Human body has multiple endocrine glands, which control multiple and important functions of the body, with the several hormones that secrete into blood. Traditionally, object of endocrine surgery is the surgical treatment of the diseases of the extra-cranial glands, including the thyroid and the parathyroids, thymus, pancreas, adrenal glands and the internal genital organs.
The diseases of the thymus will be further analysed in the thoracic surgery chapter, these of the internal genitals in the chapter of gynaecologic surgery, while these of the pancreas as part of the chapter of the hepato-pancreato-biliary surgery, due to the anatomic and surgical relevance.
The thyroid gland is located in the anterior cervical space and is responsible for the secretion of the hormones triiodothyronine (T3) and thyroxine(T4), that control important functions of the body, such as the metabolism, while their disturbances have serious impact in the cardiac function and the mental health of the patient. The term goitre or bronchocele refers to the swelling of the thyroid without defining its cause, and comes from the mistaken Hippocratic perception that its cause was “hernia (cele) of the bronchi”.
The diseases of the thyroid are classified in two main categories, these that affect the function and those that affect the morphology of the gland. The malfunctioning conditions include the pathologic secretion of the thyroid hormones causing either over- or under-secretion, without necessary affecting the size and the morphology.
Hyperthyroidism includes nervousness, weight loss, sweating, increased heart rate, arrhythmia and hypertension. Hypothyroidism on the contrary includes laziness, decreased heart rate, constipation and sometimes obesity. Concerning the morphological disorders, there is overgrowth of one or several nodules, changing the shape and the size of the gland, without necessary disordering its hormone secretion. Most frequent disorders of this category are the nodular and multinodular goitre.
The diagnostic approach of the thyroid diseases is performed with blood and hormone tests, ultrasound, scintigram and fine needle aspiration (FNA). There is great relevance between the thyroid nodules, especially the non-functioning ones, and thyroid cancer, which is the most common endocrine cancer. It is divided in well differentiated types (papillary, follicular and myeloid), which in general have good prognosis and biological course, and the non-differentiated anaplastic cancer, which is the most aggressive type.
The several conditions of the thyroid gland very often require surgical treatment. The most usual surgical procedure performed is total thyroidectomy, with exception the cases of single, unilateral and benign lesions. Surgery of the thyroid is demanding and must be performed only by specialised surgeons, using visual magnification and neuro-recognizing techniques, which are necessary for preserving vital structures, such as the nerves of voice and swallowing, vessels like the carotids and the jugular veins, trachea, oesophagus and the cervical sympathetic plexus.
The excision of the thyroid is done through a small transverse incision at the lower part of the cervix. Special forms of energy are used, such as ultrasound and radiofrequency (RF), while the protection of the delicate vocal nerves is achieved with the use of special electronic equipment (nerve stimulator).
The parathyroids are usually four small glands in the size of lentils, attached to the posterior surface of the thyroid gland. They secrete a hormone called parathormone, which is responsible for the metabolism of calcium in the human body. When the parathyroids secrete larger quantities of the hormone than normal, the deconstruction of the bones is increased, so is the calcium blood concentration.
This condition can occur as a result of hyperplasia, adenoma or cancer, while adenoma the most usual. It usually includes muscle weakness, anorexia, nausea, vomiting, peptic ulcer, and less often acute or chronic pancreatitis. The patient may present with bone pains, osteoporosis, spontaneous bone fractures, kidney stones and kidney colic pain or even psychotic symptoms.
The diagnostic approach includes blood and hormone tests, ultrasound, CT and MRI and also with a special scintigram using Sestamibi technetium. Treatment is surgical at most. The gland or the glands are excised through a small incision of few centimetres in the cervical area, by magnifying the vision of the surgical field with special devices, in order to allow the effective and safe performance of the procedure. In case of diffuse hyperplasia where all of the glands are excised, we self-transplant parathyroid tissue in the muscles of the forearm, in order to achieve balance of the calcium concentration.
Adrenal glands are two triangular glands sizing a few centimetres and locating, one at each side, on top of the kidneys. Their main function is to secrete hormones to adjust blood pressure, as well as the absorption of water and electrolytes from human body. They produce several hormones, including cortisol, aldosterone, adrenaline, noradrenaline and some quantities of oestrogens and androgens.
Object of adrenal glands surgery is the management of several tumors of the adrenals, which are sometimes able to secrete hormones. The main categories are:
- Pheochromocytoma, which causes induced secretion of adrenaline and noradrenaline, causing hypertension, increased heart rate, headache, amphiblestroid haemorrhage resulting to blindness and strokes.
- Tumors that affect the secretion of aldosterone, causing hypertension, muscle weakness, low potassium levels, arrhythmia and cardiac complications.
- Tumors that affect the secretion of cortisol and cause the so called Cushing’s syndrome. It presents with male type obesity (fat torso and thin limbs), male type body hair, skin lesions and infections, headache, hypertension, menstruation disorders, sentimental imbalance and even psychosis.
- Tumors that secrete androgens and cause the so called adrenogenital syndrome, resulting to masculinising symptoms in women, or pre-teenage masculinising syndrome in children.
- vNon-secreting tumors, that they should be excised when are of abnormal size, because they may hide malignancy.
The diagnostic approach of the adrenal diseases is made with blood and hormone tests, ultrasound, CT and MRI. Method of choice for the adrenalectomy is the robotic or laparoscopic approach. They both fulfil completely the principles of minimally invasive surgery, offering multiple advantages comparing to open surgery.
Classic open approaches should be used only in very large malignant tumors that infiltrate the adjacent tissues or have metastatic spread.