Evaluation of Ignition and Burn Risk Associated with Contemporary Fiberoptic and Distal Sensor Endoscopic Technology

PURPOSE

To evaluate the ignition and burn risk associated with contemporary fiberoptic and distal sensor endoscopic technologies.

MATERIALS AND METHODS

We used new and used SCB Xenon 300 light sources to illuminate a 4.8 mm fiberoptic cable, 10 mm laparoscope, 5 mm laparoscope, rigid cystoscope, semirigid ureteroscope, flexible cystoscope, flexible fiberoptic ureteroscope, distal sensor cystoscope, and a distal sensor ureteroscope (Karl Storz, Inc., Tuttlingen, Germany). We measured peak temperatures at the distal end of each device. We then evaluated each device on a flat and folded surgical drape to establish ignition risk. Finally, we evaluated the effects of all devices on human cadaver skin covered by surgical drape.

RESULTS

Peak temperatures recorded for each device ranged from 26.9°C (flexible fiberoptic ureteroscope) to 194.5°C (fiberoptic cable). Drape ignition was noted when the fiberoptic cable was placed against a fold of drape. Contact with the fiberoptic cable, 10 mm laparoscope, 5 mm laparoscope, and distal sensor cystoscope resulted in cadaver skin damage. Cadaver skin damage occurred despite little or no visible change to the surgical drape. Rigid and flexible fiberoptic cystoscopes and flexible fiberoptic ureteroscopes had no effect on surgical drapes or cadaver skin.

CONCLUSIONS

Fiberoptic light cables and some endoscopic devices have the potential to cause thermal injury and drape ignition. Thermal injury may occur without visible damage to drapes. Surgeons should remain vigilant regarding the risks associated with these devices and take necessary safety precautions to prevent patient injury.

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.

Comparison of outcomes in patients undergoing percutaneous renal cryoablation with sedation vs general anesthesia

OBJECTIVE

To compare the efficacy and safety of local anesthesia with conscious sedation (LACS) with general anesthesia (GA) in patients undergoing percutaneous renal cryoablation (PRC) for renal cortical neoplasms.

METHODS

We performed a retrospective review of patients undergoing PRC between 2003 and 2013. Patient demographics, tumor characteristics, and perioperative and postoperative follow-up data were recorded and analyzed. We compared 3 principal outcomes across the GA and LACS groups: anesthesia-related outcomes, treatment failure, and complications.

RESULTS

A total of 235 patients with available data were included. Of these, 82 underwent PRC under GA and 153 patients under LACS. The 2 groups were similar with regard to age, gender, body mass index, American Society of Anesthesiologists score, tumor features, preoperative serum creatinine level, and hematocrit value. The GA and LACS groups had a similar percentage of patients with biopsy-proven renal cell carcinoma (68.5% and 64.2%, respectively; P = .62). The mean follow-up time for GA and LACS was 37 and 21 months, respectively (P <.0001). The mean procedure time for GA was significantly longer compared with LACS (133 vs 102 minutes; P <.001), and the mean hospital stay was shorter under LACS (1.08 vs 1.95 days; P <.0001). There was no difference in immediate failure (0% and 1.9%; P = .051) or recurrences (11% and 3.9%, respectively; P = .051) between GA and LACS groups. There was no difference in intraoperative and postoperative treatment-related complications between the 2 groups.

CONCLUSION

PRC for small renal masses under LACS is effective and safe. PRC with LACS has the advantage of decreased procedure time and a shorter hospital stay.

Evaluation and comparison of urolithiasis scoring systems used in percutaneous kidney stone surgery

PURPOSE

Contemporary predictive tools for percutaneous nephrolithotomy outcomes include the Guy stone score, S.T.O.N.E. nephrolithometry and the CROES nephrolithometric nomogram. We compared each scoring system in the same cohort to determine which was most predictive of surgical outcomes.

METHODS

We retrospectively reviewed the records of patients who underwent percutaneous nephrolithotomy between 2009 and 2012 at a total of 3 academic institutions. We calculated the Guy stone score, the S.T.O.N.E. nephrolithometry score and the CROES nephrolithometric nomogram score based on preoperative computerized tomography images. A single observer at each institution reviewed all images and assigned scores. Univariate and multivariate analysis was done to determine the most predictive scoring system.

RESULTS

We enrolled 246 patients in study. In stone-free patients vs those with residual stones the mean Guy score was 2.2 vs 2.7, the mean S.T.O.N.E. score was 8.3 vs 9.5 and the mean CROES nomogram score was 222 vs 187 (each p <0.001). Logistic regression revealed that the Guy, S.T.O.N.E. nephrolithometry and CROES nomogram scores were significantly associated with stone-free status (p = 0.02, 0.004 and <0.001, respectively). The Guy and S.T.O.N.E. nephrolithometry scores were associated with estimated blood loss (p <0.0001 and 0.03) and length of stay (p = 0.03 and 0.009, respectively). The CROES nomogram did not predict estimated blood loss or length of stay.

CONCLUSIONS

All scoring systems and the stone burden equally predicted stone-free status. The Guy and S.T.O.N.E. nephrolithometry scores were associated with estimated blood loss and length of stay. A single scoring system should be adopted to unify reporting.

Endoscopic Management of Upper Tract Transitional Cell Carcinoma

INTRODUCTION

Upper tract urothelial carcinoma is rare and the gold standard for treatment remains radical nephroureterectomy with excision of the bladder cuff. To avoid the loss of kidney function and other morbidities associated with radical nephroureterectomy, a conservative endoscopic approach can be used in select cases, including low grade tumors. Advances in endoscopic technique and technology have facilitated this approach.

METHODS

We review the role of endoscopy in the diagnosis of upper tract urothelial carcinoma, indications for its endoscopic management, surgical technique and complications, as well as the currently available outcomes in the literature.

RESULTS

Upper tract urothelial carcinoma can be approached either ureteroscopically in a retrograde fashion or antegrade with a percutaneous technique. Several options for tissue resection and ablation exist. Appropriate patient selection is critical to success with endoscopic management and patients who undergo renal sparing therapy must be committed to a lifetime of followup with radiographs and endoscopy.

CONCLUSIONS

An endoscopic approach to upper tract urothelial carcinoma provides a nephron sparing, low morbidity option in select cases. Currently, there is moderate evidence to support the safety and efficacy of endoscopic management but definitive conclusions cannot be made until long-term outcome data are available and prospective trials are completed.

Current patterns of presentation and treatment of renal masses: a clinical research office of the endourological society prospective study

PURPOSE

To assess epidemiologic characteristics, clinical and pathologic patterns of presentation, and treatment strategies in a contemporary population with renal masses (RMs).

METHODS

The Clinical Research Office of the Endourological Society collected prospective epidemiologic, clinical, and pathologic data on consecutive patients with RMs who were treated during a 1-year period in 98 centers worldwide. Preoperative assessment and treatment were performed according to local clinical practice guidelines.

RESULTS

From January 2010 to February 2012, 4288 patients (4355 cases, 4815 tumors) were treated for a RM. The mean age of the cohort was 61.5 years, and the ratio male:female 1.8:1. Caucasians represented 75% of the population, and the median body mass index was 27. The cohort exhibited a high rate of comorbidity (65.6%), including a 48.5% rate of hypertension; one-third of patients had a combination of two or more comorbidities. One-third of patients (36%) had risk factors for renal-cell carcinoma (RCC), of which smoking and obesity were the most common. Diagnosis was incidental in 67% of cases, and 22.2% of cases had chronic kidney disease stage ≥III at presentation. Median radiologic size was 44 mm (range 2-300 mm) and 68% were cT1. Radical nephrectomy and nephron-sparing surgery (NSS) including ablation were performed in 52% and 46% of cases, respectively, while 3.6% of cases were actively surveyed. Median pathologic size was 43 mm (range 2-300 mm) and 63% of the RCCs were pT1.

CONCLUSIONS

Current patterns of presentation of RMs are consistent with the decreasing trends in age and clinical or pathologic size and increasing incidental diagnosis. Patients exhibit a considerable basal comorbidity and presence of risk factors for RCC. Half of the cases are treated by a nephron-sparing modality with an increase in the penetration of NSS techniques in the contemporary urologic practice.

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.

In vitro comparison of a novel facilitated ultrasound targeting technology vs standard technique for percutaneous renal biopsy

OBJECTIVE

To improve the understanding of the epidemiology of renal cortical neoplasms through pretreatment biopsy, we evaluated a facilitated ultrasound targeting (FUT) technology. The technology allows a needle to be passed through the transducer probe and guided along a virtual dotted line on the monitor. We compared the FUT with standard percutaneous biopsy (PB) technique.

MATERIALS AND METHODS

Forty-eight participants with various levels of training were recruited. Participants performed ultrasound-guided biopsies on phantom models using FUT and the standard biopsy technique in a randomized sequence. The phantom models consisted of pimento olives embedded in an opaque mold of Metamucil and Knox gelatin. Patients were given up to 10 attempts to achieve 3 complete specimens from the olives. Patients rated each biopsy technique. Results were stratified by level of experience.

RESULTS

The mean time to obtain 3 complete biopsy specimens was significantly faster for FUT compared with the standard technique (140 seconds vs 246 seconds, P = .0001). The mean number of attempts needed to obtain 3 specimens was significantly less with FUT compared with the standard technique (4.3 vs 5.6 attempts, P = .0007). Patients reported that FUT was significantly easier to use compared with the standard technique (P = .0005). No significant order effect was observed.

CONCLUSION

In this in vitro comparison, FUT increased the efficiency and efficacy of PB for users of all experience levels. FUT may allow urologists with limited PB experience to perform the procedure reliably and easily. Clinical evaluation of this technology is actively in progress.

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

OBJECTIVE

To evaluate performance characteristics and optics of a new generation high-definition distal sensor (HD-DS) flexible cystoscope, a standard-definition distal sensor (SD-DS) cystoscope, and a standard fiberoptic (FO) cystoscope.

METHODS

Three new cystoscopes (HD-DS, SD-DS, and FO) were compared for active deflection, irrigation flow, and optical characteristics. Each cystoscope was evaluated with an empty working channel and with various accessories. Optical characteristics (resolution, grayscale imaging, color representation, depth of field, and image brightness) were measured using United States Air Force (USAF)/Edmund Optics test targets and illumination meter. We digitally recorded a porcine cystoscopy in both clear and blood fields, with subsequent video analysis by 8 surgeons via questionnaire.

RESULTS

The HD-DS had a higher resolution than the SD-DS and the FO at both 20 mm (6.35 vs 4.00 vs 2.24 line pairs/mm) and 10 mm (14.3 vs 7.13 vs 4.00 line pairs/mm) evaluations, respectively (P <.001 and P <.001). Color representation and depth of field (P = .001 and P <.001) were better in the HD-DS. When compared to the FO, the HD-DS and SD-DS demonstrated superior deflection up and irrigant flow with and without accessory present in the working channel, whereas image brightness was superior in the FO (P <.001, P = .001, and P <.001, respectively). Observers deemed the HD-DS cystoscope superior in visualization in clear and bloody fields, as well as for illumination.

CONCLUSION

The new HD-DS provided significantly improved visualization in a clear and a bloody field, resolution, color representation, and depth of field compared to SD-DS and FO. Clinical correlation of these findings is pending.