Palliative surgery for cervical spine metastasis

The effect of radiotherapy, chemotherapy, and immunotherapy on fusion rate in spinal surgery using osteobiologics for patients with metastatic spinal disease: a systematic review

OBJECTIVE

To evaluate the impact that adjuvant therapies like radiotherapy, chemotherapy, and immunotherapy have on osteobiologic properties and bony regeneration in patients with metastatic spine disease (MSD) undergoing spinal fusion surgery.

METHODS

PubMed and ClinicalTrials.gov searches were performed. MSD patients undergoing fusion surgery with an osteobiologic and radiotherapy, chemotherapy and/or immunotherapy were included. Demographics, primary tumor, surgery, adjuvant treatments, osteobiologic type, fusion rates with scoring criteria, hardware failure, reoperation rates, follow-up, and survival were extracted. 1487 studies were screened, 20 included.

RESULTS

585 patients (464 with MSD) had fusion rates ranging from 17.9 to 100%. In the setting of radiotherapy, fusion rates of 10 studies using autologous bone graft (autograft), 5 studies using allogenic bone graft (allograft), 5 studies using combination autograft/allograft, 4 studies using biomaterial scaffolds (BMS), 3 studies using demineralized bone matrices (DBM), and 1 study using growth factors (GF), were 50-100%, 17.9-100%, 57.8-100%, 52.9-100%, 20-100%, and 100%, respectively. A higher incidence of fusion in patients with autograft or allograft receiving stereotactic body radiotherapy (SBRT) at lower biologically effective doses (BED) and at least 1-month postoperatively was noted. Chemotherapy had no impact on fusion. No studies evaluated the impact of immunotherapy on fusion.

CONCLUSIONS

SBRT at lower doses given greater than 1-month postoperatively may enhance bony fusion in patients receiving autograft, allograft, or autograft/allograft. Chemotherapy may delay bony fusion without affecting overall fusion rates. Preclinical studies suggest immunotherapy may prevent osteolysis and promote osteogenesis, but no studies have yet evaluated the clinical impact of these findings on spinal fusion. Further research is needed on osteobiologics in bony regeneration in the MSD population.

Comparison of Outcomes in Patients with Cervical Spine Metastasis After Different Surgical Approaches: A Single-Center Experience

OBJECTIVE

In patients undergoing cervical spine surgery for metastatic spine disease, we sought to 1) compare perioperative and oncologic outcomes among 3 different operative approaches, 2) report fusion rates, and 3) compare different types of anterior vertebral body replacement.

METHODS

A single-center retrospective cohort study of patients undergoing extradural cervical/cervicothoracic spine metastasis surgery between February 2010 and January 2021 was conducted. Operative approaches were anterior-alone, posterior-alone, or combined anterior-posterior, and the grafts/cages used in the anterior fusions were cortical allografts, static cages, or expandable cages. All cages were filled with autograft/allograft. Outcomes included perioperative/postoperative variables, along with fusion rates, functional status, local recurrence (LR), and overall survival (OS).

RESULTS

Sixty-one patients underwent cervical spine surgery for metastatic disease, including 11 anterior (18.0%), 28 posterior (45.9%), and 22 combined (36.1%). New postoperative neurologic deficit was the highest in the anterior approach group (P = 0.038), and dysphagia was significantly higher in the combined approach group (P = 0.001). LR (P > 0.999), OS (P = 0.655), and time to both outcomes (log-rank test, OS, P = 0.051, LR, P = 0.187) were not significantly different. Of the 51 patients alive at 3 months, only 19 (37.2%) obtained imaging ≥3 months. Fusion was seen in 11/19 (57.8%) at a median of 8.3 months (interquartile range, 4.6-13.7). Among the anterior corpectomies, the following graft/cage was used: 6 allografts (54.5%), 4 static cages (36.3%), and 1 expandable cage (9.0%), with no difference found in outcomes among the 3 groups.

CONCLUSIONS

The only discernible differences between operative approaches were that patients undergoing an anterior approach had higher rates of new postoperative neurologic deficit, and the combined approach group had higher rates of postoperative dysphagia.

Characterization and Treatment of Spinal Tumors

The prevalence of spinal tumors is rare in comparison to brain tumors which encompass most central nervous system tumors. Tumors of the spine can be divided into primary and metastatic tumors with the latter being the most common presentation. Primary tumors are subdivided based on their location on the spinal column and in the spinal cord into intramedullary, intradural extramedullary, and primary bone tumors. Back pain is a common presentation in spine cancer patients; however, other radicular pain may be present. Magnetic resonance imaging (MRI) is the imaging modality of choice for intradural extramedullary and intramedullary tumors. Plain radiographs are used in the initial diagnosis of primary bone tumors while Computed tomography (CT) and MRI may often be necessary for further characterization. Complete surgical resection is the treatment of choice for spinal tumors and may be curative for well circumscribed lesions. However, intralesional resection along with adjuvant radiation and chemotherapy can be indicated for patients that would experience increased morbidity from damage to nearby neurological structures caused by resection with wide margins. Even with the current treatment options, the prognosis for aggressive spinal cancer remains poor. Advances in novel treatments including molecular targeting, immunotherapy and stem cell therapy provide the potential for greater control of malignant and metastatic tumors of the spine.

Postoperative outcomes of subaxial cervical spine metastasis: Comparison among the anterior, posterior, and combined approaches

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The combined therapy produced better clinical results and a longer survival.

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Perioperative complications are significantly higher with combined approach.

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Anterior and posterior approach have the same neurological improvement rate.

Background

The incidence of subaxial spinal metastases increases due to longer life expectancy resulting from successful modern cancer treatments. The three most utilized approaches for surgical treatment include the anterior, posterior, and combined approaches. However, despite increasing surgical volume, data on the postoperative complication profiles of different operative approaches for this patient population is scarce.

Methods

The institutional databases of two large referral centers in Thailand were retrospectively reviewed. Patients with subaxial cervical spine metastasis who underwent cervical surgery during 2005 to 2015 were identified and enrolled. Clinical presentations, baseline characteristics, operative approach, perioperative complications, and postoperative outcomes, including pain, neurological recovery, and survival, were compared among the three surgical approaches.

Results

The 70 patients (44 with anterior approach, 14 with posterior approach, 12 with combined approach) were enrolled. There were no statistically significant differences in preoperative characteristics, including Charlson Comorbidity Index (CCI), Tomita score, and Revised Tokuhashi score, among the three groups. There were no significant differences among groups for medical complications, surgical complications, neurological recovery, verbal pain score improvement, survival time, or ambulatory status improvement. However, the combined approach did show a significantly higher rate of overall perioperative complications (p = 0.01), intraoperative blood loss (p < 0.001), and operative time (p < 0.001) compared to the other two approaches.

Conclusions

Patients in the combined approach group had the highest rates of perioperative complications. However, although the differences were not statistically significant, patients in the combined group tended to have better clinical outcomes after follow-up and the longest survival time.

The role of surgery in the treatment of metastatic bone tumor

Surgery for bone metastasis has two primary goals-palliative care to relieve pain, instability and paralysis, and tumor resection for curing the disease. Oncologically en bloc resection, followed by a reconstruction of the bone defect is the treatment of choice in single bone metastasis from renal cell carcinoma or thyroid cancer. Bone metastases may occur in the extremities, pelvis, or spine, and different resection and reconstruction methods depend on the regional anatomy. For instance, multiple options are available for reconstruction of the pelvis, especially for the acetabulum, including anatomical reconstruction using custom-made implants or recycled autologous bone grafting when a long-term prognosis is expected. Recently, for the spine, total en bloc spondylectomy is extensively performed despite the initial limitations of surgical invasiveness, such as blood loss. Principally, palliative surgery aims to maintain lasting bony stability with minimal surgical invasiveness. Intramedullary nails and plate fixation are frequently used in the extremities but the postoperative failure rate is relatively high. Therefore, surgeons should consider the use of long intramedullary nails and long-type stems for endoprosthesis reconstruction along with cement fixation to reduce the failure rate. Although short-term complications, such as dislocation, have been observed with endoprosthesis reconstruction, it is stable in the long-term follow-up. Percutaneous bone cement injection into the spine and pelvis is also effective and less invasive.

10-Year Trends in the Surgical Management of Patients with Spinal Metastases: A Scoping Review

BACKGROUND

Spinal metastases are present in approximately 20% of patients with cancer, giving a risk for neurologic dysfunction and instability. In already frail patients, surgeons strive to improve quality of life. Our goal was to review a 10-year trend in the surgical management of spinal metastases.

METHODS

A scoping review was performed systematically using PubMed to assess trends in surgical treatment for spinal metastases. The search terms used were: metastas∗, "neoplasm metastasis"[Mesh], "Spine"[Mesh], spine, spinal, "vertebral column," "vertebral body," laser, robot, radiofrequency, screws, fixation, "separation surgery," corpectomy, vertebrectomy, spondylectomy, vertebroplasty, kyphoplasty, surgery, "open surgery," "mini open surgery," "minimally invasive surgery," endoscopy, thoracoscopy, corpectom∗, vertebrectom∗, spondylectom∗, "en bloc," and MIS. The variables of interest were neurologic improvement, tumor recurrence, reoperation, and overall survival.

RESULTS

A total of 2132 articles were found within the primary query. Fifty-six studies were selected for final review. The results were organized into main surgical practices: decompression, mechanical stabilization, and pain management. For separation surgery, clinical outcomes were overall 1-year survival, 40.7%-78.4%; recurrence rate, 4.3%-22%; reoperation, 5%; and complications, 5.4%-14%. For corpectomy, clinical outcomes were overall 1-year survival, 30%-92%; reoperation, 1.1%-50%; and recurrence rate, of 1.1%-28%. Complications and reoperations with spinal instrumentation were 0%-13.6% and 0%-15%, respectively. Cement augmentation achieved pain reduction rates of 56%-100%, neurologic improvement/stability 84%-100%, and complication rates 6%-56%. Laser achieved local tumor control rate of 71%-82% at 1 year follow-up, reoperation rate of 15%-31%, and complication rate of 5%-26%.

CONCLUSIONS

Minimally invasive techniques for decompression and stabilization seem to be the preferred method to surgically treat metastatic spine disease, with good outcomes. More research with high level of evidence is required to support the long-term outcomes of these approaches.

Does the Region of the Spine Involved with Metastatic Tumor Affect Outcomes of Surgical Treatments?

OBJECTIVE

Spinal metastases occur primarily in the thoracic spine (50%-60%), less commonly in the lumbar (30%-35%), and, infrequently, in the cervical spine (10%-15%). There has been only 1 study with a limited population comparing the postoperative outcome among cervical, thoracic, and lumbar spine metastasis. The aim of this study is to identify whether the region of surgically treated spinal metastasis affects postoperative outcomes.

METHODS

A retrospective study of patients with spinal metastasis was performed. The collected data were as follows: age, gender, smoking history, tumor histology, revised Tokuhashi score, preoperative and postoperative American Spinal Injury Association score, region of spinal metastasis, ambulatory status, surgical approach, surgery time, blood loss, complications, length of hospital stay, postoperative pain relief, postoperative adjuvant therapy, and survival. Data were analyzed to identify the factors affecting the survival and postoperative functional outcome.

RESULTS

We studied 191 patients with spinal metastasis including 47 cervical spine metastases, 96 thoracic spine metastases, and 48 lumbar spine metastases, with a mean age of 60.91 ± 9.72 years. The overall median survival was 7 months (95% confidence interval, 2.9-20.63 months). Univariate analysis showed that region of the spine involved with metastasis did not significantly affect the survival and postoperative motor function improvement. Multivariate analysis showed that revised Tokuhashi score, postoperative radiotherapy, and postoperative chemotherapy were independent factors affecting survival. The rate of 30-day complications among patients with different regions of spine metastasis did not reach significance.

CONCLUSIONS

The postoperative outcomes of patients undergoing surgery for metastases are not affected by the region of the spine.

Current Overview of Treatment for Metastatic Bone Disease

The number of patients with bone metastasis increases as medical management and surgery improve the overall survival of patients with cancer. Bone metastasis can cause skeletal complications, including bone pain, pathological fractures, spinal cord or nerve root compression, and hypercalcemia. Before initiation of treatment for bone metastasis, it is important to exclude primary bone malignancy, which would require a completely different therapeutic approach. It is essential to select surgical methods considering the patient’s prognosis, quality of life, postoperative function, and risk of postoperative complications. Therefore, bone metastasis treatment requires a multidisciplinary team approach, including radiologists, oncologists, and orthopedic surgeons. Recently, many novel palliative treatment options have emerged for bone metastases, such as stereotactic body radiation therapy, radiopharmaceuticals, vertebroplasty, minimally invasive spine stabilization with percutaneous pedicle screws, acetabuloplasty, embolization, thermal ablation techniques, electrochemotherapy, and high-intensity focused ultrasound. These techniques are beneficial for patients who may not benefit from surgery or radiotherapy.

Water treadmill training attenuates blood-spinal cord barrier disruption in rats by promoting angiogenesis and inhibiting matrix metalloproteinase-2/9 expression following spinal cord injury

Background

The permeability of the blood-spinal cord barrier (BSCB) is mainly determined by junction complexes between adjacent endothelial cells (ECs), including tight junctions (TJs) and adherens junctions (AJs), which can be severely damaged after spinal cord injury (SCI). Exercise training is a recognized method for the treatment of SCI. The destruction of the BSCB mediated by matrix metalloproteinases (MMPs) leads to inflammation, neurotoxin production, and neuronal apoptosis. The failure of new blood vessels to effectively regenerate is also an important cause of delayed recovery after SCI. For the first time, we introduced water treadmill training (TT) to help SCI rats successfully exercise and measured the effects of TT in promoting recovery after SCI and the possible mechanisms involved.

Methods

Sprague-Dawley (200–250 g) rats were randomly divided into the following three groups: sham operated, SCI, and SCI + TT. Animals were sacrificed at 7 or 14 days post-surgery. The degree of neurological deficit, tissue morphology and BSCB permeability were assessed by the Basso-Beattie-Bresnahan (BBB) motor function scale and appropriate staining protocols, and apoptosis, protein expression and vascular EC ultrastructure were assessed by TUNEL staining, Western blotting, immunofluorescence and transmission electron microscopy (TEM).

Results

Our experiments showed that TT reduced permeability of the BSCB and decreased structural tissue damage. TT significantly improved functional recovery when compared with that in the SCI group; TJ and AJ proteins expression increased significantly after TT, and training reduced apoptosis induced by SCI. TT could promote angiogenesis, and MMP-2 and MMP-9 expression was significantly inhibited by TT.

Conclusions

The results of this study indicate that TT promotes functional recovery for the following reasons: TT (1) protects residual BSCB structure from further damage, (2) promotes vascular regeneration, and (3) inhibits MMP-2/9 expression to mitigate BSCB damage.

Treatment of spine metastases in cancer: a review

As a consequence of the improvements in diagnostic technology along with gains in life expectancy of cancer patients, the incidence of spine metastases has increased. Spine metastases can affect the patient's quality of life and negatively impact on their prognosis. Multidisciplinary treatments involve surgery, chemotherapy, radiosurgery and radiotherapy. Spine metastases should be treated using a multidisciplinary and integrated approach that involves spinal surgeons, medical oncologists and radiologists. More research is required to elucidate the pathological mechanisms involved in the aetiology of spine metastasis. This review describes the current situation regarding the diagnosis of spine metastasis, what is understood about the pathological development of spine metastasis and the evolution of the multidisciplinary treatments that are available for patients with spine metastases.

Minimally invasive cervical pedicle screw fixation via the posterolateral approach for metastatic cervical spinal tumors

Background

To avoid lateral misplacement of midcervical pedicle screws, we developed a method for Minimally Invasive Cervical Pedicle Screw (MICEPS) fixation via a posterolateral approach. This intramuscular approach allows for horizontal pedicle screw insertion and reduced intraoperative bleeding. We reviewed our initial experience with MICEPS fixation for patients with cervical metastases.

Methods

This study included 18 consecutive patients who received cervical spinal surgery for metastatic tumor. We treated 12 patients with conventional cervical pedicle screw fixation, and 6 patients with the MICEPS fixation technique. Average follow-up was 14 months (range 3 to 34). We inserted 117 pedicle screws using the navigation system. Average fusion area was 4.9 vertebrae (range 3 to 8). Alpha-angles between a line perpendicular to the posterior cortex of the vertebral body and the screw trajectory in the transverse plane were also measured.

Results

The average surgical time was 250 min (range 151 to 420 min) with the conventional pedicle screw fixation and 234 min (range 154 to 300 min) with the MICEPS fixation. The average total blood loss was 780 mL (range, 180-1430 mL) in the conventional pedicle screw fixation group and 180 mL (range, 70-400 mL) in the MICEPS fixation group. At the level of midcervical (C3-5), average alpha-angles was 52 degrees (range 43 to 62) in MICEPS fixation group, and 39 degrees (range 19 to 55) in conventional cervical pedicle screw group.

Conclusions

The MICEPS fixation technique uses an intramuscular approach, which is minimally invasive and reduces intraoperative bleeding. Intramuscular approach allows for horizontal pedicle screw insertion, and reduced critical screw deviation.