J Robot Surg. 2026 Oct 28;20(1):1151. doi: 10.1007/s11701-026-04087-w.
ABSTRACT
Placement of rigid oral retractors during transoral robotic surgery (TORS) elicits a sympathetic hemodynamic response that may be harmful in high-risk patients. The glossopharyngeal nerve provides sensory innervation to the oropharyngeal structures stimulated during retractor placement, yet no previous trial has evaluated glossopharyngeal nerve block (GPN block) for attenuating this response. In this prospective, single-center, randomized clinical trial, 42 patients (ASA I-II, aged 18-65 years) undergoing TORS were allocated 1:1 to the block group, which received bilateral intraoral GPN block with 2 mL of 2% lignocaine per side or the Control group, which received no block. The outcome assessor was blinded; no sham procedure was performed, and the anaesthesiologist performing the block was not blinded. The primary outcome was the proportion of patients with a > 20% increase in mean arterial pressure (MAP) from the pre-retractor baseline within 10 minutes of Feyh-Kastenbauer retractor insertion. Bayesian logistic regression with a Normal (0, 5) prior on the group coefficient was used; the pre-specified decision criterion was a posterior probability of directional benefit P (ARD < 0) exceeding 0.95. The trial was registered in the Clinical Trial Registry of India (CTRI/2022/03/041013, dated 11 March 2022) https://ctri.nic.in/Clinicaltrials/searchbyctri.php , with a date of first patient enrolment of 21/03/2022. The increase in MAP > 20% occurred in 8 of 21 patients (38.1%) in the control group versus 3 of 21 (14.3%) in the block group. The posterior mean absolute risk difference was — 23.9% (95% credible interval [CrI]: — 49.4% to 2.2%), with P (ARD < 0) = 0.964, exceeding the pre-specified threshold. Sensitivity analyses generally supported the direction of effect under neutral, sceptical, and optimistic priors (P(ARD < 0) range: 0.934-0.967), although the posterior probability under the sceptical prior did not exceed the prespecified 0.95 threshold; evidence was equivocal under the pessimistic prior (P(ARD < 0) = 0.57). Maximum MAP and heart rate were lower in the block group (P (difference < 0) = 0.998 and 0.995, respectively). Bispectral index values were comparable between groups throughout the procedure. The GPN block is associated with a high posterior probability of attenuating the hemodynamic response to mouth retractor placement in TORS. The credible intervals were wide, reflecting uncertainty about effect magnitude. A larger confirmatory trial assessing clinical endpoints is warranted.
PMID:42955463 | DOI:10.1007/s11701-026-04087-w
