There is no funding source for this study.

The study protocol was approved by the institutional review board of Istanbul University Faculty of Medicine. Informed consent was obtained from patients for this study.
1. Preoperative procedures
NOTE: Preoperative evaluation is similar to any other medically intractable epilepsy patient. Routine scalp electroencephalography (EEG) monitoring and video-EEG monitoring, interictal and ictal single photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), neuropsychological test (NPT), ophthalmological assessment with perimetry, and endocrinological assessment should be completed.
<ol>
	<li>Under general endotracheal anesthesia, place the patient supine with the head flexed on a three-pronged Mayfield head clamp. 
	NOTE: The patient can be placed on gel-based modifications if younger than 18 months.</li>
	<li>Plan the incision on Kocher&#39;s point, which is 3 cm lateral to the midline and 1 cm anterior to the coronal suture. The coronal suture can be outlined by palpation. 
	NOTE: The entry point can be adjusted using the intraoperative ultrasonography (iUSG) system for an optimal trajectory to the HH interface and normal tissue interface. Optic or frameless electromagnetic neuronavigation systems are alternatives to iUSG for achieving proper trajectory.</li>
	<li>Set the iUSG system with a burr-hole probe before beginning the primary surgical procedure. Most of the cases of HHs have normal-sized ventricles. The ventricle size can be seen in preoperative MRI.</li>
	<li>Adjust the 30&#176; rigid endoscope system according to the surgeon&#39;s preferred position. The neuroendoscope has an outer diameter of 2.7 mm with two working channels. The sheath of the neuroendoscope has an outer diameter of 3.8 mm and a stylet.</li>
	<li>Set other instruments, such as a monopolar coagulation electrode, a fiberoptic light guide, and the endovision system.</li>
	<li>Disinfect the surgical site with swabs soaked in commercially available povidone-iodine solution at least 10x. Drape the periauricular region with sterile blankets.</li>
	<li>Adjust the white balance and camera clarity options. Any sterile white dressing and sterile written material can be used for the check.</li>
</ol>
2. Surgical technique
<ol>
	<li>Make an approximately 3 cm vertical skin incision on Kocher&#39;s point using a 20-number blade. After passing the skin, connective tissue, and galea, incise the periosteum. Place the automatic retractor covering the skin, subcutaneous tissue, and the periosteum to expose the bone. Enter the right ventricle since it is the nondominant hemisphere unless there is anatomical difficulty.</li>
	<li>Open a 14 mm diameter burr hole. The size is 14 mm due to using iUSG, which can only fit for its burr-hole probe.</li>
	<li>Expand the burr-hole medially or laterally according to the ultrasonographic image, visualizing the appropriate trajectory to the HH.</li>
	<li>Irrigate the field with isotonic saline for a clear visualization of the coronal section of the ventricles. Introduce the sheath with its stylet at the level of the foramen of Monro in coronal view.</li>
	<li>Remove the stylet from the sheath and then introduce the endoscope.</li>
	<li>Under direct visualization, advance the endoscope through the foramen of Monro. Visualize the HH protruding from the floor and the lateral wall of the third ventricle. Direct vision usually appreciates the limits of the protruding HH and the normal tissue.</li>
	<li>Coagulate the lesion by monopolar cautery introduced from the working channel. Remove the lesion with microforceps. Keep dissecting until the pial and arachnoid membrane are reached. Complete resection and disconnection can be confirmed by postoperative MRI.</li>
	<li>Achieve hemostasis by irrigation with isotonic saline solution or monopolar coagulation. Massive bleeding usually does not occur; in case of occurrence, it may necessitate leaving external ventricular drainage (EVD) or converting to open microscopic surgery.</li>
	<li>After hemostasis, complete the procedure by removing the endoscopic system. Suture the subcutaneous tissue with 3-0 Vicryl and the skin with 3-0 prolene.</li>
</ol>
3. Postoperative procedures and follow-up
<ol>
	<li>Begin oral intake at 6 h postoperatively. Mobilize the patients on the next day of the operation.</li>
	<li>Monitor the patient immediately after surgery for early complications, such as transient memory loss, weight gain, thalamic and hypothalamic infarction, diabetes insipidus, pituitary insufficiency, and visual disturbance. 
	NOTE: The endoscope can cause damage to the fornix, optic chiasm and tract, and hypothalamus. The monopolar cautery can cause similar destruction through the thermal effect.</li>
	<li>Monitor the patient for intake and output balance. Ask the patient and the relatives to write down every patient&#39;s fluid intake and calculate the urine output. If the patient has pituitary insufficiency, hydrocortisone replacement therapy should be applied.</li>
	<li>Continue antiepileptic drugs (AED) till adequate follow-up has been established. AED can be reduced according to seizure outcome status and control electroencephalograms (EEG).</li>
	<li>Upon discharge, follow up the patient in the 2nd week, 1st month, 3rd month and 6th month.</li>
</ol>

<ol>
	<li>Kerrigan, J. 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=Hypothalamic+hamartoma:+Neuropathology+and+epileptogenesis.">Hypothalamic hamartoma: Neuropathology and epileptogenesis.</a> Epilepsia. 58, 22-31 (2017).</li><li>Gascon, G. G., Lombroso, C. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epileptic+(Gelastic)+Laughter.">Epileptic (Gelastic) Laughter.</a> Epilepsia. 12, 63-76 (1971).</li><li>Berkovic, S. 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=Hypothalamic+hamartoma+and+seizures:+a+treatable+epileptic+encephalopathy.">Hypothalamic hamartoma and seizures: a treatable epileptic encephalopathy.</a> Epilepsia. 44 (7), 969-973 (2003).</li><li>Wait, S. D., Abla, A. A., Killory, B. D., Nakaji, P., Rekate, H. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surgical+approaches+to+hypothalamic+hamartomas.">Surgical approaches to hypothalamic hamartomas.</a> Neurosurg Focus. 30 (2), E2 (2011).</li><li>Choi, J. U., 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+disconnection+for+hypothalamic+hamartoma+with+intractable+seizure.+Report+of+four+cases.">Endoscopic disconnection for hypothalamic hamartoma with intractable seizure. Report of four cases.</a> J Neurosurg. 100, 506-511 (2004).</li><li>Shim, K. 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=Treatment+modality+for+intractable+epilepsy+in+hypothalamic+hamartomatous+lesions.">Treatment modality for intractable epilepsy in hypothalamic hamartomatous lesions.</a> Neurosurgery. 62 (4), 847-856 (2008).</li><li>Shim, K. W., Park, E. K., Kim, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoscopic+treatment+of+hypothalamic+hamartomas.">Endoscopic treatment of hypothalamic hamartomas.</a> J Korean Neurosurg Soc. 60 (3), 294-300 (2017).</li><li>Delalande, O., Fohlen, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Disconnecting+surgical+treatment+of+hypothalamic+hamartoma+in+children+and+adults+with+refractory+epilepsy+and+proposal+of+a+new+classification.">Disconnecting surgical treatment of hypothalamic hamartoma in children and adults with refractory epilepsy and proposal of a new classification.</a> Neurol Med Chir (Tokyo). 43 (2), 61-68 (2003).</li><li>Valdueza, 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=Hypothalamic+hamartomas:+with+special+reference+to+gelastic+epilepsy+and+surgery.">Hypothalamic hamartomas: with special reference to gelastic epilepsy and surgery.</a> Neurosurgery. 34 (6), 949-958 (1994).</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=Pure+endoscopic+management+of+epileptogenic+hypothalamic+hamartomas.">Pure endoscopic management of epileptogenic hypothalamic hamartomas.</a> Neurosurg Rev. 40 (4), 647-653 (2017).</li><li>Ng, Y. 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=Endoscopic+resection+of+hypothalamic+hamartomas+for+refractory+symptomatic+epilepsy.">Endoscopic resection of hypothalamic hamartomas for refractory symptomatic epilepsy.</a> Neurology. 70, 1543-1548 (2008).</li><li>Bourdillon, P., 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=Surgical+treatment+of+hypothalamic+hamartomas.">Surgical treatment of hypothalamic hamartomas.</a> Neurosurg Rev. 44 (2), 753-762 (2021).</li><li>Feiz-Erfan, I., 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=Surgical+strategies+for+approaching+hypothalamic+hamartomas+causing+gelastic+seizures+in+the+pediatric+population:+transventricular+compared+with+skull+base+approaches.">Surgical strategies for approaching hypothalamic hamartomas causing gelastic seizures in the pediatric population: transventricular compared with skull base approaches.</a> J Neurosurg. 103, 325-332 (2005).</li><li>Dorfm&#252;ller, G., Fohlen, M., Bulteau, C., Delalande, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surgical+disconnection+of+hypothalamic+hamartomas.">Surgical disconnection of hypothalamic hamartomas.</a> Neurochirurgie. 54, 315-319 (2008).</li><li>Ng, Y. 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=Endoscopic+resection+of+hypothalamic+hamartomas+for+refractory+symptomatic+epilepsy.">Endoscopic resection of hypothalamic hamartomas for refractory symptomatic epilepsy.</a> Neurology. 70 (17), 1543-1548 (2008).</li><li>Rosenfeld, J. V., Freeman, J. L., Harvey, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Operative+technique:+The+anterior+transcallosal+transseptal+interforniceal+approach+to+the+third+ventricle+and+resection+of+hypothalamic+hamartomas.">Operative technique: The anterior transcallosal transseptal interforniceal approach to the third ventricle and resection of hypothalamic hamartomas.</a> J Clin Neurosci. 11 (7), 738-744 (2004).</li><li>Rosenfeld, J. V., Feiz-Erfan, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypothalamic+hamartoma+treatment:+surgical+resection+with+the+transcallosal+approach.">Hypothalamic hamartoma treatment: surgical resection with the transcallosal approach.</a> Semin Pediatr Neurol. 14 (2), 88-98 (2007).</li><li>Ng, Y. 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=Transcallosal+resection+of+hypothalamic+hamartoma+for+intractable+epilepsy.">Transcallosal resection of hypothalamic hamartoma for intractable epilepsy.</a> Epilepsia. 47 (7), 1192-1202 (2006).</li><li>Castinetti, F., Brue, T., Morange, I., Carron, R., R&#233;gis, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gamma+Knife+radiosurgery+for+hypothalamic+hamartoma+preserves+endocrine+functions.">Gamma Knife radiosurgery for hypothalamic hamartoma preserves endocrine functions.</a> Epilepsia. 58, 72-76 (2017).</li><li>Akai, T., Okamoto, K., Iizuka, H., Kakinuma, H., Nojima, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Treatments+of+hamartoma+with+neuroendoscopic+surgery+and+stereotactic+radiosurgery:+a+case+report.">Treatments of hamartoma with neuroendoscopic surgery and stereotactic radiosurgery: a case report.</a> Minim Invasive Neurosurg. 45 (4), 235-239 (2002).</li><li>Abla, A. 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=Gamma+Knife+surgery+for+hypothalamic+hamartomas+and+epilepsy:+patient+selection+and+outcomes.">Gamma Knife surgery for hypothalamic hamartomas and epilepsy: patient selection and outcomes.</a> J Neurosurg. 113, 207-214 (2010).</li><li>Selch, M. 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=Linear+accelerator+stereotactic+radiosurgery+for+the+treatment+of+gelastic+seizures+due+to+hypothalamic+hamartoma.">Linear accelerator stereotactic radiosurgery for the treatment of gelastic seizures due to hypothalamic hamartoma.</a> Minim Invasive Neurosurg. 48 (5), 310-314 (2005).</li><li>Hoppe, C., Helmstaedter, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser+interstitial+thermotherapy+(LiTT)+in+pediatric+epilepsy+surgery.">Laser interstitial thermotherapy (LiTT) in pediatric epilepsy surgery.</a> Seizure. 77, 69-75 (2020).</li><li>Calisto, 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=Endoscopic+disconnection+of+hypothalamic+hamartomas:+safety+and+feasibility+of+robot-assisted,+thulium+laser-based+procedures.">Endoscopic disconnection of hypothalamic hamartomas: safety and feasibility of robot-assisted, thulium laser-based procedures.</a> J Neurosurg Pediatr. 14 (6), 563-572 (2014).</li><li>Curry, D. J., Raskin, J., Ali, I., Wilfong, A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MR-guided+laser+ablation+for+the+treatment+of+hypothalamic+hamartomas.">MR-guided laser ablation for the treatment of hypothalamic hamartomas.</a> Epilepsy Res. 142, 131-134 (2018).</li><li>Wei, P. H., 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=Stereoelectroencephalography-guided+radiofrequency+thermocoagulation+for+hypothalamic+hamartomas:+Preliminary+evidence.">Stereoelectroencephalography-guided radiofrequency thermocoagulation for hypothalamic hamartomas: Preliminary evidence.</a> World Neurosurg. 114, e1073-e1078 (2018).</li><li>Bourdillon, P., 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=Stereo+electroencephalography-guided+radiofrequency+thermocoagulation+(SEEG-guided+RF-TC)+in+drug-resistant+focal+epilepsy:+Results+from+a+10-year+experience.">Stereo electroencephalography-guided radiofrequency thermocoagulation (SEEG-guided RF-TC) in drug-resistant focal epilepsy: Results from a 10-year experience.</a> Epilepsia. 58 (1), 85-93 (2017).</li><li>Wethe, J. V., 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=Cognitive+functioning+before+and+after+surgical+resection+for+hypothalamic+hamartoma+and+epilepsy.">Cognitive functioning before and after surgical resection for hypothalamic hamartoma and epilepsy.</a> Neurology. 81 (12), 1044-1050 (2013).</li><li>Choi, J. U., Kim, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Treatment+modalities+for+intractable+epilepsy+in+hypothalamic+hamartoma.">Treatment modalities for intractable epilepsy in hypothalamic hamartoma.</a> Adv Tech Stand Neurosurg. 39, 117-130 (2012).</li></ol>

The authors report no conflict of interest concerning the materials or methods used in this study.

In 2003, Delalande classified HHs into four subtypes. Type 1 HHs are small peduncular lesions attached to the tuber cinereum, type 2 HHs are lesions protruding to the third ventricle, type 3 lesions are the combination of type 1 and type 2 HHs, and type 4 HHs are large lesions with a broad attachment to both mammillary bodies and hypothalamus and have an extension to the interpeduncular cistern8. Depending on the location of the HH, various open surgery approaches have been described. For HHs near the interpeduncular cistern, the pterional approach, and for lesions near the third ventricle, transventricular or transcallosal approaches are feasible. The complication risk increases if the lesion is attached to mammillary bodies and the tuber cinereum. Destruction of the mammillary bodies may cause neuropsychological effects, and the tuber cinereum may cause poor endocrinological outcomes12.
The pterional approach is a short and direct route to the suprasellar cistern; however, access to the third ventricle is limited, and the vicinity of the internal carotid artery and branches, optic nerve, and chiasm, third cranial nerve, and infundibulum makes surgical maneuvers more limited8,14. Due to these limitations, transventricular and transcallosal approaches are used for Delalande type 2 and 4 HHs15. However, reports showed an increased risk of memory impairment by this technique. The memory deficit is mainly attributed to forniceal injury during the transcallosal interforniceal approach and mammillary body destruction during the trans ventricular approach16,17.
Stereotactic radiosurgery by Gamma-knife is another treatment alternative for HHs. Despite the delayed action of the radiosurgery, promising results have been reported. The median number of seizures was reduced from 6.2 to 0.3. The median marginal dose was 17 Gy (13 to 26)19,20,21,22. Stereotactic laser interstitial thermotherapy (LITT) is another treatment option involving a laser probe&#39;s stereotactic placement. In the literature, it has been shown that, regardless of the HH size, stereotactic LITT reduced the morbidity compared to open surgery23,24,25. Recent studies have proposed stereoelectroencephalography (SEEG)-guided radiofrequency-thermocoagulation (RF-TC). It enables the simultaneous application of RF-TC during recording, thus providing more precise lesioning26,27.
In this technical note, the full-endoscopic approach to HHs is described. This technique is also as minimally invasive as the stereotactic approach. In addition, it does not require applying a stereotactic system and targeting by fusion with MRI. The ventricular puncture can be easily accomplished by the intraoperative USG system. It does not require preoperative preparation, and therefore, it is quick. Direct visualization of the HH is possible, and lesion resection is feasible despite laser ablation or thermocoagulation. Early seizure and endocrinological improvements are usually appreciated7,10,24. It is best suited for Delalande type 2 HHs10. Furthermore, Choi et al. described the importance of disconnection surgery in treating HHs. They showed that most intraventricular and other types of HHs are excellent candidates for endoscopic surgery. They revealed that 90% of patients had more than 50% seizure control after surgery. Despite the resected volume, disconnection is considered to be more critical. Therefore, even for larger HHs, disconnection surgery can be performed for selected cases5,28,29. However, despite its advantages, the full-endoscopic technique has limitations. It is usually not feasible for lesions that extend to the interpeduncular cistern. It bears the same risk for lesions attached to mammillary bodies and tuber cinereum11. In the postoperative period, early mobilization and return to work are possible.
In conclusion, surgical techniques should be decided according to HH&#39;s location and adjusted for each patient. The full-endoscopic resection of HH is a safe and effective approach, especially in lesions extending to the third ventricle. Disconnection should be considered in each surgery and is more important than the resection rate. Seizure and endocrinological outcomes are similar to other techniques. It is a minimally invasive technique that enables a short hospital stay and early gain of functional status.

Hypothalamic hamartomas (HHs) are non-neoplastic, heterotrophic tissues that contain neuronal and glial tissue in an abnormal distribution. Incidence rates of HHs are 1 in 50,000-1,000,000 people with male predominance1. HHs present different clinical symptoms, such as precocious puberty, cognitive impairment, behavioral changes, and various types of seizures, most characteristically, gelastic seizures. Mostly gelastic seizures, as well as other seizure types, are extremely refractory to antiepileptic drugs (AEDs)2,3.
Based on their morphology and relation to the hypothalamus, there are several classifications for HHs. The symptoms and the severity depend mainly on the size, location, attachment type, and degree of hypothalamic displacement. Seizures and behavioral, cognitive, and hormonal problems mostly originate from sessile HHs. Pedunculated HHs mainly cause precocious puberty4,5,6.
Seizures can be controlled surgically either by resection or disconnection of the lesion. Most favorable outcomes were obtained from near-total or total resections4. The main goal is to prevent the spreading of the epileptic burst and thus stop secondary generalized seizures. Open surgery, either pterional, transcallosal, or transventricular approach, leads to good surgical outcomes; however, the complication rate is high, up to 30%. Laser and radiofrequency thermocoagulation-based disconnection surgeries, stereotactic radiosurgery, and focused ultrasound are also described as alternatives to open surgery. The treatment approach should be selected individually since the hypothalamic area, and close structures are critical5,6,7.
The possibility that an endoscopic approach could achieve HH resection was first described in 20038. Other authors have also shown the feasibility of endoscopic resection and disconnection surgeries for HH. These studies led us to believe that, especially in sessile intrahypothalamic HHs, a full-endoscopic approach is feasible7,9,10,11. Surgical indications are mainly medically intractable gelastic seizures, neurobehavioral deterioration, and intractable endocrinopathy. Potential risk factors for surgery are mainly memory loss, endocrinopathy, behavioral and cognitive problems, and vision loss. With recent technological advancements in neuroendoscopy and surgical instruments, this study aimed to describe our technique of full-endoscopic approach for HH resection3,12,13.
CASE PRESENTATION: 
A 15-year-old boy was born at term by normal vaginal delivery. The patient had first seizures 7 years ago. Perinatal history was unremarkable. First seizures were characterized by gelastic seizures; however, after 2 years, the seizures changed character, becoming tonic type. The seizure frequency was 9-10 times per day. Neurological examination revealed moderate mental retardation and no neurological deficit. From the beginning of the seizures, the patient was administered carbamazepine, valproic acid, phenobarbital, lamotrigine, levetiracetam, and clobazam in different combinations. But there was no improvement in his condition. Magnetic resonance imaging (MRI) revealed a hamartoma of the right hypothalamus. A routine scalp electroencephalography (EEG) showed active epileptogenic focus in the right frontocentral and temporal regions. During video-EEG, 10 seizures were recorded. The electrographic discharge showed a right-sided origin. Ictal and interictal single-photon emission computed tomography (SPECT) and positron emission tomography (PET) were noncontributory. Neuropsychological tests (NPT) were not performed, as the patient was not cooperative. The patient did not have endocrinological issues such as precocious puberty, and all hormonal parameters were within normal range. Since the patient had medically intractable seizures and moderate mental retardation, surgical resection of the HH was decided.
The patient did not have any complications after surgery, nor did he experience diabetes insipidus (DI) or any other endocrinopathies. The ophthalmological exam was normal, and there was no central hyperphagia or fever. The patient was discharged on postoperative Day 5. In the 25th month after surgery, he was followed up seizure-free, Engel class 1. A control MRI 2 years postoperatively showed no recurrence of the HH. The patient and his relatives stated that the patient had a better educational level and cognition; however, testing regarding neurocognition was not applied.

<table><tbody><tr><td>Burr-hole probe of intraoperative ultrasound system</td><td>Hitachi</td><td>UST-52114P</td><td>Aloka Linear UST-52114P, Frequency Range: 8 &amp;ndash; 3 MH, Scan Angle: 90&amp;deg; FOV</td></tr><tr><td>Fiberoptic light guide</td><td>RiwoSpine</td><td>806635231</td><td>80663523 fiber light cable &amp;Oslash; 3.5 mm, TL 2.3 m,&lt;br/&gt; 8095.09 adaptor endoscope side,&lt;br/&gt; 8095.07 adaptor projector side</td></tr><tr><td>Intraoperative Ultrasound system</td><td>Hitachi</td><td></td><td>Hitachi Arietta 70, Tokyo, Japan</td></tr><tr><td>Microforceps</td><td>RiwoSpine</td><td>89240.3023</td><td></td></tr><tr><td>Monopolar-coagulating electrode</td><td>RiwoSpine</td><td>8922095000</td><td></td></tr><tr><td>Rigid neuroendoscope</td><td>Karl Storz</td><td>8921092051</td><td>30&amp;deg; Hopkins pediatric telescope, outside diameter 2.7 mm</td></tr><tr><td>Sheath for the telescope</td><td>Karl Storz</td><td>892209510</td><td>3.8 mm outside diameter with two working channels</td></tr></tbody></table>

full-endoscopic surgery for hypothalamic hamartoma resection

Hypothalamic hamartomas (HH) are rare developmental anomalies of the inferior hypothalamus that often cause refractory epilepsy, including gelastic seizures. Surgical resection is an effective method to treat drug-resistant epilepsy and endocrinopathy in a suitable patient group. Open surgery, endoscopic surgery, ablative procedures, and stereotactic radiosurgery can be utilized. In this study, we aimed to describe the full-endoscopic approach for HH resection. The technique involves the use of an intraoperative ultrasonography (USG) system, a 30&#176; rigid endoscope system that has an outside diameter of 2.7 mm with two working channels, a stylet that has an outer diameter of 3.8 mm, a monopolar coagulation electrode, a fiberoptic light guide, and the endovision system. Microforceps and monopolar electrocautery are the two main surgical instruments for HH removal. The protocol is easy to apply after a particular learning curve has been passed and shorter than open surgical approaches. It leads to less blood loss. Full-endoscopic surgery for HH is a minimally invasive technique that can be applied safely and effectively with good seizure and endocrinological outcomes. It provides low surgical site pain and early mobilization.

An example of a patient treated by a full-endoscopic approach for HH resection has been presented. The preoperative MRI, intraoperative endoscopic view, and postoperative MRI have been shown in Figure 1, Figure 2, and Figure 3. There was minimal blood loss during the procedure, so it could not be measured. The procedure is short for a surgeon experienced in neuroendoscopy. For the represented case, the operation duration was 52 min. The method requires only a small incision, quick postoperative recovery, and early return to work. The patient is usually discharged on the postoperative day 1 if no complications are encountered. Because it is a resection and disconnection surgery, good seizure outcomes are accomplished in the early postoperative period.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/64705/64705fig01.jpg" /> 
Figure 1: Preoperative images of lesion. Preoperative T2 (A) axial, (B) sagittal, (C) coronal, (D) T2 FLAIR axial, and (E) sagittal images show an 8 x 11 x 14 mm lesion located at the inferior third ventricle protruding from the right hypothalamic region. (F) The lesion does not enhance with gadolinium administration. <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/64705/64705fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/64705/64705fig02.jpg" /> 
Figure 2: Endoscopic intraoperative view. (A, B) The HH bulging to the third ventricle from the right side is seen. (C) Monopolar cautery and microforceps are used to dissect and disconnect HH from the hypothalamic body. (D) The resection cavity is visualized at the end of the procedure. Abbreviations: A = Anterior, P = Posterior, L = Left, R = Right, HH = Hypothalamic hamartoma, MF = Microforceps, RC = Resection cavity. <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/64705/64705fig02large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/64705/64705fig03.jpg" /> 
Figure 3: Postoperative images of lesion. Postoperative T2 (A) axial, (B) T2 FLAIR sagittal, and (C) coronal images show total resection and disconnection of the HH. <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/64705/64705fig03large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

Read this Scientific Article Protocol about Full-Endoscopic Surgery for Hypothalamic Hamartoma Resection at JoVE.com

Full-Endoscopic Surgery for Hypothalamic Hamartoma Resection

Hypothalamic hamartomas are rare, non-neoplastic congenital malformations mainly arising from the inferior hypothalamus or tuber cinereum. Surgical treatment is one of the most effective options, and the surgical approach must be precisely determined for each patient. Here, we describe the full-endoscopic technique for resecting hypothalamic hamartomas.

Hypothalamic hamartomas (HH) are rare developmental anomalies of the inferior hypothalamus that often cause refractory epilepsy, including gelastic ...

full-endoscopic-surgery-for-hypothalamic-hamartoma-resection

Universidad San Sebastian

Research

JoVE Journal

Neuroscience

252 Views.  Istanbul University. Hypothalamic hamartomas are rare, non-neoplastic congenital malformations mainly arising from the inferior hypothalamus or tuber cinereum. Surgical treatment is one of the most effective options, and the surgical approach must be precisely determined for each patient. Here, we describe the full-endoscopic technique for resecting hypothalamic hamartomas.

Video: Full-Endoscopic Surgery for Hypothalamic Hamartoma Resection

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 ...

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 ...

Low-Cost Single-Port (LoCoSP) Device for a Transcervical Approach in Minimally Invasive Transhiatal Esophagectomy

Esophagectomy remains the preferred option to achieve curative treatment in advanced esophageal cancer, but the choice of surgical approach remains controversial. A transthoracic approach may improve lymph node dissection, but it has considerable morbidity and respiratory complications. Transhiatal access has been demonstrated as an efficient means of minimizing post-operative complications. Minimally invasive transhiatal esophagectomy may reduce operative trauma and morbidity as well as enhance postoperative recovery with no compromise in cancer recurrence or survival. Nevertheless, it has a technical limitation in terms of cervical esophagus dissection. Thus, a low-cost single-port device was developed to complete upper mediastinal dissection by a transcervical approach during minimally invasive transhiatal esophagectomy. This device uses a nasogastric tube, a number-eight sterile glove, a sterile sponge, and 3 permanent 5-mm trocars. The step-by-step process of transhiatal esophagectomy and the development of this device are described. This technique allows for the dissection of the upper mediastinum, as well as the esophagus over the aortic arch and behind the superior portion of the trachea. The harvesting of lymph nodes along the left recurrent laryngeal nerve and paratracheals was improved.

Low-Cost Single-Port LoCoSP Device for a Transcervical Approach in Minimally Invasive Transhiatal Esophagectomy

Here, we describe a step-by-step description of transhiatal esophagectomy and the development of a low-cost single-port device for a transcervical approach in a minimally invasive transhiatal esophagectomy.

Esophagectomy remains the preferred option to achieve curative treatment in advanced esophageal cancer, but the choice of surgical approach remains ...

Medicine

Endoscopic Cholesteatoma Surgery

Implementation of endoscopes in cholesteatoma surgery resulted in considerable changes in the management of cholesteatoma in the last two decades. Compared to the microscopic approach with an excellent but straight-line view and limited illumination, the introduction of endoscopes provides a wide-angled panoramic view. Moreover, angled lenses allow the surgeon to visualize the middle ear and its hidden recesses through a transcanal, minimally-invasive approach. The endoscope enables the surgeon to remove limited cholesteatoma of the middle ear and its recesses using an exclusive endoscopic technique by taking advantage of these benefits. This reduces the rate of residual disease and sparing external incisions and excessive temporal bone drilling as in a transmastoid approach. Since transcanal endoscopic access is mainly a one-handed technique, it implies the need for specific procedures and technical refinements. This article describes a step-by-step guide as a surgical manual for endoscopic removal of epitympanic cholesteatoma. Different techniques for cholesteatoma dissection and bone removal for epitympanectomy, including curettage and powered instruments such as drills and ultrasonic devices with their outcomes, are discussed. This may offer ear surgeons insight into technical refinements and the latest technological developments and open the horizon for different techniques.

The present protocol describes a step-by-step guide for the complete endoscopic removal of epitympanic cholesteatoma with different techniques for cholesteatoma dissection and bone removal for epitympanectomy.

Implementation of endoscopes in cholesteatoma surgery resulted in considerable changes in the management of cholesteatoma in the last two decades. ...

Full Endoscopic Transforaminal Thoracic Discectomy Operative Technique

Thoracic disc herniations are a degenerative pathology of the thoracic spine wherein a portion of nucleus pulposis herniates into the epidural space, potentially causing spinal cord or nerve root compression. Traditional surgical treatment for patients with thoracic disc herniations requires relatively invasive anterior or posterolateral approaches that involve extensive muscular dissection and removal of bone in order to access and remove the disc herniation without causing undue compression of the spinal cord. Full endoscopic thoracic discectomy is a minimally invasive technique which allows for the resection of thoracic disc herniations through a small (1 cm) incision, minimizing collateral tissue trauma and obviating the need for the extensive muscle dissection and bony removal required for traditional surgical approaches. In this article, we describe in detail the operative technique for full endoscopic thoracic discectomy and discuss the pearls and pitfalls of the technique. We also provide a review of the outcomes and complications as seen in the literature.

This protocol demonstrates the surgical technique for full endoscopic transforaminal resection of thoracic disc herniations.

Thoracic disc herniations are a degenerative pathology of the thoracic spine wherein a portion of nucleus pulposis herniates into the epidural space, ...

Full-Endoscopic Interlaminar Approach for Decompression of Lateral Recess Stenosis

For lateral recess stenosis, extensive decompression with laminectomy is still performed in most centers. However, tissue-sparing surgeries are becoming more common. Full-endoscopic spinal surgeries have the advantages of being less invasive and offering a shorter recovery time. Here, we describe the technique of the full-endoscopic interlaminar approach for the decompression of lateral recess stenosis. The full-endoscopic interlaminar approach for the lateral recess stenosis procedure took approximately 51 min (range of 39-66 min). Blood loss could not be measured due to continuous irrigation. However, no drainage was required. There were no dura mater injuries reported in our institution. Furthermore, there were no injuries to the nerves, no cauda equine syndrome, and no hematoma formation. The patients were mobilized on the same day as surgery and discharged the next day. Therefore, the full-endoscopic technique for lateral recess stenosis decompression is a feasible procedure that lowers the operational time, complications, traumatization, and rehabilitation duration.

Technical advances and increased experience in full-endoscopic spinal surgeries enable these procedures to be performed with minimal incision, muscle retraction, and bone removal.

For lateral recess stenosis, extensive decompression with laminectomy is still performed in most centers. However, tissue-sparing surgeries are becoming ...

Reoperative Hiatal Hernia Repair

Technical Considerations and Approach to Redo Foregut Surgery

Foregut surgical techniques have advanced significantly over the years and have become increasingly popular. However, new challenges and technical considerations have arisen when dealing with reoperation for complications or surgical failure. This study focuses on the technical considerations and approach when dealing with reoperative foregut surgery, particularly redo&#160;hiatal hernia repair. We describe our approach starting from the preoperative workup to the procedural steps of the surgery. The present study describes the main steps for robotic reoperative hiatal hernia repair in a patient who had previously undergone laparoscopic hiatal hernia repair with Nissen fundoplication but did not present a recurrence of reflux and dysphagia symptoms. The patient is positioned supine with arms out and a footboard for steep Trendelenburg. We place six trocars, including an assistant port and a liver retractor port,&#160;to facilitate visualization and retraction. After docking the robot, we use a combination of electrocautery and sharp dissection&#160;to free the hernia sac and reduce the hiatal hernia. The previous fundoplication is then taken down carefully and the esophagus is mobilized through a transhiatal approach with a combination of blunt and sharp dissection until at least 3 cm of intra-abdominal esophageal length is achieved, after which a leak test is performed. We then perform a crural repair to reapproximate the hiatus with two posterior stitches and one anterior stitch. Lastly, a redo Nissen fundoplication is performed over a bougie, and endoscopy is used to confirm a loose stack-of-coin appearance. By emphasizing the crucial steps of redo hiatal hernia repair, including preoperative evaluation, our goal is to provide an approach for the foregut surgeon to maximize patient outcomes.

Author Spotlight: Recent Advancements in Reoperative Foregut Surgery

Redo foregut surgery is associated with increased patient morbidity and presents a technical challenge for the surgeon. We describe our approach and considerations when performing a redo hiatal hernia repair to provide a guide for other surgeons and improve patient outcomes.

Foregut surgical techniques have advanced significantly over the years and have become increasingly popular. However, new challenges and technical ...

Improving Outcomes in Anteromesial Temporal Lobe Resections - A Demonstration of Resecting the Temporal Piriform Cortex

Anteromesial temporal lobe resection (ATLR) is a useful treatment option for drug-resistant mesial temporal lobe epilepsy (DRmTLE). Growing evidence suggests the piriform cortex plays a crucial role in the generation and propagation of seizures in DRmTLE - and that the resection of the temporal portion of the piriform cortex is associated with significantly improved rates of seizure freedom. 
Here, we present the resection of the temporal portion of the piriform cortex in ATLR, using high-resolution preoperative probabilistic tractography algorithms and fused anatomical masks of the structures of interest into the intraoperative neuronavigation and microscope head-up display (HUD). 
All patients undergoing comprehensive preoperative assessment and investigations for DRmTLE provided informed, written consent to record an intraoperative video of the procedure. Patients were identified by an expert multidisciplinary team of epileptologists, epilepsy neurosurgeons, neuropsychologists, neuropsychiatrists, and electrophysiologists at a large epilepsy surgery center. The preoperative imaging pipeline included the delineation of critical structures. This included the temporal piriform cortex, and high-resolution probabilistic tractography for essential tracts at risk (e.g., optic radiation and inferior fronto-occipital fasciculus). These were co-registered to the preoperative volumetric neuronavigation scan and uploaded to the intra-operative neuronavigation system. 
Presented here is a step-by-step procedure of ATLR, including the resection of the temporal portion of the piriform cortex. The protocol combines Advanced structural and diffusion MR imaging and intraoperative visual aids to integrate anatomical masks of critical grey matter structures and white matter tracts into the surgical workflow in the operating room.

Here, we demonstrate an approach to intraoperative neurosurgical guidance in anteromesial temporal lobe resections, specifically highlighting the use of tractography and anatomical masks to aid safe resection of the temporal portion of the piriform cortex - an area increasingly regarded as a crucial surgical target in drug-resistant mesial temporal lobe epilepsy.

Anteromesial temporal lobe resection (ATLR) is a useful treatment option for drug-resistant mesial temporal lobe epilepsy (DRmTLE). Growing evidence ...

Transumbilical Endoscopic Resection of Intra-abdominal Mesenchymal Tumor

Gastrointestinal stromal tumors (GISTs) typically occur in the stomach and proximal small intestine but can also be found in any other part of the digestive tract, including the abdominal cavity, albeit rarely. In the present case, the tumor was resected endoscopically through the anterior gastric wall. Computed tomography (CT) scan and gastroscopy of a 60-year-old woman revealed submucosal lesions in the gastric body. The possibility of a stromal tumor was considered more likely. The endoscopic surgery was performed under endotracheal anesthesia. After a solution had been injected at the lesion site in the stomach, the entire gastric wall was dissected to expose the tumor. As the lesion was in the abdominal cavity and its base was attached to the abdominal wall, it was accessed using a sterilized PCF colonoscope. A sodium chloride injection was administered at the base. The tumor was then peeled along its boundaries using the hooking and excision knife combined with the precutting knife. Subsequently, the tumor was pulled into the stomach through the incision made in the stomach and then extracted externally through the upper digestive tract using the ERCP spiral mesh basket. After confirming the absence of bleeding at the incision site, the endoscope was returned to the stomach, and the stomach opening was closed using purse-string sutures. The patient recovered satisfactorily following the surgery and was discharged on day 4. Histological examination revealed a low-risk stromal tumor (spindle cell type, &lt;5 mitosis/50 high-power fields [HPF]). Immunohistochemistry revealed positive staining for CD34 and CD117, negative staining for SMA, positive staining for DOG1, and negative staining for S100. Additionally, the expression of ki67 was 3%.

The article introduces the surgical method, endoscopic submucosal dissection (ESD) for the complete removal of intra-abdominal tumors using natural orifice transluminal endoscopic surgery (NOTES). The procedure reaches the stomach by using gastrointestinal endoscopy, creating a controlled perforation for tumor removal, followed by stitching the gastric incision.

Gastrointestinal stromal tumors (GISTs) typically occur in the stomach and proximal small intestine but can also be found in any other part of the ...

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

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.

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