A 38-year-old man from Delhi presents with left-sided flank pain and hematuria for 3 days. Vital signs are stable. Urinalysis shows RBCs 50–60/hpf and calcium oxalate crystals. Non-contrast CT abdomen performed urgently shows a 7 mm hyperdense focus within the left proximal ureter with mild upstream hydronephrosis. What is the most appropriate next step in management?

Explanation

## Clinical Context This patient presents with classic acute nephrolithiasis: flank pain, hematuria, and imaging confirmation of a small (7 mm) radiopaque stone in the proximal ureter with only mild hydronephrosis. The stone size, location, and absence of fever or renal compromise are critical factors. ## Stone Size and Spontaneous Passage **Key Point:** Stones ≤6 mm have a ~90% spontaneous passage rate; stones 6–10 mm have a ~50% passage rate; stones >10 mm rarely pass spontaneously. At 7 mm, this stone falls in the borderline range but still has a reasonable chance of spontaneous expulsion, particularly in a young patient with no obstruction-related complications. ## Management Algorithm ```mermaid flowchart TD A[Acute nephrolithiasis confirmed on NCCT]:::outcome --> B{Stone size?}:::decision B -->|≤6 mm| C[Conservative management]:::action B -->|6-10 mm| D{Fever or renal failure?}:::decision B -->|>10 mm| E[Intervention: ESWL/URS]:::action D -->|Yes| F[Urgent intervention]:::urgent D -->|No| G[Trial of conservative management]:::action C --> H[Hydration, NSAIDs, analgesia]:::action G --> H H --> I[Repeat imaging in 4-6 weeks]:::action I --> J{Stone passed?}:::decision J -->|Yes| K[Metabolic workup]:::action J -->|No| L[Intervention]:::action ``` **High-Yield:** In the absence of fever, sepsis, renal failure, or complete obstruction, conservative management ("watchful waiting") is the standard first-line approach for stones <10 mm, especially in uncomplicated cases. ## Why Conservative Management Here 1. Stone size 7 mm (reasonable passage potential) 2. Mild hydronephrosis (no severe obstruction) 3. No fever, no renal failure 4. Stable vital signs 5. Patient is young and otherwise healthy **Clinical Pearl:** NSAIDs (e.g., indomethacin) reduce ureteral peristalsis and pain; adequate hydration promotes urine flow and stone passage. Alpha-blockers (tamsulosin) may improve passage rates in distal ureteric stones. ## Indications for Intervention - Stone >10 mm - Fever + obstruction (pyonephrosis) - Renal failure - Intractable pain or vomiting - Solitary kidney with obstruction - Pregnancy with obstruction [cite:Harrison 21e Ch 283]