Determination of the function of the internal branch of the superior laryngeal nerve after thyroidectomy

Prevalence and risk factors for dysphagia in older adults after thyroid and parathyroid surgery

BACKGROUND

We aimed to determine the prevalence and risk factors for dysphagia in adults 65 years and older before and after thyroidectomy or parathyroidectomy.

METHODS

We performed a longitudinal prospective cohort study of older adults undergoing initial thyroidectomy or parathyroidectomy. We administered the Dysphagia Handicap Index questionnaire preoperatively and 1, 3, and 6 months postoperatively. We compared preoperative and postoperative total and domain-specific scores using paired t tests and identified risk factors for worse postoperative scores using multivariable logistic regression.

RESULTS

Of the 175 patients evaluated, the mean age was 71.1 years (range = 65-94), 73.7% were female, 40.6% underwent thyroidectomy, 57% underwent bilateral procedures, and 21.1% had malignant diagnoses. Preoperative swallowing dysfunction was reported by 77.7%, with the prevalence 22.4% greater in frail than robust patients (P = .013). Compared to preoperative scores, 43.4% and 49.1% had worse scores at 3 and 6 months postoperatively. Mean functional domain scores increased by 62.3% at 3 months postoperatively (P = .007). Preoperative swallowing dysfunction was associated with a 3.07-fold increased likelihood of worse functional scores at 3 months. Whereas frailty was associated with preoperative dysphagia, there was no association between worse postoperative score and age, sex, race, frailty, body mass index, smoking status, gastroesophageal reflux disease, comorbidity index, malignancy, surgical extent, or type of surgery.

CONCLUSION

Adults 65 years and older commonly report swallowing impairment preoperatively, which is associated with a 3.07-fold increased likelihood of worsened dysphagia after thyroid and parathyroid surgery that may persist up to 6 months postoperatively.

Preservation of superior laryngeal nerve in transoral surgery: A technology to enhance the recovery of swallowing function after surgery of hypopharyngeal carcinoma

OBJECTIVES

We intended to preserve the internal branch of superior laryngeal nerve in transoral surgery of hypopharyngeal squamous cell carcinoma and observe swallowing function recovery.

METHODS

26 patients with hypopharyngeal squamous cell carcinoma underwent transoral surgery with the preservation of internal branch of superior laryngeal nerve. Sensation in the pharyngolaryngeal mucosa was tested by flexible laryngoscope and swallow function was evaluated by water swallow test and MD Anderson Dysphagia Inventory questionnaire after surgery.

RESULTS

Surgeries were successfully performed in all patients. The internal branch of superior laryngeal nerve were preserved in all patients. Testing of mucosa sensation revealed the presence of the cough reflex in most patients. The water swallow test showed that 12 cases (46.15%) on the 1st day, 23 cases (88.46%) on the 7th day and 25 cases (96.15%) on the 14th day after operation had normal swallowing function. The mean score of MD Anderson Dysphagia Inventory was 98 on the 14th day after operation. All patients achieved an oral soft diet at a median of 3 days (range, 2-6 days), full normal oral diet at a median of 5.5 days (range, 4-10 days) and removal of the nasogastric tube at a median of 6 days (range, 5-11 days). During the two-year follow-up, 3 patients recured, 1 patient died of lung metastasis.

CONCLUSIONS

Preserving of the internal branch of superior laryngeal nerve in transoral surgery is feasible, and it can help to achieve a satisfactory recovery of the swallowing function after surgery of hypopharyngeal squamous cell carcinoma.

The Role of the Cerebellum in Swallowing

Swallowing is a complex activity requiring a sophisticated system of neurological control from neurones within the brainstem, cerebral cortices and cerebellum. The cerebellum is a critical part of the brain responsible for the modulation of movements. It receives input from motor cortical and sensory areas and fine tunes these inputs to produce coordinated motor outputs. With respect to swallowing, numerous functional imaging studies have demonstrated increased activity in the cerebellum during the task of swallowing and damage to the cerebellum following differing pathological processes is associated with dysphagia. Single pulses of transcranial magnetic stimulation (TMS) have been applied to the cerebellum and have been shown to evoke motor responses in the pharynx. Moreover, repetitive TMS (rTMS) over the cerebellum can modulate cerebral motor (pharyngeal) cortical activity. Neurostimulation has allowed a better understanding of the connections that exist between the cerebellum and cerebral swallowing motor areas in health and provides a potential treatment for neurogenic dysphagia in illness. In this review we will examine what is currently known about the role of the cerebellum in the control of swallowing, explore new findings from neurostimulatory and imaging studies and provide an overview of the future clinical applications of cerebellar stimulation for treating dysphagia.

Swallowing disorders after thyroidectomy: a systematic review and meta-analysis

PURPOSE

Swallowing disorders following thyroidectomy are common, even after surgery without confirmed complications. The purpose of the current systematic review is to investigate the prevalence of dysphagia at various time points after thyroidectomy, at the whole spectrum of it (total/partial, open/endoscopic, for benign/malignant disease).

METHODS

The literature available at PubMed, SciELO and Cochrane Library databases was reviewed, according to PRISMA guidelines, using the terms "dysphagia", "swallowing disorder", "deglutition disorder", "thyroidectomy" and "thyroid surgery" in the appropriate combinations. A quantitative synthesis of the results followed.

RESULTS

The systematic review of the literature resulted in 35 articles, which met the inclusion criteria and were analyzed regarding their type, sample, follow-up and results regarding post-thyroidectomy dysphagia in multiple follow-up times. A significant increase of swallowing impairment compared to baseline was recorded shortly after surgery. Dysphagia reverted to pre-operative levels 2-3 months later. Dysphagia continued to be reported in a significantly lower proportion of patients, even 1 year after surgery. No significant difference was noticed between open and endoscopic thyroid surgery at 2-3 months post-surgery.

CONCLUSIONS

The swallowing disorders reported after thyroidectomy should be expected, but are not always detectable through objective methods. This should not lead to underestimation of symptoms, since the patients' quality of life is negatively affected by the symptomatology.

Effects of Superior Laryngeal Nerve Lesion on Kinematics of Swallowing and Airway Protection in an Infant Pig Model

The superior laryngeal nerve provides detailed sensory information from the mucosal surfaces of laryngeal structures superior to the vocal folds, including the valleculae. Injury to this nerve results in airway penetration and aspiration. Furthermore, such injuries might have an impact on the function of multiple structures involved in intraoral transport and swallowing due to connections within the brainstem. We sought to determine the effects of a surgical lesion of the superior laryngeal nerve on kinematics of the tongue, hyoid, and epiglottis during swallowing. We implanted radio-opaque markers into five infant pigs under anesthesia. Then we fed milk mixed with contrast agent to the pigs while they were recorded via video fluoroscopy, before and after a surgery to transect the superior laryngeal nerve. We digitized and rated airway protection in 177 swallows. We found that in most animals, swallow duration was shorter after nerve lesion. The hyoid also traveled a shorter distance after lesion. Frequently, individuals reacted differently to the same nerve lesion. We suggest that these differences are due to individual differences in neurological connections. When comparing hyoid kinematics between swallows with successful or failed airway protection, we found more consistency among individuals. This indicates that protecting the airway requires specific sets of kinematic events to occur, regardless of the neurological differences among individuals.

Quantitative Ultrasound Assessment of Hyoid Bone Displacement During Swallowing Following Thyroidectomy

The aim of this study was to investigate temporal ultrasound measurements of the hyoid bone displacement during swallowing following thyroidectomy in women and to relate these measures to age, clinical outcomes, and upper digestive airway symptoms. The sample was divided into an experimental group (EG) of 20 women who underwent thyroidectomy (mean age = 49.55 years ± 15.14) and a control group (CG) of 20 healthy women volunteers (mean age = 40.75 years ± 15.92). Both groups were submitted to ultrasound assessment to obtain four temporal measurements of hyoid bone displacement during swallowing: elevation, anteriorization, maximum displacement, and maintenance of maximum displacement. In both groups, swallowing of ten milliliters of liquid and the same volume of thickened liquid (honey) were analyzed. The images were recorded on video (30 frames/second) and analyzed according to a standardized protocol. Temporal measurements of hyoid bone elevation and maximum displacement during swallowing of thickened liquid were significantly shorter in EG (p = 0.034 and p = 0.020, respectively). There were no differences in the swallowing of liquid, and no other variable was related to the ultrasound temporal measurements investigated. This study concludes that women who undergo thyroidectomy have a shorter time of hyoid bone elevation and maximum displacement during swallowing of 10 mL of thickened liquid.

Thyroidectomy-related Swallowing Difficulties: Review of the Literature

This study aims to provide insight into the etiology and frequency of swallowing complications that arise after thyroidectomy and to outline the available diagnostic procedures by revising the existing literature on this topic. We conducted a bibliographic search using the electronic database MEDLINE/PubMed to identify all relevant articles and 44 studies were included in the review out of a total of 218 published articles. Dysphagia after thyroid surgery is a common postoperative complication which, in the short- or long-term, significantly affects patient life quality. There is no standard diagnostic protocol for thyroidectomy-related swallowing impairment. Among the reviewed studies, 8 questionnaires and 12 instrumental diagnostic tools were used to identify swallowing difficulties related to thyroid surgery. The Swallowing Impairment Index (SIS-6) was the most-used questionnaire. Fiberoptic endoscopy is a standard diagnostic tool performed prior and after thyroid surgery, primarily to identify changes in vocal fold mobility. Although instrumental findings usually reveal non-specific alterations of swallowing; swallowing videofluoroscopy and esophageal manometry can be the most helpful tools in further management of thyroidectomy dysphagia. In patients with thyroidectomy-related swallowing difficulties and suspected laryngopharyngeal reflux, 24-hour MII-pH metry should be performed.

Long-term esophageal motility changes after thyroidectomy: associations with aerodigestive disorders

BACKGROUND

Patients undergoing thyroidectomy often complain aerodigestive disorders. In a previous study we showed the associations between voice impairment and proximal acid reflux, swallowing impairment and Upper Esophageal Sphyncter (UES) incoordination and the decrease in UES pressure in thirty-six patients observed before and soon afterwards uncomplicated thyroidectomy. This study investigated the state of post-thyroidectomy esophageal motility changes and its associations with these disorders after 18-24 months.

PATIENTS AND METHODS

The thirty-six patients prospectively recruited according to selection criteria (thyroid volume ≤60 ml, benign disease, age 18-65 years, previous neck surgery, thyroiditis, pre- or postoperative vocal cord palsy) underwent voice (VIS) and swallowing (SIS) impairment scores, esophageal manometry and pH monitoring once again.

RESULTS

After 18-24 months, both VIS and SIS recovered (respectively: p=0,022; p=0,0001); UES pressure increased (p=0,0001) nearing the preoperative values. The persistence of swallowing complaints were associated with the persistence of esophageal incoordination (p=0,03); the association between voice impairment and proximal acid reflux was confirmed (p<0,001).

CONCLUSIONS

Our study confirms that aerodigestive disorders after uncomplicated thyroidectomy, largely transient, are strictly connected with upper esophageal motility changes. In this viewpoint, the innervation of upper aerodigestive anatomical structures (larynx, pharynx, upper esophagus) and its variations should be focused.

Videoendoscopic Evaluation of Swallowing After Thyroidectomy: 7 and 60 Days

Deglutition complaints are frequent after thyroidectomy. The purpose of this study was to follow-up on patients with thyroidectomy indication to compare the videoendoscopic evaluation of swallowing on the seventh day (early postoperative, EPO) and on the 60th day after thyroidectomy, (late postoperative, LPO) and to compare patients that evolved with normal laryngeal mobility (NLM) and abnormal laryngeal mobility (ALM). Nasofibroscopic evaluation was performed preoperatively (PRE), on the EPO and LPO. Two groups were compared: ALM and NLM. The majority of people were women, age bracket 46-65, who underwent total thyroidectomy and with high frequency of carcinoma. 30 out of the 54 patients in the study had change in swallowing (55 %). Dysphagia occurred in 87 % (13/15) of patients with ALM in the EPO and remained in 67 % of them in the LPO. In the NLM group, dysphagia occurred in 44 % (17/39) in EPO and 25 % in LPO. There was a statistical difference between PRE and EPO, and PRE and LPO (P < 0,001). In the ALM group, liquid penetration and aspiration were identified in 33 % of the cases during EPO (P = 0,014); retention of food occurred in 87 % in EPO and in 60 % in LPO (P < 0,001). Dysphagia occurs in patients after thyroid surgery (regardless of larynx mobility alteration) and characterized by stasis of food in the oro and hypopharynx, which is also noticed in LPO, though more frequently in EPO.

Frequency and severity of globus pharyngeus symptoms in patients undergoing thyroidectomy: a pre-post short term cross-sectional study

Background

Globus pharyngeus is a sensation of a lump or foreign body in the throat, sometimes associated with thyroid diseases and surgery. Previous studies investigated this condition with contradictory results, mainly because not standardized instruments of measure were used. The aim of this study was to evaluate the prevalence and severity of globus pattern symptoms in a population of patients three months after a thyroidectomy, and the reduction or increase of pre-existing symptoms or the onset of new symptoms.

Methods

Ninety-five patients (65 women, 30 men, mean age 56.03 ± 12.45) were assessed for globus pattern symptoms before and three months after thyroid surgery (72 patients: benign goiter, 23 patients: papillary cancer). The Glasgow-Edinburgh Throat Scale (GETS) was translated into Italian and used as a validated instrument of measure of the severity of globus pattern symptoms.

Results

The Italian version of the GETS was reliable (Cronbach alpha = 0.85) and valid. Normative data were used to classify patients into 4 groups of severity. A significant decrease of the mean GETS score was observed at the postoperative assessment (13.02 ± 11.84 vs 8.00 ± 11.26; p < 0.01), but beside symptomatic patients who improved we could observe also two other significant groups of patients: asymptomatic patients who developed symptoms and symptomatic patients who remained symptomatic.

Conclusions

The significant decrease of the mean GETS postoperative score was mainly due to the improvement of strongly symptomatic patients. Two other significant outcomes exist and further studies are needed to understand their pathophysiological mechanism.

Esophageal Motility Changes after Thyroidectomy; Possible Associations with Postoperative Voice and Swallowing Disorders

Objective

Swallowing and voice impairment are common after thyroidectomy. We evaluated short-term functional changes in esophageal motility in a series of patients who had undergone total thyroidectomy. Several studies have investigated these symptoms by means of interviews or questionnaires.

Study Design

Prospective study.

Setting

Academic research.

Materials and Methods

Thirty-six consenting patients were prospectively recruited. Eligibility criteria were thyroid volume ≤60 mL, benign disease, and age between 18 and 65 years. Exclusion criteria were previous neck surgery, severe thyroiditis, hyperthyroidism, and pre- or postoperative vocal cord palsy. Voice impairment score, swallowing impairment score, lower esophageal sphincter pressure, esophageal motility, upper esophageal pressure, and coordination were evaluated preoperatively and 30 to 45 days after surgery.

Results

Postoperative swallowing impairment (appearance or worsening of dysphagia) was found in 20% of patients and voice impairment in more than 30%. Both preoperative and postoperative esophageal motility were similar. All patients showed an average decrease of 25% in upper esophageal pressure, although the pressure was within normal range. Swallowing alterations were associated with upper esophageal incoordination ( P < .03), and proximal acid reflux was significantly associated with voice impairment ( P < .02).

Conclusion

After uncomplicated thyroidectomy, decreased upper esophageal pressure may explain both pharyngeal (dysphagia) and laryngeal (vocal impairment) exposure to acid. In the future, proton pump inhibitor therapy protocols should be evaluated.