Comparative study of in vivo lymphatic sealing capability of the porcine thoracic duct using laparoscopic dissection devices.

PURPOSE: Sealing the lymphatic vessels during abdominal and pelvic surgery is important to prevent the leakage of lymphatic fluid and its resultant sequelae. To our knowledge we compared for the first time the quality of lymphatic sealing by each of 4 commonly used laparoscopic dissection devices. MATERIALS AND METHODS: A total of 12 domestic pigs were used to test dissecting devices, including monopolar scissors (Ethicon Endo-Surgery, Cincinnati, Ohio), Harmonic ACE Scalpel, LigaSure V, EnSeal and Trissector. A midline incision was made from mid sternum to umbilicus, the diaphragm was divided and the porcine thoracic duct was isolated. In all animals each device was used to seal an area of the duct and each seal was placed at least 2 cm from the prior seal. In group 1 the thoracic duct of 6 pigs was cannulated with a 5Fr catheter and the seal was subjected to burst pressure testing using a burst pressure measuring device (Cole-Parmer, Vernon Hills, Illinois). In the 6 pigs in group 2 each seal was immediately sent for histopathological evaluation. Specimens were given a score for the extent of cautery damage, including 0-none, 1-minimal, 2-moderate, 3-severe and 4-extreme. RESULTS: A total of 64 seals were created, of which 35 were subjected to burst pressure testing. Mean size of the thoracic duct was 2.6 mm. No acute seal failures were observed with any bipolar device or the harmonic shears. However, 2 immediate failures (33%) were seen with monopolar scissors. Mean burst pressure for monopolar scissors, Harmonic ACE Scalpel, LigaSure V, EnSeal and Trissector was 46 (range 0 to 165), 540 (range 175 to 795), 258 (range 75 to 435), 453 (range 255 to 825) and 379 mm Hg (range 175 to 605), respectively (p <0.05). Trissector, Harmonic ACE Scalpel and EnSeal generated seals with significantly higher burst pressure than that of monopolar scissors (p <0.05). Histopathological evaluation revealed that LigaSure caused less thermal damage than Trissector and EnSeal (p <0.05). CONCLUSIONS: Each device tested except monopolar scissors consistently produced a supraphysiological seal and should be suitable for sealing lymphatic vessels during laparoscopic surgery.

The 'buoy' stent: evaluation of a prototype indwelling ureteric stent in a porcine model.

OBJECTIVE To assess a prototype ureteric 'buoy' stent with a 10 F upper body tapering to a 3F tail, developed to potentially reduce stent-related irritative symptoms while providing an adequate mould for healing after endopyelotomy. MATERIALS AND METHODS Eighteen Yucatan minipigs had the stent placed either into the intact ureter (phase I) or after Acucise proximal endoureterotomy (phase II). Buoy stents were compared to 10/7 F endopyelotomy stents and to standard 7 F stents in phases I and II, respectively. The pigs were assessed for vesico-ureteric reflux, hydronephrosis and infection, before stent insertion and at harvest. Stents were weighed before and after placement and the removal force was measured. Pressure/flow studies, antegrade nephrostograms and specimens for histopathology from the renal pelvis, ureter and vesico-ureteric junction (VUJ) were obtained at harvest. RESULTS Thirteen minipigs survived the entire study. Ureteric flow with the stents in situ was better for buoy stents than for 10/7 F stents (P < 0.005). Ureteric flow after endoureterotomy and subsequent stent removal was similar for buoy stents and standard 7 F stents. None of the stents refluxed. There was no difference between stents in removal force, weight change or incidence of hydronephrosis. At 1 and 12 weeks, buoy stents tended to produce lower histopathological alteration scores than control stents, especially at the VUJ (phase I, 2.0 vs 3.9, P = 0.092; phase II, 0.6 vs 1.7, P = 0.18). CONCLUSIONS The novel buoy stents are easily placed and removed via the urethra. They can cause less VUJ inflammation than standard stents while allowing for adequate ureteric flow and healing after proximal endoureterotomy.

The EZ Trainer: validation of a portable and inexpensive simulator for training basic laparoscopic skills.

PURPOSE: We assessed the face and content validity of a new portable laparoscopic trainer, the EZ Trainer. MATERIALS AND METHODS: The portable, affordable EZ trainer system was conceived, designed and commissioned by academic surgeons from the departments of urology at our 2 institutions with the express purpose of advancing laparoscopic surgical training. A total of 42 participants, including general surgeons, obstetricians/gynecologists, urologists and industry representatives, assessed the face and the content validity of the trainer using a standard questionnaire. Participants were stratified into high (greater than 30 laparoscopic cases per year) and low (less than 30 cases per year) volume laparoscopists. RESULTS: Of the participants 96% rated the trainer as a realistic laparoscopic training format. Of high volume laparoscopists 81.5% rated the trainer as comfortable to use, 92.6% found that the trainer was a realistic practice format, 70.4% would purchase the trainer for personal use and 85.2% would recommend that the trainer be made available to surgical residents in their discipline. Of low volume laparoscopists 87% rated the trainer as comfortable to use, 93.3% found that the trainer was a realistic practice format, 73.3% would purchase the trainer for personal use and 80% would recommend that the trainer be made available to diverse surgical residents. CONCLUSIONS: The EZ trainer system has face and content validity as a portable laparoscopic trainer across a broad range of surgical disciplines.

Comparison of healing after cystotomy and repair with fibrin glue and sutured closure in the porcine model.

PURPOSE: We compared healing after laparoscopic cystotomy using fibrin glue, sutures, or a combination to determine whether fibrin glue can obviate the need for sutures and whether there is any detriment when glue is used in the presence of sutures. MATERIALS AND METHODS: In 24 Yorkshire pigs, a 3.5 cm vertical cystotomy was created laparoscopically and repaired as follows: Group 1--no closure; group 2--fibrin glue closure; group 3--suture repair; group 4--combined fibrin glue and suture repair. All animals had a Foley catheter for 1 week. In each group, three animals were harvested at 1 week (acute) and three animals were harvested at 6 weeks (chronic). RESULTS: Acute: Group 1--all pigs had an unhealed defect that leaked when evaluated by cystography. Groups 2, 3, 4--mean leak pressures were 80, 97, and 60 cm H(2)O (P = 0.36), respectively. Mean bladder capacity was not significantly different between groups. Chronic: No leakage seen on a cystogram at 1 week; at 6 weeks, bladders were filled at > or =95 to 100 cm H(2)O without leakage. Histologically, there was more inflammation in the acute group v chronic group pigs. In the acute group pigs repaired with glue or suture + glue, there was more inflammation and less epithelial continuity than in the suture alone group. At 6 weeks, there was no difference between groups. CONCLUSION: Fibrin glue provoked an intense inflammatory response that might have delayed healing acutely, resulting in a lower burst pressure in both scenarios in which it was used (i.e., alone or in combination with sutures). However, by 6 weeks, there did not seem to be any difference between groups either clinically or histopathologically.

Immediate impact of an intensive one-week laparoscopy training program on laparoscopic skills among postgraduate urologists.

INTRODUCTION: Laparoscopic techniques are difficult to master, especially for surgeons who did not receive such training during residency. To help urologists master challenging laparoscopic skills, a unique 5-day mini-residency (M-R) program was established at the University of California, Irvine. The first 101 participants in this program were evaluated on their laparoscopic skills acquisition at the end of the 5-day experience. METHODS: Two urologists are accepted per week into 1 of 4 training modules: (1) ureteroscopy/percutaneous renal access; (2) laparoscopic ablative renal surgery; (3) laparoscopic reconstructive renal surgery; and (4) robot-assisted prostatectomy. The program consists of didactic lectures, pelvic trainer and virtual reality simulator practice, animal and cadaver laboratory sessions, and observation or participation in human surgeries. Skills testing (ST) simulating open, laparoscopic, and robotic surgery is assessed in all of the M-R participants on training days 1 and 5. Tests include ring transfer, suture threading, cutting, and suturing. Performance is evaluated by an experienced observer using the Objective Structured Assessment of Technical Skill (OSATS) scoring system. Statistical methods used include the paired sample t test and analysis of variance at a confidence level of P

Effects of commonly used hemostatic agents on the porcine collecting system.

PURPOSE: Topical hemostatic agents have been particularly useful for preventing bleeding in tubeless percutaneous nephrolithotomy. In the present study, we investigated the effect of gelatin matrix hemostatic sealant (FloSeal), fibrin glue (Tisseel,), polyethylene glycol polymers (CoSeal), and bovine serum albumin/ glutaraldehyde (BioGlue) in the pig urinary collecting system after injection through a percutaneous nephrostomy (PCN) tract. MATERIALS AND METHODS: Percutaneous nephrostomy was performed in 40 kidneys in 24 domestic pigs. Animals were divided into four groups of six each: (1) FloSeal; (2) Tisseel; (3) CoSeal; and (4) BioGlue. In 16 animals that tolerated the procedure, the contralateral kidney was used as a control for PCN only. All tracts were dilated to 30F with the Amplatz dilator, and 2 mL of the hemostatic agent was injected into the collecting system before pulling back to seal the puncture. RESULTS: Among the control PCN kidneys, no obstruction was detected at the end of a 5-day period. However, three of six kidneys injected with FloSeal, Tisseel, or CoSeal and four of six kidneys injected with BioGlue were obstructed. In each of these cases, there was an associated retroperitoneal urinoma. CONCLUSION: FloSeal, Tisseel, CoSeal, and BioGlue, if injected directly into the porcine collecting system, can result in significant obstruction that does not resolve over a 5-day period. Until there are clinical data to the contrary, we believe that when using one of these hemostatic agents in association with a tubeless percutaneous procedure, a retrograde occlusion balloon catheter should be considered to prevent inadvertent injection of these materials into the collecting system.

In-vivo evaluation of flow characteristics of novel metal ureteral stent.

PURPOSE: To characterize the flow of a novel ureteral stent composed of a nickel-cobalt-chromium-molybde-num alloy and compare it with flow in a standard ureteral stent. MATERIALS AND METHODS: Six 6F Resonance stents and six 6F standard Black Beauty ureteral stents were placed in six Yucatan minipigs, with each pig serving as its own control. Flow assessment was performed on all stents via a nephrostomy tube delivering a standard rate of 0.9% saline at 35 cm H(2)O. Flow studies on the standard stents encompassed extraluminal (i.e., lumen of stent occluded with a guidewire), intraluminal (i.e., ureter secured to stent with a constricting suture), and combined (i.e., open lumen without constricting suture) flow. In the Resonance stent, only combined and intraluminal flow could be addressed, as there is no access to the lumen of this stent. RESULTS: With the Resonance stent, intraluminal flow was much greater than combined flow, with mean values of 5.15 mL/min and 2.50 mL/min, respectively (P = 0.057; SD = 7.73). Intraluminal flow was similar to combined flow in the 6F standard stent, with mean values of 7.34 mL/min and 7.30 mL/min, respectively (P = 0.88; SD = 1.76). The standard stent had significantly greater combined flow than the Resonance stent (P = 0.023) but not intraluminal flow (P = 0.247). Of note, whereas it was possible to occlude the 6F standard stent completely with a ureteral ligature (i.e., no guidewire placed in the lumen), it was not possible to occlude the Resonance stent regardless of how tightly the suture was tied. CONCLUSION: The Resonance metal alloy stent provides less overall flow than a standard stent. However, under circumstances of extrinsic ureteral compression sufficient to occlude a standard stent (e.g., extrinsic compression plus an internal guidewire), the metal stent continues to provide satisfactory drainage.

Rapid communication: effects of Steris 1 sterilization and Cidex ortho-phthalaldehyde high-level disinfection on durability of new-generation flexible ureteroscopes.

BACKGROUND AND PURPOSE: The effects of commonly used reprocessing methods on flexible ureteroscope longevity have never been examined. We prospectively studied the effects of Steris 1 sterilization and Cidex ortho-phthalaldehyde (OPA) high-level disinfection (HLD) on the image quality, physical structure, and deflective properties of two new flexible ureteroscopes. MATERIALS AND METHODS: Two identical "out-of-the-box" Storz 11278AU1 flexible ureteroscopes (Karl Storz Endoscopy, Tuttlingen, Germany) were sterilized individually using the Steris 1 system (Steris Mentor, Ohio) or disinfected with Cidex OPA (Advanced Sterilization Products, J&J, Irvine, CA) for 100 trials followed by a crossover to the other method for another 100 trials over a period of 1 year. After every five trials, optical quality, angle of deflection, and fiber damage were analyzed in the laboratory. Throughout the study, neither of these ureteroscopes was used clinically. RESULTS: After 100 trials, ureteroscope 1, which was sterilized initially in the Steris system, had a 12-mm tear on its shaft (noted after the 17th trial), 297 damaged fibers, and a 37% drop in resolution (loss of 3.75 lines/mm). There was no change in deflection from baseline. In contrast, after 100 cycles, ureteroscope 2, which was subjected to HLD with Cidex OPA, had no visible external damage, a 0% change in resolution, 10 damaged fibers, and no change in deflection. After the crossover, ureteroscope 2 developed a semilunar defect that obscured the endoscopic view, whereas there was no further significant damage to ureteroscope 1. CONCLUSION: After 100 cycles, the Steris 1 system rendered the flexible ureteroscope unusable, whereas HLD with Cidex OPA had minimal adverse impact.

Short-term impact of a laparoscopic "mini-residency" experience on postgraduate urologists' practice patterns.

BACKGROUND: To assist practicing urologists incorporate laparoscopic urology into their practice, a 5-day mini-residency (M-R) program with a mentor, preceptor, and proctor experience was established at the University of California, Irvine, and we report the initial results. STUDY DESIGN: Thirty-two urologists underwent laparoscopic ablative (n=17) or laparoscopic reconstructive (n=15) training, including inanimate model skills training, animal laboratory, and operating room observation. A questionnaire was mailed 1 to 15 months (mean, 8 months) after their M-R program, and responses were reviewed. RESULTS: A 100% response rate was achieved. The mean M-R participant age was 49 years (range 31 to 70 years). The majority of the participants (72%) had laparoscopic experience during residency training and had performed between 5 and 15 laparoscopic cases before attending the M-R program. Within 8 months after M-R, 26 participants (81%) were practicing laparoscopic surgery. Participants were performing laparoscopic radical nephrectomy (p=0.008), nephroureterectomy (p<0.0005), and pyeloplasty (p=0.008) at substantially higher rates after training. At the same time, fewer of the M-R participants were performing hand-assisted laparoscopic surgery after training (p=0.008) compared with before the M-R. Ninety-two percent of the participants indicated that they would recommend this training program to a colleague. CONCLUSIONS: A 5-day intensive laparoscopic ablative and reconstructive surgery course seems to encourage postgraduate urologists, already familiar with laparoscopy, to successfully expand the scope of their procedures to include more complex laparoscopic techniques such as nephrectomy, nephroureterectomy, and pyeloplasty into their clinical practice.

Comparison of resolution, contrast, and color differentiation among fiberoptic and digital flexible cystoscopes.

BACKGROUND AND PURPOSE: Advances in electro-optics continue to improve the urologist's ability to perform minimally invasive procedures. While the development of flexible fiberoptic cystoscopes more than 20 years ago greatly impacted the practice of urology, distal-sensor digital technology may represent the next step in the evolution of endoscopy. We compared a new distal-sensor digital flexible cystoscope with two standard fiberoptic flexible cystoscopes. MATERIALS AND METHODS: We evaluated the resolution, contrast, and color discrimination of a new ACMIICN distal-sensor digital cystoscope with >165,000 effective pixels in its clear aperture (viewing area), a new ACMI-ACN II fiberoptic cystoscope with <15,000 pixels in its clear aperture, and a Storz 1127 office fiberoptic cystoscope. Five subjects compared each cystoscope across 13 test parameters. RESULTS: There was no difference in the performance of the two fiberoptic cystoscopes. The ICN cystoscope was statistically superior to one or both fiberoptic cystoscopes across 12 of the 13 tests, including color differentiation between shades of dark red (P < 0.05), contrast discrimination along a 15-step grayscale gradient (P < 0.001 compared with the 1127 fiberoptic cystoscope only), resolution at 10 mm (7.52 line pairs/mm [lp/mm] (ICN) nu 3.58 lp/mm for both fiberoptic cystoscopes; (P < 0.001), and clear resolution of a 1-mm target at a distance of 6.1 cm (ICN) nu 3.3 cm (1127) and 3.8 cm (ACN II) (P < 0.001). CONCLUSIONS: The ICM distal-sensor all-digital cystoscope was clearly superior to two representative fiberoptic cystoscopes in vitro in terms of resolution, contrast discrimination, and red color differentiation. In-vivo performance remains to be assessed.

Comparison of results of virtual-reality simulator and training model for basic ureteroscopy training.

BACKGROUND AND PURPOSE: The traditional method of acquiring surgical skills is by apprenticeship and involves an extensive period of training with patients. Model-based and virtual reality simulation is gaining interest as alternative training, allowing repetitive practice in a low-risk environment. The objective of this study was to determine if a materials, model-based training format and an interactive virtual-reality simulator could provide equivalent teaching of basic ureteroscopy skills to the inexperienced medical student. SUBJECTS AND METHODS: Sixteen first-year medical students received the same didactic session and video viewing on cystoscopy, guidewire access to the upper urinary tract, and ureteroscopy with intracorporeal laser lithotripsy and stone extraction by the same instructor. The participants were then randomized into two study groups: Group 1 was trained on the ureteroscopy training model (TMU) from Limbs & Things and Group 2 on the Simbionix UROMentor virtual-reality simulator (VRS) until the participants could perform the procedure independently. Two months later, the participants independently performed a ureteroscopic procedure on a pig kidney/ureter model and were graded from 1 to 5 on their ability to complete the steps of the procedure and the quality of their performance (handling of tissue, efficiency, instrument handling, knowledge of instruments, flow of operation, use of assistants, and knowledge of the specific procedure) for a possible total of 35 points. RESULTS: All participants were able to perform the steps of the procedure correctly. The TMU group and the VRS group received a mean of 22.9 +/- 4.8 and 23.6 +/- 5.4 points, respectively (P = 0.38) for their qualitative assessment. CONCLUSION: The medical students' skills and ability to perform a basic ureteroscopic stone-management procedure was independent of the training modality (VRS or TMU). Incorporating either of these devices into the preliminary training of urology residents may improve their initial clinical performance of these skills.

Comparison of basic elements of human performance scores between urologists with various extents of experience.

BACKGROUND AND PURPOSE: An objective evaluation of innate ability and its ability to predict potential success as a surgical trainee is an appealing concept for the selection process of residency applications. The objective of this study was to evaluate whether basic elements of performance (BEP) could discriminate among resident applicants and urologists with various extents of surgical experience. SUBJECTS AND METHODS: One hundred forty-five participants were divided into four study groups: group A, 57 urology residency applicants to the 2002 and 2003 interview process; group B, 8 post-internship urology residents; group C, 19 urologists tested with BEP within 10 years of graduation from their residency training program; and group D, 61 urologists who had graduated from their residency training program more than 10 years prior to testing. The BEP measures consisted of 13 basic performance resources (BPR) including visual-information processing speed, visual-spatial immediate-recall capacity, and neuromotor channel capacity. RESULTS: The four study groups differed significantly in their mean age: group A=27.6 years, group B=29.1 years, group C=37.1 years, and group D=48.9 years (P<0.0005). There was essentially no significant difference between the groups with regard to immediate-recall memory, reaction time simple, or reaction time complicated. The younger participants (groups A and B) were faster than the older surgeons (groups C and D) (P<0.02). However, the older surgeons (groups C and D) were significantly more accurate than the younger groups (A and B) (P<0.0005). The only sex differences noted were in hand-grip strength and shoulder-strength scores, which were all higher in the men. CONCLUSIONS: There generally appears to be a lack of direct correlation between innate abilities and surgical experience. Urology resident applicants with no surgical experience and urology residents with limited surgical experience are faster but less accurate in innate skills testing than experienced practicing urologists.

Effect of holmium:YAG laser pulse width on lithotripsy retropulsion in vitro.

BACKGROUND AND PURPOSE: The effect of laser pulse width on calculus retropulsion during ureteroscopic lithotripsy is poorly defined because of the limited availability of variable pulse-width lasers. We used an adjustable pulse-width Ho:YAG laser to test the effect of pulse width on in vitro phantom-stone retropulsion and fragmentation efficiency. METHODS AND MATERIALS: An Odyssey 30 Ho:YAG laser (Convergent Laser Technologies, Oakland, CA) with adjustable pulse width (350 or 700 microsec) was used to treat spherical 10-mm plaster calculi in a model ureter (N = 40) and calix (N = 16) utilizing 200- and 400-microm fibers (10 Hz, 1.0 J). Calculi were placed in a waterfilled clear polymer tube, and laser energy was applied continuously in near contact until the stone had moved 8 cm. The time (seconds) and energy (joules) needed to cause the stone to traverse this distance was recorded. Stones were also placed in a stainless-steel mesh calix model in which retropulsion was limited. Laser energy was applied for 5 minutes at each pulse width. A laser-energy meter (Molectron Detector Inc, Portland OR) was used to quantify fiber transmission efficiency after 1 minute of continuous lithotripsy for each fiber at each pulse width. RESULTS: Retropulsion was greater for stones treated at 350 microsec, indicated by a shorter time to traverse the model ureter. For the 200-microrm fiber at 350 microrsec, the average time was 11.5 seconds v 20.3 seconds at 700 microsec (P < 0.001). The average total energy delivered was 114.9 J at 350 microsec v 199.8 J at 700 microsec (P < 0.001). For the 400-microm fiber at 350 microsec, the average time was 5.8 seconds v 11.9 seconds at 700 microsec (P < 0.001). The average total energy was 57.1 J at 350 microsec v 127.3 J at 700 microsec (P < 0.001). In the caliceal model, at 350 and 700 microsec with the 200- and 400-microm fibers, mass loss was 34.9% and 33.4% (P = 0.8) and 14.6% and 21.6% (P = 0.04), respectively. The reduction in energy transmission at 350 microsec and 700 microsec with the 200- microm fiber after 60 seconds of continuous lasing was 8.82% v 9%, respectively (P = 0.95). For the 400-microm fiber, the transmission loss was 18.4% at 350 microsec v 4.4% at 700 microsec (P = 0.0002). CONCLUSION: When treating ureteral calculi, retropulsion can be reduced by using a longer pulse width without compromising fragmentation efficiency. For caliceal calculi, the longer pulse width in combination with a 400-microm fiber provides more effective stone fragmentation.

What happens to hemostatic agents in contact with urine? An in vitro study.

BACKGROUND AND PURPOSE: As the indications for topical hemostatic agents increase in urology, the question arises: what happens to these agents when they enter the urinary collecting system? To answer this question, we performed a series of in-vitro experiments mixing three hemostatic agents with normal and sanguineous urine. MATERIALS AND METHODS: Four commercially available topical hemostatic products: oxidized regenerated cellulose (Surgicel; Ethicon, Somerville, NJ), fibrin sealant (Tisseel VH Kit; Baxter Health Care Corporation, Irvine, CA), gelatin matrix hemostatic sealant (FloSeal; Baxter Health Care), and polyethylene glycol (CoSeal; Cohesion Technologies, Palo Alto, CA) were studied. Human urine (10 mL) was added to samples of each substance; this was done in triplicate. The 12 sample tubes were then capped and placed on a tube shaker at slow speed and 37 degrees C. Observations regarding consistency of the material were made at 6, 12, 24, 48, 72, 96, and 120 hours (5 days). Gelatin matrix hemostatic sealant was further tested in urine with various amounts of blood or blood clot; observations were again recorded out to 5 days. RESULTS: Surgicel maintained its solid form when it initially came in contact with urine, but over a period of 5 days, it transformed into a mucoid substance with visible free-floating fibers. It did not dissolve completely in urine within 5 days. Gelatin matrix was immediately transformed by urine into a fine colloidal suspension that did not change over the 5 days of the study. Fibrin glue, after mixing of the two components (fibrinogen and thrombin) directly in the urine, and polyethylene glycol immediately formed a solid clot at the bottom of the test tube on contact with the urine. When the mixture of fibrin sealant was allowed to form for 15 minutes and then added to urine, it again maintained a solid form. After 72 hours, the fibrin glue became a semisolid gelatinous plug. On analysis at 5 days, the fibrin sealant clot had transformed into a cohesive mucoid gel, and the polyethylene glycol clot had not changed. The gelatin matrix hemostatic sealant, when in contact with blood or blood clot, appeared to either become part of a clot or to remain in a colloidal suspension. At 5 days, all clots had dissolved to fine particulate suspensions, and the gelatin matrix appeared as a fine suspension. CONCLUSION: Fibrin glue and oxidized regenerated cellulose maintain a solid form when initially placed in direct contact with urine and then assume a semisolid gelatinous state, which is still present at 5 days. Polyethylene glycol forms a solid clot initially and does not change after 5 days. Only hemostatic gelatin matrix remained as a fine particulate suspension in both normal and sanguineous urine. The implications of these findings with regard to sealing the renal parenchyma or small violations of the collecting system after percutaneous or laparoscopic surgery await in-vivo testing.

Initial impact of a dedicated postgraduate laparoscopic mini-residency on clinical practice patterns.

BACKGROUND AND PURPOSE: Laparoscopic surgical techniques are difficult to master, especially for surgeons who did not receive this type of training during their residencies. We have established a 5-day mentor-preceptor- proctor-guided postgraduate "mini-residency" (M-R) experience in minimally invasive surgery. The initial results from the first 16 participants in the laparoscopic M-R modules are presented. PARTICIPANTS AND METHODS: On the first and the last day of the M-R, all participants underwent surgical skills testing using an open-surgery, standard laparoscopic, and robot-assisted laparoscopic format. A written examination was also administered on the last day. The influence of M-R on the participants' practice pattern was then assessed by a follow-up questionnaire survey 1 to 7 months after their attendance. RESULTS: Data from the first 16 participants were analyzed. Of note, the score was significantly improved for only one of the four tested laparoscopic skills (i.e., threading a suture through loops). Nonetheless, on the follow-up survey, of the 15 respondents, two laparoscopically naïve participants had performed laparoscopic nephrectomy, and of the eight participants who had prior renal-ablative laparoscopic experience, four had performed advanced reconstructive laparoscopic cases. CONCLUSIONS: A 5-day dedicated postgraduate M-R in laparoscopy appears to be helpful for urologists wishing to incorporate this surgical approach into their practices. The "take rate" among participants is initially at the 40% level, similar to what has been previously reported after a 1 to 2-day hands-on didactic laparoscopy course.

Current trends in urologic laparoscopic surgery.

PURPOSE: We examined the status of laparoscopy in urology and the impact of residency and fellowship training on the performance of laparoscopy as primary surgeon. We also examined whether performing nonsurgical tasks requiring two-handed dexterity had any link to the adoption of laparoscopic techniques by urologists. MATERIALS AND METHODS: A total of 8760 laparoscopy questionnaires containing 135 queries were mailed to urologists listed on the American Urological Association practicing urologists mailing list. The questions sought information on area of practice, time in practice, fellowship training, ambidexterity, laparoscopic experience, and experience with robotics. The response rate was 1.8% (155 of 8760). RESULTS: There appeared to be no significant correlation between the performance of laparoscopic surgery and participation in activities requiring bimanual dexterity. However, a correlation of strong statistical significance did exist between laparoscopic residency training and performance of laparoscopy after residency (p=0.003. There also was a correlation between fellowship training in laparoscopy/endourology and doing laparoscopy as primary surgeon. CONCLUSIONS: Participation in laparoscopic surgery during residency training is a major determining factor in performance of laparoscopy as a primary surgeon in practice. Younger surgeons trained in laparoscopy during residency are performing more laparoscopy post residency than those without laparoscopic training during residency. At present, there is a need to train more urologists in laparoscopy at the postgraduate level.

In vitro and in vivo comparison of optics and performance of a distal sensor ureteroscope versus a standard fiberoptic ureteroscope.

BACKGROUND AND PURPOSE: Recent advances in distal sensor technologies have made distal sensor ureteroscopes both commercially and technically feasible. We evaluated performance characteristics and optics of a new generation distal sensor Flex-X(C) (X(C)) and a standard flexible fiberoptic ureteroscope Flex-X(2) (X(2)), both from Karl Storz, Tuttlingen, Germany. MATERIALS AND METHODS: The ureteroscopes were compared for active deflection, irrigation flow, and optical characteristics. Each ureteroscope was evaluated with an empty working channel and with various accessories. Optical characteristics (resolution, grayscale imaging, and color representation) were measured using United States Air Force test targets. We digitally recorded a renal porcine ureteroscopy and laser ablation of a stone with the X(2) and with the X(C). Edited footage of the recorded procedure was shown to different expert surgeons (n=8) on a high-definition monitor for evaluation by questionnaire for image quality and performance. RESULTS: The X(C) had a higher resolution than the X(2) at 20 and 10 mm 3.17 lines/mm vs 1.41 lines/mm, 10.1 vs 3.56, respectively (P=0.003, P=0.002). Color representation was better in the X(C). There was no difference in contrast quality between the two ureteroscopes. For each individual ureteroscope, the upward deflection was greater than the downward deflection both with and without accessories. When compared with the X(2), the X(C) manifested superior deflection and flow (P<0.0005, P<0.05) with and without accessory present in the working channel. Observers deemed the distal sensor ureteroscope superior in visualization in clear and bloody fields, as well as for illumination (P=0.0005, P=0.002, P=0.0125). CONCLUSIONS: In this in vitro and porcine evaluation, the distal sensor ureteroscope provided significantly improved resolution, color representation, and visualization in the upper urinary tract compared with a standard fiberoptic ureteroscope. The overall deflection was also better in the X(C), and deflection as well as flow rate was less impaired by the various accessories.

In vitro evaluation of ScopeSafe fibers and the scope guardian sheath in prevention of ureteroscope endolumenal working damage.

BACKGROUND AND PURPOSE: Ureteroscope breakage is commonly related to laser fiber damage. Often, the damage is mechanical and not energy related. As such, we evaluated a novel laser fiber and sheath system in preventing mechanical ureteroscope damage during fiber insertion. MATERIALS AND METHODS: We assessed 200-µm/272/3-µm laser fibers with the laser sheath in a flexible ureteroscope. Diminishment of active deflection and irrigation flow rates were compared with a standard laser fiber alone. Eight nonassembled working channel components were tested in a 0-degree/90-degree/210-degree deflection model. After insertion cycles, external and endolumenal damage to the working channel were classified. We also tested the sheath system in a 0-degree/90-degree/210-degree deflection model for fiber failure and laser damage. RESULTS: In all test trials with the sheath and for standard laser fibers in the 0-degree model, there were no channel perforations or damage. With standard laser fibers, in the 210-degree model, superficial scratches and demarcated abrasions were visible after 10 and 60 to 70 insertions for the 273-µm laser fiber and after 30 insertions (superficial scratches) for the 200-µm laser fiber. In the 90-degree model, superficial scratches occurred after 20 insertions for the 273-µm fibers and after 40 insertions for the 200-µm laser fibers. No demarcated abrasions were seen after 100 insertions. In the 210-degree model, there was one perforation with the 272-µm fiber, but none with 200-µm fiber. There were no fiber failures with sheath use; however, the sheath did not prevent laser energy damage. The laser sheath resulted in a 4.7-degree/3.8-degree (1.2%/1.5%) diminishment in deflection (up/down) for the 200 µm and a 3.5-degree/4.3-degree (1.8%/1.5%) diminishment for 272-µm laser fiber compared with standard 200/272-µm laser fiber. Irrigation flow was diminished with the sheath on both the 200-µm and 272-µm laser fiber by 28.7% and 32.6%, respectively. CONCLUSION: The Scope Guardian Sheath prevented mechanical working channel damage with minimal diminishment of deflection and irrigation flow.

Comparison of optics and performance of a distal sensor high definition cystoscope, a distal sensor standard definition cystoscope, and a fiberoptic cystoscope.

OBJECTIVE: To evaluate performance characteristics and optics of a new generation high-definition distal sensor (HD-DS) flexible cystoscope, a standard-definition distal sensor (SD-DS) cystoscope, and a standard fiberoptic (FO) cystoscope. METHODS: Three new cystoscopes (HD-DS, SD-DS, and FO) were compared for active deflection, irrigation flow, and optical characteristics. Each cystoscope was evaluated with an empty working channel and with various accessories. Optical characteristics (resolution, grayscale imaging, color representation, depth of field, and image brightness) were measured using United States Air Force (USAF)/Edmund Optics test targets and illumination meter. We digitally recorded a porcine cystoscopy in both clear and blood fields, with subsequent video analysis by 8 surgeons via questionnaire. RESULTS: The HD-DS had a higher resolution than the SD-DS and the FO at both 20 mm (6.35 vs 4.00 vs 2.24 line pairs/mm) and 10 mm (14.3 vs 7.13 vs 4.00 line pairs/mm) evaluations, respectively (P <.001 and P <.001). Color representation and depth of field (P = .001 and P <.001) were better in the HD-DS. When compared to the FO, the HD-DS and SD-DS demonstrated superior deflection up and irrigant flow with and without accessory present in the working channel, whereas image brightness was superior in the FO (P <.001, P = .001, and P <.001, respectively). Observers deemed the HD-DS cystoscope superior in visualization in clear and bloody fields, as well as for illumination. CONCLUSION: The new HD-DS provided significantly improved visualization in a clear and a bloody field, resolution, color representation, and depth of field compared to SD-DS and FO. Clinical correlation of these findings is pending.

High-fidelity simulation-based team training in urology: evaluation of technical and nontechnical skills of urology residents during laparoscopic partial nephrectomy.

INTRODUCTION: The use of low-risk simulation training for resident education is rapidly expanding as teaching centers integrate simulation-based team training (SBTT) sessions into their education curriculum. SBTT is a valuable tool in technical and communication skills training and assessment for residents. We created a unique SBTT scenario for urology residents involving a laparoscopic partial nephrectomy procedure. MATERIALS AND METHODS: Urology residents were randomly paired with a certified registered nurse anesthetists or an anesthesia resident. The scenario incorporated a laparoscopic right partial nephrectomy utilizing a unique polyvinyl alcohol kidney model with an embedded 3cm lower pole exophytic tumor and the high-fidelity SimMan3G mannequin. The Urology residents were instructed to pay particular attention to the patient's identifying information provided at the beginning of the case. Two scripted events occurred, the patient had an anaphylactic reaction to a drug and, after tumor specimen was sent for a frozen section, the confederate pathologist called into the operating room (OR) twice, first with the wrong patient name and subsequently with the wrong specimen. After the scenario was complete, technical performance and nontechnical performance were evaluated and assessed. A debriefing session followed the scenario to discuss and assess technical performance and interdisciplinary nontechnical communication between the team. RESULTS: All Urology residents (n = 9) rated the SBTT scenario as a useful tool in developing communication skills among the OR team and 88% rated the model as useful for technical skills training. Despite cuing to note patient identification, only 3 of 9 (33%) participants identified that the wrong patient information was presented when the confederate "pathologist" called in to report pathology results. CONCLUSION: All urology residents rated SBTT sessions as useful for the development of communication skills between different team members and making residents aware of unlikely but potential critical errors in the OR. We will continue to use SBTT as a useful method to develop resident technical and nontechnical skills outside of the high-risk operating environment.