Interventions for thrombosed haemodialysis arteriovenous fistulas and grafts.

BACKGROUND: Patients who present with problems with definitive dialysis access (arteriovenous fistula (AVF) or arteriovenous graft (AVG)) become catheter dependent (temporary access), a condition that often carries a higher risk of infections, central venous occlusions and recurrent hospitalisations. For AVG, primary patency rates are reported to be 30% to 90% in patients undergoing thrombectomy or thrombolysis. According to the National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (NKF-KDOQI) guidelines, surgery is preferred when the cause of the thrombosis is a stenosis at the site of the anastomosis in thrombosed AVF. The European Best Practice Guidelines (EBPG) reported that thrombosed AVF may be preferably treated with endovascular techniques, but when the cause of thrombosis is in the anastomosis, surgery provides better results with re-anastomosis. Therefore, there is a need to carry out a systematic review to determine the effectiveness and safety of the intervention for thrombosed fistulae. OBJECTIVES: This review aims to establish the efficacy and safety of interventions for failed AVF and AVG in patients receiving haemodialysis (HD). SEARCH METHODS: We searched the Cochrane Kidney and Transplant Register of Studies up to 28 January 2024 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, EMBASE, conference proceedings, the International Clinical Trials Registry Portal (ICTRP) Search Portal and ClinicalTrials.gov. SELECTION CRITERIA: The review included randomised controlled trials (RCTs) and quasi-RCTs in people undergoing HD treatment using AVF or AVG presenting with clinical or haemodynamic evidence of thrombosis. Patients had to have used an AVF or AVG at least once. DATA COLLECTION AND ANALYSIS: Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. MAIN RESULTS: Our search strategy identified 14 eligible studies (1176 randomised participants) for inclusion in this review. We included three types of interventions for the treatment of thrombosed AVF and AVG: (1) types of thrombectomy, (2) types of thrombolysis and (3) surgical procedures. Most of the included studies had a high risk of bias due to a poor study design, a low number of patients and industry involvement. Overall, there was insufficient evidence to suggest that a specific intervention was better than another for the outcomes of failure, primary patency at 30 days, technical success and adverse events (both major and minor). Primary patency at 30 days may improve with surgical compared to mechanical thrombectomy (3 studies, 404 participants: RR 1.36, 95% CI 1.07 to 1.67); however, the evidence is very uncertain. Death, access dysfunction, successful dialysis, and SONG (Standards Outcomes in Nephrology) outcomes were rarely reported. The current review is limited by the small number of available studies with a limited number of patients enrolled. Most of the studies included in this review have a high risk of bias and a low or very low certainty of evidence. Further research is required to define the most effective and clinically appropriate technique for access dysfunction. AUTHORS' CONCLUSIONS: It remains unclear whether any intervention therapy affects the patency at 30 days or failure in any thrombosed HD AV access (very low certainty of evidence). Future research will very likely change the evidence base. Based on the importance of HD access to these patients, future studies of these interventions among people receiving HD should be a priority.

Retrograde distal access versus femoral access for below the knee angioplasty.

BACKGROUND: The prevalence of peripheral artery disease (PAD) in the general population is about 12% to 14% and it increases with age. PAD increased from 164 million people in 2000 to 202 million people in 2010. More than two-thirds of people with PAD are based in low- or middle-income countries. Critical limb ischaemia (CLI) occurs in 1% to 2% of people with intermittent claudication over five years. One third of people with CLI have isolated below the knee (BTK) lesions. CLI and isolated BTK lesions are associated with a higher incidence of limb loss when compared with people with multilevel arterial disease. Endovascular procedures such as angioplasty (with or without stenting) are widely used to treat isolated BTK lesions, aiming to improve blood flow and limb salvage. The technical success of any angioplasty procedure depends on the ability to cross the target lesion. Failed attempts are underestimated in the literature and failures in the real world appear to be higher than reported. People with isolated BTK lesions undergoing angioplasty by conventional femoral access present a high failure rate to cross these lesions. Retrograde distal access may provide some advantages that can lead to successful crossing of the target lesion. OBJECTIVES: To evaluate the benefits and harms of retrograde distal access versus conventional femoral access for people undergoing below the knee angioplasty. SEARCH METHODS: The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases, and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 26 September 2022. SELECTION CRITERIA: We planned to include randomised or quasi-randomised controlled trials comparing people undergoing retrograde distal access versus people undergoing conventional femoral access (ipsilateral antegrade or contralateral retrograde) for BTK angioplasty. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed identified studies for potential inclusion in the review. We used standard methodological procedures in accordance with the Cochrane Handbook for Systematic Review of Interventions. Our primary outcomes were technical success of angioplasty procedure and major procedural complications. Our secondary outcomes were mortality rate, amputation-free survival, primary patency, minor procedural complications and wound healing. We planned to use GRADE to assess the certainty of the evidence for each outcome. MAIN RESULTS: We identified no randomised or quasi-randomised controlled trials that met the inclusion criteria. AUTHORS' CONCLUSIONS: We identified no randomised or quasi-randomised controlled trials that compared retrograde distal access versus femoral access for BTK angioplasty. High-quality studies that compare retrograde distal access versus conventional femoral access for BTK angioplasty are needed.

Terazosin and propranolol as blockers to the deleterious effect of nicotine in a random skin flap, in the rat

PURPOSE: To evaluate the effect of Terazosin and Propranolol on the prevention of necrosis induced by nicotine, in a random skin flap.METHODS: This study utilized 32 adult male Wistar-EPM rats divided, at random, into four groups of eight animals each. All the 32 animals received nicotine (2 mg/kg/day) subcutaneously, for one week before and one week after flap elevation. CG (Control) group received distilled water (0.2 ml/day) by gavage and saline (0.5 ml) intraperitoneally, for seven days in the postoperative period. TG (Terazosin) group received terazosin hydrochloride (3 mg/day) by gavage and saline, intraperitoneally, for seven days in the postoperative period. PG (Propranolol) group received propranolol (1.5 mg/day) intraperitoneally and distilled water, by gavage, following the stablished pattern. TPG (Terazosin + Propranolol) group received both drugs. On the seventh postoperative day, the distal necrotic area of the flaps was determined via the paper template method. Blood and skin samples were collected in order to allow determination of Malondialdehyde (MDA) levels. RESULTS: The control group had a mean value of 39.5 percent of necrosis; the Terazosin group 25.1 percent; the Propranolol group 34.5 percent and the Terazosin + Propranolol group 26.2 percent of necrosis. MDA levels in the serum and in the skin samples behave similarly, with an exception regarding Propranolol group in this case. CONCLUSION: Terazosin is effective in the prevention of necrosis in this animal model and Propranolol is not effective in this case.