Joint Hospital Grand Round

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

2. Sclerotherapy for thyroid cysts

3. Outline • Background information on thyroid cysts • Treatment modalities • Sclerotherapy • Conclusion

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 Campatelli A et al 1994 Yasuda K et al 1992 Bennedbaek FN et al 2003

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

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

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