Predicting Technical Success after Fistuloplasty: An Analysis of 176 Procedures.

BACKGROUND: Significant stenoses in arteriovenous fistulae (AVFs) or arteriovenous grafts (AVGs) with limitation of flow and dialysis inadequacy should prompt consideration for fistuloplasty. We sought to identify fistulae, lesions, and patient-specific variables, which predict for outcomes after fistuloplasty. METHODS: Data were extracted retrospectively from a renal access database from 2011 to 2016 of patients undergoing fistuloplasty. Demographics, comorbidities, outcomes of intervention, and flow rates documented on preintervention and postintervention duplex were collected. Secondary analysis of factors associated with postfistuloplasty flow rates of >600 mL/min, previously shown to be predictive of not requiring future intervention, was performed. RESULTS: Of 204 attempted fistuloplasties, 176 were completed. One hundred forty (79.5%) were native AVFs and 34 (19.3%), AVGs (no data for 2). Median stenosis treated was 75%, with a majority (43.8%) in the proximal outflow vein. Flow rate on duplex after fistuloplasty was significantly better in AVFs (mean improvement 189.2 mL/min) than that in AVGs (mean improvement 51.8 mL/min; P = 0.034). Greatest flow improvement occurred for needling site stenotic lesions compared with other locations (from anastomosis to central vein) but was not significant. Brachio-brachial or brachio-axillary AVGs did significantly (P < 0.05) worse than all other fistulae types. The presence of hypertension was predicted for postfistuloplasty flow rate of >600 mL/min. CONCLUSIONS: Flow rates after fistuloplasty vary depending on the type of fistula treated and the presence of hypertension. Knowledge of this can lead to better patient selection and counseling for fistuloplasty.

Predicting outcomes in native AV forearm radio-cephalic fistulae; the CAVeA2T2 scoring system.

PURPOSE: The aim of this study was to identify significant factors relating to fistula survival and create an easy-to-use scoring system for predicting fistula patency rates. METHODS: A total of 276 consecutive radio-cephalic forearm fistulae created in a single tertiary vascular unit were identified retrospectively. Numerous patient- and fistula-related demographics were noted. Cox regression analysis was used to identify significant factors predictive of reduced fistula patency rates, and significant variables weighted according to their hazard ratio. RESULTS: Five significant factors were identified: ipsilateral Central venous access, Age >73 years, anastomosed Vein <2.2 mm, previous lower limb Angioplasty and absent intra-operative Thrill (1 point for first three variables, 2 points for the latter two). The CAVeA2T2 score (maximum 7 points) significantly predicted for reduced fistula patency (p = 0.001) and a reduced rate of successful dialysis (p = 0.001). Fistulae with CAVeA2T2 scores ≥2 had 6 week and 1 year patency rates significantly below pooled published rates. Without scoring for thrill, that is in the pre-operative setting, the scoring system remained significant at all stages. CONCLUSION: The CAVeA2T2 scoring system is a potential scoring system for predicting fistula patency rates and the likelihood of dialysing through a fistula. Further studies and/or external validation is required in the context of methodological limitations. How to manage patients with a high CAVeA2T2 score is unknown.

Advances in the management of leg ulcers--the potential role of growth factors.

Venous ulcers are a major health problem because of the increased costs of the treatment and the refractory nature of the ulcers. The treatment cost is estimated to be around 1 billion dollars per year in the United States (US), and the average cost for one patient over a lifetime exceeds dollars 400,000. There has been an increasing trend in the use of growth factors in their management. Genetic engineering has revolutionised the research of wound healing, as the majority of recombinant growth factors are now available for in vitro and in vivo studies. Online searches of Medline, Pub Medical and Embase were carried out using the terms venous ulcers, leg ulcers, growth factors and growth hormone. The literature regarding the potential role of growth factors in the management of leg ulcers is reviewed. The important clinical studies are critically analysed with a view to appreciate the emerging therapies and the further research possibilities in the management of venous leg ulcers. Clinical results with the use of growth factors in non-healing wounds are encouraging. However, small sample sizes and inconsistent end points in different clinical studies have been the main hurdle in reaching a definite conclusion. Further research is needed to provide the definite evidence. Future developments may include different delivery methods for the growth factors, use of different combinations of growth factors administered simultaneously or, sequentially, bioengineered skin grafts and chemical induction of angiogenesis with the use of gene transfer techniques.