MNTM Flashcards
True about the omentum
a. triple sheath of flattened endothelium
b. L side is longer with tongue-like projections
c. has amoboid like activity
d. usually found in areas where there is infection or pathologic process
D
a. double sheath of flattened endothelium
b. R side is longer with tongue-like projections
c. no amoeboid like activity
True about the omentum
a. Lesser omentum covers the small intestine like an apron
b. The greater omentum is attached to the colon
c. The portal triad is contained inside the greater omentum.
d. NOTA
B.
Greater omentum: double-layered sheet of visceral fibroadipose tissue descending from the greater curvature of the stomach, covering the small intestines, folds back on itself and attaches onto the anterior peritoneum of the transverse colon
Lesser omentum: a.k.a hepatoduodenal + hepatogastric. The portal triad (cbd, portal vein, hepatic artery) is located within the inferolateral margin of the lesser omentum.
Free edge of lesser omentum forms _____ which is used to encircle the portal triad during a pringle manuever
foramen of winslow
Describe the Pringle Maneuver
A large atraumatic haemostat is used to clamp the hepatoduodenal ligament (free border of the lesser omentum) interrupting the flow of blood through the hepatic artery and the portal vein and thus helping to control bleeding from the liver.
The organ twists along its axis from sudden forceful movements, thrombosis, or vasculitis of omental vessels or omental venous outflow obstruction
a. Primary omental torsion
b. Secondary omental torsion
c. idiopathic segmental infarction
d. cysts
A
Secondary causes of torsion are most often due to hernias, tumors, or adhesions.
Abdominal exam findings in omental infarction (2)
peritoneal tenderness with a possible palpable mass
Ultrasound findings in omental infarction
hyperechoic noncompressible intraabdominal mass attached to the abdominal wall.
CT scan findings of omental torsion
streaking whirling pattern of fatty tissue in the anterior abdomen
mild vascular constriction in omental torsion will cause
edema
strangulation in omental torsion will cause
infarction and eventually frank gangrene
Pre-requisite conditions of torsion (2)
redundant and mobile segment
fixed point around which a segment can twist
Predisposing factors of omental torsion except
a. tongue-like/bifid configuration
b. accessory omentum
c. obesity
d. venous redundnacy
e. large and bulky with narrow pedicle
NOTA
Precipitating factors of omental torsion (6)
CHHeeSSe Coughing Heavy exertion Hyperperistalsis Sudden change in body position Straining
Predisposing factors of omental torsion (5)
VALOT Venous redundnacy Accessory omentum Large and bulky with narrow pedicle Obesity Tongue-like/bifid configuration
presents with Torsion with adhesion of the free end to a cyst, tumor, foci of intra-abdominal inflammation, post-op wounds and scarring, int./ ext. hernias
Secondary omental torsion
True about secondary omental torsion
a. precipitating factors is same as primary
b. usually unipolar
c. initially causes serosanguinous fluid
d. AOTA
A
b. usually bipolar - torsion of central component occur between two fixed points in clockwise manner
c. initially causes restricted venous return, thus congestion, and eventually edema
d. NOTA
Omental torsion usually occurs in what decade of life and gender?
4th to 5th decades of life, males
What is the predominant symptom of omental torsion?
Pain
True about symptoms of omental torsion
a. Movement intensifies the pain
b. Nausea and vomiting in 30%
c. Leukocytosis and high grade fever
d. direct but no rebound tenderness
A
b - nausea and vomiting in 50%
c. Leukocytosis and moderate fever
d. direct and rebound tenderness
True about diagnostics and management of omental torsion EXCEPT
a. CT is not sensitive but specific.
b. Treatment is Exploratory laparotomy
c. good prognosis
A; sensitive but not specific
Idiopathic segmental infarction criteria for diagnosis (4)
No CATT
Not associated with cardiovascular disease
No local intra-abdominal pathologic conditions
no history of external abdominal trauma
No torsion
True of pathology/etiology of idiopathic segmental infarction
a. condition is precipitated by thrombosis of omental vein secondary to endothelial injury
b. stretching or primary rupture of omental vein
c. gravitational pull of extremely fatty omentum
d. anatomic peculiarity of venous drainange
AOTA
True about clinical manifestation of idiopathic segmental infarction EXCEPT
a. young to middle aged adults, 3:1 male
b. non-specific manifestation
c. usually involves L lower portion
d. well-demarcated, edematous, hemorrhagic or gangrenous involved segment
e. usually adheres to parietal peritoneum or viscera
C. R lower portion
CT scan finding of Idiopathic segmental infarction
Smudged appearance
Treatment of Idiopathic segmental infarction
Exploratory laparotomy
Resection of infarcted area
Serosanguinous free fluid
Cyst from obstruction of lymphatic channels / growth of congenitally misplaced lymphatic tissue that does not communicate with the vascular system
a. Lymphangioma
b. Dermoid
c. Pseudocyst
d. True cyst
D
Describe a true omental cyst
serous fluid, unilocular or multilocular
Omental Cyst with endothelial lining
Lymphangiona
Omental Cyst with sqamous cell lining, hair, teeth, and sebaceous components.
Dermoid cyst
Omental cyst with fat necrosis, trauma and foreign body reation. Fibrous and inflammatory lining, cloudy/bloody
pseudocyst
True about omental cysts
a. usually in children, young adults
b. small cysts are asymptomatic
c. large cyst may present as abdominal mass, heaviness, pain
d. complications include torsion, infection, rupture and obstruction
e. diagnosis only at explore lap
AOTA
clinical manifestations of large omental cysts
HAP
Heaviness
Abdominal mass
Pain
Complications of omental cyst
4
ROTI
Rupture and obstruction
Torsion
Infection
Xray findings of omental cysts
soft tissue haziness and displaced bowel loops
Ultrasound/CT findings of omental cyst
fluid filled mass
Treatment of omental cyst
exploratory laparotomy
Local excision
Omental solid tumors - most metastatic carcinoma of the omentum come from (4) primary sites
COPS
Colon
Ovary
Pancreas
Stomach
(CSPO)
CT scan finding of omental metastatic carcinoma
omental cake
Primary omental solid tumors are rare, usually in ___ years old
50
True about omental solid tumors
a. mesodermal in origin
b. 30% malignant
c. benign lesions are usually lipoma, leiomyoma, fibroma, neurofibroma
d. malignant are usually leiomyosarcoma and hemangioendothelioma
C.
A. mesenchymal origin
B. 50% malignant
D. Leiomyosarcoma and hemangiopericytoma
Tx for benign omental solid tumors
Surgical excision
Treatment of malignant omental solid tumors
Resection of adjacent organs and total omentectomy
Palliation omentectomy is usually done to control _____
associated ascitis in patients with omental metastases
