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At least 163 records · Page 9Linked to original sources
PubMed1999

Impact of the filling status of the bladder and rectum on their integral dose distribution and the movement of the uterus in the treatment planning of gynaecological cancer.

PURPOSE: Determination of the impact of the filling status of the organs at risk (bladder and rectum) on the uterus mobility and on their integral dose distribution in radiotherapy of gynaecological cancer. METHODS: In 29 women suffering from cervical or endometrial cancer two CT scans were carried out for treatment planning, one with an empty bladder and rectum, the second one with bladder and rectum filled. The volumes of the organs at risk were calculated and in 14 patients, receiving a definitive radiotherapy, the position of the uterus within the pelvis was shown using multiplanar reconstructions. After generation of a 3D treatment plan the dose volume histograms were compared for empty and filled organs at risk. RESULTS: The mobility for the corpus uteri with/without bladder and rectum filling was in median 7 mm (95%-confidence interval: 3-15 mm) in cranial/caudal direction and 4 mm (0-9 mm) in posterior/anterior direction. Likewise, cervical mobility was observed to be 4 mm (-1-6 mm) mm in cranial/caudal direction. A full bladder led to a mean reduction in organ dose in median from 94-87% calculated for 50% of the bladder volume (P < 0.05, Wilcoxon's matched-pairs signed-ranks test). For 66% of the bladder volume the dose could be reduced in median from 78 to 61% (P < 0.005) and for the whole bladder from 42 to 39% (P < 0.005), respectively. No significant contribution of the filling status of the rectum to its integral dose burden was noticed. CONCLUSIONS: Due to the mobility of the uterus increased margins between CTV and PTV superiorly, inferiorly, anteriorly and posteriorly of 15, 6 and 9 mm each, respectively, should be used. A full bladder is the prerequisite for an integral dose reduction.

Cervix Uteri↗
PubMed2003

The effect of motilin on the rectum in healthy volunteers.

AIMS: The role of motilin in the regulation of upper gastrointestinal (GI) motility is well defined. However, little is known about the effects on the distal GI tract. To investigate the effect of exogenous motilin on rectal function, barostat measurements in the rectum were performed and lower abdominal symptoms were scored. METHODS: Eight fasted, healthy volunteers were infused intravenously with synthetic motilin or placebo over 90 min in a double-blind, randomized, cross-over design. Rectum volume was measured with a barostat device during constant pressure and during isobaric distensions. Lower abdominal symptoms were scored by visual analogue scales. Plasma motilin concentrations were measured by radioimmunoassay. RESULTS: Baseline rectum volumes were similar between treatments: 185 +/- 62 mL (motilin) and 136 +/- 41 mL (placebo). During the constant pressure procedure, motilin increased rectum volume [area under the effect curve (AUEC)] by 6%[95% confidence interval (CI) -3, 16] of baseline, compared with placebo. During isobaric distensions motilin increased rectum volume (AUEC) by 43 mL (95% CI 0.4, 85; P < 0.05) and compliance by 10 mL mmHg-1 (95% CI 0.3, 20; P < 0.05) relative to placebo. Motilin did not induce changes in the sensation of rectal feelings. CONCLUSION: Exogenous motilin increased rectal compliance in healthy volunteers, without affecting rectal sensations.

Adult↗
PubMed1999

Lateral ligaments of the rectum: an anatomical study.

BACKGROUND: The lateral ligaments of the rectum are surrounded by confusion and misconception. Their identification before 'hooking them on the finger', clamping and ligating is considered in many surgical texts to be an essential step in mobilization of the rectum. By contrast, it is the experience of many colorectal surgeons that the mesorectum can be dissected out either by diathermy or sharp dissection alone. METHODS: Dissection in the mesorectal plane was performed on 28 cadaveric pelves. RESULTS: In ten of the pelves, no connective tissue structure crossed from the pelvic side wall to the rectum. The remaining 18 had only very insubstantial connective tissue strands crossing this space. A total of 17 middle rectal arteries were found, all of them unilateral. Fourteen of these vessels crossed the mesorectum independent of any structure, while the remainder were part of a neurovascular bundle with a connective tissue element. CONCLUSION: It is proposed that the 'lateral ligaments' of the rectum do not exist and that the term should be dropped from surgical texts. When present, the middle rectal artery is a small vessel, close to the pelvic floor. The entire rectum may be mobilized by sharp dissection without the need for clamping or ligation of any significant structure.

Aged↗
PubMed2002

Influences of pelvic floor structures and sacral innervation on the response to distension of the cat rectum.

The contributions to the rectal response to distension of the pelvic floor structures surrounding the rectum and of the sacral spinal innervation have never been studied. Using paralysed intercollicularly decerebrate, anaesthesia-free cats, we studied pressure-volume relationships during slow ramp distensions of the rectum. Results obtained from animals with intact pelvic cavities were compared with those following mobilization of the rectum from the pelvic floor musculature. To assess the influences of spinal outflow and afferent input, rectal pressure-volume relationships were measured in the mobilized rectum following bilateral sequential transection of the spinal roots S1 to S3, first dorsal, then ventral. Isolation of the rectum from the pelvic floor structures resulted in a decrease in balloon volume in the lower range of distension pressure but did not affect volumes at higher pressures. The only afferent effect was seen after sectioning of dorsal roots S1, which resulted in a decrease in balloon volume. The only efferent effect was seen after sectioning of ventral roots S3, which decreased balloon volume further. In conclusion, the rectal response to distension depends on the properties of the rectal wall. It may be influenced by somatic inputs, inputs from the myenteric nervous plexus, and from the parasympathetic and sympathetic nervous systems. Afferent inputs and spinal autonomic reflexes may decrease the tone of the rectal musculature during distension.

Animals↗
PubMed2004

A Monte Carlo study of the impact of the choice of rectum volume definition on estimates of equivalent uniform doses and the volume parameter.

Calculations of normal tissue complication probability (NTCP) values for the rectum are difficult because it is a hollow, non-rigid, organ. Finding the true cumulative dose distribution for a number of treatment fractions requires a CT scan before each treatment fraction. This is labour intensive, and several surrogate distributions have therefore been suggested, such as dose wall histograms, dose surface histograms and histograms for the solid rectum, with and without margins. In this study, a Monte Carlo method is used to investigate the relationships between the cumulative dose distributions based on all treatment fractions and the above-mentioned histograms that are based on one CT scan only, in terms of equivalent uniform dose. Furthermore, the effect of a specific choice of histogram on estimates of the volume parameter of the probit NTCP model was investigated. It was found that the solid rectum and the rectum wall histograms (without margins) gave equivalent uniform doses with an expected value close to the values calculated from the cumulative dose distributions in the rectum wall. With the number of patients available in this study the standard deviations of the estimates of the volume parameter were large, and it was not possible to decide which volume gave the best estimates of the volume parameter, but there were distinct differences in the mean values of the values obtained.

Body Burden↗
PubMed1995

Calcium and magnesium absorption from the colon and rectum are increased in rats fed fructooligosaccharides.

We investigated the effects of fructooligosaccharides on the absorption of calcium, magnesium and water from the colon and rectum of rats fed a control diet or the control diet containing 50 g fructooligosaccharides/kg. Chromium-mordanted cellulose was used as an unabsorbable marker to calculate apparent absorption of calcium and magnesium. There was a positive correlation (r = 0.982, P < 0.001 in rats fed the control diet and r = 0.975, P < 0.001 in rats fed the fructooligosaccharides-containing diet) between the amount of chromium and the dry weight of each fecal pellet in the colon and rectum. Ratios of calcium to chromium and magnesium to chromium in fecal pellets in the colon and rectum were calibrated from the Ca:Cr and Mg:Cr ratios of cecal contents. In rats fed the fructooligosaccharides-containing diet, but not in rats fed the control diet, these ratios were correlated with the fractional length of transit along the colon and rectum, indicating linear disappearance of calcium and magnesium during the colorectal passage. Total apparent absorption of calcium and magnesium, predicted from regression equations with the Ca:Cr and Mg:Cr ratios of cecal contents, agreed well with those calculated from the Ca:Cr and Mg:Cr ratios of feces. The consumption of fructooligosaccharides did not affect net water absorption from the colon and rectum. These results indicated that fructooligosaccharides significantly increased calcium and magnesium absorption and that indigestible and fermentable carbohydrate facilitates colorectal absorption of calcium and magnesium.

Animals↗
PubMed1988

Effects of prolonged exposure to alpha,beta-methylene ATP on non-adrenergic, non-cholinergic excitatory transmission in the rectum of the chicken.

1. Effects of prolonged exposure to alpha,beta-methylene ATP (alpha,beta-Me ATP) on contractions and excitatory junction potentials (e.j.ps) evoked by non-adrenergic, non-cholinergic (NANC) excitatory nerve stimulation have been investigated in the chicken isolated rectum and longitudinal muscle strip from chicken rectum pretreated with atropine (0.5 microM), methysergide (2 microM) and pyrilamine (3 microM). 2. Alpha,beta-Me ATP (20 nM-4 microM) caused a rapid rise in tension of the longitudinal muscle of the isolated rectum preparation which returned to the baseline levels after a few minutes. The magnitude of the contractile response to NANC nerve stimulation was reduced after exposure to the drug. The inhibitory effect was related to the drug concentration; at 4 microM the nerve-mediated contraction was abolished and frequently converted to a relaxation. 3. Adenosine 5'-triphosphate (ATP, 100 microM), bovine neurotensin (2.5 nM) and K+-rich solutions (30 nM and 60 nM) all produced a transient contraction of the isolated rectum preparation. The exposure to alpha,beta-Me ATP (0.2 and 4 microM) also rendered the preparation less sensitive to these stimulant substances. 4. Alpha,beta-Me ATP (0.2 and 4 microM) caused a membrane depolarization in cells of the longitudinal muscle strip. The depolarization reached a peak within 2-3 min after application and then decayed to a steady level that was still more positive than the baseline level. The electrotonic potentials were reduced in amplitude to 44 +/- 8% (n = 7) of the normal amplitude if measured at the peak depolarization produced with 0.2 microM alpha,beta-Me ATP, and to 62 +/- 10% (n = 7) if measured at the steady-state depolarization. With 4 microM, the corresponding percentages were 33 +/- 7% (n = 8) and 55 +/- 7% (n = 8), indicating a decrease in membrane resistance. 5. The e.j.ps in response to field stimulation of the intramural nerves and Remak's nerve stimulation were decreased in amplitude and duration during exposure to alpha,beta-Me ATP (0.2 and 4 microM). 6. The smooth muscle cells regained normal membrane resistance and sensitivity to ATP on washout of alpha,beta-Me ATP (4 microM) more rapidly than the responses to NANC nerve stimulation. 7. It can be argued from the results that the suppression by alpha,beta-Me ATP of the contraction and e.j.p. evoked by NANC nerve stimulation in the chicken rectum, unlike the mammalian preparation described previously, is due mainly to a change in the electrical properties of the membrane of the smooth muscle cells, rather than being due, or only partly due, to desensitization of the purine receptor.

Adenosine Triphosphate↗
PubMed2001

Utility of an upper echoendoscope for endoscopic ultrasonography of malignant and benign conditions of the sigmoid/left colon and the rectum.

OBJECTIVE: The majority of data on colonic endoscopic ultrasound (EUS) are limited to malignant lesions in the rectum and diseases of the anal sphincter. The forward-oblique-viewing upper echoendoscope has been mostly applied for staging rectal cancer. A front-viewing echocolonoscope is available but has not been widely used because of limited indications and the expense of buying another instrument. The purpose of our study was to evaluate the utility of a forward-oblique-viewing upper echoendoscope for EUS of malignant and benign lesions of the sigmoid/left colon and the rectum. METHODS: Thirty-two EUS exams were performed for a variety of indications in the rectum and the sigmoid/left colon. The patients were prepared for the exam in a manner similar to the performance of flexible sigmoidoscopy. Flexible sigmoidoscopy was performed in all cases before performing EUS. Surgical path data were reviewed in all cases if the patient had surgery after EUS. RESULTS: Twenty-six exams were done for staging of rectosigmoid carcinoma, follow-up after chemotherapy and/or radiation, or to look for recurrence after resection of colorectal cancer. Surgical pathology results were available in 20 patients. The accuracies of EUS were 85% for T staging and 80% for N staging. Six EUS exams were for benign causes, including evaluation for the presence of a perirectal abscess in two (no abscess found), to rule out rectal varices in one (EUS confirmed rectal varices), and evaluation of submucosal lesions. One patient subsequent to EUS imaging also underwent a linear EUS-guided fine-needle aspiration of a submucosal mass in the rectum with the fine-needle aspirate consistent with a myogenic tumor. CONCLUSIONS: The forward-oblique-viewing upper echoendoscope is a versatile instrument that can be applied for EUS imaging of malignant and benign indications not only in the rectum but also in the sigmoid/left colon.

Colon↗
PubMed2004

Modulatory influences on antegrade and retrograde tonic reflexes in the colon and rectum.

Tonic reflexes in the colon and rectum are likely to be important in health and in disorders of gastrointestinal function. The aim of this study was to evaluate the fasting and postprandial "colorectal" and "rectocolic" reflexes in response to 2-min isobaric distensions of the colon and rectum, accounting for enteric sensation, compliance, and distending balloon volume. In 14 healthy fasting subjects, a dual barostat assembly was positioned (descending colon and rectum). A 2-min phasic distension was performed in the colon and rectum in random order while the opposing balloon volume was recorded. Sensation (phasic distension) and compliance (ramp distension) were also determined. The experiment was repeated postprandially. Colonic distension resulted in significant rectal tonic contraction in the fasting (rectal volume change: -35.4 +/- 8.4 ml, P < 0.01) and postprandial (-22.2 +/- 8.4 ml, P < 0.01) states. After adjustment for colonic sensitivity, for compliance, and for distending balloon volume, the rectal volume change remained significant; the extent of the tonic response, however, correlated significantly with increasing pain score (P < 0.01). In contrast, rectal distension did not produce a significant tonic response in the colon (fasting: -6.5 +/- 7.3 ml; postprandial: 2.7 +/- 7.3 ml), either unadjusted or adjusted for rectal sensitivity, compliance, and distending balloon volume. In conclusion, the colorectal reflex, but not the rectocolic reflex, can be readily demonstrated both before and after a meal in response to a 2-min isobaric distension in the colon and rectum, respectively. Although the presence of the colorectal reflex does not depend on colonic sensitivity or the volume of the distending colonic balloon, these factors modulate the reflex, especially in the fasting state.

Adult↗
PubMed1998

Effect of magnetic stimulation on the contractile activity of the rectum in the dog.

PURPOSE: Magnetic stimulation (MS) produces its effect, according to Faraday's law, by creating an electric field which can stimulate the neuromuscular tissues. The current study investigates, to our knowledge for the first time, the effect of MS on rectal pressure and evacuation with a view on its possible application in emptying the inertic or neuropathic rectum. METHODS: The rectal, rectal neck and vesical pressures as well as the EMG activity of the two rectus abdominis muscles were recorded during sacral MS with a magnetic coil while the rectum was empty and while filled. Stimulation parameters were set at 70% intensity, 20 Hz frequency and 1- to 5-second burst length. RESULTS: Sacral MS of both the filled and empty rectum effected a significant increase in rectal (p<0.01) and vesical (p<0.01) pressures and a decrease in rectal neck pressure (p<0.01). Rectal evacuation of the filled rectum using intermittent stimulation was achieved in all animals. CONCLUSION: Sacral MS resulted in a rectal evacuation. It is a simple, easy and noninvasive method that might prove applicable in the treatment of inertic constipation and neuropathic rectum.

Animals↗
PubMed2001

Features of microsatellite instability in colorectal cancer: comparison between colon and rectum.

In one third of colorectal cancer patients, tumours occur in the rectum. Unique aetiologies may underlie the increased carcinogenesis in this region of the colorectum. Microsatellite instability (MSI) was analysed in specimens obtained from 121 colorectal carcinoma patients, using five dinucleotide markers and a new fluorescent system. The incidence of microsatellite alterations in the proximal colon, the distal colon and the rectum was 44.4% (16/36), 37.2% (16/43) and 23.8% (10/42), respectively. Patterns of microsatellite alterations could be classified into two subtypes, one showing relatively small changes within 6 bases (type A) and the other exhibiting drastic changes over 8 bases (type B). All the changes observed in tumours in the rectum were type A, and no type B mutation was noted. There was a close correlation between type B mutations and high-frequency MSI (> or =2 markers), MSI-H, and between type A mutations and low-frequency MSI (1 marker), MSI-L. The type B/MSI-H phenotype significantly correlated with the proximal localisation of tumours. In the rectum, there was no tumour with the type B/MSI-H phenotype. These findings suggest that cancers occurring in the colon and the rectum have a differential molecular background for carcinogenesis.

Adenocarcinoma↗
PubMed1978

Arterial supply to the human rectum.

The arterial supply to the human rectum was studied in 42 autopsy specimens. 32 were fixed in formalin and dissected. Five were radiographed after filling their arterial bed with a radio-opaque substance. The remaining five specimens were used to prepare plastic casts of the arterial bed. The superior rectal artery is the chief rectal artery. It forms a recto-sigmoid branch, an upper rectal branch and then divides into right and left terminal branches. Terminal branches extend downwards and forwards around the lower two thirds of the rectum to the level of the levator ani. The middle rectal artery, of appreciable diameter, on one or both sides of the rectum, is found supplying a limited part of the rectum in 12% of the specimens. Its presence can be anticipated by observing the diameter of the superior rectal artery and its two terminal branches. The inferior rectal artery supplies the anal canal below the levator ani. Rectal twigs of other pelvic arteries terminate at the pararectal tissues occasionally reaching the wall of the rectum. Extramural anastomoses were not observed between the main rectal arteries, but intramural ones were present, mainly between the superior and the inferior rectal arteries.

Adult↗
PubMed2002

An optimization method for reference dose point of rectum in brachytherapy of gynecological neoplasms.

Rectum reference dose points have a direct impact on the morbidity seen in gynecological intracavitaty radiotherapy. The aim of this study is to obtain less morbidity by marking rectum with radio opaque solution. Fourteen patients with gynecological cancer who underwent external radiotherapy received 15 Gray (Gy) intracavitary radiotherapy. During the internal radiotherapy planning, radio opaque solution has been administered into the rectum to observe it on lateral radiogram. Thus rectum reference dose point and five points were marked at sites nearest to the sources. Nucletron Planning system was used for obtaining three-dimensional planning. After therapy patients were followed at every three months. Median follow-up was 18 months. Most frequently observed morbidities were grade 1-2 rectitis and cystitis in six patients. As a result, more accurate rectum dose values and less factors causing dose changing can provide better results for gynecological intracavitary brachytherapy.

Brachytherapy↗
PubMedDate not supplied

Acute heat injury to the normal swine rectum.

Intracavitary hyperthermia was applied to the rectum of normal pigs at 43 degrees, 44 degrees, 45 degrees, 46 degrees, 47 degrees and 48 degrees C for 30 min. A score of temperature-induced histological changes of each specimen was made 48 h after heating. The scores from each specimen and temperature were used for regression analysis. Judging from the regression lines of the scores obtained for rectum and oesophagus, we conclude that the thermosensitivity of the rectum is about 1 degree C higher than that of the oesophagus. It suggested that 43 degrees C/30 min could be a safe dose for normal rectum. The thermosensitivity of swine rectum is discussed.

Animals↗
PubMed2002

Tumors of the rectum and anus.

Within a ten year period we have performed 433 radical operations on the rectum. An anterior resection of rectum was done in 110 cases, low anterior resection in 60 patients, very low anterior resection was done by stapler in 32 patients and was sewn by hand in 10 patients. Colo-anal anastomoses were performed 86 times and abdominoperineal amputation of rectum sec. Miles 20 times. Local transsphincteric procedures were used 14 times. In 12 patients the colo-anal anastomosis was performed either for recurrence of tumor or after a Hartmann's procedure. In the carcinoma of the lower half of the rectum there is still an unsolved question: whether to perform a low or a very deep low anastomosis or whether an extirpation of rectum with sparing the sphincters and sewing a colo-anal anastomosis is more beneficial. In the years 1980-1995 we treated surgically 64 patients with a tumor in anal area. All patient underwent preoperative radio- and chemotherapy. In our group adenocarcinoma was demonstrated in 6 patients, squamous carcinoma in 48 patients and squamous cells of the carcinoma in situ in 10 patients.

Anastomosis, Surgical↗
PubMed2003

[Personal experience with unconventional treatment in extraperitoneal injuries of the rectum].

Because of the unannounced war state in Bosnia and Herzegovina in the period 1992-1995, there were overlapping of war and peaceful doctrine of taking care of all injuries. Many extraperitoneal and intraperitoneal injuries of colon and rectum were treated in the Cantonal Hospital Zenica and in the other war hospitals where the staff of Cantonal Hospital Zenica worked. According to the war doctrine all injuries of colon and rectum are treated operatively with obligatory making colostoma. This presentation includes 7 cases of extraperitoneal rectum injuries from great number of intra- end extraperitoneal injuries of rectum and injuries of colon, which were not treated by principles of war doctrine. We emphasize that surgical teams were experienced, had diagnostic equipment and operation hall with staff and equipment in the case of reintervention. THE AIM: Of this presentation is to point out the size of lesion and the association with the other injuries in order to decide about operative or conservative way of treatment as alternative method. It was necessary to define the patients in which we would avoid colostoma with adequate drainage procedures, first of all looking at the size of lesion and the association with the other injuries. THE MAIN DIAGNOSTIC PROCEDURE: Was rectoscopic verification of all 7 injuries with the presentation of size of lesion. THE MAIN METHOD OF TREATMENT: Was high grade quality, continuous and adequate toilette and drainage of canal of injury and perirectal area following with antibiotics (metronidasol) and stool regulation. In comparison with doctrinal treatment by making colostoma there was no significant more complications and lethal outcome by this alternative method of treatment. CONCLUSION: Six of seven cases of extraperitoneal rectum injuries with lesion not bigger than 30 mm and with small pelvis mutilation were solved using conservative method (not making colostoma).

Bosnia and Herzegovina↗
PubMed1990

[Cystic duplication of the rectum].

Cyst or intestinal duplications can arise anywhere along the gut, however those located in the rectum are very rare and only a few dozen cases have been reported. The reason that induced us to report this patient is double: first to present a new case of rectal duplication diagnosed at 45 days old that had a normal barium enema previously, second to confirm once more that the muscular complex of the rectum can be cut in the posterior middle line without any damage to the rectal continence function, as Peña's surgical approach for anorectal atresias. The case reported correspond to a newborn weighing 2,850 grs who had exomphalos of 5 cm. Wide with an integral sac and was operated by primary closure. When he was 10 days old, and because he had some intestinal disturbances compatible with malrotation, a barium enema was done that was normal. He was discharged and returned 30 days later because of striped feces and constipation. Rectal examination showed a retrorectal tumor located at left posterolateral space. Ultrasound showed a cystic mass and barium enema displayed a narrowed rectum channel. First we did a Wangesteen colostomy. Ten days later, by a sagittal posterior approach cutting the Levator and Muscular Complex of the rectum in the middle line and without opening the lumen, a tumor like a nut, sharing its muscular coat with the rectum, was excised. The Muscular Complex and the Levator were repaired with the aid of the electrostimulator. After the 7 day postoperation we made some rectal dilatations and closure of colostomy at 21 day.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1989

Experimental devascularization (devitalization) of the rectum and sigmoideum.

In 6 laboratory pigs, devascularization (devitalization) of the rectum and the adjacent part of the sigmoideum was carried out by the vasa rectalia cranialia et media ligatures with simultaneous aboral closure of the rectum at the base of the lesser pelvis and oral closure at the borderline between the rectum and the sigmoideum. The devascularized rectum was not removed but left in situ. Terminal colostomy was established. Laparotomic revision was carried out after 12 weeks, colostomy was removed and continuity of the intestine was reestablished by insertion anastomosis, by suture of the end of the colon to the anal mucosa and skin. In further two pigs, devascularization of the rectosigmoideum was carried out with colostomy and reconstruction was carried out after 12 weeks by procto-sigmoideo-anastomosis. In another 2 animals, devascularization was carried out on the lower part of the sigmoideum and continuity was immediately renewed by end-to-side sigmoideo-sigmo-ideoanastomosis. All revisions indicated that the devascularized necrotic segment shrank to form a minute fibrous tissue residue, anastomosis was patent and continence was retained for colo-proctoanastomosis. The described techniques are technically simple and could be employed as palliative surgical methods for inoperable tumours in the region of the rectum and lower part of the sigmoideum.

Anal Canal↗