A prospective randomized trial on the use of Coca-Cola Zero(®) vs water for polyethylene glycol bowel preparation before colonoscopy.

AIM: The study aimed to determine whether Coca-Cola (Coke) Zero is a safe and effective solvent for polyethylene glycol (PEG). METHOD: Between December 2013 and April 2014, 209 healthy adults (115 men, 95 women) scheduled for elective colonoscopy were randomized to use either Coke Zero (n = 100) or drinking water (n = 109) with PEG as bowel preparation. Each patient received two sachets of PEG to dissolve in 2 l of solvent, to be completed 6 h before colonoscopy. Serum electrolytes were measured before and after preparation. Bowel cleanliness and colonoscopy findings were recorded. Palatability of solution, adverse effects, time taken to complete and willingness to repeat the preparation were documented via questionnaire. RESULTS: Mean palatability scores in the Coke Zero group were significantly better compared with the control group (2.31 ± 0.61 vs 2.51 ± 0.63, P = 0.019), with a higher proportion willing to use the same preparation again (55% vs 43%). The mean time taken to complete the PEG + Coke Zero solution was significantly faster (74 ± 29 min vs 86 ± 31 min, P = 0.0035). The quality of bowel cleansing was also significantly better in the Coke Zero group (P = 0.0297). There was no difference in the frequency of adverse events (P = 0.759) or the polyp detection rate (32% vs 31.2%). Consumption of either preparation did not significantly affect electrolyte levels or hydration status. CONCLUSION: Coke Zero is a useful alternative solvent for PEG. It is well tolerated, more palatable, leads to quicker consumption of the bowel preparation and results in better quality cleansing.

An experience with video-assisted anal fistula treatment (VAAFT) with new insights into the treatment of anal fistulae.

BACKGROUND: The aim of this retrospective study was to assess our experience of 41 patients with anal fistulae treated with video-assisted anal fistula treatment (VAAFT). METHODS: Forty-one consecutive patients with cryptoglandular anal fistulae were included. Patients with low intersphincteric anal fistulae or those with gross perineal abscess were excluded. Eleven (27 %) patients had undergone prior fistula surgery with 5 (12 %) having had three or more previous operations. RESULTS: All patients underwent the diagnostic phase as well as diathermy and curettage of the fistula tracts during VAAFT. Primary healing rate was 70.7 % at a median follow-up of 34 months. Twelve patients recurred or did not heal and underwent a repeat VAAFT procedure utilising various methods of dealing with the internal opening. There was a secondary healing rate of 83 % with two recurrences. Overall, stapling of the internal opening had a 22 % recurrence rate, while anorectal advancement flap had a 75 % failure rate. There was no recurrence seen in six cases after using the over-the-scope-clip (OTSC(®)) system to secure the internal opening. CONCLUSIONS: VAAFT is useful in the identification of fistula tracts and enables closure of the internal opening. Adequate closure is essential with the method used to close large or fibrotic internal openings being the determining factor for success or failure. The OTSC system delivered the most consistent result without leaving a substantial perianal wound. Ensuring thorough curettage and drainage of the tract during VAAFT is also important to facilitate healing. We believe that this understanding will bring about a decrease in the high recurrence rates currently seen in many series of anal fistulae.

Sigmoid volvulus treated by mini-incision.

Definitive surgical management of sigmoid volvulus is usually via a midline laparotomy or laparoscopy. We report our experience with a series of five consecutive cases over a 10-year period. All patients had definitive surgery via a left iliac fossa mini-incision after prior decompression. For four patients, it was the first episode of sigmoid volvulus and one patient had a recurrent sigmoid volvulus after previous sigmoid colectomy. The latter patient had pan colonic megacolon diagnosed at initial surgery. All five cases were surgically treated successfully via a mini-incision on the left iliac fossa. There were no instances of recurrence at a median follow-up duration of 95 months (range 7-132 months). A left iliac fossa mini-incision is sufficient for the definitive management of non-perforated sigmoid volvulus. Larger studies are warranted to draw definitive conclusions.

The physiology of colonic hydrotherapy.

OBJECTIVE: Colonic hydrotherapy is widely used and many of its practitioners are medically qualified. Nonetheless, the basis of many of their practices requires physiological scrutiny. METHOD: The claims of colonic hydrotherapy are examined against known physiological facts. RESULTS: Hydrotherapy is not entirely physiological. CONCLUSION: Colonic hydrotherapy may increase the dissemination and absorption of toxins and bacteria into the body.

The use of a wound protector to prevent port site recurrence may not be totally logical.

The wound protector has been used widely to prevent port site metastases (PSM). Although port site metastases ties in with poor survival, it is not because of PSM itself, but rather because PSM is a sign of more widespread metastatic disease. Whilst being touted as a method of preventing PSM, it fails to address the bigger issue of preventing intra-abdominal recurrence. Proper surgical technique in tumour handling following rigorous oncological principles, and not just putting in a wound protector is the key to good surgery with low recurrences and excellent survival rates.

Ultra-low anterior resection for low rectal cancer: five key tips to make it easy.

The primary treatment for rectal cancer is still surgery. Surgery however, may be either preceded or followed by chemotherapy and radiotherapy as and when needed. Good surgery on its own when applied appropriately is associated with a very low rate of local recurrence. Bad surgery however, is associated with a high risk of local and systemic recurrence. The well-performed ultra-low anterior resection with total mesorectal clearance has been shown to be the most important step in the treatment of a low rectal cancer. The author details five key tips to make the performance of an ultra-low anterior resection easy. These five key tips are: tip 1 Decide on the best approach for your particular patient before surgery; tip 2 The inferior mesenteric artery is crucial in obtaining the right dissection plane; tip 3 The sigmoid colon should be used for construction of the J-pouch whenever possible; tip 4 Use of a good light source is the key to obtaining a good idea of where to operate and to keeping to the right planes; tip 5 The last key to making surgery easier is to have a good head and good hands. Surgeons must know precisely the reasons why they do what they do in the way they do. Surgery which is difficult may be expected to carry with it more risks and therefore poorer results. Surgery which goes smoothly and is easy is usually rewarded with good results. Surgeons should try to make their surgery easier and the tips offered here are steps that will do this.

Relationship between polymorphism of N-acetyltransferase gene and susceptibility to colorectal carcinoma in a Chinese population.

Human hepatic N-acetyltransferase (NAT2) is subject to a genetic polymorphism. Because NAT2 is an important enzyme for the detoxification and/or bioactivation of several carcinogenic arylamines, it has been postulated that the polymorphism of NAT2 gene is associated with the occurrence of colorectal and bladder carcinomas. Several mutations have been described in the human NAT2 gene that have been associated with reduced NAT2 activity. However, the majority are single base substitutions at positions 481 (NAT2*5A), 590 (NAT2*6A) and 857 (NAT2*7A) of the NAT2 gene. This study was performed to evaluate the relative distribution of NAT2 alleles and genotypes in 216 colorectal carcinoma patients and 187 normal individuals. The frequencies of NAT2 alleles and genotypes in the sampled Chinese population were characterized by allele-specific polymerase chain reaction. No differences were observed in the distribution of the genotypes coding rapid acetylation (homozygous wild-type and heterozygous wild-type with any of the mutations) when comparing colorectal carcinoma patients with control individuals (P > 0.05). However, the rapid acetylation genotype was associated with cancer occurring on the right site of the colon. The frequencies of the NAT2*4, NAT2*5A, NAT2*6A and NAT2*7A alleles of the NAT2 gene (0.51, 0.07, 0.32 and 0.10, respectively) in control individuals were significantly different from those in patients (0.49, 0.06, 0.26 and 0.19, respectively, P < 0.01). There was a significant increase in the frequency of patients who were compound heterozygotes of NAT2*7A and a variant non-NAT2*7A allele. The NAT2*7A allele was also seen more frequently in distal cancer.

APC mutation and phenotypic spectrum of Singapore familial adenomatous polyposis patients.

Familial adenomatous polyposis (FAP) is a familial form of colon cancer caused by mutation of the adenomatous polyposis coli (APC) gene. Although the APC gene has been extensively studied in the Caucasian population, it has not been previously described in the Chinese population. In the present study, we investigated APC mutation and phenotypic spectrum in the Singapore FAP families who are predominantly Chinese. The protein truncation test (PTT) was used to screen the entire APC gene for germline mutations in 28 unrelated families. Fifteen different mutations were identified in 22 families. Eight mutations were 1-11 basepair deletions or insertions; three involved deletions of whole exons and four were nonsense mutations. Nine of the mutations, including two complex rearrangements, are novel. Eight families including three de novo cases have the same (AAAGA) deletion at codon 1309, indicating that like the Western families, codon 1309 is also the mutation 'hot spot' for Singapore FAP families. In contrast, we did not find any mutation in codon 1061, the second hot spot for the Western population. Congenital hypertrophy of the retinal pigment epithelium (CHRPE) is consistently associated with the prescribed domain (codons 463 to 1387) and is the only phenotype with no intra-family variation. Other than CHRPE, differences in the type and frequency of extracolonic manifestations within the FAP families suggest the influence of modifying genes and environmental factors.

The Colorectal Cancer Recurrence Support (CARES) System.

Colorectal cancer has risen in incidence to become the second commonest form of cancer in Singapore. The primary treatment is surgery but up to 50% of patients still suffer from recurrence of the cancer after surgery. Early identification of recurrence will increase the effectiveness of therapy and the survival of patients. This paper describes the CARES (Cancer Recurrence Support) System, whose objective is to predict the recurrence of colorectal cancer, using Case-based Reasoning (CBR), and supported by other techniques such as data mining and natural language processing. The CARES System employs CBR to compare and contrast between the new and past colorectal cancer patient cases, and makes inferences based on those comparisons to determine the high risk patient groups. The features and functionality of the system are described.

Primary colorectal signet-ring cell carcinoma in Singapore.

BACKGROUND: Primary colorectal signet-ring cell carcinoma is a rare but distinctive tumour of the colon and rectum. The clinicopathological features are still controversial. The aim of this study is to review the clinicopathological features and management of this type of tumour in our hospital. METHODS: The clinicopathological features and survival data of all cases of primary colorectal signet-ring cell carcinoma were reviewed retrospectively. RESULTS: There were nine cases of primary colorectal signet-ring cell carcinoma in 3000 consecutive colorectal carcinoma patients seen from 1989 to 1999. There were seven male and two female patients with a mean age of 54.7 years. Three patients were younger than 40 years. The common presenting symptoms were rectal bleeding (33%) and small bowel obstruction (33%). Two (22%) patients required emergency surgery due to acute small bowel obstruction. The most common tumour location was the right colon (44%) followed by the rectum (33%). All nine patients presented at a very late stage of disease. A majority (77%) had Dukes' C disease while two (22%) had Dukes' D disease with distant dissemination. Peritoneal spread (33%) was the most frequent way of dissemination. There was no patient with liver metastases at the time of diagnosis and initial presentation. The mean survival time was 30 (range 5-108) months. The 5-year survival rate was 12%. CONCLUSIONS: Primary colorectal signet-ring cell carcinoma is frequently diagnosed late with a very poor prognosis. A high incidence of peritoneal seeding and low incidence of liver metastases appears to be a characteristic of signet-ring cell carcinoma of the colon and rectum.

An endoscopic diagnosis of appendicular intussusception in chronic appendicitis.

We report a rare case of chronic appendicitis causing recurrent intussusception in a 33-year-old man who had recurrent episodes of right iliac fossa pain diagnosed clinically and confirmed by colonoscopy. This is the first known case with the rare combination diagnosed endoscopically.

Unusual rectal perforation--an individualised approach to management.

The management of rectal perforations is controversial. Surgical repair or resection and anastomosis is usually undertaken with faecal diversion in the management of traumatic perforations. Primary repair without colostomy is less commonly employed. Five cases of rectal perforation seen in the Department of Colorectal Surgery, three from penetrating foreign objects and two from barium enema examination, are presented. The principles of management of patients with rectal perforations include faecal diversion, primary repair of rectal perforation and sphincter muscles, presacral drainage, parenteral antibiotics and distal bowel irrigation. This approach was used in the management of these five cases and the results were very satisfying.