title: Water-jet dissection in parotid surgery: an experimental study in dogs.
abstract: OBJECTIVE
  The objective of the present study was to investigate the application of the water-jet dissection method in parotid surgery by way of animal experiments, paying particular attention to the clinical and histological reactions of the facial nerve.
  
  
  METHODS
  An animal experimental study.
  
  
  METHODS
  Total bilateral parotidectomies with retention of the facial nerve were performed on 19 beagle dogs by means of the Hydro-Jet device (Andreas Pein Medizintechnik Company, Schwerin, Germany) using different jet diameters and operating pressures. All operations were performed with continuous intraoperative facial monitoring (Neurosign 100, Inomed Company, Teningen, Germany). The dogs were monitored postoperatively over an average period of 20.3 days (range, 14-35 d). Local findings and facial nerve status were documented daily. In a second phase, the dissected nerves were resected and the animals were killed. Samples of water-jet-dissected parotid tissue, as well as all dissected nerve branches, underwent histological examination and were compared with clinical and electrophysiological findings.
  
  
  RESULTS
  It was possible to perform operations easily on all parotid glands by means of the Hydro-Jet using the small, 120-microm jet at operating pressures of 40 to 60 bar and to dissect the facial nerve quickly and safely with retention of its functional capability (n = 34). The dissection of nerves using larger-diameter jets (150 and 200 microm [n = 64]) resulted in a total of two reversible and seven irreversible partial pareses.
  
  
  CONCLUSIONS
  The study has shown that it is possible to perform tissue-selective operations on the parotid gland by means of the Hydro-Jet using the 120-microm jet at operating pressures of 40 to 60 bar, ensuring safe, atraumatic dissection of the facial nerve with retention of its functional capability. The advantages of the new Hydro-Jet method offer a valuable alternative compared with the normal dissection methods adopted in parotid surgery. Thus the results of the present investigation currently are being checked within the framework of a clinical study at our clinic.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Prosper-Hospital, Recklinghausen, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Magritz
authors.forename: V
authors.initials: V
authors.lastname: Jurk
authors.forename: E
authors.initials: E
authors.lastname: Reusche
authors.forename: R
authors.initials: R
authors.lastname: Siegert
mesh_terms: D000818:Animals; D004210:Dissection / Q000295:instrumentation / Q000379:methods*; D004285:Dogs; D004576:Electromyography; D020220:Facial Nerve Injuries / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control; D005158:Facial Paralysis / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control; D005260:Female; D007431:Intraoperative Complications / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control; D008297:Male; D023421:Models, Animal; D016343:Monitoring, Intraoperative; D010306:Parotid Gland / Q000601:surgery*; D011312:Pressure; D014867:Water
chemical_list: D014867:Water