Our experience aims to promote RSP-DP in the management of benign or small low-grade malignant tumors of the body or tail of the pancreas. Furthermore, when the proximity of the tumor to the splenic vessels does not allow its preservation, we prefer the Kimura technique [4].
Due to the current advances in image technology, an increasing number of patients are being diagnosed with benign or borderline malignant tumors of the pancreas. Since these patients are expected to have excellent long-term survival rates, quality of life considerations are also a priority when choosing a surgical option. With this in mind, function-preserving and minimally invasive pancreatectomy offers several advantages [21–23]
Laparoscopic distal pancreatectomy has become a widely accepted surgical approach for the treatment of left-sided pancreatic tumors [24]. However, to perform this procedure safely, finely honed skills and advanced surgical equipment are required [25]. Splenic salvation may be abandoned because of the technical complexity of dissecting splenic vessels with the conventional laparoscopic approach. Unfortunately, overwhelming post-splenectomy infection, although uncommon, is still a serious fulminant process with a high mortality rate [2].
To date minimally invasive DP (MI-DP) with splenic vessel preservation is only performed in specialized centers and by surgeons with extensive experience in pancreatic and laparoscopic surgery. The Warshaw procedure [3] is the easier technique to preserve the spleen but has the potential risk of left-sided portal hypertension-related perigastric varices, severe splenic infarction, abscess formation and the eventual need for splenectomy. Furthermore, splenic artery and vein ligation may reduce blood supply to the residual proximal stomach which may complicate future gastric surgery if required [26]. This is not the case with the Kimura procedure [4].
Surgeons should be aware of the significance of conservation of the splenic artery and vein and be able to perform both procedures so that the technique can be tailored to the individual patient’s circumstances.
Several systematic reviews along with meta-analysis and cohort studies have shown that MI-DP had better or equivalent perioperative outcomes when compared with open distal pancreatectomy [29–31]. The advantages of MI-DP are lower blood loss, decreased morbidity, shorter length of hospital stay and rehabilitation time, less postoperative pain, less adhesions, and better aesthetic results. These favorable outcomes have been confirmed also in larger series. The International Evidence-based Guidelines on Minimally Invasive Pancreas Resection were recently published following a meeting of experts in Miami [32]. They concluded that MI-DP for benign and low-grade malignant tumors should be considered superior to open distal pancreatectomy, since it is associated with a shorter hospital stay, reduced blood loss, equivalent complication rates and better postoperative quality of life (QoL). The laparoscopic procedure does not have a negative impact on the oncologic outcome. However, because of the risk of postoperative complications, this procedure should be reserved for specialized centers [32, 33]. Preservation of the splenic vessels would be particularly advantageous in those patients undergoing pancreatic resection for benign or low-grade tumors in whom normal life expectancy would be anticipated.
Robotic surgical systems have been applied to different types of surgery. Robotic technology adds precision to movements, increases surgeon comfort, enlarges the three-dimensional field of view, suppresses tremors, provides consistent traction, instrument flexibility, and facilitates surgical suturing. Accordingly, robotics should facilitate minimally invasive complex abdominal procedures [35]. Waters et al.[35] reported the cost effectiveness and higher spleen preservation rate of robotic procedures. In addition, several investigations have been published supporting the idea that robotic surgery is superior to conventional laparoscopy for spleen preservation during distal pancreatectomy[20, 34]
However, at present, there is no conclusive evidence supporting the proposition that the robotic approach is superior to standard laparoscopy. In a recent multicenter propensity score-matched study [20], spleen preservation was planned for over one-third of patients and achieved in 72 per cent of these procedures. After matching, the robotic approach was associated with a higher splenic preservation rate than was seen during the laparoscopic approach. In addition, SVP-DP (Kimura technique) was used more often in the robotic than with the laparoscopic approach, whereas splenic vessel ligation (Warshaw technique) was more often applied in laparoscopic cases. These findings need to be confirmed in a multicenter randomized controlled trial (RCT) study which should also specifically compare cost-effectiveness of the two approaches.
Despite the extra costs involved, robotic devices may facilitate SVP-DP and have the potential to become the standard treatment for this kind of procedure[13, 35].
To our knowledge, this is the first description of the left-lateral approach RSP-DP in total right lateral decubitus position. We hypothesized that this technique could benefit patients in terms of shorter operative time, lower estimated blood loss, easier dissection, and higher preservation rate of the spleen and the splenic vessels.
To date, the lateral approach for laparoscopic distal pancreatectomy has only been evaluated primarily in technical reports or small non-comparative case series [11]. The only comparative cohort was reported by Nakamura et al., in 2011. Twenty-three patients underwent laparoscopic SP-DP. After the adoption of the lateral approach SVP-DP, none of the patients required conversion to an open operation. The authors concluded that, although the Warshaw method was acceptable with a low incidence of gastric varices, the laparoscopic lateral approach SV-DP may contribute to a safer and easier procedure[12].
Our group has been performing MI-DP with splenic vessel preservation in patients with benign or borderline (low-grade) malignant tumors during the last decade. Attempting the laparoscopic lateral approach SVP-DP through the total right lateral decubitus position provides several potential technical advantages. Placing the patient in this position (nephrectomy-like) allows gravity to help retract the stomach, colonic splenic flexure, and pancreas, facilitating access and dissection. By holding the spleen attachments in place, the autotraction of the pancreatic tail makes it easier to lift and visualize the small venous and arterial branches that need to be ligated or sealed to separate the tail of the pancreas from the splenic vessels. The easier access and better exposure allow a more precise and faster dissection that can potentially reduce operative time and blood loss. With this approach, we believe that splenic vessels are easier to visualize, identify, and isolate at the level of the tail of the pancreas than in the medial approach. It can be easily identified if there is close contact or infiltration of the vessels by the tumor and if in the event of needing ligation of the splenic vessels, this is quite easy. In addition, bleeding during dissection of the splenic vessels is relatively common and may lead to the need for conversion to the Warshaw technique or even splenectomy.
Another advantage of the left lateral approach is that the pancreas is sectioned more distally, which could preserve more pancreatic parenchyma and decrease the risk of postoperative pancreatic insufficiency in these patients with anticipated long survival. [11, 12].
In our series, we observed a mean total operative time of 323 min. This may be justified because we are still on the learning curve of robotic pancreatic surgery. But in addition, the average BMI of our patients was and 31.4 kg/m2, which represents a greater difficulty at the time of dissection. However, we think that with the lateral DC, this difficulty is less compared to the same intervention in the supine DC.
Another difficulty in our experience was the transection of the parenchyma with the robotic stapler. In four of the five cases we had to reinforce it with an additional manual suture because the thickness of the pancreatic parenchyma did not result in a secure stapled closure, although this did not mean an increase in grade B pancreatic fistula in the postoperative period.
The robotic stapler is introduced in the operation field by the assistant but is fully controlled by the surgeon operator. The stapler has a side-to-side articulation range of 108° and 54° up and down, allowing for more precise positioning, compared to 100° side-to-side for laparoscopic staplers. The autonomy of the surgeon from the console in the placement of the robotic stapler allows an easy placement of the stapler in the patient's position in lateral DC, compared with the laparoscopic stapler. In addition, the stapler is capable of measuring tissue compression before and during stapler firing, making automatic adjustments. Despite these advantages, given that the pancreatic parenchyma at the body level is generally bulkier than at the pancreatic neck, staple closure at the level of the pancreatic body is often unsatisfactory. In this circumstance, we would consider not using stapled transection and going directly to transection and manual suture.
The “da Vinci” robotic system adds a wide three-dimensional field of view, constant traction, suppression of physiological tremor, and has tools that allow seven degrees of freedom. The surgeon experiences increased dexterity, the ability to perform precise tissue dissections and advanced suturing. Application of the robotic approach to this technique could also reduce of the learning curve for junior surgeons. We believe that the robotic left lateral approach may be superior for selected patients with lesions of the tail of the distal pancreas and could be more widely adopted.
Conclusion
The left lateral approach RSP-DP in right lateral decubitus position is a feasible and safe approach for distal benign or small low-grade malignant tumors on the pancreatic tail. The improved exposure and ease of locating the splenic vessels offers the possibility of a shorter surgical time, less blood loss, and a higher percentage of splenic preservation when compared to the traditional medial approach. Robotic assistance can facilitate this technique and shorten the learning curve for this complex procedure.