A physician-validated, board-style question from the Active Transport QBank. Try it, then check the reasoning for every option.
A 57-year-old man presents with acute-onset nausea and left flank pain. He says his symptoms suddenly started 10 hours ago and have not improved. He describes the pain as severe, colicky, intermittent, and localized to the left flank. The patient denies any fever, chills, or dysuria. His past medical history is significant for nephrolithiasis, incidentally diagnosed 10 months ago on a routine ultrasound, for which he has not been treated. His family history is unremarkable. The patient is afebrile, and his vital signs are within normal limits. On physical examination, he is writhing in pain and moaning. Severe left costovertebral angle tenderness is noted. Gross hematuria is present on urinalysis. A non-contrast CT of the abdomen and pelvis reveals a 12-mm obstructing calculus at the left ureterovesical junction. Initial management, consisting of IV fluid resuscitation, antiemetics, and analgesia, is administered. Which of the following is the best next step in the management of this patient?
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A
UreteroscopyCorrect. Ureteroscopy with laser lithotripsy is the preferred definitive treatment for distal ureteral stones >10 mm at the UVJ, with high stone-free rates.
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B
Percutaneous nephrostolithotomy (PCNL)Incorrect. PCNL is indicated for large renal calculi (>2 cm) or staghorn stones, not distal ureteral stones.
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C
Extracorporeal shockwave lithotripsy (ESWL)Incorrect. ESWL has lower efficacy for distal ureteral and large (>10 mm) stones; not first-line at the UVJ.
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D
24-hour urine chemistryIncorrect. 24-hour urine chemistry guides long-term prevention after a metabolic workup; inappropriate during acute obstruction requiring intervention.
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E
Alpha-blocker (tamsulosin) for medical expulsive therapyIncorrect. Medical expulsive therapy with an alpha-blocker is appropriate for distal ureteral stones <10 mm; a 12-mm obstructing UVJ stone is too large for spontaneous passage and requires definitive urologic intervention.
↑ Tap an answer to reveal the reasoning
Answer: A. Stone management is driven primarily by stone size, location, and clinical context. This patient has an obstructing 12-mm stone at the ureterovesical junction (UVJ)—a stone this large will not pass spontaneously (only stones <5 mm reliably pass; 5-10 mm pass ~50% of the time; >10 mm rarely pass). With acute obstruction, intractable pain, and a stone too large for medical expulsive therapy, definitive stone removal is required.
Ureteroscopy (URS) with laser lithotripsy is the procedure of choice for distal ureteral stones, with the highest single-procedure stone-free rates (>90%) for stones at the UVJ. It allows direct visualization, fragmentation, and basket retrieval, and is preferred over ESWL for distal stones because of better access and efficacy. PCNL is reserved for large (>2 cm) renal stones or staghorn calculi. ESWL is less effective for distal ureteral stones and large stones, and is best for proximal/mid-ureteral or renal stones <2 cm.
24-hour urine chemistry is used in metabolic workup after a stone-forming patient is stable—not during an acute obstructive episode.
**Why each option:**
**A.** Correct. Ureteroscopy with laser lithotripsy is the preferred definitive treatment for distal ureteral stones >10 mm at the UVJ, with high stone-free rates.
**B.** PCNL is indicated for large renal calculi (>2 cm) or staghorn stones, not distal ureteral stones.
**C.** ESWL has lower efficacy for distal ureteral and large (>10 mm) stones; not first-line at the UVJ.
**D.** 24-hour urine chemistry guides long-term prevention after a metabolic workup; inappropriate during acute obstruction requiring intervention.