Taopheeq Bamidele Rabiu
Jeffrey P. Greenfield and Mark M. Souweidane
Endoscopic fenestration has been recognized as an accepted treatment choice for patients with symptomatic arachnoid cysts. The success of this procedure, however, is greatly influenced by individual cyst anatomy and location as well as the endoscopic technique used. This review was conducted to assess what variables influence the treatment success for different categories of arachnoid cysts.
Thirty-three consecutive patients who underwent endoscopic fenestration for treatment of an intracranial arachnoid cyst were identified from a prospective database. The surgical indications and techniques were reviewed, and surgical success rates and patient outcomes were assessed. Specific examples of each cyst category are included to illustrate the technical aspects of endoscopic cyst fenestration.
Endoscopic fenestration of arachnoid cysts was successful when judged by cyst decompression, and symptom resolution was noted in 32 (97%) of 33 cases. The one patient with short-term treatment failure underwent a successful repetition of the operation. There were no surgery-related morbidities or deaths.
Arachnoid cysts are a relatively benign pathological entity that can be managed by performing endoscopically guided cyst wall fenestrations into the ventricular system or cerebrospinal fluid–containing cisterns. Proper patient selection, preoperative planning of endoscope trajectory, use of frameless navigation, and advances in endoscope lens technology and light intensity combine to make this a safe procedure with excellent outcomes.
Jose Behaine, Assem M. Abdel Latif, and Jeffrey P. Greenfield
Recurrent manifestations of tethered spinal cord after an initial operative intervention for a simple fatty filum terminale is fairly uncommon. The authors present the case of an unusual clinical course in which there were 3 distinct episodes of recurrence, each time presenting predominantly as fecal incontinence and resolving with operative intervention. Typical signs of tethering were absent on radiological evaluation, and operative intervention was based on clinical grounds. Intraoperatively, sacral nerve roots to the anal sphincter were found tethered to the filar stump with electrophysiological evidence of regained activity on disentanglement. To the best of the authors’ knowledge, a similar clinical course or operative findings have not been reported.
Kim Kramer, Heather J. McCrea, Cheryl Fischer, and Jeffrey P. Greenfield
Successful delivery of intraventricular radioimmunotherapy is contingent on adequate CSF flow. The authors present a patient with medulloblastoma in whom obstructed CSF flow was causing hydrocephalus, which was initially corrected by implantation of a programmable shunting device. While managing the hydrocephalus, an endoscopic third ventriculostomy (ETV) needed to be performed in a collapsed ventricular system to ensure adequate radioimmunotherapy distribution.
This 18-month-old patient with medulloblastoma involving leptomeningeal dissemination presented for intraventricular radioimmunotherapy. A CSF 111In-DTPA scintigraphy study obtained through the existing programmable ventriculoperitoneal shunt demonstrated activity in the lateral and third ventricles, but no activity over the cerebral convexities or spinal canal, consistent with obstruction at the level of the cerebral aqueduct. By maximization of ventricular size in a controlled setting, the patient was able to undergo a trial of ETV through very small ventricles. A postoperative CINE MR imaging study confirmed patent ETV. The pressure settings on the shunt were kept at the highest opening pressure (200 mm H2O) to maximize flow through the stoma and improve the distribution of CSF throughout the subarachnoid space. The CSF flow scintigraphy study was again performed, this time with tracer activity demonstrated down the thecal sac at 3 hours, and symmetrically over the cerebral convexities at 24 hours. The patient began weekly intraventricular administration of 131I-3F8 therapy.
Successful rerouting of CSF flow for the purpose of therapeutic radioisotope administration is possible. Endoscopic third ventriculostomy can be considered in patients with programmable shunting devices; normal or slit ventricles do not preclude successful ETV.
Konstantinos Margetis, Prajwal Rajappa, Apostolos John Tsiouris, Jeffrey P. Greenfield, and Theodore H. Schwartz
A critical goal in neurosurgical oncology is maximizing the extent of tumor resection while minimizing the risk to normal white matter tracts. Frameless stereotaxy and white matter mapping are indispensable tools in this effort, but deep tumor margins may not be accurately defined because of the “brain shift” at the end of the operation. The authors investigated the safety and efficacy of a technique for marking the deep margins of intraaxial tumors with stereotactic injection of Indigo Carmine dye.
Investigational New Drug study approval for a prospective study in adult patients with gliomas was obtained from the FDA (Investigational New Drug no. 112680). At surgery, 1–3 stereotactic injections of 0.01 ml of Indigo Carmine dye were performed through the initial bur holes into the deep tumor margins before elevation of the bone flap. White light microscopic resection was conducted in standard fashion by using frameless stereotactic navigation until the injected margins were identified. The resection of the injected tumor margins and the extent of resection of the whole tumor volume were determined by using postoperative volumetric MRI.
In total 17 injections were performed in 10 enrolled patients (6 male, 4 female), whose mean age was 49 years. For all patients, the injection points were identified intraoperatively and tumor was resected at these points. The staining pattern was reproducible; it was a sphere of stained tissue approximately 5 mm in diameter. A halo of stained tissue and a backflow of dye through the needle tract were also noted, but these were clearly distinct from the staining pattern of the injection point, which was vividly colored and demarcated. Postoperative MR images verified the resection of all injection points. The mean extent of resection of the tumor as a whole was 97.1%. For 1 patient, a brain abscess developed on postoperative Day 16 and needed additional surgical treatment.
Stereotactic injection of Indigo Carmine dye can be used to demarcate multiple deep tumor margins, which can be readily identified intraoperatively by using standard white light microscopy. This technique may enhance the accuracy of frameless stereotactic navigation and increase the extent of resection of intraaxial tumors.
Mina M. Gerges, Brett Youngerman, Vijay K. Anand, Jeffrey P. Greenfield, and Theodore H. Schwartz
An 8-year-old child presented with fatigue, weight loss, and visual deterioration. MRI demonstrated a craniopharyngioma with compression of the optic chiasm and extensive edema on the hypothalamus and optic radiations. The tumor was completely removed via an endoscopic endonasal approach. Postoperatively, vision improved and hypothalamic edema completely resolved within 5 days. This video demonstrates the technical nuances of the surgery and discusses the impact of surgery on the hypothalamic nuclei in pediatric patients.
The video can be found here: https://youtu.be/wxkBmhTPi6c.
Prajwal Rajappa, Konstantinos Margetis, Dimitri Sigounas, Vijay Anand, Theodore H. Schwartz, and Jeffrey P. Greenfield
The authors report a case of a recurrent pediatric ventral pontine ependymoma that they resected through an endonasal endoscopic transclival approach. Regarding the options for a surgical approach to ventral pontine tumors, traditional far-lateral approaches are associated with considerable morbidity due to the required muscle mobilization, brain retraction, and in-line obstruction of cranial nerves before reaching the target. The endoscopic endonasal transclival approach was made appealing by eliminating all of these concerns. The patient's fully pneumatized sphenoid sinus, laterally displaced basilar artery, and the direct ventral location of the bulky disease all further supported this unconventional choice of surgical corridor to achieve a palliative brainstem decompression of an incurable recurrence.
Yakov Gologorsky, Patricia Delamora, Mark M. Souweidane, and Jeffrey P. Greenfield
✓This is the first report of a cerebellar cryptococcoma in a previously healthy, HIV-negative child. Cryptococcus neoformans is an opportunistic fungus that typically affects patients who are HIV-positive and other patients with compromised immune systems. Isolated cryptococcomas of the central nervous system (CNS) have been previously described in immunocompetent adults; however, this is the first report of a cryptococcoma in a child. The patient presented with progressive headaches and nausea and was found to have a large cerebellar hemispheric mass. The patient underwent excision of the mass, and analysis of frozen sections suggested the presence of an astrocytic tumor with pilocytic features; therefore gross-total resection was performed. Once the definitive diagnosis of a cryptococcal abscess was obtained, medical treatment with antifungal medications led to the resolution of all symptoms and the normalization of serum titers. Cryptococcoma is a rare cause of ring enhancing lesions in the cerebellum, even in apparently immunocompetent patients. The authors' experience with this case and the patient's postoperative care lead them to advocate resection of large isolated cryptococcomas of the CNS, especially those situated in the posterior fossa.
Jeffrey P. Greenfield, Caitlin Hoffman, Eugenia Kuo, Paul J. Christos, and Mark M. Souweidane
The authors' aim in this study was to determine if standardizing the evaluation of intraoperative findings during endoscopic third ventriculostomy (ETV) could predict patients with hydrocephalus in whom endoscopic treatment will fail and require ventriculoperitoneal shunt treatment. The creation of a uniform scale with predictive outcomes may reduce returns to the operating room for shunt treatment and reliance on postoperative externalized ventricular monitoring and MR imaging.
The authors evaluated the preoperative history, intraoperative findings, and postoperative monitoring and imaging findings in 109 consecutive patients undergoing 112 consecutive attempted ETVs for obstructive hydrocephalus. A 5-grade scale was developed to assess preoperative risk factors and intraoperative evaluation to unify criteria that have been suspected to influence outcome independently. A grade of 0 was assigned to patients with no negative predictors, whereas increasing scores were assigned to patients who had multiple preoperative and intraoperative risks identified. Patients' grades were compared with outcome of the procedure, utility of externalized ventricular monitoring, and results of postoperative MR imaging.
Of 112 ETVs, 77 were successful and 35 were unsuccessful. Fifty-nine patients received a grade of 0, 27 received a grade of 1, 11 received a grade of 2, and 15 received a grade of ≥ 3. In all 15 patients receiving a grade ≥ 3 attempted ETV procedures failed, and the patients required a ventriculoperitoneal shunt. Postoperative monitoring with externalized ventricular drains and MR images demonstrating radiographic evidence of flow was independently less reliable than intraoperative grading in predicting success. Patients with a grade of 0 almost uniformly had successful surgery, independent of MR imaging findings. Patients with a grade of 1 or 2 who had successful surgery almost always lacked negative intraoperative predictive findings.
Despite reliance in recent years on post-ETV MR images and externalized ventricular monitoring, these modalities, although often useful adjuncts, appear less reliable as predictive tests than a simple assessment at the time of endoscopic fenestration. By using a uniform grading scale, the authors have introduced a novel means through which intraoperative and postoperative decision making can be aided, with the goal of reducing unnecessary procedures and tests and preventing unnecessary returns to the operating room.
Ilya Laufer, Jeffrey P. Greenfield, Vijay K. Anand, Roger Härtl, and Theodore H. Schwartz
✓The authors report a case of a nonachnodroplastic dwarf with severe basilar invagination and compression of the cervicomedullary junction (CMJ) due to juvenile rheumatoid arthritis. Initially excellent reduction of the invagination and decompression of the CMJ was achieved using posterior fixation. However, 1 month postoperatively symptoms recurred and the authors found imaging evidence of recurrence as well. The patient subsequently underwent an endoscopic transnasal resection of the dens with assistance of Iso-C navigation. He recovered well and tolerated regular diet on postoperative Day 2.