Magnetic Ureteral Stent Removal Without Cystoscopy: A Randomized Controlled Trial.

INTRODUCTION: Ureteral stenting is a common procedure in urology. The cystoscopic removal of Double-J stents (DJ) causes unpleasant side effects with a negative impact on patient's quality of life. The aim of our study was to evaluate this newly developed magnetic DJ and compare it with a standard DJ regarding quality of life with indwelling DJs as well as discomfort during the removal. MATERIAL AND METHODS: The magnetic DJ (Blackstar, Urotech [Achenmühle, Germany]) is a standard 7F ureteral stent with a small magnetic cube fixed through a string on the loop of the distal part of the stent. For DJ removal, a special catheter-like retrieval instrument with a magnetic tip is inserted, the two magnets connect and the retrieval instrument is removed with the DJ. We first tested this DJ in 20 cases. Afterward we evaluated 40 consecutive cases that required a DJ placement after ureterorenoscopy in a prospective randomized manner. The quality of life was assessed by the ureteral stent symptom questionnaire. A visual analogue scale was used to document the pain by DJ removal. RESULTS: There was a significant difference regarding the pain location with the indwelling DJ (p = 0.038). The maximum pain was located in the lower abdomen and/or around the bladder (48%) with the magnetic DJ, whereas the standard DJ caused flank pain in 54% of the patients. The mean time for the magnetic DJ removal including preparation and cleaning as for a transurethral catheter insertion was 9.55 [7-14] minutes, whereas the mean time for the cystoscopic DJ removal was 21.35 [18-30] minutes. The pain caused by the removal of the magnetic DJ was significantly less than that caused by the cystoscopic DJ removal (p = 0.019). CONCLUSION: The discomfort caused by the indwelling magnetic DJ is comparable with that caused by the standard DJ. However, the magnetic DJ removal is less painful and faster.

New technology in ureteroscopy and percutaneous nephrolithotomy.

PURPOSE OF REVIEW: New developments of retrograde intrarenal and percutaneous endoscopic surgery for nephrolithiasis have significantly enhanced the indications of endourology compared to extracorporeal shock wave lithotripsy. We want to review the most significant new technologies RECENT FINDINGS: New technology to access the renal collecting system includes marker-based tracking with iPAD, laser-guided puncture on (Uro)Dyna-CT, electromagnetic tracking (only experimental), and optical tracking for ultrasound-guided puncture. Miniaturization percutaneous nephrolithotomy has been further extended and classified to Midi-PCNL (20-22F/L), Mini-PCNL (16-18F/M), Ultra/Super-mini-PCNL (12-14F/S), and Micro-PCNL (8-10F/XS). Knowledge of Ho:YAG-laser lithotripsy including power settings for fragmentation (depending on stone composition), dusting (0.5J/20Hz), and popcorn-effect/laser-burst (1J/30Hz) becomes mandatory. Also hydrodynamic mechanisms for retrieval of fragments (active/passive washout, purging, vacuum-cleaner-effect) have gained importance. Improvements of FURS focus on digital-HD-video-technology with post-processing software (NBI/SPIES) providing better resolution and increased optical field, further miniaturization of endoscopes to fit in smaller access sheath (12/14F), additional tip-less Nitinol baskets and graspers, and introduction of a robotic device (Avicenna Roboflex) to improve ergonomics of the procedure. SUMMARY: Based on recent technical developments, percutaneous nephrolithotomy and particularly flexible ureteroscopy will further gain preference in management of urolithiasis compared to ESWL. Endourology may offer a higher rate of primary success with minimal side-effects which could weigh out the slightly higher degree of invasiveness.

The Uro Dyna-CT Enables Three-dimensional Planned Laser-guided Complex Punctures.

BACKGROUND: Ultrasound and fluoroscopy are the standard imaging techniques used to perform punctures in urology. Cross-sectional and three-dimensional (3D) imaging may enable safer procedures, especially in complex cases. OBJECTIVES: To assess the feasibility of 3D planned laser-guided punctures in urology performed with the Uro Dyna-CT (Siemens Healthcare Solutions, Erlangen, Germany). DESIGN, SETTING, AND PARTICIPANTS: A total of 27 punctures using the laser-guided system syngo iGuide (Artis Zee Ceiling; Siemens Healthcare Solutions, Erlangen, Germany) for the Uro Dyna-CT have been performed to date. Patients with complex puncture indications due to unclear ultrasound findings or a suspicion of surrounding bowel were included. SURGICAL PROCEDURE: Image acquisition was performed using a customized 8s syngo iGuide protocol of the Uro Dyna-CT. The puncture tract was planned after 3D and cross-sectional image reconstruction. The puncture was performed supported by the laser-guiding system. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary end point of our assessment was accuracy and applicability of the system in a clinical setting. Secondary end points were planning time, puncture time, and radiation exposure of the patient. RESULTS AND LIMITATIONS: Overall, 24 of 27 punctures were successful. No severe complications occurred. Median radiation dose of the Uro Dyna-CT scan was 6113.1 micrograys meter squared (µGym(2); range: 1081.6-7957.2µGym(2)). The small patient cohort is the major limitation of our study. CONCLUSIONS: We believe the Uro Dyna-CT-based puncture technique is an excellent additional instrument that allows the urologist to handle complex punctures. Image acquisition leads to higher radiation doses than standard fluoroscopy but does not exceed the radiation exposure of alternative procedures such as computed tomography (CT)-guided punctures with multidetector CT, which is used mainly for complex cases. PATIENT SUMMARY: We report our experience with a three-dimensional planning and laser-guiding tool to perform complex punctures for urologic indications. The technique is feasible in the endourologic intervention suite.

Extracorporeal shock wave lithotripsy: An opinion on its future.

The development of miniaturized nephroscopes which allow one-stage stone clearance with minimal morbidity has brought the role of shock wave lithotripsy (SWL) in stone management into question. Design innovations in SWL machines over the last decade have attempted to address this problem. We reviewed the recent literature on SWL using a MEDLINE/PUBMED research. For commenting on the future of SWL, we took the subjective opinion of two senior urologists, one mid-level expert, and an upcoming junior fellow. There have been a number of recent changes in lithotripter design and techniques. This includes the use of multiple focus machines and improved coupling designs. Additional changes involve better localization real-time monitoring. The main goal of stone treatment today seems to be to get rid of the stone in one session rather than being treated multiple times non-invasively. Stone treatment in the future will be individualized by genetic screening of stone formers, using improved SWL devices for small stones only. However, there is still no consensus about the design of the ideal lithotripter. Innovative concepts such as emergency SWL for ureteric stones may be implemented in clinical routine.

Surgical navigation in urology: European perspective.

PURPOSE OF REVIEW: Use of virtual reality to navigate open and endoscopic surgery has significantly evolved during the last decade. Current status of seven most interesting projects inside the European Association of Urology section of uro-technology is summarized with review of literature. RECENT FINDINGS: Marker-based endoscopic tracking during laparoscopic radical prostatectomy using high-definition technology reduces positive margins. Marker-based endoscopic tracking during laparoscopic partial nephrectomy by mechanical overlay of three-dimensional-segmented virtual anatomy is helpful during planning of trocar placement and dissection of renal hilum. Marker-based, iPAD-assisted puncture of renal collecting system shows more benefit for trainees with reduction of radiation exposure. Three-dimensional laser-assisted puncture of renal collecting system using Uro-Dyna-CT realized in an ex-vivo model enables minimal radiation time. Electromagnetic tracking for puncture of renal collecting system using a sensor at the tip of ureteral catheter worked in an in-vivo model of porcine ureter and kidney. Attitude tracking for ultrasound-guided puncture of renal tumours by accelerometer reduces the puncture error from 4.7 to 1.8 mm. Feasibility of electromagnetic and optical tracking with the da Vinci telemanipulator was shown in vitro as well as using in-vivo model of oesophagectomy. Target registration error was 11.2 mm because of soft-tissue deformation. SUMMARY: Intraoperative navigation is helpful during percutaneous puncture collecting system and biopsy of renal tumour using various tracking techniques. Early clinical studies demonstrate advantages of marker-based navigation during laparoscopic radical prostatectomy and partial nephrectomy. Combination of different tracking techniques may further improve this interesting addition to video-assisted surgery.

The past, present and future of minimally invasive therapy in urology: a review and speculative outlook.

INTRODUCTION: Twenty-five years of SMIT represents an important date. In this article we want to elaborate the development of minimally invasive surgery in urology during the last three decades and try to look 25 years ahead. MATERIAL AND METHODS: As classical scenarios to demonstrate the changes which have revolutionized surgical treatment in urology, we have selected the management of urolithiasis, renal tumour, and localized prostate cancer. This was based on personal experience and a review of the recent literature on MIS in Urology on a MEDLINE/PUBMED research. For the outlook to the future, we have taken the expertise of two senior urologists, middle-aged experts, and upcoming junior fellows, respectively. RESULTS: Management of urolithiasis has been revolutionized with the introduction of non-invasive extracorporeal shock wave lithotripsy (ESWL) and minimally invasive endourology in the mid-eighties of the last century obviating open surgery. This trend has been continued with perfection and miniaturization of endourologic armamentarium rather than significantly improving ESWL. The main goal is now to get rid of the stone in one session rather in multiple non-invasive treatment sessions. Stone treatment 25 years from today will be individualized by genetic screening of stone formers, using improved ESWL-devices for small stones and transuretereal or percutaneous stone retrieval for larger and multiple stones. Management of renal tumours has also changed significantly over the last 25 years. In 1988, open radical nephrectomy was the only therapeutic option for renal masses. Nowadays, tumour size determines the choice of treatment. Tumours >4 cm are usually treated by laparoscopic nephrectomy, smaller tumours, however, can be treated either by open, laparoscopic or robot-assisted partial nephrectomy. For patients with high co-morbidity focal tumour ablation or even active surveillance represents a viable option. In 25 years, imaging of tumours will further support early diagnosis, but will also be able to determine the pathohistological pattern of the tumour to decide whether the patient requires removal, ablation or active surveillance. Management of localized prostate cancer underwent significant changes as well. 25 years ago open retropubic nerve-sparing radical prostatectomy was introduced as the optimal option for effective treatment of the cancer providing minimal side-effects. Basically, the same operation is performed today, but with robot-assisted laparoscopic techniques providing 7-DOF instruments, 3D-vision and tenfold magnification and enabling the surgeon to work in a sitting position at the console. In 25 years, prostate cancer may be managed in most cases by focal therapy and/or genetically targeting therapy. Only a few patients may still require robot-assisted removal of the entire gland. DISCUSSION: There has been a dramatic change in the management of the most frequent urologic diseases almost completely replacing open surgery by minimally invasive techniques. This was promoted by technical realisation of physical principles (shock waves, optical resolution, master-slave system) used outside of medicine. The future of medicine may lie in translational approaches individualizing the management based on genetic information and focalizing the treatment by further improvement of imaging technology.

Mobile augmented reality for computer-assisted percutaneous nephrolithotomy.

PURPOSE: Percutaneous nephrolithotomy (PCNL) plays an integral role in treatment of renal stones. Creating percutaneous renal access is the most important and challenging step in the procedure. To facilitate this step, we evaluated our novel mobile augmented reality (AR) system for its feasibility of use for PCNL. METHODS: A tablet computer, such as an iPad[Formula: see text], is positioned above the patient with its camera pointing toward the field of intervention. The images of the tablet camera are registered with the CT image by means of fiducial markers. Structures of interest can be superimposed semi-transparently on the video images. We present a systematic evaluation by means of a phantom study. An urological trainee and two experts conducted 53 punctures on kidney phantoms. RESULTS: The trainee performed best with the proposed AR system in terms of puncturing time (mean: 99 s), whereas the experts performed best with fluoroscopy (mean: 59 s). iPad assistance lowered radiation exposure by a factor of 3 for the inexperienced physician and by a factor of 1.8 for the experts in comparison with fluoroscopy usage. We achieve a mean visualization accuracy of 2.5 mm. CONCLUSIONS: The proposed tablet computer-based AR system has proven helpful in assisting percutaneous interventions such as PCNL and shows benefits compared to other state-of-the-art assistance systems. A drawback of the system in its current state is the lack of depth information. Despite that, the simple integration into the clinical workflow highlights the potential impact of this approach to such interventions.

Classification and detection of errors in minimally invasive surgery.

PURPOSE: To provide a comprehensive review of the classification of surgical errors as well as general measures to detect and prevent their occurrence. MATERIALS AND METHODS: Search in PubMed, Medline, and Cochrane library with combination of the key words: Endoscopy or surgical procedures, minimally invasive, and medical error. Relevant articles were selected by three senior authors involved in minimally invasive surgery (MIS). RESULTS: Error is an unintended healthcare outcome caused by a defect in the delivery of care to a patient. Surgical errors are common and account for half of all hospital adverse events (AEs). Urology is the fifth specialty in decreasing order of AE. Errors may be classified according to the place where they occur (co-face or systemic), to the outcomes (near miss, recovery, and remediation). A specific classification for errors in MIS has also been described (Cushieri), depending on the step of the surgical procedure in which they occur. Each classification serves definite purposes, and no one can be definitive over the others. No classification has been applied so far to urology. Detection through appropriate reporting is the basis for prevention. CONCLUSION: Surgical errors represent a significant proportion of all medical error. Multiple classifications exist, depending on the purposes they are intended to serve. A classification based on the place of occurrence of the errors has been adopted in the medical system; however, when referring to MIS, a finer classification is proposed.