Live porcine thirty days delayed recovery surgery: Qualitative findings with the hypersonic vitrectomy

Abstract

IntroductionQualitatively assess the possible delayed structural, macroscopic and microscopic changes in the neuro-retina, retinal vasculature, retinal pigment epithelium (RPE) and optic nerve head (ONH) after pars plana vitrectomy (PPV) surgery using a new hypersonic vitrector (HV).Materials and methodsEight live porcine eyes underwent PPV using either the HV or a conventional pneumatic guillotine vitrector (GV). The un-operated fellow eye from each pig was used as an external control. The pigs were post-operatively kept alive for 30 days before termination and enucleation of the eyes. Prior to enucleation, all eyes underwent examination of the lens and indirect ophthalmoscopy. Enucleated eyes were fixed in formalin, examined macroscopically and processed for histological assessment. Microscopic analysis included assessment of neuro-retina, retinal vasculature, RPE and ONH, as well as observation for any morphological intraocular changes. Comparison was made between: (1) treated and untreated areas of the same eye (internal control) (2) different areas within the same eye operated on using different vitrector settings (3) eyes operated on with the HV and GV (4) eyes receiving surgery and the fellow un-operated eye (external control, same pig).ResultsAll lenses had remained clear at 30 days into the postoperative period. On indirect ophthalmoscopy, the retina had remained attached in all eyes with no visible changes to the neuro-retina, retinal vasculature, RPE or ONH. Two eyes showed localized RPE depigmentation secondary to previously documented intraoperative retinal touch. The Morphological changes in the retinal layers above depigmented RPE were no different from retinal change elsewhere. There were mild and similar microscopic changes observed in the neuro-retina, retinal vasculature, RPE or ONH associated with either the HV or GV PPVs. Preliminary histological findings revealed no significant differences between eyes operated on with the HV and those operated on the GV.DiscussionAt 30 days into the postoperative period, there seemed to be similar morphological changes attributable to the use of HV and GV. Therefore, the HV promises to be a new alternative to the currently commercially available GV for PPV.

Twenty-Three–gauge Hypersonic Vitrectomy

“…3 Although Vitesse hypersonic vitrectomy got both FDA clearance and Conformité Européene mark about 3 years ago, the knowledge regarding the feasibility and the optimal setup of HV system is still very limited because only few experimental and clinical studies have so far evaluated this new technology. [3][4][5][8][9][10] In particular, only two previous case series assessed the performance of HVP in human eyes, highlighting the need of further, preferentially multicentric, clinical studies. 5,10 In this prospective, multicentric study, we assessed intraoperative and postoperative outcomes of 50 eyes that had undergone HV for various vitreoretinal diseases, aiming to evaluate its safety and effectiveness and to identify the settings ensuring the best performance of HVP.…”

Ultrasonic Vitrectomy Performance Assessment Using Micro-Extensional Rheology

“…The port, located at the side of the needle near the distal end, vibrates at US frequencies enabling focused tissue cutting capabilities by the port walls. 6 – 8 The two cutting technologies change the mechanical properties of the vitreous by breaking down the long collagen fibrils responsible for the mechanical properties of the gel-like vitreous. 9 The PB cutter mechanism uses a series of discrete cutting steps where intact vitreous is aspirated and sheared at low relative speeds.…”