This great systematic review evaluated dissolution therapies for uric acid stones. Dissolution has been widely reported usually with compounds containing sodium, potassium, magnesium and citrate or sodium bicarbonate (Mostly taken orally). The efficiency of the dissolution therapy, reported as complete or partial dissolution, was achieved in 85% of patients, being 61.7% complete dissolution and 19.8% partial dissolution. Surprisingly the patient compliance with the medication was almost 90%, and here good patient concealing based on the good evidence is key. Regarding complications, most were gastrointestinal disturbances noted in 50% of patients. Finally, a key point of this study is that dissolution therapy should be the first line of treatment for patients with uric acid stones as only 15% required surgical intervention.

I came across this very complete literature review on stent encrustation that provides most of what you need to know on the subject.

Stent encrustation is the mineral deposition or calcification of a stent that can range from micro-calcifications (being asymptomatic) to a real nightmare with obstructive encrustations and renal failure. Key risk factors include indwelling time, factors like those of stone disease and urinary infection and bacterial biofilms.

The industry has made huge efforts to make specific stents with special coatings and materials to reduce the formation of bacterial biofilms but unfortunately there is no clear evidence that they are clinically efficient, although nowadays several studies have shown that silicone stents are the least prone to calcify. To prevent such encrustations, reducing indwelling time is key, especially in cystine and brushite stones. Also, urine acidification in struvite stones and alkalinization in uric acid stone formers may be an efficient preventive method. As for already encrusted stents, invasive management may be needed; The V-GUES classification may be helpful to decide the surgical approach and counseling patients.

This great paper took data from patients filing commercial claims that had a stent within 6 months of a shock wave lithotripsy or an ureteroscopy.

The aim of the study was to identify any relationship between ureteral stent duration with several events and complications.

The results showed that patients witting 31 to 60 days for an ureteroscopy after ureteral stent placement had significantly higher inpatient admissions rates, imaging, infectious complications and increased overall cost of the disease, compared to those waiting less than 15 d. Also, patients witting more than 30 days for a shock wave lithotripsy after stent placement, had significantly higher ED visits, inpatient admissions, imaging, infectious complications and increased overall cost of the disease, compared to those waiting less than 15 days.

This article carries the important message that stone formers should be treated in less than a month after a stent.