Repeated Minimally Invasive Pancreatectomy for Intraductal Papillary Mucinous Neoplasm in the Remnant Pancreas: A Case Report

Introduction

Minimally invasive pancreatectomy (MIP) has become standard practice for management of benign and malignant pancreatic tumors [1]. Robotic and laparoscopic approaches are expected to reduce the morbidity of pancreatectomy by offering typical advantages, such as less blood loss, reduced pain, lower wound morbidity, shorter hospital stays, and quicker recovery times [2]. The indication for repeated MIP for a recurrence or de novo pancreatic neoplasm after primary pancreatic surgery is still under debate. There have been a few reported cases of repeated laparoscopic and robotic pancreatic surgery [3–7]. Performing repeated pancreatic surgery using a minimally invasive method is a challenging procedure and requires an experienced surgeon and assistant in hepato-pancreato-biliary surgery, due to the potential for severe adhesions. Recently, robotic distal pancreatectomy was successfully performed after robotic pancreaticoduodenectomy, due to the metastasis of mesenchymal chondrosarcoma [4]. Nakagawa et al conducted a laparoscopic subtotal stomach-preserving pancreaticoduodenectomy followed by laparoscopic distal pancreatectomy and reported the safety and feasibility of repeated minimally invasive pancreaticoduodenectomy [5].

The introduction of robotic surgery has facilitated the reduction of morbidity associated with pancreatic surgery [8]. Accumulation of experience in the field of robotic surgery allowed us to perform robotic pancreaticoduodenectomy after a previous minimally invasive operation. Here, we report a robotic-assisted Whipple procedure for the de novo intraductal papillary mucinous neoplasm (IPMN) of the remnant pancreas after previous laparoscopic single-branch resection of the pancreatic uncinate process.

Case Report

A 50-year-old woman was admitted to our department with a diagnosis of IPMN. In 2010, she underwent laparoscopic single-branch resection, due to a branch-type tumor in the pancreatic uncinate processs [9]. Histological examination revealed an intraductal papillary-mucinous adenoma, and the resection margin was negative. Follow-up was normal until 2015, when on the abdominal contrast-enhanced computed tomography scan, a cystic lesion of the pancreatic head with the size of 7 mm was incidentally detected (Figure 1A). The lesion was diagnosed as a de novo IPMN that involved the main pancreatic duct. No metastatic lesion was found during examination. During routine follow-up, an increase in the size of the tumor and presence of the mural nodule was observed. By July 2022, the tumor had grown to 17 mm (Figure 1B). The tumor marker carbohydrate antigen (CA19-9) was within the reference range (10.6 U/mL), but carbinoembryonic antigen (CEA) was elevated to 7.0 ng/mL. Considering the tumor’s growth, the presence of an apparent mural nodule in cystic lesion on the abdominal computer tomography, absence of metastases, and concomitant diseases, we proposed a robot-assisted Whipple procedure. All possible risks and complications were explained to the patient. Written informed consent was obtained.

The operation was performed using 6 ports in the abdominal wall (Figure 2). The operation began with laparoscopic mobilization. There were moderate adhesions in the area of the pancreatic head. After detachment of the adhesions and remobilization of the duodenum using the Kocher maneuver, the operation continued with the Da Vinci surgical system. Cystic lesion was located and dissected (Figure 3). We first resected the stomach using a linear stapler (Signia Purple 60 mm). The gastroduodenal artery was ligated. The common bile duct was isolated and crossed. The small intestine was also resected with a linear stapler (Signia Purple 60 mm). Transection of the pancreas was performed using a coagulator of monopolar scissors at the line of the superior mesenteric vein (Figure 4A). Duct-tomucosa pancreaticojejunostomy was performed with the stent placement (Figure 4B). Interrupted sutures were used for the anterior and posterior walls of the hepaticojejunostomy. The specimen was removed by making a 5-cm incision under the umbilicus. Gastrojejunostomy was carried out extracorporeally from the same incision. The operation time was 412 min, and blood loss was 50 mL. Pathological examination reported “intraductal papillary mucinous carcinoma” with negative surgical margins (Figure 5). The postoperative period was uneventful. She was discharged from the hospital on postoperative day 20.

Discussion

IPMN is a cystic formation of the pancreas with the potential for malignancy. IPMN can involve the main pancreatic duct, a side-branch duct, or both. The surgical treatment is recommended for patients with main or mixed duct IPMN, due to the high risk of invasive cancer development [10]. Branch-type IPMNs generally have a lower risk of becoming malignant, and the decision to operate is based on the tumor’s size and characteristics [11]. In recent years, advancements in minimally invasive surgery have increasingly replaced traditional open surgical procedures. Various minimally invasive resections of the pancreas have been proposed, including duodenum-preserving pancreatic head resection, ventral pancreatectomy, inferior head resection of the pancreas, and single-branch resection of the pancreas [9]. In our case, the patient first underwent laparoscopic single-branch resection. We chose laparoscopic single-branch resection of the pancreas considering the minimal invasiveness and because this operation results in the complete preservation of the normal pancreas parenchyma, without any organ reconstruction. Pathohistological investigation revealed intraductal papillary mucinous adenoma, with a negative surgical margin. After a 5-year follow-up, de novo IPMN was detected in the head of the pancreas.

Robotic pancreaticoduodenectomy allows safe implementation of minimally invasive surgery [12]. Li et al, in a meta-analysis, suggested that robotic pancreatectomy is associated with better perioperative outcomes, including a lower conversion rate, shorter postoperative hospital stay, less estimated blood loss, and more lymph node retrieval, than laparoscopic pancreatectomy [13]. Robotic surgery has advantages over laparoscopic surgery, with a magnified 3-dimensional image, 7 degrees of freedom, elimination of hand tremor, and the fulcrum effect of rigid laparoscopic instruments – allowing for precise suturing, easier tissue handling, better control of large blood vessels, and the ability to work at angles not possible with the laparoscope [14]. Peng et al conducted a meta-analysis comparing robotic pancreaticoduodenectomy with the traditional open operation and concluded that robotic surgery has a higher rate of margin-negative resections, lower overall complication rates, and shorter hospital stays [15]. Additionally, benefits include less postoperative pain and smaller incisions. However, there are limitations associated with the high medical cost and the learning curve for surgeons, which can influence operative time and blood loss [16–18]. There have also been 2 cases reported on the feasibility of robotic surgery in repeated pancreatectomy (Table 1) [4,6]. In our report, we decided to perform a repeated operation, namely, robotic pancreatoduodenectomy, due to the gradual progression and communication of the newly detected tumor with the main pancreatic duct. A multi-institutional study in Japan revealed that the overall survival rate of patients after repeated pancreatectomy was significantly higher than that of those who had not undergone surgery [19]. Our experience has shown that intraoperatively performing adhesiolysis by robotic surgery is difficult and not always feasible. In such cases, we decided to start with laparoscopic surgery and switch to robotic once the adhesions were removed. The previous single-branch resection was a minimally invasive operation, and adhesions were not as severe, which may have contributed to the success of the repeated operation. Our patient has regular postoperative follow-up. The last examination showed no abnormalities. Our experience reinforces the potential of robotic surgery to enhance patient outcomes in complex pancreatic procedures, supporting its consideration as a viable option for patients facing pancreatic neoplasms after initial minimally invasive interventions.

In 2019, the World Health Organization classification of tumors of the digestive system pathologically classified IPMNs into 3 groups: low-grade dysplasia (adenoma), high-grade dysplasia (carcinoma in situ), and invasive intraductal papillary mucinous carcinoma based on the degree of dysplasia [20]. Postoperative pathohistological findings after first and repeated operations have revealed low-grade and high-grade dysplasia, respectively. Rezaee et al reported 20% cases developing new lesions and increasing in the cyst size in the remnant pancreas after resection of low-grade dysplasia [21]. Compared with patients undergoing resection of an IPMN with low-grade dysplasia, those with an IPMN with high-grade dysplasia have an increased risk of the subsequent development of pancreatic ductal adenocarcinoma. Overall survival of high-grade dysplasia after resection is similar to that of low-grade dysplasia (median survival of 92 and 118 months, respectively) and significantly lower than that of invasive IPMN (median survival of 29 months) [21]. Patients with high-grade dysplasia should be followed-up thoroughly, and the postoperative surveillance intervals in resected main duct IPMNs need to be tailored based on the dysplasia grade [22].

Conclusions

This case demonstrates that performing a robotic Whipple procedure is both safe and feasible for patients with newly diagnosed pancreatic neoplasms who have previously undergone minimally invasive pancreatic surgery.