Next-Generation Fiberoptic and Digital Ureteroscopes.

The versatility of ureteroscopy is attributable to tremendous technological innovations over the past decades. This article provides an overview on emerging technologies in the light of past achievements, current limitations, and possible future directions. Instrument size reduction, pressure and temperature control, active suction of stone dust, multiple-axis tip deflection, variable working channel positions, robotics, ergonomics, image quality, enhanced imaging technology, three-dimensional visualization, and the competition between reusable and single-use ureteroscopes are detailed. The twentieth century has opened an exciting path for future discoveries in ureteroscopy.

Single-Use Ureteroscopes.

A PubMed search using the terms "single use" and "ureteroscope" was performed to identify published studies on this topic. In addition, the abstracts of the annual meeting of the World Congress of Endourology and the American Urologic Association since 2010 were reviewed. Here we present a review of published studies on single-use ureteroscopes.

Durability of Flexible Ureteroscopes: A Prospective Evaluation of Longevity, the Factors that Affect it, and Damage Mechanisms.

BACKGROUND: Flexible ureteroscopy is an established treatment modality for evaluating and treating abnormalities in the upper urinary tract. Reusable ureteroscope (USC) durability is a significant concern. OBJECTIVE: To evaluate the durability of the latest generation of digital and fiber optic reusable flexible USCs and the factors affecting it. DESIGN, SETTING, PARTICIPANTS: Six new flexible USCs from Olympus and Karl Storz were included. The primary endpoint for each USC was its first repair. Data on patient and treatment characteristics, accessory device use, ureteroscopy time, image quality, USC handling, disinfection cycles, type of damage, and deflection loss were collected prospectively. INTERVENTION: Ureteroscopy. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: USC durability was measured as the total number of uses and ureteroscopy time before repair. USC handling and image quality were scored. After every procedure, maximal ventral and dorsal USC deflection were documented on digital images. RESULTS AND LIMITATIONS: A total of 198 procedures were performed. The median number of procedures was 27 (IQR 16-48; 14h) for the six USCs overall, 27 (IQR 20-56; 14h) for the digital USCs, and 24 (range 10-37; 14h) for the fiber optic USCs. Image quality remained high throughout the study for all six USCs. USC handling and the range of deflection remained good under incremental use. Damage to the distal part of the shaft and shaft coating was the most frequent reason for repair, and was related to intraoperative manual forcing. A limitation of this study is its single-center design. CONCLUSIONS: The durability of the latest reusable flexible USCs in the current study was limited to 27 uses (14h). Damage to the flexible shaft was the most important limitation to the durability of the USCs evaluated. Prevention of intraoperative manual forcing of flexible USCs maximizes their overall durability. PATIENT SUMMARY: Current flexible ureteroscopes proved to be durable. Shaft vulnerability was the most important limiting factor affecting durability.

From novelty to the every-day: the evolution of ureteroscopy.

Ureteroscopy revolutionized the surgical approach to the upper urinary tract, and is well recognized as a cornerstone of modern urology. Although now commonplace, ureteroscopic equipment and techniques were truly revolutionary. A review of the innovations and innovators that developed ureteroscopic surgery sets the stage for a more thorough understanding of what can be done ureteroscopically, and may additionally better inform what limitations remain. Given that future advancements in urologic therapy will be dependent upon a similar pursuit of paradigm shifting improvements in disease management, an overview of the development of modern ureteroscopy may inspire such change.

Innovations in surgical stone disease.

PURPOSE OF REVIEW: Urinary stone disease is a condition characterized by a rich history of surgical innovation. Herein, we review the new ideas, devices and methods that are the cornerstones of contemporary surgical innovation in stone disease, specifically flexible ureteroscopy and percutaneous nephrolithotomy. RECENT FINDINGS: The new ideas being applied to flexible ureteroscopy include extending the boundaries of surgical indications and eliminating the need for intraoperative fluoroscopy. Device advancements include disposable ureteroscopes and flexi semirigid ureteroscopes. Robotic flexible ureteroscopy, the use of magnets and mobile technology applications represent progress in methods of performing flexible ureteroscopy. Three-dimensional computed tomography and printing technology are enhancing percutaneous renal access. Novel image-guided access techniques are improving the accuracy of percutaneous surgery particularly for complex cases. SUMMARY: New ideas, devices and methods are continuing to reshape the landscape of surgical stone treatment and in so doing not only have the potential to improve surgical outcomes but also to cultivate further scientific and technological advancements in this area.

Pushing the boundaries of ureteroscopy: current status and future perspectives.

Substantial advances in ureteroscopy have resulted in the incorporation of this procedure into routine urological practice in many centres worldwide. Subsequently, an abundance of clinical data and technological progression have enabled the development of novel solutions that have increased the efficacy of ureteroscopy, and reduced associated morbidity and costs. In addition the indications for this retrograde approach have been expanded, and pyelocalyceal diverticulum, infundibular stenosis, urolithiasis in pregnant women or in patients with urinary diversions, as well as upper urinary tract tumours can now be managed using this methodology. New endoscopes are continuously developed, with different manufacturers choosing various technical solutions to further increase the efficacy and safety-and sometimes decrease costs-of ureteroscopy, including miniaturization, inclusion of digital optical systems and dual working channels, and the introduction of disposable apparatus. The holmium laser, currently the most-versatile energy source available, enables tissue incision, tumour ablation, and intracorporeal lithotripsy. Modern ancillary instruments are diverse, flexible, and durable, and novel devices used in daily clinical practice can minimize ascendant migration of stone fragments and, therefore, decrease the failure rate of the retrograde ureteroscopic approach. However, the peak of ureteroscopy evolution seems to remain distant, with further improvement of endoscopes and ancillary instruments, and robot-assisted ureteroscopy representing only some of the areas in which future developments are possible.

A new era: performance and limitations of the latest models of flexible ureteroscopes.

OBJECTIVE: To comparatively study 3 of the latest models of flexible ureteroscopes using both subjective and objective parameters. MATERIALS AND METHODS: Three models of flexible ureteroscopes (Karl Storz Flex-Xc, Olympus URF-Vo, and Wolf Cobra) were evaluated during 90 procedures. For each model, 20 procedures were therapeutic for pyelocaliceal lithiasis and 10 were diagnostic. The maneuverability and visibility were scored and compared, and the irrigation flow and maximal deflection were measured in an ex vivo setting, with an empty working channel and with accessory instruments in place. Instrument durability was also reviewed. RESULTS: All models demonstrated good maneuverability, with a slight advantage for the Flex-Xc. During the diagnostic procedures, failure to access the entire pyelocaliceal system occurred in 2 cases with the URF-Vo, both because of a thin caliceal infundibulum, and in 1 case with the Cobra, because of complex caliceal architecture. Regarding visibility, although the performance of the digital models was relatively similar, the fiberoptic Cobra achieved a lower score. Loss of deflection and irrigation when using the various ancillary instruments was similar for all 3 endoscopes, but the Cobra offered supplementary flow through a secondary channel. The mean deflection loss was 5% for the URF-Vo, 9% for the Flex-Xc, and 10% for the Cobra. The visual quality of the 2 digital models remained unchanged during the study; however, in the fiberoptic ureteroscope, 58 optic fibers were broken. CONCLUSION: The latest models of flexible ureteroscopes have proved to be effective instruments for upper urinary tract endoscopic interventions. There is still room for improvement, already made possible by the technological advances.

Flow matters: irrigation flow differs in flexible ureteroscopes of the newest generation.

The development of new-generation flexible ureteroscopes has improved diagnostic and therapeutic endourological procedures. Despite technical improvement irrigation flow and quality of vision is often unsatisfactory. This study describes inter-manufactural differences in the latest available flexible ureteroscopes in terms of irrigation flow in correlation to different deflection angles and the use of 1.9 Fr. stone baskets. Irrigation flow measurements were performed in five new-generation flexible ureterorenoscopes with 3.6 Fr. working channels: Wolf (Uretero-Renoscope 270°), Storz (Flex-X² and Flex-X(c)), ACMI (DUR-D) and Olympus (URF Type P5) in 0°, 90° and 180° deflection. All measurements were carried out five times with an empty working channel as well as with inserted 1.9 Fr. stone baskets. Mean flow rates with empty instruments (SD) counted 50 ml/min (0.8), 50 (1.0), 48 (1.7), 48 (1.6) and 44 (0.7) for ACMI, Wolf, Storz (FlexX² and Flex-X(c)), and Olympus, respectively. Stone baskets significantly reduced irrigation flows in all tested ureteroscopes (p < 0.05). In channels with inserted baskets, the highest flow rates were measured for ACMI and Wolf with 12 ml/min (0.7) each. The lowest reduction of flow rate was detected in the ACMI and the Wolf ureteroscope (76.0%, 38 ml/min each). Measurements after flexion showed no significant differences between the ureteroscopes. Latest generation of flexible ureteroscopes offer various new product developments, including excellent deflection capacities. This study showed inter-manufactural differences in terms of irrigation flow rates with either empty or occupied working channels resulting in significant alterations in endoscopic view.

Do new generation flexible ureterorenoscopes offer a higher treatment success than their predecessors?

New generation flexible ureterorenoscopes offer an improved deflection mechanism and a stiffer sheath compared to their predecessors. We aimed to determine if these improvements in design lead to a higher efficacy in the treatment of nephrolithiasis. Ninety patients with upper urinary tract calculi were included into a retrospective analysis. Twenty-nine cases were treated with the conventional flexible ureterorenoscope (11274 AA, Karl Storz Endoscopy, Germany) and 61 cases were treated with the new generation device (Flex-X, Karl Storz Endoscopy). Patients' and stone characteristics, intraoperative data, treatment success and complications were retrieved from the charts and compared between the two groups. Preoperative data were comparable in both groups. Whereas stone access was also comparable (97 vs. 100%; n.s.), immediate treatment success was significantly higher for the new flexible scope (70 vs. 38%; p = 0.003). For the subgroup of lower pole stones, stone access was possible in 94 versus 100% (n.s.) and treatment success was 31 versus 69% (p = 0.0004) for the conventional and the new generation device, respectively. No major complications were observed, minor complications were comparable in both groups. Our study suggests an advantage of the new generation flexible ureterorenoscopes compared to their predecessors. They offer an increased stone free rate especially in the treatment of lower pole stones. It seems therefore advisable to switch to the latest generation flexible devices.

Changing trends in the use of ureteroscopic instruments from 1996 to 2008.

PURPOSE: Despite ongoing advances in the field of endourology, there are few reports describing specific changes adopted by urologists that have come as a result. We investigated the progression of single surgeon's clinical practice over a 12-year period, noting differences in ureteroscopes, ancillary equipment, and indications for surgery over that time. METHODS: The records of 1181 patients undergoing ureteroscopy by a single surgeon were reviewed. Consecutive patients from the years 1996 (n = 200), 1998 (n = 179), 2000 (n = 198), 2002 (n = 127), 2004 (n = 137), 2006 (n = 200), and 2008 (n = 140) were included in the study. Patients remained grouped by the year of their procedure for comparison. Compared variables included the indication for surgery, type of anesthesia, method of ureteral dilation and stabilization, specific ureteroscopes used, type and number of working instruments employed, and the method of postprocedure ureteral drainage. RESULTS: A change favoring smaller, more flexible ureteroscopes was seen. An increase in the percentage of surgeries performed for upper tract tumors paralleled decreasing trends in urolithiasis and ureteropelvic junction obstruction surgery. A divergence in the devices used for calculi and upper tract tumors was seen. CONCLUSIONS: Over the past 12 years, technological advancements in the field of endourologic surgery have resulted in shifting clinical practice for endourologists, with trends favoring smaller, actively flexible ureteroscopes, intrarenal surgery, and nitinol basket use.

Where next for the endoscope?

The concept of examining the body's interior and its organs dates back to ancient times. The roots of modern endoscopy lie in early nineteenth century Europe, and the intervening centuries have seen a steady evolution of devices and techniques. Nowadays, a wide variety of urinary tract disorders are successfully managed in a minimally invasive manner thanks to the endoscope and related technologies. Distal-sensor, 'digital', endoscopes have the potential to revolutionize the field, and change the way in which we use and think about endoscopy. Virtual endoscopy, capsule endoscopy, and a range of other techniques derived from physics and molecular biology all promise great improvements in visualization of the urinary tract and other urologic structures. Ultimately, the continued improvement of these minimally invasive technologies will enhance the quality of care that we can offer our patients.

Current status of ureteroscopic treatment for urolithiasis.

Intracorporeal treatment of urolithiasis is characterized by continuous technological evolution. In this review we present updated data upon the use of ureteroscopy for the management of urolithiasis. Novel digital flexible ureteroscopes are used in clinical practice. Ureteroscopic working tools are revolutionized resulting in safer and more efficient procedures. Special categories of stone patients such as pregnant women, children and patients on anticoagulation medication can now undergo uneventful ureteroscopy. Routine insertion of stents and access sheaths as well as bilateral ureteroscopy is still a controversial issue. Future perspectives include smaller and better instruments to visualize and treat a stone, while robotic ureteroscopy is becoming a fascinating reality.

Advanced ureteroscopy: wireless and sheathless.

BACKGROUND: The introduction of a new generation of flexible ureteroscopes significantly advanced the therapeutic and diagnostic efficacy of the instrument, allowing greater access to all aspects of the upper urinary tract and facilitating wireless ureteroscopy. PATIENTS AND METHODS: Four hundred sixty consecutive upper urinary-tract procedures were performed utilizing the 7.5F actively deflectable, flexible ureteroscope. A prospective database of these procedures was maintained. The indications, access technique, complications, success rate of stone treatment, and access to lower-pole calices were evaluated. The accumulated clinical data were compared with a published database of 1000 consecutive flexible ureteroscopies. RESULTS: A stent was in place or had recently been in place in 108 of the procedures (24%). Of the remaining 352 flexible ureteroscopic procedures, only 11% (52) required any form of ureteral dilation to facilitate ureteral access. Two hundred twenty seven procedures were performed in which no guidewire was required to place the flexible endoscope in the upper urinary tract (i.e., "wireless" ureteroscopy). CONCLUSION: Wireless no-touch flexible ureteroscopy with the new flexible instruments is a feasible and safe technique for diagnostic and therapeutic procedures in most patients, irrespective of the location of the pathology, including the distal ureter. These ureteroscopes, with their exaggerated deflection, are ushering in a new era of endoscopic treatment of the upper urinary tract. Greater instrument deflectability and control can lead to shorter procedures and fewer treatment failures.

The evolution of ureteroscopy: a modern single-institution series.

OBJECTIVES: To evaluate a modern ureteroscopy series, including the use of new technological advances, operative procedures, and potential complications, at a single institution and to compare our current experience with our prior published series and the current literature. MATERIAL AND METHODS: We retrospectively reviewed 1000 consecutive ureteroscopies performed in 961 patients from December 1999 to February 2003 at our institution. RESULTS: Semirigid and flexible ureteroscopes were used in 60.3% and 37.0% of the cases, respectively. In 2.6% of cases, a combination of both rigid and flexible ureteroscopes was required. The most common indications for ureteroscopy were as follows: stone, 57.9%; diagnostic, 20.6%; and urothelial carcinoma, 12.6%. Of the stones treated, 31.8% were proximal or middle and 59.1% distal. The overall, proximal, and distal stone-free rates were 91.7%, 87.3%, and 94.2%, respectively. Average operative time was 81 minutes (range, 5-280 minutes). Average follow-up was 2.36 months (range, 1-24 months). The overall complication rate was 1.9% (18/961), including a 0.2% (2/961) incidence of ureteral strictures. CONCLUSION: Current practice trends have shifted to an increased use of flexible ureteroscopes and more frequent ureteroscopic treatment of proximal calculi. Our single treatment stone-free rates are competitive with quoted shock wave lithotripsy success. In addition, there has been a decrease in ureteroscopic-associated complications in our series, with no ureteral avulsions. The improvements in treatment success and decrease in complications may be secondary to advances in ureteroscopic technology.

The evolution and progress of ureteroscopy.

Technology and refinements in urology have prospered with the bonding of engineers and surgeons. The introduction of fiberoptics and the development of the ureteroscope opened the doors to the field of ureteroscopy. Advances in rigid and flexible ureteroscopy with irrigating and working channels have expanded the capability of the urologist to diagnose and treat most abnormalities of the upper tracts in adult and pediatric populations. Instrument development has easily paralleled the growth and development of the ureteroscope and has improved success, patient safety, and comfort with the incorporation of access sheaths, nitinol materials, and Ho:YAG laser technology. Owing to their minimal morbidity and high success rate, ureteroscopic evaluation and therapeutic interventions in the upper tract represent the gold standard of management. Albert Einstein said, "There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle." Contemporary ureteroscopy is a historical miracle that has opened a vista of endless limits in upper tract endoscopy (Fig. 4, Box 1).

Anatomic and physiologic considerations in ureteroscopy.

The successful and safe implementation of ureteroscopic techniques depends on considerations of anatomy and physiology. Combining knowledge of the drainage system of the kidney with its vascular supply, predictive patterns of incisions can be applied within the collecting system to safely avoid vascular injury. In addition, awareness of the variation in normal and pathologic anatomy and physiology is key to effective interventions. An appreciation of the impact of ureteroscopy on normal anatomy and physiology can prevent complications and promote improved therapeutic outcomes.

Advances in video and imaging in ureteroscopy.

Advances in image processing and display technologies, such as digital imaging, HDTV, and virtual reality, will ultimately allow integration of endoscopic imaging with diagnosis and therapy during ureteroscopic procedures. Further improvements in simulation technology and telemedicine should improve surgical training and greatly benefit patient care.