Chapter 13 Flashcards
What is extremely prevalent?
Hepatic arterial anatomic variation
Where are the liver and gallbladder located?
RUQ
What does bile do?
Produced by the liver and stored in the gallbladder
Critical for the absorption of fats
Function of CCK
Released by the intestine in response to ingested fats
Causes the gallbladder to contract and propel bile through the cystic duct, into the common bile duct, and eventually into the duodenum
Central roles of the liver
Nutrient and drug metabolism
Synthesis of coagulation proteins
Detoxification of the blood
Pathway of the blood supply of the liver in m.ost people
Arterial blood from the aorta reaches hepatobiliary system via the right and left hepatic arteries, which are terminal branches of the proper hepatic artery
Blood supply of the gallbladder
Supplied by the cystic artery, which commonly arises from the right hepatic artery
Cystic artery courses through the triangle of Calot
What is the triangle of Calot composed of?
Inferior border of the liver
Common hepatic duct
Cystic duct
Pathway of replaced or recurrent left hepatic artery
Courses from the left gastric artery through the hepatogastric ligament
Pathway of replaced or recurrent right hepatic artery
When it branches off the SMA, frequently travels to the right of the common bile duct in the lateral hepatoduodenal ligament
Venous blood supply of the liver
70% of its blood supply via the portal vein
How is deoxygenated blood from the liver drained?
Drained by three large intraparenchymal hepatic veins (right, middle, left) that empty in the IVC
Where do veins of the gallbladder penetrate?
Penetrate the hepatic parenchyma in the vicinity of the gallbladder fossa
Morphologic vs functional classification of the liver
Morphologic: Divides liver into four lobes; lobes are separated by external fissures or ligaments
Functional: Divides liver into eight segments that are supplied by distinct branches of the arterial and portal blood supply.
How are segments of the liver separated according to the functional classification?
By the vertically oriented portal scissurae containing the hepatic veins and the transversely oriented portal pedicles containing the portal vein branches within the hepatic parenchyma
In the functional classification of the liver, what constitutes the right hemiliver?
What constitutes the left hemiliver?
Segments 5-8
Segments 2-4
What is the surgeon’s initial priority in evaluating the patient with hepatobiliary dz?
Determine whether pt has necrotic or infected tissue
If biliary obstruction with infection is present
If there is acute liver failure
What are the two frequently utilized diagnostic modalities in the pt who is acutely ill in order to determine if infection, a bile leak or biliary obstruction is present?
Serum bilirubin level
HIDA or DISIDA scan
RFs for the development of symptomatic gallstone dz
Obesity
Rapid weight loss or gain
Estrogen exposure
Classification of gallstones
Classified by their composition:
- Cholesterol stones
- Pigment stones
Further subdivision of pigment stones
Black or brown pigment stones
When do gallstones become symptomatic?
When they obstruct ductal structures
Presentation of biliary colic
RUQ pain, nausea and vomiting that commonly begins a few hours after a fatty meal but ultimately regresses spontaneously once the gallstone dislodges from the cystic duct
What is the term when gallstones intermittently obstruct the cystic duct?
Biliary colic
Tx of choice for cholelithiasis
Elective cholecystectomy
Sx of cholecystitis
Initially resemble those of biliary colic; however the pain persists for hours to days without resolution
PE of cholecystitis
Murphy’s sign
Febrile
Leukocytosis
What is often diagnostic of cholecystitis?
U/s
How is cholecystitis definitively diagnosed?
HIDA scan
When can a HIDA scan be frequently falsely negative?
Acalculus cholecystitis
Emphysematous cholecystitis
Persistent cystic duct obstruction leads to increased intraluminal pressure in the gallbladder, which can lead to ischemia of the gallbladder wall with subsequent perforation or necrosis
When should laparoscopic cholecystectomy be performed?
Within 24-72 hrs of hospital admission
Pattern of complication rates with cholecystectomy
Increase with greater delays before cholecystectomy
What is a possible definitive therapy for acalculous cholecystitis?
Cholecystotomy drainage
Also an option for inoperable cholecystitis pt
What is pathognomonic for gallstone ileus and should prompt exploratory laparotomy?
Plain radiograph demonstrating small bowel obstruction and air in the biliary system
What should be performed after the discovery of a gallstone ileus?
Enterolithotomy to remove the gallstone or resection of the affected intestinal segment
What is usually delayed in a gallstone ileus?
Cholecystectomy
Tx for suspected choledocholithiasis
Common duct stones may be retrieved via urgent ERCP
Alternatively, surgeon may explore the bile duct at time of either laparoscopic or open cholecystectomy
What may be useful in cases with complex ductal anatomy and to evaluate for choledocholithiasis and bile duct injury or pathology?
Intraoperative cholangiography
In a laparoscopic cholecystectomy, what should be done prior to division of structures?
Obtain the critical view of safety
When is conversion to open approach indicated in cholecystectomy?
When the delineation of ductal anatomy is difficult or if significant bleeding develops
Complications of laparoscopic cholecystectomy
Cystic duct stump leaks
Iatrogenic injury to surrounding ductal structures
Presentation of cystic duct stump leaks
Present 3 days after procedure with abd pain, fever, and/or vomiting
Confirmation of cystic duct stump leaks
HIDA scan
ERCP
Management of cystic duct stump leaks
ERCP stenting of the common bile duct as well as percutaneous drainage of the resulting biloma(s)
What are common iatrogenic complications of a cholecystectomy?
Injury to the common bile duct occurs more frequently during laparoscopic vs open approach
Electrocautery injuries
Inadvertent ligation of the common bile or hepatic duct
What should happen if the surgeon recognizes ductal injury intraoperatively?
Termination of the procedure and transfer of the pt to a tertiary care center for definitive management
What do 90% of bile duct injuries require?
Operative bile duct reconstruction via Roux-en-Y hepaticojejunostomy
How are gallbladder polypoid lesions commonly detected
U/s
Management of asymptomatic gallbladder lesions
Expectantly with ultrasonographic surveillance performed every 3-6 mos
When is laparoscopic cholecystectomy recommended in a pt with gallbladder polyps?
Any pt who has a gallbladder polyp that is >10 mm in size
When is open cholecystectomy recommended for gallbladder polyps?
Removal of larger lesions to avoid dissemination of malignancy
When are choledochal cysts more common?
Pts of Asian ethnicity
A minority of pts with choledochal cysts present with what sx?
Triad of jaundice, abd pain, and a RUQ mass
More common adult presentation of choledochal cysts
Complications such as cholangitis or pancreatitis
Imaging modality of choice for choledochal cysts
MRCP
Tx of choledochal cysts
Cyst excision with hepaticoenterostomy
Tx for type V choledochal cysts
These pts may require liver transplantation
Tx for type III choledochal cysts
Some authors advocate therapeutic transduodenal sphincteroplasty
What is the most common cause of biliary strictures?
Iatrogenic injuries
Tx of distal biliary strictures
Biliary-enteric bypass
Tx for primary sclerosing cholangitis
Biliary-enteric anastomosis
Characteristics of primary sclerosing cholangitis
Affects men more commonly than women
May progress to biliary cirrhosis and end-stage liver dz necessitating liver transplantation
Tx of biliary structures initially in pts with primary sclerosing cholangitis
Either ERCP or percutaneous biliary stenting
Presentation of pyogenic hepatic abscess
Most will have fever
Only half of pts will have abd pain
Jaundice is infrequent
What is the most sensitive and specific test for the dx of pyogenic hepatic abscess?
CT scan
What can help distinguish between pyogenic bacterial abscesses from parasitic abscesses?
Indirect hemagglutination or ELISA
When do iatrogenic pyogenic liver abscesses occur?
Following therapeutic interventions, such as:
- Radiofrequency ablation (RFA)
- Hepatic artery chemoembolization
Organisms of pyogenic liver abscess
Usually polymicrobial K. pneumoniae E. coli Streptococci B. fragilis
Tx of pyogenic liver abscess
Image-guided percutaneous drainage coupled with appropriate broad-spectrum abx therapy
