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Background The current advancement and increasing use of diagnostic imaging has led to increased detection of abdominal aortic aneurysms (AAA). Many of these patients are unfit for elective AAA surgery. Aim To investigate the outcome of conservative management of unfit patients with large AAA (>5.5 cm) who are turned down for elective surgical intervention. Patients and methods Between January 2006 and April 2017, 457 patients presented with AAA >5.5 cm. Seventy-six patients (M: F 54:22) were deemed unfit for elective repair. Mean age was 79.8 years (range 64–96). Mean AAA size was 60.22 mm (55–83). Results Forty-nine of the 76 patients (64%) had died by April 2017. Fifteen (19.7%) patients died directly because of their aneurysm rupture. A further 34 (44.7%) patients died from non-aneurysm-related causes. Conclusion Patients with large AAA deemed unfit for elective surgery have an overall poor prognosis and die mainly from other causes than AAA. Surgical intervention when rupture occurs results in poor survival.

Data on vascular patients following amputation in Ireland is lacking, limiting capability to plan services. This paper seeks to benchmark survival and rehabilitation outcomes among vascular patients in Ireland following lower extremity amputation (LEA), and compare subgroups of those undergoing transfemoral (TFA) or transtibial amputation (TTA). A review was conducted of all patients who underwent non-traumatic TFA or TTA from 2000 to 2009 in a tertiary vascular surgery centre. Demographics, surgical data, perioperative outcomes, medium-term functional outcomes, and survival were assessed. One hundred and seventy-two patients (2:1 male: female) underwent 192 non-traumatic LEAs. Median age for TFA was 75 years and TTA 67 (p = 0.002). A percentage of 36.5% had undergone prior attempts at surgical revascularization, 25% had undergone prior distal amputation or debridement. Thirty-three (17%) required stump revision. Twenty-three (13.2%) died in hospital. Median survival for those who died in hospital was 17 days (0–367), versus 17 months (2–106) for those who survived to discharge. LEA for vascular pathology has significant morbidity and mortality, with long in-patient stays and short median survival; there is need to focus on improving quality of life in postoperative pathways.

The modem emergency management of the acutely ischemic limb has evolved considerably with the introduction of catheter-directed thrombolysis. Following preservation of life, the next goal of intervention in these emergency cases, whether with surgery or thrombolysis, is limb salvage. We report our own experience with both approaches in the early outcome of the emergency management of the acutely ischemic limb. This is a retrospective review of a tertiary-level vascular unit’s experience. The inclusion criteria consisted of acute limb ischemia as defined by the guidelines of the Vascular Surgical Society of Great Britain and Ireland. Data acquisition used the hospital’s inpatient enquiry system, and its operative and radiology databases. Analysis used the χ2 test and the Yates correction factor (p 70 years: χ2 = 5.4, d.f. = 1, 0.01 < p, 0.02) (χ2: p= 0.05). Seventy-one patients underwent preoperative angiography. Successful limb salvage was achieved in 75% of cases. Overall, the amputation and mortality rates were 16.5% and 13.1%, respectively. We initially treated 62% of events with surgery and 38% with thrombolysis. In those patients who underwent thrombolysis there, 31% went on to have reconstructive surgery. Thrombolytic treatment resulted in a limb salvage rate of 69%. Thrombolysis was discontinued in six cases due to complications. Significant differences in outcome were not demonstrable between the two treatment groups (χ2 = 1.1, d.f. = 1, 0.5 < p < 0.1). Acute limb ischemia has significant morbidity and mortality rates. The use of catheter-directed thrombolysis offers the surgeon an alternative to emergency surgery. This approach does not demonstrate any increase in the rate of limb loss.

New blood vessels in atherosclerotic lesions are postulated to be responsible for plaque instability by acting as conduits for inflammatory cells. This study assessed the association between macrophage content of plaque caps of carotid atherosclerotic lesions, plaque vascularity, and endothelial-cell activation within these blood vessels. Carotid endarterectomy specimens from patients who underwent endarterectomy for carotid occlusive disease (ten symptomatic, six asymptomatic) were examined. Sequential transverse sections were obtained and were stained conventionally and immunohistochemically with CD 34 (an endothelial-cell marker) and CD 68 (a macrophage marker), as well as VCAM-1 and ICAM-1 (markers of endothelial-cell activation). Microvessel and macrophage counts were performed for the whole plaque and the plaque cap respectively. The differences in microvessel density, macrophage content, and ICAM-1 and VCAM-1 expression, between symptomatic and asymptomatic patients and in different plaque types were examined, as was the association between microvessel density and microvessel content of atherosclerotic lesions. Higher microvessel counts were observed in patients with symptomatic carotid occlusive disease (p < 0.01). Higher ICAM-1 and VCAM-1 expression was noted in new blood vessels in plaques obtained from patients with symptomatic carotid occlusive disease, compared with asymptomatic patients (p < 0.001 and p < 0.01 respectively). A close association was observed between macrophage content of the plaque cap and microvessel counts in atherosclerotic lesions (p < 0.0001), as well as ICAM-1 (p < 0.001) and VCAM-1 (p < 0.001) expression, in these microvessels. This study highlights the significance of neovascularity and endothelial-cell activation in the evolution of symptomatic carotid occlusive disease. Furthermore, it points to a relationship between the inflammatory process and angiogenesis within the plaque, which may be mediated through endothelial-cell activation.

The aim of our work was to study the relationship between Doppler ultrasound velocity measurements and the presence of histologic features of plaque instability in carotid atherosclerosis, in particular, intraplaque hemorrhage (IPH). Consecutive patients undergoing carotid endarterectomy in a one-year period were included. All patients were examined by duplex ultrasonography and carotid angiography. Endarterectomy specimens were examined histologically for features of plaque instability. The quantity of IPH was measured by digital image analysis. The associations between Peak Systolic Velocity (PSV), end-diastolic velocity (EDV), degree of ICA stenosis, shape and length of the lesion and the features of plaque instability and quantity of IPH were assessed. Seventy-four patients (20 asymptomatic, 54 symptomatic) were included. PSV was independently associated with the presence of significant IPH [p < 0.001, OR = 1.04 (95% CI = 1.01–1.06)], as was the degree of angiographic ICA stenosis [p < 0.05, OR = 0.98 (95% CI = 0.92–1.6)]. Neither EDV nor the shape of the lesion was associated with IPH (p = 0.26 and p = 0.38, respectively). A close correlation was observed between PSV and the quantity of IPH (r2 = 0.68, p < 0.0001). A significant association was observed between PSV and the presence of plaque ulceration (p < 0.05); however, this was not found to be independent of the quantity of IPH and the degree of ICA stenosis [p = 0.17, OR = 1.28 (95% CI = 0.6–2.44)]. PSV at the site of ICA stenosis appears to be associated with the quantity of intraplaque hemorrhage, independent of the angiographic degree of ICA stenosis. We propose that the role of Doppler velocity measurements extends beyond measurement of the degree of ICA stenosis. Increased ICA peak systolic velocity by itself may be an indicator of atherosclerotic plaque instability.

Nous avons etudie l'association entre la vascularisation de la plaque, au moment de la survenue des symptomes neurologiques et oculaires et la presence d'un infarctus cerebral au niveau de l'hemisphere cerebral homolaterale sur les tomodensitometries (TDM) pre-operatoires. Nous avons inclus des malades consecutifs ayant une endarteriectomie carotidienne pour stenose carotidienne. Tous les malades ont eu en pre-operatoire une TDM cerebrale sans injection de produit de contraste. Des coupes histologiques des pieces d'endarteriectomie carotidienne ont ete realisees et colorees avec un marqueur des cellules endotheliales (CD34). Des comptes des microvaisseaux ont ete realises dans les coupes colorees par le CD34 et verifies par une analyse d'images computerisees. L'association entre la densite des microvaisseaux dans les plaques atherosclereuses carotidiennes, la presence pre-operatoire d'un infarctus cerebral a la TDM et le moment des evenements neurologiques et oculaires homolateraux ont ete precises. Soixante-treize malades ont eu une endarteriectomie carotidienne, dont 17 avaient ete symptomatiques dans les 30 jours precedent l'endarteriectomie carotidienne, 11 etaient asymptomatiques et 45 autres avaient un intervalle pre-operatoire sans symptome de 31 a 540 jours (mediane 56 jours). Dix-huit malades (24,6%) avaient a la TDM un infarctus cerebral. Des comptes de microvaisseaux significativement plus importants ont ete observes chez les malades ayant a la TDM un infarctus cerebral dans l'hemisphere correspondant par rapport aux malades n'en ayant pas (p = 0,02). Il existait une relation inverse entre la densite de microvaisseaux dans les lesions atherosclereuses et le moment de l'evenement neurologique ischemique (odds ratio (OR) = 4,63, intervalle de confiance (IC) a 95% 2,95-7,28, p

Objective Colonic infarction is a recognized complication of abdominal aortic aneurysm (AAA) surgery. The clinical difficulty in establishing the diagnosis combined with the patient’s poor physiological status is usually associated with a fatal outcome. We assessed our experience with this problem to identify a possible risk factor profile for these patients. Method Patients records were identified from the operative logs, intensive care unit, Hospital Inpatient Enquiry system and vascular unit databases over a 6-year period. Results A total of 405 patients underwent AAA repair during this period; 140 as emergency ruptures. Nine patients were identified from the databases with known colonic infarction (2.2%). One was a woman. The mean age was 70 years. Seven patients had emergency ruptures (5%). Twenty independent risk factors were analysed using univariate and multivariate logistic regression models. Significant risk factors identified by using a multivariate analysis included the nature of the presenting patient, preoperative hypotension, prolonged cross-clamp time, intra-operative ischaemia and postoperative acidosis. Confirmatory diagnosis was made by colonoscopy in eight patients. One patient survived following the salvage surgery. The mean duration of survival was 10.5 days. The overall mortality was 89% of patients. Conclusion In our unit infrarenal AAA repair has a 2.2% rate of colonic infarction. A definitive diagnosis is best made by colonoscopy. A risk factor profile for the development of colonic infarction may be constructed on the basis of specific clinical parameters. Earlier intervention on the basis of this profile may ultimately reduce the current excessive mortality.

Introduction Concern about the potential detrimental side-effects of β-blockade on pulmonary function often dissuades against their perioperative use in patients undergoing major arterial surgery (especially in those with chronic obstructive pulmonary disease (COPD)). In this study we aimed to establish prospectively the clinical relevance of these concerns. Methods After ethics committee approval and individual informed consent, the pulmonary function of twenty patients (mean age 68.7 years (range 43–82), 11 males) scheduled to undergo non-emergency major vascular surgery was studied by recording symptoms and spirometry before and after institution of effective β-blockade. Fifteen patients (75%) had significant smoking histories (mean pack years/patient = 50), while 12 (60%) had COPD. Results All patients tolerated effective β-blockade satisfactorily without developing either subjective deterioration in symptoms or significant change on spirometry. The mean change in FEV1 following adequate β-blockade was 0.05 ± 0.24 liters (95% CI −0.06 to +1.61), p = 0.35, giving a mean percentage change of 3.18% ± 11.66 (95% CI −2.26 to 8.62). Conclusions Previously held concerns about worsening pulmonary function through the short-term use of β-blockers should not dissuade their perioperative usage in patients with peripheral vascular disease. Furthermore, the accuracy of pulmonary function tests in preoperative assessment and risk stratification also appears unaffected by this therapy.

Traditionally treatment of aorto-enteric fistulae involved placement of an extra-anatomic bypass and graft excision. This is associated with limb loss (10-40%) and high mortality (10-70%). More recently in situ revascularisation has been advocated.To examine our experience with the changing management of aorto-enteric fistulae over a 22-year period.Demographic, clinical, operative and pathological data were recorded retrospectively.Twenty-one patients were included. Seven had primary fistulae. Six died prior to intervention. Five had an extra-anatomical bypass (60% mortality, 40% limb loss), four had in-situ revascularisation (25% mortality), four had a primary repair (25% mortality) and two had insertion of a tube graft (primary fistulae). The overall survival rate was 38%. The postoperative survival rate was 6o%.Techniques for operative management continue to evolve. The current trend is towards a local surgical approach with prolonged and intensive postoperative antimicrobial therapy. In our experience this approach has yielded acceptable outcomes.

Duplex ultrasound criteria use a combination of velocity measurements to evaluate internal carotid artery (ICA) stenosis. These evaluations divide ICA stenosis into broad categories. The aim of this study was to design an artificial neural network (ANN) capable of predicting the exact degree of ICA stenosis based on duplex velocity measurements. Consecutive patients with significant carotid atherosclerosis underwent carotid duplex ultrasound and angiography. Peak systolic and end-diastolic velocities in the ICA and common carotid artery were measured. Multilayered perceptron ANNs were constructed and trained to predict the degree of ICA stenosis and band the degree of ICA stenosis into 10% intervals based on these measurements. The accuracy of the ANN models in predicting the degree of ICA stenosis and classifying the ICA stenosis was compared with the angiographic degree of ICA stenosis and duplex velocity criteria. A total of 208 carotid bifurcations were studied. ANNs were able to accurately predict the degree of angiographic ICA stenosis (R2 = 0.9374, p0.0001) and band the ICA stenosis into the predefined 10% intervals [sensitivity 97.3% (95% CI 90.7-99.3), specificity 97.7 % (95% CI 93.6-99.2), accuracy 97.5%]. The ANN model was more accurate [discriminant power (DP) = 4.11] in banding the degree of ICA stenosis than duplex velocity criteria (DP = 1.67) (p0.05). The accuracy of the ANN in correctly identifying70% ICA stenosis was 98.4% [sensitivity 96.4% (95% CI 93.8-99.3), specificity 98.7% (95% CI 93.4-99.8), DP = 4.21]. ANNs can accurately predict the degree of ICA stenosis. With further refinement, ANNs could replace velocity criteria in the assessment of ICA stenosis using duplex ultrasound.

Objectives. We assessed the impact of transthoracic endoscopic sympathectomy (TES) on the quality of life of patients with palmar hyperhydrosis.Design. A retrospective questionnaire based study.Methods. Patients undergoing TES at our institution between 1997 and 2002 received a SF-36 quality of life postal questionnaire. The pre- and post-operative symptoms were assessed. Statistical analysis was by means of the Student's t test.Results. Ninety-four TES were carried out in 62 patients. Forty-one cases were female. The age range was 17–64 years. The mean follow-up period was 38.46 months. Mean hospital stay was 3 days. Compensatory hyperhydrosis was reported in 29 cases and only considered severe in four cases (9.7%). Forty-one patients replied to the questionnaire (66%). The overall quality of life (as assessed by the SF-36 form) was unanimously improved (p

Background Angiogenesis is a recognized feature of the atherosclerotic process and has been described in the context of unstable coronary atherosclerotic lesions. The aim of this study was to assess the association between angiogenesis in atherosclerotic carotid plaques and microscopic features of plaque instability, in particular intraplaque haemorrhage. Methods Consecutive patients undergoing carotid endarterectomy were included. Endarterectomy specimens were divided into their constituent atherosclerotic lesions. Histological sections were prepared and stained with haematoxylin and eosin, and immunohistochemically with an endothelial cell marker (CD34). The quantity of intraplaque haemorrhage was measured in transverse histological sections using computerized image analysis. Microvessel counts were performed in CD34-stained sections and were verified through computerized image analysis. Results Some 239 atherosclerotic lesions from 73 patients were available for analysis; 73 were early lesions, 74 were raised fibroatheromas and 92 were unstable atherosclerotic plaques. One hundred and fifty lesions were not haemorrhagic; 89 exhibited intraplaque haemorrhage, of which 28 involved less than 50 per cent of the plaque sectional area. There were higher microvessel counts in plaques containing over 50 per cent haemorrhage (P < 0·0001), unstable atherosclerotic lesions (P < 0·0001) and atherosclerotic lesions obtained from symptomatic patients (P < 0·001). Conclusion There are strong associations between plaque vascularity, quantity of intraplaque haemorrhage and presence of symptomatic carotid occlusive disease.

We present the case of a healthy 43-year-old smoker who, presented with lower back pain and raised inflammatory markers. He was diagnosed with two mycotic aneurysms and Streptococcus pneumoniae as the causative agent. He was treated with high dose antibiotics for 6 weeks prior to his two separate surgical procedures. These were uncomplicated. He remains well 18 months post-surgery. There is no clear consensus as to the optimal timing of surgery for mycotic aneurysms, but surgery and antimicrobial therapy are the cornerstones of treatment. We optimised our patients' outcome by planning the timing of antimicrobial therapy, and staged surgical intervention for a successful outcome.

Developmental anomalies of the inferior vena cava (IVC) have an estimated prevalence of 0.5%, and may be the common aetiology in young patients presenting with bilateral lower limb iliofemoral thrombosis. We report a case of spontaneous bilateral iliofemoral deep venous thrombosis secondary to infrahepatic IVC agenesis. The patient had associated thrombosis of the azygous and hemiazygous venous system and collateralisation via the venous plexus of the paravertebral muscles. To our knowledge, this is the first such case reported of IVC agenesis dependent upon collateral return via the paravertebral muscles.

The incidence of graft-enteric fistulae following aortic aneurysm repair ranges from 0.4 to 2.4% with duodenal involvement in 75% of cases and carries a mortality rate approaching 55%. Graft-enteric erosion is an even rarer complication of aortic surgery. We report a case of graft-enteric erosion following trouser graft for aorto-iliac occlusive disease that involved complete cannibalization of the limb of the graft into the ileal lumen.

Patients undergoing major vascular surgery (MVS) require extensive anaesthetic assessment. This can require extended pre-operative stays. We investigated whether a newly established anaesthetic pre-operative assessment clinic (PAC) would reduce the pre-operative inpatient stay, avoid unnecessary investigations and facilitate day before surgery (DBS) admissions for patients undergoing MVS. One year following and preceding the establishment of the PAC the records of patients undergoing open or endovascular aortic aneurysm repair, carotid endarterectomy and infra-inguinal bypass were reviewed to measure pre-operative length of stay (LoS). Pre-operative LoS was significantly reduced in the study period (1.85 vs. 4.2 days, respectively, P

Currently, crude morbidity and mortality rates are used to assess vascular surgical outcome. However, as a high-risk specialty, this may not be representative of quality of care. We evaluated the POSSUM score as a measure of performance in our vascular unit, and also its usefulness on an individual patient basis for predicting outcome. A total of 106 patients were prospectively scored using the vascular-POSSUM score, and mean predicted and observed morbidity and mortality were compared with one-sample t tests. Receiver operator characteristic curves were used to determine if POSSUM scores were associated with the end-points of morbidity and mortality. Predicted and observed morbidity (41 and 35.8%, respectively) were not significantly different (P = 0.066). POSSUM did, however, over-predict mortality at 9.7% compared to the observed mortality of 5.7% (P = 0.021). While the discrimination for predicting morbidity was poor, POSSUM scores were significantly associated with mortality end-points (area under ROC curve = 0.97250). POSSUM morbidity scores closely correlate with observed outcomes. Although POSSUM did over-predict mortality, high mortality scores may be useful for identifying patients at particularly high risk post-operatively. The POSSUM score is a useful adjunct to interpretation of morbidity and mortality statistics, and we would recommend its wider implementation for surgical audit.

We studied the association between plaque vascularity, timing of neurological and ocular symptoms, and presence of cerebral infarction in the ipsilateral cerebral hemisphere on preoperative computed tomographic (CT) scan. Consecutive patients undergoing carotid endarterectomy for carotid stenosis were included. All patients underwent preoperative noncontrast cerebral CT. Histological sections were obtained from carotid endarterectomy specimens and stained with an endothelial cell marker (CD34). Microvessel counts were performed in CD34-stained sections and verified through computerized image analysis. Associations between microvessel density in carotid atherosclerotic plaques, preoperative ipsilateral CT evidence of cerebral infarction, and timing of ipsilateral neurological and ocular events were assessed. Seventy-three patients underwent carotid endarterectomy, of whom 17 were symptomatic within 30 days of carotid endarterectomy, 11 were asymptomatic, and a further 45 had a preoperative symptom-free interval of 31-540 days (median = 56). Eighteen patients (24.6%) had CT evidence of cerebral infarction. Significantly higher microvessel counts were observed in patients with CT evidence of cerebral infarction in the appropriate hemisphere compared with patients who did not (p = 0.02). There was an inverse relationship between the microvessel density in atherosclerotic lesions and the timing of ischemic neurological events (odds ratio [OR] = 4.63, 95% confidence interval [CI] 2.95-7.28, p < 0.001). This relationship was independent of patient age (OR = 1.03, 95% CI 0.55-1.99, p = 0.70), sex (OR = 1.18, 95% CI 0.47-2.05, p = 0.56), smoking (OR = 1.07, 95% CI 0.54-2.09, p = 0.84), diabetes (OR = 0.90, 95% CI 0.45-1.79, p = 0.76), and hypercholesterolemia (OR = 0.98, 95% CI 0.68-1.11, p = 0.88). This study confirms the relationship between angiogenesis in carotid atherosclerotic lesions and development and chronology of ipsilateral hemispheric neurological events.

Our ability to maintain satisfactory levels of outcome after elective abdominal aortic aneurysm (AAA) surgery is increasingly strained by rising levels of co-morbidity in the presenting population. In this study we present a comparative outcome analysis of patients undergoing elective AAA surgery 18 months before and after the establishment of a surgical high dependency unit (HDU).The preoperative status (ASA and POSSUM scores), operative factors and postoperative outcomes as well as duration of stay were calculated for 104 patients undergoing elective AAA repair (57 prior to the HDU opening and 47 patients afterwards).Patients undergoing surgery in the latter period had significantly higher ASA (2.5 +/- 0.06 versus 2.7 +/- 0.7; p = 0.007), overall POSSUM (33.2 +/- 0.5 versus 35.5 +/- 0.8; p = 0.02) and physiological POSSUM (16.3 +/- 0.3 versus 15.5 +/- 0.2; p = 0.048) scores than those operated on prior to establishment of the HDU (data are mean +/- SEM; 2-tailed p-score). The two groups had similar total lengths of hospital stay (518 versus 534 days). However, following establishment of the HDU patients occupied fewer ICU bed days (110 versus 181). This resulted in a saving of Euro 50,750.The efficiency and quality of care following elective AAA surgery can be improved by provision of HDU step-down facilities without significantly increased expenditure.

Comparative vascular surgical audit offers a validated simple method of assessing surgical performance and quality of care.

Acute limb ischaemia has a significant morbidity and mortality. In selected cases, the use of catheter directed tPA thrombolysis offers the surgeon an alternative to emergency surgery. This approach does not demonstrate any increase in the rate of limb loss.

TOS remains difficult to diagnose. Symptomatic improvement occurs in the majority following surgery (87%). The supraclavicular approach has a significantly lower complication rate when compared with the transaxillary approach.

In this unit, infrarenal AAA repair has a 2.25% rate of IC following repair. The main risk factors for this include emergency repair and preoperative hypotension. An unexplained neutrophilia and progressive renal failure should also heighten clinical suspicions; however, a definitive diagnosis is best made by colonoscopy. Despite emergency colonic resection, the prognosis remains extremely poor with a mortality approaching 90%.

Background Duplex imaging is increasingly used as a stand-alone investigation before carotid endarterectomy. There is concern regarding the wide variation in diagnostic methods of grading internal carotid artery (ICA) stenosis using duplex velocity criteria. The aim of the study was to design an artificial neural network (ANN) that is able to provide a measure of the degree of ICA stenosis based on the four most commonly used duplex velocity profiles. Methods One hundred and four consecutive patients who were admitted for assessment of carotid occlusive disease were included. All patients underwent arch injection digital subtraction angiography and carotid duplex ultrasonography. Peak systolic velocity (PSV) and end-diastolic velocity (EDV) in the ICA and common carotid artery (CCA) were measured. The degree of angiographic stenosis was measured by two blinded investigators. A three-layered perceptron ANN was constructed using the NeuroSolutionsTM version 1 software program (NeuroDimension, Gainesville, FL, USA). The accuracy of the model in predicting the degree of ICA stenosis was expressed as the mean squared error (MSE) of the actual degree of angiographic stenosis. The performance of the neural network model was compared with that of the linear regression model at predicting the degree of ICA stenosis and classifying a degree of ICA stenosis greater than 50 per cent. Results One hundred and sixty-eight carotid bifurcations were available for analysis. The MSE of the ANN at predicting the degree of ICA stenosis was 0·096 (overall accuracy of 84 per cent), which was superior to a linear regression model (MSE 0·132; overall accuracy 73 per cent) (P < 0·001). Both models were equally accurate at identifying a degree of ICA stenosis greater than 50 per cent (ANN accuracy 0·91 versus regression model accuracy 0·89; P = 0·09). Conclusion Neural network algorithms are able to predict the degree of ICA stenosis with reasonable accuracy and outperform linear regression analysis on the basis of a limited set of duplex velocity measurements. With further refinement, ANN models could replace duplex criteria in assessment of the degree of ICA stenosis.

Background Intimal angiogenesis is a recognized feature of the atherosclerotic process. It has been described in the context of unstable coronary atherosclerotic lesions. The aims of this study were to assess the association between angiogenesis in atherosclerotic plaques and microscopic features of plaque instability, in particular intraplaque haemorrhage. Methods Consecutive patients undergoing carotid endarterectomy for carotid stenosis were included in the study. Endarterectomy specimens were examined and divided into their constituent atherosclerotic lesions. Histological sections were prepared and stained with haematoxylin and eosin, and immunohistochemically with an endothelial cell marker (CD34). Each lesion was classified according to the American Heart Association classification of atherosclerotic lesions. The size of plaque haemorrhage was measured in transverse histological sections using computerized image analysis. Haemorrhagic lesions were classified according to the size of haemorrhagic area (under 50 per cent of section area; over 50 per cent of section area). Microvessel counts were performed in CD34-stained sections at × 400 magnification and were verified with computerized image analysis. The Kruskal–Wallis test was used to study the differences in microvessel count in different atherosclerotic plaque types. Results A total of 239 atherosclerotic lesions from 73 patients was available for analysis, of which 73 were early lesions, 74 were raised fibroatheromas and 92 were unstable atherosclerotic plaques. One hundred and fifty lesions were not haemorrhagic; 89 exhibited intraplaque haemorrhage, of which 28 involved less than 50 per cent of the plaque section area. In 61 lesions the haemorrhage area was over 50 per cent of the section area. There were higher microvessel counts in plaques containing more than 50 per cent haemorrhage (median 277 (range 43–467)) compared with those containing less than 50 per cent (172 (57–372)) and non-haemorrhagic plaques (81 (7–389)) (P < 0·0001). Higher microvessel counts were observed in unstable atherosclerotic lesions (median 252 (range 43–467)), compared with stable fibroatheromas (106 (14–302)) and early atherosclerotic lesions (55 (7–237)) (P < 0·0001). Conclusion There are strong associations between plaque vascularity and presence and size of haemorrhage within atherosclerotic lesions, as well as features of plaque instability. This finding highlights the likely significance of these new blood vessels in the development of plaque instability and subsequent risk of stroke.

Background Expansion of carotid atherosclerotic plaques as a result of intraplaque haemorrhage has been implicated in the development of ischaemic neurological events. The relationship between the quantity of haemorrhage in the dominant atherosclerotic lesion, the degree of internal carotid artery (ICA) stenosis and the chronology of patients' symptoms was examined. Methods Consecutive patients undergoing carotid endarterectomy were included. The nature and timing of symptoms were recorded. Aortic arch injection digital subtraction angiography was performed before operation. Carotid endarterectomy specimens were serially sectioned and examined histologically. The amount of intraplaque haemorrhage was measured with digital image analysis. The influence of timing of symptoms on the quantity of intraplaque haemorrhage was compared with Kaplan–Meier analysis. Correlation between degree of ICA stenosis and quantity of intraplaque haemorrhage was assessed by means of regression analysis. Results Seventy-four patients (20 asymptomatic, 54 symptomatic) were included. The median latency of symptoms was 28 (1–600) days. Intraplaque haemorrhage was common: 54 (73 per cent) of 74 patients. Mean(s.e.m.) cumulative symptom-free survival before operation for patients with no intraplaque haemorrhage was 0·71(0·11), compared with 0·58(0·11) in those exhibiting haemorrhage in less than 50 per cent of the plaque area, and 0·20(0·07) in lesions with over 50 per cent (P = 0·002). A close correlation was observed between the degree of ICA stenosis and haemorrhagic content of the dominant atherosclerotic lesion (r2 = 0·433, P < 0·001). Conclusion These results confirm the association between intraplaque haemorrhage and the degree of ICA stenosis. They further demonstrate an association between the size of haemorrhage and timing of neurological events, suggesting a causative role for intraplaque haemorrhage in the development of ischaemic neurological events.

Intimal hyperplasia is the universal response to endothelial denudation and occurs after a variety of vascular procedures. In a proportion of cases the smooth muscle cell proliferation may lead to stenosis of the blood vessels. These vessels exhibit increased sensitivity to noradrenaline that can be reduced by the α1-adrenergic antagonist prazosin. Because the α1-adrenergic receptor and platelet-derived growth factor (which promotes vascular smooth muscle cell proliferation) act through the same metabolic pathway, it was postulated that α1-adrenergic blockade might reduce the development of intimal hyperplasia. Twenty-eight New Zealand White rabbits underwent endothelial denudation of the aorta using a Fogarty balloon catheter. Test rabbits were treated with prazosin from the day of operation until they were killed. All rabbits were killed either 1 or 4 weeks after endothelial denudation. Intimal hyperplasia in cross-sections of the aorta was measured using an X — Y digitizer and was standardized in terms of percentage luminal reduction. Prazosintreated rabbits had significantly less luminal reduction at 1 week (0·75(1·8) versus 9·7(3·1) per cent, mean (s.d.), P