Introduction
Since 2019, we have been employing the oval tubular wound opener (Hollyx, Numazu city, Japan), which is a refined adaptation of the METRx instrument (manufactured by Sofamoa Danek), in the execution of decompression surgery for lumbar spinal canal stenosis. In this work, we present a comparative analysis of the outcomes achieved through microscopic unilateral entry bilateral decompression, utilizing this enhanced wound opener, compared to the former procedure involving the spinous process-splitting laminectomy.
Methods
There were 69 patients (48 men, 21 women), aged 43-88 years (mean 72.0 years), who underwent decompression for lumbar spinal canal stenosis at our hospital from October 2015 to December 2022. Reoperation cases, cases with fusion, and cases in which lumbar decompression was performed simultaneously with cervical or thoracic spine surgery were excluded. The number of decompressed vertebrae, blood loss, operative time, wound pain visual analogue scale (VAS), perioperative complications, and postoperative hospitalization days were investigated.
Results
Thirty-five patients (23 males and 12 females) in the microscopic laminotomy with METRx group (MML group) had a mean age of 71.7 years, and 34 patients (25 males and 9 females) had a mean age of 72.1 years in the spinous process-splitting laminectomy group (splitting group). Notably, there were no significant differences in blood loss or operative time between the two groups. However, the VAS scores pertaining to wound pain were considerably lower in the MML group. Furthermore, the MML group exhibited a significantly shorter postoperative hospitalization of 8 days (ranging from 2 to 19 days) compared to 14.9 days (ranging from 4 to 51 days) in the splitting group. When examining the length of postoperative hospitalization according to the number of decompressed vertebrae, the MML group demonstrated shorter stays, with durations of 8.1 days for 16 patients in the 1-decompression group, 6.3 days for 10 patients in the 2-decompression group, 9.8 days for 6 patients in the 3-decompression group, and 8 days for 3 patients in the 4-decompression group. In contrast, the 1-decompression, 2-decompression, 3-decompression, and 4-decompression groups in the splitting group experienced postoperative hospitalization periods of 9.4, 17.2, 23.8, and 6 days, respectively. The MML group had significantly shorter results for 2- and 3-vertebral decompression.
Discussion
Both techniques employed in this study were characterized as minimally invasive and yielded favorable results, aligning with findings reported by other authors. Notably, the MML group exhibited shorter hospital stays, suggesting a potential reduction in invasiveness. We assert that the innovation of applying an elliptical cylinder shape to the METRx instrument enables a straightforward and less invasive surgical approach.