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Ann-Christine Duhaime and Daniel Schwartz

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Jill S. Barnholtz-Sloan, Andrew E. Sloan, and Ann G. Schwartz

Object. The purpose of this study was to examine patterns of diagnosis and relative survival rates in individuals in whom a primary malignant brain tumor was diagnosed between 1973 and 1997; follow-up review of these patients continued through the end of 1999.

Methods. The study population was composed of 21,493 patients with primary malignant brain tumors that were diagnosed between 1973 and 1997. Data on these patients were obtained from the population-based Surveillance, Epidemiology, and End Results Program. The study population was divided into three cohorts based on the year of diagnosis, and these groups were compared with respect to variables of interest by performing chi-square tests and relative survival analysis with the life table method.

Over time, there were consistently more men, more Caucasians, more patients undergoing surgery, and more individuals 70 years and older who received the diagnosis of primary malignant brain tumor. An examination of proportions of individuals with astrocytoma, other; oligodendroglioma, other; and oligodendroglioma Grade III showed significant temporal changes with frontal and temporal lobe tumors occurring most often. The diagnosis was obtained at an earlier age in African-American than in Caucasian patients. Caucasians had higher proportions of glioblastoma multiforme (GBM), which was associated with decreased survival times, and of oligodendroglioma, other, whereas African Americans had higher proportions of astrocytoma, other; ependymoma Grade II or III; and medulloblastoma, all of which were associated with increased survival times. The relative survival case demonstrated a continuous improvement over time, although older patients, those who underwent biopsy only, and those with GBMs continue to have the poorest survival times. The relative survival rates of African Americans consistently were similar or worse than those of Caucasians when the groups were stratified by prognostic factors.

Conclusions. Over time, the relative survival rate of individuals with primary malignant brain tumor has improved and differences in survival are seen by examining the race of the patients.

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Ashesh D. Mehta, Douglas Labar, Andrew Dean, Cynthia Harden, Syed Hosain, Jayoung Pak, David Marks, and Theodore H. Schwartz

Object. Depth electrodes are useful in the identification of deep epileptogenic foci. Computerized tomography—magnetic resonance (CT/MR)— and angiography-guided frame-based techniques are safe and accurate but require four-point skull fixation that limits cranial access for the placement of additional grids and strips. The authors investigated the viability and accuracy of placing depth electrodes by using a commercially available frameless system.

Methods. A slotted, custom-designed adapter was built to interface with the StealthStation Guide Frame-DT and 960-525 StealthFighter. The Cranial Navigation software was used to plan the trajectory and entry site based on preoperative spoiled gradient MR imaging studies. Forty-one depth electrodes were placed in 51 targets in 20 patients. Thirty-one of these electrodes were inserted through the temporal neocortex following craniotomy and placement of subdural grids, whereas 10 were placed through burr holes. All electrodes had contact either within (71%) or touching (29%) the target, 50 of which (98%) provided adequate recordings. Although the mean distance of the distal electrode contact from the intended target was 3.1 ± 0.5 mm, the mean distance to the edge of the anatomical structure was 0.4 ± 0.9 mm. Placement via the laterotemporal approach was significantly (p < 0.001) more accurate than that via the occipitotemporal approach. No complication occurred.

Conclusions. Depth electrodes can be placed safely and accurately by using a commercially available frameless stereotactic navigation system and a custom-made adapter. Depth electrode placement to record ictal onsets during epilepsy surgery only requires the contacts to touch rather than to reside within the intended structure. The laterotemporal approach is a more accurate method of placing electrodes than is the occipitotemporal one, likely due to the increased distance from the entry point to the target.

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Andrew R. Conger, M.S., Joshua Lucas, Gabriel Zada, Theodore H. Schwartz, and Aaron A. Cohen-Gadol

Endoscopic approaches to the midline ventral skull base have been extensively developed and refined for resection of cranial base tumors over the past several years. As these techniques have improved, both the degree of resection and complication rates have proven comparable to those for transcranial approaches, while visual outcomes may be better via endoscopic endonasal surgery and hospital stays and recovery times are often shorter. Yet for all of the progress made, the steep learning curve associated with these techniques has hampered more widespread implementation and adoption. The authors address this obstacle by coupling a thorough description of the technical nuances for endoscopic endonasal craniopharyngioma resection with detailed illustrations of the important steps in the operation. Traditionally, transsphendoidal approaches to craniopharyngiomas have been restricted to lesions mostly confined to the sella. However, recently, endoscopic endonasal resections are more frequently employed for extrasellar and purely third ventricle craniopharyngiomas, whose typical retrochiasmatic location makes them ideal candidates for endoscopic transnasal surgery.

The endonasal endoscopic approach offers many advantages, including direct access to the long axis of the tumor, early tumor debulking with minimal manipulation of the optic apparatus, more precise visualization of tumor planes, particularly along the undersurface of the chiasm and the roof of the third ventricle, and a minimal-access corridor that obviates the need for brain retraction. Although much emphasis has been placed on technical tenets of exposure and “how to get there,” this article focuses on nuances of tumor resection “when you are there.” Three operative videos illustrate our discussion of technical tenets.

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Simon A. Cudlip, Franklyn A. Howe, Andrew Clifton, Martin S. Schwartz, and B. Anthony Bell

Object. Recently developed novel MR protocols called MR neurography, which feature conspicuity for nerve, have been shown to demonstrate signal change and altered median nerve configuration in patients with median nerve compression. The postoperative course following median nerve decompression can be problematic, with persistent symptoms and abnormal results on electrophysiological studies for some months, despite successful surgical decompression. The authors undertook a prospective study in patients with carpal tunnel syndrome, correlating the clinical, electrophysiological, and MR neurography findings before and 3 months after surgery.

Methods. Thirty patients and eight control volunteers were recruited to the study. The MR neurography consisted of axial and sagittal images (TR = 2000 msec, TE = 60 msec) obtained using a temporomandibular surface coil, fat saturation, and flow suppression. Maximum intensity projection images were used to follow the median nerve through the carpal tunnel in the sagittal plane.

Magnetic resonance neurography in patients with carpal tunnel syndrome demonstrated proximal swelling (p < 0.001) and high signal change in the nerve, together with increased flattening ratios (p < 0.001) and loss of nerve signal in the distal carpal tunnel (p < 0.05). Sagittal images were very effective in precisely demonstrating the site and severity of nerve compression. After surgery, division of the flexor retinaculum could be demonstrated in all cases. Changes in nerve configuration, including increased cross-sectional area, and reduced flattening ratios (p < 0.001) were seen in all patients. In many cases restoration of the T2 signal intensity toward that of controls was seen in the median nerve in the distal carpal tunnel. Sagittal images were excellent in demonstrating expansion of the nerve at the site of surgical decompression.

Conclusions. In this study the authors suggest that MR neurography is an effective means of both confirming compression of the median nerve and its successful surgical decompression in patients with carpal tunnel syndrome. This modality may prove useful in the assessment of unconfirmed or complex cases of carpal tunnel syndrome both before and after surgery.

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Andrew F. Alalade, Elizabeth Ogando-Rivas, Jerome Boatey, Mark M. Souweidane, Vijay K. Anand, Jeffrey P. Greenfield, and Theodore H. Schwartz

OBJECTIVE

The expanded endonasal endoscopic transsphenoidal approach has become increasingly used for craniopharyngioma surgery in the pediatric population, but questions still persist regarding its utility in younger children, in recurrent and irradiated tumors, and in masses primarily located in the suprasellar region. The narrow corridor, incomplete pneumatization, and fear of hypothalamic injury have traditionally relegated this approach to application in older children with mostly cystic craniopharyngiomas centered in the sella. The authors present a series of consecutive pediatric patients in whom the endonasal endoscopic approach was used to remove craniopharyngiomas from patients of varied ages, regardless of the location of the tumor and previous treatments or surgeries, to ascertain if the traditional concerns about limitations of this approach are worth reevaluating

METHODS

Eleven consecutive pediatric patients (age ≤ 18 years) underwent surgery via an endoscopic transsphenoidal approach at NewYork-Presbyterian/Weill Cornell Medical Center from 2007 to 2016. The authors recorded the location, consistency, and size of the lesion, assessed for hypothalamic invasion radiographically, calculated skull base measurements, and assessed parameters such as extent of resection, visual function, endocrinological function, weight gain, and return-to-school status.

RESULTS

The average age at the time of surgery was 7.9 years (range 4–17 years) and the tumor sizes ranged from 1.3 to 41.7 cm3. Five cases were purely suprasellar, 5 had solid components, 4 were reoperations, and 5 had a conchal sphenoid aeration. Nevertheless, gross-total resection was achieved in 45% of the patients and 50% of those in whom it was the goal of surgery, without any correlation with the location, tumor consistency, or the age of the patient. Near-total resection, subtotal resection, or biopsy was performed intentionally in the remaining patients to avoid hypothalamic injury. Anterior pituitary dysfunction occurred in 81.8% of the patients, and 63.3% developed diabetes insipidus . Two patients (18%) had a greater than 9% increase in body mass index. Visual function was stable or improved in 73%. All children returned to an academic environment, with 10 of them in the grade appropriate for their age. There was a single case of each of the following: CSF leak, loss of vision unilaterally, and abscess.

CONCLUSIONS

The endoscopic transsphenoidal approach is suitable for removing pediatric craniopharyngiomas even in young children with suprasellar tumors, conchal sphenoid sinus, recurrent tumors, and tumors with solid components. The extent of resection is dictated by intrinsic hypothalamic tumor invasiveness rather than the approach. The endoscopic transsphenoidal approach affords the ability to directly inspect the hypothalamus to determine invasion, which may help spare the patient from hypothalamic injury. Irrespective of approach, the rates of postoperative endocrinopathy remain high and the learning curve for the approach to a relatively rare tumor is steep.

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Neil Kaushal, Keith J. Orland, Andrew M. Schwartz, Jacob M. Wilson, Nicholas D. Fletcher, Anuj Patel, Bryan Menapace, Michelle Ramirez, Martha Wetzel, Dennis Devito, and Joshua Murphy

OBJECTIVE

Posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) can be associated with significant blood loss. It has been suggested that blood loss is greater in different racial groups. The purpose of this study was to evaluate differences in blood loss between African American and Caucasian patients undergoing PSF for AIS.

METHODS

A retrospective review was performed of patients aged 10–18 years with AIS who were treated with PSF from 2014 to 2017 at a single children’s healthcare system. Patient demographic, radiographic, and operative data were obtained from medical records. Intraoperative blood loss was calculated using the formula described by Waters et al. Patients who declined reporting their race or had prior spinal surgery, neuromuscular or syndromic diagnoses, a history of cardiac or thoracic surgery, or a bleeding disorder were excluded. Blood loss variables were log-transformed for normality and modeled using multivariable linear regression.

RESULTS

A total of 433 PSFs for AIS qualified for the analysis. The average age was 14.1 years, and 73.7% of the patients were female. With respect to race, 44.6% identified themselves as African American. There was no significant difference in blood loss (p = 0.31) or blood loss per level fused (p = 0.36) in African American patients. African American patients, however, did have significantly lower preoperative hemoglobin and hematocrit levels and greater operating room time than Caucasian patients (p < 0.001). There was no difference between race and transfusion rate.

CONCLUSIONS

There appears to be no relationship between race and blood loss during PSF for AIS. Standardized protocols for minimizing perioperative blood loss can be applied to both Caucasian and African American patients.