Matthew Truesdale

Comparison of biochemical failure definitions for predicting local cancer recurrence following cryoablation of the prostate

Various definitions of biochemical failure (BF) have been used to predict cancer recurrence following prostate cryoablation. However to date, none of these definitions have been validated for this use. We have reviewed several definitions of BF to determine their accuracy in predicting biopsy‐proven local recurrence following prostate cryoablation.

Differential heart rate response to magnetic seizure therapy (MST) relative to electroconvulsive therapy: A nonhuman primate model

Electroconvulsive therapy (ECT) is an effective treatment for severe depression; however, the induced therapeutic seizure acts on the autonomic nervous system and results in significant cardiac effects. This is an important consideration particularly in the elderly. Magnetic seizure therapy (MST) is in development as a less invasive alternative, but its effects on cardiac function have not been studied. We sought to model those effects in nonhuman primates to inform the development of safer neurostimulation interventions. Twenty four rhesus monkeys were randomly assigned to receive 6 weeks of daily treatment with electroconvulsive stimulation (ECS), magnetic seizure therapy (MST) or anesthesia-alone sham. Digitally acquired ECG and an automated R-wave and inter-R interval (IRI) sampling were used to measure intervention effects on heart rate (HR). Significant differences between experimental conditions were found in the HR as evidenced by changes in the immediate post-stimulus, ictal and postictal epochs. Immediate post-stimulus bradycardia was seen with ECS but not with MST. ECS induced significantly more tachycardia than MST or sham in both the ictal and postictal periods. MST resulted in a small, but statistically significant increase in HR during the postictal period relative to baseline. HR was found to increase by 25% and 8% in the ECS and MST conditions, respectively. MST resulted in significantly less marked sympathetic and parasympathetic response than did ECS. This differential physiological response is consistent with MST having a more superficial cortical site of action with less impact on deeper brain structures implicated in cardiac control relative to ECT. The clinical relevance of the topographical seizure spread of MST and its associated effects on the autonomic nervous system remain to be determined in human clinical trials.

Use of a flexible carbon dioxide laser fiber for precise dissection of the neurovascular bundle during robot-assisted laparoscopic prostatectomy.

INTRODUCTION Carbon dioxide (CO(2)) lasers deliver energy with minimal thermal spread to tissues during dissection. Excess thermal spread during dissection of the neurovascular bundle (NVB) can affect potency in men after robot-assisted radical prostatectomy (RARP). We report on a novel delivery mechanism for CO(2) laser energy through a flexible fiber to enhance accuracy of NVB dissection during RARP. MATERIALS A feasibility study of the OmniGuide BeamPath URO-LG CO(2) laser fiber for NVB dissection was performed on 10 patients with primary Gleason 3 T1c prostate cancer during RARP. Bilateral lateral fascial antegrade nerve sparing was performed. We evaluated fiber performance, safety, and efficacy. RESULTS The fiber was inserted through the 12-mm assistants port and easily manipulated by robotic instruments. Once pedicles were clipped and dissected, the laser fiber was effective in establishing planes of dissection between prostatic capsule and NVB. The endoscopically discernable thermal laser footprint was small, with minimal thermal spread during nerve sparing, meticulous dissection of NVB, and fascial layer identification. Although the laser did provide extremely accurate dissection, it was unable to serve as an adequate means of larger vessel coagulation. CONCLUSIONS The flexible CO(2) laser fiber was easily manipulated. Identification of fascial layers during nerve sparing was facilitated with the fiber. Long-term follow-up is necessary to determine efficacy of this technology versus conventional techniques on the NVB. Larger studies are currently in progress to determine if use of the flexible CO(2) laser fiber results in improvements in functional outcomes with regard to return of sexual potency after RARP.

Impact of HMG-CoA Reductase Inhibitor (Statin) Use on Blood Loss During Robot-Assisted and Open Radical Prostatectomy

BACKGROUND AND PURPOSE In addition to their lipid lowering effects, HMG-CoA reductase inhibitors (statins) have been shown to exert antithrombotic effects through downregulation of the coagulation cascade. Because statin use is widespread, it is important to understand the impact of these drugs on blood loss (BL) during surgery. We studied the impact of statin use on BL during robot-assisted radical prostatectomy (RARP) and open radical prostatectomy (ORP). PATIENTS AND METHODS A retrospective review was conducted of a database approved by the Institutional Review Board for patients who underwent RARP or ORP at a single academic institution. Patients were categorized as statin-users or statin-naïve at the time of surgery. Patient demographic information was recorded as was perioperative data, including preoperative and postoperative hematocrit (Hct) value. BL was defined as % Hct change presurgery vs postsurgery. In addition, the outcome of ≥10% drop in Hct was studied. The t test and chi-square analysis were used to compare variables across statin use groups. Univariate and multivariable logistic regression analyses were used to identify factors that impacted BL. RESULTS From 1987 to 2010, 3578 patients underwent prostatectomy for prostate cancer (RARP=945 and ORP=2633). Of these, 676 men were identified as statin-users and 2902 as statin-naïve. Mean patient age was 60.2±7.0 years. Statin-users were found to be older (P<0.001), have lower mean preoperative prostate-specific antigen (PSA) levels (P=0.002), and have higher pathologic Gleason sum scores (P<0.001). For ORP, statin use was associated with increased BL with Hct % change of 20.7% for users vs18.6% for nonusers, (P<0.001). For RARP, no significant change in Hct was seen with statin use with % changes of 12.6% and 12.5%, respectively (P=0.9). When controlling for age, Gleason sum, surgeon, date of surgery and PSA level, statin use was associated with increased BL (P=0.04). CONCLUSION Even when controlling for age, Gleason sum, surgeon, date of surgery, and PSA, statin use is associated with increased BL during RP. This information may impact preoperative planning and patient counseling for men who are taking statins while preparing for RP.

MP51-09 THE “PENANA”: A NOVEL, COST EFFECTIVE, AND HIGHLY EFFICACIOUS MODEL FOR TEACHING MALE URETHRAL ANATOMY AND SAFE FOLEY CATHETER TECHNIQUE

INTRODUCTION AND OBJECTIVES: Iatrogenic urethral catheter related injuries are common and have been shown to correlate with inadequate training among medical professionals. Urethral catheterization (UC) is a common procedure and often one of the first attempted by medical trainees. Simulation training enhances medical procedure teaching by decreasing trainee anxiety, improving patient safety and efficiently tailoring the experience for the learners, thus optimizing education. We sought to create an efficacious simulation model to teach medical students and residents male UC. METHODS: We developed a 50-minute educational curriculum utilizing didactic presentation and a banana with ends removed and longitudinal core created as a simulation model for the male urethra (00Penana00). The presentation focused on UC indications, male urethral anatomy, structure of standard and Coude catheters, and safe technique for UC. Procedural teaching utilized modified Payton technique; 1) Expert demonstration, 2) Explanation of steps, 3) Expert-guided Learner performance, 4) Learner-guided learner performance, 5) Independent Learner performance. Subjects completed pre and post intervention survey assessments to determine efficacy. Surveys measured learner knowledge and self-reported confidence at performing male UC. RESULTS: 126 learners participated in the workshop and (29 MS1, 40 MS2, and 60 PGY1) completed pre and post assessments. Prior to intervention, among medical students 36% and 1% had observed UC and 6% and 0% had performed UC using standard Foley and Coude, respectively. Following intervention, combined knowledge scores increased from 13 16% to 85 20% correct. On a 10 point scale, learners self reported confidence increased from 3.3 2.1 to 8.2 1.5 for male urethral anatomy, 1.7 1.4 to 7.9 1.6 for standard Foley UC, and 1.2 0.6 to 7.8 1.9 for Coude UC. On a 10 point scale with 10 representing very helpful, learners described the Penana model with a mean value of 8.6 1.9. Finally, 78% and 20% were extremely likely and likely, respectively, to recommend the course to a friend. CONCLUSIONS: The Penana is a highly efficacious simulation model for teaching medical students and residents safe UC technique. The low cost and universal availability of the materials makes the model easily accessible for any resource-limited education setting.

PD32-07 EVIDENCE IN SUPPORT OF USING A SINGULAR SCORE TO CHARACTERIZE A SURGEON′S OPERATIVE SPENDING BEHAVIOR

INTRODUCTION AND OBJECTIVES: Cost-control initiatives targeting physicians are currently underway to improve cost-efficient clinical care. Little is known regarding surgeon-specific cost choices. We sought to characterize surgeon periorperative spending to evaluate the accuracy of a singular score summarizing surgeon costefficiency. METHODS: All surgeons operating at UCSF Medical Center from July 2012-October 2015 across all specialties were included. Mean OR cost was calculated combining surgical supplies and time in the OR (

MP17-05 PROSPECTIVE CLINICAL TRIAL EVALUATING ANTEGRADE NEPHROSTOGRAPHY TO ASSESS URINE FLOW AFTER PERCUTANEOUS NEPHROLITHOTOMY

/minute). Cases were included if 4 surgeons performed said operation and all included surgeons completed 20 operations. Zscores, defined as [(cost of surgeon0s case) (median cost for said case across all surgeons)] / [standard deviation (SD) of all surgeons0 costs for said case], were calculated for each surgeon and surgical case performed. Estimated mean z-scores were then calculated using mixed effects modeling. Surgeons0 z-score variability was evaluated using calculated SDs. RESULTS: 257 surgeons across 17 surgical subspecialties were included in the analysis. The mean raw z-score was -0.12 ranging from -1.85 to 3.4 with SD of 0.78. The estimated z-score variability across the surgeons ranged from -0.5 to 0.5 SDs from the average estimated z-score (Figure 1). When comparing surgical subspecialties, the variability of z-scores ranged from 0.06 to -0.07. In individual subspecialties, the variability (SD) ranged from 0.25 to 0.02. CONCLUSIONS: The z-score variability across all surgeons was small, supporting consistent surgeon-spending behavior across diverse cases. This supports using a surgeon0s estimated mean z-score as a singular and accurate metric characterizing surgeons0 cost behavior.

An evaluation of patient selection criteria on predicting progression-free survival after primary focal unilateral nerve-sparing cryoablation for prostate cancer: recommendations for follow up.

INTRODUCTION AND OBJECTIVES: Percutaneous nephrolithotomy (PNL) remains an effective treatment for patients with a large stone burden. When a nephrostomy tube (NT) is left in place postoperatively, antegrade flow of urine is often confirmed with antegrade nephrostography (ANG) as edema from a chronically obstructing stone can resolve in variable amounts of time. Alternatively, antegrade flow can be estimated by injecting methylene blue dye into the NT or performing a NT capping trial. We compared the methylene blue dye test and capping trial against ANG to assess antegrade urine flow. METHODS: Consecutive patients undergoing PNL at 2 hospitals were prospectively enrolled between July and October, 2014. A cap was placed on the NT on the morning of postoperative day 1 (POD1). Capping trial failure was defined as need to uncap NT for any reason including increased pain or fever. 2 hours after capping, 7cc of methylene blue was injected into the NT and the tube recapped. Positive test was defined as the presence of blue per urethral Foley. Later that afternoon, ANG was performed to radiographically document antegrade urine flow. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) were calculated comparing capping and methylene blue tests against ANG. RESULTS: 34 subjects underwent PNL. 55.9% were left sided and 73.5% were lower pole punctures (mean age 54.9 13.9 years; mean BMI 31.7 12.7kg/m2; mean stone size 2.86 1.42cm). Capping trial was successful in 86.7% of patients. Compared to ANG, it had a sensitivity of 94.4% (CI 83.9-100%), specificity 25.0% (CI 0.5-49.5%), PPV 65.4% (47.1-83.7%), and NPV 75.0% (CI 32.6-100%) to predict antegrade urine flow. The methylene blue test was positive in 41.4% of patients. Compared to ANG, it had a sensitivity of 52.9% (CI 29.2-76.7%), specificity 75.0% (CI 50.5-99.5%), PPV 75.0% (CI 50.5-99.5%), and NPV 52.9% (CI 29.2-76.7%) to predict antegrade urine flow. CONCLUSIONS: Compared to ANG, a capping trial and methylene blue test are 94% and 53% sensitive and 25% and 75% specific respectively for confirming antegrade urine flow following PNL. In clinical practice, these tests may potentially be used in combination to obviate the need for ANG, which can be redundant and timeconsuming.