<p>Spinal cord injury (SCI) and other neurological diseases and disorders can cause urinary dysfunction that can cause serious health problems and reduce an individual's quality of life. Current methods for treating urinary dysfunction have major limitations or provide inadequate improvement in urinary symptoms. Pudendal nerve stimulation is a potential means of restoring control of bladder function in persons with neurological disease or spinal cord injury. Bladder contraction and relaxation can be evoked by pudendal afferent stimulation, and peripheral pudendal afferent branches may be ideal targets for a bladder control neural prosthesis. This dissertation investigates control of bladder function by selective activation of pudendal afferents.</p> <p>This study investigated the ability to improve both urinary continence and micturition by both direct and minimally-invasive electrical stimulation of selected pudendal afferents in &#945;-chloralose anesthetized male cats. Direct stimulation of the pudendal afferents in the dorsal nerve of the penis (DNP), percutaneous DNP stimulation, and intraurethral stimulation were used to investigate the bladder response to selective activation of pudendal afferents. Finite element modeling of the cat lower urinary tract was used to investigate the impact of intraurethral stimulation location and intraurethral electrode configuration on activation of pudendal afferents. Also, the impact of pharmacological and surgical block of sympathetic activity to the bladder on the bladder reflexes evoked by DNP stimulation was investigated to determine the role of the sympathetic bladder innervation on the mechanism of bladder activation by pudendal afferent stimulation.</p> <p>The DNP is an ideal target for restoring urinary function because stimulation at low frequencies (5-10 Hz) improves urinary continence, while stimulation at high frequencies (33-40 Hz) improves urinary voiding. Intraurethral stimulation is a valid method for clinical investigation of the ability to evoke bladder inhibition and activation via selective activation of the DNP or cranial sensory branch (CSN) of the pudendal nerve. In the cat, intraurethral stimulation can activate the bladder via two distinct neural pathways, a supraspinal pathway reflex activated by the CSN and a spinal reflex activated by the DNP. Finite element modeling revealed the importance of urethral location for selective pudendal afferent activation by intraurethral stimulation. Finally, the sympathetic bladder pathway does not play a significant role in the mechanism mediating bladder activation by DNP stimulation. These findings imply that selective pudendal afferent stimulation is a promising approach for restoring control of bladder function to individuals with SCI or other neurological disorders.</p> / Dissertation

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-12-16T17:15:33Z No. of bitstreams: 1 marcellofonsecasalgadofilho.pdf: 9000247 bytes, checksum: a234119931ed8da56fb969e17bc8b078 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-12-19T13:03:57Z (GMT) No. of bitstreams: 1 marcellofonsecasalgadofilho.pdf: 9000247 bytes, checksum: a234119931ed8da56fb969e17bc8b078 (MD5) / Made available in DSpace on 2016-12-19T13:03:57Z (GMT). No. of bitstreams: 1 marcellofonsecasalgadofilho.pdf: 9000247 bytes, checksum: a234119931ed8da56fb969e17bc8b078 (MD5) Previous issue date: 2010-04-14 / Introdução: O bloqueio do nervo dorsal do pênis (BNDP) e a anestesia local tópica (LT) com uma mistura eutética de prilocaína e lidacaína são técnicas de uso rotineiro, fácil aplicação e baixo índice de complicações na cirurgia de postectomia. Propôs-se avaliar qual delas apresenta melhor analgesia com menor efeito hemodinâmico na cirurgia de postectomia por Plastibell® em crianças. Pacientes e métodos: Este ensaio clínico randomizado foi conduzido com 41 meninos, submetidos à postectomia por Plastibell® divididos em dois grupos: LT e BNDP. O estudo foi aprovado pelo Comitê de Ética em Pesquisa em Humanos segundo as normas da declaração de Helsinki e pelo Clinical trials/FDA. Nos pacientes sorteados para a técnica LT, a pomada de mistura eutética de prilocaína e lidacaína era aplicada no prepúcio uma hora antes da cirurgia. Antes da indução anestésica, todas as crianças eram monitoradas com estetoscópio precordial e monitor multiparâmetro Datex Omeda®. A indução anestésica era padrão para os dois grupos, com concentração inspirada de sevoflurano a 8% sob máscara facial e ventilação espontânea. No grupo BNDP, fez-se o bloqueio do nervo dorsal do pênis com levobupivacaína a 0,5% na dose de 2mg/kg. Avaliaram-se a frequência cardíaca, a pressão arterial média, a frequência respiratória e os movimentos involuntários durante os momentos de indução anestésica, de bloqueio do nervo dorsal do pênis, um minuto após a incisão e no pós-operatório imediato. A dor foi avaliada na primeira e na vigésima quarta hora de pós-operatório, pela escala análogo visual de dor. Resultados: Os grupos foram homogêneos quanto à idade, peso, diâmetro da glande, comprimento do pênis e tempo cirúrgico. No grupo LT, observou-se uma tendência a aumento da freqüência cardíaca no momento 1 minuto pós-incisão (p = 0,073) e da pressão arterial media no momento 1 minuto pósincisão (p = 0,046). No grupo BNDP, houve aumento da freqüência cardíaca (p = 0,004) e da pressão arterial média (p = 0,016) no momento do bloqueio. Comparando os momentos de maiores estímulos hemodinâmicos em cada grupo (T2 no grupo LT e T1 no grupo BNDP), observamos um estímulo mais intenso no BNDP, com aumento significante da freqüência cardíaca (p = 0,001) e maior incidência de movimentos involuntários (p = 0,002). Não houve diferença na dor 7 na primeira e na vigésima quarta hora de pós-operatório entre os grupos estudados. A incidência de hematoma e edema em 24 horas de pós--operatório foi maior no grupo BNDP. Conclusão: A anestesia LT com a pomada de mistura eutética de prilocaína e lidacaína proporciona menor repercussão hemodinâmica e analgesia satisfatória ao procedimento de postectomia por Plastibell®, controle da dor pós-operatório e baixa incidência de complicações pós-operatórias em relação ao BNDP, quando ambas as técnicas estão associadas à anestesia geral inalatória com sevoflurano. / Introduction: The dorsal penile nerve block (DPNB) and local topical anesthesia (LT) with eutetic mixture lidocaine and prilocaine are current techniques with easy implementation and low complication rate in circumcision surgery. Herein, we evaluated which anesthetic technique provides better analgesia with less hemodynamic stimulation during circumcision with Plastibell® in children. Patients and methods: Forty-one boys who underwent circumcision with Plastibell® were divided at random into two groups: LT and DPNB. In LT group the ointment eutetic mixture lidocaine and prilocaine was applied to the foreskin one hour before surgery. Before inhalatory induction, all children were completely monitored. Inhalatory induction was standard for the two groups with 8% end-tidal concentration of sevoflurane on a facemask and spontaneous ventilation. After 10 minutes of anesthesia induction, the end-tidal sevoflurane concentration was decreased to 2%. In the DPNB a dorsal penile nerve block was done with levobupivacaine 0.5% (2 mg/kg). We evaluated the heart rate, respiratory rate mean arterial pressure, and involuntary movements in the moments of induction of anesthesia (T0); dorsal penile nerve block (T1); 1 minute post-incision (T2) and 1 minute after end of surgery (T3). And also pain 1 hour and 24 hours after surgery. Results: The groups were homogeneous when compared age, weight, diameter of the glands, penile length and surgical duration. In the LT group there was a tendency to increase Heart Rate at T2 (p = 0.073) and an increase of Mean Arterial Pressure at T2 (p = 0.046) when compared to the induction time. The DPNB group had an increase in Heart Rate (p = 0.004) and Mean Arterial Pressure (p = 0.016) at the block time (T1) when compared to T0 time. Comparing the moments of greatest hemodynamic stimulus for each group (T2 for LT and T1 for DPNB) we observed a more intense stimulus in DPNB group with a significant increase in Heart Rate (p = 0.001) and greater incidence of involuntary movements (57.1% vs. 10%; p = 0.002). There was no difference in the incidence of pain between the study groups. Post-operative complications were higher in DPNB, especially hematoma and edema. Conclusions: Anesthesia with eutetic mixture lidocaine and prilocaine provides satisfactory hemodynamic stable during circumcision with Plastibell®, pain control and less complication in the post 9 operative period when this technique is associated with general anesthesia with sevoflurane.

Knowledge of the course of the pudendal nerve (PN) is important when performing perineal surgery. Distances between landmarks were measured after PN dissections in 71 cadavers and after perineal procedures on 30 cadavers. Separate inferior rectal nerve (IRN) entry and medial position of the PN/IRN with shortened sacrospinous ligaments were often seen in black individuals. A PN block should therefore be placed more proximally and medially. The Richter’s stitch should be placed further from the ischial spine. During ischioanal procedures the IRN is at risk in white females, as it was more superficial. The dorsal nerve of the clitoris/penis (DNC/DNP) is in danger during the outside-in procedures in white or obese individuals, as it was closer to the inferior pubic ramus. The dorsal penile nerve block should be administered deeper in white and obese individuals, as the DNP was deeper. The above-mentioned findings should be verified in a clinical setting. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Anatomy / Unrestricted