Authors' reply to: Letter to editor regarding "The endoscopic diving technique in endonasal transsphenoidal surgery: how I do it"

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Endoscopic Endonasal Odontoidectomy Preserving Atlantoaxial Stability: a Pediatric Case

Abstract Objectives We illustrate endoscopic endonasal odontoidectomy for the Chiari-I malformation respecting craniovertebral junction (CVJ) stability. Design Case report of a 12-year-old girl affected by the Chiari-I malformation. Magnetic resonance imaging (MRI) showed tonsillar herniation, basilar invagination, and dental retroversion, causing angulation and compression of the bulbomedullary junction. Patient underwent endoscopic third ventriculostomy (ETV) with reduction of ventricular size and resolution of gait disturbances, but she complained the Valsalva-induced headaches, hiccup, and dysesthesias in the lower limbs. Endoscopic endonasal odontoidectomy was chosen to decompress the cervicomedullary junction. Setting The research was conducted at University Hospital "Ospedale di Circolo," Department of Neurosurgery at Varese in Italy. Participants Patients were from neurosurgical and ENT (ear, nose, and throat) skull base team. Main Outcome Measures A bilateral paraseptal approach was performed, using a four-hand technique. After resection of posterior edge of the nasal septum, the choana is entered and a rhinopharynx muscle–mucosal flap is dissected subperiosteal and transposed in oral cavity. The CVJ is exposed and, using neuronavigation and neuromonitoring, odontoidectomy is fulfilled until dura is reached, preserving the anterior arch of C1. Reconstruction is obtained suturing the flap previously harvested. Results Postoperative course was unremarkable and the patient experienced improvement of symptoms. Postoperative MRI documented the appearance of tight cerebrospinal fluid (CSF) film anterior to bulbomedullary junction and in retrotonsillar spaces, opening of the bulbomedullary angle, and slight tonsils reduction. No CVJ instability was occurred with any need of posterior fixation. Conclusion Endoscopic endonasal odontoidectomy is a feasible approach for CVJ malformation. In this case, bulbar decompression was achieved preserving CVJ stability and avoiding posterior fixation.The link to the video can be found at: https://youtu.be/VIobocHfCuc

Quantitative Anatomic Comparison of Endoscopic Transnasal and Microsurgical Transcranial Approaches to the Anterior Cranial Fossa

BACKGROUND: Several microsurgical transcranial approaches (MTAs) and endoscopic transnasal approaches (EEAs) to the anterior cranial fossa (ACF) have been described. OBJECTIVE: To provide a preclinical, quantitative, anatomic, comparative analysis of surgical approaches to the ACF. METHODS: Five alcohol-fixed specimens underwent high-resolution computed tomography. The following approaches were performed on each specimen: EEAs (transcribriform, transtuberculum, and transplanum), anterior MTAs (transfrontal sinus interhemispheric, frontobasal interhemispheric, and subfrontal with unilateral and bilateral frontal craniotomy), and anterolateral MTAs (supraorbital, minipterional, pterional, and frontotemporal orbitozygomatic approach). An optic neuronavigation system and dedicated software (ApproachViewer, part of GTx-Eyes II-UHN) were used to quantify the working volume of each approach and extrapolate the exposure of different ACF regions. Mixed linear models with random intercepts were used for statistical analyses. RESULTS: EEAs offer a large and direct route to the midline region of ACF, whose most anterior structures (ie, crista galli, cribriform plate, and ethmoidal roof) are also well exposed by anterior MTAs, whereas deeper ones (ie, planum sphenoidale and tuberculum sellae) are also well exposed by anterolateral MTAs. The orbital roof region is exposed by both anterolateral and lateral MTAs. The posterolateral region (ie, sphenoid wing and optic canal) is well exposed by anterolateral MTAs. CONCLUSION: Anterior and anterolateral MTAs play a pivotal role in the exposure of most anterior and posterolateral ACF regions, respectively, whereas midline regions are well exposed by EEAs. Furthermore, certain anterolateral approaches may be most useful when involvement of the optic canal and nerves involvement are suspected

The endoscopic diving technique in endonasal transsphenoidal surgery: how I do it

The endoscopic diving technique (EDT) is a procedure utilized in endonasal endoscopy, which consists of irrigating the surgical cavity during tumor removal, with a continuous flow of pressurized saline solution.Background: The endoscopic diving technique (EDT) is a procedure utilized in endonasal endoscopy, which consists of irrigating the surgical cavity during tumor removal, with a continuous flow of pressurized saline solution. Methods: The authors provide a detailed step-by-step description of the technique, shedding light on surgical tips and pitfalls. Advantages, disadvantages, and the most useful application of the technique are clarified and showed with a high-quality endoscopic video. Conclusion: EDT represents an effective and safe procedure. It allows a wide exploration of the surgical cavity, providing tumor hydro-dissection, assisting in bleeding control, and optimizing the efficacy of endoscopic transsphenoidal surgery

An Uncommon Case of Neuroenteric Cyst Located at the Lateral Cerebellomedullary Cistern

We present the case of a 42-year-old woman with a 5-week history of headache, progressive dysphagia, dysphonia, and hoarseness. A brain magnetic resonance imaging revealed an extra-axial cyst of the left lateral cerebellomedullary cistern. The subsequent histopathologic examination diagnosed a neuroenteric cyst. This case sheds light on the pivotal role of histologic identification of neuroenteric cyst, which could be crucial for further diagnostic investigations, especially in pediatric patients

Transsphenoidal surgery for pituitary adenomas in pediatric patients: a multicentric retrospective study

Introduction: Pediatric pituitary adenomas are rare lesions. Incidence is reported between 1 and 10% of all childhood brain tumors and between 3 and 6% of all surgically treated adenomas. Although pituitary adenomas present with symptoms of hormone hypersecretion or neurological disruptions secondary to mass effect, they are almost constantly benign. Characteristics of patients may vary in different studies according to age, gender, size of adenoma, hormonal activity, and recurrence rates. Methods: Data on consecutive pediatric patients who were operated for pituitary adenoma with endoscopic endonasal transsphenoidal surgery (EETS) and transsphenoidal microsurgery (TMS) in the Department of Neurosurgery, Istanbul University Cerrahpasa Medical Faculty, Istanbul, Turkey, in the Neurosurgical Unit of the San Matteo Hospital, Pavia, Italy, and in the Division of Neurological Surgery Department of Biotechnology and Life Sciences, University of Insubria-Varese, ASST Sette Laghi, Ospedale di Circolo e Fondazione Macchi, Varese, Italy, between July 1997 and May 2018, were analyzed. Twenty-seven patients (11 males and 16 females), who were 18\ua0years old or younger at the time of surgery, were included in the study. Medical records, images, and operative notes of patients were retrospectively reviewed. Results: There were 16 females (59.3%) and 11 males (40.7%). Mean age was 15.3\ua0\ub1 3.3 (4\u201318). Thirty-two surgical procedures were performed for 27 patients (6 children required second operation). Thirteen patients (48.14%) had Cushing\u2019s disease (CD), 5 patients (18.5%) had growth hormone (GH)-secreting adenoma, 5 patients (18.5%) had prolactinoma, and 4 patients (14.8%) had non-functional adenoma. Twenty-two patients (81.4%) met remission criteria, and 5 patients (18.5%) did not meet remission criteria. Four patients met remission criteria after the second operation. Conclusion: Transsphenoidal approach affords effective release of mass effect and not only restoration but also perpetuation of normal endocrine functions in the majority of pediatric pituitary adenoma patients. Satisfactory results are reported with both EETS and TMS in the literature. Despite the technical difficulties in pediatric age, transsphenoidal resection of adenoma is still the mainstay treatment that provides cure in pediatric patients

Endoscopic endonasal pituitary hemi-rotation approach to the upper clivus: anatomical study and clinical report

8nononenonePierlorenzo Veiceschi; Albert Daniele Arosio; Edoardo Agosti; Gianluca Agresta; Fabio Pozzi; Sergio Balbi; Paolo Castelnuovo; Davide LocatelliVeiceschi, PIERLORENZO MARIA; Daniele Arosio, Albert; Agosti, Edoardo; Agresta, Gianluca; Pozzi, Fabio; Balbi, Sergio; Castelnuovo, PAOLO GIOCONDO MARIA; Locatelli, David

The Helmet-Visor Pericranial Flap as a Viable Option for Anterior Cranial Base Reconstruction in Complex Oncologic Cases

Objective: To describe a novel bilaterally pedicled pericranial flap for anterior cranial base reconstruction after removal of complex frontobasal cancers extending to the frontal region, thus precluding the use of standard reconstructive techniques. Methods: In selected oncologic cranial base surgeries, the use of the standard galea frontalis pericranial flap for reconstructive purposes may be precluded by tumor infiltration. In such cases, dura mater reconstruction and exclusion of frontal sinuses from the intracranial space can be performed using a large superficial temporal artery bilaterally pedicled pericranial flap obtained from both temporoparietal regions. Surgical technique, indication, contraindication, complications, and degree of resection are recorded to evaluate the efficacy of this surgical method. Results: A 48-year-old man affected by a recurrence of frontobasal squamous cell carcinoma was surgically treated by combined transcranial and endoscopic endonasal resection. A large pericranial flap pedicled bilaterally on the parietal branches of the superficial temporal artery was obtained, transposed anteriorly, carefully watertight sutured to the dural defect, and used to exclude cranialized frontal sinuses as well. The reconstruction was successful, and the patient was discharged home on the tenth postoperative day without any complications and/or development of cerebrospinal fluid leak. Contrast-enhanced magnetic resonance imaging 3 months after surgery was clear from disease with consolidated surgical outcomes. Conclusions: This novel pericranial flap seems to be easily obtained and effective for anterior cranial base reconstruction when the use of a traditional galea frontalis flap is precluded for oncologic reasons and there are concerns for the possible development of contaminations and cerebrospinal fluid leaks

Symptomatic ecchordosis physaliphora of the upper clivus: an exceedingly rare entity

Objective This paper highlights the management of 5 patients affected by symptomatic ecchordosis physaliphora (EP), treated via endoscopic endonasal transsphenoidal-transclival approach and contextual multilayer skull base reconstruction. A detailed analysis of each case is provided, along with the review of the current body of literature. Methods A retrospective review of patients treated by means of endoscopic endonasal approach for EP from 2010 to 2020 in the Otolaryngology and Neurosurgery Departments of a tertiary-care referral center for endoscopic skull base surgery was analyzed. Only adult patients with a definitive histopathological and immunohistochemical diagnosis of EP were included in the study. A systematic literature review according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed for EP. Results Five cases of EP were retrieved and included in the study. Four patients presented with CSF leakage: in two cases after minor head trauma, in one case with associated bacterial meningitis, and in one case as only referred symptom. One patient complained diplopia due to VI cranial nerve palsy. No complications or recurrences of the disease were observed after a median follow-up of 37.2 months (range, 18-72 months). A total of 27 studies were identified with the systematic literature review, encompassing 30 patients affected by symptomatic EP who were addressed to surgical treatment. Twenty-five patients underwent complete surgical removal of the EP, while in 5 cases, only subtotal resection was performed. Conclusions EP might result in a "locus minoris resistentiae" of the skull base, predisposing, in rare cases, to CSF leakage and meningitis, spontaneously or after minor trauma. In cases of symptomatic EP, endoscopic endonasal transsphenoidal-transclival approach represents a safe and effective technique for both EP resection and contextual skull base reconstruction