Complications to thyroidectomy surgical interventions are by no means uncommon and very often manifest as voice disorders.
From a study carried out on 395 patients, designed to describe the quality of the voice after total thyroidectomy and conducted up to 12 postoperative months, it was found that 21% of these patients had voice disorders already before the surgery, while 49% developed them following the surgery. Half of the group recovered the vocal parameters within the first month after surgery and 85% of patients recovered them after 5 months. One year after the operation, the patients who still had vocal problems were 1.26%.
This showed that vocal disturbances are common after a thyroidectomy but are usually transient and less than 20% of these persist at 6 months.
Patients should always be informed about the risk of onset of vocal disorders after surgery.
Most of these disorders are attributable to a nerve injury (recurrent or external laryngeal). However, some patients report post thyroidectomy vocal disorders for which the pathogenesis has not yet been well understood from a medical point of view.
This study aimed to investigate vocal disorders related to thyroid surgery, in order to determine the frequency of subjective vocal disorders and to establish recovery times and the frequency of persistence of the disorder after one year of follow-up. The most common complaints are: hoarseness, low or weak voice, vocal fatigue. The sung voice was analyzed only in cases where the patient was already singing before the surgery.
A laryngeal evaluation with indirect laryngoscopy was conducted before surgery to determine the mobility of the larynx and the appearance of the vocal cords. One month after surgery, all patients were re-evaluated in the same way. Those with vocal disturbances after the first month were then seen once a month until the problem was resolved, all for a year. In these cases, indirect laryngoscopy and stroboscopy were performed. After a year of follow-up the difficulty in making a phone call, in speaking in a noisy environment was examined. Maximum phonation time and respiratory coordination were also evaluated.
From the results of the stroboscopic laryngeal investigation, a clear link has not yet been established between vocal disorders and damage to the external laryngeal nerve. In a randomized series of 50 thyroidectomies, an attempt was made to locate the external laryngeal nerve in the superior thyroid peduncle with a neuro stimulator. Bilateral contraction of the cricothyroid muscle was found in 20% of cases. Only two patients maintained the complaints and external laryngeal nerve palsy was attributed to them, as the nerves were not clearly identified during surgery and postoperative laryngoscopy and stroboscopy resulted in normal results.
In this study period 11 patients had internal laryngeal nerve palsy (8 transient and 3 definitive). These patients were excluded from the study because their vocal disturbances were real and not subjective due to paralysis. There were 11 women who had to be operated on for benign multinodular goiter.
Some vocal disorders persisted beyond the year. The disturbances manifested themselves as acute difficulties when calling someone, on the phone, in a noisy environment, at work, at home. The sung voice was altered in 27 out of 46 cases.
The best thing would be to be able to access the laryngeal function data before and after the surgery. Preoperative disorders can be due to several factors. A thyroid origin from recurrent laryngeal nerve palsy is rare preoperatively and if present, it is usually traced back to thyroid cancer. A preoperative dysphonia can be recognizable in a pharyngeal voice, caused by changes in the resonators caused by the encumbrance of the cervical goiter.
Dysphonia can also occur in Basedow-Graves thyroiditis. In most cases, however, the vocal disturbances occurred in a context of normal hormone levels. In these cases, postoperative recoveries cannot be expected, however, half of these patients have recovered.
Generally the most frequent disorder is a decrease in the mobility of the cord and only minimally as a paralysis of the recurrent laryngeal nerve.
Causes of speech disorders without recurrent laryngeal nerve palsy are manifold, including damage to the external laryngeal nerve, damage to the cricothyroid muscle, skeletal laryngotracheal dissection, especially when subhyoid or orotracheal tubing muscles are dissected. Surgery should be reduced to the minimum possible invasiveness, with a small cervical incision and respecting the subhyoid muscles that should be dissected only if necessary (large goiters, thyroid cancer with extraglandular extension).
The positioning of the patient's body for the operation is also a factor favoring the low vocal frequency in speech and difficulty in the acute: bent head, advanced shoulders and lowered larynx.
Osteopathically all these post-surgical pictures, with the exception of neurological paralysis, can be approached with appreciable results since the area affected by the intervention is the site of very important biomechanical-functional, fascial, lymphatic connections on which it is possible to work in a team with a speech therapist and speech therapist to significantly reduce phonatory recovery times.