Surgical and Radiologic Anatomy最新文献

A 50-year-old patient admitted for a subarachnoid hemorrhage underwent a successful surgical clipping of two aneurysms involving the anterior communicating artery and the supraclinoïd and ophthalmic segments of the right internal carotid artery. The analysis of the vertebrobasilar system through the brain computed tomography angiography and 3D modeling revealed a double origin of the right superior cerebellar artery from the basilar artery and the posterior cerebral artery. Two channels arose separately from the basilar artery and the P1 segment of the right posterior cerebral artery then merged distally to form the main trunk of the right superior cerebellar artery. To the best of our knowledge, this is the first time such a variant is reported.

Objective: To uncover the positional relationship between the lateral pterygoid plate (LPP) and foramen ovale (FO) in an adult population.

Methods: The 500 normal subjects (250 males and 250 females), who underwent cranial computed tomography scans were included into the study.

Results: Four configurations regarding FO location types were determined: the lateral type in 347 sides (34.7%), medial type in 115 sides (11.5%), the direct type in 412 sides (41.2%), and the far type in 126 sides (12.6%). The frequencies of these types were affected by sex (p < 0.001), but not side (p = 417). The most common configuration was the direct type (47.4%) in females and the lateral type (41.8%) in males. The antero-posterior and medio-lateral diameters of FO were measured as 7.35 ± 1.98 mm and 4.08 ± 1.26 mm, respectively. The antero-posterior diameter was greater in the lateral type compared to the medial and direct types (p = 0.003). The medio-lateral diameter was greater in the lateral type compared to the direct type (p < 0.001). The pterygoalar and pterygospinous bars were observed in 24 sides (2.4%) and 18 sides (1.8%), respectively. The positional relationship between FO and LPP was statistically different between presence and absence of the pterygoalar bar (p = 0.001), but not between presence and absence of the pterygospinous bar (p = 0.512). In FOs with the pterygoalar bar, the far type was seen significantly less common.

Conclusions: The incidence of the far type was 12.6%; thus, a neurosurgeon can reach FO relatively easily by tracing the base of LPP backward in more than 80% of the population.

Objective: To characterize portal vein (PV) confluence variants on contrast-enhanced CT, quantify the inferior mesenteric vein (IMV)-to-confluence distance by variant, and report previously undescribed configurations.

Methods: We first labeled variants using an extended 14-type scheme (Prado I-XII plus two new types XIII-XIV). For comparability with prior literature, these were then collapsed to three drainage categories (Thomson I/II/III: IMV → SV, true trifurcation at the SMV-SV junction, IMV → SMV) for distance analyses.

Results: After recoding to three drainage categories, the distribution was Type I/II/III = 45.7% (91/199) / 19.1% (38/199) / 34.7% (69/199). Two additional, previously unclassified variants (Types XIII-XIV) were identified on CT in 5/199 patients (2.5%). One case (Type XII, dual IMV) could not be assigned to a single drainage category and was excluded from the three-group comparisons (N = 198). Median IMV-to-confluence distances differed: 17.9 mm (Type I; interquartile range [IQR] 13.3-23.0), 0.0 mm (Type II; IQR 0.0-0.0), and 5.0 mm (Type III; IQR 3.5-7.0) (Kruskal-Wallis χ² = 159.12, p < 0.001; N = 198). Group differences were tested with Kruskal-Wallis and Bonferroni-adjusted pairwise Mann-Whitney U; agreement was assessed with Cohen's κ and ICC(2,1).

Conclusion: Classic PV confluence types predominate, but rare/novel configurations are present. The association between IMV drainage route and IMV-to-confluence distance supports variant-aware preoperative CT review to inform operative planning and patient safety.