Inferior mesenteric artery

It also appears that the incidence of hepatic adenomas is increased in women taking oral contraceptives. Ischemic bowel disease secondary to thrombosis of the celiac and superior and inferior mesenteric arteries and veins has also been reported in women using these drugs. 

The distal portion of the large intestine is the rectum. Rectal absorptive capacity is considerably less than that of the upper GI tract owing to a limited surface area, a result of the absence of microvilli. Also, the blood supply to colon and rectum is less than that to the small intestine. The rectal artery branching off the inferior mesenteric artery of the... 

Greater than 120° angulation of the proximal neck Critical inferior mesenteric artery Significant iliac occlusive disease Tortuosity of iliac vessels... 

The visceral vessels are evaluated for patency because the required coverage of the inferior mesenteric artery mandates that blood supply to the viscera be adequate from other sources (celiac and superior mesenteric arteries). With experience, some of these contraindications can be overcome with suprarenal attachment devices, additional cuffs, and limbs, but for the nascent EVAR physician the contraindications should be acknowledged and adherence to the fundamental principles of endovascular device implantation will permit good outcomes. 

The splenic flexure of the colon receives blood from both the superior and inferior mesenteric arteries. 

The Zuckerkandl organs arc para-aortic bodies of chromaffin tissue, which arc located retroperitoneally at the, level of the origin of the inferior mesenteric artery. These organs function as an accessory tissue to the autonomic nervous system in early life they usually start to degenerate during the first postnatal year. 

In this regard, mesenteric vascularity, unlike CD, has been shown to be well correlated with disease activity. Doppler sonography of the inferior mesenteric artery and superior mesenteric artery are closely related to chnical and endoscopic activity in patients... 

Mirk P, Palazzoni G, Gimondo P (1999) Doppler sonography of hemodynamic changes of the inferior mesenteric artery in inflammatory bowel disease preliminary data. AJR Am J Roentgenol 173 381-387... 

The gastrointestinal tract is supplied by the unpaired visceral arteries branching from the abdominal aorta the celiac trunk (Fig. 5.1), superior and inferior mesenteric artery. 

Walker WJ, Goldiin AR, Shaft MI, et al. (1980) Per catheter control of haemorrhage from the superior and inferior mesenteric arteries. Clin Radiol 31 71-80... 

The superior mesenteric artery (SMA) supplies the entire small bowel, cecum and colon usually up to the splenic flexure. As such this is the vessel that is commonly studied first if there are no clues that the bleeding is coming from the inferior mesenteric artery (IMA) distribution. The primary branches of the SMA have numerous interconnections both in the mesentery and via the arcade along the mesenteric margin of the bowel. This communication between mesenteric branches may provide more than one pathway to reach a site of extravasation (Fig. 6.2). 

Differences in segmental arterial supply probably also impact on the risk of infarction. The rectum is likely to tolerate embolization better than other regions since it has a dual blood supply with the superior hemorrhoidal artery off of the inferior mesenteric artery and middle hemorrhoidal arteries arising from the internal iliac circulation. This translates into increased potential for collateral blood flow and thus decreased risk of ischemia. The cecum may be more prone to ischemia since there is not a well developed arcade along the mesenteric border of the cecum and instead there are separate anterior and posterior cecal branches. The tissue supplied by these individual branches may be more susceptible to ischemia and in fact infarction of the cecum (even after microcatheter embolization) has been reported [13]. 

A personal case of anatomic variant was found during postpartum hemorrhage embolization in which the inferior mesenteric artery was the feeding vessel to the uterus (Fig. 9.4). 

Fig. 9.4a,b. A 31-year-old woman with PPH (a). Selective angiogram of the inferior mesenteric artery (IMA) showed the left colic artery supplying the uterus (arrows), b Early phase of selective angiogram of the IMA shows that the second left division feeds exclusively the uterus (arrow). (Courtesy of Patrick Garance)... 

Type I endoleak is caused by failure to achieve a circumferential seal at either the proximal (type lA) or distal end (type IB) of the stentgraft. Type IC endoleak is due to non-occluded iliac artery in patients with aorto-mono-iliac stent and femoral-femoral bypass. With type I endoleak, the aneurysm is perfused directly from the aorta or the iliac arteries (inflows). The leak usually communicates through a channel (sometimes multiple channels) with the aneurysmal sac. There are several outflow vessels, mainly lumbar arteries and inferior mesenteric artery (IMA) that communicate with the channel and or the sac (Figs. 14.1,14.2). The pressure within a type I leak is systemic. The tension on the aortic wall remains high. 

Fig. 15.1. a Contrast. enhanced CT of abdomen shows an abdominal aortic aneurysm with patent lumbar and inferior mesenteric arteries. Patient developed a type 11 endoleak after endograft placement, b Non-contrast CT shows glue embolization of the lumbar arteries and the sac through a branch of the internal iliac artery... 

Crawford ES, Morris GC, Myhre HO, Roehm JO (1977) Celiac axis, superior mesenteric artery, and inferior mesenteric artery oedusion surgical considerations. Surgery 82 856-866... 

The inferior mesenteric artery (IMA) arises from the aorta at the level of the left pedicle of L3 and supplies the left colon, sigmoid, and rectum. It is frequently occluded in older populations. Collateral flow to this distribution can come from the marginal artery of Drummond or from branches of the internal iliacs. 

The RIM catheter was specifically designed for the inferior mesenteric artery. This catheter typically seats well in the origin, which arises at the level of the left pedicle of L3. A microcatheter can then be passed coaxially into the desired branch and microcoils deposited. Superselective technique is desired. Although some collateral flow is supplied to the distal colon via internal iliac branches, care must be taken when occluding more proximal vascular territories. 

Kadir S, Lundell C, Saeed M (1991) Celiac, superior and inferior mesenteric arteries. In Kadir S (ed) Atalas of normal and variant angiographic anatomy. Saunders, Philadelphia, PA, pp 204-237... 

Computer simulations of flow in the abdominal aorta were carried out by Artoli et al., and Ahmadi and Joseph. Sample pressure and surface shear stress contours are shown in Figs. 63 and 64. The upper arteries connected to the abdominal aorta are also identified in Fig. 63. The computational domain actually included the inferior mesenteric artery and iliac bifurcation at the end of abdominal aorta. It is seen that there is noticeable pressure drop from the main abdominal aorta to the bifurcating arteries. The celiac and superior mesenteric arteries are at higher pressure compared with the left and right renal arteries. While not shown in the figures, the inferior mesenteric and iliac arteries are at lower pressure. Figure 63 also shows that the pressure decreases rapidly along the smaller arteries. 

Horseshoe kidney is the most common type of renal fusion and one of the most frequent renal anomalies. It is usually characterized hy fusion of the lower poles across the midline hy an isthmus lying anterior, seldom posterior, to the aorta and inferior vena cava (Dajani 1966). Occasionally the lower poles are connected only hy fibrous hands. The horseshoe kidney is usually positioned low in the abdomen with the isthmus lying just below the junction of the inferior mesenteric artery and aorta. The incidence varies from 1 in 400 (Glenn 1959) to 1 in 1,800 (Campbell 1970). The abnormality is more common in males. 

Fig. 7.33a,b. Contrast-enhanced MDCT obtained 4 months after operation in 5-year-old girl with short-bowel syndrome after intestinal transplantation. (Ao abdominal aorta, C colon, CIA common iliac artery, d donor, D duodenum, I ileum, IMA inferior mesenteric artery, IVC inferior vena cava, / jejunum, r recipient, SMV superior mesenteric vein.) Annotations intestinal graft lumen white asterisk), subsegmental arteries and veins in mesenteric fat of intestinal graft arrow), donor lymph node black arrowhead), proximal intestinal anastomosis between white arrowheads), distal intestinal anastomosis between white arrows). a, b Images show (a) proximal intestinal end-to-end anastomosis between white arrowheads) between recipient duodenum and donor jejunum as well as (b) distal intestinal end-to-end anastomosis between white arrows) marked by hyperdense staple line between donor ileum and recipient ascending colon... 

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