The Impact of Vein Mechanical Compliance on Arteriovenous Fistula Outcomes

© 2016 Elsevier Inc. Background Arteriovenous fistulae (AVFs) are the preferred access for hemodialysis but suffer a high early failure rate. The aim of this study was to determine how venous distensibility, as measured in vitro, relates to early outcomes of AVF formed with the sampled vein. Methods Ethical approval was obtained for all aspects of this study. During AVF formation a circumferential segment of the target vein was sampled. Mechanical stress testing of the venous segments was undertaken using a dynamic mechanical analyzer, with progressive stress loading at 2 N/min to a maximum of 10 N or until sample disruption. Stress-strain curves were obtained for vein samples and Young's modulus (YM) calculated. Duplex assessment of the fistulae was undertaken at 30 days. Results Thirty patients consented to participate with 29 samples obtained for analysis. Statistical comparison of YM demonstrated no relationship with common cardiovascular risk factors or dialysis status. Subject age greater than 65 was the only patient factor which showed a significant difference in YM (P = 0.05). Furthermore, a negative correlation was confirmed between age and YM (Pearson's r = -0.465, P < 0.05). Nine of the 29 subjects suffered an early AVF failure. Mann-Whitney U testing for differences in distribution reported that YM was significantly higher in those fistulas which failed (P < 0.005). Conclusions Reduced venous compliance appears to result in higher failure rates of AVFs. With the advancement of clinical tools such as speckle tracing ultrasound identification of vessel compliance in vivo may produce valuable additional information for clinicians planning AVF surgery

A Systematic Review of the Uptake and Adherence Rates to Supervised Exercise Programs in Patients with Intermittent Claudication

Background Intermittent claudication (IC) is a common and debilitating symptom of peripheral arterial disease and is associated with a significant reduction in a sufferer's quality of life. Guidelines recommend a supervised exercise program (SEP) as the primary treatment option; however, anecdotally there is a low participation rate for exercise in this group of patients. We undertook a systematic review of the uptake and adherence rates to SEPs for individuals with IC. Methods The MEDLINE, Embase, and PubMed databases were searched up to January 2015 for terms related to supervised exercise in peripheral arterial disease. The review had 3 aims: first, to establish the rates of uptake to SEPs, second, the rates of adherence to programs, and finally to determine the reasons reported for poor uptake and adherence. Separate inclusion and/or exclusion criteria were applied in selecting reports for each aim of the review. Results Only 23 of the 53 potentially eligible articles for uptake analysis identified on literature searches reported any details of screened patients (n = 7,517) with only 24.2% of patients subsequently recruited to SEPs. Forty-five percent of screen failures had no reason for exclusion reported. Sixty-seven articles with 4,012 patients were included for analysis of SEP adherence. Overall, 75.1% of patients reportedly completed an SEP; however, only one article defined a minimal attendance required for SEP completion. Overall, 54.1% of incomplete adherence was due to patient withdrawal and no reason for incomplete adherence was reported for 16% of cases. Conclusions Reporting of SEP trials was poor with regard to the numbers of subjects screened and reasons for exclusions. Only approximately 1 in 3 screened IC patients was suitable for and willing to undertake SEP. Levels of adherence to SEPs and definitions of satisfactory adherence were also lacking in most the current literature. Current clinical guidelines based on this evidence base may not be applicable to most IC patients and changes to SEPs may be needed to encourage and/or retain participants

A systematic review and meta-analysis of systemic intraoperative anticoagulation during arteriovenous access formation for dialysis

Purpose: Surgical arteriovenous fistula (AVF) or graft (AVG) is preferred to a central venous catheter for dialysis access. Surgical access may suffer thrombosis early after placement and systemic anticoagulation during surgical access formation may increase patency rates but would be expected to increase bleeding-related complications. A systematic review and meta-analysis of randomised controlled trials was conducted to examine the impact of systemic anticoagulation on access surgery perioperative bleeding and patency rates. Methods: We included randomised controlled trials testing systemic anticoagulation during access formation versus a control group without systemic anticoagulation reporting bleeding complications and access patency. Medline, Embase, CENTRAL and CINAHL were searched up to March 2015. Risk of bias was assessed using the Cochrane risk of bias tool and the Jadad score. Meta-analysis was performed using Cochrane Revman ® software. Results: Searches identified 445 reports of which four randomised studies involving 411 participants were included. Three studies pertained to AVF only and one included both AVF and AVG. Systemic anticoagulation led to increased bleeding events in all access [four trials; risk ratio (RR) 7.18; confidence interval (CI), 2.41 to 21.38; p < 0.001]. Patency was not improved for all access (four trials; RR, 0.64; CI, 0.37 to 1.09; p = 0.10) but was improved when AVF analysed alone (three trials; RR, 0.57; CI, 0.33 to 0.97; p = 0.04). Conclusions: The use of intraoperative systemic anticoagulation during access formation is associated with a highly significant increased risk of bleeding-related complications. A significant improvement in AVF patency was seen, though not when AVF and AVG were analysed together

Extreme low-lying carotid bifurcations

A 52-year-old male with no past medical history was referred to the transient ischaemic attack (TIA) clinic following an event at home. The transient symptoms were of an inability to move his left arm and leg for a period of approximately 15 minutes. The patient denied any numbness of the face, headaches or blurring of vision. A careful history revealed two previous transient attacks of blurred vision approximately 1–2 years prior to this presentation. He had no other co-morbidities or associated syndromes. Given this history, suggestive of TIA(s) in the right anterior circulation, an ultrasound examination of the carotid vessels was performed to include or exclude an atherosclerotic source of embolus. The ultrasound scan demonstrated an extremely short common carotid artery (CCA) of just 2.5 cm on the right, with apparently normal flows and velocities in both the external and internal carotids (ECA and ICA) but poor views of the bifurcation. Similarly, the flows and velocities in the left ICA and ECA were also normal, with the carotid bulb lying low in the base of the neck, so further imaging with a magnetic resonance angiogram (MRA) was performed (Panel A) to clarify the anatomic and ultrasound findings. This confirmed extremely low-lying bilateral carotid bifurcations (highlighted in Panel A). The short, right-side CCA bifurcates at the level of C7/T1 (Panel B) and the left carotid bifurcation is at the level of C6/C7 (Panel C)

A systematic review of management of inadvertent arterial injury during central venous catheterisation

© 2017 Wichtig Publishing. Introduction: Central venous catheterisation (CVC) is a technique commonly used to obtain vascular access and over five million CVCs are inserted annually. This systematic review of CVC-related arterial injury aims to compare outcomes reported with different management strategies. Methods: PRISMA guidelines were followed. A search of Medline, Embase, Central and CINAHL was performed. Results were limited to papers in humans and in English with duplicates removed. Details of cases including site and nature of arterial injury, use of ultrasound, methods for identifying arterial placement, management methods used, and any reported outcomes were collated from all papers. Successful management was defined as control of haemorrhage without evidence of further complications. results: We screened 2187 abstracts and 78 full manuscripts were obtained and reviewed. Twenty-four papers were of relevance and were included in this review. Amongst the papers, 80 cases of arterial injury were reported. Successful treatment by removal and compression, endovascular methods, and open surgical repair were 5.6%, 94.6% and 100%, respectively. Discussion: Removal and compression of the arterial site is a poor management method and is associated with a high rate of complications. Endovascular approaches had a high rate of success with advantages of endovascular techniques including access to arteries which are difficult to expose surgically and avoidance of general anaesthesia. Endovascular repair might be considered depending on site of injury or local expertise though surgical repair reported the best results in this review with no complications seen

Percutaneous transluminal angioplasty results in improved physical function but not balance in patients with intermittent claudication

Objective The aim of this study was to identify whether revascularization by percutaneous transluminal angioplasty (PTA) for patients with intermittent claudication improved measures of functional performance including balance. Methods A prospective observational study was performed at a single tertiary vascular center. Patients with symptomatic intermittent claudication (Rutherford grades 1-3) were recruited to the study. Participants were assessed at baseline (pre-PTA) and then 3, 6, and 12 months post-PTA for markers of (1) lower limb ischemia (treadmill walking distances and ankle-brachial pressure index), (2) physical function (6-minute walk, Timed Up and Go, and chair stand time), (3) balance impairment using computerized dynamic posturography with the Sensory Organization Test, and (4) quality of life (VascuQoL and Short Form Health Survey [SF-36]). Results Forty-three participants underwent PTA. Over 12 months, a significant improvement was demonstrated in initial (P = .04) and maximum treadmill walking distance (P = .019). Physical functional ability improved across all outcome measures (P &lt; .02), and some domains of both generic (P &lt; .03) and disease-specific quality of life (P &lt; .01). No significant improvement in balance was demonstrated by the Sensory Organization Test (P = .24). Conclusions Balance impairment is common in claudicants and does not improve with revascularization. Further research regarding effective treatment of balance impairment is required in this specific group of patients

Extracorporeal shockwave therapy for the treatment of lower limb intermittent claudication: Study protocol for a randomised controlled trial (the SHOCKWAVE 1 trial)

© 2017 The Author(s). Background: Peripheral arterial disease (PAD) has a population prevalence of 4.6% with intermittent claudication (IC) presenting as one of the earliest and most common symptoms. PAD has detrimental effects on patients' walking ability in terms of maximum walking distance (MWD) and pain-free walking distance (PFWD). Research has suggested extracorporeal shockwave therapy (ESWT) may induce angiogenesis in treated tissue; therefore, our objective is to assess the tolerability and efficacy of ESWT as a novel treatment of intermittent claudication. Methods/design: Patients with unilateral claudication will be randomised to receive either ESWT (PiezoWave 2 shockwave system) or sham treatment to the calf muscle bulk three times per week for 3 weeks. All patients are blinded to treatment group, and all assessments will be performed by a masked assessor. Treatment tolerability using a visual analogue scale, ankle-brachial pressure index, MWD, PFWD and safety will all be formally assessed as outcome measures at baseline and at 4, 8 and 12 weeks follow-up. Discussion: This trial will be the first of its kind in terms of methodology in relation to ESWT for intermittent claudication. A double-masked randomised controlled trial will provide useful information about the potential for the use of ESWT as a non-invasive treatment option and the need for further robust research. Trial registration: ClinicalTrials.gov, NCT02652078. Registered on 17 October 2014

A systematic review of high-intensity interval training as an exercise intervention for intermittent claudication

BackgroundIntermittent claudication (IC) is the most common symptom of peripheral arterial disease, which significantly affects walking ability, functional capacity and quality of life. Supervised exercise programs (SEP) are recommended as first-line treatment, but recruitment and adherence rates are poor. The time required to complete a SEP is the most common barrier to participation cited by patients who decline. High-intensity interval training (HIIT) is more time efficient than current SEPs and therefore has the potential to overcome this barrier. We conducted a systematic review to appraise the evidence for HIIT programs for IC.MethodsMEDLINE, Embase, and CENTRAL databases were searched for terms related to HIIT and IC. Randomized and nonrandomized trials that investigated HIIT for the treatment of IC were included, with no exclusions based on exercise modality, protocol, or use of a comparator arm. Outcome measures were walking distances, peak oxygen uptake, recruitment and adherence rates, and quality of life. The risk of bias was assessed using the Cochrane tool and study quality using a modified Physiotherapy Evidence Database scale.ResultsNine articles reporting eight studies were included in the review. HIIT seems to improve walking distances and oxygen uptake in relation to controls, with improvements attainable in just 6 weeks. When HIIT was compared with low-intensity exercise, it seemed that longer low-intensity programs were required to obtain similar benefits to those from short-term HIIT.ConclusionsInitial evidence suggests that HIIT may provide benefits for patients with IC. Initially, pilot studies of low-volume, short-term HIIT vs usual SEPs are required. This strategy will allow for larger randomized, controlled trials to be appropriately designed and adequately powered to further explore the potential benefits of HIIT in IC

Presurgery exercise-based conditioning interventions (prehabilitation) in adults undergoing lower limb surgery for peripheral arterial disease (Review)

Copyright © 2020 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. Background: Lower limb peripheral arterial disease (PAD) is a type of cardiovascular disease where the blood vessels that carry the blood to the legs are hardened and narrowed. The most severe manifestation of PAD is critical limb ischaemia (CLI). This condition results in symptoms of intractable rest pain, non-healing wounds and ulceration, gangrene or both. PAD affects more than 200 million people worldwide and approximately 3% to 5% of people aged over 40 have PAD, rising to 18% in people over 70 years of age. Between 5% to 10% of symptomatic PAD patients will progress to CLI over a five-year period and the five year cumulative incidence rate for asymptomatic patients with PAD deteriorating to intermittent claudication is 7%, with 21% of these progressing to CLI. Treatment options include angioplasty, bypass or amputation of the limb, when life or limb is threatened. People with CLI have a high risk of mortality and morbidity. The mortality rates during a surgical admission are approximately 5%. Within one year of surgery, the mortality rate rises to 22%. Postoperative complications are as high as 30% and readmission rates vary between 7% to 18% in people with CLI. Despite recent advances in surgical technology, anaesthesia and perioperative care, a proportion of surgical patients have a suboptimal recovery. Presurgery conditioning (prehabilitation) is a multimodal conditioning intervention carried out prior to surgery using a combination of exercise, with or without nutritional or psychological interventions, or both. The use of prehabilitation is gaining momentum, particularly in elderly patients undergoing surgery and patients undergoing colorectal cancer surgery, as a means of optimising fitness to improve the prognosis for people undergoing the physiological stress of surgery. People with PAD are characterised by poor mobility and physical function and have a lower level of fitness as a result of disease progression. Therefore, prehabilitation may be an opportunity to improve their recovery following surgery. However, as multimodal prehabilitation requires considerable resources, it is important to assess whether it is superior to usual care. This review aimed to compare prehabilitation with usual care (defined as a preoperative assessment, including blood and urine tests). The key outcomes were postoperative complications, mortality and readmissions within 30 days of the surgical procedure, and one-year survival rates. Objectives: To assess the effectiveness of prehabilitation (preoperative exercise, either alone or in combination with nutritional or psychological interventions, or both) on postoperative outcomes in adults with PAD undergoing open lower limb surgery. Search methods: The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials register to 25 September 2019. Selection criteria: We considered all published and unpublished randomised controlled trials (RCTs) comparing presurgery interventions and usual care. Primary outcomes were postoperative complications, mortality and readmission to hospital within 30 days of the surgical procedure. Data collection and analysis: Two review authors independently reviewed all records identified by the searches conducted by the Cochrane Vascular Information Specialist. We planned to undertake data collection and analysis in accordance with recommendations described in the Cochrane Handbook for Systematic Reviews of Interventions. Main results: We found no RCTs that met the inclusion criteria for this review. Authors' conclusions: We found no RCTs conducted to determine the effects of prehabilitation on mortality or other postoperative outcomes when compared to usual care for patients with PAD. As a consequence, we were unable to provide any evidence to guide the treatment of patients with PAD undergoing surgery. To perform a randomised controlled trial of presurgery conditioning would be challenging but trials are warranted to provide solid evidence on this topic

Fear of falling in claudicants and its relationship to physical ability, balance, and quality of Life

Objectives: Intermittent claudication is associated with poor physical function, quality of life (QoL), and balance impairment. Fear of falling (FoF) is a recognized contributing factor to poor physical ability. Any link between claudication and FoF is yet to be determined. This study aimed to explore the prevalence of FoF in claudicants and its relationship with physical function and QoL. Methods: A prospective observational study was performed. Fear of falling was determined using the Activities-specific Balance Confidence (ABC) questionnaire and the categorical question “Are you afraid of falling?” Physical ability and QoL (Short Form 36 and Vascular QoL) were determined. Results: A total of 161 claudicants (118 men, median age of 69 years) were assessed; 83 answered the categorical question “Are you afraid of falling?” By receiver–operating characteristic curve analysis, an ABC threshol