James Walter

Dr. James Walter


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 January 2022 in Applied Sciences
Verified
Journal Article
Open access
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James WalterJames Walter
James Walter
Ioan HutuIoan Hutu
Ioan Hutu
BTBerndt Tomancok
Berndt Tomancok
ACAlin Adrian Cumpanas
Alin Adrian Cumpanas
RBRazvan Bardan
Razvan Bardan
HMHelmut Madersbacher
Helmut Madersbacher
(1) Aims: To test a newly designed helical-wire hook electrode implanted in the bladder wall to induce contraction and promote voiding. (2) Methods: In three minipigs with a created lesion of the sacral spinal cord, four electrodes were implanted in the bladder wall, ventral to the trigone. Stimulation tests were conducted initially in conscious pigs, and later after general anesthesia. (3) Results: Electrical stimulation in the conscious animals on postoperative days 4 and 7 at 40 Hz was limited to 10 mA, because of abdominal, leg, and anal contractions with animal discomfort; bladder contractions were not induced. Electrical stimulation on postoperative days 9 and 28 at 60 mA under anesthesia induced sustained vesical wall contractions with bladder pressure variations, but without voiding. Simultaneous abdominal contractions occurred, with strong leg and anal contractions. Subsequent stimulation with a single set of electrodes or at 20 Hz induced less vesical pressure response. At autopsy, the electrodes had not migrated, and extraction forces were high, at 7.9 ± 0.9 Newtons (n = 12). (4) Conclusions: Our 28-day study has confirmed the utility of the new electrode design, preventing migration from the bladder wall and making it suitable for long-term electrode implants.

13 March 2023 in Journal of Clinical Medicine
Verified
Journal Article
Open access
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DNDorin Novacescu
Dorin Novacescu
ANAlexandru Nesiu
Alexandru Nesiu
RBRazvan Bardan
Razvan Bardan
SLSilviu Constantin Latcu
Silviu Constantin Latcu
VDVlad Filodel Dema
Vlad Filodel Dema
ACAlin Adrian Cumpanas
Alin Adrian Cumpanas
In the contemporary era of early detection, with mostly curative initial treatment for prostate cancer (PC), mortality rates have significantly diminished. In addition, mean age at initial PC diagnosis has decreased. Despite technical advancements, the probability of erectile function (EF) recovery post radical prostatectomy (RP) has not significantly changed throughout the last decade. Due to virtually unavoidable intraoperative cavernous nerve (CN) lesions and operations with younger patients, post-RP erectile dysfunction (ED) has now begun affecting these younger patients. To address this pervasive limitation, a plethora of CN lesion animal model investigations have analyzed the use of systemic/local treatments for EF recovery post-RP. Most promisingly, neuregulins (NRGs) have demonstrated neurotrophic effects in both neurodegenerative disease and peripheral nerve injury models. Recently, glial growth factor 2 (GGF2) has demonstrated far superior, dose-dependent, neuroprotective/restorative effects in the CN injury rat model, as compared to previous therapeutic counterparts. Although potentially impactful, these initial findings remain limited and under-investigated. In an effort to aid clinicians, our paper reviews post-RP ED pathogenesis and currently available therapeutic tools. To stimulate further experimentation, a standardized preparation protocol and in-depth analysis of applications for the CN injury rat model is provided. Lastly, we report on NRGs, such as GGF2, and their potentially revolutionary clinical applications, in hopes of identifying relevant future research directions.

20 June 2022 in Uro
Verified
Journal Article
Open access
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James WalterJames Walter
James Walter
JWJohn Wheeler
John Wheeler
If urinary catheters are used during surgeries, epidurals and parturition, patients and their physicians want a return to volitional voiding as soon as possible. Micturition is regained by passing a decatheterization test. Fortunately, only a small percentage of patients fail three or more of these tests and have to use catheters longer-term. Surprisingly, there are no approved drugs that are currently approved to assist with these tests; however, bethanechol, 50 mg/BID, should be considered further for this application. The drug is a bladder wall receptor stimulant and, at this moderate dosage, it is reasonable to expect it to help with decatheterization tests. This position statement includes several designs for future bethanechol use and research. In addition, an International Neuro-Urological Research Group is introduced that is promoting this drug.

27 July 2022 in Uro
Verified
Journal Article
Open access
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James WalterJames Walter
James Walter
JWJohn Wheeler
John Wheeler
AKAasma Khan
Aasma Khan
Individuals with spinal cord injury and multiple sclerosis usually use intermittent catheterization for urinary management; however, many patients will also encounter a condition of neurogenic detrusor overactivity, which causes urinary incontinence. The use of muscarinic receptor antagonists is the first-line treatment to manage this condition. These drugs, however, have significant side effects. Transcutaneous electrical nerve stimulation applied to the genital nerve (GEN) is an alternative noninvasive method that produces detrusor inhibition through neuromodulation. Despite studies demonstrating bladder inhibition with GEN, more outcomes are required regarding decreased use of bladder inhibitory medications and concerns with dangling wires. It is proposed that wireless-GEN can be used in home-use studies in order to address these limitations. If needed, wireless tibial nerve stimulation could be added to improve incontinence management.

11 November 2022 in Uro
Verified
Journal Article
Open access
PDF file
James WalterJames Walter
James Walter
JWJohn Wheeler
John Wheeler
RDRaymond Dieter
Raymond Dieter
BPBrandon Piyevsky
Brandon Piyevsky
AKAasma Khan
Aasma Khan
Spinal cord injury can either be complete with no neural communication across the injury level or incomplete with limited communication. Similarly, motor neuron injuries above the sacral spinal cord are classified as upper motor neuron injuries, while those inside the sacral cord are classified as lower motor neuron injuries. Specifically, we provide recommendations regarding the urological management of complete upper motor neuron spinal cord injuries; however, we also make limited comments related to other injuries. The individual with a complete upper motor neuron injury may encounter five lower urinary tract conditions: first, neurogenic detrusor overactivity causing urinary incontinence; second, neurogenic detrusor underactivity resulting in high post-void residual volumes; third, detrusor sphincter dyssynergia, which is contraction of striated and/or smooth muscle urethral sphincters during detrusor contractions; fourth, urinary tract infection; and fifth, autonomic dysreflexia during detrusor contractions, which produces high blood pressure as well as smooth muscle detrusor sphincter dyssynergia. Intermittent catheterization is the recommended urinary management method because it addresses the five lower urinary tract conditions and has good long-term outcomes. This method uses periodic catheterizations to drain the bladder, but also needs bladder inhibitory interventions to prevent urinary incontinence between catheterizations. Primary limitations associated with this management method include difficulties with the multiple catheterizations, side effects of bladder inhibitory medications, and urinary tract infections. Three suggestions to address these concerns include the use of low-friction catheters, wireless, genital-nerve neuromodulation for bladder inhibition, and consideration of urine egress into the urethra as a risk factor for UTI as well as egress treatment. The second management method is reflex voiding. This program uses external condoms for urine collection in males and diapers for females. Suprapubic tapping is used to promote bladder contractions. This method is not recommended because it has high rates of medical complications. In particular, it is associated with high detrusor pressure, which can lead to ureteral reflux and kidney pathology. Botulinum toxin injection into the urethral striated sphincter can manage detrusor sphincter dyssynergia, reduce voiding pressures, and risks to the kidney. We suggest a modified method for botulinum toxin injections as well as five additional methods to improve reflex voiding outcomes. Finally, the use of intermittent catheterization and reflex voiding for individuals with incomplete spinal injuries, lower motor neuron injuries and multiple scleroses are briefly discussed.

23 September 2022 in Uro
Verified
Journal Article
Open access
PDF file
James WalterJames Walter
James Walter
JWJohn Wheeler
John Wheeler
AKAasma Khan
Aasma Khan
In 50% of typical (nonneurogenic) women, at least one urinary tract infection (UTI) will occur, with cystitis being the most common UTI, with about 25% of patients experiencing recurrence. A factor not currently included in UTI risk models is egress of urine from the bladder into the urethra during bladder filling and activities of daily living. Urinary egress, if it occurs, would shorten the distance that bacteria need to travel to gain access to the bladder. Video urodynamics with contrast medium can demonstrate urinary egress; however, the observations can be difficult to conduct. Egress can be expected to be more likely in women with lower urinary tract conditions such as urge and stress incontinence. Treatment of the incontinence also reduces UTI rates and the reduction could, in part, be due to reduced urine egress. If UTI risk remains after incontinence management, then further treatment with pelvic floor exercises and pessaries could be considered to reduce the risk from potential residual urine egress. In summary, urine egress as a risk factor for UTI needs further research and clinical consideration.