Cargando…

Experimental Laboratory Modeling of Choroidal Vasculature: A Study of the Dynamics of Intraoperative Choroidal Hemorrhage during Pars Plana Vitrectomy

OBJECTIVES: Choroidal hemorrhages (CH) result from rupture of choroidal vessels leading to extravasation of blood into the suprachoroidal space. In this study, we aimed to understand the hemodynamics of CH by developing a purpose-built scale model of the choroidal vasculature and calculating stress...

Descripción completa

Detalles Bibliográficos
Autores principales: Doğramacı, Mahmut, Dikkaya, Funda, Şentürk, Fevzi, Aras, Cengiz
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Galenos Publishing 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8558693/
https://www.ncbi.nlm.nih.gov/pubmed/34702023
http://dx.doi.org/10.4274/tjo.galenos.2020.64927
_version_ 1784592622899167232
author Doğramacı, Mahmut
Dikkaya, Funda
Şentürk, Fevzi
Aras, Cengiz
author_facet Doğramacı, Mahmut
Dikkaya, Funda
Şentürk, Fevzi
Aras, Cengiz
author_sort Doğramacı, Mahmut
collection PubMed
description OBJECTIVES: Choroidal hemorrhages (CH) result from rupture of choroidal vessels leading to extravasation of blood into the suprachoroidal space. In this study, we aimed to understand the hemodynamics of CH by developing a purpose-built scale model of the choroidal vasculature and calculating stress levels in the model under different conditions. MATERIALS AND METHODS: We modeled the choroidal vasculature using a rubber tube 10 cm in length and 1 cm in diameter that was wrapped with conductive thread to enable the measurement of stress at the walls of the tube. Stress levels across the tube were continuously measured under different systemic intravascular blood pressure levels (IVP), intraocular pressure (IOP) levels, and distortion. RESULTS: Stress values across the choroidal vessel model correlated negatively with IOP and positively with IVP and distortion. All correlations were statistically significant (p<0.05) and were stronger when the model was filled with expansile tamponade compared to non-expansile tamponades. Distortion showed the strongest correlation in terms of increasing stress across the model, while IVP showed stronger correlation compared to IOP. Raising IOP to counteract the stress in the model was effective when the stress in the model was secondary to increased IVP, but this approach was not effective when the stress in the model was caused by distortion. CONCLUSION: Excessive distortion of the globe during surgical maneuvers could be the primary reason for the rarely observed intraoperative CH. Non-expansile ocular tamponade provides better support for the vascular bed against CH and should be the recommended choice of tamponade in patients with existing CH. Increasing IOP excessively is of limited effect in preventing CH in vessels that are under stress as a result of distorting surgical maneuvers.
format Online
Article
Text
id pubmed-8558693
institution National Center for Biotechnology Information
language English
publishDate 2021
publisher Galenos Publishing
record_format MEDLINE/PubMed
spelling pubmed-85586932021-11-17 Experimental Laboratory Modeling of Choroidal Vasculature: A Study of the Dynamics of Intraoperative Choroidal Hemorrhage during Pars Plana Vitrectomy Doğramacı, Mahmut Dikkaya, Funda Şentürk, Fevzi Aras, Cengiz Turk J Ophthalmol Original Article OBJECTIVES: Choroidal hemorrhages (CH) result from rupture of choroidal vessels leading to extravasation of blood into the suprachoroidal space. In this study, we aimed to understand the hemodynamics of CH by developing a purpose-built scale model of the choroidal vasculature and calculating stress levels in the model under different conditions. MATERIALS AND METHODS: We modeled the choroidal vasculature using a rubber tube 10 cm in length and 1 cm in diameter that was wrapped with conductive thread to enable the measurement of stress at the walls of the tube. Stress levels across the tube were continuously measured under different systemic intravascular blood pressure levels (IVP), intraocular pressure (IOP) levels, and distortion. RESULTS: Stress values across the choroidal vessel model correlated negatively with IOP and positively with IVP and distortion. All correlations were statistically significant (p<0.05) and were stronger when the model was filled with expansile tamponade compared to non-expansile tamponades. Distortion showed the strongest correlation in terms of increasing stress across the model, while IVP showed stronger correlation compared to IOP. Raising IOP to counteract the stress in the model was effective when the stress in the model was secondary to increased IVP, but this approach was not effective when the stress in the model was caused by distortion. CONCLUSION: Excessive distortion of the globe during surgical maneuvers could be the primary reason for the rarely observed intraoperative CH. Non-expansile ocular tamponade provides better support for the vascular bed against CH and should be the recommended choice of tamponade in patients with existing CH. Increasing IOP excessively is of limited effect in preventing CH in vessels that are under stress as a result of distorting surgical maneuvers. Galenos Publishing 2021-10 2021-10-26 /pmc/articles/PMC8558693/ /pubmed/34702023 http://dx.doi.org/10.4274/tjo.galenos.2020.64927 Text en © Copyright 2021 by Turkish Ophthalmological Association | Turkish Journal of Ophthalmology, published by Galenos Publishing House. https://creativecommons.org/licenses/by-nc-nd/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Original Article
Doğramacı, Mahmut
Dikkaya, Funda
Şentürk, Fevzi
Aras, Cengiz
Experimental Laboratory Modeling of Choroidal Vasculature: A Study of the Dynamics of Intraoperative Choroidal Hemorrhage during Pars Plana Vitrectomy
title Experimental Laboratory Modeling of Choroidal Vasculature: A Study of the Dynamics of Intraoperative Choroidal Hemorrhage during Pars Plana Vitrectomy
title_full Experimental Laboratory Modeling of Choroidal Vasculature: A Study of the Dynamics of Intraoperative Choroidal Hemorrhage during Pars Plana Vitrectomy
title_fullStr Experimental Laboratory Modeling of Choroidal Vasculature: A Study of the Dynamics of Intraoperative Choroidal Hemorrhage during Pars Plana Vitrectomy
title_full_unstemmed Experimental Laboratory Modeling of Choroidal Vasculature: A Study of the Dynamics of Intraoperative Choroidal Hemorrhage during Pars Plana Vitrectomy
title_short Experimental Laboratory Modeling of Choroidal Vasculature: A Study of the Dynamics of Intraoperative Choroidal Hemorrhage during Pars Plana Vitrectomy
title_sort experimental laboratory modeling of choroidal vasculature: a study of the dynamics of intraoperative choroidal hemorrhage during pars plana vitrectomy
topic Original Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8558693/
https://www.ncbi.nlm.nih.gov/pubmed/34702023
http://dx.doi.org/10.4274/tjo.galenos.2020.64927
work_keys_str_mv AT dogramacımahmut experimentallaboratorymodelingofchoroidalvasculatureastudyofthedynamicsofintraoperativechoroidalhemorrhageduringparsplanavitrectomy
AT dikkayafunda experimentallaboratorymodelingofchoroidalvasculatureastudyofthedynamicsofintraoperativechoroidalhemorrhageduringparsplanavitrectomy
AT senturkfevzi experimentallaboratorymodelingofchoroidalvasculatureastudyofthedynamicsofintraoperativechoroidalhemorrhageduringparsplanavitrectomy
AT arascengiz experimentallaboratorymodelingofchoroidalvasculatureastudyofthedynamicsofintraoperativechoroidalhemorrhageduringparsplanavitrectomy