ABSTRACT
OBJECTIVE: To highlight safety and efficacy of sine wave technique (SWT) in superficializing deep arterio venous fistula (AVF) and managing infiltrations and other complications. METHODS: It is a single center observational study done from Jul 2017 to July 2020. All successive cases of deep AVFs, aneurysm / pseudoaneurysms of AVFs, and AVFs requiring open venoplasty were managed with SWT. Data was collected prospectively and analyzed. SWT is based on random pattern skin flaps. Using ultrasound, a line is marked on either side of centre line (AVF) at a distance of approximately 1.5-2 cm. A sine wave is drawn starting from either of the lines to the other with multiple crests and troughs. The base of flap should be double the height of the flap, that is, about 3-4 cm. Skin is incised and flaps are raised at level of AVF. Excess fat is removed. A sliver of unhealthy skin can be sacrificed if required. Flaps are sutured back to restore sine wave continuity. RESULTS: SWT was used in a total of eleven patients. Median age was 58 years (range 10-67 years). Eight were females and three males. One was radio-cephalic and rest were brachio-cephalic AVFs. Eight AVFs were deep with median depth of 10.25mm (range 8-13mm), median body mass index of 25.5 kg/m2 (range 23.9-26.5kg/m2), median vein diameter of 7 mm (range 6-8 mm), and median flow rate of 1137.5ml/min (range 650- 1380 ml/min). Out of eight, four AVFs presented with infiltration. In other three, SWT was used for exposing AVF to treat underlying pathology (one case each of aneurysm, pseudoaneurysm & stenosis). Ten cases were done under local or regional anesthesia and one under general anesthesia. There was no peri-operative mortality or loss of AVF. Transient limb oedema developed in one case. Median time to cannulate was 20 days (range 13-28 days). Median follow up was 13 months (range 6 - 31months). Cumulative patency at 18 months was 90% (95% CI 47.3%-98.53%) and 45 % (95% CI 9.9%-87.1%) at 24months and at the end of the study. CONCLUSION: SWT is safe and effective in superficialization of deep / difficult to cannulate AVF as well a good approach to treat complications like infiltration. Post procedure cannulation time is reasonably short.
