Towards an understanding of the role of intravesical capsaicin in the treatment of detrusor hyperreflexia

Capsaicin is the pungent extract of red-hot chilli peppers. Chillies were grown as early as 5000 BC in Mexico and have been used medicinally, for a variety of seemingly unrelated disorders, for thousands of years. Animal experiments have demonstrated that capsaicin blocks a C-fibre mediated micturition reflex in spinal cats. The aim of this study was to investigate its role in the treatment of detrusor hyperreflexia due to spinal cord disease. Intravesical instillations of 1-2 mmol/l of capsaicin, dissolved as a powder in 30% alcohol in saline, were effective in 70% of patients with refractory detrusor hyperreflexia. After initial deterioration in voiding symptoms capsaicin caused an increase in the functional bladder capacity and decrease in the amplitude of hyperreflexic detrusor contractions. The beneficial effect of a single instillation lasted for 3-6 months. Even after repeated instillations over 5 years there was no evidence of pre-malignant or malignant changes in biopsies from bladders thus treated. Suprapubic discomfort during instillations was reduced by the prior use of intravesical lignocaine (40ml of 2% for 20 mins) or by anaesthetising the bladder with iontophoresis of intravesical lignocaine (electromotive drug administration) before capsaicin. Cryostat sections of flexible cystoscopic biopsies before and 6 weeks after capsaicin treatment were stained with the neuronal markers S 100 and PGP 9.5. By using computerized image analysis of lamina propria nerve densities ('MiniMOP' for S 100 and 'Seescan' imaging for PGP 9.5) it was found that intravesical capsaicin caused a reduction in densities of the presumptive sensory suburothelial nerves. Early data using electron microscopy seemed to show a reduction in the densities of clear and dense cored vesicles after capsaicin treatment. These findings indicate that capsaicin causes a sensory denervation the bladder in these patients. Intravesical capsaicin is a significant advance in Uro-Neurology and is likely to lead to the application of other vanilloids, such as resiniferatoxin, in the treatment of detrusor hyperreflexia

Retrograde ejaculation following open ureteric reimplantation: a case report

Abstract Introduction Retrograde ejaculation is not a recognized complication of ureteric reimplantation surgery. We describe this unusual complication in a 25-year-old man, with no other cause for his ejaculatory dysfunction. Case presentation A 25-year-old Caucasian man presented with left hydronephrosis ascribed to a megaureter. Following open reimplantation of the ureter, the patient developed retrograde ejaculation that did not respond to medical therapy. Conclusion The key result reported here is that retrograde ejaculation is a possible complication of open pelvic surgery, for which patients should receive counselling. This is relevant for both urologists and general physicians who consult relatively young men with ejaculatory difficulties.</p

Has robotic prostatectomy determined the fall of the laparoscopic approach?

© The Author(s) 2021. This article is licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).Robotic Assisted Laparoscopic Prostatectomy (RALP) has revolutionised the surgical management of localised Prostate Cancer in the modern era. The surgeon is provided with greater precision, more versatile dexterity and an immersive three-dimensional visual field. The impressive hardware facilitates, for example, the dissection of the peri-prostatic fascia, whilst preserving the neurovascular bundle, or the suturing of the vesico-urethral anastomosis. Prior to RALP, Laparoscopic Radical Prostatectomy (LRP) represented the first venture into the minimally invasive world. Associated with more cumbersome ergonomics, LRP has a significant learning curve when compared with the robotic approach. There has been a paucity, until recently, of high-quality literature comparing outcomes between the two operations, including the attainment of the Pentafecta of survivorship: biochemical recurrence-free, continence, potency, no postoperative complications and negative surgical margins.Peer reviewedFinal Published versio

Human Behavioral Metrics of a Predictive Model Emerging During Robot Assisted Following Without Visual Feedback

Robot assisted guiding is gaining increased interest due to many applications involving moving in noisy and low visibility environments. In such cases, haptic feedback is the most effective medium to communicate. In this paper, we focus on perturbation based haptic feedback due to applications like guide dogs for visually impaired people and potential robotic counterparts providing haptic feedback via reins to assist indoor firefighting in thick smoke. Since proprioceptive sensors like spindles and tendons are part of the muscles involved in the perturbation, haptic perception becomes a coupled phenomenon with spontaneous reflex muscle activity. The nature of this interplay and how the model based sensory-motor integration evolves during haptic based guiding is not well understood yet. In this study, we asked human followers to hold the handle of a hard rein attached to a 1-DoF robotic arm that gave perturbations to the hand to correct an angle error of the follower. We found that human followers start with a 2nd order reactive autoregressive following model and changes it to a predictive model with training. The post-perturbation Electromyography (EMG) activity exhibited a reduction in co-contraction of muscles with training. This was accompanied by a reduction in the leftward/rightward asymmetry of a set of followers behavioural metrics. These results show that the model based prediction accounts for the internal coupling between proprioception and muscle activity during perturbation responses. Furthermore, the results provide a firm foundation and measurement metrics to design and evaluate robot assisted haptic guiding of humans in low visibility environments

Miniaturized triaxial optical fiber force sensor for MRI-guided minimally invasive surgery

Proceedings of: 2010 IEEE International Conference on Robotics and Automation (ICRA'10), May 3-8, 2010, Anchorage (Alaska, USA)This paper describes the design and construction of a miniaturized triaxial force sensor which can be applied inside a magnetic resonance imaging (MRI) machine. The sensing principle of the sensor is based on an optical intensity modulation mechanism that utilizes bent-tip optical fibers to measure the deflection of a compliant platform when exposed to a force. By measuring the deflection of the platform using this optical approach, the magnitude and direction of three orthogonal force components (Fx, Fy, and Fz) can be determined. The sensor prototype described in this paper demonstrates that it can perform force measurements in axial and radial directions with working ranges of +/- 2 N. Since the sensor is small in size and entirely made of nonmetallic materials, it is compatible with minimally invasive surgery (MIS) and safe to be deployed within magnetic resonance (MR) environments.European Community's Seventh Framework Progra

An Optimal State Dependent Haptic Guidance Controller via a Hard Rein

The aim of this paper is to improve the optimality and accuracy of techniques to guide a human in limited visibility & auditory conditions such as in fire-fighting in warehouses or similar environments. At present, teams of breathing apparatus (BA) wearing fire-fighters move in teams following walls. Due to limited visibility and high noise in the oxygen masks, they predominantly depend on haptic communication through reins. An intelligent agent (man/machine) with full environment perceptual capabilities is an alternative to enhance navigation in such unfavorable environments, just like a dog guiding a blind person. This paper proposes an optimal state-dependent control policy to guide a follower with limited environmental perception, by an intelligent and environmentally perceptive agent. Based on experimental systems identification and numerical simulations on human demonstrations from eight pairs of participants, we show that the guiding agent and the follower experience learning for a optimal stable state-dependent a novel 3rd and 2nd order auto regressive predictive and reactive control policies respectively. Our findings provide a novel theoretical basis to design advanced human-robot interaction algorithms in a variety of cases that require the assistance of a robot to perceive the environment by a human counterpart