Faculty Bibliography

BACKGROUND:Venous thromboembolism (VTE) represents a significant source of morbidity and mortality in the inpatient population and is considered a leading preventable cause of death among inpatients. Neurosurgical inpatients are of particular interest because of the greater rates of immobility, steroid use, and potential consequences of postoperative hemorrhage. A consensus protocol for VTE screening in this population has not yet been developed, and institutional protocols vary widely. METHODS:We performed a retrospective review of lower extremity venous duplex ultrasonography (VDUS) usage at our institution and applied this information to the development of a neurosurgery department protocol, with consideration of high-risk patient risk factors and indications for VDUS ordering. We then implemented this protocol, which consisted of preoperative screening of patients at high risk of VTE and limited postoperative surveillance, for a 6-month period and compared VDUS usage and VTE occurrence. RESULTS:Preoperative VDUS screening before nonemergent neurosurgical procedures in high-risk patients with active cancer, an inability to ambulate, or a history of deep vein thrombosis (DVT) identified proximal DVTs that were then treated. Postoperative routine surveillance VDUS scans only diagnosed incidental isolated calf DVT for which no clinically relevant sequelae occurred. Overall, postoperative surveillance VDUS usage decreased significantly (66.9% vs. 13.5%; P = 0.001). CONCLUSIONS:Our findings lend support to preoperative screening of high-risk patients and suggest that routine postoperative VDUS surveillance of asymptomatic patients is unnecessary.

Background/UNASSIGNED:There remains no consensus on the optimal primary intervention for subdural hematoma (SDH). Although historically favored, craniotomy carries substantial morbidity and incurs significant costs. Contrastingly, the subdural evacuating port system (SEPS) is a minimally invasive bedside procedure. We assessed the benefits of SEPS over traditional craniotomy for SDH evacuation. Methods/UNASSIGNED:A single-center retrospective cohort study of SDH patients receiving craniotomy or SEPS between 2012 and 2017 was performed. Information regarding demographics, medical history, presentation, surgical outcomes, cost, and complications was collected. Pre- and postoperative hematoma volumes were calculated using 3D image segmentation using Vitrea software. Multivariate regression models were employed to assess the influence of intervention choice. Results/UNASSIGNED:= 1.000). Conclusion/UNASSIGNED:In this retrospective cohort, SEPS was noninferior to craniotomy at reducing SDH hematoma volume. The SEPS procedure was also associated with decreased length of stay hospitalization costs, and postoperative seizures and demonstrated a comparable recurrence rate to craniotomy for chronic SDH in particular.

Cerebral cavernous malformations are common vascular anomalies consisting of a cluster of capillaries without intervening brain tissue.1 A variety of approaches for resection have been undertaken,2 and a handful of case reports have described the endoscopic, endonasal, transclival approach.3 We present a case of a 51-yr-old woman with lupus and hepatitis B-associated cirrhosis who presented with diplopia, dysphagia, and ataxia. She had a left abducens nerve palsy and magnetic resonance imaging (MRI) showed a left pontine cavernous malformation. After a repeat hemorrhage, she consented to surgical resection. The lesion appeared to come to the medial pontine pial surface. Tractography indicated a rightward displacement of the left corticospinal tract. Therefore, an endoscopic, transnasal, transclival approach was chosen. A lumbar drain was placed preoperatively. The clivus and ventral petrous bone were drilled using the vidian canal to help identify the anterior genu of the petrous carotid artery. The clival dura was opened, revealing the abducens nerve exiting the ventral pons. The cavernoma was visible on the surface lateral to the nerve. It was removed using blunt dissection and the remaining cavity inspected. The skull base was reconstructed using an abdominal dermal-fat graft and Alloderm covered by a nasoseptal flap. Postoperatively she had transient swallowing difficulty. The lumbar drain was kept open for 5 d. Cerebrospinal fluid (CSF) leak was ruled out using an intrathecal fluorescein injection. She was discharged home, but presented 2 wk postoperatively with aseptic meningitis, which was treated supportively. Postoperative imaging did not show residual cavernoma.

BACKGROUND:Ecchordosis physaliphora (EP) is a congenital, uniformly asymptomatic, hamartomatous lesion of the primitive notochord. Herein we report, to our knowledge, the first credible case report of unprovoked intra-sphenoidal rupture resulting in recurrent pneumocephalus and cerebrospinal fluid (CSF) leak, definitively captured over serial imaging during clinical and radiologic surveillance. CASE DESCRIPTION/METHODS:A 68-year old woman with Marfan syndrome presented to the Emergency Department with the worst headache of life. Imaging demonstrated extensive pneumocephalus and revealed a small, dorsal midline clival lesion consistent with EP and a trans-sphenoidal defect. Remote imaging encounters confirmed typical EP without pneumocephalus or cortical defect, and an uneventful clinical course years preceding presentation. Over the ensuing months during neurosurgical follow-up, the patient reported recurrent headaches, imbalance, and unprovoked clear rhinorrhea. Further imaging demonstrates an apparently enlarging trans-sphenoidal defect which was managed by endoscopic trans-nasal resection and nasoseptal flap. Pathologic evaluation confirmed the diagnosis of EP and chronic dural defect. CONCLUSIONS:This represents, to our knowledge, the first unambiguous example of spontaneous EP rupture and recurrent pneumocephalus captured over serial imaging. The case further underscores rare, but potentially significant complications of EP and highlights management options. BACKGROUND:. Herein we report, to our knowledge, the first documented spontaneous rupture of EP resulting in recurrent pneumocephalus, credibly captured over serial radiologic surveillance. CLINICAL PRESENTATION/METHODS:A 68 year-old woman with history of hypertension, hyperlipidemia, and Marfan syndrome presented to the Emergency Department reporting the "worst headache of her life" after engaging in an interpersonal dispute the evening preceding presentation.

The transsphenoidal corridor for pituitary adenoma surgery was established as early as 1906 by Schloffer and was subsequently refined by Cushing throughout the early 20thcentury [1]. The use of intraoperative magnetic resonance imaging (iMRI) in endoscopic endonasal transsphenoidal resections, however, is a relatively contemporary addition to the surgical treatment of pituitary tumors. The morbidity of these cases has decreased over the years in light of advances in intraoperative navigation as well as improvements in endoscope dynamics and surgical instruments. Despite such improvements, a substantial number of patients require repeat surgeries or subsequent radiotherapy for residual and/or recurrent disease. This can be largely attributed to cavernous sinus invasion or suprasellar extension, which pose technical challenges to achieving gross total resections (GTRs). The rate of GTR for pituitary tumors cited in the literature varies from 59-88%.[2-3] The advantage of iMRI is that it provides the surgeon with immediate feedback regarding their progress and ability to safely achieve GTR which, in pituitary surgery, is critical for long term cure. Additionally, although there is concern for increased risk of postoperative endocrine dysfunction, Zhibin et al prove that this is not necessarily the case. In their series, 133 patients who underwent iMRI had higher rates of GTR and did not have a significant difference in postoperative hypopituitarism. [4] This study includes a combined retrospective and prospective comparative analysis of 238 patients who underwent transsphenoidal resection of a pituitary tumor from January 2013 until May 2019. All patients were operated on by one of four experienced neurosurgeons and one of three experienced otolaryngologists. There were 203 patients who did not undergo iMRI and 25 patients who did. A 3 tesla MRI magnet was used in all cases. All intraoperative images were read and interpreted by a senior neuroradiologist at our institution. Amongst the two groups, there was no statistically significant difference in patient age (p = 0.488), tumor size (microadenoma versus macroadenoma, p = 0.878), and primary versus recurrent tumor (p = 0.837). The use of iMRI did not yield a decrease in the length of stay (4.84 days in the no iMRI group and 5 in the iMRI group, p = 0.777). There were zero cases of a return to the OR for residual tumor in the intraoperative MRI group versus the non-MRI group. However, this did not reach statistical significance. This study did not yield a statistically significant difference in GTR (p = 0.75), near total resection (NTR, p = 0.167), or subtotal resection (p = 0.083). This is likely secondary to a low sample size and therefore power in the iMRI group. Finally, there was no significant difference in the number of patients requiring postoperative DDAVP (p = 0.099) or hydrocortisone (p = 0.873) after discharge. Preliminary results reveal a potential benefit of iMRI use to assess for residual disease which can be addressed immediately during the initial operation, thus decreasing the need for re-operations. Furthermore, the ability to correlate intraoperative findings with an intraoperative structure may lead to more precise identification and preservation of normal gland, which can possibly decrease the incidence of postoperative endocrine dysfunction

Direct access through the sinuses and nasopharyngeal mucosa in the endoscopic endonasal approach (EEA) raises concern for a contaminated operative environment and subsequent infection. The reported rate of meningitis in endoscopic endonasal skull base surgery in the literature ranges from 0.7 to 3.0% [1, 2]. The only factor identified as being independently associated with meningitis in a statistically significant manner is cerebrospinal fluid (CSF) leak [1-5]. However, many centers performing high volume of EEAs use postoperative antibiotic coverage independent of the presence intraoperative or postoperative CSF leak. Furthermore, while meningitis remains a severe concern, most centers use postoperative gram-positive coverage to prevent toxic shock syndrome caused by Staphylococcus aureus infection in the setting of prolonged nasal packing. There are currently a multitude of approaches regarding perioperative antibiotic coverage in EEAs [1-4]. Given the lack of consensus in the literature and our experience regarding the benefit of discontinuation of prolonged prophylactic antibiotics throughout the breadth of neurosurgical procedures, we sought to analyze the need for postoperative antibiotics in EEAs further. As such, we performed a prospective analysis compared with a retrospective cohort to delineate whether discontinuation of postoperative antibiotics leads to a change in the rate of postoperative infections. The retrospective cohort consisted of patients who underwent an EEA from January 1, 2013 to May 31, 2019. These patients all received postoperative antibiotics while nasal packing was in place (median 7 days). Starting on April 1, 2019 until August 1, 2019, we discontinued postoperative antibiotic use. Patients from this group made up the prospective cohort. The retrospective cohort had 315 patients (66% pituitary macroadenomas vs. 7% microadenomas, 4% meningiomas, 4% craniopharyngiomas, 4% chordomas, and 15% others) while the prospective group had 23 patients (57% pituitary macroadenomas, 30% craniopharyngiomas, 8% meningiomas/chordomas, and 5% others). The primary endpoint was rate of postoperative infections and specifically, meningitis and multidrug resistant organism (MDRO) infections. There was no statistically significant difference in the use of nasal packing (p = 0.085), intraoperative CSF leak (p = 0.133), and postoperative CSF leak (p = 0.507) between the two groups. There was also no significant difference in the number of patients with positive preoperative MSSA and MRSA nasal swabs (p = 0.622). There was a significant decrease in the number of patients discharged with antibiotics (55.1% in the retrospective and 4.5% in the prospective group, p = 0.000). The number of patients with positive blood cultures (p = 0.701) and positive urine cultures (p = 0.691) did not differ significantly between the two groups. Finally, there was no statistically significant difference in postoperative CSF infections (p = 0.34) or MDRO infections (0.786) between the two groups. We describe promising preliminary results that demonstrate that discontinuation of postoperative antibiotics in EEAs do not lead to a statistically significant increase in the rate of postoperative CSF or MDRO infections. The previous algorithm for postoperative antibiotic coverage in our center, like many centers, called for gram-positive coverage, which may have contributed to the overall preponderance of gram-negative meningitis cases in this cohort

BACKGROUND:Intramedullary spinal cord neoplasms (ISCN) pose significant management challenges. Advances in magnetic resonance imaging (MRI) (such as diffusion tensor imaging, DTI) have been utilized to determine the infiltrative nature and resectability of ISCN. However, this has not been applied to intraoperative decision making. OBJECTIVE:To present a case series of 2 patients with ISCN, the first to combine use of DTI, pre- and intraoperative 3-dimensional (3D) virtual reality imaging, and microscope integrated navigation with heads-up display. METHODS:Two patients who underwent surgery for ISCN were included. DTI images were obtained and 3D images were created using Surgical Theater (Surgical Theater SRP, Version 7.4.0, Cleveland, Ohio). Fiducials were used to achieve accurate surface registration to C4. Navigation confirmed the levels of laminectomy necessary. The microscope was integrated with Brainlab (Brainlab AG Version 3.0.5, Feldkirchen, Germany) and the tumor projected in the heads-up display. Surgical Theater was integrated with Brainlab to allow for real time evaluation of the 3D tractography. RESULTS:Case 1: All tracts were pushed away from the tumor, suggesting it was not infiltrative. Surgical Theater and Brainlab assisted in confirming midline despite the abnormal swelling of the cord so the myelotomy could be performed. The heads-up display outline demonstrated excellent correlation to the tumor. Gross total resection was achieved. Diagnosis of ependymoma was confirmed. Case 2: Some tracts were going through the tumor itself, suggesting an infiltrative process. Surgical Theater and Brainlab again allowed for confirmation of the midline raphe. Near total resection of the enhancing portion was achieved. Diagnosis of glioblastoma was confirmed. CONCLUSION/CONCLUSIONS:This is a proof of concept application where multi-modal imaging technology was utilized for safest maximal ISCN resection.

Objective/UNASSIGNED:To describe an unusual presentation of a follicle-stimulating hormone-secreting pituitary adenoma leading to ovarian hyperstimulation syndrome. We also discuss the pathophysiology and subsequent management of these tumors. Methods/UNASSIGNED:This is a case report and review of the literature. A 37-year-old female with menorrhagia was found to have bilateral multilocular adnexal cysts with concern for ovarian hyperstimulation syndrome. Results/UNASSIGNED:Labs revealed elevated follicle-stimulating hormone, and an eminent estradiol level. Pituitary magnetic resonance imaging revealed a macroadenoma with cavernous sinus invasion. The patient went on to have a successful transsphenoidal resection with normalization of hormones and subsequent resumption of menstrual cycles. Conclusion/UNASSIGNED:With the help of this case report, we illustrate the pathogenesis of functioning gonadotroph adenomas as well as the management challenges associated with these tumors. Our case is unique in its presentation with severe hyperestrogenemia and cavernous sinus invasion pointing towards a clinically aggressive adenoma. It is important to increase awareness of these tumors to ensure timely and effective management of their complications.

BACKGROUND:Neurovascular training models include animal models, synthetics, or computer simulation. In vivo models are expensive and require significant resources. Synthetic/computer models do not reflect the elasticity of fresh vessels. We describe an endovascular and microsurgical training model using a chicken thigh/leg. METHODS:20 chicken thigh/leg models were obtained. Angiography was utilized to understand the anatomy. Proximal cannulation with a 5-French catheter was achieved and connected to a hemostatic valve with a pump to simulate pulsatile flow. Aneurysms were created at the thigh-leg junction. For clipping training, 3 types of aneurysms were created to reproduce anatomy seen in middle cerebral, anterior communicating and posterior communicating aneurysms. RESULTS:The average cost per specimen from was $1.70 ± 0.30. The diameter of the proximal femoral artery (PFA) was 2.4 mm ± 0.2 mm. The length from the PFA to the aneurysm was 9.5 cm ± 0.7 cm. Distal catheterization was successful in all cases (n=6). Successful deployment of coils and a stent was achieved under fluoroscopic guidance. Gross over-sizing of coils and other mistakes led to aneurysm rupture. Each examiner performed an exploration of the pulsatile aneurysm, application and reapplication of a variety of clips and then final inspection of branching vessels to confirm patency. CONCLUSIONS:The chicken thigh/leg model provides training opportunities in microsurgical suturing, endovascular techniques for aneurysm obliteration, and microsurgical reconstruction of aneurysms. It combines affordability, time efficiency and reproducibility. Further studies measuring improvement in technical aneurysm management and comparison to other training models are warranted.

Background: Surgical resection of pituitary adenomas is associated with a 10 to 30% rate of temporary diabetes insipidus with ~50% resolving within 1 week and 80% resolving at 3 months.[1] Adrenal insufficiency occurs in ~ 5 % of patients and can result in an Addisonian crisis if left undiagnosed postoperatively.[1] [2] Many studies have been performed looking at readmission rates after pituitary surgery. A review of over 1,200 cases demonstrated a readmission rate of 8.5% with the most common cause being hyponatremia (29.5%).[3] To reduce the rate of readmission for hyponatremia, some groups have demonstrated the effective use of outpatient fluid restriction criteria during the first week post-op.[4] These guidelines are intended for the management of standard postoperative hormonal fluctuations which do not necessitate endocrine consultation during hospitalization.
Objective(s): Retrospectively evaluate patients undergoing endoscopic endonasal resection of pituitary adenomas to identify areas for quality improvement through the development of more standardized postoperative guidelines.
Method(s): A retrospective review of 75 patients who underwent endoscopic endonasal resection of pituitary adenomas at a single academic center from 2013 to 2018. We evaluated the average length of stay, number of laboratory studies performed, need for hormone supplementation long term and short term, rate of gross-total resection, rate of cerebrospinal fluid leak, rate of infection, and 30-day readmission rate ([Table 1]). From this, we have developed a change in guidelines aimed at reducing length of stay, redundant laboratory studies, and reduced rate of readmission.
Conclusion(s): Although our current outcomes for resection of pituitary adenoma are on par with published data, we have identified areas of possible quality improvement which have since been implemented