Thyroplasty under general anesthesia using a laryngeal mask airway and fibreoptic bronchoscope

Is Sedation of Choice in Thyroplasty Surgery? A Study on the Effects of Sedatives on Voice Quality

OBJECTIVE

In order to establish the ideal anesthetic protocol in thyroplasty type I surgery, where the intraoperative voice test is used to guide the medialization of the paralyzed fold, we have studied the effects of a sedation with midazolam premedication and adjusted intravenous doses of propofol and remifentanil on voice quality in patients without vocal fold pathology undergoing otorhinolaryngology surgery other than thyroplasty.

STUDY DESIGN

Prospective cross-sectional study included 40 adult patients.

METHOD

A voice recording was performed when the patient was fully awake and when an appropriate level of conscious sedation was reached. Following premedication with midazolam at anxiolytic doses, remifentanil and propofol were administrated by target controlled infusion pumps (TCI). These results were compared with those obtained in a previous study carried out by the same team using intravenous bolus (IV) according to weight. The recorded voice analysis was performed using the computer program Praat (v.5.3.39) for a sustained vowel.

RESULTS

All the parameters obtained from the acoustic analysis of the voice were altered after sedation with target controlled infusion in a statistically significant way. Comparing with bolus intravenous, harmonic and noise ratio (HNR) was the only parameter that decreased less in the TCI group.

CONCLUSION

The state of sedation obtained using midazolam premedication, propofol and remifentanil adjusted intravenous doses alters significantly all the voice parameters, although this alteration is considerably less than the changes produced by the medication administered in bolus IV. According to these results, the sedation and the voice test during thyroplasty surgery would present a series of limitations when it comes to guiding the medialization of the paralyzed vocal fold and therefore it could not be considered as the ideal anesthetic protocol in thyroplasty surgery.

Anesthetic Technique and Functional Outcomes in Modified Montgomery Thyroplasty

BACKGROUND

Montgomery thyroplasty type I is a surgical technique indicated in vocal cord paralysis which consists of the paralyzed cord medialization, improving the voice quality. The objective of the study is to describe in detail the anesthetic method to obtain optimal post-medialization voice results.

METHODOLOGY

Retrospective case series study including patients who underwent medialization thyroplasty using the modified Montgomery technique at the General University Hospital of Valencia between 2011 and 2021. The anesthetic technique consisted of general anesthesia with neuromuscular relaxation and a laryngeal mask. Pre- and post-surgical vocal functional data of maximum phonation times (MPT), G score, and Voice Handicap Index-30 (VHI-30) were evaluated.

RESULTS

All the patients presented an improvement in voice results, increasing MPT after surgery and a decrease in VHI-30 and G score postoperatively, with statistically significant differences between the pre- and post-surgical results (p-value < 0.05). There were no complications related to anesthesia or surgery.

CONCLUSIONS

The use of general anesthesia with muscle relaxation in modified Montgomery thyroplasty may be a good option to consider. The use of a laryngeal mask for ventilation combined with a fiberoptic check allows direct visualization of the vocal cords intraoperatively, providing good functional voice results.

Medialization Laryngoplasty: A Review for Speech-Language Pathologists

Purpose The purpose of this study is to familiarize speech-language-pathologists with the current state of the science regarding medialization laryngoplasty in the treatment of voice disorders, with emphasis on current evidence-based practice, voice outcomes, and future directions for research. Method A literature review was performed in PubMed and Embase using the keywords vocal fold/cord and laryngoplasty, thyroplasty, augmentation, or laryngeal framework. Articles published between 2010 and 2020 were reviewed for data about clinical applications, technical approach, voice-related outcomes, and basic science or clinical innovations with the potential to improve patient care. A synthesis of data was performed from articles meeting the outlined search criteria. Conclusions As key members in the multidisciplinary care of voice disorders, speech-language pathologists need to be informed of current research in medialization laryngoplasty, a procedure commonly used for patients with glottic insufficiency. Advances in anesthetic technique, office-based procedures, and the development of materials with increased bio-tolerability over the past decade have led to innovations in treatment and improved patient outcomes. Recent applications of computational and bioengineering approaches have the potential to provide new directions in the refinement of currently available techniques and the improvement of patient-based treatment outcomes.

Laryngeal mask airways in ear, nose, and throat procedures

The use of laryngeal mask airway (LMA) and its variants in ear, nose, and throat procedures have been extensively described in case reports, retrospective reviews, and randomized clinical trials. The LMA has developed a considerable following because of its lack of tracheal stimulation, which can be a considerable advantage in ear, nose, and throat (ENT) procedures. The incidence of coughing on emergence has been shown to be lower with the LMA than with the endotracheal tube (ETT). Although other approaches to smooth emergence have been described, few would argue that it is as easy to achieve a smooth emergence with an ETT as with an LMA. Although patients certainly exist for whom the LMA is contraindicated, many will experience better results with the LMA because of the features delineated in this article.

Continuous cervical epidural analgesia for Isshiki type - I thyroplasty

Thyroplasty is an operation on the upper airway to improve voice quality in patients with unilateral vocal cord paralysis. It is a difficult anaesthetic procedure that requires sharing the airway with the surgeon. We describe a good anaesthetic technique, which provides a safe airway with excellent operating conditions, using continuous cervical epidural anaesthesia and postoperative analgesia in three patients. The use of a regional anaesthetic technique provides excellent anaesthesia and analgesia while allowing the patient to phonate at the request of the surgeon intraoperatively.

Efficacy of total intravenous anesthesia without intubation for laryngeal framework surgery

CONCLUSION

Total intravenous anesthesia (TIVA) without intubation has the advantages of both conventional general anesthesia and local anesthesia. It is useful in laryngeal framework surgery because intraoperative voice monitoring while the patient remains awake is required.

OBJECTIVE

In laryngeal framework surgery, it is desirable to monitor the voice during surgery. However, surgery is conducted under general anesthesia, although such a procedure renders the patient unable to phonate during surgery. We conducted TIVA without intubation, allowing patients to breathe spontaneously while undergoing operation, and succeeded in intraoperative voice monitoring with satisfactory postoperative voice production.

SUBJECTS AND METHODS

The subjects were 21 patients who underwent surgery. For TIVA, propofol and pentazocine were used as a sedative and analgesic, respectively. A bispectral index (BIS) monitor was used to measure the depth of the anesthesia. Before the vocal folds were to be rotated, propofol administration was interrupted to arouse and instruct the patient to phonate. Guided by the phonation, the vocal folds were correctly positioned. Then propofol administration was resumed, and the wound was closed.

RESULTS

The BIS value during continued administration of propofol was around 60, but exceeded 90 in all patients within 233.6 +/- 64.5 s after cessation. They clearly remembered the conversation they had with us during surgery.

A series of thyroplasty cases under general anaesthesia

Thyroplasty is an operation on the upper airway to improve voice quality in patients with unilateral vocal cord paralysis. It requires access to an uninstrumented larynx and a functional assessment of vocal cord medialization. It is a difficult anaesthetic procedure that requires sharing the airway with the surgeon. We describe an anaesthetic technique to give good operating conditions and a safe airway, using total intravenous anaesthesia, a laryngeal mask airway and intraoperative fibreoptic endoscopic assessment of the larynx, and present a series of 13 patients. Other anaesthetic techniques for thyroplasty are described and discussed.