Postoperative wound dehiscence

Abstract

The article by Abou-Jaoude et al1Abou-Jaoude E.S. Brooks M. Katz D.G. Van Meter W.S. Spontaneous wound dehiscence after removal of single continuous penetrating keratoplasty suture.Ophthalmology. 2002; 109: 1291-1296Abstract Full Text Full Text PDF PubMed Scopus (56) Google Scholar brings to mind a postoperative complication after penetrating keratoplasty (PKP) that is rarely investigated. In this retrospective, noncomparative study of 69 eyes that underwent removal of a single running suture after PKP, the authors identified 5 that developed spontaneous wound dehiscence within the first 2 weeks after suture removal, a 7.2 % complication rate. They further concluded that patients undergoing PKP for corneal edema and patients receiving prolonged corticosteroid treatment are at risk of developing this complication. We agree that such a high complication rate is not acceptable. Closer attention for prevention is therefore necessary, given the fact that not only significant astigmatism but also a number of more severe complications may occur, particularly in patients with traumatic alteration after PKP.2Rohrbach J.M. Weidle E.G. Steuhl K.P. et al.Traumatic wound dehiscence after penetrating keratoplasty.Acta Ophthalmol Scand. 1996; 74: 501-505Crossref PubMed Scopus (39) Google Scholar Although it is difficult to obtain accurate data on incidence and the risk factors for this complication, a careful examination of related causes may be helpful. Our experience indicates that the population of keratoconus patients is also a risk group. Keratoconus is the leading indication for PKP in many clinical centers and is often characterized by an altered wound-healing response.4Kenney M.C. Nesburn A.B. Burgeson R.E. et al.Abnormalities of the extracellular matrix in keratoconus corneas.Cornea. 1997; 16: 345-351Crossref PubMed Scopus (154) Google Scholar, 5Schönherr U. Martus P. Händel A. Naumann G.O. Transplant reaction after keratoplasty for keratoconus; frequency and risk factors.Ophthalmologe. 1996; 93 ([in German]): 227-231PubMed Google Scholar, 6Sharif K.W. Casey T.A. Penetrating keratoplasty for keratoconus complications and long-term success.Br J Ophthalmol. 1991; 75: 142-146Crossref PubMed Scopus (134) Google Scholar Commonly, these are younger patients who undergo corneal grafting (mean age at our institution = 43 years) and are particularly severely affected because they are often still working. In these patients, the suture technique is of particular importance, especially regarding suture loosening and related complications. This brings us to our second issue. As correctly cited in the Discussion, a previous study did not find a relationship between wound dehiscence and the suture technique.7Binder P.S. Abel R. Polack F.M. Kaufman H.E. Keratoplasty wound separations.Am J Ophthalmol. 1975; 80: 109-115Abstract Full Text PDF PubMed Scopus (66) Google Scholar However, it is our experience, shared by other authors,8Jonas J.B. Budde W.M. Loosening of single versus double running sutures in penetrating keratoplasty for keratoconus.Graefes Arch Clin Exp Ophthalmol. 1999; 237: 522-523Crossref PubMed Scopus (6) Google Scholar, 9Davison J.A. Bourne W.M. Results of penetrating keratoplasty using a double running suture technique.Arch Ophthalmol. 1981; 99: 1591-1595Crossref PubMed Scopus (53) Google Scholar that the suture technique is an important factor and key to lowering the incidence of postoperative wound dehiscence. In these patients we proceed with a step-by-step approach that includes careful preoperative evaluation of the corneal topography, routine use of double running sutures (10-0, plus 11-0 nylon), and close follow-up, including corneal topography, as well as the limited use of topical corticosteroids. Removal of sutures is delayed 1 year postoperatively and only performed in patients with >4.5 diopters or noncorrectable irregular astigmatism. If suture removal seems to be indicated, a two-step approach is used: initial removal of the 11-0 suture after topographic study, followed by serial mapping to detect changes in corneal curvature. In the case of significant changes, particularly in the steeper axis, we wait even longer before removal of the remaining suture. By practicing this procedure, we have less than a 2% dehiscence rate.3Zhou L. Yue B.Y. Twining S.S. et al.Expression of wound healing and stress-related proteins in keratoconus corneas.Curr Eye Res. 1996; 15: 1124-1131Crossref PubMed Scopus (67) Google Scholar