IMAG 472 Unit 3 (5) PDF - Pancreas, Spleen, and Retroperitoneum

Unit 3 – Pancreas, Spleen, and Retroperitoneum The Pancreas The pancreas is divided into 4 sections Head Uncinate process Neck Body Tail Normal Location Anterior to the IVC and Aorta Retroperitoneal Posterior to the Gastroduodenal artery Inferior to the liv...

Unit 3 – Pancreas, Spleen, and Retroperitoneum The Pancreas The pancreas is divided into 4 sections Head Uncinate process Neck Body Tail Normal Location Anterior to the IVC and Aorta Retroperitoneal Posterior to the Gastroduodenal artery Inferior to the liver Posterior to the stomach ** Anterior to the splenic vein Celiac trunk usually marks the superior border Tail surrounded by Lk, spleen, stom. and splenic flexure Tail is inferomedial to the spleen The pancreas lies in a transverse plane. It is rotated, with the head slightly inferior to the tail.  Size Length (head to tail) – about 15cm. The head is the thickest part measuring 2- 3cm. AP The pancreatic duct should measure 2mm or less The pancreas has 2 ducts Duct of Wirsung – primary duct extending the length of the pancreas Duct of Santorini – secondary duct which drains the upper anterior head Pancreatic divisum – the ducts haven’t fused)  The Pancreas is both an exocrine (digestive) and an endocrine (hormonal) gland!  Exocrine Acini cells release enzymes Lipase – digests fats Amylase – digests carbohydrates Digestive enzymes require almost neutral pH for best results, so pancreatic juice contains a relatively high concentration of sodium bicarbonate to neutralize gastric acid.  Endocrine Located in the Islets of Langerhans Produces hormones that are released directly into the bloodstream Alpha, beta, and delta cells Beta cells produce insulin which causes glycogen formation from glucose in the liver and enables cells within insulin receptors to take up glucose. Alpha cells produce glucagon which causes the cells to release glucose to meet the energy needs of the body. Delta cells produce somatostatin which inhibits the production of both insulin and glucagon.  Lab Values Serum Amylase – levels 2x normal indicates acute pancreatitis; can be affected by other diseases Urine Amylase – may be elevated in pancreatitis Lipase – performed to assess damage to the pancreas Glucose – useful if looking for a glucose metabolism disorder  Scanning Techniques DIFFICULT due to surrounding stomach and bowel Iso- or hyperechoic compared to the liver 5 MHz Start in the trv plane, rotated slightly counter- clockwise Look for the splenic vein Be careful with long axis view (patient vs organ)  SMV GDA SMA Splenic v IVC A  Sagital Views PANC GDA HEPATIC A. PV PV PANC IVC IVC GB P IVC  Pancreatic duct Identify pancreatic tissue on both sides Use color so to be sure it isn’t vascular Seen transversely 2mm or less  Pancreatitis – pancreas is being digested by its own enzymes Most common cause is biliary tract obstruction Alcohol abuse is second Sonographically acute pancreatitis presents as a hypoechoic pancreas with enlargement  Hemorrhagic Pancreatitis Rapid progresson of acute pancreatitis with rupture of pancreatic vessels and subsequent hemorrhage  Phlegmonous Pancreatitis Phlegmon is an inflammatory process that spreads along fascial pathways, causing localized areas of diffuse inflammatory edema of soft tissue that may proceed to necrosis.  Pancreatic Abscess Serious Secondary to pancreatitis that developes from postoperative procedures or a neighboring infection Poorly defined hypoechoic mass  Chronic Pancreatitis Recurrent attacks of acute pancreatitis Causes continuing destruction of the pancreatic parenchyma Fibrous scarring and loss of acinar cells Plugged pancreatic duct Increased echogenicity and decreased size Calcifications A quarter has 119 grooves on its edge, a dime has one less groove!  Pancreatic Pseudocysts Pancreatitis Always acquired Pancreatic enzymes escape from the gland and break down tissue to form a sterile abcess somewhere in the abdomen. Its walls are not true cyst walls; hence the name pseudo-, or false, cyst. Pseudocysts generally take on the contour of the available space around them and therefore are not always spherical. Occasionally pseudocysts can contain internal echoes and loculations Spontaneous rupture is the most common complication of a pancreatic pseudocyst, occurring in 5% patients. In half of this 5% drainage is directly into the peritoneal cavity. Clinical symptoms are sudden shock and peritonitis. The mortality rate is 50%  Cystic lesions of the pancreas (congenital) Autosomal Dominant Polycystic Kidney Disease Von Hippel-Lindau Disease Cystic Fibrosis True Pancreatic Cysts  Exocrine Pancreatic Lesions Solid Adenocarcinoma Cystic Cystadenoma Cystadenocarcinoma  Adenocarcinoma Most common primary neoplasm >90% of all malignant pancreatic tumors 60%-70% occur in the head of the panc. Hypoechoic; irregular borders Liver,lung,lymph,bone mets Obstructive jaudice Risk factors for andenocarcinoma Smoking High fat diet Diabetes Chronic pancreatitis The Whipple procedure Remove the c-loop of the duodenum Head of the panc. Gallbladder cbd Rarely has a good outcome. Rarely doesn’t mean never! Endocrine Pancreatic Neoplasms Arise from islet cells Slow growth Most are malignant Difficult to see due to small size and location (tail and body) Hypoechoic Solitary Insulinoma (60%) Gastrinoma (18%) Metastatic disease to the pancreas is rare. Pancreatic transplants are possible Usually done for diabetes Sometimes with renal transplant RLQ Rejection shows higher resistance flow and heterogeneous echo pattern. The Spleen  Reticuloendothelial system Largest single mass of lymphoid tissue Plays an important role in the defense of the body Rarely the primary site of disease Variable size and shape (normal longitudinal measurement should be 8-13 cm Blood supplied through splenic artery and vein  Location, location, location LUQ Can be displaced by by abscess, cyst, pleural effusion, intraabdominal mass Wandering spleen describes a spleen that has migrated from it’s normal location An accessory spleen is a 2nd spleen usually located near the hilum or the inferior portion of the spleen “This is really interesting Ken, but what the hell does it do?” I have no idea  Its major function is to filter the peripheral blood Acts as a blood reservoir Produces lymphocytes and plasma cells Produces antibodies Stores iron Removes abnormal red blood cells (culling) Removes the nuclei from abnormal cells (pitting) Pools platelets  Lab work Hematocrit – indicates the % of RBC’s /volume of blood. Abnormally low readings indicate hemorrhage within the body. Bacteremia – presence of bacteria within the body. Fever and chills = infection (sepsis). Leukocytosis – increased number of white blood cells, indicative of infection. Leukopenia – decrease in the # of white blood cells. Thrombocytopenia – decrease in the number of platelets  Sonographic Evaluation Similar texture to liver Patient in the right lateral decub. Raise left arm over their head Approach the spleen intercostally from both the coronal and transverse planes Try various phases of respiration Check left pleural space while you’re there  Splenomegaly This is our most important role. Spleen should be