Kun-Yuan Chiu

Metallic stent in the treatment of ureteral obstruction: Experience of single institute

Background: The Resonance® metallic stent has been reported to be sufficient for the management of malignant extrinsic ureteral obstructions within a 12‐month time period. To determine the effectiveness in each specific patient group, we report our experience using the Resonance® stent in the treatment of ureteral obstructions. Methods: We retrospectively reviewed 20 patients (23 stents) who successfully received the Resonance® metallic stents and divided them into a patent group (n = 19) and an obstructive group (n = 4) according to the treatment results. Twenty‐one stents were inserted via cystoscopy or ureteroscopy in a retrograde fashion. The remaining two were inserted via percutaneous nephrostomy in an antegrade manner. Follow‐up serum creatinine measurements and sonography were performed. The overall ureteral patency rate and the risk of stent failure were evaluated. Results: The overall ureteral patency rate was 82.6% (19/23). Patients with previous radiotherapy had a 50% (4/8) patency rate which was significantly lower than non‐radiotherapy patients (100%, 15/15, p = 0.028). Malignant obstructions in those other than radiotherapy patients had a 100% patency rate (5/5). Benign obstructions in those other than radiotherapy patients had a 100% patency rate (10/10). In the radiotherapy patients, the mode of therapy did not dominate the stent outcome. Conclusion: Patients with ureteral obstructions can be treated sufficiently with the Resonance® metallic stent. Patients who had gynecological malignancies and received radiotherapy had a higher failure rate after Resonance® metallic stent insertion.

Malfunction of the da Vinci robotic system in urology

Objectives:  To analyze the incidence of malfunction of the da Vinci robotic system in a single center and to provide potential solutions.

Rictor-dependent AKT activation and inhibition of urothelial carcinoma by rapamycin

OBJECTIVE We previously reported a very high cumulative incidence of urothelial carcinoma in Taiwanese kidney transplant recipients. Rapamycin, the inhibitor of mTOR Complex 1, provides alternative immunosuppressive therapy after kidney transplantation with less neoplastic potential. We examined the in vivo and in vitro effects of rapamycin on urothelial carcinoma. MATERIALS AND METHODS The rat model of urothelial carcinoma was induced by 0.05% N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) in Fischer F344 rats. The anti-tumor effect of rapamycin was assessed grossly, microscopically, and by Western blot analysis. The mechanism of rapamycins attenuation of urothelial carcinoma was also evaluated by T24 cells. RESULTS Rapamycin significantly reduced urinary bladder tumor growth in the rat model of 0.05% BBN-induced urothelial carcinoma (P < 0.001). The blood trough levels of rapamycin were correlated with the occurrence of urothelial carcinoma. In vitro, rapamycin also inhibited the cell proliferation, migration, and invasion, as well as the protein expression of vascular endothelial growth factor-A of T24 urothelial carcinoma cells, whereas rapamycin did not induce significant apoptosis in T24 cells. Rapamycin decreased the expression of phospho-mTOR, phospho-S6K, cyclin D1, and VEGF-A. Rapamycin also activated AKT in T24 cells in the rat model of urothelial carcinoma. The rapamycin-associated activation of AKT was inhibited by rictor siRNA, but not raptor siRNA. CONCLUSIONS This study provides in vitro and in vivo evidence that rapamycin may inhibit the development of urothelial carcinoma. The present findings also suggest rictor-dependent AKT activation as a consequence of mTORC1 inhibition.

A novel method of laparoscopy-assisted peritoneal dialysis catheter placement.

Peritoneal dialysis (PD) is a widely used renal replacement therapy for end-stage renal disease patients. We compared our novel laparoscopic-assisted method with conventional procedures in the catheter survival and complications. Seventy-three patients who underwent PD catheter placement were enrolled in this study. Our laparoscopic methods were characterized with smaller incision and additional fixation in the lower abdomen. Catheter migration developed in 4 patients in the conventional group compared with none in the laparoscopic group. The catheter dysfunction-free survival was significantly longer among the patients in the laparoscopic group than that in the conventional group (P=0.001). There were no significant differences between the 2 groups in peritonitis, exit-site hematoma, or exit-site infection. Laparoscopy-assisted PD catheter insertion with an intraperitoneal loop fixation is safe and provides good maintenance of catheter function (See the video, Supplemental Digital Content 1, http://links.lww.com/SLE/A28).

PSA density as a better predictor of prostate cancer than percent-free PSA in a repeat biopsy

Background: The aim of our study was to identify the optimal predictor of prostate cancer among several prostate‐specific antigen (PSA) derivatives in repeat prostate biopsy. Methods: We retrospectively assessed the repeat prostate biopsy specimens, obtained between 1999 and 2008, of 212 patients with a total PSA (tPSA) of 4–10 ng/ml and normal digital rectal examination. Using a receiver operating characteristic (ROC) analysis, we assessed the predictive power of tPSA, percent free PSA (f/t PSA), PSA density (PSAD), and PSA velocity (PSAV) for the detection of prostate cancer. Results: Repeat prostate biopsy specimens were positive for prostate cancer in the case of 26 patients and negative in the case of 186 patients. The areas under the receiver operating characteristic (ROC) curves for tPSA, f/tPSA, PSAD, and PSAV were 72.7%, 57.9%, 74.4%, and 64.8%, respectively. The ROC curve analysis revealed that PSAD was a better predictor of prostate cancer than f/t PSA. Moreover, when PSAD at an optimal cutoff of 0.18 ng/ml/cc was considered as the predictor, the detection of prostate cancer was found to have a high sensitivity and specificity (77% and 69%, respectively). Conclusion: In a repeat prostate biopsy, PSAD is superior to f/t PSA as a predictor of prostate cancer. And, by assessing this predictor, an unnecessary repeat biopsy of patients with tPSA of 4–10 ng/ml can be avoided.

Trends in treatment for localized prostate cancer after emergence of robotic-assisted laparoscopic radical prostatectomy in Taiwan

Background: Radical retropubic prostatectomy remains the gold standard treatment for localized prostate cancer. However, new minimally invasive techniques have emerged, providing a less invasive approach. Robotic‐assisted laparoscopic radical prostatectomy is the ideal technique, providing good oncologic and functional outcomes. We analyzed the impact of robotic surgical systems on practice patterns among urologists to explain changes in the value of radical retropubic prostatectomy, laparoscopic radical prostatectomy and robotic‐assisted laparoscopic radical prostatectomy in a single institution in Taiwan. Methods: We retrospectively reviewed the records of patients who received prostatectomy by one of the above procedures between January 2004 and November 2009. Decisions to perform these procedures were made by patient preference. Patients who received prostate biopsies at other hospitals were transferred to our hospital specifically for robotic‐assisted prostatectomy. Results: A total of 434 radical prostatectomies were performed, of which 141 (32.49%) were radical retropubic prostatectomies, 59 (13.59%) were laparoscopic radical prostatectomies and 234 (53.92%) were robotic‐assisted laparoscopic prostatectomies. The overall number of prostatectomies has increased over time because of an increase in robotic‐assisted procedures. No decreases were seen in the number of radical retropubic prostatectomies during the evaluation period. Changes in the ratio of robotic‐assisted prostatectomies compared to radical retropubic and laparoscopic radical prostatectomies demonstrated a trend toward robotic‐assisted procedures. The percentage of cases transferred from other hospitals also increased over time from 28.57% to 68.60%. Conclusion: Our experience emphasizes the potential of robotic‐assisted prostatectomy to become the mainstream treatment for localized prostate cancer in Taiwan.

Initial Clinical Experience With Surgical Technique of Robot-assisted Transperitoneal Laparoscopic Partial Nephrectomy

Background: The incidental finding of small renal masses has increased due to widespread use of computed tomography as a diagnostic procedure. Some patients with either exophytic renal masses less than 4 cm and suboptimal renal function, a solitary kidney and bilateral renal tumors, or genetic predisposition to renal tumors are considered candidates for laparoscopic partial nephrectomy (LPN). A technical difficulty of LPN is performing laparoscopic intracorporeal suturing under the pressure of warm ischemia time. Because robotic systems have been shown to provide easier intracorporeal suturing, we hypothesized that robotic‐assisted LPN might improve efficacy. Methods: Eight patients with a mean age of 41 years and mean tumor size of 2.3 cm underwent robot‐assisted LPN between September 2006 and December 2008. Tumor excision and intracorporeal suturing under warm ischemia by renal artery clamp were performed entirely using a robotic system. All perioperative data and pathologic results were reviewed retrospectively. Results: The mean operation time was 160 minutes, and the mean estimated blood loss was 165 mL. The mean warm ischemia time was 33 minutes, and mean postoperative hospital stay was 4.3 days. Average preoperative hemoglobin was 13.0 mg/dL and postoperative hemoglobin was 11.8 mg/dL. Average preoperative creatinine was 1.1 ng/mL and postoperative creatinine was 1.28 ng/mL. There was 1 conversion to laparoscopic nephrectomy due to a positive margin on a frozen section after discussion with family about better oncologic control. The resected lesions included renal cell carcinoma in 5 patients, angiomyolipoma in 2, and a renin‐secreting renal tumor in 1 patient. Conclusion: Robot‐assisted LPN is feasible and may be a viable alternative to open or LPN in selected patients with small exophytic renal tumors. Compared with standard LPN, the robotic assisted LPN approach with precise renal reconstruction under a safe warm ischemia time is feasible and can be easily adopted by those with experience in robot‐assisted surgery.

Nortriptyline induces mitochondria and death receptor-mediated apoptosis in bladder cancer cells and inhibits bladder tumor growth in vivo.

Nortriptyline (NTP), an antidepressant, has antitumor effects on some human cancer cells, but its effect on human bladder cancer cells is not known. In this study, we used a cell viability assay to demonstrate that NTP is cytotoxic to human TCCSUP and mouse MBT-2 bladder cancer cells in a concentration and time-dependent manner. We also performed cell cycle analysis, annexin V and mitochondrial membrane potential assays, and Western blot analysis to show that NTP inhibits cell growth in these cells by inducing both mitochondria-mediated and death receptor-mediated apoptosis. Specifically, NTP increases the expression of Fas, FasL, FADD, Bax, Bak, and cleaved forms of caspase-3, caspase-8, caspase-9, and poly(ADP-ribose) polymerase. In addition, NTP decreases the expression of Bcl-2, Bcl-xL, BH3 interacting domain death agonist, X-linked inhibitor of apoptosis protein, and survivin. Furthermore, NTP-induced apoptosis is associated with reactive oxygen species (ROS) production, which can be reduced by antioxidants, such as N-acetyl-L-cysteine. Finally, we showed that NTP suppresses tumor growth in mice inoculated with MBT-2 cells. Collectively, our results suggest that NTP induces both intrinsic and extrinsic apoptosis in human and mouse bladder cancer cells and that it may be a clinically useful chemotherapeutic agent for bladder cancer in humans.

Application in robotic urologic surgery

Background: The da Vinci robot system has become the mainstay of minimally invasive surgery and has been used in numerous complex reconstructive procedures. Due to the success of this innovative technology, we attempted to expand our practical model and application of the da Vinci robot system into other urologic surgeries, beginning with robotic‐assisted laparoscopic radical prostatectomy (RALRP). Methods: We retrospectively reviewed a total of 683 patients who underwent robotic‐assisted urologic surgery between December 2005 and December 2012. We divided this 8‐year course of device use into three periods, and analyzed the surgical capability of operations in 1 day over different periods through a retrospective analysis. Results: In the first period (2005–2008), 159 cases of robotic‐assisted urologic surgeries were performed. A total of 195 cases were performed in the second group (2009–2010), and 329 cases in the third (2011–2012). Starting with radical prostatectomy in December 2005, we performed various types of procedures such as partial nephrectomy, pyeloplasty, nephroureterectomy with cystoprostatectomy, nephroureterectomy with bladder cuff, radical cystoprostatectomy/cystectomy with ileal conduit reconstruction, partial cystectomy, adrenalectomy, nephropexy, simple prostatectomy, ureteral reconstruction, and pyelolithotomy/ureterolithotomy. The mean operation times of prostatectomy, partial nephrectomy, nephroureterectomy with radical cystectomy/cystectoprostatectomy, and nephroureterectomy were 154, 140, 295, and 129 minutes, respectively. Conclusion: Based on our experience, a robotic system can be applied to many different types of urologic surgeries both safely and efficiently.

Five-year experience of peritoneal dialysis catheter placement.

Background: Peritoneal dialysis (PD) is a widely used renal replacement therapy for end‐stage renal disease (ESRD) patients. Using laparoscopic guidance for PD catheter placement, we have designed a safe method that resulted in a reduction in catheter migration. Methods: We retrospectively reviewed 250 consecutive patients who underwent PD catheter placement from January 2005 to December 2009. The patients were divided into two groups: the conventional open surgery group and the laparoscopic group. All patients received Tenckhoff straight catheters. In the laparoscopic group, the catheter was additionally fixed to the ventral abdominal wall. Data were collected and a statistical analysis was performed to compare patient characteristics, surgical complications and catheter removal between the groups. Results: Overall surgical complications in the laparoscopic group were lower than those in the conventional group (3.8% vs. 19.4%, p < 0.001), and the majority of catheter migrations and omental wraps occurred in the conventional group. Patients in the conventional group had higher American Society of Anesthesiologists scores than those in the laparoscopic group. There was no difference in the incidence of previous abdominal operation or follow‐up periods in the groups. Conclusion: Our laparoscopy‐assisted PD catheter insertion method using an intraperitoneal fixation loop is safeand can be a valuable tool in prevention of catheter migration and omental wraps.