[show abstract][hide abstract] ABSTRACT: An intention-to-treat analysis of the Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial showed that in patients with severe lower limb ischemia (SLI) due to infrainguinal disease who survived for 2 years after intervention, initial randomization to a bypass surgery (BSX)-first vs balloon angioplasty (BAP)-first revascularization strategy was associated with improvements in subsequent overall survival (OS) and amputation-free survival (AFS) of about 7 and 6 months, respectively. This study explored the value of baseline factors to estimate the likelihood of survival to 2 years for the trial cohort (Cox model) and for individual BASIL trial patients (Weibull model) as an aid to clinical decision making.
Of 452 patients presenting to 27 United Kingdom hospitals, 228 were randomly assigned to a BSX-first and 224 to a BAP-first revascularization strategy. Patients were monitored for at least 3 years. Baseline factors affecting the survival of the entire cohort were examined with a multivariate Cox model. The chances of survival at 1 and 2 years for patients with given baseline characteristics were estimated with a Weibull parametric model.
At the end of follow-up, 172 patients (38%) were alive without major limb amputation of the trial leg, and 202 (45%) were alive. Baseline factors that were significant in the Cox model were BASIL randomization stratification group, below knee Bollinger angiogram score, body mass index, age, diabetes, creatinine level, and smoking status. Using these factors to define five equally sized groups, we identified patients with 2-year survival rates of 50% to 90%. The factors that contributed to the Weibull predictive model were age, presence of tissue loss, serum creatinine, number of ankle pressure measurements detectable, maximum ankle pressure measured, a history of myocardial infarction or angina, a history of stroke or transient ischemia attack, below knee Bollinger angiogram score, body mass index, and smoking status.
Patients in the BASIL trial were at high risk of amputation and death regardless of revascularization strategy. However, baseline factors can be used to stratify those risks. Furthermore, within a parametric Weibull model, certain of these factors can be used to help predict outcomes for individuals. It may thus be possible to define the clinical and anatomic (angiographic) characteristics of SLI patients who are likely-and not likely-to live for >2 years after intervention. Used appropriately in the context of the BASIL trial outcomes, this may aid clinical decision making regarding a BSX- or BAP-first revascularization strategy in SLI patients like those randomized in BASIL.
Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 05/2010; 51(5 Suppl):52S-68S. · 3.52 Impact Factor
[show abstract][hide abstract] ABSTRACT: The Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial showed that survival in patients with severe lower limb ischemia (rest pain, tissue loss) who survived postintervention for >2 years after initial randomization to bypass surgery (BSX) vs balloon angioplasty (BAP) was associated with an improvement in subsequent amputation-free and overall survival of about 6 and 7 months, respectively. We now compare the effect on hospital costs and health-related quality of life (HRQOL) of the BSX-first and BAP-first revascularization strategies using a within-trial cost-effectiveness analysis.
We measured HRQOL using the Vascular Quality of Life Questionnaire (VascuQol), the Short Form 36 (SF-36), and the EuroQol (EQ-5D) health outcome measure up to 3 years from randomization. Hospital use was measured and valued using United Kingdom National Health Service hospital costs over 3 years. Analysis was by intention-to-treat. Incremental cost-effectiveness ratios were estimated for cost per quality-adjusted life-year (QALY) gained. Uncertainty was assessed using nonparametric bootstrapping of incremental costs and incremental effects.
No significant differences in HRQOL emerged when the two treatment strategies were compared. During the first year from randomization, the mean cost of inpatient hospital treatment in patients allocated to BSX ($34,378) was estimated to be about $8469 (95% confidence interval, $2,417-$14,522) greater than that of patients allocated to BAP ($25,909). Owing to increased costs subsequently incurred by the BAP patients, this difference decreased at the end of follow-up to $5521 ($45,322 for BSX vs $39,801 for BAP) and was no longer significant. The incremental cost-effectiveness ratio of a BSX-first strategy was $184,492 per QALY gained. The probability that BSX was more cost-effective than BAP was relatively low given the similar distributions in HRQOL, survival, and hospital costs.
Adopting a BSX-first strategy for patients with severe limb ischemia does result in a modest increase in hospital costs, with a small positive but insignificant gain in disease-specific and generic HRQOL. However, the real-world choice between BSX-first and BAP-first revascularization strategies for severe limb ischemia due to infrainguinal disease cannot depend on costs alone and will require a more comprehensive consideration of individual patient preferences conditioned by expectations of survival and other health outcomes.
Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 05/2010; 51(5 Suppl):43S-51S. · 3.52 Impact Factor
[show abstract][hide abstract] ABSTRACT: An intention-to-treat analysis of randomized Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial data showed that initial randomization to a bypass surgery (BSX)-first strategy was associated with improvements in subsequent overall survival (OS) and amputation-free survival (AFS) of about 7 and 6 months, respectively. We describe the nature and timing of first, crossover, and reinterventions and examine AFS and OS by first treatment received. We also compare vein with prosthetic BSX and transluminal with subintimal balloon angioplasty (BAP) and examine outcomes from BSX after failed BAP.
We randomly assigned 452 patients with SLI due to infrainguinal disease in 27 United Kingdom hospitals to a BSX first (n = 228) or a BAP first (n = 224) revascularization strategy. All patients have been monitored for 3 years and more than half for >5 years. We prospectively collected data on every procedure, major amputation, and death.
Patients randomized to BAP were more likely to have their assigned treatment first (94% vs 85%, P = .01, chi(2)test). BAP had a higher immediate technical failure rate of 20% vs 2.6% (P = .01, chi(2)test). By 12 weeks after randomization 9 BAP (4%) vs 23 BSX (10%) patients had not undergone revascularization; 3 BAP (1.3%) vs 13 BSX (5.8%) had undergone the opposite treatment first; and 35 BAP (15.6%) and 2 (0.9%) BSX had received the assigned treatment and then undergone the opposite treatment. BSX distal anastomoses were divided approximately equally between the above and below knee popliteal and crural arteries; most originated from the common femoral artery. About 25% of the grafts were prosthetic and >90% of vein BSX used ipsilateral great saphenous vein. Most (80%) BAP patients underwent treatment of the SFA alone (38%) or combined with the popliteal artery (42%) and crural arteries (20%). Outcome of vein BSX was better for AFS (P = 0.003) but not OS (P = 0.38, log-rank tests) than prosthetic BSX. There were no differences in outcome between approximately equal numbers of transluminal and subintimal BAP. AFS (P = 0.006) but not OS (P = 0.06, log rank test) survival was significantly worse after BSX after failed BAP than after BSX as a first revascularization attempt.
BAP was associated with a significantly higher early failure rate than BSX. Most BAP patients ultimately required surgery. BSX outcomes after failed BAP are significantly worse than for BSX performed as a first revascularization attempt. BSX with vein offers the best long term AFS and OS and, overall, BAP appears superior to prosthetic BSX.
Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 05/2010; 51(5 Suppl):18S-31S. · 3.52 Impact Factor
[show abstract][hide abstract] ABSTRACT: The Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial showed in patients with severe lower limb ischemia (rest pain, tissue loss) who survive for 2 years after intervention that initial randomization to bypass surgery, compared with balloon angioplasty, was associated with an improvement in subsequent amputation-free survival and overall survival of about 6 and 7 months, respectively. The aim of this report is to describe the angiographic severity and extent of infrainguinal arterial disease in the BASIL trial cohort so that the trial outcomes can be appropriately generalized to other patient cohorts with similar anatomic (angiographic) patterns of disease.
Preintervention angiograms were scored using the Bollinger method and the TransAtlantic Inter-Society Consensus (TASC) II classification system by three consultant interventional radiologists and two consultant vascular surgeons unaware of the treatment received or patient outcomes.
As was to be expected from the randomization process, patients in the two trial arms were well matched in terms of angiographic severity and extent of disease as documented by Bollinger and TASC II. In patients with the least overall disease, it tended to be concentrated in the superficial femoral and popliteal arteries, which were the commonest sites of disease overall. The below knee arteries became increasingly involved as the overall severity of disease increased, but the disease in the above knee arteries did not tend to worsen. The posterior tibial artery was the most diseased crural artery, whereas the peroneal appeared relatively spared. There was less interobserver disagreement with the Bollinger method than with the TASC II classification system, which also appears inherently less sensitive to clinically important differences in infrapopliteal disease among patients with severe leg ischemia.
Anatomic (angiographic) disease description in patients with severe leg ischemia requires a reproducible scoring system that is sensitive to differences in crural artery disease. The Bollinger system appears well suited for this purpose, but the TASC II classification system less so. We hope this detailed analysis will facilitate appropriate generalization of the BASIL trial data to other groups of patients affected by similar anatomic (angiographic) patterns of disease.
Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 05/2010; 51(5 Suppl):32S-42S. · 3.52 Impact Factor
[show abstract][hide abstract] ABSTRACT: A 2005 interim analysis of the Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial showed that in patients with severe lower limb ischemia (SLI; rest pain, ulceration, gangrene) due to infrainguinal disease, bypass surgery (BSX)-first and balloon angioplasty (BAP)-first revascularization strategies led to similar short-term clinical outcomes, although BSX was about one-third more expensive and morbidity was higher. We have monitored patients for a further 2.5 years and now report a final intention-to-treat (ITT) analysis of amputation-free survival (AFS) and overall survival (OS).
Of 452 enrolled patients in 27 United Kingdom hospitals, 228 were randomized to a BSX-first and 224 to a BAP-first revascularization strategy. All patients were monitored for 3 years and more than half for >5 years.
At the end of follow-up, 250 patients were dead (56%), 168 (38%) were alive without amputation, and 30 (7%) were alive with amputation. Four were lost to follow-up. AFS and OS did not differ between randomized treatments during the follow-up. For those patients surviving 2 years from randomization, however, BSX-first revascularization was associated with a reduced hazard ratio (HR) for subsequent AFS of 0.85 (95% confidence interval [CI], 0.5-1.07; P = .108) and for subsequent OS of 0.61 (95% CI, 0.50-0.75; P = .009) in an adjusted, time-dependent Cox proportional hazards model. For those patients who survived for 2 years after randomization, initial randomization to a BSX-first revascularization strategy was associated with an increase in subsequent restricted mean overall survival of 7.3 months (95% CI, 1.2-13.4 months, P = .02) and an increase in restricted mean AFS of 5.9 months (95% CI, 0.2-12.0 months, P = .06) during the subsequent mean follow-up of 3.1 years (range, 1-5.7 years).
Overall, there was no significant difference in AFS or OS between the two strategies. However, for those patients who survived for at least 2 years after randomization, a BSX-first revascularization strategy was associated with a significant increase in subsequent OS and a trend towards improved AFS.
Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 05/2010; 51(5 Suppl):5S-17S. · 3.52 Impact Factor
[show abstract][hide abstract] ABSTRACT: To compare a 'bypass-surgery-first' with a 'balloon-angioplasty-first' revascularisation strategy in patients with severe limb ischaemia (SLI) due to infrainguinal disease requiring immediate/early revascularisation.
A stratified randomised controlled trial. A Delphi consensus study of vascular surgeons' and interventional radiologists' views on SLI treatment was performed before the trial.
Twenty-seven UK hospitals.
Patients presenting with SLI as the result of infrainguinal atherosclerosis and who, in the opinion of the responsible consultant vascular surgeon and interventional radiologist, required and were suitable for both surgery and angioplasty.
Patients were randomised to either 'bypass-surgery-first' or 'balloon-angioplasty-first' revascularisation strategies.
The primary end point was amputation-free survival (AFS); secondary end points were overall survival (OS), health-related quality of life (HRQoL) and cost-effective use of hospital resources.
AFS at 1 and 3 years was not significantly different for surgery and angioplasty. Interim analysis showed that surgery was associated with significantly lower immediate failure, higher 30-day morbidity and lower 12-month reintervention rates than angioplasty; 30-day mortality was similar. Beyond 2 years from randomisation, hazard ratios (HRs) were significantly reduced for both AFS (adjusted HR 0.37; 95% CI 0.17 to 0.77; p = 0.008) and OS (HR 0.34; 95% CI 0.17 to 0.71; p = 0.004) for surgery relative to angioplasty. By 2008 all but four patients had been followed for 3 years, some for over 7 years: 250 (56%) were dead, 168 (38%) were alive without amputation and 30 (7%) were alive with amputation. Considering the follow-up period as a whole, AFS and OS did not differ between treatments but for patients surviving beyond 2 years from randomisation, bypass was associated with reduced HRs for AFS (HR 0.85; 95% CI 0.50 to 1.07; p = 0.108) and OS (HR 0.61; 95% CI 0.50 to 0.75; p = 0.009), equating to an increase in restricted mean OS of 7.3 months (p = 0.02) and AFS of 5.9 months (p = 0.06) during the subsequent follow-up period. Vein bypasses and angioplasties performed better than prosthetic bypasses. HRQoL was non-significantly better in the surgery group; amputation was associated with a significant reduction in HRQoL. Over the first year, hospital costs for bypass were significantly higher (difference 5420 pounds; 95% CI 1547 pounds to 9294 pounds) than for angioplasty. However, by 3 and at 7 years the differences in cost between the two strategies were no longer significant. Patients randomised to surgery lived, on average, 29 days longer at an additional average cost of 2310 pounds. A 36-month perspective showed not significantly different mean quality-adjusted life times for angioplasty and surgery. The Delphi study revealed substantial disagreement between and among surgeons and radiologists on the appropriateness of bypass surgery or balloon angioplasty.
The findings of our study suggest that in patients with SLI due to infrainguinal disease the decision whether to perform bypass surgery or balloon angioplasty first appears to depend upon anticipated life expectancy. Patients expected to live less than 2 years should usually be offered balloon angioplasty first as it is associated with less morbidity and cost, and such patients are unlikely to enjoy the longer-term benefits of surgery. By contrast, those patients expected to live beyond 2 years should usually be offered bypass surgery first, especially where a vein is available as a conduit. Many patients who could not undergo a vein bypass would probably have been better served by a first attempt at balloon angioplasty than prosthetic bypass. The failure rate of angioplasty in SLI is high (c. 25%) and patients who underwent bypass after failed angioplasty fared significantly worse than those who underwent surgery as their first procedure. The interests of a significant proportion of BASIL patients may have been best served by primary amputation followed by high-quality rehabilitation. Further research is required to confirm or refute the BASIL findings and recommendations; validate the BASIL survival prediction model in a separate cohort of patients with SLI; examine the clinical and cost-effectiveness of new endovascular techniques and devices; and compare revascularisation with primary amputation and with best medical and nursing care in those SLI patients with the poorest survival prospects.
Current Controlled Trials ISRCTN45398889.
Health technology assessment (Winchester, England). 03/2010; 14(14):1-210, iii-iv.
[show abstract][hide abstract] ABSTRACT: There is continuing controversy as to whether surgical bypass or angioplasty should be first-line treatment of severe limb ischemia. We undertook this study to examine angiographic and clinical factors that influence the treatment of severe limb ischemia by vascular surgeons and interventional radiologists.
Twenty consultant vascular surgeons and 17 consultant vascular interventional radiologists evaluated 596 hypothetical clinical or angiographic scenarios, and recorded whether, in their opinion, the most appropriate first-line treatment was surgical bypass, angioplasty, or primary amputation. Stepwise multiple linear regression was used to identify the factors that significantly affected responses from the entire group and from surgeons and radiologists separately.
There were significant differences between surgeons and radiologists with regard to how clinical and angiographic variables determined treatment preferences. Increasing disease severity, absence of runoff into the foot, presence of a suitable vein, and tissue loss as opposed to rest pain only (the latter only significant to surgeons) all increased the response score toward surgery. However, surgeons and radiologists weighted each of these factors quite differently. Even in the most complex statistical model, 19% of surgical and 13% of radiologic response variations remained unexplained.
Individual surgeons and radiologists vary considerably in their views of the relative merits of surgery and angioplasty in patients with severe limb ischemia. This broad gray area mandates the need for randomized controlled trial data to inform joint decision-making and to optimize patient outcome.
Journal of Vascular Surgery 06/2004; 39(5):1026-32. · 2.88 Impact Factor
[show abstract][hide abstract] ABSTRACT: To examine the level of agreement among vascular surgeons and interventional radiologists regarding their preference for the surgical or endovascular management of severe limb ischaemia.
Delphi consensus study using 596 different hypothetical patient scenarios.
Delphi consensus group for the Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial.
Twenty consultant vascular surgeons and 17 interventional radiologists completed both rounds of the study. The scenarios detailed the anatomical extent of disease, whether the patients had rest pain only or had tissue loss, and whether or not a suitable vein for bypass was available. Panellists were asked to score their treatment preference for either surgery or angioplasty on an eight-point scale. Outliers (top 10% and bottom 10% responses) were removed. If the remaining 80% of responses fell within a 3-point range, this was defined as "agreement". If they did not, this was considered "disagreement".
There was substantial disagreement in 484 (81%) of scenarios in round 1 and 401 (67%) in round 2. This disagreement was greater among surgeon than radiologists in both round 1 (83 vs 65%) and round 2 (69 vs 42%). Surgeons also demonstrated less convergence between rounds.
There is substantial disagreement between and among surgeons and radiologists with regard to the appropriateness of surgery or angioplasty for severe limb ischaemia. This lack of consensus stems from the absence of an evidence base and means that the same patient may receive entirely different treatment depending on which hospital and consultant they attend. Not only may this unexplained variation be clinically unsatisfactory, it has major implications for the planning and use of health service resources.
European Journal of Vascular and Endovascular Surgery 12/2002; 24(5):411-6. · 2.82 Impact Factor
[show abstract][hide abstract] ABSTRACT: BACKGROUND: Percutaneous transluminal angioplasty (PTA) is increasingly performed for lower limb ischaemia of all severities, despite the absence of controlled data demonstrating its efficacy. The aim of this study was to examine the indications and outcome for lower limb ischaemia over a 16-year period. METHODS: A prospectively gathered database of 1287 consecutive PTAs performed between 1982 and 1997 was analysed. Two time intervals were compared: 1982-1991 and 1992-1997. RESULTS: Since 1992 there has been a fourfold increase in the number of PTAs performed. There has been a significant increase in the number of PTAs performed for critical ischaemia, occlusive lesions and at infrainguinal sites. Although there has been a significant reduction in morbidity, the number of immediate technical and clinical failures has increased (see Table ). CONCLUSION: Despite a lack of controlled data supporting a more liberal use of PTA in the treatment of lower limb ischaemia, there has been, in this regional vascular unit, a significant increase in the perceived clinical and anatomical indications for the procedure. Randomized controlled trials are urgently required to define the role of PTA in this condition.
British Journal of Surgery 06/1999; 86(5):704. · 4.84 Impact Factor
[show abstract][hide abstract] ABSTRACT: BACKGROUND: Despite the absence of controlled data supporting endovascular treatment of iliac disease in patients with intermittent claudication (IC), there has been a significant increase in iliac percutaneous transluminal angioplasty (PTA), and in particular iliac stenting, in recent years. The clinical and haemodynamic outcome of iliac PTA, with and without stenting, was assessed in patients with IC. METHODS: A prospectively gathered computerized database of iliac PTA (n = 203) and stenting (n = 88), performed between 1 January 1991 and 31 December 1997, was analysed. RESULTS: Occlusive disease was significantly more likely than stenotic disease to be treated by primary stent deployment (19 of 88, 22 per cent) than PTA alone (11 of 203, 5 per cent) (P < 0.01, chi2 test), as were lesions in the common iliac artery (common 69 of 214 (32 per cent) versus external 14 of 65 (22 per cent); P < 0.05, chi2 test). Primary stent placement was associated with a significant increase in morbidity that delayed hospital stay (13 of 88 (15 per cent) versus seven of 203 (3 per cent); P < 0.05, chi2 test). Emergency revascularization was required in four patients who underwent PTA (2 per cent) and two who had stenting (2 per cent) (P not significant). CONCLUSION: Iliac stenting is associated with a significant increase in morbidity but with no improvement in symptomatic or haemodynamic outcome. These results do not justify the increased expense associated with the routine use of iliac stents.
British Journal of Surgery 05/1999; 86(5):704-5. · 4.84 Impact Factor
[show abstract][hide abstract] ABSTRACT: Clinical outcome was studied in 243 patients undergoing 260 carotid endarterectomies; 166 of these patients underwent serial postoperative surveillance imaging. Including perioperative events, cumulative freedom from ipsilateral stroke was 86 and 82 per cent at 5 and 10 years respectively; the mean incidence of ipsilateral stroke was 1.8 per cent per annum. Twenty patients (8 per cent) suffered cerebral ischaemic events in the hemisphere of the operated side during follow-up: eight transient ischaemic attacks (TIA) and 12 strokes (only two preceded by TIA). Two symptomatic patients were found to have occluded the operated artery but the remainder had no evidence of significant recurrent disease. Cumulative freedom from occlusion or severe (greater than 70 per cent) recurrent stenosis was 87 and 78 per cent at 5 and 10 years respectively; the mean incidence of recurrence of significant disease was 2.2 per cent per annum. No revisional surgery was performed on the operated arteries. In its current format, neither clinical nor surveillance imaging could have prevented any of the strokes observed during follow-up.
British Journal of Surgery 05/1996; 83(4):522-6. · 4.84 Impact Factor
[show abstract][hide abstract] ABSTRACT: The long-term fate of the non-operated internal carotid artery (ICA) in 219 patients undergoing contralateral carotid endarterectomy was studied; 151 patients underwent serial postoperative imaging of the vessel. Cumulative freedom from stroke in the non-operated hemisphere was 99, 96 and 86 per cent at 1, 5 and 10 years respectively, giving a mean incidence of stroke of 1 per cent per annum. Only one stroke was preceded by a transient ischaemic attack and no stroke was associated with severe (70 per cent or greater) stenosis of the ICA. Ten patients (7 per cent) with initially mild or moderate disease of the non-operated ICA progressed to severe stenosis during follow-up, but only three became symptomatic and, in each case, the onset of symptoms preceded recognition of disease progression. The long-term risk of stroke in the non-operated ICA territory is very small. Of practical importance is that none of the observed strokes could have been prevented by postoperative surveillance of this type.
British Journal of Surgery 02/1995; 82(1):44-8. · 4.84 Impact Factor
[show abstract][hide abstract] ABSTRACT: Lower-limb percutaneous transluminal angioplasty (PTA) has been used increasingly over the past decade, either alone or in conjunction with arterial reconstructive surgery. However, its impact on operation rates has not been evaluated properly. Rates of vascular operations and PTAs performed per referral for peripheral arterial disease to the regional vascular service at The Royal Infirmary, Edinburgh, were calculated for the years 1986-1992. The overall rate of PTA for peripheral arterial disease increased ninefold over this period; that for critical ischaemia increased fivefold. Rates of aortic and femoral reconstruction for all peripheral arterial disease increased by 40 and 100 per cent respectively, but rates for critical ischaemia remained static. The major amputation rate rose by 47 per cent between 1986 and 1990, and thereafter reached a plateau. Increased use of PTA was not associated with a reduction in the number of vascular operations.
British Journal of Surgery 07/1994; 81(6):832-5. · 4.84 Impact Factor
[show abstract][hide abstract] ABSTRACT: Cerebrovascular reserve (CVR) was studied in 104 consecutive patients with symptomatic carotid territory disease and ipsilateral internal carotid artery stenosis. Overall, 30 of 104 patients (29 per cent) had impaired CVR. The frequency of CVR impairment increased with the severity of internal carotid artery stenosis: impairment was present in none of 11 patients with stenosis of less than 50 per cent, four of 24 with stenosis of 50-69 per cent, 14 of 41 with stenosis of 70-89 per cent and 12 of 28 with stenosis of 90-99 per cent. Patients presenting with a stroke were significantly more likely to have impaired CVR than those with transient ischaemic attacks and/or amaurosis fugax (odds ratio 3.7 (95 per cent confidence interval (c.i.) 1.5-9.0)), as were those with a residual neurological deficit (odds ratio 4.3 (95 per cent c.i. 1.6-11.5)) and evidence of infarction from computed tomography (odds ratio 3.8 (95 per cent c.i. 1.6-9.4)).
British Journal of Surgery 02/1994; 81(1):45-8. · 4.84 Impact Factor
[show abstract][hide abstract] ABSTRACT: A radioisotopic method of quantifying mean cerebral transit time was used to assess the immediate effects of carotid endarterectomy on cerebrovascular reserve (CVR) in 69 patients. In addition, serial postoperative data were acquired on CVR, clinical status and non-invasive imaging of the internal carotid arteries in 56 patients over a period of 6-48 (median 24) months. Twenty-one patients (30 per cent) had preoperative evidence of impaired CVR in the symptomatic hemisphere. Within 4 days of surgery, however, reserve had returned to normal in 17 of the 21 patients. During follow-up, four of the 56 patients developed recurrent stenosis (> 50 per cent) or occlusion of the artery operated on but only two of these had impairment of CVR and none was symptomatic. Three patients suffered recurrent transient ischaemic attacks (TIAs) but none had recurrent internal carotid artery disease or impaired CVR. One patient suffered a TIA in the territory of the non-operated artery during follow-up in association with disease progression and CVR impairment. However, the TIA preceded recognition of either of these changes. Twelve other patients had (or developed) stenosis (> 50 per cent) in the non-operated artery during follow-up but none was symptomatic or developed impairment of CVR. Although assessment of CVR provided useful information on the frequency of haemodynamic compromise before carotid endarterectomy and on the natural history of disease progression, neither serial assessment of reserve nor non-invasive imaging of the carotid bifurcation influenced clinical practice during follow-up.
British Journal of Surgery 11/1993; 80(10):1278-82. · 4.84 Impact Factor
[show abstract][hide abstract] ABSTRACT: Changes in the patient population and trends in management were studied for 260 consecutive carotid endarterectomies performed during the periods 1975-1982 and 1983-1990. A 43% increase was observed in the number of operations (from 107 to 153), an 81% increase taking into account patients randomized to medical treatment in the European Carotid Surgery Trial. There were significant reductions in patients continuing to smoke (79 to 60%, P = 0.001), in those with systolic hypertension (21 to 11%, P = 0.018) and diastolic hypertension (26 to 12%, P = 0.002), and in those with asymptomatic carotid lesions (8 to 2%, P = 0.031). There were significant increases in the proportion of patients with strokes presenting with a residual neurological deficit (40 to 66%, P = 0.024), and in those with ocular symptoms (30 to 50%, P = 0.001) and with stenoses greater than 50% (58 to 71%, P = 0.018). This study suggests a trend for a higher risk population with more severe carotid disease. In the light of results of clinical trials, further evolution of patient selection is likely to occur and should be taken into account when evaluating the risk of carotid endarterectomy.
Journal of the Royal College of Surgeons of Edinburgh 07/1993; 38(3):138-41.
[show abstract][hide abstract] ABSTRACT: The aim of this study was to determine the accuracy of Doppler waveform characteristics in grading femoropopliteal stenoses and to determine the interobserver and intraobserver reproducibility of measuring the same waveform characteristics.
Thirty patients with isolated areas of stenosis found by arteriography were evaluated by color duplex sonography. Each patient underwent scanning by two observers on two separate occasions. Each observer was blind to the other's results. Doppler spectra were recorded in areas where color change suggested the highest velocity and also at the nearest normal proximal area. Peak systolic velocity, spectral broadening, and waveform configuration were measured at each site.
An increase in peak systolic velocity of more than 200% accurately predicted a 50% or greater reduction in luminal diameter on angiography (70% sensitivity, 96% specificity). The presence of spectral broadening and an abnormal waveform shape were found to correlate poorly with the degree of stenosis. Analysis of variance showed no significant difference between observers in velocity measurements (p = 0.78).
We conclude that although stenoses of greater than 50% can be distinguished from minor stenoses, more precise definition of the degree of narrowing is unlikely. The good repeatability of the velocity ratio makes it an excellent tool for monitoring major changes in the progression of disease.
Journal of Vascular Surgery 04/1993; 17(3):510-7. · 2.88 Impact Factor
[show abstract][hide abstract] ABSTRACT: Time, expense, risk and discomfort are incurred by arteriography in patients with intermittent claudication who might be candidates for percutaneous transluminal angioplasty (PTA). A valid screening technique could reduce the need for arteriography in patients found to have lesions not amenable to PTA. Agreement between Doppler colour flow imaging (DCFI) and angiography for detecting haemodynamically significant lesions is high, but DCFI may not identify lesions suitable for angioplasty. A total of 36 limbs in 30 patients were studied using DCFI before angiography. Agreement between the two methods was excellent (kappa = 0.91), and the predictive accuracy of DCFI for lesions amenable to PTA was good (kappa = 0.78, sensitivity 94 per cent, specificity 85 per cent, positive predictive value 83 per cent, negative predictive value 94 per cent, overall accuracy 89 per cent). DCFI is a useful screening process that may prevent unnecessary angiography, with consequent financial savings and clinical benefit.
British Journal of Surgery 10/1992; 79(9):907-9. · 4.84 Impact Factor