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F Seow-Choen

Publications and source records attributed to F Seow-Choen.

At least 19 recordsLinked to original sources
PubMed2002

Small colonic J-pouch improves colonic retention of liquids--randomized, controlled trial with scintigraphy.

PURPOSE: A small 6-cm colonic J-pouch improves stool frequency and continence, without stool evacuation problems. However, the reservoir function is not improved on physiologic studies. Hence, a scintigraphy technique was devised to study the transit of solid and liquid colonic contents in these patients. METHODS: Patients were randomly assigned to straight or colonic J-pouch anal anastomoses after ultralow anterior resection. At 1 year after surgery, they were studied by bowel questionnaire, anorectal manometry, and technetium TC 99m tin-colloid liquid test meal/I-131 microcapsule scintigraphy. In the latter, technetium TC 99m tin-colloid was ingested orally to image the colonic liquids. I-131 microcapsules taken simultaneously imaged the solid stools. After ingestion of the radioisotopes, imaging was performed at intervals of 7 to 8, 24, and 56 hours later. Two independent observers noted the presence of technetium TC 99m tin-colloid liquid and I-131 microcapsules in various areas of interest drawn over the colon. RESULTS: There were six patients (5 males, mean age, 61.5 (SE mean, 1.9) years) in the straight, and six patients (5 males, mean age, 63.2 (4.5) years) in the colonic J-pouch group. Stool frequency was more in the straight group (4.8 (0.4) vs. 3 (0.2) stools/day; P <.001). Continence, evacuation problems, and anorectal physiologic findings were not different. Technetium TC 99m tin-colloid (imaging liquids) transited significantly faster than I-131 microcapsules (imaging solids), at various areas of interest in the colon. In the colonic J-pouch patients, technetium TC 99m tin-colloid liquid was retained significantly longer in the descending colon at 24 hours (P <.05). Stool frequency was higher when technetium TC 99m tin-colloid was not retained in the descending colon at 56 hours (3.3 (0.5) vs. 4.3 (0.4) stools/day) but this did not reach statistical significance. There were no significant differences in the distribution of the ingested I-131 microcapsules between colonic J-pouch and straight groups. CONCLUSIONS: Reduced stool frequency after colonic J-pouch may be related to factors causing better retention of liquid stools in the distal colon. No difference in solid stool transit could possibly account for minimal evacuation problems in small pouches.

Aged↗
PubMed2001

High preoperative serum carcinoembryonic antigen predicts metastatic recurrence in potentially curative colonic cancer: results of a five-year study.

INTRODUCTION: Serum carcinoembryonic antigen is used mainly for tumor follow-up to detect recurrence of colonic cancer. However, raised preoperative carcinoembryonic antigen levels may be helpful for the identification of understaged cases and of patients meriting more intensive preoperative and postoperative diagnostic workup. METHODS: From a prospectively collected database, the data on 261 patients who had curative colonic carcinoma with a minimal follow-up of five years and who had preoperative carcinoembryonic antigen levels assessed were retrieved and analyzed. Outcome parameters were local and/or distant recurrence and time to recurrence. These parameters were correlated with Dukes staging and preoperative carcinoembryonic antigen levels. RESULTS: The cumulative disease-free survival of patients with a preoperative carcinoembryonic antigen level within the normal range was significantly better than that of those whose carcinoembryonic antigen was 5 ng/ml or more (P = 0.001). No patient with carcinoembryonic antigen levels less than 1 ng/ml developed metastatic recurrence. Twenty-three percent of all patients with a raised carcinoembryonic antigen above 5 ng/ml compared with 2.1 percent of patients with carcinoembryonic antigen below 5 ng/ml developed a metastasis at two years. At five years, these figures were 37.2 percent and 7.5 percent, respectively. Dukes staging and carcinoembryonic antigen levels were found to be directly correlated (P < 0.001) when all patients were included. Carcinoembryonic antigen of more of 15 ng/ml was found to be a significant adverse prognostic indicator for disease-free survival irrespective of Dukes staging (P < 0.02). Raised carcinoembryonic antigen levels predicted distant metastatic recurrence (P < 0.001) but did not predict local recurrence (P = 0.72). CONCLUSIONS: High preoperative carcinoembryonic antigen levels above 15 ng/ml predicted an increased risk of metastatic recurrence in potentially curative colonic cancer and may indicate undetectable disseminated disease. Preoperative carcinoembryonic antigen levels predict understaging and the possibility of distant recurrence. Such patients may therefore be selected for adjuvant therapy where indicated. Therefore, carcinoembryonic antigen is complementary to conventional Dukes staging for the prediction of recurrence and survival.

Aged↗
PubMed2001

Prospective, randomized trial comparing diathermy and Harmonic Scalpel hemorrhoidectomy.

PURPOSE: The aim of this study was to compare diathermy and Harmonic Scalpel hemorrhoidectomy. METHODS: Fifty consecutive patients were randomly assigned to 2 groups: Group 1 (diathermy) and Group 2 (Harmonic Scalpel). RESULTS: The median duration of surgery was 10 minutes for both groups. The median number of pethidine injections used for both groups was zero. The median number of oral analgesic tablets taken was 13 by Group 1 and 14 by Group 2 patients. The median number of tubes of lidocaine jelly used was two by Group 1 and three by Group 2. There was no statistical difference between pain scores recorded by both groups. Five patients in Group 1 developed posthemorrhoidectomy bleed vs. one patient in Group 2 (P = NS). CONCLUSION: Hemorrhoidectomy by Harmonic Scalpel is comparable to diathermy hemorrhoidectomy in terms of postoperative pain and complications.

Adult↗
PubMed2001

Biofeedback avoids surgery in patients with slow-transit constipation: report of four cases.

Biofeedback is established treatment for intractable constipation in patients with an element of pelvic floor dysfunction. In those with intractable slow-transit constipation and normal pelvic floor function, colectomy is usually recommended. We report four patients with isolated slow-transit constipation who benefited from biofeedback and avoided surgery. All four patients were extensively investigated for pelvic floor dysfunction before undergoing a standard biofeedback course of four outpatient sessions. All improved in terms of bowel frequency, laxative use, bloating, straining, and lifestyle. Improvement has been maintained for a median of nine (range, 5-12) months without the requirement for further treatment. Biofeedback represents a safe and inexpensive treatment for these patients and may avoid surgery in a significant proportion.

Adult↗
PubMed2001

Stratifying risk factors for follow-up: a comparison of recurrent and nonrecurrent colorectal cancer.

INTRODUCTION: The selection of patients for individualized follow-up and adjuvant therapy after curative resection of colorectal carcinoma depends on finding reliable prognostic criteria for recurrence. However, such criteria are not universally accepted, and follow-up is often standardized for all patients without regard for each individual's level of risk of recurrence. Such a system of follow-up is not cost-effective. METHODS: A comparison of operative findings, pathologic features, and follow-up data of 1,731 cases of nonrecurrent colorectal cancer (821 colon, 910 rectum) with 357 cases of recurrent colorectal cancer (164 colon, 193 rectum) following potentially curative surgery was made, and results were analyzed to ascertain criteria for stratifying follow-up according to risk factors. RESULTS: Single-factor analysis showed that Dukes staging and tumor invasion were significantly associated with recurrence in both rectal and colon carcinoma. Tumor fixation and grading were additional significant factors in rectal cancer. Recurrence rates, time to recurrence, site of recurrence (locoregional vs. distant), and pattern of metastatic spread were not significantly affected by original tumor site. Recurrence was not significantly affected by patient age and gender. Individual surgeon performance in this series had also no significant effects on tumor recurrence. With multivariate analysis only, Dukes staging and tumor invasion into adjacent tissues were found to be independent adverse prognostic factors for recurrence. CONCLUSIONS: Dukes staging and tumor penetration into adjacent tissues are the only significant adverse prognostic factors for tumor recurrence of colonic and rectal carcinoma. Tumor grade and tumor fixation are additional adverse prognostic factors in rectal cancer. Guidelines for follow-up may be based on these factors and follow-up thus stratified according to risk of developing recurrence.

Adult↗
PubMed2001

Consecutive series of laparoscopic-assisted vs. minilaparotomy restorative proctocolectomies.

PURPOSE: Compared with open restorative proctocolectomy, laparoscopic procedures may reduce postoperative recovery times and give a more cosmetically acceptable scar, but operative time may be prolonged. We describe a minilaparotomy technique for restorative proctocolectomy and compare recovery parameters with a laparoscopic procedure. METHODS: A consecutive series of patients undergoing laparoscopic-assisted restorative proctocolectomy were compared with a subsequent consecutive series of patients undergoing a minilaparotomy procedure. This method incorporates a suprapubic incision. Mobilization of the colon is performed in the usual manner with visualization of less accessible areas made possible by using an illuminated St. Mark's retractor. Operative and recovery parameters were analyzed for each group retrospectively. RESULTS: Twenty-five patients were compared (12 in the laparoscopic group). Wound length was significantly longer in the open group (median, 14 vs. 8.5 cm; P < 0.01), but operative times were shorter (median, 120 vs. 150 minutes; P < 0.01). There were no differences in any of the recovery parameters analyzed, including analgesic requirements, time to ileostomy function, first fluid intake, time to solid diet, length of hospital stay, and complications. CONCLUSION: The only advantage of a laparoscopic-assisted procedure over a minilaparotomy technique was the size of the wound. The minilaparotomy restorative proctocolectomy achieves the same postoperative recovery parameters and has a shorter operative time. This technique is recommended for surgeons less experienced in laparoscopy.

Adenomatous Polyposis Coli↗
PubMed2001

A comparison between open versus laparoscopic assisted colonic pouches for rectal cancer.

The aim of this prospective study was to compare the surgical outcomes in patients undergoing laparoscopic assisted vs. open ultralow anterior resection (ULAR) with the creation of a colonic pouch-anal anastomosis. Patients undergoing ULAR with creation of a colonic pouch and who either had conventional open (CO) or laparoscopic assisted (LA) surgery in colorectal cancer were studied and compared. There were 33 patients, 22 in CO group and 11 in LA group. The groups were comparable for age, sex, tumour and anastomotic heights from anal verge, stage of disease, length of specimen removed and duration of surgery. Incisions were significantly shorter in the LA group (median, 9 cm vs. 16 cm, p = 0.01). Less parenteral analgesia was required in the LA group (2 days vs. 3 days, p = 0.05), but there were no significant differences in the time to passage of flatus, commencement of oral fluids or solid foods and length of hospital stay. There was no difference in morbidity or mortality. With regards to patients with Dukes A to C disease only, at a median of 12 months of follow-up, there was no patient with local or port site recurrence in the LA group. In the CO group, there was one local recurrence and two with distal metastases. In conclusion, laparoscopic assisted ULAR with colonic J pouch anal anastomosis is feasible, easy to perform and safe. It s advantages include significantly shorter incision and lower analgesic requirements postoperatively. Return of bowel function and length of hospital stay, however, are comparable to those of conventional open surgery.

Aged↗
PubMed2001

Colonic J-pouch function at six months versus straight coloanal anastomosis at two years: randomized controlled trial.

The colonic J-pouch (pouch group) functions better than the straight coloanal anastomosis (straight group) immediately after ultra-low anterior resection, but there are few studies with long-term follow-up. This randomized controlled study compared functional outcome, anal manometry, and rectal barostat assessment of these two groups over a 2-year period. Forty-two consecutive patients were recruited, of which 19 of the straight group [17 men with a mean age of 62.1 +/- 2.3 (SEM) year] and 16 of the pouch group (11 men with a mean age of 61.3 +/- 3.2 year) completed the study. Four died from metastases and two emigrated; there was no surgical morbidity or local recurrence. At 6 months the Pouch patients had significantly less frequent stools (32.9 +/- 2.8 vs. 49 +/- 1.4/week; p < 0.05) and less soiling at passing flatus (38% vs. 73.7%; p < 0.05). At 2 years both groups had improved with no longer any differences in stool frequency (7.3 +/- 0.4 vs. 8 +/- 0.2/week) and soiling at passing flatus (38% vs. 53%). Defecation problems remained minimal in both groups. Anal squeeze pressures were significantly impaired in both groups up to 2 years (p < 0.05). The rectal maximum tolerable volume and compliance were not different between groups. Rectal sensory testing on the barostat phasic program showed impairment at 6 months and recovery at 2 years, suggesting that postoperative recovery of residual afferent sympathetic nerves may play a role in functional recovery. In conclusion, stool frequency and incontinence were less in the Pouch patients at 6 months; but after adaptation at 2 years the straight group patients yielded similar results. Nonetheless, this functional advantage can be given to patients with minimal added effort or complications by using the colonic J-pouch.

Adenocarcinoma↗
PubMed2001

Topoisomerase-I- and Alu-mediated genomic deletions of the APC gene in familial adenomatous polyposis.

Germline mutation in the adenomatous polyposis coli (APC) gene results in familial adenomatous polyposis (FAP), a heritable form of colorectal cancer. We have previously reported two novel mutations that delete exons 11 and 14 of the APC gene, respectively, at the cDNA level without any splice junction defects at the genomic level. We describe here the precise breakpoints of the two mutations and the possible mechanisms leading to the genomic rearrangement. The first rearrangement is most likely a topoisomerase-I-mediated non-homologous recombination resulting in a 2-kb deletion that deletes exon 11 of the APC gene. Both 5' and 3' breakpoints have two topoisomerase I recognition sites and runs of pyrimidines within the 10-bp sequences in their vicinity. Further, the 3' breakpoint has an adenine-thymidine-rich region. This is probably the first report of a topoisomerase-I-mediated germline mutation in a tumor suppressor gene. The second rearrangement is most likely an Alu-Alu homologous recombination resulting in a 6-kb deletion encompassing exon 14. The Alu elements at the 5' and 3' breakpoints include the 26-bp core sequence thought to stimulate recombination. In both rearrangements, partial sequences from the long interspersed nuclear element family are in the vicinity of the breakpoints. Other than serving as markers for regions of DNA damage, their precise role in the recombination events, if any, is unclear. Both deletions result in truncated APC proteins missing the beta-catenin- and axin-binding domains, resulting in severe polyposis and cancer.

Adenomatous Polyposis Coli↗
PubMed2001

Prospective randomised trial comparing ayurvedic cutting seton and fistulotomy for low fistula-in-ano.

The aim of this study was to evaluate the role of ayurvedic setons in the treatment of low fistula-in-ano. One hundred and eight patients were randomised into either conventional fistulotomy (F) or ayurvedic cutting seton insertion (C). Endpoints investigated included time to wound healing and complications of surgery. Post-operative pain scores were measured daily using a visual analog scale. Anal function was compared using a continence score. Pre- and postoperative manometry and ultrasound were also performed. After exclusions, there were 54 patients in group F and 46 in group C. There were no differences in age, sex or follow-up duration between the two groups. Healing time was similar between the groups. Group C reported more pain following operation and on the first 2-4 postoperative days, but both groups experienced the same amount of pain subsequently. In conclusion, chemical seton was more painful than conventional fistulotomy in the first few days following surgery. However, there was no difference in time to wound healing, complications or functional outcome.

Adolescent↗
PubMed2001

Tumor size is irrelevant in predicting malignant potential of carcinoid tumors of the rectum.

The malignant potential and prognosis of rectal carcinoids are said to be related to tumor size. Our study assessed if size could predict the malignant potential and hence its management. All patients in the Department of Colorectal Surgery, Singapore General Hospital, who underwent surgery for rectal carcinoid tumors between February 1991 and September 2000 were analyzed. Twenty patients (11 men), median age 48 years (range, 33-77 years) were studied. Median follow-up was 40 months (range, 5-120 months). The median tumor diameter was 2.5 cm (range, 0.1-5.0 cm). Eleven patients underwent radical resection and 9 patients had local resection for a presumed benign tumor. Morbidity was 15% and postoperative death was 5%. Overall median survival was 24 months (range, 5-120 months). One patient had an anterior resection for rectal adenocarcinoma but had an incidental 0.1-cm carcinoid tumor near the resection margin which on histology was found to have carcinoid tumor metastasis to 2 out of 12 lymph nodes. In conclusion, tumor size cannot predict malignant potential as even small tumors (<1 cm) can be malignant. Accurate preoperative staging with radical surgery may be required.

Adult↗
PubMed2001

A prospective randomised study of drains in infra-peritoneal rectal anastomoses.

Although increasing evidence suggests that prophylactic drainage after intra-peritoneal colorectal anastomoses is unnecessary, drains for infra-peritoneal rectal anastomoses, where the leak rate is higher, are widely employed still. The aim of this study was to assess the effect of prophylactic drainage after anastomosis below the peritoneal reflection. All patients attending one specialist unit over an 8-month period for elective rectal cancer resection with an infra-peritoneal anastomosis were randomised to drainage or no drainage. The incidence of anastomotic leak and complications specific to the drain as well as other complications were compared. Fifty-nine patients were analysed (31 with drain). Twenty-five of the drained and 16 of the no-drain patients had a defunctioning stoma (p=ns). The groups were comparable for demographic data, operation and anastomotic height from the anal verge. There were three leaks (10%) in the drain group and five leaks (18%) in the no-drain group (p=ns). There were 2 (7%) patients in each group with a clinical leak. There were no specific drain complications and the incidence of other complications was similar in both groups. In conclusion, this study supports the contention that there is no difference in morbidity with or without the use of a drain for infra-peritoneal anastomoses.

Adult↗
PubMed2001

Randomized trial assessing anal sphincter injuries after stapled haemorrhoidectomy.

BACKGROUND: Conventional stapled haemorrhoidectomy involves the use of a large circular anal dilator (DL technique), which may cause anal sphincter injuries. This study compared whether the procedure can be effectively performed without this dilator (ND technique), with better sphincter preservation. METHODS: Fifty-eight patients with symptomatic prolapsed irreducible haemorrhoids were randomized to DL (n = 29) and ND (n = 29) groups. Preoperative continence scoring, anorectal manometry and endoanal ultrasonography were performed. These were repeated at up to 14 weeks after operation, with additional pain scores, analgesic requirements and quality of life assessments. RESULTS: DL haemorrhoidectomy took significantly longer to perform (P = 0.02). However, there were fewer residual skin tags (P = 0.044) and less perianal pruritus (P = 0.007) at 2 weeks, although such symptoms subsided to an equivalent level in both groups afterwards. Internal anal sphincter fragmentation persisting to at least 14 weeks was found in four patients after DL, but not after ND haemorrhoidectomy (P = 0.038). However, these were asymptomatic and no differences were found in continence scores and anal pressures. The pain scores, satisfaction scores, quality of life assessments and time off work were similar. CONCLUSION: The large circular anal dilator used for stapled haemorrhoidectomy increased the risk of anal sphincter injuries, which may become problematic with ageing.

Adult↗
PubMed2001

Randomized clinical trial of local bupivacaine perfusion versus parenteral morphine infusion for pain relief after laparotomy.

BACKGROUND: Opioids are often used to decrease pain following laparotomy but are associated with unwanted side-effects. The effectiveness of local perfusion of bupivacaine 0.5 per cent following laparotomy was studied. METHODS: A prospective randomized study involving patients undergoing laparotomy for major colorectal surgery using a left iliac fossa skin crease incision was undertaken. Patients were randomized to receive either intermittent intravenous morphine infusion on demand with patient-controlled analgesia (PCA group) or continuous wound perfusion of local bupivacaine 0.5 per cent for 60 h (LA group). RESULTS: Seventy patients were recruited, 35 in each group. Patient demographics, surgical and recovery variables and complications were comparable in the two groups. The wound lengths were similar (median 14 cm in both groups). There was no statistically significant difference in postoperative pain scores at rest and with movement between the two groups, except for pain scores at rest on the first postoperative day (P = 0.03). The median total amount of morphine used was significantly greater in the PCA group (median 38 versus 0 mg in the LA group; P < 0.001). CONCLUSION: Direct continuous local wound perfusion of bupivacaine 0.5 per cent is as effective as PCA for postoperative pain relief after laparotomy. It is a safe and feasible alternative to parenteral opioids.

Adolescent↗