Publications by authors named "Camilo A Molina"

28 Publications

  • Page 1 of 1

Prevalence of spine surgery navigation techniques and availability in Africa: A cross-sectional study.

Ann Med Surg (Lond) 2021 Aug 29;68:102637. Epub 2021 Jul 29.

Department of Neurosurgery, Washington University School of Medicine, St. Louis, Missouri, USA.

Background: Africa has a large burden of spine pathology but has limited and insufficient infrastructure to manage these spine disorders. Therefore, we conducted this e-survey to assess the prevalence and identify the determinants of the availability of spine surgery navigation techniques in Africa.

Materials And Methods: A two-part questionnaire was disseminated amongst African neurological and orthopedic surgery consultants and trainees from January 24 to February 23, 2021. The Chi-Square, Fisher Exact, and Kruskal-Wallis tests were used to evaluate bivariable relationships, and a p-value <0.05 was considered statistically significant.

Results: We had 113 respondents from all regions of Africa. Most (86.7 %) participants who practiced or trained in public centers and centers had an annual median spine case surgery volume of 200 (IQR = 190) interventions. Fluoroscopy was the most prevalent spine surgery navigation technique (96.5 %), followed by freehand (55.8 %), stereotactic without intraoperative CT scan (31.9 %), robotic with intraoperative CT scan (29.2 %), stereotactic with intraoperative CT scan (8.8 %), and robotic without intraoperative CT scan (6.2 %). Cost of equipment (94.7 %), lack of trained staff to service (63.7 %), or run the equipment (60.2 %) were the most common barriers to the availability of spine instrumentation navigation. In addition, there were significant regional differences in access to trained staff to run and service the equipment (P = 0.001).

Conclusion: There is a need to increase access to more advanced navigation techniques, and we identified the determinants of availability.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.amsu.2021.102637DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8346523PMC
August 2021

First in-human report of the clinical accuracy of thoracolumbar percutaneous pedicle screw placement using augmented reality guidance.

Neurosurg Focus 2021 08;51(2):E10

Departments of1Neurosurgery and.

Objective: Augmented reality (AR) is an emerging technology that has great potential for guiding the safe and accurate placement of spinal hardware, including percutaneous pedicle screws. The goal of this study was to assess the accuracy of 63 percutaneous pedicle screws placed at a single institution using an AR head-mounted display (ARHMD) system.

Methods: Retrospective analyses were performed for 9 patients who underwent thoracic and/or lumbar percutaneous pedicle screw placement guided by ARHMD technology. Clinical accuracy was assessed via the Gertzbein-Robbins scale by the authors and by an independent musculoskeletal radiologist. Thoracic pedicle subanalysis was also performed to assess screw accuracy based on pedicle morphology.

Results: Nine patients received thoracic or lumbar AR-guided percutaneous pedicle screws. The mean age at the time of surgery was 71.9 ± 11.5 years and the mean number of screws per patient was 7. Indications for surgery were spinal tumors (n = 4, 44.4%), degenerative disease (n = 3, 33.3%), spinal deformity (n = 1, 11.1%), and a combination of deformity and infection (n = 1, 11.1%). Presenting symptoms were most commonly low-back pain (n = 7, 77.8%) and lower-extremity weakness (n = 5, 55.6%), followed by radicular lower-extremity pain, loss of lower-extremity sensation, or incontinence/urinary retention (n = 3 each, 33.3%). In all, 63 screws were placed (32 thoracic, 31 lumbar). The accuracy for these screws was 100% overall; all screws were Gertzbein-Robbins grade A or B (96.8% grade A, 3.2% grade B). This accuracy was achieved in the thoracic spine regardless of pedicle cancellous bone morphology.

Conclusions: AR-guided surgery demonstrated a 100% accuracy rate for the insertion of 63 percutaneous pedicle screws in 9 patients (100% rate of Gertzbein-Robbins grade A or B screw placement). Using an ARHMS system for the placement of percutaneous pedicle screws showed promise, but further validation using a larger cohort of patients across multiple surgeons and institutions will help to determine the true accuracy enabled by this technology.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2021.5.FOCUS21217DOI Listing
August 2021

Translating Data Analytics Into Improved Spine Surgery Outcomes: A Roadmap for Biomedical Informatics Research in 2021.

Global Spine J 2021 May 11:21925682211008424. Epub 2021 May 11.

Department of Neurological Surgery, 12275Washington University School of Medicine, St. Louis, MO, USA.

Study Design: Narrative review.

Objectives: There is growing interest in the use of biomedical informatics and data analytics tools in spine surgery. Yet despite the rapid growth in research on these topics, few analytic tools have been implemented in routine spine practice. The purpose of this review is to provide a health information technology (HIT) roadmap to help translate data assets and analytics tools into measurable advances in spine surgical care.

Methods: We conducted a narrative review of PubMed and Google Scholar to identify publications discussing data assets, analytical approaches, and implementation strategies relevant to spine surgery practice.

Results: A variety of data assets are available for spine research, ranging from commonly used datasets, such as administrative billing data, to emerging resources, such as mobile health and biobanks. Both regression and machine learning techniques are valuable for analyzing these assets, and researchers should recognize the particular strengths and weaknesses of each approach. Few studies have focused on the implementation of HIT, and a variety of methods exist to help translate analytic tools into clinically useful interventions. Finally, a number of HIT-related challenges must be recognized and addressed, including stakeholder acceptance, regulatory oversight, and ethical considerations.

Conclusions: Biomedical informatics has the potential to support the development of new HIT that can improve spine surgery quality and outcomes. By understanding the development life-cycle that includes identifying an appropriate data asset, selecting an analytic approach, and leveraging an effective implementation strategy, spine researchers can translate this potential into measurable advances in patient care.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/21925682211008424DOI Listing
May 2021

Augmented reality-mediated stereotactic navigation for execution of en bloc lumbar spondylectomy osteotomies.

J Neurosurg Spine 2021 Mar 5:1-6. Epub 2021 Mar 5.

2Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland.

En bloc spinal tumor resections are technically demanding procedures with high morbidity because of the conventionally large exposure area and aggressive resection goals. Stereotactic surgical navigation presents an opportunity to perform the smallest possible resection plan while still achieving an en bloc resection. Augmented reality (AR)-mediated spine surgery (ARMSS) via a mounted display with an integrated tracking camera is a novel FDA-approved technology for intraoperative "heads up" neuronavigation, with the proposed advantages of increased precision, workflow efficiency, and cost-effectiveness. As surgical experience and capability with this technology grow, the potential for more technically demanding surgical applications arises. Here, the authors describe the use of ARMSS for guidance in a unique osteotomy execution to achieve an en bloc wide marginal resection of an L1 chordoma through a posterior-only approach while avoiding a tumor capsule breach. A technique is described to simultaneously visualize the navigational guidance provided by the contralateral surgeon's tracked pointer and the progress of the BoneScalpel aligned in parallel with the tracked instrument, providing maximum precision and safety. The procedure was completed by reconstruction performed with a quad-rod and cabled fibular strut allograft construct, and the patient did well postoperatively. Finally, the authors review the technical aspects of the approach, as well as the applications and limitations of this new technology.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2020.9.SPINE201219DOI Listing
March 2021

Clinical Accuracy, Technical Precision, and Workflow of the First in Human Use of an Augmented-Reality Head-Mounted Display Stereotactic Navigation System for Spine Surgery.

Oper Neurosurg (Hagerstown) 2021 02;20(3):300-309

Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland.

Background: Augmented reality mediated spine surgery is a novel technology for spine navigation. Benchmark cadaveric data have demonstrated high accuracy and precision leading to recent regulatory approval. Absence of respiratory motion in cadaveric studies may positively bias precision and accuracy results and analogous investigations are prudent in live clinical scenarios.

Objective: To report a technical note, accuracy, precision analysis of the first in-human deployment of this technology.

Methods: A 78-yr-old female underwent an L4-S1 decompression, pedicle screw, and rod fixation for degenerative spine disease. Six pedicle screws were inserted via AR-HMD (xvision; Augmedics, Chicago, Illinois) navigation. Intraoperative computed tomography was used for navigation registration as well as implant accuracy and precision assessment. Clinical accuracy was graded per the Gertzbein-Robbins (GS) scale by an independent neuroradiologist. Technical precision was analyzed by comparing 3-dimensional (3D) (x, y, z) virtual implant vs real implant position coordinates and reported as linear (mm) and angular (°) deviation. Present data were compared to benchmark cadaveric data.

Results: Clinical accuracy (per the GS grading scale) was 100%. Technical precision analysis yielded a mean linear deviation of 2.07 mm (95% CI: 1.62-2.52 mm) and angular deviation of 2.41° (95% CI: 1.57-3.25°). In comparison to prior cadaveric data (99.1%, 2.03 ± 0.99 mm, 1.41 ± 0.61°; GS accuracy 3D linear and angular deviation, respectively), the present results were not significantly different (P > .05).

Conclusion: The first in human deployment of the single Food and Drug Administration approved AR-HMD stereotactic spine navigation platform demonstrated clinical accuracy and technical precision of inserted hardware comparable to previously acquired cadaveric studies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ons/opaa398DOI Listing
February 2021

Device profile of the XVision-spine (XVS) augmented-reality surgical navigation system: overview of its safety and efficacy.

Expert Rev Med Devices 2021 Jan 24;18(1):1-8. Epub 2020 Dec 24.

Department of Neurosurgery, Washington University School of Medicine, Saint Louis, USA.

: The field of augmented reality mediated spine surgery is growing rapidly and holds great promise for improving surgical capabilities and patient outcomes. Augmented reality can assist with complex or atypical cases involving challenging anatomy. As neuronavigation evolves, fundamental technical limitations remain in line-of-sight interruption and operator attention shift, which this novel augmented reality technology helps to address.: XVision is a recently FDA-approved head mounted display for intraoperative neuronavigation, compatible with all current conventional pedicle screw technology. The device is a wireless, customizable headset with an integrated surgical tracking system and transparent retinal display. This review discusses the available literature on the safety and efficacy of XVision, as well as the current state of augmented reality technology in spine surgery.: Augmented-reality spine surgery is an emerging technology that may increase precision, efficiency, and safety as well as decrease radiation exposure of manual and robotic computer-navigated pedicle screw insertion techniques. The initial clinical experience with XVision has shown good outcomes and it has received positive operator feedback. Now that initial clinical safety and efficacy has been demonstrated, ongoing experience must be studied to empirically validate this technology and generate further innovation in this rapidly evolving field.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/17434440.2021.1865795DOI Listing
January 2021

A cadaveric precision and accuracy analysis of augmented reality-mediated percutaneous pedicle implant insertion.

J Neurosurg Spine 2020 Oct 30:1-9. Epub 2020 Oct 30.

6The Spine Clinic of Los Angeles, California.

Objective: Augmented reality-mediated spine surgery (ARMSS) is a minimally invasive novel technology that has the potential to increase the efficiency, accuracy, and safety of conventional percutaneous pedicle screw insertion methods. Visual 3D spinal anatomical and 2D navigation images are directly projected onto the operator's retina and superimposed over the surgical field, eliminating field of vision and attention shift to a remote display. The objective of this cadaveric study was to assess the accuracy and precision of percutaneous ARMSS pedicle implant insertion.

Methods: Instrumentation was placed in 5 cadaveric torsos via ARMSS with the xvision augmented reality head-mounted display (AR-HMD) platform at levels ranging from T5 to S1 for a total of 113 total implants (93 pedicle screws and 20 Jamshidi needles). Postprocedural CT scans were graded by two independent neuroradiologists using the Gertzbein-Robbins scale (grades A-E) for clinical accuracy. Technical precision was calculated using superimposition analysis employing the Medical Image Interaction Toolkit to yield angular trajectory (°) and linear screw tip (mm) deviation from the virtual pedicle screw position compared with the actual pedicle screw position on postprocedural CT imaging.

Results: The overall implant insertion clinical accuracy achieved was 99.1%. Lumbosacral and thoracic clinical accuracies were 100% and 98.2%, respectively. Specifically, among all implants inserted, 112 were noted to be Gertzbein-Robbins grade A or B (99.12%), with only 1 medial Gertzbein-Robbins grade C breach (> 2-mm pedicle breach) in a thoracic pedicle at T9. Precision analysis of the inserted pedicle screws yielded a mean screw tip linear deviation of 1.98 mm (99% CI 1.74-2.22 mm) and a mean angular error of 1.29° (99% CI 1.11°-1.46°) from the projected trajectory. These data compare favorably with data from existing navigation platforms and regulatory precision requirements mandating that linear and angular deviation be less than 3 mm (p < 0.01) and 3° (p < 0.01), respectively.

Conclusions: Percutaneous ARMSS pedicle implant insertion is a technically feasible, accurate, and highly precise method.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2020.6.SPINE20370DOI Listing
October 2020

A novel predictive model of intraoperative blood loss in patients undergoing elective lumbar surgery for degenerative pathologies.

Spine J 2020 12 27;20(12):1976-1985. Epub 2020 Jun 27.

Department of Neurosurgery, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA. Electronic address:

Background Context: Intraoperative blood loss (IOBL) is unavoidable during surgery; however, high IOBL is associated with increased morbidity and increased risk for requiring allogenic blood transfusion, itself associated with poorer outcomes.

Purpose: Here we sought to develop and validate a predictive calculator for IOBL that could be used by surgeons to estimate likely blood loss.

Study Design/setting: Retrospective cohort.

Patient Sample: Series of consecutive patients who underwent elective lumbar spine surgery for degenerative pathologies over a 27-month period at a single tertiary care center.

Outcome Measures: Primary outcome was IOBL. Secondary outcome was the occurrence of "major intraoperative bleeding," defined as IOBL exceeding 1 L.

Methods: Charts of included patients were reviewed for medical comorbidities, preoperative laboratory data, surgical plan, and anesthesia records. Univariate linear regressions were performed to find significant predictors of IOBL, which were then subjected to a multivariate analysis to identify the final model. Model training was performed using 70% of the included cohort and external validation was performed using 30% of the cohort. Results of the model were deployed as a freely available online calculator.

Results: We identified 1,281 patients who met inclusion/exclusion criteria. Mean age was 60±15 years, mean Charlson Comorbidity score was 1.1±1.6, and 51.8% were male. There were no significant differences between the training and validation cohorts with regard to any of the demographic variables or intraoperative variables; tranexamic acid use and surgical invasiveness were also similar in both cohorts. Multivariate analysis identified body mass index (βₙ=7.14; 95% confidence interval [3.15, 11.13]; p<.001), surgical invasiveness (βₙ=29.18; [24.62, 33.74]; p<.001), tranexamic acid use (βₙ=-0.093; [-0.171, -0.014]; p=.02), and surgical duration (βₙ=2.13; [1.75, 2.51]; p<.001) as significant predictors of IOBL. The model had an overall fit of r=0.693 in the validation cohort. Construction of a receiver-operating curve for predicting major IOBL showed a C-statistic of 0.895 within the validation cohort.

Conclusion: Here we identify and validate a model for predicting IOBL in patients undergoing lumbar spine surgery. The model was a moderately strong predictor of absolute IOBL and was demonstrated to predict the occurrence of major IOBL with a high degree of accuracy. We propose it may have future utility when counseling patients about surgical morbidity and the probability of requiring transfusion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.spinee.2020.06.019DOI Listing
December 2020

Use of Intraoperative Indocyanine Green Angiography for Feeder Vessel Ligation and En Bloc Resection of Intramedullary Hemangioblastoma.

Oper Neurosurg (Hagerstown) 2019 12;17(6):573-579

Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland.

Background: As vascular tumors, intramedullary hemangioblastomas are associated with significant intraoperative blood loss, making them particularly challenging clinical entities. The use of intraoperative indocyanine green or other fluorescent dyes has previously been described to avoid breaching the tumor capsule, but improved surgical outcomes may result from identifying and ligating the feeder arteries and arterialized draining veins.

Objective: To describe the use of combined preoperative angiography and intraoperative indocyanine green use for the identification of feeder arteries and arterialized draining veins to decrease blood loss in the resection of intramedullary hemangioblastomas.

Methods: A patient with cervical myelopathy secondary to a large C3 hemangioblastoma and cervicothoracic syrinx underwent a C2-3 laminoplasty with resection of the lesion. To reduce intraoperative blood loss and facilitate safe lesion resection, the vascular architecture of the lesion was defined via preoperative digital subtraction angiography and intraoperative use of indocyanine green. The latter permitted ligation of the major and minor feeding arteries and arterialized veins prior to tumor breach, allowing for facile en bloc resection of the lesion.

Results: The lesion was resected en bloc with minimal blood loss (approximately 100 mL) and without intraoperative neuromonitoring signal changes. The patient remained at neurological baseline throughout their stay.

Conclusion: We present a written and media illustration of a technique for intraoperative indocyanine green use in the en bloc resection of intramedullary hemangioblastoma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ons/opz053DOI Listing
December 2019

Augmented reality-assisted pedicle screw insertion: a cadaveric proof-of-concept study.

J Neurosurg Spine 2019 03 29:1-8. Epub 2019 Mar 29.

Departments of1Neurosurgery and.

OBJECTIVE Augmented reality (AR) is a novel technology that has the potential to increase the technical feasibility, accuracy, and safety of conventional manual and robotic computer-navigated pedicle insertion methods. Visual data are directly projected to the operator’s retina and overlaid onto the surgical field, thereby removing the requirement to shift attention to a remote display. The objective of this study was to assess the comparative accuracy of AR-assisted pedicle screw insertion in comparison to conventional pedicle screw insertion methods. METHODS Five cadaveric male torsos were instrumented bilaterally from T6 to L5 for a total of 120 inserted pedicle screws. Postprocedural CT scans were obtained, and screw insertion accuracy was graded by 2 independent neuroradiologists using both the Gertzbein scale (GS) and a combination of that scale and the Heary classification, referred to in this paper as the Heary-Gertzbein scale (HGS). Non-inferiority analysis was performed, comparing the accuracy to freehand, manual computer-navigated, and robotics-assisted computer-navigated insertion accuracy rates reported in the literature. User experience analysis was conducted via a user experience questionnaire filled out by operators after the procedures. RESULTS The overall screw placement accuracy achieved with the AR system was 96.7% based on the HGS and 94.6% based on the GS. Insertion accuracy was non-inferior to accuracy reported for manual computer-navigated pedicle insertion based on both the GS and the HGS scores. When compared to accuracy reported for robotics-assisted computer-navigated insertion, accuracy achieved with the AR system was found to be non-inferior when assessed with the GS, but superior when assessed with the HGS. Last, accuracy results achieved with the AR system were found to be superior to results obtained with freehand insertion based on both the HGS and the GS scores. Accuracy results were not found to be inferior in any comparison. User experience analysis yielded “excellent” usability classification. CONCLUSIONS AR-assisted pedicle screw insertion is a technically feasible and accurate insertion method.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2018.12.SPINE181142DOI Listing
March 2019

First spine surgery utilizing real-time image-guided robotic assistance.

Comput Assist Surg (Abingdon) 2019 12 1;24(1):13-17. Epub 2019 Mar 1.

Department of Neurosurgery, Johns Hopkins School of Medicine , Baltimore , MD , USA.

Robotics in spinal surgery has significant potential benefits for both surgeons and patients, including reduced surgeon fatigue, improved screw accuracy, decreased radiation exposure, greater options for minimally invasive surgery, and less time required to train residents on techniques that can have steep learning curves. However, previous robotic systems have several drawbacks, which are addressed by the innovative ExcelsiusGPS robotic system. The robot is secured to the operating room floor, not the patient. It has a rigid external arm that facilitates direct transpedicular drilling and screw placement, without requiring K-wires. In addition, the ExcelsisuGPS has integrated neuronavigation, not present in other systems. It also has surveillance marker that immediately alerts the surgeon in the event of loss of registration, and a lateral force meter to alert the surgeon in the event of skiving. Here, we present the first spinal surgery performed with the assistance of this newly approved robot. The surgery was performed with excellent screw placement, minimal radiation exposure to the patient and surgeon, and the patient had a favorable outcome. We report the first operative case with the ExcelsisuGPS, and the first spine surgery utilizing real-time image-guided robotic assistance.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/24699322.2018.1542029DOI Listing
December 2019

Multidisciplinary surgical planning for en bloc resection of malignant primary cervical spine tumors involving 3D-printed models and neoadjuvant therapies: report of 2 cases.

J Neurosurg Spine 2019 Jan 18:1-8. Epub 2019 Jan 18.

1Department of Neurosurgery, The Johns Hopkins School of Medicine, Baltimore, Maryland; and.

Effective en bloc resection of primary spinal tumors necessitates careful consideration of adjacent anatomical structures in order to achieve negative margins and reduce surgical morbidity. This can be particularly challenging in the cervical spine, where vital neurovascular and connective tissues are present in the region. Early multidisciplinary surgical planning that includes clinicians and engineers can both optimize surgical planning and enable a more feasible resection with oncological margins. The aim of the current work was to demonstrate two cases that involved multidisciplinary surgical planning for en bloc resection of primary cervical spine tumors, successfully utilizing 3D-printed patient models and neoadjuvant therapies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2018.9.SPINE18607DOI Listing
January 2019

Pedicle screw accuracy assessment in ExcelsiusGPS® robotic spine surgery: evaluation of deviation from pre-planned trajectory.

Chin Neurosurg J 2018 3;4:23. Epub 2018 Sep 3.

Department of Neurosurgery, The Johns Hopkins School of Medicine, The Johns Hopkins Hospital, 600 N. Wolfe Street, Meyer 7-113, Baltimore, MD 21287 USA.

Background: The ExcelsiusGPS® (Globus Medical, Inc., Audubon, PA) is a next-generation spine surgery robotic system recently approved for use in the United States. The objective of the current study is to assess pedicle screw accuracy and clinical outcomes among two of the first operative cases utilizing the ExcelsiusGPS® robotic system and describe a novel metric to quantify screw deviation.

Methods: Two patients who underwent lumbar fusion at a single institution with the ExcelsiusGPS® surgical robot were included. Pre-operative trajectory planning was performed from an intra-operative CT scan using the O-arm (Medtronic, Inc., Minneapolis, MN). After robotic-assisted screw implantation, a post-operative CT scan was obtained to confirm ideal screw placement and accuracy with the planned trajectory. A novel pedicle screw accuracy algorithm was devised to measure screw tip/tail deviation distance and angular offset on axial and sagittal planes. Screw accuracy was concurrently determined by a blinded neuroradiologist using the traditional Gertzbein-Robbins method. Clinical variables such as symptomatology, operative data, and post-operative follow-up were also collected.

Results: Eight pedicle screws were placed in two L4-L5 fusion cases. Mean screw tip deviation was 2.1 mm (range 0.8-5.2 mm), mean tail deviation was 3.2 mm (range 0.9-5.4 mm), and mean angular offset was 2.4 degrees (range 0.7-3.8 degrees). All eight screws were accurately placed based on the Gertzbein-Robbins scale (88% Grade A and 12% Grade B). There were no cases of screw revision or new post-operative deficit. Both patients experienced improvement in Frankel grade and Karnofsky Performance Status (KPS) score by 6 weeks post-op.

Conclusion: The ExcelsiusGPS® robot allows for precise execution of an intended pre-planned trajectory and accurate screw placement in the first patients to undergo robotic-assisted fusion with this technology.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s41016-018-0131-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7398380PMC
September 2018

Coflex interspinous implant placement leading to synovial cyst development: case report.

J Neurosurg Spine 2018 Sep 15;29(3):265-270. Epub 2018 Jun 15.

1The Spinal Column Biomechanics and Surgical Outcomes Laboratory and.

Interspinous process devices (IPDs) have been developed as less-invasive alternatives to spinal fusion with the goal of decompressing the spinal canal and preserving segmental motion. IPD implantation is proposed to treat symptoms of lumbar spinal stenosis that improve during flexion. Recent indications of IPD include lumbar facet joint syndrome, which is seen in patients with mainly low-back pain. Long-term outcomes in this subset of patients are largely unknown. The authors present a previously unreported complication of coflex (IPD) placement: the development of a large compressive lumbar synovial cyst. A 64-year-old woman underwent IPD implantation (coflex) at L4-5 at an outside hospital for low-back pain that occasionally radiates to the right leg. Postoperatively, her back and right leg pain persisted and worsened. MRI was repeated and showed a new, large synovial cyst at the previously treated level, severely compressing the patient's cauda equina. Four months later, she underwent removal of the interspinous process implant, bilateral laminectomy, facetectomy, synovial cyst resection, interbody fusion, and stabilization. At the 3-month follow-up, she reported significant back pain improvement with some residual leg pain. This case suggests that facet arthrosis may not be an appropriate indication for placement of coflex.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2018.1.SPINE171360DOI Listing
September 2018

Minimally invasive versus conventional spine surgery for vertebral metastases: a systematic review of the evidence.

Ann Transl Med 2018 Mar;6(6):103

Department of Neurosurgery, Johns Hopkins Hospital, Baltimore, MD, USA.

One of the major determinants of surgical candidacy in patients with symptomatic spinal metastases is the ability of the patient to tolerate the procedure-associated morbidity. In other pathologies, minimally invasive (MIS) procedures have been suggested to have lower intra-operative morbidity while providing similar outcomes. We conducted a systematic review of the PubMed library searching for articles that directly compared the operative and post-operative outcomes of patients treated for symptomatic spinal metastases. Inclusion criteria were articles reporting two or more cases of patients >18 years old treated with MIS or open approaches for spinal metastases. Studies reporting results in spinal metastases patients that could not be disentangled from other pathologies were excluded. Our search returned 1,568 articles, of which 9 articles met the criteria for inclusion. All articles were level III evidence. Patients treated with MIS approaches tended to have lower intraoperative blood loss, shorter operative times, shorter inpatient stays, and fewer complications relative to patients undergoing surgeries with conventional approaches. Patients in the MIS and open groups had similar pain improvement, neurological improvement, and functional outcomes. Recent advances in MIS techniques may reduce surgical morbidity while providing similar symptomatic improvement in patients treated for spinal metastases. As a result, MIS techniques may expand the pool of patients with spinal metastases who are candidates for operative management.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.21037/atm.2018.01.28DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5900071PMC
March 2018

Percentage change in hemoglobin level and morbidity in spine surgery patients.

J Neurosurg Spine 2018 03 22;28(3):345-351. Epub 2017 Dec 22.

Departments of1Neurosurgery and.

OBJECTIVE The aim of this study was to characterize the association between percentage change in hemoglobin (ΔHb)-i.e., the difference between preoperative Hb and in-hospital nadir Hb concentration-and perioperative adverse events among spine surgery patients. METHODS Patients who underwent spine surgery at the authors' institution between December 4, 2008, and June 26, 2015, were eligible for this retrospective study. Patients who underwent the following procedures were included: atlantoaxial fusion, subaxial anterior cervical fusion, subaxial posterior cervical fusion, anterior lumbar fusion, posterior lumbar fusion, lateral lumbar fusion, excision of intervertebral disc, and excision of spinal cord lesion. Data on intraoperative transfusion were obtained from an automated, prospectively collected, anesthesia data management system. Data on postoperative hospital transfusions were obtained through an Internet-based intelligence portal. Percentage ΔHb was defined as: ([preoperative Hb - nadir Hb]/preoperative Hb) × 100. Clinical outcomes included in-hospital morbidity and length of stay associated with percentage ΔHb. RESULTS A total of 3949 patients who underwent spine surgery were identified. Of these, 1204 patients (30.5%) received at least 1 unit of packed red blood cells. The median nadir Hb level was 10.6 g/dl (interquartile range 8.7-12.4 g/dl), yielding a mean percentage ΔHb of 23.6% (SD 15.4%). Perioperative complications occurred in 234 patients (5.9%) and were more common in patients with a larger percentage ΔHb (p = 0.017). Hospital-related infection, which occurred in 60 patients (1.5%), was also more common in patients with greater percentage ΔHb (p = 0.001). CONCLUSIONS Percentage ΔHb is independently associated with a higher risk of developing any perioperative complication and hospital-related infection. The authors' results suggest that percentage ΔHb may be a useful measure for identifying patients at risk for adverse perioperative events.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2017.7.SPINE17301DOI Listing
March 2018

Transfusion of Red Blood Cells Stored More Than 28 Days is Associated With Increased Morbidity Following Spine Surgery.

Spine (Phila Pa 1976) 2018 07;43(13):947-953

Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD.

Study Design: A retrospective study.

Objective: The aim of this study was to describe the association between storage duration of packed red blood cells (PRBCs) and perioperative adverse events in patients undergoing spine surgery at a tertiary care center.

Summary Of Background Data: Despite retrospective studies that have shown that longer PRBC storage duration worsens patient outcomes, randomized clinical trials have found no difference in outcomes. However, no studies have examined the impact of giving the oldest blood (28 days old or more) on morbidity within spine surgery.

Methods: The surgical administrative database at our institution was queried for patients transfused with PRBCs who underwent spine surgery between December 4, 2008, and June 26, 2015. Patients undergoing spinal fusion, tumor-related surgeries, and other identified spine surgeries were included. Patients were divided into two groups on the basis of storage duration of blood transfused: exclusively ≤28 days' storage or exclusively >28 days' storage. The primary outcome was composite in-hospital morbidity, which included (1) infection, (2) thrombotic event, (3) renal injury, (4) respiratory event, and/or (5) ischemic event.

Results: In total, 1141 patients who received a transfusion were included for analysis in this retrospective study; 710 were transfused exclusively with PRBCs ≤28 days' storage and 431 exclusively with PRBCs >28 days' storage. Perioperative complications occurred in 119 patients (10.4%). Patients who received blood stored for >28 days had higher odds of developing any one complication [odds ratio (OR) = 1.82; 95% confidence interval (95% CI), 1.20-2.74; P = 0.005] even after adjusting for competing perioperative risk factors.

Conclusion: Blood stored for >28 days is independently associated with higher odds of developing perioperative complications in patients transfused during spinal surgery. Our results suggest that blood storage duration may be an appropriate parameter to consider when developing institutional transfusion guidelines that seek to optimize patient outcomes.

Level Of Evidence: 3.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/BRS.0000000000002464DOI Listing
July 2018

Systematic Review of the Outcomes of Surgical Treatment of Prostate Metastases to the Spine.

Global Spine J 2017 Aug 1;7(5):460-468. Epub 2017 Jun 1.

Johns Hopkins University, Baltimore, MD, USA.

Study Design: Systematic review.

Objective: Surgical decompression and reconstruction of symptomatic spinal metastases has improved the quality of life in cancer patients. However, most data has been collected on cohorts of patients with mixed tumor histopathology. We systematically reviewed the literature for prognostic factors specific to the surgical treatment of prostate metastases to the spine.

Methods: A systemic review of the literature was conducted to answer the following questions: Question 1. Describe the survival and functional outcomes of surgery or vertebral augmentation for prostate metastases to the spine. Question 2. Determine whether overall tumor burden, Gleason score, preoperative functional markers, and hormonal naivety favor operative intervention. Question 3. Establish whether clinical outcomes vary with the evolution of operative techniques.

Results: A total of 16 studies met the preset inclusion criteria. All included studies were retrospective series with a level of evidence of IV. Included studies consistently showed a large effect of hormone-naivety on overall survival. Additionally, studies consistently demonstrated an improvement in motor function and the ability to maintain/regain ambulation following surgery resulting in moderate strength of recommendation. All other parameters were of insufficient or low strength.

Conclusions: There is a dearth of literature regarding the surgical treatment of prostate metastases to the spine, which represents an opportunity for future research. Based on existing evidence, it appears that the surgical treatment of prostate metastases to the spine has consistently favorable results. While no consistent preoperative indicators favor nonoperative treatment, hormone-naivety and high Karnofsky performance scores have positive effects on survival and clinical outcomes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/2192568217710911DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5544163PMC
August 2017

Outcomes following attempted en bloc resection of cervical chordomas in the C-1 and C-2 region versus the subaxial region: a multiinstitutional experience.

J Neurosurg Spine 2014 Sep 13;21(3):348-56. Epub 2014 Jun 13.

Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland;

Object: Chordomas involving the mobile spine are ideally managed via en bloc resection with reconstruction to optimize local control and possibly offer cure. In the cervical spine, local anatomy poses unique challenges, limiting the feasibility of aggressive resection. The authors present a multi-institutional series of 16 cases of cervical chordomas removed en bloc. Particular attention was paid to clinical outcome, complications, and recurrence. In addition, outcomes were assessed according to position of tumor at the C1-2 level versus the subaxial (SA) spine (C3-7).

Methods: The authors reviewed cases involving patients who underwent en bloc resection of cervical chordoma at 4 large spine centers. Patients were included if the lesion epicenter involved the C-1 to C-7 vertebral bodies. Demographic data and details of surgery, follow-up course, exposure to adjuvant therapy, and complications were obtained. Outcome was correlated with presence of tumor in C1-2 versus subaxial spine via a Student t-test.

Results: Sixteen patients were identified (mean age at presentation 55 ± 14 years). Seven cases (44%) cases involved C1-2, and 16 involved the subaxial spine. Median survival did not differ significantly different between the C1-2 (72 months) and SA (60 months) groups (p = 0.65). A combined (staged anteroposterior) approach was used in 81% of the cases. Use of the combined approach was significantly more common in treatment of subaxial than C1-2 tumors (100% vs 57%, p = 0.04). En bloc resection was attempted via an anterior approach in 6% of cases (C1-2: 14.3%; SA: 0%; p = 0.17) and a posterior approach in 13% of cases (C1-2: 29%; SA: 0%; p = 0.09). The most commonly reported margin classification was marginal (56% of cases), followed by violated (25%) and wide (19%). En bloc excision of subaxial tumors was significantly more likely to result in marginal margins than excision of C1-2 tumors (C1-2: 29%; SA: 78%; p = 0.03). C1-2 tumors were associated with significantly higher rates of postoperative complications (C1-2: 71%; SA: 22%; p = 0.03). Both local and distant tumor recurrence was greatest for C1-2 tumors (local C1-2: 29%; local SA: 11%; distant C1-2: 14%; distant SA: 0%). Statistical analysis of tumor recurrence based on tumor location was not possible due to the small number of cases. There was no between-groups difference in exposure to postoperative adjuvant radiotherapy. There was no difference in median survival between groups receiving proton beam radiotherapy or intensity-modulated radiotherapy versus no radiation therapy (p = 0.8).

Conclusions: Compared with en bloc resection of chordomas involving the subaxial cervical spine, en bloc resection of chordomas involving the upper cervical spine (C1-2) is associated with poorer outcomes, such as less favorable margins, higher rates of complications, and increased tumor recurrence. Data from this cohort do not support a statistically significant difference in survival for patients with C1-2 versus subaxial disease, but larger studies are needed to further study survival differences.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2014.5.SPINE121045DOI Listing
September 2014

Characterization of intratumor magnetic nanoparticle distribution and heating in a rat model of metastatic spine disease.

J Neurosurg Spine 2014 Jun 4;20(6):740-50. Epub 2014 Apr 4.

Departments of Neurosurgery.

Object: The goal of this study was to optimize local delivery of magnetic nanoparticles in a rat model of metastatic breast cancer in the spine for tumor hyperthermia while minimizing systemic exposure.

Methods: A syngeneic mammary adenocarcinoma was implanted into the L-6 vertebral body of 69 female Fischer rats. Suspensions of 100-nm starch-coated iron oxide magnetic nanoparticles (micromod Partikeltechnologie GmbH) were injected into tumors 9 or 13 days after implantation. For nanoparticle distribution studies, tissues were harvested from a cohort of 36 rats, and inductively coupled plasma mass spectrometry and histopathological studies with Prussian blue staining were used to analyze the samples. Intratumor heating was tested in 4 anesthetized animals with a 20-minute exposure to an alternating magnetic field (AMF) at a frequency of 150 kHz and an amplitude of 48 kA/m or 63.3 kA/m. Intratumor and rectal temperatures were measured, and functional assessments of AMF-exposed animals and histopathological studies of heated tumor samples were examined. Rectal temperatures alone were tested in a cohort of 29 rats during AMF exposure with or without nanoparticle administration. Animal studies were completed in accordance with the protocols of the University Animal Care and Use Committee.

Results: Nanoparticles remained within the tumor mass within 3 hours of injection and migrated into the bone at 6, 12, and 24 hours. Subarachnoid accumulation of nanoparticles was noted at 48 hours. No evidence of lymphoreticular nanoparticle exposure was found on histological investigation or via inductively coupled plasma mass spectrometry. The mean intratumor temperatures were 43.2°C and 40.6°C on exposure to 63.3 kA/m and 48 kA/m, respectively, with histological evidence of necrosis. All animals were ambulatory at 24 hours after treatment with no evidence of neurological dysfunction.

Conclusions: Locally delivered magnetic nanoparticles activated by an AMF can generate hyperthermia in spinal tumors without accumulating in the lymphoreticular system and without damaging the spinal cord, thereby limiting neurological dysfunction and minimizing systemic exposure. Magnetic nanoparticle hyperthermia may be a viable option for palliative therapy of spinal tumors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2014.2.SPINE13142DOI Listing
June 2014

Alveolar soft-part sarcoma in the sacrum: a case report and review of the literature.

Skeletal Radiol 2014 Jan 4;43(1):115-20. Epub 2013 Oct 4.

The Johns Hopkins Hospital, 1550 Orleans Street CRB II Room 264, Baltimore, MD, 21207, USA.

Alveolar soft part sarcoma (ASPS) is a rare disease of the soft tissue. Although the disease is rare, it is refractory to chemotherapy and radiation. En bloc surgical resection offers the best chance of cure. In this article we report the case of a 28-year-old woman who presented with buttock and leg pain, bowel, bladder and gait impairment and a large mass in the sacrum. Following surgical excision, the lesion was proven to be ASPS. On pathology, the mass was TFE3 (transcription factor E3) positive, indicating the presence of the ASPL-TFE3 (novel gene-transcription factor) translocation. Following surgery, the patient had improvement in her pain and ambulation; however, she refused adjuvant therapy to pursue hospice care and succumbed to her disease 2 years after surgery. On a review of the literature, it was found that ASPS of the bone constitutes a rare and formidable subset of this disease. Further, metastases related to ASPS are common in the lungs, liver, brain, and lymph nodes. The degree of dissemination is a predictor of outcome, with 5-year survival of 81-88% in patients with local disease and only 20-46% in patients with metastatic disease at the time of presentation. Brain metastases at the time of presentation portend the worst prognosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00256-013-1737-xDOI Listing
January 2014

A rat model of metastatic spinal cord compression using human prostate adenocarcinoma: histopathological and functional analysis.

Spine J 2013 Nov 28;13(11):1597-606. Epub 2013 Jun 28.

Department of Neurosurgery, Johns Hopkins University School of Medicine, 600 N. Wolfe St, Meyer 7-109, Baltimore, MD 21287, USA.

Background Context: Cancer is a major global public health problem responsible for one in every four deaths in the United States. Prostate cancer alone accounts for 29% of all cancers in men and is the sixth leading cause of death in men. It is estimated that up to 30% of patients with cancer will develop metastatic disease, the spine being one of the most frequently affected sites in patients with prostate cancer.

Purpose: To study this condition in a preclinical setting, we have created a novel animal model of human metastatic prostate cancer to the spine and have characterized it histologically, functionally, and via bioluminescence imaging.

Study Design: Translational science investigation of animal model of human prostate cancer in the spine.

Methods: Luciferase-positive human prostate tumor cells PC3 (PC3-Luc) were injected in the flank of athymic male rats. PC3-Luc tumor samples were then implanted into the L5 vertebral body of male athymic rats (5 weeks old). Thirty-two rats were randomized into three surgical groups: experimental, control, and sham. Tumor growth was assessed qualitatively and noninvasively via bioluminescence emission, upon luciferin injection. To determine the functional impact of tumor growth in the spine, rats were evaluated for gait abnormalities during gait locomotion using video-assisted gait analysis. Rats were euthanized 22 days after tumor implantation, and spines were subjected to histopathological analyses.

Results: Twenty days after tumor implantation, the tumor-implanted rats showed distinct signs of gait disturbances: dragging tail, right- or left-hind limb uncoordination, and absence of toe clearance during forward limb movement. At 20 days, all rats experienced tumor growth, evidenced by bioluminescent signal. Locomotion parameters negatively affected in tumor-implanted rats included stride length, velocity, and duration. At necropsy, all spines showed evidence of tumor growth, and the histological analysis found spinal cord compression and peritumoral osteoblastic reaction characteristic of bony prostate tumors. None of the rats in the sham or control groups demonstrated any evidence of bioluminescence signal or signs of gait disturbances.

Conclusions: In this project, we have developed a novel animal model of metastatic spine cancer using human prostate cancer cells. Tumor growth, evaluated via bioluminescence and corroborated by histopathological analyses, affected hind limb locomotion in ways that mimic motor deficits present in humans afflicted with metastatic spine disease. Our model represents a reliable method to evaluate the experimental therapeutic approaches of human tumors of the spine in animals. Gait locomotion and bioluminescence analyses can be used as surrogate noninvasive methods to evaluate tumor growth in this model.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.spinee.2013.05.021DOI Listing
November 2013

A cohort cost analysis of lumbar laminectomy--current trends in surgeon and hospital fees distribution.

Spine J 2013 Nov 23;13(11):1434-7. Epub 2013 Apr 23.

Department of Neurosurgery, The Johns Hopkins University School of Medicine, Meyer 7-109 600 N. Wolfe St, Baltimore, MD 21287, USA.

Background Context: Spine-related health-care expenditures accounted for $86 billion dollars in 2005, a 65% increase from 1997. However, when adjusting for inflation, surgeons have seen decreased reimbursement rates over the last decade.

Purpose: To assess contribution of surgeon fees to overall procedure cost, we reviewed the charges and reimbursements for a noninstrumented lumbar laminectomy and compared the amounts reimbursed to the hospital and to the surgeon at a major academic institution.

Study Design/setting: Retrospective review of costs associated with lumbar laminectomies.

Patient Sample: Seventy-seven patients undergoing lumbar laminectomy for spinal stenosis throughout an 18-month period at a single academic medical center were included in this study.

Outcome Measures: Cost and number of laminectomy levels.

Methods: The reimbursement schedule of six academic spine surgeons was collected over 18 months for performed noninstrumented lumbar laminectomy procedures. Bills and collections by the hospital and surgeon professional fees were comparatively analyzed and substratified by number of laminectomy levels and patient insurance status. Unpaired two-sample Student t test was used for analysis of significant differences.

Results: During an 18-month period, patients underwent a lumbar laminectomy involving on average three levels and stayed in the hospital on average 3.5 days. Complications were uncommon (13%). Average professional fee billing for the surgeon was $6,889±$2,882, and collection was $1,848±$1,433 (28% overall, 30% for private insurance, and 23% for Medicare/Medicaid insurance). Average hospital billing for the inpatient hospital stay minus professional fees from the surgeon was $14,766±$7,729, and average collection on such bills was $13,391±$7,256 (92% overall, 91% for private insurance, and 85% for Medicare/Medicaid insurance).

Conclusion: Based on this analysis, the proportion of overall costs allocated to professional fees for a noninstrumented lumbar laminectomy is small, whereas those allocated to hospital costs are far greater. These findings suggest that the current focus on decreasing physician reimbursement as the principal cost saving strategy will lead to minimal reimbursement for surgeons without a substantial drop in the overall cost of procedures performed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.spinee.2013.03.015DOI Listing
November 2013

Ultrasonic BoneScalpel for osteoplastic laminoplasty in the resection of intradural spinal pathology: case series and technical note.

Neurosurgery 2013 Sep;73(1 Suppl Operative):ons61-6

Department of Neurosurgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA.

Background: Osteoplastic laminoplasty is a well-described technique that may decrease the incidence of progressive kyphosis when used in the setting of intradural spinal cord tumor resection.

Objective: The BoneScalpel by Aesculap (Central Valley, Pennsylvania) is an ultrasonic osteotome that precisely cuts bone while preserving the underlying soft tissues, potentially reducing the risk of dural laceration during laminoplasty. By producing osteotomies as narrow as 0.5 mm, the device may also facilitate postoperative osteointegration.

Methods: A retrospective analysis was conducted of 40 patients (mean age, 38.0 years; range, 4.0-79.7 years) who underwent osteoplastic laminoplasty using the BoneScalpel for the treatment of intradural spinal pathology at the Johns Hopkins Hospital between January 2009 and December 2011. After lesion resection, titanium plates were used to reconstruct the lamina in all cases. The technical results and procedure-related complications were subsequently noted.

Results: Successful laminoplasty was carried out in all 40 patients. Intraoperatively, 1 case of incidental durotomy was noted after use of the device, which was repaired primarily without neurological or clinical sequelae. During the follow-up period (mean, 195 days; median, 144 days), there were 2 complications (1 cerebrospinal fluid leak, 1 seroma) and no cases of immediate postoperative instability.

Conclusion: The BoneScalpel is a safe and technically feasible device for performing osteoplastic laminoplasty.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1227/NEU.0b013e318283c98bDOI Listing
September 2013

A systematic review of the current role of minimally invasive spine surgery in the management of metastatic spine disease.

Int J Surg Oncol 2011 2;2011:598148. Epub 2011 Jun 2.

Department of Neurosurgery, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Meyer Building 5-185a, Baltimore, MD 21287, USA.

Although increasingly aggressive decompression and resection methods have resulted in improved outcomes for patients with metastatic spine disease, these aggressive surgeries are not feasible for patients with numerous comorbid conditions. Such patients stand to benefit from management via minimally invasive spine surgery (MIS), given its association with decreased perioperative morbidity. We performed a systematic review of literature with the goal of evaluating the clinical efficacy and safety of MIS in the setting of metastatic spine disease. Results suggest that MIS is an efficacious means of achieving neurological improvement and alleviating pain. In addition, data suggests that MIS offers decreased blood loss, operative time, and complication rates in comparison to standard open spine surgery. However, due to the paucity of studies and low class of available evidence, the ability to draw comprehensive conclusions is limited. Future investigations should be conducted comparing standard surgery versus MIS in a prospective fashion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2011/598148DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3263667PMC
August 2012

Delayed onset of paralysis and slowed tumor growth following in situ placement of recombinant human bone morphogenetic protein 2 within spine tumors in a rat model of metastatic breast cancer.

J Neurosurg Spine 2012 Apr 20;16(4):365-72. Epub 2012 Jan 20.

Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.

Object: Recombinant human bone morphogenetic proteins (rhBMPs) are FDA-approved for specific spinal fusion procedures, but their use is contraindicated in spine tumor resection beds because of an unclear interaction between tumor tissue and such growth factors. Interestingly, a number of studies have suggested that BMPs may slow the growth of adenocarcinomas in vitro, and these lesions represent the majority of bony spine tumors. In this study, the authors hypothesized that rhBMP-2 placed in an intraosseous spine tumor in the rat could suppress tumor and delay the onset of paresis in such animals.

Methods: Twenty-six female nude athymic rats were randomized into an experimental group (Group 1) or a positive control group (Group 2). Group 1 (tumor + 15 μg rhBMP-2 sponge, 13 rats) underwent transperitoneal exposure and implantation of breast adenocarcinoma (CRL-1666) into the L-6 spine segment, followed by the implantation of a bovine collagen sponge impregnated with 15 μg of rhBMP-2. Group 2 (tumor + 0.9% NaCl sponge, 13 rats) underwent transperitoneal exposure and tumor implantation in the lumbar spine but no local treatment with rhBMP-2. An additional 8 animals were randomized into 2 negative control groups (Groups 3 and 4). Group 3 (15 μg rhBMP-2 sponge, 4 rats) and Group 4 (0.9% NaCl sponge, 4 rats) underwent transperitoneal exposure of the lumbar spine along with the implantation of rhBMP-2- and saline-impregnated bovine collagen sponges, respectively. Neither of the negative control groups was implanted with tumor. The Basso-Beattie-Bresnahan (BBB) scale was used to monitor daily motor function regression and the time to paresis (BBB score ≤ 7).

Results: In comparison with the positive control animals (Group 2), the experimental animals (Group 1) had statistically significant longer mean (25.8 ± 12.2 vs 13 ± 1.4 days, p ≤ 0.001) and median (20 vs 13 days) times to paresis. In addition, the median survival time was significantly longer in the experimental animals (20 vs 13.5 days, p ≤ 0.0001). Histopathological analysis demonstrated bone growth and tumor inhibition in the experimental animals, whereas bone destruction and cord compression were observed in the positive control animals. Neither of the negative control groups (Groups 3 and 4) demonstrated any evidence of neurological deterioration, morbidity, or cord compromise on either gross or histological analysis.

Conclusions: This study shows that the local administration of rhBMP-2 (15 μg, 10 μl of 1.5-mg/ml solution) in a rat spine tumor model of breast cancer not only fails to stimulate local tumor growth, but also decreases local tumor growth and delays the onset of paresis in rats. This preclinical experiment is the first to show that the local placement of rhBMP-2 in a spine tumor bed may slow tumor progression and delay associated neurological decline.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2011.12.SPINE11496DOI Listing
April 2012

Diagnosis and management of metastatic cervical spine tumors.

Orthop Clin North Am 2012 Jan 22;43(1):75-87, viii-ix. Epub 2011 Oct 22.

Department of Neurosurgery, Johns Hopkins University, 600 North Wolfe Street, Baltimore, MD 21287, USA.

The bony spine is overall the third most common site for distant cancer metastasis, with the cervical spine involved in approximately 8 to 20% of metastatic spine disease cases. Diagnosis and management of metastatic spine disease requires disease categorization into the compartment involved, pathology of the lesion, and anatomic region involved. The diagnostic approach should commence with careful physical examination, and the workup should include plain radiographs, magnetic resonance imaging, computed tomography, and bone scintigraphy. Management ranges from palliative nonoperative to aggressive surgical treatment. Optimal management requires proper patient selection to individualize the most appropriate treatment modality.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ocl.2011.08.004DOI Listing
January 2012
-->