The preoperative pad test as a predictor of urinary incontinence and quality of life after robot-assisted radical prostatectomy: a prospective, observational, clinical study.

PURPOSE: To assess whether the preoperative 1-h pad test could predict postoperative urinary incontinence and quality of life after robot-assisted radical prostatectomy. METHODS: A total of 329 patients who underwent robot-assisted radical prostatectomy between 2013 and 2016 were prospectively enrolled in this study. These patients were divided into the preoperative urinary continence group and the preoperative urinary incontinence group according to the 1-h pad test. The time to achieve urinary continence, lower urinary tract function evaluated by uroflowmetry and post-voided residual urine volume, and quality of life evaluated by King's Health Questionnaire and International Consultation on Incontinence Questionnaire-Short Form were compared between these two groups. RESULTS: There were 190 patients (58%) in the preoperative urinary continence group (1-h pad test ≤ 2 g) and 139 patients (42%) in the preoperative urinary incontinence group (1-h pad test > 2 g). In the preoperative urinary continence/incontinence groups, 83%/76% of patients achieved continence within 12 months, respectively, and urinary incontinence remained significantly longer in the preoperative incontinence group than in the preoperative continence group (P = 0.042). Although there were no significant differences in all quality of life items between the two groups before surgery, several items were significantly higher in the preoperative urinary continence group. CONCLUSION: Achievement of urinary continence and improvement of urinary quality of life are delayed in patients with preoperative urinary incontinence assessed by the 1-h pad test. The preoperative 1-h pad test could be a useful predictor of prolonged urinary incontinence and poor quality of life after robot-assisted radical prostatectomy.

The association between local atherosclerosis of the prostatic artery and benign prostatic enlargement in humans: Putative mechanism of chronic ischemia for prostatic enlargement.

BACKGROUND: To investigate the possible pathogenesis of the benign prostatic enlargement (BPE) induced by local atherosclerosis, the association between local atherosclerosis and prostatic enlargement was investigated, and molecular biological analyses were performed using human prostatectomy specimens. METHODS: A total of 69 consecutive patients who underwent robot-assisted radical prostatectomy (RARP) participated in this prospective study. To evaluate actual local atherosclerosis, prostatic arteries were removed during RARP. Microscopic assessment of local atherosclerosis was classified as one of three degrees of narrowing (minimal, moderate, and severe) according to the degree of obstruction of the inner cavity of the prostatic artery. The expressions of several mediators related to chronic ischemia and cell proliferation of the prostate were investigated by immunohistochemistry. RESULTS: The median age of the present cohort was 68 (range: 55-75) years. Although there was no relationship between local atherosclerosis and lower urinary symptoms evaluated by questionnaires, local atherosclerosis was significantly more severe in patients who had a history of treatment for benign prostatic hyperplasia (P = 0.02). Prostate size was significantly larger in the severe local atherosclerosis group than in the minimal and moderate local atherosclerosis groups (P < 0.001 and P = 0.03, respectively). Thepositive expression rates of hypoxia-inducible factor (HIF)-1α, malondialdehyde (MDA), transforming growth factor (TGF)-ß1 , and basic fibroblast growth factor (bFGF) in the prostate were significantly higher in patients with local atherosclerosis than in patients without local atherosclerosis (all P < 0.01, respectively). CONCLUSIONS: In human surgical specimens, there is evidence that local atherosclerosis of the prostatic artery is significantly associated with prostate size. Given the molecular evidence provided in this study, the putative mechanism for this relationship is that chronic ischemia induced upregulation of oxidative stress pathways, leading to BPE.

Effects of barbed suture during robot-assisted radical prostatectomy on postoperative tissue damage and longitudinal changes in lower urinary tract outcome.

OBJECTIVE: To compare the postoperative tissue damage and longitudinal changes in functional and patient-reported outcomes after vesicourethral anastomosis with barbed suture and nonbarbed suture in robot-assisted laparoscopic radical prostatectomy (RARP). MATERIALS AND METHODS: This was a prospective cohort study involving 88 consecutive patients who underwent RARP. These patients were categorized into the barbed suture group (n = 50) and the nonbarbed suture group (n = 38). Urethral and periurethral damages determined by magnetic resonance imaging at nine months after RARP were compared using generalized linear models. The International Prostate Symptom Score (IPSS), quality of life (QOL) index, uroflowmetry, and the 1-h pad test were measured at baseline and at 1, 3, 6, 9, and 12 months after RARP. The findings were analyzed using mixed-effects models. Confounding was adjusted for using propensity score covariate adjustment. RESULTS: The likelihood of having Grade 2/3 urethral and periurethral damages was greater in the barbed suture group than in the nonbarbed suture group (adjusted risk ratios: 2.98 and 3.85, respectively). IPSS, QOL index, and urinary leakage transiently increased at one month after RARP in both groups. QOL index was higher in the barbed suture group than in the nonbarbed suture group at 1, 9, and 12 months (P = 0.023, P = 0.025, and P = 0.011, respectively). The barbed suture group had significantly more cases of urinary incontinence than the nonbarbed suture group at 3 months (P = 0.041). Other outcomes were comparable between the two groups at all time points. CONCLUSIONS: This cohort study showed that, after RARP, barbed sutures during VUA induced more severe tissue damage as determined by MRI and greater transient aggravation of QOL and continence function than nonbarbed sutures. The present findings suggest that using nonbarbed sutures during VUA may facilitate earlier acquisition of urinary QOL and urinary continence.

Overriding TKI resistance of renal cell carcinoma by combination therapy with IL-6 receptor blockade.

Metastatic renal cell carcinoma (RCC) is a tumor entity with poor prognosis due to limited therapy options. Tyrosine kinase inhibitors (TKI) represent the standard of care for RCCs, however a significant proportion of RCC patients develop resistance to this therapy. Interleukin-6 (IL-6) is considered to be associated with poor prognosis in RCCs. We therefore hypothesized that TKI resistance and IL-6 secretion are causally connected. We first analyzed IL-6 expression after TKI treatment in RCC cells and RCC tumor specimens. Cell proliferation and signal transduction activity were then quantified after co-treatment with tocilizumab, an IL-6R inhibitor, in vitro and in vivo. 786-O RCC cells secrete high IL-6 levels after low dose stimulation with the TKIs sorafenib, sunitinib and pazopanib, inducing activation of AKT-mTOR pathway, NFκB, HIF-2α and VEGF expression. Tocilizumab neutralizes the AKT-mTOR pathway activation and results in reduced proliferation. Using a mouse xenograft model we can show that a combination therapy with tocilizumab and low dosage of sorafenib suppresses 786-O tumor growth, reduces AKT-mTOR pathway and inhibits angiogenesis in vivo more efficient than sorafenib alone. Furthermore FDG-PET imaging detected early decrease of maximum standardized uptake values prior to extended central necrosis. Our findings suggest that a combination therapy of IL-6R inhibitors and TKIs may represent a novel therapeutic approach for RCC treatment.

Impact of Sulfatase-2 on cancer progression and prognosis in patients with renal cell carcinoma.

Heparan sulfate-specific endosulfatase-2 (SULF-2) can modulate the signaling of heparan sulfate proteoglycan-binding proteins. The involvement of SULF-2 in cancer growth varies by cancer type. The roles of SULF-2 expression in the progression and prognosis of renal cell carcinomas (RCC) have not yet been fully clarified. In the present study, the expression levels of SULF-2 mRNA and protein in 49 clinical RCC samples were determined by RT-PCR and immunostaining. The existence of RCC with higher SULF-2 expression and lower SULF-2 expression compared to the adjacent normal kidney tissues was suggested. High SULF-2 expression was correlated with an early clinical stage and less invasive pathological factors. Low SULF-2 expression was correlated with an advanced stage and higher invasive factors. Three-year cancer-specific survival (CSS) for high SULF-2 RCC and low SULF-2 RCC were 100% and 71.4%, respectively (log-rank P = 0.0019), with a significantly shorter CSS observed in low SULF-2 RCC patients. The influence of SULF-2 expression level on Wnt/VEGF/FGF signaling, cell viability and invasive properties was examined in three RCC cell lines, Caki-2, ACHN and 786-O, using a SULF-2 suppression model involving siRNA or a SULF-2 overexpression model involving a plasmid vector. High SULF-2 expression enhanced Wnt signaling and Wnt-induced cell viability, but not cell invasion. In contrast, low levels of SULF-2 expression significantly enhanced both cell invasion and viability through the activation of VEGF/FGF pathways. RCC with lower SULF-2 expression might have a higher potential for cell invasion and proliferation, leading to a poorer prognosis via the activation of VEGF and/or FGF signaling.

Impact of Body Habitus on Operative Difficulties during Extraperitoneal Laparoscopic Radical Prostatectomy.

PURPOSE: The aim of the present study was to investigate whether patients' body habitus affects the operative difficulties associated with extraperitoneal laparoscopic radical prostatectomy (LRP). Therefore, the associations between body habitus and perioperative outcomes of surgery, including bleeding, operative time, and resection margins, were evaluated. MATERIALS AND METHODS: Between August 2010 and July 2012, 40 consecutive patients with preoperative magnetic resonance imaging and abdominal X-ray examinations underwent extraperitoneal LRP for localized prostate cancer at our institution. The associations between anthropometric measurements and demographics of patients, operation duration, estimated blood loss (EBL), and resection margins were analyzed retrospectively. Multivariate analyses were performed, and P < .05 was considered significant. RESULTS: On multiple regression analysis, the view of the prostatic apex (VPA) was significantly associated with EBL (P = .02), and body mass index (BMI) was significantly associated with operative time (P = .02). On multiple logistic regression analysis, protrusion of the prostate into the bladder was significantly associated with positive resection margins (P = .04). CONCLUSION: The findings of the present study suggest that poor VPA, protrusion of the prostate into the bladder, and high BMI were related to operative difficulties in extraperitoneal LRP. If operative difficulty is predicted preoperatively, it would be better to prepare blood for transfusion and/or special instruments (e.g. flexible scope), or switch to other therapeutic procedures.

[Robot-assisted radical prostatectomy: surgical techniques].

Robot-assisted radical prostatectomy (RARP) for the patients with localized prostate cancer is increasingly being adopted around the world. The da Vinci surgical system (Intuitive Surgical, Sunnyvale, CA, USA) provides the advantages of simplification and precision of exposure and suturing because of allowing movements of the robotic arm in real time with increased degree of freedom and magnified 3-dimensional view. Therefore, RARP has been expected to provide superior therapeutic benefit to patients in terms of surgical outcome to open or laparoscopic radical prostatectomy. In this review, we provide our technical aspects and tips and tricks of RARP to improve surgical outcome and postoperative quality of life.

Timing of Urinary Pad Exchanges Was the Most Important Factor Affecting Quality of Life in the Early Postoperative Period After Robot-Assisted Laparoscopic Radical Prostatectomy.

PURPOSE: The aim of the present study is to investigate the effect of pad use for postprostatectomy incontinence on urinary quality of life (QoL) after robot-assisted laparoscopic radical prostatectomy (RARP) in the early postoperative period. METHODS: Ninety patients underwent RARP simultaneously completed International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) and modified pad use questionnaire that evaluated pad use and urinary QoL and a 24-hour pad test. Pad use was also assessed by pad form, pad size, the number of pad exchanges per day, and the timing of pad exchanges (i.e., to what extent the pad was wet when the patients exchanged it.). The investigation involved patients visiting the outpatient clinic for the first time after RARP. The association between pad use and urinary QoL was investigated. RESULTS: The mean frequency of pad exchanges was 2±2/day. The mean 24-hour pad test was 139±193 g/day. Multivariate analyses revealed the timing of pad exchanges was significantly associated with QoL on the ICIQ-SF and the modified pad use questionnaire (P=0.007 and P<0.001, respectively) and the number of pad exchanges per day was significantly associated with QoL on the ICIQ-SF (P=0.01); QoL worsened with pad wetness and increasing frequency of pad exchange. The other factors relating to pad use were not significantly associated with aggravation of QoL. CONCLUSIONS: In the early postoperative period after RARP, the timing of pad exchanges was the most important factor affecting QoL. Namely, patients with postprostatectomy incontinence should wear the appropriate size of pad according to the volume of urinary incontinence and exchange pads when the pad is not too wet. On the other hand, pad form, pad size, and volume of urinary incontinence were not associated with decreased QoL.

Expression and Function of LPA1 in Bladder Cancer.

PURPOSE: LPA is one of several physiologically active lipid mediators that promote cell proliferation and invasion, and are present in serum, ascites and urine. LPA receptor is a G-protein coupled receptor that is considered a potential therapeutic target for some malignant cancers. We evaluated the expression of LPA receptors in bladder cancer and the effect of LPA in bladder cancer invasion. MATERIALS AND METHODS: Using real-time polymerase chain reaction and immunohistochemical staining we determined LPA receptor expression in bladder cancer specimens from patients with bladder cancer, including 12 with Ta or T1 and 15 with T2-T4 disease. ROCK expression, myosin light chain phosphorylation and Matrigel™ invasion assays were done and morphological observations were made to assess LPA effects in T24 cells, which were derived from bladder cancer. RESULTS: Notably LPA1 mRNA expression was significantly higher in muscle invasive bladder cancer specimens than in nonmuscle invasive specimens. Strong LPA1 expression was evident on cell membranes in muscle invasive specimens. T24 cell invasion was increased by LPA treatment and invasiveness was decreased by LPA1 siRNA or LPA1 inhibitor. LPA treatment increased ROCK1 expression and myosin light chain phosphorylation, and induced morphological changes, including lamellipodia formation and cell rounding. CONCLUSIONS: Results indicate that LPA signaling via LPA1 activation promoted bladder cancer invasion. LPA1 might be useful to detect bladder cancer with highly invasive potential and become a new therapeutic target for invasive bladder cancer treatment.

Current techniques to improve outcomes for early return of urinary continence following robot-assisted radical prostatectomy.

Although open retropubic radical prostatectomy has been the most commonly used surgical technique for patients with localized prostate cancer for decades, robot-assisted radical prostatectomy (RARP) has recently become an alternative option and widely used in Japan as well as around the world. RARP has been shown to have higher postoperative continent rates than retropubic and laparoscopic radical prostatectomy; however, urinary incontinence has remained one of the most significant causes for concern among patients who seek surgical treatment for prostate cancer, even after the introduction of RARP. The literature has shown that certain technical modifications to improve urinary continence are advocated as potential aids to reduce the risk of urinary incontinence after RARP. These modifications might be divided into 3 categories to realize the improvement of early return of urinary continence after RARP: 1) preservation, 2) reconstruction, and 3) reinforcement of the anatomic structures in the pelvis, which will make a new supporting system after radical prostatectomy. In this review, we discuss the intraoperative techniques to improve outcomes for early return of urinary continence following RARP, and provide a critical summary of current knowledge on its outcome in the literature.

The presence of antibodies against the AD2 epitope of cytomegalovirus glycoprotein B is associated with acute rejection after renal transplantation.

The aim of this study was to evaluate the association between antibodies against cytomegalovirus (CMV) glycoprotein B (gB) and acute rejection after transplantation. Seventy-seven consecutive renal transplant recipients in a D + /R+ setting were studied. Biopsy-proven rejection occurred in 35% of the recipients. Among these recipients, 85% had antibodies against CMV gB. The rate of acute rejection was significantly higher in recipients with antibodies against gB than in those without them. Antibodies against gB can be a useful predictor of acute rejection in renal transplant recipients in a D + /R+ setting.

Urinary incontinence after robot-assisted radical prostatectomy: pathophysiology and intraoperative techniques to improve surgical outcome.

Robot-assisted radical prostatectomy has been shown to have comparable and possibly improved postoperative continent rates compared with retropubic and laparoscopic radical prostatectomy. However, postoperative urinary incontinence has remained one of the most bothersome postoperative complications. The basic concept of the intraoperative technique to improve postoperative urinary continence is to maintain as normal anatomical and functional structure in the pelvis as possible. Therefore, improved knowledge of the normal structure in the pelvis should lead to a greater understanding of the pathophysiology of urinary incontinence, and further development of intraoperative techniques to improve the outcomes of urinary continence. It might be necessary to carry out three steps to realize improvement of the early return of urinary continence after robot-assisted radical prostatectomy: (i) preservation (bladder neck, neurovascular bundle, puboprostatic ligament, pubovesical complex, and/or urethral length, etc.); (ii) reconstruction (posterior and/or anterior reconstruction, and/or reattachment of the arcus tendineus to the bladder neck, etc.); and (iii) reinforcement (bladder neck plication and/or sling suspension, etc.). On the basis of these steps, further modifications during robot-assisted radical prostatectomy should be developed to improve urinary continence and quality of life after robot-assisted radical prostatectomy.

Involvement of stretch-induced Rho-kinase activation in the generation of bladder tone.

AIMS: The present study investigated the role of the Rho-kinase (ROK) pathway in the maintenance of bladder tone during the storage phase, and its effects on bladder compliance. METHODS: Muscle strips from isolated rat bladder (detrusor strips) were used to evaluate the effects of the ROK inhibitors Y-27632 and HA-1077 on resting tension, which is independent of G-protein coupled pathways. Stretch-induced ROK activation was assessed by measuring phosphorylation of MYPT1 (myosin phosphatase targeting subunit) using Western blotting. The effect of ROK inhibitors on bladder compliance during bladder filling was assessed in an in vitro whole bladder model. RESULTS: Y-27632 and HA-1077 caused concentration-dependent relaxation of detrusor strips. Stretch increased MYPT1-p[Thr853] levels by approximately 1.5-fold in normal Krebs buffer. The ROK inhibitor Y-27632 abolished the stretch-induced increase and reduced the level of MYPT1-p[Thr853] to <50% of the basal values in normal Krebs buffer. Stretch-induced phosphorylation of MYPT1 was independent of Ca(2+) originating from either extracellular or intracellular stores. When tested in the isolated whole rat bladder model, HA-1077 significantly increased bladder compliance at both 3 and 10 µM. CONCLUSIONS: This study demonstrates that the ROK pathway is constitutively active and stretch further activates the ROK pathway, which contributes to the generation of bladder tone, thereby affecting bladder compliance.

Humanised antihuman IL-6R antibody with interferon inhibits renal cell carcinoma cell growth in vitro and in vivo through suppressed SOCS3 expression.

Interleukin-6 (IL-6), one of the proinflammatory cytokines, is considered to be one of the factors associated with poor prognosis of patients with renal cell carcinoma (RCC). Suppressor of cytokine signalling-3 (SOCS3) is rapidly up-regulated by IL-6 and a negative regulator of cytokine signalling. SOCS3 not only suppresses cytokine-mediated JAK/STAT signalling, but also sustains MAPK pathways. In our study, among the RCC cell lines, IL-6 mRNA expression was the highest in the 786-O cells, which also showed the highest level of SOCS3 mRNA expression under the condition of interferon stimulation. In contrast, ACHN cells had the lowest expression of both IL-6 and SOCS3 mRNA under the same condition. Our study is undertaken to evaluate the effect of humanised antihuman IL-6 receptor (IL-6R) antibody, which completely neutralises IL-6 activity, in RCC cell proliferation and its effect on signalling pathways. IL-6R antibody, tocilizumab, significantly suppressed cell proliferation in 786-O cells with interferon stimulation. Western blot analysis revealed that the tocilizumab enhanced the interferon-induced phosphorylation of STAT1 and inhibited SOCS3 expression and the phosphorylation of both STAT3 and ERK. In contrast, the IL-6 inhibited STAT1 phosphorylation, enhanced STAT3 phosphorylation and accelerated cell proliferation in ACHN cells. The in vivo effects of combination therapy with tocilizumab and interferon showed significant suppression of 786-O tumour growth in a xenograft model. Morphological observation of the tumours revealed the apoptosis, invasion of inflammatory cells and fibrosis. These findings suggest that combination therapy using an antihuman IL-6R antibody with interferon may represent a novel therapeutic approach for the treatment of RCC.

Does body habitus of patients affect operative difficulty during retroperitoneal laparoscopic radical nephrectomy?

BACKGROUND AND PURPOSE: Because of the limited working space available during retroperitoneal laparoscopic radical nephrectomy (LRN), the body habitus of the patient is likely to affect the risk of operative difficulties. This study sought to determine whether anthropometric measurements based on CT and abdominal radiography could be used to predict operative difficulties during retroperitoneal LRN. PATIENTS AND METHODS: Between August 2004 and January 2012, 96 consecutive patients with preoperative CT and abdominal radiography examinations underwent retroperitoneal LRN for a T(1) or T(2) stage renal tumor at our institution. The association between anthropometric measurements and demographics of patients and operative duration, estimated blood loss (EBL), and perioperative complications were retrospectively analyzed. Multivariate analysis was performed, and P<0.05 was considered significant. RESULTS: Anterior perirenal fat distance (P=0.016) and distance from the 12th rib to the iliac crest (P=0.038) were independently associated with operative duration. Only anterior perirenal fat distance (P=0.001) was independently associated with EBL. No intraoperative complications and reoperations occurred. The occurrence or severity of postoperative complications was not significantly associated with anthropometric measurements. Body mass index ≥25.0 kg/m(2) was not significantly associated with operative difficulties. CONCLUSION: The anterior perirenal fat distance and the distance from the 12th rib to the iliac crest can be used to predict operative difficulties during retroperitoneal LRN.

Does periprostatic local anesthesia for prostate biopsy affect the operative difficulty of open radical prostatectomy? A prospective randomized trial.

OBJECTIVES: Periprostatic local anesthesia for transrectal ultrasound (TRUS)-guided prostate biopsy requires additional needle punctures and injection of local anesthetics into the periprostatic area. This study sought to determine the influence of periprostatic local anesthesia on the surgical difficulty of open radical prostatectomy (RP). PATIENTS AND METHODS: A total of 241 consecutive patients who underwent TRUS-guided prostate needle biopsy were randomized to receive either periprostatic nerve block (Anesthesia group; n=120) or no anesthesia (Control group; n=121). After diagnosing localized prostate cancer, patients who underwent open RP without neoadjuvant androgen deprivation therapy were evaluated as to whether perioperative nerve block affected operative duration, estimated blood loss (EBL), positive margin rate or complications. RESULTS: Twenty-one patients in the Anesthesia group and 19 patients in the Control group were investigated in the current study. In assessing the patients who underwent open RP with or without periprostatic nerve block, no significant differences in operative duration, EBL, positive margin rate or complications were seen between groups. CONCLUSION: Periprostatic nerve block does not appear to affect perioperative outcomes after open RP.

Laparoscopic nephrectomy, ex vivo angioplasty, and renal autotransplant for a renal artery aneurysm: a case report.

We describe in this report the case of a renal aneurysm in a 42-year-old woman. The aneurysm measured 27 mm in diameter, and was sited at the first bifurcation of the renal artery. We performed laparoscopic nephrectomy, ex vivo angioplasty and renal autotransplant to avoid ischemic damage to the kidney during reconstruction. The patient recovered and was discharged from the hospital without any complications. Hence, we suggest these treatments can be effectively done in patients with complex renal aneurysms.

New classification for men with lower urinary tract symptoms: cluster analysis using the International Prostate Symptom Score.

SUBJECTS AND METHODS: • Secondary analysis of anonymous data from 10,434 patients enrolled in a postmarketing surveillance study of tamsulosin in Japan was performed. Data were prospectively collected through the central register from men diagnosed with LUTS in 1100 medical institutions between October 2004 and March 2005. • Those who had received an α1-adrenoceptor antagonist within 1 week before the initial visit were excluded. • The survey items were International Prostate Symptom Score (IPSS), quality of life (QOL) score, and patient characteristics including age, bodyweight, body mass index, and LUTS-related comorbid conditions. • Data on IPSS items were used in a hierarchical cluster analysis (Ward's method). RESULTS: • Of 10,434 men with LUTS, 9910 were included in the analysis after 5% data trimming (524 patients). Five symptom clusters were identified and the symptom types of each cluster were examined. • The largest cluster (27%) consisted of patients with multiple severe symptoms, i.e. complaining of six or more symptoms with a mean score ≥2.8. In contrast, the second smallest cluster (13%) consisted of patients with minimal symptoms, i.e. complaining of essentially one or two symptom with a mean score ≤2.1. • The other three clusters were labelled based on their dominant symptoms. The clusters were weak stream (27%), storage symptoms (21%) and voiding symptoms (12%). • The storage symptoms group was older, and had more comorbidities. • The distribution of the QOL score was different among the clusters, and the percentage of patients who were very dissatisfied was highest in the multiple severe symptoms group and lowest in the minimal symptoms group. CONCLUSIONS: • Cluster analysis using the IPSS showed that men with LUTS can be classified into five characteristic symptom groups. • A new approach to symptom-based classification may be useful to elucidate the pathology of male LUTS and individualize the therapeutic strategy for affected patients, but further studies are needed.

The effect of atherosclerosis-induced chronic bladder ischemia on bladder function in the rat.

AIMS: To develop a rat model of atherosclerosis-induced chronic bladder ischemia and investigate the effect of chronic bladder ischemia on voiding behavior and bladder function. METHODS: Adult male rats were divided into three groups. The arterial injury (AI) group underwent endothelial injury of the iliac arteries and received a 2% cholesterol diet. The sham group underwent sham operation and received a 2% cholesterol diet. The control group received a regular diet. After 8 weeks, a metabolic cage study and cystometry were performed without anesthesia. Bladder blood flow was measured using a laser Doppler blood flowmeter. Histological examination of the iliac arteries and the bladder was performed. The bladder was also processed for immunohistochemical staining of oxidative stress markers. RESULTS: The metabolic cage study showed that in the AI group, voiding frequency significantly increased while voided volume significantly decreased. Cystometry showed that the frequency of reflex bladder contractions was significantly higher in the AI group. Filling-induced decrease in bladder blood flow was the greatest in the AI group. Histological study showed that in the AI group alone, atherosclerotic occlusion occurred in the iliac arteries as well as in the downstream bladder microvessels. Oxidative stress marker positive cells were more prevalent in the AI bladder than in the other bladders. CONCLUSIONS: Combined with a high-cholesterol diet, endothelial injury of iliac arteries induced arterial occlusive disease in the downstream vessels and consequent bladder ischemia in rats. This model of chronic bladder ischemia showed detrusor overactivity manifested as an increase in voiding frequency.