Use of Ultra-high-frequency Ultrasound for Aplasia Cutis Congenita of the Scalp

Abstract

Aplasia Cutis Congenita (ACC) in the scalp is a rare congenital malformation. The treatment for ACC with large defects involving the scalp, bone, and the dura is challenging. Local debridement of necrotic tissue is important to prevent lethal complications such as infection and meningitis. However, debridement has the risk of damaging the sagittal sinus or the dura. Recent developments in ultra-high-frequency ultrasound(US) systems provide frequencies of 70 MHz and capability resolution as fine as 30 μm, which could allow precise imaging of small and thin anatomical structures. The study aimed to describe the methods of precise evaluation of the defect in the scalp and safe debridement using ultra-high-frequency US. This is the first report on direct observation of a newborn's brain using ultra-high-frequency US. The boy was delivered spontaneously with a large defect of the scalp and bone. After 14 days, due to signs of infection, local debridement was performed carefully under ultra-high-frequency US-based evaluation. The dura, the sagittal sinus, and the small anatomical structures such as arachnoid granulations could be observed. Because the brain herniation gradually aggravated, dural reconstruction using fascia lata and scalp reconstruction using transposition flap was performed. Finally, good skin coverage over the defects was obtained. This method minimizes the risk of damaging the sagittal sinus and the brain parenchyma, which may cause fatal complications. Although further clinical investigations will be required to confirm its efficacy, ultra-high-frequency US has the potential to be a useful device for ACC treatment.

Fig. 1.

The infant was born with an 8 × 5 cm round defect of the scalp and bone covered with necrotic tissue.

Fig. 2.

The view of the defect at the age of 8 weeks. Blue box: the site of the sagittal sinus. The US findings are shown in Figure 3A. Green box: the area of defect of the dura. The US findings are shown in Figure 3B. Yellow arrow: protruded brain.

Fig. 3.

A, The US finding of blue box area of Figure 2. Ultra-high-frequency US showed a clear image of the dura (yellow arrow), sagittal sinus (blue arrow), subarachnoid space (orange arrow), arachnoid granulations (green arrow), pia mater (pink arrow), and brain parenchyma (red arrow). B, The ultra-high-frequency US finding of green box area of Figure 2. The brain is herniated from the defect of the dura. Yellow arrow: the dura; red arrow: brain parenchyma.

Fig. 4.

The defect of dura could be observed, and brain herniation was expected to occur. Yellow arrow: the dura; blue arrow: the area of the defect of the dura; red arrow: brain parenchyma.