Lung metastases regression with increased CD8+ T lymphocyte infiltration following preoperative spinal embolization and total en bloc spondylectomy using tumor-bearing frozen autograft in a patient with spinal metastatic leiomyosarcoma

Systematic Analysis for the Reason of Revision-Surgery After Non-Total En Bloc Spondylectomy Open Surgery Among Spinal Metastatic Tumor Cases: A Retrospective Study

OBJECTIVE

This study examines patients with metastatic spinal disease undergoing non-total en bloc spondylectomy, focusing on revision surgery reasons and its effectiveness in treating spinal instability, neurological issues, and pain.

METHODS

This study conducted a retrospective case series in a single center and included 344 patients with metastatic spinal tumor who underwent non-total en bloc spondylectomy open surgery between 2013 and 2021 and were followed up for ＞2 years.

RESULTS

Of 344 patients, 20 (7.1%) had revision surgery due to delayed infection (n = 1), fixation loosening (n = 2), and tumor recurrence (n = 17). The revision group had lower rates of radiotherapy (35%) and long-segment fixation (45%) than the unrevised group (60.2%, 74%; P < 0.001). Decompression surgery had the highest revision rate (15.8%), followed by vertebrectomy (8.9%), separation surgery (4.7%), and hybrid surgery (2.3%). Postoperative scores and survival rates were improved in the revision group (median survival 32 vs. 11 months; P < 0.05).

CONCLUSIONS

Long-segment fixation with radiotherapy may reduce revision surgery need and extend the time between surgeries. Hybrid or separation surgeries lower the likelihood of revision. Revision surgery can relieve pain and improve neurological function. Patients in the revision group have longer survival times.

Characteristics and risk factors of instrumentation failure following total en bloc spondylectomy

AIMS

The aim of this study was to investigate the incidence and characteristics of instrumentation failure (IF) after total en bloc spondylectomy (TES), and to analyze risk factors for IF.

METHODS

The medical records from 136 patients (65 male, 71 female) with a mean age of 52.7 years (14 to 80) who underwent TES were retrospectively reviewed. The mean follow-up period was 101 months (36 to 232). Analyzed factors included incidence of IF, age, sex, BMI, history of chemotherapy or radiotherapy, tumour histology (primary or metastasis; benign or malignant), surgical approach (posterior or combined), tumour location (thoracic or lumbar; junctional or non-junctional), number of resected vertebrae (single or multilevel), anterior resection line (disc-to-disc or intravertebra), type of bone graft (autograft or frozen autograft), cage subsidence (CS), and local alignment (LA). A survival analysis of the instrumentation was performed, and relationships between IF and other factors were investigated using the Cox regression model.

RESULTS

A total of 44 patients (32.4%) developed IF at a median of 31 months (interquartile range 23 to 74) following TES. Most IFs were rod fractures preceded by a mean CS of 6.1 mm (2 to 18) and LA kyphotic enhancement of 10.8° (-1 to 36). IF-free survival rates were 75.8% at five years and 56.9% at ten years. The interval from TES to IF peaked at two to three years postoperatively and continued to occur over a period of time thereafter; the early IF-developing group had greater CS at one month postoperatively (CS1M) and more lumbar TES. CS1M ≥ 3 mm and sole use of frozen autografts were identified as independent risk factors for IF.

CONCLUSION

IF is a common complication following TES. We have demonstrated that robust spinal reconstruction preventing CS, and high-quality bone grafting are necessary for successful reconstruction.Cite this article: Bone Joint J 2023;105-B(2):172-179.

Postoperative Survival and Clinical Outcomes for Uterine Leiomyosarcoma Spinal Bone Metastasis: A Case Series and Systematic Literature Review

Spinal bone metastases from uterine leiomyosarcoma (LMS) are relatively uncommon and few data are present in the literature. In this study, cases of nine consecutive patients who underwent spinal surgery for metastatic uterine LMS between 2012 and 2022 at a single institution were retrospectively reviewed. The recorded demographic, operative, and postoperative factors were reviewed, and the functional outcomes were determined by changes in Frankel grade classification during follow-up. A systematic review of the literature was also performed to evaluate operative and postoperative factors and outcomes for patients with the same gynecological metastases to the spine. For our cases, the mean time between primary tumors to bone metastases diagnosis was 5.2 years, and the thoracic vertebrae were the most affected segment. Overall, median survival after diagnosis of metastatic spine lesions was 46 months. For the systematic review, the mean time between primary tumors to bone metastases was 4.9 years, with the lumbar spine as the most involved site of metastasis. Overall, median survival after diagnosis was 102 months. Once a spinal bone lesion from LMS is identified, surgical treatment can be beneficial and successful in alleviating symptoms. Further efforts will be crucial to identify prognostic markers as well as therapeutic targets to improve survival in these patients.

Presentation, management and outcome of primary leiomyosarcoma of the spine: A systematic review

OBJECTIVE

Primary spinal leiomyosarcoma (PSL) is extremely rare. A case is presented, followed by a systematic review establishing the consensus on presentation, diagnosis, management and outcomes. Comparison being made with metastatic spinal leiomyosarcoma (MSL).

METHODS

A systematic review was conducted in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Eligibility criteria was decided upon before the literature search was conducted. Data were extracted and analysed.

RESULTS

397 articles were identified, 25 articles conformed to the eligibility criteria. 34 cases were included in the analysis. PSL had a female preponderance (69.2%) with back pain being the most common presenting symptom (60.9%). Neurological signs were present in the majority (69.6%) with tumours typically being in the thoracic spine (46.9%). Diagnosis was primarily made using MRI (64.7%) and CT (55.9%), with a histological sample being obtained in all cases. Most patients underwent operative management (91.2%) with variable use of neoadjuvant and adjuvant therapies. Operative approach differed greatly and outcome following surgical management was stated in 48.4% of cases, all noting an improvement from presentation. Patient follow up was limited (median 7 months), with the majority of patients being free of disease (43.8%).

CONCLUSIONS

PSL diagnosis is challenging with PET-CT and histopathological sampling playing an important role. There is a limited evidence base for the treatment strategies employed but surgical management is key with generally good outcomes. Prognosis for PSL would appear to be better than MSL. There is scope for more dedicated research in PSL and MSL.

Abscopal Effect of Frozen Autograft Reconstruction Combined with an Immune Checkpoint Inhibitor Analyzed Using a Metastatic Bone Tumor Model

We evaluated the abscopal effect of re-implantation of liquid nitrogen-treated tumor-bearing bone grafts and the synergistic effect of anti-PD-1 (programmed death-1) therapy using a bone metastasis model, created by injecting MMT-060562 cells into the bilateral tibiae of 6-8-week-old female C3H mice. After 2 weeks, the lateral tumors were treated by excision, cryotreatment using liquid nitrogen, excision with anti-PD-1 treatment, and cryotreatment with anti-PD-1 treatment. Anti-mouse PD-1 4H2 was injected on days 1, 6, 12, and 18 post-treatment. The mice were euthanized after 3 weeks; the abscopal effect was evaluated by focusing on growth inhibition of the abscopal tumor. The re-implantation of frozen autografts significantly inhibited the growth of the remaining abscopal tumors. However, a more potent abscopal effect was observed in the anti-PD-1 antibody group. The number of CD8+ T cells infiltrating the abscopal tumor and tumor-specific interferon-γ (IFN-γ)-producing spleen cells increased in the liquid nitrogen-treated group compared with those in the excision group, with no significant difference. The number was significantly higher in the anti-PD-1 antibody-treated group than in the non-treated group. Overall, re-implantation of tumor-bearing frozen autograft has an abscopal effect on abscopal tumor growth, although re-implantation of liquid nitrogen-treated bone grafts did not induce a strong T-cell response or tumor-suppressive effect.

Neurologic Complications of Preoperative Embolization of Spinal Metastasis: A Systemic Review of the Literature Identifying Distinct Mechanisms of Injury

BACKGROUND

Preoperative embolization of spinal metastases may improve outcomes of resection by reducing surgical blood loss and operative time. Neurologic complications are rarely reported and the mechanisms leading to injury are poorly described.

METHODS

We present 2 illustrative cases of embolization-related neurologic injury from distinct mechanisms and the findings of a systemic literature review of similar complications according to the PRISMA guidelines.

RESULTS

A 77-year-old man with a history of renal cell carcinoma presented with gait dyscoordination and arm pain/weakness. Magnetic resonance imaging showed a C7/T1 mass causing severe compression of the C7/T1 roots and spinal cord. After embolization and tumor resection/fusion, lethargy prompted imaging showing multiple posterior circulation infarcts believed to be secondary to reflux of embolic particles. A 75-year-old man with renal cell carcinoma presented with L1 level metastasis causing conus compression and experienced paraplegia after superselective particle embolization presumed to be secondary to flow disruption of the artery of Adamkiewicz. Analysis of the literature yielded 6 articles reporting instances of cranial infarction/ischemia occurring in 10 patients, 12 articles reporting spinal cord ischemia/infarction occurring in 17 patients, and 5 articles reporting symptomatic postembolization tumoral swelling in 5 patients.

CONCLUSIONS

Neurologic injury is a risk of preoperative embolization of spinal metastasis from either compromise of spinal cord vascular supply or cranial stroke from reflux of embolic particles. Postprocedural tumor swelling rarely leads to clinical deficit. Awareness of these complications and the presumed mechanisms of injury may aid clinicians in implementing interventions and in counseling patients before treatment.