Fig. 14.1
Patient and port positioning
The standard position for DP begins by placing the patient in an oblique 30° right lateral position (left side up) supported by a pillow or a roll of linen sheet behind the left mid-back, with both arms tucked along the body and protected by foam protectors. Next, “fine tuning” of the initial positioning prior to docking the robot should be performed and will depend on the tumor location. For more proximal pancreatic lesions (pancreatic neck), the patient is placed in a less-oblique angle (almost supine) with the table placed in a reverse Trendelenburg position to allow for adequate exposure of the portal-SMV junction if necessary. For true pancreatic tail lesions, additional obliquing of the patient to 45° allows the stomach to fall to the right, which improves exposure as well as facilitates the splenectomy portion of the procedure.
Pneumoperitoneum Technique
To achieve initial pneumoperitoneum, the left subcostal approach using a Veress needle technique is preferred. The insufflation tubing is connected to the needle, and the insertion is done under continuous CO2 flow. The entry into the peritoneal cavity is confirmed by a drop in CO2 pressure to near zero. [TIP: The needle insertion under pressure–monitoring technique is especially helpful in an obese patient. The ideal puncture site is just right below the costal margin between the midclavicular and anterior axillary lines. Lifting the abdomen up prior to needle insertion can help separate the omentum from the anterior abdominal wall. Gastric decompression prior to the procedure is mandatory to prevent inadvertent puncture of the distended stomach. This technique is contraindicated in patients with splenomegaly, portal hypertension, or bowel distention.] However, in a patient with previous left upper abdominal surgery, an open (Hassan’s) technique is used with the camera port. The camera port (12 mm) is placed 3–4 cm to the left of the umbilicus or at the umbilicus if the lesion is near the pancreatic neck.
Trocar Placement
As in patient positioning, choosing locations for trocar placement should be based on patient’s body habitus, location of the lesion, and the extent of dissection and/or resection. After placement of the camera port as described above, three robotic trocars (8 mm) and a 12 mm accessory ports are placed. The 12 mm accessory port and one robot port are placed on the patient’s left, while two robotic ports and, occasionally, an additional 5 mm accessory port may be needed on the patient’s right, and all are placed under direct vision. Robotic trocars are usually placed first. [TIP: Choosing the placement sites for the fourth arm and accessory ports after the docking of the surgical cart to the camera, right and left instrument ports, allows the surgeon to assess the possibility of robotic arm collision and whether the accessory ports are accessible before making incisions.] The left robotic port (R2) is placed along the left anterior axillary line at the level of the umbilicus. The right robotic port (R1) is then placed on the right upper abdomen along the pararectal (for distal lesion) or midclavicular (for more midline lesion) line, 3–4 cm above the umbilicus, while the fourth robotic port (R4) is placed along the right midclavicular (for distal lesion) or anterior axillary line (for more midline lesion) at the same level as the right robotic port. A 12 mm accessory port is then placed between the camera port and the left robot port and 4–5 cm inferiorly. The 5 mm accessory port, if needed, is positioned on the right abdomen in a mirror image to the 12 mm accessory port.
Once the trocars are placed and patient positioning confirmed, docking of the robot is then performed. The surgical cart is brought in superiorly, approximately 20° to the left of the patient’s longitudinal axis. It is important to place the robot’s fourth arm on the patient’s right side (surgeon’s left) prior to docking. Once docked, robotic instruments are placed through the robotic trocars. The R1 port holds the bipolar forceps, the R2 port uses a monopolar cautery hook, and the R4 holds the grasper forceps.
Technique
Step 1: Exposure of the Pancreatic Neck, Body, and Tail
Using the grasper forceps (R4), the anterior wall of the mid-gastric body is grasped close to the greater curvature and lifted cranially to open the lesser sac space. The gastrocolic attachments are divided below and along the gastroepiploic arcade from the prepyloric antrum to the fundus using the electrocautery hook and the bipolar coagulator. With lesions located close to the pancreatic neck, the right-sided dissection of the omentum should be carried out until the right gastroepiploic vessels and the duodenum are fully exposed. This step will help in localizing and exposing the superior mesenteric vein as it courses underneath the pancreatic neck. Short gastric vessels may be divided at this stage if splenectomy is planned. However, they should be left intact if a surgeon intends to preserve the spleen using Warshaw’s technique (en bloc resection of splenic vessels). [TIP: Viability of spleen can be assessed more definitively by injecting ICG dye and shining infrared light on the spleen (“firefly” fluorescence imaging). If there is blood flow into the spleen, it will illuminate fluorescence green (Fig. 14.2 ). If majority of the spleen does not illuminate, splenectomy should then be performed.]
Fig. 14.2
Firefly fluorescence imaging showing illuminating spleen
Once the greater curve of the stomach is adequately mobilized, complete mobilization of splenic flexure of the colon is generally accomplished prior to pancreatic mobilization. This can be performed by continuing the dissection from a medial to lateral approach or a lateral to medial approach, depending on patient anatomy, tumor size, and location.
The pancreatogastric fold (ligament) is next divided to fully expose the pancreatic body. Care is taken not to injure the left gastric vein unless subtotal pancreatectomy is to be performed. The mobilized stomach is retracted superiorly and held cranially either by the fourth arm or a retractor via an accessory port. [TIP: Suturing the stomach to the falciform ligament and diaphragm frees up the fourth arm, which would otherwise be used to hold up the stomach. In addition, having the stomach fixed in position helps to create a stable operative field (Fig. 14.3 ).] Intraoperative ultrasound of the pancreas, using a laparoscopic 8 MHz probe, can be performed if the lesion is small and in the proximal pancreas. Ultrasound images can be displayed in the surgeon console using the TilePro system.
Fig. 14.3
Tagging of stomach to the anterior abdominal wall
Step 2: Mobilization of the Pancreas and Spleen and Identification of the Proximal Splenic Vessels
Once the greater curve of the stomach and splenic flexure of the colon are mobilized, and the lesion is identified, the transverse mesocolon is retracted inferiorly to define the inferior border of the pancreas. The peritoneum overlying the inferior border of the pancreatic body is incised using the cautery hook and the loose areolar tissue posterior to the pancreas. Dissection is carried out toward the patient’s left along this plane. For pancreaticosplenectomy, mobilization of the spleen together with the distal pancreas in continuity is preferred. This approach is more efficient and less time consuming and involves less bleeding, since dissection is along the same plane leading to the splenorenal and splenophrenic ligaments, both of which are quite avascular. The fourth arm (R4) retracts the spleen medially, providing exposure of the splenorenal and splenophrenic attachments. Retraction is facilitated by leaving a small “tag” of splenorenal peritoneum connected to the spleen to be used as a handle for grasping and to prevent splenic bleeding secondary to retraction injury.
As the dissection continues to the left, the pancreas is gently lifted and rotated upward and held by the fourth arm grasper forceps. As the posterior border of the dissection proceeds, the splenic vein is identified about halfway to two-thirds superiorly from the lower border of the pancreas (Fig. 14.4). In some patients, the tortuous part of the splenic artery may be found immediately after identifying the splenic vein, indicating that the dissection has reached the superior edge of the pancreas. The lesser sac bursa is then entered by continuing the dissection between the artery and lymphatic tissue until the bursa cavity is visualized. Sometimes it is much easier to come around the upper edge of the pancreas near the upper pole of the spleen since there is less fatty lymphatic tissue and the peritoneum is much better defined. A vessel loop or an umbilical tape can then be passed behind the pancreas and looped around it to help in further pancreatic mobilization (“hanging” technique). Control of splenic artery at this location is sufficient if the margin of the proximal pancreatic resection is distal to it. For subtotal pancreatosplenectomy, it is essential to isolate and control the artery near its origin from the celiac trunk. This dissection requires an anterior approach to reach the superior aspect of the pancreas (Fig. 14.5) [TIP: To locate the origin of the splenic artery, often it is easier to start from the common hepatic artery (since it is readily recognized) and then trace back toward the celiac trunk. Lymph node dissection can also be simultaneously performed. The left gastric vein may have to be divided for better exposure. Nuisance bleeding from lymphatic tissue around the celiac region can be controlled with bipolar energy or with just pressure gauze. To avoid inadvertent ligation of celiac trunk or common hepatic artery, the splenic artery should be exposed well into the pancreas or ligated distal to the left gastric artery. The latter artery may form a common trunk with the splenic artery or arises separately from the celiac trunk.]
