Hepatocellular carcinomas supplied by inferior phrenic arteries

The origin of the inferior phrenic artery: a study in 32 South Indian cadavers with a review of the literature

BACKGROUND: Considering the paucity of information presently available concerning inferior phrenic arteries, a more definitive study seemed appropriate and necessary, both for its potential clinical applications and to provide additional data to contemporary anatomical literature. OBJECTIVE: Most anatomical textbooks of gross anatomy offer very little information concerning the anatomy and distribution of the inferior phrenic artery (IPA). For that reason, the origin of the IPA has been studied and the available literature has been reviewed. METHODS: Thirty-two human adult cadavers preserved in formalin obtained from the departments of Anatomy, Kasturba Medical College, Manipal and Mangalore were dissected and the origin of the IPA was studied. RESULTS: The IPA had its usual origin from the abdominal aorta in 28 cases but in the remaining four cases, two were arising from the celiac trunk, one from the left gastric artery and one from the right renal artery. CONCLUSION: The IPA usually originates from the aorta or celiac artery, and less frequently from the renal, hepatic or left gastric arteries. The IPA is a major source of collateral or parasitized arterial supply to hepatocellular carcinoma, second only to the hepatic artery. Literature on the IPA origin and clinical implications of variation in its origin have been reviewed in this article.

Superior phrenic artery: an anatomic study

The majority of anatomical textbooks offer very little information concerning the anatomy and distribution of the superior phrenic artery (SPA). However, in the last decade, a number of reports have appeared with reference to the transcatheter arterial chemoembolization of the collateral arterial supply of hepatic carcinoma (HC). Considering the potential role of the SPA as a source of collateral blood supply to HC, the aim of this study was to identify the origin and distribution of the SPA. One hundred formalin-fixed adult cadavers with no evidence of significant gross diaphragmatic pathology were examined. The right SPA originated from the aorta (R1) in 42%, as a branch of the proximal segment of the 10th intercostal artery (R2) in 33%, and as a branch of the distal segment of the 10th intercostal artery (R3) in 25%, of the specimens. The left SPA originated from the aorta (L1) in 51%, from proximal segment of the left 10th intercostal artery (L2) in 40%, and from the distal segment of the left 10th intercostal artery (L3) in 9%, of the specimens. In types R1, R2, L1 and L2 the SPA terminated, after a short course, within the medial and posterosuperior surfaces of the thoracic diaphragm and diaphragmatic crura. Conversely, in types R3 and L3 the lateral origin of the SPAs confined the ultimate distribution of the vessels to the posterior surface of the diaphragm. These findings could provide a better understanding of the anatomy and distribution of the arterial supply of the diaphragm and the potential involvement of the right SPA as an extrahepatic collateral artery developed in HC.

An anatomical classification of the variations of the inferior phrenic vein

The majority of anatomical textbooks of gross anatomy offer very little information concerning the anatomy and distribution of the inferior phrenic vein (IPV). However, in the last decade, an increasing number of reports have arisen, with reference to the endoscopic embolization of esophageal and paraesophageal varices, as well as venous drainage of hepatocellular carcinomas (HCC). The IPV is one of the major sources of collateral venous drainage in portal hypertension and HCC. The aim of this study was to identify the origin and distribution of the IPVs (right and left), both in normal and (selective) pathological cases. We have examined 300 formalin-fixed adult cadavers, without any visible gastrointestinal disease, and 30 cadavers derived from patients with HCC. The right IPV drained into the following: the inferior vena cava (IVC) inferior to the diaphragm in 90%, the right hepatic vein in 8%, and the IVC superior to the diaphragm in 2%. The left IPV drained into the following: the IVC inferior to the diaphragm in 37%, the left suprarenal vein in 25%, the left renal vein in 15%, the left hepatic vein in 14%, and both the IVC and the left adrenal vein in 1% of the specimens. The IPVs possessed four notable tributaries: anterior, esophageal, lateral and medial. The right IPV served as one of the major extrahepatic draining veins for all 30 cases of HCC. These findings could have potential clinical implications in the transcatheter embolization of esophageal and paraesophageal varices, as well as in mobilizing the supradiaphragmatic segment of IVC.