[Electrohydraulic intracorporeal lithotripsy of salivary calculi. In vitro and animal experiment studies].
BACKGROUND
Extracorporeal lithotripsy is now used routinely for the treatment of salivary duct stones. The question arose whether electrohydraulic intracorporeal lithotripsy, which is applied in urology and gastroenterology, might also be useful in the treatment of this disease. Before its possible clinical application the influence of electrohydraulic intracorporeal shock waves on salivary stones in vitro and any influence on the tissue in the head and neck region (in vivo) had to be investigated.


METHODS
In vitro experiments. Fifty-eight salivary stones and 11 extirpated human submandibular glands were treated by three different electrohydraulic devices. Animal experiments. Electrohydraulic shock waves were applied to the dilated Stensen's duct and other tissues (muscle, parotid gland, facial nerve) of six rabbits.


RESULTS
Of 58 salivary stones, 53 (91%) were fragmented, 39 (67%) with a remaining size of less than 1.5 mm and 14 (24%) more than 1.5 mm. In 5 cases (9%) no effects were seen at all. Fragmentation occurred independent of the mineralogical components of the stone and independent of the different lithotriptors used. The smaller the probe diameter and the larger the stone, the more shock waves were needed to achieve fragmentation. With the smaller probes the stones could not be fragmented completely. In human submandibular glands, extensive tissue lesions could be evidenced macroscopically and histologically after application of electrohydraulic shock waves in vitro. Application of electrohydraulic shock waves to the dilated parotid gland duct of rabbits led to perforations of the duct after 1-5 single pulses. Lesions of nerves and blood vessels could also be observed within the duct environment. This occurred with all of the different electrohydraulic devices, probe diameters and intensities used. In our opinion the damage produced is probably the result of both the direct effect of the plasma as well as the resultant stress wave.


CONCLUSIONS
In view of the severe damage caused to different tissues, use of the described method for the treatment of stones in the narrow human salivary ducts should be greatly restricted.
Iro
H
H
Klinik und Poliklinik für Hals-Nasen- und Ohrenkranke, Universität Erlangen-Nürnberg.
Zenk
J
J
Hosemann
W G
WG
Benzel
W
W
D000818:Animals; D002404:Catheterization / Q000295:instrumentation; D046508:Culture Techniques; D004867:Equipment Design; D006801:Humans; D008096:Lithotripsy / Q000295:instrumentation*; D010306:Parotid Gland / Q000293:injuries / Q000473:pathology; D011817:Rabbits; D012465:Salivary Duct Calculi / Q000473:pathology / Q000628:therapy*; D015494:Salivary Gland Calculi / Q000473:pathology / Q000628:therapy*; D013363:Submandibular Gland / Q000293:injuries / Q000473:pathology