Philip Wai Yan Chiu | The Chinese University of Hong Kong (original) (raw)

Papers by Philip Wai Yan Chiu

Research paper thumbnail of 718 PerOral Endoscopic Myotomy for the Treatment of Achalasia: Prospective International Multi Center Study

Data Revues 00165107 V75i4ss S0016510712018329, May 17, 2012

coordinating site, to ensure uniformity and protocol compliance. The first 4 RFA cases were super... more coordinating site, to ensure uniformity and protocol compliance. The first 4 RFA cases were supervised on-site by the principal investigator, a study monitor attended all treatments and first follow-up (FU) at each site. Central pathology review of all ER/biopsies was performed at the coordinating site. Patients with BEՅ12cm and HGD/EC were included. Visible lesions were removed with ER, followed by biopsy to exclude residual EC. Subsequent RFA was scheduled every 2-3 months until clearance of BE achieved, with max. 5 RFA sessions allowed. Escape treatment was permitted for residual BE after RFA (APC for islands Ͻ5mm, ER for islands Ͼ5mm or suspicious lesions). FU endoscopy was scheduled at 3-9 mo after the last treatment, with biopsies (4Q/2cm) from neosquamous epithelium (NSE) and Ͻ5mm distal to the neo-Z-line (gastric cardia). Endpoints were eradication of neoplasia (CR-neo) and intestinal metaplasia (CR-IM); and durability of CR-neo/CR-IM at 9-mo FU. Results: 132 patients (107M, mean 65yrs, median BE C3M6) underwent ER (en-bloc nϭ63,piecemeal nϭ56) with worst pathology: EC (nϭ78), HGD (nϭ31), LGD (nϭ7), no dysplasia (nϭ3); or no-ER (nϭ13). Worst grade post-ER/pre-RFA: HGD (nϭ36), LGD (nϭ45), no dysplasia (nϭ51). By Dec-11, 5 pts were still under treatment, 7 discontinued due to unrelated causes. After a median of 3 (3-4) treatment sessions, including ER (nϭ12) or APC (nϭ14), per intention-totreat analysis (counting drop-outs as failures) CR-neo was reached in 115/127 (91%), CR-IM in 112/127 (88%) pts. In a per-protocol analysis (censoring all drop-outs) CR-neo/CR-IM were achieved in 96% and 93% respectively. Of 5 CRneo failures, 1 was referred for surgery (T1sm1G2 cancer), 4 pts are being treated endoscopically (out-of-protocol). CR-neo was maintained in 99/100 pts reaching the 9-mo endpoint; in 1 pt a small island with focal HGD was treated with APC. IM upon single biopsy recurred in 1 pt without visible BE (1,974 NSE biopsies analyzed); focal non-dysplastic IM of the cardia was detected in 11 pts at single FU; none of which required re-treatment. Conclusion: This is the largest prospective multicenter trial on RFA combined with ER for treatment of HGD/EC in BE. Our outcomes suggest that this combined approach is highly effective and durable for eradication of neoplasia in the majority of patients.

Research paper thumbnail of Review: Palliative gastrectomy for stage IV carcinoma of stomach

Annals of the College of Surgeons Hong Kong, 2002

Currently, there is still controversy on the issue of palliative gastrectomy for patients with ad... more Currently, there is still controversy on the issue of palliative gastrectomy for patients with advanced carcinoma of stomach in terms of safety and its benefits. From the data available in the literature, palliative gastrectomy seems to be associated with a better survival rate, better relief of symptoms and similar rates of perioperative morbidity and mortality when compared with laparotomy with or without gastrojejunostomy. However, all these studies are retrospective comparative studies or series that carried significant biases. This makes interpretation of the outcome difficult. A selective approach is advocated as palliative gastrectomy carries significant risks.

Research paper thumbnail of Chilaiditi's syndrome: A nonemergent cause of “free gas under diaphragm”

The American Journal of Surgery, 2009

A 52-year-old woman had a chest radiograph performed for dysphagia. Apart from the related esopha... more A 52-year-old woman had a chest radiograph performed for dysphagia. Apart from the related esophageal abnormality, another striking feature was noted: free gas under the diaphragm. The patient, however, complained of no other gastrointestinal symptom and showed no sign of peritonism.

Research paper thumbnail of A case-controlled comparison of single-site access versus conventional three-port laparoscopic appendectomy

Surgical Endoscopy, 2010

The aim of this study was to compare patients who underwent single-site access laparoscopic appen... more The aim of this study was to compare patients who underwent single-site access laparoscopic appendectomy (SSALA) to those who underwent conventional three-port laparoscopic appendectomy (TPLA) in a case-controlled manner. Consecutive patients who underwent SSALA for suspected acute appendicitis between April and September 2009 were retrospectively compared to those who underwent TPLA between January and December 2008 in a case-controlled manner. The patients were matched for age, gender, and pathological findings. The main outcome measurements included postoperative recovery, morbidities, and mortalities. During the study period, a total of 30 patients underwent SSALA and these were matched with 60 TPLA patients. There were no significant differences in the mean operative time, hospital stay, and 30-day morbidity rate between the two groups. None of the patients required conversion. Two patients with significant contamination and abscess collection noted during SSALA required a relaparotomy for peritoneal lavage and adhesiolysis due to prolonged ileus. SSALA is feasible and the perioperative outcome was comparable to that of TPLA. However, future prospective studies will need to evaluate whether SSALA can adequately tackle patients with significant peritoneal contamination.

Research paper thumbnail of Endoscopic submucosal dissection of a broad-based rectal polyp

Research paper thumbnail of Laparoendoscopic single-site surgery cholecystectomy using a novel retraction device

Research paper thumbnail of Timing of laparoscopic cholecystectomy in acute cholecystitis: Any controversy?

Surgical Practice, 2012

Objective: The timing of laparoscopic cholecystectomy for acute cholecystitis remains controversi... more Objective: The timing of laparoscopic cholecystectomy for acute cholecystitis remains controversial. This article reviews the latest evidence for the timing of laparoscopic cholecystectomy in the management of acute cholecystitis. Methodology: Trials comparing early laparoscopic cholecystectomy (ELC; carried out within 1 week of onset of symptoms) versus delayed laparoscopic cholecystectomy (DLC; carried out at least 6 weeks after symptoms settled) for acute cholecystitis were identified from Ovid Medline, Cochrane Library and PubMed database. Only meta-analyses and randomized clinical trials were reviewed. Results: A total of seven prospective randomized trials including 670 patients and four meta-analyses were reviewed. ELC was superior to DLC in terms of a shorter hospital stay without any significant difference in perioperative mortality and morbidity. Conclusions: Current evidence supports ELC as the preferred treatment strategy for acute cholecystitis. It allows a shorter hospital stay, but shares similar operative morbidity, mortality and conversion rate as DLC.

Research paper thumbnail of Robotic-assisted thoracoscopic enucleation of esophageal leiomyoma

Journal of Robotic Surgery, 2011

Minimally invasive approaches to esophageal leiomyoma, including thoracoscopic and laparoscopic e... more Minimally invasive approaches to esophageal leiomyoma, including thoracoscopic and laparoscopic enucleation, have been shown to have better postoperative recovery compared with thoracotomy approach. We present a case of robotic-assisted thoracoscopic enucleation of esophageal leiomyoma using the da Vinci Ò S system.

Research paper thumbnail of Trangastric Endoscopic Gastrojejunostomy (TEGJ) - A Feasibility Study in Porcine Model

Gastrointestinal Endoscopy, 2009

Research paper thumbnail of The Prediction of Mortality in Bleeding Peptic Ulcers Treated with Therapeutic Endoscopy - Lesson Learnt from 3000 Patients

Gastrointestinal Endoscopy, 2006

This article has an accompanying continuing medical education activity on page 253. Learning Obje... more This article has an accompanying continuing medical education activity on page 253. Learning Objective-Identify factors associated with mortality in patients with bleeding peptic ulcer treated with therapeutic endoscopy. of patients with bleeding peptic ulcers, mortality is still 10%. This study aimed to identify predictive factors and to develop a prediction model for mortality among patients with bleeding peptic ulcers. Methods: Consecutive patients with endoscopic stigmata of active bleeding, visible vessels, or adherent clots were recruited, and risk factors for mortality were identified in this deprivation cohort by using multiple stepwise logistic regression. A prediction model was then built on the basis of these factors and validated in the evaluation cohort. Results: From 1993 to 2003, 3220 patients with bleeding peptic ulcers were treated. Two hundred eighty-four of the patients developed rebleeding (8.8%); emergency surgery was performed on 47 of these patients, whereas others were managed with endoscopic retreatment. Two hundred twenty-nine of these sustained in-hospital death (7.1%). In patients older than 70 years, presence of comorbidity, more than 1 listed comorbidity, hematemesis on presentation, systolic blood pressure below 100 mm Hg, in-hospital bleeding, rebleeding, and need for surgery were significant predictors for mortality. Helicobacter pylori-related ulcers had lower risk of mortality. The receiver operating characteristic curve comparing the prediction of mortality with actual mortality showed an area under the curve of 0.842. From 2004 to 2006, data were collected prospectively from a second cohort of patients with bleeding peptic ulcers, and mortality was predicted by using the model developed. The receiver operating characteristic curve showed an area under the curve of 0.729.

Research paper thumbnail of Radiofrequency Ablation for Benign Aldosterone-Producing Adenoma

Annals of Surgery, 2010

To evaluate the safety and efficacy of radiofrequency ablation (RFA) in treating primary aldoster... more To evaluate the safety and efficacy of radiofrequency ablation (RFA) in treating primary aldosteronism (PA) due to aldosterone-producing adenoma (APA). Radiofrequency ablation is an established technique for treating malignant solid organ neoplasm. Its application on benign functional adrenal adenoma has never been prospectively described. We prospectively evaluated a patient cohort with computed tomography (CT)-guided percutaneous RFA performed on functional APA of size 4 cm or less. Treatment success was defined as complete tumor ablation on follow-up CT scan plus normalization of serum aldosterone-to-renin ratio (ARR) at 3 to 6 months after RFA. Salvage laparoscopic adrenalectomy was offered to patients who had failed RFA and remained hypertensive. Between August 2004 and August 2008, 28 patients were referred for the procedure. Radiofrequency ablation was not performed on 4 APA because of their close proximity to major vascular structures. Twenty-four patients (11 men and 13 women) with a median age of 51.5 (range = 34-63) years underwent RFA for 11 right and 13 left APA. The median tumor diameter was 16.0 (range = 4.0-25.0) mm. There was no periprocedure hypertensive crisis or major morbidity or mortality. Minor complications occurred in 4 patients (16.7%), including 1 small pneumothorax and 3 retroperitoneal hematomas (< 3 cm), which all resolved on conservative treatment. At 3 to 6 months of follow-up, CT scan showed complete tumor ablation in all patients (100%). Primary aldosteronism was biochemically resolved in 23 patients (95.8%). Salvage adrenalectomy was not performed in the single failed patient, as she remained normotensive on repeated follow-up. The overall success rate of RFA was 95.8%. Computed tomography-guided percutaneous RFA is a safe and efficacious alternative to laparoscopic adrenalectomy in treating patients with PA due to small APA.

Research paper thumbnail of Robotic D2 subtotal gastrectomy technique for gastric cancer

Research paper thumbnail of Clinical observation of the effect of CO 2 pneumoperitoneum on haemorrheology

Annals of the College of Surgeons of Hong Kong, 2000

Research paper thumbnail of Combination of a cyclo-oxygenase-2 inhibitor and a proton-pump inhibitor for prevention of recurrent ulcer bleeding in patients at very high risk: a double-blind, randomised trial

The Lancet, 2007

Background Guidelines on pain management recommend that patients at risk of ulcers receive either... more Background Guidelines on pain management recommend that patients at risk of ulcers receive either a cyclo-oxygenase (COX 2) inhibitor or a non-steroidal anti-infl ammatory drug (NSAID) with a proton-pump inhibitor (PPI). These two treatments have similar eff ectiveness, but they are insuffi cient for protection of patients at very high risk for ulcer bleeding. We aimed to test the hypothesis that in patients with previous ulcer bleeding induced by non-selective NSAIDs, combined treatment with the COX 2 inhibitor celecoxib and the PPI esomeprazole would be better than celecoxib alone for prevention of recurrent ulcer bleeding.

Research paper thumbnail of Natural orifices transluminal endoscopic surgery: Current development and future implications

Surgical Practice, 2010

The concept of natural orifices transluminal endoscopic surgery (NOTES) started in 2000 when tran... more The concept of natural orifices transluminal endoscopic surgery (NOTES) started in 2000 when transgastric peritoneoscopy was experimental. Although numerous surgical procedures had been performed successfully in animal models, the application of NOTES in humans was limited. The main obstacles to the performance of NOTES in humans included the security of closing the gastrointestinal (GI) access site, the lack of a stable multi-tasking platform and prospective clinical studies. The present article reviews the current developments in the field of NOTES with special focus on developments in the closure of GI access, a multi-tasking platform and the potential future applications of NOTES.

Research paper thumbnail of Perigastric lymph node metastasis does not affect the survival of squamous cell carcinoma of the oesophagus treated with two-field oesophagectomy

Surgical Practice, 2007

There are some discrepancies as to the prognostic value of perigastric lymph node (LN) metastasis... more There are some discrepancies as to the prognostic value of perigastric lymph node (LN) metastasis in the survival of squamous oesophageal carcinoma. The present study aimed to compare survival following standard oesophagectomy in the treatment of squamous oesophageal carcinoma with or without perigastric abdominal LN metastasis. Methods: From 1998 to 2003, 17 patients with squamous cell carcinoma of the mid or lower oesophagus who had abdominal LN metastasis upon pathological examination underwent Ivor Lewis oesophagectomy. They did not receive further adjuvant therapy. The clinical outcomes of this cohort were compared to a control of 34 patients of similar age, gender and T staging who had no perigastric nodal diseases upon oesophagectomy. Results: There was no significant difference between the two groups in terms of the demographics, tumour size, differentiation of the tumour, duration of operation, volume of blood loss, and the type of oesophagectomy. The cumulative 3-year survival rate was similar between those with abdominal LN metastasis or those without abdominal LN metastasis (52.9% vs 47.1%; log-rank test P = 0.61).There was also no significant difference in the rates of recurrence between the two groups (58.8% vs 58.8%; P = 0.1). Conclusions: Perigastric LN metastasis over the lesser curvature, left gastric artery and pericardial regions does not affect the survival of patients with squamous cell carcinoma of the oesophagus treated by two-field oesophagectomy.

Research paper thumbnail of Randomized comparative trial of a novel one-step needle sphincterotome versus direct incision and balloon dilation used to create gastrotomies for natural orifice translumenal endoscopic surgery (NOTES) in the porcine model

Surgical Endoscopy, 2011

This study aimed to assess the feasibility, safety, and efficacy of a prototype device (the one-s... more This study aimed to assess the feasibility, safety, and efficacy of a prototype device (the one-step needle sphincterotome) versus direct incision and balloon dilation for creating transgastric access to the peritoneal cavity in a porcine model. In five swine, 24 gastrotomies were created using direct incision followed by balloon dilation (group A) or by the one-step needle sphincterotome (group B) in an in vivo nonsurvival model. The one-step needle sphincterotome is a novel instrument comprising two components including a retractable needleknife and a pull-type sphincterotome on the same instrument shaft, reducing the need to exchange instruments. The 24 gastrotomies created in the five swine all were successful. The mean time required for creation of a gastrotomy was 613.08 ± 289.64 s in group A and 310.58 ± 137.39 s in group B. The total procedural time was 830.42 ± 296.17 s in group A and 529 ± 143.97 s in group B. Both were significantly shorter in the prototype device group (P = 0.002). The mean length of gastrotomy, mean number of clips required for closure, and mean overall closure time were not significantly different. One swine from each group suffered morbidities and another experienced mortality. The one-step needle sphincterotome hastened the creation of gastrotomies for natural orifice translumenal endoscopic surgery (NOTES). The gastrotomies created by both procedures were effective means of gaining peritoneal access, and neither method demonstrated superiority in expediting closure. However, the initial blind transgastric incision by a needleknife may be associated with a risk of injuring surrounding structures.

Research paper thumbnail of Laparoscopic totally extraperitoneal inguinal hernia repair: lessons learned from 3,100 hernia repairs over 15 years

Surgical Endoscopy, 2009

... Between June1990 and May 2005, 2,356 patients under-went laparoscopic hernia repair in our in... more ... Between June1990 and May 2005, 2,356 patients under-went laparoscopic hernia repair in our institute. ... Pawanindra L, Kajla RK, Chander J et al (2003) Randomized controlled study of laparoscopic total extra-peritoneal versus open Lichtenstein inguinal hernia repair. ...

Research paper thumbnail of A case of nonampullary duodenal adenoma treated by endoscopic submucosal dissection (with video)

Gastrointestinal Endoscopy, 2010

A 73-year-old man with a history of acute pancreatitis in 2007 presented with epigastric pain of ... more A 73-year-old man with a history of acute pancreatitis in 2007 presented with epigastric pain of a few months' duration. Upper endoscopy revealed a 1.5-cm sessile polypoid lesion in the first part of the inferior wall of the duodenum, and narrow-band imaging-magnifying endoscopy revealed irregular pits with a tortuous subepithelial capillary network . A biopsy confirmed this lesion to be a villous adenoma with mild dysplasia. EUS revealed that this lesion was limited to the mucosa, and endoscopic submucosal dissection (ESD) was performed by using the Hook Knife and the Triangle Tip Knife (Olympus Co Ltd, Tokyo, Japan) (Video 1, available online at www.giejournal.org). The operating time was 50 minutes. A small perforation was encountered during the ESD procedure that was closed with endoclips (EZ 90 clips; Olympus Co Ltd) . After the procedure, 20 mg of esomeprazole administered intravenously every 12 hours was prescribed, and the patient was discharged 7 days after the procedure. Pathology confirmed the sessile polyp to be a tubular adenoma with focal epithelial dysplasia and no invasion to the submucosa. The resected margins were clear, and follow-up endoscopy 12 months after the ESD showed no recurrence.

Research paper thumbnail of The Prediction of Recurrent Bleeding Leading to Surgery or Death After Therapeutic Endoscopy and Adjunctive Use of Intravenous High Dose Omeprazole Infusion for Bleeding Peptic Ulcers

Gastrointestinal Endoscopy, 2005

Research paper thumbnail of 718 PerOral Endoscopic Myotomy for the Treatment of Achalasia: Prospective International Multi Center Study

Data Revues 00165107 V75i4ss S0016510712018329, May 17, 2012

coordinating site, to ensure uniformity and protocol compliance. The first 4 RFA cases were super... more coordinating site, to ensure uniformity and protocol compliance. The first 4 RFA cases were supervised on-site by the principal investigator, a study monitor attended all treatments and first follow-up (FU) at each site. Central pathology review of all ER/biopsies was performed at the coordinating site. Patients with BEՅ12cm and HGD/EC were included. Visible lesions were removed with ER, followed by biopsy to exclude residual EC. Subsequent RFA was scheduled every 2-3 months until clearance of BE achieved, with max. 5 RFA sessions allowed. Escape treatment was permitted for residual BE after RFA (APC for islands Ͻ5mm, ER for islands Ͼ5mm or suspicious lesions). FU endoscopy was scheduled at 3-9 mo after the last treatment, with biopsies (4Q/2cm) from neosquamous epithelium (NSE) and Ͻ5mm distal to the neo-Z-line (gastric cardia). Endpoints were eradication of neoplasia (CR-neo) and intestinal metaplasia (CR-IM); and durability of CR-neo/CR-IM at 9-mo FU. Results: 132 patients (107M, mean 65yrs, median BE C3M6) underwent ER (en-bloc nϭ63,piecemeal nϭ56) with worst pathology: EC (nϭ78), HGD (nϭ31), LGD (nϭ7), no dysplasia (nϭ3); or no-ER (nϭ13). Worst grade post-ER/pre-RFA: HGD (nϭ36), LGD (nϭ45), no dysplasia (nϭ51). By Dec-11, 5 pts were still under treatment, 7 discontinued due to unrelated causes. After a median of 3 (3-4) treatment sessions, including ER (nϭ12) or APC (nϭ14), per intention-totreat analysis (counting drop-outs as failures) CR-neo was reached in 115/127 (91%), CR-IM in 112/127 (88%) pts. In a per-protocol analysis (censoring all drop-outs) CR-neo/CR-IM were achieved in 96% and 93% respectively. Of 5 CRneo failures, 1 was referred for surgery (T1sm1G2 cancer), 4 pts are being treated endoscopically (out-of-protocol). CR-neo was maintained in 99/100 pts reaching the 9-mo endpoint; in 1 pt a small island with focal HGD was treated with APC. IM upon single biopsy recurred in 1 pt without visible BE (1,974 NSE biopsies analyzed); focal non-dysplastic IM of the cardia was detected in 11 pts at single FU; none of which required re-treatment. Conclusion: This is the largest prospective multicenter trial on RFA combined with ER for treatment of HGD/EC in BE. Our outcomes suggest that this combined approach is highly effective and durable for eradication of neoplasia in the majority of patients.

Research paper thumbnail of Review: Palliative gastrectomy for stage IV carcinoma of stomach

Annals of the College of Surgeons Hong Kong, 2002

Currently, there is still controversy on the issue of palliative gastrectomy for patients with ad... more Currently, there is still controversy on the issue of palliative gastrectomy for patients with advanced carcinoma of stomach in terms of safety and its benefits. From the data available in the literature, palliative gastrectomy seems to be associated with a better survival rate, better relief of symptoms and similar rates of perioperative morbidity and mortality when compared with laparotomy with or without gastrojejunostomy. However, all these studies are retrospective comparative studies or series that carried significant biases. This makes interpretation of the outcome difficult. A selective approach is advocated as palliative gastrectomy carries significant risks.

Research paper thumbnail of Chilaiditi's syndrome: A nonemergent cause of “free gas under diaphragm”

The American Journal of Surgery, 2009

A 52-year-old woman had a chest radiograph performed for dysphagia. Apart from the related esopha... more A 52-year-old woman had a chest radiograph performed for dysphagia. Apart from the related esophageal abnormality, another striking feature was noted: free gas under the diaphragm. The patient, however, complained of no other gastrointestinal symptom and showed no sign of peritonism.

Research paper thumbnail of A case-controlled comparison of single-site access versus conventional three-port laparoscopic appendectomy

Surgical Endoscopy, 2010

The aim of this study was to compare patients who underwent single-site access laparoscopic appen... more The aim of this study was to compare patients who underwent single-site access laparoscopic appendectomy (SSALA) to those who underwent conventional three-port laparoscopic appendectomy (TPLA) in a case-controlled manner. Consecutive patients who underwent SSALA for suspected acute appendicitis between April and September 2009 were retrospectively compared to those who underwent TPLA between January and December 2008 in a case-controlled manner. The patients were matched for age, gender, and pathological findings. The main outcome measurements included postoperative recovery, morbidities, and mortalities. During the study period, a total of 30 patients underwent SSALA and these were matched with 60 TPLA patients. There were no significant differences in the mean operative time, hospital stay, and 30-day morbidity rate between the two groups. None of the patients required conversion. Two patients with significant contamination and abscess collection noted during SSALA required a relaparotomy for peritoneal lavage and adhesiolysis due to prolonged ileus. SSALA is feasible and the perioperative outcome was comparable to that of TPLA. However, future prospective studies will need to evaluate whether SSALA can adequately tackle patients with significant peritoneal contamination.

Research paper thumbnail of Endoscopic submucosal dissection of a broad-based rectal polyp

Research paper thumbnail of Laparoendoscopic single-site surgery cholecystectomy using a novel retraction device

Research paper thumbnail of Timing of laparoscopic cholecystectomy in acute cholecystitis: Any controversy?

Surgical Practice, 2012

Objective: The timing of laparoscopic cholecystectomy for acute cholecystitis remains controversi... more Objective: The timing of laparoscopic cholecystectomy for acute cholecystitis remains controversial. This article reviews the latest evidence for the timing of laparoscopic cholecystectomy in the management of acute cholecystitis. Methodology: Trials comparing early laparoscopic cholecystectomy (ELC; carried out within 1 week of onset of symptoms) versus delayed laparoscopic cholecystectomy (DLC; carried out at least 6 weeks after symptoms settled) for acute cholecystitis were identified from Ovid Medline, Cochrane Library and PubMed database. Only meta-analyses and randomized clinical trials were reviewed. Results: A total of seven prospective randomized trials including 670 patients and four meta-analyses were reviewed. ELC was superior to DLC in terms of a shorter hospital stay without any significant difference in perioperative mortality and morbidity. Conclusions: Current evidence supports ELC as the preferred treatment strategy for acute cholecystitis. It allows a shorter hospital stay, but shares similar operative morbidity, mortality and conversion rate as DLC.

Research paper thumbnail of Robotic-assisted thoracoscopic enucleation of esophageal leiomyoma

Journal of Robotic Surgery, 2011

Minimally invasive approaches to esophageal leiomyoma, including thoracoscopic and laparoscopic e... more Minimally invasive approaches to esophageal leiomyoma, including thoracoscopic and laparoscopic enucleation, have been shown to have better postoperative recovery compared with thoracotomy approach. We present a case of robotic-assisted thoracoscopic enucleation of esophageal leiomyoma using the da Vinci Ò S system.

Research paper thumbnail of Trangastric Endoscopic Gastrojejunostomy (TEGJ) - A Feasibility Study in Porcine Model

Gastrointestinal Endoscopy, 2009

Research paper thumbnail of The Prediction of Mortality in Bleeding Peptic Ulcers Treated with Therapeutic Endoscopy - Lesson Learnt from 3000 Patients

Gastrointestinal Endoscopy, 2006

This article has an accompanying continuing medical education activity on page 253. Learning Obje... more This article has an accompanying continuing medical education activity on page 253. Learning Objective-Identify factors associated with mortality in patients with bleeding peptic ulcer treated with therapeutic endoscopy. of patients with bleeding peptic ulcers, mortality is still 10%. This study aimed to identify predictive factors and to develop a prediction model for mortality among patients with bleeding peptic ulcers. Methods: Consecutive patients with endoscopic stigmata of active bleeding, visible vessels, or adherent clots were recruited, and risk factors for mortality were identified in this deprivation cohort by using multiple stepwise logistic regression. A prediction model was then built on the basis of these factors and validated in the evaluation cohort. Results: From 1993 to 2003, 3220 patients with bleeding peptic ulcers were treated. Two hundred eighty-four of the patients developed rebleeding (8.8%); emergency surgery was performed on 47 of these patients, whereas others were managed with endoscopic retreatment. Two hundred twenty-nine of these sustained in-hospital death (7.1%). In patients older than 70 years, presence of comorbidity, more than 1 listed comorbidity, hematemesis on presentation, systolic blood pressure below 100 mm Hg, in-hospital bleeding, rebleeding, and need for surgery were significant predictors for mortality. Helicobacter pylori-related ulcers had lower risk of mortality. The receiver operating characteristic curve comparing the prediction of mortality with actual mortality showed an area under the curve of 0.842. From 2004 to 2006, data were collected prospectively from a second cohort of patients with bleeding peptic ulcers, and mortality was predicted by using the model developed. The receiver operating characteristic curve showed an area under the curve of 0.729.

Research paper thumbnail of Radiofrequency Ablation for Benign Aldosterone-Producing Adenoma

Annals of Surgery, 2010

To evaluate the safety and efficacy of radiofrequency ablation (RFA) in treating primary aldoster... more To evaluate the safety and efficacy of radiofrequency ablation (RFA) in treating primary aldosteronism (PA) due to aldosterone-producing adenoma (APA). Radiofrequency ablation is an established technique for treating malignant solid organ neoplasm. Its application on benign functional adrenal adenoma has never been prospectively described. We prospectively evaluated a patient cohort with computed tomography (CT)-guided percutaneous RFA performed on functional APA of size 4 cm or less. Treatment success was defined as complete tumor ablation on follow-up CT scan plus normalization of serum aldosterone-to-renin ratio (ARR) at 3 to 6 months after RFA. Salvage laparoscopic adrenalectomy was offered to patients who had failed RFA and remained hypertensive. Between August 2004 and August 2008, 28 patients were referred for the procedure. Radiofrequency ablation was not performed on 4 APA because of their close proximity to major vascular structures. Twenty-four patients (11 men and 13 women) with a median age of 51.5 (range = 34-63) years underwent RFA for 11 right and 13 left APA. The median tumor diameter was 16.0 (range = 4.0-25.0) mm. There was no periprocedure hypertensive crisis or major morbidity or mortality. Minor complications occurred in 4 patients (16.7%), including 1 small pneumothorax and 3 retroperitoneal hematomas (< 3 cm), which all resolved on conservative treatment. At 3 to 6 months of follow-up, CT scan showed complete tumor ablation in all patients (100%). Primary aldosteronism was biochemically resolved in 23 patients (95.8%). Salvage adrenalectomy was not performed in the single failed patient, as she remained normotensive on repeated follow-up. The overall success rate of RFA was 95.8%. Computed tomography-guided percutaneous RFA is a safe and efficacious alternative to laparoscopic adrenalectomy in treating patients with PA due to small APA.

Research paper thumbnail of Robotic D2 subtotal gastrectomy technique for gastric cancer

Research paper thumbnail of Clinical observation of the effect of CO 2 pneumoperitoneum on haemorrheology

Annals of the College of Surgeons of Hong Kong, 2000

Research paper thumbnail of Combination of a cyclo-oxygenase-2 inhibitor and a proton-pump inhibitor for prevention of recurrent ulcer bleeding in patients at very high risk: a double-blind, randomised trial

The Lancet, 2007

Background Guidelines on pain management recommend that patients at risk of ulcers receive either... more Background Guidelines on pain management recommend that patients at risk of ulcers receive either a cyclo-oxygenase (COX 2) inhibitor or a non-steroidal anti-infl ammatory drug (NSAID) with a proton-pump inhibitor (PPI). These two treatments have similar eff ectiveness, but they are insuffi cient for protection of patients at very high risk for ulcer bleeding. We aimed to test the hypothesis that in patients with previous ulcer bleeding induced by non-selective NSAIDs, combined treatment with the COX 2 inhibitor celecoxib and the PPI esomeprazole would be better than celecoxib alone for prevention of recurrent ulcer bleeding.

Research paper thumbnail of Natural orifices transluminal endoscopic surgery: Current development and future implications

Surgical Practice, 2010

The concept of natural orifices transluminal endoscopic surgery (NOTES) started in 2000 when tran... more The concept of natural orifices transluminal endoscopic surgery (NOTES) started in 2000 when transgastric peritoneoscopy was experimental. Although numerous surgical procedures had been performed successfully in animal models, the application of NOTES in humans was limited. The main obstacles to the performance of NOTES in humans included the security of closing the gastrointestinal (GI) access site, the lack of a stable multi-tasking platform and prospective clinical studies. The present article reviews the current developments in the field of NOTES with special focus on developments in the closure of GI access, a multi-tasking platform and the potential future applications of NOTES.

Research paper thumbnail of Perigastric lymph node metastasis does not affect the survival of squamous cell carcinoma of the oesophagus treated with two-field oesophagectomy

Surgical Practice, 2007

There are some discrepancies as to the prognostic value of perigastric lymph node (LN) metastasis... more There are some discrepancies as to the prognostic value of perigastric lymph node (LN) metastasis in the survival of squamous oesophageal carcinoma. The present study aimed to compare survival following standard oesophagectomy in the treatment of squamous oesophageal carcinoma with or without perigastric abdominal LN metastasis. Methods: From 1998 to 2003, 17 patients with squamous cell carcinoma of the mid or lower oesophagus who had abdominal LN metastasis upon pathological examination underwent Ivor Lewis oesophagectomy. They did not receive further adjuvant therapy. The clinical outcomes of this cohort were compared to a control of 34 patients of similar age, gender and T staging who had no perigastric nodal diseases upon oesophagectomy. Results: There was no significant difference between the two groups in terms of the demographics, tumour size, differentiation of the tumour, duration of operation, volume of blood loss, and the type of oesophagectomy. The cumulative 3-year survival rate was similar between those with abdominal LN metastasis or those without abdominal LN metastasis (52.9% vs 47.1%; log-rank test P = 0.61).There was also no significant difference in the rates of recurrence between the two groups (58.8% vs 58.8%; P = 0.1). Conclusions: Perigastric LN metastasis over the lesser curvature, left gastric artery and pericardial regions does not affect the survival of patients with squamous cell carcinoma of the oesophagus treated by two-field oesophagectomy.

Research paper thumbnail of Randomized comparative trial of a novel one-step needle sphincterotome versus direct incision and balloon dilation used to create gastrotomies for natural orifice translumenal endoscopic surgery (NOTES) in the porcine model

Surgical Endoscopy, 2011

This study aimed to assess the feasibility, safety, and efficacy of a prototype device (the one-s... more This study aimed to assess the feasibility, safety, and efficacy of a prototype device (the one-step needle sphincterotome) versus direct incision and balloon dilation for creating transgastric access to the peritoneal cavity in a porcine model. In five swine, 24 gastrotomies were created using direct incision followed by balloon dilation (group A) or by the one-step needle sphincterotome (group B) in an in vivo nonsurvival model. The one-step needle sphincterotome is a novel instrument comprising two components including a retractable needleknife and a pull-type sphincterotome on the same instrument shaft, reducing the need to exchange instruments. The 24 gastrotomies created in the five swine all were successful. The mean time required for creation of a gastrotomy was 613.08 ± 289.64 s in group A and 310.58 ± 137.39 s in group B. The total procedural time was 830.42 ± 296.17 s in group A and 529 ± 143.97 s in group B. Both were significantly shorter in the prototype device group (P = 0.002). The mean length of gastrotomy, mean number of clips required for closure, and mean overall closure time were not significantly different. One swine from each group suffered morbidities and another experienced mortality. The one-step needle sphincterotome hastened the creation of gastrotomies for natural orifice translumenal endoscopic surgery (NOTES). The gastrotomies created by both procedures were effective means of gaining peritoneal access, and neither method demonstrated superiority in expediting closure. However, the initial blind transgastric incision by a needleknife may be associated with a risk of injuring surrounding structures.

Research paper thumbnail of Laparoscopic totally extraperitoneal inguinal hernia repair: lessons learned from 3,100 hernia repairs over 15 years

Surgical Endoscopy, 2009

... Between June1990 and May 2005, 2,356 patients under-went laparoscopic hernia repair in our in... more ... Between June1990 and May 2005, 2,356 patients under-went laparoscopic hernia repair in our institute. ... Pawanindra L, Kajla RK, Chander J et al (2003) Randomized controlled study of laparoscopic total extra-peritoneal versus open Lichtenstein inguinal hernia repair. ...

Research paper thumbnail of A case of nonampullary duodenal adenoma treated by endoscopic submucosal dissection (with video)

Gastrointestinal Endoscopy, 2010

A 73-year-old man with a history of acute pancreatitis in 2007 presented with epigastric pain of ... more A 73-year-old man with a history of acute pancreatitis in 2007 presented with epigastric pain of a few months' duration. Upper endoscopy revealed a 1.5-cm sessile polypoid lesion in the first part of the inferior wall of the duodenum, and narrow-band imaging-magnifying endoscopy revealed irregular pits with a tortuous subepithelial capillary network . A biopsy confirmed this lesion to be a villous adenoma with mild dysplasia. EUS revealed that this lesion was limited to the mucosa, and endoscopic submucosal dissection (ESD) was performed by using the Hook Knife and the Triangle Tip Knife (Olympus Co Ltd, Tokyo, Japan) (Video 1, available online at www.giejournal.org). The operating time was 50 minutes. A small perforation was encountered during the ESD procedure that was closed with endoclips (EZ 90 clips; Olympus Co Ltd) . After the procedure, 20 mg of esomeprazole administered intravenously every 12 hours was prescribed, and the patient was discharged 7 days after the procedure. Pathology confirmed the sessile polyp to be a tubular adenoma with focal epithelial dysplasia and no invasion to the submucosa. The resected margins were clear, and follow-up endoscopy 12 months after the ESD showed no recurrence.

Research paper thumbnail of The Prediction of Recurrent Bleeding Leading to Surgery or Death After Therapeutic Endoscopy and Adjunctive Use of Intravenous High Dose Omeprazole Infusion for Bleeding Peptic Ulcers

Gastrointestinal Endoscopy, 2005