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Biomedical subjects

H Lau

Publications and source records attributed to H Lau.

At least 37 records · Page 2Linked to original sources
PubMed2002

A prospective comparative study of needlescopic and conventional endoscopic extraperitoneal inguinal hernioplasty.

BACKGROUND: Needlescopic inguinal hernioplasty has been made feasible with the miniaturization of instruments and recent advances in laparoscopic surgical technique. Postoperative outcome of needlescopic totally extraperitoneal inguinal hernioplasty (TEP) has not been previously compared with that of conventional TEPs. The objective of the current study is to compare the postoperative outcomes of needlescopic and conventional TEPs. METHODS: From March 1, 2001, to December 30, 2001, a total of 30 patients underwent attempted unilateral needlescopic TEPs. Of these, 12 and 18 patients underwent ambulatory and inpatient procedures, respectively. The results were compared to those of an age-matched cohort of 30 patients who underwent either ambulatory (n = 12) or inpatient (n = 18) conventional TEPs. All data were prospectively collected and analyzed. RESULTS: Needlescopic TEPs were successfully performed in 90% of patients (n = 27). Three procedures were converted to conventional TEPs because of adhesions. Demographic features, hernia types, and mean operative times of the two groups were similar. The mean pain score upon coughing on postoperative day 1 was significantly lower in patients who underwent needlescopic TEPs than in those who had conventional TEPs. Pain scores at rest and upon coughing on days 0 to 6 were otherwise comparable between the two groups. Comparisons of the mean duration of hospitalization, postoperative morbidity, and time taken to resume normal activities showed no significant difference between the two groups. CONCLUSIONS: Needlescopic TEP is a safe technique for the repair of inguinal hernia. Postoperative recovery following needlescopic and conventional TEPs was similar. Needlescopic TEP conferred a significantly lower pain score upon coughing on the first day after operation.

Ambulatory Surgical Procedures↗
PubMed2002

Management of peritoneal tear during endoscopic extraperitoneal inguinal hernioplasty.

BACKGROUND: Peritoneal tear during endoscopic extraperitoneal inguinal hernioplasty (TEP) results in pneumoperitoneum and loss of extraperitoneal space. To avoid bowel adhesions, internal herniation, and mesh migration, closure of the peritoneal opening is preferred. The present study was conducted to evaluate the efficacy of various operative techniques for the closure of peritoneal laceration. METHODS: Between April 2000 and May 2001, 100 consecutive patients undergoing 123 TEPs were recruited for the present study. The incidence of peritoneal tear and techniques for the closure of peritoneal opening were documented. Operative time and postoperative morbidity were compared among groups for which different closure methods of peritoneal laceration were used. RESULTS: The incidence of peritoneal tear was 47%. The mean operative times of unilateral TEPs with and without peritoneal laceration were 66 min and 53 min, respectively (p<0.05). Techniques for the closure of the peritoneal opening included endoscopic stapling (n = 12), endoscopic suturing (n = 14), and pretied suture loop ligation (n = 21). The mean operative times for unilateral TEPs with endoscopic stapling, pretied suture loop ligation, and endoscopic suturing of peritoneal tear were 53, 64, and 82 min, respectively (p<0.05). Comparison of postoperative morbidity showed no significant differences among the three groups. CONCLUSION: Peritoneal tear is a frequent and challenging intraoperative event during TEP. Its occurrence significantly prolongs the length of operation. Endoscopic stapling and pretied suture loop ligation are safe and quick techniques for the closure of peritoneal tear during TEP.

Adult↗
PubMed2002

Urinary retention following endoscopic totally extraperitoneal inguinal hernioplasty.

BACKGROUND: The impact of preperitoneal mesh after endoscopic totally extraperitoneal inguinal hernioplasty (TEP) on voiding function has not been previously examined. The objectives of the present study were to evaluate the incidence of and risk factors for urinary retention following TEP. METHODS: Three hundred consecutive patients who underwent TEP between June 1999 and September 2001 were recruited. Patient records were reviewed retrospectively to identify those who developed postoperative urinary retention. For each case patient, five age-matched control patients were randomly selected. We then compared the clinical data for the case and control groups. A prospective study of uroflowmetry in patients who underwent bilateral TEP was conducted to evaluate the effect of preperitoneal mesh on voiding function. RESULTS: The overall incidence of urinary retention following TEP was 4% (n = 12). Patients who developed urinary retention stayed in hospital for a significantly longer period than the control group. No significant association was found between the clinical data and postoperative urinary retention. Bilateral TEPs were not associated with significant deterioration in uroflowmetry. CONCLUSIONS: Urinary retention is a frequent morbidity after TEP and significantly prolongs the length of hospital stay. Preperitoneal Prolene mesh did not cause outflow obstruction or alter bladder contractility. No specific clinical factors were identified that might predict postoperative urinary retention, which was probably multifactorial in causation in our patient population.

Adult↗
PubMed2002

Extrahepatic portal vein aneurysm: a case report and review of the literature.

Portal vein aneurysm is a rare clinical entity with only 42 published cases in the English literature. We present a 30-yr old woman who was incidentally diagnosed with an extrahepatic portal vein aneurysm during the investigation for dyspepsia. Expectant management with regular follow-up and surveillance imaging was adopted. This pathology is increasingly encountered with the frequent use of radiological imaging modalities in the work-up of abdominal disorders. Etiology, clinical significance and management strategies for extrahepatic portal vein aneurysms are discussed.

Adult↗
PubMed2002

Distinct regional expression of SNARE proteins in the feline oesophagus.

Abstract Soluble N-ethylmaleimide-sensitive factors attachment protein receptors (SNAREs), initially found to mediate membrane fusion, have now been shown to also bind and regulate a number of membrane ion channels in neurones and neuroendocrine cells. We recently reported that the SNARE protein SNAP-25 regulates Ca(2+)- activated (K(Ca)) and delays rectifier K(+) channels (K(V)) in oesophageal smooth muscle cells. This raised the possibility that cognate and other SNARE proteins could also be present in the oesophageal smooth muscle cell to regulate these and other functions. Circular muscle tissue sections and single freshly isolated muscle cells from the oesophageal body circular and longitudinal layers, and from lower oesophageal sphincter clasp and sling regions were studied. The subcellular location of SNAP-23, SNAP-25, syntaxins 1 to 4, and vesicle-associated membrane protein (VAMP)-2 were explored using a laser scanning confocal imaging system. Feline oesophageal smooth muscle of all regions examined demonstrated the presence of SNAP-23, SNAP-25, syntaxins 1 to 4, and VAMP-2 on the plasma membrane. The intensity of these syntaxins and SNAP-25/-23 proteins varied between the different muscle groups of the oesophagus. In some regions, some SNARE proteins were also noted in the muscle cell cytoplasm. No differential expression was found for VAMP-2. The differential expression of SNAP-25 and its regulation of K(+) channels indicate the important role of SNAP-25 in regulating the distinct membrane excitability and contractility along the smooth muscle of the oesophagus. This is further contributed by its interactions with the cognate syntaxins, which are also differentially expressed in the muscle groups of the oesophageal body and lower oesophageal sphincter (LOS). These SNARE proteins probably have other functions in the smooth muscle cell, such as regulating vesicular transport processes.

Animals↗
PubMed2002

Laparoscopic incisional hernioplasty utilising on-lay expanded polytetrafluoroethylene DualMesh: prospective study.

OBJECTIVE: To evaluate the early outcomes of laparoscopic incisional hernioplasties using on-lay GORE-TEX DualMesh. DESIGN: Prospective study. SETTING: Medical centre of a regional hospital, Hong Kong. SUBJECTS AND METHODS: Between June 2000 and October 2001, 11 consecutive patients underwent attempted laparoscopic incisional hernioplasties at the University of Hong Kong Medical Centre. A prospective collection of perioperative data and assessment of postoperative outcomes was performed. RESULTS: Laparoscopic incisional hernioplasty was successfully performed for 10 (91%) patients. One patient was converted to open repair because of extensive adhesions within the peritoneal cavity. The overall mean operative time was 107 minutes. Five (45%) patients were found to have more than one hernial defect after reduction of the hernial contents. Eight (73%) patients were discharged within 2 days after operation. Postoperative morbidities included wound bruising (n=4), seroma (n=2), and prolonged suture site pain (n=1). All postoperative morbidities resolved spontaneously without intervention. With a mean follow-up of 3 months, no early recurrence was detected. CONCLUSION: Early outcomes of laparoscopic incisional hernioplasty utilising GORE-TEX DualMesh were promising. This technique confers the advantages of minimal access surgery and allows clear identification of multiple hernial defects. Extensive adhesion, which does not allow the establishment of pneumoperitoneum, is a condition that precludes the safe performance of laparoscopic repair.

Abdominal Pain↗
PubMed2001

Transitions in laparoscopic cholecystectomy: the impact of ambulatory surgery.

BACKGROUND: Ambulatory laparoscopic cholecystectomy is a common practice in the United States, but its development remains slow in most other countries. The objective of the current study was to report the impact of ambulatory surgery on the practice of laparoscopic cholecystectomy in a major teaching hospital since the inception of the service. METHODS: The hospital database of patients who underwent cholecystectomies for benign hepatobiliary pathologies was reviewed between January 1993 and December 1999. Changes in the practice of laparoscopic cholecystectomy and the length of hospital stay were analyzed. Clinical characteristics of the ambulatory and inpatient groups were compared. RESULTS: Of 2,891 laparoscopic cholecystectomies involved in the current study, 888 (31%) were performed as day cases, and 2,003 (69%) were performed as inpatient laparoscopic cholecystectomies. The annual number of ambulatory laparoscopic cholecystectomies increased from 3 (0.6%) in 1993 to 212 (48%) in 1997. This was followed by a plateau in the next 3 years. The ambulatory group comprised a significantly higher prevalence of young women (87%) who underwent surgery mainly for biliary colic (88%). CONCLUSIONS: The current study demonstrated a net trend toward ambulatory laparoscopic cholecystectomy and a shorter length of hospital stay. Almost half of our patients with gallstone disease currently are using the ambulatory laparoscopic cholecystectomy service, with young women constituting the majority. We predict that ambulatory laparoscopic cholecystectomy heralds the wave of the future, and our experience may serve as a blueprint for other institutions wishing to embark on this journey.

Adult↗
PubMed2001

A prospective trial of analgesia following endoscopic totally extraperitoneal (TEP) inguinal hernioplasty.

BACKGROUND: The extraperitoneal instillation of bupivacaine has been shown to be superior to the use of a placebo for postoperative analgesia following endoscopic extraperitoneal inguinal hernioplasty. The objective of the present study was to compare the efficacy of postoperative analgesia by local wound infiltration to instillation of the extraperitoneal space with bupivacaine. METHODS: Between 1 September 1999 and 2 June 2000, a total of 100 patients who underwent unilateral endoscopic extraperitoneal inguinal hernioplasties were recruited to receive either local wound infiltration with 10 ml of 0.5% bupivacaine (group I, n = 50) or instillation of the extraperitoneal space with 40 ml of 0.25% bupivacaine after mesh placement (group II, n = 50). Daily postoperative pain was assessed by visual analogue pain score on a scale from 0 to 10 at rest and upon coughing. Total amount of oral analgesic consumed and clinical outcomes of the two groups were compared. RESULTS: A comparison of daily pain scores of the two groups at rest and upon coughing showed no significant difference (p = ns). The mean number of oral analgesic tablets consumed were 3.2 +/- 0.5 (SEM) and 3.3 +/- 0.5 (SEM) in groups I and II, respectively (p = ns). During follow-up, asympatomatic groin collections were more common in group II (n = 4) than group I (n = 2) (p = ns). CONCLUSIONS: Compared to local wound infiltration with bupivacaine, the extraperitoneal instillation of bupivacaine did not bestow any additional analgesic benefits. Therefore, the routine infiltration of skin incisions with bupivacaine is recommended after endoscopic extraperitoneal inguinal hernioplasty.

Adult↗
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

Pharmacotherapies for attention-deficit/hyperactivity disorder: expected-cost analysis.

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is a common childhood neurobehavioral disorder characterized by inattention, hyperactivity, and impulsivity. Prevalence estimates in elementary school children generally range from 3% to 8%. ADHD is frequently treated with psychostimulant medications, which have been shown to improve both cognitive and behavioral outcomes for most children. OBJECTIVE: The goal of this study was to estimate the total expected costs for the treatment and management of school-age children with ADHD using 6 commonly prescribed pharmacotherapies: methylphenidate immediate-release/extended-release (MPH IR/ER), methylphenidate immediate-release (MPH IR), Metadate CD (branded MPH IR/ER), Concerta (branded MPH ER), Ritalin (branded MPH IR), and Adderall (a combination of dextroamphetamine and amphetamine salts). METHODS: A literature review and clinical assessment using a 27-question survey instrument were used to capture information on the clinical characteristics of ADHD, including common treatment regimens, clinical management of patients, pathways of care, and components of care. A meta-analysis provided response rates for 3 commonly used pharmacotherapies: Metadate CD, MPH IR, and Adderall. Information from the clinical assessment and the meta-analysis were used to populate a decision-analytic model to compute total expected cost for each comparator. RESULTS: The average total annual expected cost per patient was $1,487 for Metadate CD, $1,631 for Concerta. $1,792 for MPH IR/ER, $1,845 for MPH IR, $2,080 for Ritalin, and $2,232 for Adderall. CONCLUSIONS: Metadate CD had the lowest total expected cost and Adderall had the highest total expected cost among the ADHD pharmacotherapies evaluated. The differences were attributable to differences in drug-acquisition costs and the need for in-school dosing of twice-daily and thrice-daily medications.

Amphetamines↗
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↗