Impact of Body Mass Index on Cost and Clinical Outcomes After Percutaneous Nephrostolithotomy


      To evaluate the impact of body mass index (BMI) on clinical outcomes and costs associated with percutaneous nephrostolithotomy (PCNL).


      We reviewed charts of 200 consecutive patients who underwent PCNL between September 2005 and May 2007. We recorded patient and stone characteristics and perioperative outcomes. BMI was available for 150 patients (75%), who comprised our study group. We obtained direct and subcomponent costs (room and board, laboratory, pharmacy, radiology, operating room, surgical supplies, anesthesia, and recovery room). We divided patients into four BMI categories: normal weight (BMI < 25), overweight (25 ≤ BMI < 30), obese (30 ≤ BMI < 40), and morbidly obese (BMI ≥ 40). We compared groups with regard to baseline characteristics, intraoperative parameters, stone-free and complication rates, and hospital length of stay.


      Mean stone size and proportion of patients with staghorn, multiple, and bilateral calculi were similar among groups. The normal weight cohort had proportionately fewer recurrent stone formers and patients with a history of stone surgery, compared with the other groups (P = .005 and P = .03, respectively). We found no significant differences among groups with regard to stone-free and complication rates, operative time, length of stay, or need for multiple accesses. Median direct cost was marginally, but not significantly, higher in normal weight ($8124) compared with overweight ($6746), obese ($6740), and morbidly obese ($6719) patients (P = .75).


      Body mass index had no impact on efficacy or complication rates of PCNL. Despite greater perceived difficulty in performing these procedures in overweight and obese patients, it was not more costly.
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        • Lotan Y.
        • Pearle M.S.
        Economics of stone management.
        Urol Clin North Am. 2007; 34: 443-453
        • Pearle M.S.
        • Calhoun E.A.
        • Curhan G.C.
        Urologic diseases in America project: urolithiasis.
        J Urol. 2005; 173: 848-857
        • Curhan G.C.
        Epidemiology of stone disease.
        Urol Clin North Am. 2007; 34: 287-293
        • Flegal K.M.
        • Carroll M.D.
        • Ogden C.L.
        • et al.
        Prevalence and trends in obesity among US adults, 1999-2000.
        JAMA. 2002; 288: 1723-1727
        • Wolf A.M.
        • Colditz G.A.
        Current estimates of the economic cost of obesity in the United States.
        Obes Rev. 1998; 6: 97-106
        • Deane L.A.
        • Clayman R.V.
        Advances in percutaneous nephrostolithotomy.
        Urol Clin North Am. 2007; 34: 383-395
        • Preminger G.M.
        • Assimos D.G.
        • Lingeman J.E.
        • et al.
        AUA guideline on management of staghorn calculi: diagnosis and treatment recommendations.
        J Urol. 2005; 173: 1991-2000
        • Segura J.W.
        • Preminger G.M.
        • Assimos D.G.
        • et al.
        Ureteral Stones Clinical Guidelines Panel summary report on the management of ureteral calculi.
        J Urol. 1997; 158: 1915-1921
        • Bensalah K.
        • Raman J.D.
        • Bagrodia A.
        • et al.
        Does obesity impact the costs of partial and radical nephrectomy?.
        J Urol. 2008; 179: 1714-1717
        • Choban P.S.
        • Flancbaum L.
        The impact of obesity on surgical outcomes: a review.
        J Am Coll Surg. 1997; 185: 593-603
        • Hawn M.T.
        • Bian J.
        • Leeth R.R.
        • et al.
        Impact of obesity on resource utilization for general surgical procedures.
        Ann Surg. 2005; 241 (discussion 826-828): 821-826
        • Carson III, C.C.
        • Danneberger J.E.
        • Weinerth J.L.
        Percutaneous lithotripsy in morbid obesity.
        J Urol. 1988; 139: 243-245
        • El-Assmy A.M.
        • Shokeir A.A.
        • El-Nahas A.R.
        • et al.
        Outcome of percutaneous nephrolithotomy: effect of body mass index.
        Eur Urol. 2007; 52: 199-204
        • Koo B.C.
        • Burtt G.
        • Burgess N.A.
        Percutaneous stone surgery in the obese: outcome stratified according to body mass index.
        BJU Int. 2004; 93: 1296-1299
        • Pearle M.S.
        • Nakada S.Y.
        • Womack J.S.
        • et al.
        Outcomes of contemporary percutaneous nephrostolithotomy in morbidly obese patients.
        J Urol. 1998; 160: 669-673
        • Sergeyev I.
        • Koi P.T.
        • Jacobs S.L.
        • et al.
        Outcome of percutaneous surgery stratified according to body mass index and kidney stone size.
        Surg Laparosc Endosc Percutan Tech. 2007; 17: 179-183
        • Chang S.S.
        • Duong D.T.
        • Wells N.
        • et al.
        Predicting blood loss and transfusion requirements during radical prostatectomy: the significant negative impact of increasing body mass index.
        J Urol. 2004; 171: 1861-1865
        • Lee C.T.
        • Dunn R.L.
        • Chen B.T.
        • et al.
        Impact of body mass index on radical cystectomy.
        J Urol. 2004; 172: 1281-1285
        • Herman M.P.
        • Raman J.D.
        • Dong S.
        • et al.
        Increasing body mass index (BMI) negatively impacts outcomes following robotic radical prostatectomy.
        JSLS. 2007; 11: 438-442
        • Fugita O.E.
        • Chan D.Y.
        • Roberts W.W.
        • et al.
        Laparoscopic radical nephrectomy in obese patients: outcomes and technical considerations.
        Urology. 2004; 63 (discussion 252): 247-252
        • Gong E.M.
        • Orvieto M.A.
        • Lyon M.B.
        • et al.
        Analysis of impact of body mass index on outcomes of laparoscopic renal surgery.
        Urology. 2007; 69: 38-43
        • Faerber G.J.
        • Goh M.
        Percutaneous nephrolithotripsy in the morbidly obese patient.
        Tech Urol. 1997; 3: 89-95
        • Field A.E.
        • Coakley E.H.
        • Must A.
        • et al.
        Impact of overweight on the risk of developing common chronic diseases during a 10-year period.
        Arch Intern Med. 2001; 161: 1581-1586
        • Taylor E.N.
        • Stampfer M.J.
        • Curhan G.C.
        Obesity, weight gain, and the risk of kidney stones.
        JAMA. 2005; 293: 455-462
        • Raebel M.A.
        • Malone D.C.
        • Conner D.A.
        • et al.
        Health services use and health care costs of obese and nonobese individuals.
        Arch Intern Med. 2004; 164: 2135-2140
        • Quesenberry Jr, C.P.
        • Caan B.
        • Jacobson A.
        Obesity, health services use, and health care costs among members of a health maintenance organization.
        Arch Intern Med. 1998; 158: 466-472
        • Thompson D.
        • Brown J.B.
        • Nichols G.A.
        • et al.
        Body mass index and future healthcare costs: a retrospective cohort study.
        Obes Rev. 2001; 9: 210-218
        • Drain A.J.
        • Gerrard C.
        • Ferguson J.I.
        • et al.
        Does body mass index (BMI) affect cost in cardiac surgery?.
        Interact Cardiovasc Thorac Surg. 2006; 5: 282-284
        • Vincent H.K.
        • Weng J.P.
        • Vincent K.R.
        Effect of obesity on inpatient rehabilitation outcomes after total hip arthroplasty.
        Obesity. 2007; 15: 522-530