Malignant pancreatic tumours are very rare in the paediatric population. Surgical resection is the standard of care for SPT and pancreatic endocrine neoplasms. Complete resection of the tumour allows a 5-year survival rate of over 95%[14].
All four children admitted to our hospital were SPT, while 4 of the 8 children reported in the literature had SPT, 3 had insulinoma, and 1 had nonfunctional pancreatic adenoma, and no pancreatoblastoma was found. Also all eight children with SPT were female, consistent with what has been reported in the literature[15]. SPT is an uncommon carcinoma of the pancreas representing about 1-3% of exocrine pancreatic neoplasm, and about 90% of the cases are female[14]. The tumours are most often well circumscribed and located in the tail of the pancreas followed by the head[11]. In 1996 the World Health Organization (WHO) formally named it as SPT and reclassified it to be a kind of boundary malignant tumour with unclear biological behavior[15]. Tumor size greater than 5 cm, vascular and perineural invasion, lymph node metastases, necrosis and high mitotic rate are considered histopathologic features of potential tumor aggressiveness[16]. In this series, the tumor size was＞5 cm in 75% of the cases. None of our patients presented with perineural invasion, vascular invasion, regional lymph and distant metastasis.
We make use of three robotic ports and assistant ports as shown in Fig. 1. Because of the small abdominal area in children, we use an arc-shaped trocars design to increase the distance between the robotic arms, and we believe that the distance between the two robotic arms is greater than 4 cm when performing pancreatic surgery, which avoid robotic arm collisions, while it is reported in the literature that adults use the principle "One Fits All" procedure, trocars are positioned the same way of the irrespective all, and the distance between the robotic arms is 8 cm, which avoid robotic arm collisions[17 18].
For SPT located in the head of the pancreas, in addition to traditional pancreaticoduodenectomy, pancreaticoduodenectomy with preservation of the common bile duct, pancreaticoduodenectomy with preservation of the pylorus, resection of the head of the pancreas with preservation of the duodenum and tumor enucleation can be selected. Some studies suggest that duodenum-preserving pancreatectomy is feasible if the tumor is <3 mm from the main pancreatic duct and ≥3 mm from the common bile duct[19]. In one of the children, the tumor was located in the head of the pancreas, and we performed tumor enucleation with complete intraoperative resection of the tumor without damage to structures such as the pancreatic duct and bile duct, and two children were reported in the literature to undergo Pylorus pancreaticoduodenectomy because of SPT involving head and uncinate process of Pancreas. Distal pancreatectomy includes pancreatosplenectomy, spleen-preserving distal pancreatectomy, and vesselssparing spleen-preserving distal pancreatectomy. The vessels-sparing spleen-preserving distal pancreatectomy can fully retain the physiological structure and function of the spleen[7]. The spleen is an important immune organ that may cause explosive infection and septicemia after splenectomy, so preserving the spleen is more important for children than adults[19]. Four children were admitted to our hospital, 3 of whom had tumors located in the body and tail of the pancreas. Because of the difficulty in separating splenic vessels from the diseased tissues, the guardians of two children with splenectomy chose the scheme of combined splenectomy after full communication with their guardians. Two of children underwent robot-assisted distal pancreatectomy and splenectomy, with a tumor size of 16×9 cm and 6×7 cm after splenectomy, respectively. According to the literature review, 2 tumors were located in the body and tail of the pancreas, 1 underwent robotic-assisted spleen-preserving distal pancreatectomy (article did not record), and 1 robotic-assisted distal pancreatectomy and splenectomy ,which the tumor size was 6.5cm. At present, laparoscopic surgery is routinely performed for pancreatic tumors. In a meta-analysis, laparoscopic surgery and open surgery were compared for distal pancreatic tumors. It was found that there was no significant difference in short-term complications, long-term complications and productivity, while the length of hospital stay was shorter than open surgery[20].Robotic assistance offers several advantages as an adjunct to laparoscopic surgery, the Da Vinci surgical robot offers the advantages of a three-dimensional (3D) surgical field and high-resolution viewing, which allow it to overcome difficulties in complicated surgeries better than conventional laparoscopic surgery[7]. Herein, we present our technique and initial institutional experience with pediatric SPT performed using the da Vinci Xi system. Robotic surgery was found to reduce operative time and intraoperative blood loss in a study of robotic and open middle pancreatectomy[21]. When compared with the conventional operations of a pancreatoduodenectomy and distal pancreatectomy, robot-assisated has the ability to preserve the duodenum and the normal distal pancreatic parenchyma. This decreases the risk of complications caused by resection of the duodenum and the spleen and preserves pancreatic exocrine and endocrine insufficiency as well. Previous studies have suggested that spleen preservation is not recommended if tumors in the tail of the pancreas are larger than 3 cm[22], but with robotic assistance, there is still a chance to preserve the spleen for tumors in the tail of the pancreas larger than 4 cm. Robot-assisted was found to have lower conversion rate, a higher spleen preservation rate, than laparoscopic on distal pancreatic processing in a meta-analysis of pancreatic ductal adenocarcinoma[23, 24]. Our operation time was 175-395 min, with an average of 312.5 min, while the time reported in the literature was 65-480 min, with an average of 249.5 min. Details regarded the specific location of the tumour in the pancreatic head, body or tail and spleen preserved, and this may have influenced the differences in operation time. This is consistent with adult robotic pancreatic surgery times. Mean operative time in an adult robotic pancreaticoduodenal surgery was 454 min[25], In another adult robotic distal pancreatectomy procedure, the mean time was 213 min[26]，Among them, its time is longer than laparotomy and endoscopic surgery, considering that the preoperative hole layout and startup time take longer than laparoscopic time. According to our study, intraoperative blood loss was found to be 15-120ml, while robotic surgery was found to rarely lead to intraoperative bleeding in the literature review. However, according to the relevant literature in adults, the blood loss is generally 193 ml in robotic pancreatic body and tail surgery[26]，However, bleeding can be as high as 425 ml during pancreaticoduodenal surgery[25]，The data presented in the literature review are therefore considered inconsistent with facts. Therefore, increased sample size is needed to further determine blood loss in pediatric pancreatic surgery. In terms of hospital days, our study data were consistent with those reported in the literature. Two of these children had complications in the literature, increasing the length of hospital stay. At a median post-operative follow-up of 13 months (range, 6–24 months), all patients remain disease-free. There were no mortality and local recurrence or metastases, and biochemical and hormonal parameters have remained within normal limits for functional tumors in this series. This further demonstrates the oncologic safety and efficacy of this approach.