Factors influencing the outcome of extracorporeal shock wave lithotripsy in the management of salivary calculi.
OBJECTIVE
To identify the factors that affect outcome (stone clearance, partial clearance without symptoms, and residual stone with symptoms unchanged) of extracorporeal shock wave lithotripsy (ESWL). To develop and validate a predictive model for outcome of treatment.


METHODS
Prospective controlled trial.


METHODS
There were 142 salivary calculi (78 submandibular, 64 parotid) entered into a prospective clinical trial of ESWL. The results were analyzed and a predictive model generated, which was validated using a second group of patients treated by the same technique.


RESULTS
ESWL achieved complete success (stone and symptom free) in 67 (47.15%) of cases (submandibular 28/78, 35.9%; parotid 39/64, 60.9%). Partial success (residual stone and symptom free) was obtained in a further 49 (34.5%) (submandibular 29/78, 37.2%; parotid 20/64, 31.3%). Failure occurred in 26 (18.3%) of cases (submandibular 21/78, 26.9%; parotid 5/64, 7.8%).


CONCLUSIONS
ESWL can eradicate salivary calculi but its effectiveness is dependant mainly on size of the stone. Using a regression analysis model stone clearance can be reliably predicted based on stone size. A less important factor is the radiodensity of the stone, whereas a greater proportion of parotid calculi are eliminated by ESWL than submandibular calculi.
Escudier
Michael P
MP
Departments of Oral Medicine, Dental Radiology, Maxillofacial Surgery, King's College London Dental Institute, London, UK. michael.escudier@kcl.ac.uk
Brown
Jackie E
JE
Putcha
Venkata
V
Capaccio
Pasquale
P
McGurk
Mark
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D006801:Humans; D008096:Lithotripsy; D008875:Middle Aged; D011446:Prospective Studies; D012044:Regression Analysis; D015494:Salivary Gland Calculi / Q000628:therapy*; D016896:Treatment Outcome; D055815:Young Adult