Twenty-three gauge cannula system with microvitreoretinal blade trocar.

Abstract

To report on a 23-gauge cannula with a microvitreoretinal (MVR) blade trocar which improved wound closure after vitrectomy and reduced the incidence of postoperative hypotony. The resistance of inserting a 23-gauge MVR trocar-cannula through the porcine sclera was compared with that with the conventional 23-gauge trocar-cannula. The incidence of postoperative hypotony (intraocular pressure <6 mm Hg) was determined for 48 eyes that underwent vitrectomy with the 23-gauge MVR trocar-cannula and 30 eyes with the conventional 23-gauge trocar-cannula. The eyes were examined on postoperative days 1, 2 and 7. The closure of the sclerotomies was examined by optical coherence tomography in nine eyes in each group on postoperative days 1, 3 and 7, and 1 month. The resistance of inserting the MVR trocar-cannula was lower than that with the conventional trocar-cannula. In patients, a transient hypotony was found at postoperative day 1 after the vitrectomy in two eyes (4%) with the MVR trocar-cannula, and in seven eyes (23%) with the conventional trocar-cannula (p=0.023). An unclosed incision was detected in nine sclerotomies (50%) with the MVR trocar-cannula and 16 sclerotomies (89%) with the conventional trocar-cannula (p=0.028) on postoperative day 1, and the incidence of an opened incision was also significantly higher with the conventional trocar-cannula on days 3 and 7 but not after 1 month (p=0.003, p=0.008, p=0.486, respectively). The MVR trocar-cannula leads to better postoperative wound closure and reduces the incidence of postoperative hypotony.