Chordoma Treatment Surgical Techniques
At Stanford, our primary goal when performing chordoma surgery is maximal and safe resection of the tumor. Complete tumor resection is directly related to lower recurrence rates and potential cure. Endoscopic endonasal surgery is the preferred surgical option for most skull base chordomas, however, this type of surgery has a steep learning curve and requires fellowship training and extensive experience. Outcomes , such as resection or complication rates, are intimately associated with the experience of the skull base surgeon and the surgical team. At Stanford, our team includes experts in endoscopic endonsal surgery, including Dr. Fernandez-Miranda, a world-renowned expert in endoscopic endonasal surgery for skull base chordomas.
Addiionally, patients should avoid biopsies and partial tumor resection by inexperienced surgeons, as these may compromise future surgeries. Supratotal resection, including margins of normal tissue, is desirable as long as surgical complications are kept to a minimum, but only achievable in selected tumors by very experienced surgeons. The surgical team should also be able to perform complex transcranial ("open") skull base approaches as they are still necessary in selected cases, typically recurrent chordoma cases. Patients should also be sure their surgical team includes an expert radiation oncologist who can recommend the radiotherapy modality most appropriate for each individual case, including radiosurgery, intensity-modulated ratiation therapy (IMRT), and Proton Beam Therapy (PBT). At Stanford, our team includes Dr. Scott Soltys, a world authority in radiation treatment of chordomas.
Surgical Classification of the Clival Region
The Clival Region is classified anatomically in upper, middle, and lower segments.
Clival chordomas most commonly invade 2 or 3 segments of the clivus.
The anatomical relationships at each clival segment are distinct, and the technical nuances for resection of each segment are unique.
Fernandez-Miranda JC, Gardner PA, Snyderman CH, Devaney KO, Mendenhall WM, Suarez C, Rinaldo A, Ferlito A. Clival chordomas: a pathological, surgical and radiotherapeutic review. Head Neck. 2014 Jun;36(6):892-906.
Fernandez-Miranda JC. Intracranial region (Chapter 27). Gray's Anatomy, 41st Edition, Elsevier, 2016
Endoscopic Endonasal Transcavernous Posterior Clinoidectomy
Skull base chordomas often invade the upper segment of the clivus, formed by the dorsum sella and posterior clinoids. Surgical removal of the posterior clinoids is one of the most challenging technical maneuvers in skull base surgery.
Dr. JFM has described the endoscopic endonasal transcavernous approach with interdural pituitary transposition as the most effective and safest way to perform a uni- or bilateral posterior clinoidectomy.
Recent studies have shown preservation of pituitary function in most cases, with no incidences of vascular injury.
Fernandez-Miranda JC, Gardner PA, Rastelli MM Jr, Peris-Celda M, Koutourousiou M, Peace D, Snyderman CH, Rhoton AL Jr. Endoscopic endonasal transcavernous posterior clinoidectomy with interdural pituitary transposition. J Neurosurg. 2014 Jul;121(1):91-9.
Truong HQ, Borghei-Razavi H, Najera E, Igami Nakassa AC, Wang EW, Snyderman CH, Gardner PA, Fernandez-Miranda JC. Bilateral coagulation of inferior hypophyseal artery and pituitary transposition during endoscopic endonasal interdural posterior clinoidectomy: do they affect pituitary function?. J Neurosurg. 2018 Aug 3:1-6
Endoscopic Endonasal Transcavernous Posterior Clinoidectomy: Case Example
35 year-old patient had transcranial resection at outside institution achieving only partial resection.
Postop imaging showing supratotal resection after an endoscopic endonasal transcavernous approach.
The Abducens Nerve, Petrous Apex, and Dorello's Canal
The sixth cranial nerve, or abducens nerve, is often compressed by a growing chordoma at the level of the petrous apex, causing double vision, which is a common presenting symptom in chordoma patients.
Understanding the trajectory, segments, and neurovascular relationships of the abducens nerve is key to identify it during surgery and preserving it while resecting the tumor.
Dr. JFM has recently described a very reliable landmark to identify the abducens nerve in surgery, namely the petrosal process of the sphenoid bone as well as the petro-sphenoidal dural fold that covers this bony process.
(# Barges-Coll J, Fernandez-Miranda JC, Prevedello DM, Gardner P, Morera V, Madhok R, Carrau RL, Snyderman CH, Rhoton AL Jr, Kassam AB. Avoiding injury to the abducens nerve during expanded endonasal endoscopic surgery: anatomic and clinical case studies. Neurosurgery. 2010 Jul;67(1):144-54, discussion 154.)
The Jugular Tubercle and the Endonasal "Far Medial Approach"
The jugular tubercle is part of the inferior segment of the clivus and it is often invaded by chordoma. Its deep and lateral location makes it difficult to access surgically, representing a typical area of residual tumor.
Dr. JFM has described the surgical anatomy of the jugular tubercle and has defined the technical nuances required for complete resection of tumor at this location, while minimizing the risk of injury to surrounding neurovascular structures.
Fernandez-Miranda JC, Morera VA, Snyderman CH, Gardner P. Endoscopic endonasal transclival approach to the jugular tubercle. Neurosurgery. 2012 Sep;71(1 Suppl Operative):ONS146-59.
Morera VA, Fernandez-Miranda JC, Prevedello DM, Madhok R, Barges-Coll J, Gardner P, Carrau R, Snyderman CH, Rhoton AL Jr, Kassam AB. “Far-medial” expanded endonasal approach to the inferior third of the clivus: the transcondylar and transjugular tubercle approaches. Neurosurgery. 2010 Jun;66(6 Suppl Operative):211-9
Vaz-Guimaraes Filho F, Fernandez-Miranda JC, Wang EW, Snyderman CH, Gardner PA. Endoscopic endonasal "far-medial" transclival approach: surgical anatomy and technique. Operative Techniques in Otolaryngology-Head and Neck Surgery, 2013 Dec; 24(4): 222-228.
The Foramen Lacerum and the Sublacerum Route
The Endonasal "Extreme Medial" Approach to the Jugular Foramen
In extensive chordomas, the tumor can invade the ventral aspect of the jugular foramen, which is located at the infero-lateral junction of clival and temporal bones
The jugular foramen is one of the most challenging and risky areas to expose in the base of the skull as it contains critical neurovascular structures.
Dr. JFM has investigated and applied a new surgical route that allows safe and effective access to the ventral jugular foramen, the sublacerum approach, which facilitates complete tumor removal.
Vaz-Guimaraes F, Nakassa AI, Gardner PA, Wang EW, Snyderman CH, Fernandez-Miranda JC. Endoscopic endonasal approach to the ventral jugular foramen: anatomical basis, technical considerations, and clinical series. Oper Neurosurg (Hagerstown). 2017 Aug;13(4):482-491.
The Occipital Condyle and Craniocervical Junction
The craniocervical junction is formed by the occipital condyles (part of the clival bone) and first cervical vertebra. The hypoglossal nerve (responsible for tongue movement) is located between the occipital condyle (inferior) and the jugular tubercle (superior).
Skull base chordomas may invade the craniocervical junction, which increases the difficulty for tumor resection and the risks for craniocervical instability and neurovascular injury.
Dr. JFM has meticulously studied the surgical anatomy of the occipital condyles, hypoglossal canal, and craniovertebral junction to better understand these structures during surgical removal and to increase the chances for complete tumor resection with preservation of neurovascular structures.
Kooshkabadi A, Choi PA, Koutourousiou M, Snyderman CH, Wang EW, Fernandez-Miranda JC, Gardner PA. Atlanto-occipital instability following endoscopic endonasal approach for lower clival lesions: Experience with 212 cases. Neurosurgery. 2015 Dec;77(6):888-97.
Wang WH, Abhinav K, Wang E, Snyderman C, Gardner PA, Fernandez-Miranda JC. Endoscopic endonasal transclival transcondylar approach for foramen magnum meningiomas: surgical anatomy and technical note. Oper Neurosurg. 2016 Jun;12(2):153-62
52-year-old patient with diplopia giant chordoma invading lower and middle clivus
Complete tumor resection 3-year post-operative MRI
The Contralateral Transmaxillary Approach
to the Petrous Apex
The main limitation of the endoscopic endonasal approach for chordoma resection is getting enough exposure at the most lateral and posterior aspects of the petrous apex.
Mobilization of the paraclival and lacerum carotid segments is important but not sufficient for complete access to the petrous apex.
For cases that need further exposure, the Contralateral Transmaxillary Approach (CTM) is an ideal adjunct to the Endonasal Endoscopic Approach (EEA) that uses the natural corridor of the maxillary sinus to enter the petrous apex in a trajectory parallel to the petrous carotid, providing full access to the petrous apex for total or even supratotal tumor removal.
Patel CR, Wang EW, Fernandez-Miranda JC, Gardner PA, Snyderman CH. Contralateral transmaxillary corridor: an extended endoscopic endonasal approach to the petrous apex. J Neurosurg, 2017 Oct 20:1-9
Transcranial Skull Base Approaches for Clival Chordoma
Complex transcranial skull base approaches were developed by surgical pioneers in the 80’s introducing the concepts of team surgery, maximal bone removal with minimal neurovascular manipulation, and direct approach to tumor origin.
Endoscopic endonasal surgery was introduced in the 21st century and, while still evolving, has changed dramatically skull base surgery providing a less invasive and more effective approach for many skull base lesions, particularly those located ventrally such as chordomas and chondrosarcomas.
Transcranial approaches are still needed in selected chordoma cases, especially for those extending more lateral and posterior beyond the endonasal reach. The most common approaches employed at our Chordoma center are: extended middle fossa, combined transpetrosal, far lateral, and extreme lateral.
Contemporary skull base surgeons and teams should develop expertise in both transcranial and endonasal endoscopic approaches to provide the best option for each individual patient.
Chabot JD, Gardner P, Fernandez-Miranda JC. Anterior transpetrosal approach for resection of recurrent skull base chordoma: 3-dimensional operative video. Neurosurgery. 2015 Sep;11 Suppl 3:464-5.