Background
In pancreaticoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC), the superior mesenteric artery (SMA)-first approach (or the “artery-first approach”) has become the standard procedure [
1‐
6]. This approach has the following advantages: (1) the early determination of resectability before performing irreversible surgical steps, (2) reduction in intraoperative blood loss by avoiding venous congestion of the specimen, (3) negative uncinate resection margin rate, (4) and adequate lymph node dissection along the SMA [
1‐
8].
For left-sided PDAC, a novel procedure known as radical antegrade modular pancreatosplenectomy (RAMPS) was developed [
9]. Briefly, dissection was performed from the right to the left direction in 1 of 2 posterior dissection planes, contributing to the achievement of negative posterior resection margins under plane view [
9,
10]. In addition, the accompanying N1 lymph node dissection was based on an established anatomy of lymph node drainage for the left-sided pancreas [
9,
11]. The long-term oncologic outcome with RAMPS for PDAC is acceptable, with a reported 5-year survival rate of 35% [
12].
With advancements in laparoscopic instruments and techniques, some surgeons began using laparoscopic RAMPS (L-RAMPS) for carefully selected patients with left-sided PDAC [
13‐
15]. However, this procedure remains uncommon due to several technical difficulties in performing it. Moreover, there have been no reports on the artery-first approach so far in L-RAMPS.
We developed a simple and novel technique for left-sided PDAC, termed as the artery-first approach L-RAMPS. Here, we have described the details and technical advantages of our procedure and evaluated the short-term clinical outcomes of the same.
Discussion and conclusions
Our new laparoscopic procedure for left-sided PDAC, artery-first L-RAMPS using a 3D technique, was safe and feasible to perform. This procedure is advantageous as it allowed minimal intraoperative blood loss and precise lymphadenectomy.
L-RAMPS reported previously [
13‐
15] had several technical drawbacks. First, these L-RAMPS procedures [
13‐
15] were not described as artery-first approaches. During pancreatic cancer surgery, tumor infiltration to the SMA should be detected before irreversible surgical steps need to be taken, such as pancreatic transection or the division of the splenic vessels. In fact, in the PD field, the artery-first approach is fast becoming one of the standard procedures [
1‐
6].
The second drawback in these studies is that the L-RAMPS procedures were not based on the prevention of venous congestion of the specimen. The Sp.V, which is the main draining vessel, is generally a hindrance in the assessment of both the origin of the Sp.A and the anterior surface of the SMA even after pancreatic neck transection, particularly when using the laparoscopic approach. Consequently, interruption of all arterial blood flow before division of the Sp.V is technically demanding. Venous congestion of the specimen poses a risk of increasing intraoperative bleeding, which may prevent meticulous lymphadenectomy. Indeed, previous reports have indicated excessive blood loss and fewer counts of retrieved lymph nodes [
13‐
15].
The third drawback of the previously reported L-RAMPS procedures is that a dry operative field was difficult to maintain laparoscopically. Since the pancreas is one of the retroperitoneal organs, the blood and lymphatic fluid are prone to collect around the pancreas due to gravity, thereby interfering with lymphadenectomy.
To overcome these technical drawbacks, we developed artery-first L-RAMPS method using a 3D technique. Our procedure has four technical advantages. First, the 3D technique enabled interruption of the entire arterial blood supply to the specimen while preserving the Sp.V, thereby preventing venous congestion of the specimen. Early division of the DPAs from the SMA was also easier after dome-shaped dorsomedial pancreatic dissection (Fig.
2d). Intraoperative venous congestion of the specimen was not observed in any of the cases. As a result, the median amount of intraoperative blood loss was 75 mL (range, 10–130 mL), which is much lesser than 364 mL (range, 0–3000 mL), as reported by other laparoscopic studies for left-sided PDAC [
13,
16‐
20].
The second advantage was that the 3D technique enabled early detection of tumor infiltration into the SMA or to the left adrenal gland before pancreatic transection. With this, surgeons could decide between early termination of the operation and performing a combined resection of the left adrenal gland. In the original open RAMPS procedure [
9,
10,
12], the exposure of the SMA and the detection of the posterior dissection plane around the left kidney occurred after pancreatic neck transection, which is an irreversible surgical step. Indeed, combined adrenal gland resection was immediately decided during the 3D technique in case 3.
The third advantage of L-RAMPS using a 3D technique was that the spleen remained attached in the subphrenic area during most of the operation period. In general, mobilization of the spleen has a risk of injury to its capsule, which may result in uncontrollable massive bleeding that can interrupt the operative procedure. Our present technique did not cause any splenic injury in any of the patients. In addition, the dome-shaped dorsomedial pancreatic space was easily maintained with one hand by the assistant surgeon (Fig.
2), in contrast to the wide detachment of the distal pancreas and spleen. Owing to the 3D technique, the assistant surgeon could use his other hand for retraction of the transverse mesocolon.
The fourth advantage was that, in our technique, the blood and lymphatic fluid pooled in the dome-shaped dorsal space due to gravity. Therefore, we succeeded in obtaining a dry and clear operative field and could perform meticulous lymphadenectomy (Figs.
3a, b and
4a). In our series, the median retrieved lymph node count was 37 (range, 32–58), which is greater than 14 (range, 1–43) in other laparoscopic reports on L-RAMPS in high volume centers [
13,
16‐
20], resulting in oncologic acceptability. We believe that these four technical advantages led to the successful outcomes in our study.
In the case of a tumor close to the pancreatic neck, as in case 2, a minilaparotomy just above the pancreatic neck was useful for frozen pathologic examination of the pancreatic stump. Moreover, direct management through the minilaparotomy allowed quick hemostasis on the stump as well as the secure closure of the main pancreatic duct (Fig.
3d).
When the exposure of the left renal vein was difficult during the procedure, utilizing the Treitz ligament approach appeared to be helpful. In detail, after the peritoneum around the Treitz ligament is opened, the third duodenal portion can be cranially mobilized from the abdominal aorta to reach the left renal vein [
13,
21].
In this study, no intraoperative complications or massive bleeding were noted. However, our median operation time was longer than that reported otherwise due to the learning curve, which could probably be because we had never performed laparoscopic pancreatectomy for PDAC before. Moreover, cases 1 and 2 required combined resection of the transverse colon and the left adrenal gland due to direct infiltration of the tumor, respectively. Case 3 had preoperative pancreatitis. As our present technique is simple, experienced laparoscopic surgeons can probably accomplish it in a shorten span of operation time. The postoperative hospitalization seemed long in our case, probably because of the unique insurance system in Japan, wherein the cost of hospitalization is relatively low.
This study had some limitations. We included a small number of subjects, patient selection was limited, and only short-term outcomes were evaluated. We hope to evaluate the long-term oncologic outcomes for this procedure as well as apply this technique to more patients in the future. Judging from the clinical outcomes in this study, our technique has significant scope to improve minimally invasive surgical treatment for left-sided PDAC.
In conclusion, artery-first L-RAMPS using a 3D technique for left-sided PDAC is a safe and feasible procedure. This procedure may play an important role in reducing intraoperative blood loss and in ensuring high precision of lymphadenectomy. With several theoretical advantages, we believe this novel technique may become the preferred treatment for left-sided PDAC in selected cases.