Detection of increased intracranial pressure in trans‐oral robotic thyroidectomy using optic nerve sheath diameter measurement

Abstract

Background During transoral robot‐assisted thyroidectomy, there is a risk of increasing intracranial pressure because the site of CO2 insufflation is narrow and close to the brain. Methods We analyzed the pre‐ to post‐CO2 neck insufflation change in the optic nerve sheath diameter during transoral robot‐assisted thyroidectomy. Changes in vital‐signs, airway pressure, and arterial carbon dioxide pressure were analyzed along with postoperative complications. Results Among the 30 participants, the post‐CO2 inflation mean optic nerve sheath diameter (5.64 ± 0.54 mm) was higher than the pre‐induction diameter (4.81 ± 0.37 mm) with a mean difference of 0.83 (95% CI, 0.69–0.97; p < 0.001), but returned to baseline after CO2 deflation in most cases. One participant had sustained increased optic nerve sheath diameter (6.35 mm) associated with severe new‐onset postoperative headache. Conclusion Transient elevation in the intracranial pressure during low‐pressure CO2 neck insufflation in the transoral robot‐assisted thyroidectomy did not appear to adversely affect patients.

Comment on “Detection of increased intracranial pressure in trans‐oral robotic thyroidectomy using optic nerve sheath diameter measurement”

“…We read with great interest the article by Lim et al concerning the ultrasound measurement of the optic nerve sheath diameter (ONSD) in patients undergoing trans-oral robotic thyroidectomy. 1 The topic of this paper is very interesting: this kind of surgery involves the risk of an intracranial pressure increase due to the use of inhalational anesthetics and CO 2 insufflation, therefore ocular ultrasound evaluation should be performed to early identify intracranial hypertension and to avoid optic nerve damage.…”

Reply to HED‐22‐1423: Comment on “Detection of increased intracranial pressure in trans‐oral robotic thyroidectomy using optic nerve sheath diameter measurement”

“…Several adjustments should be applied to minimize the discrepancy between reported values 4 ; (i) how to interpretate retrobulbar structures, (ii) how to unify the ultrasound settings such as transducer frequency, imaging plane (transverse or sagittal), and (iii) acquisition gain. Our study 5 tried our very best to minimize possible errors by unifying ultrasound settings, acquiring images by limited investigators (one of two board‐certified anesthesiologists), and measuring the ONSD at a single time point after the complete collection of sonographic images.…”