Christopher S. Hong, Daniel M. Prevedello, and J. Bradley Elder
Tubular brain retractors may improve access to deep-seated brain lesions while potentially reducing the risks of collateral neurological injury associated with standard microsurgical approaches. Here, microscope-assisted resection of lesions using tubular retractors is assessed to determine if it is superior to endoscope-assisted surgery due to the technological advancements associated with modern tubular ports and surgical microscopes.
Following institutional approval of the tubular port, data obtained from the initial 20 patients to undergo transportal resection of deep-seated brain lesions were analyzed in this study. The pathological entities of the resected tissues included metastatic tumors (8 patients), glioma (7), meningioma (1), neurocytoma (1), radiation necrosis (1), primitive neuroectodermal tumor (1), and hemangioblastoma (1). Surgery incorporated endoscopic (5 patients) or microscopic (15) assistance. The locations included the basal ganglia (11 patients), cerebellum (4), frontal lobe (2), temporal lobe (2), and parietal lobe (1). Cases were reviewed for neurological outcomes, extent of resection (EOR), and complications. Technical data for the port, surgical microscope, and endoscope were analyzed.
EOR was considered total in 14 (70%), near total (> 95%) in 4 (20%), and subtotal (< 90%) in 2 (10%) of 20 patients. Incomplete resection was associated with the basal ganglia location (p < 0.05) and use of the endoscope (p < 0.002). Four of 5 (80%) endoscope-assisted cases were near-total (2) or subtotal (2) resection. Histopathological diagnosis, presenting neurological symptoms, and demographics were not associated with EOR. Complication rates were low and similar between groups.
Initial experience with tubular retractors favors use of the microscope rather than the endoscope due to a wider and 3D field of view. Improved microscope optics and tubular retractor design allows for binocular vision with improved lighting for the resection of deep-seated brain lesions.
Amin B. Kassam, Johnathan A. Engh, Arlan H. Mintz, and Daniel M. Prevedello
The authors introduce a novel technique of intraparenchymal brain tumor resection using a rod lens endoscope and parallel instrumentation via a transparent conduit.
Over a 4-year period, 21 patients underwent completely endoscopic removal of a subcortical brain lesion by means of a transparent conduit. Image guidance was used to direct the cannulation and resection of all lesions. Postoperative MR imaging or CT was performed to assess for residual tumor in all patients, and all patients were followed up postoperatively to assess for new neurological deficits or other surgical complications.
The histopathological findings were as follows: 12 metastases, 5 glioblastomas, 3 cavernous malformations, and 1 hemangioblastoma. Total radiographically confirmed resection was achieved in 8 cases, near-total in 6 cases, and subtotal in 7 cases. There were no perioperative deaths. Complications included 1 infection and 1 pulmonary embolus. There were no postoperative hematomas, no postoperative seizures, and no worsened neurological deficits in the immediate postoperative period.
Fully endoscopic resection may be a technically feasible method of resection for selected subcortical masses. Further experience with this technique will help to determine its applicability and safety.
Jose M. Pascual
John A. Jane Jr., Daniel M. Prevedello, Tord D. Alden, and Edward R. Laws Jr.
The majority of pediatric craniopharyngiomas are treated using a transcranial approach. Although there is an increasing acceptance of transsphenoidal resection in adults, there are few reports describing this approach in the pediatric population. The purpose of this study is to report the outcomes after transsphenoidal surgery in a consecutive series of pediatric patients with craniopharyngiomas treated at a single institution with the goal of gross-total resection (GTR).
Twenty-three patients with pathologically proven craniopharyngiomas were identified who were 18 years of age or less at the time of surgery. The medical records and imaging studies of the patients were retrospectively reviewed. One patient who was lost to follow-up after surgery was excluded.
Among the 22 patients included in the study, 11 underwent transsphenoidal surgery as the primary procedure and 11 underwent transsphenoidal surgery as a secondary procedure after a previous procedure. All patients had at least some sellar component to their tumor and all had either anterior or posterior pituitary dysfunction at presentation. In the entire cohort, a GTR was achieved in 15 (68%) of 22 patients, a radical subtotal resection in 4 (18%) of 22 patients, a subtotal resection in 1 patient, and a partial resection in 2 patients. The degree of resection was higher in the primary transsphenoidal group. After a mean follow-up of 82 months, 4 patients (18%) experienced recurrence. Recurrence occurred in 13% after GTR compared with 28.5% after all other degrees of resection. Tumor recurred in 9% of the primary transsphenoidal group and in 30% of patients who had undergone other therapies prior to the transsphenoidal operation. No patient who had panhypopituitarism experienced a gain of function postoperatively, 67% developed new panhypopituitarism, and 56% experienced new diabetes insipidus. Vision improved or normalized in 9 (64%) of 14 patients presenting with visual loss. Complications included 1 death 3 weeks postoperatively, 2 CSF leaks, and new obesity in 37%.
Transsphenoidal resection of pediatric craniopharyngiomas results in a high rate of both visual improvement and GTR with a low associated risk of recurrence. The transsphenoidal approach should be considered in selected pediatric patients with craniopharyngioma, especially those with infradiaphragmatic origin.
Marc R. Mayberg
Danielle de Lara, Leo F. S. Ditzel Filho, Jun Muto, and Daniel M. Prevedello
Choroid plexus cysts are frequent benign intraventricular lesions that infrequently cause symptoms, usually in the form of obstructive hydrocephalus. These instances are even less common in the adult population. When warranted, treatment seeks to reestablish cerebrospinal fluid flow and does not necessarily require resection of the cyst itself. Hence, endoscopic exploration of the ventricles with subsequent cyst ablation is the current treatment of choice for these lesions.
Herein we present the case of a 25-year-old female patient with a 3-week history of intermittent headaches. Investigation with computerized tomography (CT) of the head detected supratentorial hydrocephalus, with enlargement of the lateral and third ventricles. Magnetic resonance imaging revealed a homogeneous cystic lesion in the third ventricle. A right-sided, pre-coronal burr hole was carried out, followed by endoscopic exploration of the ventricular system. A third-ventriclostomy was performed. With the aid of the 30-degrees endoscope, a cyst arising from the choroid plexus was visualized along the posterior portion of the third ventricle, obstructing the aqueduct opening. The cyst was cauterized until significant reduction of its dimensions was achieved and the aqueduct opening was liberated. Postoperative recovery was without incident and resolution of the hydrocephalus was confirmed by CT imaging. The patient reports complete improvement of her headaches and has been uneventfully followed since surgery.
The video can be found here: http://youtu.be/XBtj_SqY07Q.
Rafael Martínez-Pérez, Thiago Albonette-Felicio, Douglas A. Hardesty, and Daniel M. Prevedello
Keyhole approaches, namely the minipterional approach (MPTa) and the supraorbital approach (SOa), are alternatives to the standard pterional approach to treat lesions located in the anterior and middle cranial fossae. Despite their increasing popularity and acceptance, the indications and limitations of these approaches require further assessment. The purpose of the present study was to determine the differences in the area of surgical exposure and surgical maneuverability provided by the MPTa and SOa.
The areas of surgical exposure afforded by the MPTa and SOa were analyzed in 12 sides of cadaver heads by using a microscope and a neuronavigation system. The area of exposure of the region of interest and surgical freedom (maneuverability) of each approach were calculated.
The area of exposure was significantly larger in the MPTa than in the SOa (1250 ± 223 mm2 vs 939 ± 139 mm2, p = 0.002). The MPTa provided larger areas of exposure in the ipsilateral and midline compartments, whereas there was no significant difference in the area of exposure in the contralateral compartment. All targets in the anterior circulation had significantly larger areas of surgical freedom when treated via the MPTa versus the SOa.
The MPTa provides greater surgical exposure and better maneuverability than that offered by the SOa. The SOa may be advantageous as a direct corridor for treating lesions located in the contralateral side or in the anterior cranial fossa, but the surgical exposure provided in the midline region is inferior to that exposed by the MPTa.
Case report and review of the literature
Daniel M. Prevedello, Jay Jagannathan, John A. Jane Jr., M. Beatriz S. Lopes, and Edward R. Laws Jr.
Pituitary adenomas are heterogeneous in growth rate, invasiveness, and recurrence. To understand the biological behavior of the individual adenoma more fully, cell proliferation markers such as monoclonal antibodies targeted against the Ki-67 antigen have been applied. The Ki-67 antigen is a protein related to cell proliferation and is expressed in cell nuclei throughout the entire cell cycle. The authors report the case of an extremely rapidly growing pituitary adenoma with cavernous sinus invasion. The lesion, which displayed a high Ki-67 labeling index (LI; 22%), was found in a 54-year-old woman who presented with diplopia and headaches. The patient underwent three transsphenoidal operations in less than 6 months and, ultimately, was treated with fractionated intensity-modulated radiation therapy. The relationships between high Ki-67 LIs and tumor recurrence, invasiveness, and growth velocity in pituitary adenomas are reviewed.