Development of a novel iPad-based laparoscopic trainer and comparison with a standard laparoscopic trainer for basic laparoscopic skills testing

INTRODUCTION

We developed the iTrainer (iT) as a portable laparoscopic trainer, which incorporates the iPad tablet. We then compared the iT with a standard pelvic trainer (SPT) to assess surgical skills as well as its image quality, resolution, brightness, comfort, and overall performance.

MATERIALS AND METHODS

We designed and constructed the iT to be compatible with the Apple iPad 3 and standard laparoscopic instruments. Participants were assigned to perform the thread-the-loops task on both trainers and were prospectively randomized to start on either the iT or the SPT. Each participant was allowed a 2-minute warm-up before the 2-minute testing period. We scored participants using the product of skill quality (0-4 scale) and quantity of loops threaded (0-10 scale). Participants then rated each trainer on image quality, resolution, brightness, comfort, and overall performance on a 5-point Likert scale.

RESULTS

A total of 45 subjects including 10 undergraduates, 10 medical students, 10 general surgery and urology residents, and 15 experts (fellows and attending surgeons) participated in this study. There was no significant difference between thread-the-loops task scores completed on the iT when compared with the SPT for all groups tested (p > 0.05) with the exception of the medical student group, who performed better on the SPT (p < 0.05). On evaluation of each trainer, participants rated the iT as having superior image quality and resolution when compared with the SPT (p < 0.05) but rated the SPT higher in overall performance (p < 0.05). Brightness and comfort were rated similarly for both trainers.

CONCLUSIONS

We have demonstrated face validity and criterion validity for the thread-the-loops task on the iT. The iT rated superior in image quality and resolution but inferior in overall performance compared with the SPT. The iT provides trainees a unique advantage over SPT as an additional resource to laparoscopic training as it is inexpensive, portable, and can be readily available for training.

Evaluation of the impact of three-dimensional vision on laparoscopic performance

INTRODUCTION

Recent technological advancements have led to the introduction of new three-dimensional (3D) cameras in laparoscopic surgery. The 3D view has been touted as useful during robotic surgery, however, there has been limited investigation into the utility of 3D in laparoscopy.

MATERIALS AND METHODS

We performed a prospective, randomized crossover trial comparing a 0° 3D camera with a conventional 0° two-dimensional (2D) camera using a high definition monitor (Karl Storz, Tuttlingen, Germany). All participants completed six standardized basic skills tasks. Quality testing scores were measured by the number of drops, grasping attempts, and precision of needle entry and exiting. Additionally, resolution, color distribution, depth of field and distortion were measured using optical test targets.

RESULTS

In this pilot study, we evaluated 10 medical students, 7 residents, and 7 expert surgeons. There was a significant difference in the performance in all the six skill tasks, for the three levels of surgical expertise and training levels in 2D vs 3D except for the cut the line quality score and the peg transfer quality score. Adjusting for the training level, 3D camera image results were superior for the number of rings left (p=0.041), ring transfer quality score (p=0.046), thread the rings (no. of rings) (p=0.0004), and thread the rings quality score (p=0.0002). The 3D camera image was also superior for knot tying (quality score) (p=0.004), peg transfer (time in seconds) (p=0.047), peg transfer pegs left (p=0.012), and for peg transfer quality score (p=0.001). The 3D camera system showed significantly less distortion (p=0.0008), a higher depth of field (p=0.0004) compared with the 2D camera system.

CONCLUSION

3D laparoscopic camera equipment results in a significant improvement in depth perception, spatial location, and precision of surgical performance compared with the conventional 2D camera equipment. With this improved quality of vision, even expert laparoscopic surgeons may benefit from 3D imaging.

Robotic surgical simulation

Robotic surgery has undergone exponential growth and has ever developing utilization. The explosion of new technologies and regulation have led to challenges in training surgeons who desire this skill set. We review the current state of robotic simulation and incorporation of simulation into surgical training curricula. In addition to the literature review, results of a questionnaire survey study of 21 expert and novice surgeons attending a Urologic Robotic Oncology conference using 3 different robotic skill simulation devices are discussed. An increasing number of robotic surgery simulators have had some degree of validation study of their use in surgical education curricula and proficiency testing. Although simulators are advantageous, confirmation of construct and predictive validity of robotic simulators and their reliability as a training tool will be necessary before they are integrated into the surgical credentialing process.

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.

Evaluation of potential distractors in the urology operating room

BACKGROUND AND PURPOSE

Surgical outcomes depend on patient and disease-related factors, as well as the technical skill of the surgeon. Various distractions in the operating room (OR) environment have been shown to negatively impact a surgeon's performance. A survey was conducted with the objective to evaluate and characterize distractions during urologic surgery.

METHODS

An Internet-based survey was distributed to 2057 international urologists via email between April and October 2011; questions focused on a variety of disruptive factors postulated to have a negative impact on surgical performance.

RESULTS

Of the 523 (25%) respondents, 58% practiced in North America, 42% were from an academic institution, and 68% had completed a clinical fellowship. In an average year, 83% reported having operated at least once while sleep deprived, 84% when significantly ill, 55% with a musculoskeletal injury, and 65% under significant social stress. Up to 38% reported that on at least one occasion, such "internal distractions" had significantly affected surgical performance and 14% perceived that at least one surgical complication was caused mainly by an internal distraction. Less than 50% had ever cancelled surgery because of an internal distraction. Music was routinely played in the OR by 57% of respondents, >67% reported answering pages and discussing consults while operating, and 25% reported "commonly" working with scrub nurses/techs that were unfamiliar with the procedure and/or instruments. Only 44% had consistent individual(s) assisting, and 27% reported that the scrub nurse/tech would "commonly" scrub out during a critical portion of the procedure. Overall, 14.5% reported that at least one complication had occurred mainly because of such "external" or "interactive" distractions.

CONCLUSIONS

Urologists face various distractions in the OR that can negatively impact surgical performance, potentially compromising patient outcomes and safety. Further studies are needed to elucidate the true impact of such distractions and to develop strategies to mitigate their effects.

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.

Surgical skills acquisition among left-handed trainees-true inferiority or unfair assessment: a preliminary study

INTRODUCTION

Studies involving the formal assessment of surgical skills have often reported inferior abilities among left-handed surgical trainees (LHT). Most surgical training curricula and assessment methods, however, are inherently geared toward right-handed trainees (RHT); potentially placing LHT at both a training and assessment disadvantage. We evaluated the effect of a hand dominance-based curriculum for acquisition of basic suturing and knot tying skills among medical students.

METHODS

After Institutional Review Board approval, first- and second-year medical students from the University of California, Irvine School of Medicine were recruited to participate in a basic suturing and knot tying skills course. Consenting students were randomized to either a left-handed curriculum or a right-handed curriculum consisting of (1) a 30-minute introductory video and (2) a 2-hour instructor-led, hands-on training session on basic suturing and knot tying. All instructional methods, instruments, and instructors were exclusively right-handed or left-handed for the right-handed curriculum or left-handed curriculum, respectively. Students were assessed on the performance of 2 suturing tasks, continuous running suturing and instrument knot tying, and performance assessments were conducted both immediately and 2 weeks posttraining.

RESULTS

A total of 19 students completed the training course and both assessments (8 LHT, 11 RHT). Students randomized to a curriculum "concordant" with their hand dominance performed significantly better than those randomized to a "discordant" curriculum on both tasks (p < 0.01). This difference was found at both immediate and 2 weeks posttraining assessments. Within concordant and discordant groups, there were no significant differences between LHT and RHT.

CONCLUSIONS

This preliminary study demonstrates that medical students, both LHT and RHT, immersed in a training environment that is discordant with their hand dominance might have inferior acquisition of basic suturing and knot tying skills.

Validation, correlation, and comparison of the da Vinci trainer(™) and the daVinci surgical skills simulator(™) using the Mimic(™) software for urologic robotic surgical education

PURPOSE

Virtual reality simulators with self-assessment software may assist novice robotic surgeons to augment direct proctoring in robotic surgical skill acquisition. We compare and correlate the da Vinci Trainer™ (dVT) and da Vinci Surgical Skills Simulators (dVSSS) in subjects with varying robotic experience.

MATERIALS AND METHODS

Students, urology residents, fellows, and practicing urologists with varying robotic experience were enrolled after local institutional review board approval. Three virtual reality tasks were preformed in sequential order (pegboard 1, pegboard 2, and tubes)-initially on the dVSSS and then on the dVT. The Mimic™ software used on both systems provides raw values and percent scores that were used in statistical evaluation. Statistical analysis was performed with the two-tailed independent t-test, analysis of variance, Tukey, and the Pearson rank correlation coefficient where appropriate.

RESULTS

Thirty-two participants were recruited for this study and separated into five groups based on robotic surgery experience. In regards to construct validity, both simulators were able to differentiate differences among the five robotic surgery experience groups in the tubes suturing task (p≤0.00). Sixty-seven percent (4/6) robotic experts thought that surgical simulation should be implemented in residency training. The overall cohort considered both platforms easy to learn and use.

CONCLUSIONS

Although performance scores were less in the dVT compared with the dVSSS, both simulators demonstrate good content and construct validity. The simulators appear to be equivalent for assessing surgeon proficiency and either can be used for robotic skills training with self-assessment feedback.

Positive correlation between motion analysis data on the LapMentor virtual reality laparoscopic surgical simulator and the results from videotape assessment of real laparoscopic surgeries

PURPOSE

We studied the construct validity of the LapMentor, a virtual reality laparoscopic surgical simulator, and the correlation between the data collected on the LapMentor and the results of video assessment of real laparoscopic surgeries.

MATERIALS AND METHODS

Ninety-two urologists were tested on basic skill tasks No. 3 (SK3) to No. 8 (SK8) on the LapMentor. They were divided into three groups: Group A (n=25) had no experience with laparoscopic surgeries as a chief surgeon; group B (n=33) had <35 experiences; and group C (n=34) had ≥35 experiences. Group scores on the accuracy, efficacy, and time of the tasks were compared. Forty physicians with ≥20 experiences supplied unedited videotapes showing a laparoscopic nephrectomy or an adrenalectomy in its entirety, and the videos were assessed in a blinded fashion by expert referees. Correlations between the videotape score (VS) and the performances on the LapMentor were analyzed.

RESULTS

Group C showed significantly better outcomes than group A in the accuracy (SK5) (P=0.013), efficacy (SK8) (P=0.014), or speed (SKs 3 and 8) (P=0.009 and P=0.002, respectively) of the performances of LapMentor. Group B showed significantly better outcomes than group A in the speed and efficacy of the performances in SK8 (P=0.011 and P=0.029, respectively). Analyses of motion analysis data of LapMentor demonstrated that smooth and ideal movement of instruments is more important than speed of the movement of instruments to achieve accurate performances in each task. Multiple linear regression analysis indicated that the average score of the accuracy in SK4, 5, and 8 had significant positive correlation with VS (P=0.01).

CONCLUSIONS

This study demonstrated the construct and predictive validity of the LapMentor basic skill tasks, supporting their possible usefulness for the preclinical evaluation of laparoscopic skills.

Medical students pursuing surgical fields have no greater innate motor dexterity than those pursuing nonsurgical fields

INTRODUCTION

Medical students pursue different career paths based on a variety of factors. We sought to examine the impact of innate manual dexterity, both perceived and objective, on the career interests of medical students.

METHODS

Third-year medical students from the University of California, Irvine were recruited for this study. Subjects completed a pretest questionnaire followed by assessment of gross and fine motor dexterity using the Purdue Pegboard test. A total of 6 independent trials were performed, 3 for each hand. The scores were recorded as an integer value between 0 and 25. A statistical analysis was performed using student t tests, the Fischer exact test, or the χ(2) test, where appropriate.

RESULTS

A total of 100 students completed the questionnaire while 58 completed the dexterity testing. Students interested in a surgical field (SF) were similar in handedness, gender, video game exposure, and learning style as those interested in a nonsurgical field (NSF). In the SF group, "personal skill set" was reported as the most common factor influencing career selection, and "interest in disease process/patient population" was reported most commonly by NSF students (p = 0.015). Although a perceived innate manual dexterity was higher among SF students compared with NSF students (p = 0.032), no significant objective differences were found in right hand, left hand, or combined dexterity scores.

CONCLUSIONS

Perceived "personal skill set" may influence strongly a medical student's career choice. Despite greater perceived manual dexterity, students interested in an SF do not have greater objective innate manual dexterity than those interested in an NSF.

Preoperative warming up exercises improve laparoscopic operative times in an experienced laparoscopic surgeon

BACKGROUND AND PURPOSE

Performing warm-up exercises before athletic competition or stage performance is very common; however, most surgeons do not "warm up" before performing complex surgery. We analyzed the intraoperative effects of warming up before surgery in an experienced laparoscopic surgeon.

METHODS

A retrospective review of all laparoscopic partial (LPN) and radical nephrectomies (LRN) completed by an experienced laparoscopic surgeon (RVC) were analyzed according to whether warm-up exercises were performed before surgery. Routine warm-up consisted of 15 to 20 minutes of pelvic trainer suturing exercises (forehand and backhand sutures and knot tying), using both hands. Intraoperative and postoperative parameters were examined.

RESULTS

LRN and LPN subjects were well matched among the warm-up group and nonwarm-up group. Patients in the LPN warm-up group did have significantly larger tumors (3.7 cm vs 2.4 cm, P=0.02). Despite larger tumors, surgical time was significantly less in the warm-up group (227 min vs 281 min, P=0 .04), and total operating room time trended toward significance (320 min vs 371 min, P=0.0501). Similarly, in the LRN group, operative times and total operating room time was significantly less in the preoperative warm-up group (P=0.0068 and P=0.014, respectively). Intraoperative and postoperative complications, estimated blood loss, positive margin rate, warm ischemia time, length of stay, changes in hemoglobin and creatinine levels from baseline were not significantly different between the two groups.

CONCLUSION

Performing warm-up exercises before complex laparoscopic surgery may improve operative times and performance in the operating room, especially for complex laparoscopic surgeries.

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.

Laparoscopic warm-up exercises improve performance of senior-level trainees during laparoscopic renal surgery

BACKGROUND AND PURPOSE

Surgery is a high-stakes "performance." Yet, unlike athletes or musicians, surgeons do not engage in routine "warm-up" exercises before "performing" in the operating room. We study the impact of a preoperative warm-up exercise routine (POWER) on surgeon performance during laparoscopic surgery.

MATERIALS AND METHODS

Serving as their own controls, each subject performed two pairs of laparoscopic cases, each pair consisting of one case with POWER (+POWER) and one without (-POWER). Subjects were randomly assigned to +POWER or -POWER for the initial case of each pairing, and all cases were performed ≥ 1 week apart. POWER consisted of completing an electrocautery skill task on a virtual reality simulator and 15 minutes of laparoscopic suturing and knot tying in a pelvic box trainer. For each case, cognitive, psychomotor, and technical performance data were collected during two different tasks: mobilization of the colon (MC) and intracorporeal suturing and knot tying (iSKT). Statistical analysis was performed using SYSTAT v11.0.

RESULTS

A total of 28 study cases (14+POWER, 14-POWER) were performed by seven different subjects. Cognitive and psychomotor performance (attention, distraction, workload, spatial reasoning, movement smoothness, posture stability) were found to be significantly better in the +POWER group (P ≤ 0.05) and technical performance, as scored by two blinded laparoscopic experts, was found to be better in the +POWER group for MC (P=0.04) but not iSKT (P=0.92). Technical scores demonstrated excellent reliability using our assessment tool (Cronbach ∝=0.88). Subject performance during POWER was also found to correlate with intraoperative performance scores.

CONCLUSIONS

Urologic trainees who perform a POWER approximately 1 hour before laparoscopic renal surgery demonstrate improved cognitive, psychomotor, and technical performance.

Are multiple cryoprobes additive or synergistic in renal cryotherapy?

OBJECTIVE

To investigate the relationship between multiple cryoprobes was investigated to determine whether they work in an additive or synergistic fashion in an in vivo animal model because 1.47 mm (17-gauge) cryoprobes have been introduced to the armamentarium for renal cryotherapy.

METHODS

Laparoscopic-guided percutaneous cryoablation was performed in both renal poles of 3 pigs using 3 IceRod cryoprobes. These 12 cryolesions were compared with 12 cryolesions using a single IceRod cryoprobe. Each cycle consisted of two 10-minute freeze cycles separated by a 5-minute thaw. The iceball volume was measured using intraoperative ultrasonography. The kidneys were harvested, and cryolesion surface area was calculated. The lesions were fixed and excised to obtain a volume measurement. Statistical analysis was used to compare the single probe results multiplied by 3 to the multiple probe group for iceball volume, cryolesion surface area, and cryolesion volume.

RESULTS

The iceball volume for the first freeze cycle for the single cryoprobe multiplied by 3 was 8.55 cm3 compared with 9.79 cm3 for the multiple cryoprobe group (P=.44) and 10.01 cm3 versus 16.58 cm3 for the second freeze (P=.03). The cryolesion volume for the single cryoprobe multiplied by 3 was 11.29 cm3 versus 14.75 cm3 for the multiple cyroprobe group (P=.06). The gross cryolesion surface area for the single cryoprobe multiplied by 3 was 13.14 cm2 versus 13.89 cm2 for the multiple probe group (P=.52).

CONCLUSION

The cryolesion created by 3 simultaneously activated 1.47-mm probes appears to be larger than that of an additive effect. The lesions were significantly larger as measured by ultrasonography and nearly so (P=.06) as measured by the gross cryolesion volume.

Introduction and validation of the American Urological Association Basic Laparoscopic Urologic Surgery skills curriculum

BACKGROUND AND PURPOSE

The Fundamentals of Laparoscopic Surgery (FLS(™)) skills curriculum has validity evidence supporting use for assessing laparoscopic skills for general surgeons. As charged by the American Urological Association (AUA) Laparoscopy, Robotic, and New Surgical Technology Committee, we sought to develop and validate a urology-specific FLS, referred to as the Basic Laparoscopic Urologic Surgery (BLUS(©)) skills curriculum. The psychomotor component consists of three existing FLS tasks and one new clip-applying task.

MATERIALS AND METHODS

An animate renal artery model was designed for a clip-applying skills task. We assessed the acceptability and construct validity of using BLUS for basic laparoscopic skills assessment for urologists. A cohort of practicing urologists, fellows, residents, and medical students completed the tasks at the AUA Annual Meetings in 2010 and 2011.

RESULTS

All exercises were acceptable and demonstrated excellent face and content validity (>4.5/5 on a five-point Likert scale). Practicing clinical urologists (N=81) outperformed residents and medical students (N=35) in time to completion of circle cut (P<0.01) and in keeping scissor tips toward the center of the circle (P<0.01). Practicing urologists who reported >3 laparoscopic procedures per week were faster at the peg-transfer exercise (P<0.05) and the cutting exercise (P<0.01) than those reporting one to two procedures. More errors were committed for clip-applying among practicing urologists who perform one to two laparoscopic procedures (1.24) vs. those who perform >3 procedures (0.57) per week (P<0.01).

CONCLUSIONS

All exercises including the novel clip-applying model demonstrated good acceptability and evidence of construct validity (face, content, concurrent and convergent validity) for assessment of basic laparoscopic skill for urologic surgeons.

Current minimally invasive practice patterns among postgraduate urologists

PURPOSE

To determine laparoscopic and robotic surgical practice patterns among current postgraduate urologists.

MATERIALS AND METHODS

There were 9,095 electronic surveys sent to practicing urologists with e-mail addresses registered with the American Urological Association.

RESULTS

Responses were received from 864 (9.5%) urologists; 84% report that laparoscopic or robotic procedures are performed in their practice. The highest training obtained by the primary laparoscopist was fellowship (31%), residency (23%), or 2- to 3-day courses (22%). Eighty-six percent report performance of laparoscopic nephrectomy in their practice, and 71% consider it the standard of care. Sixty-six percent of practices have access to at least one robotic unit, and 9% plan on purchasing one within a year. Attitudes toward robotics are favorable, with 80% indicating that it will increase in volume and potential procedures. Thirty-one percent state that robot-assisted prostatectomy is standard of care, while 50% believe this procedure looks promising. Respondents think that optimal training in minimally invasive techniques is fellowships (23%), minifellowships (23%), or hands-on courses (23%). Twenty-nine percent think that they were trained adequately in laparoscopy and robotics from residency, and 62% believe residents should be able to perform most laparoscopic procedures on completion of residency.

CONCLUSIONS

The practice and availability of laparoscopic and robotic procedures have increased since previous evaluations. Opinions regarding these techniques are favorable and optimistic. As the field of urology continues to see a growing demand for minimally invasive procedures, training of postgraduate urologists and residents remains essential.

Preliminary assessment of a renal tumor materials model

PURPOSE

To evaluate a materials model for laparoscopic guided cryotherapy or radiofrequency tissue ablation (RFA) of kidney tumors through expert surgeon assessment.

MATERIALS AND METHODS

During the inaugural American Urological Association 2010 Tissue Ablative course content, validity testing of a renal tumor model was undertaken. Five expert faculty in cryotherapy and RFA techniques for renal tumors performed laparoscopic ultrasonography (US) examination of the tumor model. They performed US guided placement and activation of the treatment probe into the tumor of the model. They completed a questionnaire and rated the quality of the renal tumor model on a 5 point Likert scale.

RESULTS

All of the subjects assigned a score of 5 of 5 on the Likert scale regarding the ability to identify the tumor with US, were able to deploy the ablative probe into the model under US guidance, and would recommend the use of this teaching model to residents or fellows. They thought that this tumor model was appropriate for teaching laparoscopic US imaging of a renal tumor during ablative treatment procedures, teaching and practicing laparoscopic US-guided cryotherapy, and teaching and practicing laparoscopic US-guided RFA.

CONCLUSION

We have developed a unique model that simulates small kidney tumors that can be used for training surgeons in ablative techniques.

Differences in grip forces among various robotic instruments and da Vinci surgical platforms

INTRODUCTION

The da Vinci surgical platform is becoming increasingly available and utilized. Due to the lack of haptic feedback, visual cues are necessary to estimate grip forces and tissue tensions during surgery. We directly measured the grip forces of robotic EndoWrist instruments using the three available da Vinci robotic surgical platforms.

METHODS

Robotic instruments were tested in the da Vinci S, Si, and Standard systems. A load cell was placed in a housing unit that allowed for measurement of the grip forces applied by the tip of each robotic instrument. Each instrument was tested six times, and all data were analyzed using Student's t-tests or analysis of variance when appropriate.

RESULTS

Slight differences in grip force were seen when the instrument was tested through 2 degrees of freedom at the tip (p = 0.02, analysis of variance) and when comparing a new instrument to an older instrument (p = 0.001 at the neutral position). There was no statistical difference in grip force between the left and right robotic arms. There was a broad range of grip forces between the various robotic instruments. The lowest grip force was registered in the double fenestrated grasper (2.26 ± 0.15 N), whereas the highest was seen in the Hem-o-lok clip applier (39.92 ± 0.89 N). In comparison to the S and Si, the Standard platform appeared to have significantly higher grip forces.

CONCLUSION

Different grip forces were observed among the various robotic instruments commonly used during urologic surgery and between the Standard and the S and Si platforms.

Laparoscopic transperitoneal nephrectomy for renal cancer: the University of California, Irvine, technique

The first laparoscopic nephrectomy for a renal tumor was performed 20 years ago at Washington University in St. Louis. Since that time, laparoscopic radical nephrectomy has become a standard of care when dealing with large renal tumors or other renal cancers not amenable to partial nephrectomy or ablative therapy. In the following article and videotape, the surgical technique of a laparoscopic radical nephrectomy is traced and the method of approach is documented. This approach is the one that is currently used at the University of California, Irvine, and reflects the authors' preferred operative technique.

First prize: Chitosan and the urothelial barrier: effects on ureteral intraluminal drug penetration and peristalsis

INTRODUCTION

Relaxing the ureter prior to endourologic procedures could ease instrument access. In an ex-vivo model, intraluminal nifedipine has been shown to relax the ureter. Chitosan is the deacetylation product of chitin and can alter bladder urothelium. This study examines the effect of nifedipine on peristalsis before and after pretreating the ureter with chitosan.

METHODS

Intact 4-cm tubular porcine ureteral segments were placed in a novel organ bath. To induce peristalsis, phenylephrine (10 μM) was added. Chitosan (0.5% [w/v], 30 minutes) or Krebs (control) was then used to treat the urothelium. The rate and amplitude of ureteral peristalsis was then measured. Intraluminal nifedipine (1 μM) was then added to the intraluminal reservoir. Peristaltic rate and amplitude and the time to aperistalsis were measured. Methylene blue was then added after treatment with chitosan or control to measure diffusion.

RESULTS

After Krebs pretreatment, intraluminal nifedipine (1 μM) significantly reduced peristaltic frequency (p = 0.0184) but did not stop peristalsis after 60 minutes of exposure in six trials. After chitosan, nifedipine (1 μM) stopped ureteral peristalsis within an average of 12.30 ± 4.72 minutes. Chitosan alone did not cause aperistalsis. Intraluminal methylene blue did not diffuse into the extraluminal bath after saline or chitosan pretreatment. Histological analysis of the ureter before and after pretreatment with chitosan showed no urothelial disruption.

CONCLUSIONS

By pretreating the intraluminal surface of the ureter with chitosan, nifedipine blocks ureteral peristalsis at low concentrations. Chitosan changes ureteral urothelial permeability without barrier disruption and has no observed effect on ureteral contraction.

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.

Bovine serum albumin glutaraldehyde for completely sutureless laparoscopic heminephrectomy in a survival porcine model

INTRODUCTION

Laparoscopic partial nephrectomy (LPN) has not received widespread clinical application because of its technical challenge. Bovine serum albumin glutaraldehyde (BSAG) is a hemostatic agent that is independent of the clotting cascade. We evaluated the use of BSAG as the sole agent for parenchymal and collecting system closure during LPN in a survival porcine model.

METHODS

Eighteen pigs underwent hilar clamping and LPN by longitudinal excision of the lateral one-third of the right kidney. The opened collecting system was covered with oxidized cellulose to prevent BSAG seepage into the urinary tract. BSAG was allowed to set for 10 or 5 minutes. Twelve animals underwent survival LPN BSAG only closure; six control pigs were acutely studied using saline. Urinary extravasation was evaluated by injection of furosemide and indigo carmine, and then evaluating the renal surface and bladder catheter drainage for dye. A subjective bleeding score was assigned after hilum unclamping. At 6 weeks, BSAG kidneys were harvested for burst pressure testing and histopathological analysis.

RESULTS

All 12 pigs survived for 6 weeks. No pigs had urinary extravasation. Mean percentage of kidney removed by weight was 19%. Mean warm ischemia time was 29 minutes. Five pigs required a second BSAG application to achieve a bleeding score of 0. Mean arterial and collecting system burst pressures were 301.8 and 322.4 mm Hg, respectively. Mean postoperative creatinine increase was 0.07 mg/dL.

CONCLUSION

BSAG for completely sutureless LPN in a survival porcine model was feasible.

Impact of pneumoperitoneum on renal cryotherapy

PURPOSE

Pneumoperitoneum is known to decrease blood flow to the kidney during laparoscopy. We investigated if this change in blood flow would increase the size of the cryolesion.

MATERIALS AND METHODS

Twelve Yorkshire swine underwent laparoscopy-guided percutaneous cryoablation of the upper and lower pole of each kidney at four randomized pneumoperitoneum pressures (10, 15, 20, and 25 mm Hg). Cryolesions were made with a 1.47-mm IceRod (Galil Medical, Plymouth Meeting, PA). Each site underwent two 10-minute freeze cycles separated by a 5-minute active thaw with pressurized helium gas. At the conclusion of each freeze cycle, the iceball volume was measured with intraoperative ultrasound. After completion of the four cryolesions, the kidneys were harvested, and the cryolesion surface area was calculated. The lesions were fixed in 10% buffered formalin and then excised with a 1-mm margin to obtain a volume measurement using fluid displacement.

RESULTS

Iceball volume was 3.41, 2.85, 3.44, and 2.36 cm(3) for freeze cycle 1 (p = 0.16) and 3.67, 3.34, 4.88, 3.95 cm(3) for freeze cycle 2 (p = 0.20) at 10, 15, 20, and 25 mm Hg, respectively. Cryolesion volume by fluid displacement was 4.06, 3.77, 3.97, and 3.93 cm(3) (p = 0.86) and cryolesion surface area was 4.55, 4.38, 4.39, and 4.20 cm(2) (p = 0.71) at 10, 15, 20, and 25 mm Hg, respectively.

CONCLUSIONS

In this study, pneumoperitoneum pressure between 10 and 25 mm Hg did not affect iceball size as measured by intraoperative ultrasound, cryolesion volume by fluid displacement, or cryolesion surface.

Laparoscopic renal surgery

Renal surgery, radical nephrectomy in particular, was historically the first application of laparoscopic techniques in urology. Since then, laparoscopy has been constantly evolving to claim its position in the surgical armamentarium of the urologist for the treatment of both malignant and benign diseases of the kidney and upper urinary tract. Over the years of increasing surgical experience and exposure, along with the evolution in the techniques and instruments used, laparoscopy has emerged as an equally effective and even more attractive alternative to open surgery for certain indications. The currently available load of literature is able to prove beyond any doubt the oncologic efficacy and minimal morbidity of laparoscopy for the treatment of renal masses in the form of radical or partial laparoscopic nephrectomy and nephroureterectomy. On the other hand, one can claim that laparoscopy is not far from replacing open surgery for the management of benign conditions such as ureteropelvic junction obstruction and donor nephrectomy. This review on laparoscopic renal surgery will discuss the major applications, indications, techniques and outcomes of laparoscopy in the contemporary management of benign and malignant renal diseases while focusing on its benefits and drawbacks compared to open surgery.

Evaluation of the outcomes of electrosurgical induced bowel injury treated with tissue glue/sealant versus sutured repair in a rabbit model

INTRODUCTION

Bowel injury is an uncommon, although potentially devastating, intraoperative laparoscopic complication. Questions have been raised about the possible use of a tissue adhesive to repair injured bowel. We compared glued repair and sutured repair of both large bowel (LB) and small bowel (SB) electrosurgical injuries in a rabbit model.

METHODS

Pneumoperitoneum was obtained, and four laparoscopic ports were placed in each of 48 New Zealand rabbits. The hook electrode was used in a specified manner to create an equal number of uniform full-thickness injuries to either the SB or the LB. Laparoscopic repair was performed with a 3-0 silk Lembert suture (LS), fibrin glue (FG), or BioGlue (BG), or repair was not performed (i.e., no repair, NR); the animals were monitored for 3 weeks. Adverse clinical outcomes and findings at laparotomy were recorded. Pathologic assessment included an objective scaled evaluation of the intensity of the inflammatory response and degree of healing.

RESULTS

In the SB injury group, deteriorating clinical condition necessitated early euthanasia in one animal repaired with FG, one animal repaired with BG, and two animals with NR. LS repair animals had no adverse clinical outcomes. The LB injury group had no adverse clinical outcomes regardless of the method of repair, including the control group. Of the animals that survived for 3 weeks, the animals repaired with BG had more intraabdominal adhesions (100%) than LS (33%), FG (55%), and NR (50%) (p = 0.001). The pathologic assessment revealed that BG induced a more intense inflammatory response (p < 0.05).

CONCLUSION

In the rabbit, suture repair of an electrosurgical SB injury appears to have improved outcomes when compared with a glued repair. In contrast, LB injury responded well to any form of treatment. The data suggest that suture is superior to biological glues when dealing with a laparoscopic electrosurgical bowel injury.

The UCI Seldinger technique for percutaneous renal cryoablation: protecting the tract and achieving hemostasis

PURPOSE

To describe our Seldinger technique of percutaneous renal cryoablation that was devised to facilitate renal biopsy, cryoprobe placement, and instillation of adjunctive hemostatics while protecting surrounding tissues from cryoinjury.

PATIENTS AND METHODS

This approach was used to manage 13 renal masses in 12 adult patients. Under CT-fluoroscopic guidance, an access needle was inserted to abut the surface of the tumor, followed by an Amplatz super-stiff guidewire and a customized coaxial catheter system, which was used as a conduit for needle biopsy, cryoprobe insertion, and FloSeal instillation. In addition, a porcine model was used to compare the temperature readings adjacent to the sheathed and the unsheathed cryoprobe during percutaneous renal cryoablation.

RESULTS

In all patients, the use of this access approach was accomplished without incident. Two patients needed blood transfusions. No patient had significant skin, muscle, or nerve debility. At a mean follow-up of 11 months, none had evidence of persistent disease on CT or MRI contrast imaging. In the porcine model, the customized sheath protected the surrounding tissues from reaching temperatures below 5 degrees C while temperatures down to -15 degrees C were obtained when no insulating sheath was used.

CONCLUSIONS

A modified Seldinger technique enabled us to perform percutaneous renal cryotherapy through a single access channel, which facilitated access for biopsy, cryoprobe placement, and instillation of hemostatic agents. This approach may provide a protective barrier against cryogenic damage to neighboring tissues and could theoretically help minimize the chance of tract seeding.