Mid- to Long-Term Outcomes After Resection of Thoracic Dumbbell Tumors Managed by Laminectomy and Unilateral Total Facetectomy Without Instrumented Fusion

Comparative Analysis of Microendoscopic and Open Laminectomy for Single-Level Lumbar Spinal Stenosis at L1-L2 or L2-L3

BACKGROUND

Several reports have highlighted comparable surgical outcomes between microendoscopic laminectomy (MEL) and open laminectomy (open) for lumbar spinal stenosis. However, the unilateral approach in MEL may present challenges for the upper lumbar levels, where facet joints are located deeper inside. Our objective was to compare surgical outcomes and radiographic evaluations for single-level decompression cases at L1-L2 or L2-L3 between MEL and open laminectomy.

METHODS

We analyzed patients who underwent single-level decompression for upper lumbar spinal stenosis at 12 distinguished spine centers from April 2017 to September 2021. Baseline demographics, preoperative, and 1-year postoperative patient-reported outcomes, along with imaging parameters, were compared between the MEL and open groups. To account for potential confounding, patients' backgrounds were adjusted using the inverse probability weighting method based on propensity scores.

RESULTS

Among the 2487 patients undergoing decompression surgery, 118 patients (4.7%) underwent single-level decompression at L1-L2 or L2-L3. Finally, 80 patients (51 in the MEL group, 29 in the open group) with postoperative data were deemed eligible for analysis. The MEL group exhibited significantly improved postoperative EuroQol 5-Dimension values compared to the open group. Additionally, the MEL group showed a lower facet preservation rate according to computed tomography examination, whereas the open group had a higher incidence of retrolisthesis.

CONCLUSIONS

Although overall surgical outcomes were similar, the MEL group demonstrated potential advantages in enhancing EuroQol 5-Dimension scores. The MEL group's lower facet preservation rate did not translate into a higher postoperative instability rate.

Impact of Surgical Resection Without Spinal Fusion for Thoracic Dumbbell Tumors on Postoperative Global Spinal Sagittal Alignment and Clinical Outcomes

STUDY DESIGN

A retrospective comparative study.

OBJECTIVES

This study investigated radiographical changes in global spinal sagittal alignment (GSSA) and clinical outcomes after tumor resection without spinal fusion in patients with thoracic dumbbell tumors.

METHODS

Thirty patients with thoracic dumbbell tumors who were followed up for at least 3 years were included in this study. Variations in the outcome variables were analyzed using individual GSSA parameters measured on radiography. Clinical outcomes were assessed using the modified McCormick scale (MMCS), Japan Orthopaedic Association (JOA) score, and visual analog scale (VAS). To assess the impact of the affected levels on these outcomes, we divided the patients into three groups according to the location of the tumor (upper [T1-4], middle [T5-8], or lower [T9-12] thoracic spine).

RESULTS

The GSSA parameters (cervical lordosis, T1 slope, thoracic kyphosis [global, upper, middle, and lower], thoracolumbar kyphosis, lumbar lordosis, sacral slope, pelvic incidence, and pelvic tilt) of all the patients did not change significantly after surgery. Eleven of thirty patients had preoperative gait disturbances but they could walk without support (MMCS grade I or II) at the final follow-up. The JOA score and VAS showed significant postoperative improvements. No statistically significant differences were observed in each postoperative sagittal profile or clinical outcome between the upper, middle, and lower groups.

CONCLUSIONS

Tumor resection without spinal fusion did not affect the various GSSA parameters and resulted in satisfactory clinical outcomes, indicating that spinal fusion may not always be necessary when resecting thoracic dumbbell tumors.

Spinous Process-Splitting Laminectomy Approach for Tumor Excision at Conus Medullaris or Cauda Equina Level Results in Satisfactory Clinical Outcomes Without Affecting Global Spinal Sagittal Alignment

STUDY DESIGN

Retrospective comparative study.

OBJECTIVES

The present study investigated radiographical changes in global spinal sagittal alignment (GSSA) and clinical outcomes following tumor resection using spinous process-splitting laminectomy (SPSL) approach without fixation in patients with conus medullaris (CM) or cauda equina (CE) tumor.

METHODS

Forty-one patients with CM or CE tumor (19 males, 22 females, mean age at surgery of 52.9 ± 13.0 years) were included in this study. The variations of outcome variables were analyzed in various GSSA profiles using radiographic outcomes. The clinical outcomes were assessed using Japan Orthopaedic Association (JOA) score and JOA back pain evaluation questionnaire (JOABPEQ).

RESULTS

In all cases, the various GSSA parameters (sagittal vertical axis, C2-7 lordosis, T1 slope, thoracic kyphosis, T10-L2 kyphosis, lumbar lordosis [LL; upper, middle, and lower], sacral slope, pelvic incidence, and pelvic tilt) did not significantly change in the 2-years postoperative period. Moreover, age at surgery, the number of resected laminae, preoperative T12-L2 kyphosis, or LL did not affect the postoperative changes in T12-L2 kyphosis or LL, and had no statistically significant correlation among them. The scores of each postoperative JOA domain and the Visual Analogue Scale included in the JOABPEQ were significantly improved. There was no statistical significant group difference in each sagittal profile or clinical outcomes between CM and CE groups postoperatively.

CONCLUSIONS

Tumor resection using SPSL approach did not affected the various GSSA parameters examined and resulted in satisfactory clinical outcomes, indicating that SPSL approach is a suitable surgical technique for patients with CM or CE tumor.

Resection of Cervical Dumbbell-Shaped Schwannoma Using Posterior Unilateral Approach: Impact on Postoperative Cervical Function and Clinical Outcomes

STUDY DESIGN

A retrospective comparative study.

OBJECTIVES

This study aimed to evaluate the radiographical changes in cervical sagittal alignment (CSA) and clinical outcomes after tumor resection using a posterior unilateral approach without spinal fixation for patients with cervical dumbbell-shaped schwannoma (DS).

METHODS

Seventy-three patients with DS who were followed up for at least 2 years were included. The Eden classification was used to designate the types of DS. The CSA and range of motion (ROM) were analyzed using radiographs. The clinical outcomes were assessed using the Japanese Orthopaedic Association (JOA) score and JOA cervical myelopathy questionnaire.

RESULTS

The CSA in the neutral, flexion, and extension position and cervical ROM were not significantly reduced in the follow-up period. The JOA scores showed significant improvement after surgery. The postoperative radiographic parameters and clinical outcomes of Eden type II or III DS, which needed facetectomy for the resection, did not show any statistically significant difference compared with those of Eden type I tumor, which was resected without facetectomy. Fifty-two cases (71.2%) achieved gross total resection, whereas 21 cases (28.8%) remained in partial resection (PR). One case underwent reoperation due to the regrowth of the remnant tumor whose margin was at the entrance of the intervertebral foramen.

CONCLUSIONS

Tumor resection using the posterior unilateral approach preserved CSA and resulted in favorable clinical outcomes in patients with DS. When the resection ends in PR, the proximal margin of the remnant tumor should be located distally away from the entrance of the foramen to prevent regrowth.

Feasibility and efficacy of spinal microtubular technique for resection of lumbar dumbbell-shaped tumors

Objective

Minimally invasive surgical resection of lumbar dumbbell-shaped tumors is rarely reported. We retrospectively collected clinical data of lumbar dumbbell-shaped tumors treated with the spinal microtubular technique to evaluate the feasibility, complications and efficacy of the surgical methods.

Methods

From September 2013 to August 2021, clinical data of patients with lumbar dumbbell-shaped tumors that underwent paravertebral approach and micro-tubular tumorectomy (PAMT) were collected; neurological function was assessed using the pain visual analog scale (VAS) and the Japanese Orthopaedic Association (JOA) score.

Results

A total of 46 patients that underwent PAMT were included in this study. In all patients, total resection of the tumor was performed at one stage (100%). The median follow-up period was 27.5 months (P25, P75: 16.5- 57 months). Symptoms such as pain or lower extremity weakness were significantly relieved in 46 patients. The postoperative VAS score and JOA score were significantly higher compared with preoperative scores (p <0.001), and the patients had no tumor recurrence or spinal instability. According to the Eden classification, there were 7 cases of type I, 8 cases of type II, 15 cases of type III, and 16 cases of type IV. In the comparison of the improvement of VAS score at 12 months after PAMT, there were significant differences among different types of tumors (H =15.756, p =0.001); type I was better than type III (Z =2.768, p =0.029) and type IV (Z =2.763, p =0.029), and type II was also better than type III (Z =2.679, p =0.037) and type IV (Z =2.708, p =0.034). With respect to estimated blood loss (Z =-3.041, p =0.013) and postoperative hospital stays (Z =-3.003, p =0.014), type IV was less than type III; and type IV was also less than type II about operation time (Z =-2.653, p =0.040).

Conclusion

In small lumbar dumbbell-shaped tumors, PAMT is indicated for Eden types I-IV and different pathological types of tumors, and can achieve complete resection of the tumor (GTR) in one stage with a good prognosis.