Comparison Of The Efficacy Of Unilateral Laminotomy For Bilateral Decompression Between Unilateral Biportal Endoscopy And Uniportal Endoscopy In The Treatment Of Lumbar Spinal Stenosis

Objective: In recent years,the unilateral laminotomy for bilateral decompression(ULBD)technique has become an important minimally invasive method for the treatment of lumbar spinal stenosis with bilateral lateral recess stenosis.The object of this study was to compare the short-term clinical efficacy and radiological results of ULBD in the treatment of lumbar spinal stenosis with bilateral lateral recess stenosis through unilateral biportal endoscopic(UBE)and uniportal endoscopy(UE).Methods: In the period from September 2019 to August 2020,we collected patients who underwent ULBD through UBE and UE for lumbar spinal stenosis.Patients were classified into two groups based on the surgery they had undergone.The visual analogue scales(VAS)score for back and leg pain,Oswestry disability index(ODI),operation time,hospital stays and perioperative complications were recorded before surgery,1 day after surgery and 3 months after surgery.The dural sac area was measured using lumbar MRI before and 7 days after surgery.The angle between the medial facetectomy area of the ipsilateral facet joint and the axial horizontal line was measured using lumbar CT 72 hours after surgery.The width of the superior articular process on both sides of disc-flava ligament space and the distance from the medial margin of the superior articular process to the medial margin of the pedicle on both sides of bony lateral recess was measured using lumbar CT before and 72 hours after surgery to compare and evaluate the clinical efficacy and radiological results of the two kinds of spinal endoscopy.Results: All patients were followed up for 3 months by We Chat,mobile phone and outpatient follow-up.The operation time in the UBE group was(60.31±13.97)min,and in the UE group it was(58.41±13.22)min.There was no significant difference between the two groups(P > 0.05).The length of hospital stay in the UBE group was(4.34±1.64)days,and in the UE group it was(3.73±1.35)days,and there was no significant difference between the two groups(P > 0.05).There was no statistical significance in the VAS score for back pain,VAS score for leg pain and ODI before,1 day and 3 months after surgery between the two groups(P > 0.05).In the UBE group,postoperative complications included 1 transient motor weakness and 2 dural tears.In the UE group,postoperative complications included 1 dural tear,1 transient motor weakness and 1 epidural hematoma.There was no statistical difference in the incidence of postoperative complications between the two groups(P > 0.05).The mean dural sac area of postoperative lumbar MRI in the UBE group was significantly larger than that of the UE group,and the difference between the two groups was statistically significant(P < 0.05).The mean resection angle(the angle between the medial facetectomy area of the ipsilateral facet joint and the axial horizontal line)of the UBE group was significantly lower than that of the UE group,and the difference between the two groups was statistically significant(P < 0.05).The average dural sac area in both groups of patients after operation was significantly larger than that before operation(P < 0.05).In the UBE group,there were no significant differences in disc-flava ligament space decompression rate and bony lateral recess decompression rate between ipsilateral side and contralateral side(P > 0.05).In the UE group,the decompression rate of disc-flava ligament space and bony lateral recess on the ipsilateral side were significantly higher than those on the contralateral side(P < 0.05).Conclusion: Compared with uniportal endoscopy,ULBD has the following advantages under unilateral biportal endoscopy:(1)The operative field is more extensive and clear in the limited area;(2)Higher decompression efficiency;(3)The dilatation of spinal canal and dural sac was more obvious;(4)The range of bilateral lateral recess decompression was wider,especially the contralateral lateral recess;(5)Less damage to the ipsilateral facet joint.Although the radiological results in the two groups of patients were different,they all achieved satisfactory clinical outcomes in the short-term follow-up(3 months).Unilateral laminotomy for bilateral decompression through unilateral biportal endoscopy is an effective surgical method for the treatment of lumbar bilateral lateral recess stenosis with or without central spinal stenosis.It is an effective alternative to traditional open surgery and microsurgical decompression.