Palpation Device for the Identification of Kidney and Bladder Cancer: A Pilot Study

PURPOSE: To determine the ability of a novel palpation device to differentiate between benign and malignant tissues of the kidney and bladder by measuring tissue elasticity. MATERIALS AND METHODS: A novel palpation device was developed, mainly composed of a micromotor, a linear position sensor, a force transducer, and a hemisphere tip and cylindrical body probe. Motion calibration as well as performance validation was done. The tissue elasticity of both benign and malignant tissues of the kidney and bladder was measured using this device. A single investigator performed the ex-vivo palpation experiment in twelve kidneys and four bladder specimens. Malignant tissues were made available from partial nephrectomy specimens and radical cystectomy specimens. Palpations for benign renal parenchyma tissue were carried out on nephroureterectomy specimens while non-involved areas in the radical cystectomy specimens were used for benign bladder samples. Elastic modulus (Young's modulus) of tissues was estimated using the Hertz-Sneddon equation from the experimental results. These were then compared using a t-test for independent samples. RESULTS: Renal cell carcinoma tissues appear to be softer than normal kidney tissues, whereas tissues from urothelial carcinoma of the bladder appear to be harder than normal bladder tissues. The results from renal cell carcinoma differed significantly from those of normal kidney tissues (p=0.002), as did urothelial carcinoma of the bladder from normal bladder tissues (p=0.003). CONCLUSION: Our novel palpation device can potentially differentiate between malignant and benign kidney and bladder tissues. Further studies are necessary to verify our results and define its true clinical utility.

Correlação do escore de Oxford modificado com as medidas perineométricas em pacientes incontinentes / Correlation between the modified Oxford scale and perineometry measurements in incontinent patients

Introdução: Diversas técnicas foram propostas para avaliação da musculatura do assoalho pélvico, porém, nenhum método mostrou-se capaz de medir as duas funções desses músculos: elevação e força de compressão. Na rotina de avaliação clínica é comumente empregada a palpação vaginal e, especialmente, o escore de Oxford modificado; entretanto, alguns trabalhos questionam a sensibilidade da escala de Oxford e sua correlação com medidas objetivas de força de contração muscular. Objetivo: neste estudo, propõe-se correlacionar as variáveis medidas na perineometria com o escore de Oxford modificado. Métodos: foram incluídas no estudo 45 pacientes com incontinência urinária que procuraram o ambulatório de Uroginecologia do Hospital de Clínicas de Porto Alegre. As pacientes foram submetidas à palpação vaginal, realizada por uma fisioterapeuta treinada na escala de Oxford, e a medição da força de compressão da musculatura pélvica por meio de balonete conectado a transdutor de pressão. As duas avaliações foram realizadas no mesmo dia. Resultados: encontrou-se correlação significativa (P <0,001) entre o escore de Oxford e as variáveis pressão máxima de contração e tempo de ativação muscular com coeficientes de Pearson de 0,69 e -0,532, respectivamente. Contudo, observa-se uma superposição entre as medidas perineométricas e do escore de Oxford entre categorias adjacentes. Conclusões: Os resultados mostram que apesar de estar incorporada a rotina clínica de avaliação, deve haver restrições quanto ao uso do escala de Oxford com propósitos científicos.

Background: Several techniques have been proposed for the assessment of pelvic floor muscles; however, none of them were able to measure the two main functions of these muscles: lifting and compressive force. Vaginal palpation and especially the Modified Oxford Scale (MOS) are frequently used during routine clinical evaluation, but some studies have questioned the sensitivity of the MOS and its correlation with objective measurements of muscle contraction force. Aim: the objective of this study is to correlate perineometry measurements with the MOS.Methods: Forty-five patients with urinary incontinence treated at the Urogynecology Outpatient Clinic of Hospital de Clínicas de Porto Alegre were included. The patients were submitted to vaginal palpation performed by a physical therapist trained in the MOS. The compression force of their pelvic muscles was measured by means of an air-filled ballonet connected to a pressure transducer. Both tests were carried out on the same day. Results: we found significant correlation (P < 0.001) between the MOS and the variables maximum contraction pressure andmuscular activation time with Pearson's coefficients of 0.69 and -0.532, respectively. However, we found overlapping results between the perineomtry measurements and the MOS scores in neighboring categories. Conclusions: these findings show that, although incorporated into routine clinical evaluation, there should be restrictions to the use of the MOS for scientific purposes.

Mechanical simulator for the Levator ani

O assoalho pélvico é uma estrutura muscular complexa e as disfunções uroginecológicas desta musculatura são inúmeras. O diagnóstico das disfunções uroginecológicas podem ser realizadas por anamnese, avaliação clínica (palpação digital, perineometria e observação), urodinâmica, ultrassom e ressonância magnética. Os fisioterapeutas utilizam a palpação digital vaginal para obter informações de força da musculatura do assoalho pélvico. O objetivo do presente trabalho foi desenvolver um dispositivo eletromecânico, capaz de simular in vitro o músculo levantador do ânus, a fim de treinar futuros examinadores na sensibilidade do toque digital vaginal. Cinco molas foram fixadas em um modelo anatômico de resina da pelve em uma configuração que poderia representar o músculo elevador do ânus. Uma unidade de tração composta por motor de passo interligado a uma célula de carga foi utilizada para a caracterização da força de tração do sistema mecânico. Uma fisioterapeuta bem treinada realizou quatorze séries de palpação bidigital entre as cinco molas. Neste sentido, foi possível estabelecer valores de força que se correlacionavam com os seis graus da escala modificada de Oxford. As forças médias para todas as palpações bidigitais foram comparadas usando-se o teste de ANOVA de um fator controlável. De acordo com os resultados, o grau zero representou o alongamento nulo das molas. Os graus de 1 a 5 mostraram os seguintes valores médios de força: 1 (55,69 N), 2 (56,17 N), 3 (56,94 N), 4 (59,61 N), 5 (65,36 N). O dispositivo proposto apresentou-se como uma útil ferramenta para estabelecer a relação entre a força das molas e a escala modificada de Oxford.

The pelvic floor is a complex muscular structure and the urogynaecological dysfunctions of this muscular structureare innumerable. The diagnosis of these urogynaecological dysfunctions can be performed by anamnesis, clinical evaluation (digital palpation, perineometry and observation), urodynamics and by ultrasound or magnetic resonance imaging. Physiotherapist relies on vaginal digital palpation to obtain relevant data about pelvic floor strength. The aim of the present application was to develop an electromechanical device able to simulate in vitro the levator ani muscle in order to train the sensitivity of future examiners during a vaginal digital palpation. Five springs were fixed on a resin anatomical model of the human pelvis in a configuration that could represent the levator ani muscle. A traction unit composed by a load cell and a step motor was used to produce the traction of the springs being able to measure the traction force. One well trained physiotherapist executed all the fourteen series of digital palpation procedures between the five springs. It was possible to establish force values that were correlated to the six scores of the modified Oxford scale. The meanforces obtained for the complete digital assessment were compared using one-way ANOVA. According to the results, score 0 of the modified Oxford scale represented no elongation of the springs. Scores 1 to 5 showed the following mean force values: 1 (55.69 N), 2 (56.17 N), 3 (56.94 N), 4 (59.61 N), 5 (65.36 N). The proposed device presented itself as a useful tool which is able to establish a relation between the forces of the springs and the modified Oxford scale.