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Biomedical subjects

K W Chu

Publications and source records attributed to K W Chu.

At least 37 records · Page 2Linked to original sources
PubMed2000

Risk factors for anastomotic leakage after low anterior resection with total mesorectal excision.

BACKGROUND: This study aims to analyze the risk factors for anastomotic leakage after low anterior resection with the technique of total mesorectal excision (TME). METHODS: From September 1993 to November 1998, 196 patients with rectal cancer from 3 to 12 cm from the anal verge were treated with low anterior resection with TME. The data were entered in a prospective manner, and the factors that might affect anastomotic leakage were analyzed. RESULTS: The mean level of anastomosis was 3.6 cm from the anal verge (range 1 to 5 cm). The leakage rate was 10.2%. Female gender (P = 0.01; 95% confidence interval [CI] 1.3 to 14.3; odds ratio 4.3) and presence of a diversion stoma (P = 0.01; 95% CI 1.4 to 14.2; odds ratio 4.5) were independent significant factors for lower anastomotic leakage. The absence of a stoma was associated with significantly increased leakage in male (P = 0.001) but not in female (P = 0.51) patients. CONCLUSIONS: With low anastomosis after low anterior resection with TME, diversion stoma construction should be performed routinely in men. In women, the need for diversion can be more selective.

Adult↗
PubMed2000

Total pelvic exenteration for locally advanced rectal cancer.

BACKGROUND: Since its first description in 1948, total pelvic exenteration has been a surgical option for the treatment of locally advanced rectal cancer in selected patients. During these 50 years, it has remained a formidable procedure with high mortality and substantial morbidity. This report describes the results of total pelvic exenteration for rectal cancer in terms of post-operative mortality, morbidity, and longterm survival in patients with locally advanced primary and recurrent rectal cancer. STUDY DESIGN: A study of the patient records revealed that 24 patients underwent total pelvic exenteration as the treatment for locally advanced primary or recurrent cancer of the rectum from 1983 to 1998. The charts of the patients were reviewed, and morbidity and mortality were documented. The survival of the patients was also analyzed. RESULTS: Fifteen patients had primary tumor and 9 had locally recurrent cancer. The mean age was 62 years old. There were no postoperative deaths, and the complication rate was 54%. In the treatment of primary tumor, bowel continuity was possible in 60% of the patients. Previous radiation or operation for recurrent disease was not associated with increased morbidity. The overall 5-year survival was 44%. The 5-year survival of patients with primary cancer was 64% and was significantly better than the rate for those with recurrent disease. Only one patient with recurrent disease survived more than 24 months. CONCLUSIONS: Total pelvic exenteration now can be performed with low mortality rates, but the morbidity remains high. In the treatment of primary rectal cancer, good survival (64%) can be achieved, but results are dismal for the treatment of recurrent disease. We suggest better selection of patients for this procedure, especially as a treatment for recurrent rectal cancer.

Adenocarcinoma↗
PubMed1999

Triple rubber band ligation for hemorrhoids: prospective, randomized trial of use of local anesthetic injection.

PURPOSE: Rubber band ligation is a common office procedure for hemorrhoids. Triple rubber band ligation in a single session has been shown to be a safe and economical way of treating hemorrhoids. However, postligation discomfort after triple rubber band ligation is not uncommon. The aim of this study was to evaluate the effectiveness of local anesthetic injection to the banded hemorrhoidal tissue in reducing postligation discomfort. METHODS: Patients attending an outpatient clinic for symptomatic hemorrhoids suitable for triple rubber band ligation were randomly assigned to two groups. In the treatment group rubber band ligation was performed at three columns of hemorrhoids, and 1 to 2 ml of 2 percent lignocaine was injected into the banded hemorrhoidal tissue. In the control group triple rubber band ligation was performed in a similar manner, but local anesthetic was not given. Patients were followed up by telephone at the second week and in the clinic after six weeks. RESULTS: From April to August 1996, 101 patients entered the trial and were treated with triple rubber band ligation. Sixty-two patients were randomly assigned to the local anesthetic injection group and 39 to the control group. Overall good to excellent results occurred in 89 percent of patients, and there was no difference between the two groups. Postligation pain occurred in 26 and 20 percent of patients in the treatment and control groups, respectively (P > 0.05). Postligation tenesmus occurred in 32 and 41 percent of patients in the treatment and control groups, respectively (P > 0.05). No patients suffered from septic complications or bleeding that required transfusion. CONCLUSION: Triple rubber band ligation in a single session is a safe, economical, and effective way of treating symptomatic hemorrhoids. Postligation pain and tenesmus occurred in 24 and 37 percent, respectively. Discomfort was usually tolerable. Local anesthetic injection to the banded hemorrhoidal tissue did not help to reduce postligation discomfort.

Anesthetics, Local↗
PubMed1999

Prospective evaluation of selective defunctioning stoma for low anterior resection with total mesorectal excision.

Low anterior resection with total mesorectal excision for rectal carcinoma is associated with a high anastomotic leakage rate, and the effectiveness of a defunctioning stoma in preventing anastomotic leakage remains controversial. In this study a policy of selective defunctioning stoma for stapled colorectal anastomosis after low anterior resection with total mesorectal excision in 148 consecutive patients was evaluated prospectively. A defunctioning stoma was performed in 61 patients (41%) considered at high risk of anastomotic leakage. Clinical leakage occurred in 2 patients (3.3%) with a stoma and 11 patients (12.6%) without a stoma (p = 0.047). Among those without a stoma, the leakage rate among male patients (20.9%) was significantly higher than that for female patients (4. 5%) (p = 0.022). Leakage subsided with conservative treatment in the two patients with a stoma, but seven patients without a stoma developed peritonitis requiring laparotomy. No deaths resulted from leakage, and there was one hospital death (0.6%) in the whole group. Median hospital stay was similar with and without a stoma (13.0 vs. 12.0 days) (p = 0.290). Closure of the stoma was associated with no mortality, a morbidity rate of 8.7%, and a median hospital stay of 6. 0 days. In conclusion, a defunctioning stoma is effective in preventing clinical anastomotic leakage after low anterior resection with total mesorectal excision. The relatively high incidence of leakage in the low risk group indicates the difficulty of predicting anastomotic leakage and hence the need for more liberal use of a defunctioning stoma especially in male patients.

Adult↗
PubMed1999

Inflammatory cecal masses in patients presenting with appendicitis.

An unexpected inflammatory cecal mass of uncertain etiology encountered during surgery for presumed appendicitis poses a dilemma to the surgeon when deciding the appropriate operative management. A retrospective study was performed to review the pathology and surgical management of this condition. Among 3224 patients who had emergency surgery for a diagnosis of acute appendicitis between January 1990 and December 1997, a group of 52 patients (1.6%) underwent either ileocecal resection or right hemicolectomy for an inflammatory cecal mass of uncertain etiology. The final pathologic diagnosis was cecal diverticulitis in 26 patients (50%), appendiceal phlegmon or abscess in 21 patients (40%), cecal carcinoma in 3 patients (6%), tuberculosis in 1 patient (2%) and schistosomiasis in another patient (2%). Altogether 34 patients underwent ileocecal resection, and 18 patients underwent right hemicolectomy, including the 3 patients with cecal carcinoma. Ileocecal resection was associated with a shorter mean operative time (144 vs. 201 minutes; p < 0.001), a lower morbidity rate (3% vs. 22%; p = 0.043), and a shortened mean postoperative hospital stay (6.8 vs. 11.2 days; p = 0. 011) than right hemicolectomy. There was no mortality in either group. In conclusion, most inflammatory cecal masses are due to benign pathologies and could be managed safely and sufficiently with ileocecal resection. Careful intraoperative assessment including examination of the resected specimen is essential to exclude malignancy, which would require right hemicolectomy.

Abscess↗
PubMed1998

Emergency resection and primary anastomosis for left-sided obstructing colorectal carcinoma in the elderly.

BACKGROUND: Emergency colorectal surgery in the elderly has been associated with a high mortality rate. Although the current trend for the management of obstructing left-sided colorectal carcinoma favours primary resection and anastomosis, the safety and benefits of this approach in the elderly have not been studied. METHODS: Some 57 elderly (aged more than 70 years) and 59 younger patients underwent emergency resection of an acutely obstructing left-sided colorectal carcinoma. Postoperative results in the two groups were compared. RESULTS: The primary resection rate was 95 per cent in the elderly and 89 per cent in younger patients (P = 0.70), with a primary anastomosis rate of 84 per cent and 78 per cent respectively (P = 0.64). Elderly patients had a significantly higher incidence of premorbid risk factors and postoperative cardiorespiratory complications but no increase in surgical complications. Anastomotic leaks occurred in 6 per cent of the elderly and 4 per cent of younger patients (P = 0.65), and the hospital mortality rate was 9 and 5 per cent respectively (P = 0.48). CONCLUSION: Emergency resection and primary anastomosis for left-sided obstructing colorectal carcinoma can be performed with favourable outcome in the elderly and should be the treatment of choice in most elderly patients.

Adult↗
PubMed1996

Identification of lactams as in vitro metabolites of piperidine-type phenothiazine antipsychotic drugs.

The metabolism of the piperidine-type phenothiazine antipsychotic agents thioridazine, mesoridazine and sulforidazine was studied in vitro with 10,000 g liver supernatants obtained from rats and dogs. After incubations at 37 degrees C for different time intervals, the incubates were extracted with dichloromethane and the isolated compounds analyzed by HPLC, direct probe MS and on-line HPLC-MS. Five lactam metabolites of these three drugs were unequivocally identified in the rat in vitro system, but none was found in dog preparations; at least one lactam metabolite was identified for each drug in the rat. The lactams of thioridazine and thioridazine ring sulfoxide were characterized as metabolites of thioridazine for the first time in any system. The other three lactam metabolites, namely the lactams of mesoridazine, sulforidazine and mesoridazine ring sulfoxide, were found in vitro for the first time, although they have been previously reported as in vivo metabolites of these drugs. The results indicate that rat would be a more suitable animal model than dog for further studies on the formation of lactam metabolites of these drugs.

Animals↗
PubMed1996

Acute diverticulitis of the right colon.

BACKGROUND: Acute diverticulitis of the right colon is a rare condition with a higher incidence in Oriental populations than in Occidental populations. PATIENTS AND METHODS: A retrospective review was conducted between 1982 and 1993 on 22 surgically treated Chinese patients (14 men, 8 women; mean age 47 years) with documented right colon diverticulitis. RESULTS: Most patients presented with right lower quadrant pain and local peritoneal signs. Acute appendicitis was the preoperative diagnosis in 82% (18/22) of the patients. Only one diagnosis subsequently proved correct. The pathology was easily recognized in 4 patients during surgery, while examination of the resected specimen confirmed the intraoperative suspicion in 13 patients. The right colon was resected and an ileocolonic anastomosis performed in 21 patients; the remaining patient underwent diverticulectomy and drainage of a pericolic abscess. There was no postoperative mortality, and 4 patients developed wound infection. CONCLUSIONS: Our results showed that acute diverticulitis of the right colon was encountered once in 180 cases of acute appendicitis. Local resection or colectomy with primary anastomosis without bowel preparation is the procedure of choice.

Acute Disease↗
PubMed1992

Bleeding angiodysplasia of the gastrointestinal tract.

Bleeding angiodysplasia of the gastrointestinal tract poses frustrating challenges to clinicians because these minute vascular lesions are difficult to diagnose pre-operatively and to locate intra-operatively. During the past 12 years, 24 patients were treated for histopathologically confirmed bleeding angiodysplasia of the gastrointestinal tract. Pre-operative investigations and intra-operative localization followed a fixed protocol for patients with gastrointestinal bleeding of obscure origin. The median follow-up of these 24 patients was 51 months and the results of treatment for 22 patients were excellent. Two patients had recurrent bleeding but investigations failed to determine the bleeding source.

Adult↗
PubMed1992

Obscure bleeding in the gastrointestinal tract originating in the small intestine.

In the past 12 years, we operated upon 49 patients with bleeding lesions of the small intestine. After endoscopic examination and barium studies of the upper and lower gastrointestinal tract excluded esophagogastroduodenal and lesions of the colon and rectum, preoperative examinations consisted of technetium-99m pertechnetate scan, technetium-99m labeled erythrocyte scan, barium studies of the small intestine and selective visceral angiogram. In one patient, diagnostic laparotomy had to be done before any procedure because of severe bleeding and angiosarcoma of the ileum. The results of gross examination at operation revealed bleeding lesions in 40 patients. Special intraoperative localization procedures consisting of methylene blue injection through superselectively prepositioned angiographic catheter was done on eight patients, and intraoperative enteroscopy was done on 17 patients. These two procedures were complementary, having their own indications and limitations. Our regimen of preoperative and intraoperative localization procedures was effective in the management of bleeding small intestinal lesions.

Adolescent↗
PubMed1991

Operative choledochoscopy in patients with acute cholangitis: a prospective, randomized study.

A prospective, randomized evaluation of operative choledochoscopy was carried out during emergency surgery in patients with acute cholangitis or acute suppurative cholangitis when conservative management had failed. After common bile duct exploration, 79 patients were randomized to have choledochoscopy and 78 patients to the control group. Laboratory and clinical parameters showed that choledochoscopy did not increase the incidence of septicaemia, acute pancreatitis, persistent cholangitis, postoperative wound sepsis, intraperitoneal sepsis and hospital mortality. The incidence of retained common bile duct stones detected by T tube cholangiography performed in the second postoperative week was significantly reduced (P less than 0.01) after choledochoscopy. Choledochoscopy detected stones missed by conventional common bile duct exploration in ten patients. It is concluded that choledochoscopy is a safe and effective technique in patients with acute cholangitis and acute suppurative cholangitis.

Acute Disease↗
PubMed1990

Systemic antibiotic regimens for acute cholecystitis treated by early cholecystectomy.

A total of 203 patients were randomized into a prospective trial to compare short (SC) versus long courses (LC) of systemic antibiotic for acute cholecystitis treated by early cholecystectomy. The initial pre-operative management was the same and all patients received 2 g of cefamandole intravenously just before operation. Two further doses of cefamandole 500 mg were given 6 and 12 h later for patients on SC while the antibiotic was continued at 500 mg at 6 h intervals for 7 days for patients on LC. Seven patients developed wound infection on SC compared with five patients with wound infection and an additional patient with a subphrenic abscess on LC (P greater than 0.05). Thrombophlebitis related to intravenous antibiotic injections was more common in patients on LC (P less than 0.05). Also, patients on LC had to stay statistically longer in hospital in order to complete the course of antibiotic (P less than 0.05). We therefore recommend a SC to be used, as it is more cost-effective and causes fewer complications.

Acute Disease↗
PubMed1989

Repeat selective visceral angiography in patients with gastrointestinal bleeding of obscure origin.

In the past 9 years, we have operated on 56 patients with gastrointestinal bleeding of obscure origin. Selective visceral angiography demonstrated the bleeding lesions in 24 of the 30 patients who underwent this investigation. Six of these 24 patients, however, had a negative angiogram initially and the lesions were only demonstrated on a repeat angiogram. The negative initial angiograms were due to: (1) slow bleeding from lesions in two patients; (2) a small bleeding tumour that caused only intermittent jejunojejunal intussusception in one patient; (3) technical fault in one patient; and (4) spasm of the bleeding vascular lesions and their feeding arteries in two patients. We advocate repeat angiography the following day in all patients in whom profuse bleeding continues, and during the next intestinal bleeding in those whose bleeding stops after the initial negative angiography. In patients who have repeated episodes of massive bleeding, and in whom full investigations fail to reveal the bleeding source, repeat angiography carried out 4 weeks after the bleeding has stopped can sometimes demonstrate the vascular lesions.

Angiography↗
PubMed1989

Leucocyte count and neutrophil percentage in appendicectomy for suspected appendicitis.

The total leucocyte count (TLC) and neutrophil percentage (NP) were studied prospectively in 1032 patients who underwent appendicectomy for suspected acute appendicitis. On histopathological study of the resected appendices, 97 patients had normal appendices, and 935 patients had acutely inflamed, gangrenous or perforated appendicitis. Statistically more patients with appendicitis had either raised TLC or raised NP compared with patients with normal appendices (P less than 0.001), and also compared with 357 patients who were admitted with right lower quadrant abdominal pain but were not subjected to operation (P less than 0.001). The sensitivity and specificity of raised TLC in diagnosing appendicitis for patients who underwent appendicectomy were 81.4% and 77.3%, respectively. Sensitivity increased when either raised TLC or raised NP were used, but specificity decreased. In contrast, sensitivity decreased when both raised TLC and raised NP were used together, but specificity increased. Raised TLC, preferably combined with raised NP, is a useful diagnostic aid in acute appendicitis. The TLC and NP, however, should only be interpreted in the light of physical findings in patients with suspected appendicitis because these blood tests have false positive and false negative results.

Acute Disease↗
PubMed1988

Prophylactic antibiotics in elective colorectal surgery.

A randomized prospective study was conducted on 194 patients who underwent elective colorectal surgery for carcinoma. All patients received the same mechanical bowel preparation. In addition, patients in group A received oral neomycin and erythromycin base; patients in group B received systemic metronidazole and gentamicin, while patients in group C received both oral and systemic antibiotics. Postoperative septic complications related to colorectal surgery occurred in 27.4 per cent, 11.9 per cent and 12.3 per cent respectively in groups A, B and C (chi 2 = 7; P less than 0.05). The incidence of sepsis in groups B and C was almost identical. Patients who received oral antibiotics alone (group A) had significantly higher risks of postoperative sepsis when compared with patients in either group B or group C (P less than 0.05). As there is no additional advantage of combining oral and systemic antibiotics, we recommend systemic metronidazole and gentamicin to be used with mechanical bowel preparation in elective colorectal surgery.

Administration, Oral↗
PubMed1988

Predictive value of surveillance skin and hub cultures in central venous catheters sepsis.

In a prospective study of septic complications of central venous catheters used for total parenteral nutrition, daily surveillance catheter hub cultures and twice weekly skin cultures at the catheter entry site were evaluated for their predictive value for catheter sepsis, i.e. bacteraemia with an identical species as that recovered from the catheter tip, or catheters which grew greater than or equal to 15 cfus by a semiquantitative method and/or greater than or equal to 10(3) cfus by a quantitative method. Of 142 catheters studied, 29 were identified to have catheter sepsis. For these the sensitivity of the surveillance hub culture was 34.5% and the sensitivity of the skin culture was 37.9%. When either the hub or the skin culture result was considered as an indication of catheter sepsis, the sensitivity increased to 79.3%. The positive and negative predictive value of the combined result was 44.2% and 93.3% respectively. This study suggests that simultaneous hub and skin cultures are required for a satisfactory surveillance.

Bacteria↗
PubMed1988

Influence of surgeons' experience on postoperative sepsis.

A prospective study was performed on 635 patients with appendicitis operated on by 7 trainees and 119 patients operated on by 6 senior surgeons with more than 8 years of surgical experience. In patients with normal appendices, postoperative sepsis was extremely low. For early and late appendicitis, the infection rates of the trainees decreased as experiences accumulated, but they were still higher than that of the senior surgeons. The difference in infection rates in acute appendicitis did not reach statistical significance between any of the training stages and between the various stages and the rate of the senior surgeons. The differences in infection rates in late appendicitis between stage 1 and stage 3 was significant, as was the difference in infection rates between stage 1 and the infection rate of the senior surgeons. Therefore, we have concluded that overall, the limited experience of trainees is related to the rate of postoperative sepsis in late appendicitis, although the infection rates of individual trainees vary a lot.

Appendectomy↗