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

Unilateral laminotomy with bilateral spinal canal decompression: systematic review of outcomes and complications

BACKGROUND

Unilateral laminotomy with bilateral spinal canal decompression has gained popularity recently.

AIM

To systematically review the literature of unilateral laminotomy with bilateral spinal canal decompression for lumbar spinal stenosis (LSS) aiming to assess outcomes and complications of the different techniques described in literature.

METHODS

On August 7, 2022, Pubmed and EMBASE were searched by 2 reviewers independently, and all the relevant studies published up to date were considered based on predetermined inclusion and exclusion criteria. The subject headings "unilateral laminotomy", "bilateral decompression" and their related key terms were used. The Preferred Reporting Item for Systematic Reviews and Meta-Analyses statement was used to screen the articles.

RESULTS

A total of seven studies including 371 patients were included. The mean age of the patients was 69.0 years (range: 55-83 years). The follow up duration ranged from 1 to 3 years. Rate of postoperative pain and functional improvement was favorable based on VAS, JOA, JOABPEQ, RMDW, ODI and SF-36, for example improved from a range of 4.2-7.5 preoperatively on the VAS score to a range of 1.4-3.0 postoperatively at the final follow up. Insufficient decompression was noted in 3% of the reported cases. The overall complication rate was reported at 18-20%, with dural tear at 3.6-9% and hematoma at 0-4%.

CONCLUSION

Unilateral laminotomy with bilateral decompression has favorable short- and mid-term pain and functional outcomes with low recurrence and complication rates. This, however, needs to be further confirmed in larger, long-term follow-up, prospective, comparative studies between open, and minimally invasive techniques.

Unilateral microscopic approach for lumbar spinal stenosis decompression: a scoping review

BACKGROUND

Microscopic unilateral laminotomy for bilateral decompression (ULBD) is a minimally invasive technique used in the treatment of lumbar spinal stenosis and could limit spinal instability and be associated with better clinical outcomes. However, there is ongoing debate regarding its utility compared to conventional laminectomy (CL). The primary objective was to collate and describe the current evidence base for ULBD, including perioperative parameters, functional outcomes, and complications. The secondary objective was to identify operative techniques.

METHODS

A scoping review was conducted between January 1990 and August 2022 according to the PRISMA extension for scoping reviews (PRISMA-ScR) guidelines. Major databases were searched for full text English articles reporting on outcomes following microscopic unilateral laminotomy in patients with lumbar spinal stenosis.

RESULTS

Seventeen articles met the inclusion criteria. Two studies were randomised controlled trials. Two studies were prospective data collection and the rest were retrospective analysis. Three studies compared ULBD with CL. ULBD preserves the osteoligamentous complex and may be associated with shorter operative time, less blood loss, and similar clinical outcomes when compared to CL.

CONCLUSION

This review highlights that ULBD aims to minimise disruption to the normal posterior spinal anatomy and may have acceptable clinical outcomes. It also highlights that it is difficult to draw valid conclusions given there are limited data available as most studies identified were retrospective or did not have a comparator group.

Incidence of Revision Surgery After Decompression With vs Without Fusion Among Patients With Degenerative Lumbar Spinal Stenosis

IMPORTANCE

Only limited data derived from large prospective cohort studies exist on the incidence of revision surgery among patients who undergo operations for degenerative lumbar spinal stenosis (DLSS).

OBJECTIVE

To assess the cumulative incidence of revision surgery after 2 types of index operations-decompression alone or decompression with fusion-among patients with DLSS.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study analyzed data from a multicenter, prospective cohort study, the Lumbar Stenosis Outcome Study, which included patients aged 50 years or older with DLSS at 8 spine surgery and rheumatology units in Switzerland between December 2010 and December 2015. The follow-up period was 3 years. Data for this study were analyzed between October and November 2021.

EXPOSURES

All patients underwent either decompression surgery alone or decompression with fusion surgery for DLSS.

MAIN OUTCOMES AND MEASURES

The primary outcome was the cumulative incidence of revision operations. Secondary outcomes included changes in the following patient-reported outcome measures: Spinal Stenosis Measure (SSM) symptom severity (higher scores indicate more pain) and physical function (higher scores indicate more disability) subscale scores and the EuroQol Health-Related Quality of Life 5-Dimension 3-Level questionnaire (EQ-5D-3L) summary index score (lower scores indicate worse quality of life).

RESULTS

A total of 328 patients (165 [50.3%] men; median age, 73.0 years [IQR, 66.0-78.0 years]) were included in the analysis. Of these, 256 (78.0%) underwent decompression alone and 72 (22.0%) underwent decompression with fusion. The cumulative incidence of revisions after 3 years of follow-up was 11.3% (95% CI, 7.4%-15.1%) for the decompression alone group and 13.9% (95% CI, 5.5%-21.5%) for the fusion group (log-rank P = .60). There was no significant difference in the need for revision between the 2 groups over time (unadjusted absolute risk difference, 2.6% [95% CI, -6.3% to 11.4%]; adjusted absolute risk difference, 3.9% [95% CI, -5.2% to 17.0%]; adjusted hazard ratio, 1.40 [95% CI, 0.63-3.13]). The number of revisions was significantly associated with higher SSM symptom severity scores (β, 0.171; 95% CI, 0.047-0.295; P = .007) and lower EQ-5D-3L summary index scores (β, -0.061; 95% CI, -0.105 to -0.017; P = .007) but not with higher SSM physical function scores (β, 0.068; 95% CI, -0.036 to 0.172; P = .20). The type of index operation was not significantly associated with the corresponding outcomes.

CONCLUSIONS AND RELEVANCE

This cohort study showed no significant association between the type of index operation for DLSS-decompression alone or fusion-and the need for revision surgery or the outcomes of pain, disability, and quality of life among patients after 3 years. Number of revision operations was associated with more pain and worse quality of life.

Pathomechanism and prevention of further surgery after posterior decompression for lumbar spinal canal stenosis in patients with diffuse idiopathic skeletal hyperostosis

BACKGROUND CONTEXT

Diffuse idiopathic skeletal hyperostosis (DISH) is a risk factor for further surgery after posterior decompression without fusion for patients with lumbar spinal canal stenosis (LSS). However, a strategy to prevent revision surgery has not been described.

PURPOSE

The aim of this study was to review clinical and imaging findings in LSS patients with DISH extending to the lumbar segment and to propose countermeasures for prevention of revision surgery.

STUDY DESIGN

A retrospective study.

PATIENTS SAMPLE

A total of 613 consecutive patients with LSS underwent posterior decompression without fusion at our hospital and had a minimum follow-up period of 2 years. We defined patients with DISH bridging to the lumbar segment as L-DISH cases (group D, n=111), and those without as non-L-DISH cases (group N, n=502).

OUTCOME MEASURE

Demographic data including the rate of revision surgery, neurological examination using Japanese Orthopaedic Association score, radiological studies comprised plain lumbar radiography, CT, and high-resolution MRI were assessed.

METHODS

Clinical features and imaging findings were compared in patients with and without L-DISH. Revision surgery and surgical procedures (conventional laminotomy or lumbar spinous process-splitting [split] laminotomy) were examined in the two groups. No funding was received for this study.

RESULTS

L-DISH from L2 to L4 was a risk factor for disc degeneration such as a vacuum phenomenon and for further surgical treatment. The rate of revision surgery was higher in group D than in group N (9.0% vs. 4.0%, p=.026). There was no significant difference in this rate for patients in groups D and N who underwent conventional laminotomy; however, for those who underwent split laminotomy, the rate was significantly higher in group D (16.7% vs. 2.1%, p=.0006). Furthermore, the rate of revision surgery after split laminotomy at a lower segment adjacent to L-DISH was significantly higher than that after conventional laminotomy (37.5% vs. 7.7%, p=.037).

CONCLUSIONS

A negative impact of lumbar spinous process-splitting laminotomy was found, especially with decompression at a lower segment adjacent to L-DISH. In such cases, surgery sparing the osteoligamentous structures at midline, including the spinous process and supra- and interspinous ligaments, should be selected.

Patient-specific prediction model for clinical and quality-of-life outcomes after lumbar spine surgery

OBJECTIVE

Patient demographics, comorbidities, and baseline quality of life (QOL) are major contributors to postoperative outcomes. The frequency and cost of lumbar spine surgery has been increasing, with controversy revolving around optimal management strategies and outcome predictors. The goal of this study was to generate predictive nomograms and a clinical calculator for postoperative clinical and QOL outcomes following lumbar spine surgery for degenerative disease.

METHODS

Patients undergoing lumbar spine surgery for degenerative disease at a single tertiary care institution between June 2009 and December 2012 were retrospectively reviewed. Nomograms and an online calculator were modeled based on patient demographics, comorbidities, presenting symptoms and duration of symptoms, indication for surgery, type and levels of surgery, and baseline preoperative QOL scores. Outcomes included postoperative emergency department (ED) visit or readmission within 30 days, reoperation within 90 days, and 1-year changes in the EuroQOL-5D (EQ-5D) score. Bootstrapping was used for internal validation.

RESULTS

A total of 2996 lumbar surgeries were identified. Thirty-day ED visits were seen in 7%, 30-day readmission in 12%, 90-day reoperation in 3%, and improvement in EQ-5D at 1 year that exceeded the minimum clinically important difference in 56%. Concordance indices for the models predicting ED visits, readmission, reoperation, and dichotomous 1-year improvement in EQ-5D were 0.63, 0.66, 0.73, and 0.84, respectively. Important predictors of clinical outcomes included age, body mass index, Charlson Comorbidity Index, indication for surgery, preoperative duration of symptoms, and the type (and number of levels) of surgery. A web-based calculator was created, which can be accessed here: https://riskcalc.org/PatientsEligibleForLumbarSpineSurgery/.

CONCLUSIONS

The prediction tools derived from this study constitute important adjuncts to clinical decision-making that can offer patients undergoing lumbar spine surgery realistic and personalized expectations of postoperative outcome. They may also aid physicians in surgical planning, referrals, and counseling to ultimately lead to improved patient experience and outcomes.

Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression Outside-In Approach: A Proctorship Guideline With 12 Steps of Effectiveness and Safety

Minimally invasive spinal surgery in particular lumbar endoscopic unilateral laminotomy with bilateral decompression becomes popular as it can be performed with regional anesthesia, soft tissue damages are minimized as endoscopic visualization and instruments can be brought close to operating area bypassing much of the intervening soft tissues for sufficient spinal decompression with ligamentum flavum resection despite less bony resection compared to open surgery. Overall, when well executed, it preserves spinal stability. Outside-in technique of decompression is also known as over the top decompression in minimally invasive literature. It involves maintaining deep layer of ligamentum flavum integrity till satisfactory bony decompression is achieved. Deep layer of ligamentum flavum is removed as final step of decompression. Preservation of the deep layer of ligamentum flavum protects the neural elements, allowing drills and sharp equipment to be used safely to perform bony decompression.In this study, we demonstrate the technical details of outside-in approach lumbar endoscopic unilateral laminotomy with bilateral decompression (LE-ULBD). LE-ULBD Outside-in Technique is an effective and safe procedure in relieving lumbar spinal stenosis with favorable results with a follow-up for more than 1 year.

Inside-Out Approach of Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression: A Detailed Technical Description, Rationale and Outcomes

Although lumbar stenosis was recognized as a contraindication for endoscopic spine surgery in the past, the advancement in endoscopic system design and development of approach techniques and strategies now enabled the endoscopic spine surgeons to manage all types of lumbar stenosis safely and more effectively. A full-endoscopic lumbar technique for surgical management of spinal canal stenosis is now used today in many advanced spine centers around the world as one of their standard procedures which can be done under general, regional, local anesthesia with sedation. In this technical report, we described in detail the inside-out approach of performing lumbar endoscopic unilateral laminotomy with bilateral decompression (LE-ULBD) and retrospectively reviewed hospital records of 127 patients who underwent the approach from December 2018 to March 2019 to address 1 level lumbar spinal stenosis and determined its outcome after 12-month follow-up period. Perioperative outcomes, operation time, length of hospital stay, and surgical complications were recorded and analyzed. The cross-sectional area of the thecal sac at the operated level was measured. The visual analogue scale (VAS) was assessed preoperatively, 1 month, and 12 months as well as the Oswestry Disability Index (ODI). The data were statistically analyzed (using SPSS ver. 17.0). The inside-out approach LE-ULBD was shown to effect statistically significant improvement in the VAS of leg and back pain as well as the ODI. It is a familiar, safe, and effective way of performing spinal stenosis decompression with good reproducible outcomes.

The influence of endplate (Modic) changes on clinical outcomes in lumbar spinal stenosis surgery: a Swiss prospective multicenter cohort study

PURPOSE

To investigate if the presence or absence of preoperative endplate Modic changes (MC) is predictive for clinical outcomes in degenerative lumbar spinal stenosis (DLSS) patients undergoing decompression-alone or decompression with instrumented fusion surgery.

METHODS

Two hundred five patients were included and categorized into four groups; 102 patients into the decompression-alone group with MCs, 41 patients into the fusion group with MCs, 46 patients into the decompression-alone group without MCs, and 16 patients into the fusion group without MCs. Clinical outcome was quantified with changes in spinal stenosis measure (SSM) symptoms, SSM function, NRS pain, and EQ-5D-3L sum score over time (measured at baseline, 12-, 24-, and 36-month follow-up) and minimal clinically important difference (MCID) in SSM symptoms, SSM function, and NRS pain from baseline to 36-month follow-up. To investigate if possible effects of MCs had been modified or hidden by confounding variables, we used the group LASSO method to search for good prognostic models.

RESULTS

There were no obvious differences in any of the clinical outcome measures between groups at baseline. At 12 months, most patients have improved in all outcomes and maintained improved conditions over time (no significant group differences). Between 70 and 90 percent of the patients maintained a clinically important improvement up to 36 months.

CONCLUSIONS

Endplate MCs have no significant influence on clinical outcome parameters in patients with lumbar spinal stenosis compared to patients without MCs, independent of the chosen surgical strategy. All patients benefitted from surgical therapy up to 36-month follow-up. These slides can be retrieved under Electronic Supplementary Material.