Joseph R. Linzey

Stent-assisted coiling of cerebrovascular aneurysms: experience at a large tertiary care center with a focus on predictors of recurrence

Background Stent-assisted coiling is commonly used to treat wide-necked and fusiform cerebral aneurysms. We evaluated our institutional experience with stent-assisted coiling of cerebral aneurysms to elucidate potential risk factors for recurrence. Methods A retrospective analysis of patients undergoing stent-assisted coiling of cerebral aneurysms from 2005 to 2012 resulted in 122 patients with 122 aneurysms. Demographic, peri-procedural, medical comorbidity, and follow-up data were collected. Primary outcomes of interest were procedural safety, efficacy, and aneurysm recurrence. Univariate and multivariate logistic regression and χ2 tests determined the statistical significance of the risk factors. Results All 122 stent-assisted coiling procedures led to satisfactory obliteration of the aneurysm (3.3% complication rate). Twenty-one (17.2%) patients experienced recurrence at average follow-up of 297 days. Fifteen (71.4%) clinically significant recurrences required retreatment. Eleven of 30 (36.7%) procedures using Enterprise stents had recurrence compared with only 10 of 92 (10.9%) procedures using Neuroform stents (p=0.001). Average coiling packing density (PD) was 20.3% with Enterprise stents and 22.5% with Neuroform stents (p=0.8). In multivariate logistic regression, recurrences requiring recoiling were significantly associated with Enterprise stents (OR 8.57, 95% CI 1.97 to 37.19; p=0.004), females (OR 0.19, 95% CI 0.04 to 1.00; p=0.05), and postoperative dextran use (OR 8.42, 95% CI 1.40 to 50.58; p=0.02). Aneurysms with <20% PD were more likely to have a clinically significant recurrence than aneurysms with >20% PD (19% vs 5.1%; p=0.02). Conclusions Stent-assisted coiling for wide-necked cerebral aneurysms has a high therapeutic success rate with low procedure-related morbidity and mortality. Clinically significant recurrences may occur more frequently with Enterprise stents, in aneurysms with low PD, and with post-procedural dextran use.

The Effect of Surgical Start Time on Complications Associated With Neurological Surgeries

BACKGROUND Neurosurgical procedures are necessary at all times of day. Other surgical specialties have examined the effect of surgical start time (SST) on morbidity and mortality; however, a similar study has not been performed for neurosurgical procedures. OBJECTIVE To perform a retrospective cohort study describing the association between SST and operative morbidity. METHODS We analyzed all patients undergoing neurological surgery between January 1, 2007 and August 1, 2014 at our institution. This study included 15 807 patients. A total of 785 complications were identified through the self-reported morbidity and mortality reports created by faculty and resident neurosurgeons. We used multilevel logistic regression to investigate the association of SST with morbidity. RESULTS In multilevel logistic regression, our Baseline model demonstrated that the odds of complication increased by more than 50% for start times between 21:01 and 07:00 (odds ratio [OR] 1.53, 95% confidence interval [CI] 1.03-2.29, P = .04). When accounting for the length of the surgery, the odds of a complication were even greater for later time periods 21:01 to 07:00 (OR 2.16, 95% CI 1.44-3.23, P < .001). The only statistically significant factor that predicted severity of the complication was if the operation was emergent compared to elective (OR 1.70, 95% CI 1.11-2.60, P = .02). An SST between 21:01 and 07:00 substantially contributed when severe complications were isolated (OR 1.61, 95% CI 1.50-2.90, P = .08). CONCLUSION Patients with SSTs between 21:01 and 07:00 are at an increased risk of developing morbidity compared to patients with an SST earlier in the day.

Development of the CNS TAP tool for the selection of precision medicine therapies in neuro-oncology

The number of targeted therapies utilized in precision medicine are rapidly increasing. Neuro-oncology offers a unique challenge due to the varying blood brain barrier (BBB) penetration of each agent. Neuro-oncologists face a difficult task weighing the growing number of potential targeted therapies and their likelihood of BBB penetration. We developed the CNS TAP Working Group and performed an extensive literature review for the evidence-based creation of the CNS TAP tool, which was retrospectively validated by analyzing brain tumor patients who underwent therapy targeted based on genomic results from an academic sequencing study (MiOncoseq, n = 17) or private molecular profiling (Foundation One, n = 7). The CNS TAP tool scores relevant targeted agents by applying multiple variables (i.e., pre-clinical data, clinical data, BBB permeability) to patient specific genomic information and clinical trial availability. In the Michigan cohort, the CNS TAP tool predicted the selected agent 85.7% of the time. The CNS TAP tool predicted the agent independently selected by pediatric neuro-oncologists in the Colorado cohort 50% of the time. Patients with recurrent brain tumors treated with agents predicted by the CNS TAP tool demonstrated a median progression-free survival of 4 months and four patients with recurrent high-grade glioma maintained ongoing partial responses of at least 6 months. The CNS TAP tool is a formalized algorithm to assist clinicians select the optimal targeted therapy for neuro-oncology patients. The CNS TAP tool has relatively high concordance with selected therapies and clinical outcomes in patients receiving targeted therapy in this heterogeneous retrospective cohort were promising.

Frontal sinus breach during routine frontal craniotomy significantly increases risk of surgical site infection: 10-Year retrospective analysis

BACKGROUND: Frontotemporal craniotomies are commonly performed for a variety of neurosurgical pathologies. Infections related to craniotomies cause significant morbidity. We hypothesized that the risk of cranial surgical site infections (SSIs) may be increased in patients whose frontal sinuses are breached during craniotomy. OBJECTIVE: To compare the rate of cranial SSIs in patients undergoing frontotemporal craniotomies with and without frontal sinus breach (FSB). METHODS: We performed a retrospective analysis of all patients undergoing frontotemporal craniotomies for the management of cerebral aneurysms from 2005 to 2014. This study included 862 patients undergoing 910 craniotomies. Primary outcome of interest was occurrence of a cranial SSI. Standard statistical methods were utilized to explore associations between a variety of variables including FSB, cranial SSI, and infections requiring reoperation. RESULTS: Of the 910 craniotomies, 141 (15.5%) involved FSB. Of those involving FSB, 22 (15.6%) developed a cranial SSI, compared to only 56 of the 769 without FSB (7.3%; P = .001). Cranial SSI requiring reoperation was much more likely in patients with FSB compared to those without a breach (7.8% vs 1.6%; P < .001). In those presenting with cranial SSIs, epidural abscess formation was more common with FSB compared to no FSB (27.3% vs 5.4%; P = .006). In multivariate analysis, breach of the frontal sinus was significantly associated with cranial SSI (OR 2.16; 95% CI 1.24–3.78; P = .01) and reoperation (OR 4.20; 95% CI 1.66–10.65; P = .003). CONCLUSION: Patients undergoing frontotemporal craniotomies are at significantly greater risk of serious cranial SSIs if the frontal sinus has been breached.

The Digital Age of Academic Medicine: The Role of Social Media

Abstract Social media is playing an increasingly significant role in academic medicine to improve education, disseminate research, and help stakeholders remain abreast of new research. There are multiple social media platforms that have demonstrated benefits in academic medicine including Twitter, Facebook, LinkedIn, podcasts, and blogs. Other emerging platforms have the potential to further impact the future of academic medicine. Within the established platforms, there have been many successful initiatives. Visual Abstracts allow social media users to quickly preview the key findings of a study through engaging pictures and clear diagrams. Twitter journal clubs allow scientists around the world to discuss and engage with research questions, topics, and articles. Facebooks International Hernia Collaboration is a forum for sharing clinical best practices and research that benefits a wide range of audiences. Social media use offers benefits to journals, researchers, and readers, yet there are professionalism and privacy considerations, which will remain as individuals find further applications of social media in academic medicine.

Resolution of bulbar and spinal symptoms postcranial dural arteriovenous fistula embolisation

Dural arteriovenous fistulas (DAVF) are uncommon lesions. Multiple classification systems have been proposed to attempt to describe these lesions. We describe the case of a patient with a dorsal epidural DAVF that, while cerebral in origin, presented with classic spinal DAVF symptoms. Following embolisation, the patient had complete radiographic and symptomatic resolution. Classification of these DAVFs by embryological development allows for potential stratification of DAVFs with a different biological aetiology and diverse characteristics to more fully understand disease mechanisms.

Identification and targeting of an FGFR fusion in a pediatric thalamic “central oligodendroglioma”

Approximately 1–5% of pediatric intracranial tumors originate in the thalamus. While great strides have been made to identify consistent molecular markers in adult oligodendrogliomas, such as the 1p/19q co-deletion, it is widely recognized that pediatric oligodendrogliomas have a vastly different molecular make-up. While pediatric thalamic or “central oligodendrogliomas” are histologically similar to peripheral pediatric oligodendrogliomas, they are behaviorally distinct and likely represent a cohesive, but entirely different entity. We describe a case of a 10-year-old girl who was diagnosed with an anaplastic glioma with features consistent with the aggressive entity often diagnosed as central or thalamic oligodendroglioma. We performed whole-exome (paired tumor and germline DNA) and transcriptome (tumor RNA) sequencing, which demonstrated an FGFR3-PHGDH fusion. We describe this fusion and our rationale for pursuing personalized, targeted therapy for the patient’s tumor that may potentially play a role in the treatment of similar cases.

Optic neuropathy after anterior communicating artery aneurysm clipping: 3 cases and techniques to address a correctable pitfall

Brain shifts following microsurgical clip ligation of anterior communicating artery (ACoA) aneurysms can lead to mechanical compression of the optic nerve by the clip. Recognition of this condition and early repositioning of clips can lead to reversal of vision loss. The authors identified 3 patients with an afferent pupillary defect following microsurgical clipping of ACoA aneurysms. Different treatment options were used for each patient. All patients underwent reexploration, and the aneurysm clips were repositioned to prevent clip-related compression of the optic nerve. Near-complete restoration of vision was achieved at the last clinic follow-up visit in all 3 patients. Clip ligation of ACoA aneurysms has the potential to cause clip-related compression of the optic nerve. Postoperative visual examination is of utmost importance, and if any changes are discovered, reexploration should be considered as repositioning of the clips may lead to resolution of visual deterioration.