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Biomedical subjects

K Varty

Publications and source records attributed to K Varty.

At least 19 recordsLinked to original sources
PubMed1999

Experience of supraclavicular exploration and decompression for treatment of thoracic outlet syndrome.

The purpose of this study was to assess the symptomatic outcome of patients with thoracic outlet syndrome who underwent decompression of the thoracic outlet. In our unit we prefer the supraclavicular approach, performing anterior scalenectomy with excision of fibrous bands or cervical ribs if present. Operative details were gained by theater logbook and case note review. Over a 6-year period, 31 patients (37 limbs) underwent thoracic outlet decompression. Of the 37 affected limbs, the indications for surgery were a combination of both neurological and vascular symptoms in 24 patients (65%), neurological symptoms in 24 (65%), and 4 patients (11%) had vascular symptoms alone. All patients were assessed for postoperative outcome either at out-patient clinics or by personal contact. From the results of this study we concluded that supraclavicular scalenectomy and cervical rib excision with selective first rib excision is a safe and effective procedure for most patients with thoracic outlet syndrome.

Adult↗
PubMed1999

The surgical management of acute limb ischaemia due to native vessel occlusion.

OBJECTIVES: Data from the STILE study have indicated that for patients with subacute limb ischaemia due to native vessel occlusion, surgery is both more effective, and durable than thrombolysis. The purpose of this study was to evaluate the outcome of an aggressive surgical approach in patients presenting with acute limb-threatening ischaemia. DESIGN: Details of patients presenting with salvageable acute limb ischaemia due to native artery occlusion over a 6-year period in a University hospital vascular unit setting were obtained from the vascular audit and the outcome of the surgical management of these patients was analysed. RESULTS: One hundred and seventy-four consecutive patients underwent surgery for acute native vessel limb ischaemia (76% lower, 24% upper limb). Fogarty thrombectomy or embolectomy was initially performed in 153 (89%) patients. Of these, 37 (24%) immediately underwent a further procedure: 28 (18%) had on-table thrombolysis and 14 (9%) underwent vascular reconstruction. Twenty-six patients (15%) underwent further limb salvage surgery within 30 days. Life table analysis demonstrated a limb salvage rate of 88% and 76% at 30 days and 2 years, respectively. Patient survival was 75% and 48% at the same time intervals. CONCLUSIONS: These results demonstrate that a role for aggressive surgical intervention still exists, resulting in high limb salvage rates.

Acute Disease↗
PubMed1999

Infrainguinal revascularisation in the era of vein-graft surveillance--do clinical factors influence long-term outcome?

OBJECTIVES: To investigate the variables affecting the long-term outcome of infrainguinal vein bypass grafts that have undergone postoperative surveillance. DESIGN: A retrospective analysis. PATIENTS AND METHODS: Details of 299 consecutive infrainguinal vein grafts performed in 275 patients from a single university hospital were collected and analysed. All grafts underwent postoperative duplex surveillance. Factors affecting patency, limb salvage and survival rates were examined. These factors were gender, diabetes, hypertension, aspirin, warfarin, ischaemic heart disease, run-off, graft type, early thrombectomy, level of anastomoses and indication for surgery. RESULTS: The 6-year primary, primary assisted and secondary patency rates were 23, 47, and 57%, respectively. Six-year limb salvage and patient survival were 68 and 45%, respectively. Primary patency was adversely influenced by the use of composite vein grafts. Early thrombectomy was the only factor that significantly influenced secondary patency. Limb salvage was worse in diabetic limbs, limbs with poor run-off and in grafts that required early thrombectomy. Postoperative survival was better in males, claudicants and in patients who took aspirin. CONCLUSIONS: Although co-morbid factors did not influence graft patency rates, diabetes did adversely effect limb salvage. This study, like others before it, confirms that aspirin significantly reduces long-term mortality in patients undergoing infrainguinal revascularisation.

Angioplasty↗
PubMed1998

Results of surgery and angioplasty for the treatment of chronic severe lower limb ischaemia.

OBJECTIVE: To aims of this study was to assess and compare the efficacy of PTA and surgery in the treatment of severe lower limb ischaemia. DESIGN: Prospective 12-month study of 180 consecutive patients with severe chronic lower limb ischaemia. METHODS: PTA was used as first line therapy whenever possible and appropriate. Surgical revascularisation, primary amputation and conservative therapy were used in eh remaining patients. Patient survival and limb salvage were derived using life table analysis. RESULTS: Revascularisation was attempted in 135 (75%) patients, with PTA in 82 (46%), surgery in 19 (27%) and a combination of both in four (2%). Overall 12-month survival and limb salvage was 75% and 71%, respectively. Surgery and PTA had significantly higher survival rates (91% and 78%) than primary amputation or conservative therapy (57% and 52%) (p < 0.0001 log rank test). Revascularisation with either surgery or PTA achieved the same limb salvage rate of 76%. CONCLUSION: A large proportion of patients with severe chronic lower limb ischaemia can be managed by PTA. THis management strategy produces a clinically effective outcome at 1-year.

Amputation, Surgical↗
PubMed1998

Bilateral infrainguinal vein grafts and the incidence of vein graft stenosis.

OBJECTIVES: To elucidate the incidence of significant vein graft stenosis in patients who have undergone bilateral infrainguinal vein grafts. MATERIALS: Between 1987 and 1996, 22 patients were identified from our vascular studies database as having undergone bilateral infrainguinal vein bypass grafting. METHODS: Data was obtained from the vascular studies database and by case note review. All patients had been part of a vein graft surveillance programme. RESULTS: Of the 22 patients with bilateral vein grafts, eight were excluded from further analysis because one or more of their grafts failed within 30 postoperative days. In the remaining 14 patients (28 vein grafts) there were 15 primary vein graft stenoses. Six patients (43%) had bilateral vein graft stenoses, which is significantly higher (p = 0.0008) than the predicted value of 9%, for developing bilateral vein graft stenoses. For those patients who developed a vein graft stenosis in their first grafted limb (9/14), 67% (6/14) subsequently developed a vein graft stenosis in their second grafted limb. CONCLUSION: Patients who develop vein graft stenosis in one limb are at a greater risk of developing a contralateral vein graft stenosis if that limb is grafted. This may well be due to individual vein morphology or unidentified systemic factors that play a role in the aetiology of vein graft stenosis.

Aged↗
PubMed1998

Provision of training in carotid surgery does not compromise patient safety.

BACKGROUND: Vascular surgeons perceive that carotid endarterectomy carries a higher risk of stroke if performed by a surgical trainee. Accordingly, some trainees consider that they receive a less than adequate training in carotid surgery before taking up a consultant position. The aim of this study was to establish whether the stroke rate was adversely affected if carotid endarterectomy was performed by a surgical trainee under consultant supervision. METHODS: This was a prospective study of 151 consecutive patients undergoing carotid endarterectomy between 1 January and 31 December 1996 using a standardized technique including intraoperative and postoperative transcranial Doppler monitoring and completion angioscopy. RESULTS: The overall mortality and/or disabling stroke rate was 0.7 per cent (one of 151 patients), whereas the mortality and/or any stroke rate was 1.3 per cent (two of 151). Surgical trainees performed 82 of 151 carotid endarterectomies, with a mortality rate of 1 per cent and a mortality and/or any stroke rate of 2 per cent. There was no significant difference in the incidence of retained thrombus or intimal flaps between trainees and consultants as detected by angioscopy. CONCLUSION: Vascular surgical trainees can receive a comprehensive training in carotid artery surgery without incurring an unacceptable increase in operative risk.

Aged↗
PubMed1998

Predischarge duplex imaging of infrainguinal vein grafts does not predict the development of stenoses.

BACKGROUND: The aim of this study was to determine whether predischarge duplex imaging of an infrainguinal vein graft could predict the subsequent development of graft stenosis. METHODS: Patients with infrainguinal vein grafts underwent a duplex scan of the entire graft before discharge from hospital. Grafts were classified as abnormal or normal based on the presence or absence of flow abnormalities (peak velocity ratio 1.5 or greater). All grafts were re-examined 1 month after surgery, at 3-monthly intervals for the first year and then every 6 months thereafter. A significant stenosis requiring correction was defined by a duplex-derived peak systolic velocity ratio of 3.0 or more. The relationship between the predischarge scan and subsequent development of stenosis was examined. RESULTS: Forty-four grafts were recruited. Two occluded soon after a normal predischarge scan and were excluded from subsequent analysis. Predischarge abnormalities were found in 16 grafts. The abnormality in one graft required immediate correction. A further four grafts subsequently developed significant stenoses and required angioplasty. Of the 26 grafts with no predischarge abnormalities, 11 developed significant stenoses and underwent angioplasty. Abnormal predischarge duplex scans had a sensitivity and specificity of 31 and 58 per cent respectively for the development of stenoses. The positive and negative predictive values were 31 and 58 per cent respectively. CONCLUSION: Predischarge duplex imaging cannot be used to predict the development of stenoses in infrainguinal vein grafts.

Blood Flow Velocity↗
PubMed1998

Digital ischaemia: an unusual presentation of dysbarism.

Dysbaric symptoms following ascent from a scuba dive are due to symptomatic nitrogen or air emboli with clear patterns of associated injury. This case report highlights an unusual presentation of dysbaric injury treated successfully with a prostacyclin analogue.

Adolescent↗
PubMed1996

Changes in the management of critical limb ischaemia.

A prospective study of all patients with critical limb ischaemia (CLI) who presented to a single vascular unit was undertaken for a 12-month period. There were 222 referrals in 188 patients, 80.2 per cent of which were emergency or urgent admissions. The majority (72.5 per cent) were initially investigated with colour duplex scanning to characterize the arterial lesion. Diagnostic angiography was performed in 35.1 per cent. An attempt at revascularization was made in 73.0 per cent of cases using percutaneous transluminal angioplasty (PTA) in 42.3 per cent, surgery in 24.3 per cent, and a combination of surgery and PTA in 6.3 per cent. Primary major amputation was required in 22 cases (9.9 per cent) and conservative treatments were used in 38 (17.1 per cent). The in-hospital mortality rate was 10 per cent with a limb salvage rate of 79 per cent. Diabetes was an independent risk factor for amputation (odds ratio 2.4, 95 per cent confidence interval 1.22-4.79, P = 0.012). Median hospital stay was much shorter for patients treated by PTA (4.5 days) than surgery (16 days) or primary amputation (18 days). The complication rate of PTA requiring surgery was 5.5 per cent. CLI represents a large non-elective workload for a vascular unit. The increasing use of non-invasive duplex assessment and angioplasty plays a major part in the successful management of these patients.

Adult↗
PubMed1996

Vein morphology and bypass graft stenosis.

Vein wall morphology (intimal and medial thickness) was studied in a consecutive series of 100 veins before organ culture. The development of a proliferative neointima after 14 days in culture was quantified by measuring neointimal thickness, and the relationship between this and the original vein wall morphology was investigated. The correlation between the intimal or medial thickness before culture and neointimal thickness following culture was poor (rs intima/neointima = 0.21, rs media/ neointima = 0.09). Long saphenous vein biopsies were obtained from 53 patients at the time of infrainguinal bypass surgery and their morphology was studied as above. Median intimal and medial thickness before grafting was 21 (range 2-208) and 245 (range 108-557) microns respectively. After 12 months in a colour duplex graft surveillance programme, 46 grafts were patent and 17 of these had developed a stenosis. There was no difference in intimal (28 versus 19 microns, P = 0.1) or medial (247 versus 245 microns, P = 0.47) thickness between stenosed and non-stenosed grafts respectively. Both the laboratory and clinical evidence from this study fail to support the hypothesis that pre-existing vein wall thickening is a key factor in the aetiology of vein graft stenosis.

Aged↗
PubMed1996

Work-load generated by the establishment of a non-heart beating kidney transplant programme.

The work-load generated by a non-heart-beating donor (NHBD) kidney transplant programme over a 3-year period is reported. A total of 73 referrals were made, 64 from the Accident department and 9 from the wards. Organ procurement was performed in 24 cases (33%) and resulted in the retrieval of 44 kidneys. Reasons for failure to achieve organ procurement were; refused consent (n = 13; 18%), relatives unavailable to ask for consent (n = 9; 12%), technical problems with catheter insertion or perfusion (n = 10; 14%), transplant staff unavailable (n = 1; 1%), long asystolic period (n = 8; 11%) and donor unsuitable for other reasons (n = 8; 11%). Of the 44 kidneys retrieved, 30 were transplanted locally, 8 were transplanted at other United Kingdom centres and 6 were discarded. Locally transplanted NHBD kidneys represented 21% of the total transplant programme during the time period under study. We conclude that NHBD kidneys are a good source of additional organs for transplantation, but only one-third of referrals result in a successful procurement procedure. Moreover, the setting up of a successful programme is labour-intensive and requires a highly committed staff.

Humans↗
PubMed1996

Human saphenous vein organ culture: a useful model of intimal hyperplasia?

OBJECTIVES: Although cell culture techniques and animal models of intimal hyperplasia have increased our current understanding of the aetiology of vein graft stenosis, the results of such studies have been difficult to relate to the human situation. DESIGN: The present study was designed to validate an organ culture of human saphenous vein by comparing the changes occurring in cultured vein with those seen in pathological vein graft stenoses and to identify a suitable marker of cell proliferation. MATERIALS AND METHODS: Saphenous vein segments were cultured for 14 days, fixed in formalin and processed for immunohistochemistry. Freshly excised stenoses were fixed and processed similarly. A number of markers of cell proliferation were evaluated in the culture system in order to identify the one best suited to this particular model. RESULTS: Marked similarities were observed in the cellular and extracellular matrix composition, and electron microscopy revealed that both the neointima of the cultured vein and the pathological lesion contained an abundance of smooth muscle cells of a secretory phenotype. Bromodeoxyuridine proved to be the most reliable proliferation marker and revealed that early proliferation in the superficial layers of the vein intima gave rise to the formation of neointima. Both proliferation and neointimal thickness were maximal by day 14 in culture. Proliferation declined rapidly thereafter, and the neointima was maintained. CONCLUSIONS: The changes occurring in cultured vein and graft stenoses bore many similarities, thereby justifying the use of organ culture as a valuable experimental tool.

Bromodeoxyuridine↗
PubMed1996

The development of an in vitro flow model of human saphenous vein graft intimal hyperplasia.

OBJECTIVE: Although the role of blood flow has been investigated in animal models of intimal hyperplasia, there have been no detailed studies in intact human vein owing to the difficulties in designing a suitable laboratory model. The aim of this study was to develop a flow model of human vein graft intimal hyperplasia. METHODS: Organ cultures of human saphenous vein were exposed to laminar flow by culturing in a closed circulatory system under predetermined conditions of venous and arterial shear stress for 14 days. Following fixation and processing, paraffin sections were immunostained and neointimal thicknesses measured. RESULTS: It was found that arterial flow completely inhibited neointima formation, but venous flow only partly suppressed the response when compared with vein cultured under static conditions. These results are in agreement with previous in vivo studies in a primate graft model, where increased shear stress inhibited intimal proliferation. CONCLUSION: The endothelial cell is believed to be the key mediator of haemodynamic effects which influence smooth muscle cell proliferation, and the flow rig developed in this study offers the potential to study inter-cellular interactions within the intact vessel. Furthermore, this method provides the facility to study the effects of different flow conditions on segments of vein from the same patient. This model has scope for further development and sophistication which may ultimately lead to increasing our understanding of the aetiology of vein graft stenoses, and hence formulation of preventative strategies.

Culture Techniques↗
PubMed1995

Percutaneous transluminal angioplasty of infrainguinal vein graft stenosis: long-term outcome.

The aim of this prospective study was to examine the long-term outcome of infrainguinal vein graft stenosis managed by percutaneous transluminal angioplasty (PTA) as first-line treatment. Thirty-three infrainguinal vein graft stenoses detected by graft surveillance during a 44-month period were treated initially by PTA. The median (range) follow-up after angioplasty was 39 (18-56) months. Although 19 stenoses were successfully treated by a single PTA, 14 stenoses recurred at a median (range) interval of 8.5 (1-39) months. Restenosis occurred more frequently in the distal third of a graft (P = 0.002) compared with that in the proximal or mid-grafts, and restenosis was more common in in situ than reversed vein grafts (P = 0.03). It is concluded that infrainguinal vein graft stenoses were successfully treated by single PTA. There was, however, a high restenosis rate after angioplasty of stenosis in the distal third of a vein graft and, while approximately one third of such stenoses can be treated by a single PTA, the optimal management of recurrent stenosis requires further investigation.

Angioplasty, Balloon, Coronary↗
PubMed1995

Percutaneous transluminal angioplasty for lower-limb critical ischaemia.

Percutaneous transluminal angioplasty (PTA) alone was used to treat 54 (23 per cent) of 232 lower limbs with critical ischaemia. Technical success was achieved in 49 cases (91 per cent) with an immediate symptomatic improvement in 47 (87 per cent). There was no death or limb loss attributable to PTA and three embolic complications were successfully treated by percutaneous aspiration. Symptomatic improvement and haemodynamic patency rates at 24 months were 77 and 78 per cent respectively; 27 of 34 limbs with ulceration or gangrene had healed with minor surgery by a median of 7.5 (range 3.0-18.0) months. Patient survival and limb salvage rates at the same time interval were 76 and 89 per cent respectively. These results demonstrate that, for a selected group of patients with lower-limb critical ischaemia, PTA can be a highly successful therapeutic option with a low associated morbidity.

Aged↗
PubMed1995

Vascular emergencies: what's in season?

Seasonality in ischaemic coronary artery disease is well documented with a winter/summer variation the commonest pattern. The influence of seasonal variation on events in other vascular territories is less well documented. The incidence of ruptured abdominal aortic aneurysm and emergency lower-limb ischaemia was analysed on a monthly basis over a 5-year period. A total of 372 ruptured abdominal aortic aneurysms occurred with a peak incidence in spring and autumn; however, no seasonal pattern was seen in the rate of emergency admissions with lower-limb ischaemia (n = 606). The explanation for this seasonal pattern in ruptured aneurysms is unknown. The haemodynamic adjustments to changes in climate require further study.

Aortic Aneurysm, Abdominal↗