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Biomedical subjects

K M Chu

Publications and source records attributed to K M Chu.

At least 73 records · Page 4Linked to original sources
PubMed1996

Hepatectomy with an ultrasonic dissector for hepatocellular carcinoma.

This study compared the results of hepatectomy for hepatocellular carcinoma (HCC) using an ultrasonic dissector with those of a combination of the crushing clamp and finger fracture techniques. The crushing clamp and finger fracture method was used from 1989 to 1992 in 96 patients (group 1) and the ultrasonic dissector from 1993 to 1994 in 69 patients (group 2). Data from these two sets of patients were collected prospectively. The groups were comparable in terms of preoperative liver function, tumour size and stage, and the incidence of cirrhosis. Major hepatectomy was performed in 69 patients (72 per cent) of group 1 and in 52 (75 per cent) of those in group 2. Use of the ultrasonic dissector resulted in lower mean (s.e.m.) blood loss (group 1 3.4(0.4) litres versus group 2 2.4(0.2) litres, P = 0.02), lower mean (s.e.m.) blood transfusion requirement (2.2(0.2) versus 1.2(0.2) litres, P = 0.001) and more patients not requiring blood transfusion (8 per cent of group 1 versus 32 per cent of group 2, P = 0.0001). Postoperative complications occurred in 45 patients (47 per cent) of group 1 and 19 (28 per cent) of those in group 2 (P = 0.012). There were no deaths in group 2 whereas the hospital mortality rate in group 1 was 16 of 96 (17 per cent) (P = 0.0004). A wider tumour-free resection margin (mean(s.e.m.) 1.2(0.1) versus 0.9(0.1) cm, P < 0.05) and lower serum bilirubin level throughout the postoperative period were also observed in group 2 patients. The ultrasonic dissector is better than the crushing clamp and finger fracture technique in hepatectomy for HCC.

Blood Loss, Surgical↗
PubMed1996

Combined laparoscopic and endoscopic approach in patients with cholelithiasis and choledocholithiasis.

BACKGROUND: The Optimal management of common bile duct stones in patients undergoing laparoscopic cholecystectomy remains controversial. METHODS: A prospective study was conducted in 145 of the 481 patients who had a preoperative endoscopic retrograde cholangiogram before their laparoscopic cholecystectomy. RESULTS: Endoscopic retrograde cholangiogram was successful in 138 patients (95%), and common duct calculi were found in 72 (50%) of them. Endoscopic sphincterotomy with ductal clearance was achieved in 62 of 67 patients during a mean of 1.4 sessions (range, 1 to 5). Five (3.4%) patients had complications after endoscopic intervention, all of which resolved uneventfully . Fourteen patients underwent laparoscopic common duct exploration, five had failed endoscopic extraction, five had their common duct stones left intentionally for laparoscopic intervention, and, in addition, four of the seven patients who had a failed endoscopic retrograde cholangiogram had stones identified by intraoperative cholangiogram. Ten of these 14 patients underwent a successful laparoscopic common duct exploration. Laparoscopic cholecystectomy was successfully completed in 134 of the 145 patients, and none had major intraoperative or postoperative complications. The mean postoperative stay was 2.7 days for those patients who underwent a successful laparoscopic procedure. The overall mean number of admissions for completing the treatment was 2.3. CONCLUSIONS: Combined laparoscopic and endoscopic approach is a viable option for patients with gallstones and choledocholithiasis.

Adult↗
PubMed1996

Laparoscopic endoluminal gastric surgery.

Laparoscopic endogastric surgery is a novel surgical approach that introduces the viewing laparoscope and instruments into the gastric lumen. The excellent visualization, improved instrument handling and versatility afforded by this technique enable local resection of mucosal lesions that are beyond the scope of peroral endoscopy. The authors describe this particular approach for the excision of gastric villous adenoma and early gastric cancer.

Adenoma, Villous↗
PubMed1995

Plasma and red blood cell pharmacokinetics of pimobendan enantiomers in healthy Chinese.

The pharmacokinetics of enantiomers of pimobendan and their demethylated metabolites in plasma and red cells were studied in 8 normal healthy volunteers. After racemic pimobendan 5 mg IV, the plasma concentration-time curve followed a two-compartment open-model with elimination half-lives of 1.81 h and 1.86 h for (+)- and (-)-pimobendan, respectively. The clearances and volumes of distribution postequilibrium were 13.5 ml.min-1.kg-1, 14.4 ml.min-1.kg-1; 1.74 l.kg-1 and 2.34 l.kg-1 for (+)- and (-)-pimobendan, respectively. Plasma protein binding (n = 3) of (+)-, (-)-pimobendan, (+)- and (-)-demethylated metabolites was 97.6, 97.6, 92.2 and 92.5%, respectively. The plasma concentration-time curve also followed a two-compartment open model after oral administration of 7.5 mg racemic pimobendan. The absolute bioavailabilities of (+)- and (-)-pimobendan were 0.51 and 0.55. Peak levels of (+)- and (-)-pimobendan, both at 1.2 h, were 15.8 and 16.8 ng.ml-1, respectively. The (+)- and (-)-pimobendan concentrations in red cells were determined and their pharmacokinetics were estimated using red blood cell data. Interesting phenomena were observed: the peak concentrations of (+)- and (-)-pimobendan in red blood cells were about 5.5- and 9.2-times higher than in plasma, and the AUCs were correspondingly elevated. The volume of distribution of the central compartment of (-)-pimobendan in red cell was significantly smaller than that of (+)-pimobendan. (0.24 vs. 0.42 l.kg-1.) Similar phenomena were found after IV administration.

Adult↗
PubMed1995

Pharmacokinetics and pharmacodynamics of enantiomers of pimobendan in patients with dilated cardiomyopathy and congestive heart failure after single and repeated oral dosing.

Pharmacokinetics and pharmacodynamics of pimobendan were studied in eight patients with dilated cardiomyopathy and chronic congestive heart failure after single dosing and after 2-week repeated dosing of 5 mg racemic pimobendan. Enantiomers of pimobendan and its demethylated metabolite in plasma and in red blood cells were measured. In the single-dose study, the peak plasma levels of 16.3 +/- 4.0 and 17.0 +/- 3.1 ng/ml of (+)- and (-)-pimobendan were observed at 0.9 hour after dosing. The concentration-time curves followed a two-compartment model, with terminal half-lives of 2.56 +/- 0.35 and 2.93 +/- 0.33 hours for (+)- and (-)-pimobendan (p > 0.05), respectively. The oral volumes of distribution after equilibrium were 3.26 +/- 0.74 and 3.13 +/- 0.75 L/kg, and oral clearances were 28.6 +/- 7.0 and 21.9 +/- 4.1 ml/min/kg for (+)- and (-)-pimobendan (p > 0.05), respectively. In red blood cells, the respective (+)- and (-)-pimobendan concentrations were 5.8 and 8.4 times higher than those in plasma, indicating a stereoselective partitioning of drugs between plasma and red blood cells. The pharmacodynamic effect of pimobendan was evaluated by echocardiography. The ejection fraction, mean velocity of circumferential fiber shortening, aortic flow peak velocity, cardiac index, and stroke volume index significantly increased 50% to 60%. The left ventricular end-systolic dimension, systolic blood pressure, and diastolic blood pressure significantly decreased 8% to 11%. These effects lasted for more than 8 hours. In a 2-week repeated-dose study, there was no significant dose accumulation in plasma and red blood cells. The pharmacokinetic parameters were similar to those in the single-dose study, except for significantly shorter absorption half-lives. The baseline levels of cardiac index and stroke volume index were significantly higher than the baseline levels in the single-dose study. This suggests an accumulation of pharmacodynamic effects despite a relatively short elimination half-life.

Administration, Oral↗
PubMed1995

An innovative cold tail-flick test: the cold ethanol tail-flick test.

An innovative antinociceptive test, the cold ethanol tail-flick test (CET), was developed for evaluating the actions of opioid analgesics. To select an optimal operation temperature range for the CET, temperatures from -5 degrees C to -30 degrees C were screened. After screening, temperatures ranging between -20 degrees C and -30 degrees C were both strong and effective enough to act as a noxious cold stimulus. In the following study, -20 degrees C was selected as the cold stimulus for the CET. The sensitivity and specificity of this test were challenged by opioid analgesics: an agonist (morphine) and two agonist-antagonists (buprenorphine and nalbuphine), two tranquilizers (droperidol and diazepam), and four nonopioid analgesics (acetaminophen, aspirin, indomethacin, and ketoprofen). The sensitivity of the CET was also compared with the assays using heat (radiant heat and hot water). The AD50 values determined by the CET for morphine, buprenorphine, and nalbuphine were 0.16 mg/kg, 0.22 micrograms/kg, and 0.19 mg/kg, respectively. Naloxone, an opioid antagonist, blocked the antinociceptive effects of these opioids which were determined by the CET. Furthermore, the tranquilizers and nonopioid analgesics did not show any activity in the CET. Our results show that not only can the CET assess the antinociceptive activity of both opioid agonist and mixed agonist-antagonist, it also possess the characteristics of sensitivity, specificity, simplicity, and reproducibility.

Analgesics, Opioid↗
PubMed1995

Hepatic resection for hepatocellular carcinoma. An audit of 343 patients.

OBJECTIVE: The authors summarize the results of patients who had hepatectomy for hepatocellular carcinoma over a 22-year period. SUMMARY BACKGROUND DATA: Recent reports showed improved perioperative results and long-term prognosis. METHODS: The perioperative outcome of 343 patients was studied according to three different time periods: before 1987 (n = 149); 1987 to 1991 (n = 128); and 1992 to present (n = 66). Survival analysis was made by stratifying patients into two categories--either before or after 1987. The majority of patients had large tumors (78%), cirrhosis (73%), and a major hepatectomy (73%). RESULTS: Besides an increased resectability rate (23%), there was a marked reduction of the recent morbidity (32%; p < 0.001), operative (4.5%; NS) and hospital (6%; p < 0.02) mortality rates. The recent surgical approach was identified as a significant contributory factor to the lowered hospital mortality rate. Patients in the latter part of the study had significantly better survival, with a 1-, 3- and 5-year survival rate of 68%, 45%, and 35%, respectively. Early detection and effective treatment of recurrences contributed to the improved prognosis. CONCLUSIONS: The recent management strategy and technological advances improved the results of surgical treatment for patients with hepatocellular carcinoma.

Adult↗
PubMed1995

Fungating carcinoma of the stomach: en bloc multiple organ resection and abdominal wall reconstruction.

A patient with carcinoma of the stomach invading multiple adjacent organs and fungating through the anterior abdominal wall was treated by en bloc multiple organ resection and abdominal wall reconstruction. The patient is alive and well at the time of writing, six months after the operation. The rationale for embarking on multiple organ resection for gastric cancer is discussed. However, such an aggressive surgical approach should only be applied to carefully selected patients who are medically fit and have no evidence of widespread systemic metastases.

Abdominal Muscles↗
PubMed1995

Primary lymphoma presenting as intra-abdominal mass and obstructive jaundice.

We reported a 67-yr-old man presenting with right hypochondrial pain, obstructive jaundice, and hepatic hilar mass. Biliary stenting relieved the jaundice. Percutaneous aspiration cytology of the mass was suspicious of lymphoma. He had no evidence of the disease, including lymphadenopathy, elsewhere in the body. Excision of the mass en bloc with cholecystectomy and right hemicolectomy confirmed the diagnosis of B-cell lymphoma. The patient recovered uneventfully and received nine courses of systemic chemotherapy afterward. Up to the time of writing, the patient remained disease-free 20 months after the initial presentation. This is the first case report of a primary lymphoma arising in and remaining localized to the hepatic hilar region. Moreover, it illustrates the importance of obtaining tissue diagnosis in patients with malignant jaundice.

Abdominal Neoplasms↗
PubMed1994

Perioperative nutritional support in patients undergoing hepatectomy for hepatocellular carcinoma.

BACKGROUND: Resection of hepatocellular carcinoma is associated with high rates of morbidity and mortality. Since intensive nutritional support can reduce the catabolic response and improve protein synthesis and liver regeneration, we performed a prospective study to investigate whether perioperative nutritional support could improve outcome in patients undergoing hepatectomy for hepatocellular carcinoma. METHODS: We studied 124 patients undergoing resection of hepatocellular carcinoma. Sixty-four patients (39 with cirrhosis, 18 with chronic active hepatitis, and 7 with no associated liver disease) were randomly assigned to receive perioperative intravenous nutritional support in addition to their oral diet, and 60 patients (33 with cirrhosis, 12 with chronic active hepatitis, and 15 with no associated liver disease) were randomly assigned to a control group. The perioperative nutritional therapy consisted of a solution enriched with 35 percent branched-chain amino acids, dextrose, and lipid emulsion (50 percent medium-chain triglycerides) given intravenously for 14 days perioperatively. RESULTS: There was a reduction in the overall postoperative morbidity rate in the perioperative-nutrition group as compared with the control group (34 percent vs. 55 percent; relative risk, 0.66; 95 percent confidence interval, 0.45 to 0.96), predominantly because of fewer septic complications (17 percent vs. 37 percent; relative risk, 0.57; 95 percent confidence interval, 0.34 to 0.96). There were also a reduction in the requirement for diuretic agents to control ascites (25 percent vs. 50 percent; relative risk, 0.57; 95 percent confidence interval, 0.37 to 0.87), less weight loss after hepatectomy (median loss, 0 kg vs. 1.4 kg, P = 0.01), and less deterioration of liver function as measured by the change in the rate of clearance of indocyanine green (-2.8 percent vs. -4.8 percent at 20 minutes, P = 0.05). These benefits were seen predominantly in the patients with underlying cirrhosis who underwent major hepatectomy. There were five deaths during hospitalization in the perioperative-nutrition group, and nine in the control group (P not significant). CONCLUSIONS: Perioperative nutritional support can reduce complications after major hepatectomy for hepatocellular carcinoma associated with cirrhosis.

Adult↗
PubMed1994

Preoperative endoscopic drainage for malignant obstructive jaundice.

The role of preoperative endoscopic drainage for patients with malignant obstructive jaundice was evaluated in a randomized controlled trial. A total of 87 patients were assigned to either early elective surgery (44 patients) or endoscopic biliary drainage followed by exploration (43). Thirty-seven patients underwent successful stent insertion and 25 had effective biliary drainage. Complications related to endoscopy occurred in 12 patients. After endoscopic drainage significant reductions of hyperbilirubinaemia, indocyanine green retention and serum albumin concentration were observed. Patients with hilar lesions had a significantly higher incidence of cholangitis and failed endoscopic drainage after stent placement. The overall morbidity rate (18 patients versus 16) and mortality rate (six patients in each group) were similar in the two treatment arms irrespective of the level of biliary obstruction. Despite the improvement of liver function, routine application of endoscopic drainage had no demonstrable benefit. Endoscopic drainage is indicated only when early surgery is not feasible, especially for patients with distal obstruction.

Aged↗
PubMed1994

Expandable metallic biliary stents.

Eighteen expandable metallic biliary stents were inserted in patients with malignant (16 patients) or benign (two patients) biliary strictures. Four were the Gianturco-Rosch biliary Z-stents and the remaining 14 were the Wallstent. The stents were delivered through either the endoscopic transpapillary (10 patients), percutaneous transhepatic (five patients) or combined percutaneous-endoscopic (three patients) route. No failure in implantation was encountered. Bile drainage was successful in all patients. Stent occlusions were observed in four patients with hilar obstruction due to tumour overgrowth above the stents at 30-67 days (mean 47.75 days) after insertion. The occlusions were drained percutaneously (two patients) or endoscopically (two patients). Migration of stent did not occur. After a median follow-up period of 170.5 days (range 57-731 days), 11 patients were still alive and free of jaundice. The median patency period of the stents for common bile duct and hilar obstruction was 288.5 days (range 117-731 days) and 61.5 days (range 30-188 days), respectively. The overall median patency period was 165 days. It is concluded that expandable metallic biliary stent is a useful adjunct to the treatment of malignant biliary obstructions with a better result in distal obstruction.

Aged↗
PubMed1993

Reinduction of the hypnotic effects of thiopental with NSAIDs by decreasing thiopental plasma protein binding in humans.

The effects of 14 non-steroidal anti-inflammatory drugs (NSAIDs)--naproxen, ibuprofen, mefenamic acid, ketoprofen, indomethacin, fenoprofen, diclofenac sodium, aspirin, salicylic acid, piroxicam, sulindac, fenbufen, flurbiprofen and benzydamine, on the plasma protein binding of thiopental and the clinical consequences of such interactions were studied. Four of them, naproxen, ibuprofen, salicylic acid and aspirin, very significantly decreased the protein binding of thiopental in vitro in human plasma (P < 0.005). Structurally, they were salicylates and propionic acid derivatives among the six classes of NSAIDs studied. The aspirin study demonstrated that the protein-displacing phenomenon was temperature-dependent, and concentration-dependent. Clinically, aspirin administered intravenously resulted in a significant increase in the percentage of plasma free thiopental from 16.01 +/- 3.59% to 22.27 +/- 3.96% (P < 0.001, n = 10) in patients undergoing surgery, and resulted in three of seven patients sleeping again during recovery from thiopental-induced anesthesia. Although the effect of chronic use of NSAIDs before anesthesia is uncertain, studies should be carried out to find out if naproxen, ibuprofen, and aspirin influence the depth of anesthesia, time of recovery and duration of action of thiopental.

Adult↗
PubMed1993

Hereditary hemorrhagic telangiectasis involving the ampulla of Vater presented with recurrent gastrointestinal bleeding.

We report a Chinese lady with hereditary hemorrhagic telangiectasia who presented with multiple episodes of gastrointestinal bleeding requiring transfusion. Gastroscopy, colonoscopy, isotope-labeled red blood cell scan, and selective arteriography were performed, but could not locate the source of bleeding. A bleeding lesion in the ampulla of Vater was seen when endoscopic retrograde cholangiopancreatography was attempted. She had an uneventful pylorus-preserving Whipple's operation with no further evidence of gastrointestinal bleeding. This is the first case report to show that the vascular ectasia of patients with hereditary hemorrhagic telangiectasia could manifest at the ampulla of Vater.

Ampulla of Vater↗
PubMed1992

Choice of palliation for malignant hilar biliary obstruction.

Clinical data from 50 consecutive patients with unresectable hilar tumors situated at or proximal to the common hepatic duct were retrospectively analyzed to aid in the selection of appropriate palliative measures. Thirty-four patients had cholangioenteric bypass (CEB) to either left (28 patients), right (3 patients), or both (3 patients) intrahepatic ductal systems. Sixteen patients had nonoperative drainage (NOD) established either endoscopically (4 patients), percutaneously (9 patients), or using a combined endoscopic-percutaneous approach (3 patients). When compared with patients with CEB, patients with NOD had more frequent medical problems (p less than 0.03) and lower serum albumin levels on admission (p less than 0.03). While comparable postprocedural complications (13 CEB patients versus 4 NOD patients) were observed, patients with NOD had a significantly higher hospital mortality (9 CEB patients versus 9 NOD patients, p less than 0.05). Excluding the 12 patients (6 CEB patients versus 6 NOD patients) who died within 30 days after drainage, the quality of survival of the remaining 38 patients was analyzed with reference to 6 objective parameters. Although patients with NOD had significantly more frequent admissions relating to their catheters (p less than 0.02), there was no qualitative difference in the survival rate between the two groups of patients. For selected high-risk patients with limited life expectancy, NOD should be offered. However, additional prospective studies are required to decide the best choice of palliation for patients who are not at such high risk.

Aged↗
PubMed1992

Surgery for malignant obstructive jaundice: analysis of mortality.

Surgery on patients with malignant obstructive jaundice carries formidable morbidity and mortality rates. Clinical records of 120 consecutive patients who had a serum total bilirubin levels of 100 mumol/L or greater before exploration were analyzed retrospectively to provide guidelines for better management. Although most patients underwent bilienteric bypass to either the extrahepatic (n = 45) or intrahepatic ductal system (n = 28), resection was possible in 32 (26.7%). Complications developed in 42 patients (35%), among whome 12 (10%) required reexploration and 32 (26.7%) died within the same hospitalization. Identification of risk factors associated with hospital deaths after surgery was conducted on 84 of the 120 (group A) patients randomly selected from the entire study period. Based on multivariate analysis, age greater than 65 years, a raised serum aspartate transaminase value greater than 90 IU, and serum urea level greater than 7 mmol/L before surgery were the risk factors selected from 39 different clinical (n = 6), laboratory (n = 26), and operative (n = 7) parameters studied. The predictive value was validated in the remaining 36 patients (group B), and a high-risk patient population had been isolated. Because both serum urea and aspartate transaminase values correlated significantly with the necessity of urgent exploration, aggressive nonoperative treatment should be used to control the emergency. Alternative therapeutic options or perioperative management should be considered for the selected high-risk patients before definitive surgical biliary decompression.

Adult↗