Circadian rhythm of rectal motor complexes

PURPOSE

Prolonged rectal pressure recordings have revealed that the rectum exhibits typical bursts of regular pressure waves, also called rectal motor complexes. Although there is consensus regarding the characteristics of rectal motor complexes, their function is poorly understood. Furthermore, data regarding the circadian rhythm of these complexes are either lacking or conflicting. Therefore, we conducted a study to investigate the circadian rhythm of rectal motor complexes in fully ambulant subjects. Because a meal is a powerful and physiologic stimulus to elicit colonic pressure activity, we also studied the effect of a meal on these rectal motor complexes.

METHODS

Prolonged ambulant anorectal pressure recordings were performed in 12 healthy volunteers (male:female ratio, 6:6; median age, 27 (range, 22-53) years). A total of 139 rectal motor complexes were observed in >300 hours of recording.

RESULTS

All subjects exhibited rectal motor complexes during the daytime, whereas in five subjects, no rectal motor complexes were observed during sleep. The number of rectal motor complexes was significantly lower during sleep (diurnal vs. nocturnal, 8 vs. 1 per subject, P < 0.0001). Furthermore, the duration and peak amplitude of these nocturnal rectal motor complexes were significantly reduced. On the ambulant recordings, the subjects marked a total of 20 meals. During the first 2 hours after these meals, rectal motor complexes were noted in 65 percent of the cases. The postprandial frequency of rectal motor complexes was significantly higher than the overall frequency (2/hour vs. 0.4/hour, P = 0.004).

CONCLUSIONS

These findings suggest that sleep results in a reduction of rectal motor activity, whereas a meal provides a stimulus for increased rectal motor activity in fully ambulant subjects.

Ridogrel enemas in distal ulcerative colitis

OBJECTIVE

To evaluate the effect of Ridogrel enemas (Janssen Research Foundation, Beerse, Belgium) on disease activity and mucosal inflammatory mediators in patients with active left-sided ulcerative colitis.

DESIGN AND METHODS

Eleven patients with active left-sided ulcerative colitis were evaluated in an open non-placebo-controlled pilot study. All patients were treated with Ridogrel enemas (300 mg/40 ml once daily) over four weeks. A disease activity score based on clinical, endoscopic and histological criteria was obtained before and after treatment with Ridogrel. The concentrations of thromboxane B2 (TxB2), prostaglandin E2 (PGE2), interleukin-6 (IL-6) and tumour necrosis factor alpha (TNF-alpha) were measured in mucosal biopsies before and after treatment.

RESULTS

One patient discontinued treatment because of progression of disease, the other ten patients tolerated the Ridogrel enemas well. Mucosal TxB2 concentration decreased significantly in all patients. The mucosal concentrations of the other inflammatory mediators (PGE2, IL-6 and TNF-alpha) were unaltered. The disease score decreased in five patients. However, clinical improvement was not always associated with a decrease in endoscopic and/or histological scores.

CONCLUSIONS

This pilot study shows that Ridogrel enemas selectively reduce mucosal TxB2 concentration.

Anismus: fact or fiction?

PURPOSE

Although anismus has been considered to be the principal cause of anorectal outlet obstruction, it is doubtful whether contraction of the puborectalis muscle during straining is paradoxical. The present study was conducted to answer this question.

METHODS

During the first part of the study, we retrospectively reviewed 121 patients with constipation and/or obstructed defecation (male:female, 10/111; median age, 51 years). All of these patients underwent electromyography (EMG) of the pelvic floor and the balloon expulsion test (BET) in the left lateral position. Evacuation proctography was performed in all of these patients in the sitting position. Both the posterior anorectal angle and the central anorectal angle were measured. EMG and BET were also performed in ten controls (male:female, 4/6; median age, 47). In 147 patients with fecal incontinence (male:female, 24/123; median age, 58) only EMG activity was recorded. Criteria for anismus during straining were increase or insufficient (<20 percent) decrease of EMG activity, failure to expel an air-filled balloon on BET, and decrease or insufficient (<5 percent) increase of anorectal angle on evacuation proctography. Between June 1994 and March 1995, we conducted a second prospective study in a consecutive series of 49 patients with constipation and/or obstructed defecation and 28 patients with fecal incontinence. Both groups were compared with 19 control subjects. In this study, all three tests were performed. EMG and BET were performed both in the left lateral position and in the sitting position.

RESULTS

The retrospective study was undertaken by comparing the constipated patients with the incontinent patients and the controls, and the anismus detected by EMG was found in, respectively, 60, 46, and 60 percent. Failure to expel the air-filled balloon was observed in 80 constipated patients (66 percent) and in 9 control subjects (90 percent). Based on posterior anorectal angle and central anorectal angle measurements, anismus was diagnosed in, respectively, 21 and 35 percent of constipated patients. In the prospective study, none of the tests showed significant differences regarding the prevalence of anismus between the two subgroups of patients and the control subjects. The prevalence of anismus only differed between constipated and incontinent patients when the diagnosis was based on BET in the sitting position (67 vs. 32 percent; P < 0.005). Our study shows that contraction of the puborectalis muscle during straining is not exclusively found in patients with constipation and/or obstructed defecation. The three tests most commonly used for the diagnosis of anismus showed an extremely poor agreement.

CONCLUSION

Based on these findings, we doubt the clinical significance of anismus.

Successful management of hemolysis in ABO-nonidentical orthotopic liver transplantation by steroid therapy: a case report

Hemolysis due to donor-derived B lymphocytes has been reported in patients who have undergone ABO-nonidentical orthotopic liver transplantation (OLT). Yet, until now, little was known about the management of this transplantation-induced hemolysis. In this report we describe our experience with hemolysis in a patient after OLT. In addition, based on theoretical assumption, we hypothesize that corticosteroids can be helpful in the management of ABO-nonidentical OLT-induced hemolysis.

Pathophysiological aspects and clinical outcome of intra-anal application of isosorbide dinitrate in patients with chronic anal fissure

BACKGROUND

Relaxation of the internal anal sphincter can be achieved by local application of exogenous nitric oxide donors.

AIM

To evaluate the influence of topical application of isosorbide dinitrate (ISDN) on anal pressure, anodermal blood flow, and fissure healing.

PATIENTS

Thirty four consecutive patients (male/female: 18/16; mean age (SEM): 39 (10)) with a chronic anal fissure were studied.

METHODS

All patients were treated for at least six weeks or a maximum period of 12 weeks. Before treatment and at three and six weeks 22 patients underwent conventional anal manometry and laser Doppler flowmetry of the anoderm.

RESULTS

Within 10 days the fissure related pain was resolved in all patients. At six, nine, and 12 weeks the anal fissure was completely healed in 14, 22, and 30 patients respectively. At three and six weeks manometry was performed at least one hour after the last application of ISDN. These recordings showed a reduction of the maximum resting anal pressure (mean (SD), pretreatment 111 (26) mm Hg; three weeks 86 (19); six weeks 96 (27), p < 0.001). Simultaneous recordings of anodermal blood flow showed a significant increase of flow (pretreatment 0.53 (0.17); three weeks 0.80 (0.16); six weeks 0.76 (0.31), p < 0.005). The mean (SEM) duration of follow up after successful outcome was 11 (5) months. Within this period fissure relapsed in two of 30 patients (7%), eight and 10 weeks after treatment had been stopped.

CONCLUSIONS

Local application of ISDN reduces anal pressure and improves anodermal blood flow. This dual effect results in a fissure healing rate of 88% at 12 weeks. This new and simple treatment modality seems to be an attractive alternative for the current available surgical procedures.

Ischaemic nature of anal fissure

Microvascular perfusion of the anoderm was assessed by laser Doppler flowmetry in 27 patients with anal fissure. Anal pressure was recorded simultaneously. Both measurements were repeated 6 weeks after lateral internal sphincterotomy and compared with those obtained from 27 controls. Means(s.d.) maximum anal resting pressure was significantly higher in those with a fissure than in controls (121.07(24.48) versus 68.78(16.97) mmHg, P < 0.001). Anodermal blood flow at the fissure site was significantly lower than at the posterior commissure of the controls (0.46(0.20) versus 0.76(0.28) V, P < 0.001). The fissure healed in 24 patients within 6 weeks of sphincterotomy. In these patients a significant pressure decrease was noted (35 per cent) which was accompanied by a consistent rise in blood flow (65 per cent) at the original fissure site. The increased internal sphincter tone in patients with a fissure reduces anodermal blood flow at the posterior midline. Reduction of anal pressure by sphincterotomy improves anodermal blood flow at the posterior midline, resulting in fissure healing. These findings provide evidence for the ischaemic nature of anal fissure.

Anal fissure: new concepts in pathogenesis and treatment

The posterior commissure of the anal canal is less well perfused than the other segments of the anoderm. There is growing evidence that the increased activity of the internal anal sphincter, which is found in almost all patients with a chronic anal fissure, further decreases the anodermal blood supply, especially at the posterior midline. Reduction of anal pressure, either by anal dilatation or by lateral internal sphincterotomy, is the most important step in the treatment of chronic anal fissure. However, both procedures frequently result in permanent sphincter defects and subsequent continence disturbances. Recently, nitric oxide (NO) has been identified as the chemical messenger mediating relaxation of the internal anal sphincter. It has been shown that local application of exogenous NO donors such as nitroglycerin and isosorbide-di-nitrate reduces anal pressure and improves anodermal blood flow. This dual effect results in fissure healing in more than 80% of patients.

[Intra-anal application of isosorbide dinitrate in chronic anal fissure]

OBJECTIVE

To evaluate the effect of intra-anal application of isosorbide dinitrate on the healing rate of chronic anal fissure.

DESIGN

Prospective, descriptive.

SETTING

Outpatient clinic of the department of Surgery, University Hospital Dijkzigt, Rotterdam.

METHOD

Sixteen patients with chronic (more than three months' duration) anal fissure were treated by intra-anal application of isosorbide dinitrate ointment every 3 hours, except during the night. The maximal duration of therapy was 12 weeks. Every three weeks the following aspects were investigated: clinical symptoms, side-effects and fissure healing.

RESULTS

All patients experienced mild and transient headache shortly after the beginning of the treatment. At three weeks the fissure-related pain was resolved in all patients. At 6, 9 and 12 weeks the fissure was completely healed in 9, 11 and 15 patients respectively.

CONCLUSION

The majority of chronic anal fissures can be treated effectively by local application of isosorbide dinitrate. This new and simple treatment modality appears to be an attractive alternative to the currently available surgical procedures.

Relationship between anal pressure and anodermal blood flow. The vascular pathogenesis of anal fissures

PURPOSE

The aim of this study was to investigate the relationship between anal pressure and anodermal blood flow.

METHODS

We performed Doppler laser flowmetry of the anoderm combined with anorectal manometry in 178 subjects (87 males and 91 females; median age, 55 (range, 17-87) years). This group consisted of 31 healthy volunteers, 23 patients with fecal incontinence, 17 patients with hemorrhoids, and 9 patients with anal fissure. The remaining 98 patients had other colorectal disorders. In 16 controls we examined anodermal blood flow in the four quadrants of the anal canal.

RESULTS

Perfusion of the anoderm at the posterior midline was significantly lower than in the other three segments of the anal canal (posterior midline: 0.74 +/- 0.26 V; left lateral side: 1.68 +/- 0.81 V; right lateral side: 1.57 +/- 0.52 V; anterior midline: 1.48 +/- 0.69 V, P < 0.001). In the overall group, we found a significant correlation between maximum and resting pressure and anodermal blood flow at the posterior midline (r = -0.616, P < 0.001). In the nine patients with chronic anal fissure, the mean maximum anal resting pressure was 125 +/- 26 mmHg, which was significantly higher than in patients with hemorrhoids (82 +/- 15 mmHg), controls (66 +/- 19 mmHg), and patients with fecal incontinence (42 +/- 14 mmHg, P < 0.001), whereas the blood flow at the base of the fissure was significantly lower (0.43 +/- 0.10 V vs. 0.57 +/- 0.19 V vs. 0.75 +/- 0.26 vs. 1.03 +/- 0.34 V). In ten patients we also studied the influence of anesthesia on both anal pressure and anodermal blood flow. During the administration of anesthesia, anal pressure dropped from 63 +/- 21 mmHg to 32 +/- 15 mmHg (P < 0.001), whereas anodermal blood flow at the posterior midline increased from 0.79 +/- 0.22 V to 1.31 +/- 0.35 V (P < 0.001).

CONCLUSION

Anodermal blood flow at the posterior midline is less than in the other segments of the anal canal. The perfusion of the anoderm at the posterior commissure is strongly related to anal pressure. The higher the pressure, the lower the flow. Our findings support the hypothesis that anal fissures are ischemic ulcers.

New device for adequate fixation of recording instruments in ambulant anorectal manometry

The development of a silicone fixation device to perform ambulant anorectal manometry is described. This device provides adequate fixation of recording instruments and facilitates prolonged anorectal pressure recording at home, even in patients with a high frequency of defecation.