Effects of regional hypoxia and incubation temperature on growth, differentiation, heart mass, and oxygen consumption in embryos of the leopard gecko (Eublepharis macularius).

Oviparous reptile embryos must tolerate fluctuations in oxygen availability and incubation temperature during development. In this study, regional hypoxia was simulated by painting eggs of Eublepharis macularius with melted paraffin wax to decrease the available surface area for gas exchange by approximately 80%. Experimental and control eggs were incubated at either 28 or 34 °C and embryo mass, stage, heart mass, relative heart mass, and oxygen consumption (V̇O2) were measured at 15 and 30 days of incubation. Embryo mass from the regional hypoxia treatment was reduced by about 50% at day 15 and by about 30% at day 30 of incubation, independent of incubation temperature compared to controls. Embryo stage from the regional hypoxia treatment was reduced by about 2 stages at day 15 independent of incubation temperature but there was no effect of hypoxia treatment at day 30. Absolute heart mass was reduced by about 60% in regional hypoxia embryos sampled at day 15 while relative heart mass was increased by about 30% in regional hypoxic embryos at day 30 compared to controls, suggesting that heart mass is conserved at the expense of somatic growth. Embryo V̇O2 was affected by incubation temperature at both 15 and 30 days of incubation but not by regional hypoxia treatment. These results indicate that embryos of E. macularius possess plasticity in their capacity to respond to reduction in oxygen availability during incubation, and are able to survive and continue developing when gas exchange surface area is severely limited.

Unique osmoregulatory morphology in primitive sharks: an intermediate state between holocephalan and derived shark secretory morphology.

Discovery of an unusual rectal gland in the Atlantic sixgill shark Hexanchus vitulus led us to examine the rectal glands of 31 species of sharks to study diversity in rectal-gland morphology. Twenty-four of 31 species of sharks had digitiform glands (mean width-length ratio ± SD = 0.17 ± 0.04) previously assumed to be characteristic of all elasmobranchs regardless of habitat depth or phylogenetic age. Rectal glands from the family Somniosidae were kidney bean-shaped (mean width: length ± SD = 0.46 ± 0.05); whereas those from families Echinorhinidae and Hexanchidae were lobulate (mean width: length ± SD = 0.55 ± 0.06). Rectal gland width: length were different among species with digitiform morphology and lobulate morphology (ANOVA; R2 = 0.9; df = 15, 386; 401, F = 219.24; P < 0.001). Histological and morphological characteristics of the digitiform morphology from deep-sea sharks were similar to those from shallow-water sharks. Histology of lobulate rectal glands from hexanchids were characterised by tubule bundles separated by smooth muscle around a central lumen. Additionally, we examined plasma chemistry of four species of sharks with digitiform rectal glands and two species with lobulate rectal-gland morphology to see if there were differences between morphologies. Plasma chemistry analysis showed that urea and trimethylamine N-oxide (TMAO) followed the piezolyte hypothesis, with TMAO being highest and urea being lowest in deep-sea sharks. Among electrolytes, Na+ was highest in species with lobulate rectal glands. Hexanchids and echinorhinids both have lobulate rectal glands similar to those of holocephalans, despite the more than 400 million years separating these two groups. The morphological similarities between the lobulate rectal-gland anatomy of primitive sharks and the secretory morphology of holocephalans may represent an intermediate state between Holocephali and derived shark species.

Impact of old age on patient-report outcomes and cost utility for anterior cervical discectomy and fusion surgery for degenerative spine disease.

PURPOSE: With growing older population and increasing rates of cervical spinal surgery, it is vital to understand the value of cervical surgery in this population. We set forth to determine the cost utility following anterior cervical decompression and fusion (ACDF) for degenerative disease in older patients. METHODS: Patients undergoing ACDF for degenerative diseases were enrolled into prospective longitudinal registry. Patient-reported outcomes (PROs) were recorded at baseline, 1-year, and 2-year postoperatively. Two-year medical resource utilization, missed work, and health-state values [quality-adjusted life years (QALYs)] were assessed to compute cost per QALY gained. Patients were dichotomized based on age: <65 years (younger) and ≥65 years (older) to compare the cost utility in these age groups. RESULTS: Total 218 (87%) younger patients and 33 (13%) older patients who underwent ACDF were analyzed. Both the groups demonstrated a significant improvement in PROs 2-year following surgery. The older patients had a lower mean cumulative gain in QALYs compared to younger patients at 1 year (0.141 vs. 0.28, P = 0.05) and 2 years (0.211 vs. 0.424, P = 0.04). There was no significant difference in the mean total 2-year cost between older [$21,041 (95% CI $18,466-$23,616)] and younger [$22,669 (95% CI $$21,259-$24,079)] patients (P = 0.27). Two-year cost per QALY gained in older vs. younger patients was ($99,720/QALYs gained vs. ($53,464/QALYs gained, P = 0.68). CONCLUSION: ACDF surgery provided a significant gain in health-state utility in older patients with degenerative cervical pathology, with a mean cumulative 2-year cost per QALY gained of $99,720/QALY. While older patients have a slightly higher cost utility compared to their younger counterparts, surgery in the older cohort does provide a significant improvement in pain, disability, and quality-of-life outcomes.

The relative value of postoperative versus preoperative Karnofsky Performance Scale scores as a predictor of survival after surgical resection of glioblastoma multiforme.

The Karnofsky Performance Scale (KPS) score is a widespread metric to stratify patient prognosis and determine appropriate management in glioblastoma multiforme(GBM). Low preoperative KPS values have been associated with shorter overall survival (OS). However, surgical resection can have a dramatic effect on a patient's functional status which subsequently alters their KPS score. To determine the predictive value of preoperative verses postoperative KPS scores in terms of OS in patients with GBM. We conducted a retrospective review of 163 patients who underwent initial surgical intervention for pathologically proven GBM at our institution between 2003 and 2013. Pre and postoperative performance status, demographic, operative, and treatment variables were recorded for each patient. Multivariate regression analysis identified predictors of prolonged OS. The adequacy index was calculated to compare the predictive value of preoperative and postoperative KPS score. Median preoperative and postoperative KPS scores were 70 and 80, respectively. Overall, 92 (57 %) patients experienced an improvement in their KPS score, 40 (25 %) remained stable, and 29 (18 %) declined. Higher postoperative KPS (P = 0.0001), radiation therapy (P < 0.0001), younger age (P = 0.0443) and the absence of diabetes (P = 0.0006) were each independently associated with increased OS in a multivariate regression model. Postoperative KPS score has superior predictive value compared to pre-operative KPS score (A = 0.758 vs. 1.002). Postoperative KPS scores have superior predictive capabilities in terms of OS in GBM and should replace preoperative KPS scores when estimating prognosis in this population.

Five-level cervical corpectomy for neurofibromatosis-associated spinal deformity: case report.

PURPOSE: To describe a successful five-level cervical corpectomy and circumferential reconstruction in a patient with a plexiform neurofibroma causing a severe kyphotic deformity. METHODS: Case report. RESULTS: 43-year-old man with history of Neurofibromatosis presented with signs and symptoms of myelopathy with spastic lower extremities and gait difficulties. Imaging studies demonstrated a severe kyphotic deformity of the cervical spine with associated cord compression secondary to an anteriorly positioned plexiform neurofibroma. Two-stage surgical procedure was designed to treat this lesion. Stage I consisted of tracheostomy placement, transmandibular, circumglossal approach to the anterior cervical spine, C2-C6 corpectomies, and C1-C7 reconstruction with a custom titanium cage/plate. Stage II consisted of suboccipital craniectomy, C1-C2 laminectomies, and occipital-cervical thoracic instrumented fusion (O-T8). There were no operative complications, but the patient did develop a small pulmonary embolism post-operatively treated with anticoagulation. Patient required two-weeks of inpatient rehabilitation following surgery. Gastrostomy tube and tracheostomy were successfully discontinued with preserved swallowing and respiratory function. Patient-reported outcome measurements revealed significant and sustained improvement post-operatively. CONCLUSIONS: Five-level cervical corpectomy including C2 can be safely and successfully performed via a transmandibular, circumglossal approach. Circumferential reconstruction utilizing a custom anterior titanium cage and plate system manufactured from a pre-operative CT scan was utilized in this case. Long segment occipital-cervical-thoracic reconstruction is recommended in such a case. Using such a technique, improvement in myelopathy, correction of deformity, and improved quality of life can be achieved.

Incidence of Low Back Pain After Lumbar Discectomy for Herniated Disc and Its Effect on Patient-reported Outcomes.

BACKGROUND: Long-term postdiscectomy degenerative disc disease and low back pain is a well-recognized disorder; however, its patient-centered characterization and quantification are lacking. QUESTIONS/PURPOSES: We performed a systematic literature review and prospective longitudinal study to determine the frequency of recurrent back pain after discectomy and quantify its effect on patient-reported outcomes (PROs). METHODS: A MEDLINE search was performed to identify studies reporting on the frequency of recurrent back pain, same-level recurrent disc herniation, and reoperation after primary lumbar discectomy. After excluding studies that did not report the percentage of patients with persistent back or leg pain more than 6 months after discectomy or did not report the rate of same level recurrent herniation, 90 studies, which in aggregate had evaluated 21,180 patients, were included in the systematic review portion of this study. For the longitudinal study, all patients undergoing primary lumbar discectomy between October 2010 and March 2013 were enrolled into our prospective spine registry. One hundred fifteen patients were more than 12 months out from surgery, 103 (90%) of whom were available for 1-year outcomes assessment. PROs were prospectively assessed at baseline, 3 months, 1 year, and 2 years. The threshold of deterioration used to classify recurrent back pain was the minimum clinically important difference in back pain (Numeric Rating Scale Back Pain [NRS-BP]) or Disability (Oswestry Disability Index [ODI]), which were 2.5 of 10 points and 20 of 100 points, respectively. RESULTS SYSTEMATIC REVIEW: The proportion of patients reporting short-term (6-24 months) and long-term (> 24 months) recurrent back pain ranged from 3% to 34% and 5% to 36%, respectively. The 2-year incidence of recurrent disc herniation ranged from 0% to 23% and the frequency of reoperation ranged from 0% to 13%. PROSPECTIVE STUDY: At 1-year and 2-year followup, 22% and 26% patients reported worsening of low back pain (NRS: 5.3 ± 2.5 versus 2.7 ± 2.8, p < 0.001) or disability (ODI%: 32 ± 18 versus 21 ± 18, p < 0.001) compared with 3 months. CONCLUSIONS: In a systematic literature review and prospective outcomes study, the frequency of same-level disc herniation requiring reoperation was 6%. Two-year recurrent low back pain may occur in 15% to 25% of patients depending on the level of recurrent pain considered clinically important, and this leads to worse PROs at 1 and 2 years postoperatively.

Patient-reported outcomes 3 months after spine surgery: is it an accurate predictor of 12-month outcome in real-world registry platforms?

OBJECT The health care landscape is rapidly shifting to incentivize quality of care rather than quantity of care. Quality and outcomes registry platforms lie at the center of all emerging evidence-driven reform models and will be used to inform decision makers in health care delivery. Obtaining real-world registry outcomes data from patients 12 months after spine surgery remains a challenge. The authors set out to determine whether 3-month patient-reported outcomes accurately predict 12-month outcomes and, hence, whether 3-month measurement systems suffice to identify effective versus noneffective spine care. METHODS All patients undergoing lumbar spine surgery for degenerative disease at a single medical institution over a 2-year period were enrolled in a prospective longitudinal registry. Patient-reported outcome instruments (numeric rating scale [NRS], Oswestry Disability Index [ODI], 12-Item Short Form Health Survey [SF-12], EQ-5D, and the Zung Self-Rating Depression Scale) were recorded prospectively at baseline and at 3 months and 12 months after surgery. Linear regression was performed to determine the independent association of 3- and 12-month outcome. Receiver operating characteristic (ROC) curve analysis was performed to determine whether improvement in general health state (EQ-5D) and disability (ODI) at 3 months accurately predicted improvement and achievement of minimum clinical important difference (MCID) at 12 months. RESULTS A total of 593 patients undergoing elective lumbar surgery were included in the study. There was a significant correlation between 3-month and 12-month EQ-5D (r = 0.71; p < 0.0001) and ODI (r = 0.70; p < 0.0001); however, the authors observed a sizable discrepancy in achievement of a clinically significant improvement (MCID) threshold at 3 versus 12 months on an individual patient level. For postoperative disability (ODI), 11.5% of patients who achieved an MCID threshold at 3 months dropped below this threshold at 12 months; 10.5% of patients who did not meet the MCID threshold at 3 months continued to improve and ultimately surpassed the MCID threshold at 12 months. For ODI, achieving MCID at 3 months accurately predicted 12-month MCID with only 62.6% specificity and 86.8% sensitivity. For postoperative health utility (EQ-5D), 8.5% of patients lost an MCID threshold improvement from 3 months to 12 months, while 4.0% gained the MCID threshold between 3 and 12 months postoperatively. For EQ-5D (quality-adjusted life years), achieving MCID at 3 months accurately predicted 12-month MCID with only 87.7% specificity and 87.2% sensitivity. CONCLUSIONS In a prospective registry, patient-reported measures of treatment effectiveness obtained at 3 months correlated with 12-month measures overall in aggregate, but did not reliably predict 12-month outcome at the patient level. Many patients who do not benefit from surgery by 3 months do so by 12 months, and, conversely, many patients reporting meaningful improvement by 3 months report loss of benefit at 12 months. Prospective longitudinal spine outcomes registries need to span at least 12 months to identify effective versus noneffective patient care.

Quality analysis of anterior cervical discectomy and fusion in the outpatient versus inpatient setting: analysis of 7288 patients from the NSQIP database.

OBJECT In an era of escalating health care cost and universal pressure of improving efficiency and cost of care, ambulatory surgery centers (ASCs) have emerged as lower cost options for many surgical therapies. Anterior cervical discectomy and fusion (ACDF) is one of the most prevalent spine surgeries performed and is rapidly increasing with an expanding aging population. While ASCs offer cost advantages for ACDF, there is a scarcity of evidence that ASCs allow for equivalent quality and thus superior health care value. Therefore, the authors analyzed a nationwide, prospective quality improvement registry (National Surgical Quality Improvement Program [NSQIP]) to compare the quality of ACDF surgery performed in the outpatient ASC versus the inpatient hospital setting. METHODS Patients undergoing ACDF (2005-2011) were identified from the NSQIP database based on the primary Current Procedural Terminology codes. Patients were divided into 2 cohorts (outpatient vs inpatient) based on the acute care setting documented in the NSQIP database. All 30-day surgical morbidity and mortality rates were compared between the 2 groups. Propensity score matching and multivariate logistic regression analysis were used to adjust for confounding factors and to identify the independent association of outpatient ACDF with perioperative outcomes and morbidity. RESULTS A total of 7288 ACDF cases were identified (inpatient = 6120, outpatient = 1168). Unadjusted rates of major morbidity (0.94% vs 4.5%, p < 0.001) and return to the operating room (OR) within 30 days (0.3% vs 2.0%, p < 0.001) were significantly lower in outpatient versus inpatient ACDF. After propensity matching 1442 cases (inpatient = 650, outpatient = 792) based on baseline 32 covariates, rates of major morbidity (1.4% vs 3.1%, p = 0.03), and return to the OR (0.34% vs 1.4%, p = 0.04) remained significantly lower after outpatient ACDF. Adjusted comparison using multivariate logistic regression demonstrated that ACDF performed in the outpatient setting had 58% lower odds of having a major morbidity and 80% lower odds of return to the OR within 30 days. CONCLUSIONS An analysis of a nationwide, prospective quality improvement registry representing more than 250 hospitals demonstrates that 1- to 2-level ACDF can be safely performed in the outpatient ambulatory surgery setting in patients who are appropriate candidates. In an effort to decrease cost of care, surgeons can safely consider performing ACDF in an ASC environment.

Effect of complications within 90 days on patient-reported outcomes 3 months and 12 months following elective surgery for lumbar degenerative disease.

OBJECT There is a paradigm shift toward rewarding providers for quality rather than volume. Complications appear to occur at a fairly consistent frequency in large aggregate data sets. Understanding how complications affect long-term patient-reported outcomes (PROs) following degenerative lumbar surgery is vital. The authors hypothesized that 90-day complications would adversely affect long-term PROs. METHODS Nine hundred six consecutive patients undergoing elective surgery for degenerative lumbar disease over a period of 4 years were enrolled into a prospective longitudinal registry. The following PROs were recorded at baseline and 12-month follow-up: Oswestry Disability Index (ODI) score, numeric rating scales for back and leg pain, quality of life (EQ-5D scores), general physical and mental health (SF-12 Physical Component Summary [PCS] and Mental Component Summary [MCS] scores) and responses to the North American Spine Society (NASS) satisfaction questionnaire. Previously published minimum clinically important difference (MCID) threshold were used to define meaningful improvement. Complications were divided into major (surgicalsite infection, hardware failure, new neurological deficit, pulmonary embolism, hematoma and myocardial infarction) and minor (urinary tract infection, pneumonia, and deep venous thrombosis). RESULTS Complications developed within 90 days of surgery in 13% (118) of the patients (major in 12% [108] and minor in 8% [68]). The mean improvement in ODI scores, EQ-5D scores, SF-12 PCS scores, and satisfaction at 3 months after surgery was significantly less in the patients with complications than in those who did not have major complications (ODI: 13.5 ± 21.2 vs 21.7 ± 19, < 0.0001; EQ-5D: 0.17 ± 0.25 vs 0.23 ± 0.23, p = 0.04; SF-12 PCS: 8.6 ± 13.3 vs 13.0 ± 11.9, 0.001; and satisfaction: 76% vs 90%, p = 0.002). At 12 months after surgery, the patients with major complications had higher ODI scores than those without complications (29.1 ± 17.7 vs 25.3 ± 18.3, p = 0.02). However, there was no difference in the change scores in ODI and absolute scores across all other PROs between the 2 groups. In multivariable linear regression analysis, after controlling for an array of preoperative variables, the occurrence of a major complication was not associated with worsening ODI scores 12 months after surgery. There was no difference in the percentage of patients achieving the MCID for disability (66% vs 64%), back pain (55% vs 56%), leg pain (62% vs 59%), or quality of life (19% vs 14%) or in patient satisfaction rates (82% vs 80%) between those without and with major complications. CONCLUSIONS Major complications within 90 days following lumbar spine surgery have significant impact on the short-term PROs. Patients with complications, however, do eventually achieve clinically meaningful outcomes and report satisfaction equivalent to those without major complications. This information allows a physician to counsel patients on the fact that a complication creates frustration, cost, and inconvenience; however, it does not appear to adversely affect clinically meaningful long-term outcomes and satisfaction.

The present and future of quality measures and public reporting in neurosurgery.

Quality measurement and public reporting are intended to facilitate targeted outcome improvement, practice-based learning, shared decision making, and effective resource utilization. However, regulatory implementation has created a complex network of reporting requirements for physicians and medical practices. These include Medicare's Physician Quality Reporting System, Electronic Health Records Meaningful Use, and Value-Based Payment Modifier programs. The common denominator of all these initiatives is that to avoid penalties, physicians must meet "generic" quality standards that, in the case of neurosurgery and many other specialties, are not pertinent to everyday clinical practice and hold specialists accountable for care decisions outside of their direct control. The Centers for Medicare and Medicaid Services has recently authorized alternative quality reporting mechanisms for the Physician Quality Reporting System, which allow registries to become subspecialty-reporting mechanisms under the Qualified Clinical Data Registry (QCDR) program. These programs further give subspecialties latitude to develop measures of health care quality that are relevant to the care provided. As such, these programs amplify the power of clinical registries by allowing more accurate assessment of practice patterns, patient experiences, and overall health care value. Neurosurgery has been at the forefront of these developments, leveraging the experience of the National Neurosurgery Quality and Outcomes Database to create one of the first specialty-specific QCDRs. Recent legislative reform has continued to change this landscape and has fueled optimism that registries (including QCDRs) and other specialty-driven quality measures will be a prominent feature of federal and private sector quality improvement initiatives. These physician- and patient-driven methods will allow neurosurgery to underscore the value of interventions, contribute to the development of sustainable health care solutions, and actively participate in meaningful quality initiatives for the benefit of the patients served.

The National Neurosurgery Quality and Outcomes Database Qualified Clinical Data Registry: 2015 measure specifications and rationale.

Meaningful quality measurement and public reporting have the potential to facilitate targeted outcome improvement, practice-based learning, shared decision making, and effective resource utilization. Recent developments in national quality reporting programs, such as the Centers for Medicare & Medicaid Services Qualified Clinical Data Registry (QCDR) reporting option, have enhanced the ability of specialty groups to develop relevant quality measures of the care they deliver. QCDRs will complete the collection and submission of Physician Quality Reporting System (PQRS) quality measures data on behalf of individual eligible professionals. The National Neurosurgery Quality and Outcomes Database (N(2)QOD) offers 21 non-PQRS measures, initially focused on spine procedures, which are the first specialty-specific measures for neurosurgery. Securing QCDR status for N(2)QOD is a tremendously important accomplishment for our specialty. This program will ensure that data collected through our registries and used for PQRS is meaningful for neurosurgeons, related spine care practitioners, their patients, and other stakeholders. The 2015 N(2)QOD QCDR is further evidence of neurosurgery's commitment to substantively advancing the health care quality paradigm. The following manuscript outlines the measures now approved for use in the 2015 N(2)QOD QCDR. Measure specifications (measure type and descriptions, related measures, if any, as well as relevant National Quality Strategy domain[s]) along with rationale are provided for each measure.

Minimally invasive transpsoas L2 corpectomy and percutaneous pedicle screw fixation for osteoporotic burst fracture in the elderly: a technical report.

BACKGROUND AND IMPORTANCE: Osteoporotic vertebral burst fractures are an increasingly common cause of pain and severe functional disability in the elderly. Although anterior-posterior surgical stabilization offers an efficacious and durable treatment, the associated high blood loss, long durations of surgery, and prolonged hospitalization are often not tolerable for elderly patients, who are most often medically frail with multiple comorbidities. CLINICAL PRESENTATION: We report a case of an L2 osteoporotic burst fracture in an elderly patient with significant comorbidities treated with a minimally invasive tubular direct lateral transpsoas approach for L2 vertebrectomy and anterior cage placement. The construct was supplemented by a percutaneous pedicle screw construct and adjacent level vertebroplasty. Duration of surgery was 3.5 hours with a total of 35 mL blood loss. The patient was discharged ambulating 36 hours after surgery and reported marked improvement in pain, disability, and quality of life measures at 6 weeks postoperatively. CONCLUSIONS: L2 vertebrectomy by direct lateral transpsoas tube systems supplemented by percutaneous pedicle screws can be performed safely and may allow for anterior column decompression and reconstruction in elderly or comorbid patients not otherwise able to tolerate traditional stabilization procedures.

Cost per quality-adjusted life year gained of revision fusion for lumbar pseudoarthrosis: defining the value of surgery.

STUDY DESIGN: Single cohort study of patients undergoing revision fusion for lumbar pseudoarthrosis. OBJECTIVE: To assess the 2-year comprehensive costs of revision arthrodesis for lumbar pseudoarthrosis at our institution and determine the associated cost per quality-adjusted life year (QALY) gained in this patient population. SUMMARY OF BACKGROUND DATA: The proportion of lumbar spine operations involving a fusion procedure has increased over the past 2 decades. Similarly, there has been a corresponding increase in the incidence and prevalence of pseudoarthrosis. However, the cost-effectiveness of revision surgery for pseudoarthrosis-associated back pain has yet to be examined. METHODS: Forty-seven patients undergoing revision instrumented arthrodesis for pseudoarthrosis-associated back pain were included. Two-year total back-related medical resource utilization, missed work, and health-state values (QALYs, calculated from EuroQuol 5D with US valuation) were assessed. Two-year resource use was multiplied by unit costs based on Medicare national allowable payment amounts (direct cost) and patient and care-giver work-day losses were multiplied by the self-reported gross-of-tax wage rate (indirect cost). The mean total 2-year cost per QALY gained after revision surgery was assessed. RESULTS: The mean (±SD) duration of time between prior fusion and development of symptomatic pseudoarthrosis was 2.69±3.09 years. None of the patients developed symptomatic pseudoarthrosis after 2 years of revision surgery. A mean cumulative 2-year gain of 0.35 QALYs was reported. The mean (±SD) total 2-year cost of revision fusion was $41,631±$9691 (surgery cost: $23,865±$270; outpatient resource utilization cost: $4885±$2301; indirect cost: $12,879±$8171). Revision instrumented arthrodesis was associated with a mean 2-year cost per QALY gained of $118,945. CONCLUSIONS: Revision arthrodesis was associated with improved 2-year quality of life in patients with pseudoarthrosis-related back pain. Nevertheless, in our experience revision surgery was shown to be marginally cost-effective at $118,945 per QALY gained.

Transforaminal lumbar interbody graft placement using an articulating delivery arm facilitates increased segmental lordosis with superior anterior and midline graft placement.

OBJECTIVE: Transforaminal lumbar interbody fusion (TLIF) is a frequently performed method of lumbar arthrodesis in patients failing medical management of back and leg pain. Accurate placement of the interbody graft and restoration of lordosis has been shown to be crucial when performing lumbar fusion procedures. We performed a single-surgeon, prospective, randomized study to determine whether a novel articulating versus traditional straight graft delivery arm system allows for superior graft placement and increased lordosis for single-level TLIF. METHODS: Thirty consecutive patients undergoing single-level TLIF were included and prospectively randomized to one of the 2 groups (articulated vs. straight delivery arm system). Three radiographic characteristics were evaluated at 6-week follow-up: (1) degree of segmental lumbar lordosis at the fused level; (2) the percent anterior location of the interbody graft in disk space; and (3) the distance (mm) off midline of the interbody graft placement. RESULTS: Randomization yielded 16 patients in the articulated delivery arm cohort and 14 in the straight delivery arm cohort. The articulating delivery arm system yielded an average of 14.7-degree segmental lordosis at fused level, 35% anterior location, and 3.6 mm off midline. The straight delivery arm system yielded an average of 10.7-degree segmental lordosis at fused level, 46% anterior location, and 7.0 mm off midline. All 3 comparisons were statistically significant (P<0.05). CONCLUSIONS: The study suggests that an articulating delivery arm system facilitates superior anterior and midline TLIF graft placement allowing for increased segmental lordosis compared with a traditional straight delivery arm system.

Five-level sub-axial cervical vertebrectomy and reconstruction: technical report.

PURPOSE: Regardless of the etiology, severe cervical deformities can be extremely debilitating and are a challenge to correct. Often a multi-modality team approach is required to safely and effectively reduce the deformity, provide adequate decompression, and ensure solid fixation and fusion. In cases of iatrogenic cervical deformity necessitating five-level corpectomy and fixation, the feasibility, safety, and durability of this procedure remains unknown. RESULTS: We describe a patient who presented with debilitating pain and inability to eat due to an iatrogenic chin-on-chest cervical kyphotic deformity. The patient underwent a back-front-back staged procedure requiring five-level cervical vertebrectomy, C3-T1 anterior fixation, and occipital to T5 posterior fusion, resulting in successful reduction of cervical kyphosis from 75 to 0 degrees. At 6 months post-operatively, the patient demonstrated marked improvement in neurologic function and reported substantial improvements in neck pain-specific disability (NDI) and quality of life (SF-12 and EQ-5D). CONCLUSION: The feasibility and safety of five-level vertebrectomy and reconstruction for chin-on-chest deformity remains poorly described. The current case suggests that thoughtful planning that involves maximizing the patient's health status, judicious use of traction under direct neurological examination, staged circumferential release, and design of a construct that provides anterior and posterior column support with several points of fixation beyond the axis of rotation will attenuate the risk of peri-operative morbidity and potentiate the durability of deformity correction.

Long-term outcomes after revision neural decompression and fusion for same-level recurrent lumbar stenosis: defining the effectiveness of surgery.

STUDY DESIGN: Single-cohort study of patients undergoing revision neural decompression and fusion for same-level recurrent lumbar stenosis. OBJECTIVE: To assess the long-term outcomes of revision surgery using validated patient-reported outcomes measures. SUMMARY OF BACKGROUND DATA: Recurrent lumbar stenosis may occur after lumbar spine surgery, leading to significant discomfort and radicular pain. Although numerous studies have reported clinical outcomes after primary lumbar surgery, there remains a paucity of data on the outcomes after revision surgery for recurrent same-level stenosis. METHODS: Fifty-three patients undergoing revision neural decompression and instrumented fusion for same-level recurrent stenosis-associated back and leg pain were included in this study. Baseline and 2-year visual analog scale for leg pain (LP-VAS), visual analog scale for low back pain (BP-VAS), Oswestry Disability Index (ODI), Zung self-reported depression score (ZDS), time to narcotic independence, time to return to work, health-state utility [EuroQol (EQ-5D)], and physical and mental quality of life [SF-12 physical and mental component scores (PCS and MCS)] were assessed. RESULTS: Mean±SD duration of time between index surgery and revision surgery was 4.00±4.19 years. A significant improvement from baseline was observed in BP-VAS (9.28±1.01 vs. 5.00±2.94, P=0.001), LP-VAS (9.55±0.93 vs. 3.45±2.95, P=0.001), and ODI (36.02±6.01 vs. 21.75±12.08, P=0.001). Mean±SD SF-12 PCS (7.17±11.22, P=0.001), SF-12 MCS (12.57±13.03, P=0.001), ZDS (12.37±16.80, P=0.001), and EQ-5D (0.42±0.34, P=0.001) were also significantly improved. The mean cumulative 2-year gain in health-utility state was 0.84 QALY. Median (interquartile range) duration of postoperative narcotic use was 6 (1.4-12.2) months and time of missed work was 6 (4.0-10.0) months. CONCLUSIONS: Our study suggests that revision neural decompression and instrumented fusion for recurrent same-level stenosis provides significant improvement in all patient-assessed outcome metrics and should be offered as a viable treatment option.

Association of surgical resection and survival in patients with malignant primary osseous spinal neoplasms from the Surveillance, Epidemiology, and End Results (SEER) database.

OBJECTIVE: Malignant osseous spinal neoplasms are aggressive tumors associated with poor outcomes despite aggressive multidisciplinary measures. While surgical resection has been shown to improve short-term local disease control, it remains debated whether surgical resection is associated with improved overall survival in patients with malignant primary osseous spinal neoplasms. The aim of this manuscript is to review survival data from a US cancer registry spanning 30 years to determine if surgical resection was independently associated with overall survival. METHODS: The SEER registry (1973-2003) was queried to identify cases of histologically confirmed primary spinal chordoma, chondrosarcoma, osteosarcoma, or Ewing's sarcoma of the mobile spine and pelvis. Patients with systemic metastasis were excluded. Age, gender, race, tumor location, and primary treatments were identified. Extent of local tumor invasion was classified as confined within periosteum versus extension beyond periosteum to surrounding tissues. The association of surgical resection with overall survival was assessed via Cox analysis adjusting for age, radiotherapy, and tumor invasiveness. RESULTS: 827 patients were identified with non-metastatic primary osseous spinal neoplasms (215 chordoma, 282 chondrosarcoma, 158 osteosarcoma, 172 Ewing's sarcoma). Overall, median survival was histology specific (chordoma, 96 months; Ewing's sarcoma, 90 months; chondrosarcoma, 88 months; osteosarcoma, 18 months). Adjusting for age, radiation therapy, and extent of local tumor invasion in patients with isolated (non-metastatic) spine tumors, surgical resection was independently associated with significantly improved survival for chordoma [hazard ratio (95 % confidence interval; 0.617 (0.25-0.98)], chondrosarcoma [HR (95 %CI); 0.153 (0.07-0.36)], osteosarcoma [HR (95 %CI); 0.382 (0.21-0.69)], and Ewing's sarcoma [HR (95 %CI); 0.494 (0.26-0.96)]. CONCLUSION: In our analysis of a 30-year US population-based cancer registry (SEER), patients undergoing surgical resection of primary spinal chordoma, chondrosarcoma, Ewing's sarcoma, or osteosarcoma demonstrated prolonged overall survival independent of patient age, extent of local invasion, or location. Surgical resection may play a role in prolonging survival in the multi-modality treatment of patients with these malignant primary osseous spinal neoplasms.

Cost-utility analysis of minimally invasive versus open multilevel hemilaminectomy for lumbar stenosis.

STUDY DESIGN: Two-year cost-utility study comparing minimally invasive (MIS) versus open multilevel hemilaminectomy in patients with degenerative lumbar spinal stenosis. OBJECTIVE: The objective of the study was to determine whether MIS versus open multilevel hemilaminectomy for degenerative lumbar spinal stenosis is a cost-effective advancement in lumbar decompression surgery. SUMMARY OF BACKGROUND DATA: MIS-multilevel hemilaminectomy for degenerative lumbar spinal stenosis allows for effective treatment of back and leg pain while theoretically minimizing blood loss, tissue injury, and postoperative recovery. No studies have evaluated comprehensive healthcare costs associated with multilevel hemilaminectomy procedures, nor assessed cost-effectiveness of MIS versus open multilevel hemilaminectomy. METHODS: Fifty-four consecutive patients with lumbar stenosis undergoing multilevel hemilaminectomy through an MIS paramedian tubular approach (n=27) versus midline open approach (n=27) were included. Total back-related medical resource utilization, missed work, and health state values [quality adjusted life years (QALYs), calculated from EuroQuol-5D with US valuation] were assessed after 2-year follow-up. Two-year resource use was multiplied by unit costs based on Medicare national allowable payment amounts (direct cost) and work-day losses were multiplied by the self-reported gross-of-tax wage rate (indirect cost). Difference in mean total cost per QALY gained for MIS versus open hemilaminectomy was assessed as incremental cost-effectiveness ratio (ICER: COST(MIS)-COST(OPEN)/QALY(MIS)-QALY(OPEN)). RESULTS: MIS versus open cohorts were similar at baseline. MIS and open hemilaminectomy were associated with an equivalent cumulative gain of 0.72 QALYs 2 years after surgery. Mean direct medical costs, indirect societal costs, and total 2-year cost ($23,109 vs. $25,420; P=0.21) were similar between MIS and open hemilaminectomy. MIS versus open approach was associated with similar total costs and utility, making it a cost equivalent technology compared with the traditional open approach. CONCLUSIONS: MIS versus open multilevel hemilaminectomy was associated with similar cost over 2 years while providing equivalent improvement in QALYs. In our experience, MIS versus open multilevel hemilaminectomy is a cost equivalent technology for patients with lumbar stenosis-associated radicular pain.

Uterine epithelial morphology and progesterone receptors in a mifepristone-treated viviparous lizard Pseudemoia entrecasteauxii (Squamata: Scincidae) during gestation.

Structural and functional changes to the uterus associated with maintenance of pregnancy are controlled primarily by steroid hormones such as progesterone. We tested the hypothesis that progesterone regulates uterine structural changes during pregnancy in the viviparous skink, Pseudemoia entrecasteauxii, by treating pregnant females with the progesterone receptor antagonist mifepristone at different stages of pregnancy. Expression and distribution of progesterone receptor was determined using Western blot and immunohistochemistry. During early pregnancy, mifepristone treatment resulted in altered uterine epithelial cell surface morphology and high embryo mortality, but did not affect females at mid and late stages of pregnancy. Females treated with mifepristone in early pregnancy exhibited abnormal uterine epithelial cell morphology such as lateral blebbing and presence of wide gaps between cells indicating loss of intercellular attachment. Chorioallantoic membranes of the embryo were not affected by mifepristone treatment. Two isoforms (55 kDa and 100 kDa) of progesterone receptor were identified using immunoblots and both isoforms were localized to the nucleus of uterine epithelial cells. The 55 kDa isoform was expressed throughout pregnancy, whereas the 100 kDa isoform was expressed during mid and especially late pregnancy. In P. entrecasteauxii, mifepristone may prevent successful embryo attachment in early pregnancy through its effects on uterine epithelial cells but may have little effect on pregnancy once the maternal-embryo structural relationship is established.

Type 2 diabetes mellitus and obesity are independent risk factors for poor outcome in patients with high-grade glioma.

Type 2 diabetes mellitus (DM) and obesity are known risk factors for poor outcomes in patients with systemic malignancies but are not well-studied in the brain tumor population. In this study we asked if type 2 DM and elevated body mass index (BMI) are independent risk factors for poor prognosis in patients with high-grade glioma (HGG.). We conducted a retrospective cohort study of 171 patients surgically treated for HGG at a single institution. BMI and records of pre-existing type 2 DM were obtained from medical histories. Variables associated with survival in a univariate analysis were included in the multivariate Cox model if P < 0.10. Variables with probability values >0.05 were then removed from the multivariate model in a step-wise fashion. Mean age at diagnosis was 55.0 ± 17.3 years. Fifteen (8.8%) patients had a history of type 2 DM. Fifty-eight (35.8%) patients had a BMI < 25, 55 (34.0%) BMI 25-30, and 49(30.2%) BMI > 30. Radiation therapy, temozolomide, and higher KPS score were independently associated with prolonged survival while increasing age was associated with decreased survival. DM (P = 0.001) and increasing BMI (P = 0.003) were found to be independently associated with decreased survival. Diabetics had a decreased median overall survival (312 vs. 470 days, P = 0.003) and PFS (106 vs. 166 days, P = 0.04) compared to non-diabetics. Increasing BMI (<25, 25-30, and >30) was also associated with decreased median PFS: 195 vs. 165 vs. 143 days, respectively. Pre-existing DM and elevated BMI are independent risk factors for poor outcome in patients with HGG.