Acquired von willebrand syndrome secondary to monoclonal gammopathy of undetermined significance: long-term remission after treatment with bortezomib.

Monoclonal gammopathy of undetermined significance (MGUS) is a plasma cell disorder that can precede the diagnosis of multiple myeloma. MGUS is characterized by the presence of a monoclonal paraprotein without evidence of multiple myeloma or other lymphoplasmacytic malignancies. Even though MGUS is an asymptomatic condition that does not require management strategies other than periodic follow-up to prevent complications, secondary nonmalignant diseases may arise, requiring control of the plasma cell clone. Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder that occurs in patients with no prior personal or family history of bleeding. It is associated with several other disorders, such as neoplasia, mainly hematological (including MGUS and other lymphoproliferative disorders), autoimmune, infectious and cardiac diseases. At diagnosis, patients usually present with cutaneous and mucosal bleeding, including gastrointestinal bleeding. Here, we report a case of a patient with MGUS who developed AVWS after one year of follow-up. The patient was refractory to glucocorticoids and cyclophosphamide and achieved remission only after monoclonal paraprotein was eradicated following treatment with bortezomib and dexamethasone. Our report sdemonstrates that, for refractory cases, eradication of the monoclonal paraprotein may be necessary to treat bleeding complications due to MGUS-associated AVWS.

Recombinant vs plasma-derived von Willebrand factor to prevent postpartum hemorrhage in von Willebrand disease.

von Willebrand disease (VWD) is a congenital bleeding disorder characterized by deficient or defective von Willebrand factor (VWF). Among women with VWD, postpartum hemorrhage (PPH) is common. Treatment options at delivery include plasma-derived VWF (pdVWF) and recombinant VWF (rVWF). However, limited data are available regarding their efficacy. We conducted a retrospective observational study comparing PPH in women with VWD treated at the Hemophilia Center of Western Pennsylvania between 1 February 2017 and 31 January 2018 with either rVWF or pdVWF. We compared postpartum outcomes, including PPH frequency and estimated blood loss (EBL) at delivery. There were a total of 12 deliveries, 7 vaginal and 5 cesarean. At delivery and for 3 days postpartum, 6 women received 80 IU/kg of rVWF and 6 received 80 IU/kg of pdVWF, based on prepregnancy weight, insurance, and/or patient choice. Treatment groups had similar demographics, including median age (32.0 vs 27.0 years; P = .075), bleeding scores (3.0 vs 3.5; P = .734), and prepregnancy body mass index (29.0 vs 29.2 kg/m2; P = .691). PPH occurred in 3 (25.0%) of 12 deliveries, with no difference by treatment group (2 of 6 rVWF vs 1 of 6 pdVWF; P = 1.000) and no difference in EBL by treatment group (685 vs 462 mL; P = .384) or delivery type (vaginal, P = .722 vs cesarean, P = .531). In summary, PPH occurred in one-fourth of the deliveries in women with VWD, despite a higher dose (80 IU/kg) of rVWF or pdVWF. Future trials are needed to develop and assess novel strategies to prevent PPH in VWD.

Respuesta a la prueba de desmopresina: estudio de cohorte en un hospital de Bogotá / Response to the desmopressin test: cohort study in a Bogota hospital

Introducción: La desmopresina es un análogo sintético de la vasopresina que aumenta los niveles plasmáticos del factor VIII y del factor de von Willebrand. Algunos autores señalan el tiempo de mantenimiento del efecto hemostático entre 6 y 8 h, por lo que es necesario estudiar su efecto en el tiempo. Objetivo: Determinar la variación de las variables de laboratorio de pacientes con enfermedad de von Willebrand y hemofilia tipo A posterior a la administración de desmopresina. Métodos: Estudio de cohorte retrospectivo en un hospital universitario en Bogotá. Se realizó un muestreo no aleatorio, se incluyeron 24 pacientes mayores de 18 años con diagnóstico de enfermedad de von Willebrand (67 por ciento) y hemofilia tipo A no grave (33 por ciento), a quienes se les realizó la prueba de desmopresina. Se conformaron dos grupos de pacientes, independientemente del diagnóstico: 15 pacientes con valores basales de factor VIII ; 50 UI y 13 pacientes con valores basales de antígeno von Willebrand lt; 50 UI. Se efectúo análisis estadístico descriptivo y correlacional en Stata 13. Resultados: El 87 por ciento de los pacientes del grupo I alcanzó el valor terapéutico a las 2 h de administrada la desmopresina (p= 0,000), el cual se mantuvo hasta 6 h en el 77 por ciento (p= 0,000). En el grupo II el 92 por ciento logró el valor terapéutico en 2 h (p= 0,003), que continuó hasta las 6 h en el 83 por ciento (p= 0,000). Conclusiones: La respuesta a la administración de desmopresina fue máxima a las 2 h posteriores, cuando comenzó a disminuir progresivamente, pero mantuvo el efecto terapéutico. Aunque no se encontraron efectos adversos, existe variabilidad de respuesta entre pacientes(AU)

Introduction: Desmopressin is a synthetic analog for vasopressin that increases the plasma levels of factor VIII and of von Willebrand factor. Some authors indicate maintenance time of hemostatic effect between 6 and 8 hours, so it is necessary to study its effect over time. Objective: To determine the variation of laboratory variables in patients with von Willebrand disease and type A hemophilia after desmopressin administration. Methods: Retrospective cohort study carried out in a university hospital in Bogotá. Nonrandomized sampling was used, including 24 patients older than 18 years and with a diagnosis of von Willebrand disease (67 percent) and non-severe type A hemophilia (33 percent), who underwent the desmopressin test. Two groups of patients were created, regardless of diagnosis: 15 patients with baseline values of factor-VIII 8203; #8203;lower than 50 IU and 13 patients with baseline values of von Willebrand antigen8203;8203;lower than 50 IU. Descriptive and correlational statistical analysis was performed in Stata 13. Results: 87 percent of patients in group I reached the therapeutic value two hours after desmopressin administration (p=0.000), which was maintained for up to six hours in 77 percent (p=0.000). In group II, 92 percent achieved the therapeutic value in two hours (p=0.003), which continued until six hours in 83 percent (p=0.000). Conclusions: Response to desmopressin administration was maximum at two hours, when it began to decrease progressively, but maintained the therapeutic effect. Although no adverse effects were found, there is variability of response among patients(AU)

VonvendiMC (vonicog alfa) facteur de von Willebrand recombinant: maladie de von Willebrand / Vonvendi™ (vonicog alfa) Recombinant von Willebrand factor: von Willebrand disease

MANDAT: L'Institut national d'excellence en santé et en services sociaux (INESSS) a procédé à l'évaluation du produit du système du sang VonvendiMC (vonicog alfa, BAX 111), un facteur de von Willebrand recombinant (FvWr) administré par injection intraveineuse pour le traitement et la maîtrise des épisodes hémorragiques ainsi que la prise en charge du saignement périopératoire chez les adultes (âge ≥ 18 ans) ayant reçu un diagnostic de la maladie de von Willebrand. Les produits Humate-PMC et WilateMC, présentement indiqués pour la thérapie de remplacement de FvW/Facteur VIII et inscrits à la Liste des produits du système du sang du Québec, ont été utilisés comme comparateurs. DÉMARCHE D'ÉVALUATION: Une revue des données issues de la littérature et de celles fournies par le fabricant a été réalisée afin de documenter l'efficacité, l'innocuité et l'efficience du vonicog alfa. Des données expérientielles et contextuelles issues de la consultation d'experts sont également présentées. BESOINS DE SANTÉ: La MvW est causée par un défaut quantitatif ou qualitatif du FvW associé ou non à un déficit secondaire en FVIII. Ces déficits se traduisent par des saignements prolongés, spontanés ou traumatiques, et habituellement de type muco-cutanés qui peuvent parfois mettre en danger la vie des individus atteints. Les besoins pour le traitement de la MvW au Québec sont généralement bien comblés par les stratégies thérapeutiques actuelles. La majorité des patients répondent bien à la première ligne de traitement, la DDAVPMC, mais pas tous avec la même ampleur. En cas d'une réponse inefficace ou d'une contre-indication à la DDAVPMC, les patients ont accès à un concentré de FvW/FVIII issu du plasma, Humate-PM. RÉSULTATS: Efficacité Les résultats: sont basés sur deux études de phase III (une par indication) avec peu de patients et sans aucune comparaison directe entre le vonicog alfa et ses comparateurs. Le niveau de la preuve a été jugé très faible. L'INESSS NE RECOMMANDE PAS L'AJOUT DE VONVENDIMC (VONICOG ALFA): À la Liste des produits du système du sang du Québec. Davantage de données sont requises pour soutenir une reconnaissance de la valeur thérapeutique.

MANDATE: The Institut national d'excellence en santé et en services sociaux (INESSS) evaluated the blood system product Vonvendi™ (vonicog alfa, BAX 111), an intravenously injected recombinant von Willebrand factor (rVWF) for the treatment and control of bleeding episodes and the perioperative management of bleeding in adults (age ≥ 18) diagnosed with von Willebrand disease. The products Humate-P™ and Wilate™, currently indicated as VWF/factor VIII (FVIII) replacement therapies and listed in the Liste des produits du système du sang du Québec, served as comparators. EVALUATION PROCESS: Published trials and manufacturer data were reviewed to document the efficacy, safety and efficiency of vonicog alfa. Experiential and contextual data from expert consultations are presented as well. HEALTH NEED: Von Willebrand disease is caused by a quantitative or qualitative VWF defect with or without a secondary FVIII deficiency. These deficiencies result in prolonged spontaneous or traumatic bleeding, usually mucocutaneous, which can sometimes be life-threatening. In Québec, von Willebrand disease treatment needs are, in general, adequately addressed with the current therapeutic strategies. Most patients respond well to first-line treatment, desmopressin (DDAVP™), but not all to the same extent. In cases of an ineffective response or a contraindication to DDAVP™, patients have access to a plasma-derived VWF/FVIII concentrate, Humate-P™. RESULTS: Efficacy: The results are based on two Phase III studies (one per indication) with few patients and no direct comparison between vonicog alfa and its comparators. The level of evidence was considered very low. INESSS'S RECOMMENDATION REGARDING VONICOG ALFA: In light of the available data, INESSS recommends that Vonvendi™ (vonicog alfa) not be added to the Liste des produits du système du sang du Québec. More data are needed to support the recognition of its therapeutic value.

PT-VWD posing diagnostic and therapeutic challenges - small case series.

Despite the increased worldwide awareness, over the last decade, of the platelet-type von Willebrand Disease (PT-VWD), many uncertainties remain around this rare platelet bleeding disorder. This report aims to correctly identify and study the phenotype of new patients and highlights the diagnostic and therapeutic challenges this disease remains to pose. We describe four PT-VWD cases confirmed by genetic analysis in which either the diagnosis and/or the treatment posed challenge. We provide the details of the clinical presentation, laboratory analysis, and the treatment and the responses in each case. We show that in addition to type 2B VWD, PT-VWD can be misdiagnosed as idiopathic thrombocytopenic purpura, neonatal alloimmune thrombocytopenia, and unexplained gestational thrombocytopenia. The disease can be diagnosed as early as 1 year of age and with phenotypically normal parents. Bleeding in some patients can be managed successfully using Humate P and DDAVP combined with tranexamic acid with no significant thrombocytopenia. We provide for the first time an evidence of an efficient response to rFVIIa in PT-VWD. Anaphylactic reaction to VWF preparations may be related to PT-VWD and the development of HLA antibodies is not uncommon. Progressive thrombocytopenia with normal VWF levels can be seen with PT-VWD and the platelet count was normalized at 2.5 weeks postpartum in one case. We conclude that these studies represent a record of clinical observations/interventions that help improve diagnoses/management of PT-VWD, highlight the variations in age and clinical presentations, laboratory diagnostic approaches, the importance of genetic testing for accurate diagnosis and consideration of therapeutic alternatives.

Haemostatic management of extreme challenges to haemostasis in acquired von Willebrand syndrome.

Acquired von Willebrand syndrome (AVWS) is a rare hemorrhagic condition for which very little information is available regarding the management of extreme challenges to Haemostasis. The AVWS is more common in the elderly, who are frequently exposed to invasive procedures and/or chemotherapy. Haematopoietic stem cell transplantation (HSCT) is a situation in which the haemostatic capacity is challenged by severe thrombocytopaenia, chemotherapy-associated mucosal barrier breakdown and the need for invasive procedures. In our report, we present and discuss the haemostatic management of a patient with AVWS who was refractory to Von Willebrand factor concentrate replacement during the course of an autologous HSCT to treat multiple myeloma. Patients with AVWS are frequently exposed to high-risk haemostatic challenges, and additional information about the haemostatic management of these situations is necessary.

Von Willebrand disease in children: diagnosis and management of a pediatric cohort in one single center in Argentina.

Clinical and laboratory data of children with von Willebrand disease (VWD) types have been derived from retrospective studies and small case series. This article reports on the clinical and laboratory data of a large pediatric cohort in one single Argentinian center. The biological and clinical responses to desmopressin and replacement therapies are also described. Over a 15-year period, 194 of 1150 children (16.9%) were diagnosed as having type 1 VWD (80%), type 2 VWD (19%), and type 3 VWD (1%). The distribution of the different type 2 VWD subtypes was type 2A VWD, 43%; type 2B VWD, 32%; type 2M VWD, 19%; and type 2N VWD, 6%. Eighty patients with type 1 VWD and 12 patients with type 2 VWD were prospectively evaluated to desmopressin (DDAVP) response. A complete response was observed in all children with type 1 VWD, whereas 40% of the children with severe type 1 VWD and with type 2 VWD achieved a complete response. All the children who received DDAVP as prophylaxis or treatment for bleeding had good clinical evolution. Considering the restricted availability of specialized hemostasis centers, we believe our clinical and laboratory approach appropriate for the detection of patients with different types of VWD. Further studies are necessary to determine epidemiological aspects of VWD in Argentina to estimate the necessary facilities and trained personnel for the diagnosis and management of patients with VWD.

Diagnosis and management of von Willebrand disease in a single institution of Argentina.

Von Willebrand disease (VWD) is a bleeding disorder with variable clinical expression. In this article we describe types, clinical features, genetic testing when needed, genotype/phenotype relationships, and the response to desmopressin (DDAVP) testing, according to our experience. Our findings are possible type 1, 69.6%; type 1, 13.5%; severe type 1, 0 .35%; type 3, 0.55%; type 2A, 9.5%; probable 2B, 0.6%; type 2M, 2.5%; and probable type 2N, 3.4%. The most frequent symptoms are ecchymoses-hematomas and epistaxis, and, in females >over 13 years also menorrhagia. In pregnant patients, assessment of laboratory parameters in months 7 and 8 is recommended to plan the need for prophylaxis at term. DDAVP merits to be considered as the first-choice therapy, including pregnant women and children, and no patient showed significant unwanted effects. Because this is a safe, effective, and affordable therapy, we hope to encourage clinicians, mainly pediatricians and obstetricians, to a wider use of DDAVP, especially in developing countries. We also report two patients with prophylactic treatment.

Biological and clinical response to desmopressin (DDAVP) in a retrospective cohort study of children with low von Willebrand factor levels and bleeding history.

The diagnosis and management of von Willebrand disease (VWD) in paediatrics is challenging. Our aim was to review patient's characteristics related to biological and clinical response to DDAVP in children with low von Willebrand factor (VWF) levels and bleeding history from a single institution. We included a retrospective cohort of 221 children (median age 11 years; 137 females): 27 type 1 (VWF levels within 15-30 IU dL-1) and 194 possible type 1 (VWF levels within 31-49 IU dL-1). The DDAVP infusion-test was performed in 214/221 children, 93.4% of whom showed good response. Patients with type 1 were at higher risk of DDAVP-test failure: 9/26 (34.6%) vs. 18/188 (9.6%) with possible type 1 (RR 3.44, 1.75-6.79; p= 0.002, Fisher's exact test). In 68 children, the clinical response to DDAVP was evaluated 87 times: i) to stop bleeding: menorrhagia (13), mucocutaneous (12), haemarthrosis (1); and ii) to prevent surgical bleeding: adenotonsillectomy (17), major (15) and minor surgery (10); and dental procedures (19). No major adverse events or bleeding were observed. The treatment was effective with one single dose of DDAVP in almost all patients, without antifibrinolytic or local therapy, except in a girl with severe haemorrhage during menarche who required replacement therapy. In conclusion, patients with VWD type 1 were at higher risk of no response to DDAVP infusion-test. In this series, one dose of DDAVP proved effective and safe for children with VWD. Since this is a safe, effective and affordable therapy, we consider that a wider use should be promoted, especially in developing countries.

Uso de desmopresina durante el embarazo en enfermedad de Von Willebrand / Desmopressin use during pregnancy in Von Willebrand diseases

La enfermedad de Von Willebrand es el desorden hemorragíparo más frecuente. Las mujeres constituyen una población particularmente sintomática debido al desafío hemostático de las menstruaciones y el parto. Nosotros revisamos las historias médicas de 54 mujeres con niveles disminuidos de factor von Willebrand (VWF) e historia de sangrado, quienes hubieran usado desmopresina durante el embarazo. No se observaron efectos adversos ni en las mujeres ni en los recién nacidos, incluso en los 5 expuestos a la medicación en el primer trimestre de gestación. No se observaron complicaciones locales asociadas a la colocación del catéter epidural. La DDAVP fue efectiva para prevenir el sangrado posparto. La desmopresina merece ser considerada como la primera elección de tratamiento; en aquellas pacientes con bajo niveles de VWF presentan complicaciones hemorrágicas, incluyendo mujeres embarazadas. Aunque el sangrado posparto aparece en una pequeña proporción de mujeres con VWD, no hay un modo apropiado de identificar quiénes van a sangrar. El uso de profilaxis con DDAVP debería ser tenido en cuenta como una alternativa segura y efectiva.

The von Willebrand disease (VWD) is the most frequent hemorrhagic disorder. Women with VWD are more symptomatic than men because the challenged of menses and delivery. We reviewed the records of 54 women with a low plasmatic VWF level and bleeding history, who had used desmopressin during pregnancy. No adverse effects were observed in mothers or newborns, incluiding those exposed to the drug during the first trimester. No local complication of epidural placement was observed. DDAVP was effective to prevent post-partum hemorrhage. DDAVP merits to be considered as the first choice of therapy, when patients with a previous or current low plasmatic VWF level present bleeding complications, including pregnant women. Although post-partum bleeding will appear in a small proportion of VWD women, there is no accurate way to identify who is going to bleed. The use of DDAVP should be regarded as a highly valuable option.

Patient with von Willebrand disease undergoing mitral valve repair: a strategy for the control of the coagulopathy.

We report a case of a 60 year-old woman with von Willebrand disease type I that was submitted to a mitral valve repair. The patient needed special care due coagulopathy and needed VIII factor (VIIIf) and von Willebrand factor (vWf), before, during and after surgery. There was no complication during or after surgery. Patient is asymptomatic nine months postoperatively. The correction of VIIIf and vWf allowed the realization of a safety surgery.

Paciente portadora de doença de von Willebrand submetida a cirurgia da valva mitral: uma estratégia para o controle da coagulopatia / Patient with von Willebrand disease undergoing mitral valve repair: a strategy for the control of the coagulopathy

Relatamos o caso de uma mulher de 60 anos portadora da doença de von Willebrand tipo I, submetida a cirurgia da valva mitral. A paciente necessitou de cuidados especiais em razão da coagulopatia e foi necessária a utilização de concentrado de fator VIII (VIIIf) e fator de von Willebrand (vWf) antes, durante e depois da cirurgia. Não houve complicações durante e após a cirurgia. Nove meses depois, a paciente encontra-se assintomática. A correção para valores adequados de VIIIf e vWf permitiu a realização da cirurgia com segurança.

We report a case of a 60 year-old woman with von Willebrand disease type I that was submitted to a mitral valve repair. The patient needed special care due coagulopathy and needed VIII factor (VIIIf) and von Willebrand factor (vWf), before, during and after surgery. There was no complication during or after surgery. Patient is asymptomatic nine months postoperatively. The correction of VIIIf and vWf allowed the realization of a safety surgery.

[Acquired von Willebrand disease as an unusual manifestation of primary hypothyroidism: report of two cases]. / Enfermedad de von Willebrand como manifestación clínica inhabitual del hipotiroidismo primario. Caso clínico.

Patients with hypothyroidism may have a minor increase in their bleeding tendency, causing easy bruising and menorrhagia. There is a positive correlation between factor VIII coagulant activity and thyroxin serum levels. Thus, patients with hypothyroidism have an acquired coagulation defect that is reversible with thyroxin supplementation. We report two sisters, aged 13 and 11 years, who met the criteria for von Willebrand's disease at the age of eight. Both sisters had a primary hypothyroidism due to Hashimoto's thyroiditis, diagnosed three years later. Thyroid hormone replacement normalized von Willebrand factor, factor VIII, and the bleeding diathesis disappeared. Acquired von Willebrand's disease is an unusual manifestation of hypothyroidism. However the possibility of hypothyroidism should be considered in patients presenting with von Willebrand disease.

Enfermedad de von Willebrand como manifestación clínica inhabitual del hipotiroidismo primario: Caso clínico / Acquired von Willebrand disease as an unusual manifestation of primary hypothyroidism: Report of two cases

Patients with hypothyroidism may have a minor increase in their bleeding tendency, causing easy bruising and menorrhagia. There is a positive correlation between factor VIII coagulant activity and thyroxin serum levels. Thus, patients with hypothyroidism have an acquired coagulation defect that is reversible with thyroxin supplementation. We report two sisters, aged 13 and 11 years, who met the criteria for von Willebrand's disease at the age of eight. Both sisters had a primary hypothyroidism due to Hashimoto's thyroiditis, diagnosed three years later. Thyroid hormone replacement normalized von Willebrand factor, factor VIII, and the bleeding diathesis disappeared. Acquired von Willebrand's disease is an unusual manifestation of hypothyroidism. However the possibility of hypothyroidism should be considered in patients presenting with von Willebrand disease.

Empleo del DDAVP en el manejo de la enfermedad de Von Willebrand / Treatment of Von Willebrand´s disease with DDAVP

La enfermedad de Von Willebrand (EVW) es la coagulopatía heredable más frecuente en pediatría, causada por defectos cuantitativos o cualitativos de factor Von Willebrand (FVW). El tipo 1 concentra cerca del 75 por ciento del total de pacientes con esta patología. Para este grupo desde hace 20 años se utiliza la desmopresina (DDAVP) para el tratamiento de sangramientos espontáneos y para prevención de episodios hemorrágicos secundarios a procedimientos invasivos. Los objetivos de este artículo son: una revisión actualizada del uso de este medicamento en dicha coagulopatía y la difusión de esta alternativa terapéutica que permite evitar riesgos transfusionales además de disminuir los costos. Se revisa brevemente la clasificación y fisiopatología de los distintos tipos de von Willebrand para entender la elección de el tratamiento más apropiada. Incluimos un esquema simple y seguro para ser utilizado en aquellos pacientes respondedores a desmopresina.

von Willebrand disease in the developing world.

von Willebrand disease (VWD) is considered to be the most common inherited bleeding disorder. Data on its epidemiology and impact in developing countries are limited. The biologic heterogeneity and variable presentation of VWD make diagnosis difficult. Although there is no accurate estimate of the prevalence of VWD in developing countries, available data suggest that the proportion of diagnosed cases is lower than the expected number, often accounting for only 6% to 13% of patients with hereditary bleeding disorders. Although accurate subtyping is often not possible, the number with severe disease tends to be much higher, particularly in those parts of the world where consanguinity is common. Agents used to treat patients with VWD range from plasma to purified factor concentrates. Desmopressin (DDAVP) is commonly used. Preliminary data on molecular genetics suggests that there are significant population differences. There is inadequate awareness of this condition and lack of support for these patients from the health care system in many developing countries. Concerted efforts are needed at the scientific and social levels to improve this situation.

Uso de DDAVP en pacientes portadores de enfermedad de von Willebrand sometidos a adenoamigdalectomía / Use of DDAVP in patients with von Willebrand disease undergoing adenotonsillectomy

La enfermedad de von Willebrand (EVW) es la coagulopatía más frecuente en niños. Una de las principales complicaciones de la adenoamigdalectomía es la hemorragia. Debido a su patología de base, representan un gran desafío aquellos pacientes con EVW a quienes se efectúa esta cirugía. Desde hace algunos años, se utiliza desmopresina (DDAVP) para el manejo de esta patología. Se estudiaron restrospectivamente 15 pacientes pediátricos portadores de EVW tipo I, adenoamigdalectomizados en el Hospital Clínico de la Pontificia Universidad Católica de Chile. Todos fueron hospitalizados y, previa medición del Factor VIII plasmático, se les proporcionó DDAVP. Una hora después de iniciada la infusión, se controló este factor. Si se incrementaba en 50 por ciento del valor basal, la cirugía se efectuaba sin aporte de hemoderivados; de lo contrario, se indicaba crioprecipitado. En ambos casos se utilizó ácido tranexámico como coadyuvante.La respuesta a DDAVP fue positiva en 13 pacientes (87 por ciento). En los 2 pacientes en quienes ésta no se observó se les suministró crioprecipitado. Todo el grupo estudiado evolucionó satisfactoriamente. No fue necesario utilizar crioprecipitado de apoyo o cirugías de revisión. Se concluye que DDAVP evita el uso de hemoderivados en la mayoría de los pacientes con EVW tipo I sometidos a adenoamigdalectomía, no posee efectos adversos relevantes y no aumenta los costos de la cirugía.