Endoscopic Exploration of Major Cerebral Sinuses with Intravenous Imaging

Introduction: To gain a deeper understanding of the anatomy of the major cerebral venous sinuses, we utilized an endoscope and a flexible camera to examine the chordae and arachnoid granulations within the sagittal sinus, torcular Herophili, transverse sinus, and sigmoid sinus. Our goal was to re-evaluate the significance of chordae Willisii and arachnoid granulations in the context of venous stent deployment and diagnostic cerebral venograms.

Methods: Five adult cadaveric specimens, which had been preserved in 4%formalin without any prior freezing, were utilized to investigate the major cerebral venous sinuses. After the cranial vaults were removed, an endoscope was inserted into the lumen of the superior sagittal sinus to examine the structures and morphological features of the chordae Willisii, and the topographic distribution of the arachnoid granulations. For the transverse and sigmoid sinus, a flexible camera was used intravenously. After obtaining images, granular adhesions from the junction of the transverse sinus to the sigmoid sinus were captured. The acquired fluoroscopic and endoscopic images were then comparatively assessed, encompassing microsurgical dissection, histological examination, and intravenous endoscopic imaging.

Results: We identified and confirmed various types of chordae in the lumen of the sagittal sinus: valve-like, trabecular, and laminar chordae. The laminar chordae at the posterior end of the sagittal sinus divided the sinus into two separate channels, which can pose challenges for endovascular venous stenting. Similar structures were also observed in the lumen of the torcular herophili. The majority of arachnoid granulations were found as digitations in the lumen along the lateral wall or lateral recess of the middle segment of the transverse sinus and the posterior aspect of the superior sagittal sinus. The histological evaluation of the intraluminal structures of the major sinuses confirmed the endoscopic findings.

Conclusion : When performing procedures like venous stenting, it's important to remember the hidden structures like arachnoid granulations and chordae Willis, which aren't visible on regular angiography. These factors should be kept in mind for both venous stent procedures and diagnostic angiographies.