4.左肾静脉压迫综合征（leftrenalveinentrapmentsyndrome，或称胡桃夹现象nutcrackerphenomenon）。
O O B-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis O B-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis O O O B-sym I-sym I-sym I-sym I-sym B-sym I-sym I-sym I-sym I-sym I-sym I-sym I-sym I-sym I-sym I-sym I-sym I-sym I-sym I-sym I-sym I-sym I-sym I-sym I-sym O O