Morison pouch

Morison's pouch, also known as the hepatorenal recess or subhepatic recess, is an anatomical space in the abdomen. It is located between the liver and the right kidney, extending inferiorly to the right colic flexure. This potential space in the peritoneal cavity becomes clinically significant in various medical conditions, particularly in the accumulation of fluids, such as blood or ascites.

Anatomy

Morison's pouch is the deepest part of the peritoneal cavity in the supine position. It is a part of the peritoneum that extends between the posterior aspect of the right lobe of the liver and the anterior aspect of the right kidney and adrenal gland. The space is bounded medially by the inferior vena cava and laterally by the right coronary ligament of the liver.

Clinical Significance

The clinical importance of Morison's pouch arises in the context of trauma, infection, and other pathological conditions that lead to fluid accumulation. It is a common site for the accumulation of ascites and hemoperitoneum (blood in the peritoneal cavity), especially in cases of liver trauma or rupture of an abdominal organ.

Trauma

In the setting of abdominal trauma, particularly blunt abdominal trauma, Morison's pouch is one of the first sites where hemorrhage can accumulate. The detection of fluid in Morison's pouch via imaging, such as ultrasound or CT scan, can be an early sign of internal bleeding and may necessitate further diagnostic evaluation or surgical intervention.

Ascites

In patients with liver disease, such as cirrhosis, Morison's pouch can accumulate ascites, which is the buildup of fluid in the peritoneal cavity. The detection of fluid in this space can be an indicator of the severity of liver disease or portal hypertension.

Diagnostic Imaging

Morison's pouch is a key anatomical landmark in diagnostic imaging, particularly in the assessment of abdominal trauma or disease. It is commonly evaluated using ultrasound in the FAST (Focused Assessment with Sonography for Trauma) exam, which is a rapid bedside ultrasound examination performed to assess for intra-abdominal bleeding. It can also be visualized on CT scans and MRI for more detailed assessment.

Treatment

The treatment of fluid accumulation in Morison's pouch depends on the underlying cause. In the case of trauma-induced hemoperitoneum, urgent surgical intervention may be required to stop the bleeding. For ascites, treatment may involve managing the underlying liver disease, dietary modifications, diuretics, and in some cases, paracentesis to remove the excess fluid.