Simple Modification of the Bladder Outlet Obstruction Index for Better Prediction of Endoscopically-Proven Prostatic Obstruction: A Preliminary Study

Modified bladder outlet obstruction index for powerful efficacy prediction of transurethral resection of prostate with benign prostatic hyperplasia

Background

The correlation between modified bladder outlet obstruction index (MBOOI) and surgical efficacy still remains unknown. The purpose of the study was to investigate the clinical value of the MBOOI and its use in predicting surgical efficacy in men receiving transurethral resection of the prostate (TURP).

Methods

A total of 403 patients with benign prostate hyperplasia (BPH) were included in this study. The International Prostate Symptom Score (IPSS), quality of life (QoL) index, transrectal ultrasonography, and pressure flow study were conducted for all patients. The bladder outlet obstruction index (BOOI) (P_detQ_max–2Q_max) and MBOOI (P_ves–2Q_max) were calculated. All patients underwent TURP, and surgical efficacy was accessed by the improvements in IPSS, QoL, and Q_max 6 months after surgery. The association between surgical efficacy and baseline factors was statistically analyzed.

Results

A comparison of effective and ineffective groups based on the overall efficacy showed that significant differences were observed in PSA, P_ves, P_detQ_max, P_abd, BOOI, MBOOI, TZV, TZI, IPSS-t, IPSS-v, IPSS-s, Q_max, and PVR at baseline (p < 0.05). Binary logistic regression analysis suggested that MBOOI was the only baseline parameter correlated with the improvements in IPSS, QoL, Q_max, and the overall efficacy. Additionally, the ROC analysis further verified that MBOOI was more optimal than BOOI, TZV and TZI in predicting the surgical efficacy.

Conclusion

Although both MBOOI and BOOI can predict the clinical symptoms and surgical efficacy of BPH patients to a certain extent, however, compared to BOOI, MBOOI may be a more useful factor that can be used to predict the surgical efficacy of TURP.

Trial registration retrospectively registered.

Elevated hydrostatic pressure stimulates ATP release which mediates activation of the NLRP3 inflammasome via P2X4 in rat urothelial cells

Partial bladder outlet obstruction (pBOO) is a prevalent urological condition commonly accompanied by increased intravesical pressure, inflammation, and fibrosis. Studies have demonstrated that pBOO results in increased NLRP3 inflammasome and caspase-1 activation and that ATP is released from urothelial cells in response to elevated pressure. In the present study, we investigated the role of elevated pressure in triggering caspase-1 activation via purinergic receptors activation in urothelial cells. Rat urothelial cell line, MYP3 cells, was subjected to hydrostatic pressures of 15 cmH₂O for 60 min, or 40 cmH₂O for 1 min to simulate elevated storage and voiding pressure conditions, respectively. ATP concentration in the supernatant media and intracellular caspase-1 activity in cell lysates were measured. Pressure experiments were repeated in the presence of antagonists for purinergic receptors to determine the mechanism for pressure-induced caspase-1 activation. Exposure of MYP3 cells to both pressure conditions resulted in an increase in extracellular ATP levels and intracellular caspase-1 activity. Treatment with P2X₇ antagonist led to a decrease in pressure-induced ATP release by MYP3 cells, while P2X₄ antagonist had no effect but both antagonists inhibited pressure-induced caspase-1 activation. Moreover, when MYP3 cells were treated with extracellular ATP (500 µM), P2X₄ antagonist inhibited ATP-induced caspase-1 activation, but not P2X₇ antagonist. We concluded that pressure-induced extracellular ATP in urothelial cells is amplified by P2X₇ receptor activation and ATP-induced-ATP release. The amplified ATP signal then activates P2X₄ receptors, which mediate activation of the caspase-1 inflammatory response.

Minimal Invasive Cystometry and Intra-Abdominal Pressure Assessments in Rodents: A Novel Animal Study

BACKGROUND The abdominal straining pattern can act as a novel parameter for improving the prediction of bladder outlet obstruction (BOO). To preserve detrusor function in the early stage of urinary system impairment, such as BOO, we establish a novel method for cystometry and Intra-abdominal pressure (IAP) assessments in rodents without cystostomy. MATERIAL AND METHODS Twenty mice and rats were divided into three groups (control, sham-operated and BOO group) respectively. The cystometry and IAP assessments were measured by the pediatric venous indwelling sheath and coronary dilatation catheter connected to Laborie urodynamic system on postoperative day 7. Data was collected simultaneously through urethra and rectum in each group. In addition, bladder histology was assessed to confirm BOO. RESULTS The novel method can collect the urodynamic parameters successfully, including the BLPP, IAP, MBC, etc. IAP was elevated in BOO rats, but no significantly difference was found between the sham-operated rats and the control rats. The hypertrophy of detrusor muscle in bladder section was observed by Masson trichrome staining in BOO group compared with other groups. CONCLUSIONS Our novel method based on innovative research implement for cystometry and IAP assessments in rodents is a reliable and replicable approach for evaluating the lower urinary tract function. Especially it provides detailed information to evaluate lower urinary tract structures and function in the early stage of BOO.