The interaction of laser energy with ureter tissues in a long term investigation

U. Stratmann, K. Schaarschmidt, R. R. Lehmann, A. Heinze, G. H. Willital, E. Unsold, A. P. Evan

Research output: Contribution to journalArticle

1 Scopus citations


This study investigates tissue responses after laser irradiation of the rabbit ureter, which serves as an experimental model for rectourogenital fistulae of children. Twenty-five rabbit ureters were irradiated intraluminally by a Nd:YAG laser 1320 nm (2 Watt, 20 seconds and 3 Watt, 8 seconds) via an applicator with radialsymmetrical light distribution. Immediately, 2 weeks, 4 weeks, 8 weeks, and 16 weeks after irradiation, the ureters were X-rayed with contrast solution and prepared for light and transmission electron microscopy. For the parameters employed, no apparent morphological differences could be observed. Immediately, the central laser zone showed a transmural thermonecrosis prevailed by cellular destruction, condensed ground substance and occlusion of most vascular lumina. Peripheral laser zones displayed urothelial vacuolations. Between 2 and 16 weeks, urothelial regeneration and ingrowth of granulation tissue caused a luminal stenosis or occlusion followed by transformation into scar tissue. In some peripheral laser zones, a hydroureter with marked luminal dilatation developed. We conclude that the ureter is occluded if the expanding force of the growing scar tissue exceeds the hydrostatic pressure of the obstructed urine. A laser occlusion of rectourogenital fistulae will be easier to achieve since fistula occlusion does not entail an obstruction of the urine flow.

Original languageEnglish (US)
Pages (from-to)805-816
Number of pages12
JournalScanning microscopy
Issue number3
StatePublished - Dec 1 1995
Externally publishedYes


  • Nd:YAG laser
  • healing process
  • hydroureter
  • immediate tissue response
  • luminal occlusion
  • rabbit ureter
  • radiology
  • rectourogenital fistula
  • thermal necrosis
  • ultrastructure

ASJC Scopus subject areas

  • Instrumentation

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  • Cite this

    Stratmann, U., Schaarschmidt, K., Lehmann, R. R., Heinze, A., Willital, G. H., Unsold, E., & Evan, A. P. (1995). The interaction of laser energy with ureter tissues in a long term investigation. Scanning microscopy, 9(3), 805-816.