ORIGINAL REPORTS

BILATERAL STAGHORN CALCULI 
IN AN EIGHTEEN MONTH-OLD BOY

Jose Murillo B. Netto, MD

Luis M. Perez, MD, FAAP

Leandro Ruas Batista, MD

Stuart A. Royal, MD

John R. Burns, MD

Children's Hospital, University of Alabama at Birmingham
Birmingham, Alabama

CASE REPORT

An 18-month-old white boy was referred to our service for bilateralstaghorn calculi noted on a routine chest radiograph. He had a historyof prematurity resulting in bronchopulmonary dysplasia and hydrocephalussecondary to an intraventricular bleed. These were managed with furosemideadministration during the first 3 months of life and a ventriculoperitoneal(VP) shunt. A conventional abdominal radiograph confirmed the presenceof bilateral partial staghorn stones (Fig.1a) which on intravenous urography (IVU) completely filled the lowerpole moiety of a left duplex system and partially filled the right lowerrenal pole collecting system (Fig.1b). A screening urine culture was positive for Proteus mirabilis.Voiding cystourethrogram was normal. Serum creatinine, calcium, phosphorus,uric acid, and parathyroid hormone levels were normal.
During a single general anesthetic bilateral pyelolithotomies wereperformed with intraoperative flexible nephroscopy and electrohydroliclithotripsy of accessible calyces. Bilateral indwelling JJ stents wereplaced. The follow-up abdominal radiograph revealed bilaterally reducedstone burdens (Fig.2a). Stone analysis revealed 96 % calcium phosphate (90% carbonateform and 6% hydroxyl form) and 4 % protein. Outpatient extracorporeal shockwave lithotripsy (ESWL) was performed during separate sessions on the leftand right remnant stone burdens at 1 and 3 months following open surgery,respectively. Each stone burden received 2,000 shocks at 15 kilovolts usingthe Dornier HM-3 lithotriptor. Following his last ESWL treatment, the childis free of nephrolithiasis by IVU, renal ultrasonography, and conventionalradiography performed at 6, 14 and 23 months respectively (Fig.2b). He does have small stone fragments in his retroperitoneum fromhis open surgery.
 

COMMENTS

Although nephrocalcinosis has been frequently reported in infants treatedwith furosemide, staghorn calculi have rarely been reported in this agegroup.1-3 The etiology of nephrocalcinosis associated with furosemidetherapy in infants is related to a hypercalciuric state which may be managedby observation, hydration, and thiazide therapy.4 In addition,the spot urinary calcium-creatinine ratio may aid in predicting which caseshave a greater chance of resolution.5 As in our case, staghorncalculi are generally associated with urinary tract infection with urease-splittingbacteria such as Proteus and Klebsiella.1 However,although our child had a complete and partial staghorn calculi as wellasProteus bacteriuria, his stone analysis revealed mainly a stonecomposed of calcium phosphate (apatite) rather than magnesium ammoniumphosphate (struvite).1

The treatment of staghorn calculi is more technically demanding in infantsthan older children or adults due to size of the kidneys, an increasedchance of renal artery thrombosis secondary to aggressive renal mobilization,and more difficult percutaneous access with standard equipment. Therefore,more than one surgical intervention may be required to eradicate a largerenal stone burden in an infant. Similar to the adult population, the treatmentoptions include anatrophic nephrolithotomy, pyelolithotomy, percutaneousnephrolithotomy, and ESWL.1, 3 We believe that it is criticalto completely eradicate significant stone burdens in any child in the hopeto preserve long-term renal function. Recently, the use of an 11 French(F) peel-away access sheath in combination with electrohydraulic lithotripsyor Holmium-YAG laser has made the percutaneous nephrolithotomy more attractivein infants and small children than open surgery combined with ESWL.6Previously, 24 to 30 F working percutaneous nephrostomy sheaths had beenused in children which in theory would result in significant trauma tothe infantís kidney.6

REFERENCES

1. Segura JW. Staghorn calculi. Urol Clin North Am 1997; 24 (1): 71-80.
2. Ezzedeen F, Adelman RD, Ahlfors CE. Renal calcification in preterminfants: pathophysiology and long-term sequelae. J Ped 1988; 113 (3): 532-539.
3. Burns JR, Joseph DB. Combination therapy for a partial staghorncalculus in an infant. J Endourol 1993; 7 (6): 469-471.
4. Hufnagle KG, Khan SN, Penn D, Cacciarelli A, Williams P. Renal calcifications:a complication of long-term furosemide therapy in preterm infants. Pediatrics70: 360-363, 1988.
5. Pope JC, Trusler LA, Klein AM, Walsh WF, Yared A, Brock JW. Thenatural history of nephrocalcinosis in premature infants treated with loopdiuretics. J Urol 156: 709-712, 1996.
6. Jackman SV, Hedican SP, Peters CA, Docimo SG. Percutaneous nephrolithotomyin infants and preschool age children: experience with a new technique.Urology 52: 697-701, 1998.