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Featured researches published by Wk Yuen.


Annals of Surgery | 1999

Hepatectomy for hepatocellular carcinoma: toward zero hospital deaths.

Sheung Tat Fan; Chung Mau Lo; Chi-Leung Liu; Chi-Ming Lam; Wk Yuen; Chun Yeung; John Wong

OBJECTIVE The authors report on the surgical techniques and protocol for perioperative care that have yielded a zero hospital mortality rate in 110 consecutive patients undergoing hepatectomy for hepatocellular carcinoma (HCC). The hepatectomy results are analyzed with the aim of further reducing the postoperative morbidity rate. SUMMARY BACKGROUND DATA In recent years, hepatectomy has been performed with a mortality rate of <10% in patients with HCC, but a zero hospital mortality rate in a large patient series has never been reported. At Queen Mary Hospital, Hong Kong, the surgical techniques and perioperative management in hepatectomy for HCC have evolved yearly into a final standardized protocol that reduced the hospital mortality rate from 28% in 1989 to 0% in 1996 and 1997. METHODS Surgical techniques were designed to reduce intraoperative blood loss, blood transfusion, and ischemic injury to the liver remnant in hepatectomy. Postoperative care was focused on preservation and promotion of liver function by providing adequate tissue oxygenation and immediate postoperative nutritional support that consisted of branched-chain amino acid-enriched solution, low-dose dextrose, medium-chain triglycerides, and phosphate. The pre-, intra-, and postoperative data were collected prospectively and analyzed each year to assess the influence of the evolving surgical techniques and perioperative care on outcome. RESULTS Of 330 patients undergoing hepatectomy for HCC, underlying cirrhosis and chronic hepatitis were present in 161 (49%) and 108 (33%) patients, respectively. There were no significant changes in the patient characteristics throughout the 9-year period, but there were significant reductions in intraoperative blood loss and blood transfusion requirements. From 1994 to 1997, the median blood transfusion requirement was 0 ml, and 64% of the patients did not require a blood transfusion. The postoperative morbidity rate remained the same throughout the study period. Complications in the patients operated on during 1996 and 1997 were primarily wound infections; the potentially fatal complications seen in the early years, such as subphrenic sepsis, biliary leakage, and hepatic coma, were absent. By univariate analysis, the volume of blood loss, volume of blood transfusions, and operation time were correlated positively with postoperative morbidity rates in 1996 and 1997. Stepwise logistic regression analysis revealed that the operation time was the only parameter that correlated significantly with the postoperative morbidity rate. CONCLUSION With appropriate surgical techniques and perioperative management to preserve function of the liver remnant, hepatectomy for HCC can be performed without hospital deaths. To improve surgical outcome further, strategies to reduce the operation time are being investigated.


Surgical Endoscopy and Other Interventional Techniques | 2006

Early versus delayed-interval laparoscopic cholecystectomy for acute cholecystitis : A metaanalysis

H Lau; Chung-Yau Lo; Ng Patil; Wk Yuen

BackgroundEarly laparoscopic cholecystectomy has been advocated for the management of acute cholecystitis, but little evidence exists to support the superiority of this approach over delayed-interval operation. The current systematic review was undertaken to compare the outcomes and efficacy between early and delayed-interval laparoscopic cholecystectomy for acute cholecystitis in an evidence-based approach using metaanalytical techniques.MethodsA search of electronic databases, including MEDLINE and EMBASE, was conducted to identify relevant articles published between January 1988 and June 2004. Only randomized or quasi-randomized prospective clinical trials in the English language comparing the outcomes of early and delayed-interval laparoscopic cholecystectomy for acute cholecystitis were recruited. Both qualitative and quantitative statistical analyses were performed. The effect size of outcome parameters was estimated by odds ratio or weighted mean difference where feasible and appropriate.ResultsA total of four clinical trials comprising 504 patients met the inclusion criteria. Failure of conservative treatment requiring emergency cholecystectomy occurred for 43 patients (23%) in the delayed group. Metaanalyses demonstrated a significantly shortened total length of hospital stay in the early group (weighted mean difference, −1.12; 95% confidence interval [CI], −1.42 to −0.99; p < 0.001). Pooled estimates did not show any significant differences between the two approaches in terms of operation time, conversion rate, overall complication rate, incidence of bile leakage, and intraabdominal collection.ConclusionsThe safety and efficacy of early and delayed-interval laparoscopic cholecystectomy for acute cholecystitis were comparable. Because evidence suggested that early laparoscopic cholecystectomy reduced the total length of hospital stay and the risk of readmissions attributable to recurrent acute cholecystitis, it is therefore a more cost-effective approach for the management of acute cholecystitis.


Surgical Endoscopy and Other Interventional Techniques | 2002

Learning curve for unilateral endoscopic totally extraperitoneal (TEP) inguinal hernioplasty.

H Lau; Ng Patil; Wk Yuen; F. Lee

Background: Performance of endoscopic totally extraperitoneal inguinal hernioplasty (TEP) requires specialized anatomical knowledge and surgical dexterity. The present study was undertaken to evaluate the learning curve for a general surgeon to master the technique of TEP in the absence of an experienced supervisor. Methods: A retrospective analysis of the first 120 consecutive unilateral TEPs was performed. Medical records were reviewed to evaluate demographic features, perioperative outcome, and follow-up results. The study population was divided into six consecutive groups of 20 patients. Clinical data were compared among the groups to evaluate the impact of operative experience on perioperative outcome. Results: Operative time was the only clinical parameter that showed significant improvement with experience; it reached a plateau value of <1 h after the fourth group. Conversions to transabdominal and open approaches were required in only one patient in groups 1 and 6, respectively. Comparison of demographic features, hernia types, postoperative morbidity rates, length of hospital stay, and number of days to resume normal activities showed no significant differences among the groups. All complications were minor and resolved uneventfully. No recurrence was detected during follow-up. Conclusions: The learning curve for unilateral TEP by a general surgeon peaked after performing 80 procedures. In most cases, unilateral TEP can be accomplished safely within 1 h. Even during the learning process, TEP carries a low morbidity and conversion rate.


Surgical Endoscopy and Other Interventional Techniques | 2006

Day-case endoscopic totally extraperitoneal inguinal hernioplasty versus open Lichtenstein hernioplasty for unilateral primary inguinal hernia in males: a randomized trial.

H Lau; Ng Patil; Wk Yuen

BackgroundEndoscopic totally extraperitoneal inguinal hernioplasty (TEP) is an accepted technique for the repair of recurrent and bilateral inguinal hernia, but its role in the management of unilateral primary inguinal hernia remains controversial. The current randomized trial was undertaken to compare the postoperative and 1-year outcomes of day-case TEP and open Lichtenstein hernioplasty for unilateral primary inguinal hernia in males.MethodsFrom January 2002 to January 2004, a total of 200 male patients were randomized to undergo either day-case unilateral TEP or open Lichtenstein hernioplasty under general anesthesia. The primary outcome measures included postoperative pain score, time until return to work, incidence of chronic groin pain, and recurrence rate 1 year after the operation.ResultsAll TEP procedures were successfully performed without conversion. The mean operation time for TEP (50±13.2 min) was significantly shorter than for open Lichtenstein hernioplasty (58 ± 17.6 min) (p < 0.001). The pain score at rest was significantly lower in the TEP group than in the open group on postoperative days 0, 1, 4, 5, and 6. On the average, the patients returned to work 8.6 days after TEP and 14 days after Lichtenstein hernioplasty (p = 0.006). Postoperative recovery and morbidity rates were otherwise comparable between the two groups. The incidence of chronic groin pain 1 year after TEP (9.9%) was significantly lower than after open surgery (21.7%) (p = 0.032). None of the patients in either group showed recurrence at the last follow-up assessment.ConclusionsDay-case TEP was superior to open Lichtenstein hernioplasty for the repair of unilateral primary inguinal hernia in males. The benefits of day-case TEP included less postoperative pain, a faster return to work, and a lower incidence of chronic groin pain.


British Journal of Surgery | 2011

Outcome after partial hepatectomy for hepatocellular cancer within the Milan criteria.

St Fan; Rtp Poon; Chun Yeung; C. M. Lam; Cm Lo; Wk Yuen; Ktp Ng; Chi-Leung Liu; Sc Chan

There is a trend to offer liver transplantation to patients with hepatocellular carcinoma (HCC) with tumour status within the Milan criteria but with preserved liver function. This study aimed to evaluate the outcome of such patients following partial hepatectomy as primary treatment.


Surgical Endoscopy and Other Interventional Techniques | 2003

Prevalence and severity of chronic groin pain after endoscopic totally extraperitoneal inguinal hernioplasty

H Lau; Ng Patil; Wk Yuen; F. Lee

Background: Chronic groin pain after open inguinal hernia repair is a common long-term morbidity, but its incidence after endoscopic totally extraperitoneal inguinal hernioplasty (TEP) has not been studied in detail. The objective of this study was to evaluate the prevalence and severity of chronic groin pain after TEP. Methods: Between June 1999 and September 2001, 313 consecutive patients who underwent TEP at our institution were recruited. To evaluate the incidence and severity of chronic pain, a cross-sectional telephone survey using a standardized questionnaire was conducted by a research assistant. Clinical data between the chronic pain group and the pain-free group were compared to identify any clinical factors that had a significant association with the subsequent development of chronic groin pain. Results: The prevalence of chronic groin pain was 9.2% (n = 24). The severity of the pain was mild (n = 18), moderate (n = 5), or severe (n = 1). In more than half of the patients, the groin pain occurred less often than once a month and its duration did not exceed 1 min. Only one patient reported an impairment of functional activities as a result of the pain. Multivariate analyses identified a significant association between a high postoperative pain score on coughing on postoperative day 6 and the subsequent development of groin pain. Conclusions: The prevalence of chronic groin pain in patients after TEP was low. The pain was mostly mild and transient without associated sensory symptoms. The occurrence of pain had a negligible impact on daily activities.


Surgical Endoscopy and Other Interventional Techniques | 2003

Management of peritoneal tear during endoscopic extraperitoneal inguinal hernioplasty

H Lau; Ng Patil; Wk Yuen; F. Lee

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.


Surgical Endoscopy and Other Interventional Techniques | 2002

Urinary retention following endoscopic totally extraperitoneal inguinal hernioplasty.

H Lau; Ng Patil; Wk Yuen; F. Lee

AbstractsBackground: 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.


Surgical Endoscopy and Other Interventional Techniques | 2002

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

H Lau; Ng Patil; F. Lee; Wk Yuen

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.


Surgical Endoscopy and Other Interventional Techniques | 2007

Management of herniated retroperitoneal adipose tissue during endoscopic extraperitoneal inguinal hernioplasty

H Lau; F. Loong; Wk Yuen; Ng Patil

BackgroundHerniation of retroperitoneal adipose tissue into the inguinal canal, traditionally called cord lipoma, is frequently encountered during endoscopic totally extraperitoneal inguinal hernioplasty (TEP). Failure to recognize and manage the cord lipoma accounted for 30%–50% of recurrent hernia after TEP. The present study was undertaken to evaluate the incidence, risk factors, and management of herniated retroperitoneal adipose tissue during TEP.MethodsBetween December 2002 and November 2005 all patients who underwent TEP were prospectively evaluated for the presence of cord lipoma. Clinical outcomes of patients who were treated for their cord lipoma were compared with those without cord lipoma. Risk factors for the occurrence of cord lipoma were also examined.ResultsA total of 498 patients underwent unilateral (n = 386) or bilateral (n = 112) TEP. The overall incidence of cord lipoma was 26.5% (n = 132). A higher body weight, a higher body mass index, and a larger hernial defect were significantly associated with the presence of cord lipoma. Most of the cord lipoma cases (n = 119) were reduced to pelvic peritoneal reflection line after division of the feeding vessels from surrounding structures, while the rest (n = 13) were resected. Early postoperative outcomes, including pain score, morbidities, and other recovery variables, showed no significant difference between the two groups. No recurrence occurred in the present series.ConclusionsHerniation of retroperitoneal adipose tissue into the inguinal canal occurred in more than one-fifth of the patients with inguinal hernia. Awareness and appropriate treatment of the cord lipoma helped to reduce the risk of recurrence. During TEP, the internal inguinal ring and inguinal canal should always be cleared of any herniated adipose tissue by either reduction or resection. This clearing posed no adverse effects on postoperative outcome.

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Ng Patil

University of Hong Kong

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H Lau

University of Hong Kong

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Chun Yeung

University of Hong Kong

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Hung Lau

University of Hong Kong

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St Fan

University of Hong Kong

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F. Lee

University of Hong Kong

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Chi-Ming Lam

University of Hong Kong

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Chung Mau Lo

University of Hong Kong

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