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Junichi Matsuzaki - One of the best experts on this subject based on the ideXlab platform.
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Gap between UAS and ureteroscope predicts renal stone-free rate after flexible Ureteroscopy with the fragmentation technique
World Journal of Urology, 2020Co-Authors: Mitsuru Komeya, Takehiko Ogawa, Hisakazu Odaka, Takahiko Watanabe, Hirokazu Kiuchi, Masahiro Yao, Junichi MatsuzakiAbstract:Purpose To assess the effect of our new classification on surgical outcomes after flexible Ureteroscopy (fURS) for kidney stones. Methods We retrospectively examined 128 patients after single renal fURS procedures performed using ureteral access sheaths (UASs) with the fragmentation technique. Based on the gap (calculated by subtracting the ureteroscope diameter from the UAS diameter), enrolled patients were divided into three groups: small (
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Ureteroscopy assisted retrograde nephrostomy a new technique for percutaneous nephrolithotomy pcnl
BJUI, 2012Co-Authors: Takashi Kawahara, Hideyuki Terao, Takehiko Ogawa, Yoshinobu Kubota, Minoru Yoshida, Hiroji Uemura, Junichi MatsuzakiAbstract:UNLABELLED: Study Type - Therapy (case series). Level of Evidence 4. What's known on the subject? and What does the study add? Retrograde nephrostomy was first developed by Lawson et al. in 1983, and Hunter et al. reported 30 cases of retrograde nephrostomy in 1987. This procedure uses less radiation exposure and has a shorter duration compared with the previous percutaneous nephrostomy techniques. Retrograde nephrostomy using Lawson's procedure was reported in the late 1980s by several authors. But since then, few studies have been reported about this procedure due to the development of ultrasonography assisted percutaneous nephrostomy. With the arrival and development of the flexible ureteroscope (URS) both observation and manipulation in the renal pelvis are now easily achieved. The present procedure provides less radiation exposure, less bleeding, and a shorter procedure than previous percutaneous nephrostomy techniques. Using this procedure, after the needle has exited through the skin, no further steps are required in preparation for dilatation. In the present study, we continuously visualised from puncture to inserting the nephron-access sheath with the URS. OBJECTIVE: • To describe a technique for Ureteroscopy assisted retrograde nephrostomy. PATIENTS AND METHODS: • Under general and epidural anaesthesia, the patient is placed in a modified-Valdivia position. Flexible Ureteroscopy is carried out, and a Lawson retrograde nephrostomy puncture wire is placed in the ureteroscope (URS). • After the needle has exited through the skin, no further steps are required in preparation for dilatation. RESULTS: • After informed consent was obtained, two patients (a 43-year-old man with left renal stones and a 57-year-old woman with right renal stones) underwent this procedure. • The URS was positioned in the middle posterior calyx and punctured toward the skin. CONCLUSIONS: • This procedure involves less radiation exposure and shorter surgery than the previous percutaneous nephrostomy technique. • Our technique represents another new option for percutaneous nephrolithotomy in patients with a non-dilated intrarenal collecting system.
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Ureteroscopy assisted retrograde nephrostomy for lower calyx calculi in horseshoe kidney two case reports
Journal of Medical Case Reports, 2012Co-Authors: Takashi Kawahara, Hideyuki Terao, Takehiko Ogawa, Yoshinobu Kubota, Katsuyuki Tanaka, Hiroji Uemura, Junichi MatsuzakiAbstract:Introduction We previously reported on the effectiveness of Ureteroscopy-assisted retrograde nephrostomy during percutaneous nephrolithotomy and report two cases of lower calyx calculi in horseshoe kidney that were successfully treated with Ureteroscopy-assisted retrograde nephrostomy. During the Ureteroscopy-assisted retrograde nephrostomy procedure, a ureteroscope is advanced in the desired calyx and a Lawson retrograde nephrostomy puncture wire is inserted. The wire is advanced through the calyx to exit the skin. The wire is then used for the percutaneous dilation.
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Ureteroscopy-Assisted Retrograde Nephrostomy
Journal of Endourology Part B Videourology, 2012Co-Authors: Takashi Kawahara, Hideyuki Terao, Takehiko Ogawa, Yoshinobu Kubota, Hiroji Uemura, Junichi MatsuzakiAbstract:Abstract Introduction: Lawson et al first developed retrograde nephrostomy in 1983.1 Hunter et al reported 30 cases of retrograde nephrostomy in 1985.2 Ureteroscopy (URS)-assisted retrograde nephrostomy (UARN) was reported as a new technique for percutaneous nephrolithotomy (PCNL) in 2011, and this institute performed more than 30 cases of UARN.3 This video presents the details of the UARN technique based on this experience. Materials and Methods: The patient is placed in the Galdakao-modified Valdivia position under general and epidural anesthesia.4 A ureteral access sheath (UAS) is inserted and a flexible ureteroscope (Flex-X2®; Karl Storz) is inserted through the UAS. The target calculi are carefully observed to identify the appropriate renal calyx to be punctured. A Lawson retrograde nephrostomy puncture wire (Lawson Retrograde Nephrostomy Wire Puncture Set; COOK Urological) is carefully set into the flexible URS. The flexible ureteroscope approaches the desired renal calyx again, and the route from t...
Glenn M Preminger - One of the best experts on this subject based on the ideXlab platform.
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use of ureteral access sheaths in Ureteroscopy
Nature Reviews Urology, 2016Co-Authors: Adam G Kaplan, Michael E Lipkin, Charles D Scales, Glenn M PremingerAbstract:The ureteral access sheath (UAS) facilitates the use of flexible Ureteroscopy, enabling improved minimally invasive management of complex upper urinary tract diseases. The UAS, which comes in a variety of diameters and lengths, is passed in a retrograde fashion, aided by a hydrophilic coating and other features designed to confer smooth passage into the ureter with sufficient resistance to kinking and buckling. Use of a UAS has the advantage of enabling repeated passage of the ureteroscope while minimizing damage to the ureter, thus improving the flow of irrigation fluid and visualization within the urethra with reductions in operative times, which improves both the effectiveness of the surgery and reduces the costs. Placement of the UAS carries an increased risk of ureteral wall ischaemia and injury to the mucosal or muscular layers of the ureter, and a theoretically increased risk of ureteral strictures. A ureteral stent is typically placed after Ureteroscopy with a UAS. Endourologists have found several additional practical uses of a UAS, such as the percutaneous treatment of patients with ureteral stones, and solutions to other endourological challenges.
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routine ureteral stenting is not necessary after Ureteroscopy and ureteropyeloscopy a randomized trial
Journal of Endourology, 2002Co-Authors: Robert R Byrne, Brian K Auge, John Kourambas, Ravi Munver, Fernando C Delvecchio, Glenn M PremingerAbstract:Background and Purpose: Retrospective studies have suggested that routine stenting can be avoided following Ureteroscopy. We prospectively analyzed the need for routine ureteral stent placement in patients undergoing ureteroscopic procedures. Patients and Methods: Fifty-five consecutive patients (60 renal units) were randomized into either a stent or a no-stent group following Ureteroscopy with either a 7.5F semirigid or a 7.5F flexible ureteroscope for treatment of calculi (holmium laser or pneumatic lithotripsy) or transitional-cell carcinoma (holmium laser). Intraoperative variables assessed included total stone burden, the need for ureteral dilation, and overall operative times. All patients were evaluated by questionnaire on postoperative days 0, 1, and 6 with regard to pain, frequency, urgency, dysuria, and hematuria. Results: Of the 60 renal units treated, 38 received ureteral stents (mean 5.2 days), and 22 were treated without a stent. All 10 patients requiring ureteral balloon dilation had stents...
Takehiko Ogawa - One of the best experts on this subject based on the ideXlab platform.
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Gap between UAS and ureteroscope predicts renal stone-free rate after flexible Ureteroscopy with the fragmentation technique
World Journal of Urology, 2020Co-Authors: Mitsuru Komeya, Takehiko Ogawa, Hisakazu Odaka, Takahiko Watanabe, Hirokazu Kiuchi, Masahiro Yao, Junichi MatsuzakiAbstract:Purpose To assess the effect of our new classification on surgical outcomes after flexible Ureteroscopy (fURS) for kidney stones. Methods We retrospectively examined 128 patients after single renal fURS procedures performed using ureteral access sheaths (UASs) with the fragmentation technique. Based on the gap (calculated by subtracting the ureteroscope diameter from the UAS diameter), enrolled patients were divided into three groups: small (
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Ureteroscopy assisted retrograde nephrostomy a new technique for percutaneous nephrolithotomy pcnl
BJUI, 2012Co-Authors: Takashi Kawahara, Hideyuki Terao, Takehiko Ogawa, Yoshinobu Kubota, Minoru Yoshida, Hiroji Uemura, Junichi MatsuzakiAbstract:UNLABELLED: Study Type - Therapy (case series). Level of Evidence 4. What's known on the subject? and What does the study add? Retrograde nephrostomy was first developed by Lawson et al. in 1983, and Hunter et al. reported 30 cases of retrograde nephrostomy in 1987. This procedure uses less radiation exposure and has a shorter duration compared with the previous percutaneous nephrostomy techniques. Retrograde nephrostomy using Lawson's procedure was reported in the late 1980s by several authors. But since then, few studies have been reported about this procedure due to the development of ultrasonography assisted percutaneous nephrostomy. With the arrival and development of the flexible ureteroscope (URS) both observation and manipulation in the renal pelvis are now easily achieved. The present procedure provides less radiation exposure, less bleeding, and a shorter procedure than previous percutaneous nephrostomy techniques. Using this procedure, after the needle has exited through the skin, no further steps are required in preparation for dilatation. In the present study, we continuously visualised from puncture to inserting the nephron-access sheath with the URS. OBJECTIVE: • To describe a technique for Ureteroscopy assisted retrograde nephrostomy. PATIENTS AND METHODS: • Under general and epidural anaesthesia, the patient is placed in a modified-Valdivia position. Flexible Ureteroscopy is carried out, and a Lawson retrograde nephrostomy puncture wire is placed in the ureteroscope (URS). • After the needle has exited through the skin, no further steps are required in preparation for dilatation. RESULTS: • After informed consent was obtained, two patients (a 43-year-old man with left renal stones and a 57-year-old woman with right renal stones) underwent this procedure. • The URS was positioned in the middle posterior calyx and punctured toward the skin. CONCLUSIONS: • This procedure involves less radiation exposure and shorter surgery than the previous percutaneous nephrostomy technique. • Our technique represents another new option for percutaneous nephrolithotomy in patients with a non-dilated intrarenal collecting system.
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Ureteroscopy assisted retrograde nephrostomy for lower calyx calculi in horseshoe kidney two case reports
Journal of Medical Case Reports, 2012Co-Authors: Takashi Kawahara, Hideyuki Terao, Takehiko Ogawa, Yoshinobu Kubota, Katsuyuki Tanaka, Hiroji Uemura, Junichi MatsuzakiAbstract:Introduction We previously reported on the effectiveness of Ureteroscopy-assisted retrograde nephrostomy during percutaneous nephrolithotomy and report two cases of lower calyx calculi in horseshoe kidney that were successfully treated with Ureteroscopy-assisted retrograde nephrostomy. During the Ureteroscopy-assisted retrograde nephrostomy procedure, a ureteroscope is advanced in the desired calyx and a Lawson retrograde nephrostomy puncture wire is inserted. The wire is advanced through the calyx to exit the skin. The wire is then used for the percutaneous dilation.
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Ureteroscopy-Assisted Retrograde Nephrostomy
Journal of Endourology Part B Videourology, 2012Co-Authors: Takashi Kawahara, Hideyuki Terao, Takehiko Ogawa, Yoshinobu Kubota, Hiroji Uemura, Junichi MatsuzakiAbstract:Abstract Introduction: Lawson et al first developed retrograde nephrostomy in 1983.1 Hunter et al reported 30 cases of retrograde nephrostomy in 1985.2 Ureteroscopy (URS)-assisted retrograde nephrostomy (UARN) was reported as a new technique for percutaneous nephrolithotomy (PCNL) in 2011, and this institute performed more than 30 cases of UARN.3 This video presents the details of the UARN technique based on this experience. Materials and Methods: The patient is placed in the Galdakao-modified Valdivia position under general and epidural anesthesia.4 A ureteral access sheath (UAS) is inserted and a flexible ureteroscope (Flex-X2®; Karl Storz) is inserted through the UAS. The target calculi are carefully observed to identify the appropriate renal calyx to be punctured. A Lawson retrograde nephrostomy puncture wire (Lawson Retrograde Nephrostomy Wire Puncture Set; COOK Urological) is carefully set into the flexible URS. The flexible ureteroscope approaches the desired renal calyx again, and the route from t...
Bhaskar K Somani - One of the best experts on this subject based on the ideXlab platform.
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Outcomes of Ureteroscopy for stone disease in anomalous kidneys: a systematic review
World Journal of Urology, 2019Co-Authors: Lisa Lavan, Thomas Herrmann, Christopher Netsch, Benedikt Becker, Bhaskar K SomaniAbstract:Introduction Treatment of stone disease in anomalous kidneys can be challenging. As Ureteroscopy (URS) has advanced, the number of studies reporting on outcomes of URS for stone disease in anomalous kidneys has increased. Our objective was to perform a systematic review of the literature to evaluate the outcomes of URS for stone disease in this group of patients. Methods A Cochrane style review was performed in accordance with the PRISMA guidelines using Medline, EMBASE, CINAHL, Cochrane Library, Scopus and individual urologic journals for all English language articles between inception and June 2018. Results Fourteen papers (413 patients) with a mean age of 43 years and a male to female ratio of 285:128 were included. The underlying renal anomaly was horseshoe kidney ( n = 204), ectopic kidney ( n = 117), malrotation ( n = 86), cross fused ectopia ( n = 2) and others ( n = 2). With a mean stone size of 16 mm (range 2–35 mm), the majority of stones were in the lower pole ( n = 143, 34.6%) or renal pelvis ( n = 128, 31.0%), with 18.9% ( n = 78) having stones in multiple locations. Treatment modality included the use of flexible ureteroscope in 90% of patients and ureteral access sheath used in 11 studies. With a mean operative time of 61.3 min (range 14–185 min), the initial and final SFR was 76.6% ( n = 322) and 82.3% ( n = 340), respectively. The overall complication rate was 17.2% ( n = 71), of which 14.8% were Clavien I/II and the remaining 2.4% were Clavien ≥ III complications. Conclusion Although Ureteroscopy in patients with anomalous kidneys can be technically challenging, advancements in endourological techniques have made it a safe and effective procedure. In these patients the stone-free rates are good with a low risk of major complications.
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comprehensive flexible Ureteroscopy furs simulator for training in endourology the k box model
Central European Journal of Urology 1\ 2010, 2016Co-Authors: Luca Villa, Bhaskar K Somani, T E Sener, J Cloutier, Salvatore Buttice, Francesco Marson, Achilles Ploumidis, Silvia Proietti, Olivier TraxerAbstract:Over the last two decades there has been an increase in the incidence of kidney stone disease with a simultaneous rise in the use of Ureteroscopy for its management [1]. Flexible Ureteroscopy training is variable and still largely dependent on high fidelity models and virtual reality (VR) simulation, both of which are expensive and not readily available in many parts of the world. There is also a lack of good quality bench trainers. In a recent survey of endourologists worldwide, flexible Ureteroscopy was considered as a first line treatment for stones <2 cm [2]. With this in mind, we have developed a new portable bench-training box model for training in flexible Ureteroscopy and endourology. This is a low-cost reusable model for flexible Ureteroscopy training allowing the user to manipulate the scope, place a guidewire and access sheath, use a basket to catch/relocate the stone and finally to use a Holmium YAG laser to fragment the stone. K-box The K-box (K – Box®, Porges-Coloplast, France) is a new generation portable bench-training model for flexible Ureteroscopy. It is made of polyurethane and consists of 4 independent boxes with each of these boxes representing a different training model with three separate entry and exit points (Figures 1, ,2).2). It also comes with a ‘tool tray’, which can be used within the boxes for various training exercises. To use the K-box and perform the exercises, the trainees need to have an endoscope, camera system and screen, light source and disposables such as guidewires, access sheaths, baskets and stents. Trainees can familiarize themselves with different flexible ureterscope movements such as pronation/supination, forward/backward movement, scope deflection and grasping/releasing of objects/stones mimicking the movements in the renal pelvicalyceal system. In addition to this, it allows step-by-step guidewire and access sheath placement along with stone fragmentation (Figures 3, ,4).4). Although the exercises are done with the box closed while the trainee is watching the screen, when a trainee is unsure or lost in the training model they have the option of opening the flap which enables them to see their position (almost being a surrogate for a radiological image/fluoroscopy). The newly designed flexible Ureteroscopy training model allows the surgeon to make the specific movements required when performing flexible Ureteroscopy in humans. Figure 1 K-box and its components (1.1 – portable K-box, 1.2 – box open (left) and closed (right), 1.3 – tool tray, 1.4 – K-box with water to use with laser for stone fragmentation). Figure 2 K-box with all four boxes with embossed markings (opened view) showing various configurations for manipulation of the objects within it. Figure 3 Step by step technique (3.1 – placement of guidewire, 3.2 – placement of access sheath, 3.3 – placement and manipulation of flexible ureteroscope). Figure 4 Manipulation in the pelvicalyceal system (4.1 – stone basketing with a flexible ureteroscope via the access sheath, 4.2 – movement of object from A to B). These boxes can either be used separately or in combination in any random order. A silicone aerosol spray can be used to make the inside surfaces of K-box smoother to minimize friction. To enable laser use, the K-box can be used with water allowing fragmentation of stones.
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Tips and tricks of Ureteroscopy: consensus statement Part I. Basic Ureteroscopy
Central European journal of urology, 2015Co-Authors: Nicholas J. Rukin, Bhaskar K Somani, J. Patterson, Ben R. Grey, William Finch, Samuel Mcclinton, Bo Parys, Graham Young, Haider Syed, Andy MyattAbstract:Ureteroscopy is fast becoming the first line treatment option for the majority of urinary tract stones. Ureteroscopy training can be performed in a variety of ways including simulation, hands on Ureteroscopy courses and supervised operative experience. We report an "expert consensus view" from experienced endourological surgeons, on all aspects of basic ureteroscopic techniques, with a particular focus on avoiding and getting out of trouble while performing Ureteroscopy. In this paper we provide a summary of treatment planning, positioning, cannulation of ureteric orifice, guidewire placement, rigid Ureteroscopy and stone fragmentation.
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Ureteroscopy and stones: Current status and future expectations.
World journal of nephrology, 2014Co-Authors: Anna E. Wright, Nicholas J. Rukin, Bhaskar K SomaniAbstract:Urolithaisis is becoming an ever increasing urological, nephrological and primary care problem. With a lifetime prevalence approaching 10% and increasing morbidity due to stone disease, the role of Ureteroscopy and stone removal is becoming more important. We discuss the current status of stone disease and review the ever increasing role that Ureteroscopy has to play in its management. We discuss technological advances that have been made in stone management and give you an overview of when, how and why Ureteroscopy is the most common treatment option for stone management. We touch on the role of robotic Ureteroscopy and the future of Ureteroscopy in the next 10 years.
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irrigant flow and intrarenal pressure during flexible Ureteroscopy the effect of different access sheaths working channel instruments and hydrostatic pressure
Journal of Endourology, 2010Co-Authors: Bhaskar K Somani, A Dennison, Slawomir G Kata, Ghulam Nabi, Stuart BrownAbstract:Abstract Purpose: Our aim was to determine the optimal size of access sheath for Ureteroscopy and stone lasertripsy to achieve good irrigant flow while maintaining the lowest possible intrarenal pressure. Materials and Methods: We used an in vitro anatomic model into which a pressure transducer was incorporated. Cook Peel-Away 10F, Flexor 12F, 14F, 16F single lumen, and a new 14F Flexor dual-lumen sheath were tested. Irrigant flow and intrarenal pressure were measured with an empty ureteroscope working channel and with a 1.4F or 2.4F basket within the working channel with a hydrostatic pressure of 1 m and 2 m, respectively. For the dual-lumen sheath, the irrigation was either connected to the scope or the second channel of the access sheath. Two other configurations were tested: 4F ureteral catheter placed alongside a 10F sheath (configuration 1) or a 5F ureteral catheter within a 16F access sheath (configuration 2). Results: With an empty working channel, irrigant flow increased with sheath diameter. The...
Ralph V. Clayman - One of the best experts on this subject based on the ideXlab platform.
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Extracorporeal Shockwave Lithotripsy and Intracorporeal Lithotripsy for Proximal Ureteric Calculi—A Comparative Assessment of Efficacy and Safety
Journal of Urology, 2005Co-Authors: Ralph V. ClaymanAbstract:INTRODUCTION: Extracorporeal shockwave lithotripsy (ESWL) is the treatment modality of choice of many urologists for proximal ureteric calculi. In this study, we compared the efficacy and safety of ESWL versus Ureteroscopy with holmium laser lithotripsy for the treatment of this group of stones. MATERIALS AND METHODS: Between May 1999 and October 2000, 50 patients had ESWL and another 51 patients underwent Ureteroscopy with holmium laser lithotripsy for proximal ureteric calculi. The two groups were similar in age, sex ratio and stone size. ESWL was performed with the Dornier Compact lithotriptor whereas holmium laser lithotripsy was performed via retrograde ureteric access with a Wolf 7.5 Fr semirigid ureteroscope. RESULTS: Ureteroscopy with holmium laser lithotripsy was significantly better in terms of the mean procedure time (56 min in ESWL; 25 min in Ureteroscopy; P 0.001) and the 1-month stone free rate (50% in ESWL; 80% in Ureteroscopy; P 0.001). The 3-month stone free rate was also higher for Ureteroscopy (78% in ESWL; 90% in Ureteroscopy) but this difference was not statistically significant (P 0.09). Minor complications of steinstrasse (6%) occurred in ESWL and proximal stone migration (8%) occurred during Ureteroscopy. CONCLUSION: Ureteroscopy with holmium laser lithotripsy is a viable and safe alternative to ESWL for the management of proximal ureteric calculi.
