Abdomen- Peritoneal Cavity

addison lines

lines divide the abdominal cavity into nine regions, 2 sagittal midclavicular, 2 axial: transpyloric & transtubercular

peritoneum in women vs men

in men the peritoneum is sealed, in women the peritoneum is communicated through the fallopian tubes

whats another name for the lesser sac?

the omental bursa

whats the difference between the lesser sac in infants and adults?

the lesser sac is fused in adults, in infants the lesser sac is recessed

the greater sac can be divided into what spaces?

supracolic and infracolic spaces

how do ligaments affect the peritoneal cavity?

they divide the cavity and help us understand where to look for fluid

gastrohepatic ligament

aka the lesser omentum; connects the lesser curvature of the stomach and liver

hepatoduodenal ligament

free edge of the lesser omentum, the portal triad courses through, connects liver to duodenum

falciform ligament

doubled layer of peritoneum from umbilicus to liver, contains lig teres, bifurcates into coronary lig

coronary ligament

bifurcation of falciform ligament, borders bare area of liver, limits greater sac in right subphrenic area

splenorenal ligament

aka lienorenal ligament; connects splenic hilum to posterior abdominal wall, splenic vein and artery travel through

gastrosplenic ligament

connects stomach to spleen and inferior diaphragm

broad ligament

connect uterus laterally to pelvic side walls, divides pelvis into anterior and posterior compartments

ligamentum teres

remnant of the fetal umbilical vein, contained within falciform ligament, joins LPV in porta hepatis

ligamentum venosum

remnant of ductus venosus, attached to LPV, separates LLL and caudate lobe

what are the potential spaces of the peritoneum?

R & L subphrenic and subhepatic spaces, hepatorenal space, lesser sac, R & L paracolic gutters, vesicorectal space, rectouterine space, uterovesicle space, space of retzius

left anterior subphrenic space

space between diaphragm and anterior superior liver left of falciform lig, extension of the greater sac

left posterior suprahepatic space

between diaphragm and posterior superior liver, extension of lesser sac

right subphrenic space

between right hemidiaphragm and anterior superior liver right to falciform ligament, extension of greater sac

hepatorenal space

between liver and right kidney, most gravity dependent space when supine

lesser sac/omental bursa

between posterior stomach and parietal peritoneum of pancreas

R & L paracolic gutters

grooves along the colon collect fluid, good for determining the extent of a disease

vesicorectal space

the cul de sac in men, between rectum and posterior bladder, most dependent pelvic space when supine in pelvic cavity

rectouterine space

between rectum and uterus, most gravity dependent in pelvis when supine for women

uterovesicle space

space between uterus and bladder

space of retzius

aka prevesicle space; between pubic symphysis and bladder, in both sexes

hemoperitoneum

blood in the peritoneal cavity

FAST exam

Focused Assessment with Sonography in Trauma; focuses specifically on the peritoneal cavities in trauma situations

techniques for FAST exams

use 2.5 MHz curvilinear probes, use higher freq probes for evaluating the abd wall, can put patients in trendelenburg position to show fluid mobility

sensitivities of FAST exam

sensitive to as little as 200mL of fluid in the peritoneal cavity and 20mL in the thoracic cavity

gold standard for FAST exam

CT, for hemodynamically stable patients

how can you differentiate ascites from cysts?

ascites fluid fills sharp corners and has bowel within it

seroma

fluid collection, blood products are often located adjacent, associated w/ post-op

sonographic appearance of seroma

usually anechoic w/ some possible septations

pseudomyxoma peritonei

malignancy, accumulation of mucus-secreting tumor cells, commonly assoc w/ appendix ca, low survival rate

sonographic appearance of pseudomyxoma peritonei

appears as hypoechoic solid mass, bowel loops are seen matted to the posterior abd wall

2 mechanisms that produce ascites

low serum osmotic pressure from protein loss & high portal venous pressure

clinical causes of ascites

cirrhosis, HTN, renal failure, CHF, CA, inflammatory processes

ascites treatments

paracentesis, transjugular intrahepatic portal-systemic shunting TIPS (lowers pressure)

true/false: GB wall thickening is common with ascites

true

why would hypoalbuminemia cause ascites?

cause its low protein and protein loss causes low serum osmotic pressure

2 types of ascites

transudative and exudative

transudative ascites

simple, anechoic, causes include CHF or portal hypertension

exudative ascites

complex, echogenic, contain proteins and cells, causes include malignancy or inflammatory processes

hematoma

blood clot or focal area of coagulated blood, from post-op, trauma, anticoagulants, etc; the echogenicity changes over time

when do hematomas cause a drop in hematocrit?

when they're very large, immediately next to an organ, directly beneath an incision, or disrupting a vessel

lymphocele

caused by leakage of lymph due to complication of renal, GYN, vascular or urological surgery

sonographic appearance of lymphocele

usually simple but can have septations, internal echoes usually means its something else

biloma

extrahepatic collections of bile, assoc w/ hepatic transplants due to biliary leakage

sonographic appearance of biloma

predominantly cystic masses w/ good through transmission, in RUQ or mid abdomen

urinoma

collection of urine outside of kidney, caused by renal trauma, surgery or obstruction; similar appearance to lymphocele

mesenteric cysts

benign cysts that can occur all along the mesentery

mesenteric adenopathy (lymphadenopathy)

enlargement of lymph nodes along mesentery adjacent to inflammed bowel, lymph nodes become rounded, assoc w/ IBS, appendicitis, and CAs

peritoneal mesothelioma

rare primary malignant tumor, assoc w/ asbestos exposure, can metastasize

sonographic appearance of peritoneal mesothelioma

occur as solid mass along pleura and peritoneum, can appear as a thick peritoneum, may see a small amount of ascites

peritoneal implants

deposits of CA cells that spread to the peritoneum, assoc w/ peritoneal mets & ovarian, stomach, colon CA

sonographic appearance of peritoneal implants

appears as small polyploid masses projecting from the peritoneum, common to also see complex ascites and omental caking

sonographic appearance of omental caking

appears as mid gray homogeneous thickened mass just beneath the abd wall, often seen with peritoneal implants and complex ascites

omental caking

thickening of the greater omentum, assoc w/ stomach, ovarian, colon CA

pleural effusions

fluid in the pleural space, often asymptomatic, can cause dyspnea and chest pain though, transudative and exudative

hydrothorax

a specific type of pleural effusion consisting strictly of serous, watery (transudative) fluid

transudative pleural effusion

simple, cause by hydrostatic pressure and decrease plasma oncotic pressure, causes include CHF and cirrhosis

exudative pleural effusion

cause by increase capillary permeability, causes include pneumonia and CA

pneumothorax

air in the pleural cavity, comet tail artifact between the parietal and visceral pleura

percutaneous abscess drainage PAD

sterile procedure using a small flexible catheter to aspirate abscess contents, can be drained and given antibiotics

thoracentesis

pleural fluid is aspirated slowly, no more than 1.5 L is drained to avoid hypotension and pulmonary edema