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Biomedical subjects

I C Chetter

Publications and source records attributed to I C Chetter.

At least 19 recordsLinked to original sources
PubMed2006

A non-randomised controlled trial of the clinical and cost effectiveness of a Supervised Exercise Programme for claudication.

OBJECTIVES: The main aims of treatment in patients with intermittent claudication (IC) are to improve the clinical indicators of lower limb ischaemia and patients' quality of life (QoL). The aims of this study were assess the clinical and cost effectiveness of a supervised exercise programme (SEP) in patients with IC. DESIGN: Non-randomised, controlled trial. SETTING: University teaching hospital. PATIENTS AND METHODS: Two groups of patients with IC were studied. Seventy patients were sequentially recruited before and after the establishment of a Supervised Exercise Programme at our unit. Thirty-seven patients (median age 69 years, 26 men) received conservative medical therapy (CMT) and 33 patients (median age 67 years, 22 men) received CMT plus a 3 month SEP of graduated physical exercise for sixty minutes, three times each week. Patients were assessed prior to and at 6 months following treatment. At each assessment patient reported walking distances (PRWD), treadmill claudication and maximal distances (ICD and MWD), ankle brachial pressure indices (ABPI) pre & post exercise and patient reported QoL using the SF36 questionnaire were assessed. RESULTS: Prior to intervention the two groups were well matched. Following treatment, CMT patients demonstrated no significant change in PRWD or ICD but did record a small but significant improvement in MWD. CMT was also associated with a negative effect size in the SF36 index and in 7 of the 8 SF36 QoL domains, effect size >-0.5 for the domains of Physical Function and Emotional Role. SEP patients demonstrated significant improvement in PRWD, ICD and MWD. SEP was associated with a positive effect size in the SF36 index and in 2 SF36 QoL domains but a negative effect size in a further 2 domains. However, all QoL effect sizes following SEP were < +/-0.5. Intergroup differences in effect sizes were >0.5 for the SF36 domains of Physical Function, Physical Role, Emotion Role and SF36 index. SEP resulted in a 0.027 quality adjusted life year (QALY) gain over CMT in the first year post-treatment thus the cost/QALY gained of SEP is pound1780 at 1 year. CONCLUSIONS: Compared to CMT, SEP increases walking distances, improves QoL and is a highly cost-effective treatment for IC.

Aged↗
PubMed2006

Randomized clinical trial comparing multiple stab incision phlebectomy and transilluminated powered phlebectomy for varicose veins.

BACKGROUND: The aim was to compare early postoperative subjective outcome measures in a randomized trial of multiple stab incision phlebectomy (MSIP) and transilluminated powered phlebectomy (TIPP) for the treatment of varicose veins. METHODS: Patients having surgery for varicose veins were randomized to receive either MSIP or TIPP for local avulsion of varicose veins. Operating time, number of incisions and postoperative outcome were analysed in both groups. Quality of life (QoL) was analysed before and 1 and 6 weeks after surgery using domain-specific (Burford pain scale), disease-specific (Aberdeen Varicose Vein Questionnaire) and generic (Short Form 36 and EuroQol 5D) instruments. RESULTS: Sixty-six patients consented to participate in the trial but four withdrew before surgery, so 33 patients underwent MSIP and 29 patients had TIPP. All patients had symptomatic or complicated varicose veins. There was no significant difference between groups in the total duration of surgery or the time taken for the avulsions. The number of incisions was significantly lower with TIPP. However, skin bruising at 1 and 6 weeks, and Burford pain score at 6 weeks were significantly higher in the TIPP group (P < 0.01 for bruising and P = 0.019 for pain). TIPP also had a greater adverse impact on generic QoL, resulting in a more prolonged recovery. CONCLUSION: TIPP had the advantage of fewer surgical incisions, but was associated with more extensive bruising, prolonged pain and reduced early postoperative QoL.

Adult↗
PubMed2005

Heat shock proteins in vascular disease--a review.

INTRODUCTION: There is growing evidence that heat shock proteins (HSPs), a family of stress-inducible proteins may be involved in the pathogenesis of atherosclerotic vascular diseases. Here, we systematically review the evidence behind this notion. METHODS: A detailed literature search and extensive bibliographic review of literature relating to HSPs and atherosclerotic vascular disease. RESULTS: Atherosclerotic vascular disease is classified into four main areas of presentation: carotid, coronary, aortic and peripheral vascular disease, for consideration in this review. In each of these vascular diseases, the evidence linking HSPs and atherosclerosis is outlined in a systematic manner. Current evidence suggests that components of the immune system may be involved in the pathogenesis of atherosclerosis, with HSPs acting as auto-antigens in the immune response. HSPs are detected in atherosclerotic lesions and antibodies to HSPs are increased in patients with vascular disease; the rise often correlating with the severity of atherosclerosis. The levels of anti-HSP antibodies have been shown to be independent predictors of risk and have prognostic value. CONCLUSION: There is a strong link between heat shock protein expression and the principal manifestations of atherosclerotic vascular diseases. A better understanding of this involvement could lead to the development of new and improved treatment strategies.

Aortic Diseases↗
PubMed2004

The value of abdominal examination in the diagnosis of abdominal aortic aneurysm.

BACKGROUND: There is considerable variability in the reported value of clinical examination in the diagnosis of abdominal aortic aneurysms (AAA). This study aims to assess accuracy of abdominal examination by a doctor, a nurse and the patient in the diagnosis of AAA and whether this accuracy is related to the size of the aneurysm and/or the BMI of the patient. METHODS: 164 patients, 138 men and 26 women, median age 71 years, consented to participate in this prospective, single blind, controlled study. Thirty-nine patients attending for carotid duplex were used as controls. Abdominal examination was performed by a doctor and a nurse. Patients then performed self-examination. RESULTS: Examination by a doctor, a nurse and the patient were similar in accuracy in diagnosing/excluding AAA which was directly related to AAA size and patient BMI. The Negative Predicted Value of abdominal examination exceeds 0.9 with AAA diameters > or =4 cm and the Positive Predictive Value exceeds 0.8 with AAA diameters > or =5 cm. CONCLUSIONS: Abdominal examination by a doctor, a nurse and the patient is of value in the exclusion and diagnosis of significant AAA. It should be promoted and may represent a useful adjunct to population screening with ultrasound.

Aged↗
PubMed2004

A comparative study of aortic wall stress using finite element analysis for ruptured and non-ruptured abdominal aortic aneurysms.

BACKGROUND: The decision to repair an asymptomatic abdominal aortic aneurysm (AAA) is currently based on diameter (> or =5.5 cm) alone. However, aneurysms less than 5.5 cm do rupture while some reach greater than 5.5 cm without rupturing. Hence the need to predict the risk of rupture on an individual patient basis is important. This study aims to calculate and compare wall stress in ruptured and non-ruptured AAA. METHODS: The 3D geometries of AAA were derived from CT scans of 27 patients (12 ruptured and 15 non-ruptured). AAA geometry, systolic blood pressure and literature derived material properties, were utilised to calculate wall stress for individual AAA using finite element analysis. RESULTS: Peak wall stress was significantly higher in the ruptured AAA (mean 1.02 MPa) than the non-ruptured AAA (mean 0.62 MPa). In patients with an identifiable site of rupture on CT scan, the area of peak wall stress correlated with rupture site. CONCLUSIONS: Peak wall stress can be calculated from routinely performed CT scans and may be a better predictor of risk of rupture than AAA diameter on an individual patient basis.

Aged↗
PubMed2002

How effective is acute normovolaemic haemodilution in femoro-distal bypass surgery?

BACKGROUND: Recent guidelines have emphasised the use of autologous blood in the surgical setting. The aim of this study was to analyse the efficacy and efficiency of acute normovolaemic haemodilution (ANH) as a blood conservation intervention in patients undergoing elective femoro-distal surgery for critical limb ischaemia. METHODS: Forty patients were studied prospectively. The volume of the blood collected was derived as follows: Blood volume removed = patient's blood volume (initial haematocrit - final haematocrit/average haematocrit) where final haematocrit is 30% and patient's blood volume is 70 and 65 ml/kg for a man and a woman, respectively. RESULTS: Twenty-five patients were suitable for ANH and 15 patients were excluded because of poor ventricular function, anaemia or renal disease. Nine of the 25 patients (44%) had <500ml of surgical blood loss and would have avoided homologous blood transfusion (HBT). Four of the patients lost >2000ml of blood and could not avoid HBT through ANH. Twelve patients had moderate blood loss (950-1400 ml), with eight of these patients requiring transfusion. Four patients avoided exposure to homologous blood. CONCLUSION: ANH is in evolution and as a single blood conservation intervention, contributes only modestly to blood conservation.

Aged↗
PubMed2002

POSSUM and P-POSSUM overpredict mortality for carotid endarterectomy.

OBJECTIVES: the aim was to test the predictive accuracy of POSSUM and P-POSSUM on patients undergoing CEA. DESIGN: retrospective and prospective study. MATERIALS: 499 CEAs performed by four vascular surgeons from a single unit from 1992-99. The median age was 68 (range 38-86) and 60% were men. METHODS: physiological parameters, operative parameters and the 30-day mortality were collected. Predicted mortality for each patient was calculated using POSSUM and P-POSSUM equations. Patients were stratified into risk groups and observed and predicted deaths were compared. Accuracy of the prediction was assessed using chi-squared analysis. RESULTS: the observed 30-day mortality was 1.8% (9/499). The predicted deaths using POSSUM and P-POSSUM analysis were 49 and 25 respectively compared to nine observed deaths. There was significant evidence of lack of fit of both models in predicting mortality (chi-squared analysis, p<0.05). CONCLUSIONS: POSSUM and P-POSSUM overpredict mortality and are unsuitable for comparative audit of CEA. Models developed specific for CEA might accurately predict mortality.

Adult↗
PubMed2002

A Bayesian hierarchical approach to comparative audit for carotid surgery.

OBJECTIVES: the aim of this study was to illustrate how a Bayesian hierarchical modelling approach can aid the reliable comparison of outcome rates between surgeons. DESIGN: retrospective analysis of prospective and retrospective data. MATERIALS: binary outcome data (death/stroke within 30 days), together with information on 15 possible risk factors specific for CEA were available on 836 CEAs performed by four vascular surgeons from 1992-99. The median patient age was 68 (range 38-86) years and 60% were men. METHODS: the model was developed using the WinBUGS software. After adjusting for patient-level risk factors, a cross-validatory approach was adopted to identify "divergent" performance. A ranking exercise was also carried out. RESULTS: the overall observed 30-day stroke/death rate was 3.9% (33/836). The model found diabetes, stroke and heart disease to be significant risk factors. There was no significant difference between the predicted and observed outcome rates for any surgeon (Bayesian p -value>0.05). Each surgeon had a median rank of 3 with associated 95% CI 1.0-5.0, despite the variability of observed stroke/death rate from 2.9-4.4%. After risk adjustment, there was very little residual between-surgeon variability in outcome rate. CONCLUSIONS: Bayesian hierarchical models can help to accurately quantify the uncertainty associated with surgeons' performance and rank.

Adult↗
PubMed2001

Risk modelling study for carotid endarterectomy.

BACKGROUND: The aims of this study were to identify factors that influence the risk of stroke or death following carotid endarterectomy (CEA) and to develop a model to aid in comparative audit of vascular surgeons and units. METHODS: A series of 839 CEAs performed by four vascular surgeons between 1992 and 1999 was analysed. Multiple logistic regression analysis was used to model the effect of 15 possible risk factors on the 30-day risk of stroke or death. Outcome was compared for four surgeons and two units after adjustment for the significant risk factors. RESULTS: The overall 30-day stroke or death rate was 3.9 per cent (29 of 741). Heart disease, diabetes and stroke were significant risk factors. The 30-day predicted stroke or death rates increased with increasing risk scores. The observed 30-day stroke or death rate was 3.9 per cent for both vascular units and varied from 3.0 to 4.2 per cent for the four vascular surgeons. Differences in the outcomes between the surgeons and vascular units did not reach statistical significance after risk adjustment. CONCLUSION: Diabetes, heart disease and stroke are significant risk factors for stroke or death following CEA. The risk score model identified patients at higher risk and aided in comparative audit.

Adult↗
PubMed2001

The analysis of sensitivity, specificity, positive predictive value and negative predictive value of cold provocation thermography in the objective diagnosis of the hand-arm vibration syndrome.

The diagnosis of digital artery vasospasm in the hand-arm vibration syndrome (HAVS) is clinically based, and the need for an accurate objective test to support the diagnosis has been highlighted. This study aims to analyse the potential of cold provocation thermography (CPT) to fulfill this role. CPT was performed on two groups of subjects: 10 controls and 21 patients with Raynaud's phenomenon (RP) secondary to HAVS. After taking a pre-cooling image, patients donned latex gloves and immersed their hands in water at a temperature of 5 degrees C for 1 min. The patients removed their hands from the water and discarded the gloves, and further images were taken every 30 s for 10 min. On each image, the temperatures of the tip and base were analysed for each digit. The sensitivity, specificity, positive and negative predictive values for fingertip temperatures only, fingertip and fingerbase temperatures combined, and fingertip temperature, fingerbase temperature and temperature gradient combined were determined. Patients with RP secondary to HAVS demonstrated significantly lower finger tip and base temperatures and lower digital temperature gradients at all time intervals when compared with controls (P < 0.01, Student's t-test). CPT has good sensitivity, specificity, positive predictive value and negative predictive value; it strongly supports the clinical diagnosis of digital vasospasm.

Adult↗
PubMed1999

Does angioplasty improve the quality of life for claudicants?: A prospective study.

This study aims to analyze the impact of percutaneous transluminal angioplasty (PTA) for claudication on patients' quality of life (QOL). The patients in this study included 108 claudicants, 74 men and 34 women, with a median age of 67 years (range 40-87 years), who were assessed prior to and at 1, 3, and 6 months following PTA. This is the first report to demonstrate that the previously well-documented improvements in the clinical indicators of lower-limb ischemia are accompanied by improvements in individual QOL domains and in overall global QOL. These findings are detectable within a month following PTA and last at least 6 months. The results of this study may go some way to provide proof of efficacy for the procedure and thus help justify the recently questioned widespread use of PTA in clinical practice.

Aged↗
PubMed1999

Does soluble intercellular adhesion molecule-1 (ICAM-1) affect neutrophil activation and adhesion following ischaemia-reperfusion?

OBJECTIVES: To examine the effect of reperfusion plasma and sICAM-1 on neutrophil integrin expression and neutrophil adhesion to determine if sICAM-1 has a potential role in the regulation of neutrophil adhesion. MATERIALS: Twenty-seven patients, 17 men and 10 women undergoing femorodistal surgery. Blood was taken preoperatively and from the femoral vein following the release of the cross-clamp. Neutrophils were obtained from five volunteers and incubated with phosphate buffered saline (PBS), preoperative plasma or reperfusion plasma with and without sICAM-1. Neutrophil expression of CD11b and adhesion were measured. MAIN RESULTS: Neutrophil CD11b expression did not change following incubation in the three media. Neutrophil adhesion increased significantly following exposure to reperfusion plasma compared to PBS or preoperative plasma (45.5 adhesion vs. 12.75%, p < 0.01 Mann-Whitney U-test). Soluble ICAM-1 decreased CD11b expression and adhesion in neutrophils exposed to reperfusion plasma only (CD11b expression fell from 15.9 to 3.4 mcf, p < 0.01 Mann-Whitney U-test and adhesion fell to 11.6% cells adhered, p < 0.01). CONCLUSION: An increase in CD11b expression is not required for an increase in neutrophil adhesion. The change in neutrophil adhesion produced by reperfusion plasma can be blocked by sICAM-1. Soluble ICAM-1 may have a physiological role in the regulation of neutrophil adhesion.

Aged↗
PubMed1998

The hand arm vibration syndrome: a review.

Since its first description over eight decades ago, the hand arm vibration syndrome-- vibration white finger as it was previously known--has become one of the most common prescribed diseases in the industrialized world. This article is intended to provide a broad review of existing evidence and knowledge regarding a disease which, for medicolegal reasons, demands attention from all medical personnel. Detailed discussion is presented regarding: the multifactorial aetiology of the syndrome; suggestions for clinical assessment, laboratory investigations and classification of disease severity; and strategies for the prevention and treatment of the syndrome.

Fingers↗
PubMed1998

Percutaneous transluminal angioplasty for intermittent claudication: evidence on which to base the medicine.

OBJECTIVES: This study aims to assess the impact of PTA on the quality of life (QoL) of claudicants and to analyse which patients and which arterial lesions derive the most benefit. DESIGN: A prospective observational study. MATERIALS: One hundred and seventeen claudicants undergoing PTA were studied; 35 patients had bilateral disease, whilst 82 had unilateral disease and underwent PTA to a solitary iliac lesion, solitary superficial femoral or a iliac lesion above a diseased superficial femoral artery in 24, 39 and 19 cases, respectively. METHODS: Patients completed the Short Form 36 (SF36) and EuroQol (EQ) QoL assessment instruments prior to and at 1, 3, 6, and 12 months following intervention. The SF36 produces a QoL profile, whilst the EQ produces two QoL indices. RESULTS: Claudication has a deleterious effect on QoL, especially in patients with multi-segment disease. PTA results in an immediate and lasting improvement in the QoL of claudicants. Unilateral claudicants undergoing PTA to a solitary iliac lesion demonstrate the most marked QoL benefits and 12 months post PTA report a QoL approaching that of an age-matched population. Patients with bilateral claudication undergoing unilateral PTA and unilateral claudicants undergoing PTA to a solitary SFA lesion demonstrate some QoL benefits, but at 12 months post PTA do not approach the QoL scores of an age-matched population. Unilateral claudicants undergoing iliac PTA above a diseased SFA demonstrate minimal QoL changes. CONCLUSIONS: These results should influence decision making in the management of claudication and it may be possible to prioritise PTA waiting lists to ensure patients with greatest potential benefit are treated with most urgency.

Adult↗
PubMed1998

Reduced total antioxidant capacity predicts ischaemia-reperfusion injury after femorodistal bypass.

BACKGROUND: Antioxidant defence systems are essential to protect the body from harmful free radicals released following ischaemia-reperfusion. The aim of this study was to examine the total antioxidant capacity (TAC) of patients with chronic critical leg ischaemia undergoing femorodistal bypass and to correlate this with lipid peroxidation, changes in capillary permeability and clinical outcome. METHODS: Twenty-five patients, 15 men and ten women of median age 71 (range 62-79) years, and 15 matched controls were studied. Blood was taken before operation and after reperfusion, with assays performed for malondialdehyde (a product of lipid peroxidation) and total antioxidant capacity. Changes in capillary permeability were measured by changes in the urinary albumin:creatinine ratio (ACR) following reperfusion of the ischaemic leg and expressed as a percentage increase from the preoperative value. Clinical outcome in terms of the systemic inflammatory response syndrome (SIRS) was recorded. RESULTS: Vascular patients who developed clinical evidence of a systemic inflammatory reaction following revascularization had a significantly reduced TAC compared with the controls (490 versus 860 mumol/l; P < 0.01, Mann-Whitney U test). These patients also demonstrated an increase in lipid peroxidation (0.5 versus 0.25 mumol/l, P < 0.05) and vascular permeability, as measured by the percentage increase in ACR (365 versus 130 per cent, P < 0.01). CONCLUSION: Vascular patients with a lower TAC developed increased capillary permeability as a result of ischaemia-reperfusion, which progressed to SIRS. TAC may provide a test to identify 'at risk' patients. It may be possible to augment their defence with exogenous antioxidants.

Aged↗
PubMed1998

Prospective analysis of quality of life in patients following infrainguinal reconstruction for chronic critical ischaemia.

BACKGROUND: The aims of this prospective study were to analyse the health-related quality of life (QOL) changes associated with infrainguinal arterial reconstruction for chronic critical limb ischaemia (CLI) and to assess the impact of graft patency and limb salvage. METHODS: Fifty-five consecutive patients, 28 women and 27 men of median age 71 (range 41-86) years, undergoing infrainguinal arterial reconstruction for CLI, consented to participate in the study. QOL was assessed using the Short Form 36 (SF36) health survey questionnaire, which was completed before and at 1, 3, 6 and 12 months following surgery. Graft patency was assessed by duplex imaging at the same postoperative intervals. RESULTS: CLI severely impaired QOL. Cumulative graft patency at 1, 3, 6 and 12 months after surgery was 82, 78, 76 and 64 per cent respectively. Reconstruction resulted in significant improvements in the SF36 domains Physical Functioning, Pain, Vitality and Social Functioning (P< 0.01). With a patent graft these improvements began soon after surgery and were maintained for the 12 months studied. Following irredeemable graft occlusion, patients who had secondary amputation also described some QOL improvements. CONCLUSION: A patent graft following infrainguinal arterial reconstruction for critical ischaemia results in an immediate and lasting improvement in health-related QOL.

Activities of Daily Living↗