Search PubMed⌕ Search

Biomedical subjects

R D Sayers

Publications and source records attributed to R D Sayers.

At least 109 records · Page 6Linked to original sources
PubMed1994

The influence of low molecular weight heparin on neointimal proliferation in cultured human saphenous vein.

OBJECTIVES: To investigate the effect of low molecular weight heparin (LMWH) on neointimal proliferation in cultured human saphenous vein, a model of human vein graft intimal hyperplasia. DESIGN: Dose ranging LMWH concentration study. SETTING: Culture Laboratory, Department of Surgery. MATERIALS: Fifteen segments of human long saphenous vein were incubated at 37 degrees C for 14 days in culture medium with 30% foetal calf serum. LMWH was added to one of the paired segments at 1, 10 and 100 micrograms/ml (five veins each dose). 5-bromo-2-deoxyuridine (Brd-U) was used to label proliferating cells. CHIEF OUTCOME MEASURES: Neointimal thickness (micron and proliferation index (% labelled neointimal cells). MAIN RESULTS: Neointimal thickness and proliferation index were both significantly reduced by LMWH at 100 micrograms/ml [control vs. LMWH, reduction in thickness 21 microns vs. 7 microns (median difference 12 microns, 95% conf. int. 6-18), reduction in proliferation index 33% to 6% (median difference 19%, 95% C.I. 4-32)]. CONCLUSIONS: High dose LMWH reduces neointimal proliferation in cultured human saphenous vein. The practical clinical application of these results may require the use of non anticoagulant heparin-like molecules and/or local drug delivery systems.

Cell Division↗
PubMed1994

Subintimal and intraluminal recanalisation of occluded crural arteries by percutaneous balloon angioplasty.

Advances in radiological techniques have allowed successful treatment of arterial stenoses situated in the distal arterial tree. This paper describes the experience at Leicester Royal Infirmary with percutaneous transluminal angioplasty (PTA) for the treatment of occluded crural arteries. Over a 27 month period, 21 patients with 24 ischaemic limbs have undergone PTA for crural artery occlusion. PTA was attempted in a total of 29 occluded crural arteries with a median length of occlusion of 6 cm (range 1-30 cm). Intraluminal recanalisation was used for short occlusions and the subintimal technique for long occlusions. Technical success with angiographic recanalisation of the artery was achieved in 25 out of 29 crural vessels (86%). Endovascular treatment of crural artery occlusion appears to be a safe and effective treatment which avoids the need for femorodistal surgery in patients with occluded calf vessels.

Aged↗
PubMed1994

The fate of infrainguinal PTFE grafts and an analysis of factors affecting outcome.

Ninety-five infrainguinal polytetrafluoroethylene (PTFE) bypass grafts were performed in 90 patients. Indications for surgery were severe claudication in 23 limbs (24%) and rest pain or tissue necrosis in 72 limbs (76%). Sixty-seven grafts (71%) were to the above knee popliteal artery and 28 (29%) to the infragenicular vessels. The primary, primary assisted and secondary graft patencies at 2 years in limbs with rest pain or tissue necrosis were 37, 42 and 46% respectively with a limb salvage rate of 65%. A univariate analysis was performed to identify preoperative risk factors which affected graft patency. Smoking, an ankle systolic pressure of less than 50 mmHg, presentation with rest pain or tissue necrosis and single vessel run-off all had a significant adverse effect on graft patency. However, multivariate analysis revealed that smoking was the only significant adverse variable. These findings support the view that PTFE grafts for limb salvage are worthwhile even if the distal anastomosis is below the knee and run-off is via a single vessel provided that the patient stops smoking.

Actuarial Analysis↗
PubMed1994

Transthoracic endoscopic sympathectomy for hyperhidrosis and Raynaud's phenomenon.

Over an 80 month period, 53 transthoracic endoscopic sympathectomies were performed in 34 patients. The indications for surgery were palmar hyperhidrosis in 20 procedures (38%), palmar and axillary hyperhidrosis in eight procedures (15%), Raynaud's phenomenon in 23 procedures (43%), and combined palmar hyperhidrosis and Raynaud's phenomenon in two procedures (4%). Follow-up data, obtained by a self-assessment postal questionnaire, was available for 47 procedures in 30 patients (91%). Fourteen out of 15 procedures (93%) performed for palmar hyperhidrosis, all eight procedures (100%) for palmar and axillary hyperhidrosis and 14 out of 22 procedures (64%) performed for Raynaud's phenomenon produced an immediate improvement in symptoms. These improvements were sustained in 13 procedures (87%) performed for palmar hyperhidrosis, all procedures performed for palmar and axillary hyperhidrosis (100%) but only 10 procedures (45%) performed for Raynaud's phenomenon at a median follow-up of 16, 34 and 44.5 months respectively. There were no deaths nor postoperative Horner's syndrome in these patients. The only minor complications were two small pneumothoraces. Compensatory sweating was observed after 24 procedures (51%). These results confirm that transthoracic endoscopic sympathectomy is a simple, safe and effective procedure. In patients with hyperhidrosis, the results are excellent and prolonged; in patients with Raynaud's phenomenon, immediate improvement can be achieved but the symptoms may return with time.

Adolescent↗
PubMed1993

Interventional radiology in the maintenance of infrainguinal vein graft patency.

The impact of interventional radiology on the cumulative patency rate of 112 consecutive infrainguinal vein grafts was reviewed. The primary, primary assisted and secondary cumulative patency rates at 42 months were 40, 65 and 69 per cent respectively. The difference between primary and primary assisted patency rates (40 versus 65 per cent, P = 0.001) resulted from the early detection and treatment of stenoses in 30 grafts by percutaneous transluminal angioplasty (PTA). Interventional radiology also improved the cumulative graft patency rate through PTA of one inflow and five outflow arteries, thrombolysis of two graft occlusions, embolization of two persistent arteriovenous fistulas and salvage of one graft on the first day after operation by percutaneous aspiration of distal graft thrombus. Interventional radiology has a crucial role to play in the maintenance of infrainguinal vein graft patency; provided that graft stenoses are detected early in their development by aggressive graft surveillance, PTA is a highly effective treatment.

Adult↗
PubMed1993

Changing trends in the management of lower-limb ischaemia: a 17-year review.

Over a 17-year period, 2930 vascular procedures were performed for chronic lower-limb occlusive disease. During this time, the total vascular surgical workload rose significantly as a result of an increase in the rates of arterial reconstruction and percutaneous transluminal angioplasty. Although the major lower-limb amputation rate did not change significantly, there was a decrease in the above- to below-knee ratio. In addition, there were significant increases in the percentage of patients treated over the age of 75 years and the proportion of attempted revascularizations before amputation. The mortality rates for arterial reconstruction, percutaneous transluminal angioplasty and amputation did not change significantly during the study period. The duration of hospital stay increased significantly for patients undergoing amputation and decreased significantly for those receiving arterial reconstruction.

Age Factors↗
PubMed1993

Effects of the development of modern vascular services on amputation rates in Leicester, U.K.: a preliminary report.

We have reviewed 3036 consecutive patients who underwent arterial reconstruction, percutaneous transluminal angioplasty, or a major amputation for lower limb peripheral vascular disease in Leicester between 1974 and 1990. Patient data were obtained from the Hospitals Activity Analysis database, which codes all patient discharges according to diagnosis and treatment. During this 17-year study period, 1132 patients have undergone arterial reconstruction, 706 patients have undergone percutaneous transluminal angioplasty, and 1198 patients have undergone major amputation. The results show that the number of arterial reconstructions and angioplasties for lower limb arterial occlusive disease has increased over the last 17 years. The total amputation rate has decreased slightly during the period studied, but overall the decrease has not been significant.

Amputation, Surgical↗
PubMed1993

Selection of patients with critical limb ischaemia for femorodistal vein bypass.

The merits of an aggressive policy of distal reconstruction have been questioned by some observers. To determine the factors affecting graft patency and mortality, we analysed 78 consecutive infragenicular femorodistal vein grafts performed in 72 patients with critical limb ischaemia. The primary, primary assisted and secondary graft patency rates at 36 months were 29, 57 and 64%, respectively. The limb salvage and patient survival rates at 36 months were 67 and 74%, respectively. Univariate analysis (log-rank test) was performed to identify factors affecting graft patency, limb salvage and mortality at 1 month (perioperative) and 1 year. Independent variables of age, sex, diabetes, presentation, level of anastomosis and vein technique (reversed or in situ) did not affect graft patency. The ankle systolic pressure did not predict graft patency but was an independent variable affecting mortality (p = 0.047), as did diabetes (p = 0.019). These results show that excellent limb salvage can be successfully achieved in severely ischaemic patients by adopting an aggressive approach to femorodistal bypass, and that age, gender and poor medical condition are not contraindications to femorodistal bypass. The difference between the primary and primary assisted patency rates in this series is dramatic and reflects the impact of a vein graft surveillance programme in preventing graft occlusion.

Adult↗
PubMed1993

Chronic critical leg ischaemia must be redefined.

The Second European Consensus Document on Chronic Critical Leg Ischaemia defines critical limb ischaemia in non-diabetic patients as rest pain or tissue necrosis (ulceration or gangrene) with an ankle systolic pressure (ASP) of less than or equal to 50 mmHg, or a toe pressure of less than or equal to 30 mmHg. The aim of this study was to investigate whether this definition is able to predict the outcome of patients with severe lower limb ischaemia and thus to determine the relevance of the definition in clinical practice. We have analysed 148 severely ischaemic limbs in 133 non-diabetic patients who presented with rest pain, tissue necrosis or a combination of these symptoms. Fifty-one percent of these limbs fulfilled the current definition with an ASP < or = 50 mmHg; 49% had an ASP > 50 mmHg and were thus not defined as critically ischaemic according to the current definition. We have compared actuarial limb salvage and mortality rates in patients with an ASP < or = 50 mmHg to those patients with an ASP > 50 mmHg. The 1 year limb salvage and mortality rates for ischaemic limbs fulfilling the European Consensus Document criteria were 78.7 and 36.7% respectively, compared to rates of 73.9 and 17.3% in patients who were not defined as critically ischaemic under the current definition. There were no significant differences between 1 year limb salvage or mortality rates between the two patients groups (p = 0.843, 0.078, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

The histopathology of infrainguinal vein graft stenoses.

The precise histopathological nature of vein graft stenoses is unclear. Some authors have suggested that these lesions are due to intimal hyperplasia and others have claimed that they are fibrous strictures. The aim of this study was to determine the histological nature of infrainguinal vein graft stenoses by examining sections of vein grafts that had developed stenoses and had been surgically revised. This was performed using a combined anti-smooth muscle actin/Millers elastin stain. The results show that vein graft stenoses are due to intimal hyperplasia whereby smooth muscle cells proliferate and cause thickening of the intimal layer.

Aged↗
PubMed1993

The role of pulse-generated run-off, Doppler ultrasound and conventional arteriography in the assessment of patients prior to femorocrural bypass grafting.

One of the most important prerequisites prior to femorocrural bypass is the identification of a patent calf vessel. To determine the ability of three preoperative investigations to demonstrate patent distal vessels we compared preoperative conventional arteriography, Doppler ultrasound measurement of ankle systolic pressure (ASP) and pulse generated run-off (PGR). PGR and ASP both identified significantly more calf vessels than did preoperative conventional arteriography. However, only PGR had the ability to distinguish those vessels suitable for bypass grafting from those unsuitable for grafting. These results demonstrate that PGR is the investigation of choice prior to femorocrural bypass.

Aged↗
PubMed1993

The effects of intraoperative vasodilators and angiographic contrast medium on the endothelium and smooth muscle cells of vein grafts.

Cellular injury is a major cause of intimal hyperplasia in vein grafts. The effects of exposure of vein samples to iopamidol, papaverine and iloprost were studied in vitro in an organ chamber to determine whether these agents cause endothelial and/or smooth muscle cell injury. Smooth muscle cell function was assessed by eliciting a dose response curve to noradrenaline. Endothelial cell function was assessed by measuring the degree of endothelial-dependent relaxation of sub-maximally contracted vein samples. Iopamidol and iloprost did not have any deleterious effect on endothelial or smooth muscle cell function. Papaverine did not affect endothelial-dependent relaxation but did produce a significant decrease in smooth muscle contraction. The use of these intraoperative agents during femorodistal bypass does not appear to cause functional injury to the endothelial or smooth muscle cells.

Aged↗
PubMed1993

Early results of combined carotid endarterectomy and coronary artery bypass grafting in patients with severe coronary and carotid artery disease.

The management of patients with carotid artery disease who require coronary artery bypass grafting (CABG) remains controversial. Several published series from the USA (including one with prospective randomization) advocate a combined approach of carotid endarterectomy (CEA) followed immediately by coronary artery bypass surgery. However, experience of combined carotid endarterectomy and coronary bypass grafting has not been previously reported by a centre from the United Kingdom. Between 1986 and 1991 we performed this combined procedure on 18 patients who required myocardial revascularization and had co-existing severe (> 70%) carotid stenosis. Sixteen patients (89%) had angina and 11 patients (61%) had symptomatic carotid artery disease. The perioperative mortality was 5.5% and the ipsilateral perioperative stroke rate was 5.5%. These early results are encouraging and suggest that further evaluation of combined carotid endarterectomy and coronary artery bypass surgery is warranted.

Adult↗
PubMed1993

The management of cardiac trauma by general surgeons in non-cardiothoracic units.

Cardiac trauma requiring immediate surgical intervention is usually thought of as a rare event. However, our recent experience at Leicester Royal Infirmary suggests that this clinical situation is on the increase, and has highlighted potential problems in the management of these patients. It is essential that all units that may have to deal with these patients have the necessary facilities and equipment to perform an emergency thoracotomy in the Accident and Emergency department, and that the medical and nursing staff involved have been properly trained to deal with these life-threatening emergencies.

Adolescent↗