Intraoperative evaluation of testicular vascularization and perfusion in rat testicles with indocyanine green (ICG)/near-infrared (NIR) fluorescent imaging after torsion-detorsion and reperfusion

Pediatr Surg Int. 2022 Nov;38(11):1625-1633. doi: 10.1007/s00383-022-05211-1. Epub 2022 Sep 10.

Abstract

Introduction: The aim of this study was to evaluate testicular perfusion and vascularization with intraoperative ICG/NIR imaging in a testicular ischemia-reperfusion model and to investigate the effects of ICG on testicular tissue.

Materials and methods: 24 male rats were divided into four groups. In the ICG group, only ICG was given and images of the testicles were recorded with NIR camera. In the torsion group, the testicles were left in torsion for 4 h. ICG/NIR images were obtained after torsion and detorsion. In the reperfusion group, ICG/NIR images of the testicles were obtained at the 4th hour of reperfusion. After the procedures, testicles were collected and evaluated with histological, immunohistochemical examination and qRT-PCR.

Results: There was no histologically negative effect of ICG on testicular tissue. There was no testicular perfusion in the torsion group, but perfusion started after detorsion. At the 4th hour of reperfusion, testicular perfusion continued. TNF-a, IL-6, MCP-1 and caspase-3 immunoreactivity were found to be at low levels in the control and ICG groups, while high in the torsion and reperfusion groups (p < 0.05). In qRT-PCR, TNF-a, IL-6, MCP-1 and caspase-3 expressions were lower in the control and ICG groups, but higher in the torsion and reperfusion groups.

Conclusion: There was no histologically negative effect of ICG on testicles. The ICG/NIR imaging technique seems to be a feasible method in testicular torsion and may contribute to the surgeon in the intraoperative management of testicular torsion. In testicles that started to be perfused after detorsion, perfusion still continued at the 4th hour of reperfusion. Our next goal is to test whether testicles showing ICG fluorescence in during reperfusion maintain their viability for long term.

Keywords: Indocyanine green; Near-infrared; Testicular torsion.

MeSH terms

  • Animals
  • Caspase 3
  • Humans
  • Indocyanine Green / pharmacology
  • Interleukin-6
  • Male
  • Rats
  • Reperfusion
  • Reperfusion Injury* / diagnostic imaging
  • Spermatic Cord Torsion* / diagnostic imaging
  • Spermatic Cord Torsion* / surgery
  • Testis / diagnostic imaging
  • Testis / surgery

Substances

  • Interleukin-6
  • Caspase 3
  • Indocyanine Green