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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_1367_Библиотеки_им_академика_М_И_Перельмана
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226 Gaw and Andersen
Chapter 20 / Pancreatic Surgery 227
20
Pancreatic Surgery
Janette U. Gaw, MD
and Dana K. Andersen, MD
CONTENTS
INTRODUCTION
PANCREATIC RESECTION
PANCREATIC DECOMPRESSION
PSEUDOCYST DRAINAGE
REFERENCES
INTRODUCTION
Operations on the pancreas are very serious operations, for several reasons. First, the
conditions for which operations are done are usually difficult medical problems. Most
operations, for example, are for pancreatic tumors. Although some of these tumors can
have a relatively benign natural history (neuroendocrine, cystadenomas, and cystodenocarcinoma), ductal adenocarcinoma of the pancreas, the most common tumor, is
difficult to cure with even the best surgery, and multimodality therapy. Operations are
also done for significant abdominal trauma that disrupts the pancreas, and for complications of either severe or intractable pancreatitis.
Second, operations on the pancreas usually involve the manipulation and dissection
of many anatomic structures deep in the back of the upper abdomen. They are, therefore,
often “large operations” from the standpoint of physiologic insult.
Finally, there is always the specter of pancreas-specific surgical complications. These
are the result of leaks from the pancreatic duct, from enteric anastomoses to the pancreatic duct, or from pancreatitis stimulated by the surgery. These complications are the
primary source of concern in the early postoperative period, and require experienced
teams to deal with them. Late complications are usually the result of pancreatic exocrine,
and endocrine insufficiency caused by the underlying conditions, the operation, or both.
Pancreatic surgery may be broadly categorized as either pancreatic resection or
pancreatic drainage or both. This chapter discusses some of the common operations
performed on the pancreas, indications, contraindications, as well as short- and longterm complications of these operations.
From: Clinical Gastroenterology: An Internist's Illustrated Guide to Gastrointestinal Surgery
Edited by: George Y. Wu, Khalid Aziz, and Giles F. Whalen © Humana Press Inc., Totowa, NJ
227
228 Gaw and Andersen
PANCREATIC RESECTION
Proximal Pancreaticoduoenectomy (Whipple Procedure)
Although pancreatic resection has been promoted by several surgeons in the last
60 yr, it was Kausch in Germany and Allen Whipple in the United States who successfully performed, and popularized the surgery for periampullary, and pancreatic head
carcinoma in 1909 and 1935, respectively. Since then, it has become the standard operation for carcinoma of head of pancreas. Pancreaticoduodenectomy and “Whipple procedure” are used synonymously, however, it is far more extensive surgery than the name
pancreaticoduodenectomy because it involves resection of the head, the neck and uncinate process of the pancreas; the distal bile duct and gall bladder; distal stomach, the
entire duodenum and proximal jejunum, followed by reconstruction (Fig. 1A). The
reconstruction generally consists of a pancreaticojejunostomy as the most proximal
anastomosis on the jejunal limb, followed by a choledochojejunostomy, and last, a gastrojejunostomy. A variation of the Whipple procedure is the pyloric sparing Whipple procedure in which the distal stomach is preserved to maintain normal gastric physiology.
Indications and Contraindications
The most common indication for a pancreaticoduodenectomy is resection of a tumor
of the head, neck, or uncinate process of the pancreas or periampullary tumors. Another
indication is chronic pancreatitis with imflammatory changes localized to the head of the
pancreas. Preoperative evaluation includes imaging for diagnosis, as well as staging and
determination of resectability.
The most common imaging modalities used include transabdominal ultrasound,
endoscopic ultrasound, computed tomography (CT) scan, magnetic resonance imaging
(MRI), and endoscopic retrograde cholargiopancreatography ERCP. CT scan is useful
both for the diagnosis and staging of pancreatic cancer. Endoscopic ultrasound is most
sensitive for evaluation of the local extent of the primary tumor.
Metastatic disease to the liver, peritoneum, and local invasion are contraindications
for a pancreaticoduodenctomy. However, various centers have different levels of
aggressiveness regarding portomesenteric vessel invasion and resection.
Another important aspect of preoperative evaluation is the determination of a patient’s
ability to survive the procedure. Debilitating acute or chronic diseases make the risk of
surgery unacceptable.
TANDARD WHIPPLE PROCEDURE
S
The procedure begins with an exploration of the abdomen for evidence of metastatic
disease or advanced local disease. This exploration may be initiated with a laparoscope.
The peritoneal cavity is inspected for ascitic fluid and peritoneal implantation of
metastasis. The liver surface is inspected. Following this, the extent of the tumor is
determined by mobilizing the head of the pancreas and the duodenum. The lesser sac is
entered, and the body and tail of the pancreas are examined, as well as the area of the
superior mesenteric vein, which passes under the neck of the pancreas. Invasion of
adjacent organs, superior mesenteric vessels, or portal vein is a contraindication for
resection in most centers. Once a determination has been made to resect the tumor, the
stomach is divided approx 5–7 cm from the pylorus. The biliary tract is then divided at
the common hepatic duct level. A cholecystectomy is performed. Next, the pancreas
Chapter 20 / Pancreatic Surgery 229
Fig. 1. Whipple procedure. (A) Standard Whipple procedure. (B) Pylorus sparing Whipple procedure.
is transected at the level of the superior mesenteric vein. Transection of the jejunum
10–15 cm distal to the ligament of Treitz completes the resection. Reconstruction is
achieved by bringing the jejunal limb either anterior to the transverse colon (antecolic)
or through the mesocolon (retrocolic). A pancreatico-jejunostomy is performed first,
followed by a choledacojejunostomy. Finally, a gastrojejunostomy is performed.
Given that most complications arise from the pancreaticojejunostomy, several different techniques have been described. As an alternative to the pancreaticojejunostomy
reconstruction, some surgeons perform a pancreaticogastrostomy. Both techniques yield
similar results.
YLORUS SPARING WHIPPLE PROCEDURE
P
A modification of the standard Whipple procedure involves preservation of the pylorus
and the proximal 2 cm of the duodenum (Fig. 1B). The advantages over the classical
Whipple procedure include preservation of the stomach reservoir and the pylorus, and
theoretically, maintaining a more normal gastric emptying, and hormonal control. The
reconstruction is similar to the classical pancreaticoduodenctomy except that instead of
a gastrojejunostomy, a duodenojejunostomy is performed. The theoretical disadvantage
is the inadequacy of margins during a resection for cancer. Randomized trials of the
pylorus-sparing and standard Whipple procedure have failed to reveal any differences
in outcome or morbidity.
Complications
The postoperative mortality rate is about 2–5%. The morbidity rate is about 20–50%
(1–3). Advanced age is no longer a contraindication, and recent series have increasingly
included octogenarians. Complications not specific to the procedure include cardiopulmonary events, postoperative bleeding, and infectious complications. Because of the
complex nature of the resection and reconstruction, complications can originate from
230 Gaw and Andersen
each of the different anastomoses. Leakage from the choledochojejunal anastomosis
occurs in 5–8% of patients, but is usually managed nonoperatively as most of these
resolve spontaneously. The pancreaticojejunal anastomosis leak presents a more challenging problem. The incidence of pancreatic fistula is reported to be between 3–20%,
and can result in postoperative death caused by infection and bowel injury. A reoperation
can be prevented if there is adequate drainage of the leak. Supportive care is initiated with
hyperalimentation and administration of octreotide.
Another problem seen postoperatively is delayed gastric emptying. This has been
postulated to be secondary to a deficit in an enteric hormone, motilin, in pancreatic
cancer. Erythromycin, a drug with motilin-like activity, has been recommended to
manage this problem.
Late complications of the procedure include alkaline reflux gastritis, marginal ulcers,
dumping syndrome, gastric outlet obstruction, and pancreatic fistula.
Cost
Average hospital cost is between $20,000 and $72,000 (4–7). It has been shown that
centers that perform pancreaticoduodenectomies more frequently incur a lower hospital
cost, shorter stay, and lower morbidity.
Summary
1. The reconstruction involves three anastomoses: pancreaticojejunostomy, gastrojejunostomy, and choledochojejunostomy. Leakage from these anastomoses is associated with
significant morbidity and mortality.
2. Whipple’s procedure is indicated for pancreatic carcinoma and other malignancies of the
pancreas as well as benign diseases such as chronic pancreatitis.
3. Although the morbidity and mortality is low with advancement in the technical and
supportive care for the critically ill patients, the 5-yr survival rate for carcinoma head of
pancreas is still low as the diagnosis is often delayed.
Distal Pancreatectomy
Distal pancreatectomy involves resection of the body and tail of the pancreas (Fig. 2).
It is a less-morbid procedure than proximal pancreatic resection and is performed for
either a benign or a malignant lesion of the body and tail of the pancreas.
Indications and Contraindications
Distal pancreatectomy is indicated for lesions at the body and tail of the pancreas. If
the lesion is malignant, it must be ascertained whether or not the lesion is metastatic. In
addition, a locally advanced lesion usually precludes a resection. This includes invasion
into the duodenum, involvement of the celiac axis, common hepatic artery or portal vein.
Adenocarcinoma of the pancreas occurs less frequently at the tail of the pancreas,
however, most of the tumors are large and advanced at diagnosis and less likely to be
resectable, as they do not cause any obstructive symptoms. Cystic lesions and islet cell
tumors of the body and tail of the pancreas are more typically amenable to distal
resection.
Distal pancreatectomy may also be indicated for chronic pancreatitis in selected cases
where the disease is clearly limited to the body and tail. This may result following
abdominal trauma with partial disruption of the pancreatic duct at the neck.
Chapter 20 / Pancreatic Surgery 231
Fig. 2. Distal pancreatectomy. (A) Abdominal exploration for resectability. (B) Splenic mobili-
zation and ligation of splenic artery and vein. (C) Pancreatic resection and pancreatic stump
closure. (D) Step 4. Splenic sparing distal pancreatectomy.
Management of a pseudocyst at the tail of the pancreas may also involve a distal
pancreatectomy. This is done when the cyst is small, and lies farther to the left. The
advantage of a resection includes the removal of the diseased gland associated with
the pseudocyst. However, a pseudocyst that is large or that is located fairly midline is
more amenable to a drainage procedure. A cyst that is suspicious for a cystic neoplasm
should be resected.
Trauma to the pancreas that involves the body and tail can also be managed with a
distal pancreatectomy.
Distal pancreatectomy may be performed with en-bloc splenectomy or without splenectomy depending upon the involvement of the spleen and the nature of the disease
(benign vs neoplastic).
N-BLOC SPLENECTOMY
E
The abdomen is first explored for any evidence of metastatic disease. Also, the local
extent of the tumor is determined. Invasion of the duodenum or encasement of the major
vessels precludes resection (Fig. 2A). Once it is determined the resection is possible, the
splenic artery and vein, and the short gastric vessels are ligated, and the spleen is mobilized from the retroperitoneum (Fig. 2B). This facilitates the mobilization of the tail of
the pancreas. The pancreas is then divided at the neck and the margin is sent for a frozen
section. If the margins still contain tumor, further resection is performed. The pancreatic
232 Gaw and Andersen
stump is then closed using either sutures or a stapler (Fig. 2C). No anastomosis is
performed if the proximal pancreatic duct is patent.
PLENIC-SPARING DISTAL PANCREATECTOMY
S
The spleen may be preserved if the procedure is performed for benign disease (Fig. 2D).
A spleen-sparing distal pancreatectomy may be performed laparoscopically or by an open
technique. The procedure requires dissecting the distal pancreas from the splenic vessels,
which may prove to be difficult. Conservation of the spleen may not be possible because
of the bleeding that may be encountered from the splenic vessels.
Complications
The mortality of the procedure is low, 0–5% (8–10). The complications include hemorrhage, infection, and pancreatic fistula, which occur in about 5% of the cases (11). Late
complications are secondary to the endocrine and exocrine insufficiency, however, risk
of diabetes is less than for proximal pancreatectomy.
Summary
1. Distal pancreatectomy involves resection of the body and tail of the pancreas and may
be performed with or without splenectomy.
2. It is well tolerated and has a low mortality and morbidity rate.
3. The spleen may be preserved in surgery for benign diseases.
Total/Subtotal Pancreatectomy
The first total pancreatectomy was performed in the 1940s although a near total
pancreatectomy is attributed to Billroth in 1884. It was advocated in the 1950s because
of the belief that pancreatic cancer is a multicentric disease, and a curative resection
requires a total pancreatectomy. It also includes a more extensive lymphadenectomy
which theorectically decreases the risk of local recurrence. In addition, problems with
the pancreaticojejunal anastomosis are eliminated, but with the added cost of significant
metabolic disorders, exocrine insufficiency, and diabetes in 100% of cases.
A total pancreatectomy involves removal of the entire gland, the duodenum, distal
stomach, distal bile duct, spleen, and the greater omentum (Fig. 3). This procedure was
largely abandoned after a high mortality rate was observed both early and late. The
metabolic changes that ensue are also challenging to control. As many as 50% of all of
the late deaths that occur after total pancreatectomy are a result of “iatrogenic hypoglycemia.” Moreover, a survival benefit over the Whipple procedure has not been demonstrated for similar stage tumors of the proximal pancreas. Hence, the indication for a total
pancreatectomy currently is the finding of carcinoma in the margin of a proximal pancreatectomy in a patient who can tolerate the metabolic demands of a complete resection.
Indications and Contraindications
Total pancreatectomy may be indicated in cases where there is obvious tumor along
the main pancreatic duct, and disease-free margins cannot be obtained. Rarely, a giant
cystadenocarcinoma or sarcoma extends along the whole gland, and requires a complete
resection. It may also be performed if the pancreatic remnant is friable, and will not hold
sutures for a safe reconstruction. Total pancreatectomy may also be required for diffuse
Chapter 20 / Pancreatic Surgery 233
Fig. 3. Total pancreatecctomy. (A) Mobilization of pancreas and duodenum with antrectomy. (B) Cho-
lecystectomy, transection of common hepatic duct, jejunum and splenic resection. (C) Reconstruction
with choledochojejunostomy and gastrojejunostomy.
intraductal papillary mucinous tumor of the pancreatic duct. Additionally, it may be used
to control a postoperative pancreaticojejunostomy leak.
Total pancreatectomy may also be considered for symptomatic chronic pancreatitis,
which is refractory to medical therapy. Because the latter is a benign disease, a modification (near total or subtotal pancreatectomy) is advocated by many surgeons, which
involves preserving the duodenum and the spleen. However, a subtotal pancreatectomy
should not be the procedure of choice if the duodenum or the distal common bile duct
are involved in the inflammatory process. As will be discussed later, different types of
parenchyma-preserving surgery are performed for chronic pancreatitis. However, total
pancreatectomy may be indicated in cases where a partial pancreatectomy has failed. In
addition, some surgeons recommend a total pancreatectomy in patients with diffuse
parenchymal disease who already have pancreatic endocrine and exocrine insufficiency.
At some centers, total or subtotal pancreactectomy may be combined with autologous
islet transfusion to prevent diabetes.
Procedure
For total pancreatectomy, the resectability of the tumor is first determined after the
peritoneal cavity is entered. The duodenum and head of the pancreas are mobilized using
the Kocher maneuver as described for the Whipple procedure. An antrectomy is performed (Fig. 3A), or the pylorus is preserved, as for the Whipple procedure. A cholecys-
234 Gaw and Andersen
tectomy is also performed, and the common hepatic duct is transected. The jejunum is
transected distal to the ligament of Treitz. The spleen is mobilized, and is included in the
enbloc resection (Fig. 3B). Reconstruction involves a choledochojejunostomy and either
a gastrojejunostomy or a duodeuojejunectomy if the pylorus is preserved (Fig. 3C).
A subtotal pancreatectomy involves resection of 95% of the pancreas, and preserves
the duodenum (Fig. 4). The tail and body of the pancreas are removed as described in the
Distal Pancreatectomy section. As the dissection approaches the ampullary region, the
common bile duct is identified, and preserved. The pancreatic duct at the ampulla is
divided and oversewn.
Complications
Historically, total pancreatectomy carries a high mortality, in the range of 25%. More
recently, the mortality in experienced hands has been reported at about 2–5% (1–5,12,13).
The morbidity is reported to be around 30–50% (12–14). Intraoperative and postoperative hemorrhage is a common complication with total pancreatectomy although the
incidence is reduced if performed by an experienced surgeon. Patients can also develop
infection complications from an intraabdominal source. Anastomotic leaks from the
gastrojejunostomy or choledochojejunostomy can also occur. Other complications
include cardiopulmonary complications, delayed gastric emptying, gastrointestinal
bleeding, and “brittle” diabetes.
A large part of the morbidity from total pancreatectomy, however, arises from the
metabolic derangements that result from the procedure. Both hyper- and hypoglycemia
can be life threatening. During the immediate postoperative period, patients will benefit
from frequent blood glucose measurements, and an insulin drip for tight control of the
blood sugar. Sliding-scale doses of insulin are discouraged initially because the response
to insulin administration can be erratic.
Patients will develop malabsorption and steatorrhea after total pancreatectomy, and
will require pancreatic enzyme replacement with each meal and snack. After several
months, the requirement should stabilize, although continued surveillance for the maintenance of body weight and evidence of hypoglycemia is mandatory.
Long-term management of diabetes can be particularly difficult. Hypoglycemic episodes can be frequent as a result of enhanced peripheral sensitivity to insulin, and the
loss of pancreatic glucagon. However, ketogenic episodes are rare. Patients should be
instructed to eat frequent small meals regularly. They should also carry snacks with
them in case any symptoms of hypoglycemia should occur.
Summary
1. Total pancreatectomy has a historically high mortality and morbidity.
2. Even though the mortality has improved, the physiologic derangements that follow make
it a highly morbid procedure.
3. At this time, there are limited indications for total pancratectomy. These include a diffuse
malignancy, or as a last resort, for chronic pancreatitis. When performed for benign
disease, it may be combined with autologous islet transplantation.
Duodenum-Sparing Proximal Pancreatic Resection
Up to one-third of patients with chronic pancreatitis can develop an inflammatory
mass predominantly at the head of the pancreas. The pancreatic head becomes enlarged,
Chapter 20 / Pancreatic Surgery 235
Fig. 4. Subtotal pancreatectomy.
and develops parenchymal calcifications, ductal calculi, and necrosis. When resection
is considered, some centers advocate a pancreaticoduodenectomy. However, given that
chronic pancreatitis is a non-malignant disease, a Whipple procedure may be excessive.
The duodenum-sparing pancreatic head resection spares the stomach, duodenum, and
the biliary tree, and results in decreased morbidity and mortality, but allows removal of
the central portion of the diseased pancreatic head.
Indications and Contraindications
The most common indication for a duodenum-sparing pancreatic head resection is
intractable pain caused by chronic pancreatitis. However, this operation is also performed for premalignant ductal, cystic, or solid lesions of the head of the pancreas, or
for endocrine tumors of the pancreatic head. Several variations of this operation are
discussed here.
UODENUM-PRESERVING PANCREATIC HEAD RESECTION (BEGER PROCEDURE)
D
First described by Hans Beger in 1972, the procedure involves exposure of the pancreatic
head, and mobilization of the pancreatic neck. The pancreas is transected at the level of the
neck, and a subtotal resection of the pancreatic head is performed (Fig. 5A). The uncinate
process may be included in the resection, and the intrapancreatic common bile duct is exposed
and preserved. A small rim of pancreas is left on the duodenum, as well as the posterior branch
of the gastroduodenal artery to preserve the blood supply of the duodenum. Reconstruction
involves one or two Roux-en-Y pancreaticojejunal anastomoses, one to the neck of the
pancreas, and usually another to the rim of pancreatic head (Fig. 5B). In cases where there
is a stenosis of the common bile duct, a choledochojejunostomy can also be performed. If the
main pancreatic duct is dilated and multiple stenosis exists, then a longitudinal decompression with a side-to-side anastomosis is also performed.
Complications
The perioperative mortality is reported to be 1% in a large series (15). Early complications include bleeding, anastomotic leakage, and abscess. Ischemia of the duodenum
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