A comparison study of two channels during MIS-TLIF in degenerative lumbar spinal stenosis treatment

Objective To compare the clinical effects between minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) assisted by Microendoscopic discectomy (MED) and Quadrant for the treatment of degenerative lumbar spinal stenosis (DLSS). Methods All of 59 patients suffered from DLSS treated surgically from May 2015 to October 2017 were reviewed. According to the surgery method, all cases were divided into MED group (27 cases) and Quadrant channel group (32 cases). All patients were followed up for an average of 18.5 months (11-29 months). Comparison was made on the operative time, intraoperative blood loss, postoperative drainage, postoperative time in bed, postoperative creatine kinase (CK), fusion rate and the degree of muscle fibrosis shown in MRI, as well as visual analogue scale (VAS)score and Oswestry dysfunction index (ODI) score in two groups. Results The duration of operation in MED group was significantly longer than that in Quadrant group (161.7±22.4 min vs. 145.6±19.4 min, t=4.541, P 0.05). ODI was lower in MED group than that in Quadrant group after 6 months and 12 months.The fusion rate was88.9%(24/27) in MED group and 93.8%(30/32) in Quadrant channel group. There was no statistical difference in fusion rate of two groups. 10 patients in MED group and 12 patients in Quadrant group underwent MRI examination of lumbar spine one year after operation. The ratio of postoperative and preoperative atrophy of multiplex muscle area was measured. Muscle atrophy of lower back muscle was lighter in MED group (0.12±0.05 vs. 0.22±0.04, t=-2.428, P<0.05). For intraoperative and postoperative complications, 1 case of dural sac rupture occurred in both groups. Gelatin sponge immediately with fibrin glue was used for plugging up, no postoperative cerebrospinal fluid leakage was found. In Quadrant channel group, 1 case had less blood supply of skin incision edges and epidermal necrosis while the other case had fat liquefaction. Conclusion Compared with the aid of Quadrant, MIS-TLIF assisted with MED had less blood loss, less trauma and faster recovery and could reduce the incidence of postoperative incision complication. Key words: Lumbar vertebrae; Intervertebral disc degeneration; Spinal Stenosis; Surgical procedures, minimally invasive; Spinal fusion