The murmurs heard over the liver are most often of a vascular origin. Vascular murmurs occur as a result of turbulent blood flow in arterial or venous vessels. The cause of the arterial murmur in the liver output, consistent with the systole of the left ventricle, may be atherosclerotic or dysplastic processes narrowing the lumen of the hepatic artery. The source of the hepatic vascular murmur is also an aneurysm of the hepatic artery.
The causes and formation of liver murmurs
The more common causes of liver murmurs are arteriovenous fistulas, e.g., in malignant liver tumors or in Rendu-Osler-Weber disease involving the liver. Arteriovenous fistulas can also be a consequence of liver injury, e.g. during liver biopsy.
A liver murmur occurs in large venous vessels if the blood flow in them is sufficiently rapid. The hyperdynamic nature of the portal circulation makes the murmur audible over surgically produced, and less frequently spontaneous, venous anastomoses, e.g. splenorenal shunt (left mesogastrium). Such a murmur is continuous. The cause of a similar murmur heard between the xiphoid process of the sternum and the navel is the blood flow in the open umbilical vein. For poorly understood reasons, a liver murmur may appear in the course of alcoholic hepatitis.
Inflammatory processes affecting liver murmurs
Apart from vascular factors, hepatic murmurs are caused by inflammatory processes involving the liver capsule (perihepatitis, glissonitis). These phenomena arise as a consequence of the rubbing of a thickened hepatic capsule against the surface of the liver during the respiratory movements of the diaphragm (respiratory friction).
An example of bursitis with the formation of post-inflammatory capsulopritoneal-diaphragmatic adhesions are the following processes:
- bacterial (chlamydiosis, syphilis),
- parasitic (toxocarosis),
- and peripherally lying liver abscess.
The cause of similar friction on the left side may be an infarction in the enlarged spleen.
Source: Abdominal PHYSICAL TEST WITH ELEMENTS OF DIFFERENTIAL DIAGNOSTICS; Czelej Publishing House