Minimally Invasive Surgical Techniques for Management of Painful Metastatic and Primary Spinal Tumors

Review of mechanisms of expandable spine surgery devices

INTRODUCTION

Expandable devices such as interbody cages, vertebral body reconstruction cages, and intravertebral body expansion devices are frequently utilized in spine surgery. Since the introduction of expandable implants in the early 2000s, the variety of mechanisms that drive expansion and implant materials have steadily increased. By examining expandable devices that have achieved commercial success and exploring emerging innovations, we aim to offer an in-depth evaluation of the different types of expandable cages used in spine surgery and the underlying mechanisms that drive their functionality.

AREAS COVERED

We performed a review of expandable spinal implants and devices by querying the National Library of Medicine MEDLINE database and Google Patents database from 1933 to 2024. Five major types of mechanical jacks that drive expansion were identified: scissor, pneumatic, screw, ratchet, and insertion-expansion.

EXPERT OPINION

We identified a trend of screw jack mechanism being the predominant machinery in vertebral body reconstruction cages and scissor jack mechanism predominating in interbody cages. Pneumatic jacks were most commonly found in kyphoplasty devices. Critically reviewing the mechanisms of expansion and identifying trends among effective and successful cages allows both surgeons and medical device companies to properly identify future areas of development.

Impact of Cytogenetic Abnormalities, Induction and Maintenance Regimens on Outcomes After High-Dose Chemotherapy and Autologous Stem Cell Transplantation in Patients With Newly Diagnosed Multiple Myeloma: A Decade-Long Real-World Experience

Background

High-dose chemotherapy and autologous stem cell transplant (HDT-ASCT) has become a standard of care for transplant eligible newly diagnosed multiple myeloma (NDMM) patients. While cytogenetic abnormalities have been shown to affect outcomes after HDT-ASCT in clinical trials, these trials often exclude or underrepresent elderly patients with comorbidities and those belonging to ethnic minorities. We describe our institutional experience highlighting the impact of high-risk cytogenetic abnormalities (HRCAs) on outcomes after HDT-ASCT for NDMM patients.

Methods

A total of 449 patients with NDMM who underwent HDT-ASCT between February 2012 and August 2022 were included in this retrospective analysis. HRCAs included the presence of one or more of: deletion 17p, t(14;16), t(4;14), and amplification 1q. Survival analyses, including progression-free survival (PFS) and overall survival (OS), were performed using Kaplan-Meier estimator.

Results

With a median follow-up of 29 (1 - 128) months for the entire patient population, the best overall response rate for the patients with HRCAs was lower compared to those with standard risk cytogenetics (90% vs. 96%; P = 0.01). Patients with HRCAs had an inferior PFS compared to patients with standard-risk cytogenetics (29 vs. 58 months; P < 0.001) without a difference in OS (70 months vs. not reached; P = 0.13).

Conclusions

In a multivariable analysis adjusting for factors including age, race, and comorbidities, HRCAs, non-lenalidomide-based maintenance, non-proteasome inhibitor-based maintenance, and age greater than 65 were associated with inferior PFS. Amongst these factors, only non-lenalidomide-based maintenance was associated with inferior OS.

Extensive Intracardiac Cement Embolism in a Patient Undergoing Workup for Bone Marrow Transplant

Cement emboli are a well-established complication of kyphoplasties and vertebroplasties and can easily be mistaken for wires. While kyphoplasties are commonly performed for vertebral fractures caused by metastases from malignancies such as multiple myeloma, the implication of cement emboli in bone marrow transplant (BMT) patients is not well documented. Our patient presented with an incidental intracardiac cement embolism found while undergoing workup for BMT. He was managed conservatively, but transplant workup was put on hold until the embolism could be removed due to the risks associated with cement emboli. The significance of cement emboli in immunocompromised patients needs to be further investigated.

Comparing the efficacy and safety of cement-augmented fenestrated pedicle screws and conventional pedicle screw in surgery for spinal metastases: a retrospective comparative cohort study

Background

The incidence of cancer patients with bone metastasis is increasing annually. With the advancement of medical treatment for malignant tumors, the survival time of patients with spinal metastases is gradually being prolonged, and adjacent segment vertebral metastases often occur after conventional pedicle screw (CPS) surgery, leading to spinal instability, pain and nerve function injury again, with repeated symptoms. Combined pedicle screw fixation can maintain or reconstruct the spinal stability. This study aimed to investigate the efficacy and safety of cement-augmented fenestrated pedicle screws in the posterior approach for spinal metastases by comparing with CPS.

Methods

From January 2017 to August 2019, 52 patients with spinal metastases who underwent separation surgery and internal fixation via posterior approach were retrospectively enrolled. Cases were divided into the cement-augmented pedicle screw (CAPS) group (28 cases) and the CPS group (24 cases). The baseline data [age, gender, surgical sites, surgical segment, Tomita classification, Tomita score, Tokuhashi score, spinal instability neoplastic score (SINS)], surgical information, and local progression-free survival (PFS) time were compared between the two groups. Every patient was followed-up every 3 months with imaging examination. The visual analog scale (VAS) score and Frankel grade of the two groups were recorded before and 3 months after the operation were used to evaluate the efficacy. The operation time, the amount of intraoperative blood loss, the amount of bone cement injected in the pedicle screw group, and the complications of the surgery were recorded to evaluate the safety of CAPS.

Results

The baseline characteristics were comparable between the two group. Compared with the CPS group, the CAPS group showed significantly longer operation time (163±20 vs. 138±18 min, P<0.001) and lower VAS scores (2.93±1.33 vs. 4.17±1.34, P=0.002). Adjacent segment vertebral metastasis occurred in 10 cases (2 in the CAPS group and 8 in the CPS group, P=0.017). Internal implant failure occurred in 8 cases (1 in the CAPS group and 7 in the CPS group, P=0.011). Compared with the CPS group, the CAPS group had a significantly longer local PFS time (P<0.05).

Conclusions

CAPS could be a safe and effective choice in surgery for spinal metastases with the posterior approach.

Percutaneous transforaminal endoscopic decompression combined with percutaneous vertebroplasty in treatment of lumbar vertebral body metastases: A case report

BACKGROUND

Percutaneous endoscopic lumbar discectomy (PTED) is a procedure that is commonly used to treat lumbar disc herniation and spinal stenosis. Despite its less invasiveness, this surgery is rarely used to treat spinal metastases. Percutaneous vertebroplasty (PVP) has been utilized to treat lumbar vertebral body metastases but it has not proven useful in treating sciatic patients.

CASE SUMMARY

A 68-year-old woman presented with low back pain and radicular symptoms. She couldn't straighten her legs because of severe pain. Computed tomography (CT) showed a mass lesion in the lung and bone destruction in the L4 vertebrae. The biopsy of the lung lesion revealed adenocarcinoma and the biopsy for L4 vertebrae revealed metastatic adenocarcinoma. PTED paired with PVP was performed on the patient due to the patient's poor overall physical state and short survival time. Transcatheter arterial embolization of vertebral tumors was performed before surgical resection to reduce excessive blood loss during the operation. The incision was scaled up with the TESSY technology. The pain was obviously relieved following the operation and no serious complications occurred. Postoperative CT showed that the decompression around the nerve root was successful, polymethyl methacrylate filling was satisfactory and the tumor tissue around the nerve root was obviously removed. During the 1-year follow-up period, the patient was in a stable condition.

CONCLUSION

PTED in combination with PVP is an effective and safe treatment for Lumbar single-level Spinal Column metastases with radicular symptoms. Because of the small sample size and short follow-up time, the long-term clinical efficacy of this method needs to be further confirmed.

The usefulness of vertebral needle targeting simulation training system using ray-summation imaging: experimental study

PURPOSE

Using the multi-detector computed tomography and related three-dimensional imaging technology, we developed a vertebral needle targeting simulation training system named spinal needling intervention practice using ray-summation imaging (SNIPURS). Herein, we assessed the utility of SNIPURS by evaluating changes in the learning curves of SNIPURS trainees.

METHODS

Twenty-one examinees were enrolled: seven experienced operators (expert group), seven trainees with coaching (coaching group), and seven trainees without coaching (non-coaching group). They performed six tests of vertebral needle targeting simulation on the workstation-generated spinal ray-summation images of six patients with vertebral fractures. In each test, they determined the bilateral trans-pedicular puncture points and angles on two thoracic and two lumbar vertebrae on ray-summation imaging (i.e., 8 simulations per test). The coaching group received coaching by a trainer after Tests 1 and 4, while the others did not. Scores were given based on the trans-pedicular pathway (1 point) or not (0 point). Eight virtual needles were evaluated in each of Tests 1-6.

RESULTS

Among the three groups, the expert group had the highest average scores on Tests 1-4 (expert: 3.86, 6.57, 7.43, and 7.57; coaching: 1.86, 6.14, 6, and 6.29; and non-coaching: 1.14, 4.14, 4.71, and 4.86). The coaching group's scores caught up with the expert groups' average scores on Tests 5 and 6, whereas those of the non-coaching group did not (expert and coaching: 7.86 and 8.00, non-coaching: 5.86 and 7.14). All examinees in the expert and coaching groups achieved a perfect score on the final Test 6, whereas three of the seven non-coaching trainees did not.

CONCLUSION

SNIPURS might be suitable for vertebral needle targeting training. The coaching provided during SNIPURS training helped the trainees to acquire the spinal puncture techniques in PVP.

The combination of radiofrequency ablation and vertebroplasty shows advantages over single vertebroplasty in treating vertebral neoplastic lesions

OBJECTIVE

To investigate the safety and efficacy of the combination of radiofrequency ablation (RFA) and vertebroplasty versus single vertebroplasty in treating spinal metastases.

MATERIALS AND METHODS

The data of 35 patients with vertebral neoplastic lesions who received RFA combined with vertebroplasty (group A, 15 patients with 17 lesions) or single vertebroplasty (group B, 20 patients with 24 lesions) from March 2016 to June 2019 were retrospectively compared. The data of patients' Visual Analogue Scale (VAS) scores prior to the treatments, 1 week, 1 month, 3 months, and 6 months after the treatments, injected cement volume, ratios of cement leakage were compared between the two groups.

RESULTS

All procedures were successfully done without severe complications. The VAS scores in group A were decreased more rapidly 1 week after the treatments and remained more stable at 6 months than that in group B (P < 0.05). The cement injected in group A (5.95 ± 1.45 mL, range 4-9.5 mL) was significantly more than that in group B (4.09 ± 0.55 mL, range 3.1-5.5 mL) (P < 0.05). The ratio of vascular cement leakage in group A was significantly lower than that in group B (P < 0.05), while no statistical difference was found in the non-vascular cement leakage (P > 0.05).

CONCLUSIONS

Our study shows that the combination of RFA and vertebroplasty has a better analgesic effect with more injected cement and lower rates of venous cement leakage than single vertebroplasty.

Interventional Therapies for Pain in Cancer Patients: a Narrative Review

PURPOSE OF REVIEW

Pain is a prevalent symptom in the lives of patients with cancer. In light of the ongoing opioid epidemic and increasing awareness of the potential for opioid abuse and addiction, clinicians are progressively turning to interventional therapies. This article reviews the interventional techniques available to mitigate the debilitating effects that untreated or poorly treated pain have in this population.

RECENT FINDINGS

A range of interventional therapies and technical approaches are available for the treatment of cancer-related pain. Many of the techniques described may offer effective analgesia with less systemic toxicity and dependency than first- and second-line oral and parenteral agents. Neuromodulatory techniques including dorsal root ganglion stimulation and peripheral nerve stimulation are increasingly finding roles in the management of oncologic pain. The goal of this pragmatic narrative review is to discuss interventional approaches to cancer-related pain and the potential of such therapies to improve the quality of life of cancer patients.

Metastatic spine disease in lung cancer patients: national patterns of radiation and surgical care

Background

Lung cancer is the most common source of spinal metastases. As our treatment of spinal metastases evolves, national trends in radiation therapy (RT), including spinal stereotactic neurosurgery, have yet to been established.

Methods

We performed a retrospective review of lung cancer patients within the National Cancer Database (NCDB) between 2004 and 2014 who received radiation to the vertebral column.

Results

A total of 29,144 lung cancer patients received either external beam RT (EBRT), stereotactic radiosurgery (SRS), or particle-based RT to the spine. EBRT was the most common modality throughout all years, though SRS use increased over time (Spearman's rank correlation, P<0.01). A surgical procedure on a distant metastasis was performed in 1,547 (5.3%) patients. Median survival was 6.24 months for patients receiving EBRT and 9.3 months for those receiving SRS, a significant difference (log rank test, P<0.01), which persisted when adjusting for other predictors (multivariable Cox regression, P<0.01).

Conclusions

In conclusion, spinal SRS is steadily growing in the treatment of lung metastases to the spine, and surgery on distant metastases is becoming more frequent. There was a survival advantage for patients receiving SRS over EBRT. As the use of SRS-in addition to separation surgery-grows in radioresistant pathology, further study of improved survival and recurrence rates are needed.

Multilevel percutaneous kyphoplasty in painful osteolytic vertebral metastases: a study of the efficacy and safety

Purpose: The spine is the most common skeletal site for metastatic tumors. In the treatment of vertebral metastases, the absolutely safe number of levels that can be treated via percutaneous kyphoplasty (PKP) during one procedure remains controversial. Thus, the present study aimed to evaluate the safety and efficacy of multilevel (>3) PKP for painful osteolytic vertebral metastases.

Patients and methods: We retrospectively analyzed the data from 176 patients who received PKP for painful osteolytic spinal metastases. Group A (n=104) received PKP at a maximum of three vertebral levels per procedure, while group B (n=72) received PKP at more than three levels during one operation. Surgical efficacy was assessed via a comparison of the VAS, Oswestry Disability Index (ODI), and general health (GH) and mental health (MH) scores of the Short Form-36 Health Survey before and after PKP. The complications were observed to evaluate the safety.

Results: Both groups had significantly improved VAS, ODI, GH and MH scores after PKP (P<0.05). One week after surgery, group A had significantly less pain (VAS 3.41±0.1) than group B (VAS 3.74±0.13) (P<0.05). At 3 and 6 months postoperatively, the GH score was more significantly improved in group A than group B (P<0.05). There were no significant differences between the two groups in the ODI, MH score, and complications (P>0.05).

Conclusion: Multilevel PKP is safe and results in effective pain relief, and improvement of spinal mobility and GH in patients with osteolytic vertebral metastases. However, patients who undergo PKP at more than three levels have slightly worse short-term pain relief (less than 1 week postoperatively) and improvement of GH in the long-term (more than 3 months postoperatively) compared with patients who undergo PKP at less than three levels.

Strategies for interventional therapies in cancer-related pain-a crossroad in cancer pain management

PURPOSE

Interventional therapies are important to consider when facing cancer pain refractory to conventional therapies. The objective of the current review is to introduce these effective strategies into dynamic interdisciplinary pain management, leading to an exhaustive approach to supportive oncology.

METHODS

Critical reflection based on literature analysis and clinical practice.

RESULTS

Interventional therapies act on the nervous system via neuromodulation or surgical approaches, or on primitive or metastatic lesions via interventional radiotherapy, percutaneous ablation, or surgery. Interventional therapies such as neuromodulations are constantly evolving with new technical works still in development. Nowadays, their usage is better defined, depending on clinical situations, and their impact on quality of life is proven. Nevertheless their availability and acceptability still need to be improved. To start with, a patient's interdisciplinary evaluation should cover a wide range of items such as patient's performance and psychological status, ethical considerations, and physiochemical and pharmacological properties of the cerebrospinal fluid for intrathecal neuromodulation. This will help to define the most appropriate strategy. In addition to determining the pros and cons of highly specialized interventional therapies, their relevance should be debated within interdisciplinary teams in order to select the best strategy for the right patient, at the right time.

CONCLUSIONS

Ultimately, the use of the interventional therapies can be limited by the requirement of specific trained healthcare teams and technical support, or the lack of health policies. However, these interventional strategies need to be proposed as soon as possible to each patient requiring them, as they can greatly improve quality of life.

Image-guided Percutaneous Polymethylmethacrylate-augmented Spondylodesis for Painful Metastasis in the Veteran Population

The treatment of painful spinal metastases in patients with limited life-expectancy, significant perioperative risks, and poor bone quality poses a surgical challenge. Recent advances in minimal-access spine surgery allow for the surgical treatment of patients previously considered not to be operative candidates. The addition of fenestrated screws for cement augmentation to existing image-guided percutaneous pedicle screw fixation can enhance efficiency, decrease risk of hardware complications, and improve back pain in this patient population.

The patient is a 70-year-old man with severe axial back pain due to metastatic prostate cancer and L5 pathologic fractures not amenable to kyphoplasty. In the setting of a 6-12-month life-expectancy, the primary goal of surgery was relief of back pain associated with instability with minimal operative morbidity and post-operative recovery time. This was achieved with an internal fixation construct including percutaneously placed cement-augmented fenestrated pedicle screws at L4 and S1. The patient was discharged to home on post-operative day 1 with substantial improvement of his low back pain.

Image-guided, percutaneous placement of fenestrated, cement-augmented pedicle screws is an emerging treatment for back pain associated with metastasis. Fenestrated screws allow for integrated cement augmentation. The minimal associated blood loss and recovery time make this approach an option even for patients with limited life-expectancy. This is the first report of utilization of this technique for the veteran population.

Posterior-only Stabilization for Traumatic Thoracolumbar Burst Fractures

Background

No consensus exists for the management of unstable thoracolumbar (TL) burst fractures. Surgical options include anterior, lateral, or posterior stabilization (or a combination), depending on the fracture. The potential benefits of anterior reconstruction come with increased operative time and associated morbidity. A posterior-only approach can offer stable correction without increased operative risks but may result in loss of kyphotic correction over time.

Purpose

To determine whether posterior-only stabilization is a viable treatment option for patients with traumatic TL fractures as opposed to anterior and combined approaches.

Methods

We performed a retrospective analysis of adult patients with TL burst fractures who underwent posterior­-only surgical intervention from 2005 to 2015. Operations were performed at two levels above and below the fractured segment using pedicle screw-rod fixation constructs with autograft and allograft. All patients received TL bracing for at least three months. Patients lost to follow­up were excluded.

Results

Sixty-four consecutive patients with posterior­-only stabilization were identified, with 18 lost to follow­up. Of the remaining 46 patients, 93% (n=43) were male and 7% (n=3) were female, with a mean age of 36.8 years. All patients were followed for 12 months. The mean time until the removal of the brace was 3.54 months. No patients required additional surgical intervention for spinal stabilization. Three patients experienced postoperative complications, all of which were related to infection.

Conclusions

Our data indicate that posterior­-only stabilization for traumatic TL burst fractures is a durable and effective option in select patients. The approach offers surgical intervention with a decreased perioperative risk as well as reduced morbidity and mortality, with a minimal increase in the risk of kyphotic deformity. Further prospective studies are necessary to validate these findings clinically.

Logistic regression analysis of risk factors for postoperative recurrence of spinal tumors and analysis of prognostic factors

The aim of the present study was to investigate the risk factors for postoperative recurrence of spinal tumors by logistic regression analysis and analysis of prognostic factors. In total, 77 male and 48 female patients with spinal tumor were selected in our hospital from January, 2010 to December, 2015 and divided into the benign (n=76) and malignant groups (n=49). All the patients underwent microsurgical resection of spinal tumors and were reviewed regularly 3 months after operation. The McCormick grading system was used to evaluate the postoperative spinal cord function. Data were subjected to statistical analysis. Of the 125 cases, 63 cases showed improvement after operation, 50 cases were stable, and deterioration was found in 12 cases. The improvement rate of patients with cervical spine tumor, which reached 56.3%, was the highest. Fifty-two cases of sensory disturbance, 34 cases of pain, 30 cases of inability to exercise, 26 cases of ataxia, and 12 cases of sphincter disorders were found after operation. Seventy-two cases (57.6%) underwent total resection, 18 cases (14.4%) received subtotal resection, 23 cases (18.4%) received partial resection, and 12 cases (9.6%) were only treated with biopsy/decompression. Postoperative recurrence was found in 57 cases (45.6%). The mean recurrence time of patients in the malignant group was 27.49±6.09 months, and the mean recurrence time of patients in the benign group was 40.62±4.34. The results were significantly different (P<0.001). Recurrence was found in 18 cases of the benign group and 39 cases of the malignant group, and results were significantly different (P<0.001). Tumor recurrence was shorter in patients with a higher McCormick grade (P<0.001). Recurrence was found in 13 patients with resection and all the patients with partial resection or biopsy/decompression. The results were significantly different (P<0.001). Logistic regression analysis of total resection-related factors showed that total resection should be the preferred treatment for patients with benign tumors, thoracic and lumbosacral tumors, and lower McCormick grade, as well as patients without syringomyelia and intramedullary tumors. Logistic regression analysis of recurrence-related factors revealed that the recurrence rate was relatively higher in patients with malignant, cervical, thoracic and lumbosacral, intramedullary tumors, and higher McCormick grade and patient received partial resection or biopsy. Tumor property, tumor location, McCormick grade, tumor resection, and intramedullary tumors are risk factors for the recurrence of spinal tumors. Clinical assessment of these risk factors may be helpful in selecting appropriate treatment strategies.

Unusual Metastasis of Papillary Thyroid Cancer to the Thoracic Spine: A Case Report, New Surgical Management Proposal, and Review of the Literature

Papillary thyroid carcinoma (PTC) is significantly more common than follicular thyroid carcinoma (FTC), yet FTC has a much higher tendency to metastasize to the spinal column. We present a rare case of a metastatic thoracic spinal column lesion originating from the PTC. Thyroid carcinoma is known to be highly vascular with a significant tendency to hemorrhage during surgical resection. This increased tendency to hemorrhage leads to unanticipated intraoperative risks when the type of cancer is not diagnosed before surgical resection. Complications related to intraoperative bleeding can be prevented by visualization using angiography and preoperative embolization. The type of cancer is ideally diagnosed before tumor resection either by the standard metastatic workup or histologically after the biopsy. However, limitations exist in these methods, therefore, hypervascular tumors such as metastatic thyroid cancer can go undiagnosed until after surgical resection. In addition to our case report, we present a review of the literature regarding diagnostic and treatment strategies for hypervascular thyroid tumors and propose a new algorithm for the surgical management of spinal tumors with an unknown origin for optimization of preoperative and perioperative care.