Functional Magnetic Resonance Imaging and Diffusion Tensor Tractography Incorporated Into an Intraoperative 3-Dimensional Ultrasound-Based Neuronavigation System: Impact on Therapeutic Strategies, Extent of Resection, and Clinical Outcome

Neurosurgery 67:251-264, 2010 DOI: 10.1227/01.NEU.0000371731.20246.AC

Functional neuronavigation with intraoperative 3-dimensional (3D) ultrasound may facilitate safer brain lesion resections than conventional neuronavigation.

OBJECTIVE: In this study, functional magnetic resonance imaging (fMRI) and diffusion tensor tractography (DTT) were used to map eloquent areas. We assessed the use of fMRI and DTT for preoperative assessments and determined whether using these data together with 3D ultrasound during surgery enabled safer lesion resection.

METHODS:We reviewed 51 consecutive patients with intracranial lesions in whom fMRI with or without DTT was used to map eloquent areas. To assess a possible impact of fMRI/DTT, we reviewed and analyzed the quality of the fMRI/DTT data, any change in therapeutic strategies, lesion to eloquent area distance (LEAD), extent of resection, and clinical outcome.

RESULTS: As a result of the fMRI/DTT mapping, the therapeutic strategies were changed in 4 patients. The median tumor residue for glioma patients was 11% (n = 33) and 0% for nonglioma lesions (n = 12). For gliomas, there was a significant correlation between decreasing LEAD and increasing tumor residue. Of the glioma patients, 42% underwent gross total resection (≥ 95%) and 12% suffered neurological worsening after surgery as a result of complications. Of glioma patients with an LEAD of ≤ 5 mm, 24% underwent gross total resection and 10% experienced neurological deterioration.

CONCLUSION: This study demonstrates that preoperative fMRI and DTT had direct consequences for therapeutic strategies and indicates their impact on intraoperative strategies to spare eloquent cortex and tracts. Functional neuronavigation combined with intraoperative 3D ultrasound can, in most patients, enable resection of brain lesions with general anesthesia without jeopardizing neurological function.

Non-saccular aneurysms of the supraclinoid internal carotid artery trunk causing subarachnoid hemorrhage: acute surgical treatments and review of literature

Neurosurg Rev (2010) 33:205–216. DOI 10.1007/s10143-009-0234-0

Non-saccular aneurysms (NSAs) of the internal carotid artery trunk include blood blister-like aneurysms (BBAs) and dissecting aneurysms (DAs), which are susceptible to disastrous intra- and postoperative bleeding. This study was conducted to clarify the clinical features of NSAs and the results of early bypass and trapping. Nineteen ruptured NSAs were identified in 937 patients with subarachnoid hemorrhage (SAH). The principal treatment was to trap the aneurysm following bypass surgery as soon as possible after SAH onset. Angiography revealed nine BBAs and ten DAs. Eight patients (four BBA and four DA) were treated in the chronic stage because of delayed arrival (n=3) or lack of aneurysm on initial angiography (n=3), or other reasons (n=2). The remaining 11 patients underwent early surgery using trapping after bypass, except for one BBA-type (clipped). During surgery, corresponding intraoperative findings were confirmed for each aneurysm type. There were six preoperative reruptures; five were determinant of patient outcome. In 14 patients without preoperative rerupture influencing outcome, 11 patients were independent at discharge and three patients dependent due to surgical complication. There was one case of minor intraoperative bleeding; no postoperative rerupture occurred. There was no delayed vasospasm-related deficit, although temporary symptomatic spasm occurred in three patients. Early bypass and trapping appeared to be an acceptable treatment strategy for these NSAs eliminating intra- and postoperative bleeding and not increasing a chance of delayed vasospasm.

High-grade intramedullary astrocytomas: 30 years’ experience at the Neurosurgery Department of the University of Rome “Sapienza”

J Neurosurg Spine 12:144–153, 2010. (DOI: 10.3171/2009.6.SPINE08910)

The goal in this study was to review a series of patients who underwent surgical removal of intramedul- lary high-grade gliomas, focusing on the functional outcome, recurrence rates, and technical problems continually debated in neurosurgical practice.

Methods. Between December 1976 and December 2006, 22 patients underwent removal of intramedullary high- grade gliomas. Lesions were located in the cervical spinal cord in 12 patients, and in the thoracic cord in 10.

Results. Histological examinations showed 10 Grade III astrocytomas and 12 glioblastomas. Only 2 of the 22 high-grade astrocytomas could be completely removed. The clinical postoperative status worsened in 14 patients (63.6%), was unchanged in 7 patients (31.8%), and there was 1 case of intraoperative death (4.5%). None of the 22 patients showed improvement in their neurological status postoperatively. In this series, excluding the 1 intraopera- tive death, all patients died of progression of the malignancy.

Conclusions. Surgical treatment did not ameliorate the postoperative neurological status; instead, in the majority of cases, it prompted a worsening of the deficit. Radiotherapy and chemotherapy have a little influence on the length of survival. In this series, multimodality treatment of intramedullary high-grade astrocytomas has been shown to increase length of survival without improving the neurological status.

Intrasellar Ultrasound in Transsphenoidal Surgery: A Novel Technique

Neurosurgery 66:173-186, 2010. doi: 10.1227/01.NEU.0000360571.11582.4F

OBJECTIVE: Residual tumor masses are common after transsphenoidal surgery. The risk of a residual mass increases with tumor size and parasellar or suprasellar growth. Transsphenoidal surgery is usually performed without image guidance. We aimed to investigate a new technical solution developed for intraoperative ultrasound imaging during transsphenoidal surgery, with respect to potential clinical use and the ability to identify neuroanatomy and tumor.

METHODS: In 9 patients with pituitary macroadenomas, intrasphenoidal and intrasellar ultrasound was assessed during transsphenoidal operations. Ultrasound B-mode, power-Doppler and color-Doppler images were acquired using a small prototype linear array, side-looking probe. The long probe tip measures only 3 × 4 mm. We present images and discuss the potential of intrasphenoidal and intrasellar and ultrasound in transsphenoidal surgery.

RESULTS: We present 2-dimensional, high-resolution ultrasound images. A small side-looking, high-frequency ultrasound probe can be used to ensure orientation in the midline for the surgical approach to identify important neurovascular structures to be avoided during surgery and for resection control and identification of normal pituitary tissue. The image resolution is far better than what can be achieved with current clinical magnetic resonance imaging technology.

CONCLUSION: We believe that the concept of intrasellar ultrasound can be further developed to become a flexible and useful tool in transsphenoidal surgery.

The effect of coiling vs clipping of ruptured and unruptured cerebral aneurysms on length of stay, hospital cost, hospital reimbursement, and surgeon reimbursement at the University of Florida

Neurosurgery 64:614–621, 2009 DOI: 10.1227/01.NEU.0000340784.75352.A4

There are few studies comparing the economic costs and reimbursements for aneurysm clipping versus coiling, and none are from the United States. Our hypothesis predicted that coiling would result in shorter lengths of hospitalization than clipping in patients with unruptured aneurysms and would therefore result in lower hospital charges. However, because of the severity of subarachnoid hemorrhage, there would be no difference in length of hospitalization or hospital charges in patients with ruptured aneurysms.

Methods: We compared aneurysm coiling with aneurysm clipping in patients with unruptured and ruptured aneurysms treated at the University of Florida from January 2005 to June 2007 for differences in length of hospitalization, hospital costs, hospital collections, and surgeon collections. Patient demographic and aneurysm characteristic data were obtained from a clinical database. Length of hospitalization, cost, billing, and collection data were obtained from the hospital cost accounting database. Multivariate statistical analyses of length of hospitalization, hospital costs, hospital collections, and surgeon collections were performed using factors including patient age, sex, aneurysm size, aneurysm location, aneurysm treatment, presence of subarachnoid hemorrhage, clinical grade, payor, hospital billing, and surgeon billing.

Results: There were 565 patients with cerebral aneurysms treated either surgically (306 patients, 54%) or endovascularly (259 patients, 46%). In patients without subarachnoid hemorrhage (unruptured aneurysms) (n=367), surgery, compared with endovascular treatment, was associated with longer hospitalization (P<0.001), but lower hospital costs (P<0.001), higher surgeon collections (P<0.003), and similar hospital collections. In patients with subarachnoid hemorrhage (ruptured aneurysms) (n=198), surgery was associated with lower hospital costs (P<0.011), but similar length of stay, surgeon collections, and hospital collections. Larger aneurysm size was significantly associated with longer hospitalization in the patients with unruptured aneurysms (P<0.001) and higher hospital costs for both patients with unruptured (P<0.001) and ruptured (P<0.015) aneurysms. The payor was significantly associated with hospital costs in patients with ruptured aneurysms (P<0.034) and length of stay (unruptured aneurysms, P<0.001; ruptured aneurysms, P<0.001), hospital collections (unruptured aneurysms, P<0.001; ruptured aneurysms, P<0.001), and surgeon collections (unruptured aneurysms, P<0.001; ruptured aneurysms, P<0.001) in both patients with unruptured and ruptured aneurysms. A worse clinical grade was significantly associated with higher hospital costs (P<0.001).

Conclusion: Despite a shorter length of hospitalization in patients with unruptured aneurysms, coiling was associated with higher hospital costs in both patients with unruptured and ruptured aneurysms. This is likely attributable to the higher device cost of coils than clips. The advantages of coiling over clipping would be better realized if the cost of coils could be comparably reduced to that of clips.

Tentorial meningiomas: operative nuances and perioperative management dilemmas

Acta Neurochir (2009) 151:1037–1051.DOI 10.1007/s00701-009-0421-3

Tentorial meningiomas (TM), comprising approximately 3–6% of all intracranial meningiomas, are complex entities with an intricate relationship to surrounding structures and require multiple surgical approaches. In the present study, the rationale for deciding the approaches for TMs and the perioperative management dilemmas were evaluated.
Methods  Thirty-seven patients (28 primary [supratentorial (2), infratentorial (20) and both (6)] and nine complex [cerebellopontine (CP) angle (5) and petroclival (4)] TM) underwent surgery using the occipital transtentorial, supracerebellar infratentorial, subtemporal transtentorial, bioccipital suboccipital, midline suboccipital, retrosigmoid, and combined pre and retrosigmoid approaches. The extent of excision was categorized according to Simpson’s grade.
Results  Simpson’s grade of excision was I in six, II in 11, III in nine and IV in 11 patients, respectively. Follow-up assessment (2 months to 9 years) in 27 patients (72.9%) showed that 23 patients returned to their previous activity level with either no or minimal symptoms, three returned to previous activity level with major cranial nerve palsy, and one patient required permanent assistance. One patient had recurrence and four others underwent resurgery for residual tumor. Two patients with petroclival lesions died due to aspiration pneumonitis and meningitis, respectively; one with CP angle TM presented in a poor general condition and expired following emergency ventriculoperitoneal shunt and subsequent definite surgery. Pseudomeningocele, cerebrospinal fluid leak, and cranial nerve palsy were the major morbidities.
Conclusions  Classifying TM into medial and lateral, supra and infratentorial groups helps in deciding an appropriate and safe approach. Meticulously preserving venous sinuses is important since the risk of venous infarction cannot be predicted even with radiological good venous collaterization and apparent venous sinus blockade by tumor. Laterally situated tumors carry a better prognosis when compared to the medially situated ones. Leaving a small residual tumor in an effort to preserve important neurovascular structures does not obviate the expectation of a good long-term prognosis with minimal morbidity and low recurrence rates.