Minimally invasive treatment options for calyceal diverticula include percutaneous surgery, ureteroscopy, and laparoscopic surgery. Most investigators agree that eradication of the calyceal diverticula is essential for the prevention of stone recurrence in these patients. The percutaneous approach has a high stone-free rate of 90% [9
]. Traditionally, this approach required dilatation of the ostium and fulguration of the mucosa. Recently, Kim et al. have demonstrated that dilatation of the tract is not necessary. Their technique involved the fulguration of the diverticulum using a roller-ball electrode without cannulating or dilating the infundibulum [10
]. However, this is done using hypotonic irrigation solution thus the potential risk of postoperative serum electrolyte disturbances.
Holmium:yttrium-aluminum-garnet (Ho:YAG) or the holmium laser has a wavelength of 2100
nm, which is absorbed by water [11
]. Furthermore, its depth of penetration is only 0.5 to 1
]. In addition, holmium laser provides the advantage of using normal saline as an irrigation solution. In a prospective study of holmium laser enucleation of the prostate, it was found that the procedure was not associated with dilutional hyponatremia, and it did not affect the sodium concentration postoperatively [13
]. Therefore, it is safer to use holmium laser and it allows for a longer operative time. In this initial case report, we present for the first time percutaneous Holmium laser fulguration of calyceal diverticula in 2 patients using normal saline. In the present study, the postoperative serum sodium remained stable or increased (). Furthermore, the procedures were performed in an ambulatory setting since both patients were healthy with satisfactory post-operative chest X-rays and hematocrits (). Follow-up IVP indicated stone-free status at 24 months in the first patient and at 12 months in the second patient; both were symptom-free at 30 months. However, larger sample size is required to confirm these results.
A controversy exists whether underlying urinary metabolic abnormalities in patients with calyceal diverticular stones exist [14
]. In the present study, both patients showed metabolic stone work-up abnormalities that were treated adequately ().