Paratrigeminal, Paraclival, Precavernous, or All of the Above? A Circumferential Anatomical Study of the C3-C4 Transitional Segment of the Internal Carotid Artery

2017 ◽  
Vol 14 (4) ◽  
pp. 432-440 ◽  
Author(s):  
Eleonora Marcati ◽  
Norberto Andaluz ◽  
Sebastien C Froelich ◽  
Lee A Zimmer ◽  
James L Leach ◽  
...  

Abstract BACKGROUND Although the term paraclival carotid pervades recent skull base literature, no clear consensus exists regarding boundaries or anatomical segments. OBJECTIVE To reconcile various internal carotid artery (ICA) nomenclatures for transcranial and endoscopic-endonasal perspectives, we reexamined the transition between lacerum (C3) and cavernous (C4) segments using a C1-C7 segments schema. In this cadaveric study, we obtained a 360°-circumferential view integrating histological, microsurgical, endoscopic, and neuroradiological analyses of this C3-C4 region and identified a distinct transitional segment. METHODS In 13 adult, silicone-injected, formalin-fixed cadaveric heads (26 sides), transcranial-extradural-subtemporal and endoscopic-endonasal CT­guided dissections were performed. A quadrilateral area was noted medial to Meckel's cave between cranial nerve VI, anterolateral and posterolateral borders of the lateral-paratrigeminal aspect of the precavernous ICA, and posterior longitudinal ligament. Endoscopically, a medial-paraclival aspect was defined. Anatomical correlations were made with histological and neuroradiological slides. RESULTS We identified a distinct precavernous C3-C4 transitional segment. In 18 (69%) specimens, venous channels were absent at the quadrilateral area, on the paratrigeminal border of the precavernous ICA. A trigeminal membrane, seen consistently on the superior border of V2, defined the lateral aspect of the cavernous sinus floor. The medial aspect of the precavernous ICA corresponded with the paraclival ICA. CONCLUSION Our study revealing the juncture of 2 complementary borders of the ICA, endoscopic endonasal (paraclival) and transcranial (paratrigeminal), reconciles various nomenclature. A precavernous segment may clarify controversies about the paraclival ICA and support the concept of a “safe door” for lesions involving Meckel's cave, cavernous sinus, and petrous apex.

2021 ◽  
Author(s):  
Yuanzhi Xu ◽  
Benjamin K Hendricks ◽  
Maximiliano Alberto Nunez ◽  
Ahmed Mohyeldin ◽  
Juan C Fernandez-Miranda ◽  
...  

Abstract BACKGROUND Understanding the microsurgical anatomical features of the endoscopy-assisted retrosigmoid intradural suprameatal approach (RISA) is critical for surgeons treating petroclival tumors or lesions in the cerebellopontine region that extend into Meckel's cave. OBJECTIVE To evaluate increased exposure for Meckel's cave in the RISA and assess the surgical landmarks for this approach. METHODS A standard retrosigmoid craniotomy to the cerebellopontine region was performed in 4 cadaveric specimens (8 hemispheres) with microscope-assisted endoscopy. The length and depth of the drilling region from the suprameatal tubercle to the petrous apex were analyzed. After opening Meckel's cave and mobilizing the trigeminal root completely, the landmarks for this approach were investigated. RESULTS The endoscopy-assisted RISA facilitates mobilization of the trigeminal root and enhances surgical exposure in the region of Meckel's cave and the petrous apex with increases of 10.1 ± 1.3 mm in depth, 21.4 ± 3.2 mm in length, and 6.4 ± 0.6 mm in height. The posterior and superior semicircular canals, internal auditory canal, superior petrous sinus, and internal carotid artery (petrous segment) served as important landmarks for this approach. One case illustration is presented to describe the application of this approach. CONCLUSION The RISA is suitable mainly for lesions in the posterior fossa that extend into Meckel's cave. The endoscopy-assisted reach optimizes accessibility to the petrous apex region, obviates the need for extensive drilling, and decreases the risk of internal carotid artery injury. Better realization and recognition of microsurgical landmarks and parameters of this approach are crucial for successful outcomes.


2017 ◽  
Vol 126 (3) ◽  
pp. 872-879
Author(s):  
Andrea Ruggeri ◽  
Joaquim Enseñat ◽  
Alberto Prats-Galino ◽  
Antonio Lopez-Rueda ◽  
Joan Berenguer ◽  
...  

OBJECTIVE Neurosurgical management of many vascular and neoplastic lesions necessitates control of the internal carotid artery (ICA). The aim of this study was to investigate the feasibility of achieving control of the ICA through the endoscopic endonasal approach by temporary occlusion with a Fogarty balloon catheter. METHODS Ten endoscopic endonasal paraseptal approaches were performed on cadaveric specimens. A Fogarty balloon catheter was inserted through a sellar bony opening and pushed laterally and posteriorly extraarterially along the paraclival carotid artery. The balloon was then inflated, thus achieving temporary occlusion of the vessel. The position of the catheter was confirmed with CT scans, and occlusion of the ICA was demonstrated with angiography. The technique was performed in 2 surgical cases of pituitary macroadenoma with cavernous sinus invasion. RESULTS Positioning the Fogarty balloon catheter at the level of the paraclival ICA was achieved in all cadaveric dissections and surgical cases through a minimally invasive, quick, and safe approach. Inflation of the Fogarty balloon caused interruption of blood flow in 100% of cases. CONCLUSIONS Temporary occlusion of the paraclival ICA performed through the endoscopic endonasal route with the aid of a Fogarty balloon catheter may be another maneuver for dealing with intraoperative ICA control. Further clinical studies are required to prove the efficacy of this method.


Author(s):  
Juan Ángel Aibar-Durán ◽  
Fernando Muñoz-Hernández ◽  
Carlos Asencio-Cortés ◽  
Joan Montserrat-Gili ◽  
Juan Ramón Gras-Cabrerizo ◽  
...  

2021 ◽  
Vol 27 (1) ◽  
pp. 29-33
Author(s):  
Ruslan V. Aksyonov ◽  
Orest I. Palamar ◽  
Andrii P. Huk ◽  
Dmytro I. Okonskyi ◽  
Dmytro S. Teslenko

Objective: To determine the effectiveness of intraoperative Doppler ultrasound in the surgical treatment of pituitary adenomas with invasive parasellar growth into the cavernous sinus Knosp 3 and Knosp 4. Material and Methods. During 2009–2017, 71 patients with pituitary adenomas (PA) with extension into the cavernous sinus Knosp 3 and Knosp 4 were retrospectively reviewed. According to the size PA were divided into pituitary macroadenomas, (from 10 to 40 mm) in 45 (63.4%) patients, and giant PA (over 40 mm) – in 26 (36.6%) patients. Cavernous sinus invasion Knosp 3 and 4 was identified in 47 (66.2%) and 24 (33.8%) patients respectively. Non-secreting PA - 43 (60.5%) patients and hormone-secreting PA - 28 patients (39.4%). Endoscopic endonasal trassphenoidal (EET) approach was used in all cases. Laterally expanded EET (LEEET) approach was used in 29 cases. Intraoperative Doppler ultrasound (IDUS) was used in 36 (51%) cases. Results. Intraoperative Doppler ultrasound was used in cases of Knosp 3 extension in 23 (32.4%) cases and in Knosp 4 - in 13 (18.3%) cases. Gross total resection, including extension into the cavernous sinus using IDUS was achieved in 22 (62.7%) patients. In cases where IDUS was not used, gross total resection was achieved in 19 (52.7%) cases. In cases where the IDUS was not used, recurrence rate was 7.3%, with IDUS - 5%. Biochemical remission was achieved in 22 (78.6%) cases. Liquorrhea nasalis after surgery was observed in 6 (8.4%) cases, meningoencephalitis - in 1 (1.4%) case, oculomotor palsy -3 (4.2%) cases. Conclusions. Intraoperative Doppler ultrasound is an informative method that provides safe resection of pituitary adenomas with cavernous sinus extension with a low level of possible postoperative complications. Parasellar extension of Pituitary adenomas into the cavernous sinus Knosp 4 significantly reduces the possibility of gross total resection. However, the use of intraoperative ultrasound makes it possible to determine safe boundaries for manipulation both medially and laterally from the internal carotid artery, increasing the level of radicality and the duration of clinical remission. Intraoperative Doppler ultrasound during endoscopic endonasal transsphenoidal surgery of pituitary adenomas with parasellar extension allows to identify the internal carotid artery in the tumor stroma with the existing changed skull base anatomy. Dura incision under intraoperative Doppler ultrasound reduces the risk of internal carotid artery injury.


2019 ◽  
Vol 21 (2) ◽  
pp. 39-44
Author(s):  
О. I. Sharipov ◽  
M. A. Kutin ◽  
P. L. Kalinin

The study objective is to describe the removal of the pituitary adenoma from the posterior cranial fossa through endoscopic transsphenoidal trans-cavernous approach, when the main surgical corridor was the tumor-intact cavernous sinus. Materials and methods. A 55-year-old male patient with endosupraretrosellar endocrine-inactive pituitary adenoma was admitted to N.N. Burdenko Research Center of Neurosurgery. The patient had earlier undergone two surgeries for pituitary adenoma. Using the endoscopic endonasal transsphenoidal approach, we found that these surgeries resulted in the formation of scar-altered adipose tissue in the sphenoid sinus and partly in the sella turcica; anatomical landmarks indicating the midline and the location of the internal carotid arteries were absent. We formed an access to both retro- and suprasellar portions of the tumor between the sella turcica and cavernous segment of the internal carotid artery (through the cavernous sinus); then we dissected anterior and posterior walls of the sinus and revealed a soft capsule-free pituitary adenoma, which was completely removed by a vacuum aspirator. The skull base defect was repaired using the multilayer technique with autologous tissues. Results. After surgery, neurological status and visual functions did not change. In the postoperative period, we observed no oculomotor disorders, pituitary insufficiency, diabetes insipidus, or nasal liquorrhea. Follow-up computed tomography scans revealed no signs of intracranial complications or obvious residual tumor tissue. Magnetic resonance imaging 4 month postoperatively demonstrated small laterosellar fragments of the tumor in the sella turcica. The patient was further followed up. Conclusion. Cavernous sinus is a natural anatomical corridor providing access to the structures of the posterior cranial fossa and interpeduncular cistern. The main risk (damage to the cavernous segment of the internal carotid artery) can be minimized by using intraoperative dopplerography and visual control of all manipulations.


2014 ◽  
Vol 10 (3) ◽  
pp. 448-471 ◽  
Author(s):  
Mohamed A. Labib ◽  
Daniel M. Prevedello ◽  
Ricardo Carrau ◽  
Edward E. Kerr ◽  
Cristian Naudy ◽  
...  

Abstract BACKGROUND: Injuring the internal carotid artery (ICA) is a feared complication of endoscopic endonasal approaches. OBJECTIVE: To introduce a comprehensive ICA classification scheme pertinent to safe endoscopic endonasal cranial base surgery. METHODS: Anatomic dissections were performed in 33 cadaveric specimens (bilateral). Anatomic correlations were analyzed. RESULTS: Based on anatomic correlations, the ICA may be described as 6 distinct segments: (1) parapharyngeal (common carotid bifurcation to ICA foramen); (2) petrous (carotid canal to posterolateral aspect of foramen lacerum); (3) paraclival (posterolateral foramen lacerum to the superomedial aspect of the petrous apex); (4) parasellar (superomedial petrous apex to the proximal dural ring); (5) paraclinoid (from the proximal to the distal dural rings); and (6) intradural (distal ring to ICA bifurcation). Corresponding surgical landmarks included the Eustachian tube, the fossa of Rosenmüller, and levator veli palatini for the parapharyngeal segment; the vidian canal and V3 for the petrous segment; the fibrocartilage of foramen lacerum, foramen rotundum, maxillary strut, lingular process of the sphenoid bone, and paraclival protuberance for the paraclival segment; the sellar floor and petrous apex for the parasellar segment; and the medial and lateral opticocarotid and lateral tubercular recesses, as well as the distal osseous arch of the carotid sulcus for the paraclinoid segment. CONCLUSION: The proposed endoscopic classification outlines key anatomic reference points independent of the vessel's geometry or the sinonasal pneumatization, thus serving as (1) a practical guide to navigate the ventral cranial base while avoiding injury to the ICA and (2) further foundation for a modular access system.


2019 ◽  
Vol 130 (5) ◽  
pp. 1699-1709 ◽  
Author(s):  
Ali Tayebi Meybodi ◽  
Andrew S. Little ◽  
Vera Vigo ◽  
Arnau Benet ◽  
Sofia Kakaizada ◽  
...  

OBJECTIVEThe transpterygoid extension of the endoscopic endonasal approach provides exposure of the petrous apex, Meckel’s cave, paraclival area, and the infratemporal fossa. Safe and efficient localization of the lacerum segment of the internal carotid artery (ICA) is a crucial part of such exposure. The aim of this study is to introduce a novel landmark for localization of the lacerum ICA.METHODSTen cadaveric heads were prepared for transnasal endoscopic dissection. The floor of the sphenoid sinus was drilled to expose an extension of the pharyngobasilar fascia between the sphenoid floor and the pterygoid process (the pterygoclival ligament). Several features of the pterygoclival ligament were assessed. In addition, 31 dry skulls were studied to assess features of the bony groove harboring the pterygoclival ligament.RESULTSThe pterygoclival ligament was identified bilaterally during drilling of the sphenoid floor in all specimens. The ligament started a few millimeters posterior to the posterior end of the vomer alae and invariably extended posterolaterally and superiorly to blend into the fibrous tissue around the lacerum ICA. The mean length of the ligament was 10.5 ± 1.7 mm. The mean distance between the anterior end of the ligament and midline was 5.2 ± 1.2 mm. The mean distance between the posterior end of the ligament and midline was 12.3 ± 1.4 mm. The bony pterygoclival groove was identified at the confluence of the vomer, pterygoid process of the sphenoid, and basilar part of the occipital bone, running from posterolateral to anteromedial. The mean length of the groove was 7.7 ± 1.8 mm. Its posterolateral end faced the anteromedial aspect of the foramen lacerum medial to the posterior end of the vidian canal. A clinical case illustration is also provided.CONCLUSIONSThe pterygoclival ligament is a consistent landmark for localization of the lacerum ICA. It may be used as an adjunct or alternative to the vidian nerve to localize the ICA during endoscopic endonasal surgery.


2021 ◽  
Author(s):  
Wei-Hsin Wang ◽  
Ming-Ying Lan ◽  
Carl H Snyderman ◽  
Paul A Gardner

Abstract This 59-yr-old man presented with headache, dizziness, diplopia, and right-side hearing impairment for years. The objective degree of hearing impairment was not available. Magnetic resonance imaging (MRI) showed a right petrous apex lesion centered behind the right petrous internal carotid artery and extending lateral to the medial aspect of the right internal auditory canal. A combined endoscopic endonasal and left contralateral transmaxillary (CTM) approach was performed, and gross-total resection was achieved. Peeling the cyst wall from the dura resulted in minor weeping. It was covered with a left-sided, vascularized nasoseptal flap. His dizziness and diplopia improved immediately after the surgery. Histopathology revealed an epidermoid cyst. In this surgical video, we demonstrate the key steps of the CTM approach for access to the petrous apex posterior to the petrous internal carotid artery (ICA).  The patient gave informed consent for surgery and video recording.


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