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Updated: Aug 22, 2026

Clinical Application of Microscope-Assisted Minimally Invasive Anterior Lumbar Interbody Fusion
Published on: June 16, 2023
Novel retractor for endoscopic and microsurgical spinal interventions
D Freudenstein1, F Duffner, T Bauer
1Department for Neurosurgery, University Hospital, Eberhard-Karls University Tübingen, Tübingen, Germany. dkfreude@med.uni-tuebingen.de
Abstract:
Retractors play an important role in surgery, especially using endoscopic techniques like microendoscopic discectomy. As a consequence of the minimally invasive approach the working space is frequently very restricted. All currently available systems still use tubular retractors with limitations regarding flexibility, stability and accessible working space. This paper discusses the technical aspects of a newly designed circular retractor system for endoscopic and microsurgical spinal interventions (SpineGate) and presents first clinical results in a series of 20 consecutive patients. The autoclavable system consists of a circular base plate and several valves varying in length. The variable fixation of the valves from different directions within the 360 degrees geometry of the base plate allows a continuously adjustable working space, depending on the individual anatomy. An additional fixation device is not necessary. The retractor is suitable for microendoscopic and microsurgical techniques. It is easy and safe to handle. The retractor system was successfully used in all cases without complications or instrumental malfunctions. All patients experienced good to excellent relief of their preoperative symptoms.
