- Email: [email protected]
PD13-03 ROBOTIC ANATROPHIC NEPHROLITHOTOMY: IDEA, DEVELOPMENT, EXPLORATION, ASSESSMENT AND LONG-TERM MONITORING (IDEAL) PHASE 0 STUDY
THE JOURNAL OF UROLOGYâ
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Vol. 193, No. 4S, Supplement, Saturday, May 16, 2015
differences between the groups in post-operative creatinine, or stone analyses. CONCLUSIONS: Our analysis shows that in patients undergoing ureteroscopy for renal stones between 5e20 mm that active extraction of all fragments with a basket produces a higher stone free rate (89.9%) than dusting the stone (60.9%). However, there was no difference in readmission or reintervention rates and only 1 patient in each group became symptomatic from their residual fragments. Longterm follow-up of these patients will also determine the fate of these fragments and whether they become symptomatic and require treatment.
Age (y)
Basketing Group (N¼36)
Dusting Group (N¼23)
52.5 17.9
52.7 18.7
BMI (kg/m2) mean
28.3
27.5
Stone area (mm2) mean
80.5 60.7
113.4 92.0
Hounsfield Units
1074 1333
796 390
7.7 30.6
48.7 241.4
100%
27.5%
4/36 (11.1%)
9/23(39.1%)
Laser energy used (kJ) Ureteral Access sheath used No.with residual fragments Stone free rate
89.9%
60.9%
Passed fragments since surgery
0
17/23 (73.9%)
Fragments > 4mm
0
4
Fragments 2-4mm
1
1
Fragments < 2mm
3
4
Complications total
7
2
Clavien I
3
2
Clavien II
4
0
1 (2.8%)
1 (4.3%)
59.8 31.6
40.5 14.7
Symptoms from fragments OR time (min)
Source of Funding: None
PD13-02 CAN LOW-DOSAGE, DIGITAL X-RAY SCANNING (LODOX) REPLACE COMPUTED TOMOGRAPHY (CT) AND CONVENTIONAL RADIOGRAPHY (CR) IN THE DIAGNOSTICS OF URETERAL STONES? Beat Roth*, Stefanie Hnilicka, Susan D. Meierhans Ruf, Andreas Christe, George N. Thalmann, Bern, Switzerland INTRODUCTION AND OBJECTIVES: LODOX Statscan is a whole-body, low-dose X-ray scanner with digital enhancement and enlargement capabilities which was originally developed in the 1980s in order to prevent smuggling of diamonds by mineworkers in South Africa. Ten years ago it was introduced as a screening device for the examination of trauma patients requiring only about one third of the radiation used for CR. A phantom study could show a superiority for the detection of urinary stones compared to CR. We thus prospectively evaluated LODOX as primary diagnostic imaging for ureteral stones. METHODS: 28 emergency patients (median age: 50 yrs; range: 25 e 77; median BMI 27.6; range: 18.3 e 42) presenting with acute renal colic due to a unilateral ureteral stone were included. All 28 patients underwent LODOX, CR and CT imaging. The CR and LODOX images were read by 2 blinded readers (one expert and one resident) who were only aware of the side of the colic. Stone location (if detectable) was marked on a diagram. The readings were compared to the gold standard imaging (CT). RESULTS: Median stone size was 5 mm (range: 2e12), median stone density was 800 hounsfield units (HU; range: 250 e 1500). The detection rates of LODOX vs. CR for the expert and the resident were 89% (25/28) vs. 68% (19/28; p ¼ 0.02), and 71% (21/28) vs. 61% (17/28; p ¼ 0.15), respectively. Taken the results of the expert
and the resident together (n ¼ 56 stone detections), 68% (15/22) and 77% (17/22) of proximal, 100% (8/8) and 38% (3/8) of mid, and 85% (22/26) and 62% (16/26) of distal ureteral stones were detected with LODOX and CR, respectively. The three stones that were not detected with LODOX (and also not with CR) by the expert had low density ( 300 HU). Additionally, two of these stones had low size (< 3mm), and the third was a 100% uric acid stone in the mid-ureter. The 3 patients who had ureteral stones that could not be detected by the expert with LODOX were all obese (BMI 33). The finding that LODOX detection of ureteral stones was more challenging in obese patients was confirmed by the junior resident’s results; the BMI of patients with detected vs. undetected stones was 27.2 and 32.4, respectively (p ¼ 0.044). CONCLUSIONS: The detection rate for ureteral stones using LODOX was as high as 89% in experienced hands. LODOX was significantly better for primary stone detection than CR. Due to its low radiation and its high sensitivity LODOX seems to be a promising imaging tool for patients presenting with acute renal colic. However, it has its weakness e.g. in obese patients. Source of Funding: none
PD13-03 ROBOTIC ANATROPHIC NEPHROLITHOTOMY: IDEA, DEVELOPMENT, EXPLORATION, ASSESSMENT AND LONGTERM MONITORING (IDEAL) PHASE 0 STUDY Akshay Sood*, Detroit, MI; Jay Rohde, Michael Van Winkle, Atlanta, GA; Dean Assimos, Birmingham, AL; Ashok Hemal, Salem, NC; James Peabody, Mani Menon, Detroit, MI; Khurshid Ghani, Ann Arbor, MI INTRODUCTION AND OBJECTIVES: We undertook an Idea, Development, Exploration, Assessment and Long-term monitoring (IDEAL) Phase 0 study to evaluate the ability of robotic anatrophic nephrolithotomy (RANL) for removing staghorn calculi. Our aims were: 1, develop a reproducible in vitro stone surgery model; 2, evaluate the utility of FireflyÔ (Intuitive Surgical Inc., CA) in identifying the anatrophic plane; 3, assess the feasibility of a novel technique of RANL. METHODS: We performed two RANLs in anesthetized female pigs (w20 kg). The robot was docked to the flank utilizing two robotic ports and a mini-GelPOINT (Applied Medical, CA). For creating the stone, low viscosity DenMat Precision material (DenMat Inc., CA) was injected into the renal pelvis through an incision in the renal pelvis, via a 14F Foley catheter (placed through the mini-GelPOINT). Following dissection of the anterior and posterior divisions of the renal artery, the posterior segment was clamped and 2 mg IV indocyanine green given to aid in identification of the anatrophic plane using near infra-red fluorescence (NIRF) imaging (Firefly). Next, the hilar vessels were clamped with RANL performed under warm and cold ischemia in cases 1 and 2, respectively. For cold ischemia, ice-slush was injected onto the kidney via syringes through the mini-GelPOINT. RESULTS: Replica staghorn stones could be created reliably in both pigs (mean size 5.1 cm). DenMat resin material utilized was 45e50 cc; the material solidified within 2e3 minutes. Firefly aided in precise identification of the anatrophic plane (Fig a). In both cases, the replica stones were removed successfully in toto through the anatrophic incision (Fig b). The mean console time was 114 minutes. The warm and cold ischemic times were 36 and 33 minutes, respectively. Cold ischemia led to renal surface temperature of 15.4 C. Both kidneys were closed successfully using two-layer sliding-clip renorrhaphy. Mean blood loss was 160 cc. CONCLUSIONS: The stone model described can be utilized to investigate novel surgical modalities for stone disease. We have demonstrated for the first time that use of NIRF image-guidance accurately identifies the renal avascular plane, thus permitting a true anatrophic robotic approach for staghorn stones. IDEAL Phase 1 studies are needed to validate these findings.
THE JOURNAL OF UROLOGYâ
Vol. 193, No. 4S, Supplement, Saturday, May 16, 2015
e263
PD13-05 PRESTENTING IN URETERORENOSCOPY: MULTICENTER EVALUATION BY THE INTERNATIONAL COLLABORATION IN ENDOUROLOGY (UROICE) Jan Jessen*, Sindelfingen, Germany; Alberto Breda, Barcelona, Spain; Marianne Brehmer, Aarhus, Denmark; Evangelos Liatsikos, Patras, Greece; Felix Millan Rodriguez, Barcelona, Spain; Palle Osther, Fredericia, Denmark; Cesare Scoffone, Torino, Italy; Thomas Knoll, Sindelfingen, Germany Source of Funding: None
PD13-04 COMPARISON OF FLOW CHARACTERISTICS OF NOVEL THREEDIMENSIONALLY PRINTED URETERAL STENTS VS. STANDARD URETERAL STENTS IN A PORCINE MODEL Zhamshid Okhunov*, Michael Del Junco, Renai Yoon, Garen Abedi, Christopher Pulford, Christina Hwang, Jaime Landman, Orange, CA INTRODUCTION AND OBJECTIVES: We compared the flow characteristics of novel three-dimensionally (3D) printed ureteral stents to three conventional double-pigtail stents in an ex vivo porcine model. METHODS: In 5 ex vivo porcine urinary systems with kidneys and ureters intact we deployed a 5Fr occlusion catheter in an interpolar calyx. We tested each system with antegrade irrigation with 0.9% saline at a pressure of 35 cmH2O before and after stent deployment. We evaluated three standard stents (6Fr Universaâ Soft, 7Fr PercuflexÔ, 7/10Fr Applied Endopyelotomy) and compared them to a 9Fr 3D printed prototype stent. For each stent, we measured the total, extra-luminal, and intra-luminal flow rates. RESULTS: The mean total flow rates for 3D printed stents were significantly higher than the 6Fr, 7Fr, and 7/10Fr stents (p<0.001, p¼0.003, and p<0.001 respectively). The mean extra-luminal flow rates for the 3D stents were similar to 7Fr stents, but significantly lower than 6Fr stents (p<0.001) and higher than 7/10Fr stents (p<0.001). The mean intra-luminal flow rates for the 3D printed stents were significantly higher than the 6Fr, 7Fr, and 7/10Fr stents (p<0.001, p¼0.004, and p<0.001 respectively). CONCLUSIONS: In this pilot study, 3D printed stents manifested a mean total flow rates comparable to the flow rates of contemporary stents. Continued advances in technology and material may permit functionally feasible 3D printed ureteral stents. Table 1 Mean Ex-Vivo Flow Measurements (ml/min) for Unstented and Stented Ureters (mean SD) Extraluminal Flow
Intra-luminal Flow
Total Flow as a % of Unstented Ureter
4.97 0.062
-
-
-
6Fr Universa
5.25 0.222
4.41 0.095
4.86 0.090
105.60%
7Fr Percuflex
5.49 0.130
4.01 0.138
5.16 0.057
110.40%
7/10Fr Endopyelotomy
5.18 0.140
2.56 0.309
4.82 0.139
104.20%
9Fr 3D Printed
5.66 0.148
4.00 0.176
5.54 0.293
114.90%
Stent
Total Flow*
Unstented Ureter
* Combined Extra-luminal and Intra-luminal
6Fr 7Fr 7/10Fr 9Fr
ID (mm)
OD (mm)
1.33
2.00
1.50
2.30
1.27/1.52
2.30/3.30
1.40
3.0
Source of Funding: None
Source of Funding: none
PD13-06 RETROPERITONEAL LAPAROSCOPIC TECHNIQUE IN TREATMENT OF COMPLEX RENAL STONES: 104 CASES Qiang Lu*, Pengchao Li, Jun Tao, Chao Qin, Changjun Yin, Nanjing, China, People’s Republic of
Table 2 Double-Pigtail Stent Dimensions Stent
INTRODUCTION AND OBJECTIVES: Semirigid and flexible ureterorenoscopy (URS) are safe and efficient treatment options for urolithiasis of all localizations. A JJ-insertion is often performed in preparation of definitive stone treatment. Aim of our study was to evaluate the influence of prestenting on the outcome of URS. METHODS: We analyzed 565 patients out of our prospective multicenter, multinational database who underwent URS for renal or ureteral stones from 06/2011 to 12/2013. Demographic and stone related data, surgery time, stone clearance and complications were evaluated. Univariate and multifactorial statistical analysis was performed using R comparing the prestented and not-prestented group. RESULTS: Demographic and stone-related data were comparable in both groups. 323 patients were prestented and 242 not. Overall, prestenting had significant influence on stone free rate (86.38% prestented vs 73.97% not-prestented, p¼0.0003) and complication rate (6.5% vs 14.46%, p¼0.003) but not on surgery-time (55.3436.11 vs 60.8335.28 min, p¼0.071). Subgrouped for ureteral and renal calculi, this was also true for renal stones (82.67% vs 60.19%, p¼0.0001 / 8.67% vs 19.42%, p¼0.02 / 65.7536.19 vs 69.036.37 min, p¼0.485). For ureteral stones, there was no significant influence on stone free rate (93.75% vs 90.18%, p¼0.4), but significant more complications (3.13% vs 10.71%, p¼0.02) and longer surgery times (39.9230.95 vs 49.6930.53, p¼0.015). In multifactorial analysis, the overall influence of prestenting on URS regarding stone free rate (p¼0.0002) and complications (p¼0.0044) was also confirmed while OR-time was not significantly influenced by prestenting status. Subgrouped for ureteral and kidney stones, all the results from multifactorial analysis were in line with univariate analysis. For ureteral stones, the influence of prestenting on OR-time (p¼0.023) and complications (p¼0.0267) was confirmed. Regarding stone free rate, prestented status was removed by model selection, as it had no benefit for the explanatory model. For kidney stones, prestented status had significant impact on stone free rate (p¼0.0001) and complication rate (p¼0.0267), while it was removed by model selection for surgery-time. CONCLUSIONS: Prestenting positively affects safety and efficacy of URS. This is more pronounced in the treatment of kidney stones compared with ureteral stones. Although the stone free rate for ureteral stones is comparable without prestenting, more time is needed to complete the procedure and the complication rate is higher.
INTRODUCTION AND OBJECTIVES: As a viable and versatile alternative to transperitoneal access, retroperitoneal laparoscopy is a perfect approach for the anatomy characteristics of kidney. Here, we assessed the retroperitoneal laparoscopic technique for treatment of complex renal stones. METHODS: A total of 104 patients (62 men, 42 women) with a mean age of 46.3 years, underwent retroperitoneal laparoscopy for the treatment of complex renal stones between July 2006 and October 2014. The following were criteria for inclusion: a renal pelvic stone with complications, such as nephroptosis, UPJO, or retrocaval ureter;
e262
Vol. 193, No. 4S, Supplement, Saturday, May 16, 2015
differences between the groups in post-operative creatinine, or stone analyses. CONCLUSIONS: Our analysis shows that in patients undergoing ureteroscopy for renal stones between 5e20 mm that active extraction of all fragments with a basket produces a higher stone free rate (89.9%) than dusting the stone (60.9%). However, there was no difference in readmission or reintervention rates and only 1 patient in each group became symptomatic from their residual fragments. Longterm follow-up of these patients will also determine the fate of these fragments and whether they become symptomatic and require treatment.
Age (y)
Basketing Group (N¼36)
Dusting Group (N¼23)
52.5 17.9
52.7 18.7
BMI (kg/m2) mean
28.3
27.5
Stone area (mm2) mean
80.5 60.7
113.4 92.0
Hounsfield Units
1074 1333
796 390
7.7 30.6
48.7 241.4
100%
27.5%
4/36 (11.1%)
9/23(39.1%)
Laser energy used (kJ) Ureteral Access sheath used No.with residual fragments Stone free rate
89.9%
60.9%
Passed fragments since surgery
0
17/23 (73.9%)
Fragments > 4mm
0
4
Fragments 2-4mm
1
1
Fragments < 2mm
3
4
Complications total
7
2
Clavien I
3
2
Clavien II
4
0
1 (2.8%)
1 (4.3%)
59.8 31.6
40.5 14.7
Symptoms from fragments OR time (min)
Source of Funding: None
PD13-02 CAN LOW-DOSAGE, DIGITAL X-RAY SCANNING (LODOX) REPLACE COMPUTED TOMOGRAPHY (CT) AND CONVENTIONAL RADIOGRAPHY (CR) IN THE DIAGNOSTICS OF URETERAL STONES? Beat Roth*, Stefanie Hnilicka, Susan D. Meierhans Ruf, Andreas Christe, George N. Thalmann, Bern, Switzerland INTRODUCTION AND OBJECTIVES: LODOX Statscan is a whole-body, low-dose X-ray scanner with digital enhancement and enlargement capabilities which was originally developed in the 1980s in order to prevent smuggling of diamonds by mineworkers in South Africa. Ten years ago it was introduced as a screening device for the examination of trauma patients requiring only about one third of the radiation used for CR. A phantom study could show a superiority for the detection of urinary stones compared to CR. We thus prospectively evaluated LODOX as primary diagnostic imaging for ureteral stones. METHODS: 28 emergency patients (median age: 50 yrs; range: 25 e 77; median BMI 27.6; range: 18.3 e 42) presenting with acute renal colic due to a unilateral ureteral stone were included. All 28 patients underwent LODOX, CR and CT imaging. The CR and LODOX images were read by 2 blinded readers (one expert and one resident) who were only aware of the side of the colic. Stone location (if detectable) was marked on a diagram. The readings were compared to the gold standard imaging (CT). RESULTS: Median stone size was 5 mm (range: 2e12), median stone density was 800 hounsfield units (HU; range: 250 e 1500). The detection rates of LODOX vs. CR for the expert and the resident were 89% (25/28) vs. 68% (19/28; p ¼ 0.02), and 71% (21/28) vs. 61% (17/28; p ¼ 0.15), respectively. Taken the results of the expert
and the resident together (n ¼ 56 stone detections), 68% (15/22) and 77% (17/22) of proximal, 100% (8/8) and 38% (3/8) of mid, and 85% (22/26) and 62% (16/26) of distal ureteral stones were detected with LODOX and CR, respectively. The three stones that were not detected with LODOX (and also not with CR) by the expert had low density ( 300 HU). Additionally, two of these stones had low size (< 3mm), and the third was a 100% uric acid stone in the mid-ureter. The 3 patients who had ureteral stones that could not be detected by the expert with LODOX were all obese (BMI 33). The finding that LODOX detection of ureteral stones was more challenging in obese patients was confirmed by the junior resident’s results; the BMI of patients with detected vs. undetected stones was 27.2 and 32.4, respectively (p ¼ 0.044). CONCLUSIONS: The detection rate for ureteral stones using LODOX was as high as 89% in experienced hands. LODOX was significantly better for primary stone detection than CR. Due to its low radiation and its high sensitivity LODOX seems to be a promising imaging tool for patients presenting with acute renal colic. However, it has its weakness e.g. in obese patients. Source of Funding: none
PD13-03 ROBOTIC ANATROPHIC NEPHROLITHOTOMY: IDEA, DEVELOPMENT, EXPLORATION, ASSESSMENT AND LONGTERM MONITORING (IDEAL) PHASE 0 STUDY Akshay Sood*, Detroit, MI; Jay Rohde, Michael Van Winkle, Atlanta, GA; Dean Assimos, Birmingham, AL; Ashok Hemal, Salem, NC; James Peabody, Mani Menon, Detroit, MI; Khurshid Ghani, Ann Arbor, MI INTRODUCTION AND OBJECTIVES: We undertook an Idea, Development, Exploration, Assessment and Long-term monitoring (IDEAL) Phase 0 study to evaluate the ability of robotic anatrophic nephrolithotomy (RANL) for removing staghorn calculi. Our aims were: 1, develop a reproducible in vitro stone surgery model; 2, evaluate the utility of FireflyÔ (Intuitive Surgical Inc., CA) in identifying the anatrophic plane; 3, assess the feasibility of a novel technique of RANL. METHODS: We performed two RANLs in anesthetized female pigs (w20 kg). The robot was docked to the flank utilizing two robotic ports and a mini-GelPOINT (Applied Medical, CA). For creating the stone, low viscosity DenMat Precision material (DenMat Inc., CA) was injected into the renal pelvis through an incision in the renal pelvis, via a 14F Foley catheter (placed through the mini-GelPOINT). Following dissection of the anterior and posterior divisions of the renal artery, the posterior segment was clamped and 2 mg IV indocyanine green given to aid in identification of the anatrophic plane using near infra-red fluorescence (NIRF) imaging (Firefly). Next, the hilar vessels were clamped with RANL performed under warm and cold ischemia in cases 1 and 2, respectively. For cold ischemia, ice-slush was injected onto the kidney via syringes through the mini-GelPOINT. RESULTS: Replica staghorn stones could be created reliably in both pigs (mean size 5.1 cm). DenMat resin material utilized was 45e50 cc; the material solidified within 2e3 minutes. Firefly aided in precise identification of the anatrophic plane (Fig a). In both cases, the replica stones were removed successfully in toto through the anatrophic incision (Fig b). The mean console time was 114 minutes. The warm and cold ischemic times were 36 and 33 minutes, respectively. Cold ischemia led to renal surface temperature of 15.4 C. Both kidneys were closed successfully using two-layer sliding-clip renorrhaphy. Mean blood loss was 160 cc. CONCLUSIONS: The stone model described can be utilized to investigate novel surgical modalities for stone disease. We have demonstrated for the first time that use of NIRF image-guidance accurately identifies the renal avascular plane, thus permitting a true anatrophic robotic approach for staghorn stones. IDEAL Phase 1 studies are needed to validate these findings.
THE JOURNAL OF UROLOGYâ
Vol. 193, No. 4S, Supplement, Saturday, May 16, 2015
e263
PD13-05 PRESTENTING IN URETERORENOSCOPY: MULTICENTER EVALUATION BY THE INTERNATIONAL COLLABORATION IN ENDOUROLOGY (UROICE) Jan Jessen*, Sindelfingen, Germany; Alberto Breda, Barcelona, Spain; Marianne Brehmer, Aarhus, Denmark; Evangelos Liatsikos, Patras, Greece; Felix Millan Rodriguez, Barcelona, Spain; Palle Osther, Fredericia, Denmark; Cesare Scoffone, Torino, Italy; Thomas Knoll, Sindelfingen, Germany Source of Funding: None
PD13-04 COMPARISON OF FLOW CHARACTERISTICS OF NOVEL THREEDIMENSIONALLY PRINTED URETERAL STENTS VS. STANDARD URETERAL STENTS IN A PORCINE MODEL Zhamshid Okhunov*, Michael Del Junco, Renai Yoon, Garen Abedi, Christopher Pulford, Christina Hwang, Jaime Landman, Orange, CA INTRODUCTION AND OBJECTIVES: We compared the flow characteristics of novel three-dimensionally (3D) printed ureteral stents to three conventional double-pigtail stents in an ex vivo porcine model. METHODS: In 5 ex vivo porcine urinary systems with kidneys and ureters intact we deployed a 5Fr occlusion catheter in an interpolar calyx. We tested each system with antegrade irrigation with 0.9% saline at a pressure of 35 cmH2O before and after stent deployment. We evaluated three standard stents (6Fr Universaâ Soft, 7Fr PercuflexÔ, 7/10Fr Applied Endopyelotomy) and compared them to a 9Fr 3D printed prototype stent. For each stent, we measured the total, extra-luminal, and intra-luminal flow rates. RESULTS: The mean total flow rates for 3D printed stents were significantly higher than the 6Fr, 7Fr, and 7/10Fr stents (p<0.001, p¼0.003, and p<0.001 respectively). The mean extra-luminal flow rates for the 3D stents were similar to 7Fr stents, but significantly lower than 6Fr stents (p<0.001) and higher than 7/10Fr stents (p<0.001). The mean intra-luminal flow rates for the 3D printed stents were significantly higher than the 6Fr, 7Fr, and 7/10Fr stents (p<0.001, p¼0.004, and p<0.001 respectively). CONCLUSIONS: In this pilot study, 3D printed stents manifested a mean total flow rates comparable to the flow rates of contemporary stents. Continued advances in technology and material may permit functionally feasible 3D printed ureteral stents. Table 1 Mean Ex-Vivo Flow Measurements (ml/min) for Unstented and Stented Ureters (mean SD) Extraluminal Flow
Intra-luminal Flow
Total Flow as a % of Unstented Ureter
4.97 0.062
-
-
-
6Fr Universa
5.25 0.222
4.41 0.095
4.86 0.090
105.60%
7Fr Percuflex
5.49 0.130
4.01 0.138
5.16 0.057
110.40%
7/10Fr Endopyelotomy
5.18 0.140
2.56 0.309
4.82 0.139
104.20%
9Fr 3D Printed
5.66 0.148
4.00 0.176
5.54 0.293
114.90%
Stent
Total Flow*
Unstented Ureter
* Combined Extra-luminal and Intra-luminal
6Fr 7Fr 7/10Fr 9Fr
ID (mm)
OD (mm)
1.33
2.00
1.50
2.30
1.27/1.52
2.30/3.30
1.40
3.0
Source of Funding: None
Source of Funding: none
PD13-06 RETROPERITONEAL LAPAROSCOPIC TECHNIQUE IN TREATMENT OF COMPLEX RENAL STONES: 104 CASES Qiang Lu*, Pengchao Li, Jun Tao, Chao Qin, Changjun Yin, Nanjing, China, People’s Republic of
Table 2 Double-Pigtail Stent Dimensions Stent
INTRODUCTION AND OBJECTIVES: Semirigid and flexible ureterorenoscopy (URS) are safe and efficient treatment options for urolithiasis of all localizations. A JJ-insertion is often performed in preparation of definitive stone treatment. Aim of our study was to evaluate the influence of prestenting on the outcome of URS. METHODS: We analyzed 565 patients out of our prospective multicenter, multinational database who underwent URS for renal or ureteral stones from 06/2011 to 12/2013. Demographic and stone related data, surgery time, stone clearance and complications were evaluated. Univariate and multifactorial statistical analysis was performed using R comparing the prestented and not-prestented group. RESULTS: Demographic and stone-related data were comparable in both groups. 323 patients were prestented and 242 not. Overall, prestenting had significant influence on stone free rate (86.38% prestented vs 73.97% not-prestented, p¼0.0003) and complication rate (6.5% vs 14.46%, p¼0.003) but not on surgery-time (55.3436.11 vs 60.8335.28 min, p¼0.071). Subgrouped for ureteral and renal calculi, this was also true for renal stones (82.67% vs 60.19%, p¼0.0001 / 8.67% vs 19.42%, p¼0.02 / 65.7536.19 vs 69.036.37 min, p¼0.485). For ureteral stones, there was no significant influence on stone free rate (93.75% vs 90.18%, p¼0.4), but significant more complications (3.13% vs 10.71%, p¼0.02) and longer surgery times (39.9230.95 vs 49.6930.53, p¼0.015). In multifactorial analysis, the overall influence of prestenting on URS regarding stone free rate (p¼0.0002) and complications (p¼0.0044) was also confirmed while OR-time was not significantly influenced by prestenting status. Subgrouped for ureteral and kidney stones, all the results from multifactorial analysis were in line with univariate analysis. For ureteral stones, the influence of prestenting on OR-time (p¼0.023) and complications (p¼0.0267) was confirmed. Regarding stone free rate, prestented status was removed by model selection, as it had no benefit for the explanatory model. For kidney stones, prestented status had significant impact on stone free rate (p¼0.0001) and complication rate (p¼0.0267), while it was removed by model selection for surgery-time. CONCLUSIONS: Prestenting positively affects safety and efficacy of URS. This is more pronounced in the treatment of kidney stones compared with ureteral stones. Although the stone free rate for ureteral stones is comparable without prestenting, more time is needed to complete the procedure and the complication rate is higher.
INTRODUCTION AND OBJECTIVES: As a viable and versatile alternative to transperitoneal access, retroperitoneal laparoscopy is a perfect approach for the anatomy characteristics of kidney. Here, we assessed the retroperitoneal laparoscopic technique for treatment of complex renal stones. METHODS: A total of 104 patients (62 men, 42 women) with a mean age of 46.3 years, underwent retroperitoneal laparoscopy for the treatment of complex renal stones between July 2006 and October 2014. The following were criteria for inclusion: a renal pelvic stone with complications, such as nephroptosis, UPJO, or retrocaval ureter;