A study of post operative complications after thyroid surgery

INTRODUCTION: Thyroidectomy is a common operation with an extremely low mortality1. It is associated with specific morbidities which are related to the experience of the surgeon, however2. Very low surgical morbidity rates for thyroidectomy are reported in specialised centers. In competent hands, thyroid surgery is associated with few complications and no fatality. Post operative complications may be as insignificant as edema of the flap or as dangerous and life threatening as hemorrhage or respiratory obstruction. The majority are avoidable with sound surgical technique and good preoperative preparation. With proper preoperative management, the patient will be euthyroid at the time of surgery. If the patient is hyperthyroid, laryngeal edema may result, producing respiratory obstruction. Careless technique may result in massive haemorrhage, recurrent laryngeal nerve paralysis, or both, causing respiratory embarrassment. Lack of experience or of attention to technical details may involve removal of too little or too much thyroid tissue or possibly all parathyroids, resulting in myxedema, recurrent hyperthyroidism, or parathyroid deficiency. Complication rates associated with thyroid surgery can be evaluated only through analysis of case studies and follow up data. The present study reports the clinical audit of thyroid surgery for adult patients undertaken at the Tirunelveli Medical college hospital Tirunelveli. The complications of Thyroidectomy are highlighted and compared to published data. AIMS AND OBJECTIVES: 1. The aim of the study is to compare complication rates of Bilateral sub total thyroidectomy (SBT), near total thyroidectomy (NTT) Hemithyroidectomy (Total lobectomy and isthmusectomy), and Total thyroidectomy (TT) in cohort of patients undergoing surgery for various thyroid disorders. 2. To compare complication rates after thyroidectomy for benign diseases and malignant diseases. 3. To identify ways to avoid the post operative complications. MATERIALS AND METHODS: One hundred and seventeen patients who underwent thyroid surgery, for various thyroid disorders, at the Tirunelveli Medical College Hospital, Tirunelveli, Tamilnadu, India between August 2003 to December 2005 were studied. Operations were performed by various professors, Assistant professors and also by surgical post graduates supervised by senior surgeons using various surgical techniques. Indications for surgery in this study group include forty five patients with non toxic multinodular goitre (MNG), twenty two patients with toxic multinodular goitre, thirty four patients with nontoxic solitary nodular goitre, thirteen patients with carcinoma, two patients with recurrent goitre and one patient with colloid goitre. Of these one hundred and seven patients were female and ten patients were male. These patients were broadly divided in to two categories based on the diagnosis and treatment modality. For all selected patients a thorough history was elicited followed by a complete physical examination. The basic biochemical and hematological investigations were done for all patients. It was decided to request special investigations like thyroid hormone profile and serum calcium estimation only in selected cases, where a disturbance in the functional status was suspected. Vocal cords were examined pre operatively by indirect laryngoscope in all the patients, whereas post operative vocal cord examination was performed only when hoarseness occurred. Patients were classified as having hypocalcaemia (hyperparathyroidism) if both clinical and biochemical (a fall in corrected serum calcium concentration below 8 mg/dl and or the need for calcium supplementation)23 supportive evidence were present. FNAC was done for all patients. Based on the Final diagnosis, the treatment was given as advised by the experts. OBSERVATION AND RESULTS: A total of one hundred and seventeen patients, aged between sixteen and sixty one years underwent thyroid surgery during the study period. Patients included one hundred and seven women and ten men (Females : Male, 10.7:1). Histopathological diagnosis for each case and the number of patients undergoing each type of operation is detailed in table 1. Surgical morbidity associated with thyroidectomy undertaken during the study period is detailed in table 3. Post operative hemorrhage occurred in four patients (3.42%) in which three patients, had total thyroidectomy ( 3/177 , 2.56%) and another one patient (0.85%) under went bilateral subtotal thyroidectomy of which two patients (1.71%) required urgent re exploration and others resolved spontaneously without drainage. Two patients where shifted to Intensive surgical care unit with endotracheal tube insitu due to respiratory difficulty (1.71%) and both of them were recovered well and extubated within 24 hours without any respiratory distress. The incidence of temporary recurrent laryngeal nerve palsy was found to be one each (0.85%) in total thyroidectomy and near total thyroidectomy, and three patients (2.56%) in bilateral subtotal thyroidectomy. No patients in this study group developed bilateral recurrent laryngeal nerve palsy. There were two patients (1.71%), who underwent total thyroidectomy, developed superior laryngeal nerve paresis. The incidence of temporary hyperparathyroidism was high at 5.98% (7) and 1.71% (2) of patients treated by total thyroidectomy and bilateral subtotal thyroidectomy respectively. Those patients who underwent hemithyroidectomy and near total thyroidectomy did not have hypoparathyroidism. Post operative wound infection occurred in four patients (3.42%) of which three patients (2.56%) underwent bilateral subtotal thyroidectomy and one patient (0.85%) underwent Hemithyroidectomy. After surgical drainage the wound was resutured several days later when the infection had resolved. Seroma occurred in one patient (0.85%) who underwent bilateral subtotal thyroidectomy for nontoxic multinodular goiter. Edema of flap occurred in one patient (0.85%) who underwent bilateral subtotal thyroidectomy for toxic goitre. Oesophageal injury occured in only one patient (0.85%) who underwent bilateral subtotal thyroidectomy for nontoxic multinodular goiter. (Patient had coexistent para pharyngeal pouch). There were two deaths (1.71%) noted in this series and out of which one is due to thyroid storm (0.85%) associated with hemorrhage ad respiratory obstruction in female patient who underwent bilateral subtotal thyroidectomy for toxic goiter. Another death occurred in a male patient who underwent total thyroidectomy for carcinoma thyroid. CONCLUSION: The following conclusions are drawn from this study 1. This study shows that the total thyroidectomy or hemithyroidectomy can be done with very low complication rate in cases of benign thyroid disease affecting the whole gland. 2. Hypoparathyroidism however, is a relatively common and significant complication than the recurrent laryngeal nerve injury after surgery for thyroid disorders. 3. Thyroid carcinoma, recurrent goiter, toxic goiter and total thyroidectomy are risk factors for post operative complication. 4. Complication rates are similar for bilateral subtotal thyroidectomy and total thyroidectomy, and there is a risk of recurrence with bilateral subtotal thyroidectomy. Because total thyroidectomy carries a risk of complication similar to that for bilateral subtotal thyroidectomy, it is not logical to avoid total resections. Therefore near total or total thyroidectomy may be the operation of choice for multinodular goiter. 5. Complications and sequelae of thyroid surgery can yet be reduced by careful evaluation of the surgical and medical therapeutic options have more precise surgical indications, a thorough knowledge of the surgical anatomy, a rigorous surgical technique, a systematic dissection of recurrent laryngeal nerve and parathyroid gland in case of bilateral operation and meticulousness during the procedure. 6. I conclude that the operative skills and experience determine the complication rates rather than the type of operative procedure.