[Effect of the body mass index on outcomes of ureterorenoscopy for renal stones].
BACKGROUND
Purpose of this work is to compare the outcome of ureterorenoscopy (URS) with regard to stone-free rates (SFR) and complication rates (CR) in patients with different body mass index (BMI) scores for the treatment of kidney stones.


METHODS
A retrospective chart review of all patients with known BMI, who underwent URS for kidney stones between 2006 and 2012 at our institution, was performed (n = 556 patients). The SFR and CR of obese patients were compared to overweight and normal weight patients.


RESULTS
Mean age was 52.51 years and the average BMI 27.74 kg/m2. Of the patients, 34.2 % had normal weight (22.59 ± 1.91 kg/m2), 39.6 % were overweight (27.30 ± 1.42 kg/m2), and 26.3 % were obese (35.09 ± 5.93 kg/m2). The mean ASA score differed significantly between normal weight (1.99 ± 0.57), overweight (2.03 ± 0.62), and obese (2.22 ± 0.63) patients (p ≤ 0.036). The mean stone size was 8.51 ± 6.84 mm and the mean number of stones per patient 1.9 ± 2.41, whereby the differences between groups was not significant. There were no differences between the groups regarding the use of preoperative (94.8 %) and postoperative ureteral stents (60.3 %), the Ho:YAG laser (33.6 %), the use of flexible (16.2 %) or semirigid/flexible URS (59.4 %), and the mean operative time (52.04 ± 34.55 min). There were no differences in the SFR for the upper (90 %), mid (94.7 %), and lower pole (90.2 %), multiple location (68.6 %) or the total SFR (86.3 %). Total SFR of 95.7, 88.4, and 73.7 % for urinary calculi < 5 mm, 5-9 mm, and ≥ 10 mm, respectively, were found and the differences between the patient groups was not significant. The CR was 10.4 % (differences between the patient groups not significant).


CONCLUSIONS
URS is an appropriate treatment for renal stones with high SFR and low CR regardless of patient's BMI.
Abteilung für Urologie, Asklepios Klinik Barmbek, Rübenkamp 220, 22291, Hamburg, Deutschland. f.schott@asklepios.com.
F
F
Schott
Abteilung für Urologie, Asklepios Klinik Barmbek, Rübenkamp 220, 22291, Hamburg, Deutschland.
S
S
Knipper
Abteilung für Urologie, Asklepios Klinik Barmbek, Rübenkamp 220, 22291, Hamburg, Deutschland.
A K
AK
Orywal
Abteilung für Urologie, Asklepios Klinik Barmbek, Rübenkamp 220, 22291, Hamburg, Deutschland.
A J
AJ
Gross
Abteilung für Urologie, Asklepios Klinik Barmbek, Rübenkamp 220, 22291, Hamburg, Deutschland.
C
C
Netsch
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D002648:Child; D015897:Comorbidity; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D007669:Kidney Calculi / Q000453:epidemiology* / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery*; D011183:Postoperative Complications / Q000453:epidemiology / Q000517:prevention & control*; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D018666:Ureteroscopy / Q000706:statistics & numerical data*; D055815:Young Adult
Clavien classification; Complication rate; Nephrolithiasis; Obesity; Stone free rate