Learning Curve of Robotic End-to-Side Microanastomoses.

BACKGROUND AND OBJECTIVES: Robotics are becoming increasingly widespread within various neurosurgical subspecialties, but data pertaining to their feasibility in vascular neurosurgery are limited. We present our novel attempt to evaluate the learning curve of a robotic platform for microvascular anastomoses. METHODS: One hundred and sixty one sutures were performed and assessed. Fourteen anastomoses (10 robotic [MUSA-2 Microsurgical system; Microsure] and 4 hand-sewn) were performed by the senior author on 1.5-mm caliber tubes and recorded with the Kinevo 900 (Zeiss) operative microscope. We separately compared interrupted sutures (from needle insertion until third knot) and running sutures (from needle insertion until loop pull-down). Average suture timing across all groups was compared using an unpaired Student's t test. Exponential smoothing (α = 0.2) was then applied to the robotic data sets for validation and a second set of t tests were performed. RESULTS: We compared 107 robotic sutures with 54 hand-sewn sutures. There was a significant difference between the average time/stitch for the robotic running sutures (n = 55) and the hand-sewn running sutures (n = 31) (31.2 seconds vs 48.3 seconds, respectively; P-value = .00052). Exponential smoothing (α = 0.2) reinforced these results (37.6 seconds vs 48.3 seconds; P-value = .014625). Average robotic running times surpassed hand-sewn by the second anastomosis (38.8 seconds vs 48.3 seconds) and continued to steadily decrease with subsequent stitches. The average of the robotic interrupted sutures (n = 52) was significantly longer than the hand-sewn (n = 23) (171.3 seconds vs 70 seconds; P = .000024). Exponential smoothing (α = 0.2) yielded similar results (196.7 seconds vs 70 seconds; P = .00001). However, average robotic interrupted times significantly decreased from the first to the final anastomosis (286 seconds vs 105.2 seconds; P = .003674). CONCLUSION: Our results indicate the learning curve for robotic microanastomoses is short and encouraging. The use of robotics warrants further study for potential use in cerebrovascular bypass procedures.

Augmented Reality Demonstration Survey Results From a Veteran Affairs Medical Center.

Background: Augmented reality (AR) has a wide range of potential applications to enhance health care. Understanding how the introduction of a new technology may impact employees is essential for overall health care system success. Methods: Survey responses were obtained before and after a health care-focused interactive AR demonstration at a US Department of Veterans Affairs (VA) medical center. Data were assessed with descriptive statistics, Wilcoxon signed rank matched pairs test, pooled t test, and analysis of variance. Results: A total of 166 individuals participated in the demonstration and survey. Statistically significant improvements were seen after the use of the new AR technology in each of the categories assessed using a 5-point Likert scale. Scores for perceptions of institutional innovativeness increased from 3.4 to 4.5 (a 22% increase; P < .001); employee excitement about the VA increased from 3.7 to 4.3 (a 12% increase; P < .001); and employee likelihood to continue working at VA increased from 4.2 to 4.5 (a 6% increase; P < .001). Subgroup analysis demonstrated statistically significant differences by employee veteran status, VA tenure, and sex. Respondents felt strongly that this type of work will positively impact health care and that the VA should continue these efforts. Conclusions: An AR demonstration significantly increased employee excitement and intention to continue employment at the VA and provided valuable insights about the most impactful uses of AR in health care.

Augmented Reality-Assisted Percutaneous Rhizotomy for Trigeminal Neuralgia.

BACKGROUND: Percutaneous rhizotomy of the trigeminal nerve is a common surgery to manage medically refractory trigeminal neuralgia. Traditionally, these procedures have been performed based on anatomic landmarks with fluoroscopic guidance. Augmented reality (AR) relays virtual content on the real world and has the potential to improve localization of surgical targets based on preoperative imaging. OBJECTIVE: To study the potential application and benefits of AR as an adjunct to traditional fluoroscopy-guided glycerol rhizotomy (GR). METHODS: We used traditional fluoroscopy-guided percutaneous GR technique as previously described, performed under general anesthesia. Anatomic registration to the Medivis SurgicalAR system was performed based on the patient's preoperative computerized tomography, and the surgeon was equipped with the system's AR goggles. AR was used as an adjunct to fluoroscopy for trajectory planning to place a spinal needle into the medial aspect of the foramen ovale. RESULTS: A 50-year-old woman with multiple sclerosis-related right-sided classical trigeminal neuralgia had persistent pain, refractory to medications, previous gamma knife stereotactic radiosurgery, and percutaneous radiofrequency rhizotomy performed elsewhere. The patient underwent AR-assisted fluoroscopy-guided percutaneous GR. The needle was placed into the right trigeminal cistern within seconds. She was discharged home after a few hours of observation with no complications and reported pain relief. CONCLUSION: AR-assisted percutaneous rhizotomy may enhance the learning curve of these types of procedures and decrease surgery duration and radiation exposure. This allowed rapid and correct placement of a spinal needle through the foramen ovale.

The historical evolution of microvascular decompression for trigeminal neuralgia: from Dandy's discovery to Jannetta's legacy.

Although the symptoms of trigeminal neuralgia (TN) have been well described throughout the history of medicine, its etiology was initially not well understood by most surgeons. The standard procedure used to treat TN today, microvascular decompression (MVD), evolved due to the efforts of numerous neurosurgeons throughout the twentieth century. Walter Dandy was the first to utilize the cerebellar (suboccipital) approach to expose the trigeminal nerve for partial sectioning. He made unique observations about the compression of the trigeminal nerve by nearby structures, such as vasculature and tumors, in TN patients. In the 1920s, Dandy unintentionally performed the first MVD of the trigeminal nerve root. In the 1950s, Palle Taarnhøj treated a TN patient by performing the first intentional decompressive procedure on the trigeminal nerve root solely through the removal of a compressive tumor. By the 1960s, W. James Gardner was demonstrating that the removal of offending lesion(s) or decompression of nearby vasculature alleviated pressure on the trigeminal nerve and the pain associated with TN. By the 1990s, Peter Jannetta proved Dandy's original hypothesis; he visualized the compression of the trigeminal nerve at the root entry zone in TN patients using an intraoperative microscope. In this paper, we recount the historical evolution of MVD for the treatment of TN.

History of Hemostasis in Neurosurgery.

Control of bleeding in the confined area of the skull is imperative for successful neurosurgery and the prevention of devastating complications such as postoperative hemorrhage. This paper reviews the historical evolution of methods to achieve successful hemostasis in neurosurgery from the early1800s to today. The major categories of hemostatic agents (mechanical, chemical and thermal) are delineated and discussed in chronological order. The significance of this article is in its detailed history of the kinds of hemostatic methods that have evolved with our accumulating medical and surgical knowledge, which may inform future innovations and improvements.

Elevated intracranial pressure and reversible eye-tracking changes detected while viewing a film clip.

OBJECTIVE The precise threshold differentiating normal and elevated intracranial pressure (ICP) is variable among individuals. In the context of several pathophysiological conditions, elevated ICP leads to abnormalities in global cerebral functioning and impacts the function of cranial nerves (CNs), either or both of which may contribute to ocular dysmotility. The purpose of this study was to assess the impact of elevated ICP on eye-tracking performed while patients were watching a short film clip. METHODS Awake patients requiring placement of an ICP monitor for clinical purposes underwent eye tracking while watching a 220-second continuously playing video moving around the perimeter of a viewing monitor. Pupil position was recorded at 500 Hz and metrics associated with each eye individually and both eyes together were calculated. Linear regression with generalized estimating equations was performed to test the association of eye-tracking metrics with changes in ICP. RESULTS Eye tracking was performed at ICP levels ranging from -3 to 30 mm Hg in 23 patients (12 women, 11 men, mean age 46.8 years) on 55 separate occasions. Eye-tracking measures correlating with CN function linearly decreased with increasing ICP (p < 0.001). Measures for CN VI were most prominently affected. The area under the curve (AUC) for eye-tracking metrics to discriminate between ICP < 12 and ≥ 12 mm Hg was 0.798. To discriminate an ICP < 15 from ≥ 15 mm Hg the AUC was 0.833, and to discriminate ICP < 20 from ≥ 20 mm Hg the AUC was 0.889. CONCLUSIONS Increasingly elevated ICP was associated with increasingly abnormal eye tracking detected while patients were watching a short film clip. These results suggest that eye tracking may be used as a noninvasive, automatable means to quantitate the physiological impact of elevated ICP, which has clinical application for assessment of shunt malfunction, pseudotumor cerebri, concussion, and prevention of second-impact syndrome.

A matched cohort comparison of clinical outcomes following microsurgical resection or stereotactic radiosurgery for patients with small- and medium-sized vestibular schwannomas.

OBJECTIVE A randomized trial that compares clinical outcomes following microsurgery (MS) or stereotactic radiosurgery (SRS) for patients with small- and medium-sized vestibular schwannomas (VSs) is impractical, but would have important implications for clinical decision making. A matched cohort analysis was conducted to evaluate clinical outcomes in patients treated with MS or SRS. METHODS The records of 399 VS patients who were cared for by 2 neurosurgeons and 1 neurotologist between 2001 and 2014 were evaluated. From this data set, 3 retrospective matched cohorts were created to compare hearing preservation (21 matched pairs), facial nerve preservation (83 matched pairs), intervention-free survival, and complication rates (85 matched pairs) between cases managed with SRS and patients managed with MS. Cases were matched for age at surgery (± 10 years) and lesion size (± 0.1 cm). To compare hearing outcomes, cases were additionally matched for preoperative Class A hearing according to the American Academy of Otolaryngology-Head and Neck Surgery guidelines. To compare facial nerve (i.e., cranial nerve [CN] VII) outcomes, cases were additionally matched for preoperative House-Brackmann (HB) score. Investigators who were not involved with patient care reviewed the clinical and imaging records. The reported outcomes were as assessed at the time of the last follow-up, unless otherwise stated. RESULTS The preservation of preoperative Class A hearing status was achieved in 14.3% of MS cases compared with 42.9% of SRS cases (OR 4.5; p < 0.05) after an average follow-up interval of 43.7 months and 30.3 months, respectively. Serviceable hearing was preserved in 42.8% of MS cases compared with 85.7% of SRS cases (OR 8.0; p < 0.01). The rates of postoperative CN VII dysfunction were low for both groups, although significantly higher in the MS group (HB III-IV 11% vs 0% for SRS; OR 21.3; p < 0.01) at a median follow-up interval of 35.7 and 19.0 months for MS and SRS, respectively. There was no difference in the need for subsequent intervention (2 MS patients and 2 SRS patients). CONCLUSIONS At this high-volume center, VS resection or radiosurgery for tumors ≤ 2.8 cm in diameter was associated with low overall morbidity. The need for subsequent intervention was the same in both groups. SRS was associated with improved hearing and facial preservation rates and reduced morbidity, but with a shorter average follow-up period. Facial function was excellent in both groups. Since patients were not randomly selected for surgery, different clinical outcomes may be of different value to individual patients. Both anticipated medical outcomes and patient goals remain the drivers of treatment decisions.

Schwannomas of the sinonasal tract and anterior skull base: a systematic review of 94 cases.

BACKGROUND: Schwannomas of the anterior skull base (ASB) and sinonasal tract are extremely rare. These lesions mimic other pathologies such as olfactory groove meningiomas, hemangiopericytomas, and esthesioneuroblastomas. Because of their low incidence, ASB and sinonasal tract schwannomas have not been well characterized. A systematic review of ASB and sinonasal tract schwannomas was conducted to further elucidate the presentation and surgical management of these lesions. METHODS: A MEDLINE/PubMed search was performed, identifying 71 articles representing 94 cases of ASB and sinonasal schwannomas. Each case was analyzed for demographics, clinical presentation, anatomic location, radiographic features, and surgical treatment. RESULTS: In 94 patients with ASB and sinonasal schwannomas, 44 (46.8%) were exclusively sinonasal, 30 cases (31.9%) were exclusively intracranial, 12 (12.8%) were primarily intracranial with extension into the paranasal sinuses, and 8 (8.5%) were primarily sinonasal with intracranial extension. Headaches and nasal obstruction were the most common presenting symptoms occurring in 30.9 and 29.8% of cases, respectively. Magnetic resonance imaging typically showed a hyperintense mass on T2-weighted imaging (70%) and hypointense (41%) on T1-weighted imaging. Most patients underwent surgical gross total resection via craniotomy, endoscopic endonasal approach, rhinotomy, or other sinonasal approaches. Recurrence occurred in three cases ranging from 4 months to 13 years. Postoperative complications included cerebral spinal fluid leakage, bacterial meningitis, epidural hematoma, and pneumocranium. CONCLUSION: ASB and sinonasal schwannomas are rare lesions and should be considered in the differential diagnosis of ASB masses involving the cribriform plate with sinonasal extension. Gross total resection of these lesions should be considered the goal of operative management.

Prevalence of asymptomatic incidental aneurysms: a review of 2,685 computed tomographic angiograms.

OBJECTIVE: Intracranial aneurysms are a public health issue with a potential for rupturing, causing significant morbidity/mortality. The prevalence of unruptured intracranial aneurysms, including those that are asymptomatic, varies widely, as it has been determined through autopsy studies as well as conventional angiography. However, computed tomography angiography, a less invasive procedure, has replaced the use of conventional angiography in the recent decades. The objective of the present study is to determine the prevalence of incidental aneurysms. METHODS: The present study reviews all computed tomography angiography cases within the past decade at a single institution. RESULTS: Of 2195 cases included in the study, 39 (1.8%) were found to have asymptomatic unruptured aneurysms. CONCLUSIONS: The numbers of asymptomatic incidental aneurysms have increased.

Readability assessment of Internet-based patient education materials related to acoustic neuromas.

OBJECTIVE: The objectives of this study were to assess the readability of Internet-based patient education materials related to acoustic neuromas (AN-IPEMs) by 4 widely validated readability indices, to evaluate scores against the existing sixth grade recommended reading level, and to compare the readability scores of patient education materials (PEMs) produced by professional organizations, clinical practices, hospitals, and miscellaneous sources. MATERIALS AND METHODS: AN-IPEMs from 67 web sites (6 professional societies, 33 clinical practices, 19 hospitals, and 9 miscellaneous) were assessed using Flesch Reading Ease Score (FRES), Flesch-Kincaid Grade Level (FKGL), Simple Measure of Gobbledygook (SMOG), and Gunning Frequency of Gobbledygook (Gunning FOG). Scores were then evaluated against national recommendations by 1-tailed t tests and against each other using 1-way ANOVAs. RESULTS: The average FKGL, SMOG, and Gunning FOG scores were all significantly higher than the recommended sixth grade reading level suggested by the USDHHS (p < 0.0001, single sample 1-tailed t test). Zero articles, by all indices, had a reading level equal to or below the sixth grade reading level. The FKGLs also varied between the various sources at a significant level (p = 0.01 one-way ANOVA independent samples). The average FKGLs of clinical practice and professional society AN-IPEMs were significantly higher than the average FKGLs of hospital AN-IPEMs (both p ≤ 0.05 one-tailed t-tests assuming unequal variances). CONCLUSION: AN-IPEMs are written at a level significantly higher than that suggested by national recommendations. Current AN-IPEMs may need to be revised in order to enhance patient comprehension.

Delayed neurological deterioration after mild head injury: cause, temporal course, and outcomes.

BACKGROUND: Mild head injury (MHI) complicated by an intracranial hemorrhage (ICH) is a common cause of hospital admission after head trauma. Most patients are treated nonoperatively, remain neurologically stable, and are discharged uneventfully. However, a small percentage of patients suffer delayed neurological deterioration (DND). Little is known about the characteristics of DND after an MHI complicated by ICH. OBJECTIVE: To identify the cause, temporal course, and outcomes of patients who deteriorated neurologically after presenting with MHI and ICH. METHODS: A retrospective review was performed of all adult patients presenting over 54 consecutive months with MHI and ICH. Patients who were treated nonoperatively after initial head computed tomography and had a subsequent DND (Glasgow Coma Scale score decrease ≥2) were identified. Demographics, neurological status, clinical course, radiographic findings, and outcome data were collected. RESULTS: Over 54 months, 757 patients with MHI plus ICH were admitted for observation; of these, 31 (4.1%) experienced DND. Eighty-seven percent of patients deteriorated within 24 hours after admission. Twenty-one patients (68%) deteriorated as a result of progressive intracranial hemorrhage, and 10 patients (32%) deteriorated as a result of medical causes. Seven patients (23%) died. Variables significantly associated with mortality included age > 60 years, coagulopathy, and change in Marshall computed tomography classification. CONCLUSION: The incidence of delayed neurological deterioration after MHI with ICH is low and usually occurs within 24 hours after admission. It results in significant morbidity and mortality if it is the result of progressive intracranial hemorrhage. Further research is needed to identify risk factors that can allow early detection and improve outcomes in these patients.

Geometric alopecia after preoperative angioembolization of juvenile nasopharyngeal angiofibroma.

Resection of a juvenile nasopharyngeal angiofibroma (JNA) is challenging because of high intraoperative blood loss secondary to the tumor's well-developed vascularity. Endoscopic sinus and skull base surgeons commonly collaborate with neurointerventionalists to embolize these tumors before resection in an attempt to reduce the vascular supply and intraoperative bleeding. However, angioembolization can be associated with significant complications. Geometric alopecia from angioembolization of JNA has not been previously reported in the otolaryngologic literature. In this study, we discuss geometric alopecia from radiation exposure during preoperative angioembolization of a JNA.

Assessment of mucocele formation after endoscopic nasoseptal flap reconstruction of skull base defects.

Advances in endoscopic skull base (SB) surgery have led to the resection of increasingly larger cranial base lesions, resulting in large SB defects. These defects have initially led to increased postoperative cerebrospinal fluid (CSF) leaks. The development of the vascularized pedicled nasoseptal flap (PNSF) has successfully reduced postoperative CSF leaks. Mucocele formation, however, has been reported as a complication of this technique. In this study, we analyze the incidence of mucocele formation after repair of SB defects using a PNSF. A retrospective review was performed from December 2008 to December 2011 to identify patients who underwent PNSF reconstruction for large ventral SB defects. Demographic data, defect site, incidence of postoperative CSF leaks, and rate of mucocele formation were collected. Seventy patients undergoing PNSF repair of SB defects were identified. No postoperative mucocele formation was noted at an average radiological follow-up of 11.7 months (range, 3-36.9 months) and clinical follow-up of 13.8 months (range, 3-38.9 months), making the overall mucocele rate 0%. The postoperative CSF leak rate was 2.9%. Proper closure of SB defects is crucial to prevent CSF leaks. The PNSF is an efficient technique for these repairs. Although this flap may carry an inherent risk of mucocele formation when placed over mucosalized bone during repair, we found that meticulous and strategic removal of mucosa from the site of flap placement resulted in a 0% incidence of postoperative mucocele formation in our cohort.

In-office balloon dilation and drainage of frontal sinus mucocele.

Treatment of frontal sinus disease represents one of the most challenging aspects of endoscopic sinus surgery. Frontal sinus mucocele drainage may be an exception to the rule because in many instances, the expansion of the mucocele widens the frontal sinus recess and renders surgical drainage technically undemanding. Recently, there has been an increased interest in in-office procedures in otolaryngology because of patient satisfaction and substantial savings of time and cost for both patients and physicians. Similarly, the past few years have witnessed an increased use of balloon dilation devices in sinus surgery. Previously, we have described the in-office use of this device in treating patients who failed prior conventional frontal sinusotomy in the operating room. In this report, we describe our step-by-step in-office experience using this tool for drainage of a large frontal sinus mucocele.

Postoperative cerebrospinal fluid leak after septoplasty: A potential complication of occult anterior skull base encephalocele.

Postoperative cerebrospinal fluid (CSF) rhinorrhea after septoplasty is a known entity resulting from errors in surgical technique and improper handling of the perpendicular plate of the ethmoid bone. When these occur, urgent management is necessary to prevent deleterious sequelae such as meningitis, intracranial abscess, and pneumocephalus. Encephaloceles are rare occurrences characterized by herniation of intracranial contents through a skull base defect that can predispose patients to CSF rhinorrhea. In this report, we present a case of CSF rhinorrhea occurring 2 weeks after septoplasty likely from manipulation of an occult anterior skull base encephalocele. To our knowledge, no previous similar case has been reported in the literature. Otolaryngologists should be aware of the possibility of occult encephaloceles while performing septoplasties because minimal manipulation of these entities may potentially result in postoperative CSF leakage.

Reconstruction of pterional defects after frontotemporal and orbitozygomatic craniotomy using Medpor Titan implant: cosmetic results in 98 patients.

OBJECTIVE: Reconstruction of pterional and temporal defects after frontotemporal (FT) and orbitozygomatic (OZ) craniotomy is important for avoidance of temporal hollowing, maintaining functional restoration, and achieving optimal cosmesis. The objective of this study is to describe our experience and cosmetic results with pterional reconstruction after FT and OZ craniotomy with the Medpor Titan implant. METHODS: Ninety-eight consecutive patients underwent reconstruction of pterional and temporal defects after FT and OZ craniotomy using the Medpor Titan implant. The implant was shaped to recreate the pterion to provide coverage for the cranial defect and to bolster the temporalis muscle to prevent temporal hollowing. The implant was then secured to the bone flap with titanium screws. Cosmetic evaluation was performed from both surgeon's and patient's perspective. RESULTS: Of 90 patients who underwent cosmetic assessment at the 3 month follow-up, temporalis asymmetry was noticed subjectively by three patients and noted in 7 patients by the surgeon. Orbital asymmetry was not noticed in any cases by either surgeon or patient. Overall patient satisfaction was found in 89 of 90 patients (98.9%). There were no cases of temporal hollowing. One patient had a delayed wound infection, and one had an inflammatory reaction that required removal of the implant. CONCLUSIONS: Our technique using the Medpor Titan implant is a fast and effective method for pterional reconstruction after FT and OZ craniotomy with excellent cosmetic results and patient satisfaction. The implant combines the advantages of both porous polyethylene and titanium mesh, including easy custom-shaping without sharp edges, structural support and relatively lower cost.

Challenges and surgical nuances in reconstruction of large planum sphenoidale tuberculum sellae defects after endoscopic endonasal resection of parasellar skull base tumors.

OBJECTIVES/HYPOTHESIS: Endoscopic endonasal transplanum transtuberculum (EETT) resection of parasellar skull base (SB) tumors often results in large SB defects with intraoperative high-flow cerebrospinal fluid (CSF) leaks. Reconstruction of these defects can be challenging because of the large defects size, communication with the suprasellar cistern, and close proximity to the optic nerves and chiasm. Recent studies have postulated that transplanum defects may be associated with increased postoperative CSF leakage. We review our experience with reconstruction of transplanum defects after EETT resection of parasellar SB tumors. Challenges encountered during these repairs and our operative nuances for successful reconstruction are discussed. METHODS: A retrospective analysis was performed between March 2010 and February 2012 on patients undergoing reconstruction of transplanum defects after EETT resection of parasellar SB tumors. Repair materials, defect sizes, postoperative CSF leakage, postoperative CSF diversion, and demographic data were collected. RESULTS: Nineteen patients who underwent 22 repairs with a pedicled nasoseptal flap (PNSF) were identified. The mean age was 47.6 years (range, 12-68 years). Average defect size was 5.6 cm(2) (range, 2.2-10.4 cm(2)). Three failed repairs necessitated a revision procedure. All three revisions were successfully reconstructed with the previously used PNSF. The mean follow-up period was 13.5 months (range, 1-26 months). The overall success rate was 86.4% for transplanum defects alone, as compared to 97.0% for our comprehensive PNSF experience in 99 repairs. CONCLUSION: Repair of large transplanum defects after EETT resection of parasellar SB tumors presents a unique challenge. Using a PNSF along with meticulous multilayer closure may help decrease postoperative CSF leaks.

Management of sinonasal hemangiopericytomas: a systematic review.

BACKGROUND: Hemangiopericytomas are typically found in soft-tissue, but only rarely found in the sinonasal tract. Sinonasal hemangiopericytomas have been reported mostly through case studies, and optimal treatment is considered surgical excision. Classically, open surgical methods of tumor extirpation have been considered standard of care. With the wider use of endoscopic methods, an updated systematic review in terms of treatment is warranted. METHODS: Cases were identified using a MEDLINE and PubMed search. Relevant studies were identified, and data was extracted regarding patient demographics, presenting symptoms, tumor characteristics, treatment, and outcomes. RESULTS: A total of 128 cases were collected from 56 articles, consisting of case reports and series. The most common presenting symptoms were epistaxis, nasal obstruction, and facial pain/swelling/pressure. Computed tomography (CT) and X-ray were the most common modes of imaging during diagnosis and operative planning. The tumor often occupied multiple locations in the sinonasal tract at initial presentation. Surgical resection was the mainstay of treatment in 126 of the 128 cases (98.4%), either through open resection or endoscopic techniques. Surgical removal resulted in no recurrence in 79.7% of the cases. The use of endoscopic techniques increased significantly in the past decade. This review found no significant difference in terms of recurrence between endoscopic and open treatment groups, age, gender, and unilocality vs multilocality of tumor. CONCLUSION: Surgical management remains the mainstay of treatment for hemangiopericytomas. Endoscopic resection of these lesions has increased over the last few decades and has become a safe, viable, and reasonable alternative to open resection.

Analysis of cervical sagittal alignment after screw-rod fixation.

BACKGROUND: The use of posterior instrumentation constructs is well established for subaxial cervical stabilizations/fusions. The importance of global and regional sagittal alignment has become increasingly recognized. OBJECTIVE: To perform an analysis using computed tomography scans to determine the effect of posterior instrumentation on postoperative cervical sagittal alignment at long-term follow-up. METHODS: Over a period of 6 years, 56 consecutive patients (38 male and 18 female patients; mean age, 47 years) underwent cervical screw-rod fixation. Plain radiographs, computed tomography scans, and magnetic resonance images were analyzed preoperatively to assess sagittal alignment (C2-C7). Postoperatively, computed tomography scans and serial radiographs were obtained in all patients. With the use of independent observers, changes in sagittal alignment were determined by comparing the preoperative and postoperative imaging studies. RESULTS: In total, 390 screws were placed in the cervical spines of 56 patients. Definitive radiographic fusion was detected in all 56 patients (100%). There were no incidences of instrumentation failures or lucencies surrounding any screws. Patients with preoperative kyphosis (n = 19; mean, +9.9°) improved their sagittal alignment by 6.5° (final mean, +3.4°), whereas patients with preoperative lordosis (n = 37; mean -15.44°) maintained their lordosis (final mean, -15.3°). Mean duration of follow-up was 32.5 months. CONCLUSION: Radiographic analysis showed lateral mass fixation to be safe and effective. Certain operative techniques allowed substantial deformity correction and maintenance of long-term correction of deformity. Screw-rod fixation may be an effective method for maintaining lordotic cervical alignment in previously lordotic patients and for significantly correcting kyphotic deformity in patients with a preoperative kyphosis.