The prophylactic use of C1 inhibitor in hereditary angioedema patients undergoing invasive surgical procedures: a retrospective study

BACKGROUND: Hereditary Angioedema (HAE) is a rare autosomal dominant condition characterized by episodic angioedema, which may be triggered by invasive procedures and surgery. C1 inhibitor (C1 INH) was approved in the United States and Canada in 2009 and 2010, respectively, for the treatment of acute attacks. Most recently in April 2013, it was approved in Europe for short-term prophylaxis (STP), prior to medical, dental, or surgical procedures, to prevent HAE attacks in both children and adults. Currently, C1 INH is not approved in Canada or the United States for STP of HAE attacks. Our objective was to demonstrate the effectiveness of C1 INH as a short-term prophylactic treatment for patients with Type I HAE undergoing invasive surgical procedures. METHODS: A retrospective chart review between 1997-2013 was performed at one Canadian Tertiary Care Allergy and Asthma Clinic affiliated with The Ottawa Hospital, in Ottawa, Canada. The standard dose of C1 INH for STP was 10 or 20 U/kg. RESULTS: In all 24 procedures, there were no post-procedure HAE attacks after short-term prophylactic administration of C1 INH. CONCLUSIONS: In this retrospective chart review at one tertiary care Allergy and Clinical Immunology Clinic, short-term prophylactic use of C1 INH was found to be effective at preventing post-procedure HAE attacks, in patients diagnosed with Type I HAE.