The initial thyroid surgeries, performed >100 years ago, were loaded with serious risks of general and local complications, the most common being bleeding and infection. Although today these complications are rare, bleeding, hypoparathyroidism and laryngeal nerve injury are still a cause for concern.
The complication rate increases with increasing size of the thyroid mass and also with the extent of the operation. Complications (mostly hypoparathyroidism and laryngeal nerve injury) increase, after total thyroidectomy or thyroid lobectomy (especially with lymphadenectomy) than after a simple goitre resection.
A particularly dangerous complication is postoperative bleeding, which develops within the first few hours in a closed space and can result in a haematoma compressing the upper airways. The dominating symptom is dyspnoea. The blood coming out of drains may not be enough to prevent tracheal compression. The bleeding is not likely to cause hypotension either. In this life-threatening situation it is necessary to open a wound immediately, sometimes even at the bedside, and remove the haematoma. The bleeding vessel can later be identified in the operating theatre and precise haemostasis performed. It is not always possible to find a source of bleeding during this emergency operation. However, the bleeding may never return. Before the operation, the surgeon must bear in mind that many patients who take widely used anticoagulants and antiplatelet drugs continuously may not mention this to their doctor. A gentle tissue dissection and precise haemostasis are indispensible elements during each thyroidectomy. It is not possible to eliminate completely the risk of postoperative bleeding in this procedure. In my opinion, this is the reason why two suction drains should be left in the operation field after performing each thyroid surgery, even when the haemostasis is perfect. Also, a careful dissection reduces the rate of laryngeal nerve injury and hypoparathyroidism. It is possible to adhere to these simple rules when the operation field remains clear and visible. It is more difficult during reoperation, when scars and fibrosis cover the view or while searching for a bleeding vessel during reoperation. This situation is also complicated when it is difficult to have a good view of the operating field, for instance, in retrosternal goitre.
Extensive thyroidectomy, especially in the case of undifferentiated thyroid carcinoma, may cause even rare injuries such as cervical sympathetic chain damage causing Horner syndrome, or cervical oesophagus damage. Extensive thyroidectomy may also cause lymphorrhoea, which usually subsides in 3–4 weeks after introducing conservative therapy of total parenteral nutrition and octreotide instead of oral feeding. The thyroid’s entire hormonal function ceases after total thyroidectomy. It is not a complication but a consequence of the extensiveness of the operation; the patient requires continuous hormonal treatment.
The surgeon’s experience in mitigating the general complications of thyroid surgery cannot be overemphasized. The most effective way to reduce the complication rate is to train surgeons who initially should be accompanied by an expert until he or she gains the necessary experience to be self-reliant. This is not to say that complications will not occur with the most experienced surgeons, but they can certainly be lessened.