Supraorbital and mini-pterional keyhole craniotomies for brain tumors: a clinical and anatomical comparison of indications and outcomes in 204 cases

OBJECTIVE The authors’ objective was to compare the indications, outcomes, and anatomical limits of supraorbital (SO) and mini-pterional (MP) craniotomies in patients with intra- and extraaxial brain tumors, and to assess approach selection, utility of endoscopy, and surgical field overlap. METHODS A retrospective analysis was conducted of all brain tumor patients who underwent an SO or MP approach. The analyzed characteristics included pathology, endoscopy use, extent of resection, length of stay (LOS), and complications. On the basis of preoperative MRI data, tumor heatmaps were constructed to compare surgical access provided by both routes, including coronal projection heatmaps for parasellar tumors. RESULTS From 2007 to 2020, 158 patients underwent 173 (84.8%) SO craniotomies and 30 patients underwent 31 (15.2%) MP craniotomies; 71 (34.8%) procedures were reoperations. Of these 204 operations, 110 (63.6%) SO and 21 (67.7%) MP approaches were for extraaxial tumors (meningiomas in 65% and 76.2%, respectively). Gliomas and metastases together represented 84.1% and 70% of intraaxial tumors accessed with SO and MP approaches, respectively. Overall, 56.1% of tumors accessed with the SO approach and 41.9% of those accessed with the MP approach were in the parasellar region. Axial projection heatmaps showed that SO access extended along the entire ipsilateral and medial contralateral anterior cranial fossa, parasellar region, ipsilateral sylvian fissure, medial middle cranial fossa, and anterior midbrain, whereas MP access was limited to the ipsilateral middle cranial fossa, sylvian fissure, lateral parasellar region, and posterior aspect of anterior cranial fossa. Coronal projection heatmaps showed that parasellar access extended further superiorly with the SO approach compared with that of the MP approach. Endoscopy was utilized in 98 (56.6%) SO craniotomies and 7 (22.6%) MP craniotomies, with further tumor resection in 48 (49%) and 5 (71.4%) cases, respectively. Endoscope-assisted tumor removal was clustered in areas that were generally at farther distances from the craniotomy or in angled locations such as the cribriform plate region where microscopic visualization is limited. Gross-total or near-total resection was achieved in 120/173 (69%) SO approaches and 21/31 (68%) MP approaches. Major complications occurred in 11 (6.4%) SO approaches and 1 (3.2%) MP approach (p = 0.49). The median LOS decreased to 2 days in the last 2 years of the study. CONCLUSIONS This clinical experience suggests the SO and MP craniotomies are versatile, safe, and complementary approaches for tumors located in the anterior and middle cranial fossae and perisylvian and parasellar regions. The SO route, used in 85% of cases, achieved greater overall reach than the MP route. Both approaches may benefit from expanded visualization with endoscopy.

Pneumocephalus with meningitis secondary to an old traumatic anterior cranial fossa defect

We report a case of a 30-year-old man who presented with altered mental status, fever, headache and vomiting for 3 days. An initial CT scan of the brain revealed the presence of pneumocephalus with a bony defect in the anterior cranial fossa. The pneumocephalus was not explained initially and the patient was re-examined for any signs of trauma to the face, and a review of the history revealed a series of three traumatic events months prior to this illness. Further laboratory studies revealed Streptococcus pneumoniae in the blood and bacterial meningitis. He was treated with antibiotics and was later taken up for endoscopic repair of the skull base defect. This case highlights the importance of recognising post-traumatic pneumocephalus with superimposed meningitis and sepsis months after a traumatic event to the skull base.

Metopic triangle osteotomy in trigonocephaly Piezosurgery: a technical variant to control metopic emissary veins

Premature fusion of the metopic suture results in trigonocephaly with variable degrees of anterior cranial fossa dysmorphia and craniofacial deformity. Different surgical corrective techniques that aim to reshape the forehead and enlarge the cranial volume have been described. Typical variations of the standard fronto-orbitary advancement carry the risk of relevant blood loss during frontal osteotomy, where paired emissary metopic veins are disrupted. The authors present a technical variant that preserves a bony triangle over the glabella to optimize control of these veins, which represent the major source of bleeding, and applies Piezosurgery to perform the osteotomies to minimize bone substance loss. The video can be found here: https://vimeo.com/511536423.

Endonasal Endoscopic Approach for a Psammomatous Juvenile Active Ossifying Fibroma: 2-Dimensional Operative Video

We present the case of an 18-yr-old female with 4 mo of progressive vision loss in the left eye. She underwent a computed tomography (CT) and magnetic resonance imaging (MRI), which revealed a large mass in the sphenoid sinus, sella, and anterior cranial fossa. This mass was T1 isointense, with heterogenous enhancement noted on T1 with gadolinium sequences. The mass was found to have calcifications and cystic portions on T2-weighted MRI scans and CT-based imaging. She underwent an endonasal endoscopic approach for resection of the mass. The tumor was found to be bloody, with islands of bone nests within the dura mater of the anterior cranial fossa. The patient improved postoperatively. The pathological diagnosis was found to be the psammomatoid variant of juvenile active ossifying fibroma (JAOF). We present the neuroimaging, anatomic nuances,1 and operative techniques used in this case. We also review the disease background of this rare lesion of the anterior skull base.2-4 The patient gave informed consent for the procedure and verbal consent for the publication of this article.