This study did not receive any funding.

The Institutional Review Committee of the Istanbul Faculty of Medicine approved the study protocol. Before the start of the study, the patient was asked to sign an informed consent form outlining the purpose of use and publication of their data.
1. Preoperative procedures
<ol>
	<li>Perform the operations under general anesthesia. Prepare endoscopic and optical equipment in the operating room.</li>
	<li>Check the instruments before starting the procedure (Figure 1 and Table 1).</li>
</ol>
2. Surgical technique (Figure 2)
<ol>
	<li>Place the patient in the supine position under general anesthesia. Support the patient&#39;s head with a soft head support and bend it at a 10&#176; angle.</li>
	<li>Palpate the coronal suture. The Kocher point is just anterior to the coronal suture and approximately 2.5 cm to the right of the midline.</li>
	<li>Begin the operation by following routine asepsis and antiseptic rules.
	<ol>
		<li>Make a 5 cm curvilinear incision in the right frontal region, including Kocher&#39;s point, using a #20 blade.</li>
		<li>Ensure hemostasis with bipolar cautery and dissect the skin and subcutaneous tissue.</li>
		<li>Place the automated skin retractor.</li>
		<li>Scrape the periosteum using an Adson periosteal elevator.</li>
		<li>Drill a burr hole in the anterior region using a high-speed drill and perforator.</li>
		<li>Open the dura in a cruciform shape with a #11 blade and coagulate the underlying pia with bipolar cautery.</li>
		<li>Insert the endoscope sheath into the brain parenchyma perpendicular to the burr hole and remove the obturator while holding the endoscope sheath. After entering the lateral ventricle, cerebrospinal fluid is seen to exit the endoscope sheath. 
		NOTE: The examination of tumor markers such as alpha-feto-protein and B-Hcg in the cerebrospinal fluid (CSF) sample increases the accuracy of the histological examination.</li>
		<li>Insert the 6.1 mm wide endoscope into the endoscope sheath. Visualize the lateral ventricular cavity.
		<ol>
			<li>Identify the septal and thalamostriate veins in the lateral ventricle.</li>
			<li>Identify the choroid plexus. Follow the choroid plexus anteriorly up to the third ventricle going through the Foramen of Monro (FOM).</li>
		</ol>
		</li>
		<li>Pass the ventriculoscope through the FOM to access the third ventricle.</li>
		<li>Find the floor of the third ventricle, which is usually thin due to hydrocephalus.
		<ol>
			<li>Identify the mammillary bodies and infundibular recess in the third ventricle.</li>
			<li>Ensure that the hole at the base of the third ventricle is located at the most translucent point between the infundibular recess and the mammillary bodies.</li>
		</ol>
		</li>
		<li>Locate the basilar artery and puncture anterior to the arterial complex to prevent damage and hemorrhage during surgery.</li>
		<li>Use the tip of the 4F Fogarty catheter to puncture the base of the third ventricle. Then, repeatedly inflate and deflate the balloon of the catheter to widen the opening. See the jet flow of cerebrospinal fluid when the catheter balloon is deflated.</li>
		<li>If bleeding occurs during surgery, irrigate with copious amounts of warm fluid until all bleeding has visibly stopped and CSF has cleared. 
		NOTE: There are different opinions in the literature about the fluids used to manage bleeding. However, we use Ringer&#39;s lactate solution at normal body temperature in our clinic.</li>
		<li>Move the endoscope to the posterior region of the third ventricle where the pineal gland tumor is located. 
		NOTE: The entry point and angle of the endoscope play a pivotal role in accessing these two structures, which are positioned at different locations. This is essential to avoid damage to the fornix and critical vascular structures.</li>
		<li>Identify the massa intermedia and perform dissection to allow better visualization of the posterior third ventricle.</li>
		<li>Identify the tumor and examine the growth pattern. Carefully coagulate the surface of the tumor using bipolar cautery.</li>
		<li>After complete coagulation of the tumor surface, take a biopsy using biopsy forceps. Send the biopsy to the pathology unit for frozen analysis and resect the tumor according to the histopathological diagnosis.</li>
		<li>Control local hemorrhage with irrigation and bipolar cautery.</li>
		<li>Remove the Endoscopic System.</li>
		<li>Close the wound with sutures without a drain.</li>
	</ol>
	</li>
</ol>
3. Postoperative procedures
<ol>
	<li>The hospital stay is minimal. Mobilize the patient on the second day following surgery.</li>
	<li>Perform non-contrast cranial CT and CSF flow MRI to evaluate the patency of the third ventriculostomy and exclude the presence of bleeding.</li>
	<li>Discharge patients the following day if there are no complaints.</li>
	<li>Ask the patients to follow the pathology results and attend the outpatient clinic on the tenth day and at the end of the first month.</li>
</ol>

Endoscopy from Kocher&#39;s Point Enabling Third Ventriculostomy and Pineal Biopsy

<ol>
	<li>Favero, G., Bonomini, F., Rezzani, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pineal+gland+tumors:+A+review.">Pineal gland tumors: A review.</a> Cancers (Basel). 13 (7), 1547 (2021).</li><li>Nagasawa, D. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pineal+germ+cell+tumors:+Two+cases+with+review+of+histopathologies+and+biomarkers).">Pineal germ cell tumors: Two cases with review of histopathologies and biomarkers).</a> J Clin Neurosci. 38, 23-31 (2017).</li><li>Tamrazi, B., Nelson, M., Bl&#252;ml, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pineal+region+masses+in+pediatric+patients.">Pineal region masses in pediatric patients.</a> Neuroimaging Clin N Am. 27 (1), 85-97 (2017).</li><li>Carr, C., O'Neill, B. E., Hochhalter, C. B., Strong, M. J., Ware, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomarkers+of+pineal+region+tumors:+A+review.">Biomarkers of pineal region tumors: A review.</a> Ochsner J. 19 (1), 26-31 (2019).</li><li>Iorio-Morin, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Histology-stratified+tumor+control+and+patient+survival+after+stereotactic+radiosurgery+for+pineal+region+tumors:+A+report+from+the+international+gamma+knife+research+foundation.">Histology-stratified tumor control and patient survival after stereotactic radiosurgery for pineal region tumors: A report from the international gamma knife research foundation.</a> World Neurosurg. 107, 974-982 (2017).</li><li>Liu, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+single-trajectory+endoscopic+biopsy+and+third+ventriculostomy+in+pediatric+pineal+region+tumors.">Simultaneous single-trajectory endoscopic biopsy and third ventriculostomy in pediatric pineal region tumors.</a> Acta Neurol Belg. 121 (6), 1535-1542 (2021).</li><li>Attri, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoscopic+third+ventriculostomy+and+simultaneous+tumor+biopsy+in+pineal+region+tumors+using+the+&amp;#34;single+burr+hole&amp;#34;+technique:+An+analysis+of+34+cases.">Endoscopic third ventriculostomy and simultaneous tumor biopsy in pineal region tumors using the &amp;#34;single burr hole&amp;#34; technique: An analysis of 34 cases.</a> Asian J Neurosurg. 15 (4), 976-982 (2020).</li><li>Abbassy, M., Aref, K., Farhoud, A., Hekal, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Outcome+of+single-trajectory+rigid+endoscopic+third+ventriculostomy+and+biopsy+in+the+management+algorithm+of+pineal+region+tumors:+A+case+series+and+review+of+the+literature.">Outcome of single-trajectory rigid endoscopic third ventriculostomy and biopsy in the management algorithm of pineal region tumors: A case series and review of the literature.</a> Childs Nerv Syst. 34 (7), 1335-1344 (2018).</li><li>Fukushima, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoscopic+biopsy+of+intraventricular+tumors+with+the+use+of+a+ventriculofiberscope.">Endoscopic biopsy of intraventricular tumors with the use of a ventriculofiberscope.</a> Neurosurgery. 2 (2), 110-113 (1978).</li><li>Kawsar, K. A., Haque, M. R., Chowdhury, F. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Avoidance+and+management+of+perioperative+complications+of+endoscopic+third+ventriculostomy:+The+Dhaka+experience.">Avoidance and management of perioperative complications of endoscopic third ventriculostomy: The Dhaka experience.</a> J Neurosurg. 123 (6), 1414-1419 (2015).</li><li>Yang, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoscopic+third+ventriculostomy+and+biopsy+of+a+tectal+lesion+using+flexible+neuroendoscopy+and+urological+cup+forceps:+Illustrative+case.">Endoscopic third ventriculostomy and biopsy of a tectal lesion using flexible neuroendoscopy and urological cup forceps: Illustrative case.</a> J Neurosurg Case Lessons. 5 (16), (2023).</li><li>Revuelta Barbero, J. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Combined+microsurgical-endoscopic+paramedian+supracerebellar-infratentorial+approach+for+resection+of+a+pineal+low-grade+glioma.">Combined microsurgical-endoscopic paramedian supracerebellar-infratentorial approach for resection of a pineal low-grade glioma.</a> Neurosurg Focus Video. 5 (1), 9 (2021).</li><li>Al-Saiari, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+biportal+endoscopic+management+of+pineal+region+tumors+in+patients+with+obstructive+hydrocephalus:+Technical+notes.">Simultaneous biportal endoscopic management of pineal region tumors in patients with obstructive hydrocephalus: Technical notes.</a> Chin Neurosurg J. 9 (1), 1 (2023).</li><li>Birski, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoscopic+versus+stereotactic+biopsies+of+intracranial+lesions+involving+the+ventricles.">Endoscopic versus stereotactic biopsies of intracranial lesions involving the ventricles.</a> Neurosurg Rev. 44 (3), 1721-1727 (2021).</li><li>Gurusamy, S. M., Yaakub, A., Wan Hitam, W. H., Ahmad Maulana, S. A., Wan Ibrahim, W. Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pineal+gland+tumour+with+drop+metastases:+A+case+report.">Pineal gland tumour with drop metastases: A case report.</a> Cureus. 14 (10), e29855 (2022).</li><li>Panyaping, T., Tritanon, O., Wisetsathon, P., Chansakul, T., Pongpitcha, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accuracy+of+apparent+diffusion+coefficient+values+for+distinguishing+between+pineal+germ+cell+tumour+and+pineoblastoma.">Accuracy of apparent diffusion coefficient values for distinguishing between pineal germ cell tumour and pineoblastoma.</a> Clin Radiol. 78 (7), e494-e501 (2023).</li><li>Leone, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=single+burr+hole+endoscopic+third+ventriculostomy+and+tumor+biopsy+for+pineal+lesions:+Feasibility,+safety,+and+benefits.">single burr hole endoscopic third ventriculostomy and tumor biopsy for pineal lesions: Feasibility, safety, and benefits.</a> World Neurosurg. 173, 5-11 (2023).</li><li>Morgenstern, P. F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pineal+region+tumors:+An+optimal+approach+for+simultaneous+endoscopic+third+ventriculostomy+and+biopsy.">Pineal region tumors: An optimal approach for simultaneous endoscopic third ventriculostomy and biopsy.</a> Neurosurg Focus. 30 (4), 3 (2011).</li><li>Zhang, Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Management+of+hydrocephalus+secondary+to+pineal+region+tumors.">Management of hydrocephalus secondary to pineal region tumors.</a> Clin Neurol Neurosurg. 115 (9), 1809-1813 (2013).</li><li>Xin, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoscopic-assisted+surgery+versus+microsurgery+for+pineal+region+tumors:+A+single-center+retrospective+study.">Endoscopic-assisted surgery versus microsurgery for pineal region tumors: A single-center retrospective study.</a> Neurosurg Rev. 44 (2), 1017-1022 (2021).</li><li>Choque-Velasquez, J., Resendiz-Nieves, J., Colasanti, R., Hernesniemi, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Management+of+obstructive+hydrocephalus+associated+with+pineal+region+cysts+and+tumors+and+its+implication+in+long-term+outcome.">Management of obstructive hydrocephalus associated with pineal region cysts and tumors and its implication in long-term outcome.</a> World Neurosurg. 149, e913-e923 (2021).</li><li>Chibbaro, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuroendoscopic+management+of+posterior+third+ventricle+and+pineal+region+tumors:+Technique,+limitation,+and+possible+complication+avoidance.">Neuroendoscopic management of posterior third ventricle and pineal region tumors: Technique, limitation, and possible complication avoidance.</a> Neurosurg Rev. 35 (3), 331-338 (2012).</li><li>Ahmed, A. I., Zaben, M. J., Mathad, N. V., Sparrow, O. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoscopic+biopsy+and+third+ventriculostomy+for+the+management+of+pineal+region+tumors.">Endoscopic biopsy and third ventriculostomy for the management of pineal region tumors.</a> World Neurosurg. 83 (4), 543-547 (2015).</li></ol>

The authors declare that they have no conflicts of interest.

The description of the ETV and biopsy for pineal tumors was first described in the 1970s. Historically, the fear of uncontrolled hemorrhage has always existed. However, owing to advances in endoscopic surgery techniques, bleeding control is not a major complication for experienced surgeons nowawadays9,10. According to several cases in the literature, endoscopic management has been found to be effective as an initial step for pineal region tumors presenting with h...

The pineal gland is a neuroendocrine gland located in the epithalamus that is responsible for regulating biological rhythms in vertebrates. Its anatomical boundaries include the posterior surface of the wall of the third ventricle, which forms the base of the gland, the splenium of the corpus callosum superiorly, and the thalamus surrounding both sides. It has a pinecone shape and extends posteriorly and inferiorly in the quadrigeminal cistern1,2. 
Pineal neoplasms are relatively rare tumors and are predominantly childhood malignancies, accounting for 3-11% of all childhood brain tumors compared with &lt;1% of adult brain tumors1,3,4. Age, sex, and ethnicity can modify the relative incidence of pineal neoplasms5. Pineal tumors are classified into three types: germ cell tumors, pineal parenchymal tumors, and tumors arising from neighboring anatomical regions. Germinomas are the most frequent pineal tumors, accounting for up to 50% of pineal tumors in Europe1,3.
Tumors of the pineal gland are pathologically diverse and their optimal management remains controversial6. Advances in neuroendoscopy have significantly contributed to treating pineal region tumors. Neuroendoscopic techniques are minimally invasive, effective, and safe in treating these tumors. With this technique, it is possible to treat hydrocephalus and obtain a biopsy simultaneously7. In most cases, simultaneous endoscopic third ventriculostomy (ETV) and tumor biopsy is the first-choice surgical procedure for pineal region tumors due to the effectiveness of radiotherapy and chemotherapy in most histopathological subtypes. Various techniques for simultaneous ETV and biopsy have been described, and there is currently no standard technique for performing this procedure8.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Adson periosteal elevator</td>
			<td>Ruggles-Redmond</td>
			<td>RO263</td>
			<td>Semi-sharp, 5 mm, curved 6-3/8, length 164 mm</td>
		</tr>
		<tr>
			<td>Automatic skin retractors&#160;</td>
			<td>Integra</td>
			<td>3,72,245</td>
			<td>Heiss Automatic Skin Retractor Length - Overall (mm): 102 
			Length 1 - Tip/Jaw (mm): 8</td>
		</tr>
		<tr>
			<td>Balloon catheter&#160;</td>
			<td>Edwards Fogarty</td>
			<td>120804FP</td>
			<td>Length (cm): 80, Catheter size (F): 4,&#160; Inflated balloon diameter (mm): 9</td>
		</tr>
		<tr>
			<td>Biopsy Forceps</td>
			<td>Karl Storz LOTTA CLICKLINE Grasping Forceps</td>
			<td>28164 LE</td>
			<td>Rotating, dismantling, single action jaws, diameter 2.7 mm, working length 30 cm</td>
		</tr>
		<tr>
			<td>Bipolar coagulation electrode</td>
			<td>Karl Storz LOTTA</td>
			<td>28161 SF</td>
			<td>Diameter 1.3 mm, working length 30 cm</td>
		</tr>
		<tr>
			<td>Bisture</td>
			<td>Beybi</td>
			<td>24,02,502</td>
			<td>Beybi Bisture Tip. No: 20 and No: 11</td>
		</tr>
		<tr>
			<td>High-speed drill</td>
			<td>Medtronic Midas Rex MR8</td>
			<td>MR8&#8482; Electric Plus EM850</td>
			<td>Perforator tip used</td>
		</tr>
		<tr>
			<td>Obturator</td>
			<td>Karl Storz LOTTA</td>
			<td>28164 LLO</td>
			<td>Use with Operating Sheaths for ventricular puncture</td>
		</tr>
		<tr>
			<td>Operating sheath</td>
			<td>Karl Storz LOTTA</td>
			<td>28164 LSB</td>
			<td>Graduated, rotating, outer diameter 6.8 mm, working length 13 cm</td>
		</tr>
		<tr>
			<td>Ventriculoscope</td>
			<td>Karl Storz LOTTA Ventriculoscope with HOPKINS</td>
			<td>28164 LAB</td>
			<td>Wide angle telescope 30&#176;, angled eyepiece, outer diameter 6.1 mm, length 18 cm, working channel diameter 2.9 mm, irrigation/suction channel diameter 1.6 mm</td>
		</tr>
	</tbody>
</table>

endoscopic third ventriculostomy and pineal biopsy from a single entry point

Pineal neoplasms have a significant impact on children although they are relatively uncommon. They account for approximately 3-11% of all childhood brain tumors, which is considerably higher than the &lt;1% seen in adult brain tumors. These tumors can be divided into three main categories: germ cell tumors, parenchymal pineal tumors, and tumors arising from related anatomical structures. Obtaining an accurate and minimally invasive tissue diagnosis is crucial for selecting the most appropriate treatment regimen for patients with pineal gland tumors. This is due to the diverse treatment options available and the potential risks associated with complete resection. In cases where patients present with acute obstructive hydrocephalus caused by a pineal gland tumor, immediate treatment of the hydrocephalus is necessary. The urgency stems from the potential complications of hydrocephalus, including increased intracranial pressure and neurological deficits. To address these challenges, a minimally invasive endoscopic approach provides a valuable opportunity. This technique allows clinicians to promptly relieve hydrocephalus and obtain a histological diagnosis simultaneously. This dual benefit enables a more comprehensive understanding of the tumor and assists in determining the most effective treatment strategy for the patient.

Preoperative magnetic resonance imaging (MRI) revealed a pineal tumor and triventricular hydrocephalus. Before the surgery, we ensured that our endoscope set, 4F Fogarty balloon catheter (see Figure 1), and all required materials (see Table 1) were checked. The size of the pineal tumor was initially measured at 30 mm x 15 mm x 20 mm. However, on postoperative MRI scans, it was observed that the tumor had increased in size to 35 mm x 52 mm x 45 mm, suggesting...

Author Spotlight: A Single-Entry Point Endoscopic Intraventricular Approach for Third Ventriculostomy and Pineal Biopsy

Pineal neoplasms frequently cause obstructive hydrocephalus and require histopathological diagnosis to decide the treatment regimen. They might be treated by surgical resection or chemoradiotherapy according to the pathological diagnosis. As a minimally invasive initial treatment, an endoscopic approach from Kocher's point enables both third ventriculostomy and biopsy.

Endoscopic Third Ventriculostomy and Pineal Biopsy from a Single Entry Point

Pineal neoplasms have a significant impact on children although they are relatively uncommon. They account for approximately 3-11% of all childhood brain ...

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448 Views.  Istanbul University Faculty of Medicine. Pineal neoplasms frequently cause obstructive hydrocephalus and require histopathological diagnosis to decide the treatment regimen. They might be treated by surgical resection or chemoradiotherapy according to the pathological diagnosis. As a minimally invasive initial treatment, an endoscopic approach from Kocher's point enables both third ventriculostomy and biopsy. 

Video: Author Spotlight: A Single-Entry Point Endoscopic Intraventricular Approach for Third Ventriculostomy and Pineal Biopsy

Microvascular Decompression: Salient Surgical Principles and Technical Nuances

Trigeminal neuralgia is a disorder associated with severe episodes of lancinating pain in the distribution of the trigeminal nerve. Previous reports indicate that 80-90% of cases are related to compression of the trigeminal nerve by an adjacent vessel. The majority of patients with trigeminal neuralgia eventually require surgical management in order to achieve remission of symptoms. Surgical options for management include ablative procedures (e.g., radiosurgery, percutaneous radiofrequency lesioning, balloon compression, glycerol rhizolysis, etc.) and microvascular decompression. Ablative procedures fail to address the root cause of the disorder and are less effective at preventing recurrence of symptoms over the long term than microvascular decompression. However, microvascular decompression is inherently more invasive than ablative procedures and is associated with increased surgical risks. Previous studies have demonstrated a correlation between surgeon experience and patient outcome in microvascular decompression. In this series of 59 patients operated on by two neurosurgeons (JSN and PEK) since 2006, 93% of patients demonstrated substantial improvement in their trigeminal neuralgia following the procedure&#x2014;with follow-up ranging from 6 weeks to 2 years. Moreover, 41 of 66 patients (approximately 64%) have been entirely pain-free following the operation.
In this publication, video format is utilized to review the microsurgical pathology of this disorder. Steps of the operative procedure are reviewed and salient principles and technical nuances useful in minimizing complications and maximizing efficacy are discussed.

There are many available options for management of the patient with trigeminal neuralgia. Microvascular decompression, while the most invasive of all options, is also the most effective at achieving long term remission of symptoms. Video instruction on how to maximize efficacy and minimize complications with this procedure is described.

Trigeminal neuralgia is a disorder associated with severe episodes of lancinating pain in the distribution of the trigeminal nerve. Previous reports ...

Minimally Invasive Thumb-sized Pterional Craniotomy for Surgical Clip Ligation of Unruptured Anterior Circulation Aneurysms

Less invasive surgical approaches for intracranial aneurysm clipping may reduce length of hospital stay, surgical morbidity, treatment cost, and improve patient outcomes. We present our experience with a minimally invasive pterional approach for anterior circulation aneurysms performed in a major tertiary cerebrovascular center and compare the results with an aged matched dataset from the Nationwide Inpatient Sample (NIS). From August 2008 to December 2012, 22 elective aneurysm clippings on patients &#8804;55 years of age were performed by the same dual fellowship-trained cerebrovascular/endovascular neurosurgeon. One patient (4.5%) experienced transient post-operative complications. 18 of 22 patients returned for follow-up imaging and there were no recurrences through an average duration of 22 months. A search in the NIS database from 2008 to 2010, also for patients aged &#8804;55 years of age, yielded 1,341 hospitalizations for surgical clip ligation of unruptured cerebral aneurysms. Inpatient length of stay and hospital charges at our institution using the minimally invasive thumb-sized pterional technique were nearly half that of NIS (length of stay: 3.2 vs 5.7 days; hospital charges: $52,779 vs. $101,882). The minimally invasive thumb-sized pterional craniotomy allows good exposure of unruptured small and medium-sized supraclinoid anterior circulation aneurysms. Cerebrospinal fluid drainage from key subarachnoid cisterns and constant bimanual microsurgical techniques avoid the need for retractors which can cause contusions, localized venous infarctions, and post-operative cerebral edema at the retractor sites. Utilizing this set of techniques has afforded our patients with a shorter hospital stay at a lower cost compared to the national average.

Minimally invasive thumb-sized pterional craniotomy for aneurysm clipping has afforded our patients with a shorter hospital stay at a lower cost compared to the national average.

Less invasive surgical approaches for intracranial aneurysm clipping may reduce length of hospital stay, surgical morbidity, treatment cost, and improve ...

Comprehensive Endovascular and Open Surgical Management of Cerebral Arteriovenous Malformations

Arteriovenious malformations (AVMs) are associated with significant morbidity and mortality, and have a rupture risk of ~3% per year. Treatment of AVMs must be tailored specifically to the lesion, with surgical resection being the gold standard for small, accessible lesions. Pre-operative embolization of AVMs can reduce nidal blood flow and remove high-risk AVM features such as intranidal or venous aneurysms, thereby simplifying a challenging neurosurgical procedure. Herein, we describe our approach for the staged endovascular embolization and open resection of AVMs, and highlight the advantages of having a comprehensively trained neurovascular surgeon leading a multi-disciplinary clinical team. This includes planning the craniotomy and resection to immediately follow the final embolization stage, thereby using a single session of anesthesia for aggressive embolization, and rapid resection. Finally, we provide a representative case of a 22-year-old female with an unruptured right frontal AVM diagnosed during a seizure workup, who was successfully treated via staged embolizations followed by open surgical resection.

Surgery is the gold standard for accessible arteriovenious malformations (AVMs), and pre-operative embolization can simplify this procedure. We describe our approach for staged endovascular embolization and open resection of AVMs, and provide a representative clinical example highlighting the advantages of a comprehensively trained neurovascular surgeon leading a multi-disciplinary clinical team.

Arteriovenious malformations (AVMs) are associated with significant morbidity and mortality, and have a rupture risk of ~3% per year. Treatment of AVMs ...

Neuroscience

Network Analysis of Foramen Ovale Electrode Recordings in Drug-resistant Temporal Lobe Epilepsy Patients

Approximately 30% of epilepsy patients are refractory to antiepileptic drugs. In these cases, surgery is the only alternative to eliminate/control seizures. However, a significant minority of patients continues to exhibit post-operative seizures, even in those cases in which the suspected source of seizures has been correctly localized and resected. The protocol presented here combines a clinical procedure routinely employed during the pre-operative evaluation of temporal lobe epilepsy (TLE) patients with a novel technique for network analysis. The method allows for the evaluation of the temporal evolution of mesial network parameters. The bilateral insertion of foramen ovale electrodes (FOE) into the ambient cistern simultaneously records electrocortical activity at several mesial areas in the temporal lobe. Furthermore, network methodology applied to the recorded time series tracks the temporal evolution of the mesial networks both interictally and during the seizures. In this way, the presented protocol offers a unique way to visualize and quantify measures that considers the relationships between several mesial areas instead of a single area.

This protocol describes a procedure to track the evolution of mesial network measures in temporal lobe epilepsy (TLE) patients. It is based on the combination of intracranial recordings with a novel numerical technique for data analysis. Specifically, we present a protocol for network analyses of foramen ovale recordings.

Approximately 30% of epilepsy patients are refractory to antiepileptic drugs. In these cases, surgery is the only alternative to eliminate/control ...

Endoscopic Endonasal Trans-sphenoidal Approach: Minimally Invasive Surgery for Pituitary Adenomas

Endoscopic endonasal trans-sphenoidal surgery has become the gold standard for the surgical treatment of pituitary adenomas and many other pituitary lesions. Refinements in surgical techniques, technological advancements, and incorporation of neuronavigation have rendered this surgery minimally invasive. The complication rates of this surgery are very low while excellent results are consistently obtained through this approach.
This paper focuses on the step-by-step surgical approach to pituitary adenomas, which is based on personal experience, and details the results obtained with this minimally invasive surgery.

The aim of this paper is to describe the different steps of the endoscopic endonasal approach to the sella turcica.

Endoscopic endonasal trans-sphenoidal surgery has become the gold standard for the surgical treatment of pituitary adenomas and many other pituitary ...

An Endoscopic Transcanal Transpromontorial Approach for Vestibular Schwannomas using a Computer-Based Three-Dimensional Imaging System

A 2D monocular endoscope has been used in transcanal transpromontory vestibular schwannoma surgery instead of craniotomy. However, the absence of depth perception is the limitation of this approach. With the loss of depth perception, the surgeon will be not able to perform delicate and particularly complicated surgery. A binocular endoscope has been developed to provide stereoscopic vision with better depth perception for complicated anatomic structures and has been applied in some endoscopic surgeries. However, the diameter of the endoscope is a limitation in the performance of transcanal otologic surgeries. A small diameter endoscope facilitates easier surgery in a restricted space. A computer-based 3D imaging system can obtain 3D images in real-time using a small monocular endoscope. In this study, to evaluate the feasibility of a computer-based 3D imaging system for endoscopic lateral skull base surgery, we applied this 3D imaging system in a transcanal transpromontorial approach in two patients with vestibular schwannomas. The surgical procedure was completed without complication in these two cases. There was no mortality, perioperative complications, nor notable postoperative complications. Using this computer-based 3D imaging system, a better depth perception and stereoscopic vision was observed compared to a conventional 2D endoscope. The improvement in depth perception offers superior management of the complicated surgical anatomy.

Here, we present a transcanal transpromontorial approach for vestibular schwannomas using a computer-based three-dimensional (3D) imaging system combined with a two-dimensional (2D) endoscope. This system provided stereoscopic vision, better depth perception and reduced visual fatigue. This 3D imaging system enabled the application of 3D vision technology in endoscopic lateral skull base surgery.

A 2D monocular endoscope has been used in transcanal transpromontory vestibular schwannoma surgery instead of craniotomy. However, the absence of depth ...

Role of Diffusion MRI Tractography in Endoscopic Endonasal Skull Base Surgery

Endoscopic endonasal surgery has gained a prominent role in the management of complex skull base tumors. It allows the resection of a large group of benign and malignant lesions through a natural anatomical extra-cranial pathway, represented by the nasal cavities, avoiding brain retraction and neurovascular manipulation. This is reflected by the patients' prompt clinical recovery and the low risk of permanent neurological sequelae, representing the main caveat of conventional skull base surgery. This surgery must be tailored to each specific case, considering its features and relationship with surrounding neural structures, mostly based on preoperative neuroimaging. Advanced MRI techniques, such as tractography, have been rarely adopted in skull base surgery due to technical issues: lengthy and complicated processes to generate reliable reconstructions for inclusion in the neuronavigation system. 
This paper aims to present the protocol implemented in the institution and highlights the synergistic collaboration and teamwork between neurosurgeons and the neuroimaging team (neurologists, neuroradiologists, neuropsychologists, physicists, and bioengineers) with the final goal of selecting the optimal treatment for each patient, improving the surgical results and pursuing the advancement of personalized medicine in this field.

We present a protocol to integrate diffusion MRI tractography in patient work-up to endoscopic endonasal surgery for a skull base tumor. The methods for adopting these neuroimaging studies in the pre- and intra-operative phases are described.

Endoscopic endonasal surgery has gained a prominent role in the management of complex skull base tumors. It allows the resection of a large group of ...

Neuronavigation and Laparoscopy Guided Ventriculoperitoneal Shunt Insertion for the Treatment of Hydrocephalus

Hydrocephalus is a common adult neurosurgical condition typically requiring treatment with a cerebrospinal fluid (CSF) shunt, of which the ventriculoperitoneal (VP) shunt is the most common type. Unfortunately, the failure rates of VP shunts are alarmingly high, with up to 50% of patients requiring revision surgery within 2 years. VP shunt failure may occur due to infection, or catheter mispositioning, migration, and occlusion. We undertook a joint neurosurgery and general surgery collaboration in a 7-year prospective non-randomized consecutive quality improvement cohort study to reduce the rates of ventriculoperitoneal (VP) shunt failures in 224 adult patients at a tertiary care institution. The initiative combined the use of electromagnetic stereotactic neuronavigation to guide the placement of the proximal catheter and laparoscopy to place the distal catheter under direct visualization. With laparoscopic assistance, the distal catheter was anchored through a small hole created in the falciform ligament and placed into the right retrohepatic space, free from the omentum, adhesions, or bowel that might obstruct the catheter tip. The surgeries were performed using a shunt infection prevention protocol to reduce the risk of shunt infections. Here, we present an intraoperative video of the surgical procedure. Compliance with shunt infection reduction strategies and the combined utilization of neuronavigation and laparoscopy techniques in adult VP shunt surgery resulted in a 44% reduction in the risk of overall shunt failure. The significant positive impact with regard to shunt-failure-free patient outcomes among patients who underwent VP shunt surgery using this strategy underscores the value associated with the use of these modern intraoperative techniques and cross-specialty collaboration during VP shunt surgery.

Patient outcomes of ventriculoperitoneal (VP) shunt surgery, the mainstay treatment for hydrocephalus in adults, are poor due to high shunt failure rates. We present intraoperative footage of VP shunt insertion using neuronavigation and laparoscopy guidance, with the goal to reduce the risks of proximal and distal shunt catheter failures, respectively.

Hydrocephalus is a common adult neurosurgical condition typically requiring treatment with a cerebrospinal fluid (CSF) shunt, of which the ...

An Efficient High-Speed Pneumatic Drill Craniectomy to Access the Porcine Brain

Accessing the Porcine Brain via High-Speed Pneumatic Drill Craniectomy

The use of pigs as an experimental animal model is especially relevant in neuroscience research, as the porcine and human central nervous systems (CNS) share many important functional and architectural properties. Consequently, pigs are expected to have an increasingly important role in future research on various neurological diseases. Here, a method to perform an anterior craniectomy through the porcine frontal bone is described. After a midline incision and subsequent exposure of the porcine frontal bone, anatomical landmarks are used to ensure the optimal location of the craniectomy. By careful and gradual thinning of the frontal bone with a rounded drill, a rectangular opening to the dura mater and underlying cerebral hemispheres is achieved. The presented method requires certain surgical materials, including a pneumatic high-speed drill, and some degree of surgical experience. Potential complications include unintended lesions of the dura mater or dorsal sagittal sinus. However, the method is simple, time-efficient, and offers a high degree of reproducibility for researchers. If performed correctly, the technique exposes a large portion of the unaffected pig brain for various neuromonitoring or analyses.

Author Spotlight: A Reproducible and Efficient Method for Accessing Porcine Brain via Craniectomy

This protocol describes performing a craniectomy using a high-speed pneumatic drill on a 3-month-old Danish Landrace pig. The access is made through the frontal bone and reveals the ventral dura mater and underlying cerebral hemispheres. This procedure allows for access to a large portion of the pig brain.

The use of pigs as an experimental animal model is especially relevant in neuroscience research, as the porcine and human central nervous systems (CNS) ...

Surgical Technique for Lumbar Spinal Catheter Insertion in Pigs Enabling Continuous Access to the Thecal Sac in a Terminal Setup

Pigs are increasingly used as a large animal model for pharmacologic CNS research due to the anatomical and physiological similarities between the porcine and human central nervous systems (CNS). However, accessing the cerebrospinal fluid (CSF) in larger pig breeds by conventional lumbar puncture techniques can be challenging due to an oblique orientation of the spinal spinous processes and a limited interlaminar space. Accordingly, an open surgical procedure for inserting a lumbar spinal catheter for continuous CSF sampling at the L4/L5 level in pigs is thoroughly described in this work. After positioning the pig and identifying the anatomical landmarks, a dorsal midline surgical incision is made to expose the spinous processes. By advancing the introducer needle, the spinal catheter is inserted inside the thecal sac of the spinal canal while leaving the bone structures of the spine intact. This method allows continuous infusion into or sampling from the porcine thecal sac with minimal bleeding or CSF leakage. The procedure is simple, time-efficient, and reproducible across different experimental setups, offering significant potential for various pre-clinical studies, including pharmacokinetic research, surgical training, and spinal cord injury models.

We present a technique for inserting a lumbar spinal catheter at the L4-L5 level in a 3-month-old Danish Landrace pig as part of a terminal research protocol, enabling continuous infusion or CSF sampling from the thecal sac.

Pigs are increasingly used as a large animal model for pharmacologic CNS research due to the anatomical and physiological similarities between the porcine ...