Left posterior superior mesenteric artery first approach and circumferential lymphadenectomy with total mesopancreas dissection in laparoscopic pancreaticoduodenectomy
Malignant periampullary tumors are still an aggressive lethal disease, especially pancreatic ductal adenocarcinoma (PDAC), with being set to become the second most common cause of cancer-related mortality within the next few decades . Pancreaticoduodenectomy with lymphadenectomy and total meso-pancreas (MP) dissection are considered the standard method, providing the highest survival benefit for resectable periampullary malignancies . Otherwise, several meta-analyses revealed that “SMA first approach” was associated with improved perioperative outcomes (R0-resection rate, postoperative complications including pancreatic fistula and bleeding) as well as long-term outcomes and survival . In addition, there are also studies showing that about 12% to 20% of patients with lymph node metastases on the left-sided SMA require extended lymphadenectomy (in particular, SMA circumferential lymphadenectomy) and this approach does not statistically increase complications compared to standard lymphadenectomy . High frequency of posterior retro-pancreatic tissue as well as lymph node (LN) metastasis was one of reasons for high locoregional recurrence rate following surgery for periampullary malignancies, especially PDAC . Extended lymphadenectomy to the left sided SMA makes it easier to remove systematically the MP . In addition, SMA first-approach, including from the left- posterior side, not only helps control blood vessels but also makes easier in SMA circumferential lymphadenectomy and total MP dissection . Since the first time M. Gagner et al. performed laparoscopic pancreaticoduodenectomy (LPD) in 1994, there have been studies on L-assisted PD as well as LPD and has shown great promise of becoming the optimistic choice for patients of resectable periampullary malignancies . Applying the SMA first-approach in LPD helps the surgery achieve both high radicalness as well as other benefits that laparoscopic surgery brings. All approaches have certain advantages and disadvantages. We find that left posterior SMA first-approach has many advantages such as easy pulse control due to direct access to the SMA, due to most of cases, the inferior pancreaticoduodenal artery (IPDA), the 1st jejunal artery (F1A) originates on the left side of the SMA, as well as lymph nodes and connective tissue on the left sided SMA can easily be removed. To our knowledge, there have been several studies on the application of LPD with SMA left posterior first approach and circumferential lymphadenectomy with total MP dissection for periampullary malignancies, but mostly in dynamic or how-I-do-it manuscripts . Thus, our original study aims to evaluate the feasibility, safety and efficacy in short-term outcomes of the LPD technique with SMA left posterior first approach and circumferential lymphadenectomy with total MP dissection. 

Data collection After an Institution Review Board (IRB) approval (No. 691-GCN-HĐĐĐNCYSH-ĐHYHN), all patients with a histologically proven diagnosis of resectable periampullary (pancreatic head, distal bile duct, the second portion of duodenum and ampullary) malignancies who underwent LPD with SMA left posterior first approach and circumferential lymphadenectomy with total MP dissection at the Department of Gastrointestinal and Hepato-pancreato-biliary surgery, Bach Mai Hospital from September 2021 to October 2023 were enrolled. Patients’ data were prospectively collected, including: General and preoperative information: Demographic characteristics (sex, age, height, weight, BMI, medical history), Tumor location (periampullary sites of origin: pancreatic head cancer, distal common bile duct, ampulla of Vater and second portion of duodenum) . Intraoperative data and Short-term outcomes: number of trocars, time to approach SMA, management of F1V, F1A, IPDV and IPDA; intraoperative data (blood loss, operative time, intraoperative complications), postoperative outcomes (length of hospital stay, postoperative complications, in-hospital mortality) were collected, especially including the frequency of diarrhea (defined as a condition requiring opioid antidiarrheal drug for at least 6 months after surgery) and the rate and classification of postoperative lymphorrhea according to the ISGPS’s classification . Histopathological data: the site of tumor, resected margins, lymph nodes (LNs) were marked and measured by the operating surgeon on the back-table in the operation room (Fig. ). Tumor grading, number of lymph nodes retrieved, number of metastatic lymph nodes, metastatic status of SMA left-sided LNs, pathological TNM staging (according to the eighth edition of the AJCC/UICC system ), resected margins status. The margin status was defined as follows: no cancer cells are identified microscopically at any of the resected margins (R0), microscopic tumor present at any margins or within 1 mm of a transection or circumferential margin according to the Royal College of Pathologists guidelines (R1), and gross residual tumor as determined by the surgeon intraoperatively (R2) . Surgical procedure All cases have undergone preoperative Multí-Slice Computerized Tomography scan with angiography to determine the origin location as well as understand the anatomical changes of these vascular branches (Fig. ). All cases in the study were performed according to a unified surgical procedure that have been published in our previous technical article with detailed step-by-step video . In this article, we summarize our procedure with three main stages. We use 5 or 6 trocars: one 10 mm-trocar placed through the umbilicus for camera; two 12 mm-trocars placed at the midclavicular line higher 1 cm compared to umbilicus in the right and left side for instrument; two 5 mm-trocars placed at right and left subcostal. The main surgeon stands on the right side of patient in the SMA’s first-approach and dissection phase, and changes to the middle position in the rest of the surgical phases, while the first assistant standing on the side left of the patient; the second and third assistants holding the cameras and standing on the right side of the patient. Stage 1: SMA first-approach and dissection phase The second assistant lifts the transverse colon mesentery upward, and the first assistant pulls the first jejunum to the left side. Open the peritoneum along the middle colic artery (MCA) from the mesocolon side continuously down to the mesentery of the small intestine along the axis of the SMA. Remove connective tissue and mesenteric lymph nodes from right to left on the anterior surface of the SMA and the first jejunal vascular branches. Then, cutting the ligament of Treitz to mobilize the 3rd and 4th portions of the duodenum and SMA origin from the left side. Find the J1A, ligate this branch separately or together with IPDA depending on the anatomical morphology. In some cases, J1A is small and close to J2A, so J2A can also be ligated to assess and classify the anatomy of the first jejunal vein (J1V). In the case on the anterior of SMA, simple isolate and resect it. Most of the cases we found the common trunk between the J1V, and the inferior pancreaticoduodenal vein (IPDV) goes posteriorly to the SMA: after ligation of the J1A, the SMA was dissected and lifted, approached the J1V, and resect it just below the left side of the SMA, then continue dissecting the first jejunal loop and the pancreatic uncinate process behind this vein. Then resecting the first jejunal loop with corresponding mesenteric. The dissection continues on the left side of the SMA just above the left renal vein. After resection of the first loop of the jejunum, group 14p, 14d of left sided SMA and group 15 lymph node were dissected along the J1A, middle colic artery, and right colic artery (Fig. ). We continue dissecting on the posterior side of the SMA, ligate the inferior pancreaticoduodenal artery (IPDA) on this posterior surface (Fig. ). During this phase, the duodenal pancreatic head continues to be released from the anterior surface of the aorta and vena cava (we call it the “left” Kocher maneuver). Stage 2: Resection phase After resecting the gastric across the antrum, detach the isthmus of the pancreas from the superior mesenteric vein and portal vein, cut the isthmus of the pancreas. Then, dissection of lymph nodes of the hepatic pedicle up to the hepatic hilum (LNs of groups 7, 8, 9, 12a, 12b1, 12b2, 12p). Then, pull the jejunal loop to the right side through retroperitoneal defect. Dissect systematically the meso-pancreas from the superior mesenteric artery, superior mesenteric vein, and portal vein. Resect the entire meso-pancreas both anterior and posterior sides of SMA including right-sided SMA lymph nodes. Thus, SMA circumferential lymphadenectomy were completely resect, while the neural plexus around the SMA is carefully preserved (Fig. ). Because the left side had been carefully dissected, this was very easy because only a few thin connective tissues of the meso-pancreas remained attached to the SMA. The common bile duct was always resected last during this phase. Small epigastric or suprapubic opening to remove specimens taken en bloc: duodenal pancreatic head mass, lymph nodes groups 5, 6, 7, 8, 9, 12a, 12b1, 12b2, 12v, 13, 14p, 14d (SMA circumferential lymphadenectomy) and 15 (Fig. ). Stage 3: Reconstruction phase In reconstruction stage, we do it in two ways: Total laparoscopic manual anastomosis or mini-laparotomic manual anastomosis through a small abdominal incision (about 7 cm). In all cases, we have performed a double layer pancreatoenteric end -to-side anastomosis—the modified Blumgart anastomosis. The biliary-enteric anastomosis is performed one layer, distal to the pancreatoenteric anastomosis about 10 cm. Finally, an antecolic gastro-jejunostomy is performed via a distal loop of jejunum approximately 60 cm distal to the biliary-enteric anastomosis and gastric. Statistical analysis Categorical variables were presented as a percentage of each value. Discrete variables were numeric variables that had a countable number of values between any two values. Continuous variables were expressed as mean (or median if without normal distribution) with range. Continuous variables were analyzed by the Wilcoxon rank sum test. Categorical variables were analyzed using the chi-square test or Fisher’s exact test. Statistical analysis was performed using SPSS for Windows, version 22.0 (SPSS Inc., Chicago, IL, USA). 

After an Institution Review Board (IRB) approval (No. 691-GCN-HĐĐĐNCYSH-ĐHYHN), all patients with a histologically proven diagnosis of resectable periampullary (pancreatic head, distal bile duct, the second portion of duodenum and ampullary) malignancies who underwent LPD with SMA left posterior first approach and circumferential lymphadenectomy with total MP dissection at the Department of Gastrointestinal and Hepato-pancreato-biliary surgery, Bach Mai Hospital from September 2021 to October 2023 were enrolled. Patients’ data were prospectively collected, including: General and preoperative information: Demographic characteristics (sex, age, height, weight, BMI, medical history), Tumor location (periampullary sites of origin: pancreatic head cancer, distal common bile duct, ampulla of Vater and second portion of duodenum) . Intraoperative data and Short-term outcomes: number of trocars, time to approach SMA, management of F1V, F1A, IPDV and IPDA; intraoperative data (blood loss, operative time, intraoperative complications), postoperative outcomes (length of hospital stay, postoperative complications, in-hospital mortality) were collected, especially including the frequency of diarrhea (defined as a condition requiring opioid antidiarrheal drug for at least 6 months after surgery) and the rate and classification of postoperative lymphorrhea according to the ISGPS’s classification . Histopathological data: the site of tumor, resected margins, lymph nodes (LNs) were marked and measured by the operating surgeon on the back-table in the operation room (Fig. ). Tumor grading, number of lymph nodes retrieved, number of metastatic lymph nodes, metastatic status of SMA left-sided LNs, pathological TNM staging (according to the eighth edition of the AJCC/UICC system ), resected margins status. The margin status was defined as follows: no cancer cells are identified microscopically at any of the resected margins (R0), microscopic tumor present at any margins or within 1 mm of a transection or circumferential margin according to the Royal College of Pathologists guidelines (R1), and gross residual tumor as determined by the surgeon intraoperatively (R2) . 

All cases have undergone preoperative Multí-Slice Computerized Tomography scan with angiography to determine the origin location as well as understand the anatomical changes of these vascular branches (Fig. ). All cases in the study were performed according to a unified surgical procedure that have been published in our previous technical article with detailed step-by-step video . In this article, we summarize our procedure with three main stages. We use 5 or 6 trocars: one 10 mm-trocar placed through the umbilicus for camera; two 12 mm-trocars placed at the midclavicular line higher 1 cm compared to umbilicus in the right and left side for instrument; two 5 mm-trocars placed at right and left subcostal. The main surgeon stands on the right side of patient in the SMA’s first-approach and dissection phase, and changes to the middle position in the rest of the surgical phases, while the first assistant standing on the side left of the patient; the second and third assistants holding the cameras and standing on the right side of the patient. Stage 1: SMA first-approach and dissection phase The second assistant lifts the transverse colon mesentery upward, and the first assistant pulls the first jejunum to the left side. Open the peritoneum along the middle colic artery (MCA) from the mesocolon side continuously down to the mesentery of the small intestine along the axis of the SMA. Remove connective tissue and mesenteric lymph nodes from right to left on the anterior surface of the SMA and the first jejunal vascular branches. Then, cutting the ligament of Treitz to mobilize the 3rd and 4th portions of the duodenum and SMA origin from the left side. Find the J1A, ligate this branch separately or together with IPDA depending on the anatomical morphology. In some cases, J1A is small and close to J2A, so J2A can also be ligated to assess and classify the anatomy of the first jejunal vein (J1V). In the case on the anterior of SMA, simple isolate and resect it. Most of the cases we found the common trunk between the J1V, and the inferior pancreaticoduodenal vein (IPDV) goes posteriorly to the SMA: after ligation of the J1A, the SMA was dissected and lifted, approached the J1V, and resect it just below the left side of the SMA, then continue dissecting the first jejunal loop and the pancreatic uncinate process behind this vein. Then resecting the first jejunal loop with corresponding mesenteric. The dissection continues on the left side of the SMA just above the left renal vein. After resection of the first loop of the jejunum, group 14p, 14d of left sided SMA and group 15 lymph node were dissected along the J1A, middle colic artery, and right colic artery (Fig. ). We continue dissecting on the posterior side of the SMA, ligate the inferior pancreaticoduodenal artery (IPDA) on this posterior surface (Fig. ). During this phase, the duodenal pancreatic head continues to be released from the anterior surface of the aorta and vena cava (we call it the “left” Kocher maneuver). Stage 2: Resection phase After resecting the gastric across the antrum, detach the isthmus of the pancreas from the superior mesenteric vein and portal vein, cut the isthmus of the pancreas. Then, dissection of lymph nodes of the hepatic pedicle up to the hepatic hilum (LNs of groups 7, 8, 9, 12a, 12b1, 12b2, 12p). Then, pull the jejunal loop to the right side through retroperitoneal defect. Dissect systematically the meso-pancreas from the superior mesenteric artery, superior mesenteric vein, and portal vein. Resect the entire meso-pancreas both anterior and posterior sides of SMA including right-sided SMA lymph nodes. Thus, SMA circumferential lymphadenectomy were completely resect, while the neural plexus around the SMA is carefully preserved (Fig. ). Because the left side had been carefully dissected, this was very easy because only a few thin connective tissues of the meso-pancreas remained attached to the SMA. The common bile duct was always resected last during this phase. Small epigastric or suprapubic opening to remove specimens taken en bloc: duodenal pancreatic head mass, lymph nodes groups 5, 6, 7, 8, 9, 12a, 12b1, 12b2, 12v, 13, 14p, 14d (SMA circumferential lymphadenectomy) and 15 (Fig. ). Stage 3: Reconstruction phase In reconstruction stage, we do it in two ways: Total laparoscopic manual anastomosis or mini-laparotomic manual anastomosis through a small abdominal incision (about 7 cm). In all cases, we have performed a double layer pancreatoenteric end -to-side anastomosis—the modified Blumgart anastomosis. The biliary-enteric anastomosis is performed one layer, distal to the pancreatoenteric anastomosis about 10 cm. Finally, an antecolic gastro-jejunostomy is performed via a distal loop of jejunum approximately 60 cm distal to the biliary-enteric anastomosis and gastric. 

Categorical variables were presented as a percentage of each value. Discrete variables were numeric variables that had a countable number of values between any two values. Continuous variables were expressed as mean (or median if without normal distribution) with range. Continuous variables were analyzed by the Wilcoxon rank sum test. Categorical variables were analyzed using the chi-square test or Fisher’s exact test. Statistical analysis was performed using SPSS for Windows, version 22.0 (SPSS Inc., Chicago, IL, USA). 

From September 2021 to September 2023, there were in total 31 cases of periampullary malignancies which underwent LPD with left posterior SMA first approach and circumferential lymphadenectomy with total MP dissection was proceeded in our center. Patients’ demographics with preoperative laboratory results (Table ) There were totally 16 men and 15 women in our study with the median age of 58,7 ± 9,1 years (range 35–70). BMI was 20.9 ± 2,0 kg/m2 (range 16,8—25). Preoperative biliary drainage was conducted before surgery in 14 patients (45.2%). All patients had symptoms of jaundice in laboratory tests. Technical details and short-term outcomes (Table ) For technical details, LPD was performed with 5 trocars in 27 patients (87.1%). The IPDA comes from the J1A accounting for 48.4% and originates from the left sided SMA accounting for 58%, only 22.6% originates from the right alone. The IPDV flows to J1V (which was confirmed as PDJV), or type A of PDJV according to Nagakawa’s classification, accounting for 64.5%. J1V which was located dorsal to the SMA (type 1 according to Ishikawa’s classification) accounts for 64.5%, which was located ventral to the SMA (type 2) accounts for 22.6%. total MP dissection was performed in all cases (level 2 according to Inoue’s classification). There was no case of conversion to open surgery at the stage 1. Pancreaticojejunostomy was performed using the Modified Blumgart anastomosis in all patients, with using internal stent in 9.7% patients. The mean operative time and the mean SMA approach time was 441.9 ± 73.7 min (range 330–600 min) and 99.9 ± 27.7 min (range 60–153 min), respectively. Median post-op hospital stay was 14.1 ± 4.0 days. Mean intra-operative blood loss was 143 ± 252 ml (range 50 – 1500 ml) and there was just one patient who needed intraoperative blood transfusion. Conversion to open surgery in one case at the time when the last anastomosis was almost completed, causing silent bleeding under the transverse colon mesentery, may be due to the process of pulling the jejunal loop to the right side through retroperitoneal defect, damaging the small vascular branch in the colon mesentery, when it is discovered that the bleeding is heavy and difficult to control during laparoscopy and the patient has begun hemodynamic changes, the decision to conversion is made. For short-term outcomes, postoperative grade III complications occurred in 4 cases: There was one patient with severe complication IIIb: bleeding complications < 24 h due to injury of a SMV branch, had re-operation to stop the bleeding, and was stable and discharged from the hospital after 18 days. 3 patients with complications IIIa: one case of bleeding from the inferior epigastric artery on left trocar puncture site with embolization intervention, stable discharge after 24 days; one case of grade B pancreatic fistula required drainage intervention via ultrasound and the patient was discharged stable after 22 days; and one case of persistent lymphatic fistula required embolization. Otherwise, POPF occurred in 7 cases, with 6 cases of grade A and 1 case of grade B. Lymphatic fistula happened in one case, which required percutaneous hepatic lymphangiography . 6 (19.3%) cases developed postoperative diarrhea, but only one case developed postoperative refractory diarrhea. Pathological results (Table ) All patients had a malignant tumor, including 21 cases of distal CBD or ampulla of Vater. Moderately and poorly differentiated histopathology was obtained in 27 cases (87.1%) and 14 cases (12.9%), respectively. R0/R1 margin of pancreatic parenchyma was achieved in all cases. Microscopically, there were 7 (22.6%) cases with metastatic meso-pancreas. The number of LNs harvested and metastatic LNs were 32,7 ± 13 (maximum was 74) and 7,4 ± 6 (maximum was 30), respectively. And the rate of metastatic left sided LN No. 14 was 25.8%. 

) There were totally 16 men and 15 women in our study with the median age of 58,7 ± 9,1 years (range 35–70). BMI was 20.9 ± 2,0 kg/m2 (range 16,8—25). Preoperative biliary drainage was conducted before surgery in 14 patients (45.2%). All patients had symptoms of jaundice in laboratory tests. 

) For technical details, LPD was performed with 5 trocars in 27 patients (87.1%). The IPDA comes from the J1A accounting for 48.4% and originates from the left sided SMA accounting for 58%, only 22.6% originates from the right alone. The IPDV flows to J1V (which was confirmed as PDJV), or type A of PDJV according to Nagakawa’s classification, accounting for 64.5%. J1V which was located dorsal to the SMA (type 1 according to Ishikawa’s classification) accounts for 64.5%, which was located ventral to the SMA (type 2) accounts for 22.6%. total MP dissection was performed in all cases (level 2 according to Inoue’s classification). There was no case of conversion to open surgery at the stage 1. Pancreaticojejunostomy was performed using the Modified Blumgart anastomosis in all patients, with using internal stent in 9.7% patients. The mean operative time and the mean SMA approach time was 441.9 ± 73.7 min (range 330–600 min) and 99.9 ± 27.7 min (range 60–153 min), respectively. Median post-op hospital stay was 14.1 ± 4.0 days. Mean intra-operative blood loss was 143 ± 252 ml (range 50 – 1500 ml) and there was just one patient who needed intraoperative blood transfusion. Conversion to open surgery in one case at the time when the last anastomosis was almost completed, causing silent bleeding under the transverse colon mesentery, may be due to the process of pulling the jejunal loop to the right side through retroperitoneal defect, damaging the small vascular branch in the colon mesentery, when it is discovered that the bleeding is heavy and difficult to control during laparoscopy and the patient has begun hemodynamic changes, the decision to conversion is made. For short-term outcomes, postoperative grade III complications occurred in 4 cases: There was one patient with severe complication IIIb: bleeding complications < 24 h due to injury of a SMV branch, had re-operation to stop the bleeding, and was stable and discharged from the hospital after 18 days. 3 patients with complications IIIa: one case of bleeding from the inferior epigastric artery on left trocar puncture site with embolization intervention, stable discharge after 24 days; one case of grade B pancreatic fistula required drainage intervention via ultrasound and the patient was discharged stable after 22 days; and one case of persistent lymphatic fistula required embolization. Otherwise, POPF occurred in 7 cases, with 6 cases of grade A and 1 case of grade B. Lymphatic fistula happened in one case, which required percutaneous hepatic lymphangiography . 6 (19.3%) cases developed postoperative diarrhea, but only one case developed postoperative refractory diarrhea. 

) All patients had a malignant tumor, including 21 cases of distal CBD or ampulla of Vater. Moderately and poorly differentiated histopathology was obtained in 27 cases (87.1%) and 14 cases (12.9%), respectively. R0/R1 margin of pancreatic parenchyma was achieved in all cases. Microscopically, there were 7 (22.6%) cases with metastatic meso-pancreas. The number of LNs harvested and metastatic LNs were 32,7 ± 13 (maximum was 74) and 7,4 ± 6 (maximum was 30), respectively. And the rate of metastatic left sided LN No. 14 was 25.8%. 

Our initial results showed that left posterior SMA first approach might provide a favorable short-term outcome. The operation time was around 7.5 h. 2 cases (6.5%) had intraoperative complications, but only one case had to be converted to open surgery. 90-day mortality was 0%; and the main concern about post-op complications were severe diarrhea and persistent lymphatic fistula required therapeutic lymphography, but the figure only 3.2% and 3.2%, respectively. Comparing with our similar technique in Open PD, standard key complications such as POPF, Lymphatic fistula, PPH, DGE and Diarrhea were not differentiated. Meanwhile, the number of total examined LNs was superior (32,7 ± 13 versus 27.23 ± 13.10) . Postoperative grade III complications occurred in 4 cases: There was one patient with severe complication IIIb: bleeding complications < 24 h due to injury of a SMV branch, had re-operation to stop the bleeding, and was stable and discharged from the hospital after 18 days. 3 patients with complications IIIa: one case of bleeding from the inferior epigastric artery on left trocar puncture site with embolization intervention, stable discharge after 24 days; one case of grade B pancreatic fistula required drainage intervention via ultrasound and the patient was discharged stable after 22 days; and one case of persistent lymphatic fistula required embolization. The rate of major complications (grade III, IV or V) in our study were comparable to other studies . The length of hospital stay was shorter compared to Kondo (14.1 vs 20 days), which showed the advantages of laparoscopic surgery. Though the RCT is lacking, the data about survival is promising. Median survival time range from 35.4 to 64.3 months, with better survival among resectable or no left-sided LN metastasis group . SMA first approach from the left posterior side was firstly described by Kurosaki et al. in 2011 by stretching the jejunal loop to the left, the 1st and 2nd arterial branches of the jejunal loop were identified and ligated close to the base . When stretching the jejunal loop to the left, the SMA will rotate counterclockwise and the posterior and right side will be clearly exposed so that the IPDA will be controlled and ligate from the left side. After dissection, the SMV will be seen from the posterior, and can be dissected up to the confluence with the splenic vein. Some favorable factors when choosing this approach in LPD: The arterial access area is directly from the left posterior side, which is the free edge of the artery, with the right colic artery (RCA) and middle colic artery (MCA) as landmarks for access. The colonic artery can be seen without any dissection because the connective tissue in this area is thin. The area between the SMA and the SMV, the splenic vein, and the posterior retro-pancreatic tissue is loose connective tissue, so the components can be easily separated during surgery. Through lenses and laparoscopic instruments, we can easily and clearly observe the posterior retro-pancreatic tissue. The normal anatomy of the anterior of the SMA from the origin of the MCA and the RCA to the origin of the SMA is an avascular space. The posterior aspect of the SMV and splenic vein does not have any branches coming into. The posterior surface of the duodenum and the anterior surface of the aorta and vena cava create a virtual avascular space, making it easy to dissect to the left edge of the vena cava. Most of the IPDA and F1A come from the left half of the SMA. In our study, the average SMA approach time was 99.9 ± 27.7 min. Though IPDA, J1V have anatomical variance, 100% of J1A were ligated close to the origin, 71% of J1V arteries were ligated close to the origin, 54.8% of IPDA were controlled from the left side corresponding to the rate of origin of the artery. With this dissection method, the entire MP will be removed and the entire SMA will be exposed without moving the duodenum and colon. In our study, total MP dissection was performed in all cases (level 2 according to Inoue’s classification), the nerve plexus around the artery was preserved, so the rate of postoperative diarrhea was not high and was treated stably during the hospital stay with Imodium. Left posterior SMA first approach with plexus-preserving in open PD for pancreatic head cancer was described by Inoue (2015) and Kondo (2020) . The most important part of this technique is the separation of the nerve plexus and outer fatty tissue and lymph node. The landmark for SMA root is left adrenal vein, the harvested tissue was then towards its dorsal side and below the mesocolon. In our study, we also tried to expose the first jejunal loop, right and middle colic artery, our landmark for upper side was above the left renal vein. IDPV, FJV, IDPA was then ligated; the right SMA side was then approached with meso-pancreas dissection without removal of the SMA plexus. Comparing with the original research conducted by Sato et al. in 2023 of Left posterior SMA first approach in LPD , in our technique, we emphasized the importance of MCA as a landmark for determine SMA, J1A and IPDA safely, efficiently and faciliates SMA-first approach LPD from the left and complete dissection of the mesopancreas and lymph nodes . Hirono’s prospective study with 167 patients has founded that the role of LN metastasis was more important than nerve invasion . The role of lymph node metastasis in periampullary cancer has long been demonstrated, but extended lymphadenectomy has not been recommended due to high complication rate . However, there are growing evidence that left-sided SMA lymph node metastasis account for 12–13% compared to 13–55% of the right side . Meanwhile, Hirono also showed no significant difference in the rate of diarrhea needing medication between complete circumferential lymphadenectomy and right-sided only (17.3 vs 21.7%, p > 0.05). The key point of this issue is to preserve the SMA nerve plexus as not only the rate of diarrhea decreases but also the locoregional recurrence does not change . Thus, plexus-preserving left-side superior mesenteric artery approach might be a feasible approach for these patients. The role of the IPDA and J1A: if you want to completely remove meso-pancreas, the first thing you need to do is to approach the base of the IPDA and J1A. Therefore, having a firm grasp of the anatomy preoperatively will help the surgeon be proactive during the surgery and choose the approach. Our study shows that IPDA comes from the J1A accounting for 48.4%, originates directly from the left sided SMA accounting for 32.3%. This study is also consistent with other studies such as Yoshiya Ishikawa et al.: The IPDA separated from the same trunk with the J1A in 66% cases and originated directly from the SMA in 33% of all cases . Meanwhile, Murakami et al. found that in 58.9% of cases, the IPDA separated from the same trunk with J1A, 24.2% separated independently from the SMA and 16.9% separated from both, of which 70.6% had IPDA separated on the left side of the SMA . From our research and other studies, it has been shown that in most cases, the IPDA separates from the left side of the SMA with same trunk with the J1A, this is the reason for choosing the left sided SMA first approach. This approach makes it easier to control the origin of this artery in early stage. According to Kosei Takagi's analysis, when talking about the strategy of accessing the SMA when performing LPD as well as robotic PD, he also mentioned that the left half of SMA is a difficult area to approach from the right side, especially in obese patients; and the area accounting for nearly 2/3 of the SMA circumference on the left is easily controlled if the approach is chosen from the left side . In addition to the role of the artery, the inferior pancreatic duodenal vein (IPDV) and the first jejunal vein (F1V) also play an important role when approaching from the left side. Our study found that 64.5% cases had IPDV flows to J1V (which was confirmed as PDJV), or type A of PDJV according to Nagakawa’s classification. This result is lower than the results of Yuichi Nagakawa, the author found that up to 97.6% had branches flowing to J1V branch . According to Yuichi Nagakawa et al., based on this vein, we can find the IPDA right above. This is a method of approaching the meso-pancreas from the uncinate process of the pancreas and is also a technique that helps total MP dissection. But in our opinion, approaching SMA from this right side also has disadvantages: Firstly, the IPDV usually goes posteriorly flow to J1V, it is very difficult to handle if this vein was the injury while the J1V has not been controlled. But if approached from the left side, J1V has been completely controlled so when there is damage to the IPDV, it is not difficult to handle bleeding. Second, SMA first approach from the right side will entangle the pancreatic head and SMV, so the surgeon will have to do some steps before SMA approaching and the laparoscopic viewing angle is also more difficult. Also in our study, it was shown that 35% of cases J1V which was located dorsal to the SMA (type 1 according to Ishikawa’s classification) accounts for 22.6%. In these cases, it is best to proactively ligate F1V before accessing the SMA and in cases of J1V branch located ventral to the SMA, it should be preserved when approaching from the left side to avoid stagnation of blood from the small intestine going to the SMV. Thus, mastering the anatomy of the IPDA, J1A, IPDV, and F1V before surgery plays a very important role when choosing the approach, surgical strategy, and vascular control. To the best of our knowledge, this is one of the first prospective reports about laparoscopic plexus-preserving left posterior superior mesenteric artery approach for peri-ampullary cancer. Though the results are favorable, long-term following with higher study population should standardize the technique as well as focus on the survival benefits of the technique. 

Laparoscopic pancreaticoduodenectomy with superior mesenteric artery left posterior first approach and circumferential lymphadenectomy with total meso-pancreas dissection was safe and effective with favorable short-term outcomes. 

Below is the link to the electronic supplementary material. Supplementary file1 (MP4 818854 KB) Our technical step-by-step video for left posterior SMA first approach and circumferential lymphadenectomy with total meso-pancreas dissection 

