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H Lau

Publications and source records attributed to H Lau.

At least 19 recordsLinked to original sources
PubMed2001

Predictive factors for unanticipated admissions after ambulatory laparoscopic cholecystectomy.

HYPOTHESIS: Analysis of the causes of unanticipated admission after ambulatory laparoscopic cholecystectomy may permit the identification of predictive clinical factors for postoperative admission. DESIGN: Univariate and multivariate analyses of clinical variables associated with unplanned admission in a retrospective case-control series of ambulatory laparoscopic cholecystectomies. SETTING: A major university-affiliated teaching hospital. PATIENTS: Seven hundred thirty-one consecutive patients who underwent ambulatory laparoscopic cholecystectomies between January 1, 1996, and December 31, 1999. INTERVENTION: Ambulatory laparoscopic cholecystectomy. MAIN OUTCOME MEASURES: Unplanned postoperative admissions. Univariate and multivariate analyses of 19 clinicopathologic factors were performed to identify independent predictive factors for these admissions. RESULTS: Seven hundred six patients were discharged on the day of operation. The remaining 25 required admission because of pain (n = 10), nausea and vomiting (n = 6), retention of urine (n = 5), patient preference (n = 3), and medical observation (n = 1), giving an unanticipated admission rate of 3.4%. Significant factors associated with unplanned admission included operative duration of longer than 60 minutes and thickened gallbladder wall on ultrasonographic and pathological findings. By means of logistic regression, length of operation was the only independent predictive factor. Operative time exceeding 60 minutes incurred a 4-fold increased risk for unanticipated admission. CONCLUSIONS: Operative duration was the best predictive factor for unplanned admission after ambulatory laparoscopic cholecystectomy. During selection of patients for day surgery, ultrasonographic demonstration of a thickened gallbladder wall should be taken into consideration.

Adult↗
PubMed2001

Determinant factors of pain after ambulatory inguinal herniorrhaphy: a multi-variate analysis.

Pain is common after inguinal herniorrhaphy. The objective of our study was to evaluate the significance of various clinical factors on the level of post-operative pain after ambulatory inguinal herniorrhaphy. Between January, 1996 and December, 1998, 239 ambulatory inguinal hernia repair patients were recruited. Operative techniques included nylon darn (n = 152), modified Bassini repair (n = 56), and prolene mesh hernioplasty (n = 30). Linear analogue pain scores--ranging in value from 0 to 10--were assessed by telephone interviews on the first and third post-operative days. Uni-variate and multi-variate analyses were performed to identify the significant independent determinant factors affecting the severity of post-operative pain. Clinical factors studied were age, sex, operative technique, hernia anatomy and post-operative complication(s). By uni-variate analysis, patients of age < or = 50 years and indirect inguinal hernia were associated with a significantly higher pain score on the first postoperative day 1. On post-operative day 3, patients of age < or = 50 years, with an indirect inguinal hernia and modified Bassini repair reported a significantly higher pain score. Following inguinal herniorrhaphy, multiple regression analysis showed that age was the only independent predictive factor of pain score on post-operative days 1 and 3. In conclusion, post-operative pain was not affected by surgical technique, sex, hernia anatomy and post-operative morbidity. Only age had a significant influence on the post-operative pain score following ambulatory inguinal herniorrhaphy. Therefore, the age of a patient should be taken into consideration when prescribing post-operative analgesics.

Age Factors↗
PubMed2001

Is the preferential use of ePTFE grafts in femorofemoral bypass justified?

The choice of prosthetic graft material for cross-femoral bypass has been evolving in the past two decades. Expanded polytetrafluoroethylene (ePTFE) has become our preferred graft material since 1995. However, few studies have looked into the optimal graft material in this procedure. Justification for the preferential use of ePTFE graft in lower limb revascularization remains unknown. The aim of the present study was to compare the long-term outcomes of Dacron and ePTFE grafts in femorofemoral bypass. The records of 61 consecutive patients who underwent femorofemoral bypass at the University of Hong Kong Medical Center from 1981 to 1998 were retrospectively reviewed. Dacron grafts were used in 27 patients and 34 patients had ePTFE grafts. The demographic features, patency, and limb salvage rates of the two groups of patients were compared. The 3-year primary patency rates of Dacron and ePTFE grafts were 85% (SE = 9.5%) and 66% (SE = 14.5%), respectively. The difference was not statistically significant. The limb salvage rates of Dacron and ePTFE grafts were 91% and 83% at 3 years, respectively (p = 0.27). The long-term outcomes of Dacron and ePTFE grafts in femorofemoral bypass were equivalent. The preferential use of ePTFE graft in femorofemoral bypass is not evidence based. Selection of an appropriate prosthetic graft for femorofemoral bypass should be based on the cost and its handling characteristics.

Aged↗
PubMed2001

Clinical factors influencing return to work after ambulatory inguinal herniorrhaphy in Hong Kong.

Ambulatory inguinal hernia repair is the commonest day case general surgery operation. The present study was conducted to evaluate factors influencing the contemporary pattern of convalescence following ambulatory inguinal hernia repair in Hong Kong. A total of 271 consecutive ambulatory inguinal hernia repairs were performed at a day surgery centre from December 1995 to December 1998. The convalescent period prior to resuming work was analysed by multi-variate analysis with respect to significant clinical variables. A sick leave of 3 weeks was adequate for most patients following uncomplicated ambulatory inguinal hernia repairs. Factors associated with early return to work included age </=50 years, indirect inguinal hernia and sedentary occupation. Occupation was the only independent factor affecting the duration of time off work on multi-variate analysis.

Journal Article↗
PubMed2001

Carboplatin and gemcitabine in metastatic transitional cell carcinoma of the urothelium: effective treatment of patients with poor prognostic features.

PURPOSE: To evaluate the activity and toxicity of gemcitabine and carboplatin in consecutive patients presenting with locally advanced or metastatic transitional cell carcinoma of the urothelium (TCC). PATIENTS AND METHODS: Seventeen consecutive patients referred to a single institution with locally advanced or metastatic TCC were treated with carboplatin AUC 5 on day 1 and gemcitabine 1000 mg/m2 on day 1 and 8 of a 21-day cycle. All patients were assessable for response and toxicity. Minimal eligibility criteria were used to minimize patient selection. RESULTS: Seventeen patients with measurable stage IV TCC of the urothelium were treated. The median age was 69 years (range 54-78), the median creatinine clearance was 56 ml/min (range 34-90) and 30% of patients had an ECOG performance score of two. Nine patients (53%) had visceral metastases and the majority of patients had multiple sites of metastases. There were three complete responses, seven partial responses, for an overall response rate of 58.8%. Responses were seen at all sites including the liver. One patient had a response within a previously irradiated field and three patients with prior chemotherapy had responses. Median overall survival was 10.5 months and median time to progression was 4.6 months. Toxicity was primarily haematologic with six patients having grade 3 neutropenia and six patients with grade 4 neutropenia. There were five cases of grade 3 and three cases of grade 4 thrombocytopenia. There were no episodes of febrile neutropenia and only one patient required admission for management of toxicity. Thirteen patients required dose reduction or delay due to neutropenia or thrombocytopenia. There were no treatment-related deaths. CONCLUSION: The combination of carboplatin and gemcitabine is active in metastatic transitional cell carcinoma of the urothelium with manageable toxicity in a relatively elderly group of patients with some poor prognostic features.

Aged↗
PubMed2001

Comparison of spiral CT angiography with conventional digital subtraction angiography in the evaluation of renal transplant donors: a pilot study.

Conventional digital subtraction renal arteriography (IA-DSA) has been traditionally used as the preoperative imaging modality for assessment of renal vascular anatomy for renal transplant donors. This study evaluates the potential use of spiral CT angiography in replacing IA-DSA in the preoperative assessment of this group of patients. Seven patients underwent both spiral CT angiography and IA-DSA between October 1997 and April 1998. It is concluded that spiral CT angiography can demonstrate the number, length and location of renal arteries and it is suggested that spiral CT angiography can potentially replace IA-DSA in the preoperative assessment of renal donors.

Adult↗
PubMed2001

A prospective study of early tactile stimulation after digital nerve repair.

Forty-nine patients with 65 digital nerve injuries were randomized into two groups after nerve repair. Group 1 received early tactile stimulation and Group 2 was a control group. The patients were assessed prospectively for 6 months for recovery of functional sensibility. Tactile stimulation in Group 1 was provided from 3 weeks after nerve repair with a specially designed rotating tactile stimulator and a pocket tactile stimulator. Constant two-point discrimination, moving two-point discrimination, and cutaneous pressure threshold were measured and sensibility was graded with the Medical Research Council (UK) sensibility grading. At 6 months, 68.8% of patients in Group 1 had a Medical Research Council grading of S3+ or S4 sensibility compared with 36 % in Group 2. With this prospective randomized study, the value of sensory reeducation in improving sensibility after digital nerve injury was confirmed. Starting tactile stimulation from the early postoperative period is recommended; however, use of the rotating tactile stimulator and pocket tactile stimulation need additional study.

Adult↗
PubMed2001

Efficacies of lipophilic inhibitors of dihydrofolate reductase against parasitic protozoa.

Competitive inhibitors of dihydrofolate reductase (DHFR) are used in chemotherapy or prophylaxis of many microbial pathogens, including the eukaryotic parasites Plasmodium falciparum and Toxoplasma gondii. Unfortunately, point mutations in the DHFR gene can confer resistance to inhibitors specific to these pathogens. We have developed a rapid system for testing inhibitors of DHFRs from a variety of parasites. We replaced the DHFR gene from the budding yeast Saccharomyces cerevisiae with the DHFR-coding region from humans, P. falciparum, T. gondii, Pneumocystis carinii, and bovine or human-derived Cryptosporidium parvum. We studied 84 dicyclic and tricyclic 2,4-diaminopyrimidine derivatives in this heterologous system and identified those most effective against the DHFR enzymes from each of the pathogens. Among these compounds, six tetrahydroquinazolines were effective inhibitors of every strain tested, but they also inhibited the human DHFR and were not selective for the parasites. However, two quinazolines and four tetrahydroquinazolines were both potent and selective inhibitors of the P. falciparum DHFR. These compounds show promise for development as antimalarial drugs.

Alleles↗
PubMed2001

Long-term prognosis of femoropopliteal bypass: an analysis of 349 consecutive revascularizations.

BACKGROUND: Femoropopliteal bypass is the commonest procedure for lower limb revascularization. The aim of the present study was to determine the long-term outcomes of femoropopliteal bypass and evaluate the prognostic significance of various clinical factors on the long-term results. METHODS: From 1976 to 1998, 349 consecutive primary femoropopliteal bypass operations were performed on 314 patients at the University of Hong Kong Medical Centre. Indications for operation included claudication (n = 85) and limb-threatening ischaemia (n = 264). Univariate and multivariate analyses of 14 clinical variables were undertaken to identify significant prognostic factors affecting the graft patency, limb salvage and patient survival rates. RESULTS: The overall primary patency rates of femoropopliteal bypass were 88%, 79% and 76% at 1, 3 and 5 years, respectively. Type of graft material and age of patient were independent prognostic factors of graft patency. The cumulative limb salvage rates were 90%, 86% and 86% at 1, 3 and 5 years, respectively. No clinical factor was found to be predictive of ultimate limb loss. The overall survival rates were 89%, 85% and 78% at 1, 3 and 5 years, respectively. Coronary artery disease was the main cause of late death. Gender and indication for operation were the significant predictive factors of long-term survival. CONCLUSIONS: Femoropopliteal bypass using reversed long saphenous vein provided the most durable long-term patency. Autologous saphenous vein should be the choice of vascular conduit if available. Male gender and limb-threatening ischaemia were associated with a poor survival.

Aged↗
PubMed2001

Carotid artery aneurysm secondary to cystic medial necrosis.

Carotid artery aneurysm secondary to cystic medial necrosis is a rare clinical entity. We report a 59-year-old Chinese male patient who presented with a pulsatile right neck swelling for 2 months. Partial resection of the aneurysm with primary anastomosis of the internal carotid artery was performed. Histopathological examination of the aneurysmal wall demonstrated cystic degeneration of the media with accumulation of glycosaminoglycan material, consistent with the features of cystic medial necrosis. The pathogenesis of carotid artery aneurysm secondary to cystic medial necrosis is discussed.

Aneurysm↗
PubMed2001

Laparoscopic repair of incisional hernia.

A 75-year-old man developed an incisional hernia over the upper abdomen following a wedge resection of a gastric stromal tumour in 1996. This is the first published report of a successful repair of an incisional hernia via a laparoscopic intraperitoneal on-lay technique using GORE-TEX DualMesh material in Hong Kong. Compared with conventional open repair of incisional hernia, long incisions and wound tension are avoided using the laparoscopic approach. This translates into a reduced risk of wound-related complications and facilitates recovery. In selected cases, minimally invasive surgery is a safe technique for the repair of incisional hernias.

Aged↗
PubMed2000

Patient satisfaction after ambulatory inguinal hernia repair in Hong Kong.

Ambulatory surgery was introduced to Asia in the 1990s. Acceptance of ambulatory surgery by oriental patients remains largely unknown. A telephone survey was conducted to evaluate the level of patient satisfaction following ambulatory inguinal hernia repair. A total of 157 patients (61%) completed the telephone survey. More than 90% of the respondents expressed satisfaction with regard to the pre-operative, operative and post-operative service. The majority of the respondents (>80%) preferred to undergo day surgery again in case of hernia recurrence. Our findings prove that ambulatory surgery has a high level of acceptance in Chinese patients and supports the expansion of a day surgery service in Hong Kong.

Journal Article↗
PubMed2000

Survival in patients with chronic lower extremity ischemia: a risk factor analysis.

This is a prospective cohort comparison study aiming to determine the mortality of patients with peripheral arterial occlusive disease (PAOD) and identify the risk factors affecting their survival. Data regarding demographic and biochemical risk factors, and lower limb disease severity classified by vascular laboratory criteria were collected prospectively from 665 consecutive patients presenting with symptoms of peripheral arterial occlusive disease. The effect of patient and disease risk factors on survival was analyzed by the life-table method and independent significant variables examined by a multivariate Cox regression model. The cumulative survival for all patients at 1, 3, and 5 years were 86.1, 71.2, and 55.8%, respectively, with a median survival of 72.2 months. Female sex, age, smoking, heart disease, renal disease, respiratory disease, stroke, critical ischemia, lowest anklebrachial index, no vascular reconstruction, and major amputation were associated with higher mortality. Lipid and biochemical variables were not significant determinants. Using multivariate Cox regression, age (>70), disease severity, anklebrachial index (<0.5), no vascular reconstruction, diabetes mellitus, and renal and cardiorespiratory diseases were identified as independent risk factors affecting patient survival. The survival of patients with PAOD is poor compared with the general population. Significant patient-related variables were largely coexisting diseases and advanced age, whereas the other risk factors for atherosclerosis are less influential. Disease severity may bear a direct relationship to mortality, and patients with critical ischemia have the worst prognosis. Early disease detection and timely vascular reconstruction may lead to an improvement in overall survival.

Adult↗
PubMed2000

Cumulative experience with pediatric living related liver transplantation.

PURPOSE: This study reports the authors' cumulative experience with pediatric living related orthotopic liver transplantation. METHODS: The charts of all patients who received living-related liver transplantation to study complications of transplant surgery, immunosuppression, rejection, and overall survival rate were reviewed retrospectively. RESULTS: Between November 1992 and October 1998, 30 children underwent living-related liver transplantation. Patients were between the ages of 3 months and 7 years of age (mean, 28 months). All received left lateral segmental living-related transplants. At the time of transplant, 14 of 30 patients were listed as United Network of Organ Sharing (UNOS) status 3, 11 were listed as UNOS status 2B, and 5 were listed as UNOS status 1. Indications for transplant included biliary atresia (n = 21), alpha-1-antitrypsin deficiency (n = 2), hepatitis C (n = 2), giant cell hepatitis (n = 2), hepatoblastoma (n = 1), valproic acid toxicity (n = 1), and hemangioendothelioma (n = 1). All donors were parents except for one uncle. There were no major donor complications. Minor complications included wound infection (n = 4), ventral hernia (n = 2), postoperative gastric dysmotility (n = 2), and 1 case of central line-related pneumothorax (n = 1). All but 4 recipients received primary tacrolimus immunosuppressive regimens, and the other 4 underwent conversion from cyclosporine. Initial tacrolimus therapy was begun at 0.15 mg/kg/dose PO/NG every 12 hours. Concomitant immunosuppression included methylprednisolone and mycophenolate mofetil. Fifty-three percent of patients experienced at least 1 episode of rejection, and 27% experienced multiple episodes. Immediate postoperative complications included primary nonfunction (n = 2), vascular thrombosis (n = 3), biliary leaks (n = 3), and infections (n = 17). Two patients (n = 2) required retransplantation. Complications of immunosuppressive therapy included persistent systemic hypertension (n = 6), renal tubular acidosis (n = 3), short-term hyperglycemia (n = 2), neurotoxicity (n = 2), nephrotoxicity (n = 2), food allergies (n = 8), and posttransplant lymphoproliferative disease (n = 4). All patients with PTLD were treated with immunosuppression reduction or withdrawal. Two of 4 had disease progression requiring chemotherapy. The majority of complications were treated with dose adjustments. There were 4 early deaths (13%): 1 of primary nonfunction, 2 of sepsis, and 1 of arrhythmia and renal failure. There was 1 late death of recurrent disease. Twenty-five patients (83%) are alive at 3 months to 6 years post-transplant. CONCLUSION: Living-related orthotopic liver transplantation is an effective intervention for pediatric patients with end-stage disease.

Child↗
PubMed2000

Duration of effect of botulinum toxin type A in adult patients with cervical dystonia: a retrospective chart review.

BACKGROUND: Clinical trials have established the efficacy and safety of botulinum toxin type A (BTX-A) in patients with cervical dystonia. To maintain the clinical benefits of BTX-A, injections need to be repeated whenever patients' symptoms begin to recur. OBJECTIVE: The purpose of this study was to determine, in clinical practice settings, the mean duration of effect of BTX-A in the treatment of adult patients with cervical dystonia. METHODS: A retrospective chart review was undertaken at an academic center and a private neurology practice. At each site, > or =50 patients being treated for cervical dystonia were identified and randomized for chart review. Patients had to have received the first assessable injection of BTX-A between January 1, 1998, and March 31, 1998, to coincide with the clinical availability of the most current formulation of the neurotoxin. A chart was eligible for review if the patient was aged > or =18 years, had a documented diagnosis of idiopathic cervical dystonia, was being treated with BTX-A, and had been under the continuous care of investigators from January 1, 1998, to August 31, 1999. Of the 102 patients initially identified, the first 30 from each site who met the study inclusion criteria were assessed for (1) age and sex; (2) severity of dystonia; (3) years of BTX-A use; (4) dates of first, second, third, and fourth BTX-A injections; (5) drug dose; (6) use of electromyography; (7) use of other prescribed therapies; (8) laboratory tests; and (9) adverse events. The mean interval between each visit and mean per-patient duration of effect were calculated and stratified by patient characteristics. RESULTS: The mean age of the patients was 56.4 years. Two thirds of the patients were women. Forty-one of the 60 patients (68.3%) had either moderate or severe disease, and 48 (80.0%) had experienced cervical dystonia for >5 years. The mean per-patient duration of effect across the 4 visits was 15.5 weeks (range, 12.2-24.3 weeks). The duration of effect did not differ significantly between study sites despite the differences in disease severity, drug dose, and use of adjunctive therapy. CONCLUSION: BTX-A the controls symptoms of cervical dystonia for 12 to 24 weeks, with a mean duration of effect per patient of 15.5 weeks.

Botulinum Toxins, Type A↗
PubMed2000

Population PK and PK/PD modelling of microencapsulated octreotide acetate in healthy subjects.

AIMS: To develop a population model that can describe the pharmacokinetic profile of microencapsulated octreotide acetate in healthy cholecystectomized subjects. To investigate the correlation between serum IGF-1 and octreotide concentration. METHODS: A population pharmacokinetic analysis was performed on octreotide data obtained following a single dose of 30 mg microencapsulated octreotide acetate intramuscularly. The relationship between serum IGF-1 concentration and octreotide concentration was effectively described by a population pharmacokinetic/pharmacodynamic model. RESULTS: The pharmacokinetic profile of octreotide was characterized by an initial peak of octreotide followed by a sustained-release of drug. Plateau concentration were sustained up to day 70, and gradually declined to below the detection limit by day 112. A one-compartment linear model was constructed which consisted of two absorption processes, characterized by KIR and KSR, rate constants for immediate-release and sustained-release, respectively, with first-order elimination (Ke; 1.05 h-1). The surface, unencapsulated drug was immediately absorbed into the central compartment with first-order absorption (KIR; 0.0312 h-1), while the microencapsulated drug was first released in a zero-order fashion into a depot before being absorbed into the central compartment with first-order absorption (KSR; 0.00469 h-1) during a period of tau (1680 h). Body weight and gender were important covariates for the apparent volume of distribution. The type of formulation was an important covariate for KIR but had no effect on KSR. An inhibitory Emax population pharmacokinetic/pharmacodynamic model could adequately describe the relationship between IGF-1 (expressed as percent baseline) and octreotide concentration. Baseline IGF-1 concentration was found to be a significant covariate for the baseline effect (E0). A relationship between GH concentration and octreotide concentration was not established. CONCLUSIONS: The pharmacokinetic profile of microencapsulated octreotide acetate was effectively described by the derived population model. The relationship between IGF-1 and drug concentration could be used to guide optimization of therapeutic octreotide dosage regimens.

Adult↗