Kristina Chapple

Validation of CT‐MRI fusion for intraoperative assessment of stereotactic accuracy in DBS surgery

Deep brain stimulation is typically performed with intraoperative microelectrode recording and test stimulation for target confirmation. Recent studies have shown accurate, clinically efficacious results after lead placement without microelectrode recording or test stimulation, using interventional magnetic resonance imaging (MRI) or intraoperative computed tomography (CT; iCT) for verification of accuracy. The latter relies on CT–MRI fusion. To validate CT–MRI fusion in this setting, we compared stereotactic coordinates determined intraoperatively using CT–MRI fusion with those obtained on postoperative MRI. Deep brain stimulation electrodes were implanted with patients under general anesthesia. Direct targeting was performed on preoperative MRI, which was merged with preimplantation iCT images for stereotactic registration and postimplantation iCT images for accuracy confirmation. Magnetic resonance imaging was obtained 6 weeks postoperatively for comparison. Postoperative MRI was obtained for 48 patients, with 94 leads placed over a 1‐year period. Vector error of the targeted contact relative to the initial plan was 1.1 ± 0.7 mm on iCT and 1.6 ± 0.7 mm on postoperative MRI. Variance comparisons (F‐tests) showed that the discrepancy between iCT‐ and postoperative MRI‐determined errors was attributable to measurement error on postoperative MRI, as detected in inter‐rater reliability testing. In multivariate analysis, improved lead placement accuracy was associated with frame‐based stereotaxy with the head of the bed at 0° compared with frameless stereotaxy with the head of the bed at 30° (P = 0.037). Intraoperative CT can be used to determine lead placement accuracy in deep brain stimulation surgery. The discrepancy between coordinates determined intraoperatively by CT–MRI fusion and postoperatively by MRI can be accounted for by inherent measurement error.

A Model to Prevent Fibrinolysis in Patients with Stroke Mimics

BACKGROUND Many patients with stroke-mimicking conditions receive treatment with intravenous fibrinolysis (IVF), a treatment associated with potentially serious complications. We sought to determine if any clinical or radiographic characteristics can help predict stroke mimics among IVF candidates. METHODS This retrospective study was carried out at a single institution. Patients treated with intravenous recombinant tissue plasminogen activator (rt-PA; n = 193) were divided into 3 categories: acute ischemic stroke (n = 142), aborted stroke (n = 21), and stroke mimics (n = 30). Analysis of variance and the chi-square test were used to assess differences, while logistic regression models were computed to predict groups. RESULTS Mimics treated with rt-PA did not experience complications (intracranial bleeding, systemic hemorrhage, or angioedema), and had better neurologic and functional outcomes than stroke patients (P < .05). Several variables helped differentiate strokes from mimics, including atherosclerosis on computed tomographic angiography (odds ratio [OR] 23.6; 95% confidence interval [CI] 8.4-66.2), atrial fibrillation (OR 11.4; 95% CI 1.5-86.3), age >50 years (OR 7.2; 95% CI 2.8-18.5), and focal weakness (OR 4.15; 95% CI 1.75-9.8). Other variables decreased chances of stroke: migraine history (OR 0.05; 95% CI 0.01-0.4), epilepsy (OR 0.13; 95% CI 0.02-0.8), paresthesia (OR 0.1; 95% CI 0.04-0.3), and precordialgia (OR 0.045; 95% CI 0.002-0.9). A regression model using focal weakness, computed tomographic angiography findings, and precordialgia had a 90.2% predictive accuracy. CONCLUSIONS IVF has low complication rates in stroke mimics. Certain clinical characteristics appear predictive of stroke mimics, particularly normal computed tomographic angiography. If confirmed, this may help prevent giving IVF to patients without stroke.

Cognitive functioning before and after surgical resection for hypothalamic hamartoma and epilepsy

Objective: To determine whether patients with hypothalamic hamartoma (HH) improve in their cognitive functioning after neurosurgical resection of their HH and explore what variables correlate with cognitive outcome. Methods: Thirty-two patients underwent preoperative and postoperative neuropsychological testing. The age range of patients was between 3.3 and 39.3 years (mean 12.2 years, SD 7.0). The average time interval between surgery and postoperative neuropsychological testing was 23.4 months (range 5.1–47.2 months). Tests administered varied on the basis of the patients age and clinical condition. Results: As a group, measures of overall intelligence showed improvement postsurgery, with associated improvement in processing speed. Memory scores did not demonstrate consistent improvement or decline. Duration of epilepsy, age at surgery, and level of neurocognitive functioning prior to surgery were correlated with postsurgical cognitive status. Patients who had mental retardation but were testable generally showed the greatest gains. Conclusions: Despite the great variability in level of cognitive impairment in patients with HH and refractory epilepsy, level of intelligence may show mild to moderate improvements postsurgery if no surgical complications occur. The variables that predict cognitive outcome are not fully delineated, but testable individuals with the greatest presurgical cognitive impairment and those with the shortest duration of epilepsy appear to make the greatest gains in intellectual functioning. Classification of evidence: This study provides Class IV evidence that single surgical resection for HH was associated with improvement in some subset measures of intellectual functioning, but not memory. Factors that predict better outcomes cannot be determined.

Comparison of outcomes between a less experienced surgeon using a fully endoscopic technique and a very experienced surgeon using a microscopic transsphenoidal technique for pituitary adenoma

OBJECTIVE The comparative efficacy of microscopic and fully endoscopic transsphenoidal surgery for pituitary adenomas has not been well studied despite the adoption of fully endoscopic surgery by many pituitary centers. The influence of surgeon experience has also not been examined in this setting. The authors therefore compared the extent of tumor resection (EOR) and the endocrine outcomes of 1 very experienced surgeon performing a microscopic transsphenoidal surgery technique with those of a less experienced surgeon using a fully endoscopic transsphenoidal surgery technique for resection of nonfunctioning pituitary adenomas in a concurrent series of patients. METHODS Post hoc analysis was conducted of a cohort of adult patients prospectively enrolled in a pituitary adenoma quality-of-life study between October 2011 and June 2014. Patients were followed up for 6 months after surgery. Patients were treated either by a less experienced surgeon (100 independent cases) who practices fully endoscopic surgery exclusively or by a very experienced surgeon (1800 independent cases) who practices microscopic surgery exclusively. Patient demographic characteristics, tumor characteristics, hypopituitarism, complications, and length of hospital stay were analyzed. Tumor volumes and EOR were determined by formal volumetric analysis involving manual segmentation of MR images performed before surgery and within 6 months after surgery. Logistic regression analysis was used to determine predictors of EOR. RESULTS Fifty-five patients underwent fully endoscopic transsphenoidal surgery, and 80 patients underwent fully microscopic transsphenoidal surgery. The baseline characteristics of the 2 treatment groups were well matched. EOR was similar between the endoscopic and microscopic groups, respectively, as estimated by gross-total resection rate (78.2% vs 81.3%, p = 0.67), percentage of tumor resected (99.2% vs 98.7%, p = 0.42), and volume of residual tumor (0.12 cm(3) vs 0.20 cm(3), p = 0.41). Multivariate modeling suggested that preoperative tumor volume was the most important predictor of EOR (p = 0.001). No difference was found in the development of anterior gland dysfunction (p > 0.14), but there was a higher incidence of permanent posterior gland dysfunction in the microscopic group (p = 0.04). Combined rates of major complications and unplanned readmissions were lower in the endoscopic group (p = 0.02), but individual complications were not significantly different. CONCLUSIONS A less experienced surgeon using a fully endoscopic technique was able to achieve outcomes similar to those of a very experienced surgeon using a microscopic technique in a cohort of patients with nonfunctioning tumors smaller than 60 cm(3). The study raises the provocative notion that certain advantages afforded by the fully endoscopic technique may impact the learning curve in pituitary surgery for nonfunctioning adenomas.

Comparison of sinonasal quality of life and health status in patients undergoing microscopic and endoscopic transsphenoidal surgery for pituitary lesions: a prospective cohort study.

OBJECT Despite the widespread adoption of endoscopic transsphenoidal surgery for pituitary adenomas, the sinonasal quality of life (QOL) and health status in patients who have undergone this technique have not been compared with these findings in patients who have undergone the traditional direct uninostril microsurgical technique. In this study, the authors compared the sinonasal QOL and patient-reported health status after use of these 2 surgical techniques. METHODS The study design was a nonblinded prospective cohort study. Adult patients with sellar pathology and planned transsphenoidal surgery were screened at 4 pituitary centers in the US between October 2011 and August 2013. The primary end point of the study was postoperative patient-reported sinonasal QOL as measured by the Anterior Skull Base Nasal Inventory-12 (ASK Nasal-12). Supplementary end points included patient-reported health status estimated by the 8-Item Short Form Health Survey (SF-8) and EuroQol (EQ)-5D-5L instruments, and sinonasal complications. Patients were followed for 6 months after surgery. RESULTS A total of 301 patients were screened and 235 were enrolled in the study. Of these, 218 were analyzed (111 microsurgery patients, 107 endoscopic surgery patients). Demographic and tumor characteristics were similar between groups (p ≥ 0.12 for all comparisons). The most common complication in both groups was sinusitis (7% in the microsurgery group, 13% in the endoscopic surgery group; p = 0.15). Patients treated with the endoscopic technique were more likely to have postoperative nasal debridements (p < 0.001). The ASK Nasal-12 and SF-8 scores worsened substantially for both groups at 2 weeks after surgery, but then returned to baseline at 3 months. At 3 months after surgery, patients treated with endoscopy reported statistically better sinonasal QOL compared with patients treated using the microscopic technique (p = 0.02), but there were no significant differences at any of the other postoperative time points. CONCLUSIONS This is the first multicenter study to examine the effect of the transsphenoidal surgical technique on sinonasal QOL and health status. The study showed that surgical technique did not significantly impact these patient-reported measures when performed at high-volume centers. Clinical trial registration no.: NCT01504399 ( clinicaltrials.gov ).

Comparative inpatient resource utilization for patients undergoing endoscopic or microscopic transsphenoidal surgery for pituitary lesions

UNLABELLED OBJECT.: An increasingly important measure in the health care field is utilization of hospital resources, particularly in the context of emerging surgical techniques. Despite the recent widespread adoption of the endoscopic transsphenoidal approach for pituitary lesion surgery, the health care resources utilized with this approach have not been compared with those utilized with the traditional microscopic approach. The purpose of this study was to determine the drivers of resource utilization by comparing hospital charges for patients with pituitary tumors who had undergone either endoscopic or microscopic transsphenoidal surgery. METHODS A complete accounting of all hospital charges for 166 patients prospectively enrolled in a surgical quality-of-life study at a single pituitary center during October 2011-June 2013 was undertaken. Patients were assigned to surgical technique group according to surgeon preference and then managed according to a standard postoperative institutional set of orders. Individual line-item charges were assigned to categories (such as pharmacy, imaging, surgical, laboratory, room, pathology, and recovery unit), and univariate and multivariate statistical analyses were conducted. RESULTS Of the 166 patients, 99 underwent microscopic surgery and 67 underwent endoscopic surgery. Baseline demographic descriptors and tumor characteristics did not differ significantly. Mean total hospital charges were

Predictors of resource utilization in transsphenoidal surgery for Cushing disease

74,703 ±

Long-Term Follow-up of 25 Cases of Biopsy-Proven Radiation Necrosis or Post-Radiation Treatment Effect Treated With Magnetic Resonance-Guided Laser Interstitial Thermal Therapy.

15,142 and

National treatment trends, complications, and predictors of in-hospital charges for the surgical management of craniopharyngiomas in adults from 2007 to 2011

72,311 ±

Clinical outcomes after intravenous fibrinolysis in cryptogenic strokes with or without patent foramen ovale.

16,576 for microscopic and endoscopic surgery patients, respectively (p = 0.33). Furthermore, other than for pathology, charge categories did not differ significantly between groups. A 2-step multivariate regression model revealed that length of stay was the most influential variable, followed by a diagnosis of Cushings disease, and then by endoscopic surgical technique. The model accounts for 42% of the variance in hospital charges. CONCLUSIONS Study findings suggest that adoption of the endoscopic transsphenoidal technique for pituitary lesions does not adversely affect utilization of resources for inpatients. The primary drivers of hospital charges, in order of importance, were length of stay, a diagnosis of Cushings disease, and, to a lesser extent, use of the endoscopic technique. This study also highlights the influence of individual surgeon practice patterns on resource utilization.