Gabriel A. Smith

Geographic variation and regional trends in adoption of endovascular techniques for cerebral aneurysms

OBJECT Considerable evolution has occurred in treatment options for cerebral aneurysms. Development of endovascular techniques has produced a significant change in the treatment of ruptured and unruptured intracranial aneurysms. Adoption of endovascular techniques and increasing numbers of patients undergoing endovascular treatment may affect health care expenditures. Geographic assessment of growth in endovascular procedures has not been assessed. METHODS The National Inpatient Sample (NIS) was queried for ICD-9 codes for clipping and coiling of ruptured and unruptured cerebral aneurysms from 2002 to 2008. Patients with ruptured and unruptured cerebral aneurysms were compared according to in-hospital deaths, hospital length of stay, total hospital cost, and selected procedure. Hospital costs were adjusted to bring all costs to 2008 equivalents. Regional variation over the course of the study was explored. RESULTS The NIS recorded 12,588 ruptured cerebral aneurysm cases (7318 clipped and 5270 coiled aneurysms) compared with 11,606 unruptured aneurysm cases (5216 clipped and 6390 coiled aneurysms), representing approximately 121,000 aneurysms treated in the study period. Linear regression analysis found that the number of patients treated endovascularly increased over time, with the total number of endovascular patients increasing from 17.28% to 57.59% for ruptured aneurysms and from 29.70% to 62.73% for unruptured aneurysms (p < 0.00001). Patient age, elective status, and comorbidities increased the likelihood of endovascular treatment (p < 0.00001, p < 0.00004, and p < 0.02, respectively). In patients presenting with subarachnoid hemorrhage (SAH), endovascular treatments were more commonly chosen in urban and academic medical centers (p = 0.009 and p = 0.05, respectively). In-hospital deaths decreased over the study period in patients with both ruptured and unruptured aneurysms (p < 0.00001); presentation with SAH remained the single greatest predictor of death (OR 38.09, p < 0.00001). Geographic analysis showed growth in endovascular techniques concentrated in eastern and western coastal states, with substantial variation in adoption of endovascular techniques (range of percentage of endovascular patients [2008] 0%-92%). There were higher costs in patients treated endovascularly, but these differences were likely secondary to presenting diagnosis and site-of-service variations. CONCLUSIONS The NIS database reveals a significant increase in the use of endovascular techniques, with the majority of both ruptured and unruptured aneurysms treated endovascularly by 2008. Differences in hospital costs between open and endovascular techniques are likely secondary to patient and site-of-service factors. Presentation with SAH was the primary factor affecting hospital cost and a greater percentage of endovascular procedures completed at urban academic medical centers. There is substantial regional variation in the adoption of endovascular techniques.

UDP xylose synthase 1 is required for morphogenesis and histogenesis of the craniofacial skeleton.

UDP-xylose synthase (Uxs1) is strongly conserved from bacteria to humans, but because no mutation has been studied in any animal, we do not understand its roles in development. Furthermore, no crystal structure has been published. Uxs1 synthesizes UDP-xylose, which initiates glycosaminoglycan attachment to a protein core during proteoglycan formation. Crystal structure and biochemical analyses revealed that an R233H substitution mutation in zebrafish uxs1 alters an arginine buried in the dimer interface, thereby destabilizing and, as enzyme assays show, inactivating the enzyme. Homozygous uxs1 mutants lack Alcian blue-positive, proteoglycan-rich extracellular matrix in cartilages of the neurocranium, pharyngeal arches, and pectoral girdle. Transcripts for uxs1 localize to skeletal domains at hatching. GFP-labeled neural crest cells revealed defective organization and morphogenesis of chondrocytes, perichondrium, and bone in uxs1 mutants. Proteoglycans were dramatically reduced and defectively localized in uxs1 mutants. Although col2a1a transcripts over-accumulated in uxs1 mutants, diminished quantities of Col2a1 protein suggested a role for proteoglycans in collagen secretion or localization. Expression of col10a1, indian hedgehog, and patched was disrupted in mutants, reflecting improper chondrocyte/perichondrium signaling. Up-regulation of sox9a, sox9b, and runx2b in mutants suggested a molecular mechanism consistent with a role for proteoglycans in regulating skeletal cell fate. Together, our data reveal time-dependent changes to gene expression in uxs1 mutants that support a signaling role for proteoglycans during at least two distinct phases of skeletal development. These investigations are the first to examine the effect of mutation on the structure and function of Uxs1 protein in any vertebrate embryos, and reveal that Uxs1 activity is essential for the production and organization of skeletal extracellular matrix, with consequent effects on cartilage, perichondral, and bone morphogenesis.

Impact of bone morphogenetic proteins on frequency of revision surgery, use of autograft bone, and total hospital charges in surgery for lumbar degenerative disease: review of the Nationwide Inpatient Sample from 2002 to 2008.

BACKGROUND CONTEXT Bone morphogenetic proteins (BMPs) were developed with the goal of improving clinical outcomes through the promotion of bony healing and reducing morbidity from iliac crest bone graft harvest. PURPOSE To complete a population-based assessment of the impact of BMP on use of autograft, rates of operative treatment for lumbar pseudoarthrosis, and hospital charges. STUDY DESIGN Nationwide Inpatient Sample (NIS) retrospective cohort assessment of 46,452 patients from 2002 to 2008. PATIENT SAMPLE All patients who underwent lumbar arthrodesis procedures for degenerative spinal disease. OUTCOME MEASURES Use of BMP, revision surgery status as a percentage of total procedures, and autograft harvest in lumbar fusion procedures completed for degenerative diagnoses. METHODS Demographic and geographic/practice data, hospital charges, and length of stay of all NIS patients with thoracolumbar and lumbosacral procedure codes for degenerative spinal diagnoses were recorded. Codes for autograft harvest, use of BMP, and revision surgery were included in multivariable regression analysis. RESULTS The assessment found 46,452 patients from 2002 to 2008 undergoing thoracolumbar or lumbar arthrodesis procedures for degenerative disease. Assuming a representative sample, this cohort models more than 200,000 US patients. There was steady growth in lumbar spine fusion and in the use of BMP. The use of BMP increased from 2002 to 2008 (odds ratio [OR], 1.50; 95% confidence interval [CI], 1.48-1.52). Revision procedures decreased over the study period (OR, 0.94; 95% CI, 0.91-0.96). The use of autograft decreased substantially after introduction of BMP but then returned to baseline levels; there was no net change in autograft use from 2002 to 2008. The use of BMP correlated with significant increases in hospital charges (

Extracranial ligation of ethmoidal arteries before resection of giant olfactory groove or planum sphenoidale meningiomas: 3 illustrative cases with a review of the literature on surgical techniques

13,362.39; standard deviation ± 596.28, p<.00001). The use of BMP in degenerative thoracolumbar procedures potentially added more than

Screening via CT angiogram after traumatic cervical spine fractures: narrowing imaging to improve cost effectiveness. Experience of a Level I trauma center

900 million to hospital charges from 2002 to 2008. CONCLUSIONS There was an overall decrease in rates of revision fusion procedures from 2002 to 2008. Introduction of BMP did not correlate with decrease in use of autograft bone harvest. Use of BMP correlated with substantial increase in hospital charges. The small decrease in revision surgeries recorded, combined with lack of significant change in autograft harvest rates, may question the financial justification for the use of BMP.

Impact of Preoperative Depression on Hospital Consumer Assessment of Healthcare Providers and Systems Survey Results in a Lumbar Fusion Population

OBJECT There are several surgical techniques for reducing blood loss-open surgical and endoscopic-prior to resection of giant anterior skull base meningiomas, especially when preoperative embolization is risky or not technically feasible. The authors present examples of an institutional experience using surgical ligation of the anterior and posterior ethmoidal arteries producing persistent tumor blush in partially embolized tumors. METHODS The authors identified 12 patients who underwent extracranial surgical ligation of ethmoidal arteries through either a transcaruncular or a Lynch approach. Of these, 3 patients had giant olfactory groove or planum sphenoidale meningiomas. After approval from the institution privacy officer, the authors studied the medical records and imaging data of these 3 patients, with special attention to surgical technique and outcome. The variations of ethmoidal artery foramina pertaining to this surgical approach were studied using preserved human skulls from the Hamann-Todd Osteological Collection at the Museum of Natural History, Cleveland, Ohio. RESULTS The extracranial ligation was performed successfully for control of the ethmoidal arteries prior to resection of hypervascular giant anterior skull base meningiomas. The surgical anatomy and landmarks for ethmoidal arteries were reviewed in anthropology specimens and available literature with reference to described surgical techniques. CONCLUSIONS Extracranial surgical ligation of anterior, and often posterior, ethmoidal arteries prior to resection of large olfactory groove or planum sphenoidale meningiomas provides a safe and feasible option for control of these vessels prior to either open or endoscopic resection of nonembolized or partially embolized tumors.

C5 Palsy After Cervical Spine Surgery: A Multicenter Retrospective Review of 59 Cases.

OBJECT Screening for vertebral artery injury (VAI) following cervical spine fractures is routinely performed across trauma centers in North America. From 2002 to 2007, the total number of neck CT angiography (CTA) studies performed in the Medicare population after trauma increased from 9796 to 115,021. In the era of cost-effective medical care, the authors aimed to evaluate the utility of CTA screening in detecting VAI and reduce chances of posterior circulation strokes after traumatic cervical spine fractures. METHODS A retrospective review of all patients presenting with cervical spine fractures to Northeast Ohios Level I trauma institution from 2002 to 2012 was performed. RESULTS There was a total of 1717 cervical spine fractures in patients presenting to Northeast Ohios Level I trauma institution between 2002 and 2012. CTA screening was performed in 732 patients, and 51 patients (0.7%) were found to have a VAI. Fracture patterns with increased odds of VAI were C-1 and C-2 combined fractures, transverse foramen fractures, and subluxation of adjacent vertebral levels. Ten posterior circulation strokes were identified in this patient population (0.6%) and found in only 4 of 51 cases of VAI (7.8%). High-risk fractures defined by Denver Criteria, VAI, and antiplatelet treatment of VAI were not independent predictors of stroke. CONCLUSIONS Cost-effective screening must be reevaluated in the setting of blunt cervical spine fractures on a case-by-case basis. Further prospective studies must be performed to elucidate the utility of screening for VAI and posterior circulation stroke prevention, if identified.

A revolution in preventing fatal craniovertebral junction injuries: lessons learned from the Head and Neck Support device in professional auto racing.

Study Design. A retrospective cohort study at a single institution. Objective. To determine the effect of preoperative depression on Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey scores in a lumbar fusion population. Summary of Background Data. HCAHPS surveys are used to assess the quality of the patient experience, and directly influences reimbursement for hospital systems and spine surgeons nationwide. Untreated depression has been linked to worse functional outcomes in spine surgery. We, however, aimed to elucidate whether HCAHPS survey responses were different in depressed patients. Methods. Prospectively collected functional outcome data including Patient Health Questionnaire 9, EuroQol five dimensions, and Pain Disability Questionnaire were analyzed preoperatively. Preoperative Patient Health Questionnaire 9 scores of greater than or equal to 10 (moderate to severe depression) defined our depressed cohort of patients. HCAHPS responses were obtained for each individual, allowing for real-world analysis of outcomes in this population. Results. In our 237 patient cohort, depressed patients were younger, female; were on full disability; and had lower scores on EuroQol five dimensions and Pain Disability Questionnaire preoperatively. Approximately 73.2% of depressed patients felt doctors treated them with respect, compared to 88.8% of patients without depression (P = 0.005). Also, depressed patients felt nurses treated them with less respect (P = 0.014) and that physicians did not listen to them as carefully (P = 0.029). Multivariate regression analysis revealed that patients with preoperative depression had higher odds of patients feeling less respected by both physicians and nurses. Multivariate analysis also revealed that depression was an independent predictor of lower patient satisfaction with nursing response to their needs. Conclusion. In patients undergoing lumbar fusion, preoperative depression was shown to have negative effect on patient experience measured by the HCAHPS survey. These results suggest that depression may be a modifiable risk factor for poor hospital experience. Level of Evidence: 3

Epidemiology and Outcomes of Vertebral Artery Injury in 16 582 Cervical Spine Surgery Patients: An AOSpine North America Multicenter Study.

Study Design: A multicenter, retrospective review of C5 palsy after cervical spine surgery. Objective: Postoperative C5 palsy is a known complication of cervical decompressive spinal surgery. The goal of this study was to review the incidence, patient characteristics, and outcome of C5 palsy in patients undergoing cervical spine surgery. Methods: We conducted a multicenter, retrospective review of 13 946 patients across 21 centers who received cervical spine surgery (levels C2 to C7) between January 1, 2005, and December 31, 2011, inclusive. P values were calculated using 2-sample t test for continuous variables and χ2 tests or Fisher exact tests for categorical variables. Results: Of the 13 946 cases reviewed, 59 patients experienced a postoperative C5 palsy. The incidence rate across the 21 sites ranged from 0% to 2.5%. At most recent follow-up, 32 patients reported complete resolution of symptoms (54.2%), 15 had symptoms resolve with residual effects (25.4%), 10 patients did not recover (17.0%), and 2 were lost to follow-up (3.4%). Conclusion: C5 palsy occurred in all surgical approaches and across a variety of diagnoses. The majority of patients had full recovery or recovery with residual effects. This study represents the largest series of North American patients reviewed to date.

Holospinal epidural abscess of the spinal axis: two illustrative cases with review of treatment strategies and surgical techniques

Fatal craniovertebral junction (CVJ) injuries were the most common cause of death in high-speed motor sports prior to 2001. Following the death of a mutual friend and race car driver, Patrick Jacquemart (1946-1981), biomechanical engineer Dr. Robert Hubbard, along with race car driver and brother-in-law Jim Downing, developed the concept for the Head and Neck Support (HANS) device to prevent flexion-distraction injuries during high-velocity impact. Biomechanical testing showed that neck shear and loading forces experienced during collisions were 3 times the required amount for a catastrophic injury. Crash sled testing with and without the HANS device elucidated reductions in neck tension, neck compression, head acceleration, and chest acceleration experienced by dummies during high-energy crashes. Simultaneously, motor sports accidents such as Dale Earnhardt Sr.s fatal crash in 2001 galvanized public opinion in favor of serious safety reform. Analysis of Earnhardts accident demonstrated that his cars velocity parallel to the barrier was more than 150 miles per hour (mph), with deceleration upon impact of roughly 43 mph in a total of 0.08 seconds. After careful review, several major racing series such as the National Association for Stock Car Auto Racing (NASCAR) and Championship Auto Racing Team (CART) made major changes to ensure the safety of drivers at the turn of the 21st century. Since the rule requiring the HANS device in professional auto racing series was put in place, there has not been a single reported case of a fatal CVJ injury.