Multidrug-resistant endemic clonal strain of Candida auris in India

Candida auris is a recently described rare agent of fungemia. It is notable for its antifungal resistance. A total of 15 C. auris isolates, originating from seven cases of fungemia, three cases of diabetic gangrenous foot, and one case of bronchopneumonia from a tertiary care hospital in south India, were investigated. All of the 15 isolates were identified by sequencing and 14 of these along with 12 C. auris isolates previously reported from two hospitals in Delhi, north India, two each from Japan and Korea were genotyped by amplified fragment length polymorphism (AFLP). In vitro antifungal susceptibility testing (AFST) was done by the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method. Candida auris isolates were misidentified as Candida haemulonii by VITEK. All were resistant to fluconazole [geometric mean minimum inhibitory concentration (MIC) 64 μg/ml] and 11 isolates were resistant to voriconazole (MIC ≥1 μg/ml). Forty-seven percent of the C. auris isolates were resistant to flucytosine (MIC ≥64 μg/ml) and 40% had high MIC (≥1 μg/ml) of caspofungin. Breakthrough fungemia developed in 28.6% of patients and therapeutic failure in 4 (66.7%) patients. Interestingly, the 26 Indian C. auris isolates from north and south India were clonal and phenotypically and genotypically distinct from Korean and Japanese isolates. The present study demonstrates that C. auris is a potential emerging pathogen that can cause a wide spectrum of human mycotic infections. The prevalence of a C. auris endemic clonal strain resistant to azoles and other antifungals in Indian hospitals with high rates of therapeutic failure in cases of fungemia is worrisome.

Genomic prediction in CIMMYT maize and wheat breeding programs

Genomic selection (GS) has been implemented in animal and plant species, and is regarded as a useful tool for accelerating genetic gains. Varying levels of genomic prediction accuracy have been obtained in plants, depending on the prediction problem assessed and on several other factors, such as trait heritability, the relationship between the individuals to be predicted and those used to train the models for prediction, number of markers, sample size and genotype × environment interaction (GE). The main objective of this article is to describe the results of genomic prediction in International Maize and Wheat Improvement Center's (CIMMYT's) maize and wheat breeding programs, from the initial assessment of the predictive ability of different models using pedigree and marker information to the present, when methods for implementing GS in practical global maize and wheat breeding programs are being studied and investigated. Results show that pedigree (population structure) accounts for a sizeable proportion of the prediction accuracy when a global population is the prediction problem to be assessed. However, when the prediction uses unrelated populations to train the prediction equations, prediction accuracy becomes negligible. When genomic prediction includes modeling GE, an increase in prediction accuracy can be achieved by borrowing information from correlated environments. Several questions on how to incorporate GS into CIMMYT's maize and wheat programs remain unanswered and subject to further investigation, for example, prediction within and between related bi-parental crosses. Further research on the quantification of breeding value components for GS in plant breeding populations is required.

Surgical treatment of trigeminal schwannomas

A total of 27 patients with trigeminal schwannoma were treated between 1982 and 1992 at the Neurosurgery Department of Nordstadt Hospital. Twelve cases of solitary schwannoma without any family history or physical stigmata of neurofibromatosis were included and form the basis of this study. There were four women and eight men (mean age 44 years) in this series. Duration of symptoms ranged from 2 months to 6 years. The most frequent symptoms were either pain or numbness of the ipsilateral hemiface. The surgical approach was chosen depending on the tumor type. Tumors that belonged to Type A (five cases), which were predominantly in the middle fossa, were approached using a transsylvian method; Type B (one case), which presented predominantly in the cerebellopontine angle, was operated on via a retrosigmoid suboccipital craniectomy; Type C (five cases), which were dumbbell-shaped extending into both the middle and posterior fossa, were removed via a combined temporal craniotomy-presigmoidal method; and in Type D (one case), in which tumor was primarily extracranial with intracranial extension, an infratemporal extradural approach was undertaken. There was no operative mortality or long-term disability in this series. The follow-up period ranged from 12 to 60 months; during that time magnetic resonance imaging revealed tumor recurrence in two cases after 12 and 48 months, respectively, and these were excised again. An additional 178 cases collected from the world literature are also reviewed and analyzed.

Thrombin and hemin as central factors in the mechanisms of intracerebral hemorrhage-induced secondary brain injury and as potential targets for intervention

Intracerebral hemorrhage (ICH) is a subtype of stoke that may cause significant morbidity and mortality. Brain injury due to ICH initially occurs within the first few hours as a result of mass effect due to hematoma formation. However, there is increasing interest in the mechanisms of secondary brain injury as many patients continue to deteriorate clinically despite no signs of rehemorrhage or hematoma expansion. This continued insult after primary hemorrhage is believed to be mediated by the cytotoxic, excitotoxic, oxidative, and inflammatory effects of intraparenchymal blood. The main factors responsible for this injury are thrombin and erythrocyte contents such as hemoglobin. Therapies including thrombin inhibitors, N-methyl-D-aspartate antagonists, chelators to bind free iron, and antiinflammatory drugs are currently under investigation for reducing this secondary brain injury. This review will discuss the molecular mechanisms of brain injury as a result of intraparenchymal blood, potential targets for therapeutic intervention, and treatment strategies currently in development.

Vestibular schwannomas in the modern era: epidemiology, treatment trends, and disparities in management

OBJECT

There are a variety of treatment options for the management of vestibular schwannomas (VSs), including microsurgical resection, radiotherapy, and observation. Although the choice of treatment is dependent on various patient factors, physician bias has been shown to significantly affect treatment choice for VS. In this study the authors describe the current epidemiology of VS and treatment trends in the US in the modern era. They also illustrate patient and tumor characteristics and elucidate their effect on tumor management.

METHODS

Patients diagnosed with VS were identified through the Surveillance, Epidemiology, and End Results database, spanning the years 2004-2009. Age-adjusted incidence rates were calculated and adjusted using the 2000 US standard population. The chi-square and Student t-tests were used to evaluate differences between patient and tumor characteristics. Multivariate logistic regression was performed to determine the effects of various patient and tumor characteristics on the choice of tumor treatment.

RESULTS

A total of 6225 patients with VSs treated between 2004 and 2009 were identified. The overall incidence rate was 1.2 per 100,000 population per year. The median age of patients with VS was 55 years, with the majority of patients being Caucasian (83.16%). Of all patients, 3053 (49.04%) received surgery only, with 1466 (23.55%) receiving radiotherapy alone. Both surgery and radiation were only used in 123 patients (1.98%), with 1504 patients not undergoing any treatment (24.16%). Increasing age correlated with decreased use of surgery (OR 0.95, 95% CI 0.95-0.96; p<0.0001), whereas increasing tumor size was associated with the increased use of surgery (OR 1.04, 95% CI 1.04-1.05; p<0.0001). Older age was associated with an increased likelihood of conservative management (OR 1.04, 95% CI 1.04-1.05; p<0.0001). Racial disparities were also seen, with African American patients being significantly less likely to receive surgical treatment compared with Caucasians (OR 0.50, 95% CI 0.35-0.70; p<0.0001), despite having larger tumors at diagnosis.

CONCLUSIONS

The incidence of vestibular schwannomas in the US is 1.2 per 100,000 population per year. Although many studies have demonstrated improved outcomes with the use of radiotherapy for small- to medium-sized VSs, surgery is still the most commonly used treatment modality for these tumors. Racial disparities also exist in the treatment of VSs, with African American patients being half as likely to receive surgery and nearly twice as likely to have their VSs managed conservatively despite presenting with larger tumors. Further studies are needed to elucidate the reasons for treatment disparities and investigate the nationwide trend of resection for the treatment of small VSs.

Genome-enabled prediction of genetic values using radial basis function neural networks

The availability of high density panels of molecular markers has prompted the adoption of genomic selection (GS) methods in animal and plant breeding. In GS, parametric, semi-parametric and non-parametric regressions models are used for predicting quantitative traits. This article shows how to use neural networks with radial basis functions (RBFs) for prediction with dense molecular markers. We illustrate the use of the linear Bayesian LASSO regression model and of two non-linear regression models, reproducing kernel Hilbert spaces (RKHS) regression and radial basis function neural networks (RBFNN) on simulated data and real maize lines genotyped with 55,000 markers and evaluated for several trait-environment combinations. The empirical results of this study indicated that the three models showed similar overall prediction accuracy, with a slight and consistent superiority of RKHS and RBFNN over the additive Bayesian LASSO model. Results from the simulated data indicate that RKHS and RBFNN models captured epistatic effects; however, adding non-signal (redundant) predictors (interaction between markers) can adversely affect the predictive accuracy of the non-linear regression models.

Comparison of superior-level facet joint violations during open and percutaneous pedicle screw placement

BACKGROUND

Superior-level facet joint violation by pedicle screws may result in increased stress to the level above the instrumentation and may contribute to adjacent segment disease. Previous studies have evaluated facet joint violations in open or percutaneous screw cases, but there are no reports describing a direct institutional comparison.

OBJECTIVE

To compare the incidence of superior-level facet violation for open vs percutaneous pedicle screws and to evaluate patient and surgical factors that affect this outcome.

METHODS

We reviewed 279 consecutive patients who underwent an index instrumented lumbar fusion from 2007 to 2011 for degenerative spine disease with stenosis with or without spondylolisthesis. We used a computed tomography grading system that represents progressively increasing grades of facet joint violation. Patient and surgical factors were evaluated to determine their impact on facet violation.

RESULTS

Our cohort consisted of 126 open and 153 percutaneous cases. Percutaneous procedures had a higher overall violation grade (P = .02) and a greater incidence of high-grade violations (P = .006) compared with open procedures. Bivariate analysis showed significantly greater violations in percutaneous cases for age < 65 years, obesity, pedicle screws at L4, and 1- and 2-level surgeries. Multivariate analysis showed the percutaneous approach and depth of the spine to be independent risk factors for high-grade violations.

CONCLUSION

This study demonstrates greater facet violations for percutaneously placed pedicle screws compared with open screws.

Glioblastoma in the elderly: the effect of aggressive and modern therapies on survival

OBJECTIVE

The prognosis of elderly patients with glioblastoma (GBM) is universally poor. Currently, few studies have examined postoperative outcomes and the effects of various modern therapies such as bevacizumab on survival in this patient population. In this study, the authors evaluated the effects of various factors on overall survival in a cohort of elderly patients with newly diagnosed GBM.

METHODS

A retrospective review was performed of elderly patients (≥ 65 years old) with newly diagnosed GBM treated between 2004 and 2010. Various characteristics were evaluated in univariate and multivariate stepwise models to examine their effects on complication risk and overall survival.

RESULTS

A total of 120 patients were included in the study. The median age was 71 years, and sex was distributed evenly. Patients had a median Karnofsky Performance Scale (KPS) score of 80 and a median of 2 neurological symptoms on presentation. The majority (53.3%) of the patients did not have any comorbidities. Tumors most frequently (43.3%) involved the temporal lobe, followed by the parietal (35.8%), frontal (32.5%), and occipital (15.8%) regions. The majority (57.5%) of the tumors involved eloquent structures. The median tumor size was 4.3 cm. Every patient underwent resection, and 63.3% underwent gross-total resection (GTR). The vast majority (97.3%) of the patients received the postoperative standard of care consisting of radiotherapy with concurrent temozolomide. The majority (59.3%) of patients received additional agents, most commonly consisting of bevacizumab (38.9%). The median survival for all patients was 12.0 months; 26.7% of patients experienced long-term (≥ 2-year) survival. The extent of resection was seen to significantly affect overall survival; patients who underwent GTR had a median survival of 14.1 months, whereas those who underwent subtotal resection had a survival of 9.6 months (p = 0.038). Examination of chemotherapeutic effects revealed that the use of bevacizumab compared with no bevacizumab (20.1 vs 7.9 months, respectively; p < 0.0001) and irinotecan compared with no irinotecan (18.0 vs 9.7 months, respectively; p = 0.027) significantly improved survival. Multivariate stepwise analysis revealed that older age (hazard ratio [HR] 1.06 [95% CI1.02-1.10]; p = 0.0077), a higher KPS score (HR 0.97 [95% CI 0.95-0.99]; p = 0.0082), and the use of bevacizumab (HR 0.51 [95% CI 0.31-0.83]; p = 0.0067) to be significantly associated with survival.

CONCLUSION

This study has demonstrated that GTR confers a modest survival benefit on elderly patients with GBM, suggesting that safe maximal resection is warranted. In addition, bevacizumab significantly increased the overall survival of these elderly patients with GBM; older age and preoperative KPS score also were significant prognostic factors. Although elderly patients with GBM have a poor prognosis, they may experience enhanced survival after the administration of the standard of care and the use of additional chemotherapeutics such as bevacizumab.

Thickness of subcutaneous fat as a risk factor for infection in cervical spine fusion surgery

BACKGROUND

Surgical site infections increase the incidence of morbidity and mortality as well as health-care expenses. The cost of care increases threefold to fourfold as a consequence of surgical site infection after spinal surgery. The aim of the present study was to determine the role of subcutaneous fat thickness in the development of surgical site infection following cervical spine fusion surgery.

METHODS

We performed a retrospective review of a consecutive cohort of 213 adult patients who underwent posterior cervical spine fusion between 2006 and 2008 at Duke University Medical Center. The horizontal distance from the lamina to the skin surface at the C5 level and the thickness of subcutaneous fat were measured, and the ratio of the fat thickness to the total distance at the surgical site was determined. Previously identified risk factors for the development of surgical site infection were also recorded.

RESULTS

Twenty-two of the 213 patients developed a postoperative infection. Obesity (body mass index ≥ 30 kg/m2) was not a significant risk factor for surgical site infection; the body mass index (and 95% confidence interval) was 29.4 ± 1.2 kg/m2 in the patients who developed a surgical site infection compared with 28.9 ± 0.94 kg/m2 in the patients without an infection. However, the thickness of subcutaneous fat and the ratio of the fat thickness to the lamina-to-skin distance were both significant risk factors for infection. The thickness of subcutaneous fat was 27.0 ± 2.5 mm in the patients who developed a surgical site infection group compared with 21.4 ± 0.88 mm in the patients without an infection (p = 0.042). The ratio of fat thickness to total thickness was 0.42 ± 0.019 in the patients who developed a surgical site infection compared with 0.35 ± 0.01 in the patients without an infection (p = 0.020). Multivariate analysis revealed this ratio to be an independent risk factor for developing a postoperative infection (odds ratio, 3.18; 95% confidence interval, 1.02 to 9.97).

CONCLUSIONS

The study demonstrated that the thickness of subcutaneous fat at the surgical site is a factor in the development of surgical site infection following cervical spine fusion and deserves assessment in the preoperative evaluation.

Outcomes of percutaneous and paddle lead implantation for spinal cord stimulation: a comparative analysis of complications, reoperation rates, and health-care costs

OBJECTIVES

Spinal cord stimulation (SCS) is a well-established modality for the treatment of chronic pain, and can utilize percutaneous or paddle leads. While percutaneous leads are less invasive, they have been shown to have higher lead migration rates. In this study, we compared the long-term outcomes and health-care costs associated with paddle and percutaneous lead implantation.

MATERIALS AND METHODS

We utilized the MarketScan data base to examine patients who underwent percutaneous or paddle lead SCS system implantation from 2000 to 2009. Outcomes including complications, reoperation rates, and health-care costs were evaluated in propensity score matched cohorts using univariate and multivariate analyses.

RESULTS

The study cohort was comprised of 13,774 patients. At 90 days following the initial procedure, patients in the SCS paddle group were more likely to develop a postoperative complication than patients receiving percutaneous systems (3.4% vs. 2.2%, p = 0.0005). Two-year (6.3% vs. 3.5%, p = 0.0056) and long-term (five+ years) (22.9% vs. 8.5%, p < 0.0008) reoperation rates were significantly higher in those with percutaneous lead systems. However, long-term health-care costs were similar for those receiving paddle and percutaneous leads ($169,768 vs. $186,139, p = 0.30).

CONCLUSIONS

While the implantation of paddle leads is associated with slightly higher initial postoperative complications, these leads are associated with significantly lower long-term reoperation rates. Nonetheless, long-term health-care costs are similar between paddle and percutaneous leads. Additional improvements in SCS technologies that address the shortcomings of current systems are needed to reduce the risk of reoperation due to hardware failure. Further study is required to evaluate the efficacy of newer percutaneous and paddle SCS systems and examine their comparative outcomes.

The effect of multifunctional polymer-based gels on wound healing in full thickness bacteria-contaminated mouse skin wound models

We determined whether a two-part space-conforming polyethylene glycol/dopa polymer-based gel promoted healing of contaminated wounds in mice. This silver-catalysed gel was previously developed to be broadly microbiocidal in vitro while being biocompatible with human wound cell functioning. Full-thickness wounds were created on the backs of mice. The wounds were inoculated with 10(4) CFU of each of four common skin wound contaminants, Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumanii and Clostridium perfringens. The wounds were then treated with our multifunctional polymer-based gel, the commercially available NewSkin product, or left to heal untreated. The untreated wounds were overtly infected, and presented detectable bacterial loads over the entire 21-day healing period, while the gel and NewSkin groups presented significantly smaller rises in bacterial levels and were cleared of detectable colonies by the third week, with the gel group clearing the bacteria earlier. While all three groups healed their wounds, the polymer-based gel-treated group demonstrated significantly earlier re-epithelialization and dermal maturation (P<0.05). This was reflected in a quick regain of tensile strength. This accelerated dermal maturation and regain in strength was noted in mice treated with the polymer-based gel when compared to wound treated with the commercially available Aquacel-Ag dressing (P<0.05). What distinguishes the polymer-based gel from these other products is that it is incorporated within the healing wound. These preclinical studies show that the anti-microbial polymer gel not only supports but also accelerates healing of bacterially contaminated wounds.

International, collaborative assessment of 146,000 prenatal karyotypes: expected limitations if only chromosome-specific probes and fluorescent in-situ hybridization are used

The development of chromosome-specific probes (CSP) and fluorescent in-situ hybridization (FISH) has allowed for very rapid identification of selected numerical abnormalities. We attempt here to determine, in principle, what percentage of abnormalities would be detectable if only CSP-FISH were performed without karyotype for prenatal diagnosis. A total of 146 128 consecutive karyotypes for prenatal diagnosis from eight centres in four countries for 5 years were compared with predicted detection if probes for chromosomes 13, 18, 21, X and Y were used, and assuming 100% detection efficiency. A total of 4163 abnormalities (2.85%) were found including 2889 (69. 4%) (trisomy 21, trisomy 18, trisomy 13, numerical sex chromosome abnormalities, and triploidies) which were considered detectable by FISH. Of these, 1274 were mosaics, translocations, deletions, inversions, rings, and markers which would not be considered detectable. CSP-FISH is a useful adjunct to karyotype for high risk situations, and may be appropriate in low risk screening, but should not be seen as a replacement for karyotype as too many structural chromosome abnormalities will be missed.

Cancer After Spinal Fusion

BACKGROUND:

Bone morphogenetic protein (BMP) is used in tens of thousands of spinal fusions each year. A trial evaluating a high-dose BMP formulation demonstrated that its use may be associated with an increased risk of cancer.

OBJECTIVE:

To evaluate whether BMP, as commonly used today, is associated with an increased risk of cancer or benign tumors.

METHODS:

We performed a retrospective study using the Thomson Reuter MarketScan database. We retained all patients who had no previous diagnosis of cancer or benign tumor and had at least 2 years of uninterrupted enrollment in the database before and after their operations. A propensity score--matched cohort was created to ensure greater covariate balance between treatment groups.

RESULTS:

Within the propensity score--matched cohort (n = 4698), BMP-exposed patients had a nonsignificant increase in the rate of cancer diagnosis (9.37% vs 7.92%; P = .08). After adjustment for covariates, BMP exposure was associated with a 31% increased risk of benign tumor diagnosis (odds ratio, 1.31; 95% confidence interval, 1.02-1.68; P &lt; .05). When the benign tumor diagnoses were stratified by organ type, BMP patients had significantly more diagnoses of benign nervous system tumors (0.81% vs 0.34%; P = .03), and within this group, benign tumors of the spinal meninges were much more common in the BMP-treated group (0.13% vs 0.02%; P = .002).

CONCLUSION:

The results of this large, independent, propensity-matched study suggest that the use of BMP in lumbar fusions is associated with a significantly higher rate of benign neoplasms but not malignancies.

Antimicrobial activities of silver used as a polymerization catalyst for a wound-healing matrix

Wound healing is a complex and orchestrated process that re-establishes the barrier and other functions of the skin. While wound healing proceeds apace in healthy individual, bacterial overgrowth and infection disrupts this process with significant morbidity and mortality. As such, any artificial matrix to promote wound healing must also control infecting microbes. We had earlier developed a two-part space-conforming gel backbone based on polyethyleneglycol (PEG) or lactose, which used ionic silver as the catalyst for gelation. As silver is widely used as an in vitro antimicrobial, use of silver as a catalyst for gelation provided the opportunity to assess its function as an anti-microbial agent in the gels. We found that these gels show bacteriostatic and bactericidal activity for a range of Gram-negative and Gram-positive organisms, including aerobic as well as anaerobic bacteria. This activity lasted for days, as silver leached out of the formed gels over a day in the manner of second-order decay. Importantly the gels did not limit either cell growth or viability, though cell migration was affected. Adding collagen I fragments to the gels corrected this effect on cell migration. We also found that the PEG gel did not interfere with hemostasis. These observations provide the basis for use of the gel backbones for incorporation of anesthetic agents and factors that promote wound repair. In conclusion, silver ions can serve dual functions of catalyzing gelation and providing anti-microbial properties to a biocompatible polymer.

Cerebellopontine angle meningiomas: postoperative outcomes in a modern cohort

OBJECT

Tumors of the cerebellopontine angle (CPA) have always proven difficult for neurosurgeons to optimally manage. Studies investigating the natural history and treatment of vestibular schwannomas have dominated the literature in this regard. Distinguishing meningiomas from schwannomas in this location carries particular importance as each tumor type has certain prognostic and surgical considerations. In this study, the authors have characterized the outcomes of 34 patients surgically treated for CPA meningiomas and have investigated various factors that may affect postoperative neurological function.

METHODS

The medical records of patients with CPA meningiomas who underwent surgery from 2005 to 2013 at the Duke University Health System were reviewed. Various patient, clinical, and tumor data were gathered from the medical records including patient demographics, pre- and postoperative neurological examinations, duration of symptoms, procedural details, tumor pathology and size, and treatment characteristics. Differences in continuous variables were then analyzed using the Student t-test while categorical variables were evaluated using the chi-square test.

RESULTS

A total of 34 patients underwent surgical treatment for CPA meningiomas during the 8-year period. Jugular foramen invasion was seen in 17.6% of tumors, with nearly half (41.2%) extending into the internal acoustic canal. The most common presenting symptom was hearing loss (58.8%), followed by headache (52.9%) and facial numbness/pain (50.0%). The most common cranial nerve (CN) affected was CN X (11.8%), followed by CNs VI and VII (5.9%). Postoperatively, no patients experienced a decrease in hearing, with only 5.9% of patients experiencing facial nerve palsies. Patients with tumors larger than 3 cm had a significantly higher incidence of permanent CN deficits than those with smaller tumors (45.5% vs 5.9%, respectively; p = 0.011). Also, tumor extension into the jugular foramen was associated with the occurrence of lower CN deficits, none of which occurred in tumors without jugular foramen invasion. Internal acoustic canal tumor extension was not seen to be associated with postoperative complications or CN deficits.

CONCLUSIONS

Meningiomas of the CPA are challenging lesions to treat surgically. However, the risk of facial palsy and hearing loss is significantly lower when compared with vestibular schwannomas. Novel methods for preoperative differentiation are needed to appropriately counsel patients on surgical risks. Also, due to the significant potential for neurological deficits, further studies are needed to investigate the utility of radiotherapy for these lesions.

Implanted vascular access devices (ports) in children: complications and their prevention

Implanted vascular access devices (ports) play a major role in the management of children with cystic fibrosis (CF) and many haematological conditions. With the expanding use of ports, new and more frequent complications are being encountered. To retrospectively review the complications associated with ports, the case notes of all patients who underwent insertion of a port between 1997 and 2000 were analysed. Details of the underlying disorder, type of vascular device, nature of use, and complications were recorded; 55 ports were inserted in 41 patients (a second port was required in 12, a third port in 2) during this period. Their underlying diagnoses were CF (11), haemophilia (4), haemolytic anaemias (2), immunological disorders (6), solid neoplasms (8), and leukaemia (10). Thirteen ports (24%) were removed and replaced for various complications: infection (2), blockage (4), leak (2), dislodgement (2), and malposition (3). Including four port-related problems managed conservatively (3 access problems managed by change in access technique; 1 blockage managed by urokinase), the over all complication rate was 31%. Ports thus have a high complication rate with long-term use. Selecting the right port system, proper installation of the port chamber, and efficient handling and maintenance by trained staff could prevent the vast majority of port-related complications.

Long-term Economic Impact of Coiling vs Clipping for Unruptured Intracranial Aneurysms

BACKGROUND:

Treatment of unruptured intracranial aneurysms (UIAs) involves endovascular coiling or aneurysm clipping. While many studies have compared these treatment modalities with respect to various clinical outcomes, few studies have investigated the economic costs associated with each procedure.

OBJECTIVE:

To determine the reoperation rate, postoperative complications, and inpatient and outpatient costs associated with surgical or endovascular treatment of patients with UIAs in the United States.

METHODS:

We utilized the MarketScan database to examine patients who underwent surgical clipping or endovascular coiling procedures for UIAs from 2000 to 2009, comparing reoperation rates, complications, and angiogram and healthcare resource use. Propensity score matching techniques were used to match patients.

RESULTS:

We identified 4,504 patients with surgically treated UIAs, with propensity score matching of 3,436 patients. Reoperation rates were significantly lower in the clipping group compared to the coiling group at 1- (P &lt; .001), 2- (P &lt; .001), and 5 years (P &lt; .001) following the procedure. However, postoperative complications (immediate, 30 and 90 days) were significantly higher in those undergoing surgical clipping. Although hospital length of stay and costs were higher in the clipping group for the index procedure, the number of postoperative angiograms and outpatient services used at 1, 2, and 5 years were significantly higher in the coiling group.

CONCLUSION:

Though surgical clipping resulted in lower reoperation rates, it was associated with higher complication rates and initial costs. However, overall costs at 2 and 5 years were similar to endovascular coiling due to the significantly higher number of follow-up angiograms and outpatient costs in these patients.

Spinal cord astrocytomas: a modern 20-year experience at a single institution

STUDY DESIGN

Retrospective cohort analysis.

OBJECTIVE

To examine the effect of resection on survival and neurological outcome in a modern cohort of patients with spinal cord astrocytomas and identify prognostic factors for survival.

SUMMARY OF BACKGROUND DATA

There are currently no clear treatment guidelines for the management of spinal cord astrocytomas. Additionally there is no conclusive evidence for the surgical resection of these tumors, with some studies even demonstrating worse survival with surgery. However, most studies have examined patients treated prior to the routine use of magnetic resonance imaging and advanced microsurgical techniques.

METHODS

We performed a retrospective review of 46 consecutive patients with spinal cord astrocytomas treated at our institution from 1992 to 2012. Univariate and multivariate analyses were used to identify variables associated with survival.

RESULTS

The majority of patients (67.4%) underwent surgical resection, with the remaining only receiving biopsy. Of those who underwent resection, only 12.5% of patients underwent gross total resection, all of whom had low-grade astrocytomas. Of all patients, 30.7% worsened compared with their preoperative baseline. The occurrence of worsening increased with high tumor grade (52.9% vs. 27.6%, P = 0.086) and an increased extent of resection (66.7% vs. 18.8%, P = 0.0069). Resection did not provide a survival benefit compared with biopsy alone (P = 0.53). Multivariate analysis revealed high-grade histology (hazard ratio, 11.3; 95% confidence interval, 2.41-53.2; P = 0.0021), tumor dissemination (hazard ratio, 4.24; 95% confidence interval, 1.22-14.8; P = 0.023), and an increasing number of tumor involved levels (hazard ratio, 1.31; 95% confidence interval, 0.99-1.74; P = 0.058) to be associated with worse survival.

CONCLUSION

As surgical intervention is associated with a higher rate of neurological complications and lacks a clear benefit, the resection of spinal cord astrocytomas should be reserved for select cases and should be used sparingly.

Comparison of balloon angioplasty versus debulking devices versus stenting in right coronary ostial lesions

Angioplasty of aorto-ostial stenosis is associated with lower procedural success and a higher complication rate. The aim of the present study was to compare the acute and long-term results of balloon and new device angioplasty in 110 consecutive patients with right coronary ostial lesions. Patients were divided into 3 groups according to the angioplasty device used: group I (balloon only, n = 26), group II (debulking devices including excimer laser, directional and rotational atherectomy, n = 26), group III (stent, n = 58). Procedural success was highest in group III (96%) followed by group I (88%), and group II (77%). In-hospital complications were similar among the groups (p = NS). Patients in group III achieved the highest acute gain (2.61 mm) followed by groups II (1.92 mm), and I (1.39 mm, p <0.05). During follow up, target lesion revascularization and/or bypass surgery was required in 24% of patients in group III compared with 47% and 40% in groups I and II, respectively (p <0.05). Cardiac-event free survival was highest in the stent group (74%, p <0.005) and was similar between the balloon (39%) and debulking device groups (45%). Thus, among the currently available technologies, stenting of right coronary ostial lesions appears to provide excellent angiographic and long-term results.

Complications, reoperation rates, and health-care cost following surgical treatment of lumbar spondylolisthesis

BACKGROUND

Surgery remains the mainstay for management of lumbar spondylolisthesis and is considered an effective therapeutic modality following unsuccessful nonoperative treatment. Surgical procedures include decompression, decompression with instrumented arthrodesis, and decompression with noninstrumented arthrodesis. The purpose of this study was to examine the complications, reoperation rates, and health-care costs associated with each of these procedures.

METHODS

The MarketScan database was utilized to identify 16,556 patients with a primary diagnosis of lumbar spondylolisthesis who underwent surgical treatment from 2000 to 2009. Outcomes were evaluated in propensity score-matched cohorts, with complication rates analyzed with the chi-square test, reoperation rates analyzed using the Mantel-Haenszel test, and health-care resource use analyzed using the Wilcoxon signed-rank test.

RESULTS

Complication rates were significantly higher in patients who underwent arthrodesis compared with those who had decompression alone during the initial hospitalization (8.3% versus 4.8%; p < 0.0001) and at the time of the ninety-day follow-up (9.6% versus 5.5%; p < 0.0001). Complication rates were similar for those who received instrumented and noninstrumented arthrodesis. Patients who underwent decompression alone had higher reoperation rates at two years or more than those who received arthrodesis (15.7% versus 11.9%; p = 0.034). Patients with instrumented arthrodesis trended to have higher reoperation rates than those without instrumentation at five years or more (18.4% versus 10.6%; p = 0.063). Initial hospital costs and two-year and five-year overall costs (in 2009 U.S. dollars) were higher for patients managed with arthrodesis than for those who had decompression only ($102,906 versus $89,337; p = 0.0018). Also, patients who received instrumentation had higher hospitalization costs than those without instrumentation ($39,997 versus $27,309; p = 0.023) and higher overall costs at two years ($73,482 versus $60,394; p < 0.0001), although the difference was not significant at five years (p = 0.29).

CONCLUSIONS

Patients with lumbar spondylolisthesis who underwent decompressive laminectomy and spinal arthrodesis had lower reoperation rates but higher overall costs than patients treated with laminectomy alone. Noninstrumented arthrodesis was also associated with lower long-term reoperation rates and health-care costs compared with instrumented arthrodesis. The long-term outcomes and costs of these procedures should be evaluated in conjunction with clinical efficacy to ensure the most cost-effective treatment is utilized.

LEVEL OF EVIDENCE

Therapeutic level III. See Instructions for Authors for a complete description of levels of evidence.

Meningeal melanocytoma of the C8 nerve root: case report

A case of a meningeal melanocytoma involving the C8 nerve root is presented. The clinical symptoms and the radiological investigations resembled a neurinoma of the spinal nerve root. Intraoperatively the tumor was seen to be firmly attached to the dural covering of the dorsal nerve root. By using microsurgical technique, complete removal of the tumor with preservation of the ventral nerve root was accomplished. Histological examination revealed a typical meningeal melanocytoma as described by Limas and Tio in 1972. Ten additional cases of previously reported spinal meningeal melanocytomas are reviewed. The importance of differentiating this benign lesion from meningeal malignant pigmented tumors is stressed.

Worse outcomes for patients undergoing brain tumor and cerebrovascular procedures following the ACGME resident duty-hour restrictions

OBJECT

On July 1, 2003, the Accreditation Council for Graduate Medical Education (ACGME) implemented duty-hour restrictions for resident physicians due to concerns for patient and resident safety. Though duty-hour restrictions have increased resident quality of life, studies have shown mixed results with respect to patient outcomes. In this study, the authors have evaluated the effect of duty-hour restrictions on morbidity, mortality, length of stay, and charges in patients who underwent brain tumor and cerebrovascular procedures.

METHODS

The Nationwide Inpatient Sample was used to evaluate the effect of duty-hour restrictions on complications, mortality, length of stay, and charges by comparing the pre-reform (2000-2002) and post-reform (2005-2008) periods. Outcomes were compared between nonteaching and teaching hospitals using a difference-in-differences (DID) method.

RESULTS

A total of 90,648 patients were included in the analysis. The overall complication rate was 11.7%, with the rates not significantly differing between the pre- and post-duty hour eras (p = 0.26). Examination of hospital teaching status revealed that complication rates decreased in nonteaching hospitals (12.1% vs 10.4%, p = 0.0004) and remained stable in teaching institutions (11.8% vs 11.9%, p = 0.73) in the post-reform era. Multivariate analysis demonstrated a significantly higher complication risk in teaching institutions (OR 1.33 [95% CI 1.11-1.59], p = 0.0022), with no significant change in nonteaching hospitals (OR 1.11 [95% CI 0.91-1.37], p = 0.31). A DID analysis to compare the magnitude in change between teaching and nonteaching institutions revealed that teaching hospitals had a significantly greater increase in complications during the post-reform era than nonteaching hospitals (p = 0.040). The overall mortality rate was 3.0%, with a significant decrease occurring in the post-reform era in both nonteaching (5.0% vs 3.2%, p < 0.0001) and teaching (3.2% vs 2.3%, p < 0.0001) hospitals. DID analysis to compare the changes in mortality between groups did not reveal a significant difference (p = 0.40). The mean length of stay for all patients was 8.7 days, with hospital stay decreasing from 9.2 days to 8.3 days in the post-reform era (p < 0.0001). The DID analysis revealed a greater length of stay decrease in nonteaching hospitals than teaching institutions, which approached significance (p = 0.055). Patient charges significantly increased in the post-reform era for all patients, increasing from $70,900 to $96,100 (p < 0.0001). The DID analysis did not reveal a significant difference between the changes in charges between teaching and nonteaching hospitals (p = 0.17).

CONCLUSIONS

The implementation of duty-hour restrictions correlated with an increased risk of postoperative complications for patients undergoing brain tumor and cerebrovascular neurosurgical procedures. Duty-hour reform may therefore be associated with worse patient outcomes, contrary to its intended purpose. Due to the critical condition of many neurosurgical patients, this patient population is most sensitive and likely to be negatively affected by proposed future increased restrictions.

Glutamine and glutathione counteract the inhibitory effects of mediators of sepsis in neonatal hepatocytes

BACKGROUND/PURPOSE

Surgical neonates are at risk of sepsis-associated liver dysfunction. Hydrogen peroxide (H(2)O(2)) and nitric oxide (NO) are important mediators of sepsis, which impair neonatal hepatic metabolism. Glutamine has been shown to have beneficial effects on hepatocyte metabolism during neonatal sepsis. However, the molecular basis of these effects are unknown. The aim of this study was to test the hypotheses that (1) glutamine and its dipeptides counteract the inhibitory effect of septic mediators on neonatal hepatocyte oxygen consumption and (2) the effects of glutamine are specific and not shared by other amino acids. In addition, we wished to determine the metabolic pathways and mediators involved in the action of glutamine.

METHODS

Hepatocytes were isolated from suckling rats, and O(2) consumption measured polarographically. Study A: the ability of 10 mmol/L glutamine to reverse the inhibitory effects of 1.5 mmol/L H(2)O(2) and 300 micromol/L S-Nitroso-N-acetylpenicillamine (SNAP; a nitric oxide donor) on O(2) consumption was examined. Study B: the ability of other amino acids and dipeptides of glutamine to reverse the effects of H(2)O(2) was examined. Study C: various concentrations of glutamine were tested for their ability to reverse the H(2)O(2) inhibition of O(2) consumption. Study D: the mechanism of action of glutamine was examined by incubating hepatocytes with either an inhibitor of entry into the Krebs cycle or an inhibitor of glutathione synthesis. Study E: the ability of glutathione to reverse the inhibitory effects of H(2)O(2) was examined.

RESULTS

Study A: glutamine reversed the inhibition of hepatocyte O(2) consumption exerted by either H(2)O(2) or NO. Study B: glutamine dipeptides reversed the inhibition of hepatocyte O(2) consumption by H(2)O(2), but other amino acids did not. Study C: the counteracting effect of glutamine was proportional to the dose administered. Study D: blocking entry of glutamine into the Krebs cycle did not abolish the effects of glutamine, but blocking glutathione synthesis completely abolished the effect of glutamine. Study E: exogenous glutathione reversed the inhibitory effect of H(2)O(2) on hepatocyte O(2) consumption.

CONCLUSIONS

This study found that glutamine and its dipeptides are unique in reversing the effects of septic mediators on neonatal rat liver oxidative metabolism. The effectiveness of glutamine appears to be mediated via glutathione synthesis. Addition of glutamine, glutamine dipeptides, or glutathione to total parenteral nutrition (TPN) may be beneficial in preventing liver damage in neonatal sepsis.