Success and Complications of Microsurgical Over-Top Decompression for Lumbar Spine Stenosis: Experience in a Limited Resource Center


  • Zahid Khan Department of Neurosurgery Medical and Teaching Institute (MTI), Lady Reading Hospital (LRH), Peshawar, Pakistan
  • Seema Sharafat Department of Neurosurgery Medical and Teaching Institute (MTI), Lady Reading Hospital (LRH), Peshawar, Pakistan
  • Farooq Azam lady reading hospital
  • Haidar Suleman lady reading hospital



bilateral laminectomy, decompression, degenerative spine, lumber spine, lumber stenosis, minimally invasive, spine surgery, unilateral laminotomy.


Objective:  The overtop decompression is also called the outside-in technique or bilateral decompression from the unilateral approach. The objective of the study was to evaluate the success and complications of microsurgical over-top decompression for single-level lumbar spine stenosis.

Material and Methods:  This observational study was conducted at the Neurosurgery unit at Lady Reading Hospital Peshawar from Jan 2018 to December 2021. All those patients who had undergone over-top decompression for single-level degenerative lumbar spine stenosis irrespective of age and gender were included in our study.

Results:  We had a total of 187 patients who underwent microscopic over-top decompression for lumbar spine stenosis. Four patients lost their final follow-up. The mean age of the patients was 46 years (ranging from 18 – 68 years). Spinal stenosis was more common in men (58.3%) and at L4/5 (51.87%) level. The mean duration of surgery was 56 minutes (range 35-86 minutes). Leg pain improved in 83.1% of the cases with overall patient satisfaction after surgery in 82.5% of the cases. The most common (6.95%) complication of the procedure was iatrogenic durotomy. Most of the complications were minor and treated conservatively.

Conclusions:  Overtop decompression is a safe and effective minimally invasive procedure for lumbar spine stenosis. It has good results in symptomatic improvement. There is minimal soft tissue and bony dissection. Therefore, mobility and stability of the spine are preserved. Moreover, the learning curve for microscopic overtop decompression is shallow and surgery time is short.

Author Biography

Haidar Suleman, lady reading hospital

neurosurgery department 

post graduate trainee


: Refaat, M.I., Elsamman, A.K., Rabea, A. et al. Microsurgical unilateral laminotomy for bilateral decompression of degenerative lumbar canal stenosis: a comparative study. Egypt J Neurol Psychiatry Neurosurg 2019; 55, 74.

Snopko P, Kolarovszki B, Opšenák R, Hanko M, Richterová R. Surgical site infections after degenerative lumbar spine surgery. Rozhl Chir. 2018 Winter;97(12):539-545.

: Försth P, Ólafsson G, Carlsson T, Frost A, Borgstrom F, Fritzel P, et al. A randomized, controlled trial of fusion surgery for lumbar spinal stenosis. N Engl J Med. 2016;374:1413–23.

: R3. Lee SY, Kim TH, Oh JK, et al. Lumbar Stenosis: A Recent Update by Review of Literature. Asian Spine J 2015;9:818-28. 10.4184/asj.2015.9.5.818

: Försth P, Ólafsson G, Carlsson T, Frost A, Borgstrom F, Fritzel P, et al. A randomized, controlled trial of fusion surgery for lumbar spinal stenosis. N Engl J Med. 2016;374:1413–23.

: Pao JL, Lin SM, Chen WC, Chang CH. Unilateral biportal endoscopic decompression for degenerative lumbar canal stenosis. J Spine Surg. 2020 Jun; 6(2): 438–446.

: Richard A. Lumbar laminectomy: classical versus minimally invasive surgical technique. In: Surgery of the Spine and Spinal Cord. Cham: Springer; 2016. p. 497–512.

: McCulloch JA, Young PH. Essentials of spinal microsurgery. Philadelphia: Lippincott-Raven; 1998.

: Mobbs R, Phan K. Minimally Invasive Unilateral Laminectomy for Bilateral Decompression. JBJS Essent Surg Tech. 2017. 22;7(1):e9. doi: 10.2106/JBJS.ST.16.00072. PMID: 30233944; PMCID: PMC6132588.

: Den Boogert HF, Keers JC, Marinus Oterdoom DL, Kuijlen JM. Bilateral versus unilateral interlaminar approach for bilateral decompression in patients with single-level degenerative lumbar spinal stenosis: a multicenter retrospective study of 175 patients on postoperative pain, functional disability, and patient satisfaction. J Neurosurg Spine. 2015. 23(3):326-35. Epub 2015 Jun 19.

: Mobbs RJ, Sivabalan P, Raley D, Rao P. Outcomes after decompressive laminectomy for lumbar spinal stenosis: comparison between minimally invasive unilateral laminectomy for bilateral decompression and open laminectomy. J Neurosurg Spine. 2014;21 (2):179–86. 12. Kim HS, Paudel B, Jang JS, et al. Percutaneous Full Endoscopic Bilateral Lumbar Decompression of Spinal Stenosis Through Uniportal-Contralateral Approach: Techniques and Preliminary Results. World Neurosurg 2017;103:201-9.

Minamide A, Yoshida M, Yamada H, et al. Clinical outcomes after microendoscopic laminotomy for lumbar spinal stenosis: a 5-year follow-up study. Eur Spine J 2015;24:396-403. 10.1007/s00586-014-3599-x

: Bresnahan LE, Smith JS, Ogden AT, et al. Assessment of Paraspinal Muscle Cross-sectional Area After Lumbar Decompression: Minimally Invasive Versus Open Approaches. Clin Spine Surg 2017;30:E162-8.

: Kim HS, Wu PH, Jang IT. Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression Outside-In Approach: A Proctorship Guideline With 12 Steps of Effectiveness and Safety. Neurospine. 2020; 17(1):S99-S109.

: Weinstein JN, Tosteson TD, Lurie JD, et al. Surgical versus nonsurgical therapy for lumbar spinal stenosis. N Engl J Med2008;358:794-810.

: El Morshidy EM, Ali HM, Khalifa YE, ELkady HA, Siepe CJ, Mayer MH. Microscopic decompression for lumbar spinal canal stenosis. The Egyptian Orthopaedic Journal. 2016;51:158–64.

: Pao J L. A Review of Unilateral Biportal Endoscopic Decompression for Degenerative Lumbar Canal Stenosis. Int J Spine Surg . 2021;15(3):S65-S71.

: Phan K, Teng I, Shultz K, Mobbs RJ. Treatment of lumbar spinal stenosis by microscopic unilateral laminectomy for bilateral decompression: a technical note. Orthop Surg. 2017;9:241–6.

: Müller SJ, Burkhardt BW, Oertel JM. Management of dural tears in endoscopic lumbar spinal surgery: a review of the literature. World Neurosurg. 2018;119:494–9.

: Kim JH, Kim HS, Kapoor A, et al. Feasibility of full endoscopic spine surgery in patients over the age of 70 years with degenerative lumbar spine disease. Neurospine. 2018;15:131–7.

: Çavu?o?lu H, Raya KA, Türkmenoglu ON, Tuncer C, Colak I, Aydin U. Midterm outcome after unilateral approach for bilateral decompression of lumbar spinal stenosis. Eur Spine J. 2007;16:2133–42.

: Yao R, Zhou H, Choma TJ, Kwon BK, Street J. Surgical Site Infection in Spine Surgery: Who Is at Risk? Global Spine J. 2018 Dec; 8(4 Suppl): 5S–30S.

: Atesok K, Papavassiliou E, Heffernan M J, Tunmire D, Sitnikov I, Tanaka N, et al. Current Strategies in Prevention of Postoperative Infections in Spine Surgery. Global Spine J. 2020 Apr;10(2):183-194.

: Aleem I S, Tan L A, Nassr A, , Riew, K D. Surgical Site Infection Prevention Following Spine Surgery. Global Spine J. 2020 Jan;10(1 Suppl):92S-98S.

: Krishnan R, MacNeil SD, Mehta MSM. Comparing sutures versus staples for skin closure after orthopaedic surgery: systematic review and meta-analysis. BMJ 6(1): 2016 Jan 20;6(1): e009257. doi: 10.1136/bmjopen-2015-009257.

: Ulrich NH, Burgstaller JM, Gravestock I, et al. Outcome of unilateral versus standard open midline approach for bilateral decompression in lumbar spinal stenosis: is “over the top” really better? A Swiss prospective multicenter cohort study. J Neurosurg Spine. 2019 Apr 26;:1–10.

: Overdevest GM, Jacobs W, Vleggeert-Lankamp C, Thomé C, Gunzburg R, Peul W. Effectiveness of posterior decompression techniques compared with conventionallaminectomy for lumbar stenosis. Cochrane Database Syst Rev. 2015. 11;(3):CD010036. doi: 10.1002/14651858.CD010036.pub2.

: Lee CW, Yoon KJ, Kim SW. Percutaneous Endoscopic Decompression in Lumbar Canal and Lateral Recess Stenosis - The Surgical Learning Curve. Neurospine. 2019 Mar;16(1):63-71. doi: 10.14245/ns.1938048.024. Epub 2019 Mar 31. PMID: 30943708; PMCID: PMC6449834.

: Phan K, Xu J, Schultz K, et al. Full-endoscopic versus microendoscopic and open discectomy: a systematic review and meta-analysis of outcomes and complications. Clin Neurol Neurosurg. 2017;154:1–12.

: Nomura K, Yoshida M. Assessment of the Learning Curve for Microendoscopic Decompression Surgery for Lumbar Spinal Canal Stenosis through an Analysis of 480 Cases Involving a Single Surgeon. Global Spine J 2017;7:54-8.