Quality of life and mental health measurements among patients with type 2 diabetes mellitus: a systematic review.

BACKGROUND: Over the past few decades the benefits of assessing Quality of Life (QoL) and mental health in patients with Type 2 Diabetes Mellitus (T2DM) have steadily increased with limited studies relating to the most useful method to assess these patients. This study aims to identify, review, summarise, and evaluate the methodological quality for the most validated commonly used health-related QoL and mental health assessment measurements in diabetic patients. METHODS: All original articles published on PubMed, MedLine, OVID, The Cochrane Register, Web of Science Conference Proceedings and Scopus databases were systematically reviewed between 2011 and 2022. A search strategy was developed for each database using all possible combinations of the following keywords: "type 2 diabetes mellitus", "quality of life", mental health", and "questionnaires". Studies conducted on patients with T2DM of ≥ 18 years with or without other clinical illnesses were included. Articles designed as a literature or systematic review conducted on either children or adolescents, healthy adults and/or with a small sample size were excluded. RESULTS: A total of 489 articles were identified in all of the electronic medical databases. Of these articles, 40 were shown to meet our eligibility criteria to be included in this systematic review. Approximately, 60% of these studies were cross-sectional, 22.5% were clinical trials, and 17.5% of cohort studies. The top commonly used QoL measurements are the SF-12 identified in 19 studies, the SF-36, included in 16 studies, and the EuroQoL EQ-5D, found in 8 studies. Fifteen (37.5%) studies used only one questionnaire, while the remaining reviewed (62.5%) used more than one questionnaire. Finally, the majority (90%) of studies reported using self-administered questionnaires and only 4 used interviewer mode of administration. CONCLUSION: Our evidence highlights that the commonly used questionnaire to evaluate the QoL and mental health is the SF-12 followed by SF-36. Both of these questionnaires are validated, reliable and supported in different languages. Moreover, using single or combined questionnaires as well as the mode of administration depends on the clinical research question and aim of the study.

Nature versus Number: Monocytes in Cardiovascular Disease.

Monocytes play a key role in cardiovascular disease (CVD) as their influx into the vessel wall is necessary for the development of an atherosclerotic plaque. Monocytes are, however, heterogeneous differentiating from classical monocytes through the intermediate subset to the nonclassical subset. While it is recognized that the percentage of intermediate and nonclassical monocytes are higher in individuals with CVD, accompanying changes in inflammatory markers suggest a functional impact on disease development that goes beyond the increased proportion of these 'inflammatory' monocyte subsets. Furthermore, emerging evidence indicates that changes in monocyte proportion and function arise in dyslipidemia, with lipid lowering medication having some effect on reversing these changes. This review explores the nature and number of monocyte subsets in CVD addressing what they are, when they arise, the effect of lipid lowering treatment, and the possible implications for plaque development. Understanding these associations will deepen our understanding of the clinical significance of monocytes in CVD.

A Structured Review of Antithrombotic Therapy in Peripheral Artery Disease With a Focus on Revascularization: A TASC (InterSociety Consensus for the Management of Peripheral Artery Disease) Initiative.

Peripheral artery disease affects >200 million people worldwide and is associated with significant limb and cardiovascular morbidity and mortality. Limb revascularization is recommended to improve function and quality of life for symptomatic patients with peripheral artery disease with intermittent claudication who have not responded to medical treatment. For patients with critical limb ischemia, the goals of revascularization are to relieve pain, help wound healing, and prevent limb loss. The baseline risk of cardiovascular and limb-related events demonstrated among patients with stable peripheral artery disease is elevated after revascularization and related to atherothrombosis and restenosis. Both of these processes involve platelet activation and the coagulation cascade, forming the basis for the use of antiplatelet and anticoagulant therapies to optimize procedural success and reduce postprocedural cardiovascular risk. Unfortunately, few high-quality, randomized data to support use of these therapies after peripheral artery disease revascularization exist, and much of the rationale for the use of antiplatelet agents after endovascular peripheral revascularization is extrapolated from percutaneous coronary intervention literature. Consequently, guideline recommendations for antithrombotic therapy after lower limb revascularization are inconsistent and not always evidence-based. In this context, the purpose of this structured review is to assess the available randomized data for antithrombotic therapy after peripheral arterial revascularization, with a focus on clinical trial design issues that may affect interpretation of study results, and highlight areas that require further investigation.

Venous thromboembolism following gynaecological surgery for suspected or confirmed malignancy.

BACKGROUND: Venous thromboembolism (VTE) is a serious complication following gynaecological surgery, with malignancy placing patients at an even greater risk. AIMS: To review the incidence of VTE following gynaecological surgery for suspected or confirmed malignancy with respect to prophylactic modalities and to assess the incidence and associated risk factors for bleeding complications. METHODS: A retrospective cohort study was undertaken between 2001 to 2006 on 1363 women undergoing surgery for suspected or confirmed gynaecological malignancy. Data on demographic details, diagnosis, radiotherapy/chemotherapy treatment, operative details, and hospital length of stay (LOS), thromboprophylaxis, in-hospital and 3-month readmission rates for deep vein thrombosis (DVT) and/or pulmonary embolism (PE) were collected. RESULTS: Median age was 54 years (IQR 44-66) and hospital LOS 7 days (IQR 5-9). 51.6% had a new malignancy and 33.0% benign disease. All in-hospital VTE events (0.4%; 95% CI 0.2-1.0%) occurred in women with advanced malignancy. VTE rate was 1.5% (95% CI 1.0-2.3%) at 3 months. In-hospital and 3-month non fatal PE occurred in 0.4% (95% CI 0.2-0.9%) and 1.1% (95% CI 0.7-1.8%) respectively, with a fatal PE rate of 0.1% (95% CI 0.04-0.5%). Malignancy (OR 10.3; 95% CI 1.3-80.6; P = 0.026) and duration of surgery (OR 2.1; 95% CI 1.4-3.2; P = 0.001) significantly increased bleeding risk. CONCLUSIONS: In-hospital VTE risk is higher following gynaecological surgery for malignancy than for benign disease, despite the use of thromboprophylaxis. Given the higher non fatal PE rate after discharge and increasing trend towards shorter hospital LOS, extended prophylaxis in these patients should be considered.

Monocyte Subset Recruitment Marker Profile Is Inversely Associated With Blood ApoA1 Levels.

Dyslipidemia promotes development of the atherosclerotic plaques that characterise cardiovascular disease. Plaque progression requires the influx of monocytes into the vessel wall, but whether dyslipidemia is associated with an increased potential of monocytes to extravasate is largely unknown. Here (using flow cytometry) we examined recruitment marker expression on monocytes from generally healthy individuals who differed in lipid profile. Comparisons were made between monocyte subsets, participants and relative to participants' lipid levels. Monocyte subsets differed significantly in their expression of recruitment markers, with highest expression being on either the classical or non-classical subsets. However, these inter-subset differences were largely overshadowed by considerable inter-participant differences with some participants having higher levels of recruitment markers on all three monocyte subsets. Furthermore, when the expression of one recruitment marker was high, so too was that of most of the other markers, with substantial correlations evident between the markers. The inter-participant differences were explained by lipid levels. Most notably, there was a significant inverse correlation for most markers with ApoA1 levels. Our results indicate that dyslipidemia, in particular low levels of ApoA1, is associated with an increased potential of all monocyte subsets to extravasate, and to do so using a wider repertoire of recruitment markers than currently appreciated.

Evaluation of a mobile screening service for abdominal aortic aneurysm in Broken Hill, a remote regional centre in far western NSW.

OBJECTIVES: To evaluate the feasibility of a mobile screening service model for abdominal aortic aneurysm (AAA) in a remote population centre in Australia. DESIGN: Screening test evaluation. SETTING: A remote regional centre (population: 20 000) in far western NSW. PARTICIPANTS: Men aged 65-74 years, identified from the Australian Electoral roll. INTERVENTIONS: A mobile screening service using directed ultrasonography, a basic health check and post-screening consultation. MAIN OUTCOME MEASURES: Attendance at the screening program, occurrence of AAA in the target population and effectiveness of screening processes. RESULTS: A total of 516 men without a previous diagnosis of AAA were screened, an estimated response rate of 60%. Of these, 463 (89.7%) had a normal aortic diameter, 28 (5.4%) ectatic and 25 (4.9%) a small, moderate or significant aneurysm. Two men with AAA were recommended for surgery. Feedback from participants indicated that the use of a personalised letter of invitation helped with recruitment, that the screening process was acceptable and the service valued. CONCLUSIONS: It is feasible to organise and operate a mobile AAA screening service from moderate sized rural and remote population centres. This model could be scaled up to provide national coverage for rural and remote residents.

Aspirin for prevention of venous thromboembolism in recipients of major lower-limb orthopedic surgery: a systematic review of Level I evidence.

INTRODUCTION: Major lower-limb orthopedic surgery recipients are at increased risk of venous thromboembolism (VTE). The optimal strategy for preventing VTE is a topic of ongoing debate. The use of aspirin has been implicated in reducing VTE events and is potentially advantageous compared to other agents in respect to cost, access, route of administration and reduced adverse effects such as bleeding. EVIDENCE ACQUISITION: A systematic search for Level I evidence (systematic reviews and meta-analyses of randomised-controlled trials) was performed in April 2019 to evaluate the use of aspirin for primary and secondary VTE prophylaxis compared to alternative chemical and mechanical strategies. This search encompassed three electronic databases (Pubmed, Embase and the Cochrane Database of Systematic Reviews). All references of included studies were screened for additional studies. Data was compiled and compared to the recommendations and guidelines published by major institutions. Included studies were appraised with the aid of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. EVIDENCE SYNTHESIS: In total, 21 studies were included. Interventions and outcomes identified were heterogeneous across studies. Most statistical tests applied found no difference between aspirin and other interventions in regards to deep vein thrombosis, pulmonary embolism, bleeding and mortality outcomes. CONCLUSIONS: Aspirin may be a viable alternative to established thromboprophylactic regimes for primary prevention of VTE, however in the setting of secondary prevention it is generally less efficacious. Future studies should have clearly identified and comparable outcome measures, with direct comparisons and assessment of intervention combination, dosing and treatment duration.

Prevention of venous thromboembolism through the implementation of a risk assessment tool: a comparative study in medical and surgical patients.

BACKGROUND: Hospitalized patients are at high risk of venous thromboembolism (VTE). Underutilization of thromboprophylaxis remains common despite existing clinical guidelines. The aim is to evaluate the implementation of a state wide standardized adult VTE risk assessment tool (RAT) to assist in the screening of inpatients and prescribing of appropriate thromboprophylaxis. METHODS: In total, 234 patients were audited using clinical notes and spot assessments for VTE risk at Western Sydney Local Health District over a two year period. Patients were stratified into pre- (N.=132) and postimplementation (N.=102) of the RAT. Intervention involved continuing education of staff and passive dissemination of guidelines. Prescription of pharmacological and mechanical prophylaxis and the development of thromboembolic events were evaluated. RESULTS: Overall, 39.0% of medical and 63.0% of surgical patients were risk assessed during preimplementation versus 39.2% and 92.2% during postimplementation of the RAT (P<0.0001). Usage of pharmacological prophylaxis increased from 72% to 79% and mechanical prophylaxis from 41% to 48%. VTE rates in moderate to high risk medical patients decreased from 15.2% preimplementation to 6.5% postimplementation. Rates of non-fatal and fatal pulmonary embolism (PE) were 2.3% and 0.8% respectively prior compared to 1.0% and 0.0% postimplementation. CONCLUSIONS: Standardized VTE RAT increased thromboprophylaxis usage and decreased PE rates, with a greater improvement reflected in surgical patients. These findings highlight the importance of a multifaceted approach to VTE prevention using regular audits with feedback, electronic reminders systems, prescribing tools and continuing education.

Mechanical compression in the prophylaxis of venous thromboembolism.

Venous thromboembolism (VTE) is an important cause of morbidity and mortality in a substantial number of the Australian community. There exists a considerable range of potential prophylactic measures aimed at reducing the risk of VTE. These antithrombotic regimens include pharmacological interventions and mechanical techniques to counteract venous stasis including graduated compression stockings and intermittent pneumatic compression (IPC) devices. This review particularly concentrates on evidence for the use of mechanical prophylaxis and the interrelationship with pharmacological methods of VTE prophylaxis. Mechanical and pharmacological methods of VTE prophylaxis are both effective and when used in combination have synergistic effects. Although there are a number of different IPC systems, little evidence is available at present that differentiates these on the basis of VTE prevention. Compliance and patient acceptance of IPC as a preventative measure has improved with miniaturization and device weight reduction. IPC should be used according to recommended guidelines. In moderate-risk patients when pharmacological prophylaxis is contraindicated, IPC can be used as an alternative. High-risk patients should receive both mechanical and pharmacological prophylaxis to reduce their relative risk. Until further evidence becomes available, the specific type of IPC unit chosen will generally be determined by ease of use, availability and cost.

Monocyte inflammatory profile is specific for individuals and associated with altered blood lipid levels.

BACKGROUND AND AIMS: Atherogenesis is dependent upon monocyte influx into the vessel wall. In humans, three monocyte subsets exist, the number and function of which are significantly altered in cardiovascular disease (CVD). Whether such alterations arise in individuals with a perturbed lipid profile remains largely unanswered, but is important to delineate, as adoption of a pro-inflammatory state may promote plaque formation. Here, we compared the inflammatory status of monocyte subsets and determined whether monocyte inflammatory changes are evident in individuals with a perturbed lipid profile. METHODS: Monocyte subset cytokine production, inflammatory and anti-inflammatory marker expression were determined by whole blood flow cytometry and related to participants' lipid levels. RESULTS: The intermediate and non-classical monocytes were more inflammatory than classicals as seen by their higher cytokine production (TNF-α, IL-1ß, IL-6) and M1 marker (CD86) expression, but lower levels of M2 markers (CD93, CD163). More importantly, a considerable variation was seen between participants, with all monocytes of one individual being more inflammatory than those of another. Many inter-individual differences were related to participants' lipid levels. IL-1ß production correlated negatively with Apo A1 and HDL-C. CD86 and TLR2 correlated positively with Chol:HDL-C but negatively with HDL-C and Apo A1:Apo B. Interestingly, CD163 expression correlated positively with Chol:HDL-C but negatively with Apo A1:Apo B. CONCLUSIONS: Our data indicates that priming of all monocytes to an inflammatory state occurs in individuals with a perturbed lipid profile, overriding the normal functional distinction attributed to the different monocyte subsets. As such, all monocytes may be important in CVD.

Human classical monocytes display unbalanced M1/M2 phenotype with increased atherosclerotic risk and presence of disease.

BACKGROUND: Specific monocyte and macrophage subsets have been implicated in atherosclerosis, with intermediate monocytes proportionally elevated in cardiovascular disease and M1 macrophages abundant in unstable atherosclerotic plaques. While several studies have shown altered proportions of these subsets in atherosclerosis, studies examining functional and phenotypic subset alterations remain scarce. METHODS: We used whole blood flow cytometry to investigate the expression of M1 (CD86) and M2 (CD163) markers on monocyte subsets of atherosclerotic patients and controls. RESULTS: Atherosclerotic patients had a more inflammatory monocyte profile than controls, indicated by increased intermediate subset proportions, a higher classical monocyte CD86/CD163 ratio, and elevated serum M1-related chemokines. A more inflammatory profile appeared to correlate with atherosclerotic risk, as in controls classical monocyte CD86/CD163 ratio was negatively correlated with HDL and apolipoprotein A1, and positively correlated with interleukin-1ß. CONCLUSIONS: We conclude that monocyte subsets show functional and phenotypic changes in cardiovascular disease and such changes are likely to contribute to atherosclerotic progression.

Prioritization of treatments for lower extremity peripheral artery disease in low- and middle-income countries.

INTRODUCTION: Lower extremity peripheral artery disease (PAD) is increasing in prevalence in low- and middle-income countries creating a large health care burden. Clinical management may require substantial resources but little consideration has been given to which treatments are appropriate for less advantaged countries. EVIDENCE ACQUISITION: The aim of this review was to systematically appraise published data on the costs and effectiveness of PAD treatments used commonly in high-income countries, and for an international consensus panel to review that information and propose a hierarchy of treatments relevant to low- and middle-income countries. EVIDENCE SYNTHESIS: Pharmacotherapy for intermittent claudication was found to be expensive and improve walking distance by a modest amount. Exercise and endovascular therapies were more effective and exercise the most cost-effective. For critical limb ischemia, bypass surgery and endovascular therapy, which are both resource intensive, resulted in similar rates of amputation-free survival. Substantial reductions in cardiovascular events occurred with use of low cost drugs (statins, ACE inhibitors, anti-platelets) and smoking cessation. CONCLUSIONS: The panel concluded that, in low- and middle-income countries, cardiovascular prevention is a top priority, whereas a lower priority should be given to pharmacotherapy for leg symptoms and revascularisation, except in countries with established vascular units.

Implications of low great toe pressures in clinical practice.

INTRODUCTION: The aim of this study was to observe the outcome of patients with a great toe pressure (GTP) reading of less than 40 mmHg. METHODS: Between 2002 and 2004, of 4,714 patients assessed in the Westmead Vascular Laboratory, 365 (7.7%) had GTP measurements for assessment of possible critical limb ischaemia. There were 56 limbs in 40 patients with a GTP measurement of less than 40 mmHg, and this group was studied to assess outcome factors of death, requirement for major or minor amputation, arterial reconstructive surgery, clinical stability, or documented improvement from the initial assessment. RESULTS: Patients requiring a major amputation had an average GTP of 13 mmHg and a toe brachial index (TBI) of 0.08, whereas those not undergoing a major amputation had an average GTP of 23.6 mmHg and TBI of 0.15. This association was weaker when an initial single evaluation was used as opposed to two or more serial assessments. Patients with and without a major amputation had an average ankle brachial index of 0.16 and 0.53, respectively. Diabetes mellitus requiring insulin and cerebrovascular disease were risk factors for major amputations. CONCLUSIONS: Low GTP was associated with a greater risk of major amputations. Two or more serial assessments were found to be of greater value than an initial single assessment.

Hyperglycemia is associated with adverse outcomes in patients receiving total parenteral nutrition.

OBJECTIVE: Hyperglycemia is associated with poor clinical outcomes and mortality in myocardial infarction, stroke, and general hospital patients. However, there are few data regarding the effect of hyperglycemia on outcomes in patients receiving total parenteral nutrition (TPN), a therapy that predisposes patients to hyperglycemia. The aim of this study was to determine whether elevated blood glucose levels are associated with adverse outcomes in patients receiving TPN. RESEARCH DESIGN AND METHODS: A retrospective analysis was undertaken from the medical records of 111 patients (122 treatment episodes) receiving TPN. All patients had blood drawn daily for the measurement of blood glucose levels. Outcome measures were assessed as a function of mean daily blood glucose levels while receiving TPN. RESULTS: Increased blood glucose levels were associated with an increased risk of cardiac complications (odds ratio 1.61, 95% CI 1.09-2.37, P = 0.02), infection (1.4, 1.08-1.82, P = 0.01), systemic sepsis (1.36, 1.00-1.86, P = 0.05), acute renal failure (1.47, 1.00-2.17, P = 0.05), and death (1.77, 1.23-2.52, P < 0.01). When the data were examined by quartiles of blood glucose levels, the mortality of subjects in the highest quartile was 10.9 times (95% CI 2.0-60.5, P < 0.01) that of subjects in the lowest quartile, and the risk of developing any complication was 4.3 times higher (1.4-13.1, P < 0.01). These effects were independent of age, sex, or prior diabetes status. CONCLUSIONS: Hyperglycemia is a predictor of poor outcomes in patients receiving TPN. The confirmation of a relation between blood glucose levels and adverse outcomes provides support for tight glycemic control in these patients.

Characteristics of non-diabetic foot ulcers in Western Sydney, Australia.

BACKGROUND: There are few studies investigating the characteristics, risk factors and socioeconomic status of patients with non-diabetic foot ulcers. The aim of this study was to explore the characteristics of non-diabetic foot ulcers in a large tertiary referral outpatient hospital setting in Western Sydney, Australia. METHODS: From 2011 to 2013, data from 202 patients with non-diabetic foot ulcers during their initial visit were retrospectively extracted for analysis from Westmead Hospital's Foot Wound Clinic Registry. Data including demographics, socioeconomic status and foot ulcer characteristics were recorded on a standardised data collection form. RESULTS: Demographics and physical characteristics were: 54 % male, median age 78 years [interquartile range (IQR): 64-87], median body mass index (BMI) of 23.8 kg/m(2) (IQR: 20-26.9), 35 % had loss of protective sensation and the median postcode score for socioeconomic status was 996 (IQR: 935-1034). Foot ulcer characteristics were: median cross-sectional area of 1.2 cm(2) (IQR: 0.3-5.0), 30.5 % plantar and 27 % dorsal, 22.1 % University of Texas (UT) Wound Classification for Diabetic Foot Ulcers Grade of 1C-3C (with ischaemia). CONCLUSIONS: Unlike diabetic foot ulcers, non-diabetic foot ulcers largely affected older males and females. In accordance with diabetic foot ulcer characteristics, socioeconomic status was not related to non-diabetic foot ulcers in Western Sydney. Based on the findings of this study the epidemiological pattern of non-diabetic foot ulceration and its pathogenesis requires further investigation.

Venous thromboembolism and fractured neck of femur.

The post-operative incidence of venous thromboembolism (VTE) is high for patients undergoing hip fracture surgery. Proven prophylactic measures are available although underutilized due to concern on post-operative bleeding with use of anticoagulants. This study retrospectively reviewed the clinical incidence of VTE and utilisation of thromboprophylactic protocols over an eight year period. Demographic details, mechanism of injury, VTE risk factors, prophylactic modalities (mechanical and pharmacological), operation duration, mode of anaesthesia, hospital length of stay (LOS) and post-operative complications with particular attention to suspected deep vein thrombosis (DVT) and/or pulmonary embolism (PE) were analysed. Male to female ratio was 1:2.7 with a median age of 78 years (IQR: 70-86 years) and 83 years (IQR: 77-87 years) respectively (p<0.001). Median hospital LOS was 8 days (IQR: 5-13 days) and differed with mechanism of injury. The in-hospital incidence of VTE was 1.6% (95% CI: 1.1-2.5%) with a probably underestimated three month rate of 8.2% (95% CI: 5.3-12.4%). Non fatal PE was 0.5% (95% CI: 0.2-1.0%) in-hospital and 2.6% (95% CI: 1.2-5.5%) at three months. Fatal PE was 0.5% (95% CI: 0.2-1.0%) with a three month incidence of 0.4% (95% CI: 0.1-2.4%). The in-hospital VTE incidence was kept relatively low with use of prophylactic protocols with almost all patients receiving prophylaxis by the end of the study period. Given the five-fold out of hospital increase in incidence, consideration should be given to continue prophylaxis beyond hospital discharge in this high risk group of patients.

Fluoropolymer coated Dacron or polytetrafluoroethylene for femoropopliteal bypass grafting: a multicentre trial.

BACKGROUND: This trial was designed to compare graft patency between expanded polytetrafluoroethylene (PTFE) and fluoro-polymer coated Dacron for femoropopliteal bypass in patients in whom saphenous vein was unavailable. METHODS: A multicentre prospective trial randomized 129 patients (74 men, 55 women) who underwent femoropopliteal bypass using either a PTFE or fluoropolymer coated Dacron graft. The indication for operation was disabling claudication in 68 (52.7%) and critical limb ischaemia in 61 (47.3%) patients. Distal anastomosis was above the knee in 76 (58.9%) and below the knee in 53 (41.1%) patients. RESULTS: Primary patency at 6, 12 and 24 months was 71%, 56% and 47% for PTFE and 50%, 36% and 36% for fluoropolymer coated Dacron (P = 0.002), respectively. Secondary patency at 6, 12 and 24 months was 77%, 60% and 48% for PTFE and 66%, 49% and 46% for fluoropolymer coated Dacron (P = 0.13), respectively. The superior primary patency of PTFE over fluoropolymer coated Dacron was most evident in patients with poor prognostic indicators for graft survival: critical limb ischaemia (P = 0.001); below-knee anastomosis (P = 0.01); and smaller (6 mm) diameter grafts (P = 0.002). Graft thrombosis developed in the first month in 22 of 61 (36%) patients receiving fluoropolymer coated grafts compared to six of 68 (8.8%) patients receiving PTFE, which accounts for the difference in primary patency. Successful thrombectomy in 10 of the 22 fluoropolymer coated grafts resulted in similar secondary patency. CONCLUSION: Polytetrafluoroethylene has superior primary patency and similar secondary patency to fluoropolymer coated Dacron. These results support the preferential use of PTFE in patients with critical limb ischaemia, especially when a below-knee distal anastomosis and smaller diameter graft is required.

Antiproliferative effects of low molecular weight heparin.

AIM: To investigate the effect of low molecular weight heparins (LMWH) on the inhibition of intimal hyperplasia (IH) developing in prosthetic vascular patch graft implanted into sheep carotid artery. METHODS: A gelatin sealed Dacron patch graft was implanted into the common carotid artery of sheep, which were then allocated to a control group (n = 10) or to one of four treatment groups (each group n = 10) receiving either a low dose (LD) or high dose (HD) of one of two LMWH (enoxaparin 1 or 2 mg/kg/day, dalteparin 100 or 200 units/kg/day) administered subcutaneously for 4 weeks. Anti-activated factor X and activated partial thromboplastin time were assayed from blood collected prior to and at 1 and 2 h after LMWH administration on days 3, 7, 14, 21 and 28. Animals were killed on day 28 after taking blood samples prior to, then at 0.5, 1, 2, 3, 4, 6, 8, 12 and 24 h following the last injection. Grafts were collected for analysis and measurements of intimal thickness obtained under light microscopy from eight transverse sections of each grafted artery aided by computer image analysis. An IH index was calculated by dividing the area of IH (mm2) by the width of the graft (mm). RESULTS: Intimal hyperplasia index measurements (mean +/- SD) were: controls 0.574 +/- 0.077, LD enoxaparin 0.471 +/- 0.056, LD dalteparin 0.404 +/- 0.025, HD enoxaparin 0.398 +/- 0.068, HD dalteparin 0.332 +/- 0.048. The reductions in IH index compared to controls were significant (P < 0.05) for both LD and HD dalteparin and for HD enoxaparin. CONCLUSION: Both LMWH dalteparin and enoxaparin reduced the amount of IH formation with dalteparin showing a greater effect in the present animal study. The possibility that different LMWH might exert differing antiproliferative effects requires further investigation.

New methodology for assessment of intimal hyperplasia of vascular prostheses.

BACKGROUND: When investigating the degree of formation of intimal hyperplasia (IH) quantification of the extent of the lesion is crucial to its assessment and analysis. The aim of the present study was to establish a new methodology (IH index) for estimating the degree of IH associated with vascular prosthesis implantation. METHODS: Ten female Merino sheep underwent a standard gelatin sealed Dacron (GSD) patch grafting procedure in the left common carotid artery. The grafts were harvested 4 weeks following implantation and processed for assessment of IH by two methodologies - mean intimal thickness (MIT) and IH index. The advantages and disadvantages of the two methods for expressing the degree of IH were compared. RESULTS: The IH index is less labour intensive but is as accurate as the MIT method in quantifying the IH lesion, statistical analysis showing high correlation and measurement agreement between the two methods. CONCLUSION: The IH index is a labour saving standardized methodology for quantification of IH in the current animal model.