Several conditions have been identified to cause strictures such as impacted<unk>  stones, iatrogenic injuries, tumours and radiotherapy. Iatrogenic injuries Endoscopic urological procedures are common with the advancement of medical technology which allows endoscopic procedures to be among the main operative modalities in urology. However, complications can occur, and iatrogenic injury is disruption of healthy tissue which might lead to local inflammation in the process of healing and scarring which can result in<unk> . Non-endoscopic open surgical procedures such as colon surgery where the operation field is very close to the adjacent retroperitoneal ureter is a well-known procedure where ureters can be injured, especially when surgical plans are distorted in conditions such as tethered colon cancer or advanced inflammatory bowel disease. In the same way gynaecological operations near the ureters can lead to their injury, one of the common conditions where surgical plans are not clear is the presence of advanced endometriosis. Radiotherapy Radiotherapy had been identified as a cause of<unk> s formation. Damage occur as a result of both direct and indirect insults such as direct injury to cell proteins and DNA or mutation of the DNA which leads to future insults respectively. This is not surprising as in the same way radiotherapy is expected to treat cancer and hence collateral damage can occur hence it can be challenging to treat as blood supply and vascularity are believed to be affected when stricture repair is intended. For instance, Radiotherapy of cervical cancer can cause<unk>  in 2.2% of patients at 10 years. Radiotherapy had been identified as a modality of treatment of several cancers in the pelvis and the abdomen which may lead to<unk>  formation among other urological adverse effects too such as radiation induced cystitis. Among those cancers are; /colon and Anorectal cancer, cervical cancer, endometrial cancer and prostate cancer. Impacted<unk>  stones Kidney stones are becoming more common with time, and their incidence is believed to increase recently due to unhealthy diet habits. The passage of kidney stones into ureters might lead to their impaction and the development of local inflammatory process around the stone in addition to the obstruction of the ipsilateral kidney and build up of pressure manifested as hydronephrosis. Several studies were conducted to find stricture rates which varies from one to another but it seems that modern technology and treatment approaches are minimising the chances for stricture development post impacted stone treatment.
Ureteric stricture
Glomerulonephrosis
Hydronephrosis
Pyonephrosis
Urethral stricture
Obstructive uropathy
Bladder stone
Vesicoureteral reflux