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Biomedical subjects

F Seow-Choen

Publications and source records attributed to F Seow-Choen.

At least 91 records · Page 5Linked to original sources
PubMed1999

Minimizing recurrence after sigmoid volvulus.

BACKGROUND: This study was a retrospective review of a series of patients with sigmoid volvulus to identify risk factors for recurrence and recommend appropriate treatment. METHODS: Thirty-five patients with sigmoid volvulus were treated over 8 years. RESULTS: Six patients had emergency surgery for peritonitis. Twenty-eight of the other 29 patients had successful endoscopic decompression; 15 of these patients had elective surgery during the same admission. Twelve of the 14 patients who refused operation after endoscopic decompression developed recurrent volvulus, a median of 2.8 months later. Eight subsequently agreed to surgery and underwent elective operation following repeat decompression. Of 29 patients who had surgery, 27 had sigmoid colectomy (two were initial Hartmann procedures) and two had subtotal colectomy. Six patients who had sigmoid colectomy developed recurrent volvulus. Concomitant megacolon and megarectum at the time of initial surgery were significant predictors of recurrence. CONCLUSION: Subtotal colectomy, carried out as the primary procedure if there is concomitant megacolon or megarectum, might reduce the risk of recurrent sigmoid volvulus.

Adolescent↗
PubMed1999

Surgery may be curative for patients with a localized perforation of rectal carcinoma.

BACKGROUND: Perforation at the time of operation adversely affects the prognosis of rectal cancer. These procedures have been termed 'palliative' or 'non-curative'. The long-term outcome of generalized perforations may be different from that of localized or contained perforations. Although the oncological results may be compromised when the tumour is perforated, results in cases where the perforation is contained may not be as bad as previously thought. An attempt was made to examine the intermediate and long-term results for locally contained perforated rectal cancers. METHODS: Some 848 patients with rectal cancer were operated on between March 1989 and December 1995. Of these, 42 (5 per cent) had a locally contained perforation of the rectum. Median follow-up was 23 (range 12-74) months. RESULTS: The survival of patients with locally contained tumour perforation who underwent resection without macroscopic residual disease (40 per cent at 5 years) was significantly better than that of patients with metastatic disease at the time of surgery (zero at 4 years) (P < 0.01). The survival of patients in whom the tumour was inadvertently perforated during operation was similar to that of patients with locally contained spontaneous tumour perforations. The incidence of local recurrence in these perforated cases was low provided that a wide tumour clearance was achievable at the time of operation. Operative mortality and morbidity rates were not significantly different but the incidence of postoperative wound infection was marginally higher among patients with perforation. CONCLUSION: If clear margins can be obtained at the time of operation the prognosis of locally contained perforated rectal cancers is good and approaches that of a potentially curative resection.

Adult↗
PubMed1999

Palliative surgery for locally recurrent colorectal cancer.

BACKGROUND: Recurrent colorectal cancer carries a poor prognosis. Radical re-resection is the only chance for long-term survival but suitable candidates are few. AIM: To determine the patterns of recurrence after potentially curative colorectal surgery and analyse the results of palliative surgery for patients with local recurrence. METHODS AND RESULTS: Between May 1989 and May 1995, 1,287 case records of patients with colorectal carcinoma were entered into a customized computer database. Of these, 1,103 underwent potentially curative resections (Duke's stage A, B and C). At a median of 40 months (range 2-72) following surgery, 173 patients had recurrent disease detected (98 males; 75 females) at a median of 14 months (range 3-30) after the index surgery. Twelve percent had recurrent distal and locoregional disease while 6.8% had locoregional recurrent disease alone. Thirty-seven patients with locally recurrent disease underwent surgery. Of these, only 7 patients with local recurrences were suitable candidates for resections. The remaining 30 underwent palliative surgery for emergent indications of obstruction (28) and bleeding (2). The symptoms were palliated surgically by an entero-enterostomy (13), defunctioning stoma (12), lysis of adhesions (1), exploratory celiotomy (2) and formalin application (2). Seventeen patients are alive at follow-up. Twenty patients died at a median of 4 months after surgery (range 1-15). All patients had palliation of their symptoms. CONCLUSION: Low incidences of local recurrences can be achieved after potentially curative resections for colorectal carcinoma. When recurrences occur, a small number can be salvaged with a re-resection which is the procedure of choice. Palliative procedures for emergent indications of obstruction and bleeding can give good palliation despite the absence of the possibility of cure.

Adolescent↗
PubMed1998

Prospective, randomized trial comparing pain and complications between diathermy and scissors for closed hemorrhoidectomy.

PURPOSE: The aim of this study was to assess pain and complication rates after closed hemorrhoidectomy with the use of either scissors or diathermy excision. METHODS: Ninety-one consecutive patients were prospectively randomly assigned by use of sealed envelopes to Group A (diathermy dissection; n = 44) or Group B (scissors dissection; n = 47). The resulting hemorrhoidal pedicle after hemorrhoidal dissection was transfixed and buried under the mucosa, which was closed with 3-0 chromic catgut. RESULTS: The median time taken for surgery was ten minutes in both groups. The range for Group A was 5 to 25 minutes, and the range for Group B was 5 to 20 minutes. There were no statistically significant differences in the pain scores between the two groups for any of the seven postoperative days studied. The median number of pethidine injections in Group A was 1 and in Group B was 0 (P < 0.009). The number of oral analgesic tablets used was 8 (range, 4-10) and 14 (range, 0-10) for Groups A and B, respectively (P < 0.001). The number of tubes of topical lignocaine jelly used was 14 (range, 0-22) and 14 (range, 7-88) in Groups A and B, respectively. Two patients in each group developed secondary hemorrhage, but no patient had anal stricturing. CONCLUSION: No excessive complications are seen with closed hemorrhoidectomy, and diathermy seems to require less postoperative analgesic medicine than scissors for closed hemorrhoidectomy except in the first 24 hours.

Adult↗
PubMed1998

Transanal approach to rectocele repair may compromise anal sphincter pressures.

PURPOSE: This study prospectively assessed the functional results, particularly anal sphincter impairment, following transanal repair of rectocele for chronic intractable constipation. METHOD: Twenty-one consecutive women (mean age, 47.7 (standard error of the mean, 2.7) years) had the diagnosis of rectocele obstructing defecation made on synchronized anal manometry, electromyography, and cinedefecography. All underwent a standardized transanal repair with controlled anal stretching (maximum of 4 cm) from self-retaining anal retractors. The clinical function and anorectal manometry were assessed before surgery and were repeated six months later. RESULTS: All 21 patients were subjectively satisfied with the relief from constipation after surgery. There were significant improvements in the straining at defecation (before, n = 19; after, n = 3; P = 0.001), need to digitate per vagina (before, n = 16; after, n = 0; P = 0.001), stool frequency (before, 3.8 (0.7) times weekly; after, 8.6 (1.2); P = 0.004), and laxative requirements (before, n = 7; after, n = 0; P = 0.03). Although none were clinically incontinent, there was a mean 28 mmHg impairment in resting (P < 0.05) and 42.6 mmHg impairment in maximum squeeze anal pressures (P < 0.05) after operations. There was no other morbidity. CONCLUSION: Transanal rectocele repair effectively improves constipation problems, at the risk of impaired anal sphincter function. Although clinical incontinence was minimum, an alternative approach to rectocele repair should be considered when anal sphincters are lax.

Anal Canal↗
PubMed1998

Clinical outcome and bowel function following total abdominal colectomy and ileorectal anastomosis in the Oriental population.

UNLABELLED: Total abdominal colectomy with ileorectal anastomosis is a commonly performed surgical procedure. The postoperative outcome of these patients, however, has not been studied in detail in the Asian population. AIM: The purpose of this study was to analyze the functional outcome of patients following total abdominal colectomy and ileorectal anastomosis. METHOD: All patients subjected to a total abdominal colectomy with ileorectal anastomosis during a six-year period from February 1989 to October 1995 were reviewed. RESULTS: Sixty-six patients (male:female, 40:26) with a mean age of 55.2 (range, 20-88) years underwent total abdominal colectomy with ileorectal anastomosis. Median follow-up after surgery was 26 (range, 4-78) months. Indications for surgery were synchronous or metachronous tumors (18), complicated pancolonic diverticular disease (15), obstructed tumors with impending perforation (13), familial adenomatous polyposis (7), slow-transit constipation (6), and others (7). Mean operative time was 137 +/- 48 minutes. Mean postoperative hospitalization was 13.3 +/- 11.9 days. Time to first bowel movement and commencement of solid diet were 4.7 +/- 1.8 and 7.2 +/- 2.4 days, respectively. Four patients had prolonged postoperative ileus. Average stool frequencies per day were 5.5 at one week, 4.3 at one month, 3.9 at six months, 3.2 at one year, and 2.9 at two years postoperatively. Thirty-three patients (50 percent) required antidiarrheal treatment for a transient period, but none required long-term therapy. Ninety-seven percent of all patients rated the functional outcome as good to excellent, and 3 percent said it was fair. There was two perioperative mortalities. Five cases required re-laparotomy, three for anastomotic complications and two for hemoperitoneum. Five patients had recurrent admissions for adhesion colic, which resolved with nonsurgical therapy. Ten patients succumbed on follow-up, six to tumor recurrence, two to unrelated cancers (stomach and bladder), and three to medical conditions. CONCLUSION: The functional outcome of ileorectal anastomosis is generally rated as good to excellent by patients. Acceptable bowel function and control is regained within six months of the operation and levels off at one year after surgery, and no patient requires long-term antidiarrheal medication.

Adenomatous Polyposis Coli↗
PubMed1998

Diminutive cancers of the colon and rectum: comparison between flat and polypoid cancers.

A comparative study of polypoid and flat colorectal cancers less than 20 mm in size was made. A review of the characteristics of 56 polypoid cancers and 29 flat cancers treated between April 1989 and January 1996 was performed. Both groups of cancers showed similar age and location distribution. Polypoid cancers were more likely to be well differentiated (38%) than were flat cancers (17%) (P < 0.05). Flat cancers were more likely to have reached the serosa (52% vs 12%; P < 0.01) and also demonstrated a higher frequency of lymph node involvement (41% vs p 9%) (P < 0.01) when compared to polypoid cancers. Flat colorectal cancers belong to a distinct subset which demonstrates greater biological aggressiveness than polypoid cancers of equivalent size.

Aged↗
PubMed1998

NM23-H1 immunostaining is inversely associated with tumour staging but not overall survival or disease recurrence in colorectal carcinomas.

The NM23-H1 gene product has been recently identified as a potential metastasis suppressor. Studies on breast carcinomas have shown an inverse correlation between NM23-H1 status and stage of carcinogenesis and overall survival. However, in colorectal cancer, conflicting data have been reported. This study aimed to investigate whether NM23-H1 immunostaining is correlated with tumour stage, overall survival, disease recurrence, tumour differentiation, age and sex in colorectal carcinomas for the Singapore population using chi-square analysis. The staining was performed on 141 paraffin-embedded surgical specimens collected between 1991 and 1992 using a monoclonal anti-NM23-H1 antibody. Follow-up of patients was until time of death or for 5 years. There was a very significant inverse association between tumour staging and NM23-H1 status (P = 0.0004). However, NM23-H1 expression was not significantly correlated to overall 5-year survival, disease recurrence, tumour differentiation, age or sex. Thus, although NM23-H1 may be involved in suppressing metastasis, NM23-H1 immunohistochemistry has no prognostic value in colorectal cancer. This is the first report of a significant inverse association of NM23-H1 status with tumour staging in colorectal cancer which showed no correlation with overall survival or disease recurrence. Our result thus cautions against the practice of equating an inverse relation of genetic markers with tumour staging to survival or disease recurrence.

Adult↗
PubMed1998

Marsupialization of fistulotomy wounds improves healing: a randomized controlled trial.

BACKGROUND: Marsupialization of anal fistulotomy wounds leaves less raw unepithelialized tissue to granulate and may improve wound healing. METHODS: Some 103 consecutive patients with uncomplicated intersphincteric or trans-sphincteric fistula in ano were recruited into a randomized controlled trial. Fistula tracts were identified and laid open under general anaesthesia. The patients were randomized to have either the wounds left open (LO group) or wound edges marsupialized to the fistula tract with interrupted absorbable sutures (MS group). Anal manometry was performed before operation, and 6 weeks and 3 months after surgery. RESULTS: Some 52 patients were randomized to the LO group and 51 to the MS group. There were no differences in the age, sex, fistula type and fistula length distribution between the groups. Mean follow-up times were 9 and 10.2 months respectively. Wounds in the MS group healed faster (mean(s.e.m.) 6.0 (0.4) weeks) than those in the LO group (10.0(0.5) weeks) (P < 0.001). Only one patient (2 per cent) in the MS group was incontinent of liquids after operation compared with six (12 per cent) in the LO group. There was less impairment in maximum anal squeeze pressure at 3 months after marsupialization compared with leaving fistulotomy wounds open (P < 0.05). Apart from a slightly longer operative time required for marsupialization, the hospitalization and complication rates were the same. CONCLUSION: Anal fistulotomy wounds healed faster after marsupialization. Anal squeeze pressures were better preserved and this may improve anal continence.

Adult↗
PubMed1998

Physiological and functional outcome following ultra-low anterior resection with colon pouch-anal anastomosis.

BACKGROUND: Low rectal cancer is usually managed by ultra-low anterior resection (ULAR) with total mesorectal excision and straight coloanal anastomosis. However, following this procedure patients often suffer from frequency, urgency of bowel action and, occasionally, faecal incontinence. To overcome such problems, a colon pouch may be fashioned and a subsequent colon pouch-anal anastomosis performed. The physiological and functional outcome following the use of a colon pouch are appraised. METHODS: All relevant papers identified from a Medline search and papers from cross-referencing were reviewed. RESULTS AND CONCLUSION: Creation of a colon pouch following ULAR results in reduced bowel frequency, and a lower incidence of urgency and faecal incontinence. Although there is a slightly increased incidence of evacuatory disorder and need for enemas or suppositories, this appears to be a minor problem which may possibly be overcome by using a smaller colon pouch. Compared with straight coloanal anastomosis following ULAR, the creation of a colon pouch produced a superior functional outcome.

Anal Canal↗
PubMed1998

Young age is not a poor prognostic marker in colorectal cancer.

BACKGROUND: There is still considerable controversy and debate regarding the features and prognosis of colorectal cancer in young patients. METHODS: One hundred and ten patients (5.1 per cent) under the age of 40 years with colorectal cancer (group Y; male: female ratio 48:62) were compared with 2064 patients with colorectal cancer aged 40 years or more (group O; 917 women, 1147 men). Mode of presentation, stage at diagnosis, tumour characteristics and survival were analysed. RESULTS: Predisposing malignant conditions and family history of colorectal cancer were present in 20.9 per cent of patients in group Y versus 2.2 per cent in group O (P < 0.001). Common chief complaints included change in bowel habits, bleeding from the rectum and a significantly higher incidence of abdominal pain in group Y. There was no difference in stage at presentation between the two groups (the proportion of Dukes stage A, B, C and 'D' lesions in group Y was 8.2, 24.5, 37.3 and 30.0 per cent respectively versus 10.5, 27.9, 33.4 and 28.1 per cent in group O). Tumour site and characteristics were similar in both groups. The incidence of mucinous/signet ring cell and poor grade tumours was 6.9 and 11.8 per cent respectively in group Y and 4.5 and 10.5 per cent in group O. With a mean follow-up of 31.8 months, the overall 5-year survival rate was 54.8 per cent in group Y and 54.1 per cent in group O. Comparing stage for stage, survival was not significantly different in the two groups. However, the adjusted hazard ratios of the age groups Y, M (40-59 years), S (60-79 years), and E (80 years and above) were 1.3, 1 (baseline for calculations), 1.4 and 2.4 respectively, suggesting an adverse outcome for patients in group Y compared with patients aged 40-59 years. CONCLUSION: This study revealed no difference in tumour characteristics and survival in patients with colorectal cancer aged less than 40 years compared with those aged above 40 years. However, a higher hazard ratio in the youngest group may connote a worse prognosis than that for those aged 40-59 years. A significant family history of colorectal cancer and predisposing conditions in the young warrants aggressive screening, surveillance and treatment of the underlying conditions. The detection of colorectal cancer in young patients should be no different from that in the old but demands a high index of suspicion.

Adult↗
PubMed1998

Management of anorectal foreign bodies: a cause of obscure anal pain.

BACKGROUND: Few patients with anorectal foreign bodies will freely admit to transanal introduction. The results of long-term follow-up in these patients have been sparse. METHODS: Data from April 1989 to April 1997 were extracted from a prospective computerized database. The clinical features and the results of a departmental management protocol for anorectal foreign bodies were analysed. In addition, long-term outcomes were obtained by telephone interview. RESULTS: Thirty patients (25 men, 5 women) with a mean age of 46 (range 16-72) years) were treated for this condition. While 10 patients (33.3%) admitted to transanal insertion, the remaining 20 (66.7%) complained of anal pain. Among the latter, the foreign body was subsequently found on routine digital rectal examination in nine patients (45%), on X-ray in nine (45%) and it was passed out unexpectedly after fleet enema in two (10%). Factors which raised suspicion for X-rays included atypical gender behaviour, lax anal sphincters and bloody or mucoid rectal discharge. Transanal recovery was successful with sedation in 12 (40%), general anaesthesia in 13 (43.3%), and laparotomy was needed in three (10%; which included one perforated bowel at presentation). There were two complications (6.7%; one minor rectal abrasion and one bronchopneumonia). There was no long-term faecal incontinence or re-impaction of foreign bodies at 63 (range 8-96) months of follow-up. CONCLUSIONS: Foreign bodies should be suspected in patients with obscure anal pain. Judicious transanal extraction under sedation or general anaesthesia was usually successful with minimal short- and long-term complications.

Adolescent↗
PubMed1998

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.

Adult↗
PubMed1998

Management of colonic lipomas.

BACKGROUND: Little is known of colonic lipomas, especially in an Asian population, and their management is controversial. METHODS: A computerized colonoscopy database was analysed and patients with colonic lipomas were reviewed. RESULTS: There were 16 colonic lipomas (incidence of 0.15%) in a series of 10658 consecutive colonoscopies. There were seven men and nine women, with a mean age of 61.8 years (range: 28-80 years). The size of the lipomas ranged from 1.5 to 6 cm; all those larger than 3.5 cm were symptomatic (P = 0.05). The most common symptom was mild bleeding per rectum. Right-sided lipomas were palpable while left-sided lipomas presented with obstructive symptoms. Colonoscopic removal by hot biopsy or snare polypectomy was possible where the lipomas were 2.5 cm and pedunculated. Surgery was performed in six patients (four open, two laparoscopic) for symptoms and to exclude malignancy. There was no morbidity or mortality. CONCLUSIONS: Small or pedunculated lipomas may be safely removed colonoscopically and the diagnosis confirmed histologically. Larger lipomas require surgical resection for relief of symptoms or to exclude malignancy.

Adult↗
PubMed1998

Randomized controlled trial comparing same-day discharge with hospital stay following haemorrhoidectomy.

BACKGROUND: A randomized controlled trial was conducted to compare traditional hospital stay haemorrhoidectomy (STAY) with same-day discharge haemorrhoidectomy (DAY) with regard to costs, clinical outcome and patient satisfaction. METHODS: A total of 54 consecutive patients were randomized to either STAY or DAY groups. A standardized excision of three piles was performed and the wounds were left open. The DAY patients went home on the same day but the STAY patients remained in hospital until their bowels had opened. A linear analogue pain score and patient satisfaction questionnaire were administered. During a mean follow-up of 60.5 (standard error of mean = 1.2) weeks, the complications and the total medical costs were recorded RESULTS: There were no differences in the age and sex distributions in both groups (STAY: 11 men, 16 women; mean age 40.6 (+/- 1.8) years; DAY: 10 men, 17 women; mean age 40.6 (+/- 1.9) years). Despite accounting for any readmissions, the DAY patients accumulated shorter total hospitalization stays (P < 0.001) and incurred less total medical costs (P = 0.04). The pain scores, analgesia requirements, postoperative complications, patient satisfaction and time taken off work were not different between the two groups. However, more patients in both groups preferred to stay after surgery if they should need another haemorrhoidectomy. CONCLUSIONS: Haemorrhoidectomy (with excision of three piles) can be safely performed as a day procedure, with reduced hospitalization and medical costs.

Adult↗
PubMed1998

Adjuvant chemotherapy for patients with resected Dukes' C and high-risk B2 colon cancer with fluorouracil and levamisole.

Carcinoma of the large bowel is the second leading cause of cancer mortality in Singapore. Although the great majority of patients are discovered at a stage where resection with curative intent is possible, almost half of the patients afflicted will die of it. The combination of 5-fluorouracil + levamisole used in patients with curatively resected high risk Dukes B2 and all Dukes' C colon cancers has been shown to reduce cancer recurrence rate and improve overall survival. Since 1990 adjuvant chemotherapy has been recommended for this group of patients. This report describes patients treated in Singapore, their toxicities and their outcome. A total of 341 patients were treated between 1990 and 1996. Treatment compliance was 71.8%. Toxicity was moderate with mainly grade 1-2 nausea and vomiting, diarrhoea, stomatitis, alopecia, and neutropenia. There was 1 treatment-related death. Median recurrence-free interval was 81 months and median survival was not reached at 90 months. This regimen is tolerable. Until further randomised reports comparing 5-fluorouracil + levamisole to other combinations are available, this combination chemotherapy is recommended to patients after surgical resection of the high risk Dukes' B2 and Dukes' C colon cancer to reduce cancer recurrence and improve overall survival.

Adenocarcinoma↗
PubMed1998

Local recurrence following rectal resection for cancer.

Recurrent rectal carcinoma following surgery carries an extremely poor prognosis and subsequent intervention is usually palliative. The incidence of local recurrence (LR) following curative surgery for rectal cancer has been reported to range from 3.7 to 50%. Current treatment strategy for rectal cancer aims at minimizing LR by either pre-operative radiotherapy or adjuvant chemoradiotherapy. Three hundred and fifty-four patients underwent surgical resection for rectal cancer in our department between April 1989 and March 1994, of which 47 (13%) were Dukes A, 88 (25%) Dukes B, 143 (40%) Dukes C and 76 (22%) Dukes D. Two hundred and seventy-eight (79%) patients were defined as having had curative resection (Dukes A, B and C). Overall, total LR occurred in 43 (12.2%) of 354 patients, while LR following curative resection occurred in 16 (9.4%) of the 278 patients. The incidence of LR became higher with increasing depth of invasion and lymph nodal involvement as shown by its direct relationship to stage of disease: Dukes A (0%), B (5.7%), C (14.6%) and D (22.3%). Local recurrence following resection for rectal cancer in our series is low. Pre-operative radiotherapy or adjuvant chemoradiotherapy may not further reduce this low incidence of LR significantly and its role needs to be re-evaluated for institutions with low local recurrence rates.

Adult↗