Modified no-touch technique for radio-cephalic arteriovenous fistula increases primary patency and decreases juxta-anastomotic stenosis

Beyond Conventional: A Systematic Review of Non-Conventional Techniques for Radio-Cephalic Arteriovenous Fistula

BACKGROUND

Radio-cephalic arteriovenous fistulas (RC-AVFs), the preferred vascular access for hemodialysis, have high failure rates. New techniques like the no-touch technique (NTT) and modified no-touch technique (MNTT) have shown promising results. Our objective is to highlight the effectiveness of nonconventional techniques, aiming to address the challenge of arteriovenous fistula (AVF) failure.

METHODS

We searched Medline, Google Scholar, and Clinicaltrials.gov until April 2023, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Five relevant articles were found, all involving human studies on NTT or MNTT for RC-AVF creation. We focused on primary and secondary patency rates, fistula maturation rates, and complications.

RESULTS

We reviewed 5 studies as follows: 2 were pilot studies, 2 were prospective studies, and one was retrospective study. Three used NTT, and 2 used MNTT. Among double-arm studies, 3 out of 4 showed a significantly improved primary patency with nonconventional techniques. However, one study found no significant difference between nonconventional and conventional methods (90.5% vs. 84.2%; P = 0.225). In a single-arm study, nonconventional technique (NTT) displayed 54% primary patency at 1 year. Secondary patency rates were in 3 studies. One demonstrated significant secondary patency with nonconventional methods compared to conventional (90% vs. 67.5%; P = 0.028), while another found no significant difference (90.5% vs. 84.2%; P = 0.803). In the single-arm study, the nonconventional technique (NTT) revealed 80% secondary patency at 1 year.

CONCLUSIONS

Nonconventional techniques (NTT and MNTT) show promise in improving patency rates, hinting at their potential as alternatives to the conventional technique for RC-AVF creation. Further studies are crucial to confirm their effectiveness and evaluate long-term outcomes.

Application of modified no-touch technique in rabbit arteriovenous fistula model and its effect on venous neointimal hyperplasia

BACKGROUND

To investigate the technical advantages of a modified no-touch technique (MNTT) in constructing arteriovenous fistulas (AVF) compared to the conventional technique (CT) and assess its potential to reduce neointimal hyperplasia in the outflow vein.

METHODS

Forty-seven New Zealand rabbits were randomly divided into three groups: control, CT, and MNTT. Rabbits in control group were observed using ultrasound and then euthanized to obtain external jugular vein (EJV) for Hematoxylin-eosin (H-E). We established common carotid artery (CCA)-EJV AVF using MNTT in the MNTT group and the CT in the CT group. AVF patency and complications were compared between the CT and MNTT groups. Rabbits with patent AVF in both groups were observed using ultrasound 2 weeks after surgery to evaluate changes in the vessel diameter and blood flow spectrum of the AVFs. H-E staining measured the intima thickness of EJV adjacent to the anastomosis and histologic characteristics of the AVF at 2 and 4 weeks after surgery.

RESULTS

Five rabbits died after surgery with common symptoms of sneezing, coughing, runny nose, anorexia, and diarrhea; two in the MNTT group and three in the CT group. There were significant differences in the diameter (p = 0.010) and peak systolic velocities (PSV) (p = 0.001) of EJV between the CT and MNTT groups 2 weeks after surgery. Spiral laminar flow (SLF) was observed in CCA and EJV adjacent to anastomosis in the MNTT group. Additionally, histological observations showed less venous neointimal hyperplasia in the MNTT group than in the CT group 4 weeks after surgery.

CONCLUSION

The rabbit model of CCA-EJV AVF established using MNTT demonstrated fewer complications, larger vein diameters, and reduced venous neointimal hyperplasia, indicating that this maybe an ideal animal model to further investigate the application of MNTT in AVF surgery.

A modified technique for arteriovenous fistula anastomosis: Preserving the surrounding tissue of the vein without the use of vascular clamps

BACKGROUND

This pilot study describes a new technique for creating an arteriovenous fistula (AVF) and presents the preliminary outcomes after 1 year of follow-up.

METHODS

The study included 19 patients (10 males, 9 females) with a mean age of 62 years (range 26-88 years). All patients received an AVF using a modified technique in which the surrounding tissues were not removed from the veins and no elastic loops or vascular clamps were used.

RESULTS

Immediate patency was obtained for all patients. The proportion of patients experiencing primary patency at 30 days and 6 months was 89.5% and 83.1%, respectively, and cumulative patency at 30 days and 6 months was 100%. At 1 year of follow-up, primary patency was 83.1% and cumulative patency was 100%.

CONCLUSIONS

Complete preservation of the surrounding venous tissue in the absence of vascular clamps successfully established AVF, with a high surgical success rate.