Rigid sigmoidoscopy: an evaluation of three parameters regarding diagnostic accuracy

Iatrogenic perforation at colonic imaging

AIM

Adequate colonic imaging is generally an invasive procedure with attendant risks, particularly perforation. Endoscopy, barium enema and computed tomographic colonography (CTC) are the main techniques for investigating patients with symptoms of, or screening for, colorectal cancer. The potential complications of these investigations have to be weighed against the benefits. This article reviews the literature on the incidence, presentation and management of iatrogenic colonic perforation at colonic imaging.

METHOD

A literature review of relevant studies was undertaken using PubMed, Cochrane library and personal archives of references. Manual cross-referencing was performed, and relevant references from selected articles were reviewed. Studies reporting complications of endoscopy, barium enema and CT colonography were included in this review.

RESULTS

Twenty-four studies were identified comprising 640,433 colonoscopies, with iatrogenic perforation recorded in 585 patients (0.06%). The reported perforation rate with double-contrast barium enema was between 0.02 and 0.24%. Serious complications with CTC were infrequent, though nine perforations were reported in a case series of 24,365 patients (0.036%) undergoing CTC.

CONCLUSION

Perforation remains an infrequent and almost certainly under-reported, complication of all colonic imaging modalities. Risk awareness, early diagnosis and active management of iatrogenic perforation minimizes an adverse outcome.

Home rectal evacuation prior to a colorectal clinic appointment: a prospective, randomized, controlled, single-blind trial

OBJECTIVE

The presence of faeces in the rectum can limit the effectiveness of diagnostic rigid sigmoidoscopy and therapeutic proctoscopy. This study was undertaken to determine whether home self-administration of a Microlette Micro-enema® or two glycerine suppositories improves the view on rigid sigmoidoscopy and to assess patient acceptability.

PATIENTS AND METHODS

Patients referred with colorectal symptoms were prospectively randomized into three groups of 50. Patients in Groups I and II were sent a Microlette Micro-enema® or two glycerine suppositories, respectively, along with instructions for home self-administration. Group III comprised unmedicated controls.

RESULTS

Compliance was 98%. There was no significant difference in faecal loading between Groups I and II, but both groups had significantly more patients with empty rectums in comparison with Group III (P < 0.001). The median (interquartile range) distances in cm from the anal verge reached on rigid sigmoidoscopy in Groups I, II and III were 15.0 (15.0-20.0), 18.0 (15.0-20.0) and 15.0 (4.25-15.0), respectively (Groups I vs III and Groups II vs III P < 0.001; Groups I vs II P = 0.03). Quality of views on rigid sigmoidoscopy were best in Group II (Groups I vs III and Groups II vs III P < 0.001; Groups I vs II P = 0.04). Four patients in Group I and two in Group II found home self-administration of the enema/suppositories inconvenient or unacceptable.

CONCLUSION

Home self-administration of two glycerine suppositories prior to a colorectal clinic visit is simple, inexpensive and acceptable to patients and allows better views on rigid sigmoidoscopy.

Self-Administered Disposable Micro-Enemas before Outpatient Sigmoidoscopy

Many colorectal carcinomas can be diagnosed by rigid sigmoidoscopy. One important limiting factor in the usefulness of this investigation is the presence of faeces; another is inability to negotiate the recto-sigmoid bend. 101 patients (47 men) were sent a Microlax enema with instruction to use it before their first attendance in the outpatient department. The grade of preparation [on a scale of 0 (empty rectum) to 3, with grades 0 and 1 providing an adequate view], height achieved with the sigmoidoscope and whether or not the extent of the examination was limited by faeces were recorded. These data were compared with results in 78 patients (38 men) who did not receive any special preparation.

There were no serious difficulties with self-administration. An adequate view was obtained in 89 (88%) of those who had received an enema and in 41 (53%) of those who were unprepared (P< 0.001, χ2 test). The height achieved and the percentage of patients in whom the sigmoidoscopy was not limited by faeces were also significantly increased.

The mailing of micro-enemas to patients who are likely to need sigmoidoscopy is a cheap measure that increases diagnostic yield and saves reattendances.

Existence of a high pressure zone at the rectosigmoid junction in normal Indian men

PURPOSE

A hypertonic, electrically hyperactive segment has been described in the rectosigmoid region mainly in constipated persons. Anatomic or manometric evidence to satisfy the criteria for a sphincter here is, however, inconclusive. We evaluated the pressure profile of the rectosigmoid region in normal Indian men.

METHODS

Fifteen male volunteers with regular bowel habits were studied. Rectosigmoid manometry (1 cm station pull-through) was done in the fasting state using a water-perfused system and three-lumen catheter with radially oriented recording ports 5 cm apart.

RESULTS

Eight volunteers had a zone of high pressure. Proximal extent of this zone was identified as the station with a rise in basal pressure of at least 10 mmHg over the previous station. A further rise of at least 10 mmHg in subsequent distal stations was considered essential for defining the existence of the zone. This zone had a median length of 3 cm, with midpoint at median 18 cm from the anal verge and median highest pressure of 36 mmHg. There was no antegrade pressure gradient across the zone; rectal pressures were higher than those in the sigmoid in 12 of 15 volunteers.

CONCLUSIONS

Approximately one-half of normal Indian men with regular bowel habits have a high pressure zone in the rectosigmoid region. The role of diet or defecation posture in its etiology and its effect on bowel habit need to be studied.