Controversies in IPAA for Ulcerative Colitis: A Systematic Review of Different Anastomotic Techniques

BACKGROUND

Available techniques for IPAA in ulcerative colitis include handsewn, double-stapled, and single-stapled anastomoses. There are controversies, indications, and different outcomes regarding these techniques.

OBJECTIVE

To describe technical details, indications, and outcomes of 3 specific types of anastomoses in restorative proctocolectomy.

DATA SOURCE

Systematic literature review for articles in the PubMed database according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria.

STUDY SELECTION

Studies describing outcomes of the 3 different types of anastomoses, during pouch surgery, in patients undergoing restorative proctocolectomy for ulcerative colitis.

INTERVENTION

IPAA technique.

MAIN OUTCOME MEASURES

Postoperative outcomes (anastomotic leaks, overall complication rates, and pouch function).

RESULTS

Twenty-one studies were initially included: 6 studies exclusively on single-stapled IPAA, 2 exclusively on double-stapled IPAA, 6 studies comparing single-stapled to double-stapled techniques, 6 comparing double-stapled to handsewn IPAA, and 1 comprising single-stapled to handsewn IPAA. Thirty-seven studies were added according to authors' discretion as complementary evidence. Between 1990 and 2015, most studies were related to double-stapled IPAA, either only analyzing the results of this technique or comparing it with the handsewn technique. Studies published after 2015 were mostly related to transanal approaches to proctectomy for IPAA, in which a single-stapled anastomosis was introduced instead of the double-stapled anastomosis, with some studies comparing both techniques.

LIMITATIONS

A low number of studies with handsewn IPAA technique and a large number of studies added at authors' discretion were the limitations of this strudy.

CONCLUSIONS

Handsewn IPAA should be considered if a mucosectomy is performed for dysplasia or cancer in the low rectum or, possibly, for re-do surgery. Double-stapled IPAA has been more widely adopted for its simplicity and for the advantage of preserving the anal transition zone, having lower complications, and having adequate pouch function. The single-stapled IPAA offers a more natural design, is feasible, and is associated with reasonable outcomes compared to double-stapled anastomosis. See video from symposium.

Mucin levels in glands of the colonic mucosa of rats with diversion colitis subjected to enemas containing sucralfate and n-acetylcysteine alone or in combination

PURPOSE

To evaluate the tissue content of neutral and acidic mucins, sulfomucins and sialomucins in colonic glands devoid of intestinal transit after enemas containing sucralfate and n-acetylcysteine alone or in combination.

METHODS

Sixty-four rats underwent intestinal transit bypass. A colonic segment was collected to compose the white group (without intervention). After derivation, the animals were divided into two groups according to whether enemas were performed daily for two or four weeks. Each group was subdivided into four subgroups according to the substance used: control group: saline 0.9%; sucralfate group (SCF): SCF 2 g/kg/day; n-acetylcysteine group (NAC): NAC 100 mg/kg/day; and SCF+NAC group: SCF 2 g/kg/day + NAC 100 mg/kg/day.Neutral and acidic mucins were stained by periodic acid-Schiff and alcian-blue techniques, respectively. The distinction between sulfomucins and sialomucin was made by the high alcian-blue iron diamine technique. The content of mucins in the colonic glands was measured by computerized morphometry. The inflammatory score was assessed using a validated scale. The results between the groups were compared by the Mann-Whitney's test, while the variation according to time by the Kruskal-Wallis' test (Dunn's post-test). A significance level of 5% was adopted.

RESULTS

There was reduction in the inflammatory score regardless of the application of isolated or associated substances. Intervention with SCF+NAC increased the content of all mucin subtypes regardless of intervention time.

CONCLUSIONS

The application of SCF+NAC reduced the inflammatory process of the colonic mucosa and increased the content of different types of mucins in the colonic glands of segments excluded from fecal transit.

IS IT POSSIBLE TO OPTIMIZE STAPLED HEMORRHOIDOPEXY OUTCOMES BY ENLARGING OPERATIVE CRITERIA INDICATIONS? RESULTS OF A TAILORED PROCEDURE WITH ASSOCIATED RESECTION IN A COMPARATIVE PERSONAL SERIES

BACKGROUND

Since its introduction, stapled hemorrhoidopexy has been increasingly indicated in the management of hemorrhoidal disease.

AIM

Our primary end point was to evaluate the incidence of recurrent disease requiring another surgical intervention. On a secondary analysis, we also compared pain, complications, and patient's satisfaction after a tailored surgery.

METHODS

We retrospectively reviewed 196 patients (103 males and 93 females) with a median age of 47.9 years (range, 17-78) who were undergoing stapled hemorrhoidopexy alone (STG; n=65) or combined surgery (CSG; n=131, stapled hemorrhoidopexy associated with resection).

RESULTS

Complications were detected in 11 (5.6%) patients (4.6% for STG vs. 6.1% for CSG; p=0.95). At the same time, symptoms recurrence (13.8% vs. 8.4%; p=034), reoperation rate for complications (3.1% vs. 3.0%; p=1.0), and reoperation rate for recurrence (6.1% vs. 4.6%; p=1.0) were not different among groups. Grade IV patients were more commonly managed with simultaneous stapling and resection (63% vs. 49.5%), but none of them presented symptoms recurrence nor need reoperation due to recurrence. Median pain score during the first week was higher in CSG patients (0.8 vs. 1.7). After a follow-up of 24.9 months, satisfaction scores were similar (8.6; p=0.8).

CONCLUSION

Recurrent symptoms were observed in 10% of patients, requiring surgery in approximately half of them. Even though the association of techniques may raise pain scores, a tailored approach based on amplified indication criteria and combined techniques seems to be an effective and safe alternative, with decreased relapse rates in patients suffering from more advanced hemorrhoidal disease. Satisfaction scores after hemorrhoidopexy are high.

Sucralfate enemas reduce the oxidative tissue damage and preserves the contents of E-cadherin and ?-catenin in colonic mucosa without fecal stream

PURPOSE

To evaluate the effects of sucralfate enemas in tissue contents of E-cadherin and ?-catenin in an experimental diversion colitis.

METHODS

Thirty-six male Wistar rats were submitted to a proximal colostomy and a distal mucous fistula. They were allocated into three groups: first group received daily saline enemas (2 mL/day) and the two other groups daily enemas with sucralfate at dosage of 1 or 2 g/kg/day, respectively. Six animals of each group were euthanized after two weeks and six animals after four weeks. The inflammation of the excluded mucosa was evaluated by histological analysis. The oxidative damage was quantified by measurement of malondialdehyde tissue levels. The expression of E-cadherin and ?-catenin was identified by immunohistochemistry, and its contents were quantified by computer-assisted image analysis.

RESULTS

Sucralfate enemas reduced inflammation in animals subjected to treatment with 2 g/kg/day by four weeks, and the levels of oxidative damage in mucosa without fecal stream irrespective of concentration and time of intervention. E-cadherin and ?-catenin content increased in segments without fecal stream in those animals subjected to treatment with sucralfate.

CONCLUSIONS

Sucralfate reduces the inflammation and oxidative stress and increases the tissue content of E-cadherin and ?-catenin in colonic mucosa devoid to the fecal stream.

Effects of anti-TNF-α in experimental diversion colitis

Purpose:

To evaluate the effects of infliximab on the inflammation of the colonic mucosa devoid from fecal stream.

Methods:

Twenty-four rats were submitted to a Hartmann's procedure. They remained for 12 weeks with the fecal derivation to development of diversion colitis on excluded colorectal stump. After this period, they were divided into 3 groups: one group received intervention with saline (2.0 mL / week), other group infliximab at doses of 5 mg/kg/week and the other 10 mg/kg/week for five consecutively weeks. Concluded the intervention period, the animals were euthanized to remove colon segments with and without fecal stream. Colitis was diagnosed by histological analysis and the degree of inflammation by validated score. The neutrophilic infiltrate was evaluated by tissue expression of myeloperoxidase identified by immunohistochemical. The tissue content of myeloperoxidase was measured by computer-assisted image analysis.

Results:

The inflammatory score was high in colonic segments without fecal stream. The intervention with infliximab reduced the inflammatory score in excluded colonic segments. The content of myeloperoxidase was reduced in colonic segments of animals treated with infliximab mainly in high concentrations.

Conclusion:

Intervention with infliximab reduced the inflammation and the neutrophil infiltrate in colonic segments devoid of the fecal stream.

PROGNOSTIC FACTORS FOR LEFT COLECTOMY FOR COLON CANCER: A TEN YEARS EXPERIENCE OF A SINGLE UNIVERSITY INSTITUTION

Background:

Colorectal cancer is the third most common cancer in the world. In Brazil, it is the leading cause of cancer in the gastrointestinal tract.

Aim:

To evaluate the preoperative, perioperative, and postoperative risk factors for recurrence and overall survival of patients with left colon cancer operated during a ten-year period.

Methods:

Patients with left colon cancer surgically treated underwent clinical preoperative workout and cancer staging. The following factors were studied: gender, age, tumor location, T stage, lymph node yield, N stage, M stage, histological type, and tumor differentiation. It was analyzed the influence in five-year overall survival.

Results:

A total of 173 patients underwent left colectomy for colon cancer. There was a slight predominance of male gender with 50.9%. The mean age was 60.8 years old. Fifteen (8.7%) tumors were located at splenic flexure, 126 (72.8%) at sigmoid colon, and 32 (18.5%) at descending colon. The median length of hospital stay was seven days. Mean survival was 47.5 months. At 60 months seven patients (4%) lost follow-up, 38 patients (21.9%) deceased and 135 patients (78%) were alive. Overall survival time was 48 months.

Conclusion:

Advanced stages (T3-T4, N+ and M+) were the only factors associated with poor long term survival in left colon cancer.

Short-term outcomes after laparoscopic colorectal surgery in patients with previous abdominal surgery: A systematic review

AIM: To perform a systematic review focusing on short-term outcomes after colorectal surgery in patients with previous abdominal open surgery (PAOS).

METHODS: A broad literature search was performed with the terms “colorectal”, “colectomy”, “PAOS”, “previous surgery” and “PAOS”. Studies were included if their topic was laparoscopic colorectal surgery in patients with PAOS, whether descriptive or comparative. Endpoints of interest were conversion rates, inadvertent enterotomy and morbidity. Analysis of articles was made according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

RESULTS: From a total of 394 citations, 13 full-texts achieved selection criteria to be included in the study. Twelve of them compared patients with and without PAOS. All studies were retrospective and comparative and two were case-matched. The selected studies comprised a total of 5005 patients, 1865 with PAOS. Among the later, only 294 (16%) had history of a midline incision for previous gastrointestinal surgery. Conversion rates were significantly higher in 3 of 12 studies and inadvertent enterotomy during laparoscopy was more prevalent in 3 of 5 studies that disclosed this event. Morbidity was similar in the majority of studies. A quantitative analysis (meta-analysis) could not be performed due to heterogeneity of the studies.

CONCLUSION: Conversion rates were slightly higher in PAOS groups, although not statistical significant in most studies. History of PAOS did not implicate in higher morbidity rates.

Prognostic factors of surgically-treated patients with cancer of the right colon: a ten years' experience of a single universitary institution

BACKGROUND

Colorectal cancer is one of the most common malignancies in the world. There are many controversies in the literature about the prognostic value of primary tumor location. Many studies have shown higher survival rates for tumors in the right colon, and worse prognosis for lesions located more distally in the colon.

AIM

To analyze the results of surgical treatment of right-sided colon cancers patients operated in one decade period and identify the prognostic factors that were associated with lower overall survival in stages I-IV patients.

METHODS

A retrospective review from the prospectively collected database identified 178 patients with right-sided colon cancer surgically treated with curative intent. Demographic factors (gender and age), tumor factors (site, T stage, N stage, M stage, histological type and tumor differentiation), and lymph node yield were extracted to identify those associated with lower overall survival.

RESULTS

Mean age was 65 (± 12) years old, and 105 (56.1%) patients were female. Most common affected site was ascending colon (48.1%), followed by cecum (41.7%) and hepatic flexure (10.2%). Mean length of hospital stay was 14 (± 2.8) days. T stage distribution was T1 (4.8%), T2 (7.5%), T3 (74.9%), and T4 (12.8%). Nodal involvement was present in 46.0%, and metastatic disease in 3.7%. Twelve or more lymph nodes were obtained in 87.2% of surgical specimens and 84.5% were non-mucinous tumors. Mean survival time was 38.3 (± 30.8) months. Overall survival was affected by T stage, N stage, M stage, and final stage. Lymph node involvement (OR=2.06) and stage III/IV (OR=2.81) were independent negative prognostic factors.

CONCLUSION

Right-sided colon cancer presented commonly at advanced stage. Advanced stage and lymph node involvement were factors associated with poor long term survival.

Optimal timing for assessment of tumor response to neoadjuvant chemoradiation in patients with rectal cancer: do all patients benefit from waiting longer than 6 weeks?

PURPOSE

To estimate the metabolic activity of rectal cancers at 6 and 12 weeks after completion of chemoradiation therapy (CRT) by 2-[fluorine-18] fluoro-2-deoxy-d-glucose-labeled positron emission tomography/computed tomography ([(18)FDG]PET/CT) imaging and correlate with response to CRT.

METHODS AND MATERIALS

Patients with cT2-4N0-2M0 distal rectal adenocarcinoma treated with long-course neoadjuvant CRT (54 Gy, 5-fluouracil-based) were prospectively studied (ClinicalTrials.org identifier NCT00254683). All patients underwent 3 PET/CT studies (at baseline and 6 and 12 weeks from CRT completion). Clinical assessment was at 12 weeks. Maximal standard uptake value (SUVmax) of the primary tumor was measured and recorded at each PET/CT study after 1 h (early) and 3 h (late) from (18)FDG injection. Patients with an increase in early SUVmax between 6 and 12 weeks were considered "bad" responders and the others as "good" responders.

RESULTS

Ninety-one patients were included; 46 patients (51%) were "bad" responders, whereas 45 (49%) patients were "good" responders. "Bad" responders were less likely to develop complete clinical response (6.5% vs. 37.8%, respectively; P=.001), less likely to develop significant histological tumor regression (complete or near-complete pathological response; 16% vs. 45%, respectively; P=.008) and exhibited greater final tumor dimension (4.3 cm vs. 3.3 cm; P=.03). Decrease between early (1 h) and late (3 h) SUVmax at 6-week PET/CT was a significant predictor of "good" response (accuracy of 67%).

CONCLUSIONS

Patients who developed an increase in SUVmax after 6 weeks were less likely to develop significant tumor downstaging. Early-late SUVmax variation at 6-week PET/CT may help identify these patients and allow tailored selection of CRT-surgery intervals for individual patients.

Accuracy of positron emission tomography/computed tomography and clinical assessment in the detection of complete rectal tumor regression after neoadjuvant chemoradiation: long-term results of a prospective trial (National Clinical Trial 00254683)

BACKGROUND

Neoadjuvant chemoradiation (CRT) therapy may result in significant tumor regression in patients with rectal cancer. Patients who develop complete tumor regression have been managed by treatment strategies that are alternatives to standard total mesorectal excision. Therefore, assessment of tumor response with positron emission tomography/computed tomography (PET/CT) after neoadjuvant treatment may offer relevant information for the selection of patients to receive alternative treatment strategies.

METHODS

Patients with clinical T2 (cT2) through cT4NxM0 rectal adenocarcinoma were included prospectively. Neoadjuvant therapy consisted of 54 grays of radiation and 5-fluorouracil-based chemotherapy. Baseline PET/CT studies were obtained before CRT followed by PET/CT studies at 6 weeks and 12 weeks after the completion of CRT. Clinical assessment was performed at 12 weeks after CRT completion. PET/CT results were compared with clinical and pathologic data.

RESULTS

In total, 99 patients were included in the study. Twenty-three patients were complete responders (16 had a complete clinical response, and 7 had a complete pathologic response). The PET/CT response evaluation at 12 weeks indicated that 18 patients had a complete response, and 81 patients had an incomplete response. There were 5 false-negative and 10 false-positive PET/CT results. PET/CT for the detection of residual cancer had 93% sensitivity, 53% specificity, a 73% negative predictive value, an 87% positive predictive value, and 85% accuracy. Clinical assessment alone resulted in an accuracy of 91%. PET/CT information may have detected misdiagnoses made by clinical assessment alone, improving overall accuracy to 96%.

CONCLUSIONS

Assessment of tumor response at 12 weeks after CRT completion with PET/CT imaging may provide a useful additional tool with good overall accuracy for the selection of patients who may avoid unnecessary radical resection after achieving a complete clinical response. Cancer 2012;3501-3511. © 2011 American Cancer Society.

Laparoscopic total mesorectal excision for rectal cancer after neoadjuvant treatment: targeting sphincter-preserving surgery

BACKGROUND/AIMS

Laparoscopic total mesorectal excision for rectal cancer is under scrutiny. This study aimed at analyzing feasibility, adequacy of resection, impact on early outcomes after neoadjuvant chemoradiation therapy, and to investigate trend towards indication of laparoscopy for sphincter-preservation in a single university medical center.

METHODOLOGY

Patients with distal rectal cancer submitted to neoadjuvant treatment followed by laparoscopic total mesorectal excision were prospectively enrolled. The studied parameters were: demographics, previous surgery, BMI, type of operation, rate of sphincter-preserving surgery, duration of surgery, conversion, specimen retrieval, lymphadenectomy, distal and radial margins, intra and postoperative morbidity, reoperations, hospital stay, and mortality.

RESULTS

From January 2000 to July 2010, 68 patients were enrolled. Mean age was 60 (30-87) years. There were 27 anterior and 41 abdominoperineal resections. Six patients underwent a totally laparoscopic resection and coloanal anastomosis. There was a trend (p=0.003) towards more sphincter-preserving surgery. Conversion was 4.5%. Intraoperative complication was 7.4%. Postoperative complications occurred in 15%. Mortality was 3%. Lymph-node harvest was 11 (0-33). Mean distal margin was 2.5cm (1-4). Radial margins were positive in 3 (10%) cases.

CONCLUSIONS

Laparoscopic total mesorectal excision after neoadjuvant treatment is feasible and safe. Sphincter-preserving laparoscopic oncologic rectal surgery has been accomplished more frequently.

The role of carcinoembriogenic antigen in predicting response and survival to neoadjuvant chemoradiotherapy for distal rectal cancer

PURPOSE

Carcinoembriogenic antigen (CEA) is the most frequently used tumor marker in rectal cancer. A decrease in carcinoembriogenic antigen after radical surgery is associated with survival in these patients. Neoadjuvant chemoradiotherapy may lead to significant primary tumor downstaging, including complete tumor regression in selected patients. Therefore, we hypothesized that a decrease in CEA after neoadjuvant chemoradiotherapy could reflect tumor response to chemoradiotherapy, affecting final disease stage and ultimately survival.

METHODS

Patients with distal rectal cancer managed by neoadjuvant chemoradiotherapy and available pretreatment and postchemoradiotherapy levels of CEA were eligible for the study. Outcomes studied included final disease stage, relapse, and survival, and these were compared according to initial CEA level, post-chemoradiotherapy CEA level, and the reduction in CEA.

RESULTS

Overall 170 patients were included. Post-chemoradiotherapy CEA levels <5 ng/ml were associated with increased rates of complete clinical response and pathologic response. Additionally, postchemoradiotherapy CEA levels <5 ng/ml were associated with increased overall and disease-free survival (P = 0.01 and P = 0.03). There was no correlation between initial CEA level or reduction in CEA and complete response or survival.

CONCLUSION

A postchemoradiotherapy CEA level <5 ng/ml is a favorable prognostic factor for rectal cancer and is associated with increased rates of earlier disease staging and complete tumor regression. Postchemoradiotherapy CEA levels may be useful in decision making for patients who may be candidates for alterative treatment strategies.

Rectal and pouch recurrences after surgical treatment for familial adenomatous polyposis

BACKGROUND

Familial adenomatous polyposis (FAP) is a genetic disease characterized by multiple adenomatous colorectal polyps and different extracolonic manifestations (ECM). The present work is aimed to analyze the outcome after surgical treatment regarding complications and cancer recurrence.

METHODS

Charts from patients treated between 1977 and 2006 were retrospectively analyzed. Clinical and endoscopic data, results of treatment, pathological reports and information about recurrence were collected.

RESULTS

Eighty-eight patients (41 men [46.6%] and 47 women [53.4%]) were assisted. At diagnosis, associated colorectal cancer (CRC) was detected in 53 patients (60.2%), whose average age was higher than those without CRC (40.0 vs. 29.5 years). At colonoscopy, polyposis was classified as attenuated in 12 patients (14.3%). Surgical treatment consisted in total proctocolectomy with ileostomy (PCI, 15 [17.4%]), restorative proctocolectomy (RPC, 27 [31.4%]), total colectomy with ileal-rectum anastomosis (IRA, 42 [48.8%]), palliative segmental resection (1 [1.2%]) and internal bypass (1 [1.2%]). Two patients were not operated on due to religious reasons and advanced disease. Complications occurred in 25 patients (29.0%), more commonly after RPC (48.1%). There was no operative mortality. Local or distant metastases were detected in six (11.3%) patients with CRC treated to cure. During the follow-up of 36 IRA, cancer developed in the rectal cuff in six patients (16.6%), whose average age was higher than in patients without rectal recurrence (45.8 vs. 36.6 years). Five of them have had colonic cancer in the resected specimen. Among the 26 patients followed after RPC, cancer in the ileal pouch developed in 1 (3.8%).

CONCLUSIONS

(1) Within the present series, FAP patients presented a high incidence of associated CRC and diagnosis was generally established after the third decade of life; (2) operative complications occurred in about one third of the patients, being more frequent after the confection of an ileal reservoir; (3) rectal cancer after IRA was detected in 16.6% of patients and it was associated with greater age and previous colonic carcinoma; (4) both continuous and long-term surveillance of the rectal stump and ileal pouch are necessary during follow-up.

Diet and colorectal cancer: current evidence for etiology and prevention

The etiology of colorectal cancer (CRC) involves the interaction of cell molecular changes and environmental factors, with a great emphasis on diet components. But the paths connecting lifestyle characteristicas and the colorectal carcinogenesis remain unclear. Several risk factors are commonly found in western diets, such as high concentrations of fat and animal protein, as well as low amounts of fiber, fruits and vegetables. A large number of experimental studies have found a counteractive effect of fiber on neoplasia induction, especially in relation to fermentable fiber (wheat bran and cellulose). Epidemiological correlation studies have also indicated that a greater ingestion of vegetables, fruit, cereal and seeds is associated to a lower risk for colorectal neoplasia. Moreover, beneficial properties of fiber (especially from vegetable sources) were documented in more than half of case-control studies. Nevertheless, recent epidemiological data from longitudinal and randomized trials tended not to support this influence. Future research should evaluate what sources of fiber provide effective anti-neoplasic protection, carrying out interventional studies with specific fibers for longer periods. Red meat, processed meats, and perhaps refines carbohydrates are also implicated in CRC risk. Recommendantions to decrease red meat intake are well accepted, although the total amount and composition of specific fatty acids may have distinct roles in this setting. Current evidence favors the substitution of long and medium-chain fatty acids and arachidonic acid for short-chain fatty acids and eicosapentaenoic acid. Excess boy weight and excess energy intake inducing hyperinsulinemia have been also associated to CRC, as well as personal habits such as physical inactivy, high alcohol consumption, smoking and low consumption of folate and methionine. Thus, current recommendations for decreasing the risk of CRC include dietary measures such as increased plant food intake; the consumption of whole grains, vegetables and fruits; and reduced red meat intake.

Pharmacological nutrition in inflammatory bowel diseases

Inflammatory Bowel Diseases--ulcerative colitis and Crohn's disease--are chronic gastrointestinal inflammatory diseases of unknown etiology. Decreased oral intake, malabsorption, accelerated nutrient losses, increased requirements, and drug-nutrient interactions cause nutritional and functional deficiencies that require proper correction by nutritional therapy. The goals of the different forms of nutritional therapy are to correct nutritional disturbances and to modulate inflammatory response, thus influencing disease activity. Nutritional intervention may improve outcome in certain individuals; however, because of the costs and complications of such therapy, careful selection is warranted. Total parenteral nutrition has been used to correct and prevent nutritional disturbances and to promote bowel rest during active disease, mainly in cases of digestive fistulae with a high output. Its use should be reserved for patients who cannot tolerate enteral nutrition. Enteral nutrition is effective in inducing clinical remission of disease in adults and promoting growth in children. Recent research has focused on the use of specific nutrients as primary treatment agents. Although some reports have indicated that glutamine, short-chain fatty acids, antioxidants and immunonutrition with omega-3 fatty acids are an important therapeutic alternative in the management of inflammatory bowel diseases, the beneficial reported effects have yet to be translated into the clinical practice. The real efficacy of these nutrients still need further evaluation through prospective and randomized trials.

Impact of parenteral n-3 fatty acids on experimental acute colitis

The present study was undertaken to investigate the effects of parenteral lipid emulsions (LE) enriched with n-3 fatty acids (n-3 FA) in experimental acute colitis. Seventy-four adult male Wistar rats were randomized into six groups, five of which had acetic acid-induced colitis. The animals received a fat-free diet and water ad libitum in individual metabolic cages. By a central venous catheter, saline was infused (0.5 ml/h) into the control groups CS (without colitis) and CC (with colitis), while the test groups received specific LE for 7 days. The n-3/n-6 FA ratio and the lipidic compositions regarding long chain (LCT) and medium chain (MCT) triglycerides were: group L--1:7.7 (LCT, n = 12), M--1:7.0 (MCT and LCT, n = 12), LW-3--1:4.5 (LCT plus n-3 FA, n = 12) and MW-3--1:3.0 (MCT and LCT plus n-3 FA, n = 13). The frequency of diarrhea, oral intake/body weight ratio, intestinal alterations, macrophage cellularity were evaluated and colonic concentrations of leukotrienes (LTB4, LTC4), prostaglandins (PGE2) and thromboxanes (TXB2) were measured. Groups M, MW-3 and LW-3 had less diarrhea than the CC group (P<0.05). Average oral intake/body weight ratio in MW-3 animals was comparable to the CS and better than the CC group. n-3 FA treated rats (LW-3 and MW-3) presented less intestinal inflammatory alterations than CC rats. Mucosal ulcer formation in MW-3 group did not differ from CS rats. M and MW-3 rats had less macrophages in the colon than the CC group. Compared with CC group, lower concentrations of LTB4 in the CS, LW-3 and MW-3 groups; of PGE2 in the CS, M and MW-3 groups; and of TXB2 in the CS and MW-3 groups were found. Mean concentrations of LTC4 did not differ among the groups. Thus, a LCT-containing LE with a low n-3-n-6 ratio does not modify inflammatory colitis manifestations; LE with a high n-3-n-6 ratio reduces diarrhea, preserves oral intake-weight ratio, attenuates morphological consequences and decreases colonic concentrations of inflammatory mediators; MCT/LCT-containing LE with 1:3 n-3-n-6 ratio exerts the most profound beneficial impact on the inflammatory response.

Low rectal cancer: impact of radiation and chemotherapy on surgical treatment

INTRODUCTION

The aim of this study was to evaluate the impact of combined radiotherapy and chemotherapy (leucovorin and 5-fluorouracil) on the treatment of potentially resectable low rectal cancer using the following end points: 1) toxicity of this combined modality regimen; 2) clinical and pathologic response rate and local control; 3) down-staging of the tumor and its influence on the number of sphincter-saving operations; 4) disease-free interval, patterns of relapse, and overall survival.

METHODS

From 1991 to 1996, 118 patients with potentially resectable cases of histologically proven adenocarcinoma and no distant metastases were enrolled into this protocol. All patients were evaluated by clinical and proctologic examination, abdominal computed tomography, transrectal ultrasound, and chest radiography. Therapy consisted of 5,040 cGy (6 weeks) and concurrent leucovorin (20/mg/m2/day) with bolus doses of 5-fluorouracil administered intravenously at 425 mg/m2/day for three consecutive days on the first and last three days of radiation therapy. After two months, all patients underwent repeat evaluation and biopsy of any suspected residual lesions or scar tissue.

RESULTS

Median follow-up was 36 months. Toxicity of chemotherapy regimen was minimum. Thirty-six patients (30.5 percent) were classified as being complete responders. In six of these patients, complete response was confirmed by the absence of tumor in the surgical specimens (3 abdominoperineal resections and 3 proctosigmoidectomies with coloanal anastomosis). In the remaining 30 patients, confirmation of a complete response was made by the absence of symptoms, negative findings on physical examination, and biopsy, transrectal ultrasound, and pelvic computed tomographic test results during follow-up. Eighty-two patients (69.4 percent) were considered incomplete responders. Residual lesions had already been identified during the first examination in 74 patients. In the other eight patients, residual tumor was only identified after 3 to 14 months. All patients underwent surgical treatment, except one patient who refused surgery. Eighty-seven patients underwent 90 surgical procedures: local excision, 9; coloanal anastomosis, 36; abdominoperineal resection, 4; Hartmann's procedure, 1. Isolated local recurrences occurred in five patients (4.3 percent) and combined local and distant failure in eight patients (6.7 percent). Ninety patients are alive and disease-free at a median follow-up of 36 months.

CONCLUSIONS

Combined up-front chemoradiotherapy was associated with tolerable and acceptable side effects. A significant number of patients had complete disappearance of their tumors (30.5 percent) within a median follow-up of 36 months. This regimen spared 26.2 percent of patients from surgical treatment and allowed sphincter-saving management in 38.1 percent of patients who may have required abdominoperineal resection. Preliminary results of this trial suggests a reduction in the number of local recurrences and reinforces the concept that infiltrative low rectal cancer may be initially treated by chemoradiotherapy.

[Laparoscopic abdominoperineal resection of rectum. Analysis of 18 cases]

Laparoscopic abdominoperineal resection (APR-L) represents a truly laparoscopic operation which feasibility has been demonstrated by several authors. The wish to offer a minimally invasive procedure to patients that will deal with permanent colostomy was responsible for the authors' initial experience with the method which began in 1992. Hospital charts of patients who underwent APR-L to this date were reviewed and data regarding duration of the operation, intraoperative complications, need for conversion and characteristics of the postoperative period were assessed. Seventeen patients with the diagnosis of adenocarcinoma of the low rectum and one with squamous carcinoma of the anal canal underwent APR-L in a selective basis. The duration of the procedure was between two and six hours. There were no intraoperative complications. There was one conversion due to a large uterus that impaired pelvic dissection. One patient underwent laparotomy in the postoperative course as result of abdominal distension and incipient pelvic herniation of a small bowel wall through perineal wound. There were no septic complications and mean hospital stay was seven days. Perineal hernia occurring in the late postoperative period was seen in two patients. One of these underwent surgical correction through a conventional approach. Authors conclude that APR-L is feasible with low morbidity. Rectal oncologic dissection through video-laparoscopic access seems to be preserved and the method seems to be superior to the conventional access when considering that there is no need for abdominal incision.

[Technical and histological standardization of experimental colitis with trinitrobenzenosulfonic acid (TNBS)]

Attempts to reproduce inflammatory colitis have created many experimental models. Since the pioneer work of Morris et al. (1989), trinitrobenzenosulfonic (TNBS) solutions have been used with different dosages. The aims of this work were standardize the induction of colitis, evaluate the clinical and intestinal effects of different doses and verify the reproducibility of the intestinal inflammatory process. Wistar rats were inoculated endo rectally with 2.5 ml solutions of different concentrations of TNBS and ethanol, and the rats were sacrificed after 14 days. According to the solution concentrations of TNBS (mg) and ethanol (%), six groups of animals were established: Control (saline), 30 mg/30%, 30 mg/40%, 30 mg/50%, 50 mg/10% and 50 mg/30%. Statistical analysis of food ingestion showed no differences between groups (p = 0.247). The 30/50 group presented greater weight loss when compared to 50/10 and 50/30 groups (p = 0.012). Groups 30/50 and 30/40 showed greater degrees of macroscopic lesion than control and 50/10 group (p < 0.05). Histologic lesion was not uniform to all rats regardless of the solution employed. Group 50/10 presented the less severe histologic alterations; on the other hand, 30/40 and 30/50 groups had important changes on mucosal thickness, on vascularization and ulceration. The authors conclude that experimental colitis with TNBS 1) cause intestinal lesions that are not uniform to all animals, although they may be reproduced in many of them; 2) with the same doses of TNBS, the increase in ethanol concentrations leads to a greater inflammatory process, intestinal thickness, vascularization, abscess formation and intestinal ulceration; 3) 50/10 and 50/30 solutions make less severe lesions when compared to 30/40 and 30/50 solutions; 4) 30/50 solution was the best one, as it produces inflammation 90% of the animals, increases in wall thickness in 50%, abscess in 70% and ulceration in 38%.

Protective effects of glutamine enriched diets on acute actinic enteritis

Radiotherapy plays an important role in cancer treatment, although it may cause collateral effects and sever complications due to cellular damage of peritumoral tissues. Recently different nutritional resources have been indicated to achieve intestinal protection during cancer irradiation. The aim of this study was to set the role of glutamine in acute actinic enteritis prevention. Sixty-five Wistar male rats (200 g) were maintained in individual metabolic cages, where body weight and food ingestion were carefully monitored daily. The animals were chosen at random in three groups and fed isocaloric and isoproteid diets: 1) CRt (23)-polymeric-casein diet (CD); 2) GRt (22)-polymeric-casein diet supplemented with 2% glutamine (GD), and 3) ERt (20)--elemental diet supplemented with 2% glutamine (ED). After an adaptation period (seven days), all rats received 1500 cGy of abdominal radiation in five equal daily doses of 300 cGy. After three days post radiation the rats were submitted to jejunal perfusion test with polyethylene-glicol 4000. Finally, small bowel and colon were resected for histological evaluation. It was observed that ERt group had greater average daily food intake than CRt and GRt groups during all periods (p < 0.05). All rats had equal weight gain during adaptation period; during irradiation all the animals had weight loss, but ERt group had smaller weight loss than CRt. All rats recovered weight after irradiation, and ERt group presented better results than the others (p < 0.05). Sodium transepithelial transport average values (mEq/min/cm) were negative and not statistically different in all groups. Small bowel histological evaluation in ERt and GRt rats were better than CRt rats, by preserving mucosal cellularity and increasing mitosis number and villi length (p < 0.05). Simultaneously, ERt group had greater number of rats with normal villuscrypt relation than CRt of CRt groups (p < 0.05). Large bowel histological data showed that the average crypt's length in ERt and GRt rats were greater than in CRt ones (p < 0.05). By the present work, an elemental diet enriched with 2% glutamine favored greater food ingestion and lessened weight loss during and after radiotherapy. Glutamine-supplemented polymeric or elemental diets given to rats before, during and after abdominal radiotherapy showed protective effects against radiation injury, by supporting mucosal structure and recovery.

[The role of glutamine in nutrition in clinical practice]

Nutritional therapy using nutrients with pharmacological properties has been intensively discussed in the recent literature. Among these nutrients, glutamine has gained special attention. Glutamine is the most abundant amino acid in the blood stream of the mammals and, besides it has been considered a non-essential amino acid, glutamine is a non-dispensable nutrient in catabolic states. In this situation, there are alterations in its inter-organic flux, leading to lower plasmatic concentrations. Glutamine is the main fuel to enterocytes and it has an important role in the maintenance of intestinal structure and functions. Moreover, supplementation with glutamine has proved to be beneficial to the immunological system functions, improves nitrogen balance and nutritional parameters in the post-operative period and lessens protein loss in severe catabolic states. For these reasons, glutamine enriched-diets must be considered in the nutritional support of many diseases; new controlled, prospective and randomized studies will help to define what group of patients can really benefit from glutamine supplementation.

[Rectal endometriosis]

Colorectal endometriosis is a relatively rare entity that may have a wide array of clinical symptoms and radiographic findings. A 42-year-old female patient with rectal endometriosis treated with danazol under CA 125, CA 19-9 and estrogen monitoring is described. The treatment was successful and the patient underwent excision of reproductive organs without colorectal excision.

[Protective effects of glutamine and elemental diet in acute actinic enterocolitis: histological evaluation]

Radiotherapy plays nowadays an important role in malignancies treatment. However, collateral effects and severe complications owing to cellular damage of peritumoral tissues may occur. Different nutritional resources have been recently indicated to achieve intestinal protection during cancer irradiation. PURPOSE--The aim of this study was to set the role of glutamine and elemental diets in acute actinic enteritis prevention. METHOD--Sixty-five adult male Wistar rats with average weight of 200g were maintained in individual metabolic cages; daily body weight and food ingestion were carefully monitored. The animals were randomized into three groups and fed isocaloric and isonitrogenous diets: 1) CRt-polymeric-casein diet; 2) GRt-polymeric-casein diet supplemented with 2% glutamine and 3) ERt-elemental diet supplemented with 2% glutamine. After an adaptation period (seven days), all rats received abdominal radiation in five daily doses of 300cGy. Four days after the rats were operated on to resect the small intestine and colon for histological evaluation. RESULTS--Small intestine histological data in ERt and GRt rats were better than CRt rats, by preserving mucosal cellularity and increasing mitosis number and villi length. Simultaneously, ERt group had greater number of rats with normal villus-crypt relation than CRt or GRt groups. Large intestine histological data showed that the average crypts length in ERt and GRt rats were greater than in CRt ones. CONCLUSION--Glutamine-supplemented polymeric or elemental diets given to rats before, during and after abdominal radiotherapy showed protective effects against radiation injury, by supporting mucosal structure and recovery.

[Primary lymphomas of the large intestine]

Primary colorectal lymphomas are rare tumors that comprise 0.5 to 2% of large bowel malignancies and 10 to 20% of gastrointestinal lymphomas. Between 1982-1993 ten patients were treated in the Colorectal Unit of the "Hospital das Clínicas" of the University of São Paulo, representing 2% of the neoplasms in this period. Age varied from 22 to 76 years, with median around 50 years, and male/female ratio 8:2. Weight loss, right iliac palpable mass and bowel habit alterations were the most common symptoms. Definitive diagnostic was only set with histological evaluation of the surgical specimen in all colon tumors. Four patients had advanced disease classified as stages III or IV. The tumors were located in ileocecal region (7 cases), transverse colon (1 case), sigmoid colon (1 case) and rectum (1 case). Colon lymphomas were treated by radical surgical resection and chemotherapy; the patient with rectal lymphoma received radiotherapy and chemotherapy because of local tumor spread. Histological data showed 6 large cell lymphomas and 4 small cleaved cells lymphomas. Lymphnodal involvement and tumor size were the main prognostic factors in the series: 80% of the patients in advanced stage (III or IV) and 66% of those with tumors larger than 10 cm died during the first year of the follow-up.