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MP80-12 COST ANALYSIS OF URETERAL STENTING AFTER UNCOMPLICATED URETEROSCOPIC LASER LITHOTRIPSY FOR UROLITHIASIS: A DECISION MODEL ANALYSIS
THE JOURNAL OF UROLOGYâ
Vol. 193, No. 4S, Supplement, Tuesday, May 19, 2015
laterality, rate of positive urine cultures or stone size. Total score > 1.7 was marginally correlated with recurrent status (78% vs. 25%, p¼0.071) and BD score > 0.6 approached significance (55% vs. 0%, p¼0.057). RP score > 1.1 was not associated with recurrent status (p¼0.85). CONCLUSIONS: This standardized grading system suggests Bellini duct plugging on ureteroscopy may be associated with recurrent stones. Future studies with larger numbers of patients will help further determine the utility of this grading system.
Demographics, Baseline Characteristics, and Papillae Grading Outcomes First-time Stone Formers (n¼5)
Recurrent Stone Formers (n¼9)
Total Papillae (%)
23 (31%)
51 (69%)
Age
65.2 12
45.1 11
Female
60
89
Male
40
11
Caucasian
60
44
African American
40
22
Hispanic
0
33
BMI (kg/m2)
34.2 8.9
28.0 5.4
0.128
Charlson Comorbidity Index
3.4 0.9
1.9 1.6
0.08
Smoking
60
22
0.158
Diuretics
40
44
0.872
Prior UTI
20
33
0.597
(+) Family History of Stones
20
33
0.597
1.3 0.5
0.8 0.2
0.0551
6 0.5
6.6 1.1
0.389
Parameter
Sex (%):
p value
0.0073 0.207
Race (%):
0.337
History of (%):
e1023
MP80-11 COMPARISION OF EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY VERSUS URETEROSCOPY HOLMIUM LASER LITHOTRIPSY IN THE MANAGEMENT OF URETERAL STONES: A COST-EFFECTIVENESS ANALYSIS Daniel Lo pez-Aco n, David VivasAlberto Budía*, Vicent Caballer, Jose Consuelo, María Angeles Conca, Pilar Bahílo, Marta Trassierra, Valencia, Spain INTRODUCTION AND OBJECTIVES: In the treatment of ureteral stones, we compared the safety and cost-effectiveness of ureterorenoscopy and intracorporeal lithotripsy with Holmium:YAG laser (URS) vs Extracorporeal Shock Wave Lithotripsy (ESWL). METHODS: 197 patients who were diagnosed and treated for ureteral stones between June 2012 and December 2013, participated in a prospective study. Each patient selected their preferred modality of treatment. 95 patients (48,2%) were in ESWL group and 102 patients (51.8%) were in URS group. ESWL was performed under mild sedation with pethidine hydrochloride for a maximum of 4 sessions, and URS was performed with semirigid or flexible ureterorenoscopes and intracorporeal Holmium:YAG laser lithotripsy under general or spinal anesthesia. The safety and effectiveness of both treatments were assessed and calculated. The direct cost analysis included costs of: hospitalization, operating theatre and lithotripter procedure, health staff, materials and re-treatments for each procedure applied. Additionally, the postoperative visit costs were registered. The data of the global expenditure was extracted from the hospital’s economic information department. A decision tree analysis was modelled for each alternative to estimate the incremental cost effectiveness ratio (ICER). We conducted a Monte Carlo Simulation for a probabilistic sensitivity analysis. RESULTS: Both groups were comparable in terms of side, size, composition of the stone and need for a previous double J ureteric stent. The global stone-free rate was 98%(100) for ureteroscopy plus Holmium and 81%(77) for ESWL (p <0.001). In patients with stones <1cm, the URS was significantly better than the ESWL with stone-free rates of 98.3%(56) and 81,7%(49) respectively. For stones >1 cm there were also differences: 97,8%(44) stone-free rate in the URS group and 80%(28) in the ESWL group (p¼0,01). The overall complication rate was significantly higher in ESWL group (18,95%) as compared to the URS group (1,96%). However, all complications in the ESWL group were Clavien I or II type. The average cost of the SWL group was 973,09 euros, while in the URS group it was 1.537,49 euros. The estimated ICER showed that ESWL was dominant versus first line URS. After performing the Monte Carlo simulation, the dominance of ESWL prevalied regardless of the size of stone (100% for stones < 1 cm and 92,2% for stones >1 cm). CONCLUSIONS: The results of this study indicate that ESWL is more cost-effective than URS for the treatment of ureteral stones. Source of Funding: none
Preoperative: Serum Cr (mg/dL) Urine pH Laterality (%):
0.5
Bilateral
0
22
Left
60
44
Right
40
33
20%
67%
0.094
(+) Urine Culture (%) Stone Size (cm)
20%
11%
0.649
1.36 0.6
0.99 0.4
0.201
Grading Outcomes: 1.51 0.3
1.84 0.8
0.4
% Total Score > 1.7
25
78
0.071
% RP Score > 1.1
50
56
0.853
% BD Score > 0.6
0
56
0.057
Mean Total Score
COST ANALYSIS OF URETERAL STENTING AFTER UNCOMPLICATED URETEROSCOPIC LASER LITHOTRIPSY FOR UROLITHIASIS: A DECISION MODEL ANALYSIS Hin Yu Vincent Tu*, Edward Matsumoto, Hamilton, Canada
Presented with: Multiple stones (%)
MP80-12
Source of Funding: none
INTRODUCTION AND OBJECTIVES: Routine ureteral stenting after uncomplicated ureteroscopy and laser lithotripsy (ULL) is debatable. Purported advantages include preventing ureteral obstruction and facilitating stone passage; disadvantages include stent colic, stent migration and subsequent cystoscopic stent removal. The purpose of our study is to determine whether stenting after uncomplicated ULL is an efficient expenditure of health care resources. METHODS: A decision model was developed to estimate expected costs, complication free outcomes (CFO) and quality-
THE JOURNAL OF UROLOGYâ
e1024
adjusted life years after ULL with and without stenting. Complications were defined as any unplanned hospital visits within the first six postoperative weeks including emergency room visits, admissions to hospital or surgeries. They were graded according to the validated Revised Clavien classification. A comprehensive literature review was performed to determine complication rates and quality of life (QOL) utility values. Costs of surgical procedures were obtained from the Ontario Case Costing Initiative. Sensitivity analyses were performed to determine which parameters affected the outcome of our model. A willingness-to-pay threshold of $3000 was implemented and adopted from drug-eluting stent literature for cardiovascular disease. RESULTS: ULL without stenting was more cost-effective than ULL with stenting in achieving a CFO. ULL with and without stenting cost $3828 and $3248 respectively to achieve an overall complication grade of 0.03 and 0.1 (p<0.05) respectively. Overall complication rates in the stented versus non-stented groups were 2.6% and 6.5% respectively. Sensitivity analysis demonstrated that ULL without stenting remained the most cost-effective if the overall complication rate without stenting remained below 11%, or if the cost of ULL without stenting did not exceed $2275. Due to the paucity of health related QOL data in literature regarding stenting post-ULL, a cost-utility analysis could not be performed. CONCLUSIONS: Our study demonstrated that despite the increased postoperative complication rates associated with non-stented ULL, it was still more cost-effective due to the lower initial surgical costs. A cost-utility analysis was not performed due to the paucity of QOL data in this study population.
Vol. 193, No. 4S, Supplement, Tuesday, May 19, 2015
RESULTS: Out of 41 cases, 15 (37%) were obese (BMI 30). For non-obese patients, average BMI was 23.5, and for obese patients, average BMI was 41.6. In non-obese patients, average PIP was 17.46, 18.10 and 17.90 cm H2O in the supine, early prone and late prone positions respectively; for obese patients average PIP was 23.97, 26.13 and 23.73 cm H2O. There was a statistically significant difference in average PIP between obese and non-obese patients in all 3 positions (p<0.0001, p<0.0001 and p¼0.0009 respectively). There was also a statistically significant change in PIP from the supine to early prone position (p¼0.03) in the obese cohort, but there was no significant difference between supine and late prone position (p¼0.90). There was no statistically significant difference between any positions in non-obese patients (p¼0.16 and p¼0.83 respectively). CONCLUSIONS: Changes in positioning do not affect PIP in non-obese patients. Though there is a statistically significant increase in airway resistance in obese patients, this occurs with initial positioning and PIP normalizes to supine levels by the end of the case. Thus, it appears that the negative effects of positioning on airway resistance and respiratory compliance in obese patients are transient, and that prone positioning for PCNL in obese patients remains a safe and viable option. Source of Funding: None
MP80-14 SLEEP POSTURE COULD PREDICT THE SIDE OF UNILATERAL UROLITHIASIS FORMATION Wei-Ming Cheng*, Tuz-Hao Huang, Yu-Hua Fan, Alex T. L. Lin, Kuang-Kuo Chen, Shi-Chuan Chang, Taipei City, Taiwan
Source of Funding: None
MP80-13 DOES THE PEAK INSPIRATORY PRESSURE INCREASE IN THE PRONE POSITION? AN ANALYSIS RELATED TO BMI. Michael Siev*, Piruz Motamedinia, David Leavitt, David Hoenig, Arthur Smith, Zeph Okeke, New Hyde Park, NY INTRODUCTION AND OBJECTIVES: Percutaneous nephrolithotomy (PCNL) is performed most commonly in the prone position to facilitate access to the renal collecting system. There is concern that the prone position, especially in obese patients, results in negative effects on ventilation, due to restriction of chest compliance and respiratory mechanics. This study analyzes the change in airway resistance between supine and prone positioning of patients undergoing PCNL. METHODS: In this IRB-approved study, between May and October 2014, we retrospectively reviewed 41 patients who underwent prone PCNL while all intraoperative respiratory parameters were continuously recorded. Peak inspiratory pressure (PIP) was selected as a marker of airway resistance and respiratory compliance, and was assessed in supine position, 1 minute after being turned prone (early prone) and at the end of the case (late prone). Results were stratified based on BMI and data were compared using the paired t-test with p < 0.05 considered significant.
INTRODUCTION AND OBJECTIVES: Most urolithiasis forms unilaterally. The published data suggest that sleep posture may alter renal hemodynamics during sleep and promote stone formation. In the present study, we investigated the correlation of sleep posture with stone formation sites in patients with unilateral urolithiasis. METHODS: We retrospectively reviewed the archives of polysomnography for evaluation of obstructive sleep apnea (OSA) between January 1st 2011 and August 31st 2014 and enrolled the patients who experienced extracorporeal shock wave lithotripsy or ureteroscopic lithotripsy for unilateral renal or ureteral stones. Supine, right and left decubitus, and prone sleep postures were defined when patients stayed in the posture for more than 50% of the time during sleep. Others were categorized as rotisserie-like posture. We analyzed the correlation between sleep posture and urolithiasis site. RESULTS: A total of 67 patients were included. 63 (94.0%) were males. Mean age was 51.0 11.8 years. Mean body mass index (BMI) was 29.0 6.7 kg/m2. Sleep postures correlated to urolithiasis sites were showed in the Table. Right decubitus posture was prone to right side urolithiasis (88.9% versus 41.4%, p ¼ 0.011). Furthermore, patients with right side urolithiasis present with less rapid eye movement (REM) ratio (6.9 4.2% versus 10.9 6.9%, p ¼ 0.014). Both right decubitus posture and lower REM ratio remained to be significantly correlated to right side urolithiasis on multivariate analysis (95% CI 0.009 - 0.720, p ¼ 0.024; 95% CI 1.032 - 1.253, p ¼ 0.009, respectively). In patients with optimal sleep efficacy on polysomnography, which was defined as the duration of sleep divided by the duration in bed over 85%, lower stage I ratio (6.6 4.1% versus 26.1 17.7%, p ¼ 0.016), higher stage III ratio (11.89 3.1% versus 3.4 4.9%, p ¼ 0.048), and less sleep stage change among stage I to III and REM (90.0 18.4 times versus 222.7 108.3 times, p ¼ 0.008) were significant predictive factors for formation of ipsilateral stone as sleep posture. Age, gender, BMI, or other polysomnographic parameters were failed to show association with urinary stone sites. CONCLUSIONS: Unilateral urolithiasis formation is correlated to sleep posture. Deeper sleep stage with less sleep stage change may consolidate such correlation.
Vol. 193, No. 4S, Supplement, Tuesday, May 19, 2015
laterality, rate of positive urine cultures or stone size. Total score > 1.7 was marginally correlated with recurrent status (78% vs. 25%, p¼0.071) and BD score > 0.6 approached significance (55% vs. 0%, p¼0.057). RP score > 1.1 was not associated with recurrent status (p¼0.85). CONCLUSIONS: This standardized grading system suggests Bellini duct plugging on ureteroscopy may be associated with recurrent stones. Future studies with larger numbers of patients will help further determine the utility of this grading system.
Demographics, Baseline Characteristics, and Papillae Grading Outcomes First-time Stone Formers (n¼5)
Recurrent Stone Formers (n¼9)
Total Papillae (%)
23 (31%)
51 (69%)
Age
65.2 12
45.1 11
Female
60
89
Male
40
11
Caucasian
60
44
African American
40
22
Hispanic
0
33
BMI (kg/m2)
34.2 8.9
28.0 5.4
0.128
Charlson Comorbidity Index
3.4 0.9
1.9 1.6
0.08
Smoking
60
22
0.158
Diuretics
40
44
0.872
Prior UTI
20
33
0.597
(+) Family History of Stones
20
33
0.597
1.3 0.5
0.8 0.2
0.0551
6 0.5
6.6 1.1
0.389
Parameter
Sex (%):
p value
0.0073 0.207
Race (%):
0.337
History of (%):
e1023
MP80-11 COMPARISION OF EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY VERSUS URETEROSCOPY HOLMIUM LASER LITHOTRIPSY IN THE MANAGEMENT OF URETERAL STONES: A COST-EFFECTIVENESS ANALYSIS Daniel Lo pez-Aco n, David VivasAlberto Budía*, Vicent Caballer, Jose Consuelo, María Angeles Conca, Pilar Bahílo, Marta Trassierra, Valencia, Spain INTRODUCTION AND OBJECTIVES: In the treatment of ureteral stones, we compared the safety and cost-effectiveness of ureterorenoscopy and intracorporeal lithotripsy with Holmium:YAG laser (URS) vs Extracorporeal Shock Wave Lithotripsy (ESWL). METHODS: 197 patients who were diagnosed and treated for ureteral stones between June 2012 and December 2013, participated in a prospective study. Each patient selected their preferred modality of treatment. 95 patients (48,2%) were in ESWL group and 102 patients (51.8%) were in URS group. ESWL was performed under mild sedation with pethidine hydrochloride for a maximum of 4 sessions, and URS was performed with semirigid or flexible ureterorenoscopes and intracorporeal Holmium:YAG laser lithotripsy under general or spinal anesthesia. The safety and effectiveness of both treatments were assessed and calculated. The direct cost analysis included costs of: hospitalization, operating theatre and lithotripter procedure, health staff, materials and re-treatments for each procedure applied. Additionally, the postoperative visit costs were registered. The data of the global expenditure was extracted from the hospital’s economic information department. A decision tree analysis was modelled for each alternative to estimate the incremental cost effectiveness ratio (ICER). We conducted a Monte Carlo Simulation for a probabilistic sensitivity analysis. RESULTS: Both groups were comparable in terms of side, size, composition of the stone and need for a previous double J ureteric stent. The global stone-free rate was 98%(100) for ureteroscopy plus Holmium and 81%(77) for ESWL (p <0.001). In patients with stones <1cm, the URS was significantly better than the ESWL with stone-free rates of 98.3%(56) and 81,7%(49) respectively. For stones >1 cm there were also differences: 97,8%(44) stone-free rate in the URS group and 80%(28) in the ESWL group (p¼0,01). The overall complication rate was significantly higher in ESWL group (18,95%) as compared to the URS group (1,96%). However, all complications in the ESWL group were Clavien I or II type. The average cost of the SWL group was 973,09 euros, while in the URS group it was 1.537,49 euros. The estimated ICER showed that ESWL was dominant versus first line URS. After performing the Monte Carlo simulation, the dominance of ESWL prevalied regardless of the size of stone (100% for stones < 1 cm and 92,2% for stones >1 cm). CONCLUSIONS: The results of this study indicate that ESWL is more cost-effective than URS for the treatment of ureteral stones. Source of Funding: none
Preoperative: Serum Cr (mg/dL) Urine pH Laterality (%):
0.5
Bilateral
0
22
Left
60
44
Right
40
33
20%
67%
0.094
(+) Urine Culture (%) Stone Size (cm)
20%
11%
0.649
1.36 0.6
0.99 0.4
0.201
Grading Outcomes: 1.51 0.3
1.84 0.8
0.4
% Total Score > 1.7
25
78
0.071
% RP Score > 1.1
50
56
0.853
% BD Score > 0.6
0
56
0.057
Mean Total Score
COST ANALYSIS OF URETERAL STENTING AFTER UNCOMPLICATED URETEROSCOPIC LASER LITHOTRIPSY FOR UROLITHIASIS: A DECISION MODEL ANALYSIS Hin Yu Vincent Tu*, Edward Matsumoto, Hamilton, Canada
Presented with: Multiple stones (%)
MP80-12
Source of Funding: none
INTRODUCTION AND OBJECTIVES: Routine ureteral stenting after uncomplicated ureteroscopy and laser lithotripsy (ULL) is debatable. Purported advantages include preventing ureteral obstruction and facilitating stone passage; disadvantages include stent colic, stent migration and subsequent cystoscopic stent removal. The purpose of our study is to determine whether stenting after uncomplicated ULL is an efficient expenditure of health care resources. METHODS: A decision model was developed to estimate expected costs, complication free outcomes (CFO) and quality-
THE JOURNAL OF UROLOGYâ
e1024
adjusted life years after ULL with and without stenting. Complications were defined as any unplanned hospital visits within the first six postoperative weeks including emergency room visits, admissions to hospital or surgeries. They were graded according to the validated Revised Clavien classification. A comprehensive literature review was performed to determine complication rates and quality of life (QOL) utility values. Costs of surgical procedures were obtained from the Ontario Case Costing Initiative. Sensitivity analyses were performed to determine which parameters affected the outcome of our model. A willingness-to-pay threshold of $3000 was implemented and adopted from drug-eluting stent literature for cardiovascular disease. RESULTS: ULL without stenting was more cost-effective than ULL with stenting in achieving a CFO. ULL with and without stenting cost $3828 and $3248 respectively to achieve an overall complication grade of 0.03 and 0.1 (p<0.05) respectively. Overall complication rates in the stented versus non-stented groups were 2.6% and 6.5% respectively. Sensitivity analysis demonstrated that ULL without stenting remained the most cost-effective if the overall complication rate without stenting remained below 11%, or if the cost of ULL without stenting did not exceed $2275. Due to the paucity of health related QOL data in literature regarding stenting post-ULL, a cost-utility analysis could not be performed. CONCLUSIONS: Our study demonstrated that despite the increased postoperative complication rates associated with non-stented ULL, it was still more cost-effective due to the lower initial surgical costs. A cost-utility analysis was not performed due to the paucity of QOL data in this study population.
Vol. 193, No. 4S, Supplement, Tuesday, May 19, 2015
RESULTS: Out of 41 cases, 15 (37%) were obese (BMI 30). For non-obese patients, average BMI was 23.5, and for obese patients, average BMI was 41.6. In non-obese patients, average PIP was 17.46, 18.10 and 17.90 cm H2O in the supine, early prone and late prone positions respectively; for obese patients average PIP was 23.97, 26.13 and 23.73 cm H2O. There was a statistically significant difference in average PIP between obese and non-obese patients in all 3 positions (p<0.0001, p<0.0001 and p¼0.0009 respectively). There was also a statistically significant change in PIP from the supine to early prone position (p¼0.03) in the obese cohort, but there was no significant difference between supine and late prone position (p¼0.90). There was no statistically significant difference between any positions in non-obese patients (p¼0.16 and p¼0.83 respectively). CONCLUSIONS: Changes in positioning do not affect PIP in non-obese patients. Though there is a statistically significant increase in airway resistance in obese patients, this occurs with initial positioning and PIP normalizes to supine levels by the end of the case. Thus, it appears that the negative effects of positioning on airway resistance and respiratory compliance in obese patients are transient, and that prone positioning for PCNL in obese patients remains a safe and viable option. Source of Funding: None
MP80-14 SLEEP POSTURE COULD PREDICT THE SIDE OF UNILATERAL UROLITHIASIS FORMATION Wei-Ming Cheng*, Tuz-Hao Huang, Yu-Hua Fan, Alex T. L. Lin, Kuang-Kuo Chen, Shi-Chuan Chang, Taipei City, Taiwan
Source of Funding: None
MP80-13 DOES THE PEAK INSPIRATORY PRESSURE INCREASE IN THE PRONE POSITION? AN ANALYSIS RELATED TO BMI. Michael Siev*, Piruz Motamedinia, David Leavitt, David Hoenig, Arthur Smith, Zeph Okeke, New Hyde Park, NY INTRODUCTION AND OBJECTIVES: Percutaneous nephrolithotomy (PCNL) is performed most commonly in the prone position to facilitate access to the renal collecting system. There is concern that the prone position, especially in obese patients, results in negative effects on ventilation, due to restriction of chest compliance and respiratory mechanics. This study analyzes the change in airway resistance between supine and prone positioning of patients undergoing PCNL. METHODS: In this IRB-approved study, between May and October 2014, we retrospectively reviewed 41 patients who underwent prone PCNL while all intraoperative respiratory parameters were continuously recorded. Peak inspiratory pressure (PIP) was selected as a marker of airway resistance and respiratory compliance, and was assessed in supine position, 1 minute after being turned prone (early prone) and at the end of the case (late prone). Results were stratified based on BMI and data were compared using the paired t-test with p < 0.05 considered significant.
INTRODUCTION AND OBJECTIVES: Most urolithiasis forms unilaterally. The published data suggest that sleep posture may alter renal hemodynamics during sleep and promote stone formation. In the present study, we investigated the correlation of sleep posture with stone formation sites in patients with unilateral urolithiasis. METHODS: We retrospectively reviewed the archives of polysomnography for evaluation of obstructive sleep apnea (OSA) between January 1st 2011 and August 31st 2014 and enrolled the patients who experienced extracorporeal shock wave lithotripsy or ureteroscopic lithotripsy for unilateral renal or ureteral stones. Supine, right and left decubitus, and prone sleep postures were defined when patients stayed in the posture for more than 50% of the time during sleep. Others were categorized as rotisserie-like posture. We analyzed the correlation between sleep posture and urolithiasis site. RESULTS: A total of 67 patients were included. 63 (94.0%) were males. Mean age was 51.0 11.8 years. Mean body mass index (BMI) was 29.0 6.7 kg/m2. Sleep postures correlated to urolithiasis sites were showed in the Table. Right decubitus posture was prone to right side urolithiasis (88.9% versus 41.4%, p ¼ 0.011). Furthermore, patients with right side urolithiasis present with less rapid eye movement (REM) ratio (6.9 4.2% versus 10.9 6.9%, p ¼ 0.014). Both right decubitus posture and lower REM ratio remained to be significantly correlated to right side urolithiasis on multivariate analysis (95% CI 0.009 - 0.720, p ¼ 0.024; 95% CI 1.032 - 1.253, p ¼ 0.009, respectively). In patients with optimal sleep efficacy on polysomnography, which was defined as the duration of sleep divided by the duration in bed over 85%, lower stage I ratio (6.6 4.1% versus 26.1 17.7%, p ¼ 0.016), higher stage III ratio (11.89 3.1% versus 3.4 4.9%, p ¼ 0.048), and less sleep stage change among stage I to III and REM (90.0 18.4 times versus 222.7 108.3 times, p ¼ 0.008) were significant predictive factors for formation of ipsilateral stone as sleep posture. Age, gender, BMI, or other polysomnographic parameters were failed to show association with urinary stone sites. CONCLUSIONS: Unilateral urolithiasis formation is correlated to sleep posture. Deeper sleep stage with less sleep stage change may consolidate such correlation.