Modified Transpetrosal–Transtentorial Approach for Resection of Large and Giant Petroclival Meningioma: Technical Nuance and Surgical Experiences

Background Meningiomas arising from the petroclival area remain a challenge for neurosurgeons. Various approaches have been proposed to achieve maximum resection with minimal morbidity and mortality. Also, some articles correlated preservation of adjacent veins with less neurologic deficits. Objective To describe the experiences in using a new technique to achieve maximal resection of petroclival meningiomas and preserving the superior petrosal veins (SPVs) and the superior petrosal sinus (SPS). Methods A retrospective analysis of 26 patients harboring a true petroclival meningioma with a diameter ≥25 mm and undergoing surgery with the modified transpetrosal–transtentorial approach (MTTA) was performed. Results Fifty-four percent of 22 patients complained of severe headache at presentation. There was also complaint of cranial nerve (CN) deficit, with CN VII deficit being the most common (present in 42% of patients). The average tumor size (measured as maximum diameter) was 45.2 mm, and most of the tumors compressed the brainstem. Total resection was achieved in 12 patients (46.2%), whereas the others were excised subtotally (54.8%). Most of the patients had WHO grade I (96.1%) meningioma; only one had a grade II (3.8%) meningioma. In addition, clinical improvement and persistence of symptoms were observed in 17 (65.4%) and 8 (30.7%) patients, respectively, and postoperative permanent CN injury was observed in 3 (11.5%) patients. Conclusion Using the MTTA, maximal resection with preservation of the CNs and neurovascular SPV-SPS complex can be achieved. Therefore, further studies and improvements of the technique are required to increase the total resection rate without neglecting the complications that may develop postoperatively.

Fatal hemorrhagic complication after coil embolization of a petrosal arteriovenous shunt

Background Cerebello-pontine AVMs (CPAVMs) and petrous apex dural arteriovenous fistulae (DAVFs) are rare and sometimes difficult to distinguish. We report a fatal hemorrhagic complication after coil embolization of the petrosal vein draining a trigeminal AVM misdiagnosed as a DAVF. Case presentation A 73-year-old woman with a petrous apex arteriovenous shunt with dual dural and pial arterial supply presented with posterior fossa hemorrhage. The draining petrosal vein was catheterized and coiled via the superior petrosal sinus. Two episodes of contrast extravasation occurred during coiling, but the lesion was completely occluded at the end of the procedure. The patient developed a fatal posterior fossa hemorrhage in the recovery room. Microscopic pathology revealed numerous dilated vessels within the trigeminal nerve. Conclusion CPAVMs and DAVFs with pial drainage should be distinguished pre-operatively. Occlusion of a pial vein (as opposed to a sinus) in the treatment of an arteriovenous shunt carries hemorrhagic risk if a liquid embolic agent is not used to completely occlude all pathological vessels.

Posterior Fossa Venous Drainage

This paper aims to make simple the evaluation of the main veins related to the brainstem and cerebellum. Posterior fossa venous drainage is best understood in context with its three main collectors: superior: toward the Vein of Galen; posterior: toward the torcular complex; and anterior: toward the superior petrosal sinus. A fourth possible drainage path, often harder to distinguish, is directed toward the inferior petrosal sinus. Veins of these four systems are frequently connected to one another. Despite traditionally being considered less regular than its arterial disposition, posterior fossa venous anatomy follows specific patterns that are easy to identify. The three more representative veins of each venous confluent have been selected, to help in recognizing them angiographically. Since pial large veins are primarily located over the surface of the encephalon, most related anatomical structures can be confidently identified. This is of special interest when angiographic 2D or 3D studies are evaluated and provide fundamental assistance in locating precise structures. To better aid in understanding venous disposition, an overview of embryologic and fetal development is also discussed.

Transarterial embolization of dural arteriovenous fistulas of the lateral sinuses with stent-assisted sinus protection

BackgroundThe balloon-assisted sinus protection technique has been described as a sinus-preserving technique during transarterial embolization (TAE) of dural arteriovenous fistulas (DAVFs). However, some serious complications of this technique have been documented.ObjectiveTo describe our preliminary experience with a new technique called stent-assisted sinus protection (SSP).MethodsWe performed a retrospective analysis of seven consecutive patients with type I or IIa DAVFs of the lateral sinus treated by TAE with a closed-cell stent temporarily deployed in the sinus.ResultsOf the seven patients, four had type I DAVF, and three had type IIa DAVF. The patency of all involved sinuses and their tributaries (including the inferior anastomotic vein and the superior petrosal sinus) was preserved. At the end of the procedure, all stents were successfully retrieved with embolic particles trapped in their meshes. No procedural complications were noted. Clinical follow-up was satisfactory, with complete resolution or significant reduction of pulsatile tinnitus.ConclusionsSSP appears to be feasible and probably safe. However, larger studies are needed to confirm these preliminary results.

Balloon-backstop technique: Preserving physiologic venous drainage during transvenous coil embolization of sigmoid sinus dural arteriovenous fistulas

Dural arteriovenous fistulas can lead to catastrophic intracranial hemorrhage if left untreated. Transvenous embolization can cure arteriovenous fistulas, but preserving normal venous structures can be challenging. Inadvertent embolization of a functioning vein can result in catastrophic venous infarction or hemorrhage. Here, we report a case using balloon-assistance to facilitate preservation of the superior petrosal sinus during transvenous embolization of a sigmoid sinus dural arteriovenous fistula.

Posterior petrosal approach for microsurgical resection of petroclival meningioma: 3-Dimensional operative video

Background: Petroclival meningiomas are challenging lesions considering their deep location and close relationship with many vital neurovascular structures.[1-8] Case Description: We present the case of a 54-year-old male presenting a history of headache, dizziness, and tinnitus on the left side, associated with left facial hypoesthesia. Preoperative imaging depicted a lesion highly suggestive of a petroclival meningioma with important compression of the brainstem. Considering worsening of symptoms, size, and location of this lesion, microsurgical resection was indicated. A left posterior petrosal approach was employed with aid of neurophysiological monitoring. The patient was placed in a true lateral position and an arciform incision was done. First, the mastoidectomy was performed and then the craniotomy around encompassing both posterior and middle cranial fossae. Middle and posterior fossa dural incisions were connected through coagulation of the superior petrosal sinus. Then tentorium was all the way cut to the incisura. After that, sigmoid sinus can be mobilized posteriorly, increasing exposure of presigmoid space. The area since jugular foramen up to the supratentorial region was fully exposed, allowing safe total resection of the lesion. Postoperative imaging demonstrated complete tumor removal. Patient presented improvement of symptoms, with no new neurological deficits on follow-up. Conclusion: The posterior petrosal approach provided a shorter pathway and direct angle of attack to the tumor attachment, allowing successful resection.[1,6] Extensive laboratory training is essential to get familiarized with the complex anatomical relationships in that area. Informed consent was obtained from the patient for the procedure and publication of this operative video.

Petrosal Approach With Preservation of the Superior Petrosal Sinus (the Graceful Petrosal) for Resection of Giant Trigeminal Schwannoma: 2-Dimensional Operative Video

Trigeminal schwannomas are benign tumors amendable to curative surgical resection.1 Excellent outcomes, with preservation and improvement of cranial nerve function, including trigeminal nerve function, have been reported with microsurgical resection through skull base approaches.2 Dumbell shaped tumors, involving the middle and posterior fossa, are more challenging.3 They are resected via a middle cranial fossa approach with the expanded Meckel cave providing access to the posterior fossa. However, tumors with a large caudal extension below the internal auditory meatus typically cannot be adequately accessed with this approach and the posterior petrosal approach is utilized.2 Specific venous anatomy might deter from cutting the tentorium. This article describes the surgical resection of a trigeminal schwannoma with a large posterior fossa component through a petrosal approach without cutting the tentorium.4 The patient is a 34-yr-old man who presented with headaches and gait disturbance. Neurological exam revealed hypoesthesia and hypoalgesia in the left V1 and V2 distributions. Magnetic resonance imaging (MRI) revealed a large dumbbell-shaped schwannoma causing brainstem compression. Magnetic resonance venography (MRV) demonstrated temporal lobe venous drainage into the superior petrosal sinus and tentorium proximal to the transverse sigmoid junction. A single temporal-suboccipital bone flap and a retro-labrynthine mastoidectomy were performed. The petrous apex was drilled and Meckle's cave opened. The presigmoid dura was opened and extended toward the petrous apex region beneath the tentorium. This provided access to and safe resection of the tumor. A gross total tumor resection was achieved. The patient remained stable neurologically and was without tumor recurrence at 3 yr postoperatively. The patient had consented to the procedure. Figures in video at 4:06 from Jafez et al, Preservation of the superior petrosal sinus during the petrosal approach, J Neurosurg. 2011;114(5):1294-1298, with permission from JNSPG.