Arteriography Evaluation of Splanchnic Artery Occlusive Disease

Splanchnic artery occlusive disease can involve the origin, branches, or distal arteries of the splanchnic arteries, depending on the underlying pathologic process. The newer imaging modalities (including ultrasound, computed tomography [CT], and magnetic resonance angiography [MRA]) provide much of the diagnostic information about splanchnic artery occlusive disease that can be derived from catheter-based angiography. Diagnostic angiography is performed only when necessary information about the splanchnic circulation or small vessel disease cannot be obtained by CT or MRA. It is usually performed before surgical or percutaneous intervention. In patients with acute occlusive or nonocclusive mesenteric ischemia, urgent arteriography should be performed for prompt diagnosis and appropriate treatment.

This chapter reviews the vascular anatomy, equipment, and technique used in catheterization of the visceral arteries and in arteriographic evaluation of splanchnic artery occlusive disease.

Vascular Anatomy

Performance and interpretation of visceral angiographic procedure depend on thorough knowledge of the vascular anatomy. Many variations occur in the branching patterns of the celiac and superior mesenteric arteries as a result of differing degrees of persistence of the dual blood supply from the primitive double aortas. The three major splanchnic arteries supplying the abdominal visceral organs are celiac artery (CA), superior mesenteric artery (SMA), and inferior mesenteric artery (IMA).

Celiac Artery

The celiac trunk, also called the celiac axis, arises from the ventral surface of the aorta below the aortic hiatus of the diaphragm between the T12 and L1 vertebral bodies. It supplies blood to the supper abdominal viscera (including the stomach, duodenum, spleen, pancreas, omentum, liver, diaphragm, and distal esophagus). The first portion of the celiac trunk, the celiac artery descends caudally for 1 to 2 cm and then curves ventrocaudally or ventrocranially ( Figure 1 A ). It gives off the left gastric artery and then divides into the splenic and common hepatic arteries.

The inferior phrenic arteries can arise from the celiac axis proximal to the origin of the left gastric artery. Rarely, the dorsal pancreatic and middle colic arteries arise from the celiac axis as a common trunk and supply the transverse colon.

The splenic artery courses along the cranial aspect of the body and tail of the pancreas. Its branches are the dorsal pancreatic, pancreatica magna, caudal pancreatic, short gastric, and left gastroepiploic arteries. The common hepatic artery courses to the right and anteriorly, gives rise to the gastroduodenal artery, and becomes the proper hepatic artery. It then divides into the right, middle, and left hepatic arteries in the hilus of the liver. Other extrahepatic nonparenchymal branches of the hepatic artery are the right gastric (from the common hepatic), the accessory left gastric (from left hepatic), the falciform (from the middle or left hepatic) and cystic (from right hepatic) arteries.

The gastroduodenal artery supplies the duodenum and pancreas through the posterior and anterior pancreatic arcade arteries and the stomach through the right gastroepiploic artery. The celiac artery communicates with the superior mesenteric artery through the branches of the celiac artery, including the pancreatic arcade arteries of the gastroduodenal artery and dorsal pancreatic artery.

One or more of the branches of the CA can have a replaced origin from the aorta or the SMA. The left gastric artery can arise from the aorta. Rarely the splenic artery has an aberrant origin from the SMA. The left hepatic artery arises from the left gastric artery in about 25% of patients. The right hepatic artery has a completely replaced origin from the SMA in 18% of people and a partially replaced origin in 8%.

Superior Mesenteric Artery

The superior mesenteric artery arises from the ventral surface of the aorta approximately 1 to 2 cm below the origin of the celiac axis at the level of the disc space of the first and second lumbar vertebral bodies (see Figure 1 A). Rarely the SMA arises from the celiac axis as a celiacomesenteric trunk or caudal to the origins of the renal arteries. The proximal part of the SMA courses behind the body of the pancreas in close proximity to the uncinate process in a 45- to 60-degree angle to the aorta. This angle may be more severe in patients with chronic mesenteric ischemia, making transfemoral stenting of SMA stenosis difficult. It ranges 8 to 10 mm in width at angiography. It supplies the duodenum, the pancreas, the small intestine, the cecum, and the ascending and transverse parts of the colon.

The branches of the SMA are the inferior pancreaticoduodenal, middle colic, jejunal, ileal, right colic, and ileocolic arteries, respectively (see Figure 1 B). The first branch of the SMA usually is the inferior pancreaticoduodenal (IPD) artery, which arises from the SMA or from the proximal jejunal branch. The anterior and posterior branches of the IPD ascend and anastomose with the anterior and posterior branches of the gastroduodenal artery. The jejunal (2–7) and ileal (7–17) branches arise from the left side of the SMA. These arteries form multiple mesenteric arcades, which increase in number distally. The vasa recta from the terminal arcades enter the bowel wall without intercommunication.

The middle colic artery usually arises from the anterior surface of the SMA, distal to the origin of the IPD. The right branch runs along the mesenteric border of the proximal part of the transverse colon and anastomoses with the ascending branches of the right colic and ileocolic arteries. The left branch of the middle colic artery courses along the distal transverse colon and anastomoses with the left colic branch of the IMA.

The right colic artery has various origins. It can arise from the SMA as a common right colic–middle colic trunk or as an ileocolic-right colic trunk. A true right colic artery is present in only 13% of persons. Differentiation of the right colic from the middle colic and ileocolic arteries is difficult because of their anatomic variations and position changes of the bowel.

The ileocolic artery is usually the terminal branch of the SMA and courses to the right side of the abdomen. Its ascending branch anastomoses with the descending branch of the right colic artery. Inferiorly it gives rise to cecal, appendicular, and ileal branches.

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