โ๐๐ฝ๐ฝ๐ฟ๐ผ๐ฎ๐ฐ๐ต ๐๐ผ ๐ฎ๐ฐ๐๐๐ฒ ๐๐ต๐ฟ๐ผ๐บ๐ฏ๐ผ๐๐ถ๐ฐ ๐บ๐ฒ๐๐ฒ๐ป๐๐ฒ๐ฟ๐ถ๐ฐ ๐ถ๐๐ฐ๐ต๐ฒ๐บ๐ถ๐ฎ ๐ผ๐ณ ๐ฆ๐ ๐ ( Superior mesenteric artery )โ
โขThe operative approach to acute thrombotic mesenteric ischemia differs from that of embolic occlusion.
โขMesenteric flow cannot be restored by a simple embolectomy and alternatives are required. Most common procedure required is bypass of the SMA usually from the infrarenal aorta or from one of the iliac arteries. While suprarenal bypass is preferred in elective surgery for chronic ischemia, an infrarenal origin of bypass is more expeditious in the acutely ischemic patient and avoids acute hemodynamic consequences of suprarenal clamping in a patient which is acutely ill.
โขBecause bowel resection is usually required, autogenous saphenous vein is the preferred conduit and should be harvested from the proximal thigh.
โขWhen the bypass is performed, there should be sufficient redundancy to allow a โlazy Cโ loop,traveling from right to left in the abdomen to avoid sharp kinking.
โขThe bypass is usually performed on the lateral side of the SMA slightly posterior, so that it can lie without compromise when the viscera are returned to the abdomen. While it is tempting to use very short bypasses, these may be prone to kinking and perioperative thrombosis.
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In the acute setting,
revascularization is usually restricted to the SMA alone.
When there is no suggestion of intestinal necrosis & angiography reveals high-grade stenosis( chronic ischemia or thrombosis) rather than vascular occlusion, an endovascular approach may be attempted like angioplasty with placement of a balloon expandable nitinol stent.