This study investigated the risk of secondary bleeding after proctological surgery in patients who received antithrombotic therapy. The results showed that patients with antithrombotic therapy exhibited higher risk of secondary bleeding than control group. According to previous studies, the frequency of secondary bleeding after hemorrhoid surgery is 0.6–2.4% [12, 13, 15] and it is likely to occur on 6-9th postoperative day [14, 15]. In our report, the incidence of secondary bleeding was slightly higher, because our hospital is one of the tertiary referral centers that treat high risk patients. As a result, 25% of the patients enrolled in this study were ASA-PS3 and about 35% of patients had cardiovascular disease.
A previous study showed that perioperative antiplatelet therapy for noncardiac surgery confers minimal bleeding risk with no thrombotic complications, which indicated that antiplatelet therapy was safe perioperatively . This was in agreement with the results of the current study. Previously, there has been a study on the risk of secondary bleeding in patients receiving perioperative antithrombotic therapy during proctological surgery . Multivariate analysis in that study revealed that administration of clopidogrel, discontinuing anticoagulant drugs, and bridging to LMWH were significantly high risk factors of secondary bleeding. Our study also showed that anticoagulant therapy, including warfarin, and DOAC, was associated with increased severity of secondary bleeding.
In this study, we showed that antithrombotic therapy during proctological surgery could lead to high risk of secondary bleeding. Hence, additional postoperative care is required for such cases. Since there was no cardiovascular, pulmonary, or cerebrovascular event and mortality during perioperative period, it was hypothesized that temporary modification or discontinuation of their medication could be done during proctological surgery for patients receiving antithrombotic therapy.
This study revealed that patients receiving perioperative antithrombotic therapy had high risk for secondary bleeding after proctological surgery and the severity of secondary bleeding was the highest in patients receiving DOAC and the lowest in those receiving aspirin. Since secondary bleeding caused by aspirin tend to be mild, aspirin could be administered during proctological surgery, while considering the risk of cardiovascular event caused by withdrawal. The medications of the patients receiving anticoagulant therapy should be tailored, while considering the risk of cardiovascular events, to minimize the severity of secondary bleeding. Based on the risk of cardiovascular events associated with mechanical heart valve, atrial fibrillation, and deep vein thrombosis, it is necessary to determine whether anticoagulant therapy can be discontinued temporarily or bridged to heparin before surgery. It has previously been recommended that anticoagulant therapy should be resumed after 12–24 hours postoperatively (evening of the day of surgery or the next morning after surgery) , however, in this study, the patients received warfarin. Generally, with warfarin therapy, the mean time attaining an INR ≧ 2.0 is about 5 days, but same effect is achieved in a shorter time with DOAC. Our results that the median onset of secondary bleeding was 5 days after surgery indicated that resumption of DOAC could be delayed until the 5th postoperative day, which was more delayed than our current practice (after 12–24 hours after surgery). Although surgeons must have already acknowledged to pay attention to the patients with antithrombotic therapy when they undergo proctological surgery, the actual data on postoperative outcome have been rarely available in the literature, in particular for those with DOAC. The incidence of postoperative bleeding and the timing of discontinuation and resumption of antithrombotic drugs remains to be investigated, in particular for patients with DOAC. Previous review articles recommended the discontinuation of antiplatelet or anticoagulant therapy about 5 to 7 days before and after any forms of surgery for hemorrhoids [16, 17]. Yano et al.  reported that 23 out of 1294 patients (1.7%) underwent second operation for postoperative bleeding after hemorrhoidectomy. In their study, 3.6% of the patients had previous use of anticoagulants and that did not correlate with the increased incidence of postoperative bleeding. They also described that anticoagulant therapy was routinely discontinued about 3 to 10 days before surgery and resumed 7 days after surgery .
There were several limitations of this study. First, this study was performed retrospectively at a single institute and the number of cases were small. Second, our study employed both antiplatelet and anticoagulant therapies, which could lead to varied results in the target population due to the different purposes of each type of antithrombotic therapy.