Medullary Sponge Kidney Treatment & Management
- Author: Amit K Ghosh, MD, DM, FACP; Chief Editor: Vecihi Batuman, MD, FACP, FASN more...
Approach Considerations
Asymptomatic adults with medullary sponge kidney
Advise patients about the benign nature of medullary sponge kidney, and inform them about the possibility of renal calculi and urinary tract infections (UTIs) due to the condition. Obtaining periodic urinalysis and abdominal radiographs is recommended, although guidelines for the frequency of radiologic surveillance in asymptomatic adults are unclear.
Asymptomatic children with medullary sponge kidney
In asymptomatic children with medullary sponge kidney, conduct regular surveillance for Wilms tumor and other abdominal tumors.
Patients with medullary sponge kidney and recurrent nephrolithiasis
Patients are advised to drink plenty of fluids in order to have a daily urinary output in excess of 2L. A 24-hour urine collection for potential kidney stone risk factors (eg, calcium, citrate, uric acid, magnesium, sodium, oxalate, phosphate) can be very helpful in treating the metabolic factors contributing to nephrolithiasis.[1, 10]
Patients with medullary sponge kidney and distal RTA
Adjust the dosage and timing of potassium citrate supplementation to increase the urinary pH to a maximum of 7.0-7.2. Overalkalinization can lead to calcium phosphate precipitation and stone formation.
Patients with medullary sponge kidney and UTI
Medullary sponge kidney in these patients must be treated aggressively until the urine is clear. Proteus infection can lead to the formation of struvite stones and requires aggressive antibacterial therapy.
Prevention of stone formation
As previously mentioned, Fabris et al advised that patients with medullary sponge kidney be screened using 24-hour urine collection to evaluate for stone risk factors (ie, hypocitraturia, hypercalciuria, hyperuricosuria, hyperoxaluria).[8] Patients who demonstrate abnormality in any of these test results should be considered for treatment with potassium citrate to prevent stone formation. The starting dose of potassium citrate is 20 mEq/day and should be adjusted to keep a urinary citrate level of 450 mg/day and a urinary pH level of less than 7.5.
Surgery
Patients with medullary sponge kidney and symptomatic nephrolithiasis can be treated with extracorporeal shock wave lithotripsy (ESWL), percutaneous surgery, or ureteroscopy. Partial nephrectomy must be performed in severe cases with segmental renal involvement.
In rare cases in which patients with medullary sponge kidney are suffering from severe urosepsis, unilateral nephrectomy is performed.
Consultations
Urologic consultation may be essential in patients with medullary sponge kidney presenting with recurrent nephrolithiasis or acute urinary tract obstruction. Patients with congenital abnormalities associated with medullary sponge kidney may also need urologic surveillance.
Diet
Patients with medullary sponge kidney and hypercalciuria should avoid a high-protein diet. Patients are advised to drink plenty of fluids in order to generate a daily urinary output in excess of 2L.
Fick GM, Gabow PA. Hereditary and acquired cystic disease of the kidney. Kidney Int. Oct 1994;46(4):951-64. [Medline].
Gambaro G, Feltrin GP, Lupo A, et al. Medullary sponge kidney (Lenarduzzi-Cacchi-Ricci disease): a Padua Medical School discovery in the 1930s. Kidney Int. Feb 2006;69(4):663-70. [Medline].
Yagisawa T, Kobayashi C, Hayashi T, et al. Contributory metabolic factors in the development of nephrolithiasis in patients with medullary sponge kidney. Am J Kidney Dis. Jun 2001;37(6):1140-3. [Medline].
Forster JA, Taylor J, Browning AJ, et al. A review of the natural progression of medullary sponge kidney and a novel grading system based on intravenous urography findings. Urol Int. 2007;78(3):264-9. [Medline].
Levine E, Hartman DS, Meilstrup JW, et al. Current concepts and controversies in imaging of renal cystic diseases. Urol Clin North Am. Aug 1997;24(3):523-43. [Medline].
Palubinskas AJ. Renal pyramid structure opacification in excretory urography and its relation to medullary sponge kidney. Radiology. Dec 1963;81:963-70. [Medline].
Higashihara E, Nutahara K, Tago K, et al. Medullary sponge kidney and renal acidification defect. Kidney Int. Feb 1984;25(2):453-9. [Medline].
Fabris A, Lupo A, Bernich P, et al. Long-term treatment with potassium citrate and renal stones in medullary sponge kidney. Clin J Am Soc Nephrol. Sep 2010;5(9):1663-8. [Medline].
Lang EK, Macchia RJ, Thomas R, et al. Improved detection of renal pathologic features on multiphasic helical CT compared with IVU in patients presenting with microscopic hematuria. Urology. Mar 2003;61(3):528-32. [Medline].
McPhail EF, Gettman MT, Patterson DE, Rangel LJ, Krambeck AE. Nephrolithiasis in Medullary Sponge Kidney: Evaluation of Clinical and Metabolic Features. Urology. Oct 17 2011;[Medline].
| Frequency | Clinical Findings | Etiology |
| Common* | Nephrolithiasis (calcium oxalate, calcium apatite) | Hypercalciuria Increased oxalate concentration Tubular acidification defects Hypocitraturia |
| Hematuria (gross 10-20%, microscopic) | Acute pelvic obstruction UTI, renal stones, or absence of both | |
| UTI | Sterile pyuria common even in absence of stones Presence of renal stones | |
| Rare | Chronic kidney disease | Repeated urinary obstruction Repeated pyelonephritis due to urease-producing organisms (Proteus) |
| *Asymptomatic | ||
| Radiologic Test | Appearance |
| Plain radiograph | Normal or enlarged kidney Medullary nephrocalcinosis indicated by isolated, single or multiple precaliceal concretions or clusters of grapelike calcifications |
| Excretory urogram* | Papillary blush Faint pyramidal striation Papillary streaking or brushlike appearance Precaliceal tubular dilatation filled with contrast Papillary blush and multiple precaliceal dilatation Bouquet of flowers |
| CT scan | Papillary calcification Hyperdense papilla Ectasia of precaliceal tubules |
| *Findings limited to medullary pyramids | |
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