Unfavorable anatomical factors influencing the success of retrograde intrarenal surgery for lower pole renal calculi.
OBJECTIVE
To determine the unfavorable factors, related to lower pole anatomical characteristics (LPACs), influencing the success of retrograde intrarenal surgery (RIRS) for lower pole renal calculi (LPC).


METHODS
We reviewed the data of 36 patients who underwent RIRS for LPC between October 2012 and October 2013. The infundibulopelvic angle (IPA), infundibular length (IL) and infundibular width (IW) were measured on preoperative intravenous urographies. On follow-up stone-free status was defined as complete clearance at the first month kidney-ureter-bladder X-ray and computed tomography if necessary.


RESULTS
The median stone size was 10 mm (range, 5-35). The stone-free rates according to LPACs at the first month follow-up were 100% (n = 17), 57.9% (n = 11), 90% (n = 18), 62.5% (n = 10), 90.5% (n = 19) and 60% (n = 9) for patients with IPA ≥ 70°, IPA < 70º, IL < 3 cm, IL ≥ 3 cm, IW ≥ 5 mm and IW < 5 mm, respectively. While IPA and IW were associated with success of RIRS for LPC in multivariate analysis (P = .003 and P = .046, respectively), only IW was found to be a significant factor after applying multivariate analysis (P = .05).


CONCLUSIONS
The results of our study demonstrated that only IW had a significant effect on the success rate of RIRS for LPC.
Department of Urology, Faculty of Medicine, Uludag University, Bursa, Turkey.
Hakan
H
Kilicarslan
Department of Urology, State Hospital, Eskisehir, Turkey. yurdaerkaynak@hotmail.com.
Yurdaer
Y
Kaynak
Department of Urology, Faculty of Medicine, Uludag University, Bursa, Turkey.
Yakup
Y
Kordan
Department of Urology, Faculty of Medicine, Uludag University, Bursa, Turkey.
Onur
O
Kaygisiz
Department of Urology, Faculty of Medicine, Uludag University, Bursa, Turkey.
Burhan
B
Coskun
Department of Urology, Faculty of Medicine, Uludag University, Bursa, Turkey.
Kadir Omur
KO
Gunseren
Department of Urology, Faculty of Medicine, Uludag University, Bursa, Turkey.
Feyzi Mutlu
FM
Kanat
D005260:Female; D005471:Fluoroscopy; D006801:Humans; D007669:Kidney Calculi / Q000175:diagnosis / Q000628:therapy*; D007682:Kidney Pelvis / Q000000981:diagnostic imaging*; D008096:Lithotripsy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009403:Nephrostomy, Percutaneous / Q000379:methods*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D018666:Ureteroscopy / Q000379:methods