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Background The primitive trigeminal artery (PTA) is the most common and the largest persistent carotid-basilar anastomosis. Primitive trigeminal artery variants (PTAVs) are anastomoses between the internal carotid artery and cerebellar arteries. These vessels pose a risk of hemorrhagic or ischemic complications during neurosurgical procedures in the parasellar and intrasellar regions. The aim of this study was to determine the prevalence of both PTA and PTAVs and their clinically important anatomic features. Methods Major electronic databases were thoroughly searched for studies on PTA and PTAV. References in the included articles were also evaluated. Data regarding prevalence, laterality, origin, course patterns, and associated anomalies were extracted and pooled into a meta-analysis. Results A total of 39 studies (110,866 patients) were included in the meta-analysis. The total pooled prevalence estimate of PTA and PTAVs combined was 0.4% (95% confidence interval [CI], 0.3–0.5). Individually, PTA was present in 0.3% of patients and PTAV in 0.2%. Both arteries most often originated from the C4 internal carotid artery and took a course lateral to the dorsum sellae. The anterior inferior cerebellar artery type was the predominant PTAV (72.1%). Basilar artery hypoplasia was found in 42.5% of patients with a PTA. Conclusions PTA and PTAVs are rare vessels, but they are clinically important because they can contribute to trigeminal neuralgia. Knowledge of the potential course of these arteries is essential in neuroradiology and neurosurgery, especially in minimally invasive procedures such as the endoscopic endonasal transsphenoidal approach to the pituitary gland and the percutaneous gasserian ganglion procedure.

Objective The retroinfundibular and upper clival regions are challenging to access using the endoscopic endonasal approach because these regions are obstructed by the dorsum sellae and posterior clinoid processes. We evaluated the safety and clinical efficacy of endoscopic dorsum sellar resection (DSR) and identified the optimal indications for endoscopic DSR in patients with craniopharyngioma. Methods A retrospective study was conducted of patients who had undergone treatment with an endoscopic endonasal approach from January 2014 to January 2019. We identified a total of 50 patients who had undergone DSR. The indications for DSR included the following: 1) a tumor involving the upper clivus; 2) a tumor located behind the dorsum sellae; and 3) a tumor involving the interpeduncular or prepontine cistern. We evaluated the clinical outcomes, postoperative endocrinological status, and surgical morbidities. Results Of the 50 patients, 16 had been treated for craniopharyngioma, 30 for chordoma, 2 for pituitary adenoma, 1 for schwannoma, and 1 for chondrosarcoma. An extradural approach for DSR with posterior clinoidectomy was performed in 33 patients (66.0%) and an interdural transcavernous approach in 17 patients (34.0%). The overall gross total tumor resection rate was 92.0% (46 of 50 patients). Postoperatively, 28 of 33 patients (84.8%) with normal pituitary function preoperatively showed preservation of hormonal function postoperatively. Conclusions DSR with or without posterior clinoidectomy is a challenging procedure that requires considerable effort and advanced surgical techniques. However, it can be safely performed with accumulating experience and a thorough knowledge of the surrounding anatomical structures.

Background The anterior transpetrosal (ATP) approach is the most appropriate approach for petroclival meningiomas (PCMs), which are typically located from the dorsum sellae to the upper border of the internal auditory meatus (IAM). Although neurosurgeons can resect over this area if the tumor is detached from the dura, tumors within the indication area for PCMs are not appropriate for the ATP approach, because it can be difficult to evaluate whether the tumor is attached to or only touching the dura. In this study, we investigated the tumor extension area based on an evaluation of the feeding artery to achieve a more accurate assessment of the dural attachment area. Methods Using various angiography techniques, we studied 51 feeding arteries from 24 patients who had undergone surgical treatment of primary petroapex meningiomas and PCMs via the ATP approach. We measured the lower and posterior extension distances, the extension rate of the cavernous sinus and Meckel's cave, and the midline extension rate of the tumors. Results The ascending pharyngeal artery (AphA) was the predominant feeding artery for tumors with lower extension. We determined that tumors extending over the lower border of IAM in cases in which the feeding artery was not the AphA can be resected using the ATP approach. Conclusions This study shows an association between the predominant feeding artery and tumor extension area and demonstrates that an evaluation of the dural attachment area based on the feeding artery can aid selection of the appropriate surgical approach.

To explore the surgical methods and clinical effect of endoscopic endonasal approaches for the treatment of invasive pituitary adenomas (IPAs).A retrospective analysis was made of the clinical data of 74 patients (75 procedures) with IPAs treated by different endoscopic endonasal approaches at the Department of Neurosurgery, The First Affiliated Hospital of Shenzhen University from May 2014 to August 2017. The data include clinical manifestation, imaging features, surgical methods and complications, resection rate, cure rate, prognosis, and complications in different Knosp classifications and Hardy stages. The transcavernous approach was used in 47 patients, the lateral-cavernous approach was used in 14 patients, the tuberculum sella planum approach was used in 8 patients, and the diaphragma sellae open or dorsum sellae cut approach was used in 6 patients.The gross total resection (GTR) rate was 70.7% (53 patients) and tumor residue rate was 29.3% (22 patients). GTR rate for pituitary adenoma according to Knosp classification was 89.3% in grade 3 and 28.6% in grade 4. The biology cure rate was 75.0% and 23.8%, respectively. There was significance between them (P 0.05). In addition, the GTR rate of Hardy stage was 90.5% in stage C, 90.0% in stage D, 26.1% in stage E, and the biology cure rate was 80.1%, 75.0%, and 13.0%, respectively. There was significance among them (P 0.05) Postoperative severe complications included 9 patients (12.0%) with cerebrospinal fluid leaks, 26 patients (34.7%)with electrolyte imbalance, 36 patients (48.0%) with transient diabetes insipidus, 22 patients (29.3%) with hypopituitarism, 2 patients (2.7%) with permanent hypopituitarism, and 2 patients (2.7%)with epistaxis. The follow-up lasted 2-41 months (average, 19.3 months). No patient experienced recurrence after GTR, 1 patient undergoing subtotal experienced recurrence and underwent reoperation, 3 patients underwent postoperative Gamma Knife treatment, and 2 patients with refractory IPA were given temozolomide and metformin chemotherapy.According to the invasiveness of IPA, choosing the appropriate endoscopic surgical approach is helpful in removing tumors and reducing complications.

Basilar bifurcation is a challenging site for aneurysm clipping. Anatomical factors such as size and projection of the aneurysm, distance between the aneurysm neck and the dorsum sellae, and location of the basilar bifurcation contribute to surgical complexity. Endovascular treatment has been used more frequently than microsurgical clipping, especially for posterior circulation lesions. Thus, the upcoming generation of neurosurgeons will have increasingly less access to the microsurgical treatment of such lesions. We present the case of a 45-year-old female patient who presented sudden mental confusion characterized by disorientation in time, space, and person. Investigative acute cerebral magnetic resonance imaging revealed diffusion restriction in the left posterior cerebral and superior cerebellar arteries. The clinical and cardiologic investigations revealed no abnormalities, but computed tomographic angiography and digital arteriography revealed a low-riding basilar bifurcation aneurysm and a very small aneurysm in the right internal carotid artery. The wide neck precluded coil embolization, and the appropriate stent was not covered by our public health insurance. Considering the young age, surgical treatment was proposed. Microsurgical clipping was performed using the right pre-temporal approach. In this two-dimensional video, we show the steps to reach the low-riding basilar bifurcation aneurysm neck. The positioning, transzygomatic pterional craniotomy, intradural anterior clinoidectomy, and posterior cavernous sinus opening are shown, and the surrounding anatomy is illustrated.

Background Cerebrospinal fluid (CSF) rhinorrhea after medical therapy for pituitary prolactinoma is a rare but well-described phenomenon. To our knowledge, no CSF leaks have been reported after targeted medical treatment of pituitary or anterior skull base metastases. We report this unusual case to raise awareness of spontaneous CSF leaks in the setting of skull base metastatic disease. Case Presentation A 66-year-old woman presented with epidermal growth factor receptor–mutant stage IV adenocarcinoma of the lung. Headache workup revealed a large sellar and clival lesion consistent with metastatic disease. Systemic erlotinib chemotherapy was initiated with a robust positive response. Approximately 1 week after chemotherapy initiation, the patient noted clear discharge from the right nostril. Her oncologist first diagnosed her with allergic rhinitis, but she presented with meningitis 4 days after diagnosis of CSF leak and was admitted for intravenous antibiotics and definitive repair of a CSF leak via an endoscopic endonasal approach. An erosion of bone and dura was found at the dorsum sellae where tumor had regressed due to the chemotherapy. A multilayer skull base repair was made uneventfully, and she recovered fully with no leakage seen at 2-month follow-up. Conclusions All members of the treatment team should be aware of this possibility of CSF leak after initiation of systemic chemotherapy and tumor regression and urgently refer patients for repair if a leak should develop before the development of meningitis.

Background The sellar spine is a rare, bony growth that typically arises from the dorsum sellae. Few cases have been described in the literature thus far, and most are asymptomatic and incidentally found. We describe the case of a 19-year-old female in whom a sellar spine was noted to be associated with pituitary glandular deformation and symptomatic optic apparatus compression. Case Description The medical records including clinical data, pathologic, and imaging findings pertaining to the single patient presented herein were retrospectively reviewed. The patient underwent resection of the hyperostotic sellar spine for decompression of the optic chiasm and pituitary gland via an endoscopic endonasal approach. She immediately reported complete resolution of her bitemporal visual deficits. Her headaches completely resolved, she had no further transient visual deficits, and all other prior presenting symptoms and signs resolved. Conclusion Recognition of a sellar spine can be elusive, and removal of a symptomatic one may be technically challenging. It is important to consider this entity in the differential diagnosis of a patient with headaches and bitemporal visual deficits.