‘ An investigation of the nervous control of defecation ’ by Denny-Brown and Robertson: a classic paper revisited

In 1935 two young neurologists, Derek Denny-Brown and E. Graeme Robertson, published an article explaining the mechanisms underlying human defaecation based on a manometric study in patients with sacral root and spinal cord lesions, and normal subjects. This article is still routinely cited in studies of rectal and sphincter ani function. Unfortunately, however, the article itself is not written well, being composed of long convoluted sentences and containing 79 often indecipherable figures. Difficult-to-understand articles were common to the publications of Denny-Brown, who became one of the most prominent neurologists of the twentieth century. In accord with our prior work explaining Denny-Brown and Robertson's earlier paper on micturition, we provide here what we hope is a clear explanation of the methods and results in their study on defaecation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73905/1/j.1463-1318.2004.00636.x.pd

Fistulotomy and drainage of deep postanal space abscess in the treatment of posterior horseshoe fistula

BACKGROUND: Posterior horseshoe fistula with deep postanal space abscess is a complex disease. Most patients have a history of anorectal abscess drainage or surgery for fistula-in-ano. METHODS: Twenty-five patients who underwent surgery for posterior horseshoe fistula with deep postanal space abscess were analyzed retrospectively with respect to age, gender, previous surgery for fistula-in-ano, number of external openings, diagnostic studies, concordance between preoperative studies and operative findings for the extent of disease, operating time, healing time, complications, and recurrence. RESULTS: There were 22 (88%) men and 3 (12%) women with a median age of 37 (range, 25–58) years. The median duration of disease was 13 (range, 3–96) months. There was one external opening in 12 (48%) patients, 2 in 8 (32%), 3 in 4 (16%), and 4 in 1 (4%). Preoperative diagnosis of horseshoe fistula was made by contrast fistulography in 4 (16%) patients, by ultrasound in 3 (12%), by magnetic resonance imaging in 6 (24%), and by physical examination only in the remainder (48%). The mean ± SD operating time was 47 ± 10 min. The mean ± SD healing time was 12 ± 3 weeks. Three of the 25 patients (12%) had diabetes mellitus type II. Nineteen (76%) patients had undergone previous surgery for fistula-in-ano, while five (20%) had only perianal abscess drainage. Neither morbidity nor mortality developed. All patients were followed up for a median of 35 (range, 6–78) months and no recurrence was observed. CONCLUSIONS: Fistulotomy of the tracts along the arms of horseshoe fistula and drainage of the deep postanal space abscess with posterior midline incision that severs both the lower edge of the internal sphincter and the subcutaneous external sphincter and divides the superficial external sphincter into halves gives excellent results with no recurrence. When it is necessary, severing the halves of the superficial external sphincter unilaterally or even bilaterally in the same session does not result in anal incontinence. Close follow-up of patients until the wounds completely healed is essential in the prevention of premature wound closure and recurrence

Can the outcome of pelvic-floor rehabilitation in patients with fecal incontinence be predicted?

Purpose: Pelvic-floor rehabilitation does not provide the same degree of relief in all fecal incontinent patients. We aimed at studying prospectively the ability of tests to predict the outcome of pelvic-floor rehabilitation in patients with fecal incontinence. Materials and methods: Two hundred fifty consecutive patients (228 women) underwent medical history and a standardized series of tests, including physical examination, anal manometry, pudendal nerve latency testing, anal sensitivity testing, rectal capacity measurement, defecography, endoanal sonography, and endoanal magnetic resonance imaging. Subsequently, patients were referred for pelvic-floor rehabilitation. Outcome of pelvic-floor rehabilitation was quantified by the Vaizey incontinence score. Linear regression analyses were used to identify candidate predictors and to construct a multivariable prediction model for the posttreatment Vaizey score. Results: After pelvic-floor rehabilitation, the mean baseline Vaizey score (18, SD±3) was reduced with 3.2 points (p<0.001). In addition to the baseline Vaizey score, three elements from medical history were significantly associated with the posttreatment Vaizey score (presence of passive incontinence, thin stool consistency, primary repair of a rupture after vaginal delivery at childbed) (R2, 0.18). Th

Amplitude and recovery velocity of relaxation induced by rectoanal inhibitory reflex and its importance for obstructive evacuation Amplitude e recuperação da velocidade do relaxamento induzida pelo reflexo inibitório retoanal e sua importância na evacuação obstrutiva

BACKGROUND: The rectoanal inhibitory reflex has an important rule in the fecal continence mechanism. Alterations in this reflex can be associated with compromised anal sphincteric function. AIM: To identify possible correlation between rectoanal inhibitory reflex parameters and intestinal constipation due to obstructive evacuation. PATIENTS: Sixty nine patients with intestinal constipation had been submitted to anorectal manometry. It was selected 29 patients (27 female, mean age of 42.3 (19-73) years) having intestinal constipation owing to obstructive evacuation. Thirteen individuals without anorectal functional complaints (eight female, mean age 52.5 (28-73) years) formed the control group. RESULTS: The mean value of resting anal pressure before rectoanal inhibitory reflex in the proximal and distal anal canals were 61.8 mm Hg and 81.7 mm Hg respectively, for the constipated patients, and 46.0 mm Hg and 64.5 mm Hg, respectively, for asymptomatic individuals. The mean pressure at the point of maximal relaxation in constipated patients was 29.0 mm Hg in the proximal anal canal, and 52.1 mm Hg in the distal anal canal, whilst in the asymptomatic group they were 17.8 mm Hg and 36.3 mm Hg, respectively. The mean percentage difference between the mean resting anal pressure and the mean point of maximal relaxation pressure in the proximal anal canal (amplitude of relaxation) was 54.1% in constipated patients and 54.3% in asymptomatic individuals. In the distal anal canal it was, respectively, 35.6% in constipated patients, and 38.5% in the control group. The average recovery velocity of relaxation in the proximal anal canal was 4.06 mm/second in constipated patients and 2.98 mm/second in asymptomatic individuals, giving a significant difference between the two groups, as well as in the distal anal canal (3.9 mm/second and 2.98 mm/second, respectively) CONCLUSION: The greater recovery velocity of the resting anal pressure in the proximal anal canal in constipated patients than in controls may be associated with obstructive evacuation.<br>RACIONAL: A constipação intestinal é queixa muito freqüente, sendo o motivo de grande número de consultas médicas. No entanto, apesar dos avanços na compreensão da fisiologia anorretocólica, ainda representa problema clínico de difícil solução. OBJETIVO: Identificar possível correlação entre dados fisiológicos presentes no reflexo inibitório retoanal e a constipação intestinal por evacuação obstruída. MATERIAL E MÉTODOS: Foram selecionados 69 exames de pacientes, submetidos previamente a manometria anorretal no Laboratório de Fisiologia Anorretal da Faculdade de Ciências Médicas da Universidade Estadual de Campinas, Campinas, SP. 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 8 do sexo feminino, com média de idade de 52,5 (28-73) anos. No reflexo inibitório retoanal foi analisada a pressão anal de repouso média, o ponto de máximo relaxamento e a velocidade de recuperação até atingir a pressão basal, todos nos níveis proximal e distal do canal anal. A seguir foi realizado o estudo comparativo entre esses dados. RESULTADOS: O valor médio da pressão anal de repouso média pré-indução do reflexo inibitório retoanal no nível proximal foi, nos pacientes constipados, de 61,8 mm Hg e no nível distal, 81,7 mm Hg, enquanto que nos assintomáticos encontraram-se 46,0 mm Hg e 64,5 mm Hg, respectivamente, para os níveis proximal e distal. A média da pressão no ponto de máximo relaxamento nos pacientes constipados foi 29,0 mm Hg no nível proximal do canal anal e 52,1 mm Hg no nível distal, enquanto que no grupo de assintomáticos foi 17,8 mm Hg e 36,3 mm Hg, respectivamente, no canal anal proximal e no distal. A média da diferença percentual entre a pressão anal de repouso média e a pressão no ponto de máximo relaxamento no nível proximal, que indicou a amplitude do relaxamento, 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 velocidade de recuperação no nível proximal foi 4,06 mm/seg. nos constipados e 2,98 mm/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. CONCLUSÃO: A amplitude de relaxamento, apesar de ser maior no canal anal proximal tanto em constipados, como em controles normais, não parece ter participação no mecanismo da evacuação obstruída. A maior velocidade de recuperação da pressão de repouso em nível proximal em constipados do que em controles normais pode estar associada à condição de evacuação obstruída, uma vez que o canal anal tenderá mais rapidamente ao fechamento na sua porção proximal e, portanto, a maior dificuldade de iniciar a evacuação