Outpatient telemedicine in neurosurgery: 15,677 consecutive encounters in a comparative analysis of its effectiveness and impact on the surgical conversion rate.

OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic has necessitated the use of telehealth visits (THVs). The effects on neurosurgical practice have not been well characterized, especially concerning new-patient THVs. Therefore, the authors of this study reviewed their institution's experience with outpatient clinic visits and THVs from before the COVID-19 pandemic to the present to focus on clinical metrics, rates of surgery, and the effects of implementing THVs in order to better understand their implications for clinical practice as more data emerge over time. METHODS: The authors reviewed 15,677 consecutive new outpatient in-person visits (IPVs), THVs, and neurosurgical procedures/cases proceeding from their institution between 2018 and 2022 for trends and associations related to THVs. RESULTS: Among spine patients, there was no difference in the proportion of encounters that led to surgery (surgical conversion rate) between THVs and IPVs (p = 0.49). Among cranial patients, THVs were negatively associated with conversion (OR 0.73, p = 0.03). On average, patients using THVs lived further from the hospital (p < 0.001); however, the patient catchment area appeared unchanged. The median distance to the hospital among THV patients was counterbalanced by a decreased distance for spine patients pursing IPVs (p < 0.001), with no significant change to case volume. There was no change in distance to the hospital among cranial patients. For both cranial and spine patients, surgical conversion was more likely among those who lived a great distance from the hospital if their initial encounter was an IPV (p = 0.007 and < 0.001, respectively). However, there was no relationship between distance from the hospital and surgical conversion among THV patients (p = 0.565). The availability of THVs did not significantly affect follow-up time (p = 0.837). For new patients at IPVs, there was no difference in time to the operating room between cranial and spine cases; for new patients at THVs, however, time to the operating room was significantly faster for cranial cases than for spine cases (p = 0.0018). CONCLUSIONS: Compared to IPVs, THVs lead to decreased surgical conversion for cranial patients but not spine patients. THVs do not appear to increase the catchment area. For patients who live far from the hospital, an IPV is associated with surgical conversion. Surgical conversion is faster following cranial THVs than after spine THVs. THVs did not increase the duration of follow-up.

Virtual fluoroscopy for intraoperative C-arm positioning and radiation dose reduction.

Positioning of an intraoperative C-arm to achieve clear visualization of a particular anatomical feature often involves repeated fluoroscopic views, which cost time and radiation exposure to both the patient and surgical staff. A system for virtual fluoroscopy (called FluoroSim) that could dramatically reduce time- and dose-spent "fluoro-hunting" by leveraging preoperative computed tomography (CT), encoded readout of C-arm gantry position, and automatic 3D-2D image registration has been developed. The method is consistent with existing surgical workflow and does not require additional tracking equipment. Real-time virtual fluoroscopy was achieved via mechanical encoding of the C-arm motion, C-arm geometric calibration, and patient registration using a single radiograph. The accuracy, time, and radiation dose associated with C-arm positioning were measured for FluoroSim in comparison with conventional methods. Five radiology technologists were tasked with acquiring six standard pelvic views pertinent to sacro-illiac, anterior-inferior iliac spine, and superior-ramus screw placement in an anthropomorphic pelvis phantom using conventional and FluoroSim approaches. The positioning accuracy, exposure time, number of exposures, and total time for each trial were recorded, and radiation dose was characterized in terms of entrance skin dose and in-room scatter. The geometric accuracy of FluoroSim was measured to be [Formula: see text]. There was no significant difference ([Formula: see text]) observed in the accuracy or total elapsed time for C-arm positioning. However, the total fluoroscopy time required to achieve the desired view decreased by 4.1 s ([Formula: see text] for conventional, compared with [Formula: see text] for FluoroSim, [Formula: see text]), and the total number of exposures reduced by 4.0 ([Formula: see text] for conventional, compared with [Formula: see text] for FluoroSim, [Formula: see text]). These reductions amounted to a 50% to 78% decrease in patient entrance skin dose and a 55% to 70% reduction in in-room scatter. FluoroSim was found to reduce the radiation exposure required in C-arm positioning without diminishing positioning time or accuracy, providing a potentially valuable tool to assist technologists and surgeons.

Accuracy of C2 pedicle screw placement using the anatomic freehand technique.

OBJECTIVE: The objective of this study is to evaluate the incidence and prognostic factors of breach rates following the placement of C2 pedicle screws using the anatomic, freehand technique. METHODS: We retrospectively reviewed the medical records of all patients who underwent C2 transpedicular instrumentation over six years at a single institution. All intraoperative, image-guided techniques were excluded. Breaches were ascertained from immediate postoperative CT images. All images were analyzed by three independent reviewers. The screw length was correlated with (1) the breach rate and (2) the breach severity. Severity of the breached screws reflects the screw circumference (0-360°) perforating the pedicle wall (Grade 1-Grade 4). RESULTS: Of the 341 C2 pedicle screws inserted in 181 patients, the average screw length was 22.93±3.7mm. The average distance from the foramen transversarium to the screw insertion point was 13.17±2.63mm. The distance from the medial rim of the pedicle to the dura of spinal cord was 3.53±1.57mm. Of the 341 screws, the overall breach rate was 17.3% (n=59). Of the 59 breaches, 89.83% of screws (n=53) breaching the spinal canal was statistically significantly higher than the 10.17% of screws (n=6) breaching the foramen transversarium (p<0.001). Moreover, 27 (45.8%) were Grade 1, 16 (27.1%) Grade 2, 6 (10.2%) Grade 3, and 10 (16.9%) Grade 4. None of the C2 breaches resulted in neurological sequela. No association was found between breach rate and gender, race or age. While the average screw length was 22.93±3.7mm [12-34mm], screw length did not predict a cortical violation (p=0.4) or severity of the breach (p=0.42) in a multiple regression model. CONCLUSIONS: In this cohort study on the anatomic freehand placement of C2 pedicle screws, the breach rate was 17.3%. Lateral breaches were more common than medial breaches. Screw length was not statistically correlated with cortical violation or severity of breach. Therefore, screw length is not a prognostic factor for C2 pedicle screw misplacement.

Somatic mutations of SUZ12 in malignant peripheral nerve sheath tumors.

Neurofibromatosis 1 is a hereditary syndrome characterized by the development of numerous benign neurofibromas, a small subset of which progress to malignant peripheral nerve sheath tumors (MPNSTs). To better understand the genetic basis for MPNSTs, we performed genome-wide or targeted sequencing on 50 cases. Sixteen MPNSTs but none of the neurofibromas tested were found to have somatic mutations in SUZ12, implicating it as having a central role in malignant transformation.

Factors associated with improved outcomes following decompressive surgery for prostate cancer metastatic to the spine.

BACKGROUND: Metastatic spinal cord compression from prostate cancer is a debilitating disease causing neurological deficits, mechanical instability, and intractable pain. Surgical management may improve quality of life. OBJECTIVE: To define postoperative outcomes and explore associations with prolonged survival for patients with metastatic prostate cancer. METHODS: Retrospective chart reviews were performed of all patients undergoing spinal surgery for metastatic cancer from June 1, 2002 to August 31, 2011. Patient demographics, surgical details, adjuvant therapies, outcomes, complications, and postoperative survival were reviewed. RESULTS: Twenty-seven patients with prostate cancer underwent surgery at a median age of 65 years (range, 46-82 years). After surgery, 93% of patients had preserved or improved neurological status, 56% of nonambulatory patients recovered ambulation, 43% of incontinent patients recovered continence, and 23% experienced complications. Postoperative Frankel grades were significantly improved by at least 1 letter grade at 1 month (P = .03). The median analgesic and steroid usage was significantly lower up to 3 months and 6 months postoperatively, respectively (P = .007, .005). Median survival following surgery was 10.2 months, and patients with castration-resistant prostate cancer had a shorter median survival than those with hormone-naïve disease (9.8 vs 40 months). Better preoperative performance status was an independent predictor of survival (P = .02). Younger age (P = .005) and instrumentation greater than 7 spinal levels (P = .03) were associated with complications. CONCLUSION: Spinal surgery for prostate metastases improves neurological function and decreases analgesic requirements. Our findings support surgical intervention for carefully selected patients, and knowledge of preoperative hormone sensitivity and performance status may help with risk stratification.

Short-term progressive spinal deformity following laminoplasty versus laminectomy for resection of intradural spinal tumors: analysis of 238 patients.

OBJECTIVE: Gross total resection of intradural spinal tumors can be achieved in the majority of cases with preservation of long-term neurological function. However, postoperative progressive spinal deformity complicates outcome in a subset of patients after surgery. We set out to determine whether the use of laminoplasty (LP) vs laminectomy (LM) has reduced the incidence of subsequent spinal deformity following intradural tumor resection at our institution. METHODS: We retrospectively reviewed the records of 238 consecutive patients undergoing resection of intradural tumor at a single institution. The incidence of subsequent progressive kyphosis or scoliosis, perioperative morbidity, and neurological outcome were compared between the LP and LM cohorts. RESULTS: One hundred eighty patients underwent LM and 58 underwent LP. Patients were 46 +/- 19 years old with median modified McCormick score of 2. Tumors were intramedullary in 102 (43%) and extramedullary in 102 (43%). All baseline clinical, radiographic, and operative variables were similar between the LP and LM cohorts. LP was associated with a decreased mean length of hospitalization (5 vs 7 days; P = .002) and trend of decreased incisional cerebrospinal fluid leak (3% vs 9%; P = .14). Following LP vs LM, 5 (9%) vs 21 (12%) patients developed progressive deformity (P = .728) a mean of 14 months after surgery. The incidence of progressive deformity was also similar between LP vs LM in pediatric patients < 18 years of age (43% vs 36%), with preoperative scoliosis or loss of cervical/lumbar lordosis (28% vs 22%), or with intramedullary tumors (11% vs 11%). CONCLUSION: LP for the resection of intradural spinal tumors was not associated with a decreased incidence of short-term progressive spinal deformity or improved neurological function. However, LP may be associated with a reduction in incisional cerebrospinal fluid leak. Longer-term follow-up is warranted to definitively assess the long-term effect of LP and the risk of deformity over time.

Translaminar versus pedicle screw fixation of C2: comparison of surgical morbidity and accuracy of 313 consecutive screws.

OBJECTIVE: C2 translaminar (TL) screws rigidly capture the posterior elements of C2, avoid risk of vertebral artery injury, and are less technically demanding than C2 pedicle (PD) screws. However, a C2-TL screw breach places the spinal cord at risk, and the durability of C2-TL screws remains unknown. It is unclear if TL versus PD screw fixation of C2 is truly associated with less operative morbidity, greater accuracy of screw placement, or equivalent durability. METHODS: We retrospectively reviewed the records of 167 consecutive patients undergoing posterior cervical fusion with either PD or TL screw fixation of C2. Perioperative morbidity, breach of the C2 lamina or pedicle on postoperative computed tomographic scans, and rates of operative revision were compared between PD and TL screw constructs in axial (C1-C2 or C1-C3) and subaxial (C2 and caudal) cervical fusions. RESULTS: In total, 152 C2-TL screws and 161 C2-PD screws were placed in 167 patients. Thirty-one (19%) cases of axial cervical fusion (C1-C2 or C1-C3) were performed (mean age, 63.8 +/- 20.6 years) with either C2-TL (16 [52%]) or C2-PD (15 [48%]) screw fixation. One hundred thirty-six (81%) cases of subaxial cervical fusion (C2-caudal) were performed (mean age, 57.9 +/- 14.7 years) with either C2-TL (66 [49%]) or C2-PD (70 [51%]) screw fixation. For both axial and subaxial cervical fusions, baseline patient characteristics and all measures of perioperative morbidity were similar between C2-TL and C2-PD screw cohorts. In total, 11 (7%) PD screws breached the pedicle (0 requiring acute revision) versus only 2 (1.3%) TL screws that breached the C2 lamina (1 requiring acute revision) (P = 0.018). By 1 year postoperatively, pseudoarthrosis or screw pullout requiring reoperation was required in 4 (6.1%) patients with C2-TL screws versus 0 (0%) patients with PD screws (P < 0.05 for subaxial constructs). No cases of C2-TL or C2-PD axial fusion required reoperation or screw pullout or pseudoarthrosis. CONCLUSION: In our experience, radiographic breach of C2 pedicle screws occurred more frequently than C2 laminar screw breach. However, this was not associated with an increase in morbidity. By 12 months postoperatively, C2-TL screws were associated with a greater incidence of operative revision when used in subaxial constructs but similarly effective for axial cervical constructs. The 1-year durability of C2-TL screws might be inferior to C2 pedicle screws for subaxial fusions, but equally effective for axial cervical fusions.

Long-term clinical outcomes following en bloc resections for sacral chordomas and chondrosarcomas: a series of twenty consecutive patients.

STUDY DESIGN: Retrospective study of 20 consecutive patients who underwent en bloc tumor excision of sacral chordomas and chondrosarcomas. OBJECTIVE: To evaluate the functional and oncological outcomes following en bloc tumor excision for sacral chordomas and chondrosarcomas. SUMMARY OF BACKGROUND DATA: Chordomas and chondrosarcomas are 2 of the most common malignant primary tumors of the sacrum in adults. To date, few large clinical series with en bloc resection of these tumors exist. METHODS: An institutional primary spine tumor surgical database was retrospective reviewed. Twenty consecutive patients with sacral chordomas and chondrosarcomas who underwent primary en bloc tumor excisions from 2002 to 2007 were included in the study. Surgical margin, perioperative complications, and postoperative functional status in these patients were analyzed. Disease-free survival following en bloc tumor excision was determined using the Kaplan-Meier method. RESULTS: The study cohort included 8 males and 12 females with an average age of 53.5 years and a man follow-up of 47.8 months. Wide or marginal en bloc resection was achieved in 14 patients. In 6 other patients, tumor was identified at the surgical margins, and they were considered to have contaminated/intralesional resections. The 30-day perioperative morbidities in this series included 1 death from pulmonary embolism and 9 wound complications. Forty percent of the patients had normal bladder and bowel functions after surgery, while 60% of the patients had partial or complete loss of bladder and bowel functions. All but 2 patients in this group remained ambulatory after the surgery. The mean disease-free survival for patients with wide or marginal en bloc tumor excisions was 51 months, but the mean disease-free survival was only 17.5 months for patients who had contaminated/intralesional resections. CONCLUSION: Wide or marginal en bloc excision of sacral chordoma and chondrosarcoma is associated with significant improvement in disease-free survival with acceptable perioperative morbidity rate.

Factors associated with progression-free survival and long-term neurological outcome after resection of intramedullary spinal cord tumors: analysis of 101 consecutive cases.

OBJECT: With the introduction of electrophysiological spinal cord monitoring, surgeons have been able to perform radical resection of intramedullary spinal cord tumors (IMSCTs). However, factors associated with tumor resectability, tumor recurrence, and long-term neurological outcome are poorly understood. METHODS: The authors retrospectively reviewed 101 consecutive cases of IMSCT resection in adults and children at a single institution. Neurological function and MR images were evaluated preoperatively, at discharge, 1 month after surgery, and every 6 months thereafter. Factors associated with gross-total resection (GTR), progression-free survival (PFS), and long-term neurological improvement were assessed using multivariate regression analysis. RESULTS: The mean age of the patients was 41 +/- 18 years and 17 (17%) of the patients were pediatric. Pathological type included ependymoma in 51 cases, hemangioblastoma in 15, pilocytic astrocytoma in 16, WHO Grade II astrocytoma in 10, and malignant astrocytoma in 9. A GTR was achieved in 60 cases (59%). Independent of histological tumor type, an intraoperatively identifiable tumor plane (OR 25.3, p < 0.0001) and decreasing tumor size (OR 1.2, p = 0.05) were associated with GTR. Thirty-four patients (34%) experienced acute neurological decline after surgery (associated with increasing age [OR 1.04, p = 0.02] and with intraoperative change in motor evoked potentials [OR 7.4, p = 0.003]); in 14 (41%) of these patients the change returned to preoperative baseline within 1 month. In 31 patients (31%) tumor progression developed by last follow-up (mean 19 months). Tumor histology (p < 0.0001) and the presence of an intraoperatively identified tumor plane (hazard ratio [HR] 0.44, p = 0.027) correlated with improved PFS. A GTR resulted in improved PFS for hemangioblastoma (HR 0.004, p = 0.04) and ependymoma (HR 0.2, p = 0.02), but not astrocytoma. Fifty-five patients (55%) maintained overall neurological improvement by last follow-up. The presence of an identifiable tumor plane (HR 3.1, p = 0.0004) and improvement in neurological symptoms before discharge (HR 2.3, p = 0.004) were associated with overall neurological improvement by last follow-up (mean 19 months). CONCLUSIONS: Gross-total resection can be safely achieved in the vast majority of IMSCTs when an intraoperative plane is identified, independent of pathological type. The incidence of acute perioperative neurological decline increases with patient age but will improve to baseline in nearly half of patients within 1 month. Long-term improvement in motor, sensory, and bladder dysfunction may be achieved in a slight majority of patients and occurs more frequently in patients in whom a surgical plane can be identified. A GTR should be attempted for ependymoma and hemangioblastoma, but it may not affect PFS for astrocytoma. For all tumors, the intraoperative finding of a clear tumor plane of resection carries positive prognostic significance across all pathological types.