Ureteropelvic junction (UPJ) obstruction is a condition that affects the urinary system, specifically the point where the ureter connects to the renal pelvis in the kidney. This obstruction occurs when there is a partial or complete blockage at the ureteropelvic junction, impeding the flow of urine from the kidney to the bladder.

Symptoms of ureteropelvic junction obstruction may include flank pain, abdominal pain, blood in the urine (hematuria), and recurrent urinary tract infections. In some cases, individuals may not experience any symptoms, and the condition may be discovered incidentally.

Diagnosis typically involves imaging tests. Treatment options for ureteropelvic junction obstruction depend on the severity of the condition. Early detection and appropriate management are crucial for preventing complications and preserving kidney function in individuals with ureteropelvic junction obstruction. Here i will give up-to date informations about UPJ obstruction.

What is ureteropelvic junction

The ureteropelvic junction (UPJ) is a specific anatomical region in the urinary system where the ureter connects to the renal pelvis. To understand this, it’s helpful to know the basic anatomy of the urinary system.

The urinary system consists of the kidneys, ureters, bladder, and urethra. The kidneys filter waste products and excess fluids from the blood to form urine. The urine then flows from the kidneys to the bladder through narrow tubes called ureters. Each kidney has a funnel-shaped structure called the renal pelvis, and the ureter connects to this renal pelvis at a point known as the ureteropelvic junction.

The role of the ureteropelvic junction is crucial because it serves as the exit point for urine to move from the kidney into the ureter, facilitating its journey to the bladder for eventual elimination from the body. Any obstruction or narrowing at this junction can interfere with the normal flow of urine, leading to a condition known as ureteropelvic junction obstruction.

In summary, the ureteropelvic junction is the specific location where the ureter connects to the renal pelvis in the kidney, playing a vital role in the urinary system’s function by allowing the passage of urine from the kidney to the ureter and ultimately to the bladder.

What is UPJ obstruction?

Ureteropelvic junction (UPJ) obstruction is a medical condition characterized by a blockage or narrowing at the point where the ureter (the tube that carries urine from the kidney to the bladder) connects to the renal pelvis (the upper part of the kidney). This obstruction hinders the normal flow of urine from the kidney to the bladder, leading to various symptoms and potential complications.

Causes of UPJ obstruction

UPJ obstruction can have various causes, and it may be classified into congenital (present from birth) or acquired (developed after birth) conditions. Here are some common causes:

1. Congenital Abnormalities:

1. Intrinsic Narrowing: Some individuals may have a naturally narrow or tight ureteropelvic junction due to developmental factors. This congenital condition can restrict the flow of urine from the renal pelvis to the ureter.
2. Abnormal Blood Vessels: Anomalous blood vessels near the ureteropelvic junction can compress or obstruct the urinary passage, leading to UPJ obstruction.
3. Aberrant Crossing Vessels: In some cases, blood vessels may cross over the ureter, causing compression and obstruction.

2. Scarring or Fibrosis:

2. Previous Surgery: Surgical procedures involving the urinary system or nearby structures may result in scarring that can lead to UPJ obstruction.
3. Inflammation: Inflammatory conditions, such as previous infections or conditions causing chronic inflammation, may contribute to scarring and fibrosis around the ureteropelvic junction.

• Kidney Stones: The presence of kidney stones in or around the ureteropelvic junction can obstruct the flow of urine.
• Pregnancy: In some cases, pregnant women may develop UPJ obstruction due to compression of the ureter by the enlarging uterus.

5. Tumors or Masses:

5. Intrinsic Tumors: Tumors or growths within the ureter or at the ureteropelvic junction can obstruct urine flow.
6. Extrinsic Compression: Tumors or masses outside the ureter, such as adjacent abdominal or pelvic tumors, may compress the ureter and cause obstruction.

• Trauma: Trauma to the abdominal or pelvic region, such as injuries from accidents or surgeries, can lead to UPJ obstruction.
• Infection or Inflammation: Chronic infections or inflammatory conditions affecting the ureteropelvic junction may contribute to scarring and narrowing, leading to obstruction.

Symptoms

UPJ obstruction can present with a variety of symptoms, although some individuals may not experience any noticeable signs. Common symptoms associated with UPJ obstruction include:

• Flank Pain: Pain or discomfort in the side of the lower back or abdomen is a typical symptom. This pain is often intermittent and may be triggered by factors such as increased fluid intake.
• Abdominal Pain: In addition to flank pain, some individuals may experience generalized abdominal pain.
• Hematuria: Blood in the urine (hematuria) may occur. The presence of blood may be visible to the naked eye or detected through microscopic analysis of the urine.
• Urinary Tract Infections (UTIs): Recurrent urinary tract infections can be a sign of UPJ obstruction. The obstruction may lead to stagnant urine, providing an environment conducive to bacterial growth.
• Nausea and Vomiting: Severe cases of UPJ obstruction may cause a backup of urine, leading to pressure on the kidney and resulting in symptoms such as nausea and vomiting.

It’s important to note that some individuals with UPJ obstruction may be asymptomatic, especially if the condition is mild or if the obstruction is present from birth (congenital) and the body has adapted to it over time.

Diagnosis

UPJ obstruction involves a combination of clinical evaluation, imaging studies, and sometimes specialized tests. Here are the common diagnostic approaches:

• Clinical History and Physical Examination: The healthcare provider will gather information about the patient’s medical history, including any symptoms such as flank pain, hematuria, or recurrent urinary tract infections. A physical examination may reveal tenderness in the flank region.
  • Ultrasound: This non-invasive imaging technique uses sound waves to create images of the urinary system. It can help visualize the kidneys, ureters, and bladder, and identify any signs of obstruction or dilation of the renal pelvis.
  • Computed Tomography (CT) Scan: CT scans provide detailed cross-sectional images of the urinary tract, aiding in the identification and characterization of UPJ obstruction.
  • Magnetic Resonance Imaging (MRI): MRI can be used to visualize the anatomy of the kidneys and urinary tract, providing additional information about the obstruction.

Voiding Cystourethrogram (VCUG): In some cases, a VCUG may be performed. This involves injecting a contrast dye into the bladder and capturing X-ray images as the patient urinates. It helps assess the flow of urine and can identify any abnormalities in the ureteropelvic junction.

• Diuretic Renal Scintigraphy (MAG3 Scan): This nuclear medicine test involves injecting a small amount of a radioactive substance (MAG3) into the bloodstream. Images are then taken to assess kidney function and drainage. It helps determine the severity of the obstruction.
  • Urodynamic Studies: Urodynamic studies may be used in some cases to assess bladder and urethral function. While not commonly used for UPJ obstruction, they can provide additional information in certain situations.

Indications for surgery

The decision to perform surgery for UPJ obstruction is generally based on several factors, taking into account the severity of symptoms, the impact on kidney function, and the overall health of the patient. Indications for surgery include:

• Persistent or Severe Symptoms: If an individual experiences persistent or severe symptoms such as flank pain, abdominal pain, hematuria (blood in urine), or recurrent urinary tract infections, surgical intervention may be considered to alleviate these symptoms.
• Decreased Kidney Function: UPJ obstruction can lead to the accumulation of urine in the kidney, causing pressure and potentially impairing kidney function. Surgery may be recommended to prevent or address kidney damage and preserve renal function.
• Hydronephrosis: The presence of significant hydronephrosis (dilation or swelling of the kidney) due to UPJ obstruction may be an indication for surgery. Surgery aims to relieve the obstruction and restore normal urine flow, reducing the dilation of the renal pelvis and associated pressure.
• Recurrent Urinary Tract Infections: If UPJ obstruction contributes to recurrent urinary tract infections, surgery may be considered to prevent future infections and their potential impact on kidney health.
• Failure of Conservative Management:  n cases where conservative approaches, such as observation and medication, fail to provide relief or if symptoms worsen over time, surgery may be recommended.
• Impaired Drainage on Imaging Studies: Imaging studies, such as ultrasound, CT scans, or nuclear medicine tests, may reveal impaired drainage of urine from the kidney, indicating the need for surgical correction.

How to prepare before operation?

UPJ operation involves a series of steps to ensure that both the patient and the healthcare team are well-prepared for the procedure. Here are general guidelines for preparing before a UPJ operation:

• Medical Evaluation: Undergo a thorough medical evaluation, including physical examination and relevant diagnostic tests. Provide a detailed medical history, including information about current medications, allergies, and previous surgeries.
• Discussion with Surgeon: Engage in detailed discussions with the surgeon to understand the specific details of the planned operation, including the chosen surgical approach (open, laparoscopic, robotic) and potential risks and benefits.
• Preoperative Testing: Complete any required preoperative tests, which may include blood tests, imaging studies, and electrocardiogram (ECG) to assess overall health and identify potential risk factors.
• Medication Management: Follow the surgeon’s instructions regarding the management of medications before the operation. This may involve adjustments to certain medications or the temporary discontinuation of specific drugs, especially blood-thinning medications.
• Fasting: Follow the fasting guidelines provided by the surgical team. Typically, patients are required to refrain from eating or drinking for a specified period before the scheduled surgery.
• Hygiene and Skin Preparation: Shower or bathe using a prescribed antiseptic solution the night before or the morning of the surgery to reduce the risk of infection.
• Clothing and Personal Items: Wear comfortable, loose-fitting clothing to the hospital on the day of the surgery. Bring personal items such as identification, insurance information, and any necessary personal care items.
• Support System: Arrange for a support system to assist with transportation to and from the hospital and to provide support during the recovery period.
• Instructions for Arrival: Follow any specific instructions provided by the surgical team regarding the time of arrival at the hospital or surgical center.
• Postoperative Planning: Discuss postoperative care and recovery expectations with the surgeon, including any restrictions on activities, medications, and follow-up appointments.

Treatment of UPJ obstruction

The treatment of UPJ obstruction depends on the severity of the condition, the presence of symptoms, and the impact on kidney function. Here are some common treatment approaches:

• Observation: In cases where UPJ obstruction is mild and asymptomatic, healthcare providers may choose a conservative approach of close monitoring without immediate intervention. Regular follow-up examinations and imaging tests may be recommended.
• Medications: Pain management: Over-the-counter or prescription pain medications may be prescribed to alleviate flank or abdominal pain associated with UPJ obstruction. Antibiotics: In cases where there are recurrent urinary tract infections (UTIs) due to stasis of urine, antibiotics may be prescribed to prevent and treat infections.
• Surgical Intervention: Pyeloplasty: Pyeloplasty is a surgical procedure designed to reconstruct the ureteropelvic junction. The obstructed or narrowed segment is removed, and the healthy portions of the ureter and renal pelvis are reconnected to reestablish a wide, unobstructed passage for urine.

Types:

1. Open Pyeloplasty: A traditional surgical approach involving a larger incision.
2. Laparoscopic Pyeloplasty: Minimally invasive surgery using small incisions and specialized instruments.
3. Robotic-assisted Pyeloplasty: Similar to laparoscopic pyeloplasty but with the assistance of a robotic surgical system.

• Endopyelotomy: In some cases, a less invasive procedure called endopyelotomy may be considered. This involves using a special instrument to make a small incision or create a passage through the obstruction using endoscopic techniques.
  • Stent Placement: Temporary stents may be placed to keep the ureter open and maintain urine flow. Stents are typically used in certain situations, such as before or after surgery, to facilitate healing.
  • Percutaneous Nephrostomy Tube: In severe cases where urine flow is significantly compromised, a nephrostomy tube may be inserted through the skin into the kidney to bypass the obstruction and allow urine to drain directly.

What to do patients after operation?

After undergoing a UPJ operation, patients need to follow postoperative care instructions to promote healing, minimize complications, and ensure a smooth recovery. Here are general guidelines for patients after a UPJ operation:

• Hospital Stay: The length of the hospital stay depends on the specific surgical approach (open, laparoscopic, robotic) and individual recovery progress. During the hospital stay, healthcare providers will monitor vital signs, manage pain, and observe for any signs of complications.
  • Pain Management:Take prescribed pain medications as directed to manage postoperative pain. Communicate any concerns about pain levels or potential side effects to the healthcare team.
  • Activity and Rest: Follow the surgeon’s recommendations regarding physical activity and rest. Gradually resume light activities as advised, avoiding strenuous exercise or heavy lifting during the initial recovery period.
  • Hydration and Nutrition: Stay well-hydrated and maintain a balanced diet to support healing. Follow any dietary recommendations provided by the healthcare team.
  • Medication Management: Take prescribed medications, including antibiotics or other medications, as instructed by the healthcare team. Discuss the resumption of any previously discontinued medications with the surgeon.
  • Follow-Up Appointments: Attend all scheduled follow-up appointments with the surgeon for postoperative assessments. Discuss any concerns, symptoms, or changes in health during these appointments.
  • Wound Care: Follow instructions for wound care, which may include keeping the incision site clean and dry.  Report any signs of infection, such as increased redness, swelling, or discharge, to the healthcare team.
  • Urinary Catheter Management: If a urinary catheter was placed during the operation, follow guidelines for catheter care and removal, as directed by the healthcare team.
  • Monitoring for Complications: Be vigilant for signs of potential complications, such as persistent fever, worsening pain, or changes in urine color or output.
  • Seek prompt medical attention if any concerning symptoms arise.
  • Resumption of Normal Activities: Gradually resume normal activities based on the surgeon’s recommendations. Avoid driving until approved by the surgeon, especially if taking pain medications that may affect alertness.

Conclusion

In conclusion, UPJ obstruction is a condition characterized by a blockage or narrowing at the point where the ureter connects to the renal pelvis in the kidney. This obstruction disrupts the normal flow of urine, leading to symptoms such as flank pain, abdominal pain, hematuria, and recurrent urinary tract infections.

Diagnosis involves a thorough clinical evaluation and various imaging studies. Treatment options for UPJ obstruction range from observation and conservative measures for mild cases to surgical intervention for more severe or symptomatic cases.

Early detection and appropriate management are crucial to prevent complications and preserve kidney function. Individuals experiencing symptoms suggestive of UPJ obstruction should seek medical attention for a comprehensive evaluation and personalized treatment plan tailored to their specific needs and circumstances. Regular follow-up and communication with healthcare providers are essential to monitor progress and address any ongoing concerns.

Prof. Dr. Emin ÖZBEK

Urologist

Istanbul- TURKEY