Lumbar canal stenosis is a common indication for decompressive spine surgery. Decompression is indicated for cases who fail to respond to medical management or cases with severe clinical symptoms .
The target of lumbar spinal stenosis surgery is decompression of the neural canal and the lumbar foramina while preserving much of the anatomy and the biomechanics of the lumbar spine. The traditional surgeries of wide laminectomy, medial facetectomy, and foraminotomy are accused of causing local tissue trauma and postoperative instability, which increases in the need for fusion procedures.
Several studies described the ULBD technique; showing good outcomes, less blood loss, and reasonable operation times. Few of these reports compared ULBD technique and open laminectomy, which is still a common practice in our country that is why we conducted this comparative study between both techniques .
We performed our laminotomy through the more symptomizing or the radiologically more stenotic side. Proper undercutting of the spinous process, tilting of the operating table, and the use of the surgical microscope allowed adequate visualization of the contralateral lateral recess and foramen. The main advantage of the technique is sparing the midline bony and ligamentous structures, as well as the contralateral lumbar muscles.
Concerning the number of levels operated, in the study published by El Morshidy and colleagues 2016, 36.8% were decompressed in one level, 39.6% two levels, 19.8% three levels, and 3.8% four levels. The most common level was also L4/5, followed by L3/4 and L5S1. In 16% of cases, discectomy was needed . This was similar to our studied cases.
The length of operation was significantly higher in group B (102.8 min/level) than group A (83 min/level); this was like the results published by Khoo and colleagues who reported an operative duration of 109 min for a single level micro-endoscopic unilateral laminotomy and 88 min for open laminectomy . In our study, upgrading our skills in microscopic approach for decompression of lumbar canal stenosis and use of hemi-laminectomy retractors and Kerrison rongeur instead of tubular retractors and drill increased the operative time needed for surgery. The mean blood loss was significantly higher among group A than group B which is matching but lesser amount than results described by Thomé and colleagues .
The first step in evaluation of a new of a new surgical technique must be analysis of its safety compared with the current standard of care. Our study did not show any significant difference between the complication rates of both groups. All the complications met in the study were dural tears (5% of cases); we did not meet any root injuries or postoperative increase in radiculopathy. These facts matched the results published by Çavuşoğlu and colleagues, who showed durotomy rates for laminectomy to range from 5 to 15% and unilateral laminotomy with contralateral decompression in 3.5–12% . None of our cases showed postoperative instability that required further intervention.
There was no statistically significant difference between both groups regarding the visual pain analogue scale pre- and postoperative as well as the neurogenic claudication outcome score (NCOS) pre- and postoperative. In the retrospective study conducted by Den Boogert and colleagues, patients in the ULBD group reported better overall satisfaction with the procedure and a reduction in visual analogue scale .
The small number of cases and the short follow-up period were the main limitations of our study as increasing evidence suggests that outcomes may deteriorate over time .