Pancreatitis Case File

Pancreatitis Case File

Eugene C. Toy, MD, Lawrence M. Ross, MD, PhD, Han Zhang, MD, Cristo Papasakelariou, MD, FACOG

CASE 22

A 30-year-old man is admitted to the hospital for severe constant abdominal pain with nausea and vomiting since the previous day. He states that the pain radiates straight to his back and feels “like it’s boring a hole right through me from front to back.” He reports no other medical problems, but drinks one or two 6-packs of beer each weekend. He denies having diarrhea or fever. The serum amylase and lipase levels are markedly elevated.

⯈ What is the most likely diagnosis?

⯈ What is the anatomical location of the structure involved?

ANSWER TO CASE 22:

Pancreatitis

Summary: A 30-year-old man who drinks alcohol is admitted to the hospital for

severe abdominal pain with nausea and vomiting for 24-h duration. He states that

the pain radiates straight to his back. The serum amylase and lipase levels are markedly

elevated.

• Most likely diagnosis: Acute pancreatitis

• Anatomical location of the structure affected: Retroperitoneal, posterior to the stomach and the lesser peritoneal sac (omental bursa)

CLINICAL CORRELATION

The pancreas is a retroperitoneal organ, posterior to the stomach and lesser sac, partly surrounded by the duodenum. It is an exocrine gland that secretes digestive enzymes and an endocrine gland that produces insulin and glucagon to regulate blood glucose levels. Noninfectious inflammation of the pancreas is most commonly caused by alcohol abuse or gallstones. The inflammation is secondary to autodigestion of the pancreatic tissue by the exocrine secretions. Marked vomiting is typical, and serum amylase or lipase levels are elevated. Immediate management includes restricting oral intake, monitoring fluid and electrolyte balance, and pain control. The pancreatitis sometimes may be so severe as to produce hemorrhage into the pancreas or pulmonary injury. These complications are associated with higher mortality rates.

APPROACH TO:

The Pancreas

Objectives

1. Be able to describe the anatomy of the pancreas and its relations to the duodenum and spleen

2. Be able to describe the retroperitoneal relations of the pancreas

DEFINITIONS

PANCREATITIS: Inflammation of the pancreas

RETROPERITONEAL: Posterior or external to the peritoneal cavity

OMENTAL BURSA: Subdivision of the peritoneal cavity posterior to the stomach and lesser omentum

DISCUSSION

The pancreas is a retroperitoneal gland that is exocrine (secretes digestive enzymes released into the duodenum) and endocrine (source of insulin and glucagon released into the bloodstream). It lies posterior to the omental bursa (lesser sac). The gland is anatomically divided into head, neck, body, and tail regions and is diagonally placed across the posterior abdominal wall (Figure 22-1). The head of the pancreas lies within the curve of the second and third parts of the duodenum, and its inferior portion forms a hooklike uncinate process that lies posterior to the superior mesenteric vessels. The neck lies at the L1 vertebral level, with the pylorus of the stomach immediately superior. The portal vein is formed posteriorly by the union of the splenic vein and superior mesenteric vein (SMV). The body of the gland passes superiorly to the left, with the tortuous splenic artery along its superior border. The short tail of the pancreas lies within the splenorenal ligament and may contact the hilum of the spleen (Table 22-1).

The exocrine pancreas is drained by a main pancreatic duct, which begins in the tail and passes to the right through the body, neck, and inferior portion of the head. The duct pierces the wall of the second part of the duodenum in close association with the common bile duct, with which it typically unites to form the hepatopancreatic ampulla, which, in turn, opens through the major duodenal papilla. Several smooth muscle sphincters surround these ducts, which may enter the duodenum separately at the papilla. The superior portion of the head is drained by an accessory pancreatic duct that usually joins the main duct but may drain separately into the duodenum at the minor duodenal papilla. The head of the pancreas receives

Figure 22-1. The pancreas and its blood supply. (Reproduced, with permission, from Lindner HH. Clinical Anatomy. East Norwalk, CT: Appleton & Lange, 1989:346.)

Table 22-1 • STRUCTURES POSTERIOR TO THE PANCREAS
Head	Neck	Body	Tail
IVC	SMA and SMV	Aorta	Splenic vein
Right renal vessels	Splenic vein	SMA
Left renal vein	Portal vein (formed)	Splenic vein Left kidney and suprarenal gland Left renal vessels

its arterial blood supply primarily from superior and inferior pancreaticoduodenal arteries from the celiac and superior mesenteric artery (SMA), respectively, whereas the neck, body, and tail receive branches from the splenic artery.

The duodenum is the first, shortest, widest, and least mobile portion of the small intestine. It is anatomically subdivided into four parts, and its C-shaped configuration is intimately related to the pancreas. The superior or first part is the posteriorly directed continuation of the pylorus of the stomach, and it lies at the L1 vertebral level. Its first portion or ampulla (clinically, the duodenal cap) is intraperitoneal, within the hepatoduodenal ligament. The remainder is retroperitoneal. The descending or second part is retroperitoneal, lies opposite L1 through L3, and receives the pancreatic and bile ducts (hepatopancreatic ampulla) at the major duodenal papilla on its posteromedial wall. The horizontal or third part is also retroperitoneal, passes to the left, and crosses L3. The SMA and SMV cross this part of the duodenum anteriorly. The ascending or fourth part lies on the left side of the L3 and L2 vertebrae and is retroperitoneal, except perhaps for the last few millimeters as it becomes continuous with the jejunum at the duodenojejunal junction, indicated anatomically by the suspensory ligament of Treitz. The clinically important relations of the duodenum are listed in Table 22-2. The duodenum is supplied by superior and inferior pancreaticoduodenal arteries from the celiac artery and SMA, respectively.

The spleen is the largest lymph organ of the body and functions as if it were a lymph node for the circulatory system. It is intraperitoneal, suspended in the left upper quadrant by the gastrosplenic and splenorenal ligaments (subdivisions of the greater omentum). It lies parallel to the 10th rib and overlaps the 9th and 11th ribs. It has a convex diaphragmatic surface and concave hilum, where the ligaments attach. The splenic artery (a major branch of the celiac artery) enters, and the splenic vein exits the spleen through the hilum and is within the splenorenal ligament, in addition to the tail of the pancreas.

Table 22-2 • ANATOMICAL RELATIONS OF THE DUODENUM
	Anterior	Posterior	Medial	Superior
Superior or first part	Gallbladder Quadrate lobe of liver	Bile duct Gastroduodenal artery Portal vein IVC		Epiploic foramen
Descending or second part	Transverse mesocolon Transverse colon Small intestines	Hilum right kidney Renal vessels and pelvis Right ureter Right psoas muscle	Head of pancreas Bile and pancreatic ducts
Horizontal or third part	SMA and SMV Small intestines	IVC and aorta Right ureter Right psoas muscle		Head and uncinate process of pancreas SMA and SMV
Ascending or fourth part	Root of mesentery	Aorta, left side Left psoas muscle	Head of pancreas	Body of pancreas

COMPREHENSION QUESTIONS

22.1 You are at surgery and are about to mobilize the second portion of the duodenum and the head of the pancreas. You note an artery and vein passing anteriorly to the uncinate process of the pancreas and the third portion of the duodenum. Which vessels are these?

A. SMA and SMV

B. Inferior mesenteric artery and vein

C. Gastroduodenal artery and vein

D. Superior pancreaticoduodenal artery and vein

E. Middle colic artery and vein

22.2 As you proceed to elevate the duodenum and pancreas, you note two veins posterior to the neck of the pancreas uniting to form a large vein that passes superiorly. Which large vein has been formed?

A. Splenic vein

B. IVC

C. Portal vein

D. Right gastric vein

E. Middle colic vein

22.3 As you continue, you also note a large, tortuous artery passing to the left along the superior border of the pancreas. This is likely to be which of the following?

A. Left renal artery

B. IMA

C. Splenic artery

D. Left gastroomental (gastroepiploic) artery

E. Left colic artery

22.4 A 34-year-old man is involved in a motor vehicle accident. He is brought into the emergency room and is noted to have a hematoma involving the pancreas. What is the most likely location of this hematoma?

A. Intraperitoneal midline

B. Intraperitonal right side

C. Intraperitoneal left side

D. Retroperitoneal midline

E. Retroperitoneal behind spleen

ANSWERS

22.1 A. The SMA and SMV emerge from between the head and uncinate process of the pancreas to cross the uncinate process and the third portion of the duodenum.

22.2 C. The portal vein is formed by the union of the superior mesenteric and splenic veins posterior to the neck of the pancreas.

22.3 C. The splenic artery, the most tortuous artery of the body, is located along the superior border of the pancreas as it passes to the left toward the spleen.

22.4 D. Abdominal and pelvic blunt-force trauma such as a motor vehicle accident is commonly associated with retroperitoneal hematoma, such as involving the pancreas. The pancreas is located in the retroperitoneal space, and hematomas are typically in the midline. CT imaging can be used to identify these injuries.

ANATOMY PEARLS

⯈ The pancreas is retroperitoneal, posterior to the omental bursa.

⯈ The splenic artery passes along the superior border of the pancreas, whereas the splenic vein lies posterior.

⯈ The portal vein is formed posterior to the neck of the pancreas.

⯈ The hepatoduodenal papilla (bile and pancreatic ducts) opens onto the major duodenal papilla on the posteromedial wall of the second part of the duodenum.

⯈ The second part of the duodenum is related to the right kidney hilum, pelvis and ureter, and renal vessels posteriorly.

⯈ The third part of the duodenum is crossed anteriorly by the SMA and SMV.

References

Gilroy AM, MacPherson BR, Ross LM. Atlas of Anatomy, 2nd ed. New York, NY: Thieme Medical Publishers; 2012:170−177. 

Moore KL, Dalley AF, Agur AMR. Clinically Oriented Anatomy, 7th ed. Baltimore, MD: Lippincott Williams & Wilkins; 2014:265−268, 282−283. 

Netter FH. Atlas of Human Anatomy, 6th ed. Philadelphia, PA: Saunders; 2014: plates 281, 284, 286−287, 289, 294.

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