Acute forefoot ischaemia: an unreported complication of dorsalis pedis artery aneurysm.
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Acute Disease↗
Biomedical subjects
Y G Wilson
Publications and source records attributed to Y G Wilson.
Focal myositis - a new presentation.
This article is a case report and review of literature of a very rare condition, not previously written in general surgical literature, including a new presentation
Adult↗
Ruptured abdominal aortic aneurysms: selecting patients for surgery.
OBJECTIVES: Mortality from ruptured abdominal aortic aneurysm (RAAA) remains high. Despite this, withholding surgery on poor-prognosis patients with RAAA may create a difficult dilemma for the surgeon. Hardman et al. identified five independent, preoperative risk factors associated with mortality and proposed a model for preoperative patient selection. The aim of this study was to test the validity of the same model in an independent series of RAAA patients. METHODS: A consecutive series of patients undergoing surgery for RAAA was analysed retrospectively by case-note review. Thirty-day operative mortality and the presence of the five risk factors: age (> 76 years), creatinine (Cr) (> 190 mumol/l), haemoglobin (Hb) (< 9 g/dl), loss of consciousness and electrocardiographic (ECG) evidence of ischaemia were recorded for each patient. RESULTS: Complete data sets existed for 69 patients (mean age: 73 years, range: 38-86 years, male to female ratio: 6:1). Operative mortality was 43%. The cumulative effect of 0, 1 and 2 risk factors on mortality was 18%, 28% and 48%, respectively. All patients with three or more risk factors died (eight patients). CONCLUSIONS: These results lend support to the validity of the model. The potential to avoid surgery in patients with little or no chance of survival would spare unnecessary suffering, reduce operative mortality and enhance use of scarce resources.
Adult↗
Vein quality in infrainguinal revascularisation: assessment by angioscopy and histology.
The concept of vein quality has been slow to gain widespread acceptance, but an increasing body of evidence suggests that vein quality is relevant to the success of bypass grafting for peripheral vascular disease. The angioscope represents an additional tool for monitoring and preparing vein grafts during infrainguinal revascularisation. Within the overall theme of vein quality, this paper presents the cumulative experience with vascular endoscopy at Bristol Royal Infirmary. In clinical studies, the diagnostic role of angioscopy in quality control was evaluated by grafting preexisting, angioscopically detected, intraluminal abnormalities and correlating them with histological appearances. There were significant associations between angioscopy/histology grades and graft patency. To enable quantification of images, an innovative computerised video image processing method has been developed and validated against simultaneous ultrasound measurements of segments of saphenous vein. The therapeutic applications of angioscopy in vein graft preparation were studied prospectively in patients undergoing in situ femoropopliteal/distal bypasses by randomisation to full angioscopic or conventional preparation. There was a significant reduction in wound morbidity. Completion angioscopy and arteriography were complementary in the detection of technical defects. Harvested vein was maintained in organ culture to assess further the influence of pre-existing pathology and the potentially traumatic effects of angioscopy on development of neointimal hyperplasia. There was a significant correlation between the extent of pre-existing abnormality and smooth muscle cell proliferative activity in culture and although angioscopy caused endothelial cell loss, this did not stimulate neointimal hyperplasia in vitro. This work confirms that vein quality can be evaluated prospectively by angioscopy and that substandard vein is associated with inferior patency rates. Angioscopic and histological evaluation, together with vein organ culture studies, have definite application in helping to elucidate the mechanisms underlying graft failure.
Adult↗
Vein quality influences neointimal hyperplasia in an organ culture model of human saphenous vein.
OBJECTIVES: The severity of pre-existing pathological changes in human saphenous vein (HSV) correlates with the development of vein graft stenosis and graft patency. The aim of this study was to investigate the influence of pre-existing intimal hyperplasia on development of the neointima in vitro, using an organ culture model. MATERIALS AND METHODS: Segments of HSV were harvested during coronary artery bypass surgery. Histology was performed on part of the vein; the remainder was maintained in culture. Pre-existing intimal thickness (PIT) in HSV from day 0 and neointimal thickness (NIT) in cultured HSV were measured using computerised image analysis on histological sections. Day 0 and 14 veins were compared with respect to intimal hyperplasia. RESULTS: Twelve pairs of veins were examined. A mean tissue ATP of 297 nmoles/g wet weight for cultured. HSV confirmed cell viability. Mean PIT was 180 microns (CI: 86-274) and mean NIT was 60 microns (CI: 48-72), with a significant correlation between them using the Spearman Rank test (Rs = 0.72; p = 0.008). CONCLUSIONS: Pre-existing vein quality as measured by PIT correlates with the development of neointimal hyperplasia in culture, adding further support to clinical evidence that poor vein quality predisposes to vein graft stenosis due to an inherent susceptibility to intimal hyperplasia.
Graft Occlusion, Vascular↗
Embolisation from atrial myxomas: a cause of acute on chronic limb ischaemia.
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Adult↗
Duplex assessment of run-off before femorocrural reconstruction.
BACKGROUND: This study was a prospective evaluation of colour duplex imaging for the assessment of distal run-off before femorocrural reconstruction. METHODS: Patients with critical ischaemia who required a distal bypass underwent preoperative run-off assessments using dependent Doppler, arteriography and duplex imaging by a vascular surgeon, radiologist and technologist respectively; each was blinded to the findings of the others. Preoperative data were compared with intraoperative clinical findings and completion flow studies/ arteriograms. RESULTS: Forty-three consecutive patients (33 men, ten women; mean age 78 (range 53-95) years; 12 diabetic) undergoing 44 femorocrural reconstructions for critical ischaemia were assessed. The 30-day primary cumulative graft patency for the series was 86 per cent. Dependent Doppler correctly predicted a suitable run-off vessel in 21 limbs but was indeterminate in four and unrecordable in 19. Arteriography correctly predicted a suitable run-off vessel in 32 cases, but was indeterminate in six and failed to demonstrate run-off in three patients. Arteriography suggested an inferior vessel in three cases. Duplex correctly predicted a suitable run-off vessel for all 44 grafts. CONCLUSION: Duplex imaging is superior to arteriography for preoperative assessment of distal run-off for femorocrural reconstruction.
Aged↗
Vein graft stenosis: incidence and intervention.
OBJECTIVES: The incidence of vein graft stenosis ranges from 5%-45%. Reported rates appear to be increasing as technological advances make detection easier. The aim of this study was to review our experiences with regard to the incidence of stenosis in infrainguinal bypass grafts and the outcome of intervention for salvage of failing grafts. DESIGN: Retrospective review of graft surveillance records. SETTING: Vascular Studies Unit, Bristol Royal Infirmary. METHODS: A Duplex-based graft surveillance (GS) programme was used from January 1989 to June 1994 to study 275 primary graft procedures in 250 patients with lower limb ischaemia. Patients were scanned at 1 week, 6 weeks and 3, 6, 9 and 12 months postoperatively. RESULTS: One year cumulative limb salvage, patient survival and primary, primary assisted and secondary patencies were 91%, 83%, 67%, 77% and 84% respectively. Duplex scanning detected 85 vein graft stenoses in 59 patients: an incidence of 21.5%. In addition, 64 potentially graft-threatening inflow (14) and outflow (50) problems were detected in the native vessels of 52 patients from clamp damage or progression of disease (POD). Of the 85 graft stenoses, 40 were treated by balloon angioplasty (PTA) and 20 by surgical intervention and 1 patient's symptoms were treated by chemical sympathectomy. Twenty-four patients were not actively treated. Of the 64 grafts affected by POD, 20 were treated by PTA, 15 by surgery, one with anti-coagulation and 28 had no treatment. Comparing patients with non-treated and treated lesions, the respective 12 month cumulative patencies for patients with graft stenoses were 75% and 87.5% as against 86% and 83% for patients with POD (log rank test 0.1). CONCLUSIONS: These results uphold the perceived benefits of a GS programme, although the evidence from the non-treated cases in this series reinforces a need for a large, prospective, randomised trial to confirm the case for GS.
England↗
Angioscopically-assisted in situ saphenous vein bypass for infrainguinal revascularisation.
OBJECTIVES AND STUDY DESIGN: The diagnostic capability of angioscopy for endoluminal evaluation is established and its superiority over arteriography for completion studies has been confirmed. The therapeutic use of angioscopy in vein graft preparation is more controversial. The aim of this prospective study was to establish whether angioscopic vein preparation confers real benefits over existing techniques. METHODS: Forty-seven patients were randomised to either full angioscopic (ANG) vein preparation (23 patients) or conventional (CON) in situ grafting (19 patients). All patients underwent completion studies with arteriography and angioscopy and postoperatively, entered a Duplex graft surveillance programme. RESULTS: There was a significant difference in the incidence of wound morbidity: 26% in the ANG group as against 63% in the CON group (Fisher's exact test: p = 0.043), but no significant differences with respect to duration of operation, duration of vein graft preparation, length of hospital stay and both 30 day and 12 month secondary cumulative patencies (log rank test: p > 0.5). Completion angioscopy detected eight persistent valve cusps in six patients, all missed at arteriography, but failed to detect arteriovenous fistulae. CONCLUSIONS: Angioscopic preparation reduces wound morbidity and complements arteriography for detecting intraoperative defects. A large, prospective, randomised trial is now warranted to fully evaluate the potential therapeutic role of angioscopy with respect to current vascular practice.
Aged↗
Angioscopy for quality control of saphenous vein during bypass grafting.
OBJECTIVES: Although autogenous vein is the conduit of choice for infrainguinal bypass grafting, some 20-30% of vein grafts fail during the first year postoperatively. Many of these failed veins are now known to have pre-existing pathological changes. Angioscopy enables intraoperative endoluminal visualisation of veins and can reveal anomalies, some previously unsuspected, despite preoperative Duplex ultrasound mapping and normal external appearances. The aim of this study was to compare angioscopic findings with contemporary histological appearances and with subsequent graft outcome and ultimately, to identify those endoluminal features which might be predictive for failure. METHODS: Angioscopic vein inspection was carried out using Olympus 1.4 and 2.2mm angioscopes in patients undergoing femoropopliteal/distal bypass. Severe disease in the veins of five patients led to preferential use of polytetrafluoroethylene (PTFE) for above-knee bypasses. The remaining 38 videotaped sequences were reviewed by two surgeons and scored using a scale of 0 to 3, based on frequency and distribution of angioscopically detected lesions. These included haemorrhagic mural plaques, flimsy intraluminal strands, webs/bands and mobile/adherent thrombus. Vein harvested at operation was assessed by a pathologist according to the level of pre-existing abnormality. RESULTS: There were significant associations between angioscopy/histology scores and graft survival (chi 2 = 22.00; df:3; p < 0.001; chi 2 = 22.43; df:3; p < 0.001 respectively). There was a significant correlation between angioscopy and histology scores (R8 = 0.725; p < 0.001). CONCLUSIONS: Angioscopy allows immediate identification of the at risk, poor quality vein graft at the time of surgery, without the delays inherent with histological preparation and assessment. Recognition of abnormalities at angioscopy may ultimately improve graft outcome by prospectively eliminating use of poor vein.
Adult↗
Detection of sub-critical arterial stenoses by hyperaemic Doppler.
OBJECTIVES: This study assessed the potential of hyperaemic Doppler to detect sub-critical stenoses using a flowrig model. METHODS: Pulsatile flow of a blood substitute was produced in a compliant circuit. A cadaver carotid artery, constricted by a silk suture produced a variable, focal stenosis. Forty-seven stenoses were created in five arteries. Pressure gradients and Doppler measurements were recorded simultaneously across each stenosis at low (200 ml/min) and high (400 ml/min) flow rates. The change in peak velocities between the arterial segment 2cm proximal to the stenosis (V1), and the stenotic jet (V2) were used to calculate three Doppler indices: (i) V2/V1 ratio, (ii) V2-V1 difference, (iii) a modified 'Bernoulli' value. A high flow pressure gradient of > or = 15% of the resting distal pressure (% delta P), represented a significant stenosis. RESULTS: There was improved correlation between Doppler indices and % delta P at high flow (r = 0.87 to 0.88) compared to low flow rates (r = 0.81 to 0.84). Optimum V2/V1 cut off values were determined by received operator characteristics (ROC) curve analysis. At low flow five sub-critical stenoses were not detected (sensitivity 82.8%) yet all but one of these lesions were identified at high flow (sensitivity of 96.6%). The V2-V1 and Bernoulli indices did not improve on the discriminant ability of the V2/V1 ratio. CONCLUSIONS: The V2/V1 ratio is sensitive to haemodynamic changes at enhanced flow rates across ideal arterial stenoses. The potential of hyperaemic Doppler to detect sub-critical lesions and so avoid intraarterial pressure measurements deserves further in vivo study.
Arterial Occlusive Diseases↗
Hyperhomocysteinaemia is a risk factor for vein graft stenosis.
OBJECTIVES: Many infrainguinal vein graft failures are due to progressive vein graft stenosis (VGS) from intimal hyperplasia. Systemic factors have been implicated in the aetiology of intimal hyperplasia. Hyperhomocysteinaemia (HHCA) is established as an independent risk factor for coronary and peripheral arterial disease. The objective of this study was to examine the influence of HHCA and other serological factors upon the development of VGS. STUDY DESIGN: Thirty-eight patients who had undergone infrainguinal vein bypass were recruited to a case/control study from a graft surveillance program. Nineteen patients with documented VGS were matched against controls without stenosis for age, sex, length of time from surgery, diabetes, smoking history and preoperative symptom score. All patients were recalled for Duplex ultrasound scans, venesection and carbon monoxide estimation which were performed in a blinded fashion. RESULTS: Statistical analysis of all parameters revealed that plasma homocysteine was significantly elevated in patients with VGS (p < 0.3, Wilcoxon rank sum). CONCLUSIONS: These results suggest that HHCA is a previously unidentified risk factor for VGS. Patients with HHCA are susceptible to VGS and preoperative investigation would allow identification of patients at risk.
Adult↗
Influence of angioscopic vein graft preparation on development of neointimal hyperplasia in an organ culture model of human saphenous vein.
PURPOSE: Angioscopy for in situ vein graft preparation has been criticized on the basis that the trauma of instrumentation may predispose to accelerated intimal hyperplasia, jeopardizing patency rates following infrainguinal revascularization. The aim of this study was to assess the effects of angioscopic preparation on endothelial integrity and smooth muscle cell (SMC) behavior in an established organ culture model of human saphenous vein (HSV). METHODS: HSV was harvested from 12 patients during bypass surgery before and after angioscopic preparation. Endothelial integrity was evaluated by immunohistochemical staining with JC-70 and scanning electron microscopy (SEM); remaining segments of pre- and postangioscopy vein were maintained in culture for 14 days in medium supplemented with 30% fetal calf serum. Viability was confirmed by measurement of tissue adenosine triphosphate on day 14 and thickness of the neointima was measured by computerized image analysis of histologic sections. Monoclonal antibodies to proliferating cell nuclear antigen (PCNA) were used as an immunohistochemical marker for proliferating SMCs. RESULTS: There was a significant reduction in the percentage staining by JC-70 (71.3% versus 20.4%) in pre- versus postangioscopy vein (p = 0.002 by Wilcoxon's rank test; n = 12). This was supported by SEM images. Despite this, there were no significant differences between the pre- and postangioscopy HSVs after 14 days of culture with respect to neointimal thickness (61 versus 56 microns) and staining with PCNA (4.80 versus 4.08 nuclei per 10 microns), all according to Wilcoxon's rank test. CONCLUSIONS: Angioscopic vein graft preparation is associated with endothelial cell loss but does not induce additional neointimal hyperplasia in HSV in vitro. These results suggest that angioscopic manipulation does not alter SMC behavior.
Adenosine Triphosphate↗
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↗
Homocysteine: an independent risk factor for the failure of vascular intervention.
Hyperhomocysteinaemia is an independent risk factor for the early development of arterial disease. Homocysteine and cardiovascular risk factors were assessed in 41 young and 25 older patients with vascular disease. As homocysteine may act by the generation of free radicals, total antioxidant capacity was measured. Hyperhomocysteinaemia was found in 29 per cent of patients but there was no difference between young and older patients. Homocysteine level was unrelated to other cardiovascular risk factors. Young age, diabetes and hyperhomocysteinaemia were independent risk factors for the failure of vascular procedures (P = 0.006). Patients with hyperhomocysteinaemia had raised total antioxidant capacity. The potential of identifying and treating a subgroup of patients with a poor prognosis deserves further study.
Adult↗
Postocclusive hyperaemic duplex scan: a new method of aortoiliac assessment.
Aortoiliac duplex scanning, while accurate, is time-consuming and technically demanding. This study aimed to develop a fast, non-invasive screening test for aortoiliac disease. Colour duplex scanning was used to record common femoral Doppler ultrasonographic waveforms following 3 min of arterial occlusion using a thigh cuff in 25 patients with normal aortoiliac segments and 25 patients with significant aortoiliac disease. The latter patients had a prolonged period of postocclusive hyperaemic flow compared with the former. End diastolic velocity, 70 s after cuff release, was a significant discriminant between the two groups (sensitivity of 88 per cent, accuracy of 92 per cent). The postocclusive hyperaemic duplex (PHD) test performed well when used prospectively in a further 50 limbs (sensitivity of 86 per cent, accuracy of 84 per cent). The test was more sensitive than femoral pulse palpation and compared favourably with arteriography. The PHD test provides a simple, noninvasive assessment for aortoiliac disease that can be performed on the initial outpatient clinic visit.
Aged↗
Carotid endarterectomy: are we under-performing?
An audit of the number of carotid endarterectomies performed over the last 4 years was performed in the south western region. For the years 1990, 1991, 1992 and 1993 the number of cases were 126, 165, 165 and 164 respectively. It is estimated for this region that about 600 operations should be carried out per annum. This under-performance may reflect a lack of knowledge about the potential benefits of surgery.
Endarterectomy, Carotid↗
Treatment of intermittent claudication: the impact on quality of life.
OBJECTIVES: To measure changes in claudicant's quality of life after surgery, angioplasty or unsupervised exercise. To explore the relationship between clinical indicators of limb perfusion and patient's perception of health change. DESIGN: Prospective study. SETTING: University Hospital vascular outpatients. MATERIALS AND METHODS: 202 claudicants referred for Duplex of lower limb arterial disease over a 12 month period. The short form 36 questionnaire was used to determine quality of life. Ankle pressures and walking distances were determined. MAIN RESULTS: The SF-36 was completed by 186 patients (92%) before and after treatment (34 operative patients, 74 angioplasty and 78 treated by exercise alone). Baseline quality of life was worse in surgical patients. Unsupervised exercise produced minimal changes in quality of life. Angioplasty and operation produced similar, significant improvements in physical functioning and pain. Changes in physical function or pain scores were unrelated to changes in ankle pressure. CONCLUSIONS: Unsupervised exercise programs are unlikely to significantly improve patient's quality of life. The benefits of surgery and angioplasty support a relaxation in the indications for investigation and treatment of claudicants. Patients with impaired perceived health should not be denied treatment on the basis of preintervention ankle pressure or walking distance alone.
Analysis of Variance↗