PubMed Health⌕ Search

Biomedical subjects

M G Wyatt

Publications and source records attributed to M G Wyatt.

At least 19 recordsLinked to original sources
PubMed2006

The mid-term effect of bare metal suprarenal fixation on renal function following endovascular abdominal aortic aneurysm repair.

OBJECTIVE: The aim of this study was to assess the mid term effect of proximal bare metal fixation design on renal function in patients undergoing endovascular repair (EVR) of abdominal aortic aneurysm (AAA). METHODS: Consecutive EVR patients for AAA from December 1995-2001 were included and grouped to either infrarenal (Group 1) or uncovered suprarenal (Group 2) fixation. Peri-operative renal function and at 6, 12 and 24 months was determined by serum creatinine (sCr mmol l(-1)) and Cockroft-Gault creatinine clearance (CrC ml min(-1)). Changes in renal function were compared using non-parametric analysis. RESULTS: Of the 179 EVR procedures during this six-year period, paired renal data was available for 135 patients at a minimal follow-up of 6 months (Gp1, n = 63; Gp2, n = 72). Median pre-EVR sCr and CrC were 113, 57 in Group 1 and 108, 58 in Group 2, p = NS. There was no significant deterioration in renal function within or between either group at 2 years post-EVR: median sCr, CrC values were 118, 56 (Group 1) and 111, 56 (Group 2), all p = NS. CONCLUSION: This study suggests mid-term renal function remains unaffected following EVR of AAA, irrespective of proximal fixation type. Designs to improve stent durability and EVR applicability do not appear to compromise renal function.

Aged↗
PubMed2004

The Vanguard endovascular stent-graft: mid-term results from a single centre.

PURPOSE: Despite initial enthusiasm for endovascular aortic repair, few descriptions of longer-term follow-up of any endovascular device have been published. This paper represents the experience of a single centre with the Vanguard device over a 5-year period. METHODS: Fifty-five patients with a median age of 71 years (range 45-87 years) and aneurysm diameter of 59 mm (45-84 mm) received a bifurcated Vanguard stent-graft between December 1995 and July 1999. Follow-up was according to the Eurostar criteria (clinical assessment, plain film radiography and computed tomography) at 1, 3, 6, 12, 18 and 24 months and then annually thereafter. RESULTS: All primary stent deployments were successful. Median duration of surgery was 120 min (70-360 min). Median post-operative stay was 3 days (1-19 days) with a peri-operative mortality of 5.5%. In the follow-up period (median 40 months, range 6-64 months) there was one aneurysm associated death, and 14 deaths due to other causes. There have been three device migrations, 12 occluded graft limbs, four type II endoleaks and nine type III endoleaks. At 48 months, this has resulted in a survival rate of 67%, an endoleak free survival of 81% and intervention free survival of 59% (Kaplan-Meier). CONCLUSION: Medium term results with the Vanguard device appear to be at least equivalent to open repair with regard to morbidity and mortality. Nevertheless, several delayed complications appear to be related to endograft limb distortion. Important lessons have been learnt in relation to the deployment of bifurcated endografts to reduce the incidence of secondary limb related problems.

Aged↗
PubMed2003

Outcome following surgery for thoracic outlet syndrome.

INTRODUCTION: the diagnosis of thoracic outlet syndrome (TOS) relies heavily on subjective rather than objective assessment criteria. Subsequently, published results after surgical decompression vary considerably. This study aimed to use a symptom-based patient-directed questionnaire to assess the outcome after decompression for TOS. METHODS: sixty patients who underwent decompression procedures were identified from a prospectively maintained vascular database. Patient records were analysed for details regarding initial presentation, investigation, type of procedure used for decompression and management. Outcome questionnaires were sent to all identified patients to give a patient-based outcome measure. RESULTS: eighty-four per cent of patients responded. In 90% of these patients there was an improvement in symptoms post-surgery with a median follow up of 43 months. The results were not influenced by the procedure or approach used. CONCLUSION: surgery remains an effective tool in the management of TOS. A simple patient-directed questionnaire as used in this study could assist in the standardisation of outcome assessment.

Adolescent↗
PubMed2001

A dual strategic approach to mega-aortic aneurysms.

Staged resection of mega-aortas with Borst's two-stage elephant trunk (ETK) is the gold standard but has a higher mortality and morbidity compared to single-segment repair. We report the first case of combined surgical and covered-stent approach in Europe. Location and dilatation of the proximal landing zone accounts for the majority of failures in covered-stenting but an ETK is stable, easy to localise and gives an excellent seal. In high-risk cases where surgical resection is not offered, stenting is an option. The lack of a thoracotomy is an advantage in often-frail patients recovering from stage-I and shortens ITU-stay. Therefore, a combined approach is an acceptable alternative in selected individuals.

Aged↗
PubMed2001

Fatal subdural haemorrhage following lumbar spinal drainage during repair of thoraco-abdominal aneurysm.

A 63-year-old male patient collapsed and died from a major subdural haemorrhage 5 days after elective repair of a Type III thoraco-abdominal aortic aneurysm. The anaesthetic technique had included the use of a lumbar cerebrospinal fluid drain. The management of the patient is described, and the association between subdural haemorrhage and cerebrospinal fluid drainage is discussed.

Aortic Aneurysm, Abdominal↗
PubMed1997

Critical and subcritical ischaemia.

OBJECTIVES: To stratify leg ischaemia into high and low risk groups with respect to outcome. METHODS: An evaluation of 20 recent publications, reporting the results of 6118 patients with critical ischaemia. Low and high risk patient groups are identified by the definition of critical ischaemia. These groups are analysed with respect to outcome of the patient and limb. MAIN OUTCOME MEASURES: Major amputation and mortality. RESULTS: From these data subcritical (rest pain and/or ankle pressure > 40 mmHg, n = 4089) and critical (tissue loss and/or ankle pressure < 40 mmHg, n = 2029) risk group of patients was identified. The 1, 3 and 5-year mortality is 26%, 44% and 56% with or without reconstruction. For patients in the low risk group, 27% did not lose their leg within the year if treated conservatively. For patients in the high risk group, amputation was required by 95% if treated conservatively, compared to 25% if treated with arterial reconstruction. CONCLUSION: Reconstructive surgery should be viewed from the following, more realistic, perspective. For patients with rest pain (and/or ankle pressure > 40 mmHg), 100% cumulative patency is equivalent to 64% resolution of symptoms at 1 year, as the rest may have improved without treatment. For high risk patients (tissue loss and/or ankle pressure < 40 mmHg), 100% cumulative patency is equivalent to 93% limb salvage at 1 year. Future reports should identify these two groups separately, as the dominant difference between outcome studies is the proportion of subcritical patients in the study rather than better surgical or radiological techniques. This stratification also has an important bearing on pharmacotherapy trials.

Amputation, Surgical↗
PubMed1996

Isolated tibial vessel disease: treatment options and outcome.

Tibial vessel disease is an important cause of limb ischaemia, particularly in diabetics. Revascularisation by angioplasty and bypass is increasingly feasible. The aim of this study was to review treatment and outcome in patients with this patterns of disease. We have performed 25 procedures in 20 patients since September, 1989. Six patients (5 diabetic) underwent 9 tibial angioplasties for stenotic lesions causing critical ischaemia or short-distance claudication. In 6 procedures there was single vessel run-off. Eight angioplasties were radiologically successful with a median increase in ankle-brachial index (ABI) of 0.15 [range: 0.00-0.44] at a median follow-up of 9 months. A further 4 patients (3 diabetic) with critical ischaemia underwent popliteal-distal, in-situ vein bypass for tibial occlusions. Distal anastomosis was onto the dorsalis pedis artery or distal anterior artery. Three grafts remain patent with successful limb salvage and ABI's greater than 1.0. Angioplasty is also useful for distal disease progression following femoro-popliteal bypass. Six patients with "at-risk" grafts underwent 8 tibial angioplasties for stenotic lesions in distal run-off. Radiologically, 6 procedures were successful with a median increase in ABI of 0.21 [range: 0.00-0.38] at a median follow-up of 7 months. There were less favourable results when a "graft-distal" bypass performed to salvage an occluded femoro-popliteal graft with diseased run-off vessels. Three of 4 grafts reoccluded within 3 months, 2 patients requiring amputation. We advocate an aggressive policy towards localised distal disease causing foot ischaemia.

Aged↗
PubMed1995

Preferential use of vein for above-knee femoropopliteal grafts.

OBJECTIVES: Many centres preferentially use polytetrafluoroethylene (PTFE) for above-knee femoropopliteal bypass as surgery is simplified and patency rates are comparable to vein, which is preserved for subsequent revisions or for distal disease progression. In this Unit, vein remains first choice graft material. The aim of this study was to audit our results with respect to above-knee bypass to establish the demand for vein for secondary reconstruction and to document the ultimate fate of the limb. PATIENTS: Between 1983 and 1992, 112 above-knee reconstructions were performed on 109 patients (89 vein and 23 PTFE grafts). PTFE was used where vein was absent or inadequate. Life table analysis of primary graft patency, limb salvage and patient survival up to 36 months follow-up concurs with previously reported series. RESULTS: Twenty-eight vein grafts (31%) and 11 PTFE grafts (48%) occluded during a median follow-up of 64 months (8-116 months). In only four cases was vein required for secondary procedures. The remainder were salvaged by thrombectomy and local procedures for technical problems. Amputation rates following graft occlusion were 12% in the vein group (20% of these being above-knee) as against 26% in the PTFE group (80% above knee). CONCLUSIONS: The demand for vein for secondary procedures is low. Amputation rates when vein grafts do occlude are half those of PTFE and amputation level is significantly influenced by graft type. We advocate preferential use of vein in above-knee femoropopliteal bypass.

Adult↗
PubMed1995

Femorotibial bypass: the learning curve.

Femorotibial bypass is still infrequently performed in many district hospitals, because it is time consuming and the risk of failure is high, especially during the learning curve. This article reviews the results of a single consultant surgeon and his team after starting femorotibial bypass de novo in a district general hospital. During the period 1987 to 1992, 85 femorotibial grafts were performed in 76 patients for ulceration and gangrene (57), rest pain (19) and severe claudication (9). Sixty-six were autogenous vein, 15 were PTFE with distal vein cuff, two were composites and two were umbilical vein. Overall, 22 grafts (26%) failed within the first 30 days (two were salvaged) and 21 amputations were required (five despite patent grafts). There were three early deaths (mortality 3.9%). At the end of 1993, 39 limbs had been amputated and 24 patients had died (eight with amputations). Twenty-three (44% of survivors) were alive with patent grafts. These disappointing early results were due to an initial technical learning curve, after which increased confidence may have led to reconstructing some patients with inadequate distal arteries. A more selective approach is now used. Limb salvage can be achieved in a worthwhile proportion of these patients and 3-year primary patency rates are similar to those of teaching hospitals in this country.

Aged↗
PubMed1994

Femoropopliteal angioplasty for severe limb ischaemia.

Fifty patients undergoing 51 percutaneous transluminal angioplasties of the femoropopliteal segment for severe limb ischaemia were reviewed regularly. They comprised 30 men and 20 women of median age 70 (range 56-85) years. There were two deaths within 30 days. At 2 years the cumulative patient survival rate was 60 per cent. Eleven angioplasties were technical failures, 25 failed in the first 6 months and 14 were successful at 6 months' follow-up; in addition one patient died from myocardial infarction within 30 days of technically successful angioplasty. Subsequent vascular procedures were successful in 11 limbs following failed angioplasty. The primary limb survival rate was 42 per cent at 2 years. There were eight major complications after angioplasty, requiring amputation in five instances. Of the 23 long occlusions (greater than 5 cm) that were recanalized and dilated, 22 procedures failed within 6 months. The run-off score and diabetic status did not predict outcome. In this group of patients angioplasty had a low durability. Dilatation of long occlusions is associated with high rates of reocclusion and, on the basis of these results, should not be performed.

Aged↗
PubMed1991

Intra-arterial streptokinase infusion in acute lower limb ischaemia.

Between 1986 and 1988, 38 patients (29 men and nine women), median age 65 years (range 38-85 years), underwent local intra-arterial streptokinase therapy for acute lower limb ischaemia. Three patient groups were identified: 15 with acute on chronic ischaemia (group 1), 12 postangioplasty (group 2) and 11 postfemorodistal bypass (group 3). Distal arteriographic run-off was a significant discriminant between success and failure in group 1 (n = 15, chi 2 = 11.5, P = 0.001) and in the overall group (n = 38, chi 2 = 17.2, P less than 0.001). In group 2, four patients with good run-off had an unsuccessful outcome; this was due in all cases to technical problems (haemorrhage in two and intimal dissection in two). In group 3, two patients with good run-off had unsuccessful streptokinase infusions. In both cases the graft failed in the early postoperative period (less than 30 days). By contrast, the four patients whose grafts occluded after 30 days had successful streptokinase infusions and long-term graft patency was achieved by further surgery and balloon dilatation. In all groups, no patient with a poor run-off had a successful outcome following streptokinase administration. The role of local intra-arterial streptokinase therapy in the critically ischaemic limb remains controversial, but these results suggest that an adequate run-off is an important factor in the selection of patients for treatment.

Acute Disease↗
PubMed1991

Effect of weight on claudication distance.

Conservative measures to improve claudication distance include advice on smoking, exercise, diet and weight reduction. Although the effects of smoking, exercise and diet are established, the effect of weight is less clear. The aim of this study was to investigate the effect of carrying extra weight on the maximum walking distance in stable claudicants. Twenty stable claudicants were exercised on a treadmill (3.5 km/h, 0 degrees slope) carrying 0, 2.5, 5, 7.5 and 10 kg weights in randomized sequence. Maximum claudication distance and ankle: brachial pressure indices were recorded. Patients were categorized into mild or severe claudicants depending on their ability to walk 200 m. A response index (RI) was calculated as the reduction in claudication distance per kilogram load; RI = [CD0-CD10]/10 m/kg, where CD0 and CD10 represent claudication distance with 0 and 10 kg weights, respectively. Claudication distance was significantly reduced in subjects carrying 5 kg or more (P less than 0.01). A linear relationship was demonstrated between the mean claudication distance and the load carried (r = 0.98, P less than 0.01) with a mean response index of 10.2 m/kg. The mean(s.e.m.) RI in mild claudicants (25.9(9.5) m/kg) was greater than the value observed in the severe claudicants (3.3(0.8) m/kg; P less than 0.01, Mann-Whitney U test). This study demonstrates that weight adversely affects claudication distance and suggests that weight reduction may deserve greater emphasis in the management of some patients with intermittent claudication.

Adult↗
PubMed1991

Impedance analysis to identify the at risk femorodistal graft.

Computer-assisted impedance analysis is a newly developed technique to identify femoropopliteal and distal vein graft stenoses before failure. Pulsatile flow is measured from the proximal and distal graft by use of an 8Mhz Doppler velocimeter. A pulse volume recorder measures pulsatile pressure within the thigh and calf. Fourier transfer analysis is performed on paired Doppler pulse volume recorder waveforms and an impedance score derived for the thigh and calf, respectively. In a retrospective review of 50 nonreversed femoropopliteal/distal grafts performed for limb salvage, postoperative biplanar intraarterial digital subtraction arteriography was compared with impedance analysis. Arteriography showed graft or runoff stenoses in 22 grafts (at risk) and 28 normal grafts (controls). Impedance scores were significantly higher in the at risk group (0.58 + [0.43 to 0.72]*), when compared with the controls (0.34 + [0.30 to 0.38], p less than 0.001*). A thigh or calf impedance score of greater than 0.45 was able to detect 20 of 22 stenoses, including 6 lesions in grafts with normal resting and postexercise ankle pressures. This score was then applied prospectively and compared with serial biplanar digital subtraction arteriography in a further 56 femoropopliteal/distal bypasses for limb salvage. Thirty-three of 34 lesions were successfully predicted and impedance scores were significantly higher in the at risk limbs (0.56 + [0.44 to 0.68]*) when compared with the controls (0.38 + [0.35 to 0.41], p less than 0.001*). In this series impedance analysis proved more sensitive than resting or stressed ankle pressures and, unlike Duplex scanning, was able to detect runoff as well as graft stenoses.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗