Intraventricular tumors present a unique challenge for the neurosurgeon. Their deep location and proximity to eloquent neurovascular anatomy complicate surgical approach and resection [
Neuroendoscopy was introduced in the early 1900s, adopted initially by Dandy [
Early reports have demonstrated endoscopic resection of intraventricular masses to be effective and safe [
The goal of this report is to review the relevant literature describing the endoscopic resection of intraventricular masses as a whole, both cystic and solid, to provide a better understanding of this technique’s virtues and limitations.
Pubmed literature searches were performed using search terms “(endoscop*) AND ventric*”, “(endoscop*) AND tumor”, “((neuro-endoscop*) OR neuroendoscop*) AND tumor”, and “(tumor) AND ventric*”. Additional articles were located via cross-referencing of articles discovered initially through Pubmed searches. Articles included in the study were required to originate from peer-reviewed, English language journals describing the attempted resection (e.g., biopsies and cyst fenestrations without attempted resection were excluded) of an intraventricular tumor (e.g., suprasellar neoplasms without intraventricular extension were excluded) by purely endoscopic means (e.g., “endoscope-assisted” microsurgical resections were excluded) through a single endoscope (“dual-port” resections were excluded). Care was taken to exclude any redundant patient data from the analysis, and five articles required exclusion from the study due to an inability to definitively distinguish study patients in these five articles from patients in other study articles by the same author. In these five cases, the earlier of the two conflicting publications was omitted. Selected articles were also required to report on one or more of the following variables:
Data collected from these 40 studies included tumor type, location within the ventricular system, tumor size, the presence of hydrocephalus preoperatively, operative technique, success of endoscopic resection, rates of intraoperative hemorrhage, and other procedure-related complications, rates of tumor recurrence, and length of clinical and/or radiographic follow-up.
Estimates regarding the completeness of endoscopic resection were obtained most commonly by surgeon or observer recollection and self-report, but were also obtained through assessments of postoperative imaging studies and chart review in some cases. Complete endoscopic resection was defined as gross total resection of all visible tumor as confirmed by visual intraoperative assessment or by the absence of any visible tumor residual on postoperative contrast magnetic resonance imaging (MRI). Near-complete resection was defined as resection of all but a very small amount of tumor adherent to nearby tissues. Partial resection was defined by a considerable tumor remnant as assessed either intraoperatively or on postoperative contrast MRI.
Statistical analysis was performed using the Student
The entire patient population consisted of 668 patients with intraventricular tumors who underwent attempted endoscopic resection. The publication dates of the 40 articles ranged from 1994 to 2012, and the number of patients (
Colloid cysts were the most frequently encountered tumor by far (
demonstrating articles included in the study by publication year with corresponding data regarding tumor histology, number of patients (
Author | Year |
|
Tumor histology |
Preoperative Hydrocephalus |
Navigation/ |
Adjunctive procedures |
Mean OR time |
Mean hospital stay |
Complications |
Complete or near-complete resection |
Recurrence |
---|---|---|---|---|---|---|---|---|---|---|---|
Lewis et al. [ |
1994 | 7 | Colloid cyst (7) | 5 | 0 | No | 127 | 1.7 | 1 | 7 (100) | 1 |
Abdullah and Caemaert [ |
1995 | 3 | Craniopharyngioma (3) | ND | ND | ND | ND | ND | 0 | 1 (33.4) | 2 |
Abdou and Cohen [ |
1998 | 13 | Colloid cyst (13) | 13 | 0 | No | ND | ND | 0 | 10 (76.9) | 0 |
Gaab and Schroeder [ |
1998 | 19 | Colloid cyst (7), Subependymoma (3), low-grade astrocytoma (2), germinoma (1), pineal cyst (1), epidermoid cyst (1), hemangioma (1), cavernoma (1), CPP (1), ependymoma (1) | 11 | Navigation (4) | ETV (2), septostomy (1), stent (2) | 85 | ND | 3 | 13 (68.4) | 1 |
King et al. [ |
1999 | 13 | Colloid cyst (13) | 12 | 0 | Septostomy (13) | 94 | 2.3 | 2 | 10 (83.3) | 0 |
Rodziewicz et al. [ |
2000 | 12 | Colloid cyst (12) | 6 | 0 | Septostomy (12) | ND | ND | 1 | 11 (91.7) | 1 |
Decq et al. [ |
2000 | 22 | Colloid cyst (22) | 21 | 0 | No | ND | ND | 0 | 14 (63.6) | 1 |
Kehler et al. [ |
2001 | 10 | Colloid cyst (10) | ND | ND | ND | ND | ND | 3 | 9 (90) | 1 |
MacArthur et al. [ |
2002 | 7 | Colloid cyst (3), low-grade astrocytoma (1), ependymoma (1), unknown (2) | ND | ND | ND | ND | ND | ND | 4 (57.1) | 0 |
Jho and Alfieri [ |
2002 | 2 | Colloid cyst (2) | ND | 0 | No | ND | ND | 0 | 2 (100) | 0 |
Sgaramela et al. [ |
2003 | 1 | Colloid cyst (1) | ND | ND | ND | ND | ND | 0 | 1 (100) | 0 |
Hellwig et al. [ |
2003 | 20 | Colloid cyst (20) | 19 | Stereotaxy (9), Navigation (11) | Intraoperative ventriculography (11) | 250 (stereotactic), 150 (navigated) | 7 | 4 | 18 (90) | 1 |
Husain et al. [ |
2003 | 25 | Colloid cyst (11), ependymal cyst (2), choroid plexus cyst (2), septum Pellucidum cyst (2), arachnoid cyst (2), neurocysticercosis (2), craniopharyngioma (2), pineoblastoma (1), pineal Cyst (1) | ND | 0 | No | ND | 3 | 2 | 20 (80) | ND |
Souweidane [ |
2005 | 2 | Colloid cyst (1), glioneuronal tumor (1) | 1 | 0 | No | ND | ND | 0 | 2 (100) | 0 |
Jeon et al. [ |
2005 | 1 | Choroid plexus cyst (1) | 1 | 0 | No | ND | 37 | 1 | 1 (100) | ND |
Longatti et al. [ |
2006 | 61 | Colloid cysts (61) | 53 | 0 | No | 87 | 6.7 | 4 | 38 (62.3) | 7 |
Souweidane and Luther [ |
2006 | 7 | Ependymoma (2), central neurocytoma (2), low-grade glioneuronal tumor (2), subependymoma (1) | 7 | 0 | No | 117 | 2.6 | 2 | 5 (71.4) | 0 |
Harter et al. [ |
2006 | 1 | Dysembryoplastic neuroepithelial tumor (1) | 1 | ND | ND | ND | ND | ND | 1 (100) | ND |
Lekovic et al. [ |
2006 | 2 | Hypothalamic hamartomas (2) | ND | Navigation (2) | No | ND | ND | 0 | 1 (50) | ND |
Grondin et al. [ |
2007 | 25 | Colloid cysts (25) | 22 | 0 | No | 104 | 3.8 | 3 | 24 (96) | 1 |
Horn et al. [ |
2007 | 28 | Colloid cysts (28) | 17 | Navigation (28) | No | 174 | 5.4 | 3 | 10 (52.6), ND |
0 |
Levine et al. [ |
2007 | 35 | Colloid cysts (35) | ND | ND | ND | ND | ND | 7 | 32 (91.4) | 7 |
Greenlee et al. [ |
2008 | 35 | Colloid cysts (35) | ND | Frameless stereotaxy (35) | No | 93 | 3 | 3 | 29 (82.8) | 1 |
El-Ghandour [ |
2009 | 10 | Colloid cysts (10) | 10 | 0 | ETV (2) | ND | ND | 1 | 8 (80) | 0 |
Stark et al. [ |
2009 | 1 | Papillary ependymoma (1) | 1 | Navigation (1) | No | ND | ND | 1 | 1 (100) | 0 |
Romano et al. [ |
2009 | 1 | Central neurocytoma (1) | 1 | 0 | ETV (1) | ND | ND | 0 | 1 (100) | 0 |
Oertel et al. [ |
2009 | 11 | Unidentified (11) | ND | 0 | ETV (11) | 71 | ND | 9 | 4 (36.3) | ND |
Mishra et al. [ |
2010 | 59 | Colloid cyst (59) | 59 | Navigation (59) | No | ND | ND | 19 | 53 (89.8) | 0 |
Najjar et al. [ |
2010 | 7 | Colloid cyst (3), craniopharyngioma (1), low-grade astrocytoma (1), pineal cyst (1), unknown (1) | 6 | Navigation (2) | ETV (1), Septostomy (2) | ND | ND | 0 | 4 (57.1) | 1 |
Boogaarts et al. [ |
2011 | 90 | Colloid cyst (90) | ND | Stereotaxy (18) | ETV (7) | 79 | ND | 32 | 46 (57.5), ND |
24 |
Ahmad and Sandberg [ |
2010 | 1 | CPP (1) | 1 | 0 | ETV (1) | ND | ND | 0 | 1 (100) | 0 |
Naftel et al. [ |
2011 | 4 | Colloid cyst (2), hypothalamic hamartoma (2) | 1 | Navigation (2) | No | ND | ND | 0 | 3 (75) | ND |
Dlouhy et al. [ |
2011 | 4 | Colloid cyst (3), pineoblastoma (1) | ND | ND | ND | ND | ND | ND | 4 (100) | ND |
Delitala et al. [ |
2011 | 7 | Colloid cyst (7) | 4 | Navigation (4) | No | ND | ND | 0 | 6 (85.7) | 0 |
Sood et al. [ |
2011 | 2 | Pineal cyst (1), Pineoblastoma (1) | 2 | 0 | No | ND | ND | ND | 2 (100) | ND |
Wilson et al. [ |
2012 | 22 | Colloid cyst (22) | 19 | Navigation (19) | No | 180 | ND | 0 | 21 (95.4) | 0 |
Margetis and Souweidane [ |
2012 | 67 | Colloid cyst (67) | ND | Navigation (67) | No | ND | ND | 4 | 66 (98.5) | 3 |
Mohanty et al. [ |
2012 | 3 | Craniopharyngioma (2), subependymoma (1) | 2 | 0 | VP-shunt placement (2) | ND | ND | 2 | 2 (66.7) | 0 |
Selvanathan et al. [ |
2013 | 1 | Ependymoma (1) | 1 | Navigation | ETV | ND | ND | 1 | 1 (100) | 1 |
Drees et al. [ |
2012 | 26 | Hypothalamic hamartoma (26) | ND | ND | ND | ND | ND | 14 | 0 (0) | ND |
| |||||||||||
Total: 40 |
Total: 668 |
Total: 296/352 patients (84.1%) | Total: 262/581 patients (45.1%) | Total: 70/581 patients (12.0%) | Mean: 107.5 minutes | Mean: 4.8 days | Total: 123/592 patients (20.8%) | Total: 487/649 patients (75.0%) | Total: 53/533 patients (9.9%) |
CPP: choroid plexus papilloma, ND: no data, ETV: endoscopic third ventriculostomy, VP-shunt: ventriculoperitoneal shunt, and min: minutes.
displaying the various tumor histologies included in the study with corresponding data regarding the number of studies included, the number of patients, resection success, complication rates, and recurrence rates for each tumor type.
Tumor histology | Studied included |
Patients |
Complete or near-complete |
Complications |
Recurrence |
---|---|---|---|---|---|
Colloid Cyst | 21 | 569 | 441/550 patients (80.2%) | 83/556 patients (14.9%) | 49/498 patients (9.8%) |
Hypothalamic hamartoma | 3 | 30 | 2/30 patients (6.7%) | 14/30 patients (46.7%) | ND |
Unidentified | 3 | 14 | 6/14 patients (42.8%) | 9/12 patients (75%) | 0/3 patients (0%) |
Craniopharyngioma | 4 | 8 | 4/8 patients (50%) | 1/8 patients (12.5%) | 2/5 patients (40%) |
Ependymoma | 5 | 7 | 7/7 patients (100%) | 4/6 patients (66.6%) | 1/7 patients (14.3%) |
Subependymoma | 3 | 5 | 2/5 patients (40%) | 2/5 patients (40%) | 0/3 patients (0%) |
Low-grade astrocytoma | 3 | 4 | 1/4 patients (25%) | 0/3 patients (0%) | 0/4 patients (0%) |
Pineal cyst | 4 | 4 | 3/4 patients (75%) | 0/3 patients (0%) | 0/2 patients (0%) |
Pineoblastoma | 3 | 3 | 3/3 patients (100%) | 0/2 patients (0%) | ND |
Central neurocytoma | 2 | 3 | 2/3 patients (33.4%) | 0/3 patients (0%) | 0/3 patients (0%) |
Choroid plexus cyst | 2 | 3 | 3/3 patients (100%) | 1/3 patients (33.4%) | ND |
Choroid plexus papilloma | 2 | 2 | 2/2 patients (100%) | 0/2 patients (0%) | 0/2 patients (0%) |
Septum pellucidum cyst | 1 | 2 | 2/2 patients (100%) | 0/2 patients (0%) | ND |
Ependymal cyst | 1 | 2 | 2/2 patients (100%) | 0/2 patients (0%) | ND |
Arachnoid Cyst | 1 | 2 | 0/2 patients (0%) | 0/2 patients (0%) | ND |
Neurocysticercosis | 1 | 2 | 1/2 patients (50%) | 1/2 patients (50%) | ND |
Neuroepithelial tumor | 2 | 2 | 2/2 patients (100%) | 0/1 patient (0%) | 0/1 patient (0%) |
Glioneuronal tumor | 2 | 2 | 2/2 patients (100%) | 0/2 patients (0%) | 0/2 patients (0%) |
Cavernoma | 1 | 1 | 1/1 patient (100%) | 1/1 patient (100%) | 0/1 patient (0%) |
Hemangioma | 1 | 1 | 1/1 patient (100%) | 0/1 patient (0%) | 0/1 patient (0%) |
Epidermoid cyst | 1 | 1 | 0/1 patient (0%) | 1/1 patient (100%) | 1/1 patient (100%) |
Germinoma | 1 | 1 | 1/1 patient (100%) | 1/1 patient (100%) | 0/1 patient (0%) |
ND: no data.
Various techniques for neuroendoscopic resection of intraventricular tumors have been described in detail elsewhere [
All procedures were performed with the patient under general anesthesia in a supine position. The patient’s head was most commonly placed on a soft headrest, except where neuronavigation or stereotaxy was used, in which case the patient’s head was placed in a 3-point pin fixation device. Preoperative antibiotics were always administered, but prophylactic antiepileptics frequently were not. The average operative time was 107.5 minutes and the average hospital stay was
Ventricular access was most commonly attained through a right-sided approach (unless asymmetric left-sided ventriculomegaly was present, in which case a left-sided approach was preferred). In all cases of hypothalamic hamartoma resection, ventricular access was performed contralateral to the greatest extent of tumor mass. Incision was made over the intended ventricular access site and a standard burr hole was created. The burr hole was most commonly placed at some variant of Kocher’s point, although slightly more lateral (5–7 cm lateral to midline) on occasion. [
The dura is incised in cruciate fashion and coagulated, followed by ventricular puncture and the introduction of an endoscope. Often a small-diameter peel-away introducer sheath containing a navigation probe and/or small-diameter rigid endoscope is used for initial ventricular puncture, although some authors preferred to perform initial ventricular puncture with a ventricular needle or catheter, followed by the introduction of an endoscope into the needle or catheter tract [
After entry into the ventricle, the tumor is inspected and its relationship to the surrounding anatomy is assessed. In some cases, visualization required the use of a 30° rigid endoscope or flexible neuroendoscope. A larger diameter rigid endoscope with multiple working channels is then introduced, through which tumor manipulation, coagulation, and resection take place. In the case of 59 colloid cysts and a single ependymoma, flexible neuroendoscopes were used for the majority of the procedure [
Cystic tumors were frequently penetrated and gently aspirated, after which the cyst wall was coagulated and resected piecemeal or
Navigation and/or stereotactic localization tools were used in 266 procedures (45.1% of 581 procedures reporting such data) [
Complete or near-complete tumor resection was achieved in 487 of 649 patients (75.0%) for whom completeness of endoscopic resection was reported. Complete resections were seen after initial resection attempts in 80.2% of colloid cysts, compared with 45.5% of other tumors (
Column graphs displaying the variances in (a) resection success, (b) recurrence rate, and (c) complication rate seen with navigated endoscopic resection versus freehand, cystic tumors versus non-cystic, and large tumors (size > 2 cm) versus small (size ≤ 2 cm). *= statistically significant result.
Procedures in addition to the tumor resection were attempted during the same operative session in 70 patients (12.0% of patients for whom such data was reported). These adjunctive procedures included endoscopic third ventriculostomy (
Perioperative complications were seen in 123 out of 592 patients (20.8%) for whom data regarding complications was reported. These complications included hemorrhage (intraventricular,
In the large majority of study patients, clinical morbidity was either unchanged or improved at most latent follow-up. There were no deaths reported to have occurred as a result of any of the 668 procedures. Postoperative morbidity increases were seen in 54 patients (9.5% of 569 patients for whom the relevant data was supplied) due to a variety of complications, including post-operative infarct, intraventricular hemorrhage, and meningitis or ventriculitis. Clinical outcomes are summarized in Table
Tumor recurrence was seen in 53 of the 533 patients (9.9%) for whom data regarding recurrence was reported throughout an average of 31 months of follow-up. Recurrence was discovered, on average, 39 months after the initial resection in these 53 patients (range, 6–79 months). Tumor recurrence was seen in 9.8% of colloid cysts (49/498 patients reporting) compared with 11.1% of other tumors (4/36 patients reporting) (
Neuro-endoscopy offers solutions to some of the challenges faced with intraventricular tumor surgery. Endoscopic approaches to intraventricular pathology provide improved illumination and visualization of an anatomically remote and otherwise-difficult-to-reach location without the degree of tissue dissection and retraction often required with microsurgical techniques [
Neuroendoscopic approaches to intraventricular pathology also afford the surgeon an opportunity to treat associated hydrocephalus concomitantly, although tumor resection alone may be sufficient to restore cerebrospinal fluid (CSF) flow in some cases [
Neuroendoscopic resection appears to be most safe and effective [
Neuroendoscopic resection is also best suited for relatively avascular tumors [
Ventriculomegaly is another factor which favors a neuroendoscopic approach. Small ventricles are thought to be unfavorable for neuroendoscopy because visibility and maneuverability in this setting are greatly reduced [
Several of the limitations of neuroendoscopic tumor resection derive from a fundamental inadequacy of modern neuroendoscopic technology. As previously noted, solid masses greater than 2 cm in diameter, and those with considerable vascularity, are less amenable to neuroendoscopic resection due to the elementary nature of tools currently available for endoscopic dissection and hemostasis.
The large majority of cases included in this study used forceps, suction catheters, and bipolar cautery as the primary tools for dissection, resection, and hemostasis, respectively. Several series, however, report on the use of assistive devices (e.g., CUSA, NICO Myriad aspirator, Micro ENP Ultrasonic Hand Piece, and the Suros device) designed to allow for rapid tumor dissection and removal through an endoscopic approach. Although surgeons who use these devices frequently report their being helpful, objective data regarding their overall benefit is lacking [
Endoscopic tumor resections are also frequently said to result in inferior rates of gross total resection [
Some apprehension about the use of endoscopy for tumor resection arises from the perception that tumors resected endoscopically are more likely to recur [
The use of stereotactic and/or neuronavigational guidance for endoscopic tumor resection is commonly reported in the neurosurgical literature, particularly in cases where ventriculomegaly is absent [
The overall complication rate of 20.8% seen in this study is consistent with values reported elsewhere for endoscopic resection (0–25%) [
We present the largest analysis to date of outcomes for endoscopic resection of intraventricular tumors. Limitations of this study include the following:
The goal of this study was to better characterize the advantages and disadvantages of the endoscopic approach to intraventricular tumors. Our results indicate that endoscopic tumor resection, when applied in the appropriate setting, is safe and effective.
Further improvements in the outcomes of neuroendoscopic tumor resection rely heavily on the development of endoscopic technology. Dissection tools allowing for the rapid and safe removal of large, solid tumors are lacking, as are effective means of acquiring prompt hemostasis through an endoscopic approach. More data is needed on the outcomes of endoscopic resection of tumors other than colloid cysts. Finally, randomized trials comparing surgical and endoscopic tumor resections would provide a better characterization of the virtues and limitations of each technique.
Microsurgical resection remains the gold standard of intraventricular tumor resection [
The authors have no financial or any other conflict of interests to disclose. Specifically, the authors have no direct financial relationship to any commercial entities mentioned within the paper.