Inferior Phrenic ArteriesEdit
The inferior phrenic arteries are a pair of arteries that supply the inferior surface of the diaphragm and nearby structures. In most individuals, they arise as the first ventral branches of the abdominal aorta, just above the celiac trunk, and travel upward to reach the diaphragmatic surface. They may also originate from other nearby sources, such as the celiac trunk or renal arteries, in a portion of people. Each artery typically gives off small branches to the diaphragm, with a notable branch system to the adrenal glands.
Along with their diaphragmatic branches, the inferior phrenic arteries frequently give rise to the superior suprarenal arteries, which supply the adrenal glands. These arteries participate in an anastomotic network with the thoracic and abdominal arterial regions, helping to maintain blood flow to the diaphragm and suprarenal glands under varying physiologic conditions. The inferior phrenic arteries also contribute to collateral circulation to nearby organs and can give off small abdominal wall branches as they ascend.
Anatomy
Origin and course - The typical origin is from the abdominal aorta just above the level of the celiac trunk, with the right and left arteries usually present as distinct vessels. In a notable minority of cases, the inferior phrenic arteries can arise from the celiac trunk, from the renal arteries, or from other nearby sources. See abdominal aorta and celiac trunk for context. - After originating, each artery ascends to the inferior surface of the diaphragm, coursing posterior to the peritoneum and entering the diaphragmatic muscle where it distributes its branches.
Branches - Diaphragmatic branches supply the inferior aspect of the diaphragmatic muscle and contribute to the diaphragmatic arterial arcade. - Superior suprarenal arteries arise from the inferior phrenic arteries and supply the upper portion of the adrenal gland. - In some individuals, branches extend to adjacent structures or participate in anastomoses with the thoracic aorta–derived superior phrenic arterys.
Relation to other vessels - The inferior phrenic arteries form part of the arterial network around the diaphragm and interact with the superior phrenic arterys, which may originate from the thoracic aorta or other sources. - They may participate in collateral pathways that connect the abdominal and thoracic circulations, especially in circumstances where primary diaphragmatic blood flow is altered.
Variation
Origin and prevalence - The most common origin is the abdominal aorta just above the celiac trunk, but origins from the celiac trunk, the renal arteries, or other nearby vessels occur with noticeable frequency. - Laterality is typically symmetric, but there can be differences in size between the right and left arteries.
Branches and anatomical variants - The pattern of diaphragmatic branches is relatively conserved, but the extent of involvement of the superior suprarenal arteries can vary. - Accessory or aberrant inferior phrenic arteries may exist in some individuals, potentially altering patterns of perfusion to the diaphragm and suprarenal organs.
Clinical significance
Surgical and radiologic relevance - The inferior phrenic arteries are important during surgeries involving the diaphragm, upper abdominal organs, or retroperitoneal space, due to their proximity and potential for bleeding if they are injured. - In radiologic procedures and interventional radiology, these arteries can be involved in embolization or selective catheterization when targeting tumors or vascular anomalies near the diaphragm or adrenal region. They can serve as collateral feeders to liver lesions, particularly hepatocellular carcinoma, in certain treatment strategies. See hepatocellular carcinoma for related context.
Pathophysiology and disease - Variations in origin or course can complicate surgical planning or imaging interpretation. Recognizing potential origins from the celiac trunk, renal arteries, or abdominal aorta helps in anticipating anatomical differences during procedures. - In trauma or inflammatory disease affecting the diaphragm or adrenal glands, the inferior phrenic arteries may participate in altered perfusion patterns and bleeding risk.