Abstract
Background A cylindrical working tube with a diameter of 16 mm has been used for endoscopic
posterior lumbar spinal surgery. However, intraoperative muscle resection is significant
when using the current conventional tubular retractor.
Objective To describe a novel tubular retractor for microendoscopic surgery and to analyze
the outcomes of lumbar decompressive laminotomy using this retractor.
Materials and Methods We devised a novel tubular retractor by changing the medial and lateral sides of
the conventional 16-mm cylindrical tubular retractor to planes with a mediolateral
dimension of 10 mm (rectangular tubular retractor hereafter). The amount of muscle
resection, osteotomy angle on the approach side, and operating time were compared
between 25 intervertebral levels treated by bilateral decompression through a unilateral
approach using the rectangular tubular retractor and 31 intervertebral levels treated
with the same surgery using a 16-mm cylindrical tubular retractor.
Results Due to the short mediolateral dimension, muscle resection decreased by 86%. The rectangular
tubular retractor also decreased early postoperative wound pain. Because the craniocaudal
dimension of the tubular retractor was maintained, surgical difficulty did not increase,
resulting in only a slight increase in operating time. The facet joint on the approach
side could be sufficiently preserved.
Conclusions The rectangular tubular retractor reduced surgical invasiveness without increasing
surgical difficulty.
Keywords
paravertebral muscle - lumbar spinal stenosis - minimally invasive surgery
