Amir R. Dehdashti

"Introduction. Surgery for craniopharyngioma" published on Oct 2026 by American Association of Neurological Surgeons.

Background: Proximal arterial control is critical for safe and effective microsurgical clipping of ophthalmic segment aneurysms (OSAs). Traditionally, this is achieved via neck dissection and temporary clamping of the cervical internal carotid artery (ICA). Advances in endovascular technology have introduced temporary balloon occlusion (TBO) as a potentially less invasive alternative. This study aims to assess the utility of TBO during microsurgical clipping of OSAs. Methods: A retrospective review was conducted of all patients at a single institution who underwent microsurgical OSA clipping with planned TBO. Patient demographics, presentation, aneurysm morphology, occlusion outcomes, complications, recurrence, and functional outcomes based on modified Rankin score (mRS) at follow-up were evaluated. Patients who underwent balloon inflation for proximal control (+ TBO) were compared with those who did not (-TBO). Results: A total of 34 patients with 35 OSAs were included. A temporary balloon guide catheter was successfully navigated to the cervical carotid in all cases. TBO was performed in 19 patients (20 aneurysms) during aneurysm clipping. Aneurysm sizes ranged from 2.8 to 18.0 mm (mean: 6.7 mm), with neck sizes ranging from 1.6 to 8.1 mm (mean: 4.2 mm). The + TBO group had a significantly higher proportion of wide-necked aneurysms (> 4 mm) compared to the -TBO group (55.0% vs. 26.7%; p = 0.008) and more frequently required anterior clinoidectomy (84.2% vs. 46.7%; p = 0.020). Complete or near-complete (< 2 mm remnant) aneurysm occlusion was achieved in all cases. There was one complication (2.9%) with permanent sequela and median mRS at follow-up was 0. There were no significant differences in complication rates or functional outcomes between the + TBO and -TBO groups. Conclusion: Endovascular-assisted TBO is a safe and effective minimally invasive alternative to open neck dissection for achieving proximal control during OSA clipping. TBO may be particularly advantageous for managing wide-neck aneurysms.

Background: Although air embolism is a rare intraoperative complication associated with sitting or semi-sitting positioning during neurosurgical procedures, it carries a high morbidity and mortality rate. Prompt recognition is paramount; however, the treatment options are limited. We present the first case of intraoperative venous air embolism (VAE) that was successfully treated with venovenous extra-corporal membrane oxygenation (VVECMO) in a patient undergoing retro-sigmoid craniotomy for a vestibular schwannoma resection in the sitting position. Case Description: We present a young male who developed VAE requiring VV-ECMO after undergoing vestibular schwannoma resection through right retro-sigmoid craniotomy in sitting position. Diagnosis was made intraoperatively with the aspiration of air through the subclavian central venous catheter. Patient developed both indirect and direct pathophysiological changes of air embolism. Successful VV-ECMO resulted in resolution of indirect effects and good prognosis of the patient. Conclusion: Acuteness of judgment, understanding, and prompt response is required to diagnose and successfully treat pulmonary air embolism. In this report, we will discuss the occurrence, diagnosis, pathophysiology, and treatment of acute pulmonary air embolism in an operative setting. To date successful treatment of air embolism through venovenous extracorporeal membranous oxygenation, secondary to neurosurgical procedure has not been reported.

BACKGROUND AND OBJECTIVES: Preventive treatment of unruptured intracranial aneurysms (UIAs) requires assessment of treatment risks vs expected benefit. Although established scores exist to estimate rupture and growth risk, currently, no externally validated tools exist to estimate the risks of microsurgical treatment of UIAs. Clinical prediction models based on machine learning enable generation of personalized risk estimates for each individual patient based on their specific patient and aneurysm characteristics. METHODS: Using data from 20 international centers from the prediction of adverse events after microsurgery for intracranial unruptured aneurysms study on patients treated microsurgically for UIAs, we developed and externally validated clinical prediction models for 3 outcomes measured at hospital discharge: poor neurological outcome (modified Rankin Score ≥3), new sensorimotor neurological deficits, and all-cause adverse events (Clavien-Dindo Grade ≥1). RESULTS: A total of 3705 patients were included. Data from 13 centers (2881, 78%) were used for model development. Fully trained models were evaluated on 824 patients (22%) from 7 additional centers. Average age was 56 ± 12 years, and 1049 (28%) were male. At discharge, poor neurological outcome was seen in 514 patients (14%). New sensorimotor deficits were observed in 534 patients (14%), and 894 patients (24%) experienced adverse events until discharge. At external validation, prediction of poor neurological outcome was achieved with good calibration and an area under the curve (AUC) = 0.70 (95% CI: 0.63-0.75). Similarly, new neurological deficits were predicted with good calibration and with an AUC = 0.69 (95% CI: 0.63-0.74). Prediction of all-cause adverse events only achieved an AUC = 0.59 (95% CI: 0.55-0.64) with fair calibration. The prediction model was integrated into a web application accessible at https://neurosurgery.shinyapps.io/PRAEMIUM/. CONCLUSION: The developed models for prediction of poor neurological outcome and new sensorimotor neurological deficits at discharge exhibit good calibration and fair discrimination based on a multinational external validation, indicating that the predicted probabilities correspond well to real-world risks and may thus be clinically useful in more objectively estimating the risk of microsurgical treatment.

Purpose: Flow diverting stents are a mainstay treatment of intracranial aneurysms (IA). They rely on reduction of intra-aneurysmal blood flow velocity along with endothelialization to induce thrombus formation and promote occlusion. Patients with hematologic disorders (HDs) can have abnormal fluid dynamics and blood cell/metal interactions that can affect the mechanism of action of flow diversion (FD). We sought to determine the outcomes of patients with various HD after receiving FD treatment for IA.Materials and Methods: This retrospective chart review examined 11 patients with various HD who received FD for their IAs. HD were classified as either coagulopathies (e.g., factor deficiencies, von Willebrand disease) or hemoglobinopathies (e.g., sickle cell disease [SCD]). Patient outcomes were assessed clinically and radiographically, with radiographic outcomes based on O’Kelly-Marotta (OKM) scores from follow-up angiograms.Results: The total sample included 11 patients with 29 IAs. The median age was 50 years and 81.8% were female. All patients were on pre-procedural dual antiplatelet therapy. Out of the 29 total aneurysms, 17 were treated with FD and 15 originated from the paraophthalmic segment. Seven patients received surface modified stents. The median number of deployed stents during initial treatment was 2. The average aneurysm diameter was 5.03 mm (standard deviation: 3.88 mm). Patients with SCD were the only group to experience complications, with 2 out of 3 patients suffering a post-operative stroke. Seven patients with 8 treated aneurysms experienced complete occlusion at last follow-up with a mean time to OKMD score of 16.8 months.Conclusion: Despite a small sample size, this series raises concern for the use of FD in patients with SCD. While FD still resulted in adequate rates of aneurysm occlusion, treatment methodology must be tailored for patients with HD.

Intracranial aneurysms (IAs) affect about 3% of the population, often leading to catastrophic outcomes upon rupture. Vasa vasorum, microvessels supplying arterial walls, are conjectured to induce inflammation and leakage in IAs that drive adverse remodeling. Using scanning immunofluorescent multiphoton imaging and micro–computed tomography to visualize intact IA specimens, we identified an extensive vasa vasorum plexus in the IA wall. Our quantitative analyses show significant colocalization of vasa vasorum with calcifications, a strong correlation with increased wall thickness ( R ² = 0.96, P < 0.001), and associations with well-defined multiaxially oriented collagen fibers. These findings highlight a more nuanced role for vasa vasorum, suggesting both adverse and protective remodeling influences, which may critically affect IA rupture risk. Contrary to the prevailing view of vasa vasorum as solely adverse, this study underscores the contribution to IA wall stability and the need to elucidate their functional impact on IA pathophysiology. Hence, these microvessels warrant further investigation for therapeutic targeting.

Background: Glomus jugular tumors (GJTs), a subset of paragangliomas, are highly vascularized neoplasms arising in the jugular foramen, typically affecting middle-aged women. Although benign, GJTs often present with critical cranial neuropathies such as hearing loss, swallowing disturbances, and facial weakness and can cause venous outflow obstruction from jugular vein compression. In symptomatic cases, early intervention is warranted and involves surgical resection. Approaches include transmastoid approach, juxtacondylar approach, infratemporal approaches, transotic approach, extreme lateral infrajugular transtubercular exposure (ELITE), or a combination thereof. Due to the highly vascularized nature of these tumors and the relative fragility of nearby cranial nerves, significant bleeding and neurological deficits can occur as a consequence of resection. Intraoperative bleeding, however, can be reduced with preoperative embolization. Case Description: We present the case of a 57-year-old woman with a right-sided GJT extending into the jugular foramen and compressing the facial nerve. Given her progressive symptoms, we felt that radiosurgery was not an ideal treatment. The goals of the procedure were to decompress the facial nerve and achieve maximal safe tumor resection. We utilized the ELITE approach with tailored mastoidectomy, allowing anterolateral access to the tumor. The mastoidectomy allows skeletonization of the sigmoid sinus and jugular bulb as well as the fallopian canal housing the facial nerve. To minimize postoperative cranial nerve palsies, neuromonitoring was used to limit facial nerve manipulation, and an intrabulbar dissection approach was employed to avoid iatrogenic injury to other neurovascular structures. The patient consented to the procedure and the publication of her images. Conclusion: This case highlights a surgical approach that prioritizes both tumor resection and cranial nerve protection and offers insights into strategies for optimizing outcomes in GJT management. Furthermore, this case underscores the importance of tailored, precise techniques to minimize surgical morbidity for patients with these challenging lesions.