Background:Discectomy performed open or with an operating microscope remains the standard surgical management. Tubular retractor system is being increasingly used. Potential benefits include less muscle and local damage, better cosmesis, decreased pain and operative time and faster recovery after surgery. We have evaluated the outcome of micro endoscopic discectomy (MED) utilizing tubular retractors in terms of safety and efficacy of the technique.Materials and Methods:188 consecutive patients who underwent surgery for herniated disc using the tubular retractors between April 2007 and April 2012 are reported. All patients had a preoperative MRI (Magnetic Resonance Imaging) and were operated by a single surgeon with the METRx system (Medtronic, Sofamor-Danek, Memphis, TN) using 18 and 16 mm ports. All patients were mobilized as soon as pain subsided and discharged within 24-48 hours post surgery. The results were evaluated by using VAS (Visual Analog Scale 0-5) for back and leg pain and ODI (Oswestry Disability Index). Patients were followed up at intervals of 1 week, 6 weeks, 3 months, 6 months, 12 months and 2 years.Results:The mean age of patients was 46 years (range 16-78 years) and the sex ratio was 1.5 males to 1 female. The mean followup was 22 months (range 8-69 months). The mean VAS scale for leg pain improved from 4.14 to 0.76 (P < 0.05) and the mean VAS scale for back pain improved from 4.1 to 0.9 (P < 0.05). The mean ODI changed from 59.5 to 22.6 (P < 0.05). The mean operative time per level was about 50 minutes (range 20-90 minutes). Dural punctures occurred in 11 (5%) cases. Average blood loss was 30 ml (range 10-500 ml). A wrong level was identified and later corrected in a case of revision discectomy. Four patients with residual disc-herniation had revision MED and three patients with recurrent disc herniation later underwent fusion. One patient had wound infection which needed a debridement.Conclusion:MED for herniated discs effectively achieves the goals of surgery with minimal access. The advantages of the procedure are cosmesis, early postoperative recovery and minimal postoperative morbidity.

Background:The aim of the present prospective study is to evaluate whether the touted advantages of minimal invasive-transforaminal lumbar interbody fusion (MI-TLIF) translate into superior, equal, or inferior outcomes as compared to open-transforaminal lumbar interbody fusion (O-TLIF). This is the first study from the Indian subcontinent prospectively comparing the outcomes of MI-TLIF and O-TLIF.Materials and Methods:All consecutive cases of open and MI-TLIF were prospectively followed up. Single-level TLIF procedures for spondylolytic and degenerative conditions (degenerative spondylolisthesis, central disc herniations) operated between January 2011 and January 2013 were included. The pre and postoperative Oswestry Disability Index (ODI) and visual analog scale (VAS) for back pain and leg pain, length of hospital stay, operative time, radiation exposure, quantitative C-reactive protein (QCRP), and blood loss were compared between the two groups. The parameters were statistically analyzed (using IBM® SPSS® Statistics version 17).Results:129 patients underwent TLIF procedure during the study period of which, 71 patients (46 MI-TLIF and 25 O-TLIF) fulfilled the inclusion criteria. Of these, a further 10 patients were excluded on account of insufficient data and/or no followup. The mean followup was 36.5 months (range 18-54 months). The duration of hospital stay (O-TLIF 5.84 days + 2.249, MI-TLIF 4.11 days + 1.8, P < 0.05) was shorter in MI-TLIF cases. There was less blood loss (open 358.8 ml, MI 111.81 ml, P < 0.05) in MI-TLIF cases. The operative time (O-TLIF 2.96 h + 0.57, MI-TLIF 3.40 h + 0.54, P < 0.05) was longer in MI group. On an average, 57.77 fluoroscopic exposures were required in MI-TLIF which was significantly higher than in O-TLIF (8.2). There was no statistically significant difference in the improvement in ODI and VAS scores in MI-TLIF and O-TLIF groups. The change in QCRP values preoperative and postoperative was significantly lower (P < 0.000) in MI-TLIF group than in O-TLIF group, indicating lesser tissue trauma.Conclusion:The results in MI TLIF are comparable with O-TLIF in terms of outcomes. The advantages of MI-TLIF are lesser blood loss, shorter hospital stay, lesser tissue trauma, and early mobilization. The challenges of MI-TLIF lie in the steep learning curve and significant radiation exposure. The ultimate success of TLIF lies in the execution of the procedure, and in this respect the ability to achieve similar results using a minimally invasive technique makes MI-TLIF an attractive alternative.

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Background:The conventional interlaminar approach is adequate for access to most disc herniations in lumbar spine surgery. The access to cranially and caudally migrated disc fragments, by conventional interlaminar fenestration, requires an extension of the fenestration with the potential destruction of the facet joint complex and consequent postsurgical instability. To describe the technique and results of the translaminar technique of targeted discectomy using tubular retractors for the surgical treatment of cranially and caudally extruded discs.Materials and Methods:The study period extended from January 2008 to December 2014. All patients with lumbar herniated discs who failed conservative management were selected for surgery and underwent routine erect radiographs and magnetic resonance imaging (MRI) of the lumbar spine. The patients with cranially or caudally migrated discs were included in this study. The technique involves approaching migrated disc through an oval window (sculpted through an 18 mm tubular retractor using a burr) in the lamina precisely over the location of the migrated disc as predicted by the preoperative MRI (inferior lamina for inferior migration and superior lamina for superior migration). The perioperative parameters studied were operative time, blood loss, complications, Oswestry Disability Index (ODI), and visual analog scale (VAS) for leg pain before surgery and at last followup. In the study, 4 patients underwent a postoperative computed tomography-scan with a three-dimensional reconstruction to visualize the oval window and to rule out any pars fracture. All technical difficulties and complications were analyzed.Results:17 patients in the age group of 41–58 years underwent the translaminar technique of targeted discectomy. The migration of disc was cranial in 12 patients and caudal in 5 patients. Fourteen of the affected discs were at the L4–L5 level and three were at the L5-S1 level. The mean VAS (leg pain) scale improved from 8 to 1 and the mean ODI changed from 59.8 to 23.6. There were no intraoperative or postoperative complications encountered in this study. Furthermore, no patient in the present study required a conventional laminotomy or medial facetectomy. There was no evidence of iatrogenic pars injury or instability at the last followup. There were no recurrences till the last followup.Conclusions:The targeted translaminar approach preserves structures important for segmental spinal stability thus causing minimal anatomical disruption. This approach allows access to the extruded disc fragment and intervertebral disc space comparable to classical approaches.

Microendoscopic techniques can be extended to excise lesions of the spine. It is a safe procedure in experienced hands. The advantages are minimal morbidity, minimal postoperative pain and discomfort, less analgesic dependence, and better cosmesis. The authors recommend this technique for accessible lesions involving the spine.