Complications in the management of metastatic spinal disease

Robotic assisted surgery for the treatment of spinal metastases: A case series

OBJECTIVE

Spinal metastases can significantly affect quality of life in patients with cancer and present complex neurosurgical challenges for surgeons. Surgery with instrumentation is often indicated to alleviate pain, preserve neurological function, and ensure mechanical stability. However, distortions in the bony anatomy due to oncological disease can decrease the accuracy of pedicle screw placement. Robotic-assisted surgery may offer an opportunity to increase screw accuracy and improve navigation of spinal lesions compared to conventional techniques. Therefore, we presented our institutional experience evaluating robotic-assisted surgical fixation for spinal metastases.

METHODS

Patients undergoing robotic-assisted surgery at a large tertiary care center between January 2019 - January 2023 for the treatment of spinal metastases were identified. Patient characteristics, including demographics, tumor pathology, surgical complications, and post-operative outcomes were extracted. The Gertzbein Robbins classification system (GRS) was used to assess pedicle screw placement accuracy in patients with post-operative computed tomography.

RESULTS

Twenty patients were identified, including 7 females (35 %), with an overall median age of 66 years (range: 39-80 years) and median BMI of 25 kg/m2 (range: 17-34 kg/m2). An average of four spinal levels were instrumented, with metastases located primarily in the thoracic (n=17, 85 %) spine. Common primary tumor types included prostate (n=4), lung (n=2), and plasma cell (n=2) cancers. Most pedicle screws (92 %) were classified as GRS A in patients with postoperative imaging. Post-operative complications were unrelated to the use of the robot, and included pulmonary embolism (n=1), deep vein thrombosis (n=2), and gastric symptoms (n=3). Three patients were readmitted at 30 days, with one reoperation due to tumor recurrence. Four patients were deceased within 6 months of surgery.

CONCLUSIONS

Despite the inherent high-risk nature of these surgeries, this study underscores the safety and efficacy of robotic-assisted surgery in the management of spinal metastases. Robots can be helpful in ensuring accuracy of pedicle screw placement in patients with metastatic disease.

The Utility of 'Minimal Access and Separation Surgery' in the Management of Metastatic Spine Disease

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To compare outcomes of percutaneous pedicle screw fixation (PPSF) to open posterior stabilization (OPS) in spinal instability patients and minimal access separation surgery (MASS) to open posterior stabilization and decompression (OPSD) in metastatic spinal cord compression (MSCC) patients.

METHODS

We analysed patients who underwent surgery for thoracolumbar metastatic spine disease (MSD) from Jan 2011 to Oct 2017. Patients were divided into minimally invasive spine surgery (MISS) and open spine surgery (OSS) groups. Spinal instability patients were treated with PPSF/OPS with pedicle screws. MSCC patients were treated with MASS/OPSD. Outcomes measured included intraoperative blood loss, operative time, duration of hospital stay and ASIA-score improvement. Time to initiate radiotherapy and perioperative surgical/non-surgical complications was recorded. Propensity scoring adjustment analysis was utilised to address heterogenicity of histological tumour subtypes.

RESULTS

Of 200 eligible patients, 61 underwent MISS and 139 underwent OSS for MSD. There was no significant difference in baseline characteristics between MISS and OSS groups. In the MISS group, 28 (45.9%) patients were treated for spinal instability and 33 (54.1%) patients were treated for MSCC. In the OSS group, 15 (10.8%) patients were treated for spinal instability alone and 124 (89.2%) were treated for MSCC. Patients who underwent PPSF had significantly lower blood loss (95 mL vs 564 mL; P < .001) and surgical complication rates(P < .05) with shorter length of stay approaching significance (6 vs 19 days; P = .100) when compared to the OPS group. Patients who underwent MASS had significantly lower blood loss (602 mL vs 1008 mL) and shorter length of stay (10 vs 18 days; P = .098) vs the OPSD group.

CONCLUSION

This study demonstrates the benefits of PPSF and MASS over OPS and OPSD for the treatment of MSD with spinal instability and MSCC, respectively.

Remineralization of lytic spinal metastases after radiotherapy

BACKGROUND CONTEXT

Palliative radiotherapy (RT) can lead to remineralization of osteolytic lesions thereby potentially restoring some of the weight-bearing capacity and preventing vertebral collapse. It is not clear, however, under which circumstances remineralization of osteolytic lesions occurs.

PURPOSE

The aim of this study was to investigate the change in bone mineral density in spinal metastases after RT compared to a reference region, and find associated factors.

STUDY DESIGN

Retrospective analysis within prospective observational cohort OUTCOME MEASURES: change in bone mineral density measured in Hounsfield Units (HU).

PATIENT SAMPLE

patients treated with RT for (painful) bone metastases.

METHODS

Patients with spinal metastases were included if computed tomography scans both pre- and post-RT were available. Bone density was measured in HU. A region of interest (ROI) was drawn manually in the metastatic lesion. As a reference, a measurement of bone density in adjacent, unaffected, and non-irradiated vertebrae was used. Factors tested for association were origin of the primary tumor, RT dose and fractionation scheme, and concomitant use of bisphosphonates.

RESULTS

A total of 31 patients with 49 spinal metastases, originating from various primary tumors, were included. The median age on baseline was 58 years (IQR: 53-63) and median time between baseline and follow-up scan was 8.2 months (IQR: 3.0-18.4). Difference in HU in the lesion before and after treatment was 146.9 HU (95% CI 68.4-225.4; p<.01). Difference in HU in the reference vertebra between baseline and first follow-up was 19.1 HU (95% CI -47.9 to 86.0; p=.58). Difference between reference vertebrae and metastatic lesions on baseline was -194.1 HU (95% CI -276.2 to -112.0; p<.01). After RT, this difference was reduced to -50.3 HU (95% CI -199.6 to 99.0; p=.52). Patients using bisphosphonates showed a greater increase in HU, 194.1 HU versus 60.6 HU, p=.01.

CONCLUSIONS

Palliative radiation of osteolytic lytic spinal metastases is positively associated with an increased bone mineral density at follow-up. The use of bisphosphonates was linked to an increased bone mineral density when used during or after RT.

Clinical Outcome and Histological Findings After Induced Leakage of PMMA Loaded With Methotrexate and Cisplatin During Vertebroplasty: Experimental Model in Pigs

STUDY DESIGN

Animal experimental model.

OBJECTIVE

To study the clinical behavior and histological changes in the spinal cord, nerve roots and perivertebral muscles of the spine after induced leakage of polymethylmethacrylate (PMMA) loaded with antiblastic drugs during vertebroplasty in an animal model of pigs.

METHODS

We performed vertebroplasty on 25 pigs. The animals were divided into 3 groups: vertebroplasty with PMMA alone (control group), vertebroplasty with PMMA loaded with methotrexate (MTX) and vertebroplasty with PMMA loaded with cisplatin (CYS). At 2 vertebral levels, epidural and prevertebral, massive cement leaks were induced. Animals were evaluated daily. Two weeks later, the pigs were sacrificed, and the tissues that came in contact with the cement were analyzed.

RESULTS

The clinical results for each of the groups were reported. The control group had no clinical alterations. In the MTX group, 2 pigs died before 1 week due to pneumonitis. In the CYS group, 4 animals had motor impairment, and 3 of the 4 had paraplegia. The histological results were as follows: the control and MTX groups showed synovial metaplasia, inflammatory reaction, crystal deposits, and giant cell reaction in the dura mater and muscle and all the animals in the CYS group had spinal cord and muscular necrosis.

CONCLUSIONS

Massive cement leak after vertebroplasty with PMMA loaded with cisplatin is extremely toxic to the spinal cord and muscles around the spine. Therefore, its use cannot be recommended for the treatment of vertebral metastases. Using PMMA loaded with methotrexate seems to be a safe procedure, but further research is needed.

Hardware Failure in Spinal Tumor Surgery: A Hallmark of Longer Survival?

Objective: Instrumentation failure in spine tumor surgery is a common reason for revision operation. Increases in patient survival demand a better understanding of the hardware longevity. The study objective was to investigate risk factors for instrumentation failure requiring revision surgery in patients with spinal tumors.Methods: A retrospective cohort from a single tertiary care specialty hospital from January 2005 to January 2021, for patients with spinal primary or metastatic tumors who underwent surgical intervention with instrumentation. Demographic and treatment data were collected and analyzed. Kaplan-Meier analysis was performed for overall survival, and separate univariate and multivariate regression analysis was performed.Results: Three hundred fifty-one patients underwent surgical intervention for spinal tumor, of which 23 experienced instrumentation failure requiring revision surgery (6.6%). Multivariate regression analysis identified pelvic fixation (odds ratio [OR], 10.9), spinal metastasis invasiveness index (OR, 1.11), and survival of greater than 5 years (OR, 3.6) as significant risk factors for hardware failure. One- and 5-year survival rates were 57% and 8%, respectively.Conclusion: Instrumentation failure after spinal tumor surgery is a common reason for revision surgery. Our study suggests that the use of pelvic fixation, invasiveness of the surgery, and survival greater than 5 years are independent risk factors for instrumentation failure.

Negative Pressure Wound Therapy in Facilitating Wound Healing after Surgical Decompression for Metastatic Spine Disease

BACKGROUND

The risk of wound related complications, including surgical site infections (SSIs), in patients undergoing surgery for metastatic spine disease (MSD) is high. Consequently, patients requiring wound revision surgery face delay in resuming oncological care and incur additional hospitalization. Recent reports suggest that negative pressure wound therapy (NPWT) applied on a closed wound at the time of surgery, significantly reduces post-operative wound complications in degenerative spine disease and trauma setting. Here, we report a single institution experience with incisional NPWT in patients undergoing surgery for MSD.

METHODS

We compared rates of wound complications requiring surgical revision in a surgical cohort of patients with or without NPWT from 2015 to 2020. Adult patients with radiographic evidence of MSD with mechanical instability and/or accelerated neurological decline were included in the study. NPWT was applied on a closed wound in the operating room and continued for 5 days or until discharge, whichever occurred first.

RESULTS

A total of 42 patients were included: 28 with NPWT and 14 without. Patient demographics including underlying comorbidities were largely similar. NPWT patients had higher rates of prior radiation to the surgical site (36% vs. 0%, p = 0.017) and longer fusion constructs (6.7 vs. 3.9 levels, p < 0.001). Three patients (21%) from control group and none from NPWT group contracted SSI requiring wound washout (p = 0.032).

CONCLUSIONS

Our data suggests that SSI and wound dehiscence are significantly reduced with the addition of incisional NPWT in in this vulnerable population.

Radiotherapy dose calculations in high-Z materials: comprehensive comparison between experiment, Monte Carlo, and conventional planning algorithms

Purpose. To compare the accuracies of the AAA and AcurosXB dose calculation algorithms and to predict the change in the down-stream and lateral dose deposition of high energy photons in the presence of material with densities higher that commonly found in the body.Method. Metal rods of titanium (d = 4.5 g cm^-3), stainless steel (d = 8 g cm^-3) and tungsten (d = 19.25 g cm^-3) were positioned in a phantom. Film was position behind and laterally to the rods to measure the dose distribution for a 6 MV, 18 MV and 10 FFF photon beams. A DOSXYZnrc Monte Carlo simulation of the experimental setup was performed. The AAA and AcurosXB dose calculation algorithms were used to predict the dose distributions. The dose from film and DOSXYZnrc were compared with the dose predicted by AAA and AcurosXB.Results. AAA overestimated the dose behind the rods by 15%-25% and underestimated the dose laterally to the rods by 5%-15% depending on the range of materials and energies investigated. AcurosXB overestimated the dose behind the rods by 1%-18% and underestimated the dose laterally to the rods by up to 5% depending on the range of material and energies investigated.Conclusion. AAA cannot deliver clinically acceptable dose calculation results at a distance less than 10 mm from metals, for a single field treatment. Acuros XB is able to handle metals of low atomic numbers (Z ≤ 26), but not tungsten (Z = 74). This can be due to the restriction of the CT-density table in Eclipse^TMTPS, which has an upper HU limit of 10501.

Comparison of Minimally Invasive Total versus Subtotal Resection of Spinal Tumors: A Systematic Review and Meta-Analysis

OBJECTIVE

With the advent of minimally invasive techniques, minimally invasive spine surgery (MISS) has become a realistic option for many spine cases. This study aims to evaluate the operative and clinical outcomes of MISS for total versus subtotal tumor resection from current evidence.

METHODS

A literature search was performed using the search term (Minimally invasive surgery OR MIS) AND (spine tumor OR spinal tumor). Studies including both minimally invasive total and subtotal resection cases with operative or clinical data were included.

RESULTS

Seven studies describing 159 spinal tumor cases were included. Compared with total resection, subtotal resection showed no significant differences in surgical time (mean difference (MD), 9.44 minutes; 95% confidence interval [CI], -47.66 to 66.55 minutes; P = 0.37), surgical blood loss (MD, -84.72 mL; 95% CI, -342.82 to 173.39 mL; P = 0.34), length of stay (MD, 1.38 days; 95% CI, -0.95 to 3.71 days; P = 0.17), and complication rate (odds ratio, 9.47; 95% CI, 0.34-263.56; P = 0.12). Pooled analyses with the random-effects model showed that neurologic function improved in 89% of patients undergoing total resection, whereas neurologic function improved in 61% of patients undergoing subtotal resection.

CONCLUSIONS

Our analyses show that there is no significant difference in operative outcomes between total and subtotal resection. Patients undergoing total resection showed slightly better improvement in neurologic outcomes compared with patients undergoing subtotal resection. Overall, this study suggests that both total and subtotal resection may result in comparable outcomes for patients with spinal tumors. However, maximal safe resection remains the ideal treatment because it provides the greatest chance of long-term benefit.

Characteristics and Predictors of Radiographic Local Failure in Patients With Spinal Metastases Treated With Palliative Conventional Radiation Therapy

Purpose

Although local control is an important issue for longer-term survivors of spinal metastases treated with conventional external beam radiation therapy (EBRT), the literature on radiographic local failure (LF) in these patients is sparse. To inform clinical decision-making, we evaluated rates, consequences, and predictors of radiographic LF in patients with spinal metastases managed with palliative conventional EBRT alone.

Methods and Materials

We retrospectively reviewed 296 patients with spinal metastases who received palliative EBRT at a single institution (2006-2013). Radiographic LF was defined as radiologic progression within the treatment field, with death considered a competing risk. Kaplan-Meier, cumulative incidence, and Cox regression analyses determined overall survival estimates, LF rates, and predictors of LF, respectively.

Results

There were 182 patients with follow-up computed tomography or magnetic resonance imaging; median overall survival for these patients was 7.7 months. Patients received a median of 30 Gy in 10 fractions to a median of 4 vertebral bodies. Overall, 74 of 182 patients (40.7%) experienced LF. The 6-, 12-, and 18-month LF rates were 26.5%, 33.1%, and 36.5%, respectively, while corresponding rates of death were 24.3%, 38.1%, and 45.9%. Median time to LF was 3.8 months. Of those with LF, 51.4% had new compression fractures, 39.2% were admitted for pain control, and 35.1% received reirradiation; median time from radiation therapy (RT) to each of these events was 3.0, 5.7, and 9.2 months, respectively. Independent predictors of LF included single-fraction RT (8 Gy) (hazard ratio [HR], 2.592; 95% confidence interval [CI], 1.437-4.675; P = .002), lung histology (HR, 3.568; 95% CI, 1.532-8.309; P = .003), and kidney histology (HR, 4.937; 95% CI, 1.529-15.935; P = .008).

Conclusions

Patients experienced a >30% rate of radiographic LF by 1 year after EBRT. Single-fraction RT and lung or kidney histology predicted LF. Given the high rates of LF for patients with favorable prognosis, assessing the risk of death versus LF is important for clinical decision-making.

Gender disparities in clinical presentation, treatment, and outcomes in metastatic spine disease

BACKGROUND

The incidence of metastatic spine disease (MSD) is increasing among cancer patients. Given the poor outcomes and high rates of morbidity associated with MSD, it is important to determine demographic factors that could impact interventions and outcomes for this patient population. The objectives of this study were to compare in-hospital mortality and complication rates, clinical presentation, and interventions between female and male patients diagnosed with MSD.

METHODS

Patient data were collected from the United States National Inpatient Sample (NIS) database from the years 2012-2014. Descriptive statistics were used to compare data from 51,800 cases; subsequently, multivariable logistic regression analyses were conducted to assess the effect of gender on outcomes.

RESULTS

Males had significantly higher rates of in-hospital mortality (OR 1.30; 95 % CI 1.09-1.56, p = 0.004) and were more likely to have received surgical intervention than females (OR 1.34; 95 % CI 1.16-1.55, p < 0.001). Additionally, female patients were more likely to present with vertebral compression fracture (p < 0.001), while metastatic spinal cord compression (MSCC) and paralysis were more common in male patients (p < 0.001). There was no significant difference in rates of in-hospital complications between female and male patients.

CONCLUSION

Given the significant differences in mortality, disease course, treatment, and in-hospital complications between female and male patients diagnosed with MSD, additional prospective studies are necessary to understand how to meaningfully incorporate these differences into clinical care and prognostication going forward.

Characteristics of Patients and Treatment Recommendations from a Multidisciplinary Spinal Tumor Program

Objective: We describe characteristics of patient and treatment recommendations from a spinal tumor board at one institution, including representation from palliative care.

Background: The impact of prospective multidisciplinary input for patients with spinal tumors is poorly understood despite their increasing complexity.

Methods: We retrospectively reviewed 622 cases sequentially discussed at a weekly spinal tumor board, and abstracted patient and treatment information from the medical record and meeting minutes.

Results: From April 2017 to February 2019, 622 cases representing 438 unique patients were discussed. The median age was 62 years (range 21–92). Most patients had spinal tumors originating from metastases (91.78%), including breast (14.3%), nonsmall cell lung cancer (13.4%), prostate (10.9%), and renal cell cancer (8.8%), and the remainder had primary central nervous system (4.3%) or benign tumors (3.9%). Sixty-five percent of patients were alive at last follow-up. Conventional external beam radiotherapy was the most common treatment recommendation (33.8%) followed by surgery (26.2%), stereotactic body radiation therapy (17.8%), imaging follow-up (16.6%), and vertebroplasty (15.9%). Palliative care was the primary treatment recommended for 4.5%, and no therapy recommended for 4.0%. Treatment recommendation involved two modalities for 29% of cases, and three in 1.3% of cases. In four cases, biopsy to confirm pathology changed management due to unexpected findings of osteomyelitis, hematopoiesis, or new diagnosis of plasmacytoma.

Conclusions: Multidisciplinary input is integral to the optimal care of spinal tumor patients. The high risk of death highlights the need to prioritize modalities that optimize quality of life in the context of a patient's individual prognosis.

The Incidence and Management Trends of Metastatic Spinal Tumors in South Korea: A Nationwide Population-based Study

STUDY DESIGN

Population-based study. From 2008 to 2017, data from the national database of the Korean Health Insurance Review & Assessment Service were analyzed. The national insurance system and all medical expense bill data of the entire population are included in the database.

OBJECTIVE

The aim of this study was to elucidate the incidence and management trends of metastatic spinal tumors in South Korea.

SUMMARY OF BACKGROUND DATA

The spine is the most common location of bone metastases. However, population-based studies in this topic are limited.

METHODS

The International Classification of Disease, 10th revision, medical behavior, and examination codes were used to identify the incidence and management trends of metastatic spinal tumors. The Cochran-Armitage trend test was used in statistical analysis.

RESULTS

Overall, 38,007 patients (average age, 61 years) diagnosed with metastatic spinal tumors were analyzed. Metastatic tumors were most common in patients in their 60s (25.7%). The 10-year incidence of spinal metastases in South Korea was 6.68 cases per 100,000 population. The age-adjusted incidence per 100,000 population decreased from 8.16 cases in 2008 to 6.18 in 2017 (P = 0.03). Sex-adjusted incidence rates in men increased from 8.60 per 100,000 persons in 2008 to 8.70 in 2017 (P < 0.001); those of women decreased from 8.20 per 100,000 persons in 2008 to 4.15 in 2017 (P < 0.05). The most common primary tumor site was the lung (26.9%), followed by the breast (16.9%), prostate (10.8%), and liver (8.1%). Radiation therapy was constant at about 3500 cases per annum (P = 0.62); surgical treatment increased from 1158 to 1382 cases (P < 0.001). Resection and instrumentation surgeries increased significantly (P < 0.001), whereas cementation decreased continuously. Total healthcare costs increased significantly from $19,925,296 in 2008 to $30,268,217 in 2017 (P < 0.001).

CONCLUSION

The incidence of metastatic spinal tumors decreased in South Korea. Resection and instrumentation procedures increased, and total healthcare costs increased rapidly.

LEVEL OF EVIDENCE

3.

SPINAL METASTASIS: DIAGNOSIS, TREATMENT AND PROGNOSIS - INTEGRATIVE REVIEW FROM 2012 TO 2017

ABSTRACT Care of the patient with spinal metastasis is challenging. The topic of this article is the treatment and prognosis of spinal metastases, aiming to enumerate and analyze literature that addresses this treatment and prognosis. The methodology used was an integrative review in the Virtual Health Library. Nineteen articles were identified demonstrating that there is research and scientific production in this area. The thematic units and their categories are: treatment decision - prognostic scales or clinical neurological evaluation; types of treatment - minimally invasive and/or traditional; and effectiveness of prognostic scales higher or lower probability of success, which provide insight into the different possibilities of patient evaluation and their applicability in practice. When making the diagnosis, planning the treatment, and establishing a prognosis, the professional must be in sync with current precepts and act based on the objective and subjective characteristics of the patients, such as beliefs and values, which although immeasurable, influence the survival and the effectiveness of treatment. Level of evidence I; Integrative Review.

The impact of surgical timing on neurological outcomes and survival in patients with complete paralysis caused by spinal tumours

Aims

The aim of this study was to explore the prognostic factors for postoperative neurological recovery and survival in patients with complete paralysis due to neoplastic epidural spinal cord compression.

Patients and Methods

The medical records of 135 patients with complete paralysis due to neoplastic cord compression were retrospectively reviewed. Potential factors including the timing of surgery, muscular tone, and tumour characteristics were analyzed in relation to neurological recovery using logistical regression analysis. The association between neurological recovery and survival was analyzed using a Cox model. A nomogram was formulated to predict recovery.

Results

A total of 52 patients (38.5%) achieved American Spinal Injury Association Impairment Scale (AIS) D or E recovery postoperatively. The timing of surgery (p = 0.003) was found to be significant in univariate analysis. In multivariate analysis, surgery within one week was associated with better neurological recovery than surgery within three weeks (p = 0.002), with a trend towards being associated with a better neurological recovery than surgery within one to two weeks (p = 0.597) and two to three weeks (p = 0.055). Age (p = 0.039) and muscle tone (p = 0.018) were also significant predictors. In Cox regression analysis, good neurological recovery (p = 0.004), benign tumours (p = 0.039), and primary tumours (p = 0.005) were associated with longer survival. Calibration graphs showed that the nomogram did well with an ideal model. The bootstrap-corrected C-index for neurological recovery was 0.72.

Conclusion

In patients with complete paralysis due to neoplastic spinal cord compression, whose treatment is delayed for more than 48 hours from the onset of symptoms, surgery within one week is still beneficial. Surgery undertaken at this time may still offer neurological recovery and longer survival. The identification of the association between these factors and neurological recovery may help guide treatment for these patients. Cite this article: Bone Joint J 2019;101-B:872–879.

Advances in personalized treatment of metastatic spine disease

The spine is one of the most common sites of bony metastases, and its involvement leads to significant patient morbidity. Surgical management in these patients is aimed at improving quality of life and functional status throughout the course of the disease. Resection of metastases often leads to critical size bone defects, presenting a challenge to achieving adequate bone regeneration to fill the void. Current treatment options for repairing these defects are bone grafting and commercial bone cements; however, each has associated limitations. Additionally, tumor recurrence and tumor-induced bone loss make bone regeneration particularly difficult. Systemic therapeutic delivery, such as bisphosphonates, have become standard of care to combat bone loss despite unfavorable systemic side-effects and lack of local efficacy. Developments from tissue engineering have introduced novel materials with osteoinductive and osteoconductive properties which also act as structural support scaffolds for bone regeneration. These new materials can also act as a therapeutic reservoir to sustainably release drugs locally as an alternative to systemic therapy. In this review, we outline recent advancements in tissue engineering and the role of translational research in developing implants that can fully repair bone defects while also delivering local therapeutics to curb tumor recurrence and improve patient quality of life.

Malignant epidural spinal cord compression secondary to testicular cancer (mixed choriocarcinoma and seminoma) in the immediate post radical orchidectomy period

Acute spinal cord compression in the immediate postoperative period from a possible choriocarcinoma syndrome (CCS) on hemorrhagic epidural spinal metastasis has never been described before and needs to be promptly recognized and managed. A low hemoglobin associated with choriocarcinoma should raise suspicion of this syndrome.

Surgical Intervention vs. Radiation Therapy: The Shifting Paradigm in Treating Metastatic Spinal Disease

The spine is one of the most common sites to which metastatic cancer is likely to spread and is one of the leading causes of morbidity and mortality in cancer patients. While no medical treatments have been definitively shown to extend the life expectancy of patients with spinal metastasis, interventional options may be the only viable option in improving outcomes. Currently, two main options exist: surgical resection and radiotherapy, with radiotherapy being the primary treatment modality. In this review, we discuss the research comparing the efficacy and outcomes of radiotherapy and surgical resection in treating spinal metastasis. We conclude that while radiosurgery will continue to remain a major treatment modality, surgical intervention has proven to have equal to or superior outcomes at improving function, symptoms, and life expectancy for patients with metastatic spinal disease and should be considered a primary modality in an expanding subset of patients.

Practicality of using the figure-of-eight bandage to prevent fatal wound dehiscence after spinal tumor surgery for upper thoracic metastasis

OBJECT

Serious postoperative wound problems can frequently develop after surgery with perioperative RT for upper thoracic metastatic lesions. The figure-of-eight bandage can restrict excessive shoulder motion, which could prevent wound dehiscence. The purpose of this study was to describe the efficacy of using the figure-of-eight bandage to prevent postoperative wound dehiscence.

METHODS

Between February 2005 and July 2015, we retrospectively evaluated the medical records of cancer patients who underwent surgery with or without RT for spinal metastasis involving the upper thoracic spine. From January 2009, all patients received figure-of-eight bandaging immediately postoperatively, which was then maintained for 2 months. The outcome measures were the incidence and successful management of wound dehiscence following application of the figure-of-eight bandage.

RESULTS

One hundred and fifteen patients (71 men and 44 women) were enrolled in the present study. A figure-of-eight bandage in conjunction with a thoracolumbosacral orthosis (TLSO) was applied to 78 patients, while only TLSO was applied to 37 patients. The overall rate of wound dehiscence was 4.34% and the mean duration before wound dehiscence was 27.0 days (range, 22-31 days) after surgery. In the TLSO-only group, wound dehiscence occurred in four patients (10.81%), meanwhile there was only one case (1.33%) of wound dehiscence in the group that had received the figure-of-eight bandage with TLSO. Three of four patients with wound dehiscence in the TLSO only group died from unresolved wound problems and another patient was treated with wound closure followed by the application of the figure-of-eight bandage. The only patient with wound dehiscence among the patients who received both the figure-of-eight bandage and TLSO was managed by primary wound closure without further complication.

CONCLUSION

Current study suggests that the figure-of-eight bandage could prevent wound dehiscence and be used to treat wound problems easily.

Life Expectancy and Metastatic Spine Scoring Systems: An Academic Institutional Experience

STUDY DESIGN

A retrospective data collection study with application of metastatic spine scoring systems.

OBJECTIVES

To apply the Tomita and revised Tokuhashi scoring systems to a surgical cohort at a single academic institution and analyze spine-related surgical morbidity and mortality rates.

SUMMARY OF BACKGROUND DATA

Surgical management of metastatic spine patients requires tools that can accurately predict patient survival, as well as knowledge of morbidity and mortality rates.

METHODS

An Oregon Health & Science University (OHSU) Spine Center surgical database was queried (years 2002-2010) to identify patients with an ICD-9 code indicative of metastatic spine disease. Patients whose only surgical treatment was vertebral augmentation were not included. Scatter plots of survival versus the Tomita and revised Tokuhashi metastatic spine scoring systems were statistically analyzed. Spine-related morbidity and mortality rates were calculated.

RESULTS

Sixty-eight patients were identified: 45 patients' (30 male patients, mean age 45 y) medical records included operative, morbidity, and mortality statistic data and 38 (26 male patients, mean age 54 y) contained complete metastatic spine scoring system data. Of the 38 deceased spine metastatic patients, 8 had renal cell, 7 lung, 4 breast, 2 chondrosarcoma, 2 prostate, 11 other, and 4 unknown primary cancers. Linear regression analysis revealed R values of 0.2570 and 0.2009 for the revised Tokuhashi and Tomita scoring systems, respectively. Overall transfusion, infection, morbidity, and mortality rates were 33% and 9%, and 42% and 9%, respectively.

CONCLUSIONS

Application of metastatic prognostic scoring systems to a retrospective surgical cohort revealed an overall poor correlation with the Tomita and revised Tokuhashi predictive survival models. Morbidity and mortality rates concur with those in the medical literature. This study underscores the difficulty in utilizing metastatic spine scoring systems to predict patient survival. We believe a scoring system based on cancer type is needed to account for changes in treatment paradigms with improved patient survival over time.

Spinal Metastatic Disease: A Review of the Role of the Multidisciplinary Team

Historically, a simple approach centered on palliation was applicable to the majority of patients with metastatic spinal disease. With advances in diagnosis and treatment, a more complicated algorithm has devolved requiring a multidisciplinary approach with institutional commitment and support. We performed a database review including pertinent articles exploring the multidisciplinary management of spinal metastatic disease. The wide variation in clinical presentation and tumor response to treatment necessitates a multidisciplinary approach that integrates the diagnosis and treatment of the cancer, symptom management, and rehabilitation for optimal care of patients with spinal metastases. Advances in the field of radiology have led to earlier and more focused diagnosis of spinal metastasis and acts to guide therapy. Advances in surgical techniques, neurophysiologic monitoring, and anesthetic expertise have allowed surgeons to perform more extensive procedures leading to improved outcomes and reduced morbidity. Radiation oncology input that is essential as external beam radiation therapy can provide significant pain relief. Non-operative measures may include bisphosphonate infusions, management of complications (e.g. hypercalcemia of malignancy), monoclonal antibody infusions, and chemotherapy if indicated in the treatment of the primary malignancy. Input from psychology services is necessary to address the biopsychosocial ramifications of spinal metastasis. Allied health professionals in the form of physiotherapists, social workers, and dieticians also contribute in maximizing patients' quality of life and well-being.

Robotic versus fluoroscopy-guided pedicle screw insertion for metastatic spinal disease: a matched-cohort comparison

OBJECTIVE

Robot-guided pedicle screw placement is an established technique for the placement of pedicle screws. However, most studies have focused on degenerative disease. In this paper, the authors focus on metastatic spinal disease, which is associated with osteolysis. The associated lack of dense bone may potentially affect the automatic recognition accuracy of radiography-based surgical assistance systems. The aim of the present study is to compare the accuracy of the SpineAssist robot system with conventional fluoroscopy-guided pedicle screw placement for thoracolumbar metastatic spinal disease.

METHODS

Seventy patients with metastatic spinal disease who required instrumentation were included in this retrospective matched-cohort study. All 70 patients underwent surgery performed by the same team of experienced surgeons. The decision to use robot-assisted or fluoroscopy-guided pedicle screw placement was based the availability of the robot system. In patients who underwent surgery with robot guidance, pedicle screws were inserted after preoperative planning and intraoperative fluoroscopic matching. In the “conventional” group, anatomical landmarks and anteroposterior and lateral fluoroscopy guided placement of the pedicle screws. The primary outcome measure was the accuracy of screw placement on the Gertzbein-Robbins scale. Grades A and B (< 2-mm pedicle breach) were considered clinically acceptable, and all other grades indicated misplacement. Secondary outcome measures included an intergroup comparison of direction of screw misplacement, surgical site infection, and radiation exposure.

RESULTS

A total of 406 screws were placed at 206 levels. Sixty-one (29.6%) surgically treated levels were in the upper thoracic spine (T1–6), 74 (35.9%) were in the lower thoracic spine, and the remaining 71 (34.4%) were in the lumbosacral region. In the robot-assisted group (Group I; n = 35, 192 screws), trajectories were Grade A or B in 162 (84.4%) of screws. The misplacement rate was 15.6% (30 of 192 screws). In the conventional group (Group II; n = 35, 214 screws), 83.6% (179 of 214) of screw trajectories were acceptable, with a misplacement rate of 16.4% (35 of 214). There was no difference in screw accuracy between the groups (chi-square, 2-tailed Fisher’s exact, p = 0.89). One screw misplacement in the fluoroscopy group required a second surgery (0.5%), but no revisions were required in the robot group. There was no difference in surgical site infections between the 2 groups (Group I, 5 patients [14.3%]; Group II, 8 patients [22.9%]) or in the duration of surgery between the 2 groups (Group I, 226.1 ± 78.8 minutes; Group II, 264.1 ± 124.3 minutes; p = 0.13). There was also no difference in radiation time between the groups (Group I, 138.2 ± 73.0 seconds; Group II, 126.5 ± 95.6 seconds; p = 0.61), but the radiation intensity was higher in the robot group (Group I, 2.8 ± 0.2 mAs; Group II, 2.0 ± 0.6 mAs; p < 0.01).

CONCLUSIONS

Pedicle screw placement for metastatic disease in the thoracolumbar spine can be performed effectively and safely using robot-guided assistance. Based on this retrospective analysis, accuracy, radiation time, and postoperative infection rates are comparable to those of the conventional technique.

Decompression surgery for spinal metastases: a systematic review

OBJECTIVE The aim of this study was to systematically review the literature on reported outcomes following decompression surgery for spinal metastases. METHODS The authors conducted MEDLINE, Scopus, and Web of Science database searches for studies reporting clinical outcomes and complications associated with decompression surgery for metastatic spinal tumors. Both retrospective and prospective studies were included. After meeting inclusion criteria, articles were categorized based on the following reported outcomes: survival, ambulation, surgical technique, neurological function, primary tumor histology, and miscellaneous outcomes. RESULTS Of the 4148 articles retrieved from databases, 36 met inclusion criteria. Of those included, 8 were prospective studies and 28 were retrospective studies. The year of publication ranged from 1992 to 2015. Study size ranged from 21 to 711 patients. Three studies found that good preoperative Karnofsky Performance Status (KPS ≥ 80%) was a significant predictor of survival. No study reported a significant effect of time-to-surgery following the onset of spinal cord compression symptoms on survival. Three studies reported improvement in neurological function following surgery. The most commonly cited complication was wound infection or dehiscence (22 studies). Eight studies reported that preoperative ambulatory or preoperative motor status was a significant predictor of postoperative ambulatory status. A wide variety of surgical techniques were reported: posterior decompression and stabilization, posterior decompression without stabilization, and posterior decompression with total or subtotal tumor resection. Although a wide range of functional scales were used to assess neurological outcomes, four studies used the American Spinal Injury Association (ASIA) Impairment Scale to assess neurological function. Four studies reported the effects of radiation therapy and local disease control for spinal metastases. Two studies reported that the type of treatment was not significantly associated with the rate of local control. The most commonly reported primary tumor types included lung cancer, prostate cancer, breast cancer, renal cancer, and gastrointestinal cancer. CONCLUSIONS This study reports a systematic review of the literature on decompression surgery for spinal metastases. The results of this study can help educate surgeons on the previously published predictors of outcomes following decompression surgery for metastatic spinal disease. However, the authors also identify significant gaps in the literature and the need for future studies investigating the optimal practice with regard to decompression surgery for spinal metastases.

En Bloc Resections in the Spine: The Experience of 220 Patients During 25 Years

BACKGROUND AND OBJECTIVE

En bloc resections aim at surgically removing a tumor in a single, intact piece. Approach must be planned for the complete removal of the tumor without violation of its margins. The shared knowledge of the morbidity, mortality, risk assessment for local disease recurrence, complications, and death, related to spine tumors excised en bloc could improve the treating physician's apprehension of the diseases and decision making process before, during, and after surgical treatment. The purpose of this study was to review and report the experience gained during 25 years in one of the world's biggest spine oncologic centers.

METHODS

A retrospective study of prospective collected data of 1681 patients affected by spine tumors, of whom 220 had en bloc resections performed.

RESULTS

Most tumors were primary-165 cases (43 benign and 122 malignant); metastases occurred in 55 patients. A total of 60 patients died from the disease and 33 local recurrences were recorded. A total of 153 complications were observed in 100 of 216 patients (46.2%); 64 of these patients (30%) suffered 1 complication, whereas the rest had 2 or more. All complications were categorized according to temporal distribution and severity. These were further divided into 7 groups according to the type of complication. There were 105 major and 48 minor complications. Seven patients (4.6%) died as a result of complications. There were 33 local recurrences (15.28%) recorded. Contaminated cases, surgical margins of the resected tumor-intralesional, marginal, and malignant tumors-were statistically significant independent risk factors for local recurrence of the tumor. Contamination, local recurrence, neoadjuvant radiotherapy, number of levels resected, and metastatic tumors compared with primary malignant tumor were shown to be independent risk factors for a patient's death.

CONCLUSIONS

Treatment of spinal aggressive benign and malignant bone tumors with en bloc resection is beneficial in terms of better local control and prognosis, although it is a highly demanding and risky procedure. Margins are the key point of this procedure, thus a careful preoperative oncologic and surgical staging is necessary to define the optimal surgical approach. The adverse event profile of these surgeries is high. Therefore, it should be performed by experienced and multidisciplinary teams in specialized high volume centers.

Predictors for surgical complications of en bloc resections in the spine: review of 220 cases treated by the same team

PURPOSE

Identify risk factors, enabling reduction of the rate of complications and improve outcome in en bloc resection surgeries.

METHODS

A retrospective study of prospective collected data of 1681 patients affected by spine tumors treated from 1990 to 2015 by the same team.

RESULTS

A total of 220 en bloc resections that were performed on 216 patients during that period. Most of the tumors were primary-165 cases (43 benign and 122 malignant), metastases occurred in 55 cases. Median FU was 45 months (0-371). 153 complications were observed in 100 patients (46.2 %). 64 (30 %) suffered one complication, while the rest had two or more. There were 105 major and 48 minor complications. Seven patients (4.6 %) died as a result of complications. The combined approach, neoadjuvant chemotherapy and neoadjuvant radiotherapy were statistically significant independent risk factors for complications occurrence. 33 patients (15.2 %) suffered from local recurrence. Reoperations were mostly due to tumor recurrences, but also to hardware failures, wound dehiscence, hematomas and aortic dissection.

CONCLUSION

The rate of complication is higher in multisegmental resections and when double combined approach is performed. Reoperations display greater morbidity owing to dissection through scar/fibrosis from previous operations and possibly from RT. Careful treatment planning and, in the event of uncertainty, referral to a specialty center must be stressed. The high risk of complications should not discourage surgeons from performing en bloc resection when needed. Most of the patients who sustain complications benefit from the better local control resulting from en bloc resection.

Influence of internal fixation systems on radiation therapy for spinal tumor

In this study, the influence of internal fixation systems on radiation therapy for spinal tumor was investigated in order to derive a theoretical basis for adjustment of radiation dose for patients with spinal tumor and internal fixation. Based on a common method of internal fixation after resection of spinal tumor, different models of spinal internal fixation were constructed using the lumbar vertebra of fresh domestic pigs and titanium alloy as the internal fixation system. Variations in radiation dose in the vertebral body and partial spinal cord in different types of internal fixation were studied under the same radiation condition (6 MV and 600 mGy) in different fixation models and compared with those irradiated based on the treatment planning system (TPS). Our results showed that spinal internal fixation materials have great impact on the radiation dose absorbed by spinal tumors. Under the same radiation condition, the influence of anterior internal fixation material or combined anterior and posterior approach on radiation dose at the anterior border of the vertebral body was the greatest. Regardless of the kinds of internal fixation method employed, radiation dose at the anterior border of the vertebral body was significantly different from that at other positions. Notably, the influence of posterior internal fixation material on the anterior wall of the vertebral canal was the greatest. X‐ray attenuation and scattering should be taken into consideration for most patients with bone metastasis that receive fixation of metal implants. Further evaluation should then be conducted with modified TPS in order to minimize the potentially harmful effects of inappropriate radiation dose.

PACS number: 87.55.D‐

Features and Outcome of Surgical Management of Spinal Tumors in a Cohort of Nigerian Patients

OBJECTIVE

There is a dearth of information on operated cases of spinal tumors in patients in sub-Saharan Africa. The objective of this study was to evaluate the histologic pattern, anatomic distribution, and extent and outcome of surgery of Nigerian patients with spinal tumors.

METHODS

This retrospective study comprised a cohort of Nigerians who underwent surgery for spinal tumors. Data obtained included patient demographics, duration of symptoms, anatomic location, imaging findings, Frankel grading before and after surgery, and type and outcome of surgery. Univariate analysis was performed, and results were compared with results from other parts of the world.

RESULTS

There were 59 patients (male-to-female ratio 1:1.1) with a bimodal age distribution. The highest (20.34%) incidence was seen in the 20-29 age group. More than half (58.06%) of the patients presented with a duration of symptoms of at least 6 months (duration of symptoms was >12 months in 35.48%). Motor deficit was present in 97.73% of patients at presentation. Functional grading was Frankel A in 38.10% of patients, Frankel C in 26.19%, Frankel B in 16.67%, Frankel D in 16.67%, and Frankel E in 2.38%. The tumors were mostly in the thoracic region (65.45%), and 58% were extradural in location. Gross total tumor excision was performed in 50.88% of the cases, and subtotal resection was performed in 24.56%. Spinal stabilization was performed in 17.86% with spinous process wiring and vertical strut being the most common method of stabilization (80%) among this group. Metastasis was the most common histologic tumor type (23.21%). Meningioma accounted for 12.50% of tumors, and ependymoma, astrocytoma, and hemangioma each accounted for 7.14%. The most common source of metastasis was the prostate (38.46%). Postoperatively, 45% of patients improved neurologically, 52.5% remained the same, and 2.5% deteriorated. There was no perioperative mortality.

CONCLUSIONS

Metastasis was the most common histologic type of spinal tumor in this study, and the most common location was extradural. The outcome was satisfactory in most cases with neurologic function remaining the same or improving after surgery in most patients.

Spinal tumor surgery: management and the avoidance of complications

BACKGROUND

Complication avoidance is paramount to the success of any surgical procedure. In the case of spine tumor surgery, the risk of complications is increased because of the primary disease process and the radiotherapy and chemotherapeutics used to treat the disease. If complications do occur, then life-saving adjuvant treatment must be delayed or withheld until the issue is resolved, potentially impacting overall disease control.

METHODS

We reviewed the literature and our own best practices to provide recommendations on complication avoidance as well as the management of complications that may occur. Appropriate workup of suspected complications and treatment algorithms are also discussed.

RESULTS

Appropriate patient selection and a multidisciplinary workup are imperative in the setting of spinal tumors. Intraoperative complications may be avoided by employing proper surgical technique and an understanding of the pathological changes in anatomy. Major postoperative issues include wound complications and spinal reconstruction failure. Preoperative surgical planning must include postoperative reconstruction. Patients undergoing spinal tumor resection should be closely monitored for local tumor recurrence, recurrence along the biopsy tract, and for distant metastatic disease. Any suspected recurrence should be closely watched, biopsied if necessary, and promptly treated.

CONCLUSIONS

Because patients with spinal tumors are normally treated with a multidisciplinary approach, emphasis should be placed on the recognition of surgical complications beyond the surgical setting.

Co-delivery of siRNA and doxorubicin to cancer cells from additively manufactured implants

Tumors in load bearing bones are a major clinical problem as recurrence is common after surgery. Void filling scaffolds that kill residual cancer cells by releasing chemotherapy and siRNA/chitosan nanoparticles may offer a solution to this problem.

Trends in the surgical treatment for spinal metastasis and the in-hospital patient outcomes in the United States from 2000 to 2009

BACKGROUND CONTEXT

Surgical treatment for spinal metastasis is still controversial. However, with the improvements in treatment for primary tumors, the survival rate of patients with spinal metastasis is enhanced. At the same time, surgical technique for spinal metastasis has also improved.

PURPOSE

The purpose of this study was to examine trends in the surgical treatment for spinal metastasis and in-hospital patient outcomes on a national level.

STUDY DESIGN/SETTING

This was an epidemiologic study using national administrative data from the Nationwide Inpatient Sample (NIS) database.

PATIENT SAMPLE

All discharges in the NIS with a diagnosis code of secondary malignant neoplasm of the spinal cord/brain, meninges, or bone who also underwent spinal surgery from 2000 to 2009 were included.

OUTCOME MEASURES

Trends in the surgical treatment for spinal metastasis, in-hospital complications and mortality, and resource use were analyzed.

METHODS

The NIS was used to identify patients who underwent surgical treatment for spinal metastasis from 2000 to 2009, using the International Classification of Diseases, Ninth revision, Clinical Modification codes. Trends in the surgical treatment for spinal metastasis and in-hospital patient outcomes were analyzed.

RESULTS

From 2000 to 2009, there was an increasing trend in the population growth-adjusted rate of surgical treatment for spinal metastasis (1.15-1.77 per 100,000; p<.001). Average Elixhauser comorbidity score increased over time (2.6-3.8; p<.001), and the overall in-hospital complication rate increased over time (14.8%-27.7%; p<.001), whereas in-hospital mortality rate and length of hospital stay remained stable over time (5.2%-4.6%, p=.413; 10.6-10.8 days, p=.626). Inflation-adjusted mean hospital charges increased more than two-fold over time ($50,390-$110,173; p<.001).

CONCLUSIONS

During the last decade, surgical treatment for spinal metastasis has increased in the United States. The overall in-hospital complication rate and hospital charges increased, whereas the in-hospital mortality rate and length of hospital stay remained stable.

[Solitary spinal metastases. Is aggressive surgical management justified?]

Advances in oncological and surgical therapies have led to a significant increase in life expectancy of cancer patients and also prolonged survival of patients with isolated or multiple metastases. Among the skeletal manifestations the spine is the most often affected site. Using novel imaging techniques with higher resolution and use of metabolic signatures, the screening of cancer patients has improved considerably. Consequently, the diagnosis of metastases is becoming increasingly more sensitive. Therefore, but also due to more effective polychemotherapy protocols, singular or solitary metastases are more frequently observed either in the early stages or as a result of a controlled malignant tumor entity (stable disease). The questions whether a solitary metastasis really exists (illusion or reality?) and its radical oncological and surgical treatment as a circumscribed singular tumor manifestation, is really relevant for the overall prognosis, remains controversial. However, it seems evident that a biologically favorable underlying tumor biology, radical treatment of the primary tumor and a long metastasis-free interval are valid predictors of a good oncological outcome. In the presence of a solitary metastasis under these circumstances (typical example: solitary metastasis of renal cell carcinoma many years after radical tumor nephrectomy) a radical surgical procedure (en bloc spondylectomy) can significantly improve the long-term prognosis of this patient group in combination with adjuvant chemotherapy and/or radiotherapy. However, a thorough evaluation of the overall survival prognosis, a detailed and complete staging followed by a treatment consensus in the interdisciplinary tumor board has to precede any therapeutical decisions.