Summary
An international registry was established by the Subcommittee on von Willebrand Factor
of the SSC/ISTH on the treatment of patients with types of von Willebrand disease
(vWd) unresponsive to DDAVP infusion. Data was collected on 76 surgical events in
64 patients from 19 treatment centers. Thirty-three non-mucosal, 12 mucosal, 10 orthopedic
and 21 dental procedures were reported. In the 76 surgical events, 14 cases prophylactically
received cryoprecipitate while 62 received factor VIII (FVIII) concentrate. Surgical
hemostasis was reported as satisfactory, good, or excellent in 75 of the 76 cases.
Post-infusion bleeding times were measured in only three of 14 surgical events treated
with cryoprecipitate. All three cases had a reduction but not correction of the bleeding
time. The post-infusion bleeding time was measured in 27 of 62 cases in which FVIII
concentrates were used. The bleeding time was normalized in 15, reduced but not normalized
in eight, and not changed from baseline in four. Data was also collected from 16 treatment
centers on 50 serious bleeding events in 35 patients. These included 19 gastrointestinal,
15 other mucosal, four central nervous system, seven orthopedic, and five other bleeds.
Eleven cases received cryoprecipitate and 39 received FVIII concentrate as primary
therapy. The efficacy of treatment was considered good or excellent in 49 of 50 cases.
Post-infusion bleeding times were measured in only 15 of the 50 reported bleeding
events. The post-infusion bleeding time was normalized in six, decreased but not normalized
in eight, and not changed from baseline in one. In this retrospective survey, FVIII
concentrates were subjectively as efficacious as cryoprecipitate in both the surgical
setting and for the treatment of severe bleeds in patients with types of vWd unresponsive
to DDAVP. Since the bleeding time was monitored during therapy in only a minority
of these cases, a definitive relationship between the efficacy of therapy and normalization
or reduction of the bleeding time in these two clinical settings cannot be established
from this study. A prospective study on the use of FVIII and/or vWf concentrates in
these clinical settings is necessary to address this issue.
