JOURNAL OF ENDOUROLOGY Volume 28, Number 10, October 2014 ª Mary Ann Liebert, Inc. Pp. 1183–1187 DOI: 10.1089/end.2014.0286
Ureteroscopy and Percutaneous Procedures
Comparison of the Efficacy and Morbidity of Flexible Ureterorenoscopy for Lower Pole Stones Compared with Other Renal Locations Baptiste Jacquemet, MD,1 Lucille Martin, MD,1,2 Julie Pastori, MD,1 Vincent Bailly, MD,1 Guillaume Guichard, MD,1 Ste´phane Bernardini, MD, PhD,1 Eric Chabannes, MD,1 Hugues Bittard, MD,1–3 and Franc¸ois Kleinclauss, MD, PhD1–4
Abstract
Background and Purpose: Flexible ureterorenoscopy (f-URS) for lower pole stones (LPS) compared with other renal locations can be challenging because of anatomic and technical considerations. We aimed to compare the stone-free rate (SFR) and surgical complication rate with f-URS for LPS vs other renal locations. Patients and Methods: We performed a retrospective, single-center study including 371 f-URS for renal stone retrieval performed in our institution between January 2004 and December 2010. Among the 371 procedures included in this analysis, 139 were performed for stones located in a single renal location other than the lower pole (group 1), and 232 for at least one stone located in the lower pole (group 2). We compared the efficacy (SFR) and the morbidity of f-URS between the two groups. The success of the procedure was defined as a complete SFR 6 months after f-URS. Results: Age, sex, history of urolithiasis, body mass index, and preoperative stent placement did not differ between the two groups. No differences in stone characteristics were observed between both groups except stone size under 10 mm that was significantly higher in group 2 (P = 0.018). Technical aspects of the procedure did not differ between the groups, except for more frequent use of an access sheath in group 2 (P = 0.007). SFR was comparable between groups (P = 0.774). The complication rate was similar in both groups, as was the severity of complications. By multivariate analysis, stone size >10 mm (P < 0.0001) and multiple stone locations (P = 0.001) were associated with f-URS failure, but lower pole location did not impact on SFR. Conclusion: In our study, stone location, in particular LPS, did not have any impact on efficacy and morbidity of f-URS. Only multiple locations and stone size >10 mm seemed to significantly decrease the SFR, without impacting morbidity.
Introduction
M
anagement of lower pole stones (LPS) can represent a therapeutic challenge. Before the development of flexible ureterorenoscopy (f-URS), extracorporeal shockwave lithotripsy (SWL) was the gold standard treatment for patients with small or moderate size LPS in view of its efficacy, low complication rate, and good tolerance. For larger stones, percutaneous nephrolithotomy (PCNL) is the recommended treatment. The stone-free rate (SFR) after SWL treatment for LPS, however, varies from 25% to 85%.1 These results are lower than those for other renal locations. The anatomy of the lower
pole calix, especially the infundibulopelvic angle, as well as gravity have been proposed as possible factors responsible for poor clearance of fragments after SWL.2–4 PCNL has proven to be highly successful for the management of LPS, regardless of stone size. It is associated with higher morbidity5,6 than SWL and f-URS, however, although results are reportedly comparable between PCNL and f-URS for the management of LPS.5 With the development of endoscopic techniques and the miniaturization of equipment, f-URS coupled with endocorporeal lithotripsy by holmium-yttrium-aluminum-garnet laser seems to represent a minimally invasive and effective therapeutic approach for LPS, achieving a higher SFR than
1
Department of Urology and Renal Transplantation, University Hospital of Besanc¸on, France. University of Franche-Comte´, Besanc¸on, France. Groupe de Recherche en Urologie, Besanc¸on, France. 4 INSERM UMR 1098, Besanc¸on, France. 2 3
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SWL, with a comparable complication rate.7,8 Indeed, Pearle and associates9 reported a significantly higher SFR after f-URS compared with SWL for LPS for lower pole caliceal calculi measuring 1 cm or less. Despite technologic and technical progress, however, the drawback of f-URS is that deflection of the flexible ureterorenoscope is limited when the working channel is used. This makes access to the lower pole difficult, leading to the use of specific techniques to access the lower pole calix.10 The objective of this study was to evaluate the impact of stone location on the efficacy and morbidity of f-URS by comparing procedures performed for LPS with those performed for other renal locations. Patients and Methods
We performed a retrospective study between January 2004 and December 2010. All f-URS performed for upper urinary tract stone retrieval in our institution were eligible for the analysis, corresponding to a total of 497 procedures in 373 patients. Of these, 126 procedures performed for ureteral stone location were excluded, and the remaining 371 procedures were included in this analysis. Each procedure was considered on an individual basis. Among the 371 procedures included in this analysis, 139 were performed for stones located in a renal location other than the lower pole (group 1), and 232 procedures were for stones located in the lower pole (group 2). Multiple stone locations including at least one lower pole location were included in group 2, whereas patients with multiple stone locations without any lower pole location were included in group 1.
Recorded data included demographic data for each patient (age, body mass index [BMI], preoperative stent placement), stone characteristics (stone composition, location, diameter of the largest stone), procedural characteristics (procedure duration, relocation, use of ureteral access sheath, placement of ureteral stent), mean length of stay and procedural outcomes (i.e., the SFR at 6 months), surgical complications according to the Clavien-Dindo classification11 (hematuria, flank pain, and sepsis). Follow-up was standardized and included simple radiography coupled with ultrasonography or renal CT scan. The primary end point was success of f-URS (SFR) defined according to a very stringent definition of the SFR—namely, complete stone-free status at the last follow-up visit at 6 months. Presence of residual fragments was considered a failure, regardless of the size of the residual fragment(s). All f-URS were performed by experienced operators (EC, GG, SB, HB, FK) following a standardized protocol previously described by Delorme and colleagues.12 Endoureteral Double-J stents or ureteral stents could be used in this study, at the surgeon’s discretion. Statistical analysis
Statistical analysis was performed using Prism software (GraphPad, San Diego, CA) and XLstat software (Addinsoft, Brooklyn, NY). Categoric variables were analyzed using the chi-square test or Fisher exact test where applicable. Continuous variables were analyzed parametrically using the Student t test. A P value < 0.05 was considered statistically significant. For multivariate analysis, impact of history of
Table 1. Patient, Stone, and Procedural Characteristics in the Study Population
Patient characteristics Age (years) Female sex (n, %) BMI (kg/m2) BMI > 30 kg/m2, (n, %) History of urolithiasis (n, %) Preoperative stent placement (n, %) Stone characteristics Stone size (mm) 20 mm (n, %) Stone composition Calcium oxalate (n, %) Phosphate (n, %) Uric acid (n, %) Calcium phosphate (n, %) Procedure characteristics Duration (minutes) Ureteral dilation (n, %) Access sheath (n, %) Monobloc extraction (n, %) Fragments extraction (n, %) Postoperative drainage (n, %) Stone relocation *P < 0.05 group 1 vs group 2. BMI = body mass index.
Group 1 (139 procedures)
Group 2 (232 procedures)
51.6 – 16.08 61 (43.9%) 25.9 – 5.06 28 (20.5%) 71 (51.1%) 87 (62.6%)
51.5 – 14.9 99 (42.7%) 25.8 – 4.94 47 (20.5%) 137 (59.1%) 134 (58%)
0.96 0.82 0.88 1 0.14 0.38
9.9 – 5.48 67 (48.5%) 63 (46.3%) 9 (8.1%)
9.6 – 5.67 142 (61.2%) 85 (36.6%) 5 (6.9%)
0.65 0.018* 0.07 0.66
72 15 5 15
130 18 16 29
0.47 0.35 0.22 0.68
(52%) (11%) (3.9%) (11%)
99.4 – 43.53 20 (14.3%) 93 (66.9%) 25 (18.2%) 80 (57.4%) 128 (92.1%) 0
(56%) (7.9%) (6.9%) (12.5%)
100.9 – 46.42 30 (12.8%) 186 (80.2%) 43 (18.7%) 150 (64.3%) 215 (93.1%) 46 (19.8%)
P
0.76 0.69 0.007* 0.91 0.19 0.72 -
IMPACT OF STONE LOCATION
1185
Table 2. Outcomes and Complications of Flexible Ureterorenoscopy Procedures
Mean length of stay (days) Stone-free rate (n, %) Stone-free rate for stones
Ureteroscopy and Percutaneous Procedures
Comparison of the Efficacy and Morbidity of Flexible Ureterorenoscopy for Lower Pole Stones Compared with Other Renal Locations Baptiste Jacquemet, MD,1 Lucille Martin, MD,1,2 Julie Pastori, MD,1 Vincent Bailly, MD,1 Guillaume Guichard, MD,1 Ste´phane Bernardini, MD, PhD,1 Eric Chabannes, MD,1 Hugues Bittard, MD,1–3 and Franc¸ois Kleinclauss, MD, PhD1–4
Abstract
Background and Purpose: Flexible ureterorenoscopy (f-URS) for lower pole stones (LPS) compared with other renal locations can be challenging because of anatomic and technical considerations. We aimed to compare the stone-free rate (SFR) and surgical complication rate with f-URS for LPS vs other renal locations. Patients and Methods: We performed a retrospective, single-center study including 371 f-URS for renal stone retrieval performed in our institution between January 2004 and December 2010. Among the 371 procedures included in this analysis, 139 were performed for stones located in a single renal location other than the lower pole (group 1), and 232 for at least one stone located in the lower pole (group 2). We compared the efficacy (SFR) and the morbidity of f-URS between the two groups. The success of the procedure was defined as a complete SFR 6 months after f-URS. Results: Age, sex, history of urolithiasis, body mass index, and preoperative stent placement did not differ between the two groups. No differences in stone characteristics were observed between both groups except stone size under 10 mm that was significantly higher in group 2 (P = 0.018). Technical aspects of the procedure did not differ between the groups, except for more frequent use of an access sheath in group 2 (P = 0.007). SFR was comparable between groups (P = 0.774). The complication rate was similar in both groups, as was the severity of complications. By multivariate analysis, stone size >10 mm (P < 0.0001) and multiple stone locations (P = 0.001) were associated with f-URS failure, but lower pole location did not impact on SFR. Conclusion: In our study, stone location, in particular LPS, did not have any impact on efficacy and morbidity of f-URS. Only multiple locations and stone size >10 mm seemed to significantly decrease the SFR, without impacting morbidity.
Introduction
M
anagement of lower pole stones (LPS) can represent a therapeutic challenge. Before the development of flexible ureterorenoscopy (f-URS), extracorporeal shockwave lithotripsy (SWL) was the gold standard treatment for patients with small or moderate size LPS in view of its efficacy, low complication rate, and good tolerance. For larger stones, percutaneous nephrolithotomy (PCNL) is the recommended treatment. The stone-free rate (SFR) after SWL treatment for LPS, however, varies from 25% to 85%.1 These results are lower than those for other renal locations. The anatomy of the lower
pole calix, especially the infundibulopelvic angle, as well as gravity have been proposed as possible factors responsible for poor clearance of fragments after SWL.2–4 PCNL has proven to be highly successful for the management of LPS, regardless of stone size. It is associated with higher morbidity5,6 than SWL and f-URS, however, although results are reportedly comparable between PCNL and f-URS for the management of LPS.5 With the development of endoscopic techniques and the miniaturization of equipment, f-URS coupled with endocorporeal lithotripsy by holmium-yttrium-aluminum-garnet laser seems to represent a minimally invasive and effective therapeutic approach for LPS, achieving a higher SFR than
1
Department of Urology and Renal Transplantation, University Hospital of Besanc¸on, France. University of Franche-Comte´, Besanc¸on, France. Groupe de Recherche en Urologie, Besanc¸on, France. 4 INSERM UMR 1098, Besanc¸on, France. 2 3
1183
1184
JACQUEMET ET AL.
SWL, with a comparable complication rate.7,8 Indeed, Pearle and associates9 reported a significantly higher SFR after f-URS compared with SWL for LPS for lower pole caliceal calculi measuring 1 cm or less. Despite technologic and technical progress, however, the drawback of f-URS is that deflection of the flexible ureterorenoscope is limited when the working channel is used. This makes access to the lower pole difficult, leading to the use of specific techniques to access the lower pole calix.10 The objective of this study was to evaluate the impact of stone location on the efficacy and morbidity of f-URS by comparing procedures performed for LPS with those performed for other renal locations. Patients and Methods
We performed a retrospective study between January 2004 and December 2010. All f-URS performed for upper urinary tract stone retrieval in our institution were eligible for the analysis, corresponding to a total of 497 procedures in 373 patients. Of these, 126 procedures performed for ureteral stone location were excluded, and the remaining 371 procedures were included in this analysis. Each procedure was considered on an individual basis. Among the 371 procedures included in this analysis, 139 were performed for stones located in a renal location other than the lower pole (group 1), and 232 procedures were for stones located in the lower pole (group 2). Multiple stone locations including at least one lower pole location were included in group 2, whereas patients with multiple stone locations without any lower pole location were included in group 1.
Recorded data included demographic data for each patient (age, body mass index [BMI], preoperative stent placement), stone characteristics (stone composition, location, diameter of the largest stone), procedural characteristics (procedure duration, relocation, use of ureteral access sheath, placement of ureteral stent), mean length of stay and procedural outcomes (i.e., the SFR at 6 months), surgical complications according to the Clavien-Dindo classification11 (hematuria, flank pain, and sepsis). Follow-up was standardized and included simple radiography coupled with ultrasonography or renal CT scan. The primary end point was success of f-URS (SFR) defined according to a very stringent definition of the SFR—namely, complete stone-free status at the last follow-up visit at 6 months. Presence of residual fragments was considered a failure, regardless of the size of the residual fragment(s). All f-URS were performed by experienced operators (EC, GG, SB, HB, FK) following a standardized protocol previously described by Delorme and colleagues.12 Endoureteral Double-J stents or ureteral stents could be used in this study, at the surgeon’s discretion. Statistical analysis
Statistical analysis was performed using Prism software (GraphPad, San Diego, CA) and XLstat software (Addinsoft, Brooklyn, NY). Categoric variables were analyzed using the chi-square test or Fisher exact test where applicable. Continuous variables were analyzed parametrically using the Student t test. A P value < 0.05 was considered statistically significant. For multivariate analysis, impact of history of
Table 1. Patient, Stone, and Procedural Characteristics in the Study Population
Patient characteristics Age (years) Female sex (n, %) BMI (kg/m2) BMI > 30 kg/m2, (n, %) History of urolithiasis (n, %) Preoperative stent placement (n, %) Stone characteristics Stone size (mm) 20 mm (n, %) Stone composition Calcium oxalate (n, %) Phosphate (n, %) Uric acid (n, %) Calcium phosphate (n, %) Procedure characteristics Duration (minutes) Ureteral dilation (n, %) Access sheath (n, %) Monobloc extraction (n, %) Fragments extraction (n, %) Postoperative drainage (n, %) Stone relocation *P < 0.05 group 1 vs group 2. BMI = body mass index.
Group 1 (139 procedures)
Group 2 (232 procedures)
51.6 – 16.08 61 (43.9%) 25.9 – 5.06 28 (20.5%) 71 (51.1%) 87 (62.6%)
51.5 – 14.9 99 (42.7%) 25.8 – 4.94 47 (20.5%) 137 (59.1%) 134 (58%)
0.96 0.82 0.88 1 0.14 0.38
9.9 – 5.48 67 (48.5%) 63 (46.3%) 9 (8.1%)
9.6 – 5.67 142 (61.2%) 85 (36.6%) 5 (6.9%)
0.65 0.018* 0.07 0.66
72 15 5 15
130 18 16 29
0.47 0.35 0.22 0.68
(52%) (11%) (3.9%) (11%)
99.4 – 43.53 20 (14.3%) 93 (66.9%) 25 (18.2%) 80 (57.4%) 128 (92.1%) 0
(56%) (7.9%) (6.9%) (12.5%)
100.9 – 46.42 30 (12.8%) 186 (80.2%) 43 (18.7%) 150 (64.3%) 215 (93.1%) 46 (19.8%)
P
0.76 0.69 0.007* 0.91 0.19 0.72 -
IMPACT OF STONE LOCATION
1185
Table 2. Outcomes and Complications of Flexible Ureterorenoscopy Procedures
Mean length of stay (days) Stone-free rate (n, %) Stone-free rate for stones
