SHM Converge Scientific Abstract ePoster Gallery-When Diarrhea Masks the Truth: A Hidden Stone in Transplanted Kidney

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This case describes a 48-year-old man with a deceased-donor kidney transplant who presented with 3 days of watery diarrhea, fever/chills, weakness, poor oral intake, and decreased urine output. He denied flank pain, dysuria, or abdominal symptoms suggestive of a stone. On exam, he was hemodynamically stable with only mild nonlocalizing abdominal tenderness, and notably lacked CVA tenderness.<br /><br />Initial labs showed severe acute kidney injury and metabolic derangements: creatinine 32.0 mg/dL (baseline 3.6), BUN 165, potassium 6.1, phosphorus 13.4, and severe metabolic acidosis. Infectious workup, including stool cultures and viral testing, was negative. He initially required supportive care and urgent hemodialysis.<br /><br />Because transplanted kidneys are denervated, classic renal colic may be absent. Further evaluation identified an obstructing ureteral stone in the transplanted kidney. Interventional radiology was urgently consulted for nephrostomy tube placement to decompress the graft. After decompression, he developed post-obstructive diuresis with steady improvement in renal function, allowing discontinuation of hemodialysis. He was later discharged with outpatient urology follow-up for ureteroscopy, laser lithotripsy, ureteral stent placement, and eventual nephrostomy tube removal.<br /><br />Key teaching points are that nephrolithiasis in kidney transplant recipients is uncommon but important, occurring in about 1.4%–1.7% of recipients. Symptoms may be atypical or absent because the graft is denervated. CT is the diagnostic gold standard, since ultrasound can be limited by baseline hydronephrosis in transplanted kidneys. Management should be individualized; small nonobstructive stones may be observed, while obstructive stones threatening graft function require urgent decompression.

Asset Subtitle

Scott Nishioka

Meta Tag

Author List Christina Chong, Faris Abu Za'nouneh, Joshua Knapp, Scott Nishioka

Category Clinical Vignettes

Concept Nephrolithiasis

Concept Acute Kidney Injury

Concept Obstructive Urolithiasis

Concept Computed Tomography

Concept Renal Transplant Recipient

Distinguished Non-Finalist

Presenter Organization University of Hawaii

Presenting Author Scott Nishioka

Track Adult

Keywords

kidney transplant

obstructing ureteral stone

acute kidney injury

denervated graft

nephrostomy tube

post-obstructive diuresis

hemodialysis

transplant nephrolithiasis

computed tomography

ureteroscopy

Nephrolithiasis

Acute Kidney Injury

Obstructive Urolithiasis

Computed Tomography

Renal Transplant Recipient