Effect of medical management on recurrent stone formation following percutaneous nephrolithotomy.
OBJECTIVE
Percutaneous nephrolithotomy is a commonly used procedure for treatment of large or complex renal calculi. In some instances postoperative residual stone fragments are an unavoidable result. Yet to our knowledge no study has examined the impact of medical management on stone formation in patients with or without residual fragments following percutaneous nephrolithotomy. Thus, we have conducted the first investigation of aggressive medical management following percutaneous nephrolithotomy and its impact on stone formation rates in patients with and without residual fragments.


METHODS
A total of 70 patients who underwent percutaneous nephrolithotomy and received counseling regarding selective medical management following a comprehensive metabolic evaluation, were identified. Patients were placed into 4 groups following percutaneous nephrolithotomy, that is stone-free or residual fragments, who underwent or did not undergo medical therapy. New stone formation was assessed by spontaneous stone passage in the absence of residual stone fragments, stone passage without change in the number of residual fragments, surgical removal of newly formed stones, or appearance of new stones or increase in size of stone or fragments on abdominal radiographs. Stone remission rates were also calculated.


RESULTS
Selective medical therapy significantly decreased stone formation rates in the stone-free (0.67 stones per patient per year vs 0.02) and residual fragment groups (0.67 stones per patient per year vs 0.02) as determined by the Wilcoxon signed rank test (p<0.0001). Moreover, remission was observed in a higher proportion of patients in the medically treated stone-free and residual fragment groups (87% and 77%) when compared to the same groups without medical therapy (29% and 21%, chi-square test p<0.0001).


CONCLUSIONS
Our findings suggest that comprehensive metabolic evaluation and aggressive medical management can control active stone formation and growth in patients with or without residual stone fragments after percutaneous nephrolithotomy. Given the inherent morbidity and increased costs attendant with repeat procedures, medical management should be instituted in patients following percutaneous nephrolithotomy without regard to stone-free status.
Kang
David E
DE
Comprehensive Kidney Stone Center, Duke University Medical Center, Durham, North Carolina 27710, USA.
Maloney
Michaella M
MM
Haleblian
George E
GE
Springhart
W Patrick
WP
Honeycutt
Emily F
EF
Eisenstein
Eric L
EL
Marguet
Charles G
CG
Preminger
Glenn M
GM
D000493:Allopurinol / Q000627:therapeutic use*; D004232:Diuretics / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D006074:Gout Suppressants / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D053040:Nephrolithiasis / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000601:surgery*; D009403:Nephrostomy, Percutaneous; D019357:Potassium Citrate / Q000627:therapeutic use; D011860:Radiography, Abdominal; D012189:Retrospective Studies; D055502:Secondary Prevention; D049993:Sodium Chloride Symporter Inhibitors / Q000627:therapeutic use; D013997:Time Factors; D016896:Treatment Outcome
D004232:Diuretics; D006074:Gout Suppressants; D049993:Sodium Chloride Symporter Inhibitors; D000493:Allopurinol; D019357:Potassium Citrate