Eddy Lo

Department of SurgeryUCH

Joint Hospital Grand Round

Sclerotherapy for thyroid cysts

Outline

Background information on thyroid cysts

Treatment modalities

Sclerotherapy

Conclusion

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 nodulesCauses

Haemorrhage into and degeneration of a pre-existing nodule

Retention cystsInfarcted adenomaHuge follicles

Miller JM et al 1981De Los Santos ET et al 1990Yasuda K et al 1992

Thyroid nodule

Treatment

IndicationsSymptomaticCosmesisPatient’s preference

Modalitiessimple aspirationsurgerypercutaneous sclerotherapy

Simple aspiration

Satisfactory non-operative treatment

Fluid sent for cytological examination

Recurrence rate varies from 10-80%

Crile GJ 1966Jensen F et al 1976

Surgery

Usually hemithyroidectomyCurativeDefinite histologyGA risksSurgical risks

BleedingWound CxScarRLN injury

Sclerotherapy for thyroid cysts

Minimal invasive procedureGeneral anaesthesia not requiredDone as day caseMinimal side effectsEasy to performCan be repeatedLow cost

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

USG image of normal thyroid gland

Thyroid cyst

Agents

Tetracycline

OK-432

Ethanol

TetracyclineOne 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

Tetracycline

S/ELocal pain

Haematoma

Fatigue

Febrile sensation

Vocal cord paralysis

Treece GL et al 1983Goldfarb WB et al 1987Lee JK et al 1989

Tetracycline

No significant difference in effect when compared to NS in RCTTetracycline (43%) vs NS (47%)

Not commonly used

Hegedus L et al 1988

OK-432

Lyophilized mixture of low-virulence group A streptococcus pyogenes and pen G potassium

Mechanism of actionInduce inflammatory reaction in cyst wallsFluid drainageShrinkageFibrotic adhesion

OK-432Cure rate ranges from 67-73% 25-89% showed reduction in cyst volumeNot readily a/v in HKChance of success

No. of previous aspirationsCyst volume

S/ELocal painTemporary feverHaematoma Roh JL et al 2008

Cho SH et al 2008Roh JL et al 2006Chang HS et al 1998

Ethanol

Induce functional ablation and shrinkage

Success rate up to 95%

RCT showed ethanol is superior to NS

FailureLarge cystMulti-cystic lesions Yasuda K et al 1992

Bennedbaek FN et al 2003

Campatelli A et al 1994

Ethanol

S/E:Local pain and burning sensationLocal haematomaDrunken feelingVocal cord paralysisRespiratory 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 1996Mauz PS et al 2004

Summary

Sclerotherapy is effective

small cyst (<4cm)

solitary

simpleYasuda K et al 1992

Summary

surgery sclerotherapy

Success rate (%) 100 70-80

histology yes no

risk GA risk / surgical risk minimal

No. of procedure one May need multiple attempts

cost expensive cheap

recurrence no <10%

Thyroid cyst

simple

<4cm

aspiration sclerotherapy

surgery

complex

>4cm

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

SolitarySmall (<4cm)simple

Thank you