Clinical Comparison between Three Single-Use Flexible Ureteroscope Models: A Real-World Experience.

INTRODUCTION: Studies comparing different single-use flexible ureteroscope (su-fURS) models are lacking. The objective was to compare three types of su-fURS: the Uscope 3022 (PUSEN), LithoVue (Boston Scientific), and EU-scope (Innovex). METHODS: This was a retrospective study comparing the clinical outcomes from patients undergoing flexible ureteroscopy with one of the three su-fURS for upper urinary tract stone treatment between September 2019 and 2021. Analysis included total surgery and fluoroscopy time, post-procedure ureteral catheter, stone-free rate (SFR), and complications. RESULTS: There were 104 cases with the Uscope 3022, 141 with LithoVue, and 80 with EU-scope. Groups were comparable in terms of stone size, location and density, and prior double-J stent presence. Multivariate analysis showed no difference in terms of SFR: 79% (Uscope 3022), 77.5% (LithoVue), and 81% (EU-scope); p = 0.38. Significant differences were found for total surgery and fluoroscopy time, as well as ureteral access sheath use (p < 0.001), favoring the EU-scope group. DISCUSSION/CONCLUSION: The three devices evaluated are highly effective in treatment of kidney stones. Reasons for difference in total surgery and fluoroscopy time and access sheath use are not clear. However, this could be explained by technical aspects of these devices, such as external diameter, optical resolution, and field of view.

Endoscopic treatment of lower pole stones: is a disposable ureteroscope preferable? Results of a prospective case-control study.

INTRODUCTION: The best option for lower pole stone management is still under debate. With the recent incorporation of disposable ureteroscopes, discussion on this topic has been renewed. The aim of the present study was to compare the results obtained with flexible disposable ureteroscopes with those obtained using reusable ureteroscopes in the treatment of inferior calyx stones. MATERIAL AND METHODS: A case-control study was carried out using data registered prospectively in a database at our center. The clinical results obtained in two groups of patients were analyzed. In the first group of patients, a reusable flexible fiber-optic ureteroscope (Cobra®, Richard Wolf) was used, and in the second group, a disposable flexible ureteroscope was used (Uscope 3022®, Pusen Medical). The variables analyzed included: operative time, fluoroscopy time, need for postprocedure ureteral catheter, stone-free rate (fragments <1 millimeter) and complications. The results were evaluated using a Student's t test, a Mann-Whitney test and a Fisher's test. RESULTS: There were 31 cases with disposable ureteroscopes and 30 cases with a reusable ureteroscope. Both groups were comparable in their demographic and clinical variables. The characteristics regarding length, width and angle of the infundibulum (measured by retrograde ureteropyelography) were also comparable. There were no differences in the clinical findings with respect to the stone-free rate, need for a ureteral catheter, complications or hospital stay. Significant differences were found in the average surgery time (56.1 vs. 77 minutes; P = 0.01) and in the fluoroscopy time (66.1 vs. 83.4 seconds; P = 0.02), both favoring the use of single use ureteroscopes. CONCLUSIONS: In this study, disposable flexible ureteroscopes have been validated as an option that is in the least equivalent to reusable ureteroscopes based on clinical results. The shorter surgical and fluoroscopy durations are possible advantages considering the high costs associated with time spent in the operating room and the need to reduce ionizing radiation.

Retrograde intrarenal surgery using the single - use flexible ureteroscope Uscope 3022 (Pusen™): evaluation of clinical results.

INTRODUCTION: Reusable endoscopes have some limitations regarding their continued use. To sort out these problems, several disposable devices have appeared on the market. Our objective is to show our clinical results with a new digital flexible single-use ureteroscope. MATERIALS AND METHODS: This study presents a prospective series of patients who underwent endoscopic surgery as treatment for renal stones using the digital disposable endoscope Uscope 3022™. Demographic, procedure and stone information were registered including surgery time, stone-free rate, need of ureteral catheterization and complications, among others. The behavior of the ureteroscope in terms of image quality and problems associated with flexibility and the working channel were also registered. RESULTS: A total of 71 procedures were included in the analysis. The mean age was 49.9 years old, with 70.4% of male patients. Mean stone size was 11.4 mm (4 to 40 mm). The most frequent stone location was in the lower calyces (28.2%). The stone burden was high (>2 cm) in 8.4% of patients. The mean surgical time was 56.6 minutes (15-180 min). In 94.4% of the cases, a laser was used with dusting parameters. The global stone-free rate (SFR) was 95.2%, but in the subgroups analysis SFR were significantly superior in stones less than 10 mm (97.9%) versus stones between 10 and 20 mm (94.5%) and greater than 20 mm (78.3%) (p <0.01). The postoperative placement of double-J stents was required in 66.2% of patients. Two minor complications were recorded and they were related to the ureteral access sheath used. There were no problems regarding the performance of the ureteroscope. CONCLUSIONS: The clinical data observed in this series does not differ from the results traditionally obtained with other reusable devices. To our knowledge, this series is the first worldwide report evaluating the clinical behavior and results in humans of the Uscope 3022.

Renal tumor models: evaluation of ease of implementation, quality of composition, and imaging characteristics.

BACKGROUND AND PURPOSE: With the rise in detection of small renal masses that are amenable to nephron-sparing surgical approaches, there has been an increasing need for renal tumor models that create discrete lesions suitable for training exercises. We aim to investigate a handful of commonly used compounds, subjectively evaluating their ease of implementation and imaging characteristics. MATERIALS AND METHODS: After an initial ex vivo study, we selected five compounds for an in vivo porcine investigation. These compounds included metagel with barium, Smooth-Cast 320, Silfome with and without barium, and Kromopan. The compounds were injected under laparoscopic guidance with the aim of creating discrete renal tumors. The kidneys were then imaged under ultrasonography and CT. The animals were euthanized, and nephrectomy was performed. Handling characteristics were noted. RESULTS: All compounds were relatively easy to inject. Most of the compounds were susceptible to some degree of subcapsular spread. Kromopan had a high propensity for infiltration of the collecting system. On imaging, metagel was clearly distinguishable from normal renal parenchyma on both CT and ultrasonography. Silfome and Smooth-Cast were difficult to resolve on ultrasonography. Metagel was prone to rupture during surgical manipulation. CONCLUSIONS: No single compound provided the ideal combination of ease of implementation, resistance to extravasation, ease of resolution on imaging, and resistance to rupture. Therefore, compound selection should be dictated by the particular aims of a training simulation.

Sliding-clip renorrhaphy provides superior closing tension during robot-assisted partial nephrectomy.

OBJECTIVE: Recently, our institution refined a technique for robot-assisted renorrhaphy utilizing sliding Weck Hem-O-Lock clips, which are tightened by the surgeon seated at the console and locked into place with a LapraTy clip. In addition to the relative ease of implementation, we believe that our technique also provides a superior strength of closure over other commonly used techniques. METHODS: An in vivo porcine model was used to compare a sliding-clip technique against an assistant-placed LapraTy-only closure, and a surgeon-placed simple suture closure. A force gauge was used to record the maximum tension that could be applied during each closure method before the suture ripped through the renal parenchyma, thus illustrating the relative strength of each closure. RESULTS: The simple suture closure performed relatively poorly, ripping through parenchyma at a mean force of 11.3 N. The LapraTy-only method allowed a maximum applicable mean force of 16.7 N. The sliding Weck clip with a LapraTy bolster provided the tightest closure, allowing for a mean force of 32.7 N before ripping through parenchyma. Statistical analysis reveals that a sliding-clip technique provides a significantly tighter closure than both of the other tested methods. CONCLUSION: A sliding-clip technique allows for more tension to be safely applied to the closure of a partial nephrectomy defect than other commonly used methods. We believe that this is primarily attributable to the larger footprint of the Hem-O-Lock clip, which allows for the tension to be distributed over a greater surface area. The LapraTy then ensures the security of the closure by holding the Weck clip in place. Further studies are necessary to determine if this increased tension translates into appreciably better hemostasis.

Robot-assisted partial nephrectomy: evaluation of learning curve for an experienced renal surgeon.

PURPOSE: The learning curve for robot-assisted partial nephrectomy (RAPN) has not been extensively studied. We therefore evaluated the learning curve of RAPN for a fellowship-trained laparoscopic surgeon with extensive prior experience with laparoscopic partial nephrectomy (LPN). We also examined the potential effect of tumor size on the learning curve. PATIENTS AND METHODS: We prospectively evaluated 38 consecutive patients undergoing RAPN by a single surgeon (S.B.B.). Sixteen patients had tumors <2 cm, and 22 patients had tumors >2 cm. Warm ischemia times and overall operative times were recorded as indices of learning progression. RESULTS: Average operative time for tumors <2 cm was 131.9 minutes (115.3-148.5 minutes) and for tumors >2 cm was 145.8 minutes (131.1-160.5 minutes). The difference between the operative times for tumors <2 and >2 cm was not statistically significant (p = 0.23). Average warm ischemia time for tumors <2 cm was 21 minutes (16.9-25.1 minutes) and for tumors >2 cm was 24.7 minutes (21.3-28.1 minutes). This difference was also not statistically significant (p = 0.20). Defined by the overall operative time, the learning curve for RAPN was 16 cases, and by ischemic time, the learning curve was 26 cases. Tumor size did not have an effect on the learning curve. CONCLUSIONS: The learning curve for RAPN is short for surgeons already experienced with LPN. The learning curve for portions performed under warm ischemia is slightly longer, implying that the critical portions of the procedure require more experience to become facile. Tumor size does not appear to have a significant impact on the learning curve for surgeons experienced with LPN.

Selective versus nonselective arterial clamping during laparoscopic partial nephrectomy: impact upon renal function in the setting of a solitary kidney in a porcine model.

INTRODUCTION: Laparoscopic partial nephrectomy has emerged as a standard of care for small renal masses. Nevertheless, there remains concern over the potential for irreversible insult to the kidney as a result of exposure to warm ischemia. We aim to investigate the utility of selective segmental arterial clamping as a means to reduce the potential for ischemic damage to a solitary kidney during laparoscopic partial nephrectomy utilizing a porcine model. MATERIALS AND METHODS: A total of 20 domestic swine were randomized into four equal groups. Each subject underwent laparoscopic radical nephrectomy to create the condition of a solitary kidney. On the contralateral side, a laparoscopic lower pole partial nephrectomy was performed, employing either selective or nonselective vascular clamping for either 60 or 90 minutes. Postoperatively, clinical status and serial serum studies were closely monitored for 1 week. RESULTS: There were no intraoperative complications. The 90-minute nonselective clamping produced devastating effects, resulting in rapid deterioration into florid renal failure within 72 hours. The 60-minute nonselective clamping group experienced modest but significant rises in both blood urea nitrogen and creatinine. Both 60- and 90-minute selective clamping groups performed well, with no significant rises in creatinine over a 7-day period, and no instances of renal failure. CONCLUSIONS: Selective arterial clamping is a safe and feasible means of vascular control during laparoscopic partial nephrectomy. In the porcine model, selective clamping appears to improve functional outcomes during prolonged periods of warm ischemic insult. Prospective evaluation of the technique in humans is necessary to determine if selective arterial control confers long-term functional benefits in patients with limited renal reserve.

Robotic-assisted partial nephrectomy: surgical technique using a 3-arm approach and sliding-clip renorrhaphy.

INTRODUCTION: For the treatment of renal tumors, minimally invasive nephron-sparing surgery has become increasingly performed due to proven efficiency and excellent functional and oncological outcomes. The introduction of robotics into urologic laparoscopic surgery has allowed surgeons to perform challenging procedures in a reliable and reproducible manner. We present our surgical technique for robotic assisted partial nephrectomy (RPN) using a 3-arm approach, including a sliding-clip renorrhaphy. MATERIALS AND METHODS: Our RPN technique is presented which describes the trocar positioning, hilar dissection, tumor identification using intraoperative ultrasound for margin determination, selective vascular clamping, tumor resection, and reconstruction using a sliding-clip technique. CONCLUSION: RPN using a sliding-clip renorrhaphy is a valid and reproducible surgical technique that reduces the challenge of the procedure by taking advantage of the enhanced visualization and control afforded by the robot. The renorrhaphy described is performed under complete control of the console surgeon, and has demonstrated a reduction in the warm ischemia times in our series.

Robotic-assisted partial nephrectomy: surgical technique using a 3-arm approach and sliding-clip renorrhaphy

INTRODUCTION: For the treatment of renal tumors, minimally invasive nephron-sparing surgery has become increasingly performed due to proven efficiency and excellent functional and oncological outcomes. The introduction of robotics into urologic laparoscopic surgery has allowed surgeons to perform challenging procedures in a reliable and reproducible manner. We present our surgical technique for robotic assisted partial nephrectomy (RPN) using a 3-arm approach, including a sliding-clip renorrhaphy. MATERIAL AND METHODS: Our RPN technique is presented which describes the trocar positioning, hilar dissection, tumor identification using intraoperative ultrasound for margin determination, selective vascular clamping, tumor resection, and reconstruction using a sliding-clip technique. CONCLUSION: RPN using a sliding-clip renorrhaphy is a valid and reproducible surgical technique that reduces the challenge of the procedure by taking advantage of the enhanced visualization and control afforded by the robot. The renorrhaphy described is performed under complete control of the console surgeon, and has demonstrated a reduction in the warm ischemia times in our series.

Robotic partial nephrectomy with sliding-clip renorrhaphy: technique and outcomes.

BACKGROUND: Robotic partial nephrectomy (RPN) is emerging as an alternative to traditional laparoscopic partial nephrectomy (LPN). Despite the potential advantages of the robotic approach, renorrhaphy remains a challenging portion of the procedure. OBJECTIVE: To present our technique and outcomes for RPN, including sliding-clip renorrhaphy. DESIGN, SETTING, AND PARTICIPANTS: Between 2007 and 2008, 50 patients underwent RPN performed by a single attending surgeon. SURGICAL PROCEDURE: In this paper, we describe our technique for RPN, including a sliding-clip renorrhaphy, which is distinguished by the use of Weck Hem-O-Lock clips that are slid into place under complete control of the surgeon seated at the console and secured with a LapraTy clip. For the first 13 procedures, traditional tied-suture or assistant-placed clip closures were performed; sliding-clip renorrhaphy was performed in the remaining 37 cases. RESULTS AND LIMITATIONS: Mean tumor size was 2.5 cm. Mean operative time was 145.3 min, and mean overall warm ischemia time was 17.8 min. Mean estimated blood loss was 140.3 ml. The learning curve for overall operative time was 19 cases; the learning curve for portions of the case performed under warm ischemia (including tumor resection and renorrhaphy) was 26 cases. The introduction of a sliding-clip renorrhaphy produced significant reductions in overall operative time and warm ischemia time, while blood loss and hospital stay remained stable over our experience. Limitations of RPN include cost and increased reliance on the bedside assistant. CONCLUSIONS: Sliding-clip renorrhaphy provides an efficient and effective repair that is under nearly complete control of the surgeon. This technique appears to contribute to significantly shorter overall operative times and, perhaps most critically, to shorter warm ischemia times. The learning curve for RPN using this technique appears to be foreshortened compared with LPN.

Camera and trocar placement for robot-assisted radical and partial nephrectomy: which configuration provides optimal visualization and instrument mobility?

Proper camera and trocar placement is critical to the success of minimally invasive procedures. For robot-assisted renal surgery, two basic trocar configurations have been described. The medial approach, using a 30° downward-angled lens mimics a traditional transperitoneal laparoscopic configuration. An alternative configuration, using a 0° or 30° upward-angled lens approach locates the camera laterally, evoking a position sense similar to a retroperitoneal approach. Our objective is to compare the differences between these two standard approaches for robot-assisted renal surgery. After performing a review and analysis of available literature, our group tested both the medial and lateral camera approaches during robotic renal surgery performed in human patients. The medial approach provides a wide field of view, because of the relatively greater distance to the target structures and a horizon line closer to the patient's midline. The lateral configuration offers significantly different visualization. The relative proximity to the target structures and a higher horizon line results in a comparatively restricted field of vision. Instrument mobility is comparable between the two approaches. Meta-analysis of the literature reveals that both approaches provide comparable overall operative times for both radical and partial nephrectomy, though there is a trend towards shorter overall operative times for partial nephrectomy performed through a medial approach. The medial trocar configuration provides a familiar working environment for both surgeon and assistant; the wide-angle view enables enhanced visualization of surrounding structures and tracking of the instruments inserted by the assistant. The lateral approach offers the potential advantage of a closer view of the kidney, but does so at the expense of a significantly restricted field of view. In our experience, a medial trocar configuration offers significant advantages over the lateral trocar configuration, and is, therefore, the standard approach at our high-volume center.