Transforaminal access during lumbar endoscopy

Abstract

There are three basic methods for access to the disc and epidural space during lumbar endoscopy. The inside-out technique was initiated by Kambin and Hijikata as arthroscopic microdiscectomy. Kambin’s original technique required visualization of the annulus using a round cannula followed by the use of 3 and 5 mm trephines inside the cannula to fenestrate the visualized annulus. Access was known as Kambin’s “safe” triangle. Anthony T. Yeung, M.D., modified Kambin’s approach with a blunt 2-hole dilator to anesthetize the annulus, then bluntly fenestrate the anesthetized annulus, followed by insertion of a beveled cannula over the dilator. This was generically known as the inside-out technique or Yeung Endoscopic Spine System (YESS™). Yeung’s philosophy and technique emphasizes visualizing the disc for intradiscal therapy. It was developed with Richard Wolf and FDA approved in 1997. Hoogland, Yeung’s fellow endoscopic pioneer, utilized an outside-in technique with disposable reamers outside the dilator, marketed as the Joimax technique that was later modified by Hoogland as MaxMore. A “targeted” technique known generically as percutaneous endoscopic lumbar discectomy (PELD) later emerged.