PMC8769441_01
3D-CT angiography. (A) Preoperative non-enhanced CT: Right ICA was highly calcified (red circle). Hyoid bone (HB) (purple circle) was positioned lateral to ICA. (B) Preoperative 3D-CTA MIP image: ICA ran medial to ECA. HB (purple circle) and superior horn of thyroid cartilage (SHTC) (green circle) positioned lateral to carotid arteries. (C) Preoperative 3D-CTA reconstruction image: ICA (arrow) ran medial to ECA (arrowhead). HB and SHTC covered carotid artery. The length of SHTC was 2.4 cm. (D) Postoperative 3D-CTA reconstruction image: ICA and HB both return to their natural position. SHTC was partially removed and its length was 0.86 cm. ECA: external carotid artery, ICA: internal carotid artery.
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F1
Three-dimensional CTA (3D-CTA) (Fig. 1) detected highly calcified bilateral carotid arteries, and the right side was especially severe. Postoperative 3D-CTA showed ICA running normalized naturally after surgery (Fig. 1D).
Intraoperative view. (A) The view after retracting sternocleidomastoid muscle posteriorly. The blue dotted line shows the line of greater horn of hyoid bone (HB), and the green dotted line shows the superior horn of thyroid cartilage (SHTC). (B) The view after retracting HB and removal SHTC and dissecting connective tissue around carotid sheath. ECA: external carotid artery, ICA: internal carotid artery. (C) Superimposition of the views in (A) and (B). While the images in (A) and (B) were photographed, the camera was not moved, and zoom or focus operations were not performed. HB and thyroid cartilage covered the carotid sheath as preoperative 3D-CTA showed.
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F2
After skin and platysma incision and retraction of the sternocleidomastoid muscle, the greater horn of HB and SHTC was detected easily (Fig. 2). 3D-CTA revealed that these two structures covered the carotid artery, but there was no compression or adherence between these bony structures and the carotid artery that would compromise the operation.