Percutaneous nephrostomy is a minimally invasive procedure used to drain urine from the kidney when normal urine flow is obstructed. A needle is inserted through the skin and kidney under imaging guidance. A catheter is then passed through the needle into the renal pelvis, allowing urine to drain into an external collection bag. This procedure is commonly used to relieve urinary tract obstruction caused by conditions such as kidney stones, tumors, or ureteral strictures. Depending on the underlying condition, it provides temporary or long-term relief and can improve kidney function and alleviate symptoms associated with urinary obstruction.
Why Do You Need Percutaneous Nephrostomy & Drainage?
Percutaneous nephrostomy and drainage are necessary when a blockage in the urinary tract prevents normal urine flow from the kidney to the bladder. This obstruction can result from various conditions such as kidney stones, tumors, ureteral strictures, or congenital abnormalities. Here's why percutaneous nephrostomy and drainage are needed:
- Relief of Urinary Obstruction: The procedure bypasses the obstructed portion of the urinary tract, allowing urine to drain directly from the kidney into an external collection bag. This relieves pressure on the kidney and urinary system, preventing complications such as hydronephrosis (swelling of the kidney) and kidney damage.
- Management of Kidney Stones: Percutaneous nephrostomy is commonly used to drain urine from the kidney when a large kidney stone obstructs the urinary tract. It provides a route for accessing and fragmenting the stone using extracorporeal shock wave lithotripsy (ESWL) or laser lithotripsy.
- Treatment of Urinary Tract Infections: Drainage of infected urine from the kidney can help treat and prevent urinary tract infections (UTIs) associated with urinary obstruction. By removing stagnant urine that harbors bacteria, percutaneous nephrostomy reduces the risk of recurrent infections and sepsis.
- Preparation for Surgical Intervention: In cases where definitive treatment, such as ureteroscopy or nephrolithotomy, is required to remove the obstruction, percutaneous nephrostomy provides temporary drainage and prepares the patient for subsequent surgical procedures.
Types of Percutaneous Nephrostomy & Drainage
Percutaneous nephrostomy and drainage encompass various techniques and approaches tailored to the specific needs of patients with obstructive uropathy or other urinary tract disorders. Here are the types of percutaneous nephrostomy and drainage:
- Standard Percutaneous Nephrostomy: A needle is inserted percutaneously through the skin and into the renal collecting system under imaging guidance. A guide wire is then advanced through the needle into the renal pelvis, followed by dilation of the tract using serial dilators. A nephrostomy tube is finally inserted over the guide wire, allowing urine to drain externally into a collection bag
- Ultrasound-guided Percutaneous Nephrostomy: This approach utilizes real-time ultrasound imaging to guide needle insertion and tract dilation. Ultrasound guidance offers advantages in patients with challenging anatomy or in situations where fluoroscopy may not be readily available.
- Fluoroscopy-guided Percutaneous Nephrostomy: Fluoroscopic guidance involves using X-ray imaging to visualize the urinary tract anatomy and guide needle placement, tract dilation, and nephrostomy tube insertion. Fluoroscopy allows for precise localization of the renal collecting system and accurate placement of the nephrostomy tube.
- Antegrade Nephrostomy vs. Retrograde Nephrostomy: Antegrade nephrostomy involves accessing the renal collecting system through the kidney cortex, whereas retrograde nephrostomy accesses the renal pelvis via the ureter using a retrograde ureteral catheterization technique.
- Balloon Dilation Nephrostomy: In some cases, balloon dilation may dilate the tract after initial needle insertion, facilitating the insertion of larger nephrostomy tubes or stent placement.
How Patients are Selected for the Procedure?
Selecting patients for percutaneous nephrostomy and drainage involves a comprehensive evaluation by a multidisciplinary team comprising interventional radiologists, urologists, nephrologists, and other specialists. Several factors influence the decision-making process:
- Urinary Obstruction: Patients with obstructive uropathy due to conditions such as kidney stones, tumors, ureteral strictures, or congenital abnormalities may require percutaneous nephrostomy and drainage to relieve urinary obstruction.
- Imaging Studies: Diagnostic imaging, such as ultrasound, CT scans, or MRI, is crucial for assessing the anatomy of the urinary tract, identifying the location and severity of obstruction, and determining the feasibility of percutaneous access to the renal collecting system.
- Renal Function: Evaluation of renal function, including serum creatinine levels and estimated glomerular filtration rate (eGFR), helps assess the degree of kidney dysfunction and guide treatment decisions. Patients with compromised renal function may benefit from prompt drainage to prevent further deterioration.
- Clinical Presentation: Patients presenting with symptoms such as flank pain, hematuria, renal failure, or signs of sepsis due to urinary obstruction may require urgent intervention with percutaneous nephrostomy to alleviate symptoms and prevent complications.
- Comorbidity Evaluation: Assessing comorbid conditions such as cardiovascular disease, coagulopathy, or infection is essential to evaluating the patient's overall risk profile and guiding treatment decisions.
- Patient Preferences: Patient preferences, goals of care, and treatment expectations play a significant role in the decision-making process. Shared decision-making between patients and healthcare providers ensures that treatment plans align with patients' values and preferences.
Risks and Benefits Associated with the Chosen Percutaneous nephrostomy & drainage.
Percutaneous nephrostomy and drainage offer risks and benefits that patients and healthcare providers should consider carefully. Here's an overview of the risks and benefits associated with the procedure:
Benefits of Percutaneous nephrostomy & drainage:
- Relief of Urinary Obstruction: Percutaneous nephrostomy and drainage effectively relieve urinary obstruction by bypassing the obstructed portion of the urinary tract. This allows urine to drain directly from the kidney into an external collection bag, alleviating symptoms such as flank pain, hematuria, and renal dysfunction.
- Preservation of Renal Function: Percutaneous nephrostomy and drainage help preserve renal function and prevent complications such as hydronephrosis and renal failure by relieving urinary obstruction and preventing further kidney damage.
- Treatment of Infection: Drainage of infected urine from the kidney can help treat and prevent urinary tract infections (UTIs) associated with urinary obstruction. By removing stagnant urine that harbors bacteria, percutaneous nephrostomy reduces the risk of recurrent infections and sepsis.
- Preparation for Further Intervention: Percutaneous nephrostomy and drainage provide temporary or long-term urine drainage, preparing patients for subsequent surgical interventions to address the underlying cause of urinary obstruction, such as ureteroscopy, nephrolithotomy, or tumor resection.
Risks of Percutaneous nephrostomy & drainage:
- Bleeding: There is a risk of bleeding at the needle insertion site or along the tract during percutaneous nephrostomy and drainage. This risk is higher in patients with coagulopathy or underlying bleeding disorders.
- Infection: Percutaneous nephrostomy and drainage can introduce bacteria into the urinary tract, increasing the risk of urinary tract infection (UTI) or systemic infection (sepsis). Strict sterile techniques are essential to minimize this risk.
- Pain and Discomfort: Patients may experience pain, discomfort, or irritation at the catheter insertion site or along the drainage tract, particularly during the initial post-procedural period. Pain management measures may be required to alleviate discomfort.
- Malposition or Dislodgement: The nephrostomy tube may be malpositioned or dislodged, leading to inadequate drainage or leakage of urine into the surrounding tissues. Close monitoring and prompt intervention are necessary to address these complications.
- Tube Blockage or Dysfunction: Nephrostomy tubes may become blocked or dysfunctional due to blood clots, debris, or kinking, compromising urine drainage and potentially causing renal dysfunction. Regular flushing and drainage system maintenance are essential to prevent tube-related complications.
How is Percutaneous Nephrostomy & Drainage Performed?
Percutaneous nephrostomy and drainage is a minimally invasive procedure performed by interventional radiologists or urologists to alleviate urinary obstruction by providing an alternative route for urine drainage from the kidney. Here's an overview of how the procedure is typically performed:
- Pre-procedure Preparation: Before the procedure, the patient undergoes a thorough evaluation, including diagnostic imaging (such as ultrasound, CT scan, or MRI) to assess the anatomy of the urinary tract and identify the location and severity of obstruction. Laboratory tests may also be conducted to evaluate renal function and assess the risk of bleeding or infection.
- Anesthesia: Local anesthesia is administered to numb the skin and underlying tissues at the catheter insertion site. In some cases, conscious sedation or general anesthesia may be provided to keep the patient comfortable and relaxed during the procedure.
- Needle Insertion: Using imaging guidance (such as ultrasound or fluoroscopy), a needle is inserted percutaneously through the skin and into the renal collecting system. The needle is advanced into the renal pelvis, typically through the posterior or lateral aspect of the kidney.
- Guidewire Placement: Under imaging guidance, a guide wire is then passed through the needle and into the renal pelvis. The needle is then withdrawn, leaving the guide wire in place to facilitate tract dilation and catheter insertion.
- Tract Dilation: The tract is dilated using serial dilators or a balloon catheter to create a pathway for the nephrostomy tube.
- Nephrostomy Tube Placement: A nephrostomy tube, typically made of soft, flexible material, is inserted over the guide wire and advanced into the renal pelvis. The tube is secured in place with sutures or an adhesive dressing.
- Drainage and Monitoring: Once the nephrostomy tube is in place, urine drains from the kidney into an external collection bag or drainage system. The patient is monitored for any immediate complications, such as bleeding or leakage of urine.
- Post-procedure Care: After the procedure, the patient is monitored briefly in a recovery area before being transferred to a hospital room or discharged home. Instructions are provided for caring for and maintaining the nephrostomy tube, including drainage bag management, hygiene, and signs of complications.