Laparoscopic Duodenum-Preserving Pancreatic Head Resection via Inferior Infracolic Approach: A Surgical Approach for Benign Lesions

Abstract

Minimally invasive pancreatic resections are gaining popularity despite being technically demanding. However, in contrast to laparoscopic pancreatoduodenectomy (LPD), laparoscopic duodenum-preserving pancreatic head resection (LDPPHR) has not yet obtained wide acceptance. This could be attributed to the technical challenges involved in preserving the blood supply of the duodenum and bile duct.

This study describes and demonstrates all the steps of LDPPHR. A 48-year-old woman was diagnosed with a 3.0 cm x 2.5 cm pancreatic head cystic mass, which was detected unexpectedly. The surgery was performed using the 3D laparoscopy via an inferior infracolic approach. The operation lasted approximately 310 min with 100 mL of blood loss. Postoperatively, the patient experienced no complications and was discharged 5 days later. Pathology revealed intraductal papillary mucinous neoplasms.

LDPPHR via an inferior infracolic approach is feasible and safe when performed by experienced surgeons in selected patients with thin mesenteric fat layers. The described technique for LDPPHR via inferior infracolic approach should be well standardized and performed at high-volume centers with experienced surgeons in both open and laparoscopic pancreatology.

Introduction

In 1972, Prof. Berger first proposed the duodenum-preserving pancreatic head resection (DPPHR) and Roux-en-Y pancreatic-enteral reconstruction as a treatment for chronic pancreatitis¹. DPPHR has become the primary surgical treatment for benign lesions of the pancreatic head due to its low incidence of postoperative complications and mortality, as well as its ability to maintain the endocrine and exocrine functions of the pancreas and high remission rate of abdominal pain^2,3,4. DPPHR only removes the diseased pancreatic head while preserving the duodenum, stomach, jejunum, common bile duct, and gallbladder that need to be removed in Whipple surgery, resulting in minimal damage and high postoperative quality of life^3,5.

Laparoscopic duodenum-preserving pancreatic head resection (LDPPHR) has made significant progress in the last decade and is gradually replacing duodenum-preserving pancreatic head resection (DPPHR)^6,7. The key to this surgical procedure is to ensure the blood supply of the duodenum and bile duct in order to avoid damage to the duodenum and bile duct, as well as duodenal necrosis and stenosis or atresia of the bile duct caused by ischemia^7,8. A few experienced medical centers have reported LDPPHR^9,10,11. As maintaining the integrity of the duodenum and biliary system and preserving complex blood supplies are necessary, the surgical procedure is challenging. It is essential to be very familiar with the special anatomical relationship between the pancreatic head and the duodenum while implementing LDPPHR, which is a difficult surgery that requires stronger surgical skills and psychological qualities.

Previous studies have proved that preserving the integrity of both anterior and posterior pancreaticoduodenal arterial arcades, as well as only preserving the posterior collateral branches of the arteries, will not cause duodenal ischemic necrosis^11,12. Some surgeons preserve a thin layer of pancreatic tissue adhering to the common bile duct to avoid ischemia of the bile duct and duodenum but increase the incidence of pancreatic fistula¹³. In this study, the inferior infracolic approach was chosen for LDPPHR due to the patient with a thin mesenteric fat layer. By taking advantage of the amplification of the 3D laparoscopy, we successfully removed the pancreas from the lateral wall of the common bile duct (CBD) and the medial side of the duodenal ring without intraoperative fluorescence image guidance. This approach ensured the integrity of the vascular arch and reduced intraoperative blood loss, thereby minimizing the risk of pancreatic fistula.

Protocol

This protocol follows the guidelines of the human research ethics committee of the Sixth Affiliated Hospital, Sun Yat-sen University. Written informed consent was obtained from the patients for performing this study.

NOTE: A 48-year-old female patient presented with an incidental finding of a 3.0 cm x 2.5 cm asymptomatic mass in the head of the pancreas. The patient's clinical history showed a healthy status. Endoscopic ultrasound (EUS) showed a cystic lesion of the pancreatic head.

1. Preoperative workup

1. Determine the surgical approach based on the computed tomography (CT) scan to determine the extent of the tumor and any abnormal vasculature, see Figure 1.
2. Check for contraindications carefully.
   NOTE: There are relative contraindications to LDPPHR, including tumors in the portal vein or superior mesenteric vein that need vascular reconstruction, as well as previous major abdominal surgery with possible complications. It depends on preoperative imaging diagnosis and intraoperative diagnosis of vascular invasion. The preoperative enhanced CT and MR imaging are valuable.

2. Anesthesia

1. Apply the antibiotic (2 g of Ceftriaxone sodium) 30 min before the surgery to prevent infection. Puncture and catheterize the radial artery (catheter size, 20 G) and a central venous (catheter size, 8 Fr) under ultrasound guidance.
   NOTE: The amount of anesthesia administered differs greatly among patients, primarily dependent on individual characteristics such as age and other medical factors.

3. Surgical technique

1. Operation setting
   1. Position the patient in a reverse Trendelenburg position with the head elevated 30° and legs split apart, see Figure 2.
   2. Set the standing position as depicted in Figure 2. Use a 5-port technique to perform the procedure.
      NOTE: The first surgeon is on the right side, the second surgeon is on the left side, and the first assistant stands between the patient's legs, respectively.
   3. Place the sub-umbilical 10 mm trocar and then four trocars along a semi-circular plane after creating the pneumoperitoneum. Place two 10 mm trocars to the left and right of the umbilicus and two 10 mm trocars four fingers subcostal to the left and right in the anterior axillary line, see Figure 2.
2. Exploration phase
   1. Exclude peritoneal and liver metastases using diagnostic laparoscopy as a routine step. Explore the anterior abdominal wall, the surface of abdominal viscera, pelvic cavity, and the surface of abdominal viscera, the mesentery and the small intestine and stomach and adjacent structures, and the omental bursa in order.
      1. Ensure that the exploration follows a specific sequence, usually from top to bottom, first examining solid organs before hollow ones, starting with the abdominal cavity followed by the pelvic cavity.
      2. Conduct a comprehensive examination of all abdominal organs, such as the liver, spleen, stomach, intestines, mesentery, peritoneum, uterus, and adnexa. Simultaneously, perform a focused examination on suspicious areas of pathology.
      3. Utilize non-traumatic graspers to gradually inspect the intestinal tract, progressing in approximately 5 cm segments per examination from the duodenal suspensory ligament to the ileocecal region and repeating the process in the opposite direction. Ensure that the examination encompasses both the intestinal tract and mesentery.
   2. Retract the ligament to the ventral abdominal wall by placing a straight needle transcutaneously in the epigastric region around the Teres ligament.
3. Dissection phase
   1. Suspend the transverse colon enteric fat over the liver falciform ligament to expose the infracolic compartment (see Figure 3A).
   2. Make an incision in front of the duodenum's transverse mesocolon to expose the pancreatic head using an ultrasonic scalpel (see Figure 3B).
   3. Expose the infracolic compartment between the transverse colon and the pancreatic head, fully free the superior mesenteric vein (SMV) from the uncinate process of the pancreas, and transect its tributary using clips (see Figure 3C).
   4. Dissect the inferior margin of the uncinate process of the pancreas using an ultrasonic scalpel, and pull up the margin of the uncinate process of the pancreas to expose the sub pancreaticoduodenal vessels branch into the uncinate process of the pancreas and transect them using clips (see Figure 3D).
   5. Restore the transverse colon position and section the gastrocolic ligament to expose the pancreas behind the stomach. Position the patient's head low and right upside. Suspend the stomach body over the liver falciform ligament to set free it from the pancreas using a red urine catheter and a clip (see Figure 3E).
   6. Expose the common hepatic artery (CHA) and gastroduodenal artery (GDA) (see Figure 3F). Removed the pancreas from the medial side of the duodenal ring and anterior superior pancreaticoduodenal artery (ASPDA), and ligate and detach the branches of ASPDA into the uncinate process of the pancreas using a clip.
   7. Cut off the peritoneum at the lower margin of the pancreatic head, ligate, and detach the right gastroepiploic vein. Flip the uncinate process of the pancreas to the head side to expose the SMV to transect the pancreatic neck with Harmonic scissors in front of the SMV.
      NOTE: The cystic tumor was found behind the uncinate process of the pancreas (see Figure 3G).
   8. Detach the pancreatic head from the right and dorsal edges of the SMV. Then, detach the upper part to expose the distal CBD.
   9. Perform dissection along the left and dorsal margins of the common bile duct (CBD) to expose and safeguard the posterior superior pancreatic duodenal artery (PSPDA) (see Figure 3H). This artery originates from the GDA and extends its branches into the distal CBD and the ampulla of Vater. Severe the anterior superior pancreatic duodenal artery (ASPDA) to facilitate deeper dissection.
   10. Dissect, ligate, and cut off the main pancreatic duct to the ampulla finally using an ultrasonic scalpel (see Figure 3I).
4. Reconstruction phase
   1. Transect the jejunum at a distance of 20 cm from the distal Treinz ligament for pancreatojejunal anastomosis and jejunal anastomosis.
   2. Insert an external ventricular drainage catheter after identifying the main pancreatic duct. Perform an end-to-side pancreaticojejunostomy (duct-to-mucosa) (see Figure 3J) and side-to-side jejunojejunostomy.
   3. Place the specimen inside a bag and remove it through a 5 cm incision on the lower abdomen. Place two drainage catheters near the pancreaticojejunostomy and the CBD and bring them out through two trocar port sites.
      NOTE: The texture at the pancreatic stump is quite tough, so we perform an end-to-side pancreaticojejunostomy to reduce the risk of pancreatic fistula. The diameter of drainage catheters with side holes is 1.5 cm.

Representative Results

The patient's total pancreatic head, including the cystic tumor, was removed in 3 h with 100 mL of blood loss. The pancreatojejunal (PJ) anastomosis and jejunal anastomosis were completed in 60 min after the pancreatic head was removed from the body. The entire recovery period after surgery went smoothly, with no signs of postoperative pancreatic fistula. The amylase levels in both drains on postoperative day 3 were 1373 U/L and 804 U/L, respectively, but decreased to normal levels by day 5 when the drains were removed. The patient was discharged on the 6^th postoperative day.

Postoperative pathology revealed a 2.5 x 1.5 cm intraductal papillary mucinous neoplasm (IPMN) (see Figure 4A-D). Microscopically, the resection margins were radical (R0), and no lymph nodes had tumor cells. The patient's first postoperative imaging at approximately 1 month is shown in Figure 4E,F.

Figure 1: CT images. (A-D) showed low-density multiple intercommunicating cystic lesions within the uncinate process of the pancreas. Please click here to view a larger version of this figure.

Figure 2: Surgical position setting and trocar placement. Please click here to view a larger version of this figure.

Figure 3: Dissection phase of the surgery. (A) Suspend the transverse colon enteric fat over the liver falciform ligament to expose the infracolic compartment. (B) Dissect the anterior peritoneum of the duodenum horizontal part to expose the pancreatic head. (C) Transect SMV tributary using clips. (D) Transect the sub pancreaticoduodenal vessels branch into the uncinate process of the pancreas. (E) Suspend the stomach body over the liver falciform ligament to set free it from the pancreas using a red urine catheter and a clip. (F) Expose the common hepatic artery (CHA) and gastroduodenal artery (GDA). (G) The cystic tumor was circled with a blacked dashed line. (H) Expose and protect PSPDA. (I) The main pancreatic duct to the ampulla. (J) Set-up for the P-J anastomosis. Please click here to view a larger version of this figure.

Figure 4: Tumor sample. (A,B) Images of tumor sample, scale bars=1 cm.(C,D) The H&E staining of tumor sample, scale bars=100 µm. (E,F) Postoperative CT images. Please click here to view a larger version of this figure.

Duration of surgery	180 min
Blood loss	100 mL
Day of discharge	6 days
Rmovement of drainage tube	5 days
Tumor size	2.5 cm × 1.5 cm
Pathological type	intraductal papillary mucinous neoplasms (IPMN)
Lymphnodes metastasis	negative
First post-operative CT	1 month after operation

Table 1: Surgical outcomes and postoperative details of the patient.

Discussion

LDPPHR only removes the diseased pancreatic head while preserving the duodenum, stomach, jejunum, common bile duct, and gallbladder that need to be removed in Whipple surgery. Compared to pancreaticoduodenectomy (PD) and pylorus-preserving pancreaticoduodenectomy (PPPD), LDPPHR showed enhancements in mid- and long-term results encompassing hospital stay duration, quality of life, post-surgery recovery, and maintenance of exocrine function^5,14. DPPHR only removes the diseased pancreatic head, which reduces the extent of pancreatic resection and protects the physiological and anatomical integrity. This may explain why DPPHR has a better preservation of the exocrine function compared to PD¹⁵. It is still a challenging surgery due to the need to maintain the integrity of the duodenum and biliary system and preserve the complex blood supply. Classically, some pancreatic tissues are left on the duodenum side and in the distal CBD in Beger's procedure to preserve the pancreatic duodenal arterial arcade. It can provide adequate blood supply to the duodenum, distal CBD, and ampulla of Vater¹⁶.

By taking advantage of the amplification of the enhanced 3D laparoscopy, the pancreatic duodenal arterial arcade to the duodenum, distal CBD, and ampulla of Vater will be better preserved due to the clearer 3D vision. In addition, under clearer 3D vision, it is feasible that pancreas tissue would be removed from the lateral wall of the CBD and the medial side of the duodenal ring.

Just the same with open abdominal surgery, the key surgical points of LDPPHR are to ensure the blood supply in the duodenum and bile duct. It is reported that an important factor in avoiding ischemia is the preservation of the posterosuperior pancreatoduodenal artery¹⁷. In this case, we preserved the retropancreatic fascia along the CBD to ensure the blood supply and avoid injury to the CBD. Reliable pancreaticojejunostomy is an important factor in decreasing the pancreatic fistula rate.

To enhance the procedure of LDPPHR, the utilization of intravenous indocyanine green fluorescent can be implemented. This approach enables real-time navigation with fluorescent display, facilitating the guidance of surgical dissection and mitigating the risk of injury to the biliary tract^{9,11,18,19,20}. However, in cases of swelling of the pancreatic head, the fluorescence laparoscope remains less than satisfactory in protecting the lower segment of the common bile duct. By contrast, with a 3D laparoscopic imaging system, important structures can be preserved more easily, resulting in a faster continence recovery. There is no standardized approach for LDPPHR. LDPPHR is demanding with respect to surgical experience, proficiency in anatomy, and suturing skills. Also, it requires precise planning that relies on preoperative imaging. Due to the two limitations, it is not possible to perform this procedure at relatively low-level centers. Which approach will be chosen for LDPPHR likely depends on the local anatomy of the lesions of the pancreatic head. In our opinion, the inferior infracolic approach is more suitable for patients with a thin mesenteric fat layer since it is more convenient to dissect the inferior pancreaticoduodenal artery via the inferior infracolic approach.

The LDPPHR method is both safe and feasible for the treatment of benign lesions of the pancreatic head. However, further studies are needed in surgical methods, minimally invasive surgery, and preoperative patient selection to improve long-term outcomes.

Materials

Name	Company	Catalog Number	Comments
3D Laparoscope	STORZ	TC200,TC302
Cisatracurium Besylate Injection	Hengrui Pharma	H20183042
Drainage catheters	Jiangsu YUBANG MED-DEVICE	YB-B-III
Harmonic ACE Ultrasonic Surgical Devices	Ethicon Endo-Surgery	HAR36
Ligating Clips	Teleflex Medical
Nacrotrend anaesthesia monitoring system	Monitor Technik	Bad Bramsted
Trocar	Ethicon Endo-Surgery	10 mm