Should we stop anti-thrombotic agents prior to vitrectomy?

Abstract

All retinal surgeons are occasionally faced with the dilemma of operating on a patient who is taking anti-thrombotic medication. Although there is clear guidance that anti-thrombotics pose little risk in cataract surgery, the situation is more confused when it comes to vitreoretinal surgery [1], and there are wide variations in practice. Vitrectomies are more likely to be affected by haemorrhagic complications than clear cornea phacoemulsification, and the consequences of bleeding into the eye during a vitrectomy can be very serious. The paper by Meillon & colleagues goes some way towards reducing our confusion.Retinal surgeons want to know, BIs the risk of haemorrhagic complications greater in patients on anti-thrombotics than in patients who are not taking these drugs?^, and, secondly, BIf the anti-thrombotic treatment is stopped, does this reduce the risk of haemorrhagic complications?M eillon's study looked at 804 consecutive vitreoretinal surgeries, the majority of which were vitrectomies. Two hundred and eighteen of these patients were on anti-thrombotic treatment. Treatment was stopped in only 23 patients (10.6% of the total taking anti-thrombotic drugs), so the study does not have sufficient power to answer the second of the two questions authoritatively. However, if the risk of haemorrhagic complications is negligible, stopping anti-thrombotic treatment is unnecessary, and the question becomes irrelevant.Fifty-three developed a haemorrhagic complication intraoperatively or within 4 weeks of surgery. Nearly 60% of these were intravitreal haemorrhages. They found no increased risk of bleeding from oral anti-coagulants, but, in univariate analysis, anti-platelet agents were associated with a greater risk of haemorrhagic complications. Anecdotally, we are aware of reports of severe intra-operative haemorrhage associated with anti-platelet agents-particularly clopidogrel [1].The risk of haemorrhage is likely to be affected by the indication for vitrectomy. We would expect a lower risk in surgery for macular hole or epiretinal membrane, compared to delamination for proliferative diabetic retinopathy [2]. Bleeding complications occurred in 17.6% of eyes undergoing surgery for complications of proliferative diabetic retinopathy, compared to 5.8% of eyes undergoing other operations (Fisher's exact test, p = 0.004). Vitreous cavity haemorrhage is a common complication of diabetic vitrectomy, occurring in over 20% of cases in one series [3].This study does not report the outcomes of the eyes that had a haemorrhagic complication. Apart from the vitreous cavity haemorrhages, there were ten sub-retinal bleeds, five choroidal haemorrhages, and one suprachoroidal haemorrhage, and it is these last 16 events that are most likely to be sight-threatening. The incidence of these complications in patients who were not taking anti-platelet agents was 1.1%, but in those who were taking these drugs, the incidence was 6.1% (Fisher's exact test, p = 0.001).Although these complications were potentially sight-threatening, it is lik...

Visual outcomes and prognostic factors following 23G vitrectomy for vitreous hemorrhage in eyes with proliferative diabetic retinopathy

“…Other potential complications apart from vitreous cavity hemorrhage are subretinal bleeding and choroidal or suprachoroidal hemorrhage. The authors of the same study recommended reducing the risk of intraocular bleeding by pretreating with IVB rather than stopping antiplatelet drugs (11) , which was also in agreement with our attitude.…”

“…a risk factor for bleeding following PPV, the severity of thromboembolic events precipitated by the cessation of antiplatelet drugs exceeds the negative visual impact of the VH (11) . Other potential complications apart from vitreous cavity hemorrhage are subretinal bleeding and choroidal or suprachoroidal hemorrhage.…”