Patients and methods
All patients with haemophilia A or B who underwent major surgery, either as elective or as emergency, with rFVIIIFc or rFIXFc as the clotting factor concentrate (CFC) for hemostasis were included in this study. None of them were positive for inhibitors before. The factor was administered once daily or once every 36-48 hours depending on the product. The factor assays were done with a one stage APTT method. The CFC support was continued till suture removal, usually 10 days. Other supportive measures included tranexamic acid,at physician discretion.
Results
A total of 57 patients underwent surgery. There were 45 patients with haemophilia A and 12 with haemophilia B. Of those with haemophilia A, - 37 (82.2%) had severe, 3 (11.1%) moderate and 5 (6.7%) mild disease. Of those with haemophilia B, 7 (58.3%) had severe,3 (25 %) moderate and 2 (16.7%) mild disease.
The median age was 30 years (range: 1-70). Among those with haemophilia A, there were 4 with inhibitor titre <5 BU, 3 more developed inhibitor 3-7 days following surgery, 1 of >5 BU, requiring bypassing agents. None with haemophilia B had inhibitor.
The surgical procedures included 40 (70.1%) orthopaedic, 6 (10.5%) abdomino-perineal, 4(7%) urological and 3(5.2%) neurosurgical and 1(1.7%) each - venricular septal defect repair, skin graft, tympanoplasty and coronary angioplasty. The orthopaedic surgeries included pseudotumour excision (n=9), bilateral total knee replacement (bilateral n=4, unilateral n=1), total hip replacement (n=3), open reduction and internal fixation of fracture (n=11), corrective osteotomies/soft tissue release (n=6), amputation (n=1), arthrodesis (n=1), laminectomy (n=1), implant removal (n=1),intra articular repair(n=1)and curettage (n=1).
For those with haemophilia A, the median recovery assay pre-op was 108% (range: 50-200).The median trough levels for post- operative days +1,+3,+5 ,+7 were 40% (11-138), 36.5% (13-94), 36.4% (1.4-118), and 27%(1.6-77) respectively. Among 35 patients with severe haemophilia undergoing major surgery, the median total factor used was 305 (125-563)IU/kg.
The median recovery assay for those with haemophilia B prior to surgery was 70.1%(50-165).The median trough levels for post operative days+1,+3,+5 ,+7 were 49.8% (28-70.7), 40.7%(31.6-56.2), 42.3%(11.6-58.2), and 40.5%(24.5-59.4) respectively. The median total factor used was 400 (134-1000)IU/kg.
Seventeen of those with haemophilia A (37.8%) required transfusion of at least 1 packed red cell each as per expected blood loss in those surgeries. Two patients required FFP and 1 patient required platelet transfusion as well for DIC. One patient had sustained injury to axillary artery during surgery and the other one had undergone resection of extensive pseudotumour. There was no unexpected post-operative bleeding.
In those with haemophilia B, 2(16.7%) patients required transfusion of packed red cell as per expected blood loss in those surgeries. No other blood product was required. There was no excessive bleed during the perioperative period.
Conclusions
Modest doses of rFVIIIFc and rFIXFc can be used safely for major surgery in haemophilia with effective haemostasis and monitored with one stage APTT based assays. The less frequent administration makes these agents a more convenient option.
Disclosures
No relevant conflicts of interest to declare.
Major surgery management in patients with haemophilia A and inhibitors on emicizumab prophylaxis without global coagulation monitoring