Iatrogenic Ureteral Injuries - Causes, Risk Factors, Symptoms, Diagnosis, and Management

What Are Iatrogenic Ureteral Injuries?

There are various types of injuries that affect the human body. There are several causes of injuries like accidents, car crashes, burns, and surgery. Among all the types of injuries, the ones that are caused during surgery or medical examinations are known as iatrogenic injuries. When these injuries originate from the ureters, they are known as iatrogenic ureteral injuries. Ureters are tube-like structures that get injured during gynecological examinations or pelvic surgery. The patients on long-term radiation therapy are most likely to suffer from ureteral injuries. If they are left untreated for long, the complications like ureteral strictures, urinoma, sepsis, and kidney failure usually arise. It is important to determine the cause of the injuries before proceeding with the treatment.

What Are Ureters?

The urinary system contains organs that are designed to perform their specific functions. The organs of the urinary system mainly include the kidneys, the ureters, the urinary bladder, and the urethra. The kidneys filter blood from urine and maintain the fluid and electrolyte levels of the body. The ureters are tube-like structures attached to the kidneys on one end and the urinary bladder on the other. They receive the urine from the kidneys and transport it to the bladder. From the bladder, the urine exits the body through the urethra. If the ureters are injured or become narrow due to injuries, the urine remains in the kidneys. As a result, the kidneys swell and fail to function over time.

What Are the Iatrogenic Causes of Ureteral Injuries?

The ureters are located in the space behind the abdominal cavity (retroperitoneal space), so they are well protected from trauma and injuries. However, structures like the vagina, cervix, colon, rectum, and testes are present close to the ureters. These organs are the most common sites of general and gynecologic surgeries. In addition, the ureters receive their blood supply from the arteries common to these organs. The close proximity to the genital tract organs, and the common blood supply, make ureters vulnerable to injuries. Direct and indirect trauma are the two common mechanisms of iatrogenic ureteral injuries. The causes of iatrogenic ureteral injuries have been described below:

1. Gynecologic Surgery - Gynecologic surgeries are one of the most common causes of ureteral injuries. The injury mainly occurs in the lowest part of the ureter, where it attaches to the bladder. Another site where the ureter is most vulnerable to injury is the infundibulopelvic ligament. It is a ligament of the ovary (the organ that produces the ovum or the egg) that contains the arteries and veins to supply the ureters. The injury occurs when surgical clamps are put on these vessels to stop bleeding. The clamp might damage the ureters or their arteries.

2. Hysterectomy - It is a procedure in which the uterus is removed surgically. The risk of ureteral injury increases when the uterus is large in size, the patient has previously undergone pelvic surgery, and the pelvic organ has prolapsed into the uterus. A ureteral injury might occur when a surgical clip is placed to close the artery or during cauterization. The surgical procedure in which the tissue is destroyed using a hot or cold instrument or by an electric current is known as cauterization.

3. Colorectal Surgery - The colon is a part of the large intestine that removes water and electrolytes from the stools and converts them to solid waste. The rectum is an organ that receives and holds the stools. Colorectal surgery is done to treat colon and rectal cancers and other inflammatory diseases of the intestine. When the diseased tissue is removed during colorectal surgery, the ureters might get resected or injured. The left ureter is more commonly injured compared to the right one.

4. Vascular Surgeries - Vascular surgeries are mainly done to repair the blood vessels that are blocked. These surgeries cause intense inflammation of tissues around the ureters. As a result, the ureters become narrow or develop a fistula.

5. Urologic Procedures - The urologic procedures mainly include ureteroscopy, cystoscopy, lithotripsy, and prostate procedures. During these procedures, the instruments are inserted through the urethra to treat the problems of the urinary tract and other organs. The injuries commonly include perforation, narrowing, and avulsion of the ureters. Ureteroscopy increases the risk of ureteral injuries to a large extent resulting in their damage.

6. Radiation Therapy - Radiation therapy does not pose a major threat to ureters. However, the effects are visible after a long time, and the ureters might become narrow. The flow of urine gets obstructed if the ureters are damaged due to radiation.

What Are the Risk Factors for Iatrogenic Ureteral Injuries?

The factors that increase the risk of iatrogenic ureteral injuries are listed below:

• The uterus size is larger than 12 weeks of pregnancy.

• The growth of tissues outside the uterus (endometriosis) increases the risk of ureteral injuries.

• Cysts present in the ovaries are larger than 4 centimeters.

• The patient has undergone abdominal surgery before.

• Radiotherapy also increases the risk of ureteral injury, but the effects are visible later.

• The organs of the urinary tract have not developed completely or are defective.

• Cancer is in the advanced stage.

What Are the Signs and Symptoms of Iatrogenic Ureteral Injuries?

The ureteral injuries need to be diagnosed at the earliest to avoid complications. The signs and symptoms of ureteral injuries are listed below:

1. The patient experiences pain in the lower back and abdominal region.

2. Pain between the 12th rib and the spine (costovertebral angle).

3. Hematuria, or the presence of blood in the urine, is commonly seen.

4. The patient experiences pain and a burning sensation while passing urine.

5. Fever, nausea, and vomiting might occur randomly without any cause.

6. Abnormal discharge from the vagina.

7. Presence of a lump or mass in the abdomen or pelvis.

8. The urine leaks out as the patient is unable to empty the bladder.

What Methods Are Used to Diagnose Iatrogenic Ureteral Injuries?

Ureteral injuries are diagnosed on the basis of medical history, physical exam, and laboratory and imaging tests. The diagnostic methods have been described below:

• Medical History - The medical history gives a better understanding of the health of the patient and the signs and symptoms of ureteral injuries. It also gives an idea about the surgical treatment that a patient has undergone in the past to know the cause of injury.

• Physical Examination - The doctor palpates the area between the rib and the sign to check for tenderness (costovertebral angle tenderness).

• Laboratory Tests - The following laboratory tests are usually recommended:

• Urinalysis - The patient collects the urine in a container or a sterile bag provided by the hospital. The urine sample is then sent to the laboratory for examination under a microscope. It helps to detect blood, bacteria, pus, and white blood cells in the urine.

• Urine Culture - The urine sample obtained from the patient is sent to the laboratory for examination. It is left unattended for a few days to allow the bacteria to grow. It helps to rule out urinary tract infections because the symptoms of ureteral injuries and urinary tract infections are similar.

• Blood Tests - The doctor recommends the patient undergo a blood test to check the general health of the patient and if any infection is present in the body or not.

• Imaging Tests - The following imaging tests are usually recommended:

• Computerized Tomography (CT) Scans - In this procedure, the patient is laid on a table that slides into a tunnel-like device where the X-rays are taken. It is the most commonly used method of diagnosis because it provides three-dimensional (3D) images of the kidneys and other organs. It is better to take the X-rays after injecting a contrast medium in ureteral injuries.

• Magnetic Resonance Imaging (MRI) Technique - As the name suggests, this technique uses magnetic fields and radio waves to produce images of the organs. It is one of the most effective imaging methods that help to diagnose traumatic injuries to the urinary tract.

• Retrograde Pyelography - In this procedure, a tube known as a catheter is inserted into the urinary bladder through the urethra. The dye is injected into the body through the catheter. X-rays are taken as the dye flows through the urinary tract. Ureteral strictures or other injuries of the ureters due to surgical procedures are easily visible on the X-rays.

• Intravenous Pyelography - The dye is injected into the body through the vein of the patient. X-rays are taken from different angulations to view the urinary system. If the ureters are injured, the dye gets collected in the kidneys and does not flow further. The ureters might not be visible if they are damaged.

How to Manage Iatrogenic Ureteral Injuries?

The treatment of iatrogenic ureteral injuries depends upon the location and extent of the injury. The surgical methods have been described below:

1. Ureteral Reconstruction - Ureteral reconstruction is done in several stages in the patients unable to tolerate the surgery. The stages of ureteral reconstruction surgery are listed below:

   • The ureters are mobilized carefully from their positions, keeping the blood supply intact.

   • The damaged tissues are removed (debridement) until the edges start bleeding.

   • The cut ends of the ureters are attached to each other with the help of stitches.

   • Make sure the attachment is water-tight and remains stable under tension.

   • The repaired uterus must be isolated from the infections. It can be covered with the fat present in the space behind the abdomen to prevent further damage.

2. Ureteroureterostomy - It is a surgical procedure done to repair the defects in the upper and middle parts of the ureters. In this procedure, an opening or an incision is made in the lower part of the abdomen to examine the ureters. Next, the ureters are joined together with the help of sutures. As a result, a single Y-shaped tube is formed that drains the urine from the kidneys to the bladder.

3. Ureteroneocystostomy - In this procedure, an incision is made in the lower abdomen to reach the urinary bladder and the ureters. First, the bladder and the ureters are carefully visualized. Next, the ends of the ureters are attached to the bladder giving a tunnel-like appearance. It is done when the lower part of the ureter is damaged due to surgery.

What Are the Complications of Iatrogenic Ureteral Injuries?

Ureteral injuries damage the ureters to a large extent. If they are left untreated for long, the following complications occur:

• Hydronephrosis - It is a condition in which the kidneys swell due to the backflow of urine. The ureters become damaged due to the injuries and restrict the flow of urine. When the urine does not flow through them, it returns back to the kidneys and increases pressure on them, resulting in hydronephrosis.

• Ureteral Stricture - Ureteral stricture is the scarring and narrowing of the ureters due to several causes, including iatrogenic injuries. Narrow ureters make the flow of urine difficult.

• Urinary Tract Infections - The risk of urinary tract infections increases to a large extent because the urine remains in the body due to ureteral injury. As a result, the bacteria grow in the urine and infect the urinary tract.

Conclusion:

Iatrogenic ureteral injuries occur when the ureters are damaged during surgery or other operative procedures, including the lower abdominal region. The patient usually experiences fever, pain, and a burning sensation while passing urine. Sometimes, it might be thought of as a urinary tract infection, and medications are prescribed. However, the medications only treat the symptoms and do not repair the ureters. It is important to undergo imaging tests to diagnose ureteral injuries because laboratory tests alone cannot help. There are surgical options available to repair the damaged ureters. Therefore, the patient need not worry about the injury and consult the doctor at the earliest to avoid complications.