The specific extent of the neck and body of the pancreas is not clearly defined but is generally considered to be the pancreatic tissue in front of the superior mesenteric vein. For benign tumors or borderline tumors in the neck and body of the pancreas, the main surgical modalities are pancreaticoduodenectomy with or without pyloric preservation, pancreatic segment resection, and simple pancreatic tumor enucleation[3–4]. With the concept of preserving pancreatic function, the operation process of pancreaticoduodenectomy is complicated and there are many postoperative complications, so it is not the best surgical method for pancreatic neck and body tumors. Although simple pancreatic tumor enucleation can preserve more normal pancreatic tissue, this procedure is generally suitable for tumors < 3 cm in diameter that is not close to the main pancreatic duct[4]. In this study, the average pancreatic tumor diameter of the patient was 2.9 cm, and the majority of the tumor was located in the pancreatic neck tissue in front of the superior mesenteric vein area, so pancreatic segment resection was used first. Intraoperative rapid freezing pathology is an effective means to determine the final surgical method, if the intraoperative pathology suggests that the tumor is malignant, then according to the specific situation during the operation, laparoscopic pancreaticoduodenectomy or laparoscopic distal pancreatectomy was performed after obtaining the consent of the patient's family. In this paper, one patient was diagnosed intraoperatively as a benign tumor and was diagnosed postoperatively as a malignant tumor, although the family no longer requested to continue to accept radical dissection surgery, it brought challenges to the standardization of surgery. Therefore, the selection of laparoscopic central pancreatectomy needs to be cautious for the diagnosis of benign and malignant tumors that cannot be judged clearly by preoperative imaging.
Table 1
Perioperative data of patients
Number | Gender | Age | operation time (min) | Intraoperative bleeding volume (ml) | Intraoperative transfusion | Tumor size (cm) | Pathological diagnosis | Grade of pancreatic fistula | Readmission to hospital | Re-operation |
1 | Male | 67 | 465 | 200 | No | 2.5×2.5×2.0 | IPMN | A | No | No |
2 | Female | 39 | 420 | 150 | No | 2.0×1.5×1.5 | SCN | B | No | No |
3 | Female | 66 | 307 | 200 | No | 2.5×1.5×1.5 | SCN | B | No | Yes |
4 | Male | 51 | 215 | 100 | No | 2.0×1.5×1.5 | IPMN | B | No | No |
5 | Male | 31 | 494 | 400 | No | 5.5×4.0×3.0 | SPN | B | No | No |
6 | Male | 76 | 348 | 100 | No | 2.5×2.5×1.5 | IPMN | B | No | No |
7 | Female | 39 | 187 | 100 | No | 2.5×2.0×2.0 | SCN | B | No | No |
8 | Female | 38 | 380 | 200 | No | 5.0×2.5×2.5 | SPN | B | No | No |
9 | Female | 59 | 274 | 50 | No | 2.0×1.5×1.5 | MCN | B | Yes | No |
10 | Female | 79 | 448 | 200 | No | 5.0×4.0×4.0 | MCN | B | No | No |
11 | Female | 64 | 180 | 200 | No | 1.2×1.0×1.0 | MCN (G1) | B | No | Yes |
12 | Female | 73 | 315 | 300 | No | 1.0×1.0×1.0 | IPMN | B | No | No |
13 | Male | 28 | 180 | 50 | No | 2.5×2.0×1.5 | SCN | C | No | No |
14 | Female | 65 | 140 | 50 | No | 1.2×1.0×0.8 | MCN (G1) | A | No | No |
15 | Female | 36 | 190 | 50 | No | 2.3×2.0×1.5 | SPN | A | No | No |
16 | Male | 68 | 215 | 50 | No | 2.0×1.0×1.0 | IPMN | B | No | No |
17 | Female | 54 | 560 | 200 | No | 8.2×7.0×6.5 | SCN | B | No | No |
18 | Female | 64 | 225 | 100 | No | 2.0×1.5×1.5 | SCN | A | No | No |
19 | Female | 29 | 282 | 100 | No | 5.0×3.0×1.0 | MCN | B | No | No |
20 | Female | 66 | 515 | 800 | Yes | 8.5×5.0×4.0 | PDCA | B | No | No |
21 | Male | 72 | 270 | 200 | No | 3.0×2.5×2.2 | MCN (G1) | C | No | No |
IPMN: Intraductal Papillary Mucinous Neoplasm; SPN: Solid Pseudopapillary neoplasms; SCN: Serous Cystic Neoplasm; MCN: Mucinous Cystic Neoplasms; NEN: neuroendocrine neoplasm; PDAC: Pancreatic ductal adenocarcinoma.
The gastroduodenal artery and the superior pancreaticoduodenal artery descend anterior to the right margin of the pancreatic neck, which is to the left of the pancreatic segment of the common bile duct (Fig. 3A). Theoretically, when determining the right incisal margin of the pancreatic neck, it is sufficient to position the pancreatic incisal margin to the left of the vertical line of the gastroduodenal artery to ensure that the pancreatic segment of the common bile duct is not damaged when the right incisal margin of the pancreas is dissected (Fig. 3B [4]). It has been shown that about 3% of the gastroduodenal arteries are traveled on the right side of the common bile duct[5]. Therefore, in practice, it is not completely certain whether the common bile duct injury and stenosis are actually caused. Our experience is : 1) According to the patient's CT and MRI before surgery, it is necessary to carefully identify: a. the travel of the common bile duct in the pancreas, b. measuring preliminarily the distance between the gastroduodenal artery and the common bile duct, c. identifying the approximate location of the tumor to determine the distance between the right incisal margin of the tumor and the common bile duct and whether it will exceed the vertical line of the gastroduodenal artery, d. whether there is variation in the gastroduodenal artery; 2) If the right incisal margin of the tumor may exceed the vertical line of the gastroduodenal artery, we generally use intraoperatively fluorescence imaging (indole green 2.5mg, intravenous bolus) to assist the visualization of the common bile duct (Fig. 4), and then proceed to dissect the pancreas after the common bile duct is completely visualized. According to the principle that fluorescence imaging can penetrate approximately 5–10 mm of tissue[6], if fluorescence appears during the dissection of the pancreas, it indicates that the incisal margin may be close to the common bile duct, and this would remind us of avoiding damaging the common bile duct during the dissection process. If there is extravasation of the contrast medium, it indicates that there may be a rupture in the common bile duct or even that the common bile duct is severed. 3) In the process of the dissection of the right margin of the pancreas, although there is no damage to the common bile duct, it may cause stenosis of the lower section of the common bile duct due to the heat conduction of the ultrasonic knife. In uncertain cases, we will use intraoperative cholangiography to determine whether the common bile duct is intact (Fig. 5). Of course, this method is not suitable for every operation, and it is only carefully chosen when there is a high suspicion of common bile duct stenosis, after all, the cholangiography process accompanied by the puncture and suture of the common bile duct which may also cause some degree of damage to the common bile duct.
The International Study Group of Pancreatic Fistula (ISGPS) has classified the degree of postoperative pancreatic fistula into 3 categories since 2016: 1) biochemical leakage: although the drainage fluid amylase is increased, it has no clinical significance, and it no longer specifically refers to pancreatic fistula; 2) grade B pancreatic fistula: need to change the postoperative treatment, continuous drainage for > 3 weeks, percutaneous or endoscopic puncture and drainage, angiographic intervention for hemostasis, no infection that caused organ failure; 3) grade C pancreatic fistula: second surgery, organ failure, and death[7]. The probability of postoperative pancreatic fistula is higher than that of other surgical procedures because the partial resection of the neck and body of the pancreas resulted in there are two severed ends in the pancreas. Our general approach was to use the continuous double-layer suture method to close the head of the pancreas with 3 − 0 gastrointestinal thread and the severed end of the body of the pancreas was anastomosed by the traditional duct-to-mucous Roux-en-Y pancreaticojejunostomy, and the silicone support tube was placed before anastomosis according to the size of the patient's pancreatic duct. The drainage tubes were placed separately below the pancreatic-intestine anastomotic stoma and the severed end of the head of the pancreas, and the wound was covered with the large omentum as much as possible so that it would not be too extensive even if the pancreatic fistula occurred after surgery. However, whether the method of covering with large omentum can really play a clinical role needs further study. On the postoperative day, the "somatostatin 3mg q12h micropump" was used to suppress pancreatic secretion (5–7 days), and then adjust the dose of somatostatin for "2mg q12h micropump" to prevent transient diarrhea (2–3 days) according to the volume of drainage fluid and amylase levels of the patient. Before removing the drainage tube, the whole abdomen CT is routinely reviewed to assess whether the patient has encapsulated fluid and if the patient does not have obvious encapsulated fluid in the operative area and one of the following conditions is met, the drainage tube can be removed: 1) the drainage volume of the abdominal drainage tube is < 10 ml/d for 3 consecutive days, and the amylase of the drainage fluid is < 500 U/L; 2) if the drainage volume of the abdominal drainage tube is < 10 ml/d for 3 consecutive days, but the amylase of the drainage fluid is > 500 U/L, the drainage tube should be pulled out for 1–2 cm daily until the lateral hole of the drainage tube is exposed on the patient's skin surface; (3) If the drainage volume of the abdominal drainage tube is > 10 ml/d and the amylase of the drainage fluid is > 500 U/L, the patient should be discharged from the hospital with the tube and self-record the drainage volume daily and review weekly in the outpatient clinic. When one of the first 2 conditions is met, the drainage tube can be removed.
In conclusion, laparoscopic central pancreatectomy is safe and feasible after careful preoperative planning and combined with the aid of intraoperative fluoroscopic laparoscopy and cholangiography, but the probability of postoperative pancreatic fistula is high and this operation needs to be performed by an experienced surgeon.