A pancreatic resection is an operation to remove part of the pancreas. It is mostly performed to treat pancreatic neoplasms or in selected patients with chronic pancreatitis. Removal of the entire pancreatic gland is uncommon, but may be necessary in some cases. Here are outlined the key steps of pancreatic resections. Click on the following links to obtain more information.
Panctreaticoduodenectomy (PD) is most commonly performed for pancreatic head and periampullary malignancy, but may also be indicated in select cases of chronic pancreatitis or benign periampullary tumors. It is a major operation that involves the removal of the head of the pancreas, the duodenum, the gallbladder and the common bile duct (Figure 1). A short length of small intestine beyond the duodenum is also removed. In the classic Kausch-Whipple operation, the pylorus (outlet of the stomach) and the distal (lower) part of the stomach are removed, while in the Longmire-Traverso operation (pylorus-preserving pancreaticoduodenectomy), the stomach and the pylorus are not removed.
After resection, the end of the remaining bile duct; the remaining pancreas and the stomach are then connected to the small bowel to ensure flow of bile, digestive juices and food into the intestines (Figure 2). Three anastomoses are constructed:
- Pancreatic anastomosis. The pancreatic remnant is anastomosed to the jejunum (pancreatico-jejunostomy) or to the posterior wall of the stomach (pancreatico-gastrostomy).
- Biliary anastomosis. Hepatico-jejunostomy is performed between common hepatic duct remnant and a site on the jejunum distal to the pancreaticojejunal anastomosis.
- Enteric anastomosis. In Whipple PD, an antecolic anastomosis is constructed between the stomach and the jejunum; in Longmire-Traverso PD, an antecolic duodeno-jejunal anastomosis is created.
Different technical modifications of reconstruction techniques have been proposed, but none resulted superior in meta-analyses. The choice of the reconstruction technique to adopt depends on the surgeon’s preference and institutional practices.
Figure 1. Whipple pancreaticoduodenectomy
Figure 2. Reconstruction after Whipple pancreaticoduodenectomy (pancreatico-jejunostomy)
Left (or distal) pancreatectomy is performed to treat pancreatic diseases of the tail and body. This operation involves surgical resection of the body and tail of the pancreas to the left of the superior mesenteric-portal vein confluence. Left pancreatectomy can be carried out with or without associated splenectomy. The choice of procedure depends upon the disease process, and the characteristics of the lesion.
- Left pancreatectomy with splenectomy: The spleen, which is located near this part of the pancreas and shares some of the same blood vessels, needs to be removed as part of the procedure when the underlying pancreatic neoplasm is aggressive. Left pancreatectomy with splenectomy enables ligation of splenic vessels at their origin and an adequate lymph node clearance (Figure).
- Spleen-preserving left pancreatectomy: This procedure is reserved for benign/borderline pancreatic lesions and cysts, and for localized neuroendocrine tumors. There are two distinct approaches to preserve the spleen during the dissection of the distal pancreas. The classic design is to identify, isolate, and preserve the splenic artery and vein (Kimura procedure). Alternatively, the splenic artery and vein are ligated with the pancreas, and perfusion of the spleen is assured by the short gastric vessels (Warshaw procedure). Both are accepted as appropriate techniques to address a mass in the tail of the pancreas.
The pancreatic stump can be either hand-sutured, closed with a stapler, or sealed with harmonic scalpel. These stump closure techniques seem to be equivalent.
Minimally invasive surgery is becoming the paradigm in left pancreatic resections (laparoscopic and robot-assisted left pancreatectomy). In the next future, the number of left pancreatic resection performed with minimally invasive techniques is likely to increase due to a variety of factors including increased operator experience across centres and acceptance of the technique on the basis of demonstrated outcomes in premalignant and malignant lesions. For more information on the minimally invasive pancreatic surgery click here.
Figure. Left pancreatectomy with splenectomy. Image taken from WebMD.
Total pancreatectomy involves the resection of the whole pancreas, the common bile duct, the gallbladder, the duodenum, a short segment of small intestine beyond the duodenum, the pylorus (outlet of the stomach), the distal (lower) part of the stomach, the spleen, and regional lymph nodes (Figure 1A).
After resection, the end of the remaining bile duct and the stomach are connected to the small bowel to ensure flow of bile and food into the intestines (Figure 2). Two anastomoses are constructed (Figure 1B):
- Biliary anastomosis. Hepatico-jejunostomy is performed between common hepatic duct remnant and a site on the jejunum.
- Enteric anastomosis. An antecolic anastomosis is constructed between the stomach and the jejunum; distal to the hepatico-jejunostomy.
Indications to single-stage elective total pancreatectomy include the presence of a multifocal neoplasm (intraductal papillary mucinous neoplasia, pancreatic metastases from clear cell renal carcinoma, neuroendocrine tumor in the setting of MEN1), or the presence of an intraductal papillary mucinous neoplasm involving the entire main pancreatic duct. Single-stage unplanned total pancreatectomy may be necessary after an initial partial pancreatectomy because of positive resection margins on intraoperative frozen section. Two-stage total pancreatectomy (completion pancreatectomy) is performed because of severe postoperative complications or neoplastic recurrence in the pancreatic remnant after previous pancreatic resection.
Total pancreatectomy is invariably associated with the development of exocrine insufficiency (inability to properly digest food) and endocrine insufficiency (diabetes mellitus). Management of pancreatic insufficiency include pancreatic enzyme replacement therapy and insulin therapy. Exocrine insufficiency and diabetes may be particularly hard to control in the first months after the operation, but studies have indicated that quality of life in the long term is satisfactory.
Figure 1. A: resection phase; B: reconstruction.
MIDDLE SEGMENT PANCREATECTOMY
Middle segment pancreatectomy consists of a limited resection of the midportion of the pancreas. This procedure allows a surgeon to preserve pancreatic parenchyma and consequently long-term endocrine and exocrine pancreatic function. Indications to middle segment pancreatectomy include benign and borderline neoplasms of the pancreatic body.
After identification and isolation of major vascular structures around the pancreatic body and neck, the segment of the pancreas with the tumor is transected to the left and to the right of the lesion (Figure 1A). The cephalic stump is sutured with interrupted stitches after elective ligation of the Wirsung’s duct or by means of a stapler.
The reconstruction phase involves one or two anastomoses:
- Pancreatic anastomosis. The pancreatic distal remnant is anastomosed to a jejunal Roux-en-Y loop (pancreatico-jejunostomy, Figure 1B) or to the posterior wall of the stomach (pancreatico-gastrostomy).
- Enteric anastomosis. After pancreatic-jejunostomy, the Roux loop is connected to the distal jejunum.
Figure 1. A: Middle pancreatectomy; B: reconstruction by pancreatic-jejunostomy on the distal stump
ENUCLEATION OF PANCREATIC NEOPLASMS
A pancreatic enucleation procedure is an operation designed to remove small (<2 cm), benign tumors of the pancreas. This procedure involves shelling out the tumor from the surrounding pancreas. For enucleation to be performed safely, the lesion should be at least 2-3 mm distant from the main pancreatic duct and not too deep in the parenchyma. If the lesion is too close to a duct, the risk of inadvertent ductal damage is substantial, and may result in a particularly hard to treat pancreatic fistula. Therefore, the distance between the tumor and the main pancreatic duct should be assessed preoperatively by means of magnetic resonance imaging with cholangio-pancreatography. Intra-operative ultrasound should be also performed to confirm the relationship between the neoplasm and the main pancreatic. Moreover, it allows clear identification of the lesion, and evaluation of its morphology and site.
The incidence of postoperative complications, particularly pancreatic fistula, is high, despite the majority of fistulas have an indolent course. The main advantage of enucleation is the preservation of almost all the pancreatic parenchyma, thereby minimizing the risk of long-term exocrine and endocrine insufficiency.
Enucleation can be performed using a minimally invasive approach. For more information click here.