REVIEW URRENT C OPINION
Benefits and risks of ureteral access sheaths for retrograde renal access Alberto Breda a, Angelo Territo b, and Juan Manuel Lo´pez-Martı´nez a
Purpose of review Ureteral access sheath (UAS) became increasingly popular worldwide. However, the safety of its routine use remains controversial. The aim of the current revision is to provide a systematic review on the benefits and disadvantages of the UAS. Recent findings A systematic review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. Two reviewers independently searched the literature, finally identifying 20 articles valuable for this review. The use of UAS demonstrated several advantages to facilitate retrograde intrarenal access, lower intrarenal pressure, protect the ureter, protect the scope, and expedite stone extraction. Despite this, there is also some evidence that UAS use may be associated with acute ureteral injury and long-term complications, apparently related to maneuvers for UAS insertion and mucosal or deeper layers of injury and ischemia. Furthermore, there are still pending questions on the possible increase in stone-free rates, and decrease in operative time and costs. Summary Although the use of UAS is associated with some risk and limiting factors, it appears from this systematic review that its use is common and safe for the retrograde intrarenal access. Therefore, UAS is highly recommended for the treatment of upper tract disease by means of retrograde intrarenal surgery. Keywords retrograde intrarenal surgery, ureteral access sheath, ureterorenoscopy
INTRODUCTION In recent years, urology has experienced a real explosion in the development of new technologies. Thanks to technical improvements of the endoscopic equipment, endourology found applicability in almost all upper urinary tract diseases, allowing effective and safe interventions and diminishing patient discomfort. Flexible ureteroscopy (FURS) has certainly progressed to the forefront of the endourologist’s armamentarium and allowed us to improve the exploration and study of the upper urinary tract, with diagnostic and therapeutic purposes. The progress has been the result of technological development of optical and digital flexible ureteroscopes, nitinol technology including baskets, holmium laser and laser fibers, as well as refinement of endoscopic techniques and development of ureteral access sheath (UAS). The UAS was introduced in 1974 to facilitate passing of an ureteroscope into the ureter [1]; it was immediately lauded for its ability to access the upper tract cavities and evaluate any portion of the kidney, rapidly repeat www.co-urology.com
entrance into the ureter and collecting system, lower the intrarenal pressure during pulse irrigation, improve visibility, avoiding ureteral lesion when extracting stone fragments, improve the drainage, and protect the scope [2,3]. Despite this, there have been some concerns related to UAS use and ureteral injuries [4 ]. Although these issues appear to be limited to certain difficult cases, there are still some concerns related to UAS indications and use. The scope of this review is to identify the benefits of UAS as well as define the possible risk associated with its use and contraindications or limitations. &
a
Department of Urology, Fundacio` Puigvert, University Autonoma of Barcelona, Barcelona, Spain and bDepartment of Urology, University of Modena and Reggio Emilia, Italy Correspondence to Alberto Breda, University Autonoma of Barcelona, Fundacio‘ Puigvert, Spain, Calle Cartagena 340–350, 08025 Barcelona, Spain. Fax: +34 934169730; e-mail: [email protected] Curr Opin Urol 2016, 26:70–75 DOI:10.1097/MOU.0000000000000233 Volume 26 Number 1 January 2016
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Benefits and risks of ureteral access sheaths Breda et al.
Advantages
KEY POINTS The review summarized the most recent evidence in terms of advantages, disadvantages, risk, and controversial aspects; related to the use of UAS. It seems to be enough in-vitro and in-vivo evidence to assert that the use of UAS lowers the risk of bacteremia and sepsis. According to the reports, when properly used, UAS does not increase the risk of acute ureteral injury. Recent large prospective nonrandomized studies seem to show no benefits it terms of SFR when using UAS.
Fast, repeatable, and safe access to the upper urinary tract with improved vision The use of the UAS facilitates the entrance to the upper urinary tract by allowing a direct entrance from the outside into the ureter and calyceal system. Therefore, many centers have documented routine use of UAS during FURS both for stone and upper tract urothelial carcinoma (UTUC) [2,5]. After stone fragmentation, fragments can be removed through the UAS reducing trauma or risk of ureteral lesions [2]. Furthermore, because of the ability to continuously use high-pressured irrigation, there is evidence of improved vision as opposed to sole ureteroscopy use without UAS [6].
MATERIALS AND METHODS A MEDLINE search for peer-reviewed studies published between 1992 and 2015 was performed using the keywords ‘Ureteral Access Sheath’, ‘Ureteroscopy and UAS’, ‘Retrograde Intrarenal Surgery and UAS’, ‘Ureteral damage and UAS’, ‘Intra-Renal Pressure and UAS’ ‘Complications and UAS’, ‘Ureteral complications and UAS’, and ‘UAS and cost’. We considered as inclusion criteria original articles including prospective and randomized studies, retrospective well designed studies, systematic reviews, and meta-analysis in English language. Abstracts, letters to the editor, technical notes, case reports, series shorter than 10 cases, comprehensive reviews, and articles written in languages other than English were not considered valuable for this review. The reference lists of the eligible articles were reviewed by two authors and a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria and the Oxford Center for Evidence-Based Medicine level of scientific evidence (website: http://www.cebm.net/ ?o¼1025) was performed.
RESULTS AND DISCUSSION The review identified 320 articles with the use of the above mentioned keywords. After a careful screening, 21 articles were considered suitable for the purpose of this study and for the evidence making process. The articles are underlined in the flow chart of Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. (Fig. 1) According to these results, the use of UAS is popular and diffused among endourologists. Despite this there are still some controversial points to take in to consideration. Herein we describe the advantages, disadvantages, and controversies of the use of the UAS.
Reduction of the intrarenal pressure Irrigation systems are key for visualization during all ureteroscopic procedures [7]. Pressurized saline irrigation is commonly used during ureteroscopy, which can cause an increase in intrarenal pressure [7]. There are concerns that this high pressure could be dangerous if no drainage was applied. High intrarenal pressure is in fact associated with urinary sepsis because of possible calyceal rupture and/or bacterial backflow [6]. Laboratory data reported by Rehman et al. [6] have shown that the simultaneous use of the UAS with pressurized irrigation through the flexible ureteroscope enhances visualization of the upper tract while maintaining low (
Benefits and risks of ureteral access sheaths for retrograde renal access Alberto Breda a, Angelo Territo b, and Juan Manuel Lo´pez-Martı´nez a
Purpose of review Ureteral access sheath (UAS) became increasingly popular worldwide. However, the safety of its routine use remains controversial. The aim of the current revision is to provide a systematic review on the benefits and disadvantages of the UAS. Recent findings A systematic review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. Two reviewers independently searched the literature, finally identifying 20 articles valuable for this review. The use of UAS demonstrated several advantages to facilitate retrograde intrarenal access, lower intrarenal pressure, protect the ureter, protect the scope, and expedite stone extraction. Despite this, there is also some evidence that UAS use may be associated with acute ureteral injury and long-term complications, apparently related to maneuvers for UAS insertion and mucosal or deeper layers of injury and ischemia. Furthermore, there are still pending questions on the possible increase in stone-free rates, and decrease in operative time and costs. Summary Although the use of UAS is associated with some risk and limiting factors, it appears from this systematic review that its use is common and safe for the retrograde intrarenal access. Therefore, UAS is highly recommended for the treatment of upper tract disease by means of retrograde intrarenal surgery. Keywords retrograde intrarenal surgery, ureteral access sheath, ureterorenoscopy
INTRODUCTION In recent years, urology has experienced a real explosion in the development of new technologies. Thanks to technical improvements of the endoscopic equipment, endourology found applicability in almost all upper urinary tract diseases, allowing effective and safe interventions and diminishing patient discomfort. Flexible ureteroscopy (FURS) has certainly progressed to the forefront of the endourologist’s armamentarium and allowed us to improve the exploration and study of the upper urinary tract, with diagnostic and therapeutic purposes. The progress has been the result of technological development of optical and digital flexible ureteroscopes, nitinol technology including baskets, holmium laser and laser fibers, as well as refinement of endoscopic techniques and development of ureteral access sheath (UAS). The UAS was introduced in 1974 to facilitate passing of an ureteroscope into the ureter [1]; it was immediately lauded for its ability to access the upper tract cavities and evaluate any portion of the kidney, rapidly repeat www.co-urology.com
entrance into the ureter and collecting system, lower the intrarenal pressure during pulse irrigation, improve visibility, avoiding ureteral lesion when extracting stone fragments, improve the drainage, and protect the scope [2,3]. Despite this, there have been some concerns related to UAS use and ureteral injuries [4 ]. Although these issues appear to be limited to certain difficult cases, there are still some concerns related to UAS indications and use. The scope of this review is to identify the benefits of UAS as well as define the possible risk associated with its use and contraindications or limitations. &
a
Department of Urology, Fundacio` Puigvert, University Autonoma of Barcelona, Barcelona, Spain and bDepartment of Urology, University of Modena and Reggio Emilia, Italy Correspondence to Alberto Breda, University Autonoma of Barcelona, Fundacio‘ Puigvert, Spain, Calle Cartagena 340–350, 08025 Barcelona, Spain. Fax: +34 934169730; e-mail: [email protected] Curr Opin Urol 2016, 26:70–75 DOI:10.1097/MOU.0000000000000233 Volume 26 Number 1 January 2016
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Benefits and risks of ureteral access sheaths Breda et al.
Advantages
KEY POINTS The review summarized the most recent evidence in terms of advantages, disadvantages, risk, and controversial aspects; related to the use of UAS. It seems to be enough in-vitro and in-vivo evidence to assert that the use of UAS lowers the risk of bacteremia and sepsis. According to the reports, when properly used, UAS does not increase the risk of acute ureteral injury. Recent large prospective nonrandomized studies seem to show no benefits it terms of SFR when using UAS.
Fast, repeatable, and safe access to the upper urinary tract with improved vision The use of the UAS facilitates the entrance to the upper urinary tract by allowing a direct entrance from the outside into the ureter and calyceal system. Therefore, many centers have documented routine use of UAS during FURS both for stone and upper tract urothelial carcinoma (UTUC) [2,5]. After stone fragmentation, fragments can be removed through the UAS reducing trauma or risk of ureteral lesions [2]. Furthermore, because of the ability to continuously use high-pressured irrigation, there is evidence of improved vision as opposed to sole ureteroscopy use without UAS [6].
MATERIALS AND METHODS A MEDLINE search for peer-reviewed studies published between 1992 and 2015 was performed using the keywords ‘Ureteral Access Sheath’, ‘Ureteroscopy and UAS’, ‘Retrograde Intrarenal Surgery and UAS’, ‘Ureteral damage and UAS’, ‘Intra-Renal Pressure and UAS’ ‘Complications and UAS’, ‘Ureteral complications and UAS’, and ‘UAS and cost’. We considered as inclusion criteria original articles including prospective and randomized studies, retrospective well designed studies, systematic reviews, and meta-analysis in English language. Abstracts, letters to the editor, technical notes, case reports, series shorter than 10 cases, comprehensive reviews, and articles written in languages other than English were not considered valuable for this review. The reference lists of the eligible articles were reviewed by two authors and a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria and the Oxford Center for Evidence-Based Medicine level of scientific evidence (website: http://www.cebm.net/ ?o¼1025) was performed.
RESULTS AND DISCUSSION The review identified 320 articles with the use of the above mentioned keywords. After a careful screening, 21 articles were considered suitable for the purpose of this study and for the evidence making process. The articles are underlined in the flow chart of Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. (Fig. 1) According to these results, the use of UAS is popular and diffused among endourologists. Despite this there are still some controversial points to take in to consideration. Herein we describe the advantages, disadvantages, and controversies of the use of the UAS.
Reduction of the intrarenal pressure Irrigation systems are key for visualization during all ureteroscopic procedures [7]. Pressurized saline irrigation is commonly used during ureteroscopy, which can cause an increase in intrarenal pressure [7]. There are concerns that this high pressure could be dangerous if no drainage was applied. High intrarenal pressure is in fact associated with urinary sepsis because of possible calyceal rupture and/or bacterial backflow [6]. Laboratory data reported by Rehman et al. [6] have shown that the simultaneous use of the UAS with pressurized irrigation through the flexible ureteroscope enhances visualization of the upper tract while maintaining low (
