Risk of angioedema following invasive or surgical procedures in HAE type I and II--the natural history

Background

Hereditary angioedema (HAE), caused by deficiency in C1-inhibitor (C1-INH), leads to unpredictable edema of subcutaneous tissues with potentially fatal complications. As surgery can be a trigger for edema episodes, current guidelines recommend preoperative prophylaxis with C1-INH or attenuated androgens in patients with HAE undergoing surgery. However, the risk of an HAE attack in patients without prophylaxis has not been quantified.

Objectives

This analysis examined rates of perioperative edema in patients with HAE not receiving prophylaxis.

Methods

This was a retrospective analysis of records of randomly selected patients with HAE type I or II treated at the Frankfurt Comprehensive Care Centre. These were examined for information about surgical procedures and the presence of perioperative angioedema.

Results

A total of 331 patients were included; 247 underwent 700 invasive procedures. Of these procedures, 335 were conducted in 144 patients who had not received prophylaxis at the time of surgery. Categories representing significant numbers of procedures were abdominal (n = 113), ENT (n = 71), and gynecological (n = 58) procedures. The rate of documented angioedema without prophylaxis across all procedures was 5.7%; in 24.8% of procedures, the presence of perioperative angioedema could not be excluded, leading to a maximum potential risk of 30.5%. Predictors of perioperative angioedema could not be identified.

Conclusion

The risk of perioperative angioedema in patients with HAE type I or II without prophylaxis undergoing surgical procedures ranged from 5.7% to 30.5% (CI 3.5–35.7%). The unpredictability of HAE episodes supports current international treatment recommendations to consider short-term prophylaxis for all HAE patients undergoing surgery.

Retrochorionic hematoma in congenital afibrinogenemia: resolution with fibrinogen concentrate infusions

Without treatment, pregnancies in patients with congenital afibrinogenemia terminate in miscarriage at 5-6 weeks of gestation. Animal model studies have suggested that implantation site bleeding contributes to miscarriage in afibrinogenemia; however, retrochorionic hematoma in human congenital afibrinogenemia has not been previously observed. A patient with congenital afibrinogenemia receiving fibrinogen prophylaxis developed a retrochorionic hematoma in the first trimester. With continuous intensified fibrinogen concentrate replacement the hematoma resolved over 6 weeks, and the patient delivered a healthy infant. Median fibrinogen levels in the first trimester were 48 mg/dL and in second and third trimester 44 mg/dL. Median fibrinogen levels under 60 mg/dL may be adequate to maintain pregnancy in patients with congenital afibrinogenemia, although it is possible that higher levels might reduce the risk of hemorrhagic events.

Portal vein thrombosis in a patient with severe haemophilia A and F V G1691A mutation during continuous infusion of F VIII after intramural jejunal bleeding--successful thrombolysis under heparin therapy

We report on a 14-year-old boy with severe haemophilia A who developed a portal vein thrombosis during continuous infusion of F VIII. For treatment of a posttraumatic intramural jejunal haematoma with extension into the mesenterium the patient received continuous infusion (CI) of a high purity F VIII concentrate, starting with an initial bolus injection of 100 IU F VIII/kg bw and followed by 4-5 IU F VIII/kg bw/h i.v. F VIII plasma activity ranged between 47 and 88%. Resorption of the haematoma was proven by abdominal ultrasonic follow-ups. After 3 weeks of CI a thrombus formation in the portal vein was detected by ultrasound and confirmed by duplex ultrasound. Subsequent to diagnosis the patient was heparinised with unfractionated heparin (UFH 300-450 IU/kg/d i.v.). In order to induce further resorption of the haematoma. F VIII concentrate was given concomitantly (50 IU/kg bw twice daily) during the initial phase of treatment. After 14 days of anticoagulant therapy with UFH, the regimen was changed to low molecular weight heparin (LMWH; Fraxiparin 0.3; 2850 IU anti-X activity/d s.c.; bw 60 kg). F VIII dosage was gradually reduced with advanced resorption of the haematoma and thereafter switched to prophylaxis (40 IU/kg bw 3 times weekly). Complete lysis of the thrombus was observed after 6 months of treatment with UFH and LMWH respectively without any further complications. Thereafter LMWH was discontinued. Thrombophilic screening revealed no abnormalities except heterozygous F V G1691A.

CONCLUSION

The coexistence of a common prothrombotic risk factor and haemophilia may cause severe complications, in particular if the bleeding disorder has to be corrected temporarily by administration of the concerning deficient agent.