An international experience of electronic communication and implementation of eHealth solutions in a vascular surgery clinic.

INTRODUCTION: Communication is key to any successful relationship with the patient-physician partnership being no different. Recent advances in technology have provided us with an array of new communication tools such as the mobile phone, computer, internet, and email. This new technology has revolutionized communications; however, limitations to their widespread use include access, literacy, and willingness for both the physician and patient to change. METHODS: To gather international data, questionnaires were completed by patients attending vascular surgery outpatient clinics in hospitals in Ireland and Canada. RESULTS: Five hundred ninety-seven patients participated in the study. Of the participants, 83.2% were over 50 years old. The mean age was 63.1 years, with a range of 18-95 years. Overall, home phone call was the most preferred method of communication with 41.0% of patients selecting this option. Of the patients, 82.4% had a mobile phone but just 48.5% use text message. In those over the age of 70, 72.1% use a mobile phone and just 25.3% use text message. Of the participants, 64.1% had access to a computer, and 67.2% had access to the internet with a decline in the usage of both with increasing age. DISCUSSION: Within this patient population, the use of technologies decreases with increasing age of the patients. This demonstrates a large population of service users who are contented with conventional methods of communication. Change within healthcare ICT is inevitable, and therefore, these patients need to be guided and educated to allow a smooth transition from the old to the new.

A Systematic Review and Meta-analysis of Thrombotic Events Following Endovenous Thermal Ablation of the Great Saphenous Vein.

OBJECTIVES: A systematic review and meta-analysis was performed to determine the incidence of thrombotic events following great saphenous vein (GSV) endovenous thermal ablation (EVTA). METHODS: MEDLINE, Embase and conference abstracts were searched. Eligible studies were randomised controlled trials and case series that included at least 100 patients who underwent GSV EVTA (laser ablation or radiofrequency ablation [RFA]) with duplex ultrasound (DUS) within 30 days. The systematic review focused on the complications of endovenous heat induced thrombosis (EHIT), deep venous thrombosis (DVT), and pulmonary embolism (PE). The primary outcome for the meta-analysis was deep venous thrombotic events which were defined as DVT or EHIT Type 2, 3, or 4. Secondary outcomes for the meta-analysis were EHIT Type 2, 3, or 4, DVT and PE. Subgroup analyses were performed for both the RFA and EVLA groups. Pooled proportions were calculated using random effects modelling. RESULTS: Fifty-two studies (16,398 patients) were included. Thrombotic complications occurred infrequently. Deep venous thrombotic events occurred in 1.7% of cases (95% CI 0.9-2.7%) (25 studies; 10,012 patients; 274 events). EHIT Type 2, 3, or 4 occurred in 1.4% of cases (95% CI 0.8-2.3%) (26 studies; 10,225 patients; 249 events). DVT occurred in 0.3% of cases (95% CI = 0.2%-0.5%) (49 studies; 15,676 patients; 48 events). PE occurred in 0.1% of cases (95% CI = 0.1-0.2%) (29 studies; 8223 patients; 3 events). Similar results were found when the RFA and EVLA groups were analysed separately. CONCLUSION: Thrombotic events occur infrequently following GSV EVTA. Given the large numbers of procedures worldwide and the potential for serious consequences, further research is needed on the burden of these complications and their management.

Can a Neutrophil-Lymphocyte Ratio Derived from Preoperative Blood Tests Predict Arteriovenous Fistula Maturation?

BACKGROUND: To evaluate the association between inflammatory markers expressed as neutrophil-lymphocyte ratio (NLR) and process of arteriovenous fistula (AVF) maturation. METHODS: A retrospective review of patients with end-stage renal disease referred for formation of a new AVF in one center. Patients referred to the vascular service in the University Hospital of Limerick for creation of vascular access between 2009 and 2013. The association between NLR, calculated from preoperative blood tests, and functional fistula maturation, as determined by successful use of the AVF for 6 consecutive hemodialysis sessions, was investigated using univariate and logistic regression analyses. A logistic regression analysis was carried out to assess potential influence from other factors related to AVF maturation. Stepwise regression test was performed including the NLR. RESULTS: Overall AVF functional maturation rate in our study was 53.7% (66/123). Patients with matured AVFs had an NLR of 4.850 (1.8-15.7) compared with 3.554 (1.7-15.0); this difference was found to be significant (P = 0.024). Female gender (P = 0.008) and a history of kidney transplant (P = 0.004) were the only independent factors of fistula maturation outcome in a logistic regression model. CONCLUSION: Increased level of NLR was found to be associated with fistula maturation; however, more studies are needed to validate this finding.

One-stage vs. two-stage brachio-basilic arteriovenous fistula for dialysis access: a systematic review and a meta-analysis.

INTRODUCTION: A brachiobasilic arteriovenous fistula (BB-AVF) can provide access for haemodialysis in patients who are not eligible for a more superficial fistula. However, it is unclear whether one- or two-stage BB-AVF is the best option for patients. AIM: To systematically assess the difference between both procedures in terms of access maturation, patency and postoperative complications. METHODS: Online search for randomised controlled trials (RCTs) and observational studies that compared the one-stage versus the two-stage technique for creating a BB-AVF. RESULTS: Eight studies were included (849 patients with 859 fistulas), 366 created using a one-stage technique, while 493 in a two-stage approach. There was no statistically significant difference between the two groups in the rate of successful maturation (Pooled risk ratio = 0.95 [0.82, 1.11], P = 0.53). Similarly, the incidence of postoperative haematoma (Pooled risk ratio = 0.73 [0.34, 1.58], P = 0.43), wound infection (Pooled risk ratio = 0.77 [0.35, 1.68], P = 0.51) and steal syndrome (Pooled risk ratio = 0.65 [0.27, 1.53], P = 0.32) were statistically comparable. CONCLUSION: Although more studies seem to favour the two-stage BVT approach, evidence in the literature is not sufficient to draw a final conclusion as the difference between the one-stage and the two-stage approaches for creation of a BB-AVF is not statistically significant in terms of the overall maturation rate and postoperative complications. Patency rates (primary, assisted primary and secondary) were comparable in the majority of studies. Large randomised properly conducted trials with superior methodology and adequate sub-group analysis are needed before making a final recommendation.

Predictive parameters of arteriovenous fistula functional maturation in a population of patients with end-stage renal disease.

INTRODUCTION: With increasing numbers of patients diagnosed with ESRD, arteriovenous fistula (AVF) maturation has become a major factor in improving both dialysis related outcomes and quality of life of those patients. Compared to other types of access it has been established that a functional AVF access is the least likely to be associated with thrombosis, infection, hospital admissions, secondary interventions to maintain patency and death. AIM: Study of demographic factors implicated in the functional maturation of arteriovenous fistulas. Also, to explore any possible association between preoperative haematological investigations and functional maturation. METHODS: We performed a retrospective chart review of all patients with ESRD who were referred to the vascular service in the University Hospital of Limerick for creation of vascular access for HD. We included patients with primary AVFs; and excluded those who underwent secondary procedures. RESULTS: Overall AVF functional maturation rate in our study was 53.7% (52/97). Female gender showed significant association with nonmaturation (P = 0.004) and was the only predictor for non-maturation in a logistic regression model (P = 0.011). Patients who had history of renal transplant (P = 0.036), had relatively lower haemoglobin levels (P = 0.01) and were on calcium channel blockers (P = 0.001) showed better functional maturation rates. CONCLUSION: Female gender was found to be associated with functional non-maturation, while a history kidney transplant, calcium channel-blocker agents and low haemoglobin levels were all associated with successful functional maturation. In view of the conflicting evidence in the literature, large prospective multi-centre registry-based studies with well-defined outcomes are needed.

Role of far infra-red therapy in dialysis arterio-venous fistula maturation and survival: systematic review and meta-analysis.

INTRODUCTION: A well-functioning arteriovenous fistula (AVF) is the best modality for vascular access in patients with end-stage renal disease (ESRD) requiring haemodialysis (HD). However, AVFs' main disadvantage is the high rate of maturation failure, with approximately one third (20%-50%) not maturing into useful access. This review examine the use of Far-Infra Red therapy in an attempt to enhance both primary (unassisted) and secondary (assisted) patency rates for AVF in dialysis and pre-dialysis patients. METHOD: We performed an online search for observational studies and randomised controlled trials (RCTs) that evaluated FIR in patients with AVF. Eligible studies compared FIR with control treatment and reported at least one outcome measure relating to access survival. Primary patency and secondary patency rates were the main outcomes of interest. RESULTS: Four RCTs (666 patients) were included. Unassisted patency assessed in 610 patients, and was significantly better among those who received FIR (228/311) compared to (185/299) controls (pooled risk ratio of 1.23 [1.12-1.35], p = 0.00001). In addition, the two studies which reported secondary patency rates showed significant difference in favour of FIR therapy--160/168 patients--compared to 140/163 controls (pooled risk ratio of 1.11 [1.04-1.19], p = 0.003). CONCLUSION: FIR therapy may positively influence the complex process of AVF maturation improving both primary and secondary patency rates. However blinded RCTs performed by investigators with no commercial ties to FIR therapy technologies are needed.

Randomised controlled trial comparing European standard class 1 to class 2 compression stockings for ulcer recurrence and patient compliance.

The aim of this study was to determine the rate of venous ulcer recurrence and the level of compliance in patients wearing European class 1 or class 2 compression stockings. A total of 100 patients with healed venous leg ulcers were recruited, and were randomised to either class 1 (n = 50) or class 2 (n = 50) compression stockings. Follow-up was at 1 week, 3, 6, 9 and 12 months to monitor ulcer recurrence and compliance. Patients had a duplex scan to identify the source of venous incompetence. The rate of ulcer recurrence after 12 months was 16·1%, and the difference in recurrence rate between classes was not statistically significant (P = 0·287) although greater numbers in class 1 developed a recurrence. Participants (88·9%) were compliant; non-compliant patients were at a significantly greater risk of recurrence (P≤ 0·0001). Thirteen patients had both superficial and deep incompetence; those randomised to class 1 stockings (n = 4) developed ulcer recurrence. Patients with a history of multiple episodes of ulceration were more likely to develop a recurrence (P = 0·001). The lowest venous ulcer recurrence rates were seen in patients who were compliant with hosiery regardless of the compression level. Patients with both superficial and deep incompetence had a lower rate of recurrence with class 2 compression.

New pulsatile hydrostatic pressure bioreactor for vascular tissue-engineered constructs.

Mechanical conditioning represents a potential means to enhance the biochemical and biomechanical properties of tissue-engineered cell constructs. Bioreactors that can simulate physiologic conditions can play an important role in the preparation of tissue-engineered constructs. Although various forms of bioreactor systems are currently available, these have certain limitations, particularly when these are used for the creation of vascular constructs. The aim of the present report is to describe and validate a novel pressure bioreactor system for the creation of vascular tissue. Here, we present and discuss the design concepts, criteria, as well as the development of a novel pressure bioreactor. The system is compact and easily housed in an incubator to maintain sterility of the construct. Moreover, the proposed bioreactor, in addition to mimicking in vivo pressure conditions, is flexible, allowing different types of constructs to be exposed to various physiologic pressure conditions. The core bioreactor elements can be easily sterilized and have good ergonomic assembly characteristics. This system is a fundamental tool, which may enable us to make further advances in bioreactor technology and tissue engineering. The novel system allows for the application of pressure that may facilitate the growth and development of constructs needed to produce a tissue-engineered vascular graft.

Vessel asymmetry as an additional diagnostic tool in the assessment of abdominal aortic aneurysms.

OBJECTIVE: Abdominal aortic aneurysm (AAA) rupture is believed to occur when the local mechanical stress exceeds the local mechanical strength of the wall tissue. On the basis of this hypothesis, the knowledge of the stress acting on the wall of an unruptured aneurysm could be useful in determining the risk of rupture. The role of asymmetry has previously been identified in idealized AAA models and is now studied using realistic AAAs in the current work. METHODS: Fifteen patient-specific AAAs were studied to estimate the relationship between wall stress and geometrical parameters. Three-dimensional AAA models were reconstructed from computed tomography scan data. The stress distribution on the AAA wall was evaluated by the finite element method, and peak wall stress was compared with both diameter and centerline asymmetry. A simple method of determining asymmetry was adapted and developed. Statistical analyses were performed to determine potential significance of results. RESULTS: Mean von Mises peak wall stress +/- standard deviation was 0.4505 +/- 0.14 MPa (range, 0.3157-0.9048 MPa). Posterior wall stress increases with anterior centerline asymmetry. Peak stress increased by 48% and posterior wall stress by 38% when asymmetry was introduced into a realistic AAA model. CONCLUSION: The relationship between posterior wall stress and AAA asymmetry showed that excessive bulging of one surface results in elevated wall stress on the opposite surface. Assessing the degree of bulging and asymmetry that is experienced in an individual AAA may be of benefit to surgeons in the decision-making process and may provide a useful adjunct to diameter as a surgical intervention guide.

Fibrin: a natural biodegradable scaffold in vascular tissue engineering.

Arterial occlusive disease remains a major health issue in the developed world and a rapidly growing problem in the developing world. Although a growing number of patients are now being effectively treated with minimally invasive techniques, there remains a tremendous pressure on the vascular community to develop a synthetic small-diameter vascular graft with improved long-term patency rates. The field of tissue engineering offers an exciting alternative in the search for living organ replacement structures. Several methodologies have emerged for constructing blood vessel replacements with biological functionality. Common strategies include cell-seeded biodegradable synthetic scaffolds, cell self-assembly, cell-seeded gels and xenogeneic acellular materials. A wide range of materials are being investigated as potential scaffolds for vascular tissue engineering applications. Some are commercialised and others are still in development. Recently, researchers have studied the role of fibrin gel as a three-dimensional scaffold in vascular tissue engineering. This overview describes the properties of fibrin gel in vascular tissue engineering and highlights some recent progress and difficulties encountered in the development of cell fibrin scaffold technology.