Injuries to the ureters, or the tubes that connect the kidneys to the bladder, are fairly rare since the structures are well-protected within the body, but there are certain situations that can damage them. Probably the most common is when inadvertent ureteral injuries occur during surgical procedures within the abdomen, such as colorectal surgeries or hysterectomies. They may also be the result of abdominal trauma, particularly with wounds like gunshots or stabbings that penetrate internally. Kidney stones passing through the ureters may also damage them, as can certain other diseases like fibrosis and cancer.
The most frequent reason for people to have ureteral injuries is when surgery on nearby tissues damages them. Gynecological procedures, particularly hysterectomies, are often to blame. Colorectal and vascular surgeries in the abdomen can also lead to unintended ureteral damage. They may also be the result of procedures done on the urologic system, such as endoscopic surgeries that involve inserting instruments into the ureter itself, as well as surgical removal of tumors and sometimes radiation treatments.
Another potential cause of ureteral injuries is external trauma. While it is possible for a blunt trauma to the abdomen such as a blow or fall to hurt the ureters, it is fairly unlikely. Far more often, the cause of ureteral damage is an injury that penetrates the abdominal cavity and causes a perforation or puncture of the structures, such as a knife wound or gunshot.
Kidneys stones can also be a source of ureteral injuries. As these stones pass from the kidneys into the ureters, they may become lodged in the passages and block the flow of urine, which has the potential to damage both structures. The hard stones may also cause bruising or inflammation as they pass through the tubes. Also, if an endoscopic procedure is required to help remove the stone or place a stent to aid in urine drainage, the risk of injury is even greater.
Ureteral injuries can also occur due to disease. Retroperitoneal fibrosis can cause a buildup of tissue in the abdomen that can then put pressure on the ureters. Cancerous tumors within the abdominal cavity may also push on them. This can become particularly problematic for the ureters if the cancer spreads to the nearby lymph nodes. In addition to any problems caused by the cancer itself, the treatments for cancer — surgery, radiation, and chemotherapy — can lead to additional ureteral injury.