Erica H. Lambert

THE INCREASING USE OF INTRAVESICAL THERAPIES FOR STAGE T1 BLADDER CANCER COINCIDES WITH DECREASING SURVIVAL AFTER CYSTECTOMY

Intravesical therapy (IVT), chemo and immunotherapy, has made conservative, bladder‐sparing strategies a viable option for managing patients with high grade T1 bladder cancer. However, many of these patients will have recurrence and occasionally progression, questioning delayed intervention. This study examines the patterns of use of IVT in high‐grade T1 bladder cancer and the subsequent impact on survival for patients ultimately proceeding to radical cystectomy (RC).

Effect of Escalating Versus Fixed Voltage Treatment on Stone Comminution and Renal Injury During Extracorporeal Shock Wave Lithotripsy: A Prospective Randomized Trial

PURPOSE ESWL is a minimally invasive, efficacious therapy for most renal stones. However, an optimal voltage treatment protocol ensuring effective stone comminution while minimizing tissue injury is not well established. We performed a prospective, randomized trial of the stone-free rate and renoprotective effect of an escalating vs a fixed voltage treatment strategy during ESWL. MATERIALS AND METHODS Between February 2006 and June 2008 we enrolled 45 patients undergoing ESWL for a renal stone in this institutional review board approved trial. A Dornier DoLi 50 lithotriptor was used. Patients were randomized to receive the escalating strategy of 500 shocks at 14k V, 1,000 at 16 kV and 1,000 at 18 kV or the fixed strategy of 2,500 shocks at 18 kV. Abdominal x-ray was done to determine the stone-free rate at 1 month. Voided urine was analyzed for beta2-microglobulin and microalbumin before, immediately after and 1 week after ESWL to evaluate renal damage. RESULTS Median patient age was 48 years. Median stone size was 8 mm. Of patients in the escalating group 81% were stone-free vs 48% in the fixed group (p <0.03). There was a significant difference between microalbumin and beta2-microglobulin 1 week after the procedure (p = 0.046 vs 0.045). There was trend toward a difference in microalbumin and beta2-microglobulin immediately after the procedure (p = 0.17 and 0.25, respectively). CONCLUSIONS This prospective, randomized study shows that an escalating voltage treatment strategy produces better stone comminution than a fixed strategy. The study suggests that there may be a protective effect against damage caused by ESWL with an escalating treatment strategy.

Second Prize: A Sealed Bladder Cuff Technique During Laparoscopic Nephroureterectomy Utilizing the LigaSure™ Electrosurgical Device: Laboratory and Clinical Experience

INTRODUCTION Laparoscopic nephroureterectomy (LNU) is a safe, minimally invasive approach for management of upper tract urothelial tumors. Controversy exists over the optimal technique for the distal ureter and bladder cuff (DUBC) excision. We examined the novel technique of using the LigaSure bipolar electrosurgical device in laboratory investigations and during clinical LNU to manage the DUBC. PATIENTS AND METHODS Initial investigations were undertaken in the porcine model. Areas of both normal porcine ureters and bladders, and ex vivo human ureters from radical nephrectomy specimens were sealed with the LigaSure and stained with nicotinamide adenine dinucleotide (NADH) and hematoxylin and eosin to examine the length of treatment effect and the viability of the ablated tissue. Clinically, we performed 22 LNU for proximal urothelial tumors using the LigaSure for the management of the DUBC. Intraoperative cystoscopy assessed cuff resection and bladder leakage. On postoperative day 10, a cystogram was performed. RESULTS In the porcine model, the technique sealed the bladder effectively with a mean burst pressure of 14 mm Hg. Cellular staining revealed no viable urothelial tissue in the seal area and an additional 2 mm outside this area. Eighteen patients had a successful seal/ablation intraoperatively. Cystoscopy revealed cautery artifact and blanching over the former position of the ureteral orifice. CONCLUSION The LigaSure device ablates and seals urothelial tissue with no viable cells in the clamped and adjacent blanched tissue. Our technique is technically feasible, removes an adequate bladder cuff, typically maintains a closed urinary system, and adheres to sound oncological principles. This procedure could be performed in both laparoscopic and open nephroureterectomy for proximal upper tract transitional cell tumors.

MP19-05 COMPUTERIZED SIMULATION OF FLUID DYNAMICS WITHIN THE RENAL COLLECTING SYSTEM AND THEIR ASSOCIATION WITH NEPHROLITHIASIS

performed to assess for variables associated with 24-hour urine parameters. RESULTS: Compared to patients with normal BMD, patients with low BMD were older (67 vs 50 yrs, p<0.0001), were male (69% vs 34%, p1⁄40.001), had HTN (81.8% vs 24.7%, p<0.0001), underwent percutaneous nephrolithotomy (20% vs 0%, p1⁄40.003), had higher 24hour urine calcium (219 vs 147, p<0.0001), increased visceral fat area (251 vs 179 cm, p1⁄40.003) and had larger stone volume (259 vs 78.4 mm, p1⁄40.009). Multivariate analysis revealed older age (p1⁄40.004) and elevated urine calcium (p1⁄40.0002) correlated with low BMD. Linear regression demonstrated that lower BMD was associated with higher urine calcium (-coefficient 0.247, p1⁄40.020) and lower urinary citrate (-coefficient 0.331, p1⁄40.009). CONCLUSIONS: CT-based diagnosis of low mineral bone density is associated with derangement in 24-hour urine calcium and citrate in kidney stone formers, as well as larger stone volumes.