Perioperative Management of Patients With Hereditary Angioedema With Special Considerations for Cardiopulmonary Bypass

Hereditary angioedema (HAE) is a rare autosomal dominant disorder mostly due to the deficiency of C1-esterase inhibitor (C1-INH). Reduced C1-INH activity below ~38% disrupts homeostasis of bradykinin (BK) formation by increasing kallikrein activation and causes recurrent angioedema attacks affecting the face, extremities, genitals, bowels, oropharynx, and larynx. HAE symptoms can be debilitating and potentially life-threatening. The recent clinical developments of biological and pharmacological agents have immensely improved acute and long-term care of patients with moderate-to-severe HAE. The therapies are given as on-demand and/or prophylaxis, and self-administration is highly recommended and performed with some agents via intravenous or subcutaneous route. Perioperative clinicians need to be familiar with the symptoms and diagnosis of HAE as well as available therapies because of the potential need for airway management, sedation, or anesthesia for various medical and surgical procedures and postoperative care. Cardiovascular surgery using cardiopulmonary bypass is a unique condition in which heparinized blood comes into direct contact with an artificial surface while pulmonary circulation, a major reserve of angiotensin-converting enzyme (ACE), becomes excluded. These changes result in systemic kallikrein activation and BK formation even in non-HAE patients. The objectives of this review are (1) to review pathophysiology of HAE and laboratory testing, (2) to summarize pertinent pharmacological data on the prophylactic and on-demand treatment strategies, and (3) to discuss available clinical data for perioperative management in cardiovascular surgery.