Anterior inferior petrosectomy: defining the role of endonasal endoscopic techniques for petrous apex approaches

Object Historically, surgery to the petrous apex has been addressed via craniotomy and open microscopic anterior petrosectomy (OAP). However, with the popularization of endoscopic approaches, the petrous apex can further be approached endonasally by way of an endoscopic endonasal anterior petrosectomy (EAP). Endonasal anterior petrosectomy is a relatively new procedure and has not been compared anatomically with OAP. The authors hypothesized that the EAP and OAP techniques approach different portions of the petrous apex and therefore may have different applications. Methods Four cadaveric heads were used. An OAP was performed on one side and an EAP was performed on the contralateral side; the limits of bony resection were defined. The extent of bony resection was then evaluated using predissection and postdissection thin-slice CT scans. The comparative resection was then reconstructed using 3D modeling on Brainlab workstations. Results The average resection volumes for EAP and OAP were 0.297 cm3 and 0.649 cm3, respectively, representing a comparative percentage of 46% (EAP/OAP). An EAP and OAP achieved resection of 29% and 64% of the total petrous apex volume, respectively. Indeed, EAP addressed the inferior portion of the petrous apex located adjacent to the petroclival suture more completely than OAP, where 45% of the bone overlying the petroclival suture (petroclival angle to the jugular foramen) was resected with the EAP, while 0% was resected with the OAP. Conclusions In anatomically normal cadavers, OAP achieved nearly a 50% larger volumetric resection than EAP. Furthermore, while OAP appears to completely address the superior portion of the petrous apex, EAP appears to have a niche in approaches to lesions in the inferior petrous apex. Given these results, the authors propose that OAP be redefined as the “superior anterior petrosectomy,” while EAP be referred to as the “inferior anterior petrosectomy,” which more clearly defines the role of each approach in anterior petrosectomy.

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Endoscopic endonasal translacerum approach to the inferior petrous apex

Journal of Neurosurgery ◽

10.3171/2015.1.jns142526 ◽

2016 ◽

Vol 124 (4) ◽

pp. 1032-1038 ◽

Cited By ~ 19

Author(s):

Masaaki Taniguchi ◽

Nobuyuki Akutsu ◽

Katsu Mizukawa ◽

Masaaki Kohta ◽

Hidehito Kimura ◽

...

Keyword(s):

Carotid Artery ◽

Surgical Simulation ◽

Internal Auditory Canal ◽

Jugular Foramen ◽

Petrous Apex ◽

Partial Removal ◽

Endoscopic Endonasal ◽

Anatomical Features ◽

Petrous Portion ◽

Sufficient Space

OBJECT The surgical approach to lesions involving the inferior petrous apex (IPA) is still challenging. The purpose of this study is to demonstrate the anatomical features of the IPA and to assess the applicability of an endoscopic endonasal approach through the foramen lacerum (translacerum approach) to the IPA. METHODS The surgical simulation of the endoscopic endonasal translacerum approach was conducted in 3 cadaver heads. The same technique was applied in 4 patients harboring tumors involving the IPA (3 chordomas and 1 chondro-sarcoma). RESULTS By removing the fibrocartilaginous component of the foramen lacerum, a triangular space was created between the anterior genu of the petrous portion of the carotid artery and the eustachian tube, through which the IPA could be approached. The range of the surgical maneuver reached laterally up to the internal auditory canal, jugular foramen, and posterior vertical segment of the petrous portion of the carotid artery. In clinical application, the translacerum approach provided sufficient space to handle tumors at the IPA. Gross-total and partial removal was achieved in 3 and 1 cases, respectively, without permanent surgery-related morbidity and mortality. CONCLUSIONS The endoscopic endonasal translacerum approach provides reliable access to the IPA. It is indicated alone for lesions confined to the IPA and in combination with other approaches for more extensive lesions.

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Anterior Inferior Petrosectomy: Defining the Role of Endonasal Endoscopic Techniques for Petrous Apex Approaches

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0034-1370447 ◽

2014 ◽

Vol 75 (S 01) ◽

Author(s):

Puya Alikhani ◽

Jamie Van Gompel ◽

Mark Tabor ◽

Harry van Loveren ◽

Sivero Agazzi ◽

...

Keyword(s):

Petrous Apex ◽

Endoscopic Techniques

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Endoscopic endonasal and transorbital approaches to petrous apex lesions

Journal of Neurosurgery ◽

10.3171/2021.2.jns203867 ◽

2021 ◽

pp. 1-10

Author(s):

Won Jae Lee ◽

Sang Duk Hong ◽

Kyung In Woo ◽

Ho Jun Seol ◽

Jung Won Choi ◽

...

Keyword(s):

Demographic Data ◽

Csf Leak ◽

Petrous Apex ◽

Mr Images ◽

Lateral Direction ◽

Endoscopic Endonasal ◽

Complete Obliteration ◽

Superior Portion ◽

Surgical Corridor

OBJECTIVE The petrous apex (PA) is one of the most challenging areas in skull base surgery because it is surrounded by numerous critical neurovascular structures. The authors analyzed the clinical outcomes of patients who underwent endoscopic endonasal approach (EEA) and transorbital approach (TOA) procedures for lesions involving PA to determine the perspectives and proper applications of these two approaches. METHODS The authors included patients younger than 80 years with lesions involving PA who were treated between May 2015 and December 2019 and had regular follow-up MR images available for analysis. Patients with meningioma involving petroclival regions were excluded. The authors classified PA into three regions: superior to the petrous segment of the internal carotid artery (p-ICA) (zone 1); posterior to p-ICA (zone 2); and inferior to p-ICA (zone 3). Demographic data, preoperative clinical and radiological findings, surgical outcomes, and morbidities were reviewed. RESULTS A total of 19 patients with lesions involving PA were included. Ten patients had malignant tumor (chondrosarcoma, chordoma, and osteosarcoma), and 6 had benign tumor (schwannoma, Cushing’s disease, teratoma, etc.). Three patients had PA cephalocele (PAC). Thirteen patients underwent EEA, and 5 underwent TOA. Simultaneous combined EEA and TOA was performed on 1 patient. Thirteen of 16 patients (81.3%) had gross- or near-total resection. Tumors within PA were completely resected from 13 of 16 patients using a view limited to only the PA. Complete obliteration of PAC was achieved in all patients. Postoperative complications included 2 cases of CSF leak, 1 case of injury to ICA, 1 fatality due to sudden herniation of the brainstem, and 1 case of postoperative diplopia. CONCLUSIONS EEA is a versatile surgical approach for lesions involving all three zones of PA. Clival tumor spreading to PA in a medial-to-lateral direction is a good indication for EEA. TOA provided a direct surgical corridor to the superior portion of PA (zone 1). Patients with disease with cystic nature are good candidates for TOA. TOA may be a reasonable alternative surgical treatment for select pathologies involving PA.

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Endoscopic balloon dilation as an adjunct to extended endoscopic approaches to the skull base

Journal of Neurosurgery ◽

10.3171/2012.2.jns111815 ◽

2012 ◽

Vol 116 (6) ◽

pp. 1215-1218 ◽

Cited By ~ 3

Author(s):

Jeffrey C. Bedrosian ◽

Victor Garcia-Navarro ◽

Edward D. McCoul ◽

Vijay K. Anand ◽

Theodore H. Schwartz

Keyword(s):

Balloon Dilation ◽

Middle Cranial Fossa ◽

Petrous Apex ◽

Invasive Technique ◽

Surgical Removal ◽

Endoscopic Drainage ◽

Endoscopic Endonasal ◽

Access Method ◽

Cranial Fossa

Cholesterol granulomas (CGs) are benign, expanding cystic lesions surrounded by a thick fibrous capsule and filled with fluid, formed by the degradation of blood elements. The goal of surgery is to open the granuloma widely, creating a well-drained cavity. The endonasal endoscopic approach for this extradural lesion is a minimal access method for surgical removal or fenestration. The role of balloon dilation in creating a wide fenestration has not been previously described. The authors describe a patient with a recurrent petrous apex CG who underwent an endoscopic, endonasal, transmaxillary transpterygoid approach to the petrous apex. A balloon sinuplasty catheter was used to dilate the surgical fenestration to maintain continued patency. The authors report on their first experience using balloon dilation combined with endoscopic drainage of the petrous apex. The excellent surgical outcome of this minimally invasive technique holds promise for future endonasal approaches to the middle cranial fossa.

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Endoscopic Endonasal Petrosectomy: Anatomical Investigation, Limitations, and Surgical Relevance

Operative Neurosurgery ◽

10.1093/ons/opy195 ◽

2018 ◽

Vol 16 (5) ◽

pp. 557-570 ◽

Cited By ~ 3

Author(s):

Hamid Borghei-Razavi ◽

Huy Q Truong ◽

David T Fernandes Cabral ◽

Xicai Sun ◽

Emrah Celtikci ◽

...

Keyword(s):

Abducens Nerve ◽

Jugular Foramen ◽

Petrous Apex ◽

Anatomical Landmarks ◽

Endoscopic Endonasal ◽

Computed Tomographic ◽

Alternative Approach ◽

Computed Tomographic Scan ◽

Internal Acoustic Canal

Abstract BACKGROUND The endoscopic endonasal approach (EEA) was recently added to the neurosurgical armamentarium as an alternative approach to the petrous apex (PA) region. However, the maximal extension, anatomical landmarks, and indications of this procedure remain to be established. OBJECTIVE To investigate the limitations and suggest a classification of PA lesions for endoscopic petrosectomy. METHODS Five anatomical specimens were dissected with EEA to the PA. Anatomical landmarks for the surgical steps and maximal limits were noted. Pre- and postprocedural computed tomographic scan and image-guidance were used. Relevant surgical cases were reviewed and presented. RESULTS We defined 3 types of petrosectomy: medial, inferior, and inferomedial. Medial petrosectomy was limited within the paraclival internal carotid artery (ICA) anteriorly, lacerum ICA inferiorly, abducens nerve superiorly, and petrous ICA laterally. Among those, abducens nerve and petrous ICA are surgical limits. Full skeletonization of the paraclival ICA and removal of the lingual process are essential for better access to the medial aspect of PA. Inferior petrosectomy was defined by the lacerum foramen synchondrosis anteriorly, jugular foramen inferiorly, internal acoustic canal posteriorly, and PA superolaterally. Those are surgical limits except for the foramen lacerum synchondrosis. The connective tissue at the pterygosphenoidal fissure was a key landmark for the sublacerum approach. Clinical cases in 3 types of PA lesions were presented. CONCLUSION The EEA provides access to the medial and inferior aspects of the PA. Several technical maneuvers, including paraclival and lacerum ICA skeletonization, sublacerum approach, and lingual process removal, are key to maximize PA drilling.

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