[Suture complications in penetrating keratoplasty]

Penetrating keratoplasty with mechanical trephines is currently standard treatment for corneal blindness. This operation requires graft suturing in contrast to the emerging posterior lamellar procedures. Loosening or rupturing of graft sutures can give rise to microbial infections or graft rejections. We investigate herein the incidence of suture-related graft infections, graft rejections and the percentage of resuturings in a large cohort after penetrating keratoplasty.

We reviewed the follow-up data of 2950 consecutive penetrating keratoplasties performed between 1988 and 2003. We counted suture loosening, suture rupturing as well as consecutive microbial infections or graft rejections. All grafts had been sutured with Hoffmann's double running cross stitch procedure.

The percentage of suture loosening and suture rupturing totalled 5 % after 3 years (Kaplan-Meier estimation). Fourteen percent of this group experienced suture-related graft infections. Graft rejections occurred more often as well (30 vs. 22 % in the reminder without suture loosening, p < 0.01). A total of 8 % required resuturings within the first three postoperative years. However, nearly half (4 %) were performed for early postoperative leakage from the graft-host interface. A second accumulation of resuturings occurred between the 12th and 18th month after surgery. These operations mostly became necessary after graft protrusion/dehiscence following complete suture removal. Only 0.9 % of the complete group suffered from the aforementioned sequela of suture loosening.

The overall percentage of severe sequalae from suture loosening or rupturing is as low as 0.9 %. This complication can thus be considered insignificant in comparison to, e. g., graft rejections that occur in every fifth patient. The sutures should not be removed completely before the first 18 postoperative months in conventional penetrating keratoplasty. This policy will most likely reduce the percentage of resuturings for graft protrusion or dehiscence following complete suture removal.