Novel Standalone Motion-Sparing Pelvic Fixation Prevents Short-Term Insufficiency Fractures After Midsacrectomies Without Sacrificing Normal, Mobile Lumbar Segments Traditionally Used for Stabilization

BACKGROUND AND OBJECTIVES

Sacrectomy is often the treatment of choice to provide the greatest chance of progression-free and overall survival for patients with primary malignant bone tumors of the sacrum. After midsacrectomy, the stability of the sacropelvic interface is diminished, resulting in insufficiency fractures. Traditional stabilization involves lumbopelvic fixation but subjects normal mobile segments to fusion. The purpose of this study was to determine whether standalone intrapelvic fixation is a safe adjunct to midsacrectomy, avoiding both sacral insufficiency fractures and the morbidity of instrumenting into the mobile spine.

METHODS

A retrospective study identified all patients who underwent resection of sacral tumors at 2 comprehensive cancer centers between June 2020 and July 2022. Demographic, tumor-specific, operative characteristics and outcome data were collected. The primary outcome was presence of sacral insufficiency fractures. A retrospective data set of patients undergoing midsacrectomy without hardware placement was collected as a control.

RESULTS

Nine patients (5 male, 4 female), median age 59 years, underwent midsacrectomy with concomitant placement of standalone pelvic fixation. No patients developed insufficiency fractures during the 216 days of clinical and 207 days of radiographic follow-up. There were no adverse events attributable to the addition of standalone pelvic fixation. In our historical cohort of partial sacrectomies without stabilization, there were 4/25 patients (16%) with sacral insufficiency fractures. These fractures appeared between 0 and 5 months postoperatively.

CONCLUSION

A novel standalone intrapelvic fixation after partial sacrectomy is a safe adjunct to prevent postoperative sacral insufficiency fractures in patients undergoing midsacrectomy for tumor. Such a technique may allow for long-term sacropelvic stability without sacrificing mobile lumbar segments.

Low-Intensity Pulsed Ultrasound Neuromodulation of a Rodent's Spinal Cord Suppresses Motor Evoked Potentials

OBJECTIVE

Here we investigate the ability of low-intensity ultrasound (LIUS) applied to the spinal cord to modulate the transmission of motor signals.

METHODS

Male adult Sprague-Dawley rats (n = 10, 250-300 g, 15 weeks old) were used in this study. Anesthesia was initially induced with 2% isoflurane carried by oxygen at 4 L/min via a nose cone. Cranial, upper extremity, and lower extremity electrodes were placed. A thoracic laminectomy was performed to expose the spinal cord at the T11 and T12 vertebral levels. A LIUS transducer was coupled to the exposed spinal cord, and motor evoked potentials (MEPs) were acquired each minute for either 5- or 10-minutes of sonication. Following the sonication period, the ultrasound was turned off and post-sonication MEPs were acquired for an additional 5 minutes.

RESULTS

Hindlimb MEP amplitude significantly decreased during sonication in both the 5- (p < 0.001) and 10-min (p = 0.004) cohorts with a corresponding gradual recovery to baseline. Forelimb MEP amplitude did not demonstrate any statistically significant changes during sonication in either the 5- (p = 0.46) or 10-min (p = 0.80) trials.

CONCLUSION

LIUS applied to the spinal cord suppresses MEP signals caudal to the site of sonication, with recovery of MEPs to baseline after sonication.

SIGNIFICANCE

LIUS can suppress motor signals in the spinal cord and may be useful in treating movement disorders driven by excessive excitation of spinal neurons.

Novel Approach of Femur Shortening With Insertion of Expandable Rod to Achieve End-to-End Repair of Sciatic Nerve Laceration

BACKGROUND

Sciatic nerve injuries are challenging for diagnosis and treatment. Particularly in proximally located high-grade injuries, neurorrhaphy often has poor outcomes. Most advocate autologous grafting and some more recently have suggested the value of knee flexion braces to facilitate end-to-end repair.

OBJECTIVE

To describe a case of femur shortening to facilitate tension-free, end-to-end sciatic nerve neurorrhaphy.

METHODS

The patient was a 17-year-old man who was injured by the propeller of a motor boat and suffered a series of lacerations to both lower extremities including transection of his right sciatic nerve in the proximal thigh. After extensive mobilization of the nerve, a greater than 7-cm gap was still present. The patient was treated with femur shortening to facilitate end-to-end coaptation. He subsequently had an expandable rod placed which was lengthened 1 mm per day until his leg length was symmetric.

RESULTS

Within 7 months postoperatively, the patient had an advancing Tinel sign and paresthesias to the dorsum of his foot. Nine months postoperatively, he had early mobility in his plantarflexion.

CONCLUSION

We present a novel method of femur shortening with insertion of an expandable rod to facilitate direct end-to-end and tension-free sciatic nerve neurorrhaphy in a proximally located injury. Furthermore, larger scale and comparative studies are warranted to further explore this and other techniques.

First Experience With Postoperative Transcranial Ultrasound Through Sonolucent Burr Hole Covers in Adult Hydrocephalus Patients

BACKGROUND

Managing patients with hydrocephalus and cerebrospinal fluid (CSF) disorders requires repeated head imaging. In adults, it is typically computed tomography (CT) or less commonly magnetic resonance imaging (MRI). However, CT poses cumulative radiation risks and MRI is costly. Ultrasound is a radiation-free, relatively inexpensive, and optionally point-of-care alternative, but is prohibited by very limited windows through an intact skull.

OBJECTIVE

To describe our initial experience with transcutaneous transcranial ultrasound through sonolucent burr hole covers in postoperative hydrocephalus and CSF disorder patients.

METHODS

Using cohort study design, infection and revision rates were compared between patients who underwent sonolucent burr hole cover placement during new ventriculoperitoneal shunt placement and endoscopic third ventriculostomy over the 1-year study time period and controls from the period 1 year before. Postoperatively, trans-burr hole ultrasound was performed in the clinic, at bedside inpatient, and in the radiology suite to assess ventricular anatomy.

RESULTS

Thirty-seven patients with sonolucent burr hole cover were compared with 57 historical control patients. There was no statistically significant difference in infection rates between the sonolucent burr hole cover group (1/37, 2.7%) and the control group (0/57, P = .394). Revision rates were 13.5% vs 15.8% (P = 1.000), but no revisions were related to the burr hole or cranial hardware.

CONCLUSION

Trans-burr hole ultrasound is feasible for gross evaluation of ventricular caliber postoperatively in patients with sonolucent burr hole covers. There was no increase in infection rate or revision rate. This imaging technique may serve as an alternative to CT and MRI in the management of select patients with hydrocephalus and CSF disorders.

Ultrasound monitoring of microcirculation: An original study from the laboratory bench to the clinic

OBJECTIVE

Monitoring microcirculation and visualizing microvasculature are critical for providing diagnosis to medical professionals and guiding clinical interventions. Ultrasound provides a medium for monitoring and visualization; however, there are challenges due to the complex microscale geometry of the vasculature and difficulties associated with quantifying perfusion. Here, we studied established and state-of-the-art ultrasonic modalities (using six probes) to compare their detection of slow flow in small microvasculature.

METHODS

Five ultrasonic modalities were studied: grayscale, color Doppler, power Doppler, superb microvascular imaging (SMI), and microflow imaging (MFI), using six linear probes across two ultrasound scanners. Image readability was blindly scored by radiologists and quantified for evaluation. Vasculature visualization was investigated both in vitro (resolution and flow characterization) and in vivo (fingertip microvasculature detection).

RESULTS

Superb Microvascular Imaging (SMI) and Micro Flow Imaging (MFI) modalities provided superior images when compared with conventional ultrasound imaging modalities both in vitro and in vivo. The choice of probe played a significant difference in detectability. The slowest flow detected (in the lab) was 0.1885 ml/s and small microvasculature of the fingertip were visualized.

CONCLUSIONS

Our data demonstrated that SMI and MFI used with vascular probes operating at higher frequencies provided resolutions acceptable for microvasculature visualization, paving the path for future development of ultrasound devices for microcirculation monitoring.

Nerve Root Sparing En Bloc Resection of Sacral Chondrosarcoma: Technical Note and Review of the Literature

BACKGROUND

Total en bloc sacrectomy provides the best long-term local control for large primary bony sacral tumors, but often requires lumbosacral nerve root sacrifice leading to loss of ambulation and/or bowel, bladder, and/or sexual dysfunction. Nerve-sparing techniques may be an option for some patients that avoid these outcomes and accordingly improve postoperative quality of life.

OBJECTIVE

To describe the technique for a posterior-only en bloc hemisacrectomy with maximal nerve root preservation and to summarize the available literature.

METHODS

A 38-yr-old woman with a 7.7 × 5.4 × 4.5 cm biopsy-proven grade 2 chondrosarcoma involving the left L5-S2 posterior elements underwent a posterior-only left hemisacrectomy tri-rod L3-pelvis fusion. A systematic review of the English literature was also conducted to identify other descriptions of high sacrectomy with distal sacral nerve root preservation.

RESULTS

Computer-aided navigation facilitated an extracapsular resection that allowed preservation of the left-sided L5 and S3-Co roots. Negative margins were achieved and postoperatively the patient retained ambulation and good bowel/bladder function. Imaging at 9-mo follow-up showed no evidence of recurrence. The systematic review identified 4 prior publications describing 6 total patients who underwent nerve-sparing sacral resection. Enneking-appropriate resection was only obtained in 1 case though.

CONCLUSION

Here we describe a technique for distal sacral nerve root preservation during en bloc hemisacrectomy for a primary sacral tumor. Few prior descriptions exist, and the present technique may help to reduce the neurological morbidity of sacral tumor surgery.

Sacroplasty Augmentation of Instrumented Pelvic Reconstruction After High Sacrectomy: A Technical Case Report

BACKGROUND AND IMPORTANCE

En bloc resection of sacral tumors is the most effective treatment to help prevent recurrence. Sacrectomy, however, can be destabilizing, depending on the extent of resection. Various surgical techniques for improving stability and enabling early ambulation have been proposed.

CLINICAL PRESENTATION

Here, we report a case in which we use PMMA (poly[methyl methacrylate]) to augment pelvic instrumentation to improve mechanical stability after sacrectomy for en bloc resection of a solitary fibrous tumor.

CONCLUSION

We highlight the use of sacroplasty augmentation of pelvic ring reconstruction to provide biomechanical stability without the need for fusion of any mobile spine segments, which allowed for early patient ambulation and no appreciable loss of range of motion or mobility.

Ultrasound in Traumatic Spinal Cord Injury: A Wide-Open Field

Traumatic spinal cord injury (SCI) is a common and devastating condition. In the absence of effective validated therapies, there is an urgent need for novel methods to achieve injury stabilization, regeneration, and functional restoration in SCI patients. Ultrasound is a versatile platform technology that can provide a foundation for viable diagnostic and therapeutic interventions in SCI. In particular, real-time perfusion and inflammatory biomarker monitoring, focal pharmaceutical delivery, and neuromodulation are capabilities that can be harnessed to advance our knowledge of SCI pathophysiology and to develop novel management and treatment options. Our review suggests that studies that evaluate the benefits and risks of ultrasound in SCI are severely lacking and our understanding of the technology's potential impact remains poorly understood. Although the complex anatomy and physiology of the spine and the spinal cord remain significant challenges, continued technological advances will help the field overcome the current barriers and bring ultrasound to the forefront of SCI research and development.

Evaluating the Effects of Cerebrospinal Fluid Protein Content on the Performance of Differential Pressure Valves and Antisiphon Devices Using a Novel Benchtop Shunting Model

BACKGROUND

Hydrocephalus is managed by surgically implanting flow-diversion technologies such as differential pressure valves and antisiphoning devices; however, such hardware is prone to failure. Extensive research has tested them in flow-controlled settings using saline or de-aerated water, yet little has been done to validate their performance in a setting recreating physiologically relevant parameters, including intracranial pressures, cerebrospinal fluid (CSF) protein content, and body position.

OBJECTIVE

To more accurately chart the episodic drainage characteristics of flow-diversion technology. A gravity-driven benchtop model of flow was designed and tested continuously during weeks-long trials.

METHODS

Using a hydrostatic pressure gradient as the sole driving force, interval flow rates of 6 valves were examined in parallel with various fluids. Daily trials in the upright and supine positions were run with fluid output collected from distal catheters placed at alternating heights for extended intervals.

RESULTS

Significant variability in flow rates was observed, both within specific individual valves across different trials and among multiple valves of the same type. These intervalve and intravalve variabilities were greatest during supine trials and with increased protein. None of the valves showed evidence of overt obstruction during 30 d of exposure to CSF containing 5 g/L protein.

CONCLUSION

Day-to-day variability of ball-in-cone differential pressure shunt valves may increase overdrainage risk. Narrow-lumen high-resistance flow control devices as tested here under similar conditions appear to achieve more consistent flow rates, suggesting their use may be advantageous, and did not demonstrate any blockage or trend of decreasing flow over the 3 wk of chronic use.

Epidural Oscillating Cardiac-Gated Intracranial Implant Modulates Cerebral Blood Flow

BACKGROUND

We have previously reported a method and device capable of manipulating ICP pulsatility while minimally effecting mean ICP.

OBJECTIVE

To test the hypothesis that different modulations of the intracranial pressure (ICP) pulse waveform will have a differential effect on cerebral blood flow (CBF).

METHODS

Using an epidural balloon catheter attached to a cardiac-gated oscillating pump, 13 canine subjects underwent ICP waveform manipulation comparing different sequences of oscillation in successive animals. The epidural balloon was implanted unilaterally superior to the Sylvian sulcus. Subjects underwent ICP pulse augmentation, reduction and inversion protocols, directly comparing time segments of system activation and deactivation. ICP and CBF were measured bilaterally along with systemic pressure and heart rate. CBF was measured using both thermal diffusion, and laser doppler probes.

RESULTS

The activation of the cardiac-gate balloon implant resulted in an ipsilateral/contralateral ICP pulse amplitude increase with augmentation (217%/202% respectively, P < .0005) and inversion (139%/120%, P < .0005). The observed changes associated with the ICP mean values were smaller, increasing with augmentation (23%/31%, P < .0001) while decreasing with inversion (7%/11%, P = .006/.0003) and reduction (4%/5%, P < .0005). CBF increase was observed for both inversion and reduction protocols (28%/7.4%, P < .0001/P = .006 and 2.4%/1.3%, P < .0001/P = .003), but not the augmentation protocol. The change in CBF was correlated with ICP pulse amplitude and systolic peak changes and not with change in mean ICP or systemic variables (heart rate, arterial blood pressure).

CONCLUSION

Cardiac-gated manipulation of ICP pulsatility allows the study of intracranial pulsatile dynamics and provides a potential means of altering CBF.

Abstract 6268: Use of the anti-viral drug ribavirin as a radiosensitizing agent in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a squamous cell carcinoma with a propensity for metastasis, leading many patients to fail available treatments and/or present with advanced-stage disease. There is currently a scarcity of targeted therapies for NPC, despite working knowledge of several proteins with key roles in NPC cancer biology. These include EZH2, Snail, eIF4E, and IMPDH, which are all overexpressed in NPC and correlated with poor patient prognosis. These proteins are known to be targeted by ribavirin, a well-characterized anti-viral drug that has recently been repurposed as an anti-cancer agent in several solid and hematologic malignancies. In the present study, we investigated the potential of ribavirin as a targeted therapy and radiosensitizing agent in five human NPC cell lines. We show in vitro, using cellular growth assays, flow cytometry, BrdU cell proliferation assays, scratch wound assays, and invasion assays, that ribavirin decreases NPC cellular proliferation, migration, and invasion and promotes cell cycle arrest and cell death. Modulation of EZH2, Snail, eIF4E, IMPDH, and mTOR were observed in western blots and enzymatic activity assays in response to ribavirin treatment. In vivo, monotherapy with ribavirin reduced flank tumor growth in multiple NPC xenograft models. Given that radiation therapy is a mainstay of NPC treatment, we next investigated the effects of combining ribavirin with radiation. Using clonogenic assays and flow cytometry, we demonstrate that ribavirin enhanced the cytotoxic effects of radiation on NPC cells in vitro. Most importantly, using a flank tumor xenograft model, we show that pre-treatment with ribavirin potentiated the effects of radiation therapy in vivo. Our work suggests that NPC responds to ribavirin-mediated EZH2, Snail, eIF4E, IMPDH, and mTOR modulation and positions ribavirin for clinical evaluation as a targeted therapy and radiosensitizing agent in this cancer.

Citation Format: Sakibul Huq, Joshua Casaos, Riccardo Serra, Michael Peters, Yuanxuan Xia, Andy Ding, Jeffrey Ehresman, Jayanidhi Kedda, Manuel Morales, Noah Gorelick, Tianna Zhao, Wataru Ishida, Alexander Perdomo-Pantoja, Arba Cecia, Chenchen Ji, Ian Suk, David Sidransky, Mariana Brait, Henry Brem, Nicolas Skuli, Betty Tyler. Use of the anti-viral drug ribavirin as a radiosensitizing agent in nasopharyngeal carcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6268.

Repurposing the FDA-Approved Antiviral Drug Ribavirin as Targeted Therapy for Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is a squamous cell carcinoma with a proclivity for systemic dissemination, leading many patients to present with advanced stage disease and fail available treatments. There is a notable lack of targeted therapies for NPC, despite working knowledge of multiple proteins with integral roles in NPC cancer biology. These proteins include EZH2, Snail, eIF4E, and IMPDH, which are all overexpressed in NPC and correlated with poor prognosis. These proteins are known to be modulated by ribavirin, an FDA-approved hepatitis C antiviral that has recently been repurposed as a promising therapeutic in several solid and hematologic malignancies. Here, we investigated the potential of ribavirin as a targeted anticancer agent in five human NPC cell lines. Using cellular growth assays, flow cytometry, BrdU cell proliferation assays, scratch wound assays, and invasion assays, we show in vitro that ribavirin decreases NPC cellular proliferation, migration, and invasion and promotes cell-cycle arrest and cell death. Modulation of EZH2, Snail, eIF4E, IMPDH, mTOR, and cyclin D1 were observed in Western blots and enzymatic activity assays in response to ribavirin treatment. As monotherapy, ribavirin reduced flank tumor growth in multiple NPC xenograft models in vivo Most importantly, we demonstrate that ribavirin enhanced the effects of radiotherapy, a central component of NPC treatment, both in vitro and in vivo Our work suggests that NPC responds to ribavirin-mediated EZH2, Snail, eIF4E, IMPDH, and mTOR changes and positions ribavirin for clinical evaluation as a potential addition to our NPC treatment armamentarium.

Abstract B06: Repositioning the FDA-approved antiviral drug ribavirin as targeted therapy for nasopharyngeal carcinoma

Purpose: Nasopharyngeal carcinoma (NPC) is a squamous cell carcinoma that is often diagnosed at an advanced stage, leading to poor disease-free and overall survival. Accumulating literature suggests that elevated protein expression of enhancer of zeste homolog 2 (EZH2), eukaryotic initiation factor 4E (eIF4E), and inosine-5’-monophosphate dehydrogenase (IMPDH)—proteins implicated in myriad cancers—correlates with poor prognosis in NPC. These three proteins are modulated by the Food and Drug Administration-approved antiviral drug ribavirin, which has recently been repositioned by our laboratory and others as a promising anticancer agent. Based on this intersection of molecular signature and drug targets, we investigated the potential of ribavirin as a therapeutic agent for NPC.

Experimental Design: We assessed antineoplastic efficacy of ribavirin on six human NPC cell lines in vitro using cellular growth assays, flow cytometry, and scratch wound assays. Mechanistic pathways involved were investigated using genomic expression datasets, Western blots, and enzymatic activity assays. The effects of combining ribavirin with radiation were assessed using clonogenic assays and flow cytometry. Finally, we evaluated the effects of ribavirin on tumor growth in vivo using two human cell line-derived xenograft models.

Results: Ribavirin significantly decreased NPC cellular proliferation and migratory capacity in addition to promoting cell cycle arrest and cell death. Modulation of the EZH2, Snail, eIF4E, and IMPDH pathways was observed in response to ribavirin treatment. Ribavirin significantly enhanced the cytotoxic effects of radiation therapy in NPC. Most importantly, ribavirin significantly reduced flank tumor growth in two NPC xenograft models.

Conclusions: Our work suggests that ribavirin has potent anticancer effects in NPC and could represent a safe and promising addition to current NPC treatment regimens.

Citation Format: Sakibul Huq, Joshua Casaos, Michael Peters, Yuanxuan Xia, Andy Ding, Manuel Morales, Noah Gorelick, Riccardo Serra, Tianna Zhao, Wataru Ishida, Alexander Perdomo-Pantoja, Arba Cecia, Chenchen Ji, Ian Suk, David Sidransky, Mariana Brait, Henry Brem, Nicolas Skuli, Betty Tyler. Repositioning the FDA-approved antiviral drug ribavirin as targeted therapy for nasopharyngeal carcinoma [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr B06.

Minimizing cotton ball retention in neurological procedures

Neurosurgical operations are long and intensive medical procedures, during which the surgeon must constantly have an unobscured view of the brain in order to be able to properly operate, and thus must use a variety of tools to clear obstructions (like blood and fluid) from the operating area. Currently, cotton balls are the most versatile and effective option to accomplish this as they absorb fluids, are soft enough to safely manipulate the brain, act as a barrier between other tools and the brain, and function as a spacer to keep anatomies of the brain open and visible during the operation. While cotton balls allow neurosurgeons to effectively improve visibility of the operating area, they may also be accidentally left in the brain upon completion of the surgery. This can lead to a wide range of post-operative risks including dangerous immune responses, additional medical care or surgical operations, and even death. This project seeks to develop a unique medical device that utilizes ultrasound technology in order to minimize cotton retention after neurosurgical procedures in order to reduce undesired post-operative risks, and maximize visibility.

Minimizing cotton retention in neurosurgical procedures: which imaging modality can help?

Cotton balls are used in neurosurgical procedures to assist with hemostasis and improve vision within the operative field. Although the surgeon can reshape pieces of cotton for multiple intraoperative uses, this customizability and scale also places them at perpetual risk of being lost, as blood-soaked cotton balls are visually similar to raw brain tissue. Retained surgical cotton can induce potentially life-threatening immunologic responses, impair postoperative imaging, lead to a textiloma or misdiagnosis, and/or require reoperation. This study investigated three imaging modalities (optical, acoustic, and radiographic) to find the most effective method of identifying foreign bodies during neurosurgery. First, we examined the use of dyes to increase contrast between cotton and surrounding parenchyma (optical approach). Second, we explored the ability to distinguish surgical cotton on or below the tissue surface from brain parenchyma using ultrasound imaging (acoustic approach). Lastly, we analyzed the ability of radiography to differentiate between brain parenchyma and cotton. Our preliminary testing demonstrated that dark-colored cotton is significantly more identifiable than white cotton on the surface level. Additional testing revealed that cotton has noticeable different acoustic characteristics (eg, speed of sound, absorption) from neural tissue, allowing for enhanced contrast in applied ultrasound imaging. Radiography, however, did not present sufficient contrast, demanding further examination. These solutions have the potential to significantly reduce the possibility of intraoperative cotton retention both on and below the surface of the brain, while still providing surgeons with traditional cotton material properties without affecting the surgical workflow.

Use of an Articulating Hinge to Facilitate Cervicothoracic Deformity Correction During Vertebral Column Resection

BACKGROUND

Surgical treatment of severe cervicothoracic kyphotic deformity may require the use of 3-column osteotomies such as the pedicle subtraction osteotomy and vertebral column resection (VCR), or VCR with anterior longitudinal ligament resection. Such procedures are extensive and are associated with high intra- and perioperative morbidity, in part, due to the need for risky reduction maneuvers.

OBJECTIVE

To describe a novel technique utilizing a laterally placed articulating hinge to facilitate kyphotic deformity correction of the cervicothoracic spine.

METHODS

A patient with severe chin-on-chest deformity of the cervicothoracic spine presented for evaluation and a 2-stage VCR with anterior longitudinal ligament resection was planned. To reduce the risk of intraoperative neurological injury and for increased control during reduction maneuvers, lateral instrumentation was placed through the chest wall resection above and below the level of VCR, which was adjoined with an articulating hinge rod apparatus.

RESULTS

Satisfactory reduction of the kyphosis was achieved utilizing the hinge rod apparatus for controlled deformity correction. The patient remained neurologically intact following this procedure with improvement in their spinal alignment.

CONCLUSION

We present a novel technique utilizing a lateral hinge rod apparatus for efficient, controlled correction of severe kyphotic deformity.

Neoplatonic Symbolism by Michelangelo in Sistine Chapel's Separation of Light from Darkness

Upon discovery of Michelangelo's concealed neuroanatomical images in "Separation of Light from Darkness," by Suk and Tamargo in 2010, there remained a compelling need to investigate in greater detail the reasoning behind Michelangelo's depiction of imagery of the brain, brainstem, spinal cord, eyeballs and optic nerves in the Sistine Chapel. At cursory glance, "Separation of Light from Darkness" depicts God's first act of Genesis 1:3-5 (King James Bible), in which he creates light and separates it from the darkness, enveloping the world he has just created. It is a seemingly simple, conspicuous act, but careful analysis reveals that Michelangelo used his artistic, academic, and poetic genius to embed layers of symbolic meanings. The authors believe that the great artist infused a visual metaphor of a scene from Plato's "Allegory of the Cave" in Book VII of The Republik (~380BC) to represent his key ideologies in Neoplatonism and pious convictions Michelangelo painted the Sistine Chapel during the flourishing period of High Renaissance (~1475-1527). High Renaissance art followed and reflected the period of 'rebirth' in which philosophy, literature, art, and sciences drew on ancient knowledge from Classical Antiquity, principally the ancient Greeks. The Renaissance was a period of rapid growth where people applied new found knowledge to the Classical Greek studies of Socrates, Plato, and Aristotle (from about the 4th to 3rd century BC). One of the most influential ancient philosophers was Plato (~428-348 BC) whose teachings propagated throughout Athens for about two centuries around his lifetime, through his established school, the Academy. His philosophy of Neoplatonism was resurrected by an Italian baron, Cosimo I de Medici who employed Marsilio Ficino (1433-99) to lead the Florentine Platonic Academy (of which Michelangelo was a student) and translate all of Plato's writings into Latin Through analysis of Michelangelo's paintings, his preliminary sketches, poems, written letters, and the political and religious context of his time, the authors attempt to provide key evidence to reveal the meaning and symbolism behind Michelangelo's concealed anatomic representations.

Anti-PD-1 antitumor immunity is enhanced by local and abrogated by systemic chemotherapy in GBM

The immunosuppressive effects of chemotherapy present a challenge for designing effective cancer immunotherapy strategies. We hypothesized that although systemic chemotherapy (SC) exhibits negative immunologic effects, local chemotherapy (LC) can potentiate an antitumor immune response. We show that LC combined with anti-programmed cell death protein 1 (PD-1) facilitates an antitumor immune response and improves survival (P < 0.001) in glioblastoma. LC-treated mice had increased infiltration of tumor-associated dendritic cells and clonal expansion of antigen-specific T effector cells. In comparison, SC resulted in systemic and intratumoral lymphodepletion, with decreased immune memory in long-term survivors. Furthermore, adoptive transfer of CD8⁺ cells from LC-treated mice partially rescued SC-treated mice after tumor rechallenge. Last, the timing of chemo- and immunotherapy had differential effects on anti-PD-1 efficacy. This study suggests that both mode of delivery and timing have distinct effects on the efficacy of anti-PD-1. The results of this work could help guide the selection and scheduling of combination treatment for patients with glioblastoma and other tumor types.

En Bloc Resection of a Giant Cell Tumor in the Sacrum via a Posterior-Only Approach Without Nerve Root Sacrifice: Technical Case Report

BACKGROUND AND IMPORTANCE

Giant cell tumors (GCTs) are rare primary bone neoplasms. The best long-term prognosis is achieved via complete tumor excision, but this feat is challenging in the spine due to proximity of blood vessels and nervous tissue. When occurring in the sacrum, GCTs have been removed in an en bloc fashion via combined anterior/posterior approaches, oftentimes with nerve root sacrifice. The purpose of this article is to present a case of a single-staged, posterior-only approach for en bloc resection of a sacral GCT without nerve root sacrifice.

CLINICAL PRESENTATION

A 45-year-old female presented with intractable lower back and leg pain, saddle anesthesia, and lower extremity weakness. She underwent imaging studies, which revealed a lesion involving the S1 and S2 vertebral bodies. Computed tomography guided biopsy revealed the lesion to be a GCT. The patient underwent a posterior-only approach without nerve root sacrifice to achieve an en bloc resection, followed by lumbopelvic reconstruction.

CONCLUSION

Sacrectomy via a single-staged posterior approach with nerve root preservation is a challenging yet feasible procedure for the treatment of giant cell tumors in carefully selected patients.

Single-Staged Multilevel Spondylectomy for En Bloc Resection of an Epithelioid Sarcoma With Intradural Extension in the Cervical Spine: Technical Case Report

BACKGROUND AND IMPORTANCE

Occurrence of spinal epithelioid sarcomas is rare, with few cases reported in the literature. Although wide local resection is the recommended treatment, this technique is challenging in the spine.

CLINICAL PRESENTATION

The case of a 17-year-old male with a recurrent epithelioid sarcoma with intradural extension in the cervical spine is presented. Because of nerve root involvement, the patient presented with right upper extremity weakness. The patient underwent a posterior C1-C4 spondylectomy to achieve an en bloc resection, followed by reconstruction from the occiput to T4. The right vertebral artery and C1-C4 nerve roots were sacrificed because of tumor involvement. After 3 years of follow-up the patient is disease-free but has persistent right deltoid weakness.

CONCLUSION

Cervical spondylectomy via a single-staged posterior approach is a challenging yet feasible procedure for the treatment of epithelioid sarcomas. To the best of the authors' knowledge, this is the first report of complete resection of an epithelioid sarcoma with intradural extension in the cervical spine. Although neurovascular structures may warrant sacrifice, this procedure may provide improved long-term prognosis.

Extravascular optical coherence tomography: evaluation of carotid atherosclerosis and pravastatin therapy

BACKGROUND AND PURPOSE

Extravascular optical coherence tomography (OCT), as a noninvasive imaging methodology with micrometer resolution, was evaluated in a murine model of carotid atherosclerosis by way of assessing the efficacy of pravastatin therapy.

METHODS

An OCT device was engineered for extravascular plaque imaging. Wild-type mice and apolipoprotein E-deficient (ApoE(-/-)) mice were randomized to 3 treatment groups: (1) wild-type on a diet of standard rodent chow (n=13); (2) ApoE(-/-) on a high-fat, atherosclerotic diet (HFD; n=13); and (3) ApoE(-/-) on a HFD given daily pravastatin (n=13). Mice were anesthetized and the left common carotid was surgically exposed. Three-dimensional (3D; 2 spatial dimensions+time) and 4D (3 spatial dimensions+time) OCT images of the vessel lumen patency were evaluated. After perfusion, in situ OCT imaging was performed for statistical comparison with the in vivo results and final histology.

RESULTS

Intraoperative OCT imaging positively identified carotid plaque in 100% of ApoE(-/-) mice on HFD. ApoE(-/-) mice on HFD had a significantly decreased lumen patency when compared with that in wild-type mice (P<0.001). Pravastatin therapy was found to increase lumen patency significantly in ApoE(-/-) mice on HFD (P<0.01; compared with ApoE(-/-) on HFD). The findings were confirmed with OCT imaging after perfusion and histology.

CONCLUSIONS

OCT imaging offers the potential for real-time, detailed vessel lumen evaluation, potentially improving surgical accuracy and outcomes during cerebrovascular neurosurgical procedures. Pravastatin significantly increases vessel lumen patency in the ApoE(-/-) mouse on HFD.

Three-level en bloc spondylectomy for chordoma

BACKGROUND

En bloc resection of spinal and sacral chordomas may convey a survival benefit. However, these procedures often are complex and require the surgeon to plan a procedure that results in negative tumor margins, protects vital neurovascular structures, and concludes with a viable biomechanical reconstruction.

OBJECTIVE

We present a case of a 3-level en bloc lumbar spondylectomy and reconstruction.

METHODS

A case of a 45-year-old woman with biopsy-proven exophytic L4 chordoma is presented. The patient underwent successful L3-L5 en bloc spondylectomy and reconstruction over 3 stages.

RESULTS

The patient did well following the procedure, and was neurologically intact at 6-week follow-up.

CONCLUSION

Three-level en bloc spondylectomy with lumbopelvic reconstruction is a challenging yet feasible procedure.

5-Level spondylectomy for en bloc resection of thoracic chordoma: case report

BACKGROUND AND IMPORTANCE

Primary tumors of the spine are considered for en bloc resection to improve local control and even obtain cure. Anatomic restrictions often prohibit extensive resections with negative margins that are safe and feasible. We report the first case involving a patient with a large chordoma of the thoracic spine who underwent a successful 5-level spondylectomy with bilateral chest wall resection for en bloc resection without neurologic compromise.

CLINICAL PRESENTATION

A 26-year-old woman with a chest mass was found to have a T1-5 chordoma via a percutaneous biopsy. En bloc resection of the mass was thought to be the best option for long-term local control and possible cure. She presented without neurologic or pulmonary dysfunction. The patient underwent a 3-stage procedure. The first stage involved a posterior C2-T8 exposure, allowing release of posterior elements from C7 to T6 and instrumented stabilization from C2 to T8. T1-5 ribs were cut bilaterally, and 2 wire saws were placed ventral to the thecal sac at the C7-T1 and T5-6 disc levels. The second stage involved a right-sided thoracotomy, and the T5-6 wire saw was used to complete the lower osteotomy. The third stage involved completion of the C7-T1 osteotomy with the wire saw, delivery of the tumor specimen en bloc, ventral reconstruction of the spine with a titanium mesh cage, and bilateral thoracoplasty.

CONCLUSION

This is the first case report of a 5-level spondylectomy for en bloc resection of an extensive thoracic chordoma via a bilateral thoractomy without neurologic compromise.

Sublabial approach for the treatment of symptomatic basilar impression in a patient with Klippel-Feil syndrome

BACKGROUND

Basilar impression (BI) is an uncommon condition in which there is upward displacement of the elements forming the foramen magnum, causing translocation of vertebral elements into the brainstem. Most commonly a developmental anomaly, BI is often associated with congenital conditions such as Down syndrome. Symptomatic BI is often difficult to treat surgically secondary to the anatomic variants associated with many of the coinciding congenital syndromes.

OBJECTIVE

To present a feasible approach for the treatment of BI.

METHODS

We present an alternative surgical approach for the treatment of symptomatic BI in a 37-year-old woman with Klippel-Feil syndrome. Because of the altered anatomy, traditional approaches such as the transoral-transpharyngeal, transmandibular circumglossal, and transcervical endoscopic routes were not feasible.

RESULTS

We chose a staged sublabial, transnasal, transpalatal route for the anterior brainstem decompression followed by posterior fixation. The patient tolerated the procedures well and at last follow-up had nearly complete resolution of symptoms.

CONCLUSION

The sublabial route is an alternative approach for anterior decompression in patients with symptomatic basilar impression and altered anatomic circumstances such as that caused by Klippel-Feil syndrome.

Lumbopelvic reconstruction after combined L5 spondylectomy and total sacrectomy for en bloc resection of a malignant fibrous histiocytoma

BACKGROUND

Primary sacral neoplasms that extend superiorly to involve the distal lumbar spine represent complex surgical problems. Treatment options for these patients are often limited to hemicorporectomy.

OBJECTIVE

To detail our surgical technique for en bloc resection of a sarcoma involving the L5 vertebral segment and sacrum and the reconstruction of the lumbopelvic junction.

METHODS

A 52-year-old woman presented with intractable pain secondary to a sarcoma involving the L5 vertebral segment and sacrum. She underwent a combined L5 spondylectomy and total sacrectomy for en bloc resection of her neoplasm. A novel lumbopelvic reconstruction technique was used to establish a liaison between the lumbar spine and pelvis.

RESULTS

Operative complications included a venous vascular injury and a nonviable myocutaneous flap. Postoperatively, the patient had complete resolution of her pain. Unfortunately, the patient developed metastatic disease and died 5 months after her initial surgical procedure.

CONCLUSION

We describe a patient who underwent a combined L5 spondylectomy and total sacrectomy for en bloc resection of a lumbosacral sarcoma. Additionally, we report a novel technique to reconstruct the lumbopelvic junction. The operative procedures are detailed with the aid of radiographs, intraoperative photographs, and illustrations.

A new technique for intraoperative reduction of occipitocervical instability

BACKGROUND

Occipitocervical instability with vertical migration of the odontoid is a rare but potentially debilitating anomaly of the craniocervical junction. Anterior decompression by means of a transoral or transcervical approach followed by posterior instrumentation commonly is used to treat this pathology.

OBJECTIVE

To develop an innovative operative technique to correct reducible occipitocervical instability using a purely posterior approach.

CLINICAL PRESENTATION

Two patients presented to our institution with occipitocervical instability. One patient developed vertical migration of the odontoid secondary to a retropharyngeal abscess after radiation treatment. The second patient developed occipitocervical instability as a result of pathological destruction of C2 from a breast metastasis. Both patients were myelopathic with severe neck pain.

TECHNIQUE

Both patients were brought to the operating room for intraoperative reduction and fixation using a purely posterior approach. This new technique obviated the need for an anterior decompression procedure or preoperative halo reduction. Postoperatively, both patients had excellent restoration of spinal alignment as well as improvement in both pain and myelopathy.

CONCLUSION

We achieved intraoperative reduction of occipitocervical instability through a purely posterior approach. This technique adds a tool to the armamentarium of techniques used for the treatment of occipitocervical instability.

Midsacral amputation for en bloc resection of chordoma

BACKGROUND

En bloc resection, with adequate surgical margins, of primary malignant bone tumors of the sacrum is associated with long term disease control and potential cure. Resection of sacral tumors is difficult due to the proximity of neurovascular and visceral structures, and complete, or even partial, sacrectomy often results in functional loss for the patient.

OBJECTIVE

We describe the technique for en bloc resection of a sacral chordoma through a mid-sacral amputation.

RESULTS

We demonstrate successful removal of a large sacral tumor with wide surgical margins while preserving neurologic function.

CONCLUSION

This technique for midsacral amputation to remove a sacral tumor en bloc minimizes local recurrence and maximizes neurovascular function.

Posterior-Only Approach For Total En Bloc Spondylectomy For Malignant Primary Spinal Neoplasms: Anatomic Considerations and Operative Nuances

MALIGNANT PRIMARY SPINAL tumors are rare tumors that are locally invasive and can metastasize. The majority of these tumors have a poor response rate to chemotherapy and conventional radiotherapy. Studies have shown that long-term survival and the potential for cure is best achieved with en bloc surgical excision of these tumors with negative surgical margins. Total en bloc spondylectomy involves removal of vertebral segment(s) in whole to achieve wide tumor excision. Total en bloc spondylectomy can be performed through staged or combined anterior and posterior approaches, or from a posterior-only approach. The posterior-only approach offers the advantage of achieving complete tumor excision and circumferential spinal reconstruction in a single setting. In this report, we discuss the operative management of malignant primary vertebral tumors using the posterior-only approach for total en bloc spondylectomy. The oncological considerations and surgical nuances that allow for safe but aggressive surgical excision of primary spinal tumors to achieve favorable oncological and neurological outcomes are highlighted.

Posterior vertebral column subtraction osteotomy: a novel surgical approach for the treatment of multiple recurrences of tethered cord syndrome

Recurrent tethered cord syndrome (TCS) has been reported to develop in 5–50% of patients following initial spinal cord detethering operations. Surgery for multiple recurrences of TCS can be difficult and is associated with significant complications. Using a cadaveric tethered spinal cord model, Grande and colleagues demonstrated that shortening of the vertebral column by performing a 15–25-mm thoracolumbar osteotomy significantly reduced spinal cord, lumbosacral nerve root, and terminal filum tension. Based on this cadaveric study, spinal column shortening by a thoracolumbar subtraction osteotomy may be a viable alternative treatment to traditional surgical detethering for multiple recurrences of TCS.

In this article, the authors describe the use of posterior vertebral column subtraction osteotomy (PVCSO) for the treatment of 2 patients with multiple recurrences of TCS. Vertebral column resection osteotomy has been widely used in the surgical correction of fixed spinal deformity. The PVCSO is a novel surgical treatment for multiple recurrences of TCS. In such cases, PVCSO may allow surgeons to avoid neural injury by obviating the need for dissection through previously operated sites and may reduce complications related to CSF leakage. The novel use of PVCSO for recurrent TCS is discussed in this report, including surgical considerations and techniques in performing PVCSO.

En bloc total sacrectomy performed in a single stage through a posterior approach

OBJECTIVE

Total sacrectomies are performed for extensive en bloc tumor resections. Exposure traditionally combines a posterior approach with a laparotomy to facilitate vascular control. We present a case of a total en bloc sacrectomy performed entirely through the posterior approach, thereby avoiding the need for a laparotomy.

CLINICAL PRESENTATION

A 57-year-old man presented with sacral pain and loss of bowel and bladder function. A large sacral mass was identified and submitted to biopsy. Results were consistent with an osteoblastoma, although osteosarcoma could not be excluded on pathological examination. The patient was taken to the operating room for a total sacrectomy and en bloc resection of the mass.

TECHNIQUE

Lateral iliac osteotomies were performed, followed by an L5-S1 discectomy and resection of the annulus, thus mobilizing the sacrum. Gradual distraction of the interspace coupled with upward traction of the sacrum provided an anterior exposure through which the internal iliac vessels were controlled, dissected, and divided. A combined transperineal approach completed the posterior dissection and the tumor was delivered en bloc. Lumbopelvic reconstruction was performed simultaneously.

CONCLUSION

With the use of interspace distraction and sacral elevation to facilitate vascular control, a total sacrectomy was performed without the need for the anterior exposure of a laparotomy.

Open reduction of C1-C2 subluxation with the use of C1 lateral mass and C2 translaminar screws

OBJECTIVE

Spinal cord compression secondary to a subluxation of one vertebral body over another can be achieved with reduction of the translational deformity. Intraoperative reduction of C1-C2 subluxations can be technically challenging when one uses traditional techniques (e.g., wiring and transarticular screw fixation). The popularization of C1 lateral mass and C2 pedicle screws has allowed surgeons to achieve a more complex realignment at this region of the spine. Control of both C1 and C2 with independent fixation can be used to obtain reduction. In certain instances, placement of C2 pedicle screws is not possible. The use of C2 translaminar screws (if the C2 lamina is present and suitable) is an alternative method of fixation in C2 and can be used for intraoperative reduction.

CLINICAL PRESENTATION

A 15-year-old boy with juvenile rheumatoid arthritis presented with spinal cord compression secondary to a C1-C2 subluxation. The C2 pedicle anatomy precluded safe placement of C2 pedicle screws. An alternative method of fixation with the use of C2 translaminar screws and reduction was performed to obtain proper alignment and decompress the spinal cord.

TECHNIQUE

C1 lateral mass screws and C2 translaminar screws are inserted in the usual fashion. Two contoured rods, two rod holders, and two distractors, combined with C1 lateral mass screws and C2 translaminar screws, were used to achieve reduction. Concomitant distraction between the C2 translaminar screw head and the rod holder resulted in ventral translation of C2 on C1, decompressing the spinal cord. The reduction was maintained by tightening the C2 locking nut onto the rod.

CONCLUSION

The use of C2 translaminar screws (if the C2 lamina is present and suitable) is an alternative method of fixation in C2. C1 lateral mass and C2 translaminar screw fixation provide a powerful means of reducing C1-C2 subluxations and maintaining alignment, achieving indirect decompression of the spinal cord.

Open Reduction of C1–C2 Subluxation with the Use of C1 Lateral Mass and C2 Translaminar Screws

Objective:

Spinal cord compression secondary to a subluxation of one vertebral body over another can be achieved with reduction of the translational deformity. Intraoperative reduction of C1–C2 subluxations can be technically challenging when one uses traditional techniques (e.g., wiring and transarticular screw fixation). The popularization of C1 lateral mass and C2 pedicle screws has allowed surgeons to achieve a more complex realignment at this region of the spine. Control of both C1 and C2 with independent fixation can be used to obtain reduction. In certain instances, placement of C2 pedicle screws is not possible. The use of C2 translaminar screws (if the C2 lamina is present and suitable) is an alternative method of fixation in C2 and can be used for intraoperative reduction.

Clinical Presentation:

A 15-year-old boy with juvenile rheumatoid arthritis presented with spinal cord compression secondary to a C1–C2 subluxation. The C2 pedicle anatomy precluded safe placement of C2 pedicle screws. An alternative method of fixation with the use of C2 translaminar screws and reduction was performed to obtain proper alignment and decompress the spinal cord.

Technique:

C1 lateral mass screws and C2 translaminar screws are inserted in the usual fashion. Two contoured rods, two rod holders, and two distractors, combined with C1 lateral mass screws and C2 translaminar screws, were used to achieve reduction. Concomitant distraction between the C2 translaminar screw head and the rod holder resulted in ventral translation of C2 on C1, decompressing the spinal cord. The reduction was maintained by tightening the C2 locking nut onto the rod.

Conclusion:

The use of C2 translaminar screws (if the C2 lamina is present and suitable) is an alternative method of fixation in C2. C1 lateral mass and C2 translaminar screw fixation provide a powerful means of reducing C1–C2 subluxations and maintaining alignment, achieving indirect decompression of the spinal cord.

En Bloc Total Sacrectomy Performed in a Single Stage through a Posterior Approach

Objective:

Total sacrectomies are performed for extensive en bloctumor resections. Exposure traditionally combines a posterior approach with a laparotomy to facilitate vascular control. We present a case of a total en bloc sacrectomy performed entirely through the posterior approach, thereby avoiding the need for a laparotomy.

Clinical Presentation:

A 57-year-old man presented with sacral pain and loss of bowel and bladder function. A large sacral mass was identified and submitted to biopsy. Results were consistent with an osteoblastoma, although osteosarcoma could not be excluded on pathological examination. The patient was taken to the operating room for a total sacrectomy and en bloc resection of the mass.

Technique:

Lateral iliac osteotomies were performed, followed by an L5–S1 discectomy and resection of the annulus, thus mobilizing the sacrum. Gradual distraction of the interspace coupled with upward traction of the sacrum provided an anterior exposure through which the internal iliac vessels were controlled, dissected, and divided. A combined transperineal approach completed the posterior dissection and the tumor was delivered en bloc. Lumbopelvic reconstruction was performed simultaneously.

Conclusion:

With the use of interspace distraction and sacral elevation to facilitate vascular control, a total sacrectomy was performed without the need for the anterior exposure of a laparotomy.

Reduction of cerebrospinal fluid rhinorrhea after vestibular schwannoma surgery by reconstruction of the drilled porus acusticus with hydroxyapatite bone cement

Object

Cerebrospinal fluid (CSF) rhinorrhea remains a significant cause of morbidity after resection of vestibular schwannomas (VSs), with rates of rhinorrhea after this procedure reported to range between 0 and 27%. The authors investigated whether reconstruction of the drilled posterior wall of the porus acusticus with hydroxyapatite cement (HAC) would decrease the incidence of postoperative CSF rhinorrhea.

Methods

A prospective observational study of 130 consecutive patients who underwent surgery for reconstruction of the posterior wall of the drilled porus acusticus with HAC was conducted between October 2002 and September 2005. All patients underwent a retrosigmoid transmeatal approach for VS resection and were followed up to document cases of CSF rhinorrhea, incisional CSF leak, meningitis, or rhinorrhea-associated meningitis. A cohort of 150 patients with VSs who were treated with the same surgical approach but without HAC reconstruction served as a control group.

Results

The authors found that HAC reconstruction of the porus acusticus wall significantly reduced the rate of postoperative CSF rhinorrhea in their patients. In the patients treated with HAC, rhinorrhea developed in only three patients (2.3%) compared with 18 patients (12%) in the control group. This was a statistically significant finding (p = 0.002, odds ratio = 5.8).

Conclusions

The use of HAC in the reconstruction of the drilled posterior wall of the porus acusticus, occluding exposed air cells, greatly reduces the risk of CSF rhinorrhea.

Total L-5 spondylectomy and reconstruction of the lumbosacral junction

✓The authors describe a technique for total L-5 spondylectomy and reconstruction of the lumbosacral junction. The technique, which involves separately staged posterior and anterior procedures, is reported in two patients harboring neoplasms that involved the L-5 level. The first stage consisted of a posterior approach with removal of all posterior bone elements of L-5 and radical L4–5 and L5–S1 discectomies. Lumbosacral and lumbopelvic instrumentation included pedicle screws as well as iliac screws or a transiliac rod. The second stage consisted of an anterior approach with mobilization of vascular structures, completion of L4–5 and L5–S1 discectomies, and removal of the L-5 vertebral body. Anterior lumbosacral reconstruction included placement of a distractable cage and tension band between L-4 and S-1. Allograft bone was used for fusion in both stages. No significant complications were encountered. At more than 1 year of follow-up, both patients were independently ambulatory, without evidence of recurrent or metastatic disease, and adequate lumbosacral alignment was maintained. The authors conclude that this technique can be safely performed in appropriately selected patients with neoplasms involving L-5.

Surgical treatment strategies and outcome in patients with breast cancer metastatic to the spine: a review of 87 patients

Aggressive surgical management of spinal metastatic disease can provide improvement of neurological function and significant pain relief. However, there is limited literature analyzing such management as is pertains to individual histopathology of the primary tumor, which may be linked to overall prognosis for the patient. In this study, clinical outcomes were reviewed for patients undergoing spinal surgery for metastatic breast cancer. Respective review was done to identify all patients with breast cancer over an eight-year period at a major cancer center and then to select those with symptomatic spinal metastatic disease who underwent spinal surgery. Pre- and postoperative pain levels (visual analog scale [VAS]), analgesic medication usage, and modified Frankel grade scores were compared on all patients who underwent surgery. Univariate and multivariate analyses were used to assess risks for complications. A total of 16,977 patients were diagnosed with breast cancer, and 479 patients (2.8%) were diagnosed with spinal metastases from breast cancer. Of these patients, 87 patients (18%) underwent 125 spinal surgeries. Of the 76 patients (87%) who were ambulatory preoperatively, the majority (98%) were still ambulatory. Of the 11 patients (13%) who were nonambulatory preoperatively, four patients were alive at 3 months postoperatively, three of which (75%) regained ambulation. The preoperative median VAS of six was significantly reduced to a median score of two at the time of discharge and at 3, 6, and 12 months postoperatively (P < 0.001 for all time points). A total of 39% of patients experienced complications; 87% were early (within 30 days of surgery), and 13% were late. Early major surgical complications were significantly greater when five or more levels were instrumented. In patients with spinal metastases specifically from breast cancer, aggressive surgical management provides significant pain relief and preservation or improvement of neurological function with an acceptably low rate of complications.

Endoscopic image-guided odontoidectomy for decompression of basilar invagination via a standard anterior cervical approach

✓Symptomatic irreducible basilar invagination has traditionally been approached through a transoral–transpharyngeal route with resection of the anterior portion of C-1 and the odontoid. Modification of this exposure with either a Le Fort osteotomy or a transmandibular osteotomy and circumglossal approach has increased the access to pathological conditions in this region. These traditional routes all require traversing the oral cavity and accepting the associated potential complications. The authors have developed a novel surgical approach, an endoscopic transcervical odontoidectomy, which allows access for resection of the odontoid and for brainstem and spinal cord decompression without traversing the oral cavity. In this paper they describe the technique and its advantages and present three cases in which patients underwent the endoscopic transcervical odontoidectomy for basilar invagination.

Three consecutive patients (age range 42–74 years) who had irreducible basilar invagination underwent the endoscopic transcervical odontoidectomy. All were symptomatic and had neck pain and myelopathy. All were evaluated preoperatively and postoperatively with computed tomography and magnetic resonance imaging. In all cases the procedure resulted in complete decompression. There were no serious complications. No patient required prolonged intubation, tracheostomy, or enteral tube feeding. One patient had an intraoperative cerebrospinal fluid leak, which had no postoperative sequelae.

The authors present an alternative surgical approach for treating ventral compression of the brainstem and spinal cord. The technique is safe and effective for decompression and provides a surgical route that can be added to the armamentarium of treatments for pathological conditions in this region.

Concomitant Conus Medullaris Ependymoma and Filum Terminale Lipoma: Case Report

OBJECTIVE:

Ependymomas of the conus medullaris-cauda equina-filum terminale region are typically solitary lesions. In this report, we describe the clinical presentation, radiographic findings, operative details, and pathological features of a patient with a conus medullaris ependymoma and a filum terminale lipoma.

CLINICAL PRESENTATION:

A 40-year-old woman presented with increasing low back pain and bowel and bladder dysfunction. Magnetic resonance imaging revealed a partially cystic enhancing lesion at the conus medullaris and a T1-weighted hyperintense mass within the filum terminale.

INTERVENTION:

An L2-L3 laminotomy/laminoplasty was performed for gross total resection of the mass. Histopathological examination demonstrated a conus medullaris ependymoma and filum terminale lipoma. The patient experienced complete resolution of her preoperative symptoms.

CONCLUSION:

Spinal cord ependymomas are almost exclusively single lesions and their coexistence with other pathological entities is rare. In this report, we describe a patient with a concomitant conus medullaris ependymoma and filum terminale lipoma.

Frameless stereotaxy in a transmandibular, circumglossal, retropharyngeal cervical decompression in a Klippel-Feil patient: technical note

Frameless stereotaxy, while most commonly applied to intracranial surgery, has seen an increasing number of applications in spinal surgery. Its use in the spine has been described to a greater degree in posterior rather than anterior surgical approaches, presumably due to the relative paucity of anatomical landmarks appropriate for frameless stereotactic registration in the anterior spine. This technical note illustrates the previously undescribed, successful use of frameless stereotaxy to the transmandibular, circumglossal, retropharyngeal surgical approach in a patient with Klippel-Feil syndrome.

Spinal pelvic reconstruction after total sacrectomy for en bloc resection of a giant sacral chordoma. Technical note

Although radical resection prolongs the disease-free survival period, surgical management of primary sacral tumors is challenging because of their location and often large size. Moreover, in cases of lesions for which a radical resection necessitates total sacrectomy, reconstruction is required. The authors have previously described a modified Galveston technique in which a liaison between the spine and pelvis is achieved using lumbar pedicle screws and Galveston rods embedded into the ilia; additionally, a transiliac bar reestablishes the pelvic ring. Although this reconstruction technique achieves stabilization, several biomechanical limitations exist. In the present report the authors present the case of a patient who underwent spinal pelvic reconstruction after a total sacrectomy was performed to remove a giant sacral chordoma. They describe a novel spinal pelvic reconstruction technique that addresses some of the biomechanical limitations.

Neuroendoscopy: past, present, and future

Neuroendoscopy began with a desire to visualize the ventricles and deeper structures of the brain. Unfortunately, the technology available to early neuroendoscopists was not sufficient in most cases for these purposes. The unique perspective that neuroendoscopy offered was not fully realized until key technological advances made reliable and accurate visualization of the brain and ventricles possible. After this technology was incorporated into the device, neuroendoscopic procedures were rediscovered by neurosurgeons. Endoscopic third ventriculostomy and other related procedures are now commonly used to treat a wide array of neurosurgically managed conditions. A seemingly limitless number of neurosurgical applications await the endoscope. In the future, endoscopy is expected to become routine in modern neurosurgical practice and training.

A superciliary approach for anterior cranial fossa lesions in children. Technical note

Many subfrontal and orbitofrontal craniotomy techniques have been proposed and developed for anterior cranial fossa lesions. The purpose of this study was to evaluate the surgical experience with the frontolateral keyhole craniotomy through a superciliary skin incision in children. The keyhole craniotomy is a modification of the traditional pterional approach. This modified approach, a craniotomy with a 2.5 x 3-cm bone opening just above the eyebrow through a superciliary incision, has been previously described in adults for many lesions situated in the anterior cranial fossa, including tumors and aneurysms. The authors review their experience in using this approach in 27 children for a variety of intracranial lesions. This approach was used for 28 procedures in children ranging in age from 1 to 16 years (mean age 10 years). The lesions included arachnoid cysts, cerebrospinal fluid fistulas, and tumors; no vascular lesions were treated. The authors have found this craniotomy to be a safe and simple approach for treating anterior cranial fossa and suprasellar lesions in children.

En bloc resection of multilevel cervical chordoma with C-2 involvement. Case report and description of operative technique

Chordomas are locally aggressive neoplasms with an extremely high propensity to recur locally following resection, despite adjuvant therapy. This biological behavior has led most authors to conclude that en bloc resection provides the best chance for the patient's prolonged disease-free survival and possible cure. The authors present a case of an extensive upper cervical chordoma treated by en bloc resection, reconstruction, and long-segment stabilization. Total spondylectomy of C2-4 with sacrifice of the right C2-4 nerve roots and a segment of the right vertebral artery was performed. The inherent anatomical complexities of en bloc resection in the upper cervical spine are discussed. To the authors' knowledge, this represents the first report of an en bloc resection for multi-level cervical chordoma.

Spinal cord ependymoma: radical surgical resection and outcome

OBJECTIVE

Several authors have noted increased neurological deficits and worsening dysesthesia in the postoperative period in patients with spinal cord ependymoma. We describe the neurological progression and pain evolution of these patients over the 1-year period after surgery. In addition, our favored method of en bloc tumor resection is illustrated, and the rate of complications, recurrence, and survival in this group of patients is addressed.

METHODS

We operated on 26 patients (12 male and 14 female) with low-grade spinal cord ependymomas between 1975 and 2001. The median age at diagnosis was 42 years. Tumors extended into the cervical cord in 13 patients, the thoracic cord in 7 patients, and the conus medullaris in 6 patients. Eleven patients had previous surgery and/or radiation therapy.

RESULTS

We achieved a gross total resection in 88% of patients, whereas 8% had a subtotal resection and 4% had a biopsy. Only 1 patient developed a recurrence over a mean follow-up period of 31 months.

CONCLUSION

We conclude that radical surgical resection of spinal cord ependymomas can be safely achieved in the majority of patients. A trend toward neurological improvement from a postoperative deficit can be expected between 1 and 3 months after surgery and continues up to 1 year. Postoperative dysesthesias begin to improve within 1 month of surgery and are significantly better by 1 year after surgery. The best predictor of outcome is the preoperative neurological status.

Surgical strategy for spinal metastases

STUDY DESIGN

A new surgical strategy for treatment of patients with spinal metastases was designed, and 61 patients were treated based on this strategy.

OBJECTIVES

To propose a new surgical strategy for the treatment of patients with spinal metastases.

SUMMARY OF BACKGROUND DATA

A preoperative score composed of six parameters has been proposed by Tokuhashi et al for the prognostic assessment of patients with metastases to the spine. Their scoring system was designed for deciding between excisional or palliative procedures. Recently, aggressive surgery, such as total en bloc spondylectomy for spinal metastases, has been advocated for selected patients. Surgical strategies should include various treatments ranging from wide or marginal excision to palliative treatment with hospice care.

METHODS

Sixty-seven patients with spinal metastases who had been treated from 1987-1991 were reviewed, and prognostic factors were evaluated retrospectively (phase 1). A new scoring system for spinal metastases that was designed based on these data consists of three prognostic factors: 1) grade of malignancy (slow growth, 1 point; moderate growth, 2 points; rapid growth, 4 points), 2) visceral metastases (no metastasis, 0 points; treatable, 2 points: untreatable, 4 points), and 3) bone metastases (solitary or isolated, 1 point; multiple, 2 points). These three factors were added together to give a prognostic score between 2-10. The treatment goal for each patient was set according to this prognostic score. The strategy for each patient was decided along with the treatment goal: a prognostic score of 2-3 points suggested a wide or marginal excision for long-term local control; 4-5 points indicated marginal or intralesional excision for middle-term local control; 6-7 points justified palliative surgery for short-term palliation; and 8-10 points indicated nonoperative supportive care. Sixty-one patients were treated prospectively according to this surgical strategy between 1993-1996 (phase 2). The extent of the spinal metastases was stratified using the surgical classification of spinal tumors, and technically appropriate and feasible surgery was performed, such as en bloc spondylectomy, piecemeal thorough excision, curettage, or palliative surgery.

RESULTS

The mean survival time of the 28 patients treated with wide or marginal excision was 38.2 months (26 had successful local control). The mean survival time of the 13 patients treated with intralesional excision was 21.5 months (nine had successful local control). The mean survival time of the 11 patients treated with palliative surgery and stabilization was 10.1 months (eight had successful local control). The mean survival time of the patients with terminal care was 5.3 months.

CONCLUSIONS

A new surgical strategy for spinal metastases based on the prognostic scoring system is proposed. This strategy provides appropriate guidelines for treatment in all patients with spinal metastases.