Ex vivo feasibility study of endoscopic intraductal laser ablation of the breast

Objective: To determine the feasibility and safety of breast endoscopic thulium laser ablation for treatment of intraductal neoplasia. Study Design: Ductoscopy is a minimally invasive endoscopic approach of the milk ducts of the breast via the nipple. Besides diagnosis in women with pathologic nipple discharge (PND), it allows non-invasive removal of intraductal lesions with a stalk like papillomas. Removal, however, is often incomplete and flat lesions cannot be targeted. We therefore developed laser ductoscopy. Methods: Dosimetry of laser ductoscopy was assessed in thirteen mastectomy specimens, applying power settings of 1–5 W with 100–1000 ms pulsed exposure to a 375-μm outer diameter thulium fiber laser. Subsequently histology was obtained from the breast tissue that was treated with the Thulium laser. Results: Endoscopic view was maintained during ductoscopic laser ablation at 1–3 W. Increasing power to 4–5 W caused impaired vision due to shrinkage of the main duct around the ductoscope tip. Histology revealed localized ablation of the duct wall. Conclusion: We show for the first time that laser ductoscopy is technically feasible. The Thulium laser enables a superficial intraductal ablation and is a useful tool for intraductal interventions. An in vivo prospective study is needed to further demonstrate its potential. Lasers Surg. Med. 50:137–142, 2018.