Decompression of Lumbar Canal Stenosis With a Bilateral Interlaminar Versus Classic Laminectomy Technique

A Prospective Randomized Study

Mohamed A. R. Soliman, MD, MSc; Ahmed Ali, MD, MSc


Neurosurg Focus. 2019;46(5):e3 

In This Article

Abstract and Introduction


Objective: The aim of this study was to compare the radiological and clinical results of bilateral interlaminar canal decompression and classic laminectomy in lumbar canal stenosis (LCS).

Methods: Two hundred eighteen patients with LCS were randomized to surgical treatment with classic laminectomy (group 1) or bilateral interlaminar canal decompression (group 2). Low-back and leg pain were evaluated according to the visual analog scale (VAS) both preoperatively and postoperatively. Disability was evaluated according to the Oswestry Disability Index (ODI) preoperatively and at 1 month, 1 year, and 3 years postoperatively. Neurogenic claudication was evaluated using the Zurich Claudication Questionnaire (ZCQ) preoperatively and 1 year postoperatively. The two treatment groups were compared in terms of neurogenic claudication, estimated blood loss (EBL), and intra- and postoperative complications.

Results: Postoperative low-back and leg pain declined as compared to the preoperative pain. Both groups had significant improvement in VAS, ODI, and ZCQ scores, and the improvements in ODI and back pain VAS scores were significantly better in group 2. The average EBL was 140 ml in group 2 compared to 260 ml in group 1. Nine patients in the laminectomy group developed postoperative instability requiring fusion compared to only 4 cases in the interlaminar group (p = 0.15). Complications frequency did not show any statistical significance between the two groups.

Conclusions: Bilateral interlaminar decompression is an effective method that provides sufficient canal decompression with decreased instability in cases of LCS and increases patient comfort in the postoperative period.


LUMBAR canal stenosis (LCS) is common in the elderly as a result of hypertrophy of the ligamentum flavum, spine aging, disc degeneration, facet joint growth, and osteophytes constricting the spinal canal and resulting in nerve root compression.[3] The main symptoms are low-back pain and leg pain and numbness that increase with exertion (neurogenic claudication).[31] When patients do not respond to conservative treatment, surgery is indicated.[2] As technology advances, minimally invasive approaches are increasing. One of these minimally invasive methods is bilateral interlaminar canal decompression.[40] In this study, we compare the radiological and clinical results obtained in classic decompressive laminectomy cases and those achieved in bilateral interlaminar decompression cases.

A classic decompressive laminectomy is the most common surgical approach for LCS decompression. It permits maximal operative decompression of the neural canal and/or bilateral foramina, but there is damage to the paraspinal muscles, the posterior bone compartment, the supraspinous ligament, the interspinous ligament, and occasionally the capsular facet.[2,3,31,40]

Many techniques have been described for LCS decompression including microhemilaminotomy, interlaminar microdecompression, intersegmental microdecompression, recapturing microlaminoplasty, and segmental microsublaminoplasty.[28] In particular, unilateral[13] and bilateral laminotomy have been described for bilateral canal decompression.[20,23]

The microsurgical method is ideal for sufficient bilateral decompression of the spinal canal or foramen, with minimal paraspinal muscle separation. Thus, it helps to stabilize the spine while the vital bones and soft tissues are secured and at the same time decompressing the spinal canal and/or foramen.[13]

Success rates of the microsurgical methods are as high as 90%; however, studies reporting these rates were without a control group, had few patients with not necessarily the same symptoms, or were retrospective.[34] Some investigators did not find a significant advantage to the microsurgical methods over the classic laminectomy.[27] Moreover, in the few qualified studies, investigators reported a higher incidence of preoperative neurological morbidity.

As a result, some authors of a systematic review concluded that laminectomies should be reserved for severe LCS cases.[6] This study had a sufficiently sized population with comparative data; however, it was not a prospective trial. Our aim in the current prospective study was to compare the clinical outcomes and safety between bilateral interlaminar decompression and classic laminectomy in patients with LCS.