[7].
Hepatic peribiliary cysts are benign lesions that can be monitored without intervention after being accurately diagnosed. However, in Japan, surgery is performed in cases in which malignancy cannot be completely ruled out, in patients with jaundice, and in patients with repeated episodes of cholangitis [2]. If the cyst is located around a large bile duct near the porta hepatis and is impossible to distinguish from a malignant tumor, open hepatic resection is generally performed [2]; however, there is one reported case in which laparoscopic surgery was performed in Japan [2]. Open surgery is considered highly invasive, and minimally invasive surgery should be chosen if possible, especially for benign tumors. In the present case, it was difficult to rule out malignancy, so we decided to perform minimally invasive robotic surgery in accordance with recent reports of the effectiveness of minimally invasive robot-assisted liver resection [5].
In our case, the patient was female and the imaging findings were somewhat atypical because the cyst did not form a series of beads, making it difficult to distinguish from hepatic mucinous cystic neoplasm. In addition, the cyst had increased in size during 2 years of follow-up, so the possibility of malignancy could not be ruled out. Therefore, surgery was chosen. We decided to perform robotic-assisted hepatectomy because it is less invasive with less intraoperative bleeding and less postoperative pain than open surgery [5].
The perihilar accessory glands are also of interest as a source of intraductal papillary neoplasms of the bile duct and cholangiocarcinomas, and there are reports of cholangiocarcinoma thought to have originated from hepatic peribiliary cysts [6]. Therefore, as more cases are accumulated and a relationship between hepatic peribiliary cysts and cholangiocarcinoma is suggested, surgery may become the treatment of choice for hepatic peribiliary cysts.
In conclusion, the diagnosis rate of hepatic peribiliary cystsis expected to improve with advances in imaging technology. However, there are cases, such as the present case, in which surgery is warranted. In the present case, robot-assisted hepatic subsegmentectomy was performed safely and achieved good results. Our results suggest that robotic surgery may be useful for the treatment of hepatic peribiliary cysts for which surgery cannot be avoided.