The outcomes of TAE with NBCA for acute arterial bleeding (only one RH patient was included) and postpartum hemorrhage under coagulopathic conditions have been described previously.6, 12 The efficacy of TAE with the NBCA Glubran 2 has been evaluated mainly in acute RH caused by trauma and arteriovenous malformation6,9,15−17; however, patients with RH under coagulopathic conditions have rarely been reported in the literature. This might partly be due to the ambiguity of defining “coagulopathic condition” in this setting. Yemenites T et al. 6 defined abnormal values of platelet count (< 5 × 104/µL and/or INR < 1.5) as a condition of coagulopathy because these values require correction by the infusion of platelets or fresh frozen plasma. Moreover, Kane-matsu M et al.18 determined the condition of coagulopathy in patients with postpartum hemorrhage with a disseminated intravascular coagulation scoring system. PT and APTT are considered predictive factors in initial coagulopathy profile-related mortality.7,19 In the present study, the selection criteria for coagulopathic conditions mainly depended on the indicators of PT, INR, APTT and platelet count, and eight patients with coagulopathy and acute RH who suffered from anticoagulant drugs or liver cirrhosis were included.
Under coagulopathic conditions, it has been reported that the achievement of he-mostasis with absorbable gelatin sponge particles is not satisfactory, and this condition is frequently associated with the mechanism of poorly enhanced hemostatic capacity and prohibited thrombus formation.6,8,13,20 TAE with microcoils is more feasible and effective than with gelatin sponge particles, especially in terms of hemostasis and the prevention of recurrent hemorrhage in patients under coagulopathic conditions.6 However, in two of the eight patients in the present study, adequate hemostasis was not achieved after TAE with gelatin sponge particles, polyvinyl alcohols or microcoils; then, the patients were successfully treated with repeat complement Glubran 2 embolization, which was similar to the treatment for arterial bleeding reported by Yemenites T et al.6,21 This rescue success was mainly attributed to the physicochemical property of Glubran 2, which works independently of its hemostatic capacity. Polymerization can occur immediately upon contact with blood, leading to instant and complete vessel occlusion. This material appears to be an appropriate and promising alternative for coagulopathy when complete hemostasis is difficult to achieve with gelatin sponge particles, polyvinyl alcohols and/or microcoils.
The NBCA Glubran 2 is commonly mixed with lipiodol at concentration ratios from 1:1 to 1:106, 11, depending on the distance from the microcatheter tip to the bleeding site as well as the arterial flow speed. Dilution of Glubran 2 prolongs the polymerization time and thereby enables the mixture to travel a greater distance. It has been noted that NBCA provides quick, stable thrombus and that the treatment time for TAE with NBCA is significantly shorter than that for TAE with gelatin sponge particles and/or microcoils, even in severe coagulopathy.13,18 Interestingly, one patient in our study with severe coagulopathy was successfully treated; the concentration ratio was 1:2, and the treat-ment time was 14 min; the concentration ratio used was higher and the treatment time was similar to those used for mild coagulopathy. Therefore, employing Glubran 2 may have great potential as a primary alternative tool in the presence of RH with severe coagulopathy; in particular, conventional materials inevitably require prolonged time periods and patients with ongoing extravasation. Further studies are needed to confirm this conclusion, and considerable experience is required to achieve optimal results with Glubran 2, particularly in coagulopathy.
The results of this study further enhance the suggestions demonstrating that NBCA is a potent embolic material under various conditions. In the present study of patients with acute RH in the setting of coagulopathic conditions, both technical and clinical success were achieved in all patients; it seemed that Glubran 2 was effective in terms of ceasing acute RH, even under the condition of coagulopathy. Alina et al. 22 commented that patients under coagulopathic conditions after TAE were more likely to experience recurrent hemorrhage than patients without these conditions in gastro-intestinal hemorrhage. Regarding the hemostasis of RH, no recurrence was observed in patients after TAE with Glubran 2, and the use of NBCA in the setting of coagulopathy seemed to contribute to a reduction in the rescue of recurrent hemorrhage. In terms of the safety of TAE with Glubran 2 for RH, no complications occurred mid-TAE procedure related to embolization. Two patients experienced aggravation of their back muscle aches after TAE, but they spontaneously resolved within one month without any specific treatment. One patient with severe coagulopathy developed subarachnoid hem-orrhage, which was caused by severe coagulation disorder, was treated conservatively and recovered without permanent sequelae. Preserving renal function is a crucial factor in renal embolization. In the current study, renal function was not affected, achieving the aim of preserving as much renal function as possible. Therefore, we consider that TAE with Glubran 2 does not add to the risk of complications for patients with RH under coagulopathic conditions.
The present study has a number of limitations. First, TAE with Glubran 2 for acute RH under coagulopathic conditions has the common limitations of NBCA8,15−18, in-cluding microcatheter lumen instant occlusion, difficulty controlling precisely occluded sites, and NBCA/lipiodol mixture composition, which seems to require a long learning curve and is restricted to the knowledge and experience of clinicians with NB CA. Second, our cohort was relatively small and retrospective, and with all its inherent limitations, a multi-institutional prospective study may be required to determine the indications for coagulopathic conditions and the medical costs of TAE with Glubran 2. Third, the aim of the present study mainly focused on evaluating the preliminary out-comes of TAE with Glubran 2 for RH under coagulopathic conditions. No comparison was conducted between Glubran 2 and conventional embolic materials or between coagulopathic and non-coagulopathic conditions, which may need to be shown subse-quently. Nevertheless, to the best of our knowledge, the present study may be by far the sole study and the largest case series regarding TAE with the use of Glubran 2 as the embolic material for RH under coagulopathic conditions.