Postoperative epidural hematoma covering the galeal flap in pediatric moyamoya disease patients:clinical manifestation, risk factors, and management

Abstract

Purpose

Postoperative epidural hematoma (EDH), blood collection between the inserted galeal flap and the overlying skull flap (epigaleal flap hematoma), is a frustrating complication of the surgical treatment of moyamoya disease (MMD) in pediatric patients. The symptoms of postoperative EDH are often similar to those of postoperative cerebral ischemia, and may cause confusion during clinical decision-making. We designed this study to evaluate the incidence, clinical presentation, risk factors, and treatment outcomes of postoperative EDH in pediatric MMD patients.

Materials and methods

We performed a retrospective review of 148 pediatric patients with 250 craniotomies who underwent indirect bypass revascularization surgery between January 2002 and December 2006. This group consisted of 60 males and 88 females and the mean age at surgery was 7.5 (range 1-18) years.

Results

Of the 250 craniotomies, postoperative EDH was detected in 32 cases. In 12 cases of EDH, surgical treatment was necessary (4.8% of 250 craniotomies). During the same period, 743 non-MMD craniotomy operations were performed. Six of the 743 EDH cases required postoperative surgical treatment, significantly less than the percentage of EDH requiring postoperative treatment in MMD patients (0.8%, p<0.001). The average time interval between craniotomy surgery and the detection of EDH was 1.8 days (range 0-5) in MMD patients and 0.5 days (range 0-2

p=0.018) in the non-MMD craniotomy group. . Postoperative EDH was observed in significantly fewer cases (17 of 191

p=0.001) when a subcutaneous drain (SCD) was inserted over the bone flap, than when a SCD was not inserted (14 of 55 cases). The international normalized ratio (PT INR) of mean prothrombin time in the immediate postoperative blood test was 1.27 (± 0.17) in the EDH group and 1.20 (± 0.11) in the non-EDH group (p=0.008). Central galeal flap tenting suturing and immediate postoperative platelet count were not related to the incidence of postoperative EDH following pediatric MMD surgery. Indication for the surgical evacuation of EDH was determined by the symptoms, signs, and volume of the hematoma. Our indication of EDH evacuation surgery was regarded as acceptable

however, surgery could be a better option in some patients who have a medium-sized EDH with focal neurological deficits.

Conclusions

Post-operative EGH is more likely following craniotomy in MMD than non-MMD and may occur in a delayed fashion. Insertion of a SCD and immediate correction of an abnormal PT INR value can decrease the incidence of postoperative EDH following surgery for pediatric MMD. Evacuation surgery for EDH is indicated according to the symptoms, signs, and size of hematoma.