Morphological Variability of Dural Venous Sinus Grooves and Internal Bony Findings: Clinical and Surgical Considerations

10.1055/a-2649-2161

We read with great interest the recent article by Triantafyllou et al[1] titled “Anatomical Variability of the Transverse and Sigmoid Sinus Grooves: Implications for Skull Base Surgery,” in which the authors provide a thorough morphological assessment of the bony grooves corresponding to the transverse and sigmoid sinuses in a Greek skeletal sample. Their work adds to the growing body of anatomical literature emphasizing the surgical relevance of posterior cranial fossa venous anatomy.

We commend the authors for their comprehensive approach and would like to share a few reflections to further contextualize and expand upon their findings.

The authors' attention to groove morphology is valuable, as it is a subject that remains vastly under characterized in both classical and contemporary anatomical literature. Despite the central role of the dural venous sinuses in intracranial venous hemodynamics and their importance in venous sinus pathologies and skull base procedures, much remains to be understood about their morphometry and anatomical variants, especially in relation to the surrounding osseous topography. In that regard, this study represents a valuable step forward.

One of the most compelling findings was the statistically significant positive correlation between the widths of the sigmoid and transverse sinus grooves. While intuitive in theory, since these sinuses are functionally continuous, this observation is infrequently documented in anatomical studies. It is worth noting, however, that the authors did not specify the precise segmental location of the measurements. This is particularly relevant, as both the transverse and sigmoid sinuses are known to have segmental divisions with variable morphometric profiles. Previous studies, including ours, have emphasized the importance of this segmentation, especially given its correlation with pathophysiologic processes such as venous sinus stenosis and sinus thrombosis.[2] [3] [4]

Additionally, the most common pattern of communication reported was the confluence type; notably, they did not observe variant configurations beyond the classic right- or left-dominant, bifurcated, or confluence/symmetrical types. For instance, we encountered some cases where the groove for the oblique occipital sinus joined the right transverse sinus groove at the confluence.[5] Furthermore, the authors did not identify any granular foveolae, an important internal parameter often associated with the presence of arachnoid granulations.[6] Whether these discrepancies reflect methodological differences, population-specific traits, or clinical/environmental factors remains uncertain; yet these constitute essential limitations, as transparently acknowledged by the authors. Moreover, these observations raise intriguing questions about venous hemodynamics and vascular health in the studied population, as well as more broadly. Could such differences positively or negatively influence intracranial hemodynamics and thereby impact the prevalence of dural venous sinus pathologies such as venous sinus stenosis, idiopathic intracranial hypertension, cerebral venous sinus thrombosis, and pulsatile tinnitus?

We are especially grateful to the authors for citing several of our team's studies. We want to take this opportunity to highlight a particular aspect of our recent work: the angulation of the dural venous sinuses in the posterior cranial fossa. This raises the question of whether differences in angulation exist between the soft tissue and the underlying bony grooves. It also emphasized how such angulation may influence regional venous hemodynamics and contribute to the development of associated pathologies.[5] [7] Similarly, our proposed classification of internal groove morphology, based on the presence of granular foveolae, absence of transverse sinus groove, and emissary foramina, also offers potential for clinical translation.[8] These morphological features may reflect compensatory adaptations of the intracranial venous system in both physiological and pathological states. Their anatomical configurations, particularly within the posterior cranial fossa, may help explain individual variability in venous outflow patterns and susceptibility, or even relative resistance, to disease.[7] [8] [9]

In addition to venous anatomy, our team has also recently highlighted the presence of the sigmoid sinus artery—an arterial branch traversing the lateral surface of the sigmoid sinus, often through the mastoid foramen.[10] This underrecognized structure, which may take extradural or intradural (and even intraosseous) paths, has important implications during the transmastoid approach, where its inadvertent injury could result in bleeding or compromise of the sinus wall. The study not only reinforces the complexity of the region but also highlights that both venous and arterial structures must be accounted for in surgical planning.

In conclusion, the anatomical intricacies of the posterior cranial fossa remain an area that is ripe for further exploration. The study by Triantafyllou et al[1] provides valuable insight into venous sinus groove variability and raises important questions about population-specific anatomy and its clinical considerations. We congratulate the authors on their contribution and look forward to future studies that further illuminate the interplay between cranial morphology, vascular anatomy, and neurosurgical relevance.

Publikationsverlauf

Eingereicht: 28. August 2025

Angenommen: 07. September 2025

Artikel online veröffentlicht:
03. Oktober 2025

• References

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