Abstract
Purpose: :
To analyze construction and healing of sutureless vitrectomy wounds constructed with 20g, 23g, and 25g surgical entry systems.
Methods: :
Young adult New Zealand Albino rabbits were used to analyze the Dorc, Synergetics, Alcon and Bausch and Lomb entry systems. Incisions into the sclera were made obliquely at 10, 30-45, and 90 degrees. Incisions were made with and without globe stabilization. Each wound was stretched and instrument exchanges were made to simulate surgical stress on the wound. Conjunctiva was repositioned upon removal of each cannula. Two rabbits were used for each system and each time point. Study eyes were fixed at euthanasia (wks 1 and 3). Tissue was stained with H/E. Masked histopathologic analysis of scleral wounds was performed on serial sections.
Results: :
Self-sealing wounds were able to be created utilizing all 3 size entry systems but less likely in 20g and 23g systems than 25g. Smaller gauge wounds had less vitreous plugging and epithelial ingrowth. When made obliquely, all types of wounds healed well with good scleral tissue apposition. 20g and 23g vertical entry wounds did not heal well and were characterized by large vitreous plugs through the open channel in the sclera. At 1 week, oblique wounds had some collagen deposition present, with better healing by 3 weeks as expected. (Multiple representative histology sections illustrating the effect of trocar and wound architecture will be presented.)
Conclusions: :
Self sealing incisions can be made with 20g, 23g, and 25g entry systems. Wound technique and use of oblique incisions were much more important in larger wounds. The practice of using intraocular air/gas in 23g surgery reflects the clinical need for internal tamponade. These findings further illustrate the point that as the wound size increases, the angle of blade entry becomes more critical. Conjunctival stabilization and trocar design also contribute to wound architecture.
Keywords: wound healing • vitreoretinal surgery • pathology: experimental