Combined Retrosigmoid and Limited Anterior Petrosectomy (“Reverse Petrosectomy”)

OBJECTThis study proposes a variation of the transorbital endoscopic approach (TOEA) that uses the lateral orbit as the primary surgical corridor, in a minimally invasive fashion, for the posterior fossa (PF) access. The versatility of this technique was quantitatively analyzed in comparison with the anterior transpetrosal approach (ATPA), which is commonly used for managing lesions in the PF.METHODSAnatomical dissections were carried out in 5 latex-injected human cadaveric heads (10 sides). During dissection, the PF was first accessed by TOEAs through the anterior petrosectomy, both with and without lateral orbital rim osteotomies (herein referred as the lateral transorbital approach [LTOA] and the lateral orbital wall approach [LOWA], respectively). ATPAs were performed following the orbital approaches. The stereotactic measurements of the area of exposure, surgical freedom, and angles of attack to 5 anatomical targets were obtained for statistical comparison by the neuronavigator.RESULTSThe LTOA provided the smallest area of exposure (1.51 ± 0.5 cm2, p = 0.07), while areas of exposure were similar between LOWA and ATPA (1.99 ± 0.7 cm2 and 2.01 ± 1.0 cm2, respectively; p = 0.99). ATPA had the largest surgical freedom, whereas that of LTOA was the most restricted. Similarly, for all targets, the vertical and horizontal angles of attack achieved with ATPA were significantly broader than those achieved with LTOA. However, in LOWA, the removal of the lateral orbital rim allowed a broader range of movement in the horizontal plane, thus granting a similar horizontal angle for 3 of the 5 targets in comparison with ATPA.CONCLUSIONSThe TOEAs using the lateral orbital corridor for PF access are feasible techniques that may provide a comparable surgical exposure to the ATPA. Furthermore, the removal of the orbital rim showed an additional benefit in an enhancement of the surgical maneuverability in the PF.

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Custom-tailored transdural anterior transpetrosal approach to ventral pons and retroclival regions

Journal of Neurosurgery ◽

10.3171/jns.2006.104.1.38 ◽

2006 ◽

Vol 104 (1) ◽

pp. 38-46 ◽

Cited By ~ 31

Author(s):

Hans-Jakob Steiger ◽

Daniel Hänggi ◽

Walter Stummer ◽

Peter A. Winkler

Keyword(s):

Carotid Artery ◽

Cranial Nerves ◽

Extent Of Resection ◽

Venous Congestion ◽

Petrous Apex ◽

Anterior Transpetrosal Approach ◽

Target Field ◽

Custom Made ◽

Anterior Petrosectomy ◽

Spinal Catheter

Object The extradural anterior petrosectomy approach to the pons and midbasilar artery (mid-BA) has the main disadvantage that the extent of resection of the petrous apex cannot be as minimal as desired given that the surgical target field is not visible during bone removal. Unnecessary or excessive drilling poses the risk of injury to the internal carotid artery, vestibulocochlear organ, and seventh and eighth cranial nerves. The use of a custom-tailored transdural anterior transpetrosal approach can potentially avoid these pitfalls. Methods A technique for a transdural anterior petrosectomy was developed in the operating theater and anatomy laboratory. Following a subtemporal craniotomy and basal opening of the dura mater, the vein of Labbé is first identified and protected. Cerebrospinal fluid ([CSF] 50–100 ml) is drained via a spinal catheter. The tent is incised behind the entrance of the trochlear nerve toward the superior petrosal sinus (SPS), which is coagulated and divided. The dura is stripped from the petrous pyramid. Drilling starts at the petrous ridge and proceeds laterally and ventrally. The trigeminal nerve is unroofed. The internal acoustic meatus is identified and drilling is continued laterally as needed. The bone of the Kawase triangle toward the clivus can be removed down to the inferior petrosal sinus if necessary. Anterior exposure can be extended to the carotid artery if required. It is only exceptionally necessary to follow the greater superior petrosal nerve toward the geniculate ganglion and to expose the length of the internal acoustic canal. The modified transdural anterior petrosectomy exposure has been used in nine patients—two with a mid-BA aneurysm, two with a dural arteriovenous fistula, one with a pontine glioma, three with a pontine cavernoma, and one with a pontine abscess. In one patient with a mid-BA aneurysm, subcutaneous CSF collection occurred during the postoperative period. No CSF fistula or approach-related cranial nerve deficit developed in any of these patients. There was no retraction injury or venous congestion of the temporal lobe nor any venous congestion due to the obliteration of the SPS or the petrosal vein. Conclusions The custom-made transdural anterior petrosectomy appears to be a feasible alternative to the formal extradural approach.

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Reply to letter: Endoscopic transpalpebral transorbital anterior petrosectomy: does safer surgical freedoms necessitates modifications?

Acta Neurochirurgica ◽

10.1007/s00701-018-3594-9 ◽

2018 ◽

Vol 160 (8) ◽

pp. 1585-1586 ◽

Cited By ~ 1

Author(s):

Alberto Di Somma ◽

Norberto Andaluz ◽

Luigi Maria Cavallo ◽

Joaquim Enseñat ◽

Alberto Prats-Galino ◽

...

Keyword(s):

Anterior Petrosectomy

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Anterior Petrosectomy

10.18791/nsatlas.v5.ch04.3 ◽

2016 ◽

Cited By ~ 1

Author(s):

Aaron Cohen-Gadol

Keyword(s):

Anterior Petrosectomy

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Microsurgical Resection of a Petroclival Epidermoid Cyst Using an Anterior Petrosectomy Approach: 2-Dimensional Operative Video

Operative Neurosurgery ◽

10.1093/ons/opab364 ◽

2021 ◽

Author(s):

Kunal V Vakharia ◽

Ryan M Naylor ◽

Ashley M Nassiri ◽

Colin L W Driscoll ◽

Michael J Link

Keyword(s):

Epidermoid Cyst ◽

Cranial Nerves ◽

Residual Tumor ◽

Middle Meningeal Artery ◽

Neural Tube Closure ◽

Petrous Apex ◽

Meckel’S Cave ◽

Postoperative Mri ◽

Meckel's Cave ◽

Anterior Petrosectomy

Abstract Epidermoid cysts are rare, benign lesions that result from inclusion of ectodermal elements during neural tube closure.1 Cysts are composed of desquamated epithelial cells and restrict diffusion on magnetic resonance imaging (MRI).2,3 Symptoms are attributable to anatomic location.4,5 In this video, we illustrate the surgical treatment of an epidermoid cyst located in the right cerebellopontine angle, petrous apex, and Meckel's cave. The patient, a 33-yr-old female with right-sided V1 trigeminal hypoesthesia, underwent surveillance imaging for 2 yr. However, she developed progressive V1 and V2 trigeminal hypoesthesia and imaging revealed enlargement of the lesion. Therefore, surgical resection was pursued. The patient consented to the procedure. The patient underwent a right middle fossa craniotomy and anterior petrosectomy. After identifying the greater superficial petrosal nerve and cutting the middle meningeal artery as it exited foramen spinosum, Kawase's triangle was drilled, and the dura over Meckel's cave and the subtemporal dura were opened. The lesion was resected, taking care to preserve the trigeminal nerve and the basilar artery. A retrosigmoid craniotomy was then fashioned. The cyst and its capsule were dissected off the brainstem and cranial nerves utilizing natural corridors between the trigeminal and vestibulocochlear nerves as well as between the facial and lower cranial nerves. Gross total resection was confirmed on postoperative MRI, and she was discharged home on postoperative day 5. Three months after surgery, she underwent formal pinprick testing, which revealed 95% loss of sensation in V1, 20% loss in V2, and normal sensation in V3. Three-month postoperative MRI showed no residual tumor.

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Dissection of Extended Middle Fossa and Anterior Petrosectomy Approach

Neurovascular Surgery ◽

10.1007/978-981-10-8950-3_9 ◽

2018 ◽

pp. 59-77

Author(s):

Tetsuro Sameshima

Keyword(s):

Middle Fossa ◽

Anterior Petrosectomy

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Anterior Petrosal Approach for the Resection of a Petrous Apex Meningioma with Tentorial Infiltration

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0038-1677496 ◽

2019 ◽

Vol 80 (S 03) ◽

pp. S304-S304

Author(s):

Diego Mendez-Rosito

Keyword(s):

Trigeminal Neuralgia ◽

Free Edge ◽

Gross Total Resection ◽

Petrous Apex ◽

Anatomical Landmarks ◽

Middle Fossa ◽

Total Resection ◽

Middle Fossa Approach ◽

Anterior Petrosectomy ◽

Surgical Corridor

Objective The anterior petrosal approach is an extension of the middle fossa approach, characterized by drilling of the posteromedial triangle of the middle fossa. Drilling the Kawase's rhomboid creates a surgical corridor to the posterior fossa after splitting the tentorium. We present a case of a petrous apex meningioma invading the tentorium and causing trigeminal neuralgia. Results The patient was positioned in a Mayfield with the head rotated. A frontotemporal incision was done. A basal craniotomy was done to allow epidural dissection. The anatomical landmarks were identified. The surgical video is analyzed together with cadaveric dissections to highlight landmarks when doing an anterior petrosectomy. The tentorium was identified and the infiltrated region was coagulated and removed. The tentorium was sharply sectioned until the free edge of the tentorium was opened. The tumor in the petrous apex was identified and removed. The trigeminal nerve was decompressed and a gross total resection was achieved with resolution of the symptoms. Conclusion The anterior petrosal approach is a useful corridor to remove tumors in the petrous apex that infiltrate the tentorium. A thorough knowledge of the anatomical landmarks is crucial to identify and delineate the limits of the Kawase's rhomboid. After evaluating different surgical corridors, the anterior petrosal approach allows a gross total resection including the removal of the infiltrated tentorium and a resolution of the symptoms.The link to the video can be found at: https://youtu.be/p4KPUnM_bww.

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