UNASSIGNED: The pterional craniotomy, described by Yasargil and Fox in 1975, constitutes the most traditional and important surgical access in vascular neurosurgery. Minimally invasive alternatives include the minipterional (MP) and lateral supraorbital (LSO) craniotomies, which avoid complications such as injury to the frontal branch of the facial nerve, temporal muscle dysfunction, depression of the craniotomy site, frontal sinus opening, and cosmetically unacceptable outcomes. We evaluated and compared the exposures provided by MP and LSO craniotomies through quantitative measurements of the surgical exposure area around the circle of Willis and parasellar regions, as well as angular and linear exposures of the internal carotid artery (ICA) bifurcation, middle cerebral artery (MCA), midpoint of the anterior communicating artery, and tip of the basilar artery (BA).
UNASSIGNED: Seven fresh cadavers were dissected at the São Paulo Medical Examiner\'s Office, SP, and three at the skull base laboratory of Weill Cornell Medical College, New York, USA. The craniotomies were performed sequentially, initially with the LSO craniotomy followed by the MP. After the craniotomy, the surgical exposure area, craniotomy area, and angular exposures in the horizontal and vertical axes were determined.
UNASSIGNED: The MP craniotomy provided better angular exposure for the ipsilateral MCA, while the LSO craniotomy and BA provided better vertical axis exposures. The LSO craniotomy provided better angular exposure in the vertical axis for the midpoint of the anterior communicating artery and contralateral ICA bifurcation. Regarding surgical exposure and craniotomy area, there were no statistically significant differences.
UNASSIGNED: The MP craniotomy offers a significantly larger surgical exposure compared to the LSO craniotomy, with specific advantages regarding angular exposure to important neurovascular structures. This study provides important quantitative data to guide the choice between these minimally invasive access techniques in vascular neurosurgery.

BACKGROUND: The pterional or frontosphenotemporal craniotomy has stood the test of time and continues to be a commonly used method of managing a variety of neurosurgical pathology. Already described in the beginning of the twentieth century and perfected by Yasargil in the 1970s, it has seen many modifications. These modifications have been a normal evolution for most neurosurgeons, tailoring the craniotomy to the patients\' specific anatomy and pathology. Nonetheless, an abundance of variations have appeared in the literature.
METHODS: A search strategy was devised according to the 2020 Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) statement. To identify articles investigating the variations in the pterional approach, the following search terms were applied: (pterional OR minipterional OR supraorbital) AND (approach OR craniotomy OR technique).
RESULTS: In total, 3552 articles were screened with 74 articles being read in full with 47 articles being included for review. Each article was examined according the name of the technique, temporalis dissection technique, craniotomy technique and approach.
CONCLUSIONS: This systematic review gives an overview of the different techniques and modifications to the pterional craniotomy since it was initially described. We advocate for the use of a more standardised nomenclature that focuses on the target zone to simplify the management approach to supratentorial aneurysms.

Surgical access to the middle fossa can be technically challenging. As neurosurgery evolves to minimally invasive approaches, the objective of this study is to demonstrate the extension of the Minipterional approach to access the middle fossa. We present a new surgical approach to the middle fossa for the treatment of secondary trigeminal neuralgia. Three cases are reported to illustrate the following techniques: a patient with petrotentorial meningioma and trigeminal neuralgia, a patient with an arachnoid cyst compressing the fifth nerve, and a patient with a middle cerebral artery aneurysm and a long history of TN (trigeminal neuralgia) refractory to medical and surgical treatments. All three experienced full symptom controls with no permanent neurological deficits. Therefore, the Minipterional technique might represent a feasible, effective, and safe option to treat refractory secondary TN. It also allows approaching these lesions when the posterior fossa approach is compromised by anatomical distortion and enables the simultaneous treatment of secondary trigeminal neuralgia and other lesions, such as aneurysms and meningiomas.

The objective of the study was to assess the esthetic efficacy of acellular dermal matrix (ADM) implantation to prevent frontotemporal depression (FTD) following minipterional craniotomy (MPT) to clip unruptured intracranial aneurysms.
We retrospectively compared the incidence of FTD in 100 patients treated without ADM from March to July 2019 and 100 patients treated with ADM from August to December 2019. ADM was implanted in the interfascial layer to cover the temporalis muscle. The specific location and degree of FTD were analyzed by measuring the thickness and area of multiple points (P1-P12) and regions (S1-S3) through brain computed tomography preoperatively and 1 year postoperatively.
In the non-ADM group, the thickness at P1, P2, P5, P6, and P9 was reduced and the area of S1 and S2 was smaller after surgery than before surgery (P < 0.05), similar to the incision and suture site of the temporalis muscle. However, in the ADM group, the preoperative and postoperative measurements were not different. FTD recognition was significantly lower in the ADM group (6.0%) than that in the non-ADM group (17.0%) (P = 0.015) and occurred in the retroorbital region through P1, P2, P5, and P6, with the area under the receiver operating characteristic curves of 0.840, 0.766, 0.811, and 0.751, respectively. ADM implantation was the only significant predictive factor for FTD recognition in multivariate logistic regression analysis (odds ratio = 0.30; 95% confidence interval: 0.11-0.79; P = 0.015).
Even MPT cannot completely prevent FTD in the retroorbital region. ADM implantation in MPT can help to improve esthetic satisfaction.

UNASSIGNED: The aim of this study was to assess the feasibility, safety and efficiency of minipterional craniotomy (MPT) for surgical clipping of anterior circulation aneurysms.
UNASSIGNED: A retrospective study was conducted to compare the MPT from Jan 2015 to Dec 2018 and conventional pterional craniotomy (CPT) from Jan 2012 to Dec 2013 in unruptured intracranial aneurysms (UIA) and ruptured intracranial aneurysms (RIA). The feasibility and safety of MPT and CPT were assessed by analyzing medical records, radiologic imaging, and clinical outcomes. The efficiency of MPT and CPT were based on a survey research of temporomandibular dysfunction, facial nerve paralysis, and facial asymmetry.
UNASSIGNED: Total 628 patients who underwent 458 MPT (UIA:313, RIA:145) and 170 CPT (UIA: 106, RIA: 64) with anterior circulation aneurysms were included in this study. The baseline characteristics between MPT and CPT had no difference (p>0.05). There was no difference in the incidence of postoperative hemorrhage or ischemic lesions between MPT and CPT (p>0.05). The incidence of surgical wound infection was lower in MPT (0.4%) than CPT (3.5%) (p=0.002). More than 90% of postoperative pain disappeared faster in MPT (14.25±4.83 days) than CPT (27.59±10.35 days), and the feeling of facial asymmetry in surgical side was also lower for MPT (1.7%) than CPT (7.6%) (p<0.001). In the MPT, no patients presented with progress to chronic pain, masticatory disability, discomfort of maximal mouth opening or permanent facial palsy.
UNASSIGNED: We suggest that MPT and CPT had similar clinical outcomes, and MPT showed better functional and cosmetic outcomes than CPT in terms of temporomandibular dysfunction, facial nerve paralysis, and facial asymmetry. Therefore, MPT for surgical clipping of anterior circulation aneurysms can be a compatible technique that satisfies the feasibility, safety and efficiency.

Numerous minimally invasive approaches to the skull base have been successively developed. Knowledge of the surgical nuances of a specific approach may facilitate approach selection. This study sought to compare the nuances of an extended version of the minipterional craniotomy (EMPT) with those of the transorbital endoscopic approach (TOEA) to the anterior and middle cranial fossae (ACF and MCF, respectively).
To quantitatively analyze and compare the area of exposure and surgical freedom between EMPT and TOEA to the ACF and MCF.
EMPT and TOEA were carried out in 5 latex-injected cadaveric heads, bilaterally (10 sides). For each approach, the area of exposure, surgical freedom, and angle of attack were obtained with neuronavigation and statistically compared.
No significant difference was found between the mean area of exposure of EMPT and TOEA at the ACF and MCF (P = .709 and .317, respectively). The mean exposure area at the ACF was of 13.4 ± 2.6 cm2 (mean ± standard deviation) and 13.0 ± 1.9 cm2 for EMPT and TOEA, respectively. Except for the crista galli, EMPT afforded a larger area of surgical freedom at all targets. EMPT also achieved significantly greater attack angles in vertical axis except to the crista galli. The horizontal attack angles to all targets were similar between approaches.
EMPT and TOEA offer a comparable area of exposure at the ACF and MCF in the cadaver; however, the instrument maneuverability afforded by EMPT is superior. Further studies are necessary to better define their precise surgical application.

OBJECTIVE: Minimally invasive alternatives to the pterional craniotomy include the minipterional and the supraorbital craniotomy (SOC). The latter is performed via either an eyebrow or an eyelid skin incision. The purpose of this systematic review was to analyze the type and the incidence of approach-related complications of these so-called \"keyhole craniotomies\".
METHODS: We review pertinent articles retrieved by search in the PubMed/Medline database. Inclusion criteria were all full-text articles, abstracts, and posters in English, up to 2016, reporting clinical results.
RESULTS: A total of 105 articles containing data on 5837 surgeries performed via a minipterional or either of the 2 variants of the SOC met the eligibility criteria. Pain on mastication was the most commonly reported approach-related complication of the minipterional approach, and occurred in 7.5% of cases. Temporary palsy of the frontal branch of the facial nerve and temporary supraorbital hypesthesia were associated with the SOC eyebrow variant, and occurred in 6.5%, respectively in 3.6% of cases. Transient postoperative periorbital edema and transient ophthalmoparesis occurred in 36.8% and 17.4% of cases, respectively, when the SOC was performed via an eyelid skin incision. The risk of occurrence of the latter 2 complications was related to the removal of the orbital rim, which is an obligatory part of the SOC approach through the eyelid but optional with the SOC eyebrow variant.
CONCLUSIONS: Each of the 3 keyhole approaches has a specific set and incidence of approach-related complications. It is essential to be aware of these complications to make the safest individual choice.

OBJECTIVE: To report our experience with the minipterional (MPT) craniotomy approach for anterior circulation aneurysms and to discuss the clinical outcomes as well as to evaluate the advantages of this unique approach.
METHODS: Single-center retrospective review of 57 cases involving anterior circulation aneurysms both ruptured and unruptured aneurysms treated with the MPT. We analyzed the clinical and patient demographic data, aneurysm characteristics, surgical outcomes, and complications in these individuals.
RESULTS: Between July 2008 and March 2014, of the 57 patients reviewed: 45 had middle cerebral artery (MCA), 6 had internal carotid artery terminus, and 7 had posterior communicating artery aneurysms. 20 of the 57 patients presented with a ruptured aneurysm. The average aneurysm size was 5.8 mm. The length of hospitalization for unruptured aneurysm cases ranged between 3 and 5 days. The average follow-up for all cases was 21.5 months. Successful clipping of the aneurysms was obtained in all patients. None of the cases required additional skin incisions or craniotomy extensions. The overall surgical outcomes were favorable. There was no postoperative facial nerve damage, temporalis muscle wasting, or symptoms of paresthesias around the incision line. Two patients developed a postoperative stroke manifested as symptoms of unilateral arm and facial weakness, receptive aphasia, and dysarthria.
CONCLUSIONS: The MPT provides a reliable and less invasive alternative to the standard pterional craniotomy. Furthermore, ruptured and unruptured anterior circulation aneurysms can safely and effectively be treated with limited bone removal which provides better cosmetic outcomes and excellent postoperative temporalis muscle function.

Pterional craniotomy (PT) has long been the standard approach for the treatment of middle cerebral artery (MCA) aneurysms, even though it may cause temporalis muscle atrophy, facial nerve injury, and masticatory difficulties. Minipterional craniotomy (MPT) is an alternative approach that may provide the same surgical corridor, limiting the risk of postoperative esthetic and functional complications. From January 2011 to December 2014 we consecutively performed 68 craniotomies for surgical treatment of unruptured MCA aneuryms: 37 were standard PT and 31 were MPT. There were no significant differences in mean age, sex, and aneurysm topography between the two groups. The mean skin incision length was 14 cm in the PT group and 6 cm in the MPT group. According to the Glasgow Outcome Scale (GOS) and modified Rankin Scale (mRS), there were no significant differences in clinical outcome at discharge or follow-up between the two groups. Also, the rates of complete aneurysm exclusion were comparable. However, the number of patients complaining of masticatory disorders was higher among those treated with PT. Finally, the number of complications observed in the PT group was higher than that in the MPT group, but only the differences in mean hospitalization length and necessity for a dural patch for reconstruction were statistically significant. In conclusion, the MPT approach is a safe and effective alternative to the standard PT for the treatment of unruptured MCA aneurysms.

The pterional approach was described in the 1970s and has become the most utilized cranial approach with many variations described, including the minipterional technique. Although described recently as an alternative to the pterional approach for anterior circulation aneurysms, to our knowledge a large series of cases using the minipterional approach in both ruptured and unruptured aneurysms has not been described. We present our clinical experience with the minipterional craniotomy in more than 100 ruptured and unruptured anterior circulation aneurysms. The results of 86 consecutive patients with 102 ruptured non-giant, anterior circulation aneurysms treated with early surgery utilizing the minipterional craniotomy were analyzed. Postoperative angiography was carried out in all cases. Outcome results were classified as excellent in 67 (77.9%), and good in seven (8.1%), while 16 (13.9%) patients died. The minipterional technique provides adequate surgical exposure and excellent outcomes for both ruptured and unruptured anterior circulation aneurysm clipping. It constitutes a safe and effective alternative to the pterional approach, with equivalent or potentially better aesthetic and functional outcomes.