Abstract
Purpose: :
To compare the blade sharpness and incision architecture of various 25- and 23-ga sutureless trocar and MVR blades at oblique and straight angles of entry.
Methods: :
The 25- and 23-ga test samples included new MVR blade designs, conventional trocar blades, and round-tipped trocars (23-ga only). A Scanning Electron Microscope (SEM) imaged cutting surfaces of each blade (n=7). In another test, high magnification imaging measured the incision length and linearity of straight and obliquely angled incisions through a circular silicon coupon (n=70). Wound proof pressure testing was conducted on porcine sclerotomy sites after simulated vitrectomy (n=30).
Results: :
Incision shape and SEM analysis showed distinct differences in blade design and incision geometry: conventional beveled trocar blades generated asymmetrical chevron-shaped incisions, round-tipped trocar blades generated semi-circular incisions, new symmetrical MVR blades generated linear incisions, while a fourth MVR blade design generated a flattened M-shaped incision. The new 25-ga symmetrical MVR blade generated the smallest wound geometry with an incision length of 19.9 ± 0.9 µm (straight incision), linearity measurement of 0.2 ± 0.1 µm (straight incision), oblique incision length of 18.2 ± 1.1 µm, and oblique linearity measurement of 0.8 ± 0.2 µm (all P<0.05). In wound leakage tests, the new symmetrical MVR blades leaked the least in every test (4 tests per blade).
Conclusions: :
Compared to all tested blades, the new symmetrical MVR blades suggest better wound architecture by generating less wound leakage, shorter incision lengths, and more linear wound apposition.
Keywords: vitreoretinal surgery