Laser Coronary Atherectomy and Polymeric Coronary Wires in Uncrossable Lesions: A Word of Caution

Background Excimer laser coronary atherectomy (ELCA) represents one of the last available options in case of balloon uncrossable lesions but no bench testing or clinical experience has been reported with polymeric wires. We aimed to assess whether ECLA use can disrupt or melt the cover and coating of coronary wires. Methods A total of 22 wires (10 polymer-jacketed and 12 hydrophilic non polymeric) were tested in an uncrossable lesion model. Two ELCA tests were performed over each wire at 8 and 4 cms from the tip with low and high settings, respectively. Microscopic analysis was performed at baseline images and after each test. Wire disruption was classified as Grade 1 (superficial scratches), Grade 2 (coil damage or solution of continuity of the polymeric cover) and Grade 3 (wire rupture/core disruption or de-coiling). Results After 44 ELCA simulations, wire disruption occurred in 16 cases (36.3%). Overall, events were more common for polymer-jacketed than for hydrophilic wires (12 vs 4, p=0.004). No grade 3 events occurred. Grade 2 events occurred in 9 cases (20.5%) and were more frequent with polymer- jacketed wires (8 vs 1, p=0.006). With low ELCA settings only polymer-jacketed wires suffered disruption (5 vs 0, p=0.009). With higher settings 11 events occurred (7 of Grade 2 and 4 of Grade 1) and incidence of grade 2 events was higher for polymer-jacketed wires (6 vs 1, p=0.02). Conclusions ELCA might be a safe option for coronary uncrossable lesions but its use with high settings over polymer-jacketed wires is discouraged. CONDENSED ABSTRACT We aimed to assess whether ECLA use can disrupt coronary wires in balloon/microcatheter uncrossable lesion model. Forty-four in-vitro experiments were performed over hydrophilic-coated and polymer-jacketed coronary wires with different ELCA settings. Wire disruption was classified as Grade 1 (scratches), Grade 2 (coil or polymeric cover damage) and Grade 3 (core disruption/de- coiling). Wire disruption occurred 36.3% of cases and was more common for polymer-jacketed wires than for hydrophilic-coated wires (p=0.004). With high ELCA settings the incidence of grade 2 events was higher for polymer-jacketed wires (p=0.02). This discourages the use of ELCA with high settings over polymer-jacketed wires. ### Competing Interest Statement Dr. Amat-Santos is proctor for Boston Scientific. Dr. Gasparini is proctor for Asahi and Terumo. ### Funding Statement No funding was received. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Not Applicable The details of the IRB/oversight body that provided approval or exemption for the research described are given below: N/A I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Not Applicable I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Not Applicable I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Not Applicable Data are available for other investigators under request.