Struvite and Staghorn Calculi Guidelines

Updated: Apr 28, 2023
  • Author: Maxwell Meng, MD; Chief Editor: Bradley Fields Schwartz, DO, FACS  more...
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Guidelines Summary

The American Urological Association/Endourological Society have published a guideline on the surgical management of stones. [11, 12] Recommendations relevant to adult patients with struvite and staghorn calculi include the following:

  • Clinicians should obtain a non-contrast computed tomography (CT) scan on patients before performing percutaneous nephrolithotomy (PNL) (strong recommendation; evidence level grade C)
  • Clinicians may obtain a non-contrast CT scan to help select the best candidate for shockwave lithotripsy (SWL) versus ureteroscopy (conditional recommendation; grade C)
  • Clinicians may obtain a functional imaging study (DTPA or MAG‐3) if clinically significant loss of function in the involved kidney or kidneys is suspected (conditional recommendation; grade C)
  • Clinicians must obtain a urinalysis prior to intervention; a urine culture should be obtained in patients with clinical or laboratory signs of infection (strong recommendation; grade B)
  • Clinicians should obtain a complete blood cell count and platelet count in patients undergoing procedures where there is a significant risk of hemorrhage or for patients with symptoms suggesting anemia, thrombocytopenia, or infection; serum electrolytes and creatinine should be obtained if reduced kidney function is suspected (expert opinion)
  • In patients with complex stones or anatomy, clinicians may obtain additional contrast imaging if further definition of the collecting system and the ureteral anatomy is needed (conditional recommendation; grade C)
  • In symptomatic patients with a total renal stone burden >20 mm, clinicians should offer PNL as first-line therapy (strong recommendation; grade B)
  • In patients with total renal stone burden >20 mm, clinicians should not offer SWL as first-line therapy (moderate recommendation; grade C)
  • Nephrectomy may be performed when the involved kidney has negligible function in patients requiring treatment (conditional recommendation; grade C)
  • For patients with symptomatic (flank pain), non-obstructing, caliceal stones without another obvious etiology for pain, clinicians may offer stone treatment (moderate recommendation; grade C)
  • SWL should not be offered as first-line therapy to patients with >10 mm lower pole stones (strong recommendation; grade B)
  • Patients with lower pole stones >10 mm in size should be informed that PNL has a higher stone-free rate but greater morbidity (strong recommendation; grade B)
  • Flexible nephroscopy should be a routine part of standard PNL (strong recommendation; grade B)
  • Normal saline irrigation must be used for PNL and ureteroscopy (strong recommendation; grade B)
  • Patients not considered candidates for PNL may be offered staged ureteroscopy (moderate recommendation; grade C)
  • Alpha-blockers may be prescribed to facilitate passage of stone fragments after SWL (moderate recommendation; grade B)
  • SWL should not be used in patients with anatomic or functional obstruction of the collecting system or ureter distal to the stone (strong recommendation; grade C)
  • Staghorn stones should be removed if attendant comorbidities do not preclude treatment (clinical principle)
  • When residual fragments are present, endoscopic procedures should be offered to render the patient stone free, especially if infection stones are suspected (moderate recommendation; grade C)
  • Stone material should be sent for analysis (clinical principle)
  • Open/ laparoscopic /robotic surgery should not be offered as first-line therapy to most patients with stones; exceptions include rare cases of anatomic abnormalities, with large or complex stones, or those requiring concomitant reconstruction (strong recommendation; grade C)
  • A safety guide wire should be used for most endoscopic procedures (expert opinion)
  • Antimicrobial prophylaxis should be administered prior to stone intervention and is based primarily on prior urine culture results, the local antibiogram, and in consultation with the current Best Practice Policy Statement on Urologic Surgery Antibiotic Prophylaxis (clinical principle)
  • If purulent urine is encountered during endoscopic intervention, the clinician should abort stone removal procedures, establish appropriate drainage, continue antibiotic therapy, and obtain a urine culture (strong recommendation; grade C)
  • If initial SWL fails, endoscopic therapy should be offered as the next treatment option (moderate recommendation; grade C)
  • Ureteroscopy should be used as first-line therapy in most patients who require stone intervention in the setting of uncorrected bleeding diatheses or who require continuous anticoagulation/antiplatelet therapy (strong recommendation; grade C)