The Potential of Minimally Invasive Surgery to Treat Metastatic Spinal Disease versus Open Surgery: A Systematic Review and Meta-Analysis

Analysis of the efficacy of separation surgery for severe neurological compression in multiple myeloma: a retrospective analysis of 35 cases

PURPOSE

To investigate the effectiveness and safety of separation surgery for Epidural Spinal Cord Compression (ESCC) graded ≥ 2 in patients with Multiple Myeloma (MM), analyze factors influencing surgical outcomes, and develop a preliminary treatment decision framework for these patients.

METHODS

A retrospective analysis was conducted on clinical data from 35 MM patients who underwent separation surgery for ESCC graded ≥ 2 between 2013 and 2018. Patient data, including baseline information, surgical details, complications, and pre-operative as well as one-month post-operative efficacy evaluation indicators were recorded. Statistical analysis was performed on pre-operative and post-operative efficacy indicators to determine if there were significant improvements (p < 0.05). Ordered logistic regression was utilized to assess factors associated with an unfavorable post-operative quality of life outcome.

RESULTS

Compared to pre-operative values, at one-month post-surgery, patients showed significant improvements in Frankel Score Classification (4 vs 5, p < 0.05), Karnofsky Performance Score (30 vs 70, p < 0.05), and Visual Analogue Scale (8 vs 3, p < 0.05). Complications occurred in 7 cases (20%). The number of segments with ESCC (OR = 0.171, p < 0.05) and pre-operative chemotherapy (OR = 5.202, p = 0.05) were identified as independent factors influencing patient outcomes. Patients with more than two vertebral segments with ESCC exhibited significantly worse post-operative conditions.

CONCLUSIONS

Separation surgery effectively alleviates pain, improves neurological function, and enhances the quality of life in patients with ESCC graded ≥ 2 due to MM.

Does Patient Blood Management Affect Outcomes in Metastatic Spine Tumour Surgery? A Review of Current Concepts

STUDY DESIGN

Narrative review.

OBJECTIVE

The spine is the most common site of metastases, associated with decreased quality of life. Increase in metastatic spine tumour surgery (MSTS) has caused us to focus on the management of blood, as blood loss is a significant morbidity in these patients. However, blood transfusion is also not without its own risks, and hence this led to blood conservation strategies and implementation of a concept of patient blood management (PBM) in clinical practise focusing on these patients.

METHODS

A narrative review was conducted and all studies that were related to blood management in metastatic spine disease as well as PBM surrounding this condition were included.

RESULTS

A total of 64 studies were included in this review. We discussed a new concept of patient blood management in patients undergoing MSTS, with stratification to pre-operative and intra-operative factors, as well as anaesthesia and surgical considerations. The studies show that PBM and reduction in blood transfusion allows for reduced readmission rates, lower risks associated with blood transfusion, and lower morbidity for patients undergoing MSTS.

CONCLUSION

Through this review, we highlight various pre-operative and intra-operative methods in the surgical and anaesthesia domains that can help with PBM. It is an important concept with the significant amount of blood loss expected from MSTS.

LEVEL OF EVIDENCE

Not applicable.

A spatial registration method based on 2D-3D registration for an augmented reality spinal surgery navigation system

BACKGROUND

In order to provide accurate and reliable image guidance for augmented reality (AR) spinal surgery navigation, a spatial registration method has been proposed.

METHODS

In the AR spinal surgery navigation system, grayscale-based 2D/3D registration technology has been used to register preoperative computed tomography images with intraoperative X-ray images to complete the spatial registration, and then the fusion of virtual image and real spine has been realised.

RESULTS

In the image registration experiment, the success rate of spine model registration was 90%. In the spinal model verification experiment, the surface registration error of the spinal model ranged from 0.361 to 0.612 mm, and the total average surface registration error was 0.501 mm.

CONCLUSION

The spatial registration method based on 2D/3D registration technology can be used in AR spinal surgery navigation systems and is highly accurate and minimally invasive.

[Translated article] The role of minimally invasive spine surgery in the treatment of vertebral metastasis (Part 1): A clinical review

Spinal metastases represent a significant burden on the quality of life in patients affected by active oncological disease due to the high incidence of pain syndromes, spinal deformity, and neurological impairment. Surgery plays a decisive role in improving quality of life by controlling pain, restoring neurological function and maintaining spinal stability, as well as contributing to the response to medical therapy. Minimally invasive surgery (MIS) is a treatment option in certain patients with high surgical risk since it has a low rate of complications, intraoperative bleeding, hospital stay, and offers similar results to open surgery. In this review, we present the role of MIS in this pathology and some cases treated in our hospital.

[Translated article] The role of minimally invasive spine surgery in the treatment of vertebral metastasis: A narrative review

BACKGROUND

Spinal metastases are a very common problem which dramatically affects the quality of life of cancer patients. The objective of this review is to address the issue of how minimally invasive surgery can play an important role in treating this pathology.

METHODS

A literature review was performed, searching in the Google Scholar, PubMed, Scopus and Cochrane databases. Relevant and quality papers published within the last 10 years were included in the review.

RESULTS

After screening the 2184 initially identified registers, a total of 24 articles were included for review.

CONCLUSION

Minimally invasive spine surgery is specially convenient for fragile cancer patients with spinal metastases, because of its reduced comorbidity compared to conventional open surgery. Technological advances in surgery, such as navigation and robotics, improve accuracy and safety in this technique.

The role of minimally invasive spine surgery in the treatment of vertebral metastasis: A narrative review

BACKGROUND

Spinal metastases are a very common problem which dramatically affects the quality of life of cancer patients. The objective of this review is to address the issue of how minimally invasive surgery can play an important role in treating this pathology.

METHODS

A literature review was performed, searching in the Google Scholar, PubMed, Scopus and Cochrane databases. Relevant and quality papers published within the last 10 years were included in the review.

RESULTS

After screening the 2184 initially identified registers, a total of 24 articles were included for review.

CONCLUSION

Minimally invasive spine surgery is specially convenient for fragile cancer patients with spinal metastases, because of its reduced comorbidity compared to conventional open surgery. Technological advances in surgery, such as navigation and robotics, improve accuracy and safety in this technique.

The role of minimally invasive spine surgery in the treatment of vertebral metastasis (part 1): A clinical review

Spinal metastases represent a significant burden on the quality of life in patients affected by active oncological disease due to the high incidence of pain syndromes, spinal deformity, and neurological impairment. Surgery plays a decisive role in improving quality of life by controlling pain, restoring neurological function and maintaining spinal stability, as well as contributing to the response to medical therapy. Minimally invasive surgery (MIS) is a treatment option in certain patients with high surgical risk since it has a low rate of complications, intraoperative bleeding, hospital stay, and offers similar results to open surgery. In this review, we present the role of MIS in this pathology and some cases treated in our hospital.

Separation Operation Followed by Stereotactic Radiotherapy in the Treatment of Spinal Metastasis From Hepatocellular Carcinoma: A Retrospective Cohort Study

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Spinal metastasis from hepatocellular carcinoma is rapidly progressive and predisposes to spinal disability, cord compression and further neural injury, leading to poor prognosis. Currently, it is still challenging to look for a treatment strategy that can improve the quality of life of patients and even directly prolong the survival time. This study attempts to evaluate the clinical efficacy of separation operation combined with postoperative stereotactic radiotherapy (SRT/SRS) in the treatment of hepatocellular carcinoma patients developing spinal metastasis and epidural spinal cord compression.

METHODS

Patients with metastases spinal cord compression from hepatocellular carcinoma were studied retrospectively and divided into two groups, the SO group (who undergo separation operations combined with postoperative SRS, n = 32) and RT group (who received only SRS, n = 28). The visual Analogue Scale (VAS) pain score, Frankel grade, Karnofsky performance score, and Quality of Life (SF-36) score were comparatively analyzed between the two groups.

RESULTS

Significantly higher VAS pain scores, Frankel grades, Karnofsky performance scores and Quality of Life (SF-36) scores were demonstrated in patients with combination treatment than in patients with SRS alone.

CONCLUSIONS

Separation operations are effective surgical procedure for the treatment of spinal metastatic tumor from hepatocellular carcinoma with spinal cord compression. The combination with postoperative SRS can significantly improve the quality of life in this patient population via spinal canal decompression and spinal stability reconstruction.

Spine Metastasis: Patients With Poor Performance Status (ECOG) Could benefit From Palliative Surgical Care! A Prospective Cohort Study

STUDY DESIGN

This study used a French prospective national multi-center database of patients with spine metastasis (SpM).

OBJECTIVE

The main challenge was to clarify if SpM patients presenting poor ECOG-PS could benefit from a surgical intervention.

BACKGROUND

Spine metastases (SpM) are debilitating lesions commonly found in the evolution of cancer. At present, patients with poor ECOG-PS do not benefit from surgical care.

MATERIALS AND METHODS

Between 2014 and 2017, 176 SpM patients with poor initial ECOG-PS (3 or 4) were identified.

RESULTS

The median overall survival of patients was 2.1 months (SD 0.2). Seventy-one patients (40.3%) underwent surgery: for 49 patients (27.8%) the intervention consisted of a simple decompression and for 22 patients (12.5%) the previous was associated with an osteosynthesis. Patients who underwent surgery demonstrated significantly longer median overall survival than those who did not: 3.5 months (SD 0.4) versus 1.6 (SD 0.2) ( P <0.0001). No significant differences between operated/nonoperated patients were noted concerning median age (66.4 vs. 64.2 y, P =0.897), the median number of SpM (4.1 vs. 4.2, P =0.374), ECOG-PS 4 ratio (41.6 vs. 39.3%, P =0.616), or for primary tumors ( P =0.103). Patients who underwent surgery statistically improved their neurological impairment according to the Frankel score: 5/11 (45.4%) from A to C, 5/17 (29.4%) from B to C or D, 6/11 (54.5%) from C to D and 2/4 (50%). Twelve patients (16.9%) presented a postoperative complication.

CONCLUSION

Patients with poor ECOG-PS could benefit from surgery. Even though survival gain is small, it permits the preservation of their neurological function. By making ambulation possible, pain is decreased during the last months of their lives.

Surface deformation tracking in monocular laparoscopic video

Image-guided surgery has been proven to enhance the accuracy and safety of minimally invasive surgery (MIS). Nonrigid deformation tracking of soft tissue is one of the main challenges in image-guided MIS owing to the existence of tissue deformation, homogeneous texture, smoke and instrument occlusion, etc. In this paper, we proposed a piecewise affine deformation model-based nonrigid deformation tracking method. A Markov random field based mask generation method is developed to eliminate tracking anomalies. The deformation information vanishes when the regular constraint is invalid, which further deteriorates the tracking accuracy. Atime-series deformation solidification mechanism is introduced to reduce the degradation of the deformation field of the model. For the quantitative evaluation of the proposed method, we synthesized nine laparoscopic videos mimicking instrument occlusion and tissue deformation. Quantitative tracking robustness was evaluated on the synthetic videos. Three real videos of MIS containing challenges of large-scale deformation, large-range smoke, instrument occlusion, and permanent changes in soft tissue texture were also used to evaluate the performance of the proposed method. Experimental results indicate the proposed method outperforms state-of-the-art methods in terms of accuracy and robustness, which shows good performance in image-guided MIS.

Assessing the accuracy of a new 3D2D registration algorithm based on a non-invasive skin marker model for navigated spine surgery

Purpose

We assessed the accuracy of a new 3D2D registration algorithm to be used for navigated spine surgery and explored anatomical and radiologic parameters affecting the registration accuracy. Compared to existing 3D2D registration algorithms, the algorithm does not need bone-mounted or table-mounted instruments for registration. Neither does the intraoperative imaging device have to be tracked or calibrated.

Methods

The rigid registration algorithm required imaging data (a pre-existing CT scan (3D) and two angulated fluoroscopic images (2D)) to register positions of vertebrae in 3D and is based on non-invasive skin markers. The algorithm registered five adjacent vertebrae and was tested in the thoracic and lumbar spine from three human cadaveric specimens. The registration accuracy was calculated for each registered vertebra and measured with the target registration error (TRE) in millimeters. We used multivariable analysis to identify parameters independently affecting the algorithm’s accuracy such as the angulation between the two fluoroscopic images (between 40° and 90°), the detector-skin distance, the number of skin markers applied, and waist circumference.

Results

The algorithm registered 780 vertebrae with a median TRE of 0.51 mm [interquartile range 0.32–0.73 mm] and a maximum TRE of 2.06 mm. The TRE was most affected by the angulation between the two fluoroscopic images obtained (p < 0.001): larger angulations resulted in higher accuracy. The algorithm was more accurate in thoracic vertebrae (p = 0.004) and in the specimen with the smallest waist circumference (p = 0.003). The algorithm registered all five adjacent vertebrae with similar accuracy.

Conclusion

We studied the accuracy of a new 3D2D registration algorithm based on non-invasive skin markers. The algorithm registered five adjacent vertebrae with similar accuracy in the thoracic and lumbar spine and showed a maximum target registration error of approximately 2 mm. To further evaluate its potential for navigated spine surgery, the algorithm may now be integrated into a complete navigation system.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11548-022-02733-w.

Treatment of Metastatic Spinal Disease; what the Radiologist needs to know

Advancements in technology and multidisciplinary management have revolutionized the treatment of spinal metastases. Imaging plays a pivotal role in determining the treatment course for spinal metastases. This article aims to review the relevant imaging findings in spinal metastases from the perspective of the treating clinician, describe the various treatment options, and discuss factors influencing choice for each available treatment option. Cases that once required radical surgical resection or low-dose conventional external beam radiation therapy, or both, are now being managed with separation surgery, spine stereotactic radiosurgery/stereotactic body radiation therapy, or both, with decreased morbidity, improved local control, and more durable pain control. The primary focus in determining treatment choice is now on tumor control outcomes, treatment-related morbidity, and quality of life.

Is minimally invasive orthopedic surgery safer than open? A systematic review of systematic reviews

BACKGROUND

To assess the safety of minimally invasive surgery (MIS) for orthopedic spinal, upper limb and lower limb procedures, this systematic review of systematic reviews compared their complications with open procedures.

MATERIALS AND METHODS

A literature search was conducted electronically (PubMed, Cochrane library and Web of Science; May 8, 2021) without language restriction in the past five years. Reviews that consulted at least two databases, compared MIS with open orthopedic surgery, and reported the following: intraoperative, post-operative or total complications, function, ambulation, pain, hospital stay, reoperation rate and operation time were included. Article selection, quality assessment using AMSTAR-2, and data extraction were conducted in duplicate on predesigned forms. In each review, a subset analysis focusing on prospective cohort and randomized studies was additionally performed.

PROSPERO

CRD42020178171.

RESULTS

The search yielded 531 articles from which 76 reviews consisting of 1104 primary studies were included. All reviews were assessed as being low quality. Compared to open surgery, MIS had fewer total, postoperative and intraoperative complications in 2/10, 2/11 and 2/5 reviews of spinal procedures respectively, 1/3, 1/4 and 1/2 reviews of upper limb procedures respectively, and 4/6, 2/7 and 0/2 reviews of lower limb procedures respectively.

CONCLUSIONS

MIS had greater overall safety compared to open surgery in spinal procedures. In upper limb and lower limb procedures, MIS was not outright superior to open procedures in terms of safety hence a general preference of MIS is not justified on the premise of a better safety profile compared to open procedures.

Impact of Spinal Instrumentation on Neurological Outcome in Patients with Intermediate Spinal Instability Neoplastic Score (SINS)

Background: Adequate assessment of spinal instability using the spinal instability neoplastic score (SINS) frequently guides surgical therapy in spinal epidural osseous metastases and subsequently influences neurological outcome. However, how to surgically manage ‘impending instability’ at SINS 7−12 most appropriately remains uncertain. This study aimed to evaluate the necessity of spinal instrumentation in patients with SINS 7−12 with regards to neurological outcome. Methods: We screened 683 patients with spinal epidural metastases treated at our interdisciplinary spine center. The preoperative SINS was assessed to determine spinal instability and neurological status was defined using the Frankel score. Patients were dichotomized according to being treated by instrumentation surgery and neurological outcomes were compared. Additionally, a subgroup analysis of groups with SINS of 7−9 and 10−12 was performed. Results: Of 331 patients with a SINS of 7−12, 76.1% underwent spinal instrumentation. Neurological outcome did not differ significantly between instrumented and non-instrumented patients (p = 0.612). Spinal instrumentation was performed more frequently in SINS 10−12 than in SINS 7−9 (p < 0.001). The subgroup analysis showed no significant differences in neurological outcome between instrumented and non-instrumented patients in either SINS 7−9 (p = 0.278) or SINS 10−12 (p = 0.577). Complications occurred more frequently in instrumented than in non-instrumented patients (p = 0.016). Conclusions: Our data suggest that a SINS of 7−12 alone might not warrant the increased surgical risks of additional spinal instrumentation.

Minimally invasive separation surgery for the treatment of spinal metastases with small incision and freehand pedicle screw fixation: the surgical learning curve

BACKGROUND

Minimally invasive separation surgery (MISS) is a safe and effective surgical technique, the current optimal treatment for spinal metastases. However, the learning curve for this technique has not been analyzed. This study aimed to define and analyze the surgical learning curve of MISS for the treatment of spinal metastases with small incision and freehand pedicle screw fixation.

METHODS

A continuous series of 62 patients with spinal metastases who underwent MISS were included. Each patient's operative data were accurately counted. The improvement of the patients' neurological function was followed up after surgery to evaluate the surgical treatment effect. Logarithmic curve-fit regression was used to analyze the surgical learning curve of MISS. The number of cases needed to achieve proficiency was analyzed. Based on this cut-off point, this series of cases was divided into the early phase and later phase groups. The influence of the time sequence of MISS on surgical data and surgical efficacy was analyzed.

RESULTS

The operative time decreased gradually with the number of surgical cases increasing and stabilized after the 20th patient. There was no statistical difference in demographic characteristics and preoperative characteristics between the two groups. The mean operative time in the later phase group was about 39 min shorter than that in the early phase group (mean 227.95 vs. 189.02 min, P = 0.027). However, it did not affect other operative data or the surgical treatment effect.

CONCLUSION

The learning curve of MISS for spinal metastases is not steep. With the increase of surgeons' experience, the operative time drops rapidly and stabilizes within a certain range. MISS can be safely and effectively performed at the beginning of a surgeon's caree.

Anterior Corpectomy and Plating with Carbon-PEEK Instrumentation for Cervical Spinal Metastases: Clinical and Radiological Outcomes

Background: Anterior cervical corpectomy and plating has been recognized as a valuable approach for the surgical treatment of cervical spinal metastases. This study aimed to report the surgical, clinical and radiological outcomes of anterior carbon-PEEK instrumentations for cervical spinal metastases. Methods: Demographical, clinical, surgical and radiological data were collected from 2017 to 2020. The Neck Disability Index (NDI) questionnaire for neck pain, EORTC QLQ-C30 questionnaire for quality of life, Nurick scale for myelopathy and radiological parameters (segmental Cobb angle and cervical lordosis) were collected before surgery, at 6 weeks postoperatively and follow-up. Results: Seventeen patients met inclusion criteria. Mean age was 60.9 ± 7.6 years and mean follow-up was 12.9 ± 4.0 months. The NDI (55.4 ± 11.7 to 25.1 ± 5.4, p < 0.001) scores and the EORTC QLQ-C30 global health/QoL significantly improved postoperatively and at the last follow-up. The segmental Cobb angle (10.7° ± 5.6 to 3.1° ± 2.2, p < 0.001) and cervical lordosis (0.9° ± 6.7 to −6.2 ± 7.8, p = 0.002) significantly improved postoperatively. Only one minor complication (5.9%) was recorded. Conclusions: Carbon/PEEK implants represent a safe alternative to commonly used titanium ones and should be considered in cervical spinal metastases management due to their lower artifacts in postoperative imaging and radiation planning. Further larger comparative and cost-effectiveness studies are needed to confirm these results.

Minimally Invasive Surgery for Spinal Metastasis: A Review

OBJECTIVE

Minimally invasive surgery (MIS) techniques have advanced the treatment of metastatic diseases to the spine. The objective of this review is to describe clinical outcomes, benefits, and complications of these techniques.

METHODS

All relevant clinical studies describing the role of MIS, computer-assisted navigation (CAN), robot-assisted (RA) procedures, and laser interstitial thermal therapy (LITT) in the treatment of metastatic spine diseases were identified from PubMed, MEDLINE, and relevant article bibliographies.

RESULTS

For MIS articles, we filtered 1480 results and identified 26 studies. For CAN, we searched 464 articles to identify 18 articles for review. For RA, we searched 321 results to identify 7 studies for review. For LITT, we identified 21 articles for review.

CONCLUSIONS

MIS for the treatment of spine metastasis has significant potential benefits in reducing surgical site infections, hospital stay, and blood loss without compromising instrument accuracy or overall outcomes. Overall, MIS and its adjuncts have the potential to reduce the risks involved in the treatment of patients with metastatic disease to the spinal column without compromising the benefits of decompression and stabilization of the spine.

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.

Minimally Invasive versus Open Surgery for Spinal Metastasis: A Systematic Review and Meta-Analysis

Bones are the third most common location for solid tumor metastasis affecting up to 10% of patients with solid tumors. When the spine is involved, thoracic and lumbar vertebrae are frequently affected. Access to spinal lesions can be through minimally invasive surgery (MIS) or traditional open surgery (OS). This study aims to determine which method provides an advantage. Following the PRISMA (Preferred Inventory for Systematic Reviews and Meta-Analysis) guidelines, a systematic review was conducted to identify studies that compare MIS with OS in patients with spinal metastatic disease. Data were analyzed using Review Manager ver. 5.3 (RevMan; Cochrane, London, UK). Ten studies were included. Operative time was similar among groups at −35.23 minutes (95% confidence interval [CI], −73.36 to 2.91 minutes; p=0.07). Intraoperative bleeding was lower in MIS at −562.59 mL (95% CI, −776.97 to −348.20 mL; p<0.00001). OS procedures had higher odds of requiring blood transfusions at 0.26 (95% CI, 0.15 to 0.45; p<0.00001). Both approaches instrumented similar numbers of levels at −0.05 levels (95% CI, −0.75 to 0.66 levels; p=0.89). We observed a decreased need for postoperative bed rest at −1.60 days (95% CI, −2.46 to −0.74 days; p=0.0003), a shorter length of stay at −3.08 days (95% CI, −4.50 to −1.66 days; p=0.001), and decreased odds of complications at 0.60 (95% CI, 0.37 to 0.96; p=0.03) in the MIS group. Both approaches revealed similar reintervention rates at 0.65 (95% CI, 0.15 to 2.84; p=0.57), effective rates of reducing metastasis-related pain at −0.74 (95% CI, −2.41 to 0.94; p=0.39), and comparable scores of the Tokuhashi scale at −0.52 (95% CI, −2.08 to 1.05; p=0.41), Frankel scale at 1.00 (95% CI, 0.60 to 1.68; p=1.0), and American Spinal Injury Association Scale at 0.53 (95% CI, 0.21 to 1.37; p=0.19). MIS appears to provide advantages over OS. Larger and prospective studies should fully detail the role of MIS as a treatment for spine metastasis.

Intraoperative blood loss in oncological spine surgery

OBJECTIVE

Intraoperative blood loss in patients undergoing oncological spine surgery poses a major challenge for vulnerable patients. The goal of this study was to assess how the surgical procedure, tumor type, and tumor anatomy, as well as anesthesiological parameters, affect intraoperative blood loss in oncological spine surgery and to use this information to generate a short preoperative checklist for spine surgeons and anesthesiologists to identify patients at risk for increased intraoperative blood loss.

METHODS

The authors performed a retrospective analysis of 430 oncological patients who underwent spine surgery between 2013 and 2018 at the university medical spine center. Enrolled patients had metastatic tumor of the spine requiring surgical decompression of neural structures and/or stabilization including tumor biopsy using an open, percutaneous, and/or combined dorsoventral approach. Patients requiring vertebro- and kyphoplasty or biopsy only were excluded. Statistical analyses performed included a multiple linear regression analysis.

RESULTS

The mean intraoperative blood loss in the study patient cohort was 1176 ± 1209 ml. In total, 33.8% of patients received intraoperative red blood cell transfusions. The statistical analyses showed that tumor histology indicating myeloma, operative procedure length, epidural spinal cord compression (ESCC) score, tumor localization, BMI, and surgical strategy were significantly associated with increased intraoperative blood loss or risk of needing allogeneic blood transfusions. Anesthesiological parameters such as the American Society of Anesthesiologists (ASA) Physical Status classification score were not associated with blood loss. Multiple linear regression analysis demonstrated good predictive value (r = 0.437) for a five-item preoperative checklist to identify patients at risk for high intraoperative blood loss.

CONCLUSIONS

The analyses performed in this study demonstrated key factors affecting intraoperative blood loss and showed that a simple preoperative checklist including these factors can be used to identify patients undergoing surgery for metastatic spine tumors who are at risk for increased intraoperative blood loss.

ABBREVIATIONS

ABT = allogeneic blood transfusion; ASA = American Society of Anesthesiologists; ESCC = epidural spinal cord compression; KW = Kruskal-Wallis; MET = metabolic equivalent of task; RBC = red blood cell.

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.

Low Implant Failure Rate of Percutaneous Fixation for Spinal Metastases: A Multicenter Retrospective Study

OBJECTIVE

To evaluate incidence and types of implant failure observed in a series of patients with spinal metastases (SM) treated with minimally invasive stabilization surgery without fusion.

METHODS

In this multicenter, retrospective, observational study, we reviewed the files of patients >18 years old who underwent surgery for SM using percutaneous spinal stabilization without fusion with a minimum 3-month follow-up. The following variables were included: demographics, clinical findings, prior radiation history, SM location, epidural spinal cord compression scale, Spinal Instability Neoplastic Scale, neurological examination, and surgery-related data. Primary outcome measure was implant failure rate, as observed in patients' last computed tomography scan. Multivariable analysis was performed to identify baseline factors and factors associated with implant failure.

RESULTS

Analysis included 72 patients. Mean age of patients was 62 years, 39 patients were men, and 75% of patients had an intermediate Spinal Instability Neoplastic Scale score. Tumor separation surgery was performed in 48.6% of patients. Short instrumentation was indicated in 54.2% of patients. Three patients (4.2%) experienced implant failure (2 screw loosening, 1 screw cut-out); none of them required revision surgery. In 73.6% of cases, survival was >6 months. No significant predictors of failure were identified in the multivariate analysis.

CONCLUSIONS

A low implant failure rate was observed over the short and medium term, even when short instrumentations without fusion were performed. These findings suggest that minimally invasive stabilization surgery without fusion may be an effective and safe way to treat complicated SM.

A Comparative Study Between Minimally Invasive Spine Surgery and Traditional Open Surgery for Patients With Spinal Metastasis

STUDY DESIGN

A retrospective study was conducted.

OBJECTIVE

This study aims to compare the perioperative outcomes of minimal invasive spine surgery (MISS) and traditional open surgery (TOS) for thoracolumbar spine metastasis.

SUMMARY OF BACKGROUND DATA

TOS for metastatic spinal tumors has many disadvantages, such as significant blood loss and high complication rate. MISS may change the treatment modality, but its safety and efficacy for spinal metastasis are lacking.

METHODS

We retrospectively reviewed clinical data from 154 consecutive patients registered in our institute who underwent separation surgery for spinal metastases from January 2017 to December 2019. Forty-nine patients received MISS and 105 patients had TOS. The demographic and perioperative data were collected and compared between two approaches.

RESULTS

There were no significant differences in baseline characteristics between the MISS and TOS group, except the sex (P = 0.04). The mean intraoperative blood loss in MISS group was lower than that in TOS group (748.57 vs. 950.48 mL, P = 0.039). The operative time was comparable between both groups (mean 213.45 vs. 221.03 minutes, P = 0.78). The postoperative drainage before discharge in MISS group was remarkably less than that in TOS group (mean 494.02 vs. 1099.10 mL, P = 0.0004). As compared to TOS group, patients in MISS group had lower complication rate, although the difference is not significant (9.52% vs. 6.12%, P = 0.55). The infection rate of MISS group was two-fold lower than that in the TOS group, although the difference is not significant (P = 0.43). The mean hospital stay of MISS group is 7.35 days, which is significantly shorter than TOS group (9.94 days, P = 0.0007). Patients in both groups exhibited similar postoperative neurological outcomes.

CONCLUSION

MISS is a safe and effective technique that could be considered the optimal treatment for patients with spinal metastasis and myelopathy and thus is an excellent alternative in managing thoracolumbar spine metastasis.

LEVEL OF EVIDENCE

3.

Prognostic Significance of a Novel Score Model Based on Preoperative Indicators in Patients with Breast Cancer Spine Metastases (BCSM)

Background

Surgery remains the mainstay of treatment for breast cancer spinal metastasis (BCSM) to relieve symptoms and improve the quality of life of BCSM patients. Therefore, it is important to effectively predict the prognosis of patients to determine whether they can undergo surgical operation. However, the prevalent methods for prognosis evaluation lack specificity and sensitivity for indicated malignancies like breast cancer because they are built on a relatively small number of heterogeneous types of primary tumors. The aim of the present study was to explore a novel predictive model based on the clinical, pathological and blood parameters obtained from BCSM patients before they received surgical intervention.

Methods

Altogether, 144 patients were included in this study. Univariate and multivariate analyses were performed to investigate the significance of preoperative parameters and identify independent factors for prognostic prediction of BCSM. A nomogram for survival prediction was then established and validated. Time-dependent ROC (TDROC) curves were graphed to evaluate the accuracy of the novel model vs other scoring systems including Tomita Score, revised Tokuhashi Score, modified Bauer Score and New England Spinal Metastasis Score. P values <0.05 were considered statistically significant.

Results

Independent factors, including preoperative postmenopausal (P=0.034), visceral metastasIs (P=0.021), preoperative Frankel Score (P=0.001), estrogen receptor status (P=0.014), platelet-to-lymphocyte ratio (P=0.012), lymphocyte-monocyte ratio (P<0.001) and albumin-globulin ratio (P=0.017), were selected into the nomogram model with the C-index of 0.834 (95% CI, 0.789–0.890). TDROC curves showed that the Changzheng Hospital (CZ) Score system had the best performance and exhibited the largest IAUC value in comparison with the other scoring systems.

Conclusion

We constructed a nomogram model known as CZ Score based on the significant factors to predict the prognosis for BCSM patients. The result showed that CZ Score had a better value for prognostic evaluation and surgical decision-making as compared with the other scoring systems.

Clinical efficacy and safety of bone cement combined with radiofrequency ablation in the treatment of spinal metastases

Background

To investigate the clinical efficacy and safety of bone cement combined with radiofrequency ablation (RFA) in the treatment of spinal metastases.

Methods

The medical records of patients with spinal metastatic tumor admitted to our hospital from January 2016 to December 2018 were retrospectively analyzed. Based on different surgical methods, the patients were divided into groups A (treated with RFA combined with bone cement) and B (treated with bone cement only). Group A included 35 patients with 47 segments of diseased vertebral bodies. Group B consisted of 52 patients with 78 vertebral segments. Pain, quality of life score, vertebra height, bone cement leakage, postoperative tumor recurrence, and complications were assessed 3 days and 1 and 6 months after surgery.

Results

All the patients had smooth operation without paraplegia, spinal cord injury, and perioperative death. Visual analogue scales (VAS) and Oswestry Disability Index (ODI) scores of the two groups significantly improved 3 days and 1 month after surgery compared with those before surgery (P < 0.05), but no significant difference was observed between the two groups (P > 0.05). Six months after surgery, the VAS and ODI scores of patients in group A were lower than those in group B, with statistically significant differences (P < 0.05). The postoperative vertebral body height of the two groups significantly increased compared with that before surgery, and the difference was statistically significant (P < 0.05). Meanwhile, no significant difference was observed between the two groups (P > 0.05). Postoperative bone cement permeability in group A was 6.4%, and postoperative tumor recurrence rate was 11.4%. The permeability of bone cement in group B was 20.5%, and the tumor recurrence rate was 30.8%. The bone cement permeability and tumor recurrence rate in group A were lower than those in group B, with statistically significant differences (P < 0.05).

Conclusions

Bone cement combined with RFA for the treatment of spinal metastases can achieve good efficacy, desirable analgesic effect, low incidence of complications, small surgical trauma, and high safety. The proposed method has the value of clinical popularization and application.

Treatment Strategy for Metastatic Spinal Tumors: A Narrative Review

Metastatic spinal tumors are common, and their rising incidence can be attributed to the expanding aging population and increased survival rates among cancer patients. The decision-making process in the treatment of spinal metastasis requires a multidisciplinary approach that includes medical and radiation oncology, surgery, and rehabilitation. Various decision-making systems have been proposed in the literature in order to estimate survival and suggest appropriate treatment options for patients experiencing spinal metastasis. However, recent advances in treatment modalities for spinal metastasis, such as stereotactic radiosurgery and minimally invasive surgical techniques, have reshaped clinical practices concerning patients with spinal metastasis, making a demand for further improvements on current decision-making systems. In this review, recent improvements in treatment modalities and the evolution of decision-making systems for metastatic spinal tumors are discussed.

Making the Most of Systematic Reviews and Meta-analyses in Spine Surgery: A Primer for the Practicing Spine Surgeon

STUDY DESIGN

Review.

OBJECTIVE

To provide practicing spine surgeons a primer with key insights for reading, interpreting, and clinically integrating systematic reviews and meta-analyses.

SUMMARY OF BACKGROUND DATA

Evidence-based medicine (EBM) refers to a family of standardized techniques for critical appraisal of clinical research. Within the contemporary spine literature, EBM is most commonly encountered in the form of systematic reviews and meta-analyses. Although these analytic techniques are potentially useful when appropriately applied to well-formulated questions with adequate primary data in the literature, the rapid and somewhat indiscriminate increase in volume of systematic reviews and meta-analyses published may be associated with an overall dilution in their quality, as well as misperceptions regarding the applicability of particular EBM studies to spine surgery in general.

METHODS

The collective experience of spine specialists with vested interests in advancing EBM and its utility was summarized into a primer.

RESULTS

We emphasize components that are pertinent methodologically (search strategy, study number, meta-analysis, bias, and certainty), and pertinent clinically (outcomes) to interpreting, and clinically integrating systematic reviews and meta-analyses into spine surgery practice.

CONCLUSIONS

Armed with these insights into these five perspectives, we anticipate that practicing spine surgeons will be better equipped to interpret systematic reviews and meta-analyses in a fashion that will meaningfully impact their patient care.

LEVEL OF EVIDENCE

2.

Predicting tumor-specific survival in patients with spinal metastatic renal cell carcinoma: which scoring system is most accurate?

OBJECTIVE

Although several prognostic scores for spinal metastatic disease have been developed in the past 2 decades, the applicability and validity of these models to specific cancer types are not yet clear. Most of the data used for model formation are from small population sets and have not been updated or externally validated to assess their performance. Developing predictive models is clinically relevant as prognostic assessment is crucial to optimal decision-making, particularly the decision for or against spine surgery. In this study, the authors investigated the performance of various spinal metastatic disease risk models in predicting prognosis for spine surgery to treat metastatic renal cell carcinoma (RCC).

METHODS

Data of patients who underwent surgery for RCC metastatic to the spine at 2 tertiary centers between 2010 and 2019 were retrospectively retrieved. The authors determined the prognostic value associated with the following scoring systems: the Tomita score, original and revised Tokuhashi scores, original and modified Bauer scores, Katagiri score, the Skeletal Oncology Research Group (SORG) classic algorithm and nomogram, and the New England Spinal Metastasis Score (NESMS). Regression analysis of patient variables in association with 1-year survival after surgery was assessed using Cox proportional hazard models. Calibration and time-dependent discrimination analysis were tested to quantify the accuracy of each scoring system at 3 months, 6 months, and 1 year.

RESULTS

A total of 86 metastatic RCC patients were included (median age 64 years [range 29-84 years]; 63 males [73.26%]). The 1-year survival rate was 72%. The 1-year survival group had a good performance status (Karnofsky Performance Scale [KPS] score 80%-100%) and an albumin level > 3.5 g/dL (p < 0.05). Multivariable-adjusted Cox regression analysis showed that poor performance status (KPS score < 70%), neurological deficit (Frankel grade A-D), and hypoalbuminemia (< 3.5 g/dL) were associated with a higher risk of death before 1 year (p < 0.05). The SORG nomogram, SORG classic, original Tokuhashi, and original Bauer demonstrated fair performance (0.7 < area under the curve < 0.8). The NESMS differentiates survival among the prognostic categories with the highest accuracy (area under the curve > 0.8).

CONCLUSIONS

The present study shows that the most cited and commonly used scoring systems have a fair performance predicting survival for patients undergoing spine surgery for metastatic RCC. The NESMS had the best performance at predicting 1-year survival after surgery.

Pearls for Interpreting Neurosurgical Systematic Reviews and Meta-Analyses: Lessons From a Collaborative Effort

Systematic reviews and meta-analyses in the neurosurgical literature have surged in popularity over the last decade. It is our concern that, without a renewed effort to critically interpret and appraise these studies as high or low quality, we run the risk of the quality and value of evidence-based medicine in neurosurgery being misinterpreted. Correspondingly, we have outlined 4 major domains to target in interpreting neurosurgical systematic reviews and meta-analyses based on the lessons learned by a collaboration of clinicians and academics summarized as 4 pearls. The domains of (1) heterogeneity, (2) modeling, (3) certainty, and (4) bias in neurosurgical systematic reviews and meta-analyses were identified as aspects in which the authors’ approaches have changed over time to improve robustness and transparency. Examples of how and why these pearls were adapted were provided in areas of cranial neuralgia, spine, pediatric, and neuro-oncology to demonstrate how neurosurgical readers and writers may improve their interpretation of these domains. The incorporation of these pearls into practice will empower neurosurgical academics to effectively interpret systematic reviews and meta-analyses, enhancing the quality of our evidence-based medicine literature while maintaining a critical focus on the needs of the individual patients in neurosurgery.

[Intraoperative and late complications after spinal tumour resection and dorsoventral reconstruction]

BACKGROUND

Spinal tumors are a continuously growing pathology group among the spinal diseases. The often-difficult circumstances increase vulnerability to a wide range of intervention-related complications, which can occur at different times in the course of the disease and must be included in the consideration of the indication.

OBJECTIVES

The aim of the work is to present the wide spectrum of complications in the surgical treatment of spinal tumors, as well as their treatment and prophylaxis through optimal therapy management.

MATERIALS AND METHODS

The article summarizes the current literature.

RESULTS

The literature describes complication rates of 10-67% after metastatic surgery of the spinal column. The most common complications are infections and internal, especially pulmonary, complications. Other relevant complications include surgical positioning/surgical access/instrumentation/mechanical failure, and anesthesiological, neurological, vascular and oncological complications. The socio-economic costs for patients with complications compared to those for patients without complications are twice as high. A special risk situation exists with radical spinal tumor resections. Negative predictors are previous operations, previous irradiation and local recurrences.

CONCLUSIONS

An early, interdisciplinary concept can reduce complications significantly. Due to the planning intensity, surgical expertise and comprehensive structural requirements, treatment in an interdisciplinary tumour centre is necessary.

Lesion positioning method of a CT-guided surgical robotic system for minimally invasive percutaneous lung

BACKGROUND

Robot-assisted puncture has gradually attracted more attention and practical clinical application. The lesion positioning and the needle positioning are the basis to ensure the accuracy of puncture and the key techniques in insertion operation.

METHODS

A lesion positioning method is established which is realized only by the robot-CT system without using external positioning system, and an omnidirectional needle positioning method is also developed and realized by using VRCM, in order to make the puncture needle always keep pointing to the lesion point. A CT-guided surgical robotic system used for minimally invasive percutaneous lung is designed and the physical prototype is manufactured, to perform in-vitro experiments, thereby to validate the effectiveness of the lesion positioning method and the feasibility of omnidirectional needle positioning method.

RESULTS

The accuracy of established lesion positioning method based on three non-collinear markers is within 3 mm, which is similar to that of the least squares method based on the five non-coplanar markers, but the positioning efficiency can be improved by about 40%, and the non-collinearity of markers is easier to be satisfied than non-coplanarity in practical applications. The average calculation error of the established positioning method is 0.997 mm. Moreover, the omnidirectional positioning of the puncture needle under the designed surgical robot is feasible.

CONCLUSIONS

The designed surgical robot has good control accuracy and it can satisfy the requirements for use. The established lesion positioning method can provide a good precision basis for robot-assisted puncture surgery. The suitable insertion point and insertion posture can be determined by the developed omnidirectional needle positioning method. This study can provide theoretical reference for further study of path planning or autonomous positioning.

Stereotactic body radiation therapy and minimally invasive surgery in the management of spinal metastases: a change in the paradigm

The main goal of treatment in spinal metastatic patients is local control of the disease, pain relief and the maintenance of ambulation. Traditionally, wide surgical resection of the tumour followed by adjuvant radiation and/or chemotherapy has been recommended. Currently, single-fraction or hypofractionated stereotactic body radiation therapy (SBRT) yields a one-year local control rate of over 95% with minimum morbidity, even for tumours previously considered radioresistant. In addition, by posterolateral and circumferential decompression and stabilisation of the spinal cord, it is feasible to create a 2 to 3 mm epidural margin between the dura mater and the tumour (separation surgery), enough to deliver safe and ablative doses of SBRT to the vertebrae. As these patients tend to be frail, such interventions should ideally be minimally invasive, thereby reducing surgical aggressiveness and helping to minimise the delay of any systemic therapies.

Current state of minimally invasive spine surgery

Over the past two decades, minimally invasive surgical approaches have become increasingly feasible, efficient and popular for the management of a wide range of spinal disorders, with a growing body of research demonstrating numerous advantages of these techniques over the traditional open approach. In this article, we review the technologies and innovations that are expanding the horizon of minimally invasive spine surgery (MISS), and highlight high-quality peer-reviewed literature in the past year that expands our knowledge and understanding of indications, advantages and limitations of MISS.

Patient-Oriented Aesthetic Outcome After Lumbar Spine Surgery: A 1-Year Follow-Up Prospective Observational Study Comparing Minimally Invasive and Standard Open Procedures

BACKGROUND

Despite recent treatment developments, back pain and related disabilities still represent a challenge for practitioners. Among the available surgical techniques, many different features and outcomes have been investigated; however, aesthetic result was missing among them. The present investigation was designed to prospectively compare patient-oriented aesthetic results after minimally invasive surgery (MIS) and standard open surgery (SOS) for the lumbar spine.

METHODS

This was a prospective observational study with 1-year follow-up. Patients who underwent SOS were assigned to group 1 and MIS to group 2. Patient-oriented aesthetic result evaluation was collected using a dedicated visual aesthetic analogue scale. The Vancouver Scar Scale was used to exclude objective underlying influencing factors. The Oswestry Disability Index and a 10-point itemized visual analogue scale for back pain were administered to assess the clinical and functional status. Follow-up data were collected before discharge at 1, 6, and 12 months. Statistical analysis was conducted, and P < 0.05 was considered as significant.

RESULTS

We enrolled 74 patients, 44 in group 1 and 30 in group 2. The 2 groups were homogeneous for demographic and clinical data. No clinical or functional differences were measured at the end of follow-up. Visual aesthetic analogue scale reported greater mean values in group 1 at every follow-up time.

CONCLUSIONS

Patients seem to prefer the aesthetic result from a single midline incision after SOS compared with MIS. The use of specific techniques could be considered if there is scientific evidence reporting greater aesthetic outcome, having similar clinical and functional ones.