Effect of the American Urological Association Annual Review course on the results of the urology qualifying examination.

PURPOSE: In this study we assess the impact of a urology dedicated review course on the scores of the corresponding board qualifying examination for attendees of the urology review course. MATERIALS AND METHODS: The ABU (American Board of Urology) Qualifying Examination scores from 2009, 2010 and 2011 were categorized into group 1 candidates who attended the AUA (American Urological Association) Annual Review Course the same year, and group 2 candidates who did not attend the AUA Annual Review Course that same year, and were compared. The scores of the preceding year's In-Service Examination were also compared for the same groups of candidates and compared to their subsequent first time taken Qualifying Examination scores. RESULTS: There was no difference in Qualifying Examination scores of resident candidates attending vs not attending the AUA Annual Review Course in all 3 years. The overall failure rate was low, and essentially the same for all candidates in all years regardless of attendance at the AUA Annual Review Course at 2% in 2009, 2% in 2010 and 4% in 2011. Of group 1 candidates the majority (80% to 98%) considered the Annual Review Course helpful or very helpful in preparation for the Qualifying Examination. CONCLUSIONS: The majority of candidates are adequately prepared to pass their Qualifying Examination at the conclusion of their residency training program regardless of their attendance of the AUA Annual Review Course. This course may help bolster the confidence of the candidate preparing for their Qualifying Examination.

High fidelity simulation based team training in urology: a preliminary interdisciplinary study of technical and nontechnical skills in laparoscopic complications management.

PURPOSE: Simulation based team training provides an opportunity to develop interdisciplinary communication skills and address potential medical errors in a high fidelity, low stakes environment. We evaluated the implementation of a novel simulation based team training scenario and assessed the technical and nontechnical performance of urology and anesthesiology residents. MATERIALS AND METHODS: Urology residents were randomly paired with anesthesiology residents to participate in a simulation based team training scenario involving the management of 2 scripted critical events during laparoscopic radical nephrectomy, including the vasovagal response to pneumoperitoneum and renal vein injury during hilar dissection. A novel kidney surgical model and a high fidelity mannequin simulator were used for the simulation. A debriefing session followed each simulation based team training scenario. Assessments of technical and nontechnical performance were made using task specific checklists and global rating scales. RESULTS: A total of 16 residents participated, of whom 94% rated the simulation based team training scenario as useful for communication skill training. Also, 88% of urology residents believed that the kidney surgical model was useful for technical skill training. Urology resident training level correlated with technical performance (p=0.004) and blood loss during renal vein injury management (p=0.022) but not with nontechnical performance. Anesthesia resident training level correlated with nontechnical performance (p=0.036). Urology residents consistently rated themselves higher on nontechnical performance than did faculty (p=0.033). Anesthesia residents did not differ in the self-assessment of nontechnical performance compared to faculty assessments. CONCLUSIONS: Residents rated the simulation based team training scenario as useful for interdisciplinary communication skill training. Urology resident training level correlated with technical performance but not with nontechnical performance. Urology residents consistently overestimated their nontechnical performance.

Validation study of a virtual reality robotic simulator--role as an assessment tool?

PURPOSE: Virtual reality simulators are often used for surgical skill training since they facilitate deliberate practice in a controlled, low stakes environment. However, to be considered for assessment purposes rigorous construct and criterion validity must be demonstrated. We performed face, content, construct and concurrent validity testing of the dV-Trainer™ robotic surgical simulator. MATERIALS AND METHODS: Urology residents, fellows and attending surgeons were enrolled in this institutional review board approved study. After a brief introduction to the dV-Trainer each subject completed 3 repetitions each of 4 virtual reality tasks on it, including pegboard ring transfer, matchboard object transfer, needle threading of rings, and the ring and rail task. One week later subjects completed 4 similar tasks using the da Vinci® robot. Subjects were assessed on total task time and total errors using the built-in scoring algorithm and manual scoring for the dV-Trainer and the da Vinci robot, respectively. RESULTS: Seven experienced and 13 novice robotic surgeons were included in the study. Experienced surgeons were defined by greater than 50 hours of clinical robotic console time. Of novice robotic surgeons 77% ranked the dV-Trainer as a realistic training platform and 71% of experienced robotic surgeons ranked it as useful for resident training. Experienced robotic surgeons outperformed novices in many dV-Trainer and da Vinci robot exercises, particularly in the number of errors. On pooled data analysis dV-Trainer total task time and total errors correlated with da Vinci robot total task time and total errors (p = 0.026 and 0.011, respectively). CONCLUSIONS: This study confirms the face, content, construct and concurrent validity of the dV-Trainer, which may have a potential role as an assessment tool.

A history and evolution of laparoscopic nephrectomy: perspectives from the past and future directions in the surgical management of renal tumors.

June 25, 2010 marks the twentieth anniversary of the first clinical laparoscopic nephrectomy. Since the advent of this procedure a paradigm shift toward minimally invasive options for urological surgery has been witnessed, resulting in rapid technological innovations and improved patient outcomes. A history of the minimally invasive surgical management of renal masses is presented with a focus on laparoscopic nephrectomy.

Best practices for robotic surgery training and credentialing.

PURPOSE: With the rapid and widespread adoption of robotics in surgery, the minimally invasive surgical landscape has changed markedly within the last half decade. This change has had a significant impact on patients, surgeons and surgical trainees. This is no more apparent than in the field of urology. As with the advent of any new surgical technology, it is imperative that we develop comprehensive and responsible training and credentialing initiatives to ensure surgical outcomes and patient safety are not compromised during the learning process. MATERIALS AND METHODS: A literature search was conducted on surgical training curricula as well as robotic surgery training and credentialing to provide best practice recommendations for the development of a robotic surgery training curriculum and credentialing process. RESULTS: For trainees to attain the requisite knowledge and skills to provide safe and effective patient care, surgical training in robotics should involve a structured, competency based curriculum that allows the trainee to progress in a graduated fashion. This structured curriculum should involve preclinical and clinical components to facilitate the proper adoption and application of this new technology. Robotic surgery credentialing should involve an expert determined, standardized educational process, including a minimum criterion of proficiency. CONCLUSIONS: Rather than being based on a set number of completed cases, robotic surgery credentialing should involve the demonstration of proficiency and safety in executing basic robotic skills and procedural tasks. In addition, the accreditation process should be iterative to ensure accountability to the patient.

Sprayed fibrin sealant as the sole hemostatic agent for porcine laparoscopic partial nephrectomy.

PURPOSE: Tisseel® is used to control minor bleeding during laparoscopic procedures. The DuploSpray MIS™ spray system allows thin, even application over a larger surface area. We use sprayed Tisseel as the sole agent to control hemorrhage and seal the renal collecting system after severe porcine laparoscopic partial nephrectomy. METHODS AND MATERIALS: We performed staged bilateral severe laparoscopic partial nephrectomy in 12 Yucatan pigs using a longitudinal cut from upper to lower pole through the entire collecting system. In each pig 1 kidney was harvested immediately while the other was harvested after 4 weeks. After hilar clamping laparoscopic partial nephrectomy was done with cold scissors in 6 pigs while LigaSure™ was used in the other 6. Sprayed Tisseel was applied, and bleeding and urinary leakage were evaluated. Additional Tisseel was applied for repeat bleeding. We performed retrograde pyelogram (chronic) and burst pressure testing of the arterial and collecting systems. RESULTS: All animals survived 4 weeks. One urinoma was seen on retrograde pyelogram in the cold cut group. Average hilar clamp time was similar in the acute and chronic study arms. Average estimated blood loss was significantly less in the LigaSure group (p = 0.0045). Average arterial burst pressure was significantly different in the chronic and acute groups (605.8 vs 350.4 mm Hg, p = 0.008) but average collecting system burst pressure was similar (186.3 and 149.5 mm Hg, respectively). CONCLUSIONS: Sprayed Tisseel without suturing effectively sealed the arterial and collecting system after severe laparoscopic partial nephrectomy in the porcine model.

Prospective randomized trial of three different methods of nephrostomy tract closure after percutaneous nephrolithotripsy.

OBJECTIVE: • To evaluate the safety and efficacy of 'tubeless' nephrostomy tract closure in reducing postoperative morbidity after percutaneous nephrolithotomy (PCNL). MATERIALS AND METHODS: • In all, 31 patients undergoing PCNL were randomized into three groups, each with a different method of nephrostomy tract closure: using either a gelatin matrix haemostatic sealant (FloSeal), fascial stitch or Cope loop nephrostomy tube. • We compared operative time, estimated blood loss (EBL), postoperative stay, analgaesics use, changes in creatinine and haemoglobin levels, and stone clearance rate, as well as postoperative short-form (SF)-36 quality-of-life and pain analogue scores at five different time points after surgery. • All data were analysed using a one-way anova test. • A repeated measures anova test was used selectively to assess the progression of SF-36 and pain analogue scores. RESULTS: • The preoperative variables operative time, EBL, postoperative stay (P = 0.45), analgaesia use (P = 0.79), changes in creatinine (P = 0.28) and haemoglobin (P = 0.09) levels, and postoperative SF-36 scores were not significantly different. • In contrast, the differences in analogue pain scales at 1 week after surgery (P = 0.02) and the trends of analogue pain score progression (P = 0.03) were statistically significant. • Three patients underwent second-look procedures for residual stones and there was one case of postoperative pyelonephritis in a multiple sclerosis patient. CONCLUSIONS: • The Cope loop closure patients recovered fastest, while FloSeal closure patients experienced initial increase in pain followed by resolution at 1 month. • As a result of the small study group sizes, it is difficult to show any significant difference in postoperative pain, especially in long-term follow-up; further clinical evaluation is necessary.

Laparoscopic partial nephrectomy: six degrees of haemostasis.

OBJECTIVE: • To describe six steps for haemostasis and collecting system closure ('six degrees of haemostasis') that are reproducible and that minimize the two most concerning complications of laparoscopic partial nephrectomy: haemorrhage and urine leakage. METHODS: • A retrospective study of 23 consecutive laparoscopic partial nephrectomy cases performed by a single surgeon between 2005 and 2008 using the 'six degrees of haemostasis' was carried out. RESULTS: • There were no cases of intraoperative, postoperative or delayed bleeding. • There were no cases of urine leakage. CONCLUSION: • The 'six degrees of haemostasis' technique for laparoscopic partial nephrectomy described in the present study provides a reliable and reproducible method to reassure the surgeon of haemostasis and provide a decreased risk of urine leakage.

Impact of a laparoscopic renal surgery mini-fellowship program on postgraduate urologist practice patterns at 3-year followup.

PURPOSE: To assist practicing urologists incorporate laparoscopic renal surgery into their practice we established a 5-day mini-fellowship program with a mentor, preceptor and a potential proctor at our institution. We report the impact of our mini-fellowship program at 3-year followup. MATERIALS AND METHODS: A total of 106 urologists underwent laparoscopic ablative (44) or laparoscopic reconstructive (62) renal surgery training. The 1:2 teacher-to-attendee experience included tutorial sessions, hands-on inanimate and animate skills training, and clinical case observations. Participants were asked to complete a detailed questionnaire on laparoscopic practice patterns 1, 2 and 3 years after the mini-fellowship. RESULTS: The questionnaire response rate at 1 to 3 years was 77%, 65% and 68%, respectively. Of responders 72%, 71% and 71% performed laparoscopic renal surgery at 1 to 3 years, respectively. Of the 106 participants 32 (39%) had previous laparoscopic experience, including 78% who responded to the questionnaire at 3 years. Of those surgeons there was an increase in the practice of laparoscopic radical nephrectomy (88% vs 72%), nephroureterectomy (56% vs 13%), pyeloplasty (40% vs 6%) and partial nephrectomy (32% vs 6%) at 3 years. Of the 106 participants 74 (70%) were laparoscopy naïve, including 48 (65%) who responded to the questionnaire at 3 years. The take rate in this group was 76%, 52%, 34% and 23% for laparoscopic radical nephrectomy, nephroureterectomy, pyeloplasty and partial nephrectomy, respectively. Of the participants 90% indicated that they would recommend this training to a colleague. CONCLUSIONS: An intensive 5-day laparoscopic ablative and reconstructive renal surgery course enabled postgraduate urologists to effectively introduce and expand the volume and breadth of their laparoscopic renal surgery practice.

In vitro, ex vivo and in vivo isotherms for renal cryotherapy.

PURPOSE: Preoperative planning for renal cryotherapy is based on isotherms established in gel. We replicated gel isotherms and correlated them with ex vivo and in vivo isotherms in a porcine model. MATERIALS AND METHODS: PERC-17 CryoProbes (1.7 mm) and IceRods (1.47 mm) underwent trials in gel, ex vivo and in vivo porcine kidneys. Temperatures were recorded at 13 predetermined locations with multipoint thermal sensors. RESULTS: At the cryoprobe temperatures were not significantly different along the probe in any medium for either system (p = 0.0947 to 0.9609). However, away from the probe ex vivo and in vivo trials showed warmer temperatures toward the cryoprobe tip for each system (p = 0.0003 to 0.2141). Mean +/- SE temperature 5 mm distal to the cryoprobe tip in vivo was 19.2C +/- 16.1C for CryoProbes and 27.3C +/- 11.2C for IceRods. Temperatures were consistently colder with CryoProbes than with IceRods in gel (p <0.00005), ex vivo (p <0.00005) and in vivo (p = 0.0014). At almost all sites temperatures were significantly colder in gel and in ex vivo kidney than in in vivo kidney for CryoProbes (p = 0.0107 and 0.0008, respectively) and for IceRods (each p <0.00005). CONCLUSIONS: Gel and ex vivo isotherms do not predict the in vivo pattern of freezing. Thus, they should not be used for preoperative planning. The cryoprobe should be passed 5 mm beyond the tumor border to achieve suitably cold temperatures. Multipoint thermal sensor probes are recommended to record actual temperature during renal cryotherapy.

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.

Long-term impact of a robot assisted laparoscopic prostatectomy mini fellowship training program on postgraduate urological practice patterns.

PURPOSE: Robot assisted laparoscopic prostatectomy has stimulated a great deal of interest among urologists. We evaluated whether a mini fellowship for robot assisted laparoscopic prostatectomy would enable postgraduate urologists to incorporate this new procedure into clinical practice. MATERIALS AND METHODS: From July 2003 to July 2006, 47 urologists participated in the robot assisted laparoscopic prostatectomy mini fellowship program. The 5-day course had a 1:2 faculty-to-attendee ratio. The curriculum included lectures, tutorials, surgical case observation, and inanimate, animate and cadaveric robotic skill training. Questionnaires assessing practice patterns 1, 2 and 3 years after the mini fellowship program were analyzed. RESULTS: One, 2 and 3 years after the program the response rate to the questionnaires was 89% (42 of 47 participants), 91% (32 of 35) and 88% (21 of 24), respectively. The percent of participants performing robot assisted laparoscopic prostatectomy in years 1 to 3 after the mini fellowship was 78% (33 of 42), 78% (25 of 32) and 86% (18 of 21), respectively. Among the surgeons performing the procedure there was a progressive increase in the number of cases each year with increasing time since the mini fellowship training. In the 3 attendees not performing the procedure 3 years after the mini fellowship training the reasons were lack of a robot, other partners performing it and a feeling of insufficient training to incorporate the procedure into clinical practice in 1 each. One, 2 and 3 years following the mini fellowship training program 83%, 84% and 90% of partnered attendees were performing robot assisted laparoscopic prostatectomy, while only 67%, 56% and 78% of solo attendees, respectively, were performing it at the same followup years. CONCLUSIONS: An intensive, dedicated 5-day educational course focused on learning robot assisted laparoscopic prostatectomy enabled most participants to successfully incorporate and maintain this procedure in clinical practice in the short term and long term.

Preliminary study of virtual reality and model simulation for learning laparoscopic suturing skills.

PURPOSE: Repetitive practice of laparoscopic suturing and knot tying can facilitate surgeon proficiency in performing this reconstructive technique. We compared a silicone model and pelvic trainer to a virtual reality simulator in the learning of laparoscopic suturing and knot tying by laparoscopically naïve medical students, and evaluated the subsequent performance of porcine laparoscopic cystorrhaphy. MATERIALS AND METHODS: A total of 20 medical students underwent a 1-hour didactic session with video demonstration of laparoscopic suturing and knot tying by an expert laparoscopic surgeon. The students were randomized to a pelvic trainer (10) or virtual reality simulator (10) for a minimum of 2 hours of laparoscopic suturing and knot tying training. Within 1 week of the training session the medical students performed laparoscopic closure of a 2 cm cystotomy in a porcine model. Objective structured assessment of technical skills for laparoscopic cystorrhaphy was performed at the procedure by laparoscopic surgeons blinded to the medical student training format. A video of the procedure was evaluated with an objective structured assessment of technical skills by an expert laparoscopic surgeon blinded to medical student identity and training format. The medical students completed an evaluation questionnaire regarding the training format after the laparoscopic cystorrhaphy. RESULTS: All students were able to complete the laparoscopic cystorrhaphy. There was no difference between the pelvic trainer and virtual reality groups in mean +/- SD time to perform the porcine cystorrhaphy at 40 +/- 15 vs 41 +/- 10 minutes (p = 0.87) or the objective structured assessment of technical skills score of 8.8 +/- 2.3 vs 8.2 +/- 2.2 (p = 0.24), respectively. Bladder leak occurred in 3 (30%) of the pelvic trainer trained and 6 (60%) of the virtual reality trained medical student laparoscopic cystorrhaphy procedures (Fisher exact test p = 0.37). The only significant difference between the 2 groups was that 4 virtual reality trained medical students considered the training session too short compared to none of those trained on the pelvic trainer (p = 0.04). CONCLUSIONS: There is no significant difference between the pelvic trainer and virtual reality trained medical students in proficiency to perform laparoscopic cystorrhaphy in a pig model, although both groups require considerably more training before performing this procedure clinically. The pelvic trainer training may be more user-friendly for the novice surgeon to begin learning these challenging laparoscopic skills.

Preliminary evaluation of a genitourinary skills training curriculum for medical students.

PURPOSE: Basic urology training in medical school is considered important for many medical and surgical disciplines. We developed a 2-day intensive genitourinary skills training curriculum for medical students beginning their clinical clerkship training years and evaluated the initial experience with this program. MATERIALS AND METHODS: All 94 third-year medical students at the University of California, Irvine were required to participate in a 5.5-hour genitourinary examination skills training program. The teaching course included 1.5 hours of didactic lecture and video presentation with questions and answers, followed by 5, 45-minute hands-on stations including male Foley catheter placement, female Foley catheter placement, testicular examination and digital rectal examination training with a standardized patient, virtual reality cystourethroscopy and, lastly, a urologist led tutorial of abnormal genitourinary findings. The students completed questionnaires before and after the course concerning their experience. At the end of the course the students rated the usefulness of each part of the curriculum and evaluated the faculty. In addition, they were required to complete a multiple choice examination that included 4 genitourinary specific questions. RESULTS: All 94 medical students completed the genitourinary skills training course. Before the course less than 10% of students reported comfort with genitourinary skills, including testicular examination (5%), digital rectal examination (10%), male Foley catheter placement and female Foley catheter placement (2%). Following the course the comfort level improved in all parameters of digital rectal examination (100%) and testicular examination, male Foley catheter placement and female Foley catheter placement (98%). The students rated in the order of most to least useful training 1) standardized patient for testicular examination and digital rectal examination teaching, 2) male Foley catheter placement and female Foley catheter placement training, 3) didactic lecture, 4) tutorial of abnormal genitourinary examination findings and 5) virtual reality cystourethroscopy. On the examination questions following the course 80% to 98% of the class answered each urology content question correctly. CONCLUSIONS: An intensive skills training curriculum significantly improved medical student comfort and knowledge with regard to basic genitourinary skills including testicular examination, rectal examination, and Foley catheter placement in the male and female patient. Further followup will be performed to determine the application of these skills during clinical clerkship rotations.

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.

Laboratory evaluation of laparoscopic vascular clamps using a load-cell device--are all clamps the same?

PURPOSE: The use of effective vascular clamps is key to successful laparoscopic partial nephrectomy. Based on our clinical experience the occlusive capabilities of vascular clamps appeared to be quite variable. We compared the occlusive force of currently available laparoscopic vascular clamps. MATERIALS AND METHODS: The jaw force of 3 laparoscopic vascular clamps (Aesculap(R), Klein Surgical Systems, San Antonio, Texas and Karl Storztrade mark) were measured by clamping a 2.2 mm compression load cell (Interface Advanced Force Measurement, Scottsdale, Arizona) in pound-force. The variables tested were handheld Satinsky, DeBakey and Storz clamps vs bulldog clamps, proximal, middle and distal application position, new vs used bulldog clamps and new vs used Satinsky handheld clamps. In addition, handheld clamps were tested according to the force generated by the notches in the locking mechanism. Force retention was also determined for all instruments after clamping a 20Fr latex rubber catheter for an hour. Finally, leak pressure studies were performed using a harvested porcine artery to determine the relationship between jaw force and leak pressure in mm Hg of bulldog and Satinsky handheld clamps using a pressure gauge (Cole-Parmer(R)). RESULTS: Handheld vascular clamps provided greater force than bulldog clamps. The proximal position closest to the hinge provided the greatest force across all instruments. Compared to new clamps the 2-year-old Klein Surgical Systems bulldog clamps showed a greater than 40% decrease in jaw force at all positions, whereas the 3-year-old Aesculap bulldog clamps decreased in jaw force by less than 9% at all positions. The 2-year-old Satinsky handheld clamps showed a decrease of 20%, 9% and 0% at the distal, middle and proximal jaw positions, respectively. Also, there was a positive correlation between force and the number of notches applied in handheld clamps. In addition, all instruments maintained jaw force after 1 hour of continuous clamping. Finally, leak pressure studies performed with used clamps showed that Klein Surgical Systems bulldog, Aesculap bulldog and Satinsky handheld clamps leaked at a pressure of 153 to 223, 465 to 795 and 1,500 to 2,600 mm Hg, respectively. CONCLUSIONS: Vascular clamps have varying occlusive forces according to clamp type, manufacturer, jaw and teeth characteristics, jaw clamping position and duration of use. However, across all clamps the jaw force was greatest at the proximal position. This is most important when applying laparoscopic bulldog clamps. In contrast, all handheld vascular clamps generated higher force than intracorporeal bulldog clamps. At 1 notch the handheld vascular clamps provided supraphysiological occlusion force regardless of position or manufacturer.

Histological evaluation of cold versus hot cutting: clinical impact on margin status for laparoscopic partial nephrectomy.

PURPOSE: While most laparoscopic nephron sparing surgery is performed using cold scissors, energy based devices may also be used. A criticism of this approach has been the potential thermal destruction of the cellular architecture at the tumor margin, precluding the ability to accurately determine whether tumor cells are present. We clinically characterized the histological appearance of tumor margins excised with cold scissors, and bipolar and ultrasonic shears. MATERIALS AND METHODS: We evaluated 40 renal mass excisions performed by a total of 3 urologists at our institution between February 2003 and March 2007. There were 10 bipolar (5 mm LigaSure), 20 ultrasonic (Harmonic Scalpel) and 10 cold excisions. All slides were randomly evaluated twice by a single pathologist blinded to surgeon and excision method. Histological interpretation of the margin was scored as clear vs indeterminate. Variables, including margin fragmentation, artifact, extravascular blood clot, parenchymal hemorrhage, capillary congestion and vessel sealing, were assessed and scored on a scale of 0 to 3, that is 0--none, 1-1% to 25%, 2-26% to 50% and 3--greater than 50%. RESULTS: The pathologist was able to confidently identify cells at the margin as being malignant or benign in all cases. Histologically the ultrasonic scalpel demonstrated increased fragmentation and extravascular blood clotting compared with those of the other cutting methods (p <0.025 and <0.026, respectively). The ultrasonic scalpel also showed increased artifact depth compared to that of cold cutting (p <0.001). There were no statistical differences between the groups regarding margin artifact, parenchymal hemorrhage or capillary congestion. No statistical significance was observed in any variables between bipolar and cold cutting. CONCLUSIONS: Despite some degree of cellular damage the ability to determine whether cells at the margin were benign or malignant was not affected by using an energy based bipolar or ultrasonic device.

Percutaneous and laparoscopic cryoablation of small renal masses.

PURPOSE: We reviewed our 4-year experience with percutaneous cryoablation and laparoscopy for treating small renal masses. MATERIALS AND METHODS: After institutional review board approval we retrospectively analyzed renal cryoablation procedures performed between March 2003 and October 2007. An in-depth analysis was performed concerning demographics, hospital course and short-term outcome with respect to percutaneous vs laparoscopic cryoablation. RESULTS: A total of 37 patients underwent treatment for 43 renal masses. Of the 37 patients 19 underwent laparoscopic cryoablation (24 tumors) and 18 underwent percutaneous cryoablation (19 tumors) using computerized tomography fluoroscopy. For percutaneous cryoablation a saline instillation was used in 58% of cases to move nonrenal vital structures away from the targeted renal mass. There were 5 cases of hemorrhage requiring transfusion, all of which were associated with the use of multiple cryoprobes. The transfusion rate in the percutaneous and laparoscopic cryoablation groups was 11.1% and 27.8%, respectively. Operative time was significantly longer in the laparoscopic cryoablation group compared to the percutaneous cryoablation group at 147 (range 89 to 209) vs 250.2 (range 151 to 360) minutes, respectively. The overall complication rate (including transfusion) was lower in the percutaneous cryoablation group compared to the laparoscopic cryoablation group (4 of 18 [22.2%] vs 8 of 20 [40%], respectively). Hospital stay was significantly shorter in the percutaneous vs laparoscopic cryoablation group at 1.3 vs 3.1 days, p <0.0001, respectively. Narcotic use in the percutaneous cryoablation group was more than half that used by the laparoscopic cryoablation group (5.1 vs 17.8 mg, p = 0.03, respectively). Among patients with biopsy proven renal cell carcinoma during a median followup of 11.4 and 13.4 months in the percutaneous and laparoscopic cryoablation groups, cancer specific survival was 100% and 100%, respectively, and the treatment failure rate was 5.3% and 4.2%, respectively. CONCLUSIONS: Percutaneous cryoablation is an efficient, minimally morbid method for the treatment of small renal masses and it appears to be superior to the laparoscopic approach. Short-term followup has shown no difference in tumor recurrence or need for re-treatment. Of note, hemorrhage was solely associated with the use of multiple probes.