Renal artery occlusion

　　It is often caused by embolism due to intracavitary wall thrombosis (atrial arrhythmia, previous myocardial infarction, vegetations of bacterial endocarditis) or atherosclerotic embolism. Less common causes are fat or tumor embolism. Renal artery thrombosis can be secondary to vascular trauma after existing atherosclerosis (surgery, angiography, angioplasty) or intimal tear or rupture of renal artery aneurysm. Acute occlusive damage to the renal artery (another cause of occlusion) is less common than the aorta, but more common than any other peripheral artery. Pre-existing atherosclerotic diseases or fibrous dysplasia are often prone to spontaneous or traumatic occlusions, but angioplasty has become a common cause.

　　The most common complications of renal artery occlusion are subcapsular hematoma of the kidney, renal parenchymal necrosis, hypertension, and acute renal failure.

　　1,Subcapsular hematoma of the kidney:It is often caused by hematoma due to occlusion caused by renal puncture.

　　2, Renal parenchymal necrosis:It is a destructive complication of renal parenchyma caused by ischemia in the renal medullary area and/or severe infection, usually confined to the renal papilla. Although this condition can be considered an acute pyelonephritis in the acute process, it should essentially be attributed to chronic interstitial nephritis.

　　Definitive diagnosis of renal artery occlusion usually relies on renal artery angiography, but intravenous contrast-enhanced spiral CT is also sensitive and specific. Renal blood flow reduction is observed in radioactive nuclear renal imaging, or there may be an absence of blood flow on the side with severe thromboembolic disease. Although renal imaging is non-invasive, the image quality for surgical purposes may not be satisfactory. Double Doppler ultrasound examination is also sensitive and specific, but it is time-consuming and highly dependent on the operator's professional skills. The value of magnetic resonance imaging is uncertain. A history of atrial fibrillation, recent myocardial infarction or trauma, or a past history of embolic episodes; symptoms and signs, complete absence of excretory function and normal collecting system on the affected side are strong evidence of renal obstruction. The impairment of excretion caused by ureteral obstruction requires other examinations, such as ultrasound examination or excretory urography.

　　Immoderate diet has a certain impact on the occurrence of the disease (such as nutritional deficiency, drinking causing disharmony between the spleen and kidneys), and the diet should be light and avoid spicy, cold, and raw foods to prevent the formation of phlegm. During the remission period, the therapy usually focuses on nourishing the lung, spleen, and kidneys, and it is not advisable to eat fish, shrimps, crabs, raw chicken, and other irritants. During the acute infection period, the diet should be light and nutritious, and it is advisable to avoid spicy and hot foods. The dietary therapy should be used in combination with the diagnosis and treatment situation.

　　Partial occlusion of the renal artery often has no symptoms and is ignored because the segmental infarction or renal ischemia is not accompanied by infarction. This occlusion can lead to persistent hypertension. When renal infarction is suspected, careful search should be made for extrarenal embolic signs (such as skin lesions, focal neuropathy defects).

　　When completely occluded, persistent painful costal pain and local tenderness may occur, with fever, nausea, and vomiting. A unilateral renal artery or bilateral renal artery occlusion on one side of a solitary kidney can cause complete anuria and acute renal failure. In such cases, hypertension is uncommon or temporary.

　　Immoderate diet has a certain impact on the occurrence of the disease (such as nutritional deficiency, drinking causing disharmony between the spleen and kidneys), and the diet should be light and avoid spicy, cold, and raw foods to prevent the formation of phlegm. During the remission period, the therapy usually focuses on nourishing the lung, spleen, and kidneys, and it is not advisable to eat fish, shrimps, crabs, raw chicken, and other irritants. During the acute infection period, the diet should be light and nutritious, and it is advisable to avoid spicy and hot foods. The dietary therapy should be used in combination with the diagnosis and treatment situation.

　　Anticoagulant or thrombolytic therapy alone can improve renal function only when the occlusion is incomplete and if effective thrombolysis begins within 90 to 180 minutes (the ischemic tolerance of normal kidneys). However, this rapid diagnosis and treatment is rarely achieved.

　　Surgical recovery for vascular patency in surgical procedures is associated with a high mortality rate, while renal function does not recover significantly. However, surgery, especially when performed in the first few hours, is a treatment option for patients with traumatic renal artery thrombosis. For patients with severe renal failure, if the function has not recovered within 4 to 6 weeks, surgical vascular replacement surgery can be considered. This late thrombectomy procedure is only helpful to a few patients. Anticoagulant prophylaxis is usually administered with heparin injection, followed by warfarin oral administration.