A stepwise approach for functional near infrared spectroscopy measurement during natural bladder filling

Background

Functional near infrared spectroscopy (fNIRS) is a versatile, noninvasive, and inexpensive tool that can be used to measure oxyhemoglobin (O2Hb) changes in the cortical brain caused by increasing bladder sensation during filling in upright posture. This study's purpose is to provide a rigorous methodologic template that can be implemented for comparative studies of fNIRS in the diagnosis and management of lower urinary tract symptoms including overactive bladder (OAB) and other forms of lower urinary tract dysfunction.

Methods

Participants without any urologic conditions completed a validated oral hydration protocol facilitating and equilibrating natural bladder filling. First desire to void and real time bladder sensation (0-100%) were recorded using a Sensation Meter. A 24-channel fNIRS template simultaneously recorded prefrontal cortical O2Hb. Each channel was analyzed between "first desire" to void and 100% sensation, defined in this study as the period of "high sensation". Channels were sub-divided by cortical regions: right (nine channels), left (nine channels), middle (six channels).

Results

A total of eight participants (male: n=4, female: n=4) were enrolled with mean age 39±19.9 years and body mass index (BMI) of 25±3.93 kg/m2. There were no differences in age, BMI, race, or OAB survey scores based on biological sex. Signal acquisition improved with power bank use, postural head support for motion reduction, and head cap optimization. Acceleration-based concurrent motion measurement was effectively utilized to remove motion artifacts. O2Hb concentration patterns appeared irregular during low sensation and increased during high sensation after first desire across the frontal cortex.

Conclusions

Employing a stepwise approach, this study defined a methodological guide for improved prefrontal fNIRS signal acquisition and analysis during bladder filling. The technique demonstrated that prefrontal fNIRS cortical O2Hb increases with elevated bladder sensation in normal subjects and sets the stage for comparative studies in individuals with OAB and other forms of lower urinary tract dysfunction.

Oncologic outcomes following radical nephroureterectomy for upper tract urothelial carcinoma: a literature review

Background and Objective

Radical nephroureterectomy (RNU) represents the gold standard treatment for non-metastatic upper tract urothelial cancer. We sought to provide a comprehensive review of reported oncologic outcomes of the RNU procedure and of factors that might impact these outcomes.

Methods

A non-systematic review of the literature was conducted by performing an electronic literature search using PubMed with "radical nephroureterectomy" and "oncologic outcomes" as free text search terms. Both original articles and systematic reviews were considered. Search was limited to articles in English that were published in the last 20 years.

Key Content and Findings

Open and laparoscopic RNU offer comparable oncologic outcomes. In more recent years, the discussion has de facto shifted towards the "oncological safety" of robotic RNU, which also seems to offer comparable oncologic outcomes. Several studies have looked at the impact of different treatment-, patient- and tumor-related factors. Among treatment-related factors, attention has been given to diagnostic ureteroscopy and the risk of intravesical recurrence. Surgical wait time and perioperative blood transfusion have also been studied. Perioperative chemotherapy, specifically adjuvant therapy, was shown to improve survival. Among patient-related factors, baseline chronic kidney disease, diabetes mellitus, body mass index, and systemic inflammation have gained recent attention. Some tumor related factors, such as stage, grade, location, and multifocality may negatively impact survival outcomes. Lymphovascular invasion and histologic variants are clinically significant pathological findings.

Conclusions

RNU is a procedure with measured long-term oncologic outcomes. Minimally invasive techniques have gained an established role as they seem to offer comparable oncologic "safety", although special attention is needed in relation to the method of bladder cuff excision. Robotic RNU is gaining popularity, and while evidence remains limited, the current literature supports the oncologic safety of this procedure. Several factors, which can be categorized as treatment-related, patient-related, and tumor-related, might impact the oncologic outcomes of UTUC patients undergoing RNU. These factors can provide crucial information to stratify patients based on their relative risk of disease recurrence and mortality which may guide clinical decision-making.

A porcine bladder model of pre-clinical urodynamics demonstrates increased afferent nerve activity during filling

INTRODUCTION AND OBJECTIVES

Urodynamics are the accepted gold standard for the evaluation of multiple forms of voiding dysfunction. However, the tests are expensive, invasive, poorly reproducible, and often prone to artifacts. Therefore, there is a pressing need to develop next-generation urodynamics. The purpose of this study was to develop a novel ex vivo porcine bladder urodynamics model with afferent pelvic nerve signaling that can be used as a preclinical surrogate for bladder sensation.

METHODS

Porcine bladders including the ureters and vascular supply were harvested from local abattoirs using an established protocol in both male and female animals. Ex vivo bladder perfusion was performed using physiologic MOPS (3-(N-morpholino) propanesulfonic acid) buffer solution. The pelvic nerve adjacent to the bladder was grasped with micro-hook electrodes and electroneurogram (ENG) signals recorded at 20 kHz. Bladders were filled with saline at a nonphysiologic rate (100 mL/min) to a volume of 1 L using standard urodynamics equipment to simultaneously record intravesical pressure. ENG amplitude was calculated as the area under the curve for each minute, and ENG firing rate was calculated as number of spikes (above baseline threshold) per minute. At the conclusion of the experiment, representative nerve samples were removed and processed for nerve histology by a pathologist (hematoxylin and eosin and S100 stains).

RESULTS

A total of 10 pig bladders were used, and nerve histology confirmed the presence of nerve in all adequately processed samples. Vesical pressure, ENG firing rate, and ENG amplitude all increased as a function of filling. During filling tertiles (low fill: min 1-3, med fill: min 4-6, and high fill: min 7-10), normalized pressures were 0.22 ± 0.04, 0.38 ± 0.05, and 0.72 ± 0.07 (cmH2O). Similarly, normalized ENG firing rates were 0.08 ± 0.03, 0.31 ± 0.06, and 0.43 ± 0.04 spikes/minute, respectively, and normalized nerve amplitudes were 0.11 ± 0.06, 0.39 ± 0.06, and 0.56 ± 0.14) μV, respectively. Strong relationships between average normalized pressure values and averaged normalized ENG firing rate (r2  = 0.66) and average normalized ENG amplitude (r2  = 0.8) were identified.

CONCLUSIONS

The ex vivo perfused porcine bladder can be used as a preclinical model for the development of next-generation urodynamics technologies. Importantly, the model includes a reproducible method to measure afferent nerve activity that directly correlates with intravesical pressure during filling and could potentially be used as a surrogate measure of bladder sensation.

The use of low-intensity extracorporeal shockwave therapy in management of erectile dysfunction following prostate cancer treatment: a review of the current literature

Background and Objective

Erectile dysfunction (ED) is a prevalent and impactful complication post definitive management of prostate cancer. The mechanism of ED is thought to be secondary to vascular and neural injury as well as corporal smooth muscle damage with resultant fibrosis. The use of penile rehabilitation in ED following treatment for prostate cancer has been studied. Low-intensity extracorporeal shockwave therapy (Li-ESWT) is a novel treatment for ED thought to stimulate neovascularization and nerve regeneration, and as such, has gained interest in treatment of ED related to radical prostatectomy or radiation therapy. Herein, we performed a narrative review on the use of Li-ESWT in management of ED following treatment for prostate cancer.

Methods

A literature review was performed using PubMed and Google Scholar. Studies evaluating Li-ESWT following prostate cancer treatment were included.

Key Content and Findings

We identified three randomized controlled trials and two observational studies that assessed use of Li-ESWT for ED after prostate surgery. Use of Li-ESWT across most studies showed improvements in the International Index of Erectile Function-erectile function (IIEF-EF) domain scores, but this improvement was not statistically significant. Additionally, use of Li-ESWT in an early versus delayed fashion does not appear to affect changes in long-term sexual function scores. No data on use of Li-ESWT after radiotherapy were identified.

Conclusions

There is a paucity of data regarding use of Li-ESWT for penile rehabilitation in treatment of ED post-prostate cancer therapy. Current protocols for Li-ESWT are not standardized and have a limited number of participants with short duration of follow-up. Additional evaluation is needed to determine optimal Li-ESWT protocols. Ideally, studies should have longer follow-up to truly evaluate the clinical significance of Li-ESWT in the treatment of post-prostatectomy ED. Furthermore, the role of Li-ESWT after radiotherapy remains elusive.

Condom usage by a population of delinquent southern male adolescents

Of sexually active delinquent male adolescents admitted to a detention facility over a 6-month period from 1987 to 1988, 69% reported condom usage. Review of the medical records of a similar group of detainees from the same facility in 1984 revealed a 44% reported condom usage rate, suggesting a marked increase in utilization. Stated reasons for condom use in 1987-1988 included prevention of sexually transmitted diseases (63%) and pregnancy (33%). More than one reason was given by 20%.

Organic substances in potable water and in its precursor. III. The closed-loop stripping procedure compared with rapid liquid extraction

An attempt is made to define the role of gas chromatography in the investigation of organic substances in water, which is important because the handling of water samples before gas chromatographic (GC) analysis depends entirely on the information expected from the subsequent separation, identification and quantification. Practical long-term experience with the previously published closed-loop stripping procedure (with intermediate adsorption on activated carbon) is described and further refinements are reported. A rapid and simple liquid extraction method is described, based on shaking 11 of water with a small volume (0.5-1 ml) of solvent and subsequent high-resolution GC analysis of the extract. Qualitative and semi-quantitative information at the parts per 10(12) level is easily obtained. Further studies of recovery rates under conditions where the volatility and polarity of extracted organic substances are varied are described for both methods. The suitability of both methods for the analysis of different types of water samples is discussed.