Endourology and Stones Obesity in Percutaneous Nephrolithotomy. Is Body Mass Index Really Important? n Meza Martınez, Andrew John Vicens Morton, Carlos Torrecilla Ortiz, Alcides Iva Helena Vila Reyes, Sergi Colom Feixas, Jose Francisco Suarez Novo, and Eladio Franco Miranda OBJECTIVE
MATERIALS AND METHODS
RESULTS
CONCLUSION
To evaluate the influence of obesity in the results of percutaneous nephrolithotomy (PCNL) in terms of efficacy and safety and to evaluate other aspects such as fluoroscopy time, radiation exposure, total operative time, hemoglobin loss, hospital stay, and the need of auxiliary procedures. We evaluated prospectively all the PCNLs performed at our institution between 2011 and 2012. A series of perioperative and postoperative details were recorded in our database. The patients were distributed in 4 groups using World Health Organization’s classification of body mass index (BMI): normal weight, 25 kg/m2; overweight, 25-29.9 kg/m2; obese, 30-39.9 kg/m2; and morbidly obese, 40 kg/m2. Modified Clavien classification was used for reporting the complications. Results were compared between the groups using the chi square and multivariate logistic regression tests. A total of 255 procedures were performed between January 2011 and December 2012. Overall stone clearance was 76.3% and complication rate using the modified Clavien grading system was 31.4%. No statistical differences in terms of complication rate and stone free rate were noted between the 4 groups. Total operative time and radiation doses increase along with BMI. No difference was found in fluoroscopy time, failure to gain access, hospital stay, or need for auxiliary procedures. Obesity does not increase complications in PCNL, and the efficacy of the technique is similar to normal weight patients with appropriate expertise. Total operative time and radiation exposure increase along with BMI, putting patients at risk. UROLOGY 84: 538e543, 2014. 2014 Elsevier Inc.
W
orldwide overweight and obesity have been increasing not just in industrialized but in developing countries as well.1,2 During the last 2 decades, it has been more frequent in clinical practice to encounter obese patients with large renal stones that demand treatment. Percutaneous nephrolithotomy (PCNL) is the standard of care for intrarenal calculi 2 cm.3 Recently, The Clinical Research Office of the Endourological Society (CROES) published the results of a prospective PCNL database reporting lower stone free rate (SFR) and prolonged operative time in super obese patients contrary to contemporary series with results independent of body mass index (BMI). We evaluate the influence of obesity in the results of this technique.
OBJECTIVE The main objective was to evaluate the influence of overweight and obesity in the results of the PCNL in Financial Disclosure: The authors declare that they have no relevant financial interests. From the Stone Disease Unit, Department of Urology, Hospital Universitario de Bellvitge, Barcelona, Spain Reprint requests: Alcides Ivan Meza Martınez, M.D., Departamento de Urologıa, Hospital Universitario de Bellvitge, Feixa Llarga s/n, Hospitalet de Llobregat, Barcelona 08907, Spain. E-mail: [email protected] Submitted: December 15, 2013, accepted (with revisions): March 30, 2014
538
ª 2014 Elsevier Inc. All Rights Reserved
terms of efficacy and safety. Other aspects were evaluated as well, including total operative and fluoroscopy time, radiation exposure, hemoglobin loss, hospital stay, and the need of auxiliary procedures.
MATERIALS AND METHODS We included in our prospective study all the PCNLs performed at our institution between January 2011 and December 2012. Sample size was calculated with GPower, version 3.1,4 to achieve 80% power to detect a theoretical effect size (W) of at least 0.2 with chi square test using a significance level alpha of 0.05. A series of preoperative, intraoperative, and postoperative details were recorded in our database with emphasis on BMI, stone clearance, and postoperative complications. Stone burden, defined as the greatest cross-sectional area of the stone viewed anteroposteriorly and measured in square centimeters, was calculated from preoperative noncontrast computed tomography in all cases. Fluoroscopy time and total radiation exposure were provided by the Phillips BV Endura fluoroscopy C-arc. The patients were distributed in 4 groups using the World Health Organization classification for obesity: normal weight, BMI 25; overweight, BMI ¼ 25-29.9; obese, 30-39.9; and morbidly obese group, BMI 40 kg/m2. SFR was defined as no residual fragments in the imaging follow-up. The modified Clavien classification was used for grading and reporting the complications. http://dx.doi.org/10.1016/j.urology.2014.03.062 0090-4295/14
Table 1. Preoperative characteristics Characteristic N Age, y, mean SD M:F BMI, kg/m2 HTA, n (%) Diabetes, n (%) Previous kidney surgery, n (%) PCNL Open Both Stone area, cm2, mean SD Stone shape, n (%) Complete staghorn Incomplete staghorn Multiple lithiasis (>3)
Normal Weight
Overweight
Obesity
Morbidly Obese
P Value*
77 51.9 15.8 53%: 47% 22.7 19 (24.7%) 10 (13.0%)
93 56.2 13.3 61%: 39% 27.3 43 (46.2%) 21 (22.6%)
75 54.7 12.1 53%: 47% 33.7 35 (46.7%) 12 (16%)
10 58.4 11.2 30%: 70% 44.1 5 (50.0%) 4 (40%)
.17 .24
MATERIALS AND METHODS
RESULTS
CONCLUSION
To evaluate the influence of obesity in the results of percutaneous nephrolithotomy (PCNL) in terms of efficacy and safety and to evaluate other aspects such as fluoroscopy time, radiation exposure, total operative time, hemoglobin loss, hospital stay, and the need of auxiliary procedures. We evaluated prospectively all the PCNLs performed at our institution between 2011 and 2012. A series of perioperative and postoperative details were recorded in our database. The patients were distributed in 4 groups using World Health Organization’s classification of body mass index (BMI): normal weight, 25 kg/m2; overweight, 25-29.9 kg/m2; obese, 30-39.9 kg/m2; and morbidly obese, 40 kg/m2. Modified Clavien classification was used for reporting the complications. Results were compared between the groups using the chi square and multivariate logistic regression tests. A total of 255 procedures were performed between January 2011 and December 2012. Overall stone clearance was 76.3% and complication rate using the modified Clavien grading system was 31.4%. No statistical differences in terms of complication rate and stone free rate were noted between the 4 groups. Total operative time and radiation doses increase along with BMI. No difference was found in fluoroscopy time, failure to gain access, hospital stay, or need for auxiliary procedures. Obesity does not increase complications in PCNL, and the efficacy of the technique is similar to normal weight patients with appropriate expertise. Total operative time and radiation exposure increase along with BMI, putting patients at risk. UROLOGY 84: 538e543, 2014. 2014 Elsevier Inc.
W
orldwide overweight and obesity have been increasing not just in industrialized but in developing countries as well.1,2 During the last 2 decades, it has been more frequent in clinical practice to encounter obese patients with large renal stones that demand treatment. Percutaneous nephrolithotomy (PCNL) is the standard of care for intrarenal calculi 2 cm.3 Recently, The Clinical Research Office of the Endourological Society (CROES) published the results of a prospective PCNL database reporting lower stone free rate (SFR) and prolonged operative time in super obese patients contrary to contemporary series with results independent of body mass index (BMI). We evaluate the influence of obesity in the results of this technique.
OBJECTIVE The main objective was to evaluate the influence of overweight and obesity in the results of the PCNL in Financial Disclosure: The authors declare that they have no relevant financial interests. From the Stone Disease Unit, Department of Urology, Hospital Universitario de Bellvitge, Barcelona, Spain Reprint requests: Alcides Ivan Meza Martınez, M.D., Departamento de Urologıa, Hospital Universitario de Bellvitge, Feixa Llarga s/n, Hospitalet de Llobregat, Barcelona 08907, Spain. E-mail: [email protected] Submitted: December 15, 2013, accepted (with revisions): March 30, 2014
538
ª 2014 Elsevier Inc. All Rights Reserved
terms of efficacy and safety. Other aspects were evaluated as well, including total operative and fluoroscopy time, radiation exposure, hemoglobin loss, hospital stay, and the need of auxiliary procedures.
MATERIALS AND METHODS We included in our prospective study all the PCNLs performed at our institution between January 2011 and December 2012. Sample size was calculated with GPower, version 3.1,4 to achieve 80% power to detect a theoretical effect size (W) of at least 0.2 with chi square test using a significance level alpha of 0.05. A series of preoperative, intraoperative, and postoperative details were recorded in our database with emphasis on BMI, stone clearance, and postoperative complications. Stone burden, defined as the greatest cross-sectional area of the stone viewed anteroposteriorly and measured in square centimeters, was calculated from preoperative noncontrast computed tomography in all cases. Fluoroscopy time and total radiation exposure were provided by the Phillips BV Endura fluoroscopy C-arc. The patients were distributed in 4 groups using the World Health Organization classification for obesity: normal weight, BMI 25; overweight, BMI ¼ 25-29.9; obese, 30-39.9; and morbidly obese group, BMI 40 kg/m2. SFR was defined as no residual fragments in the imaging follow-up. The modified Clavien classification was used for grading and reporting the complications. http://dx.doi.org/10.1016/j.urology.2014.03.062 0090-4295/14
Table 1. Preoperative characteristics Characteristic N Age, y, mean SD M:F BMI, kg/m2 HTA, n (%) Diabetes, n (%) Previous kidney surgery, n (%) PCNL Open Both Stone area, cm2, mean SD Stone shape, n (%) Complete staghorn Incomplete staghorn Multiple lithiasis (>3)
Normal Weight
Overweight
Obesity
Morbidly Obese
P Value*
77 51.9 15.8 53%: 47% 22.7 19 (24.7%) 10 (13.0%)
93 56.2 13.3 61%: 39% 27.3 43 (46.2%) 21 (22.6%)
75 54.7 12.1 53%: 47% 33.7 35 (46.7%) 12 (16%)
10 58.4 11.2 30%: 70% 44.1 5 (50.0%) 4 (40%)
.17 .24
