Solved on SIR Connect: Decompressing chronic severe hydronephrosis

This column summarizes patient cases posted to SIR Connect (SIR’s popular online member community), the responses from other SIR members and how that feedback helped the original poster. To see how SIR’s online community can help you, visit SIR Connect at connect.sirweb.org.

Original post, lightly edited for flow:

bit.ly/38m6KQ5

I have an 89-year-old male patient with chronic stage IV chronic kidney disease (CKD; Cr of 3.2; GFR 15–20) and have been asked to place a trial left nephrostomy tube to help improve renal function. He has an ileal conduit (age unknown) with a 2.5-year history of severe left hydronephrosis and significant cortical thinning. The right kidney has multiple areas of cortical thinning and stones.

Given the chronic nature of this patient’s severe hydronephrosis, associated cortical thinning and right renal appearance, I don’t think this patient will benefit from nephrostomy tube placement. Additionally, given the fact that he has an ileal conduit, there is a good chance that his urine is contaminated and that he may experience potential bacteremia, making the risk higher than the benefit.

My question: would a nephrostomy tube help renal function in this scenario?

Figure 1. Top: Axial CT demonstrates severe left renal hydronephrosis with cortical thinning

(arrow) and right renal atrophy. Bottom: Sagittal left renal ultrasound depicts severe

hydronephrosis with cortical thinning and increased echogenicity, not significantly changed since examination in 2014 (not shown).

What specifically prompted you to reach out regarding this case?

I was confident that the patient did not need a percutaneous nephrostomy (PCN) given renal imaging and history of severe hydronephrosis dating back 2.5 years. However, the urologists and nephrologist were looking to have the kidney decompressed because of the patient’s renal failure but neither team was aware of the chronicity of the hydronephrosis and the appearance of the kidney. Given the multidisciplinary discussion, I felt it worthwhile to check with my colleagues.

What post or posts were most valuable to you and why?

I found that the recommendation from Susan O’Horo, MD, FSIR, of a loopogram was something I had not thought of and will be useful in future cases.

How would surgical history such as an ileal conduit alter your thinking of your approach? What was the outcome in this case?

Given the presence of an ileal conduit and history of stents (removed 3 years prior for unknown reasons), the patient most likely had a long-standing stricture.

After discussion with the nephrology and urology teams, they agreed that the procedure risk outweighed any benefit and no longer recommended it. Additionally, the patient refused, saying he was aware he had had this for many years and he wanted to recover from his acute illness prior to doing any more procedures.

Additional commentary

PCNs are often placed to relieve urinary obstruction in the acute to subacute setting1–3 as renal function can completely recover if the duration of obstruction is 1 week4. Comparatively, decompression of chronic hydronephrosis is of limited benefit as minimal improvement in renal function is expected after 12 weeks5,6 due to the effects of cell injury, apoptosis and fibrosis7.

Patient selection in the subacute to early chronic setting remains challenging as data on decompressing a chronically dilated system remains sparse. Recently, Sharma et al. suggested that renal cortical thickness, corticomedullary differentiation, status of the contralateral kidney, echogenicity, pre-PCN creatinine and intrapelvic pressure can help determine renal function recoverability and aid in patient selection for PCN placement.8

When considering decompression of a chronically dilated system, initial diagnosis of obstruction can be made noninvasively via ultrasound, CT, MR urography (in the setting of uroenteric diversion) or technetium-99m MAG3 diuretic renography.9,10 Invasive diagnosis includes a perfusion pressure flow study (Whitaker test)2, nephrostogram or loopogram.

When considering trial PCN placement, it is of utmost importance to discuss the procedure expectations with both patients and clinicians, as PCN can cause pain and anxiety and decrease quality of life.11 In the above case, an analysis of clinical history and thoughtful conversations between the interventional radiologist, referring physicians and patient led to the determination that the potential minimal benefit in renal function was outweighed by the risks and side-effects of PCN placement.

References

  1. Ramchandani P, Cardella JF, Grassi CJ, et al. Quality improvement guidelines for percutaneous nephrostomy. J Vasc Interv Radiol. 2003;14(9 Pt 2):S277–281.
  2. Dagli M, Ramchandani P. Percutaneous nephrostomy: Technical aspects and indications. Semin Intervent Radiol. 2011;28(4):424–437.
  3. Pabon-Ramos WM, Dariushnia SR, Walker TG, et al. Quality improvement guidelines for percutaneous nephrostomy. J Vasc Interv Radiol. 2016;27(3):410–414.
  4. Young M, Leslie SW. Percutaneous nephrostomy. In: StatPearls. Treasure Island (FL) 2020.
  5. Better OS, Arieff AI, Massry SG, Kleeman CR, Maxwell MH. Studies on renal function after relief of complete unilateral ureteral obstruction of three months' duration in man. Am J Med. 1973;54(2):234–240.
  6. Sacks SH, Aparicio SA, Bevan A, Oliver DO, Will EJ, Davison AM. Late renal failure due to prostatic outflow obstruction: A preventable disease. BMJ. 1989;298(6667):156–159.
  7. Ucero AC, Gonçalves S, Benito-Martin A, et al. Obstructive renal injury: From fluid mechanics to molecular cell biology. Open Access J Urol. 2010;2:41–55.
  8. Sharma U, Yadav SS, Tomar V. Factors influencing recoverability of renal function after urinary diversion through percutaneous nephrostomy. Urol Ann. 2015;7(4):499–503.
  9. El-Ghar ME, Shokeir AA, El-Diasty TA, Refaie HF, Gad HM, El-Dein AB. Contrast enhanced spiral computerized tomography in patients with chronic obstructive uropathy and normal serum creatinine: A single session for anatomical and functional assessment. J Urol. 2004;172(3):985–988.
  10. Zielonko J, Studniarek M, Markuszewski M. MR urography of obstructive uropathy: Diagnostic value of the method in selected clinical groups. Eur Radiol. 2003;13(4):802–809.
  11. Fernández-Cacho LM, Ayesa-Arriola R. Quality of life, pain and anxiety in patients with nephrostomy tubes. Rev Lat Am Enfermagem. 2019;27:e3191.