Meyer, Fredric B.

Abstract Dr Thoralf Sundt III joined the department of neurosurgery at Mayo Clinic in 1969 and served as chairman from 1980 until his death in 1992. Dr Sundt was a pioneer in the field of cerebrovascular neurosurgery and among his many contributions to neurosurgical technology was the introduction of the Sundt clip graft (Codman, Raynham, Massachusetts), which was developed in partnership with Dr George Kees. This device is a vessel-encircling Teflon or Dacron graft loaded on a circular metallic spring initially designed to repair injuries to vessel walls during intracranial aneurysm surgery, 1 which was not an uncommon complication resulting from the use of contemporary aneurysm clips. 2 When used for this purpose, the clip graft has demonstrated both safety and efficacy in a modern series of surgical treatment of intracranial aneurysm. 3 An additional application of the clip graft is the direct clipping of aneurysms, particularly side-wall aneurysms, though Dr Sundt recognized that the potential to occlude perforating arteries adjacent to the aneurysm neck would limit the general use of the clip graft for aneurysm clipping. 2 In the following video, we present archival footage of Dr Sundt utilizing the Sundt clip graft during intracranial aneurysm surgery. The 3 cases are of the treatment of posterior communicating, middle cerebral, and anterior communicating artery aneurysms and depict the potential applications of the clip graft during aneurysm surgery. We also present footage of animal experiments Dr Sundt performed to validate the use of the clip graft. This footage likely represents some of the first microscopic neurosurgical recordings ever made. The patients consented to the procedure and to presentation of video recordings at the time of initial surgery. Image of Sundt at 0:11, Reproduced with permission from the American Association of Neurological Surgeons, 5550 Meadowbrook Dr, Rolling Meadows, IL 60008. Figures at 2:26 and 2:28, from Park PJ, Meyer FB, The Sundt clip graft, Neurosurgery , 2010;66(6 suppl operative):300-305, by permission of the Congress of Neurological Surgeons. Figure at 2:35, ©2009 Mayo, Clingman. Used with permission.

OBJECTIVE Surgical site infection (SSI) is a rare but significant complication after vagus nerve stimulator (VNS) placement. Treatment options range from antibiotic therapy alone to hardware removal. The optimal therapeutic strategy remains open to debate. Therefore, the authors conducted this retrospective multicenter analysis to provide insight into the optimal management of VNS-related SSI (VNS-SSI). METHODS Under institutional review board approval and utilizing an institutional database with 641 patients who had undergone 808 VNS-related placement surgeries and 31 patients who had undergone VNS-related hardware removal surgeries, the authors retrospectively analyzed VNS-SSI. RESULTS Sixteen cases of VNS-SSI were identified; 12 of them had undergone the original VNS placement procedure at the authors’ institutions. Thus, the incidence of VNS-SSI was calculated as 1.5%. The mean (± standard deviation) time from the most recent VNS-related surgeries to infection was 42 (± 27) days. Methicillin-sensitive staphylococcus was the usual causative bacteria (58%). Initial treatments included antibiotics with or without nonsurgical procedures (n = 6), nonremoval open surgeries for irrigation (n = 3), generator removal (n = 3), and total or near-total removal of hardware (n = 4). Although 2 patients were successfully treated with antibiotics alone or combined with generator removal, removal of both the generator and leads was eventually required in 14 patients. Mild swallowing difficulties and hoarseness occurred in 2 patients with eventual resolution. CONCLUSIONS Removal of the VNS including electrode leads combined with antibiotic administration is the definitive treatment but has a risk of causing dysphagia. If the surgeon finds dense scarring around the vagus nerve, the prudent approach is to snip the electrode close to the nerve as opposed to attempting to unwind the lead completely.

The American Board of Neurological Surgery (ABNS) was incorporated in 1940 in recognition of the need for detailed training in and special qualifications for the practice of neurological surgery and for self-regulation of quality and safety in the field. The ABNS believes it is the duty of neurosurgeons to place a patient’s welfare and rights above all other considerations and to provide care with compassion, respect for human dignity, honesty, and integrity. At its inception, the ABNS was the 13th member board of the American Board of Medical Specialties (ABMS), which itself was founded in 1933. Today, the ABNS is one of the 24 member boards of the ABMS. To better serve public health and safety in a rapidly changing healthcare environment, the ABNS continues to evolve in order to elevate standards for the practice of neurological surgery. In connection with its activities, including initial certification, recognition of focused practice, and continuous certification, the ABNS actively seeks and incorporates input from the public and the physicians it serves. The ABNS board certification processes are designed to evaluate both real-life subspecialty neurosurgical practice and overall neurosurgical knowledge, since most neurosurgeons provide call coverage for hospitals and thus must be competent to care for the full spectrum of neurosurgery. The purpose of this report is to describe the history, current state, and anticipated future direction of ABNS certification in the US.

OBJECTIVE Acute traumatic subdural hematoma (atSDH) can be a life-threatening neurosurgical emergency that necessitates immediate evacuation. The elderly population can be particularly vulnerable to tearing bridging veins. The aim of this study was to evaluate inpatient morbidity and mortality, as well as predictors of inpatient mortality, in a national trauma database. METHODS The authors queried the 2016–2017 National Trauma Data Bank registry for patients aged 65 years and older who had undergone evacuation of atSDH. Patients were categorized into three age groups: 65–74, 75–84, and 85+ years. A multivariable logistic regression model was fitted for inpatient mortality adjusting for age group, sex, race, presenting Glasgow Coma Scale (GCS) category (3–8, 9–12, and 13–15), Injury Severity Score, presence of coagulopathy, presence of additional hemorrhages (epidural hematoma [EDH], intraparenchymal hematoma [IPH], and subarachnoid hemorrhage [SAH]), presence of midline shift > 5 mm, and pupillary reactivity (both, one, or none). RESULTS A total of 2508 patients (35% females) were analyzed. Age distribution was as follows: 990 patients at 65–74 years, 1096 at 75–84, and 422 at 85+. Midline shift > 5 mm was present in 72% of cases. With regard to additional hemorrhages, SAH was present in 21%, IPH in 10%, and EDH in 2%. Bilaterally reactive pupils were noted in 90% of patients. A major complication was observed in 14.4% of patients, and the overall mortality rate was 18.3%. In the multivariable analysis, the presenting GCS category was found to be the strongest predictor of postoperative inpatient mortality (3–8 vs 13–15: OR 3.63, 95% CI 2.68–4.92, p < 0.001; 9–12 vs 13–15: OR 2.64, 95% CI 1.79–3.90, p < 0.001; 30% of overall variation), followed by the presence of SAH (OR 2.86, 95% CI 2.21–3.70, p < 0.001; 25% of overall variation) and the presence of midline shift > 5 mm (OR 2.40, 95% CI 1.74–3.32, p < 0.001; 11% of overall variation). Model discrimination was excellent (c-index 0.81). Broken down by age decile group, mortality increased from 8.0% to 15.4% for GCS 13–15 to around 36% for GCS 9–12 to almost as high as 60% for GCS 3–8, particularly in those aged 85 years and older. CONCLUSIONS The present results from a national trauma database will, the authors hope, assist surgeons in preoperative discussions with patients and their families with regard to expected postoperative outcomes following surgical evacuation of an atSDH.

OBJECTIVEThe sitting or semisitting position in neurosurgery allows for several technical advantages, including improved visualization of the surgical field. However, it has also been associated with an increased risk of venous air embolisms and positioning-related complications that limit its commonplace adoption. The authors report a large, single-center series of cervical spine procedures performed with patients in the sitting or prone position in order to assess the perceived risk of intraoperative and postoperative complications associated with the sitting position.METHODSNoninstrumented, single-level posterior cervical spine procedures performed with patients in the sitting/semisitting or prone position from 2000 to 2016 at a single institution were reviewed. Institutional abstraction tools (DataMart and Chart Plus) were used to collect data from the medical records. The two positions were compared with regard to preoperative factors, intraoperative variables, and postoperative outcomes. Multivariable logistic regression models were fitted for 30-day readmission, 30-day return to the operating room, and complication rates.RESULTSA total of 750 patients (sitting, n = 480; prone, n = 270) were analyzed. The median age was 53 years for those who underwent surgery in the prone position and 50 years for those who underwent surgery in the sitting position (IQRs 45–62 years and 43–60 years, respectively), and 35% of the patients were female. Sitting cases were associated with significantly longer anesthetic times (221 minutes [range 199–252 minutes] vs 205 minutes [range 179–254 minutes]) and operative times (126 minutes [range 101–163 minutes] vs 149 minutes [120–181 minutes]). Cardiorespiratory events in the postanesthesia care unit (PACU) were comparable between the two groups, with the exception of episodes of apnea (2.6% vs 0.6%, p = 0.041) and hypoventilation (4.4% vs 0.8%, p < 0.003), which were more frequent in the prone-position cohort. On multivariable analysis, the effect of the sitting versus the prone position was not significant for 30-day readmission (OR 0.77, 95% CI 0.34–1.71, p = 0.52) or reoperation (OR 0.71, 95% CI 0.31–1.60, p = 0.40). The sitting position was associated with lower odds of developing any complication (OR 0.31, 95% CI 0.16–0.62, p < 0.001).CONCLUSIONSBased on the intraoperative and postoperative complications chosen in this study, the sitting position confers a similar safety profile to the prone position. This can be explained by a more anatomic positioning accounting for reduced temporary neurological deficits and reduced PACU-associated hypoventilation noted in this series. Nevertheless, the findings may also reflect institutional familiarity, experience, and mastery of this position type, and outcomes may not reflect practices in general.

OBJECTIVE Multiple endocrine neoplasia type 1 (MEN1) is a rare, autosomal-dominant tumor disorder characterized by the development of pituitary tumors and other endocrine neoplasms. Diagnosis is made clinically based on the development of 2 or more canonical lesions (parathyroid gland, anterior pituitary, and enteropancreatic tumors) or in family members of a patient with a clinical diagnosis of MEN1 and the occurrence of one of the MEN1-associated tumors. The goal of this study was to characterize pituitary tumors arising in the setting of MEN1 at a single institution. The probability of tumor progression and the likelihood of surgical intervention in patients with asymptomatic nonfunctional pituitary adenomas were also analyzed. METHODS A retrospective review of a prospectively maintained institutional database was performed for patients with MEN1 diagnosed from 1970 to 2017. Data included patient demographics, tumor characteristics, treatment strategies, and outcomes. RESULTS A review of the database identified 268 patients diagnosed with MEN1, of whom 158 (59%) were female. Among the 268 patients, 139 (51.8%) had pituitary adenomas. There was a higher prevalence in women than in men (65% vs 35%, p < 0.005). Functional adenomas (57%) were more common. Prolactin-secreting adenomas were the most common functional tumors. Macroadenomas were seen in 27% of patients and were more likely to be symptomatic and locally aggressive (p < 0.001). Forty-nine patients (35%) underwent transsphenoidal resection at some point during their disease course. In 52 patients who were initially observed with MEN1 asymptomatic nonfunctional adenomas, only 5 (10%) progressed to need surgery. In MEN1 patients, an initial parathyroid lesion is most likely followed in order by pituitary, pancreatic, adrenal, and, finally, rare carcinoid tumors. CONCLUSIONS Asymptomatic nonfunctional pituitary adenomas in patients with MEN1 may be followed safely with MRI. In this series, parathyroid tumors developed at the lowest median age of all cardinal tumors, and development of additional cardinal MEN1 lesions followed a predictable pattern. This pattern of disease progression could have significant implications for disease surveillance in clinical practice and may help to target clinical resources to the lesions most likely to develop next. This may aid with early detection and treatment and warrants further study.

ObjectivesThe aim of this study was to perform a whole-brain analysis of alterations in brain mechanical properties due to normal pressure hydrocephalus (NPH).Materials and MethodsMagnetic resonance elastography (MRE) examinations were performed on 85 participants, including 44 cognitively unimpaired controls, 33 with NPH, and 8 who were amyloid-positive with Alzheimer clinical syndrome. A custom neural network inversion was used to estimate stiffness and damping ratio from patches of displacement data, accounting for edges by training the network to estimate the mechanical properties in the presence of missing data. This learned inversion was first compared with a standard analytical approach in simulation experiments and then applied to the in vivo MRE measurements. The effect of NPH on the mechanical properties was then assessed by voxel-wise modeling of the stiffness and damping ratio maps. Finally, a pattern analysis was performed on each individual's mechanical property maps by computing the correlation between each person's maps with the expected NPH effect. These features were used to fit a classifier and assess diagnostic accuracy.ResultsThe voxel-wise analysis of the in vivo mechanical property maps revealed a unique pattern in participants with NPH, including a concentric pattern of stiffening near the dural surface and softening near the ventricles, as well as decreased damping ratio predominantly in superior regions of the white matter (family-wise error correctedP< 0.05 at cluster level). The pattern of viscoelastic changes in each participant predicted NPH status in this cohort, separating participants with NPH from the control and the amyloid-positive with Alzheimer clinical syndrome groups, with areas under the receiver operating characteristic curve of 0.999 and 1, respectively.ConclusionsThis study provides motivation for further development of the neural network inversion framework and demonstrates the potential of MRE as a novel tool to diagnose NPH and provide a window into its pathogenesis.

Abstract Systematic reviews and meta-analyses in the neurosurgical literature have surged in popularity over the last decade. It is our concern that, without a renewed effort to critically interpret and appraise these studies as high or low quality, we run the risk of the quality and value of evidence-based medicine in neurosurgery being misinterpreted. Correspondingly, we have outlined 4 major domains to target in interpreting neurosurgical systematic reviews and meta-analyses based on the lessons learned by a collaboration of clinicians and academics summarized as 4 pearls. The domains of (1) heterogeneity, (2) modeling, (3) certainty, and (4) bias in neurosurgical systematic reviews and meta-analyses were identified as aspects in which the authors’ approaches have changed over time to improve robustness and transparency. Examples of how and why these pearls were adapted were provided in areas of cranial neuralgia, spine, pediatric, and neuro-oncology to demonstrate how neurosurgical readers and writers may improve their interpretation of these domains. The incorporation of these pearls into practice will empower neurosurgical academics to effectively interpret systematic reviews and meta-analyses, enhancing the quality of our evidence-based medicine literature while maintaining a critical focus on the needs of the individual patients in neurosurgery.