# Microendoscope-Assisted Posterior Decompression Technique Using a 12-mm Tubular Retractor of the SYNCHA Novel Microendoscopic System for Cervical Spondylotic Radiculopathy: A Technical Note

## TL;DR

This paper introduces a new minimally invasive surgical technique using a 12-mm tubular retractor with the SYNCHA system to treat cervical spondylotic radiculopathy.

## Contribution

The novel contribution is the application of the SYNCHA system's 12-mm tubular retractor for posterior decompression in cervical spondylotic radiculopathy.

## Key findings

- The 12-mm tubular retractor provided a consistent field of view comparable to the 16-mm retractor.
- Adequate decompression was achieved despite the limited working space of the 12-mm retractor.
- The technique is safe, minimally invasive, and potentially advantageous over other endoscopic spinal surgeries.

## Abstract

The microendoscope-assisted posterior decompression technique for degenerative spinal disorders has gained popularity as a useful minimally invasive spinal surgery in Japan. We performed the technique in >9,000 cases of intervertebral lumbar disc herniation, lumbar spinal canal stenosis, cervical spondylotic myelopathy, and cervical spondylotic radiculopathy (CSR). We primarily used the METRx microendoscopic system (Medtronic Sofamor Danek, Minneapolis, MN) with a 16-mm tubular retractor. The SYNCHA (Teijin Nakashima Medical, Okayama, Japan) is a novel microendoscopic system developed by Yoshida. The features of this system include (1) a ball-link mechanism enabling joystick action and (2) tubular retractors ranging from 12 to 18 mm in diameter with lineup at 2 mm intervals. We are currently performing posterior decompression surgeries using a 12-mm tubular retractor that enables reduced invasiveness.

The current study describes a technique using the SYNCHA system with a 12-mm tubular retractor for CSR. The technique was employed in seven cases of CSR. Surgical procedures were performed according to the methods using a 16-mm tubular retractor as described previously by Adamson. Thanks to its joystick action, the 12-mm tubular retractor provided a consistently equivalent field of view compared to the 16-mm tubular retractor. Despite the limited working space, it was possible to perform adequate decompression by using the 12-mm tubular retractor. Microendoscope-assisted posterior decompression technique using the SYNCHA microendoscopic system with a 12-mm tubular retractor is not only safe, minimally invasive, and effective for the treatment of CSR, but it may also provide advantages over full-endoscopic spinal surgery (FESS) and biportal endoscopic spinal surgery (BESS).