Andrea A. Brock

Managing overlapping surgery: an analysis of 1018 neurosurgical and spine cases

OBJECTIVE Overlapping surgery-the performance of parts of 2 or more surgical procedures at the same time by a single lead surgeon-has recently come under intense scrutiny, although data on the effects of overlapping procedures on patient outcomes are lacking. The authors examined the impact of overlapping surgery on complication rates in neurosurgical patients. METHODS The authors conducted a retrospective review of consecutive nonemergent neurosurgical procedures performed during the period from May 12, 2014, to May 12, 2015, by any of 5 senior neurosurgeons at a single institution who were authorized to schedule overlapping cases. Overlapping surgery was defined as any case in which 2 patients under the care of a single lead surgeon were under anesthesia at the same time for any duration. Information on patient demographics, premorbid conditions, surgical variables, and postoperative course were collected and analyzed. Primary outcome was the occurrence of any complication from the beginning of surgery to 30 days after discharge. A secondary outcome was the occurrence of a serious complication-defined as a life-threatening or life-ending event-during this same period. RESULTS One thousand eighteen patients met the inclusion criteria for the study. Of these patients, 475 (46.7%) underwent overlapping surgery. Two hundred seventy-one patients (26.6%) experienced 1 or more complications, with 134 (13.2%) suffering a serious complication. Fourteen patients in the cohort died, a rate of 1.4%. The overall complication rate was not significantly higher for overlapping cases than for nonoverlapping cases (26.3% vs 26.9%, p = 0.837), nor was the rate of serious complications (14.7% vs 11.8%, p = 0.168). After adjustments for surgery type, surgery duration, body mass index, American Society of Anesthesiologists (ASA) physical classification grade, and intraoperative blood loss, overlapping surgery remained unassociated with overall complications (OR 0.810, 95% CI 0.592-1.109, p = 0.189). Similarly, after adjustments for surgery type, surgery duration, body mass index, ASA grade, and neurological comorbidity, there was no association between overlapping surgery and serious complications (OR 0.979, 95% CI 0.661-1.449, p = 0.915). CONCLUSIONS In this cohort, patients undergoing overlapping surgery did not have an increased risk for overall complications or serious complications. Although this finding suggests that overlapping surgery can be performed safely within the appropriate framework, further investigation is needed in other specialties and at other institutions.

Jugulotympanic paragangliomas: 75 years of evolution in understanding

Jugulotympanic paragangliomas were first described approximately 75 years ago. Since that time, there has been considerable evolution in knowledge of tumor biology, methods of classification, and appropriate management strategies. This paper attempts to summarize these gains in information.

A prospective analysis of hypovitaminosis D and mortality in 400 patients in the neurocritical care setting

OBJECTIVE Hypovitaminosis D is highly prevalent among the general population. Studies have shown an association between hypovitaminosis D and multiple negative outcomes in critical care patients, but there has been no prospective evaluation of vitamin D in the neurological critical care population. The authors examined the impact of vitamin D deficiency on in-hospital mortality and a variety of secondary outcomes. METHODS The authors prospectively collected 25-hydroxy vitamin D levels of all patients admitted to the neurocritical care unit (NCCU) of a quaternary-care center over a 3-month period. Demographic data, illness acuity, in-hospital mortality, infection, and length of hospitalization were collected. Univariate and multivariable logistic regression were used to examine the effects of vitamin D deficiency. RESULTS Four hundred fifteen patients met the inclusion criteria. In-hospital mortality was slightly worse (9.3% vs 4.5%; p = 0.059) among patients with deficient vitamin D (≤ 20 ng/dl). There was also a higher rate of urinary tract infection in patients with vitamin D deficiency (12.4% vs 4.2%; p = 0.002). For patients admitted to the NCCU on an emergency basis (n = 285), higher Simplified Acute Physiology Score II (OR 13.8, 95% CI 1.7-110.8; p = 0.014), and vitamin D deficiency (OR 3.0, 95% CI 1.0-8.6; p = 0.042) were significantly associated with increased in-hospital mortality after adjusting for other factors. CONCLUSIONS In the subset of patients admitted to the NCCU on an emergency basis, vitamin D deficiency is significantly associated with higher in-hospital mortality. Larger studies are needed to confirm these findings and to investigate the role of vitamin D supplementation in these patients.

Neuroprotective strategies and the underlying molecular basis of cerebrovascular stroke

Stroke is a leading cause of disability in the US. Although there has been significant progress in the area of medical and surgical thrombolytic technologies, neuroprotective agents to prevent secondary cerebral injury and to minimize disability remain limited. Only limited success has been reported in preclinical and clinical trials evaluating a variety of compounds. In this review, the authors discuss the most up-to-date information regarding the underlying molecular biology of stroke as well as strategies that aim to mitigate this complex signaling cascade. Results of historical research trials involving N-methyl-d-aspartate and α-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor antagonists, clomethiazole, antioxidants, citicoline, nitric oxide, and immune regulators have laid the groundwork for current progress. In addition, more recent studies involving therapeutic hypothermia, magnesium, albumin, glyburide, uric acid, and a variety of other treatments have provided more options. The use of neuroprotective agents in combination or with existing thrombolytic treatments may be one of many exciting areas of further development. Although past trials of neuroprotective agents in ischemic stroke have been limited, significant insights into mechanisms of stroke, animal models, and trial design have incrementally improved approaches for future therapies.

GoPro Hero Cameras for Creation of a Three-Dimensional, Educational, Neurointerventional Video

Neurointerventional education relies on an apprenticeship model, with the trainee observing and participating in procedures with the guidance of a mentor. While educational videos are becoming prevalent in surgical cases, there is a dearth of comparable educational material for trainees in neurointerventional programs. We sought to create a high-quality, three-dimensional video of a routine diagnostic cerebral angiogram for use as an educational tool. A diagnostic cerebral angiogram was recorded using two GoPro HERO 3+ cameras with the Dual HERO System to capture the proceduralist’s hands during the case. This video was edited with recordings from the video monitors to create a real-time three-dimensional video of both the actions of the neurointerventionalist and the resulting wire/catheter movements. The final edited video, in either two or three dimensions, can serve as another instructional tool for the training of residents and/or fellows. Additional videos can be created in a similar fashion of more complicated neurointerventional cases. The GoPro HERO 3+ camera and Dual HERO System can be used to create educational videos of neurointerventional procedures.

Emerging Technologies in Flow Diverters and Stents for Cerebrovascular Diseases

Purpose of ReviewStents and flow diverters have revolutionized the treatment of cerebrovascular disease. Guglielmi coils, flexible microcatheters, and first-generation intracranial stents, such as Neuroform (Stryker Neurovascular) and Enterprise stents (Codman/DePuy-Synthes), have paved the way for the development of the Pipeline Embolization Device (PED) (ev3/Covidien/Medtronic) and other endovascular approaches.Recent FindingsThis review discusses the historical development of flow diverter technologies from the PED to similar devices, such as the Surpass stent (Stryker Neurovascular), the Flow-Redirection Endoluminal Device (FRED; MicroVention, Inc.), the SILK stent (Balt Extrusion), and the p64 Flow Modulation Device (Phenox). In addition, the potential use of drug-eluting stents and various bioresorbable scaffolds (e.g., poly-l-lactic acid, magnesium), new developments in stent material (e.g., thin-film nitinol), design (e.g., biocompatible polymers, embedded microcircuitry, flow models), and potential applications for flow diverters will be considered.SummaryEndovascular treatment of cerebrovascular disease is rapidly advancing via continued development of new technology.

327 A Prospective Analysis of Hypovitaminosis D and Mortality in 400 Patients in the Neurocritical Care Setting.

INTRODUCTION Hypovitaminosis D is highly prevalent among the general population. Studies have shown an association between hypovitaminosis D and multiple negative outcomes in critical care patients, but there has been no prospective evaluation of hypovitaminosis D in the neurological critical care population. The authors examined the impact of vitamin D deficiency on in-hospital mortality and a variety of secondary outcomes in the neurocritical care unit. METHODS The authors prospectively collected 25-hydroxy vitamin D levels on all patients admitted to the neurocritical care unit of a quaternary-care center over a 3-month period. Demographic data, illness acuity, in-hospital mortality, infection, and length of hospitalization were collected. Univariate and multivariable logistic regression were used to examine the effects of vitamin D deficiency. RESULTS Four hundred sixty-one patients met the inclusion criteria. In-hospital mortality was slightly worse (9.3% vs 4.5%, P = .059) among patients with deficient vitamin D (≤20 ng/dL). There was also a higher rate of urinary tract infection in patients with vitamin D deficiency (12.4% vs 4.2%, P = .002). For patients admitted to the neurocritical care unit emergently (n = 285), higher SAPS II score (odds ratio [OR], 13.33; 95% confidence interval [CI], 1.69-100; P = .014) and vitamin D deficiency (OR, 3.03; 95% CI, 1.14-8.06; P = .027) were significantly associated with increased in-hospital mortality on multivariable analysis. CONCLUSION In the subset of patients admitted to the neurocritical care unit emergently, vitamin D deficiency is significantly associated with higher in-hospital mortality. Larger studies are needed to confirm these findings and to investigate the role of vitamin D supplementation in these patients.

Outcomes in adults with cerebral venous sinus thrombosis: A retrospective cohort study

Most patients with cerebral venous sinus thrombosis (CVST) treated with anticoagulation have good outcomes. We examined which factors were associated with poor outcomes after treatment. We retrospectively reviewed patients ≥18 years old who were diagnosed with CVST between 1997 and 2015. Good (modified Rankin score [mRS] ≤2) and poor outcomes were dichotomized. Demographic, historical, clinical, imaging, and treatment characteristics were compared. Eighty-nine patients received treatment for CVST (52.8% males, 74.2% Caucasian). Sixty-eight (76.4%) had good outcomes and 21 (23.6%) had poor outcomes. Poor outcome was associated with systemic or central nervous system (CNS) infection (p = 0.002), lower use of heparin-only therapy than interventional-only treatments (p = 0.003), and increased use of craniectomy (p = 0.002). Good outcomes were associated with migrainous headache on presentation (p = 0.01) and involvement of superficial cortical vessels only (p = 0.02). No prothrombotic or imaging findings correlated with poor outcome. Multivariable analysis showed that any clinical risk factor (p = 0.02) and headache (p = 0.02) predicted improved outcome whereas systemic or CNS infection (p = 0.02) and craniectomy (p = 0.02) predicted poor outcome. A published risk score showed a moderate ability to predict good outcome but not poor outcome. Overall sensitivity (23.8%), specificity (75.0%), and positive (24.0%) and negative (77.0%) predictive value suggested moderate prediction of good outcome and limited prediction of poor outcome. Rates of poor outcomes in CVST were comparable with previous investigations (23.6%), but prediction of poor outcome remains challenging in patients with CVST. Our results suggested that systemic infection and craniectomy were the most robust predictors of poor outcome.

Postoperative Pain Control with the Fentanyl Patch and Continuous Paravertebral Anesthetic Infusion after Posterior Occipitocervical Junction Surgery.

Postoperative pain is a significant concern for patients who undergo surgery via a midline posterior approach to the occipitocervical junction and spinal axis. The development of the disposable, ambulatory pain pump presents a novel alternative for treatment of postoperative pain. The authors describe a multimodal treatment algorithm for postoperative pain after posterior occipitocervical junction surgery that uses the On-Q pain catheter system (I-Flow Corp., Lake Forest, CA) and a fentanyl patch. The On-Q PainBuster catheter system is a disposable, ambulatory device that allows for continuous anesthetic delivery directly into or adjacent to the wound. On-Q catheters are placed in the nuchal musculature for continuous infusion of 0.5% bupivacaine. The On-Q catheter infusion is continued for three days, and the catheters are then withdrawn. Patients are also provided with a transdermal fentanyl patch at the start of surgery. In regards to complications at our facility, there have been no cases of respiratory depression or arrest postoperatively and no wound infections, but one case of inadvertent subdural placement. The technique described for the use of the fentanyl patch and a continuous anesthetic delivery device in surgery of the occipitocervical junction presents a novel alternative to the current standard of care in pain control after suboccipital decompression.

A retrospective evaluation of automated optimization of deep brain stimulation parameters

Objective We performed a retrospective analysis of an optimization algorithm for the computation of patient-specific multipolar stimulation configurations employing multiple independent current/voltage sources. We evaluated whether the obtained stimulation configurations align with clinical data and whether the optimized stimulation configurations have the potential to lead to an equal or better stimulation of the target region as manual programming, while reducing the time required for programming sessions. Methods For three patients (five electrodes) diagnosed with essential tremor, we derived optimized multipolar stimulation configurations using an approach that is suitable for the application in clinical practice. To evaluate the automatically derived stimulation settings, we compared them to the results of the monopolar review. Results We observe a good agreement between the findings of the monopolar review and the optimized stimulation configurations, with the algorithm assigning the maximal voltage in the optimized multipolar pattern to the contact that was found to lead to the best therapeutic effect in the clinical monopolar review in all cases. Additionally, our simulation results predict that the optimized stimulation settings lead to the activation of an equal or larger volume fraction of the target compared to the manually determined settings in all cases. Conclusions Our results demonstrate the feasibility of an automatic determination of optimal DBS configurations and motivate a further evaluation of the applied optimization algorithm.