Ultrasound-guided supraclavicular brachial plexus anaesthesia improves arteriovenous fistula flow characteristics in end-stage renal disease patients

Intraoperative vascular mapping improves patient eligibility for arteriovenous fistula creation

BACKGROUND

We assessed the utility of intraoperative vein mapping performed by the operating surgeon for evaluating vessel suitability for arteriovenous fistula (AVF) creation.

METHODS

In a retrospective review of 222 AVFs, vein diameter measurements were compared between intraoperative and preoperative mapping in the same anatomical location. AVF creation was based on intraoperative vein diameter ≥2 mm, using a distal to proximal and superficial veins first approach. Potential selection of access type based on preoperative findings alone was analyzed.

RESULTS

The mean diameter of the veins used for AVF creation measured 3.6 ± 0.8 mm on intraoperative duplex versus 2.5 ± 0.9 mm when the same veins were measured on preoperative duplex. Based on preoperative mapping alone, 23% of patients would have received a more proximal AVF and 5% would have needed a graft. AVFs created more distally based on intraoperative findings had similar maturation rates compared to the rest of the cohort, 79% versus 84% (p = 0.2).

CONCLUSIONS

Intraoperative vein mapping can be used to evaluate vessel suitability for AVF and compared to pre-operative vein mapping may increase the eligibility of distal veins for fistula creation while reducing the need for AV grafts.

Long-Term Functional Patency and Cost-Effectiveness of Arteriovenous Fistula Creation under Regional Anesthesia: a Randomized Controlled Trial

BACKGROUND

Regional anesthesia improves short-term blood flow through arteriovenous fistulas (AVFs). We previously demonstrated that, compared with local anesthesia, regional anesthesia improves primary AVF patency at 3 months.

METHODS

To study the effects of regional versus local anesthesia on longer-term AVF patency, we performed an observer-blinded randomized controlled trial at three university hospitals in Glasgow, United Kingdom. We randomly assigned 126 patients undergoing primary radiocephalic or brachiocephalic AVF creation to receive regional anesthesia (brachial plexus block; 0.5% L-bupivacaine and 1.5% lidocaine with epinephrine) or local anesthesia (0.5% L-bupivacaine and 1% lidocaine). This report includes findings on primary, functional, and secondary patency at 12 months; reinterventions; and additional access procedures (primary outcome measures were previously reported). We analyzed data by intention to treat, and also performed cost-effectiveness analyses.

RESULTS

At 12 months, we found higher primary patency among patients receiving regional versus local anesthesia (50 of 63 [79%] versus 37 of 63 [59%] patients; odds ratio [OR], 2.7; 95% confidence interval [95% CI], 1.6 to 3.8; P=0.02) as well as higher functional patency (43 of 63 [68%] versus 31 of 63 [49%] patients; OR, 2.1; 95% CI, 1.5 to 2.7; P=0.008). In 12 months, 21 revisional procedures, 53 new AVFs, and 50 temporary dialysis catheters were required. Regional anesthesia resulted in net savings of £195.10 (US$237.36) per patient at 1 year, and an incremental cost-effectiveness ratio of approximately £12,900 (US$15,694.20) per quality-adjusted life years over a 5-year time horizon. Results were robust after extensive sensitivity and scenario analyses.

CONCLUSIONS

Compared with local anesthesia, regional anesthesia significantly improved both primary and functional AVF patency at 1 year and is cost-effective.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Local Anaesthesia versus Regional Block for Arteriovenous Fistulae, NCT01706354.

Regional versus local anesthesia for arteriovenous fistula creation in end-stage renal disease: a systematic review and meta-analysis

There is a consensus in the literature that regional anesthesia (RA) improves local hemodynamic parameters in comparison to local anesthesia (LA) during arteriovenous fistula (AVF) surgical construction. However, the effects of both techniques on fistula patency and failure rates are still controversial. The aim of this meta-analysis is to synthesize evidence from published randomized trials and observational studies regarding the safety and efficacy of RA versus LA in AVF surgical construction. A computer literature search of PubMed, Scopus, Web of Science, and Cochrane Central retrieved six randomized trials (462 patients) and one retrospective study (408 patients). Pooling data using RevMan software (version 5.3) showed that RA was superior to LA in terms of primary fistula patency rate (RR = 1.22, 95% CI [1.08, 1.37], p = 0.0010); however, both types were comparable in terms of primary fistula failure rate (RR = 0.81, 95% CI [0.47, 1.40], p = 0.46). In comparison to LA, RA was associated with improved hemodynamic parameters including fistula blood flow (MD = 25.08, 95% CI [19.40, 30.76], p<0.00001), brachial artery diameter (SMD = 2.63, 95% CI [2.17, 3.08], p<0.00001), and outflow venous diameter (SMD = 0.93, 95% CI [0.30, 1.75], p = 0.004). Postoperative complications were comparable between both groups (OR = 0.23, 95% CI [0.05, 0.97], p = 0.05). In conclusion, RA was associated with higher primary patency rates of AVF and improved local blood flow in comparison to LA; however, both procedures were comparable in terms of primary failure rates and postoperative complications. Larger well-designed trials with longer follow-up periods should compare both techniques in terms of long-term patency rates and safety outcomes.

Effect of regional versus local anaesthesia on outcome after arteriovenous fistula creation: a randomised controlled trial

BACKGROUND

Arteriovenous fistulae are the optimum form of vascular access in end-stage renal failure. However, they have a high early failure rate. Regional compared with local anaesthesia results in greater vasodilatation and increases short-term blood flow. This study investigated whether regional compared with local anaesthesia improved medium-term arteriovenous fistula patency.

METHODS

This observer-blinded, randomised controlled trial was done at three university hospitals in Glasgow, UK. Adults undergoing primary radiocephalic or brachiocephalic arteriovenous fistula creation were randomly assigned (1:1; in blocks of eight) using a computer-generated allocation system to receive either local anaesthesia (0·5% L-bupivacaine and 1% lidocaine injected subcutaneously) or regional (brachial plexus block [BPB]) anaesthesia (0·5% L-bupivacaine and 1·5% lidocaine with epinephrine). Patients were excluded if they were coagulopathic, had no suitable vessels, or had a previous failed ipsilateral fistula. The primary endpoint was arteriovenous fistula patency at 3 months. We analysed the data on an intention-to-treat basis. This study was registered with ClinicalTrials.gov (NCT01706354) and is complete.

FINDINGS

Between Feb 6, 2013, and Dec 4, 2015, 163 patients were assessed for eligibility and 126 patients were randomly assigned to local anaesthesia (n=63) or BPB (n=63). All patients completed follow-up on an intention-to-treat basis. Primary patency at 3 months was higher in the BPB group than the local anaesthesia group (53 [84%] of 63 patients vs 39 [62%] of 63; odds ratio [OR] 3·3 [95% CI 1·4-7·6], p=0·005) and was greater in radiocephalic fistulae (20 [77%] of 26 patients vs 12 [48%] of 25; OR 3·6 [1·4-3·6], p=0·03). There were no significant adverse events related to the procedure.

INTERPRETATION

Compared with local anaesthesia, BPB significantly improved 3 month primary patency rates for arteriovenous fistulae.

FUNDING

Regional Anaesthesia UK, Darlinda's Charity for Renal Research.