Increased Dose in Spine Stereotactic Radiosurgery for Metastatic Disease: Are We Underestimating the Risks?

Background and Objectives: The recently published Spine Stereotactic Radiosurgery (SSRS) ESTRO guidelines advise against treating spinal metastatic disease with a single dose equal to or smaller than 18 Gy, prioritizing local control over the potential for complications. This study aims to assess the necessity and validity of these higher dose recommendations by evaluating the outcomes and experiences with lower radiation doses. Materials and Methods: A retrospective evaluation of SSRS patients treated at a single institute was conducted. The outcomes and complications of this cohort were compared to the current literature and the data supporting the new ESTRO guidelines. Results: A total of 149 treatment sessions involving 242 spinal levels were evaluated. The overall local control rate was 91.2%. The mean radiation dose for the local control group compared to the local failure group was similar (17.5 vs. 17.6 Gy, not significant). The overall complication rate was 6%. These results are consistent with previous publications evaluating SSRS for metastatic spinal disease. Conclusions: SSRS dose escalation may increase local control efficacy but comes with a higher risk of complications. The evidence supporting the strong recommendations in the recent ESTRO guidelines is not robust enough to justify a universal application. Given the palliative nature of treatment for metastatic patients, dose determination should be individualized based on patient conditions and preferences, with a detailed discussion about the risk-benefit ratio of increased doses and the level of evidence supporting these recommendations.

Post-operative dysphagia following ventral cervical approach: complication or side-effect? Retrospective analysis and review of the literature.

OBJECTIVE: To ameliorate the clinical decision-making process when debating between a ventral or dorsal cervical approach by elucidating whether post-operative dysphagia be regarded as a complication or a transient side effect. METHODS: A literature review of studies comparing complication rates following ventral and dorsal cervical approaches was performed. A stratified complication rate excluding dysphagia was calculated and discussed. A retrospective cohort of patients operated for degenerative cervical myelopathy in a single institution comprising 665 patients was utilized to analyze complication rates using a uniform definition for dysphagia. RESULTS: Both the ventral and the dorsal approach groups exhibited comparable neurological improvement rates. Since transient dysphagia was not considered a complication, the dorsal approach was associated with higher level of overall complications. CONCLUSIONS AND RELEVANCE: Inconsistencies in the definition of dysphagia following ventral cervical surgery impedes the interpretation of trials comparing dorsal and ventral complication rates. A uniform definition for complications and side effects may enhance the validity of medical trials.

In-thrombus thrombin secretion: a new diagnostic marker of atrial fibrillation in cryptogenic stroke.

Endovascularly retrieved clots may be a potential resource for diagnosing stroke etiology. This method may influence secondary prevention treatment. We measure thrombin activity eluted by serially washing clots. We concluded that an assay measuring the change in thrombin in clots retrieved during acute stroke endovascular thrombectomy procedures may serve as a diagnostic marker of the origin of the clot. The suggested mechanism for these differences may be the clot location before its retrieval, with high blood flow causing thrombin washout in atherosclerotic clots, in contrast to atrium appendage low blood flow retaining high thrombin levels.

Short-term post-operative complications in 207 patients with multi-level degenerative cervical myelopathy: the effect of surgical approach.

INTRODUCTION: Degenerative cervical myelopathy (DCM) is a common condition often treated by surgical decompression and fusion. The objective of this paper was to compare short-term post-operative complication rates of patients with multi-level DCM treated with decompression and fusion using either an anterior or a posterior cervical approach. MATERIAL AND METHODS: A retrospective evaluation of patients' charts, imaging studies and operative reports of patients operated for multilevel subaxial DCM from 2011 to 2016 at a single institution was performed. Patients who were operated upon for the treatment of three stenosed spinal levels or above and who underwent anterior cervical discectomy and fusion, or anterior cervical corpectomy and fusion, or posterior cervical laminectomy and fusion, were included. Short-term post-operative complications were compared between the anterior and posterior approaches. RESULTS: Overall, 207 patients were included in this study. 156 were operated via an anterior approach and 51 via a posterior approach. The mean number of treated levels was 3.4 and 4.3 for the anterior and posterior approach groups, respectively (p < 0.001). In the posterior approach group, the proportion of stenosed spinal levels within all operated levels was significantly lower than in the anterior approach group (p = 0.025). Early post-operative neurological status change was favourable for both groups. Deep wound infection rate was significantly higher in the posterior approach group (7.8% vs. none; p = 0.001). CONCLUSIONS: Posterior cervical laminectomy and fusion is significantly associated with an increased rate of deep wound infection and wound revision surgery compared to the anterior approach. We recommend the anterior approach as the valid option in treating multi-level DCM.

Anterior cervical approach for the treatment of axial or high thoracic levels.

PURPOSE: Application of the anterior sub-axial cervical approach to the axial spine or the high thoracic spine has been previously described. Evaluation methods to determine the feasibility of these approaches were also described but alternative method was utilized in the current study. We describe our experience expanding the boundaries of anterior cervical approach utilizing a novel algorithm for approach selection. MATERIALS AND METHODS: A retrospective analysis of patients' files and imaging data of all anterior cervical approach to treat pathologies above C2-3 disc space or below C7-D1 disc space. The decision to proceed with standard approach was based on CT or MRI scans and the pre-operative cervical range of motion. Post-operative course and surgical complications will be discussed. RESULTS: During a two year period 13 patients had undergone anterior cervical approach to the axial spine (3 patients) or the thoracic spine (10 patients). Ten patients were treated for tumour resection, one for trauma, one for myelopathy and the last for infective osteomyelitis with epidural abscess. Three patients were previously operated in another hospital via the posterior approach with remaining compressive mass necessitating anterior decompression. Complications were recorded in 30% of the patients. CONCLUSIONS: Approach to the axial or the high thoracic spine is more challenging and harbors approach-related complication. Pre-operative evaluation of patients imaging allows harnessing the standard approach for treatment of extreme levels with relative safety and efficiency. Spine surgeons' awareness to this technique may increase surgical efficacy while reducing the complication rates.

In-thrombus thrombin secretion: a new diagnostic marker of atrial fibrillation in cryptogenic stroke.

BACKGROUND: Endovascularly retrieved clots are a potential resource for diagnosing stroke etiology, which may influence secondary prevention treatment. In this study we measured thrombin activity eluted by serially washing clots. METHODS: Clots were retrieved from 68 patients with acute ischemic stroke, freshly frozen and classified by standard criteria into proven atrial fibrillation (AF, 18 patients), atherosclerotic origin (AS, 15 patients), cryptogenic stroke (Cr, 17 patients) and other known causes (18 patients). Thawed clot samples were washed by transferring them into 1 mL buffer in seven hourly cycles and a fluorescent substrate assay was used to measure secreted thrombin activity. The clots were also examined histologically. Artificial fibrin and red blood cell-rich clots were similarly assayed for wash-eluted thrombin activity as an external control. RESULTS: Thrombin activity eluted from clots of AF origin decreased significantly with time in contrast to steady levels eluted from AS origin thrombi (P<0.0001 by repeated measures ANOVA). The Cr stroke group was indistinguishable from the AF group and differed statistically from the AS group (P=0.017 by repeated measures ANOVA). In artificial clots we found a biphasic activity pattern, with initially decreasing levels of eluted thrombin (AF pattern) and then, with continuing washes, steady eluted thrombin levels (AS pattern). CONCLUSIONS: An assay measuring the change in thrombin in clots retrieved during acute stroke endovascular thrombectomy procedures may serve as a diagnostic marker of the origin of the clot. The suggested mechanism for these differences may be the clot location before its retrieval, with high blood flow causing thrombin washout in atherosclerotic clots, in contrast to atrium appendage low blood flow retaining high thrombin levels.

Intraoperative imaging and navigation for C1-C2 posterior fusion.

BACKGROUND: Cervical axial spine fusion is challenging as the anatomy is extremely variable, and screw misplacement can lead to severe complications. C1 lateral mass screws and C2 pedicle screws are routinely placed under either fluoroscopic guidance or imaging-assisted navigation. Here, we compared the two for axial screw placement. METHODS: We retrospectively evaluated patients' treated from 2011-2016 utilizing the Harm's procedure for C1-C2 screw fixation performed under either fluoroscopic guidance (nine patients) or image-assisted O-arm navigation (five patients). The groups had similar demographic and risk factors. Variables studied included operative time, estimated blood loss (EBL), accuracy of screw placement, screw reposition rates, and reoperation rates. RESULTS: The mean EBL was 555CC and 260CC, respectively (not a significant difference) utilizing fluoroscopic versus O-arm navigation. Of interest, the mean surgical duration was 27 min longer in the O-arm versus fluoroscopy group (P = 0.03). Ten C2 pedicle screws were performed using O-arm navigation. Alternatively, as 9 of 18 C2 pedicles were considered "risky" for the placement of fluoroscopic-guided pedicle screws, laminar screws were utilized. Although the accuracy rate of C1 and C2 screw placement was higher for the navigated group, this finding was not significant. Similarly, despite complications involving two unacceptably placed screws from the fluoroscopic guidance group, there were no neurological sequelae. CONCLUSION: Axial cervical spine instrumentation is challenging. Utilization of Imaging-assisted navigation increases the accuracy and safety of screw placement.