Clinical Cases - Duodenum, Pancreas, Liver, & Gallbladder
M.S., a generally healthy 74-year-old woman, visited her physician with the following complaints: progressive jaundice over the last week or so, frequent bowel movements with pale, greasy feces, a lack of energy, weight loss, and back pain. The physician ordered a series of tests, which suggested that the jaundice was of an obstructive, not metabolic, nature. Abdominal ultrasound demonstrated the presence of a growth on the head of the pancreas, and further tests indicated that the lesion was a pancreatic carcinoma . After consultation with a surgeon, M.S. elected to have a cholecystojejunostomy performed to correct the obstruction and prevent the discomfort and pruritis that usually accompany obstructive jaundice. The pancreatic tumor was deemed inoperable, and M.S. was referred to her local hospice for assistance as her disease progressed.
Questions to consider:
- How does the tumor in the head of the pancreas relate to the jaundice experienced by the patient?Tumors in the head of the pancreas often obstruct the common bile duct, resulting in blockade of the normal bile recycling circuit. This blockade prevents excretion of bilirubin, a yellow-colored pigment that is a red blood cell breakdown product. The accumulation of bilirubin in various tissues, including the skin, causes jaundice.
- How might the pancreatic carcinoma relate to M.S.'s back pain?Compression of somatic nerves on the posterior abdominal wall as a pancreatic carcinoma expands would likely cause back pain.
- Pancreatic carcinomas frequently metastasize to the liver, resulting in significant hepatomegaly. Why is the liver a common target for metastasis?Blood-borne metastases from a pancreatic tumor would enter the portal vein via either the splenic or superior mesenteric vein. All blood in the portal system filters through the liver before entering the inferior vena cava. The liver's microscopic structure makes it a likely resting place for wandering tumor cells.
- What other organs, due to their proximity to the pancreas, may be susceptible to invasion by a pancreatic carcinoma?The structures in the immediate vicinity of the head of the pancreas, including duodenum, common bile duct, spleen, suprarenal gland, transverse colon, and stomach are all vulnerable to invasion by a pancreatic carcinoma.
- What important structures are at risk for compression by an expanding pancreatic carcinoma?The common bile duct, pancreatic duct, portal vein, and inferior vena cava are all susceptible to compression by an expanding pancreatic carcinoma.
A fifty-six year old, slightly obese female presents to your clinic with complaints of nausea, epigastric pain, vomiting, and tenderness, which she describes as radiating or boring through her back for the past 24 hours. She reports she is not on any medications, does not use alcohol, has made no recent trips outside of the country and that her total cholesterol was elevated (greater than 200) on her last trip to the physician's office. On physical exam you note, that she is slightly tachycardic (110), BP - 100/60, and her temperature is 101.5. You note that she is slightly jaundiced and has slight abdominal distension. She has diminished bowel sounds, and on palpation she is tender but has no rebound pain and does not guard her abdomen. The physician you are working with suspects the patient is suffering from pancreatitis secondary to gallstones . The physician orders serum and urinary amylase, serum lipase, glucose, calcium levels, WBC , bilirubin, - all of which are elevated except for the calcium, which is lowered. In addition he orders an ultrasound and CT. The patient's CT demonstrated that some pancreatic tissue did not enhance with IV contrast - the physician informs you that this is indicative of necrotizing pancreatitis . The patient was referred to a surgeon and taken to the O.R. for surgical debridement and placed on antibiotics.
Questions to consider:
- What are some causes of pancreatitis?
- What was the likely primary cause in this case?
Blockage of the common bile duct by gallstones, which caused a reflux into the pancreas or blocked the pancreatic duct.
- What structures could be affected by this disease process?
Uncinate process, head of the pancreas, bile duct, duodenum, and mesenteric vessels and spleen, as the inflammation spreads via vascular pathways.
- Describe the blood supply to the head, body and tail of the pancreas :
Head: Supplied by the gastroduodenal artery (from common hepatic branch of celiac trunk), which gives off the posterior superior and anterior superior pancreaticoduodenal arteries. The superior mesenteric artery also supplies the head via the anterior and posterior inferior pancreaticoduodenal arteries.
Body/Tail: The dorsal pancreatic artery, a branch of the splenic artery sends a branch to the left that forms the inferior pancreatic artery. Branches of the splenic artery and the inferior pancreatic artery in turn provide multiple branches to the tail.
A 48-year-old male with a history of alcoholism is brought into the ER with severe epigastric pain and hematemesis. Upon physical examination you find him to be jaundiced and tachycardic with low blood pressure. Other physical findings include spider nevi (hemangiomas) on the cheeks, neck, upper extremities, and torso; ascites; splenomegaly; and tortuous dilated veins radiating from the umbilicus (caput medusae ). The patient also tells you that he often has bloody stools, which prompts you to perform a rectal examination during which you find internal hemorrhoids. After completing your work-up, you correctly make a diagnosis of alcoholic cirrhosis of the liver.
Questions to consider:
- Discuss the etiology of the following symptoms considering the anatomy of the portal venous system: hematemesis, caput medusae, internal hemorrhoids.Destruction of hepatocytes due to excessive alcohol ingestion leads to replacement of normal tissue by fibrous tissue followed by hardening and contraction of the tissue around hepatic vessels which causes increased resistance to blood flow through the liver, or portal hypertension. This forces shunting of blood from portal to systemic venous systems and the engorgement of the portocaval anastomoses, since that is the path of least resistance. The major portosystemic anastomoses occur between the following veins :
PORTAL SIDE SYSTEMIC SIDE Superior rectal vein Middle and inferior rectal veins - To IVC Esophageal tributaries of the left gastric vein Esophageal veins - To Azygos vv. - SVC Paraumbilical veins Subcutaneous veins of anterior abdominal wall - To IVC
Engorgement of these shunts causes varicosities between the mucosa and muscular wall of the bowel and predisposition to rupture which explains the symptoms of hematemesis and internal hemorrhoids. Caput Medusae are from varicosities of subcutaneous veins in the area of the navel.
- What is the cause of ascites and splenomegaly?When portal hypertension occurs, the high pressure is transferred to the splenic, superior mesenteric, and inferior mesenteric veins. This causes fluid to ooze out of the capillary beds and accumulate in the abdominal cavity. Also, as the portal system does not have valves, the increased pressure in the splenic vein causes engorgement and subsequent enlargement of the spleen.
- Suggest possible treatments for lowering the blood pressure in the portal system.Surgically creating a shunt between the high pressure portal system and the low pressure systemic veins: Portocaval anastomosis (between the portal vein and the inferior vena cava) or splenorenal anastomosis (between left renal and splenic vein).
A forty year old slightly obese female presents to your E.R. with spasmodic, colicky pain in her right upper quadrant, with some right shoulder discomfort and accompanying nausea and vomiting. She reports that she has been running a fever over the past twenty-four hours. On physical exam you note heart rate 110, blood pressure 110/70, respiratory rate 20, and temperature 102. She is noticeably uncomfortable on deep inspiration, and palpation reveals an increase in pain while palpating the RUQ. The physician suspects that the patient is suffering from an acute episode of cholecystitis and orders an ultrasound study; ; the study reveals a large stone lodged within the cystic duct. The patient is prepped for a laparoscopic cholecystectomy.
Questions and answers:
- What is cholecystitis , and what are some of its causes?
Cholecystitis means inflammation of the gallbladder. This generally occurs as a result of the formation of gallstones that become lodged in a portion of the gallbladder and block passage of bile through the cystic duct.
- What is the clinical presentation of cholecystitis?
Nausea, vomiting, fever, colicky spasmodic pain to the right upper quadrant which does not tolerate deep palpation, and possibly an enlarged gallbladder.
- What is the most common clinical diagnostic test?
Ninety percent of the time an ultrasound of the gallbladder is an accurate means to assess the presence of a gallstone; in other instances either nuclear medicine scans with radioactive nucleotide contrast or endoscopic retrograde cholangiopancreatography (ERCP) may be useful to diagnose the presence of gallstones.
- What three parts of the gallbladder would be visualized on ultrasound?
The fundus, body, and neck.
- Why might the patient experience right shoulder discomfort?
The primary nerves that innervate the gallbladder originate from the celiac plexus (which provides sympathetic innervation), and the vagus nerve (provides parasympathetic). Sensory innervation is provided by the right phrenic nerve (C3, 4, 5). The stimulation of the right phrenic nerve is responsible for the referred pain to the right shoulder.
- During a laparoscopic cholecystectomy the surgeon is responsible for dissecting out the cystohepatic triangle (of Calot) ; can you define the borders of the triangle ?
Cystic duct inferiorly, liver superiorly, and hepatic duct medially. Identification of these structures as well as the major blood vessels ensures minimal damage to the bile duct.
Woodburne & Burkel, p. 460-6
Robbins Pathology, p.905-7
Updated: 11January 2012
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