1. Eddy Lo Department of Surgery UCH Joint Hospital Grand Round

2. Sclerotherapy for thyroid cysts

3. Outline Background information on thyroid cysts Treatment modalities Sclerotherapy Conclus ion

4. Thyroid cysts Thyroid nodule is a common clinical problem 6-26% of solitary thyroid nodules are cystic lesions Often benign ( 0.9 to 10% malignant) Most derived from hyperplastic nodules Causes Haemorrhage into and degeneration of a pre-existing nodule Retention cysts Infarcted adenoma Huge follicles Miller JM et al 1981 De Los Santos ET et al 1990 Yasuda K et al 1992

5. Thyroid nodule

6. Treatment Indications Symptomatic Cosmesis Patient’s preference Modalities simple aspiration surgery percutaneous sclerotherapy

7. Simple aspiration Satisfactory non-operative treatment Fluid sent for cytological examination Recurrence rate varies from 10-80% Crile GJ 1966 Jensen F et al 1976

8. Surgery Usually hemithyroidectomy Curative Definite histology GA risks Surgical risks Bleeding Wound Cx Scar RLN injury

9. Sclerotherapy for thyroid cysts Minimal invasive procedure General anaesthesia not required Done as day case Minimal side effects Easy to perform Can be repeated Low cost

10. Methods USG guided FNA of the cyst Followed by injection of the sclerosant No anaesthesia required FU with USG Procedure will be repeated if necessary

11. USG image of normal thyroid gland

12. Thyroid cyst

16. Agents Tetracycline OK-432 Ethanol

17. Tetracycline One of the earliest sclerosant used Mechanism is thought to be related to its low pH Cyst resolution percentage up to 59% to 95% Significantly higher success rate than simple aspiration

18. Tetracycline S/E Local pain Haematoma Fatigue Febrile sensation Vocal cord paralysis Treece GL et al 1983 Goldfarb WB et al 1987 Lee JK et al 1989

19. Tetracycline No significant difference in effect when compared to NS in RCT Tetracycline (43%) vs NS (47%) Not commonly used Hegedus L et al 1988

20. OK-432 Lyophilized mixture of low-virulence group A streptococcus pyogenes and pen G potassium Mechanism of action Induce inflammatory reaction in cyst walls Fluid drainage Shrinkage Fibrotic adhesion

21. OK-432 Cure rate ranges from 67-73% 25-89% showed reduction in cyst volume Not readily a/v in HK Chance of success No. of previous aspirations Cyst volume S/E Local pain Temporary fever Haematoma Roh JL et al 2008 Cho SH et al 2008 Roh JL et al 2006 Chang HS et al 1998

22. Ethanol Induce functional ablation and shrinkage Success rate up to 95% RCT showed ethanol is superior to NS Failure Large cyst Multi-cystic lesions Yasuda K et al 1992 Bennedbaek FN et al 2003 Campatelli A et al 1994

23. Ethanol S/E: Local pain and burning sensation Local haematoma Drunken feeling Vocal cord paralysis Respiratory arrest (single case report) Leakage of ethanol causing toxic necrosis of larynx and paraglandular fibrosis Extensive scarring making subsequent operation difficult Iacconi P et al 1996 Mauz PS et al 2004

24. Summary Sclerotherapy is effective small cyst (<4cm) solitary simple Yasuda K et al 1992

25. Summary surgerysclerotherapy Success rate (%)10070-80 histologyyesno riskGA risk / surgical riskminimal No. of procedureoneMay need multiple attempts costexpensivecheap recurrenceno<10%

26. Thyroid cyst simple <4cm aspiration sclerotherapy surgery complex >4cm

27. Conclusion Percutaneous sclerotherapy with ethanol or OK-432 is simple, safe and effective non- operative alternative for the treatment of benign cystic lesions of thyroid Solitary Small (<4cm) simple

28. Thank you