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Is there still a place for abdominoperineal resection of the rectum?

During the past two decades, low anterior resection (LAR) with colo-rectal or colo-anal anastomosis has replaced abdominoperineal resection (APR) as the primary surgical therapy for rectal cancer. Several studies, although not prospectively randomized, have shown that the outcome after LAR with deep anastomosis and APR is comparable concerning mortality, local recurrence rate and survival. Adequate clearance of the tumour, and not the surgical procedure performed, is the determinant factor influencing the outcome. Whereas most tumours in the upper third and mid-rectum are amenable to a sphincter-saving procedure (SSP), the lower third of the rectum is of debate in this respect. Small tumours (T1) in the lower third can be treated by peranal local excision. Low grade tumours with a T2 or T3 stage located above 3 cm from the dentate line are treated by SSP. There is still a place for for advanced tumours (T3 and T4) below 5 cm from the anal verge, in case of deficiency of the anal sphincter, and when the sphincter complex is infiltrated by the tumour. Preoperative staging measures are essential for patients selection in relation to height of the tumour above the anal canal, depth of tumour invasion into the rectal wall, and presence or absence of regional lymph node metastases. Biology of rectal cancer and its implication on surgery, preoperative staging of rectal cancer, technique and results of the main three surgical options, and the advent of laparoscopy are discussed in this article.

Abdomen↗

Buttonhole ulceration and perforation of the rectum.

Three laparoscopies were performed with treatment of cul-de-sac endometriosis near the rectum Two patients had a subsequent laparotomy for rectal perforation. The bowel damage appears to have been from a combination of failure to appreciate the position of the bowel with anatomy distorted by endometriosis, dissecting into healthy tissue with a carbon dioxide laser, desiccating healthy tissue with bipolar electrosurgery, and thermal spread into healthy tissue from the desiccated endometriotic tissue. Gynecologists must be aware of this potential complication when treating endometriosis near the rectum.

Adult↗

Lectin cytochemical characterization of the N- and O-linked oligosaccharides in the human rectum.

The oligosaccharides of the mucus glycoproteins of the human rectum are important for the lubricant and protective role suggested for the rectal mucus. Changes in oligosaccharide composition are observed in several colon diseases, and some of these changes could be used as diagnostic and prognostic indicators. Thus, a previous knowledge of the normal mucus glycoproteins is necessary. The aim of the present study is the characterization of the oligosaccharides of the goblet cells and enterocytes of the human rectum. For this, a battery of 15 lectins, in combination with chemical and enzymatic deglycosylation procedures, was used. Our results suggest the presence of N-acetylglucosamine (GlcNAc), Man, Glc, N-acetylneuraminic acid (Neu5Ac)(alpha2-6)- and Neu5Ac(alpha2-3)-linked, N-acetylgalactosamine (GalNAc) and Gal(beta1-3)GalNAc in the oligosaccharides of the goblet cells. Moreover, N-linked oligosaccharides specifically contained Gal(beta1-4)GlcNAc, while AAA-positive Fuc was only detected in O-linked oligosaccharides. Some of these carbohydrates were only visualized after removal of N- or O-linked oligosaccharides, suggesting a high level of approximation between the oligosaccharide chains, that render the carbohydrate inaccessible to the lectins. Differences in the labelling pattern between the goblet cells of the surface epithelium and the upper half of the crypts, and those of the lower half of the crypts suggests a maturation process for the goblet cells, which modifies the oligosaccharide composition of the secreted glycoproteins, as they ascend throughout the crypts. This maturation process includes the incorporation of new carbohydrates (GlcNAc), and the masking (Neu5Ac(alpha2-3)-linked) or unmasking (Glc and GalNAc) of others.

Fucose↗

Pharmacological characterization of 5-HT4 receptors mediating relaxation of canine isolated rectum circular smooth muscle.

This study aimed to characterize for the first time in vitro 5-HT4 receptors in the canine gastrointestinal tract. For this purpose, we used circular muscle strips of the canine isolated rectum. In the presence of methysergide (60 microM), 5-HT induced relaxation of methacholine (1 microM)-precontracted muscle strips, yielding a monophasic sigmoidal concentration-relaxation curve (pEC50 7.2+/-0.07). Tetrodotoxin (0.3 microM) did not affect the curve to 5-HT, suggesting the inhibitory 5-HT receptor is located on the smooth muscle. Granisetron (0.3 microM) did also not affect the curve to 5-HT, which excludes the 5-HT3 receptor mediating the relaxation to 5-HT. The presence of methysergide rules out the involvement of 5-HT1, 5-HT2 or 5-HT7 receptors. 5-HT, the selective 5-HT4 receptor agonists R076186, prucalopride (R093877) and SDZ HTF-919 and the 5-HT4 receptor agonists cisapride and 5-MeOT relaxed the muscle strips with a rank order of potency R076186 = 5-HT > cisapride > prucalopride > or = SDZ HTF-919 > 5-MeOT. The selective 5-HT4 receptor antagonists GR 125487, RS 39604 and GR 113808 competitively antagonized the relaxations to 5-HT, yielding pK(B) estimates of 9.7, 7.9 and 9.1, respectively. The selective 5-HT4 receptor antagonist SB 204070 shifted the curve to 5-HT rightward and depressed the maximal response (apparent pA2 10.6). GR 113808 (10 nM) produced a parallel rightward shift of the curve to the selective 5-HT4 receptor agonists R076186 (pA2 8.8). It is concluded that 5-HT induces relaxation of the canine rectum circular muscle through stimulation of a single population of smooth muscle 5-HT4 receptors. For the first time, a nonhuman species was shown to exhibit relaxant 5-HT4 receptors in the large intestine.

5-Methoxytryptamine↗

Reinnervation of the rectum with a somatic nerve: a canine study.

The purpose of this communication was to evaluate the possibility of rectal stimulation through nerve autografting. Eleven mongrel dogs were studied. The abdomen was opened under anesthesia. The obturator nerve was cut at its entrance into the obturator foramen and was embedded in a tunnel within the musculature of the rectal wall. Six months later, the abdomen was re-opened and bilateral pelvic ganglionectomy was done to denervate the rectum. As the urinary bladder was also denervated subsequent to the pelvic ganglionectomy, cystostomy was performed. Two bipolar electrodes were applied to the obturator nerve. The effects of electrostimulation were evaluated under basic conditions after urecholine and atropine administration and after xylocaine topical application to the obturator nerve. After bilateral pelvic neurectomy, the basic rectal pressure dropped (P < 0.05) and there was no response to urecholine or to atropine injection. Obturator nerve electrostimulation induced evoked potentials within the nerve as well as rectal pressure rise (P < 0.001); the former was abolished with xylocaine topical application to the nerve and the latter with atropine administration. Microscopic examination revealed that the Schwann cells and axons grew in the connective tissue between the rectal muscle bundles. In conclusion, reinnervation of the denervated rectum using a somatic nerve implant is possible. To our knowledge this study is the first to show "smooth' muscle excitability by stimulation of a somatic nerve implant.

Anesthetics, Intravenous↗

A study of the origin of the electric activity of the rectum: is it neurogenic or myogenic?

The rectum possesses electric activity, the origin of which is yet undetermined. The current study investigates the possible source of these waves. Three electrodes were sutured serially to the serosal surface of the rectum in 10 dogs. The rectal pressure was measured by a perfused catheter. Simultaneous recordings of the electric activity and rectal pressure were done before and after bilateral pelvic ganglionectomy and rectal myotomy. Regular slow waves or pacesetter potentials (PPs) followed by inconsistent action potentials (APs) were recorded. They exhibited the same frequency, amplitude and velocity from three electrodes in the individual animal. APs were associated with minor rectal pressure rise. After pelvic ganglionectomy, PPs and APs were recorded but with irregular frequency, amplitude and conduction, a picture of 'rectoarrhythmia'. The rectoarrhythmic waves were registered proximally but not distally to the myotomy. In conclusion, the rectal electric waves persist after bilateral pelvic ganglionectomy but exhibit a 'rectoarrhythmic' pattern. This is suggested to indicate that the waves are not initiated by, but may be under the control of, the extrarectal autonomic innervation. A 'pacemaker' is postulated to exist at the rectosigmoid junction triggering impulses that spread in the rectal wall along the muscle bundles or the myenteric nerve plexus.

Action Potentials↗

Fate of the rectum in patients undergoing total colectomy for Crohn's disease.

BACKGROUND: This study aimed to analyse disease recurrence and fate of the rectum in patients who had a total colectomy for Crohn's disease. METHODS: One hundred and forty-four patients who had a total colectomy for Crohn's colitis were reviewed retrospectively. Ileorectal anastomosis (IRA) was performed in 118 patients, while 26 never had an IRA after colectomy because of severe anorectal lesions. Factors associated with recurrence and rectal preservation failure were studied. RESULTS: The probability of clinical recurrence after IRA was 58 and 83 per cent at 5 and 10 years respectively. The probability of rectal preservation at 5 and 10 years was 70 and 63 per cent after colectomy, and 86 and 86 per cent after IRA, respectively. Patients with extraintestinal manifestation had a higher risk of recurrence and of rectal preservation failure. Previous ileal involvement was associated with a higher rate of ileal recurrence after IRA. After IRA, prophylactic treatment with 5-aminosalicylic acid was associated with a lower rate of recurrence and of failure to preserve the rectum. CONCLUSION: Overall, 63 per cent of patients had a functioning IRA 10 years after total colectomy. Absence of extraintestinal manifestation and prophylactic treatment with 5-aminosalicylates after IRA were the main factors associated with long-term rectal preservation.

Adolescent↗

Dialysis of the rectum for sampling drug concentrations in the luminal extracellular fluid of the gut: technique and precision.

BACKGROUND: It is useful to measure the luminal concentration of drugs which act in the gut. Dialysis of the rectum has not previously been used or validated for this purpose. AIM: To determine the precision of rectal dialysis for measuring rectal drug concentrations. METHODS: To establish the duration of dialysis required to approach equilibrium, the rate of methotrexate diffusion into dialysis bags was first determined in vitro. The precision of rectal dialysis for sampling the methotrexate concentration of colonic lumen extracellular fluid was determined in seven subjects who underwent two consecutive dialysis procedures. Subjects treated with subcutaneous methotrexate for refractory inflammatory bowel disease were studied. RESULTS: Methotrexate crossed the dialysis membrane by a first-order process, and after a 2 h in vitro dialysis, equilibration was 74 +/- 2% (mean +/- s.d.) complete. Rectal dialysis was well tolerated by all subjects. The mean +/- s.e. methotrexate concentration of 3.6 +/- 1.1 nmol/L in the first dialysate was not significantly different from 3.6 +/- 0.9 nmol/L in the second dialysate. P = 0.99 (paired two-tailed t-test). Similar precision was obtained for an endogenous molecule, potassium, secreted by the rectal mucosa. CONCLUSIONS: Dialysis of the rectum is a well tolerated and precise technique for sampling the colonic lumen extracellular fluid for quantitative analyses of exogenous and endogenous substances.

Antirheumatic Agents↗

Serotonin type-4 receptors modulate the sensitivity of intramural mechanoreceptive afferents of the cat rectum.

It has been suggested that serotonin (5-hydroxytryptamine) type-4 (5-HT4) receptors modulate the sensitivity of intrinsic afferents of the intestinal mucosa. We studied the involvement of 5-HT4receptors in the modulation of extrinsic afferent sensitivity of the intestinal wall. During distension ramps, mechanoreceptive rectal afferents in sacral dorsal roots were examined in decerebrate anaesthesia-free cats using the selective 5-HT4receptor partial agonist, tegaserod (HTF 919), and the 5-HT4receptor antagonist, SB 203186. The static discharge rate of the afferents evoked by rectal distension decreased after intravenous (i.v.) administration of tegaserod at intraluminal pressures above 30 mmHg, with the most effective reduction occurring at 50 mmHg. The effect was dose-dependent, with maximal reduction occurring at 1.2 mg kg-1 bodyweight, and could be partly reversed by i.v. administration of SB 203186. Tegaserod did not alter the pressure-volume relationship (compliance) of the rectum. It is tentatively concluded that 5-HT4receptor activation has an inhibitory effect on intramural mechanoreceptors in the cat's rectum. Our results are in line with the observation that tegaserod relieves the sensory symptoms of patients suffering from irritable bowel syndrome.

Animals↗

Compliance, tone and sensitivity of the rectum in different subtypes of irritable bowel syndrome.

Irritable bowel syndrome (IBS) consists of various subtypes. It is not known whether these subtypes share a common pathophysiology. Evaluation of motor and sensory function of the rectum using a barostat may help to explore a common pathophysiological background or differences in pathophysiology in subtypes of IBS. We have evaluated compliance, tone and sensitivity of the rectum, in both fasting state and postprandially, using a computerized barostat in 15 patients with diarrhoea-predominant IBS (IBS-D), 14 patients with constipation-predominant IBS (IBS-C) and compared the results with those obtained in 12 healthy controls. Rectal compliance as calculated over the steep part of the pressure-volume curve (17-23 mmHg) was decreased in both IBS groups (IBS-D 8.0 +/- 1.4 mL mmHg-1; IBS-C 5.6 +/- 1.1 mL mmHg-1) compared with controls (24.7 +/- 3.5 mL mmHg-1). The perception of urge was increased only in IBS-D patients, whereas pain perception was significantly increased in both IBS groups. Spontaneous adaptive relaxation was decreased in IBS-D patients. Postprandially, rectal volume decreased significantly in the controls and in IBS-D patients, but not in IBS-C patients. In conclusion, both rectal motor and sensory characteristics are different between IBS-D and IBS-C patients. Therefore, testing of rectal visceroperception, adaptive relaxation and the rectal response to a meal may help distinguish groups of patients with different subtypes of irritable bowel syndrome.

Adult↗

A comparative study of the effects of a colorectal valve on the oro-anal transit time in patients with an augmented and valved rectum for urinary diversion.

OBJECTIVES: To evaluate the effect of the interposed colorectal valve on the flow of the proximal colonic contents to the rectum in patients with a valved urinary diversion to the rectum. PATIENTS AND METHODS: The oro-anal transit time (OATT) and segmental colonic transit time (SCTT) were estimated in two groups of 15 patients each (10 women and five men). In group 1, patients had a colorectal valve and in group 2 (control) they had no valve in the rectosigmoid area. The OATT and SCTT were evaluated using the 7-day method, whereby each patient swallowed 10 ring-shaped radio-opaque markers daily for 6 days, and a single abdominal radiograph was taken on day 7. The OATT and SCTT were then estimated as the number of retained markers divided by the daily dose of markers. RESULTS: The mean (sd) OATT was not significantly different (P=0.185), at 1.85 (1.21) days in group 1 and 2.49 (1.38) days in group 2. There were no sex differences in the values between the groups. The SCTT in the four areas of the colon again showed no significant differences within or between groups (P>0.05). CONCLUSION: Using a colorectal valve to functionally isolate the urinary rectal reservoir and thus reduce the high incidence of metabolic acidosis has no significant effect on intestinal transit times.

Adult↗

Human papillomavirus type 16-associated primary squamous cell carcinoma of the rectum.

Primary squamous cell carcinoma (SCC) of the colorectum is an extremely rare malignancy of unknown etiology and pathogenesis. We describe an 87-year-old man with primary SCC of the rectum. Routine histology demonstrated a squamous metaplasia-dysplasia sequence of the rectal mucosa with subsequent malignant transformation. Molecular biologic analysis using polymerase chain reaction (PCR) and in situ hybridization revealed the presence of human papillomavirus type 16 (HPV-16) DNA within metaplastic, dysplastic, and SCC lesions and in tumor-free rectal mucosa. Moreover, nested reverse-transcription PCR showed transcriptional activity of the viral E6/E7 oncogenes in tumor tissue and tumor-free rectal mucosa. By contrast, 4 typical adenocarcinomas of the rectum and their adjacent normal mucosa were found to be negative for HPV by nested PCR. In line with the well-established concept of HPV-associated anogenital carcinogenesis, our results strongly suggest an etiologic role of HPV-16 in the pathogenesis of the metaplasia-dysplasia-SCC sequence in the case described.

Adenocarcinoma↗

[Radiologic investigations following abdomino-perineal resection of the rectum (author's transl)].

After abdominoperineal resection of the rectum specific alterations due to operation and disease can be distinguished. In over eighty percent the ureters and the urinary bladder are concerned. The topography of the small-intestine in the sacral cavity reveals alterations of the pelvic floor which generally are local recurrences of carcinoma. In both examinations special importance has to be laid on a lateral view of the pelvis. Indications and results of supplementary examinations are discussed. Computed tomography will deliver additional informations for the diagnosis of recurrent carcinoma; the value of CT is checked at the moment. Considering the amount and importance of treatable illness following resection of the rectum a standardized program for examination seems inevitable. Our experience with over 400 cases is, that this program can reveal important informations for postoperative care which up to now has often been underestimated, even from a radiologic point of view.

Colectomy↗

[Computer tomographic findings after resection of the rectum (author's transl)].

Computed tomography findings in the pelvis after resection of the rectum, obtained from 48 patients primarily suspected of recurrent carcinoma, are represented. Compared with conventional radiographic methods CT demonstrates directly in most cases the presence of a pelvic mass, its extension and relationship to adjacent soft tissue. In some cases this is advantageous for further diagnostic procedures, but also for treatment and further check-up. False conclusions are discussed. The distinction between recurrent carcinoma and retroperitoneal fibrosis in the pelvis, frequently enhanced by retarded healing of the sacral cavity, remains a problem. Progress in the early diagnosis of recurrence of pelvic mass could be made by regular CT check-up during the first two years after resection of the rectum, to increase the value of palliative radiotherapy treatment indicated in any case. As CT, however, is expensive and not always available, this demand cannot be met and the value of conventional radiographic methods remains at present unquestioned.

Colectomy↗

[Anastomotic protection with a transanal tube after rectum resection and total mesorectal excision].

Between October 1998 and December 1999 50 patients with a primary cancer of the rectum were treated by sphincter saving anterior resection of the rectum and total mesorectal excision. Eight patients were given a neoadjuvant combined radio-chemotherapy. The anastomoses were performed in the triple-stapling technique with a Premium Plus CEEA stapling device (Fa. Tyco Health Care, Tönisvorst, Germany) or with a Proximate ILS curved stapling device (Fa. Ethicon Endo Surgery, Norderstedt, Germany). The anastomoses were situated in 7 cm or in lower distance from the anal skin. In all patients with complete anastomotic tissue rings the anastomoses were protected with the transanal tube. The integrity of the anastomosis (n = 48) was checked for completeness in the 2nd and 12th postoperative week. The patients were sigmoidoscoped and the anastomoses were controlled by transanal ultrasonography. During the hospital stay 2 patients (4.2 %) with a clinically evident anastomotic leakage were detected. 3 patients (6.2 %) with an asymptomatic anastomotic leakage were detected by computertomography. The anastomoses of 27 patients (56.2 %) were clinically and by ultrasonographical examination intact. In these patients a postoperative radiogram was not indicated. Relaparotomy was necessary in one patient for bleeding, in two patients for anastomotic leaks and in three patients for ileus (12.5 %). Because of low anastomotic leakage rate and low morbidity we find the transanal tube to be at least equivalent to conventional colostoma for anastomotic protection.

Adult↗

[Options for quality improvement in the treatment of rectum carcinoma].

By means of a prospective multi centre study, 13 419 cases of surgically treated patients with rectum carcinomas were registered between 1.1.2000 and 31.12.2003 and assessed in regard to possible problems concerning indications and operative procedures. Beside a high rate of non-local resective procedures in T1-low risk carcinomas, unnecessary extirpations in cases of tumour localisation over 8 cm from the anal verge were found. Tumours of the lower two-thirds of the rectum were treated by incomplete TME in 20 % of the patients. In addition, there seems to be too low a rate of neo-adjuvant therapy procedures. Protective stomata were frequently foregone after low anterior resection. Endoscopic interventional methods were still used reluctantly in inoperable situations.

Germany↗

Angiodysplasia in the colon and rectum. Endoscopic morphology, localisation and frequency.

In a prospective study, the occurrence of angiodysplasia was investigated by total colonoscopy in 1938 patients. Angiodysplasia was found in 59 patients, i.e. 3%. 12 out of 59 patients were admitted for acute or chronic peranal hemorrhage or anemia. 47 out of 59 patients were asymptomatic. The site of the lesions was as follows: cecum 37%, ascending colon 17%, transverse colon 7%, descending colon 7%, sigmoid colon 18% and rectum 14%. Histological confirmation was obtained in 15 out of 37 biopsies. The endoscopic appearance was variable, most of the vascular dilatations being smaller than 5 mm (n = 47), with a homogeneous (n = 35) or inhomogeneous (n = 24) structure and a regular (n = 34) or irregular (n = 25) border. The lesions were single (n = 34) as well as multiple (n = 25), they were usually flat (n = 54), seldom slightly prominent (n = 5). Concomitant pathological findings in the bowel were diagnosed in 33 out of 59 patients: diverticula in 32%, adenomas in 24% and carcinomas in 8.5%. Right hemicolectomy for bleeding angiodysplasia is indicated only if endoscopic therapy has failed and other colorectal sources of bleeding, and especially angiodysplasia in the left colon and rectum have been excluded by endoscopy or angiography.

Adolescent↗

Endometriosis of the colon and rectum: an indication for peroperative coloscopy.

Endometriosis in women is a frequent disease and not uncommon is the implant of ectopic endometrium in the colon and rectum. In the present study three cases are reported without intestinal symptoms related to endometriosis, in which the intraoperative findings of thickened and stricturing areas of the colon and rectum--generally attached to the posterior portion of the uterus and presenting the aspects of a cancer--caused serious differential diagnostic problems, and made the choice of treatment difficult. These problems were solved by peroperative coloscopy that, revealing an extrinsic compression of the colonic and rectal wall in the presence of an intact mucosa, indicated the conservative treatment of the lesions in all three cases.

Adult↗