Nephrostomy

Authors: Dr Jim Koukounaras*
                            Dr Stuart Lyon *

What are the prerequisites for having a nephrostomy tube insertion?

Nephrostomy is the creation of a communication between the skin and kidney. Placement of a nephrostomy catheter from the skin via this tract into the renal pelvicalyceal system or via the collecting system of the kidney into the ureter allows therapeutic drainage of an obstructed system. The catheter and tract can also be used during the same procedure or later to facilitate stenting of a narrowed ureter or removal/other treatment of stones obstructing the ureter.

Retrograde ureteric stenting by a urologist in order to bypass the obstruction and allow internal drainage is preferable to nephrostomy in most circumstances, if it is technically possible. Nephrostomy is usually preferred in a septic patient.

All patients with urinary obstruction should be discussed with a urologist before referral for nephrostomy tube placement in order to determine if retrograde stenting is possible. If it is not possible, then the insertion of a nephrostomy is likely the only method of relieving the obstruction.

The prognosis of the patient is important. An invasive procedure may not be appropriate for a patient with a very poor prognosis.

It is important to relay the following information to the radiologist once a nephrostomy is indicated:

• underlying cause of the obstruction, if known;
• clinical evidence of sepsis;
• underlying renal disease and history of urological surgery;
• pregnancy status;
• allergies to medication and iodinated contrast;
• anticoagulation medication and bleeding disorders.

The following examinations should be carried out:

• FBE;
• U+E/eGFR;
• INR, APTT, PT.

Other investigations may be required depending on the patient and departmental protocols.

Finally, any relevant medical imaging should be made available.

Depending on the clinical urgency, the nephrostomy may be delayed in order to optimise the patient’s clinical condition. For example, reversing warfarin, cross-matching blood in an anaemic patient or obtaining further imaging if there are anatomical concerns.

What are the absolute contraindications for a nephrostomy?

Absolute contraindication for nephrostomy insertion is exceedingly rare. Severe, uncorrectable bleeding disorders and rare anatomical variations (e.g. retrorenal colon) would be the commonest absolute contraindications.

What are the relative contraindications for a nephrostomy?

Relative contraindications for a nephrostomy include correctable bleeding disorders and anticoagulation, severe hyperkalaemia and contrast allergy. These should be corrected or adequate prophylaxis initiated. Pregnancy is not a contraindication, though special care is required.

What are the adverse effects of a nephrostomy?

Post-nephrostomy insertion, the patient may suffer some pain or discomfort and the draining urine is likely to be bloodstained. The pain should be able to be controlled with simple analgesics. Haematuria normally clears and pain stops by 7 days post-procedure. Other complications are rare, however several issues need to be considered.

Immediate post-procedure (in hospital care)

Any clinical signs of significant bleeding (haemodynamic instability or increasing haematuria) should be reported immediately. Also, any sign of sepsis needs to be reported, as bacteraemia and septic shock are possible complications.

Finally, the tube must be monitored. Evidence of dislodgement or retraction must be observed. The drainage should be monitored both for amount and consistency, as turbid, viscous or bloodstained urine can block the tube. Injection of a small amount of normal saline may clear the obstruction.

Later post-procedural care

The most concerning post nephrostomy complications are:

• increasing pain despite analgesia;
• increasing macroscopic haematuria.

Increasing macroscopic haematuria could mean the development of a pseudoaneurysm of the renal artery or one of its branches.

Increasing pain could indicate sepsis, bleeding, tube blockage or a perinephric collection.

Increasing pain or haematuria after the first week should be reported to the proceduralist.

Documented urine infection (macroscopically and cultured), without clinical evidence of infection, and in the presence of a draining nephrostomy, does not require treatment.

Are there alternative imaging tests, interventions or surgical procedures to a nephrostomy?

Retrograde ureteric stenting by a urologist in order to bypass the obstruction and allow internal drainage is preferable to nephrostomy in most circumstances, if it is technically possible. Nephrostomy is usually preferred in a septic patient.

Further information about nephrostomies:

The nephrostomy can be removed relatively easily once the cause of the obstruction has been resolved. Occasionally, it will need to be removed under image guidance (e.g. to avoid entangling a ureteric stent during removal).

A patient requiring a long-term nephrostomy will need to be educated about its care. If the nephrostomy stops draining or dislodges, they should report it immediately. Reinsertion is often possible, provided the tract has not closed. If urine is still draining from the tract, then it is very likely that the nephrostomy can be reinserted without difficulty.

The nephrostomy will require routine replacement periodically. This can be carried out in a radiology suite as an outpatient. This is a relatively straight forward procedure compared to the initial insertion.

Useful websites about nephrostomies:

CIRSE | Cardiovascular and Interventional Radiological Society of Europe
www.cirse.org/index.php?pid=1057

*The author has no conflict of interest with this topic.

Page last modified on 26/7/2017.