Pneumocephalus after posterior fossa surgery in the lounging position: risk analysis of intracranial air collections and clinical outcome by voxel-based volumetry
Notice bibliographique
Résumé
OBJECTIVE: Semisitting or lounging patient positions offer several advantages in neurosurgical procedures, particularly for the resection of large and highly vascularized posterior fossa lesions. However, concerns persist regarding potentially severe complications such as tension pneumocephalus (TP) and venous air embolisms. The aim of this study was to assess the extent and distribution of postoperative pneumocephalus and to identify risk factors of TP. METHODS: This retrospective analysis included consecutive patients who underwent posterior fossa surgery in the lounging position from January 2010 to November 2020 at a single center. Postoperative cranial CT scans acquired within 24 hours after surgery were registered and normalized to the common Montreal Neurological Institute space to measure intraventricular, subdural, and total intracranial air using voxel-based volumetry. TP was defined as intracranial air associated with reduced consciousness, and its treatment was typically performed via external ventricular drain (EVD) placement or subdural air exchange through mini burr hole trepanation. Patient characteristics, surgical details, and clinical outcome were evaluated. RESULTS: Overall, 836 patients (462 female, mean age 48.7 years) were included. The indication for surgery was resection of a posterior fossa tumor (96.1%, n = 803), vascular pathology (2.6%, n = 22), malformation (1.1%, n = 9), or other pathology (0.2%, n = 2). Lateral suboccipital and midline suboccipital approaches were performed in 93.8% (n = 784) and 6.2% (n = 52) of patients, respectively. Intracranial air was detected in all patients, with a mean volume of 74 ± 59 mL. The volumetric analysis revealed significantly higher mean volumes of intracranial air (midline: 94 ± 72 mL, lateral: 73 ± 58 mL) [t(828) = 2.44, p = 0.008 (95% CI 4-38)] and intraventricular air (midline: 29 ± 32 mL, lateral: 3 ± 14 mL) [t(828) = 11.36, p < 0.001 (95% 21-30)] in midline approaches compared with lateral approaches. TP occurred in 3.0% of patients, with higher rates (15.4%) in those who underwent midline craniotomies compared with lateral approaches (2.0%) [χ2(1) = 31.14, p < 0.001]. Patients with TP required longer ventilation, intensive care unit stays, and hospitalizations, although Karnofsky Performance Status scores did not differ significantly at follow-up. The logistic regression analysis identified surgical approach, age, duration of surgery, and sex as independent predictors of TP [χ2(4) = 41.34, p < 0.001]. The area under the curve (AUC) analysis indicated that intraventricular air volumes ≥ 27.6 mL were associated with EVD placement (AUC = 0.92, sensitivity = 0.90, specificity = 0.95). TP was managed effectively in all cases, with no long-term sequelae. CONCLUSIONS: These findings suggest that the lounging position can be performed safely with careful monitoring for TP, particularly in older male patients and those undergoing longer surgeries via midline approaches. Awareness of risk factors and early postoperative imaging can help mitigate complications and improve patient outcomes.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».