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Biomedical subjects

C M Lo

Publications and source records attributed to C M Lo.

At least 145 records · Page 8Linked to original sources
PubMed1995

Hospital mortality of major hepatectomy for hepatocellular carcinoma associated with cirrhosis.

OBJECTIVE: To define the safety of major hepatectomy for hepatocellular carcinoma (HCC) associated with cirrhosis and the selection criteria for surgery in terms of hospital mortality. DESIGN: Major hepatectomy for HCC in the presence of cirrhosis is considered to be contraindicated by many surgeons because the reported mortality rate is high (26% to 50%). Previous workers recommended that only selected patients with Child's A status or indocyanine green (ICG) retention at 15 minutes of less than 10% undergo major hepatectomy. A survey was made, therefore, of our patients with HCC and cirrhosis undergoing major hepatectomy between 1989 and 1994. SETTING: A tertiary referral center. PATIENTS: The preoperative, intraoperative, and postoperative data of 54 patients with cirrhosis who had major hepatectomy were compared with those of 25 patients with underlying chronic active hepatitis and 22 patients with normal livers undergoing major hepatectomy for HCC. The data had been prospectively collected. INTERVENTION: Major hepatectomy, defined as resection of two or more liver segments by Goldsmith and Woodburn nomenclature, was performed on all the patients. MAIN OUTCOME MEASURE: Hospital mortality, which was defined as death within the same hospital admission for the hepatectomy. RESULTS: Preoperative liver function in patients with cirrhosis was worse than in those with normal livers. The intraoperative blood loss was also higher (P = .01), but for patients with cirrhosis, chronic active hepatitis, and normal livers, the hospital mortality rates (13%, 16%, and 14%, respectively) were similar. The hospital mortality rate for patients with cirrhosis in the last 2 years of the study was only 5%. Patients with cirrhosis could tolerate up to 10 L of blood loss and survive the major hepatectomy. By discriminant analysis, an ICG retention of 14% at 15 minutes was the cutoff level that could maximally separate the patients with cirrhosis with and without mortality. CONCLUSION: Major hepatectomy for HCC in the presence of cirrhosis is associated with a mortality rate that is not different from the rate for patients with normal livers. An ICG retention of 14% at 15 minutes would serve as a better selection criterion than the 10% previously used.

Adult↗
PubMed1995

Impedance analysis of MDCK cells measured by electric cell-substrate impedance sensing.

Transepithelial impedance of Madin-Darby canine kidney cell layers is measured by a new instrumental method, referred to as electric cell-substrate impedance sensing. In this method, cells are cultured on small evaporated gold electrodes, and the impedance is measured in the frequency range 20-50,000 Hz by a small probing current. A model for impedance analysis of epithelial cells measured by this method is developed. The model considers three different pathways for the current flowing from the electrode through the cell layer: (1) in through the basal and out through the apical membrane, (2) in through the lateral and out through the apical membrane, and (3) between the cells through the paracellular space. By comparing model calculation with experimental impedance data, several morphological and cellular parameters can be determined: (1) the resistivity of the cell layer, (2) the average distance between the basal cell surface and substratum, and (3) the capacitance of apical, basal, and lateral cell membranes. This model is used to analyze impedance changes on removal of Ca2+ from confluent Mardin-Darby canine kidney cell layers. The method shows that reduction of Ca2+ concentration causes junction resistance between cells to drop and the distance between the basal cell surface and substratum to increase.

Animals↗
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↗
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

Risk factors for liver transplantation across the ABO barrier.

A retrospective study was performed to identify risk factors affecting the fate of liver allografts transplanted across the ABO barrier. Over a 5-year period, 30 patients received 31 emergency OLTs with ABO-incompatible allografts. One-year graft and patient survival rates were 37.1% and 48.4%, respectively. This group was compared with 199 ABO-compatible OLTs performed under similar emergency conditions. Significantly higher incidence of rejection, hepatic artery thrombosis, and biliary stricture were found in ABO-incompatible grafts. The graft or patient survival of patients with O blood group or fulminant hepatic failure was not affected by ABO incompatibility. In contrast, the 1-year survival of recipients with non-O blood group was only 13.3% and the 1-year survival of those undergoing retransplantation was only 27.7% after ABO-incompatible OLT. A multivariate analysis using the Cox proportional hazard model identified non-O blood group (relative risk 3.43) and retransplantation (relative risk 2.46) as the most important risk factors for patient survival after ABO-incompatible OLT. We conclude that the use of ABO-incompatible grafts is justified in emergency cases when no other donor is available, but should be proscribed in patients with non-O blood group. The value of ABO-incompatible grafts in retransplantation is questionable and requires further investigation.

ABO Blood-Group System↗
PubMed1994

Resection for extrahepatic recurrence of hepatocellular carcinoma.

A total of 277 patients with hepatocellular carcinoma (HCC) underwent hepatic resection over a 20-year period. Twelve of 36 patients with recurrence confined to extrahepatic organs underwent surgical resection. There were no complications but one patient died in hospital from secondary intrahepatic recurrence. The 1-, 2- and 5-year survival rates for these 12 patients after hepatic resection were 92, 52 and 26 per cent respectively and were better than those of 24 patients who did not undergo resection for recurrence. The mean survival following resection for recurrent disease was 19.7 months and the longest survival time was nearly 8 years. Secondary recurrence after resection of metastases developed more commonly in the liver than in extrahepatic organs. Among the eight patients who survived for more than 4 months after the second operation, secondary recurrence developed in the liver and extrahepatic organs in eight and four patients respectively. In selected patients with isolated extrahepatic recurrence of HCC, surgery is effective in controlling extrahepatic disease and offers the only chance of long-term survival.

Abdominal Neoplasms↗
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

pH changes in pulsed CO2 incubators cause periodic changes in cell morphology.

It is common in animal cell culture to utilize media that are buffered with bicarbonate ions and elevated CO2 concentrations in the incubator gas. Many modern incubators maintain these concentrations by monitoring the level of CO2 and injecting the gas when the value drops below a certain set point. This feedback system results in small oscillations in the incubator CO2 concentration of about 0.5%, resulting in oscillating pH values in the medium bathing the cells. These oscillations are very small and cannot be detected using a standard pH combination electrode, and until now no one has noticed any effect on the cells. In this study, however, we demonstrate that these periodic changes can result in detectable changes in cell morphology and therefore do affect cell behavior. Using electric cell-substrate impedance sensing (ECIS) to detect subtle alterations in cell morphology, we have measured cellular changes that when analyzed with the Fast Fourier Transform have a periodicity that matches those of the CO2 addition. This effect becomes particularly prominent when the culture medium has been acidified by cell metabolism reducing the liquid's buffer capacity. We have further analyzed the cyclical morphological changes employing a model of cell-electrode interactions in the ECIS measurement. We conclude that: (1) the periodic changes in cell morphology are most apparent if the medium is partially spent and if the surface to volume ratio of the culture vessel is high and (2) for confluent WI-38/VA13 fibroblasts and bovine pulmonary endothelial cells (B3B3), the main periodic morphological changes manifest themselves primarily as alterations in paracellular resistance.

Animals↗
PubMed1994

Evaluation of indocyanine green retention and aminopyrine breath tests in patients with malignant biliary obstruction.

Impaired hepatic function is a major contributory factor to the high incidence of postoperative morbidity and mortality in patients with malignant biliary obstruction. Dynamic hepatic function tests such as indocyanine green (ICG) retention and aminopyrine breath tests were evaluated in such patients to define whether they were clinically useful for prediction of postoperative morbidity and mortality. Forty-four patients with malignant biliary obstruction undergoing surgery for relief of obstructive jaundice were recruited into the study. Indocyanine green retention and aminopyrine breath tests were carried out in all patients pre-operatively and repeated in 36 patients postoperatively. The ICG retention was abnormal in all patients before surgery and there was significant improvement 2 weeks after surgery (32.8 +/- 2.5% vs 18.3 +/- 2.8%, P = 0.001). The change in ICG retention levels correlated with the serum bilirubin levels but the pre-operative ICG retention value could not predict postoperative morbidity and mortality. The aminopyrine breath test was abnormal in all but one patient. It correlated with pre-operative prothrombin time of the patients before surgery but it did not improve significantly after surgery and was not predictive of postoperative outcome. It is concluded that both ICG retention and aminopyrine breath tests have limited clinical value in the pre-operative evaluation of patients with malignant biliary obstruction.

Aged↗
PubMed1993

Early treatment of acute biliary pancreatitis by endoscopic papillotomy.

BACKGROUND: Most patients with acute biliary pancreatitis have stones in the biliary tract or ampulla of Vater. Because these stones may be passed spontaneously soon after a patient is admitted to the hospital, the importance of early operative removal is not known. We tested the hypothesis that endoscopic papillotomy within 24 hours of admission decreased the incidence of complications in patients with acute biliary pancreatitis. METHODS: We studied 195 patients with acute pancreatitis who were randomly assigned to one of two groups: 97 patients underwent within 24 hours after admission emergency endoscopic retrograde cholangiopancreatography (ERCP) followed by endoscopic papillotomy for ampullary and common-bile-duct stones, and 98 patients received initial conservative treatment and selective ERCP with or without endoscopic papillotomy only if their condition deteriorated. RESULTS: One hundred twenty-seven patients ultimately proved to have biliary stones. Emergency ERCP with or without endoscopic papillotomy resulted in a reduction in biliary sepsis as compared with conservative treatment (0 of 97 patients vs. 12 of 98 patients, P = 0.001). The decrease in biliary sepsis occurred both in patients predicted to have mild pancreatitis (0 of 56 patients in the group that received emergency ERCP vs. 4 of 58 patients in the conservative-treatment group, P = 0.14) and in patients predicted to have severe pancreatitis (0 of 41 patients vs. 8 of 40 patients, P = 0.008). In all patients who had unrelenting biliary sepsis, persistent ampullary or common-bile-duct stones were identified. There were no major differences in the incidence of local complications (10 patients in the group that received emergency ERCP vs. 12 patients in the conservative-treatment group) or systemic complications (10 patients vs. 14 patients) of acute pancreatitis between the two groups, but the hospital mortality rate was slightly lower in the group undergoing emergency ERCP with or without endoscopic papillotomy (5 patients vs. 9 patients, P = 0.4). CONCLUSIONS: Emergency ERCP with or without endoscopic papillotomy is indicated in the treatment of patients with acute pancreatitis.

Acute Disease↗
PubMed1993

Monitoring motion of confluent cells in tissue culture.

Cell movements in confluent fibroblastic cell layers have been followed with a new instrumental method. Using the electric cell-substrate impedance sensor (ECIS), cell motions on the scale of nanometers are manifested as fluctuations in the impedance of small gold film electrodes that serve as cell substrata. These fluctuations have been recorded and numerically processed for cells at 27 and 37 degrees C, for cells deprived of all external nutrients over extended periods of time, and for cells exposed to different levels of cytochalasin D. Results suggest that the movements in confluent layers detected via ECIS can be correlated with cell metabolic activity.

Cell Line↗
PubMed1993

Appraisal of hepaticocutaneous jejunostomy in the management of hepatolithiasis.

Hepaticocutaneous jejunostomy offers the advantage of permanent percutaneous access to the biliary tract in patients with complex biliary problems. The long-term value, however, has not been assessed. In 41 patients who underwent this procedure for intrahepatic stones, there was no hospital mortality, and the postoperative morbidity rate was 10%. The presence of the cutaneous stoma facilitated postoperative flexible choledochoscopy for dilatation of biliary strictures and extraction of residual stones. On follow-up, symptoms recurred in 12 patients (29%) at a median time of 27 months (range: 1 to 97 months). Reconstruction of the cutaneous stoma and flexible choledochoscopy via the jejunal loop helped to resolve the acute cholangitis (n = 4) and to eradicate recurrent stones in all cases. Hepaticocutaneous jejunostomy was also beneficial in the management of three patients who experienced further recurrence of symptoms. There was no major difficulty in reconstructing the cutaneous stoma and in performing choledochoscopy via the jejunal loop. The overall complication rate related to the cutaneous stoma was 15%. Repeat laparotomy for recurrent disease was required in only one patient who underwent a second bilio-enteric anastomosis for a nondilatable left duct stricture. We conclude that hepaticocutaneous jejunostomy is a valuable procedure in the management of hepatolithiasis.

Adult↗
PubMed1993

Prediction of the severity of acute pancreatitis.

We conducted a prospective study to validate our previous finding that serum urea and plasma glucose levels on admission could predict the outcome of acute pancreatitis. Forty-two (24%) of 176 patients developed complications related to the attack of acute pancreatitis and were classified as having severe disease. By logistic regression analysis of 17 admission parameters, serum urea and plasma glucose levels were again the factors with independent significance in defining the outcome. By adopting the same cutoff levels as in our previous study (serum urea level greater than 7.4 mmol/L and plasma glucose level greater than 11.0 mmol/L), and the presence of either factor above the cutoff level as indicative of severe disease, the sensitivity of prediction was 79%, specificity 67%, and overall accuracy 70%. All the deaths were correctly predicted by this urea/glucose criteria. The overall accuracy was also found to be comparable with those of the APACHE II (cutoff level greater than 11) and Ranson's scoring systems. We conclude that the simple prognostic criteria for acute pancreatitis were validated; these criteria have the potential to stratify risk rapidly at the time of admission for patients who might benefit from an aggressive interventional protocol.

Acute Disease↗
PubMed1992

Endoscopic biliary drainage for severe acute cholangitis.

BACKGROUND: Emergency surgery for patients with severe acute cholangitis due to choledocholithiasis is associated with substantial morbidity and mortality. Because recent results suggested that emergency endoscopic drainage could improve the outcome of such patients, we undertook a prospective study to determine the role of this procedure as initial treatment. METHODS: During a 43-month period, 82 patients with severe acute cholangitis due to choledocholithiasis were randomly assigned to undergo surgical decompression of the biliary tract (41 patients) or endoscopic biliary drainage (41 patients), followed by definitive treatment. Hospital mortality was analyzed with respect to the use of endoscopic biliary drainage and other clinical and laboratory findings. Prognostic determinants were studied by linear discriminant analysis. RESULTS: Complications related to biliary tract decompression and subsequent definitive treatment developed in 14 patients treated with endoscopic biliary drainage and 27 treated with surgery (34 vs. 66 percent, P greater than 0.05). The time required for normalization of temperature and stabilization of blood pressure was similar in the two groups, but more patients in the surgery group required ventilatory support. The hospital mortality rate was significantly lower for the patients who underwent endoscopy (4 deaths) than for those treated surgically (13 deaths) (10 vs. 32 percent, P less than 0.03). The presence of concomitant medical problems, a low platelet count, a high serum urea nitrogen concentration, and a low serum albumin concentration before biliary decompression were the other independent determinants of mortality in both groups. CONCLUSIONS: Endoscopic biliary drainage is a safe and effective measure for the initial control of severe acute cholangitis due to choledocholithiasis and to reduce the mortality associated with the condition.

Acute Disease↗
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↗