Limited damage of tissue mimic caused by a collapsing bubble under low-frequency ultrasound exposure.

In this study, we investigated the bubble induced serious damage to tissue mimic exposed to 27-kHz ultrasound. The initial bubble radius ranged from 80 to 100 µm, which corresponded approximately to the experimentally-evaluated resonant radius of the given ultrasound frequency. The tissue mimic consisted of 10 wt% gelatine gel covered with cultured canine kidney epithelial cells. The collapsing bubble behaviour during the ultrasound exposure with negative peak pressures of several hundred kPa was captured by a high-speed camera system. After ultrasound exposure, a cell viability test was conducted based on microscopic bright-field images and fluorescence images for living and dead cells. In the viability test, cells played a role in indicating the damaged area. The bubble oscillations killed the cells, and on occasion detached layers of cultured cells from the gel. The damaged area was comparable or slightly larger than the initial bubble size, and smaller than the maximum bubble size. We concluded that only a small area in close proximity to the bubble could be damaged even above transient cavitation threshold.

Choledochal cyst and duodenal atresia: a rare combination of malformations.

A rare case of congenital duodenal atresia (DA) associated with a choledochal cyst (CC) is reported. At 38 weeks of gestation, a 1,610-g girl was born by cesarean section with a prenatal diagnosis of congenital DA. After the disease was confirmed by radiographs, she underwent a duodenoduodenostomy for complete separation of the duodenum with an annular pancreas. Thirty-two months after the initial operation, she developed upper abdominal pain and acholic stools. Abdominal ultrasonography demonstrated a CC and dilated intrahepatic bile ducts. Magnetic resonance cholangiopancreatography showed an anomalous arrangement of the choledochus and the main pancreatic duct. A diffusely dilated extrahepatic bile duct was resected, and a hepaticoduodenostomy was performed after a cholecystectomy. The patient was discharged without complications. We could not find a similar case report in the English literature. Although it is not reported that there is a close relation of DA and CC in embryologic development, the presence of this combination should be considered.

Choledochal cyst and duodenal atresia: a rare combination.

A rare case of congenital duodenal atresia (DA) associated with a choledochal cyst (CC) is reported. At 38 weeks of gestation, a 1,610-g girl was born by cesarean section with a prenatal diagnosis of DA. After the disorder was confirmed by X-ray, she underwent a duodenoduodenostomy for a complete separation of the duodenum with an annular pancreas. Thirty-two months after the initial operation, she developed upper abdominal pain and acholic stools. Abdominal ultrasonography demonstrated a CC and dilatated intrahepatic bile ducts. Magnetic resonance cholangiopancreatography showed an anomalous arrangement of the choledochus and main pancreatic duct. A diffusely dilatated extrahepatic bile duct was resected, and a hepaticoduodenostomy was performed after cholecystectomy. The patient was discharged without complications. We could not find a similar case report in the English literature. Although it is not reported that there is a close relationship in embryologic development of DA and CC, one should be aware of the possibility of this combination.