Robotic pancreatic resection . Personal experience with 105 cases

Objective: the first robotic pancreatic resection in Brazil was performed by our team in 2008. Since March 2018, a new policy prompted us to systematically employ the robot in all minimally invasive pancreatic surgery. The aim of this paper is to review our experience with robotic pancreatic resection. Methods: all patients who underwent robotic pancreatic resection from March 2018 through December 2019 were identified. Descriptive data were collected. Preoperative variables included age, sex, and indication for surgery. Intraoperative variables included operative time, bleeding, blood transfusion. Results: 105 patients underwent robotic pancreatectomy. Median age was 60.5 years old. Fifty-five patients were female. 51 patients underwent robotic pancreatoduodenectomies, 34 distal pancreatectomy. Morbidity was 23.8%, mainly related to postoperative pancreatic fistula and one death occurred (mortality of 0.9%). Three patients (2.8%) were converted to open surgery. Four patients had delayed gastric emptying and two presented bleeding. Twenty-four patients had pancreatic fistula that was treated conservatively with late removal of the pancreatic drain. No patient required percutaneous drainage, reintervention or hospital readmission. Conclusions: the robotic platform is useful for the reconstruction of the alimentary tract after pancreatoduodenectomy or after central pancreatectomy. It may increase the preservation of the spleen during distal pancreatectomies. Pancreas sparing techniques, such as enucleation, resection of uncinate process and central pancreatectomy, should be used to avoid exocrine and/or endocrine insufficiency. Robotic resection of the pancreas is safe and feasible for selected patients. It should be performed in specialized centers by surgeons with experience in both open and minimally invasive pancreatic surgery.


INTRODUCTION
M inimally invasive surgery has been increasingly used in the last three decades. However, minimally pancreatic operations were slowly implemented, due to the anatomic complexity of the organ, its retroperitoneal location, and the high post-operative morbidity due mainly to the digestive enzyme-rich secretions the prancreas produces 1,2 .
Our experience with laparoscopic pancreatic resection began in 2001 with benign or low-grade neoplasms, followed by more complex procedures such as central pancreatectomy and pancreatoduodenectomies 3 .
The first robotic pancreatic resection in Brazil was performed by our team in 2008 4 . However, the high-cost and the absence of specific instruments for this complex procedure halted its use in our center for 10 years. Since

Preoperative assessment
A variety of imaging modalities were used for assessing pancreatic lesions, including ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MR) and endoscopic US. The use of relevant clinical information and key radiologic features were essential for adequate lesion characterization, and differentiation, and therefore for surgical planning. Preoperative workup included MR and endoscopic US for most patients.

Patient positioning and port placement
The patient is placed in a supine position and

Total pancreatectomy
It is similarly carried out as the pancreatectoduodenectomy described above. The main difference is that the pancreas is not divided and the head and the uncinate process are detached from the superior mesenteric artery and the portal vein using the artery-first approach. Once this maneuver is accomplished, the head and the uncinate process of the pancreas are lifted to the left, and the dissection of the distal pancreas is similarly performed as the distal pancreatectomy, described below ( Figure 2B). This operation can be done with the preservation of the spleen or with a splenectomy, depending on the diagnosis. The reconstruction of the alimentary tract only includes the hepaticojejunostomy and the duodenojejunostomy as already described ( Figure   4).

Distal pancreatectomy without splenectomy
The Once the pancreas is free from these vessels ( Figure 2C), it is retrieved inside a plastic bag through the infraumbilical port, usually with minimal or without incision enlargement.
One drain is placed near the pancreatic stump.

Distal pancreatectomy with splenectomy
The The ultrasonography is again performed to guarantee a negative margin. The pancreas is divided with the harmonic scalpel for the identification of the main pancreatic duct.

Robotic pancreatic resection. Personal experience with 105 cases
The surgical specimen is removed. The next step is to perform the Roux-en-Y limb. The jejunum is divided with a stapler, 30 cm from the Treitz angle. The Roux-en-Y loop is constructed with a latero-lateral jejunojejunostomy, using the stapler. The opening is closed in a two-layer running suture and the Jejunal loop is brought through an opening in the transverse mesentery. The reconstruction is done with duct-to mucosa pancreatojejunostomy as previously described (Figure 3). The mesenteric breach is closed with interrupted sutures and the cavity is drained.

Enucleation
The operation begins with the opening of the retrocavity and the exposure of the pancreas. An ultrasonography is performed to locate the tumor and to evaluate its distance from the main pancreatic duct that if too close may hinder the operation (Figures 5A-B).
The enucleation is usually performed with the Maryland robotic instrument using low bipolar energy (Figures 5C-D). The hemostasis is achieved by compression rather than suture to avoid a lesion to the main pancreatic duct. Once accomplished, the surgical specimen is retrieved, and the pancreatic area is drained.

Resection of the uncinate process
The

DISCUSSION
Robotic pancreatic surgery has been increasingly used, worldwide in the last few years 7-10 . Robotic pancreatic surgery has shown to be safe for benign lesions and for selected patients with malignancies 8 .
Robotic pancreaticoduodenectomy is associated with fewer wound complications, shorter hospital stays, and decreased overall complication rates including minimal In 2008, we performed the first robotic pancreatectomy in Latin America but at that time, we did not find any advantage over the standard laparoscopic pancreatectomy 4 . We believed that it should be reserved for more complex operations. There was a lack of specialized robotic instruments and the cost was prohibitive for its disseminated use in our country. Since