoscopy or laparotomy. Twenty-two patients underwent fine needle aspiration of ovarian cysts under ultrasound control. Four patients were pregnant, and in two of these, aspiration of the cyst was performed transvaginally. The aspirate was examined cytologically and correlated with histology where available. The technique and results are discussed. No complications occurred. It is concluded that fine needle aspiration under ultrasound guidance is simple, safe and useful in the management of ultrasonically benign unilocular ovarian cysts in pre-menopausal women. It is of particular use in pregnancy, and in patients unsuitable for laparoscopy or surgery. Surgery can be reserved for cysts which recur after aspiration, cysts with a haemorrhagic aspirate, cysts in post-menopausal women and those with ultrasonic criteria of malignancy.

Adult↗
PubMed1990

Extremity doses during interventional radiology.

The radiation doses received by the unprotected parts of a radiologist undertaking biliary and renal interventional techniques using an overcouch X-ray tube have been measured with thermoluminescent dosimeters. Mean doses to the eyes, thyroid and fingers ranged from 0.27 to 1.29 mSv per examination. The results substantiate the need for such monitoring but the study demonstrates that the doses to the radiologist can be kept to an acceptable level with careful technique.

Environmental Exposure↗
PubMed1988

A protocol for the safe treatment of acute lower limb ischaemia with intra-arterial streptokinase and surgery.

Over a 5-year period 70 patients, presenting with subacute ischaemia of the lower limb (more than 12 h), were treated with low-dose intra-arterial streptokinase. There were 72 infusions and effective lysis was achieved in 52 (72 per cent), with an average infusion time of 25 h. A total of 23 (32 per cent) also underwent percutaneous transluminal angioplasty when lysis showed an underlying stenosis, and a further 19 (26 per cent) required surgery to remove persistent stenosis, organized thrombus or atheromatous debris. Significant bleeding occurred in 4 patients (6 per cent) and 13 (18 per cent) underwent amputation. There were five deaths (7 per cent), one of which was directly related to the infusion, while three were due to myocardial infarction. All of the major complications occurred in the early part of the study and both the selection of patients and the technique of infusion were modified to improve safety. Complementary treatment by percutaneous transluminal angioplasty and surgery was used more frequently in the later part of the study. The technique is not recommended for the white leg of acute ischaemia (less than 12 h), or for lysis of clot in a retroperitoneal Dacron graft, but may be uniquely valuable to demonstrate the cause of subacute ischaemia.

Acute Disease↗
PubMed1988

U.S. lung cancer mortality and declining cigarette tobacco consumption.

The usual method for estimating population exposure to cigarette tobacco has been annual per capita consumption of cigarettes, expressed as pack-years or numbers of cigarettes consumed. This technique is shown to result in an inaccurate estimate of exposure. It underestimates by 11 years the latency period from peak exposure to peak mortality. Over the years, cigarettes changed markedly. Filters came into prominence and tobacco was "fluffed". On average, tobacco content of cigarettes decreased 39.1% from 1953 to 1981. National per capita consumption of cigarette tobacco declined by 43%. Total exposure to cigarette tobacco has been declining for males for approximately 35 years; for females for 20 years. As of 1982, the secular trend for lung cancer mortality was declining for women below age 45 and for most age groups of men below 65. We appear to be at the threshold of a reversal in overall lung cancer mortality.

Adult↗
PubMed1985

Low-dose intra-arterial streptokinase: benefit versus risk.

Twenty-six unselected patients presenting with acute arterial ischaemia of a limb were treated with low-dose intra-arterial streptokinase under the joint care of a radiologist and a vascular surgeon. The results are reported and complications described. It is suggested that co-operative radiological and surgical management is essential and a shortened protocol for the safer administration of the drug is suggested.

Adult↗