Robot Assisted Distal Pancreatectomy with Celiac Axis Resection (DP-CAR) for Pancreatic Cancer: Surgical Planning and Technique

We will be presenting our surgical planning and technique for robot assisted distal pancreatectomy with celiac access resection. Preoperative planning begins with identifying a locally advanced pancreatic cancer of the body or tail of the pancreas. Cross-sectional imaging is obtained that demonstrates the mass and any arterial or venous involvement.

Our patient is a 65-year-old woman who presented with vague abdominal pain. She underwent multiple CT imaging studies, ultimately demonstrating a pancreatic mass. Biopsy confirmed a diagnosis of pancreatic adenocarcinoma.

Here, you can see her pretreatment mass, which clearly demonstrates involvement of the celiac access. Given this imaging study, the patient underwent preoperative chemotherapy initially with FOLFIRINOX and eventually transitioned to gemcitabine/nab-paclitaxel. She had a promising clinical response with the dramatic reduction in her serum CA 19-9 levels.

Given this response, the decision was made to proceed to surgery. Here we can see a representative image of the patient's post-treatment CT imaging, which demonstrated persistent soft tissue infiltrations surrounding the celiac access. However, in this patient, the root of the celiac access appears to be uninvolved and therefore we expected a negative margin at this site.

This CT scan also affords another opportunity to evaluate this patient's arterial and venous anatomy for any abnormalities. The following is a schematic representation of the port sites used in the procedure. In addition to four eight-millimeter robotic ports, we utilized two assistant ports:five-millimeter in the right lower quadrant and a 15-millimeter in the left lower quadrant, to serve as a future extraction site.

A five-millimeter port is placed in the right flank for the liver retractor. After a diagnostic laparoscopy confirms no evidence of metastatic disease, the lesser sac is opened and the greater curvature of the stomach is mobilized completely with a combination of hook and bipolar cautery, with care to preserve the gastrum of plug vessels. Here, you see a still shot of the mobilization of the greater curvature of the stomach.

Here, you can see highlighted, the lesser SAC, the greater curve, and the spleen. Once the stomach is mobilized, it is retracted cephalad with the liver retractor and the dissection of the hepatic artery begins. The station eight A hepatic artery node is dissected and removed and sent for permanent pathological evaluation.

The common hepatic artery, gastroduodenal artery, and proper hepatic artery are then dissected and identified. Intraoperative ultrasound then demonstrates pulsatile flow in the proper hepatic artery. Here is another still shot highlighting the relationship between the proper hepatic artery, which is under the ultrasound probe, the common hepatic artery and gastroduodenal artery.

Additionally, below the figure is a schematic of the intraoperatively obtained triphasic ultrasound waveform within the proper hepatic artery prior to clamping. After identification of the proper hepatic artery, the common hepatic artery is then clamped and pulsatile flow is demonstrated after clamping on ultrasound, relying on retrograde flow through the gastroduodenal artery. Adequate profusion in the distal liver parenchyma is also confirmed after clamping the common hepatic artery.

At this time, if there's not demonstration of adequate retrograde flow through the gastroduodenal artery, consideration must be given to aborting the procedure or performing an arterial jump graft from the aorta to the hepatic artery to achieve adequate flow. At this time, attention is turned to the inferior border of the pancreas to identify the superior mesenteric vein. Once the vein is carefully identified, the pancreas is lifted off of the vein and the retro pancreatic tunnel overlying the vein is created.

Here, we see another still shot highlighting the relationship between the body of the pancreas, the superior mesenteric vein, and the retro pancreatic tunnel overlying the vein. After the tunnel is fully dissected, a thread of umbilical tape is passed and used to aid in retraction. The pancreas is divided using an endovascular stapler.

Once the pancreatic neck is divided, further dissection of the retroperitoneum continues laterally to identify and isolate the splenic vein. The splenic vein is dissected circumferentially, and then a loop is placed around it. After this, another staple load is used to divide the splenic vein.

The coronary vein is then identified and ligated with a bipolar vessel sealer to facilitate further dissection and exposure. Finally, attention is once again turned to the common hepatic artery, which is divided utilizing another staple load after pulsatile flow in the gastroduodenal artery is again confirmed. As you can see, highlighted in the still shot, the relationship between the hepatic artery, currently clamped by the stapler, and the gastroduodenal artery, which is being closely evaluated for pulsatile flow.

Attention is then turned to the left gastric artery, which is ligated utilizing another staple load. Once these arterial structures are divided, the specimen is retracted laterally and the dissection continues cephalad and laterally to divide the nerve fibers and connective tissue overlying the aorta to identify the superior mesenteric artery. The ultrasound probe is once again utilized to confirm identification of the SMA and its relationship to the aorta.

Here, you can see a still shot highlighting the superior mesenteric artery, as well as the dense lymphatic and perineural tissue that overlies the aorta and the superior mesenteric artery in this dissection. Once the superior mesenteric artery is identified, dissection continues towards the root and then cephalad from the route through additional dense lymphatic and perineural tissue until the muscle fibers of the diaphragmatic crura are encountered. These tissues are taken with a bipolar vessel sealing device and hook cautery.

As our dissection continues cephalad, you can see that it approaches very closely to the inferior vena cava laterally, as we take this dense connective tissue. Here, you can begin to see the muscle fibers of the diaphragmatic crura merge in the dissection. Ultimately, this dissection approaches the root of the celiac access and a combination of careful electrocautery dissection and lateral retraction of the specimen isolates the origin of the celiac axis orthogonally to the aorta.

This allows the celiac axis to be ligated at the origin on the aorta safely with another endovascular staple load. As a specimen is retracted to the patient's left, note how the celiac axis is rotated along with the specimen to facilitate an angle for the stapler. In this still shot, you can clearly see the relationship and orientation between the celiac axis and the aorta that we start to achieve prior to ligation.

Again, the celiac access route is ligated utilizing a vascular staple load. The retroperitoneal dissection is then completed in a lateral manner to completely free the distal pancreas and spleen. The spleen is separated from the pancreas and both are placed into separate specimen bags and extracted through the left lower quadrant, 50 millimeter port site.

Following removal of the specimen, here you can see the resection bed with the important anatomy labeled. Finally, attention is then turned to the distal liver parenchyma to assess for adequate profusion and the stomach is carefully evaluated for any external signs of ischemia. A drain is then left in the resection field, terminating along the pancreatic staple line.

The patient tolerated the procedure well, and her postoperative course was without complication. Her post-treatment pathology demonstrated a moderately differentiated pancreatic ductal adenocarcinoma, ypt1c with zero out of 21 nodes involved and all margins were noted to be negative. Planning for a robot assisted distal pancreatectomy with celiac access resection begins with proper patient selection, with preoperative imaging to delineate anatomy and tumor involvement to determine the adequate pre-surgical treatment which must be initiated.

Patients of this approach include the finding of inadequate retrograde flow through the gastroduodenal artery, which must prompt either the need for arterial reconstruction or aborting the procedure. The stomach must also be carefully monitored for ischemic changes during division of major arterial and venous structures. However, the remnant gastroepiploic vessels are often sufficient to maintain perfusion.

If at any time that the dissection does not feel safe or feasible, converting to a traditional open surgical approach must be considered. The use of the robotic platform for complex pancreatic resections has increased as surgeon experience grows and the technology becomes more accessible. Our institution has experience with utilizing the robotic platform for both pancreaticoduodenectomy and distal pancreatectomy, however, our approach is only one of many.

In conclusion, we believe that with proper preoperative planning, patient selection, and surgeon experience our approach for robot assisted distal pancreatectomy with celiac access or section is safe and feasible for the management of locally advanced pancreatic tumors of the body and tail of the pancreas.