Anzer Shah M.1 , Deepa George
BACKGROUND Thyroid surgery is a common surgical procedure. Complications such as bleeding, hypoparathyroidism and Recurrent Laryngeal Nerve Injury (RLNI) represent nearly half of all the complications of thyroid surgery. Thyroidectomy patients are routinely evaluated preoperatively for vocal cord mobility with indirect laryngoscopy. In the immediate postoperative period after extubation, they are again examined by direct laryngoscopy to assess vocal cord mobility. Transcutaneous ultrasound (USG) is an easy, noninvasive alternative to the above methods. The development of gray-scale, real-time, high-resolution, Bmode USG helps in visualization of the normal anatomy of the larynx, and the movements of the true and false cords. It can be an alternative to the more invasive direct examination of the vocal cords using direct laryngoscopy or videorhinolaryngoscopy (VRL). There are numerous studies involving laryngeal ultrasound and direct laryngoscopy for assessment of vocal cord movement for thyroidectomy patients, but comparative studies of these two methods for assessment of vocal cord mobility after thyroidectomy are limited in number. METHODS After obtaining institutional ethical committee clearance, a prospective observational study among 60 participants was done. General anaesthesia was given, and the patients were positioned for thyroidectomy surgery. After the surgery, direct laryngoscopy was done to assess the vocal cord mobility. Heart rate, blood pressure, and duration of the direct laryngoscopy were recorded. After this, under strict aseptic precautions, the neck was scanned with a high frequency linear probe (frequency: 8-12 Hz) and the vocal cord mobility was recorded. Surgical dressing was kept after the procedure. RESULTS Analysis of the monitored data shows that the findings of direct laryngoscopy and ultrasonography of the neck were consistently similar. In some difficult airway cases, laryngoscopy proved to be difficult, but USG could still monitor the cord movement. Patients had sympathetic stimulation as evidenced by rise in blood pressure, heart rate during direct laryngoscopy. During ultrasonographic examination of neck, no such sympathetic stimulation was observed. The images seen through USG were easily interpreted and the study shows that direct laryngoscopy can be replaced by ultrasonography. CONCLUSIONS Use of ultrasonography for vocal cord movement examination in post thyroidectomy patients, yields consistent results comparable to those of direct laryngoscopy and the former has the potential to replace the latter.
