True aqueductal tumors: a unique entity

True aqueductal tumors-a unique entity

Acta Neurochir (2015) 157:169–177

Pure aqueductal tumors (ATs) differ from pineal region and tectal/tegmental tumors in that they are epicentered within the aqueduct. Nevertheless, these tumors are rarely described as a separate type of tumor, and are often grouped with other lesions located in the same vicinity. The present multicenter study focuses on our experience treating patients with pure ATs.

Methods Data from three large tertiary centers was collected retrospectively, including presenting symptoms, treatment paradigm, surgical approaches, pathology, and outcome.

Results Between 1999 and 2013, 16 patients with AT were diagnosed and treated at the three tertiary centers. Ages at presentation ranged from 5.5 to 57 years. Thirteen patients presented with hydrocephalus-related symptoms, and two were identified incidentally. Thirteen patients underwent an endoscopic third ventriculostomy, and two of these underwent a simultaneous endoscopic biopsy (one grade II ependymoma, one non-specified low-grade glioma). Two others underwent shunt placement. Three patients underwent resection due to tumor progression. Pathologies included glioblastoma multiforme, glioneural tumor, and ependymoma grade II. All non-resected tumors remained stable or grew only minimally.

Conclusions ATs are a rare entities that usually present with obstructive hydrocephalus. Treatment includes primarily cerebrospinal fluid drainage (preferably via an endoscopic third ventriculostomy). Simultaneous endoscopic biopsy may be done in selected cases. Tumor resection should be reserved for growing tumors; the trans-fourth ventricular or transchoroidal approaches are probably safer than other approaches used to reach the tectal region.

The Mirroring Technique: A Navigation-Based Method for Reconstructing a Symmetrical Orbit and Cranial Vault

Mirroring technique

Neurosurgery 73[ONS Suppl 1]:ons24–ons29, 2013

The reconstruction of orbital structures and the cranial vault curvature can be challenging after trauma or wide resections for tumors. Sophisticated methods have been developed recently, but these are resource- and time-consuming.

OBJECTIVE: We report the mirroring technique, which is an effective and costless application for navigation-guided reconstruction procedures.

METHODS: At the time of the reconstruction, high-resolution images are reloaded while forcing a left-right axial flip. The pointer subsequently enables a virtual 3- dimensional projection of the position of the contralateral normal anatomy.

RESULTS: This method was applied successfully in 2 cases of en plaque sphenoid wing meningiomas with secondary exophthalmia.

CONCLUSION: The mirroring technique represents an accurate method of outlining the contralateral normal anatomy onto the pathological side based on navigation guidance.

KEY WORDS:

Intraoperative Seizures During Awake Craniotomy: Incidence and Consequences: Analysis of 477 Patients

Awake cranio

Neurosurgery 73:135–140, 2013

Awake craniotomy (AC) for removal of intra-axial brain tumors is a well-established procedure. However, the occurrence and consequences of intraoperative seizures during AC have not been well characterized.

OBJECTIVE: To analyze the incidence, risk factors, and consequences of seizures during AC.

METHODS: The database of AC at Tel Aviv Medical Center between 2003 to 2011 was reviewed. Occurrences of intraoperative seizures were analyzed with respect to medical history, medications, tumor characteristics, and postoperative outcome.

RESULTS: Of the 549 ACs performed during the index period, 477 with complete records were identified. Sixty patients (12.6%) experienced intraoperative seizures. The AC procedure failed in 11 patients (2.3%) due to seizures. Patients with intraoperative seizures were significantly younger than nonseizing patients (45 6 14 years vs 52 6 16 years, P = .003), had a higher incidence of frontal lobe involvement (86% vs % 57%, P , .0001), and had higher prevalence of a history of seizures (P = .008). Short-term motor deterioration developed postoperatively in a higher percentage of patients with intraoperative seizures (20% vs 10.1%, P = .02) with a longer hospitalization period (4.0 6 3.0 days vs 3.0 6 3.0 days, P = .045).

CONCLUSION: Although in most cases intraoperative seizures will not result in AC failure, the surgical team should be prepared to treat them promptly to avoid intractable seizures. Intraoperative seizures are more common in younger patients with a tumor in the frontal lobe and those with a history of seizures. Moreover, they are associated with a higher incidence of transient postoperative motor deterioration and protracted length of hospital stay.

A Comparison of Language Mapping by Preoperative Navigated Transcranial Magnetic Stimulation and Direct Cortical Stimulation During Awake Surgery

A_Comparison_of_Language_Mapping_by_Preoperative

Neurosurgery 72:808–819, 2013

Navigated transcranial magnetic stimulation (nTMS) is increasingly used in presurgical brain mapping. Preoperative nTMS results correlate well with direct cortical stimulation (DCS) data in the identification of the primary motor cortex. Repetitive nTMS can also be used for mapping of speech-sensitive cortical areas.

OBJECTIVE: The current cohort study compares the safety and effectiveness of preoperative nTMS with DCS mapping during awake surgery for the identification of language areas in patients with left-sided cerebral lesions.

METHODS: Twenty patients with tumors in or close to left-sided language eloquent regions were examined by repetitive nTMS before surgery. During awake surgery, language-eloquent cortex was identified by DCS. nTMS results were compared for accuracy and reliability with regard to DCS by projecting both results into the cortical parcellation system.

RESULTS: Presurgical nTMS maps showed an overall sensitivity of 90.2%, specificity of 23.8%, positive predictive value of 35.6%, and negative predictive value of 83.9% compared with DCS. For the anatomic Broca’s area, the corresponding values were a sensitivity of 100%, specificity of 13.0%, positive predictive value of 56.5%, and negative predictive value of 100%, respectively.

CONCLUSION: Good overall correlation between repetitive nTMS and DCS was observed, particularly with regard to negatively mapped regions. Noninvasive inhibition mapping with nTMS is evolving as a valuable tool for preoperative mapping of language areas. Yet its low specificity in posterior language areas in the current study necessitates further research to refine the methodology.

Failed awake craniotomy: a retrospective analysis in 424 patients undergoing craniotomy for brain tumor

Awake cranio

J Neurosurg 118:243–249, 2013

Awake craniotomy for removal of intraaxial tumors within or adjacent to eloquent brain regions is a well-established procedure. However, awake craniotomy failures have not been well characterized. In the present study, the authors aimed to analyze and assess the incidence and causes for failed awake craniotomy.

Methods. The database of awake craniotomies performed at Tel Aviv Medical Center between 2003 and 2010 was reviewed. Awake craniotomy was considered a failure if conversion to general anesthesia was required, or if adequate mapping or monitoring could not have been achieved.

Results. Of 488 patients undergoing awake craniotomy, 424 were identified as having complete medical, operative, and anesthesiology records. The awake craniotomies performed in 27 (6.4%) of these 424 patients were considered failures. The main causes of failure were lack of intraoperative communication with the patient (n = 18 [4.2%]) and/or intraoperative seizures (n = 9 [2.1%]). Preoperative mixed dysphasia (p < 0.001) and treatment with phenytoin (p = 0.0019) were related to failure due to lack of communication. History of seizures (p = 0.03) and treatment with multiple antiepileptic drugs (p = 0.0012) were found to be related to failure due to intraoperative seizures. Compared with the successful awake craniotomy group, a significantly lower rate of gross-total resection was achieved (83% vs 54%, p = 0.008), there was a higher incidence of short-term speech deterioration postoperatively (6.1% vs 23.5%, p = 0.0017) as well as at 3 months postoperatively (2.3% vs 15.4%, p = 0.0002), and the hospitalization period was longer (4.9 ± 6.2 days vs 8.0 ± 10.1 days, p < 0.001). Significantly more major complications occurred in the failure group (4 [14.8%] of 27) than in the successful group (16 [4%] of 397) (p = 0.037).

Conclusions. Failures of awake craniotomy were associated with a lower incidence of gross-total resection and increased postoperative morbidity. The majority of awake craniotomy failures were preventable by adequate patient selection and avoiding side effects of drugs administered during surgery.

Frameless robotically targeted stereotactic brain biopsy

J Neurosurg 116:1002–1006, 2012. (http://thejns.org/doi/abs/10.3171/2012.1.JNS111746)

Frameless stereotactic brain biopsy has become an established procedure in many neurosurgical centers worldwide. Robotic modifications of image-guided frameless stereotaxy hold promise for making these procedures safer, more effective, and more efficient. The authors hypothesized that robotic brain biopsy is a safe, accurate procedure, with a high diagnostic yield and a safety profile comparable to other stereotactic biopsy methods.

Methods. This retrospective study included 41 patients undergoing frameless stereotactic brain biopsy of lesions (mean size 2.9 cm) for diagnostic purposes. All patients underwent image-guided, robotic biopsy in which the Surgi-Scope system was used in conjunction with scalp fiducial markers and a preoperatively selected target and trajectory. Forty-five procedures, with 50 supratentorial targets selected, were performed.

Results. The mean operative time was 44.6 minutes for the robotic biopsy procedures. This decreased over the second half of the study by 37%, from 54.7 to 34.5 minutes (p < 0.025). The diagnostic yield was 97.8% per procedure, with a second procedure being diagnostic in the single nondiagnostic case. Complications included one transient worsening of a preexisting deficit (2%) and another deficit that was permanent (2%). There were no infections.

Conclusions. Robotic biopsy involving a preselected target and trajectory is safe, accurate, efficient, and comparable to other procedures employing either frame-based stereotaxy or frameless, nonrobotic stereotaxy. It permits biopsy in all patients, including those with small target lesions. Robotic biopsy planning facilitates careful preoperative study and optimization of needle trajectory to avoid sulcal vessels, bridging veins, and ventricular penetration.

Trigonal and peritrigonal lesions of the lateral ventricle—surgical considerations and outcome analysis of 20 patients

Neurosurg Rev DOI 10.1007/s10143-010-0271-8

The aim of this study is to review the results and clinical outcome of patients with surgically treated lesions within the trigone of the lateral ventricle.

This is a retrospective case series of 20 (eight male, 12 female) patients with lesions of the trigone of the lateral ventricle operated between 1998 and 2008. All lesions were removed via the transcortical temporal and transcortical parietal route. Surgical complications and outcome were assessed using the modified Rankin Scale (mRS).

There were four children and 16 adults with a mean age of 42±22 years (min=1, max=74). Eight (40%) lesions grew within the trigone of the dominant hemisphere. In 17 cases, the lesion was purely intraventricular, and in three cases, a slight paraventricular extension was seen. The mean size was 4.5 cm of maximal diameter. Surgical removal was achieved via the transcortical parietal route in 13 cases (65%) and the transcortical temporal route in seven cases (35%). In all cases, complete resection was possible. According to the mRS, 13 patients improved, five remained the same, and two were lost to follow-up. One patient had an increased visual field deficit postoperatively and new hemiparesis and aphasia, but returned to the preoperative level within a few weeks. In one patient, an acute myocardial infarction occurred due to previous cardiac stent placement and instent stenosis.

Even large trigonal lesions can be resected with low morbidity using a transcortical approach depending on the peritrigonal extension of the tumor.

Primary Intramedullary Tumors of the Spinal Cord

SPINE Volume 34, Number 22S, pp S69 –S77, 2009

Study Design. Clinically based systematic review.

Objective. To define optimal clinical care for primary intramedullary spinal cord tumors using a systematic re- view with expert opinion.

Methods. Focused questions on the treatment of primary intramedullary spinal cord tumors were refined by a panel of spine oncology surgeons, medical and radiation oncologist. Keyword were searched through Medline database and pertinent abstracts and manuscripts obtained. The quality of literature was rated as high, moderate, low, or very low. Using the GRADE evidence based review system the proposed questions were answered using the literature review and expert opinion. These treatment recommendations were then rated as either strong or weak based on the quality of evidence and clinical expertise.

Results. The literature searches revealed low and very low quality evidence with no prospective or randomized studies. The MEDLINE search engine returned 9000 articles which was restricted to articles about human subjects and written in the English language. The subsequent search resulted in a return of: “spinal cord tumor” (5053), “ependymoma” (580), “astrocytoma” (420), and “glioma” (235) articles. Seventeen articles referenced timing of surgical intervention and symptomatology for intramedullary spinal cord tumors. One hundred fifty-eight chemotherapy and 183 radiation therapy articles for intramedullary spinal cord tumors were reviewed.

Conclusion. The most important factor in determining the IMSCT patient’s long-term neurologic and functional outcome after surgery is the patient’s preoperative neurologic status. However, this must be taken in the context of the underlying tumor histology. Therefore, resection is reserved for progressive neurologic decline and serial monitoring for asymptomatic individuals. Adjuvant therapy is an option for high grade astrocytomas (WHO grades 3–4).