Dissertation

Efficacy and Safety of a Low-Energy-Application-Protocol (LEAP) for Endovenous Laser Ablation (EVLA) of Incompetent Truncal Veins With a 1940nm Laser System

Setia, Abhay

2024

Overview

1.1. Background:The aim of this study was to develop and evaluate an exact, pre-defined, reproducible therapy protocol for endovenous Laser Ablation (EVLA) with 1940nm laser system and radial fibre, to optimize EVLA and minimize adverse thermal complications, whilst maintaining high occlusion rates. This study presents the short-term (1-month) and midterm (12-months) results of EVLA with 1940nm-laser and flush placement of the radial fibre-tip, supported by a 4-Zone, low-energy-application-protocol (LEAP).1.2. Materials and methods:The EVLA procedures were performed with a Thulium-Fibre-Laser-System (Vela XL, Starmedtec GmbH, Starnberg, Germany) with radial fibre (Saturn Side Fibre, 600µm/400 µm Radial Fibre, Light Guide Optics, LGO, Meckenheim, Germany) with intraoperative duplex ultrasound monitoring. The preoperative patient’s data, intraoperative parameters and the postoperative follow-up results were documented on the home-made standardized 4-Zone, LEAP protocol. Great saphenous vein (GSV) and small saphenous vein (SSV) were divided in 4 and 2 zones respectively with corresponding set power levels. Zone-1 (4W) extended from the sapheno femoral junction to the level of the perineum, Zone-2 (4W) perineum to the upper border of patella, Zone-3 (3W) patella to tibial tuberosity for the GSV and the sapheno-popliteal junction to tibial tuberosity for the SSV, Zone-4 (2W) from the tibial tuberosity to ankle joint. Power was increased by 1 W for veins >10 mm and decreased by 1W when intraoperative fibre sticking was encountered. Pullback-velocity was max. 1mm/s.1.3. Results:A total of 152 consecutive patients (185 procedures) were recruited in this prospective non-randomized study between 01st June 2017 and 30th July 2019. Mean follow-up time was 11.9 Months. Follow-up was 100% at 1M and 85.9% (159/185) at 12M. Average Linear Endovenous Energy Density (LEED), median power for GSV were Zone-1: 42J/cm (4W); Zone-2: 33J/cm (3W); Zone-3: 27J/cm (3W); Zone-4: 22J/cm (2W). The corresponding values for SSV were Zone-3: 34J/cm (3W); Zone-4: 27J/cm (2W). Occlusion rates were 98.9% (1-month) and 93.7% (12-months). Complications at 1M were low; laser-induced paraesthesia (LIP 2.2%) and endovenous heat induced thrombosis (EHIT 1.6%). Persistent LIP at 12M was observed in 0.5% of treated limbs.1.4. Conclusion:The proposed 4-Zone, low-energy-application-protocol, an effort to standardize EVLA execution and documentation, supports the operating surgeon to focus on critical elements of EVLA like flush placement of radial fibre and adequate dosimetry, to achieve an effective and durable vein occlusion and to avoid adverse events. This strategy shows good mid-term results with minimal complications. Long-term followup and application in further centres are necessary to prove its reproducibility. Such a guiding tool could improve the ability to analyse, compare and review different EVLA wavelengths and fibre types.

• Publisher: ProQuest Dissertations & Theses
• Subject: Ablation / Lasers / Optics / Thrombosis