Solitary caecal ulcer syndrome: our experience with this benign condition.

AIM: Solitary caecal ulcer syndrome is rare. We describe our experience of 10 patients with the condition. METHOD: A prospectively collected database of patients undergoing colonoscopy or surgery with histology reporting a solitary caecal ulcer was reviewed from 1999 to 2008. Patients with known carcinoma of the colon, cytomegalovirus infection, amoebiasis, inflammatory bowel disease, immunosuppression and history of nonsteroidal anti-inflammatory drug use were excluded. RESULTS: Ten patients were found to have a solitary caecal ulcer. All were of Chinese ethnicity, of median age 61 years. The most common presenting symptoms were haematochezia and right-sided abdominal pain. Histological findings included ulceration sharing some features of solitary rectal ulcer syndrome, but with differences to suggest a different aetiology. CONCLUSION: Solitary caecal ulcer syndrome should be included in the differential diagnosis of lower gastrointestinal haemorrhage, right iliac fossa pain or when computed tomography imaging demonstrates caecal wall thickening. The diagnosis can only be made on histopathological examination.

Genome-wide scan identifies a copy number variable region at 3q26 that regulates PPM1L in APC mutation-negative familial colorectal cancer patients.

Familial adenomatous polyposis (FAP) is an autosomal dominantly inherited form of colorectal cancer (CRC) caused by mutation in the adenomatous polyposis coli (APC) gene. However, APC mutations are not detected in 10-50% of FAP patients. We searched for a new cancer gene by performing genome-wide genotyping on members of an APC mutation-negative FAP variant family and ethnicity-matched healthy controls. No common copy number change was found in all affected members using the unaffected members and healthy controls as baseline. A 111 kb copy number variable (CNV) region at 3q26.1 was shown to have copy number loss in all eight polyps compared to matched lymphocytes of two affected members. A common region of loss in all polyps, which are precursors to CRC, is likely to harbor disease-causing gene in accordance to Knudsen's "two-hit" hypothesis. There is, however, no gene within the deleted region. A 2-Mb scan of the genomic region encompassing the deleted region identified PPM1L, coding for a novel serine-threonine phosphatase in the TGF-beta and BMP signaling pathways. Real-time PCR analyses indicate that the 3'UTR of PPM1L transcript was down-regulated more than two-folds in all six polyps and tumors compared to matched mucosa of the affected member. This down-regulation was not observed in APC mutation-positive FAP patients. Our results suggest that the CNV region at 3q26 harbors an element that regulates the expression of an upstream candidate tumor suppressor, PPM1L, thus providing a novel mechanism for colorectal tumorigenesis in APC mutation-negative familial CRC patients.

The fourth branch of the superior rectal artery and its significance in transanal haemorrhoidal dearterialisation.

INTRODUCTION: Transanal haemorrhoidal dearterialisation is a non-excisional surgical method for the treatment of haemorrhoidal disease. It uses a Doppler ultrasound probe to accurately identify the site to suture-ligate the piles, resulting in a decrease in the arterial inflow to the piles and their subsequent regression. METHODS: A total of 140 consecutive patients who underwent transanal haemorrhoidal dearterialisation were studied. The number and locations of the haemorrhoidal arteries were documented. The presenting symptoms and their subsequent resolution were noted. RESULTS: The median number of haemorrhoidal arteries ligated was four. Seventy-five patients (53.6%) had four haemorrhoidal arteries ligated. A total of 82 patients (58.6%) had a 'fourth' haemorrhoidal artery in the left anterior one o'clock position. Symptoms of bleeding, prolapse, pain and itching resolved in 92, 65, 68 and 60% of patients who presented with the respective symptoms preoperatively. CONCLUSION: There is a fourth haemorrhoidal artery consistently found in the left anterior one o'clock position. Adequate treatment of this artery minimises the recurrence of haemorrhoidal symptoms.

Single-incision laparoscopic surgery for right hemicolectomy: our initial experience with 10 cases.

BACKGROUND: Published data has confirmed the oncological safety and efficacy of laparoscopic colorectal surgery. Continued surgical innovation has seen the recent resurgence of single-port laparoscopic surgery. We present a series of 10 cases of single-incision laparoscopic surgery (SILS) for right hemicolectomy, with the aim of reaffirming the feasibility and favourable short-term results of this technique. METHODS: Ten patients underwent SILS for right hemicolectomy using the SILS port, between June 2009 and August 2009. A longitudinal periumbilical incision was used as the access point for all cases. Data analysed included age, gender, American Society of Anaesthesiology score, body mass index (BMI), location of disease, duration of surgery, length of incision and duration of hospital stay. Inclusion criteria were no prior abdominal surgery, no intra-abdominal sepsis, no distant metastases and a BMI of <30. RESULTS: All 10 cases of right hemicolectomy were successfully performed using the SILS port through a single periumbilical incision. The median age of patients was 64 years (range 48-83 years), with a median body mass index of 21.5 kg/m(2) (range 18.9-25.6 kg/m(2)). The median duration of surgery and hospital stay was 83 min (range 60-125 min) and 6 days (range 5-11 days), respectively. No morbidity or mortality was associated with this technique, and all patients recovered uneventfully. CONCLUSION: This case series illustrates that SILS for right hemicolectomy is feasible and safe. However, the routine use of this innovative technique in malignant disease cannot be recommended without further large-scale prospective trials.

Meta-analysis of defunctioning stomas in low anterior resection for rectal cancer.

BACKGROUND: A defunctioning stoma is frequently created to minimize the impact of any subsequent anastomotic leak after a low rectal anastomosis. This review evaluates the need for routine stoma formation. METHODS: A meta-analysis was performed of randomized controlled trials (RCTs) and non-randomized studies with an interventional group evaluating the need for a defunctioning stoma after low anterior resection for rectal cancer. Primary outcomes analysed included clinical anastomotic leak rate, reoperation rate and mortality related to leak. RESULTS: Four RCTs and 21 non-randomized studies, with 11,429 patients in total, were analysed. Meta-analysis of the RCTs showed a lower clinical anastomotic leak rate (risk ratio (RR) 0.39 (95 per cent c.i. 0.23 to 0.66); P < 0.001) and a lower reoperation rate (RR 0.29 (0.16 to 0.53); P < 0.001) in the stoma group. Meta-analysis of the non-randomized studies showed a lower clinical anastomotic leak rate (RR 0.74 (0.67 to 0.83); P < 0.001), lower reoperation rate (RR 0.28 (0.23 to 0.35); P < 0.001) and lower mortality rate (RR 0.42 (0.28 to 0.61); P < 0.001) in the stoma group. CONCLUSION: A defunctioning stoma decreases clinical anastomotic leak rate and reoperation rate. It is recommended after low anterior resection for rectal cancer.

Systematic review of intraoperative colonic irrigation vs. manual decompression in obstructed left-sided colorectal emergencies.

AIMS: A systematic review was conducted to determine if manual decompression is a safe alternative to intraoperative colonic irrigation prior to primary anastomosis in obstructed left-sided colorectal emergencies. METHODS: Search for relevant articles from 1980 to 2007 was conducted on Medline, Embase and the Cochrane Controlled Trials Register using the keywords "colonic lavage, irrigation, decompression, washout, obstructed and bowel preparation", either singularly or in combination. Trials in English publications with similar patient characteristics, inclusion criteria and outcome measures were selected for analysis. Thirty-day mortality, anastomotic leak rates and post-operative wound infection were studied as outcome variables. Analysis was performed with RevMan 4.2 software. RESULTS: Seven trials were identified for systematic review, with a total of 449 patients. Data from the single randomised controlled trial and one prospective comparative trial were analysed separately. Results from the remaining five studies were pooled into two arms of a composite series, one with colonic irrigation and one without. Results showed no significant difference in the anastomotic leak rates and mortality rates between the colonic irrigation and manual decompression arms in the randomised and comparative trials. The composite series, however, showed significantly better results with manual decompression (RR 6.18, 95% CI 1.67-22.86). The post-operative infection rate was similar in both groups. CONCLUSION: Manual decompression was comparable to colonic irrigation for primary anastomosis in obstructed left-sided colorectal emergencies, with no significant increase in mortality, leak or infection rates.

Laparoscopic high anterior resection with natural orifice specimen extraction (NOSE) for early rectal cancer.

Laparoscopic surgery for colorectal cancer requires an abdominal incision to extract the resected specimen. We describe a technique for laparoscopic resection of an early-stage upper rectal cancer in a 51-year-old man followed by transanal specimen delivery, hence avoiding the need for making any additional abdominal incisions for retrieval of the specimen. Pneumoperitoneum was created, followed by medial-tolateral mobilization of the sigmoid colon, and take down of the splenic flexure and division of the inferior mesenteric vessels laparoscopically. The upper rectum distal to the tumour and proximal colon was transected with a laparoscopic stapler. The specimen was retrieved transanally via an opening in the rectal stump. The proximal colon was then delivered transanally and the anvil of the circular stapler inserted before returning it to the pelvic cavity. The rectal stump was transected again just below the opening to close off the stump, and the colorectal anastomosis was then completed intracorporeally. The patient, a 51-year-old male (BMI 18.6 kg/m(2)) with a 2.5-cm, early-stage posterior rectal cancer 12 cm from the anal verge, underwent the above-described procedure. Postoperative recovery was uneventful. He resumed normal daily activities 1 week after surgery. Histology confirmed a T1N0 upper rectal cancer. In the effort to minimize surgical trauma and postoperative pain, natural orifice specimen extraction techniques have been attempted. This procedure may be applicable to benign tumours and early colorectal cancer, and serves as an intermediate step between laparoscopic and natural orifice surgery.

Adenocarcinoma of the anal transitional zone after double stapled ileal pouch-anal anastomosis for ulcerative colitis.

The development of adenocarcinoma in the anal transitional zone, after restorative proctocolectomy for ulcerative colitis, is rare. We report the first Asian and sixth known case. A 41-year-old Indian lady had a long standing history of ulcerative colitis. Restorative proctocolectomy and stapled ileal pouch-anal anastomosis without mucosectomy was performed. She remained asymptomatic until 3 years later when she complained of discomfort on defecation. A poorly differentiated adenocarcinoma in the anal transition zone was diagnosed and she subsequently underwent an abdomino-perineal resection. The previously reported cases in the literature are reviewed. We also discuss the suggested surveillance for high-risk patients who have undergone an ileal-anal pouch anastomosis.

A 6-year review of surgical morbidity and oncological outcome after high anterior resection for colorectal malignancy with and without splenic flexure mobilization.

OBJECTIVE: High anterior resection (HAR) for colorectal cancer is traditionally performed with routine mobilization of the splenic flexure. This is a retrospective review of mortality and morbidity following HAR in which the splenic flexure has been preserved. METHOD: From a prospective database, all patients who had undergone elective HAR for colorectal cancer between 1999 and 2005 were identified. Morbidity, mortality, pathology and survival data for patients having HAR with and without splenic flexure mobilization were analysed. RESULTS: A total of 707 patients were identified. Five hundred and thirty-one had HAR with preservation of the splenic flexure. In these patients outcome was: anastomotic leak (0.4%), wound infection (3.6%), anastomotic stricture (0.4%) and 30-day mortality (0.9%). No statistical significant difference was found for postoperative morbidity (P = 0.1926), 30-day mortality (P =0.3285), lymph node harvest (P = 0.2127) or survival (P = 0.1457) compared with patients in whom the splenic flexure was mobilized. Longitudinal resection margins were greater following HAR with splenic flexure mobilization (P < 0.0001). CONCLUSION: No morbidity, oncological or survival disadvantage in performing splenic flexure preserving HAR was found.

A prospective study assessing anal plug for containment of faecal soilage and incontinence.

OBJECTIVE: Faecal incontinence is a common and embarrassing problem for many individuals. Some patients remained symptomatic despite the availability of different treatments. There is a limited range of commercially available products designed to cope with faecal incontinence. The anal plug has been developed to contain the loss of stool. This study aimed to evaluate the use of anal plug in Asian patients with intractable faecal soilage and incontinence judged by clinical and functional outcomes. METHOD: A prospective study of consecutive patients with intractable faecal incontinence was carried out. Suitable patients tested the anal plug for 3 weeks. They completed a structured questionnaire on its use including the ASCRS quality of life questionnaire for faecal incontinence. RESULTS: Thirty patients, median age 63 (interquartile range 52-70) years, participated in the trial. Nineteen of 30 patients were comfortable wearing the plug, seven patients withdrew from the study because of discomfort, and four had tolerable discomfort and managed to complete the trial protocol. Patients who tolerated the plug found that it was highly successful in controlling faecal incontinence. Twenty-one of 30 patients wished to continue to use the plug regularly after the study. There was a trend toward improvement in quality of life scores during the study. CONCLUSION: The anal plug was effective in containing faecal incontinence and was well tolerated in the majority of patients selected for this treatment.

Mapping of hereditary mixed polyposis syndrome (HMPS) to chromosome 10q23 by genomewide high-density single nucleotide polymorphism (SNP) scan and identification of BMPR1A loss of function.

BACKGROUND: Hereditary mixed polyposis syndrome (HMPS) is characterised by colonic polyps of mixed histological types that are autosomal dominantly inherited and eventually lead to colorectal cancer (CRC). Study of the molecular basis of HMPS will enhance our knowledge of the genetic basis of the mixed polyposis-carcinoma sequence in both hereditary and sporadic CRC. METHODS/RESULTS: We performed a genomewide linkage search on 15 members of a three-generation HMPS family using the GeneChip Human Mapping 10K Array and identified a 7 cM putative linkage interval on chromosome 10q23. Subsequently, 32 members from two HMPS families were typed with nine microsatellite markers spanning the region and the linkage was confirmed with a maximum multi-point logarithm of the odds (LOD) score of 4.6 (p<0.001). The 10q23.1-10q23.31 haplotypes segregate with the disease in both families. We screened for mutations in four candidate genes within the linkage region and identified an 11 bp deletion in the bone morphogenesis protein receptor 1A (BMPR1A) gene in one family. CONCLUSIONS: Our results indicate that BMPR1A mutation accounts for HMPS. The data suggest that inactivating BMPR1A can initiate colorectal tumourigenesis via the mixed polyposis-carcinoma sequence.

Successful resuscitation after carbon dioxide embolism during laparoscopic-assisted abdomino-perineal resection.

We report a 67-year-old woman who underwent laparoscopic-assisted abdomino-perineal resection for rectal carcinoma. She sustained hypotension of 40/20 mmHg associated with bradycardia (heart rate 30 to 45 beats per minute) and an end-tidal carbon dioxide level of zero when she was raised to a head-up position at the end of surgery to facilitate pelvic irrigation. Pulmonary air embolism was confirmed by aspiration of 15 millilitres of foamy blood from her central venous line. Resuscitation was successful and she recovered completely with no neurological deficits.

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.

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.

Caecal mass on barium enema study--a case for routine colonoscopy.

Prolapse of the ileal mucosa through the ileo-caecal valve or minor ileo-caecal intussuception is not uncommon and may occasionally be mistaken radiologically for a caecal neoplasm, especially if intestinal obstruction, abdominal pain or rectal bleeding is present. Colonoscopic visualisation and biopsy is important before surgery is advised. We describe a case of ileal mucosa prolapse masquerading as a caecal neoplasm on barium enema study. Colonoscopy showed prolapse of the ileal mucosa which was easily reduced by air insufflation and therefore unnecessary surgery was avoided.

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.

Update of genetics in colorectal carcinomas: genomic instability and somatic evolution.

INTRODUCTION: Currently, there are two contrasting viewpoints on what drives the process of carcinogenesis. The genomic (DNA or chromosomal) instability model contends that an increased mutation rate early in carcinogenesis is necessary for the multistage process, while the somatic evolution model postulates that normal mutation rate with selective advantage and clonal expansion is sufficient to cause cancer. METHODS: Evidence from colorectal carcinoma (CRC) for and against the two models are compared and contrasted. RESULTS: With the exception of hereditary non-polyposis colorectal carcinoma (HNPCC) where DNA instability attributable to mismatch repair deficiency is clearly demonstrated, the majority of CRC appear to progress through the selection of a series of mutations without the need of first acquiring a mutator phenotype. Aneuploidy or chromosomal instability is more likely to be a consequence of non-random selection of mutations in genes residing on the chromosome rather than the direct cause of cancer. Nevertheless, aneuploidy and/or DNA alterations can lead to secondary instability, hence, contributing to the phenotypes associated with carcinoma. CONCLUSIONS: Present knowledge, thus, points to multiple, mutually non-exclusive pathways for different cancer populations, further emphasising tumour heterogeneity.

Primary anorectal malignant melanoma: clinical features and results of surgical therapy in Singapore--a case series.

INTRODUCTION: Primary malignant melanoma arising from the anorectum is uncommon. The natural history of anorectal malignant melanoma is that of a very poor prognosis with early dissemination of disease. Successful surgical treatment has been rare. The present series reviews the clinical features and results of surgical management of patients with anorectal malignant melanoma treated in the Department of Colorectal Surgery, Singapore General Hospital. MATERIALS AND METHODS: Data for all patients treated for anorectal malignant melanoma during an 11-year period from 1989 to 1999 were reviewed. The age, sex, presenting symptoms, duration of symptoms prior to diagnosis, size of tumour, extent of disease, type of surgery and length of survival were analysed. RESULTS: Four men and 2 women, ranging in age from 31 to 81 years with histologically proven primary anorectal malignant melanoma, were included in the study. The most common (67%) presenting symptom was rectal bleeding. The mean tumour size was 2.5 cm (range 1 to 5 cm). All underwent abdomino-perineal resection. Three died of disseminated disease within 17 months while the other 3 were still alive at the time of this study; the longest up to 6.5 years from the time of diagnosis. CONCLUSION: The prognosis of primary anorectal malignant melanoma is poor. However, it is worthwhile treating aggressively as long-term survivor may be encountered in some.