Thyroidectomy
The thyroidectomy is the surgical removal of the entire thyroid . It is used to treat thyroid cancer or benign goiter (goiter). If the procedure is only performed on one side, it is called a hemithyroidectomy . With a goiter resection (removal of a benign enlargement of the thyroid gland ), the thyroid gland is only partially removed in order to obtain a functional remainder.
indication
The main indication is malignant goiter . Thyroidectomy should be performed as soon as possible after a diagnosis of thyroid cancer. If the thyroid gland is overactive ( hyperthyroidism ) at the same time , it must first be treated with medication until the concentration of thyroid hormones in the blood has normalized , otherwise a thyrotoxic crisis can occur during the operation .
Thyroidectomy is also used in the treatment of benign diffuse or nodular goiter when pathologically altered thyroid tissue would have to be left with a partial removal of the thyroid gland. Often one side is removed surgically, the other subtotally resected ( Dunhill operation ).
For more information on indications for benign goiter, see goiter resection .
Preliminary examinations
The examinations that led to the indication for surgery are described in the main articles Examination of the thyroid gland and thyroid cancer .
The pre-operative examinations include the clinical physical examination , especially cardiovascular examinations and usually an X-ray examination of the lungs. The blood count , electrolytes , blood coagulation , kidney function and CRP (to rule out inflammation ) are also determined.
The special examinations before a goiter resection include the repeated determination of the thyroid hormones and an examination by the ear, nose and throat specialist to assess the mobility of the vocal cords .
Operating principle
After exposing the front of the thyroid gland, the isthmus on the front wall of the trachea is passed under, clamped, severed and provided with hemostatic piercing. The two thyroid lobes are then largely detached from the environment and the associated blood vessels ( arteria thyroidea superior , arteria thyroidea inferior and the accompanying veins ; for details see thyroid ) severed. Carefully protecting the vocal cord nerves ( recurrent laryngeal nerve ) - neuromonitoring is usually used for the exact identification of this - and the parathyroid glands , the trachea is approached, the connective tissue layer between thyroid and trachea is cut and the flap is removed.
Elimination of pain
The anesthesia is now the standard for thyroidectomy. Until the beginning of the 1970s, the operation was also performed under local anesthesia , since an air embolism was feared if a large vein was accidentally opened. The awake patient could counteract this by actively pressing. There is no longer any danger with modern positive pressure ventilation with PEEP (positive end-expiratory pressure).
storage
The patient is positioned with the upper body straightened by about 30 °. The head rests tilted backwards in a bowl so that the neck is overstretched and the thyroid gland is easily accessible.
Access
The standard is the Kocher collar cut, a 5 to 7 cm long, curved cross-section about two cross fingers above the jugulum . The incision is marked on the awake patient before the operation and, if possible, placed in the course of a skin fold for cosmetic reasons. The skin and subcutaneous fatty tissue are severed and pushed up and down by the muscles. The straight neck muscles are divided in the midline and pushed off on both sides by the thyroid gland, which is now freely accessible. In the case of very large thyroid glands, transverse transection of the short, straight neck muscles is sometimes necessary. In extreme exceptional cases , a thyroid gland that is strongly extended retrosternally can only be triggered by means of a partial median sternotomy (longitudinal division of the upper part of the sternum).
Extension of the intervention
If lymph node metastases are known preoperatively (in the case of goiter maligna ) or if these are found during the operation, a radical thyroidectomy with neck dissection for regional lymphadenectomy is performed. For this purpose, Kocher's collar cut is expanded to become a “door wing cut”, in which a straight longitudinal cut is made in the center line, which ends just below the chin and is widened transversely to both sides.
Wound closure
Before the wound is closed, Redon drains are inserted to drain blood or wound secretions . The wound is closed in three layers : muscles and subcutaneous tissue are each closed with absorbable sutures, the skin with monofilament plastic sutures. The skin is often closed using the cosmetically favorable intracutaneous suture technique. Alternatively, adaptation plasters or tissue adhesives can also be used.
Risks
Unspecific surgical risks
Bleeding during (intraoperative) or after the operation (postoperatively) can be threatening due to the good blood flow to the thyroid gland; in the event of foreseeable difficulties (recurrent goiter), blood reserves are provided in advance .
Due to the good blood circulation, wound infection and wound expansion occur very rarely, are easy to recognize and treat, but usually leave behind very poor cosmetic results. Postoperative thromboses and pulmonary embolisms are also rare due to the rapid mobilization of the patient.
Specific operational risks
A complete severing of the vocal cord nerves ( recurrent laryngeal nerve ) leads to permanent paralysis of the vocal muscles ( recurrent palsy ) with persistent hoarseness. Damage caused by crushing or overstretching the nerve, etc. Ä. also leads to temporary functional failure , but is mostly reversible , so it heals without special therapy. Recurrent palsy on both sides can - due to the closure of the glottis due to the lack of tension in the vocal muscles - lead to complete obstruction of the trachea with an acute risk of suffocation. This may make it necessary to create a permanent tracheostoma . The exact representation of the recurrent laryngeal nerve is therefore mandatory today according to the guideline . Neuromonitoring is usually used to avoid recurrence violations . Injury to the superior laryngeal nerve is very rare, as it is easier to avoid in terms of surgery .
The unintentional removal of or damage to the parathyroid glands (epithelial cells, parathyroid gland), which in many cases are very difficult to identify, leads to derailment of the calcium metabolism ( hypocalcaemia ) with the consequence of tetany , which, however, is usually due to the addition of calcium in combination Can be remedied well with vitamin D and is not permanent ( see also hypoparathyroidism ). Epithelial cells that have been removed or cut off from the circulation are retransplanted ( autologous transplantation ) by sewing them into a muscle (e.g. sternocleidomastoid muscle ). If the need for radiation is foreseeable, for example in the case of anaplastic thyroid carcinoma, prophylactic removal of the epithelial cells and their replantation away from the radiation area (e.g. in a muscle of the forearm) is also possible.
The risk of serious complications in thyroid cancer depends primarily on the location and extent of the tumor and can therefore not be described with reliable figures.
Postoperative controls and follow-up care
Details on tumor follow-up can be found in the main article Thyroid Cancer
The mobility of the vocal cords is demonstrated either by laryngoscopy directly when anesthesia is released or by checking the phonation (for this purpose the patient is simply asked to speak) in order to detect recurrent palsy immediately. If there are signs of recurrent palsy, breathing must be monitored by intensive care medicine.
The serum calcium level is determined on the first postoperative day; if it is significantly lower, damage to the epithelial cells must be assumed and calcium must be added if necessary.
In case of doubt, rebleeding ( hematoma ) can be distinguished from simple postoperative swelling by means of sonography .
If there are no complications, the patient can get up on the evening of the day of the operation and drink fluids. You can eat normally from the first postoperative day and mobility is not restricted. Usually only small amounts of pain medication are required. Only in those cases in which the neck muscles had to be incised transversely due to the size of the goiter, extreme turning movements of the head is not recommended for the first 10 to 15 days.
After thyroidectomy including neck dissection , the disturbance of mobility and the level of pain depend on the extent of the lymphadenectomy and the associated partial removal of muscles, connective tissue and blood vessels. It can therefore require longer support of the neck muscles, for example with a Schanz tie .
The drains are removed on the 2nd, and discharge from hospital at the earliest on the 3rd, usually on the 4th or 5th day after the operation. The skin suture is removed after about a week. The remaining scar is still noticeable for the first eight to twelve weeks and only then develops its final width and color. Ideally, the end result would be difficult to see a fine line in a fold of skin, but the extent of scarring varies from patient to patient. After neck dissection via the “door leaf cut”, the scarring is of course much more extensive.
Follow-up care consists of regular monitoring of thyroid hormones and TSH. Except for the completely removed small papillary carcinoma in situ of the thyroid gland, radioiodine therapy (RJT) is then carried out regularly . In this context, a new scintigraphy is made that provides information on the completeness of the thyroidectomy and also shows previously undiscovered lymph node or distant metastases. RJT reliably combats small remaining tumor residues, lymph node metastases and also iodine-storing distant metastases. This does not apply to the non-iodavid (no iodine-storing) tumors, for example anaplastic or medullary carcinomas . The success of the RJT is documented three months later by another scintigraphy.
Sonographic controls are initially carried out closely (every 3 months), new control scintigraphies initially at annual intervals.
The loss of function of the removed thyroid is compensated for by hormone replacement therapy (hormone substitution) in which L-thyroxine (free T4) is administered in tablet form . The appropriate dosage is determined by determining the TSH value, which should be between 0.05 and 0.1 mU / l for thyroid carcinomas. After benign diseases, a target TSH of 0.4 to 0.9 mU / l is recommended with an initial dose of 1 µg L-thyroxine per kg body weight.
history
In 1791, the French surgeon Pierre-Joseph Desault performed the first described thyroid resection.
The thyroidectomy - at that time still under the name strumectomy, which is no longer common today - was carried out in 1876 by the Swiss surgeon and Nobel Prize winner (1909) Emil Theodor Kocher as a total extirpation of a goiter (in the sense of today's terminology more like a thyroidectomy) and in 1878 under the title " Extirpation of a retrooesophageal goiter ”. In the following 10 years he made a significant contribution to improving the surgical technique and was able to reduce the mortality rate as a result of total extirpation considerably. In 1883, Kocher published that total extirpation could lead to a condition similar to cretinism . This could be prevented by leaving some thyroid tissue in the patient's body. The Kocher collar cut and the Kocher clips , which are still used today, are named after Emil Theodor Kocher .
In 1884 von Rehn performed the first thyroid resection for hyperthyroidism in Germany.
literature
- S2k guidelines for the operative therapy of malignant thyroid diseases of the German Society for General and Visceral Surgery e. V. (DGAV). In: AWMF online (as of 2012)
- H.-D. Röher: Surgery of the thyroid gland. In: HD Röher (Ed.): Surgery head and neck. (= Surgical operation theory. Volume 1). 2nd Edition. Urban & Schwarzenberg Publishing House, Munich / Vienna / Baltimore 1990, ISBN 3-541-14412-2 .
- V. Bay, P. Matthaes: Thyroid. In: F. Baumgartl, K. Kremer, HW Schreiber (ed.): Special surgery for the practice. Volume 1, part 1. Georg Thieme Verlag, Stuttgart 1973, ISBN 3-13-445301-0 , p. 482 ff.
- Frank Bauer: The influence of the ligature of the inferior thyroid artery on the complication rates in the surgery of benign goiter. Evaluation of surgical quality assurance in East Germany 1998, p. 36 ff. ( Uni-halle.de )
Individual evidence
- ↑ J. Witte: Radicality principles in the surgery of differentiated thyroid carcinomas taking into account parameters relevant to prognosis. Dissertation. uni-duesseldorf.de
- ↑ U. Scharlau, H. Steffen, K. Hermann: The benign nodular goiter - current treatment strategies from a surgical point of view. In: Ärzteblatt MVP , 07/2008; aerzteblatt-mvp.de (PDF) as of September 7, 2008
- ↑ J. DuBose et al. a .: Honest and sensitive surgeons: the history of thyroid surgery. In: Curr Surg. , 61 (2), Mar-Apr 2004, p. 241. PMID 15051267
- ↑ a b Emil Theodor Kocher. In: Encyclopædia Britannica . Retrieved February 9, 2008 .
- ↑ a b I. W. Müller u. a .: The Chronicle of Medicine . Chronik-Verlag, 1993, ISBN 3-611-00273-9 , p. 314.
- ↑ J. Glamsch: Intraoperative neuromonitoring of the recurrent laryngeal nerve with the help of the Neurosign® 100 during operations on the thyroid gland. Dissertation. Würzburg, August 2002, p. 1. From: K. Oberdisse, E. Klein, D. Reinwein: The diseases of the thyroid. Georg Thieme Verlag, Stuttgart 1990 ( uni-wuerzburg.de )
