You will usually see a nephrostomy procedure carried out on an IR list by an interventional radiologist, some hospitals will even have a dedicated nephrostomy & ‘neph’ exchange list as it is quite a common procedure.
The Seldinger Technique
The Seldinger technique, also known as Seldinger wire technique, is a medical procedure used to obtain safe access to blood vessels and other hollow organs percutaneously (through the skin). It is named after Dr. Sven Ivar Seldinger, a Swedish radiologist who introduced the procedure in 1953.
The Seldinger technique involves:
- Placing a needle directly into the hollow organ to gain access (usually using ultrasound guidance)
- A guidewire is threaded through the needle
- The needle is removed over the guidewire, leaving the guidewire in situ
- A catheter is fed over the guidewire through the skin into the hollow organ
- The guidewire is then removed through the catheter
Bloodless Brodel Line
There is a longitudinal avascular plane (line of Brodel) between the posterior and anteriorsegmental arteries just posterior to the lateral aspect of the kidney through which incision results in significantly less blood loss.
A nephrostomy catheter may be placed short term to provide relief from urine build-up, yet some patients are discharged with a long-term nephrostomy lasting from 30-90 days. If further drainage is required, the catheter will be exchanged for a new one & this is known as a nephrostomy exchange. As the access has already been established, this can be done by an IR nurse as it is a relatively simple procedure.
Nephrostomy catheters usually have a pig-tail tip which locks in place (locking pigtail) to provide securement in the renal pelvis of the kidney, making it less likely to be accidentally pulled out. However, this can sometimes cause discomfort to the patient & so companies may offer alternative designs. The external part of the catheter is secured to the skin with a securement dressing & a drainage bag is attached to the catheter which can be fastened to the patient via a Velcro leg strap.
Placing a nephrostomy catheter is generally a safe procedure. The most common associated complication is infection. Patients should be aware of the following symptoms as they may indicate an infection:
- A fever over 101°F (38.3°C)
- Pain in your side or lower back
- Swelling, redness, or tenderness at the site of your dressing
- Urine that is very dark or cloudy, smells bad or is pink or red
If an occlusion in the ureter is causing hydronephrosis, a ureteric stent may be used in conjunction with a nephrostomy catheter to establish patency & provide drainage. A ureteric stent may also be used:
- On its own if hydronephrosis has been managed
- As a preventative measure for stone occlusion prior to lithotripsy
- As a proactive measure for inflammation post PCNL
‘Historically, placement of a percutaneous nephrostomy tube for drainage has been an integral part of the standard PCNL procedure but in recent years, the procedure has been modified to what has been called ‘tubeless’ PCNL, in which nephrostomy catheter is replaced with internal drainage provided by a double-J stent ureteric stent’ Agrawal MS, 2010
The placement of a ureteric stent is similar to placing a nephrostomy catheter:
- The Seldinger technique is used to gain access along the Brodel line of the kidney
- The ureteric stent (also called a double J stent) is fed over the guidewire & then completely pushed down the ureter using a ‘pusher device’.
- The distal end of the ureteric stent sits in the bladder & the proximal end of the stent sits in the renal pelvis.
Double J stents can also be used to maintain patency of the ureter for an illeal conduit. In this case, the distal pigtail sits in the renal pelvis and the proximal pigtail sits on the outside of the skin against the externalised ileum. It is then covered with an ostomy bag to collect the urine.
The main complications associated with ureteric stents include:
- Malposition (too short or long/outside ureter)
- Constant feeling of needing to urinate if ureteric stent is too long & sat against the bladder wall
- Inadequate relief of obstruction (crush related occlusion)
- Ureteral erosion / fistula
- Forgotten Stent