M.S. Michel

Technical characterization of an ultrasound source for noninvasive thermoablation by high-intensity focused ultrasound

Objective To develop a generator for high‐intensity focused ultrasound (HIFU, a method of delivering ultrasonic energy with resultant heat and tissue destruction to a tight focus at a selected depth within the body), designed for extracorporeal coupling to allow various parenchymal organs to be treated.

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

Abstract 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.

Ureteroscopy for Stone Treatment Using New 270° Semiflexible Endoscope: In Vitro, Ex Vivo, and Clinical Application

BACKGROUND AND PURPOSE The use of flexible ureteroscopy for diagnosis and management of upper urinary tract diseases is limited both by loss of maximum active deflection through the inserted working probes and a high frequency of damage with consequent costs. A newly developed ureteroscope (Flex-X, Karl Storz) with a maximized angle of deflection was introduced to overcome these problems. The aim of our study was to compare this new ureteroscope with an established device in vitro, ex vivo, and in a clinical approach. MATERIALS AND METHODS Angles of maximum active deflection and maximum irrigation flow were measured for both scopes in vitro with an empty working channel and after introduction of different lithotripsy and stone extraction probes. In addition, the loss of maximum active deflection and broken optical fibers of the scopes were assessed after 100 flexible ureteroscopies in an ex-vivo pig cadaver model. The clinical performance of both ureteroscopes was evaluated in 32 patients for management of lower pole stones. RESULTS The new ureteroscope displays highly improved deflection compared with the standard scope; deflection angles as much as 270 degrees with an empty working channel were achieved. Thin probes did not inhibit maximum deflection. Durability in ex vivotrials was high. Only minimal loss of maximum deflection and three broken optical fibers were observed. In clinical usage, a stone-free rate of 100% was achieved after 4 weeks. In three patients, the opening mechanism of a basket did not work with maximum deflection because of high friction. CONCLUSION The new ureterorenoscope facilitates retrograde stone management and might diminish repair intervals. Further development of comparable devices will support flexible ureterorenoscopy as a standard stone management procedure.

The modern management of upper tract urothelial cancer: surgical treatment

In recent years several investigators reported the results of endoscopic treatment of UUT tumours, initially based on efforts to preserve renal function in patients with single kidneys or bilateral tumours. In this article we review current concepts and oncological outcomes of the surgical management of UUT-TCC considering recent technical developments. Is the standard RNU still necessary? Can organsparing techniques be used safely?

Classification of Complications: Is the Clavien-Dindo Classification the Gold Standard?

We congratulate de la Rosette et al. for focusing on the practicability of standardised documentation of complications following percutaneous nephrolithotomy (PCNL) [1]. The Clinical Research Office of the Endourological Society PCNL Study Group database [2] will permit us to (1) collect and analyse all complications, (2) summarise and classify complications using the Clavien-Dindo system, (3) create a set of complications-management combinations, and (4) evaluate the intersurgeon validity of the Clavien system using an Internet-based survey. The paper by de la Rosette et al. will stimulate discussion about several topics.

Prolonged Cold Ischemia Time for Laparoscopic Partial Nephrectomy with a New Cooling Material: Freka-Gelice—A Comparison of Four Cooling Methods

BACKGROUND AND PURPOSE It is well known that hypothermia protects renal tissue from ischemic damage. So far, no standardized cooling method for laparoscopic surgery has been established. The traditionally used cooling method during open partial nephrectomy (OPN) is crushed ice applied around the kidney; for laparoscopic use, transarterial and transureteral perfusion cooling are described. We compared these three cooling methods with Freka-Gelice (FG), a new gel-like cooling material, and present our initial preliminary results in an ex-vivo porcine model. MATERIALS AND METHODS To prove cooling effectiveness, FG was compared with superficial crushed ice (NaCl-ice), with transureteral perfusion (TUP), and with transarterial perfusion (TAP) cooling in ex-vivo porcine kidneys. The temperature decrease over 120 minutes and practical application were evaluated. RESULTS No significant difference was found for the mean value distribution at different time points for NaCl-ice and FG (P = 0.18). TUP and TAP showed insufficient temperature decrease. Mean temperatures for NaCl-ice and FG were 4.75 degrees C and 7.02 degrees C at 30 minutes, 0.72 degrees C and 2.47 degrees C at 60 minutes, and -0.19 degrees C and 2.35 degrees C at 120 minutes, respectively. FG was easy to use because of its gel-like consistence. CONCLUSION TUP and TAP did not provide a fast and sufficient temperature decrease for renal hypothermia in this ex-vivo model. FG shows sufficient cooling qualities comparable with conventionally used NaCl-ice. Because of its gel-like consistence, FG can be used for laparoscopic partial nephrectomy, because insertion through a trocar is possible.

New Endourologic Technology for Simultaneous Holmium:YAG Laser Lithotripsy and Fragment Evacuation for PCNL: Ex-Vivo Comparison to Standard Ultrasonic Lithotripsy

Percutaneous nephrolithotomy (PCNL) is a well established procedure and accepted as the standard of care for the treatment of large renal calculi. Since the introduction of the holmium:yttrium-aluminum-garnet (Ho:YAG) laser into clinical practice in 1990, it has been used successfully to treat various urologic conditions. Today it is the modality of choice for retrograde intracorporeal stone disintegration ureteroscopically, and has also been used successfully for PCNL. One disadvantage when using the Ho:YAG laser for disintegration of renal calculi is the need for graspers to extract fragments and the mobilization of fragments due to the lack of simultaneous suction. We present our experience with a Ho:YAG laser in combination with simultaneous suction in an in-vitro model using a new endourologic technique in comparison to conventional ultrasonic lithotripsy.

Bladder wall tension during physiological voiding and in patients with an unstable detrusor or bladder outlet obstruction

To develop and evaluate a new clinical method for measuring bladder wall tension (BWT) on detrusor contraction during physiological voiding and under pathological conditions, as in experimental trials during subvesical obstruction the ability to generate pressure increases, whereas the contractile force per cross‐sectional area of detrusor muscle decreases.

Hemostatic Properties of Four Devices for Partial Nephrectomy: A Comparative ex Vivo Study

PURPOSE Laparoscopic partial nephrectomy (LPN) is a common minimally-invasive treatment modality for renal tumors, and achieving hemostasis during excision is a major challenge. The aim of our study was to investigate the hemostatic potential of four different devices for realizing this under standardized conditions. MATERIALS AND METHODS LPN was performed on a standardized model of blood-perfused ex-vivo porcine kidneys. Each of the four devices (Greenlight KTP laser, Habib Sealer, LigaSure, and SonoSurg) as well as a scalpel (for comparison) were used to perform 10 excisions with the renal artery and vein clamped, and another 10 were performed with no clamping. Treatment time (TT), blood loss (BL), and the ease of handling of the device were measured and histologic examination of the margins was carried out. RESULTS In general, TT was faster and there was less BL with clamping than without in all cases. TT was shortest for the KTP laser (6.07+/-1.2 minutes; P<0.0001), followed by the LigaSure (8.78+/-0.42 minutes), the SonoSurg (15.9+/-1.28 minutes), and the Habib (21.7+/-3.4 min). The SonoSurg showed a significantly higher BL without clamping (66+/-6 ml, p<0.0001) but there were no significant differences between the other devices. With clamping, BL four all four devices was comparable (13+/-2 ml) and without statistical significance (p=0.5). TT was shortest for the KTP laser (3.27+/-0.55 min, p<0.0001) followed by the LigaSure (6.47+/-0.38 s), the SonoSurg (8.35+/-3 min) and the Habib (9.71+/-1.18 minutes). The excised surface was completely coagulated for all of the devices except for the SonoSurg. CONCLUSION Our ex-vivo study suggests that hemostatic potential and the coagulative effect of all four devices is inadequate. Furthermore, none of the devices produced clean and sharp resection margins, which is a prerequisite for negative surgical margins.

TURP in Patients With Biopsy-Proven Prostate Cancer: Sensitivity for Cancer Detection

OBJECTIVES Recent laser techniques for the treatment of benign prostatic obstruction result in a significant amount of vaporization. Therefore, less tissue is retrieved for histologic evaluation. This might be an argument in favor of monopolar transurethral resection of the prostate (TURP). The aim of this retrospective study was to determine the ability to detect prostate cancer (PCa) in the TURP specimen of patients with biopsy-proven PCa and to gain information about the value of the TURP specimen during benign prostatic obstruction treatment. METHODS The charts of 154 patients with biopsy-proven PCa who had undergone standard TURP before high-intensity focused ultrasound therapy were retrospectively reviewed. The pre- and postoperative characteristics and histologic features were analyzed to identify the sensitivity of TURP in terms of PCa detection. Patients with incidentally detected PCa or a history of radiotherapy or chemotherapy were excluded. All patients underwent TURP by an experienced surgeon (>1000 procedures). The histologic features were evaluated and the chips completely analyzed for PCa detection. The Mann-Whitney U test and chi(2) test were used for statistical analysis. RESULTS Of the 154 patients, 84 fulfilled the inclusion criteria. The mean patient age was 69.8 years (range 59-82). The mean prostate-specific antigen level was 9.8 ng/dL, the mean prostate volume was 31.7 cm(3), and the average amount of resected tissue was 17.9 g. PCa was detected in 45 of 84 patients (54%). No significant differences between the group with histologic findings positive for PCa and the group with negative findings could be found in any of the recorded parameters. CONCLUSIONS Only 54% of the PCa cases were detected by TURP. Therefore, the worth of the obtained tissue sample during TURP seems questionable.