STAGHORN CALCULI

Staghorn calculi denote a branching stone that can occupy ALL or part of the kidney pelvis with branching into multiple or ALL the renal calyces.

 

Management of struvite or staghorn calculi

Staghorn calculi denote a branching stone that can occupy ALL or part of the kidney pelvis with branching into multiple or ALL the renal calyces. They are mostly often composing of struvite (Mg PO⁴) (magnesium ammonium phosphate) and/or Ca⁺HCO³ (Calcium carbonate) apatite. These calculi are strongly complicated with UTI (urinary tract infections) and recurrent infectious episodes of the stone. Staghorn stones can induce septic episodes, decline in renal function that will substantially complicated by ESKD (end-stage kidney disease) if not properly treated. Considering that medical therapy alone can be commonly unsuccessful, most ptns may necessitate definitive surgical interference. The fundamental surgical alternates for staghorn calculi may include the following:

1)    PNL (Percutaneous nephrolithotomy),

2)    SWL (shock-wave lithotripsy),

3)    Combined PNL + SWL, &

4)    Open surgical interference.

 

Recommendations: The following lines of recommendations can be applied to adult ptns with a non-cystine, non-uric acid staghorn stone with 2 equally well-functioning kidneys or a single kidney with normal renal function. Furthermore, an assumption that the medical status of the ptn is generally tolerating general anaesthesia and any of the 4 modules of therapy. Given the poor outcome that expected with not removing the staghorn stone, all newly diagnosed ptns should commence an urgent stone removal intervention.  

o   PNL (Percutaneous nephrolithotomy): advised as a 1^st line of therapy for most ptns.

o   PNL should be the last procedure in ptns requiring combined therapy with PNL + SWL, to ascertain total removal of calcular fragments.

o   SWL as monotherapy is suggested, with placing of adequate renal drain prior to the procedure (often a ureteral stenting), applied only in selected ptns with small stone volume with normal anatomical collecting system.

For ptns with small fragments persisting 8 weeks after procedure implantation, proper AB therapy in addition to 40-60 mEq of K⁺ Citrate per day. Considering that the outcome of percutaneous nephrolithotomy is simulating open surgery, but with less morbidity rates, open surgery (anatrophic nephrolithotomy) is advised only in a highly selected circumstances, as following:

1)    Ptns with a large stone burden, particularly with anatomical extremely distorted collecting system, where a reasonably less invasive interventions will not be successful in removing the stone.

2)    Ptns with Morbid obesity with technically difficult endoscopic & fluoroscopic application.

 

Ptns with a staghorn stone in a failing or poorly functioning kidney, particularly with chronic infection, nephrectomy seems to be reasonable therapeutic option. After successful therapy, periodically monitored (every 6-12 mo) should be implemented as newly formed stone could be expected, sometimes involving the contralateral kidney. Urologic radiology with plain abdominal radiographs or a non-contrasted renal CT scanning & 24-h urine examination may help determining stone recurrence and the efficacy of medical stone therapy.