Biomedical subjects

F P Mok

Publications and source records attributed to F P Mok.

16 recordsLinked to original sources

PubMed1997

Endoscopic sphincterotomy: 7-year experience.

The present study documents the indications and results of endoscopic sphincterotomy (ES) performed over 7 years in a surgical endoscopy unit. Potential improvement of results over this time period was analyzed. ES was associated with rare but undesirable morbidity and mortality. Specific improvement of results over time has not been reported. ES was attempted in 706 patients (336 men, 370 women) from 1987 to 1994 and was accomplished in 689 patients (97.6%). Complications occurred in 50 patients (7.1%), 13 of whom required emergency operative intervention. The overall 30-day mortality was 4.7% (n = 33), and procedure-related mortality was 0. 7% (n = 5). There was a significant decrease in hospital mortality (p < 0.01) and operative intervention for procedure-related complications (p < 0.001) after 1990. Procedure-related mortality has been reduced from 1.3% to 0.3% since 1990 (p = 0.1). ES in emergency situations or for malignant biliary obstruction did not adversely affect the outcome. It was concluded that ES can be performed safely in most patients. With increasing experience, procedure-related morbidity and mortality can possibly be reduced.

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↗

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

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

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↗

PubMed1991

Acute cholangitis secondary to hepatolithiasis.

In a series of 88 patients with acute cholangitis secondary to hepatolithiasis, 26 (30%) required emergency therapeutic intervention because of septicemic shock (n = 15), persistent fever (n = 8), or spreading peritonitis (n = 3). Analysis was made to define factors that predisposed to failure of conservative treatment and characteristics that could predict the need for emergency biliary decompression. The age, incidence of concomitant medical diseases, previous biliary surgery, positive blood culture, bacterial strains resistant to antibiotics used, and multiplicity of bacterial strains in bile cultures in patients who required emergency intervention were similar to these factors in patients who had elective operations after successful conservative management. The incidence of intrahepatic segmental obstruction by stones or strictures was similar, but many more patients who required emergency intervention had concomitant extrahepatic obstruction due to impacted common ductal stones or strictures. Logistic regression analysis of clinical, hematological, and biochemical data showed that maximum pulse rate within 24 hours of presentation (greater than 100 beats per minute, relative risk, 2.8) and platelet count at the time of admission (less than 150 x 10(9)/L, relative risk, 5.2) were the factors with independent significance in predicting the need for emergency therapeutic procedures. This finding may serve as a guideline for identifying high-risk patients for early intervention.

Adolescent↗

PubMed1991

Emergency surgical treatment for nonvariceal bleeding of the upper part of the gastrointestinal tract.

Endoscopic and biochemical data were collected prospectively from 1,530 patients admitted with nonvariceal bleeding of the upper part of the gastrointestinal tract between September 1985 and June 1989. Therapeutic endoscopy was done for 93 patients who underwent emergency surgical treatment for bleeding, subsequently required in 29 patients with seven postoperative fatalities. In contrast, 31 (15.7 per cent) of 198 patients (mortality rate of 9.6 per cent at 30 days) died in the hospital who had undergone emergency operation in whom therapeutic endoscopy had not been performed; data for this latter group is now presented. At admission, a greater likelihood of emergency operation was associated with a systolic blood pressure of 100 millimeters of mercury and endoscopic stigmatas of recent hemorrhage (ESRH) (p less than 0.001). Rebleeding rates for the presence of fresh blood, active spurting and oozing hemorrhage or visible vessel in an ulcer base were 26.5, 28.9 and 35.9 per cent, respectively. Endoscopic stigmatas were thus associated with an increased risk of bleeding (p less than 0.0001) and rebleeding led to a sixfold increase in the mortality rate. Congestive cardiac failure, chronic obstructive airway disease, chronic renal failure and a history of previous malignant disease were each associated with postoperative mortality rates of more than 50 per cent. An increased risk of mortality after emergency operation was related to age (p less than 0.0001), preoperative (p less than 0.002) and total (p less than 0.0001) blood transfusion requirement. Immediate operation after resuscitation and endoscopy was required in 87 patients; 11 deaths (hospital mortality rate of 12.7 per cent and 9.2 per cent at 30 days) occurred in this group compared with 20 fatalities (18.0 per cent) documented in 111 patients (9.9 per cent at 30 days) who underwent surgical treatment for rebleeding. We conclude that age, concomitant medical illness and preoperative and total transfusion requirements are each related to outcome after emergency operations. Such urgent intervention is best avoided if at all possible in patients with severe concomitant medical illness.

Acute Disease↗

PubMed1991

Treatment of hepatolithiasis: improvement of result by a systematic approach.

In previous decades the result of treatment of hepatolithiasis has been unsatisfactory. The incidence of residual stones after surgery might reach 77%. In the past 6 years we adopted a systematic approach comprised of accurate delineation of disease in the liver and biliary tract by direct cholangiography, ultrasonography, and computed tomography; tailored surgical treatment according to the extent of involvement of the liver and biliary tract; access to the intrahepatic ducts through the left duct or round ligament approach when there was difficulty with common bile duct exposure; routine use of flexible choledochoscopy; and application of electrohydraulic lithotripsy for large and impacted stones. Complete stone clearance was achieved in 114 of 127 patients (89.8%). Of those patients who had incomplete stone clearance, only six cases (4.7%) were related to technical failure of postoperative choledochoscopy. The incidence of stone recurrence was 15.8%, the lowest rate so far reported. It was the same regardless of whether a biliary drainage procedure had been performed, but the treatment for recurrent stones was facilitated by previous hepaticocutaneous jejunostomy. Overall the surgical treatment required for stone recurrence was of a lesser magnitude than that in the past.

Adolescent↗

PubMed1990

Doxorubicin for unresectable hepatocellular carcinoma. A prospective study on the addition of verapamil.

A prospective study was conducted to assess the safety and efficacy of the addition of oral verapamil to intravenous Adriamycin (doxorubicin) for the management of patients with unresectable hepatocellular carcinoma (HCC). All 28 patients studied had histologically verified disease, and cirrhosis was present in 20 of the 21 patients with adequate tissue sampling. The overall median survival was 57 days. Chemotherapy was terminated in seven patients after one course of treatment. Partial response and complete response were noted in four patients (19%) and one patient (4.8%), respectively, among the 21 patients evaluated. Side effects related to the chemotherapy were present in all patients studied. Death from fulminating sepsis occurred in three of the 13 patients with leukopenia. Symptomatic myocardial dysfunction developed in one patient. The addition of verapamil apparently did not potentiate the tumoricidal effect of systemic Adriamycin on HCC but probably did increase its complications.

Carcinoma, Hepatocellular↗

PubMed1990

Bleeding duodenal ulcer. A prospective evaluation of risk factors for rebleeding and death.

There were 12 hospital deaths in 433 patients (2.8%, 1.6% at 30 days) presenting with bleeding duodenal ulcer. Excluding patients who underwent immediate operation or early elective surgery, where ulcer size was measured at initial endoscopy rebleeding was evident in 40/288 patients (13.9%) and was associated with an increased mortality (0.4% v 12.5%) (p less than 0.0001). Rebleeding rates for ulcers less than or equal to 1 cm and greater than 1 cm were respectively 28/239 (11.7%) and 12/49 (24.5%) (p less than 0.02). Rebleeding occurred in 13/186 patients (7.0%) in whom endoscopic stigmata of recent haemorrhage were absent and in 27/102 (26.5%) with such stigmata (p less than 0.0001). The mortality rate for patients without stigmata was 3/186 (1.6%) whilst mortality figures for patients with ulcers less than or equal to 1 cm and greater than 1 cm in size were respectively 0/77 and 3/25 (12.0%) when stigmata were identified. Ulcers greater than 1 cm were more frequent in the greater than 60 year age group, more likely to have stigmata and carried an increased risk of rebleeding and mortality.

Age Factors↗

PubMed1989

Bleeding gastric ulcer: a prospective evaluation of rebleeding and mortality.

Clinical laboratory and endoscopic data were collected prospectively in 268 patients with bleeding gastric ulcer who were admitted between September 1985 and November 1987. There were 22 deaths, giving a hospital mortality rate of 8.2%. Surgery was undertaken in 68 patients (25.4%) with a mortality rate of 17.6% (11.8% at 30 days). There was one fatality in 104 (1.0%) patients less than or equal to 60 years compared with 21 deaths (12.8%) in patients greater than 60 years (P less than 0.001). Cirrhosis (P less than 0.01), malignant disease (P less than 0.03), chronic obstructive airways disease (P less than 0.02), congestive cardiac failure (P less than 0.02) and ischaemic heart disease (P less than 0.08) were each associated with an increased risk of mortality. Outcome in patients greater than 60 years was related to systolic blood pressure at admission (P less than 0.03), haemoglobin (P less than 0.02), serum bilirubin (P less than 0.02), and total transfusion requirements (P less than 0.001). For ulcers less than or equal to 1 cm, 1- less than or equal to 2 cm, greater than 2 cm in size, mortality rates were 1.9%, 11.4% and 18.0%, respectively. Initial endoscopy findings of a visible vessel, fresh blood, or active spurting/oozing haemorrhage were associated with rebleeding rates necessitating emergency surgery of 30.0%, 36.4% and 40.0%, respectively. There was no evidence of rebleeding in 187 patients (79.9%) managed conservatively and only five patients (2.7%) in this group succumbed, whereas rebleeding did occur in 47 patients (20.1%) with 13 subsequent deaths (27.7%; P less than 0.001). In patients greater than 60 years the presence of endoscopic stigmata of recent haemorrhage should lead to early consideration of therapeutic endoscopy and/or early surgery, particularly for ulcers greater than 1 cm in size.

Adolescent↗

PubMed1988

Portal thrombosis complicating appendicitis: ultrasound detection and hepatic computed tomography lobar attenuation alteration.

Lobar attenuation difference of liver on computed tomography was seen in a case of portal pyemia complicating perforated appendicitis. Left portal vein thrombus was detected first by ultrasound and subsequently confirmed by computed tomography. The left lobe of the liver showed greater contrast enhancement during the dynamic computed tomography study. The possible cause of this lobar attenuation difference is discussed.

Adult↗

PubMedDate not supplied

Hepatectomy for large hepatocellular carcinoma: the optimal resection margin.

The necessary resection margin (RM) for cure during hepatectomy for hepatocellular carcinoma (HCC) remains conjectural. From January, 1972 to June, 1988, a total of 96 patients who had complete macroscopic extirpation of their large tumor (greater than or equal to 5 cm in largest diameter) were studied retrospectively to determine the macroscopic distance of RM required to secure histological disease clearance. Positive histological RM, which was found in 31 (32.3%) patients, had significantly compromised both disease-free survival (p less than 0.04) and overall survival (p less than 0.006) of these patients. Among the 65 patients with detailed measurement of macroscopic RM, a significant reduction of residual histological disease was observed when a 0.5 cm margin had been established (p less than 0.05). Further extension of margin had no additional benefit. The presence of microsatellite (p less than 0.03) and multiple tumor nodules (p less than 0.03) was associated with an increased risk of positive histological margins among the 15 pathological parameters evaluated, including macroscopic RM. Since measurement of RM is an unreliable guide, histological confirmation is the only means for establishing the diagnosis of complete tumor clearance. Within safety limits dictated by anatomical factors and severity of underlying cirrhosis, aggressive surgery should be offered for patients with large HCC; however, resection is not advisable unless a 0.5 cm margin can be secured with certainty, especially for multinodular lesions.

Adult↗

PubMedDate not supplied

Bleeding peptic ulcer: a prospective evaluation of risk factors for rebleeding and mortality.

Clinical, endoscopic, and laboratory data were collected prospectively in 701 patients with bleeding peptic ulcer. The overall rebleeding rate was 16.1% and increased the risk of a fatal outcome by 17 fold (1.2% versus 20.6%, p less than 0.001). Rebleeding was documented in more than 75% of the group who did not survive following initial conservative management. Rebleeding was more likely (24.1% versus 14.2%, p less than 0.02) when shock was present on admission and the risk of a rebleed was doubled in patients over 60 years of age (22.1% versus 10.9%, p less than 0.001). Ulcers greater than 1 cm in size carried twice the risk of rebleeding (23.9% versus 12.4%, p less than 0.002). Concomitant medical illness had a significant adverse effect on outcome (p less than 0.05). Shock on admission was associated with a doubling of mortality figures (9.5% versus 3.7%, p less than 0.01). The identification of endoscopic stigmata of recent hemorrhage (ESRH) tripled the risk of mortality (7.5% versus 2.4%, p less than 0.002), ESRH were more frequently encountered when ulcer size was larger than 1 cm (61.4% versus 39.8%, p less than 0.001). Respective mortality rates for ulcers less than or equal to 1 cm and greater than 1 cm in size were 1.6% and 12.5% (p less than 0.001), corresponding mortality figures for patients over 60 years of age being 4.4% and 16.4% (p less than 0.002). The risk of a rebleed tripled (6.7% versus 2.6%, p less than 0.02) when ESRH were evident. There was a 6-fold increase in mortality following emergency surgery when compared with conservative management of patients in whom no surgical intervention was necessary (2.6% versus 14.9%, p less than 0.001). In summary, age over 60 years, previous medical illness, shock on admission, large ulcer size, and ESRH were each associated with an increased risk of rebleeding and mortality.

Female↗

PubMedDate not supplied

Hepatic resection for small hepatocellular carcinoma: the Queen Mary Hospital experience.

The clinico-pathological features and long-term results of 39 patients with resected small hepatocellular carcinoma (HCC) managed over 19 years in Hong Kong were retrospectively studied (mean diameter +/- standard deviation: 3.6 +/- 1.3 cm). Thirty-one patients were symptomatic and the majority (n = 33) of them had cirrhosis. When compared with 182 patients with large HCC operated within the same period, these patients with small HCC had a significantly higher incidence of spontaneously ruptured lesions (p less than 0.03). Following hepatic resection-major lobectomy (n = 19) and limited hepatic resection (n = 20), operative and hospital deaths occurred in 7.7% and 12.8% of patients, respectively. The size of the lesion had little influence on prognosis. The overall survival at 1, 3, and 5 years was 59%, 28%, and 11%, respectively, which was comparable to patients with large HCC greater than or equal to 5 cm. Further stratification of these 39 patients according to a diameter of greater than 3 cm (n = 22) or less than or equal to 3 cm (n = 17) showed no difference in long-term outcome. When compared with large tumors, frequent encapsulation (p less than 0.04) and less venous permeation (p less than 0.03) were encountered in small HCC. As the extent of hepatectomy had no effect on long-term outcome, limited hepatectomy for patients with small HCC is probably the procedure of choice. A 1 cm macroscopic resection margin is apparently adequate to ensure complete histological disease clearance.

Adult↗