Pterional Craniotomy Research Articles

Preserving the Facial Nerve During Orbitozygomatic Craniotomy: Surgical Anatomy Assessment and Stepwise Illustration.

Surgical safety and efficiency during an orbitozygomatic (OZ) osteotomy rely on thorough knowledge of the surgical anatomy of the facial nerve. Although the anatomy of the facial nerve and its relation to the pterional craniotomy are described, a thorough assessment of facial nerve preservation techniques during the OZ approach and its variations is lacking. We assessed the surgical anatomy of the facial nerve related to the OZ approach and provided a thorough stepwise description on how to preserve it. The OZ approach was performed bilaterally in 15 cadaveric heads. The interfascial and subfascial techniques were performed to study their nuances in preserving the facial nerve. We compared the 2 techniques and provided a thorough description on how to preserve the facial nerve during each step of the OZ approach. At the zygomatic arch, the facial nerve was found between the galea and the superficial temporal fascia. A cut in the fascia at the posterior end of the zygomatic arch did not cross any facial nerve branches. The subfascial technique was simpler, more efficient, and provided more structural protection of the facial nerve branches than the interfascial technique. The frontal division of the facial nerve is related directly to dissection over the zygomatic bone and may be injured during fascial dissection or osteotomies. Both interfascial and subfascial techniques are feasible to use during the OZ craniotomy and provide ample exposure of the OZ unit. Regarding the preservation of the facial nerve branches, we favor the subfascial method.

Delayed-onset post-craniotomy headache responsive to botulinum toxin A: a case series.

We report here the case of four patients presenting with delayed-onset temporal pain after pterional craniotomy. They reported similar symptoms: attacks of pain over the temporal region, ipsilateral to the operative site, irradiating around the eye and lasting from 10min to 1 h. All patients had hypertrophy of at least one part of the temporalis muscle. All responded dramatically to botulinum toxin A injection (25 to 50 Botox® units) into the temporalis muscle. We suggest that the headaches were caused by aberrant nerve regeneration following surgical injury to the frontal branch of the facial nerve.

Silicone Oil in Optic Chiasm: Case Report and Review of the Literature

Purpose: To report a case of silicone oil migration into optic chiasm with resultant visual field defect in the fellow eye. We also summarize the risk factors and pathogenic mechanisms responsible for the silicone oil migration and the subsequent neurological effects associated with it. Methods: A 36-year-old gentleman presented with a history of vitrectomy with silicone oil tamponade in the left eye with sudden-onset temporal field defect in the right eye. Silicone oil was identified in left optic nerve and left half of optic chiasm. Intrachiasmatic and intraneural silicone oil was removed by left pterional craniotomy. Result: Prompt visual field recovery in the right eye after the neurosurgical intervention was noted. Conclusion: Intracranial migration of silicone oil is rare, with only a handful of cases reported in the literature. Intrachiasmal and intraneural silicone oil is associated with loss of nerve fibers and resultant vision and visual field loss. Prompt neurosurgical intervention results in the improvement of visual field defects. So early identification and neurosurgical intervention is warranted. Vitreoretinal surgeons should be aware of transneural migration of silicone oil, and a high degree of suspicion is warranted when patient develops visual symptoms in the fellow eye, particularly in cases with glaucomatous optic neuropathy and secondary elevated intraocular pressure or in any disc malformation.

Carotid-Falciform Optic Neuropathy: Microsurgical Treatment.

Several recent reports have implicated vascular ectasia and vessel contact in dysfunction of the visual apparatus. A subset of patients with prechiasmatic visual deterioration have an ectatic internal carotid artery (ICA) that displaces and flattens the optic nerve (ON) rostrally as the ON exits the skull base. We describe a proposed pathophysiologic mechanism and a straightforward surgical technique for dealing with this problem. Via an ipsilateral pterional craniotomy, the bony roof of the optic canal is removed. The falciform ligament is opened in parallel to the ON. Adhesions between the ICA and ON are then dissected, and a Teflon pledget is placed between the ICA and ON to complete the decompression. Patients both in the literature and in this series experienced an improvement in their vision postoperatively. We propose that 3 mechanisms contribute to this caroticofalciform optic neuropathy: 1)mass effect from ICA ectasia, 2) ON irritation from vessel pulsatility, and 3) indirect compression by the falciform ligament from above. This disease process can be treated safely using standard microsurgical techniques with excellent outcomes.

Epithelioid Hemangioendothelioma of Cavernous Sinus

AbstractEpithelioid hemangioendothelioma is an uncommon vascular neoplasm. It is rare in the intracranial location. Its occurrence in the region of cavernous sinus is reported only once. Here, we report a case of 49-year-old man who presented with a headache, pain in the right eye, diplopia, and ptosis due to third and sixth cranial nerve involvement. Imaging showed an enhancing lesion in the region of cavernous sinus on the right side. Pterional craniotomy, combined extradural and intradural approach, and subtotal excision of the tumor was done. Histopathology and immunohistochemistry were suggestive of epithelioid hemangioendothelioma which is a rare tumor in this location. We report this case because of its rarity and uncommon location.

A case report of the unilateral approach to the ruptured right ICA aneurysm together with tuberculum sella meningioma and left ICA aneurysm

BackgroundTuberculum sellae meningioma associated with aneurysm is extremely rare with a limited number of individual cases previously reported. Because of the complicated anatomical structure of the skull base, comorbid disease in the sellae region is a challenging problem and is associated with high mortality in neurosurgery.Case presentationThis case report describes a rare case of comorbid bilateral internal carotid artery aneurysms and tuberculum sellae meningioma. This 58-year-old female presented with headache and nausea. She had lost her light perception in the right eye, and the right optic disc was degenerated. She also had a 5-year history of hypertension. This patient underwent a right pterional craniotomy, and we accomplished to clip the bilateral intracranial aneurysms and concurrently remove the tumor. After the surgery, we confirmed that both of the aneurysms were completely isolated, and the tumor was adequately resected. This patient had not suffered other neurological deficits. Unfortunately, her visual acuity had not recovered.ConclusionsAs we know, this is the first report of a unilateral surgical approach to clip the bilateral intracranial aneurysms and concurrently remove the tumor. It may provide a reference for clinical treatment of the similar disease.

Assessment of the Temporopolar Artery as a Donor Artery for Intracranial-Intracranial Bypass to the Middle Cerebral Artery: Anatomic Feasibility Study.

Intracranial-intracranial bypass is a valuable cerebral revascularization option. Despite several advantages, one of the main shortcomings of the intracranial-intracranial bypass is the possibility of ischemic complications of the donor artery. However, when sacrificed, the temporopolar artery (TPA) is not associated with major neurologic deficits. We sought to define the role of TPA as a donor for revascularization of the middle cerebral artery (MCA). Pterional craniotomy was performed on 14 specimens. The TPA was released from arachnoid trabecula, and the small twigs to the temporal lobe were cut. The feasibility of side-to-side and end-to-side bypass to the farthest arterial targets on insular, opercular, and cortical MCA branches was assessed. The distance of the bypass point was measured in reference to limen insulae. A total of 15 TPAs were assessed (1 specimen had 2 TPAs). The average cisternal length of the TPA was 37.3 mm. For side-to-side bypass, the TPA was a poor candidate as an intracranial donor, except for the cortical orbitofrontal artery, which was reached in 87% of cases. However, the end-to-side bypass was successfully completed for most arteries (87%-100%) on the anterior frontal operculum and more than 50% of the cortical or opercular middle and posterior temporal arteries. There was no correlation between the TPA's cisternal length and maximum bypass reach. When of favorable diameter, the TPA is a competent donor for intracranial-intracranial bypass to MCA branches at the anterior insula, and anterior frontal and middle temporal opercula (arteries anterior to the precentral gyrus coronal plane).

Surgical Technique for High-Flow Internal Maxillary Artery to Middle Cerebral Artery Bypass Using a Superficial Temporal Artery Interposition Graft.

Extracranial-to-intracranial high-flow bypass often requires cranial, cervical, and graft site incisions. The internal maxillary artery (IMA) has been proposed as a donor to decrease invasiveness, but its length is insufficient for direct intracranial bypass. We report interposition of a superficial temporal artery (STA) graft for high-flow IMA to middle cerebral artery (MCA) bypass using a middle fossa approach. To assess the feasibility of an IMA-STA graft-MCA bypass using a new middle fossa approach. Twelve specimens were studied. A 7.5-cm STA graft was obtained starting 1.5 cm below the zygomatic arch. The calibers of STA were measured. After a pterional craniotomy, the IMA was isolated inside the infratemporal fossa through a craniectomy within the lateral triangle (lateral to the posterolateral triangle) in the middle fossa and transposed for proximal end-to-end anastomosis to the STA. The Sylvian fissure was split exposing the insular segment of the MCA, and an STA-M2 end-to-side anastomosis was completed. Finally, the length of graft vessel was measured. Average diameters of the proximal and distal STA ends were 2.3 ± 0.2 and 2.0 ± 0.1 mm, respectively. At the anastomosis site, the diameter of the IMA was 2.4 ± 0.6 mm, and the MCA diameter was 2.3 ± 0.3 mm. The length of STA graft required was 56.0 ± 5.9 mm. The STA can be used as an interposition graft for high-flow IMA-MCA bypass if the STA is obtained 1.5 cm below the zygomatic arch and the IMA is harvested through the proposed approach. This procedure may provide an efficient and less invasive alternative for high-flow EC-IC bypass.

Post-operative orofacial pain, temporomandibular dysfunction and trigeminal sensitivity after recent pterional craniotomy: preliminary study.

Surgical trauma at the temporalis muscle is a potential cause of post-craniotomy headache and temporomandibular disorders (TMD). The aim of this study was to evaluate the prevalence of pain, masticatory dysfunction and trigeminal somatosensory abnormalities in patients who acquired aneurysms following pterional craniotomy. Fifteen patients were evaluated before and after the surgical procedure by a trained dentist. The evaluation consisted of the (1) research diagnostic criteria for TMD, (2) a standardized orofacial pain questionnaire and (3) a systematic protocol for quantitative sensory testing (QST) for the trigeminal nerve. After pterional craniotomy, 80% of the subjects, 12 patients, developed orofacial pain triggered by mandibular function. The pain intensity was measured by using the visual analog scale (VAS), and the mean pain intensity was 3.7. The prevalence of masticatory dysfunction was 86.7%, and there was a significant reduction of the maximum mouth opening. The sensory evaluation showed tactile and thermal hypoesthesia in the area of pterional access in all patients. There was a high frequency of temporomandibular dysfunction, postoperative orofacial pain and trigeminal sensory abnormalities. These findings can help to understand several abnormalities that can contribute to postoperative headache or orofacial pain complaints after pterional surgeries.

Development of a Novel Pterional Craniotomy Simulator

Development of a Novel Pterional Craniotomy Simulator

Carotid Cavernous Fistula: Role of Open Surgery in The Era of Endovascular Treatment

A 18-year-old right handed girl presented with progressive proptosis, chemosis, diplopia and an orbital bruit of right eye, 3 days after alleged history of fall from a tree, The intraocular pressure was increased. The suspected diagnosis of a direct carotid cavernous fistula (CCF) was confirmed by CT angiography CT Angiography showed direct fistulous communication of cavernous segment of right internal carotid artery with right cavernous sinus (type A right CCF) and linear minimally displaced fracture of right zygomatic arch and linear undisplaced fracture of wall of right orbit. The patient underwent right pterional craniotomy and transcavernous occlusion of fistula of right internal carotid artery (ICA). Surgery was performed with gradual resolution of the symptoms and normalization of the intraocular pressure.The pathogencsis, symptomatology, treatment of carotid cavernous fistulas are discussed.Nepal Journal of Neuroscience, Volume 14, Number 1, 2017, Page: 36-39

Bitemporal Postoperative Hemorrhage Following Pterional Craniotomy for the Treatment of an Internal Carotid Aneurysm

Introduction Postoperative hemorrhage is a well-known complication after intracranial surgeries. It usually occurs at the site of the operation; however, there are many reports of cerebellar hemorrhage following supratentorial craniotomies. Despite that, there are only three cases of multiple postoperative supratentorial hemorrhages (distant from the site of the operation) following aneurysm clipping in the current literature. Case Report A 52-year-old previously healthy woman underwent a left pterional craniotomy for the clipping of an unruptured aneurysm. The surgery was performed without any intraoperative rupture or other occurrences. On the follow-up computed tomography (CT) scan performed 24h after surgery, bilateral posterior temporal lobe hematomas were identified, and they had no relation to the surgical site. The patient developed symptomatic vasospasm, with right-sided hemiparesis. This complication was treated conservatively, and the outcome was good. Conclusions Intracerebral hemorrhage far from the site of the craniotomy is an infrequent complication after neurosurgical procedures, especially in vascular neurosurgery. The present report warns of the occurrence of this entity even in asymptomatic patients.

Quantification of Working Volumes, Exposure, and Target-Specific Maneuverability of the Pterional Craniotomy and Its Minimally Invasive Variants

Quantitative comparison of minimally invasive and standard cranial approaches remains a methodologic challenge. The aim of this study was to apply a new digital, navigation-based method to quantify multiple parameters of the pterional, supraorbital, lateral supraorbital and mini-pterional approaches and to describe a target-specific maneuverability score. Supraorbital, lateral supraorbital, mini-pterional, and standard pterional craniotomies were performed on 8 sides in 4 cadaver heads. The limits of superficial and deep exposure and surgical target points were registered with image-guidance (Medtronic Stealth). A custom software (Guided Therapeutics Eyes II Software [GTxEyesII]) calculated superficial and deep surface areas, working volumes, and target distances. Volumes were reconstructed digitally and visualized with GTxEyesII. Finally, we defined for each approach a target-specific maneuverability score based on surface exposure, target distance, target position, and anatomical obstacles. Surface exposure and volumes were significantly smaller for keyhole approaches compared with standard pterional craniotomy (P < 0.01). Maneuverability index scores showed the greatest values for standard pterional craniotomies, but nearly equally high scores could be achieved by one or several of the less-invasive approaches for most of the targets. The combination of a navigation-based measurement method with custom software (GTxEyesII) provides a powerful tool for visualization and quantification of surgical approaches. Compared with standard pterional craniotomy, alternative keyhole craniotomies offer comparable deep exposure with smaller working volumes and relatively high maneuverability for specific targets.

Surgical treatment of anterior cranial fossa dural arterio-venous fistulas (DAVFs): a two-centre experience.

Anterior cranial fossa dural arterio-venous fistulas (DAVFs) represent 6% of all intracranial DAVFs; characteristically they show an aggressive behaviour with high risk of intracranial haemorrhage. Peculiar anatomical features, such as feeding by the ethmoidal arteries and the pattern of venous drainage (frequently with varices that mimic aneurysmal dilatation), can be evaluated in detail only by digital subtraction angiography (DSA), which represents the "gold standard" in the diagnosis of such cranial fistulas. Recent technological developments in endovascular management of this type of DAVF have partially reduced the morbidity risk related to this modality of treatment. Our purpose is to present our experience in the surgical management of 14 patients with anterior cranial fossa DAVFs, with attention paid to the possible role of preoperative embolisation in these cases and to the surgical technique. Between 1999 and 2015, 14 patients with anterior cranial fossa DAVFs were submitted to surgery in two neurosurgical departments; the mean age was 63years old; nine DAVFs caused intracranial haemorrhage (subarachnoid haemorrhage in three cases, intracerebral haemorrhage in six cases). Pre-operative embolisation was attempted in an early case and was successfully done in one recent case. In all patients, the surgical approach chosen was a pterional craniotomy with a low margin on the frontal bone in order to gain the exposure of the anterior cranial fossa and especially of the olphactory groove region; the resection of the falx at its insertion on the crista galli was needed in five cases in order to get access to the contralateral afferent vessels. Cauterisation of all the dural feeders on and around the lamina cribrosa was needed in all cases; venous dilatations were evident in eight patients (in seven out of nine patients with ruptured DAVF and in one out of five patients with unruptured DAVF) and were removed in all cases. One patient harboured an ophthalmic artery aneurysm, which was excluded by clipping. One patient died 5days after surgery due to the severity of the pre-operative haemorrhage. Postoperative DSA showed the disappearance of the DAVF and of the venous pseudo-aneurysms in all cases. Clinical outcome was favourable (without neurological deficits) in 11 patients; three patients presented an unfavourable clinical outcome, due to the severity of the initial haemorrhage. Surgical exclusion of the anterior cranial fossa DAVFs still represents the gold standard for such lesions, due to low post-operative morbidity and to complete protection against future rebleedings; endovascular techniques may help the surgeon in complex cases.

Review of “Preservation of the Nerves to the Frontalis Muscle During the Pterional Craniotomy” by Poblete T, Jiang X, Komune N, Matsushima K, Rhoton AL in J Neurosurg 122

Review of “Preservation of the Nerves to the Frontalis Muscle During the Pterional Craniotomy” by Poblete T, Jiang X, Komune N, Matsushima K, Rhoton AL in J Neurosurg 122

New approach for transcranial exposure of the internal maxillary artery: surgical anatomy and technique

Objective To introduce a new approach through the middle cranial fossa for easy access and safe exposure of the Internal Maxillary Artery (IMA). Methods Ten specimens were prepared for surgical simulation. After pterional craniotomy and exposing the floor of middle fossa, a two-step drilling was performed. First, a triangular craniectomy was completed anterolateral to the foramen spinosum. By following the middle meningeal artery or deep temporal artery and dividing the lateral pterygoid muscle, the proximal part of IMA was located. Second, a bone slot was drilled in a posterior-to-anterior direction from the anterior aspect of the first craniectomy. Tracing the proximal part, the main trunk of IMA was obtained. The size of the two craniectomies, depth of IMA from the surface of middle fossa, and the length of exposed IMA were measured. Results The proposed two-step drilling technique allowed both the IMA's trunk andbranches of the trigeminal nerve to be manipulated safely. In six specimens, IMA ran medially to the pterygoid muscle and in the others ran laterally to it. The total craniectomy measured 27.8±4.2 mm in the anterior-posterior direction, and the posterior portion measured 13.3±1.5 mm in the lateral-medial direction. The depth from middle fossa to IMA (16.8±3.2 mm) was equal to the length of IMA exposed (17.6±3.3 mm). Conclusion This new approach provides an efficient and safe method to consistently locate and isolate a segment of IMA. Key words: Cranial fossa, middle; Internal maxillary artery; Dissection

Diagnostic, évolution et pronostic des kystes supra-sellaires de découverte anténatale

Suprasellar arachnoid cysts (SAC) in children are considered rare, but the incidence is increasing due to the improvement of prenatal diagnosis. We present 15 cases of SAC diagnosed during the antenatal period between 2005 and 2015. The records were reviewed retrospectively by specifying the radiological characteristics, treatment modalities, outcomes, and long-term monitoring. Mean follow-up was 71 months. The forms (SAC-1) accounted for 2 cases (13%) with hydrocephalus. We observed 8 (53%) lower forms (SAC-2) with interpeduncular cistern expansion without hydrocephalus. The 5 (33.5%) remaining patients showed asymmetrical forms (SAC-3). Six patients (40%) were treated by ventriculo-cysto-cisternostomy, 1 by fetoscopy, 1 (6.5%) by ventriculo-peritoneal shunt, 2 (13.5%) by pterional craniotomy, and 6 (40%) were simply followed. The surgical outcomes were initially favorable in 9 cases (100%), 1 patient (13%) had to be re-treated later. Non-operated patients were all type 2 and showed no radiological changes. In the long-term, 1 patient (6.5%) had endocrine disruption, 1 had delayed development, 2 (13.5%) had minor neuropsychological impairments, and 1 had epilepsy. Combined monitoring with prenatal MRI and ultrasound can be used to distinguish three subtypes of SAC. SAC-1 and SAC-3 have an excellent prognosis after treatment in the perinatal period. SAC-2 can benefit from simple monitoring and remain asymptomatic in their majority. This classification allows a better prognosis estimation and better treatment decision.

Frontobasal Aneurysm: Relatively a Rare Neurosurgical Entity

Distal Anterior Cerebral Artery (DACA) aneurysms are rarer. Its more so with the aneurysm of fronto basal branch of DACA. These aneurysms are smaller in size and are multiple in number in many instances. They rupture easily and present with intracerebral hemorrhage (ICH) in addition to subarachnoid hemorrhage (SAH).Here we present a male patient with SAH and left frontal base interhemispheric ICH. CT angiography showed multiple small aneurysms at right frontobasal artery. Successful clipping of all the aneurysms was done in the single sitting by left pterional craniotomy and subfrontal and interhemispheric approach.Nepal Journal of Neuroscience 12:91-93, 2015

Complete Resection of Cavernous Malformations in the Hypothalamus: A Case Report and Review of the Literature

Objective Cavernous malformation (CM) originating from the hypothalamus is extremely rare and the deep location presents a challenge for its neurosurgical management. We report such a case to better understand its clinical features. Methods and Results A 40-year-old male patient presented with impaired vision in the left eye. Magnetic resonance imaging (MRI) revealed a regularly shaped round lesion located in the suprasellar cistern, and a clinical diagnosis of hypothalamic CM was made. Complete microsurgical excision was performed via a right pterional craniotomy. The patient showed good recovery with no further visual acuity or field deficits postoperatively. No CM recurrence or rebleeding was seen on follow-up MRI scans performed over the course of two years. Conclusions For patients with cavernous malformation in the hypothalamus, accurate preoperative diagnosis with complete surgical removal by an appropriate surgical approach can contribute to satisfactory outcomes.

Assessment of the effect of short-term factors on surgical treatments for hypertensive intracerebral haemorrhage

BackgroundHypertension is the most common cause of intracerebral haemorrhages (ICHs), yet the short-term impact factors associated with hypertensive intracerebral haemorrhages (HICHs) in patients who undergo different surgical treatments are still unknown. Materials and methodsAll consecutive patients with acute HICHs admitted to our hospital from January 2012 to March 2015 were enrolled in the study. Patients were either randomly divided or assigned according to their family’s preference into three groups (those undergoing minimally invasive aspiration, keyhole craniotomy or haematoma aspiration with extended pterional and decompressive craniotomy). Patients’ information and clinical characteristics were collected to identify risk factors influencing the short-term effects of the procedures. ResultsThere were significant differences among the groups: haematoma aspiration with extended pterional and decompressive craniotomy was the optimal method, resulting in fewer complications, higher Glasgow Outcome Scale (GOS) scores and better short-term outcomes. Surgical treatment, Glasgow Coma Scale (GCS) scores, haemorrhage volume and degree of midline shift were risk factors for the short-term effects associated with HICH. ConclusionsHaematoma aspiration with extended pterional and decompressive craniotomy is suitable for treating HICH patients. Surgical treatment, GCS score, haemorrhage volume and degree of midline shift influence the short-term effects observed following HICH surgery.