Short summary

Voice alteration, swallowing dysfunction, affected airflow, and diminished quality of life are all common complication to goiter, but also to the surgical treatment hereof.

Through a PhD -project with four prospective studies we intend to achieve a significant better understanding of each of these areas. A total of 72 patients will be recruited for each study and the results are expected in 2018. The aim of this study is to investigate the influence of surgical treatment for non-toxic goiter on voice, swallowing function, tracheal airflow, and quality of life.

Rationale

Benign non-toxic goiter affects approximately 10% of the Danish population. Thyroidectomy is a commonly used treatment for large goiter with more than 2,200 thyroidectomies performed each year in Denmark. Many questions regarding the complication to this surgery are undetermined - primarily due to prior insufficient technologies for examination.

A common complication is post-surgical voice alterations affecting 25-29 % of the patients after thyroidectomy.  But in the estimation of this prevalence non-validated questionnaires are often used. With today's technological development this is clearly insufficient and objective evaluation are necessary to give patient relevant information to extent and prevalence of this complication.

A recently accepted systematic review from our research group found that 47-83% of goiter patients referred for thyroid surgery experience swallowing problems often evaluated by again non-validated questionnaires. Objective methods to investigate the swallowing problems, have previous been used, and they identified an increase the oesophageal transit time and disturbance of the oesophageal motility as a potential cause of this problem. However, these studies used older screening methods and are therefore not able to answer import questions such as: What is the likely location and likely cause of this prolonged transit time. This would be possible when applying newer examination methods.

The systematic review also identified that upper airway obstruction was present in 26-60% of patients with goiter referred to thyroidectomy. Within months after thyroidectomy this upper airway obstruction is significantly reduced or nearly eliminated, but the changes in airflow after surgery have never been correlated to objective anatomical changes.

The question of the influence of voice disturbances, swallowing dysfunction, and changes in the airflow on the quality of life of patients with goiter and the effect of surgical treatment are unanswered. To evaluate this and other questions a validated thyroid specific quality of life questionnaire have recently been developed in cooperation between Copenhagen- and Odense University Hospital (OUH), but this have never been applied to evaluate the effect of thyroidectomy on goiter patients.

The aims of the study are therefore:

To investigate the influence of surgical treatment for non-toxic goiter on voice, swallowing function, tracheal airflow, and quality of life.

Description of the cohort

All patients undergoing hemi- or total thyroidectomy at Odense University Hospital for benign symptomatic non-toxic goiter are offered participation in this study. We estimate that approximately 180 patients are eligible for inclusion in this study from November 2014 - April 2016.

Data and biological material

Patient data

• Patient characteristics: (sex, age, diagnosis, serum-TSH, serum-T₃, serum-T₄, serum-antithyroid peroxidase antibodies, ionized Ca²⁺, tobacco use, drug use, thyroid ultrasound examination)
• Operation parameters: (operation type, surgeon, operation time, blood loss, complications with surgery or anaesthesia, thyroid volume, confirmed use of nerve stimulator and more variables collected in the THYKIR database)

Quantitative and qualitative voice analyses

• Perception (GRBAS scale)
• Videostroboscopy including high speed video-stroboscopy (closure, regularity, mucosal wave, and symmetry)
• Acoustic quality of voice (jitter, shimmer, F₀-range, softest intensity, noise-to-harmonic range, Soft phonation-index, voice turbulence index)
• Phonotogram (voice intensity and range)
• Aerodynamics
• Voice Handicap Index 

High Resolution Oesophageal Manometry

• Hiatal hernia
• Lower Oeophageal Pressure (Basal)
• eSleeve, IRP (Residual)
• Upper Oesophageal Pressure (Mean Basal Pressure, Mean Residual Pressure)
• Eosophageal Motility (Peristaltic, Simultaneus, Failed, mean wave amplitude, mean wave duration, velocity)
• Pressure in the upper oesophageal sphincter:
• Upper oesophageal sphincter residual pressure (mmHg)
• Upper oesophageal relaxation duration (msec)
• Peak-pharyngeal pressure (mmHg)
• Contraction duration
• Total swallow duration

Magnetic Resonance Imaging of the neck

• Reduction in tracheal volume from lower border of the cricoid cartilage to the most distal element of the goiter before surgery
• Midline deviation of the trachea
• Thyroid volume
• Smallest cross sectional area of the trachea
• Largest thyroid encirclement of the trachea measured in degrees around the circumference of the trachea 

Pulmonary function test

• Forced expiratory volume in 1 sec.
• Forced vital capacity
• Forced inspiratory flow at 50 % of the vital capacity
• Forced expiratory flow at 50 % of the vital capacity Peak flow (PEF)

ThyPRO questionnaire score

Collaborating researchers and departments

Department of Otolaryngology - Head and Neck Surgery, Odense University Hospital

• Jesper Roed Sørensen, MD
• Consultant ågot Møller Grøntved
• Consultant Helle Døssing, PhD
• Consultant and Professor Christian Godballe, PhD

Department of Nuclear Medicine, Odense University Hospital

• Jeppe Kiilerich Lauridsen, MD

Department of Endocrinology, Copenhagen University Hospital

• Torquil Watt, MD, PhD

Department of Pediatrics, Odense University Hospital

• Simone Markøv, MD

Department of Cardiac, Thoracic and Vascular Surgery, Odense University Hospital

• Consultant Søren Kruse-Andersen, DMSc

Department of Endocrinology and Metabolism, Odense University Hospital

• Consultant and Professor Laszlo Hegedüs, DMSc
• Consultant and Associate Professor Steen Joop Bonnema, DMSc, PhD

Publications associated with the project

Sorensen JR, et al. The impact of goitre and its treatment on the trachea, airflow, oesophagus and swallowing function. A systematic review. Best Pract Res Clin Endocrinol Metab 2014;28:481-94.