Neto, Carlos D. Pinheiro

BACKGROUND AND OBJECTIVES: Endoscopic transnasal surgery offers a minimally invasive alternative to transcranial approaches for accessing midline skull base lesions involving the petrous apex and petroclival region. However, lateral access, particularly behind the petrous internal carotid artery (ICA), remains limited. The contralateral transmaxillary (CTM) approach provides a more direct surgical trajectory, more parallel to the petrous ICA. Yet, lateral access through this approach can be restricted by anatomic barriers, including the pterygoid process and lateral buttress of the maxillary sinus. We aimed to evaluate the contralateral transmaxillary-transpterygoid (CTMP) approach, with and without the lateral buttress removal (CTMP-LBR), to determine whether these modifications could enhance surgical access to the petroclival region. METHODS: Ten sides from 5 formalin-fixed, latex-injected cadaveric specimens were dissected to compare CTM, CTMP, and CTMP-LBR approaches. Petrous bone drilling was directed posterolaterally behind the petrous ICA toward the region medial to the cochlea. In addition, 30 sides from computed tomography angiography scans were analyzed to obtain radiographic measurements for each approach. RESULTS: Compared with CTM, both CTMP and CTMP-LBR significantly increased access for retrocarotid petrous bone drilling ( P < .001) and yielded a wider surgical angle relative to midline ( P < .001), in both cadaveric and radiographic analyses. In dissections, 20% of sides required CTM only, 50% benefited from CTMP, and 30% required CTMP-LBR to achieve adequate lateral access. Radiographic analysis revealed that CTMP required a median of 4 mm of pterygoid drilling, whereas CTMP-LBR required 9 mm and enabled a trajectory parallel to the petrous ICA with only 11 mm of soft tissue displacement. Patients with smaller angles between the petrous ICA and the horizontal plane were significantly more likely to benefit from CTMP over CTM ( P = .005). CONCLUSION: Modification of the CTM approach with pterygoid drilling and optional LBR improves retrocarotid access. Preoperative evaluation of the petrous ICA angle may help optimize patient-specific planning in endoscopic petroclival surgery.

Abstract Prolactinomas comprise half of all pituitary adenomas. This study explores the significance of measuring intraoperative (IO) prolactin (PRL) levels in guiding surgical decision-making and predicting operative success. Retrospective cohort study design of consecutive patients with prolactinomas who underwent transsphenoidal resection from June 2021 to May 2023. IO PRL was measured after tumor resection was completed. Remission was defined as normalization of PRL levels during follow-up without medication. Outcomes included factors associated with remission, utilizing significance thresholds at p < 0.05. Thirteen patients were included with a 5.3-month median follow-up (range, 3–15 months). Most of the tumors were microadenomas (61%), with a median preoperative PRL level of 116 ng/mL (range, 25–471). Gross total resection was achieved in 69% of patients, all of whom attained remission. The median IO PRL was 19.8 ng/mL (range, 1–329), the postoperative day 1 PRL of 3.6 ng/mL (range, 1–203), and the latest PRL at 9.3 ng/mL (range, 1–137). A ≥40% decline in IO PRL from baseline was identified as the optimal cutoff for predicting biochemical remission, with 89% sensitivity, 75% specificity, and 85% accuracy. Monitoring PRL levels intraoperatively may be a useful biomarker aiding surgeon's assessment of the extent of tumor resection and guide surgical decision-making. Further refinement of the immunoassay assay and clinical testing with more extensive prospective studies are needed.