Thyroid Operation - Introduction
This section contains information on the details of a thyroid operation, including what tests are done before surgery, the types of operation available and the details of operations.There are various sections written in detail for surgeons, which may contain pictures of surgery that some people may not wish to see.
In Mr Lynn's view there is no substitute for experience in thyroid surgery, and ideally the surgeon should perform at least 50 thyroidectomies a year.In 2007 the BAETS audit of thyroid surgery in the UK showed that 61% of its members reported performing less than 50 thyroidectomies a year.(www.baes.info) Data from the USA has shown that low volumes of thyroid surgery are associated with a totally unacceptable complication rate compared with surgeons like Mr Lynn who performs more than 100 thyroidectomies a year.The BAETS feels that 25 thyroid operations a year is the lower threshold per year to maintain competency.If one considers that no more than 25% of patients will have cancer it means that operating on less than 10 thyroid cancer cases a year is considered satisfactory.This in my view is a very inappropriate view and is most likely the reason for the high complication rate quoted by members of the BAETS.
Prior to most thyroid operations, apart from total thyroidectomy for Grave's Disease, a fine needle biopsy of thyroid should be performed (FNA).This procedure is relatively painless, can be performed with or without local anaesthesia, and ideally be performed under ultrasound control.A small needle(25-27 guage) is inserted into the periphery of the nodule and the sample obtained by an up and down movement.As soon as blood appears the needle is rotated and removed.The patient is told not to swallow during the aspiration. The aspiration is done at least twice and ideally the pathologist should be present to check the adequacy of the specimin. If a cyst is aspirated it is important to biopsy the cyst wall. Only when the nodule is calcified or very fibrous is it necessary to use a Franzen's pistol (syringe holder). If a patient with a solitary thyroid nodule is not offered a FNA under ultrasound control they are advised to seek a second opinion.
The assessment of the results of fine needle aspiration is complex and the interpretation of the results is listed below.The classification is the THY diagnostic category system and ranges from THY1 which is non diagnostic, to THY5 which is diagnostic of thyroid malignancy. All results of FNA biopsy are discussed by Mr Lynn with his multidisplinary team members(MDT).
#THY1. Non-diagnostic: should be repeated immediately.
#THY2. Non-neoplastic (not malignant): should be repeated in 3-6 months and if a similar result is obtained and the lesion is considered to be not clinically high risk it may be watched and not removed.In high risk cases thyroid lobectomy is justified.
#THY3. Follicular lesion or suspected follicular cancer: these lesions should be removed and subjected to formal histology.The percentage of THY3 lesions varies from center to center on rare occasions a lesion may be classified as THY3 because it is an inadequate specimin in such cases is is perfectly correct to repeat the FNA and if the sample is adequate to re-classify it.If the lesion is malignant it should be treated as per the guidelines for the management of follicular thyroid cancer.
Mr Lynn has considerable concerns about the management of THY3 lesions.He thinks that the suggestion that thyroid ultrasound is more reliable in diagnosing cancer than FNA is wrong and dangerous.He has encountered radiologists, who despite the finding of THY3 cytology, tell the patient that the lesion is not malignant.Although the risk of malignancy can be low, it is impossible to exclude malignancy without removing the lesion by at least a thyroid lobectomy.Some groups classify the THY3 lesions into 3A and 3B categories.This results in reported malignancy rate of 28.2% for THY3A and 13% THY3B.This confirms that a watch, wait and re-scan policy is not acceptable even in THY3B lesions.In sick patients a lobectomy can be safely done with a minimal invasive technique under local anaesthesia.
#THY4. Suspicious of cancer: if THY4 has been given due to a lack of material available to exclude medullary thyroid cancer or lymphoma then the FNA must be repeated and tissue subjected as appropriate to either immunocytochemistry (medullary thyroid cancer) or flow cytometry (lymphoma).In all other cases a THY4 report indicates the need for an immediate thyroid exploration, the extent of which is discussed by Mr Lynn with his MDT members since either lobectomy or total thyroidectomy may be initially appropriate.
#THY5. Diagnostic of thyroid cancer: the patient must have surgery, but the extent of surgery depends on the type of tumour, its size and the tumour staging.A plan is discussed by Mr Lynn with his MDT members.
In 2003 EUROCARE reported the UK survival for thyroid cancer as the worst in Europe.There were several factors affecting the reported results including accurate registration and UK regional variation. Few if any thyroid cancers are treated now without MDT input and when this occurs short term 5 year survival for thyroid cancer has been reported in a UK regional center as 83% (Gill et al Clinical Oncology, Sept 2008: 20:7,568).
