In the course of industrialization in rural areas there are a lot of obstruction factors, one important factor of which is system.
在农村工业化推进过程中存在许多阻碍因素，制度因素是其中一个重要方面。
2
Conclusion Ureteral stent is a factor for causing obstruction in normal ureter.
结论对正常的上尿路，内支架是一个梗阻因素。
3
Conclusions: the existence of crossing segmental vessels might not be the only initiating factor in the cause of the obstruction of UPJ in this disease.