**6. Treatment of nonocclusive mesenteric ischemia**

The primary treatment for NOMI is medical, with extensive critical care support and prompt arteriography. Operative exploration is reserved for signs of peritonitis that suggest the presence of gangrenous bowel that requires excision. Interventional therapies can be initiated at the time of the diagnostic arteriogram and are targeted at relieving vasospasm using intra-arterial infusions of vasodilator medications. The most common intra-arterial agent is phosphodiesterase inhibitor papaverine and prostaglandin (22). Surgical exploration is required for all patients who have evidence of any threatened bowel, regardless of the underlying cause. The prognosis is poor, despite the absence of organic obstruction in the principal arteries.

Mesenteric Vascular Disease 243

commonly used to control the bleeding that accompanies aneurysm rupture (29), and prophylactic treatment of incidentally discovered intact aneurysms has become common (particularly those well-collateralized aneurysms that are imbedded within the pancreatic or hepatic parenchyma). Embolization has become the preferred treatment in patients at high

> Arterial Location Incidence of Aneurysms Splenic 60.0% Hepatic 20.0%

surgical risk or for aneurysms in locations that are difficult to approach surgically.

Superior mesenteric 5.5%

Gastric or gastroepiploic 4.0% Jejunal, ileal, or colic 3.0%

Gastroduodenal 1.5% Inferior mesenteric Rare

The most common of the splanchnic artery aneurysms and account for as many as 60% of all reported splanchnic aneurysms (32). The most common clinical risk factors reported in association with Splenic Artery Aneurysm are female gender, a history of multiple pregnancies, and portal hypertension. A classic calcified ring may be noted in the left upper quadrant on a plain x-ray film of the abdomen.the patients may have an abdominal bruit, the majority of physical examinations are normal in patients with asymptomatic lesions. When rupture occurs, patients usually complain of acute left-sided abdominal pain. Shock, abdominal distention, and death can result from free intraperitoneal rupture of an Splenic Artery Aneurysm. The overall mortality of ruptured Splenic Artery

Splenic aneurysms that have ruptured or are symptomatic require urgent treatment. Additionally, aneurysms in pregnant women or those of childbearing age also absolutely warrant treatment. Less stringent indications for treatment include aneurysms that are

Endovascular exclusion of has been used more recently with general success. Treatment options include coil embolization of the splenic artery both proximal and distal to the

The hepatic artery is the second most common location for aneurysmal degeneration in the splanchnic circulation. The causes are degenerative ("atherosclerotic"), medial degeneration,

noted to be enlarging or those greater than 2 cm in diameter.

aneurysm itself, thereby effectively "trapping" the lesion (34, 35).

Pancreaticoduodenal or pancreatic 2.0%

Table 1. Incidence of Aneurysms of the Splanchnic Arterial Circulation (30, 31)

**7.2 Splenic artery aneurysm** 

Aneurysm is high (33).

**7.3 Hepatic artery aneurysms** 

Celiac 4.0%

Fig. 6. Retrograde aortoceliac–superior mesenteric artery bypass
