Intensidade e velocidade da recuperação do relaxamento esfincteriano induzido pelo reflexo inibitorio retoanal e sua correlação com constipação por evacuação obstruida

Orientador: Juvenal Ricardo Navarro GoesTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias MedicasResumo: A constipação intestinal é uma queixa muito freqüente, sendo o motivo de um grande número de consultas médicas. No entanto, apesar dos avanços na compreensão da fisiologia anorretocólica, ainda representa um problema clínico nem sempre resolvido. O objetivo deste trabalho é identificar possível correlação entre dados fisiológicos presentes no RIRA e a constipação intestinal por evacuação obstruída. Para isso foram selecionados 69 exames de pacientes, que tinham sido submetidos, previamente, à manometria anorretal no Laboratório de Fisiologia Anorretal no Gastrocentro da FCM ¿ UNICAMP. Destes, após serem aplicados os critérios de exclusão e inclusão, foram selecionados 29 pacientes com constipação intestinal por evacuação obstruída, sendo 27 do sexo feminino e média de idade de 42,3 (19-73) anos. Da mesma forma, foram selecionados 13 indivíduos sem queixas funcionais anorretais, sendo oito do sexo feminino, com média de idade de 52,5 (28-73) anos. No RIRA foi analisada a pressão anal de repouso média (PARM), o ponto de máximo relaxamento (PMR) e a velocidade de recuperação (VR) até atingir a pressão basal, todos nos níveis proximal e distal do canal anal. A seguir foi realizado o estudo comparativo entre esses dados. Os resultados mostraram que o valor médio da PARM pré-indução do RIRA no nível proximal foi, nos pacientes constipados, de 61,8 mmHg e no nível distal, 81,7 mmHg, enquanto que nos assintomáticos encontrou-se 46,0 mmHg e 64,5 mmHg, respectivamente, para os níveis proximal e distal. A média da pressão no PMR nos pacientes constipados foi 29,0 mmHg no nível proximal do canal anal e 52,1 mmHg no nível distal, enquanto que no grupo de assintomáticos foi 17,8 mmHg e 36,3 mmHg respectivamente, no canal anal proximal e no distal. A média da diferença percentual entre a PARM e a pressão no PMR no nível proximal foi 54,1 % nos constipados e 54,3% nos assintomáticos. No nível distal, a média da diferença foi 35,6% nos constipados e 38,5% no grupo-controle. A média da VR no nível proximal foi 4,06 mm/seg. nos constipados e 2,98mm/seg nos assintomáticos, sendo a diferença entre as duas estatisticamente significativa. A média da velocidade de recuperação no grupo de constipados no nível distal do canal anal foi 3,9 mm/seg. e 2,98 mm/seg. nos normais, sendo a diferença entre as duas também significativa do ponto de vista estatístico. A análise dos resultados, obtidos da avaliação dos parâmetros do RIRA, mostrou que o relaxamento esfincteriano em pacientes constipados foi mais acentuado no canal anal proximal do que no distal, da mesma forma como o observado nos controles normais. A velocidade de recuperação da pressão anal de repouso em canal anal proximal e distal foi maior nos pacientes constipadosAbstract: Intestinal constipation is a very common complaint and is thus a common reason for consultations with physicians. The prevalence in the United State of America varies from 2 to 14.7% of the population. In Brazil there are no epidemiological studies on this subject, however it is known that there is a high incidence. Intestinal constipation occurs due to organic and functional factors. Functional constipation may either be associated with a functional alteration of the colon, which in this case is called colonic inertia, or an involvement of the voiding mechanism in the anorectal region, which is denominated constipation by obstructive evacuation. The latter, which is of interest in this study, can by diagnosed and evaluated through several tests, among which are the defecography and anorectal manometry. In anorectal manometry, the rectoanal inhibitory reflex (RAIR) is evaluated. The morphologic alterations detected in the various phases of RAIR have been associated with the genesis of constipation by obstructive evacuation. The aim of this work is to identify a possible correlation between the physiological data present in RAIR and constipation by obstructive evacuation. A total of 69 patients with intestinal constipation, who had previously been submitted to anorectal manometry in the Physiological Anorectal Laboratory in the Gastrocentro of FCM ¿ Unicamp, Brazil were investigated. After the inclusion and exclusion criteria were applied, 29 patients suffering from constipation by obstructive evacuation were selected. Of these 27 were female and the mean age was 42.3 (19-73) years. In the same way a control group of a total of thirteen individuals without anorretal symptoms were evaluated, eight of whom were male and the mean age was 52.5 (28-73) years. The Average Resting Anal Pressure (ARAP), the Maximum Relaxation Point (MRP) and the Recovery Velocity until reaching the base pressure, both at the proximal and distal regions of the anal tract were analyzed during RAIR. After this a comparative study of the results was performed. The results demonstrated that the pre-induced ARAP at RAIR at the proximal level was 61.8 mmHg and at the distal level it was 81.7 mmHg in constipated patients. In asymptomatic individuals, however, the ARAP was 46.0 mmHg and 64.5 mmHg at the proximal and distal levels respectively. The mean MRP in constipated patients was 29 mmHg at the proximal level of the anal tract and 52.1 mmHg at the distal level, when in the control group it was 17.8 mmHg and 36.3 mmHg respectively at the proximal and distal levels. The differences between the ARAP and MRP at the proximal level in constipated patients was 54.1% and in asymptomatic individuals it was 54.3%. At the distal level the difference was 35.6% and 38.5% in the experimental and control groups respectively. The recovery velocity at the proximal level was 4.06 mm/second in constipated patients and 2.98 mm/second in the asymptomatic group with a statistically significant difference. At the distal level the recovery velocity of constipated individuals was 3.9 mm/second whilst for the control group the rate was 2.98 mm/second again giving a statistically significant difference. An analysis of the results obtained from the analysis of the RAIR showed that sphincter relaxation in constipated individuals was more stressed at the proximal level of the anal canal than at the distal level which was also observed in controls. The recovery velocity of the resting anal pressure at both the proximal and distal levels was greater in constipated patients than in controlsDoutoradoCirurgiaDoutor em Cirurgi