Adam G. Kaplan

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.

Current status of metal stents for managing malignant ureteric obstruction

Obstruction of the ureters caused by extrinsic compression from a primary tumour or retroperitoneal lymph node masses is not unusual in the course of advanced pelvic malignancies. Most of the cases are of gynaecological or gastrointestinal origin, and the situation can be aggravated by peri‐ureteric fibrosis, a long‐term adverse event of previous chemotherapy or radiotherapy. Undoubtedly upper urinary tract decompression and maintenance of ureteric patency, even as a palliative measure, is important in managing these patients. Options for upper tract decompression include percutaneous nephrostomy, retrograde stenting and open urinary diversion. Plastic stents have long been used for managing malignant ureteric obstruction, but their overall success remains limited. Plastic stents often fail to be placed correctly, require regular exchange, and are faced with a high incidence of encrustation and migration. For these reasons plastic stents have been unsuccessful for long‐term maintenance of ureteric patency. To overcome these limitations metal stents were introduced and recently developed in an effort to ensure better long‐term patency of the obstructed ureter, fewer hospital admissions for stent change and better overall quality of life. In the present review the clinical applications of different types of metal stents are discussed, with a specific focus on the latest advances and the future options for managing malignant ureteric obstruction.

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.

Use of ureteral access sheaths in ureteroscopy

The ureteral access sheath (UAS) facilitates the use of flexible ureteroscopy, enabling improved minimally invasive management of complex upper urinary tract diseases. The UAS, which comes in a variety of diameters and lengths, is passed in a retrograde fashion, aided by a hydrophilic coating and other features designed to confer smooth passage into the ureter with sufficient resistance to kinking and buckling. Use of a UAS has the advantage of enabling repeated passage of the ureteroscope while minimizing damage to the ureter, thus improving the flow of irrigation fluid and visualization within the urethra with reductions in operative times, which improves both the effectiveness of the surgery and reduces the costs. Placement of the UAS carries an increased risk of ureteral wall ischaemia and injury to the mucosal or muscular layers of the ureter, and a theoretically increased risk of ureteral strictures. A ureteral stent is typically placed after ureteroscopy with a UAS. Endourologists have found several additional practical uses of a UAS, such as the percutaneous treatment of patients with ureteral stones, and solutions to other endourological challenges.

Skin treatment and tract closure for tubeless percutaneous nephrolithotomy: University of California, Irvine, technique.

BACKGROUND AND PURPOSE After percutaneous nephrolithotomy (PCNL), a nephrostomy tube has been routinely placed to ensure hemostasis, provide drainage, and maintain access to the collecting system should a second-look procedure be necessary. Recently, efforts have been expended to either reduce the size of the nephrostomy tube or eliminate it altogether. We describe the tubeless technique of closure and skin treatment after PCNL using FloSeal as a sealant for tubeless PCNL. TECHNIQUE A 7F 11.5-mm occlusion balloon catheter is passed retrograde over the through-and-through guidewire. Next, under endoscopic guidance, with a rigid or flexible nephroscope, the 30F Amplatz sheath is pulled back to the torn edge of the calix through which the nephrostomy tract enters the kidney. Under endoscopic guidance, the balloon is inflated at the torn edge. Next, the long metal laparoscopic FloSeal applicator is passed through the 30F sheath until it encounters resistance from the occlusion balloon catheter. FloSeal is injected down the sheath as the sheath is slowly withdrawn simultaneously with the FloSeal applicator until both have cleared the nephrostomy incision. The through-and-through guidewire is pulled per the urethra under fluoroscopic control until its tip is in the renal pelvis. A 7F double pigtail stent is passed retrograde over the through-and-through guidewire. A bladder catheter is placed. A running subcuticular suture of 4-0 poliglecaprone is placed, and cyanoacrylate adhesive is used to close the skin. No dressing is applied. CONCLUSION For patients who have been rendered completely stone free during uncomplicated PCNL, administration of hemostatic gelatin matrix to the nephrostomy tract may achieve immediate hemostasis and eliminate the need for placement of a nephrostomy tube. Although there have not been any clinical reports of urinary obstruction caused by the application of hemostatic sealants in the PCNL tract, we recommend using an occlusion balloon and subsequent placement of an indwelling ureteral stent to ensure maximum safety.

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.

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.

Robotic radical anterior pelvic exenteration: the UCI experience.

Abstract Robotic technology may be a promising tool in reduction of morbidity in radical anterior pelvic exenteration for invasive bladder cancer. We report our initial experience with robotic-assisted radical anterior pelvic exenteration in females in an attempt to evaluate the techniques feasibility and outcomes. A retrospective review of our bladder cancer database was performed. Twelve women that underwent robotic-assisted radical anterior pelvic exenteration, bilateral pelvic lymphadenectomy, and urinary diversion for clinically localized urothelial carcinoma of the bladder between 2004 and 2008 were included in this retrospective study. Median age was 73.0 +/- 9.6 years and median body mass index (BMI) was 23.5 +/- 5.0 kg/m2. Ten patients underwent ileal conduit diversion, one had an orthotopic neobladder and one an Indiana pouch. Median total operating time was 6.4 +/- 1.5 hours with median console and diversion times of 4.7 +/- 0.9 and 2.5 +/- 1.5 hours respectively. Median blood loss was 275.0 +/- 165.8 ml. Median length of stay was 8.0 +/- 1.6 days. Four patients were T2N0 or less, five T3N0, one T3N1 and two patients T4N0. There was one patient with positive surgical margins. Median number of lymph nodes removed was 23.0 +/- 11.4. Median follow-up of 9.0 +/- 6.0 months was available for ten patients. One had a recurrent ureteroenteric stricture, one had colpocleisis for vault prolapse, and three had metastatic disease. Robotic-assisted laparoscopic anterior pelvic exenteration appears to be a favorable surgical option with acceptable operative, pathological, and short-term clinical outcomes. According to the UCI experience, robotic anterior exenteration appears to achieve the clinical and oncologic goals for the surgical treatment of bladder cancer.

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.

Evaluation of a Novel Single-Use Flexible Ureteroscope

INTRODUCTION A novel single-use flexible ureteroscope promises the optical characteristics and maneuverability of a reusable fourth-generation flexible ureteroscope. In this study, the LithoVue Single-Use Digital flexible ureteroscope was directly compared with contemporary reusable flexible ureteroscopes, with regard to optics, deflection, and irrigation flow. METHODS Three flexible ureteroscopes such as the LithoVue (Single Use; Boston Scientific), Flex-Xc (Karl Storz, Germany), and Cobra (Richard Wolf, Germany) were assessed in vitro for image resolution, distortion, color representation, grayscale imaging, field of view, and depth of field. Ureteroscope deflection was tested with an empty channel followed by placement of a 200 μm laser fiber and a 1.9F wire basket, a 2.0F nanoelectric pulse lithotripsy (NPL) probe, and a 2.4F NPL probe. Ureteroscope irrigation flow was measured using normal saline at 100 cm, with an empty channel followed by a 200 μm laser fiber, a 1.9F wire basket and a 2.0F NPL probe. RESULTS The LithoVue showed the largest field of view, with excellent resolution, image distortion, and depth of field. No substantial difference was demonstrated in color reproducibility or in the discernment of grayscales between ureteroscopes. The LithoVue maintained full deflection ability with all instruments in the working channel, although the Flex-Xc and Cobra ureteroscopes showed loss of deflection ranging from 2° to 27°, depending on the instrument placed. With an empty channel, the LithoVue showed an absolute flow rate similar to the Flex-Xc ureteroscope (p = 0.003). It maintained better flow with instruments in the channel than the Flex-Xc ureteroscope. The Cobra ureteroscope has a separate 3.3F instrument channel, keeping flow rates the same with instrument insertion. CONCLUSION The LithoVue Single-Use Digital ureteroscope has comparable optical capabilities, deflection, and flow, making it a viable alternative to standard reusable fourth-generation flexible digital and fiberoptic ureteroscopes.