Sign In

A subscription to JoVE is required to view this content. Sign in or start your free trial.

In This Article

  • Summary
  • Abstract
  • Introduction
  • Protocol
  • Representative Results
  • Discussion
  • Acknowledgements
  • Materials
  • References
  • Reprints and Permissions

Summary

In the present protocol, a urethral stricture induction was developed in Wistar rats, followed by urethral reconstruction with a buccal mucosa graft. A retrograde urethrogram and laser Doppler assessment were performed, validating urethral reconstruction (after stricture formation) and graft placement.

Abstract

Urethral reconstruction is an important area of expertise for urologists. The buccal mucosa is considered the best option when urethral grafting is necessary, although in some cases, it is inappropriate or needs to be optimized to repair a given stricture. Therefore, developing innovative procedures and evaluating their putative success in experimental models is crucial to fit the clinical need. With this goal, this study describes a protocol in which urethral stricture was induced by electrocautery in Wistar rats. Urethral reconstruction was performed 1 week later with a buccal mucosa graft, harvested from the lower lip, and placed in a ventral onlay fashion. A retrograde urethrogram showed a significant improvement in urethral diameter after urethroplasty compared to the respective value after stricture induction. Additionally, the graft placement was assessed by blood perfusion analysis using laser Doppler. As expected, a dark blue area corresponded to the non-vascularized buccal mucosa graft. This procedure can successfully simulate the normal pathophysiological process of urethral injury and tissue modulation, as well as urethral reconstruction using a buccal mucosa graft in a reproducible manner, and serve as the basis for future research based on tissue engineering or urethral grafts.

Introduction

Urethral reconstruction is a major challenge for urological surgeons in the management of urethral injury in the setting of strictures, trauma, or congenital defects1. With curative intent, urethroplasty is the treatment of choice for most patients, with long (>2 cm) and anterior urethral defects requiring some form of substitution urethroplasty2. Many tissues have been used as urethral substitutes, including full or split-thickness skin grafts of genital or extragenital areas, bladder wall mucosa, or the widespread buccal mucosa2. Buccal mucosa grafts have several advantages, such as coming from ....

Protocol

All animal procedures were performed according to Directive 2010/63/EU. The procedures were approved by the institutional Animal Welfare Body, licensed by DGAV, the Portuguese competent authority for animal protection (license number 0421/000/000/2021). Male Wistar Han IGS (Crl:WI(Han) rats (400-500 g) at 12-14 weeks of age were used for the present study. The animals were obtained from a commercial source (see Table of Materials).

1. Preparation of solutions

Representative Results

A total of 12 male Wistar rats, weighing 400-500 g and 12-14 weeks old, were used for urethral stricture induction. A retrograde urethrogram (RUG1) was performed 1 week later8, confirming the success of the technique. The urethral diameter was measured in millimeters at the level of the stricture induction. After this, a urethroplasty with a buccal mucosa graft was performed in the ventral face of the rat urethra. The same rats were submitted to a second retrograde urethrogram (RUG2) 14 days after.......

Discussion

Urethroplasty with buccal mucosa grafts is a major cornerstone in urethral reconstruction. However, innovative procedures should be developed to optimize those already described and establish new ones, such as tissue-engineered materials and biological grafts, to reduce complications and morbidity. Several procedures have been published to establish preclinical models and define surgical techniques. Souza et al.1 conducted a study including 12 New Zealand rabbits. A ventral longitudinal skin incis.......

Acknowledgements

We thank João Leitão, head of the Radiology department of Centro Hospitalar Universitário Lisboa Norte, and Catia Fernandes, technician of the Radiology department of Centro Hospitalar Universitário Lisboa Norte, for their cooperation in the realization of urethrograms.

....

Materials

NameCompanyCatalog NumberComments
AtipamezoleOrionPharmaANTISEDAN (atipamezole) is indicated for the reversal of the sedative and analgesic effects.
BuprenorphineRichterPharmaBuprenorphine is a derivative of the opioid alkaloid thebaine that is a more potent (25-40 times) and longer lasting analgesic than morphine.
Carl Zeiss Opmi-1 FC Surgical Stereo MicroscopeCarl Zeiss Microscopy, GermanyOPMI 1 FC from ZEISS symbolizes quality, precision and reliability. The manual system is easy to use and delivers high fidelity images with the legendary ZEISS optics.
CarprofenZoetisCarprofen is a non-steroidal anti-inflammatory drug (NSAID) of the propionic acid class.
Catheter 22 G. x 1''B BraunIntrocan SafetyIV Catheter of fluorinated ethylene propylene (FEP) with firmer construction for
arterial access.
EnrofloxacinBayerEnrofloxacin is a fluoroquinolone antibiotic.
FentanylBraun3644960Fentanyl is a powerful synthetic opioid analgesic.
FlumazenilFresenius KabiBenzodiazepine antagonist is used for the complete or partial reversal of the sedative effects caused by benzodiazepines.
High temperature cauteryFiabF7244Disposable cautery, sterile, high temperature (1200 °C), 28 mm fine tip.
Instillagel gelFarco-pharmaCellulose-based lubricant with local anaesthetic and disinfecting properties.
IopromideBayerNon-ionic injectable contrast medium, with iodine.
Laser Doppler imaging system (perfusion imager moorLDI2-HIR and dedicated software)MoorLDI-V6.0, Moor Instruments Ltd, Axminster, UK5710The angiogenesis models uses Laser Doppler imaging to assess blood perfusion in the hind limbs, one of which is ligated surgically. Dedicated measurement and comparison software allows the definition of regions of interest for blood flow assessment on the ischaemic versus non-ischaemic limb to establish a "reperfusion ratio" which can be assessed as often as needed and over a number of days on the same subject.
Lubrithal Eye GelDechraEye gel used in animals for prevention of dry eyes during anaesthesia. Lubricating and moisturising action on cornea and conjunctiva.
Male Wistar Han IGS (Crl:WI(Han) ratsCharles River Laboratories, SpainTwelve to fourteen-week-old
MetedomidinVirbac037/01/07RFVPTMedetomidine is a synthetic drug used as surgical anesthetic.
MidazolamLabesfalBenzodiazepine medication is used for anesthesia and procedural sedation.
Monoplan Angiography SystemPhilips Medical SystemsAzurion 7 M20A stationary diagnostic fluoroscopic x-ray system specifically designed to optimize the capability of users to visually and quantitatively evaluate the anatomy and function of blood vessels of the heart, brain and other organs, as well as the lymphatic system.
Mosquito forcepsHenry Schein102-4346Hartman-Mosquito Hemostatic Forcep Curved 3-1/2" Stainless Steel
Needle HolderHenry Schein100-2570Needle holder Mayo-Hegar, stainless steel, 14 cm
Ophtalmic Needle HolderAsicoAE-6143Needle holder barranquer most delicate without lock
Pentobarbital SodiumEcupharPentobarbital Sodium is the sodium salt of pentobarbital used for euthanasia.
Pointed ForcepsAesculapBD335RMicroforceps, 0.30 mm tip
Polysorb 6.0Medtronic (Covidien)UL-101Coated Synthetic Absorbable Suture aimed to reduce the inflammatory reaction in tissues, followed by gradual encapsulation of the suture by fibrous connective tissue.
Providone-IodineMylanPovidone-iodine 10% is an antiseptic drug, used as a disinfectant before and after surgery.
Scalpel Blade nº11B BraunBB511Carbon steel, sterile
Spring ScissorHenry Schein600-4826Surgical scissors 31 castroviejo
Surgical ForcepsAesculapBD33RMicroforceps, 0.20mm tip
Surgical ScissorAesculapMA873RMicro Iris Scissor, curved shrap tips
SurgiPro 7.0Medtronic (Coviden)VP-702-XNon-Absorbable Monofilament Polypropylene Suture indicated for use in general soft tissue ligation.

References

  1. Souza, G. F., Calado, A. A., Delcelo, R., Ortiz, V., Macedo, A. Histopathological evaluation of urethroplasty with dorsal buccal mucosa: an experimental study in rabbits. International Brazilian Journal of Urology. 34 (3), 345-354 (2008).
  2. Andrich, D. E., Mundy, A. R.

Explore More Articles

Urethral StrictureBuccal Mucosa GraftUrethroplastyRat ModelPenile Skin IncisionElectrocauteryUrethral CatheterizationBuccal Mucosa HarvestingPenile DeglovingUrethral SpatulationGraft Placement

This article has been published

Video Coming Soon

JoVE Logo

Privacy

Terms of Use

Policies

Research

Education

ABOUT JoVE

Copyright © 2024 MyJoVE Corporation. All rights reserved