Tony Wing Chung Mak

Impact of wound edge protection devices on surgical site infection after laparotomy: multicentre randomised controlled trial (ROSSINI Trial).

Objective To determine the clinical effectiveness of wound edge protection devices in reducing surgical site infection after abdominal surgery. Design Multicentre observer blinded randomised controlled trial. Participants Patients undergoing laparotomy at 21 UK hospitals. Interventions Standard care or the use of a wound edge protection device during surgery. Main outcome measures Surgical site infection within 30 days of surgery, assessed by blinded clinicians at seven and 30 days and by patient’s self report for the intervening period. Secondary outcomes included quality of life, duration of stay in hospital, and the effect of characteristics of the patient and operation on the efficacy of the device. Results 760 patients were enrolled with 382 patients assigned to the device group and 378 to the control group. Six patients in the device group and five in the control group did not undergo laparotomy. Fourteen patients, seven in each group, were lost to follow-up. A total of 184 patients experienced surgical site infection within 30 days of surgery, 91/369 (24.7%) in the device group and 93/366 (25.4%) in the control group (odds ratio 0.97, 95% confidence interval 0.69 to 1.36; P=0.85). This lack of benefit was consistent across wound assessments performed by clinicians and those reported by patients and across all secondary outcomes. In the secondary analyses no subgroup could be identified in which there was evidence of clinical benefit associated with use of the device. Conclusions Wound edge protection devices do not reduce the rate of surgical site infection in patients undergoing laparotomy, and therefore their routine use for this role cannot be recommended. Trial registration Current Controlled Trials ISRCTN 40402832

Electroacupuncture Reduces Duration of Postoperative Ileus After Laparoscopic Surgery for Colorectal Cancer

BACKGROUND & AIMS We investigated the efficacy of electroacupuncture in reducing the duration of postoperative ileus and hospital stay after laparoscopic surgery for colorectal cancer. METHODS We performed a prospective study of 165 patients undergoing elective laparoscopic surgery for colonic and upper rectal cancer, enrolled from October 2008 to October 2010. Patients were assigned randomly to groups that received electroacupuncture (n = 55) or sham acupuncture (n = 55), once daily from postoperative days 1-4, or no acupuncture (n = 55). The acupoints Zusanli, Sanyinjiao, Hegu, and Zhigou were used. The primary outcome was time to defecation. Secondary outcomes included postoperative analgesic requirement, time to ambulation, and length of hospital stay. RESULTS Patients who received electroacupuncture had a shorter time to defecation than patients who received no acupuncture (85.9 ± 36.1 vs 122.1 ± 53.5 h; P < .001) and length of hospital stay (6.5 ± 2.2 vs 8.5 ± 4.8 days; P = .007). Patients who received electroacupuncture also had a shorter time to defecation than patients who received sham acupuncture (85.9 ± 36.1 vs 107.5 ± 46.2 h; P = .007). Electroacupuncture was more effective than no or sham acupuncture in reducing postoperative analgesic requirement and time to ambulation. In multiple linear regression analysis, an absence of complications and electroacupuncture were associated with a shorter duration of postoperative ileus and hospital stay after the surgery. CONCLUSIONS In a clinical trial, electroacupuncture reduced the duration of postoperative ileus, time to ambulation, and postoperative analgesic requirement, compared with no or sham acupuncture, after laparoscopic surgery for colorectal cancer. ClinicalTrials.gov number, NCT00464425.

Systematic review of the clinical effectiveness of wound-edge protection devices in reducing surgical site infection in patients undergoing open abdominal surgery

Objective:Assess the existing evidence on the clinical effectiveness of wound-edge protection devices (WEPDs) in reducing the surgical site infection (SSI) rate in patients undergoing open abdominal surgery. Background:Surgical site infections are a common postoperative complication associated with considerable morbidity, extended hospital stay, increased health care costs, and reduced quality of life. Wound-edge protection devices have been used in surgery to reduce SSI rates for more than 40 years; however, they are yet to be cited in major clinical guidelines addressing SSI management. Methods:A review protocol was prespecified. A variety of sources were searched in November 2010 for studies containing primary data on the use of WEPDs in reducing SSI compared with standard care in patients undergoing open abdominal surgery. The outcome of interest was a well-specified, clinically based definition of an SSI. No language or time restrictions were applied. The quality assessment of the studies and the quantitative analyses were performed in line with the principles of the Cochrane Collaboration. Results:Twelve studies reporting primary data from 1933 patients were included in the review. The quality assessment found all of them to be at considerable risk of bias. An exploratory meta-analysis was performed to provide a quantitative indication on the effect of WEPDs. The pooled risk ratio under a random effects model was 0.60 (95% confidence interval, 0.41–0.86), indicating a potentially significant benefit from the use of WEPDs. No indications of significant between-study heterogeneity or publication bias, respectively, were identified. Conclusions:Evidence to date suggests that WEPDs may be efficient in reducing SSI rates in patients undergoing open abdominal surgery. However, the poor quality of the existing studies and their small sample sizes raise the need for a large, good quality randomized controlled trial to validate this indication.

Long-term oncologic outcomes of laparoscopic versus open surgery for rectal cancer: a pooled analysis of 3 randomized controlled trials.

Objective:To compare long-term oncologic outcomes between laparoscopic and open surgery for rectal cancer and to identify independent predictors of survival. Background:Few randomized trials comparing laparoscopic and open surgery for rectal cancer have reported long-term survival data. Methods:Data from the 3 randomized controlled trials comparing curative laparoscopic (n = 136) and open surgery (n = 142) for upper, mid, and low rectal cancer conducted at the Prince of Wales Hospital, Hong Kong, between September 1993 and August 2007 were pooled together for this analysis. Survival and disease status were updated to February 2012. Survival was calculated using the Kaplan-Meier method, and independent predictors of survival were determined using the Cox regression analysis. Results:The demographic data of the 2 groups were comparable. The median follow-up time of living patients was 124.5 months in the laparoscopic group and 136.6 months in the open group. At 10 years, there were no significant differences in locoregional recurrence (5.5% vs. 9.3%; P = 0.296), cancer-specific survival (82.5% vs. 77.6%; P = 0.443), and overall survival (63.0% vs. 61.1%; P = 0.505) between the laparoscopic and open groups. There was a trend toward lower recurrence rate at 10 years in the laparoscopic group than in the open group among patients with stage III cancer (P = 0.078). The Cox regression analysis showed that stage III cancer, lymphovascular permeation, and blood transfusion, but not the operative approach, were independent predictors of poorer cancer-specific survival. Conclusions:This pooled analysis with a follow-up of more than 10 years confirms the long-term oncologic safety of laparoscopic surgery for rectal cancer.

Characterization of rare transforming KRAS mutations in sporadic colorectal cancer

KRAS mutational status has been shown to be a predictive biomarker of resistance to anti-EGFR monoclonal antibody (mAb) therapy in patients with metastatic colorectal cancer. We report the spectrum of KRAS mutation in 1506 patients with colorectal cancer and the identification and characterization of rare insertion mutations within the functional domain of KRAS. KRAS mutations are found in 44.5% (670/1506) of the patients. Two cases are found to harbor double mutations involving both codons 12 and 13. The frequencies of KRAS mutations at its codons 12, 13, 61, and 146 are 75.1%, 19.3%, 2.5%, and 2.7%, respectively. The most abundant mutation of codon 12 is G12D, followed by G12V and G12C while G13D is the predominant mutation in codon 13. Mutations in other codons are rare. The KRAS mutation rate is significantly higher in women (48%, 296/617) than in men (42.1%, 374/889, P = 0.023). Tumors on the right colon have a higher frequency of KRAS mutations than those on the left (57.3% vs. 40.4%, P < 0.0001). Two in-frame insertion mutations affect the phosphate-binding loop (codon 10–16) of KRAS are identified. One of them has never been reported before. Compared with wild-type protein, the insertion variants enhance the cellular accumulation of active RAS (RAS-GTP) and constitutively activate the downstream signaling pathway. NIH3T3 cells transfected with the insertion variants show enhanced anchorage-independent growth and in vivo tumorigenicity. Potentially these mutations contribute to primary resistance to anti-EGFR mAb therapy but the clinical implication requires further validation.

Quality of life after laparoscopic vs open sphincter-preserving resection for rectal cancer

AIM To compare quality of life (QoL) outcomes in Chinese patients after curative laparoscopic vs open surgery for rectal cancer. METHODS Eligible Chinese patients with rectal cancer undergoing curative laparoscopic or open sphincter-preserving resection between July 2006 and July 2008 were enrolled in this prospective study. The QoL outcomes were assessed longitudinally using the validated Chinese versions of the European Organization for Research and Treatment of Cancer QLQ-C30 and QLQ-CR38 questionnaires before surgery and at 4, 8, and 12 mo after surgery. The QoL scores at the different time points were compared between the laparoscopic and open groups. A higher score on a functional scale indicated better functioning, whereas a higher score on a symptom scale indicated a higher degree of symptoms. RESULTS Seventy-four patients (49 laparoscopic and 25 open) were enrolled. The two groups of patients were comparable in terms of sociodemographic data, types of surgery, tumor staging, and baseline mean QoL scores. There was no significant decrease from baseline in global QoL for the laparoscopic group at different time points, whereas the global QoL was worse compared to baseline beginning at 4 mo but returned to baseline by 12 mo for the open group (P = 0.019, Friedman test). Compared to the open group, the laparoscopic group had significantly better physical (89.9 ± 1.4 vs 79.2 ± 3.7, P = 0.016), role (85.0 ± 3.4 vs 63.3 ± 6.9, P = 0.005), and cognitive (73.5 ± 3.4 vs 50.7 ± 6.2, P = 0.002) functioning at 8 mo, fewer micturition problems at 4-8 mo (4 mo: 32.3 ± 4.7 vs 54.7 ± 7.1, P = 0.011; 8 mo: 22.8 ± 4.0 vs 40.7 ± 6.9, P = 0.020), and fewer male sexual problems from 8 mo onward (20.0 ± 8.5 vs 76.7 ± 14.5, P = 0.013). At 12 mo after surgery, no significant differences were observed in any functional or symptom scale between the two groups, with the exception of male sexual problems, which remained worse in the open group (29.2 ± 11.3 vs 80.0 ± 9.7, P = 0.026). CONCLUSION Laparoscopic sphincter-preserving resection for rectal cancer is associated with better preservation of QoL and fewer male sexual problems when compared with open surgery in Chinese patients. These findings, however, should be interpreted with caution because of the small sample size of the study.

Automatic Detection and Classification of Colorectal Polyps by Transferring Low-Level CNN Features From Nonmedical Domain

Colorectal cancer (CRC) is a leading cause of cancer deaths worldwide. Although polypectomy at early stage reduces CRC incidence, 90% of the polyps are small and diminutive, where removal of them poses risks to patients that may outweigh the benefits. Correctly detecting and predicting polyp type during colonoscopy allows endoscopists to resect and discard the tissue without submitting it for histology, saving time, and costs. Nevertheless, human visual observation of early stage polyps varies. Therefore, this paper aims at developing a fully automatic algorithm to detect and classify hyperplastic and adenomatous colorectal polyps. Adenomatous polyps should be removed, whereas distal diminutive hyperplastic polyps are considered clinically insignificant and may be left in situ . A novel transfer learning application is proposed utilizing features learned from big nonmedical datasets with 1.4–2.5 million images using deep convolutional neural network. The endoscopic images we collected for experiment were taken under random lighting conditions, zooming and optical magnification, including 1104 endoscopic nonpolyp images taken under both white-light and narrowband imaging (NBI) endoscopy and 826 NBI endoscopic polyp images, of which 263 images were hyperplasia and 563 were adenoma as confirmed by histology. The proposed method identified polyp images from nonpolyp images in the beginning followed by predicting the polyp histology. When compared with visual inspection by endoscopists, the results of this study show that the proposed method has similar precision (87.3% versus 86.4%) but a higher recall rate (87.6% versus 77.0%) and a higher accuracy (85.9% versus 74.3%). In conclusion, automatic algorithms can assist endoscopists in identifying polyps that are adenomatous but have been incorrectly judged as hyperplasia and, therefore, enable timely resection of these polyps at an early stage before they develop into invasive cancer.

Reduction of surgical site infection using a novel intervention (ROSSINI): study protocol for a randomised controlled trial

BackgroundSurgical site infection (SSI) is a common complication following abdominal surgery. It is associated with considerable morbidity and mortality, and its management results in significant cost to health services within both primary and secondary care. Some surgeons believe that the use of a wound-edge protection device may reduce the incidence of SSI. Whilst there is some encouraging evidence showing that such devices may lead to a reduction in SSI, there are no controlled trials of sufficient size or quality to support their routine use.Methods/Design750 patients will be recruited from around 20 surgical units within the United Kingdom. Patients undergoing laparotomy through any major abdominal incision for any indication, elective or emergency, are eligible. Patients under the age of 18, those undergoing a laparoscopic assisted procedure or who have undergone laparotomy within the previous 3 months, and those who are unable to give informed consent will be excluded. Patients will be randomised (1:1 ratio) to the use of a wound-edge protection device or no wound-edge protection device during surgery.Follow up will consist of blinded clinical wound reviews at 5-7 days and 30-33 days postoperatively with a self-completed questionnaire covering the intervening period. Quality of life questionnaires will be completed prior to surgery and at the subsequent wound review points and information on resource usage will also be captured.The primary outcome measure is SSI within 30 days of surgery. Secondary outcomes include the impact of the degree of wound contamination, patient comorbidity, and operative characteristics on the efficacy of a wound-edge protection device in reducing SSI and whether the use of a wound-edge protection device has an effect on health-related quality of life or length of hospital stay and is cost-effective.DiscussionRossini is the first multicentre observer-blinded randomised controlled trial of sufficient size and quality to establish whether the use of a wound-edge protection device in adult patients undergoing abdominal surgery leads to a lower rate of SSI. The results of this study will be used to inform current surgical practice and may potentially benefit patients undergoing surgery in the future.Trial registration numberCurrent Controlled Trials ISRCTN: ISRCTN40402832

RASAL2 promotes tumor progression through LATS2/YAP1 axis of hippo signaling pathway in colorectal cancer

BackgroundPatients with colorectal cancer (CRC) have a high incidence of regional and distant metastases. Although metastasis is the main cause of CRC-related death, its molecular mechanisms remain largely unknown.MethodsUsing array-CGH and expression microarray analyses, changes in DNA copy number and mRNA expression levels were investigated in human CRC samples. The mRNA expression level of RASAL2 was validated by qRT-PCR, and the protein expression was evaluated by western blot as well as immunohistochemistry in CRC cell lines and primary tumors. The functional role of RASAL2 in CRC was determined by MTT proliferation assay, monolayer and soft agar colony formation assays, cell cycle analysis, cell invasion and migration and in vivo study through siRNA/shRNA mediated knockdown and overexpression assays. Identification of RASAL2 involved in hippo pathway was achieved by expression microarray screening, double immunofluorescence staining and co-immunoprecipitation assays.ResultsIntegrated genomic analysis identified copy number gains and upregulation of RASAL2 in metastatic CRC. RASAL2 encodes a RAS-GTPase-activating protein (RAS-GAP) and showed increased expression in CRC cell lines and clinical specimens. Higher RASAL2 expression was significantly correlated with lymph node involvement and distant metastasis in CRC patients. Moreover, we found that RASAL2 serves as an independent prognostic marker of overall survival in CRC patients. In vitro and in vivo functional studies revealed that RASAL2 promoted tumor progression in both KRAS/NRAS mutant and wild-type CRC cells. Knockdown of RASAL2 promoted YAP1 phosphorylation, cytoplasm retention and ubiquitination, therefore activating the hippo pathway through the LATS2/YAP1 axis.ConclusionsOur findings demonstrated the roles of RASAL2 in CRC tumorigenesis as well as metastasis, and RASAL2 exerts its oncogenic property through LATS2/YAP1 axis of hippo signaling pathway in CRC.

A Simple Assessment of Peritoneal Transport in Stable Continuous Ambulatory Peritoneal Dialysis Patients

We studied the peritoneal transport properties in 175 stable continuous ambulatory peritoneal dialysis (CAPD) patients seeking a simple and handy assessment of peritoneal permeability to small solutes. Measurement of creatinine in biological fluid was known to suffer from interference by high glucose concentration in the sample. Furthermore, the interference is also affected by the creatinine concentration of the specimen. Peritoneal transport properties were studied by determining the dialysate to plasma ratio of creatinine concentration (D/P) at the fourth hour of the peritoneal equilibration test, and the mass transfer area coefficient of creatinine (MTACCr) or glucose (MTACGlu). The ratio of glucose concentration in peritoneal dialysate effluent (PDE) at 4 and 0 h (G4/G0) was examined and compared with various peritoneal parameters. There were significant logarithmic correlations between D/P or G4/G0 with MTACCr (r = 0.96 and 0.79, respectively, p < 0.0001). The correlation between G4/G0 and D/P was linear (r = –0.82, p < 0.0001). A fairly good agreement was present between G4/G0 and D/P by Bland and Altman’s method. The bias was –0.93% with 95% confidence interval –23.29% to 21.43% of the measured value. Systematic error was found when D/P or G4/G0 were compared with MTACCr. D/P under estimated MTACCr in the high range. The reverse happened for G4/G0. Net ultrafiltration (NUF) also correlated with MTACCr, D/P and G4/G0 (r = –0.32, p < 0.001; –0.26, p < 0.01; and 0.16, p < 0.05, respectively.In conclusion, the use of G4/G0 as a measure of peritoneal transport in CAPD is an acceptable alternative to D/P. It is highly reproducible and avoids correction of interference when creatinine transport parameters are measured. Because of the logarithmic relations of G4/G0 (or D/P) with MTACCr, the former should not be directly converted to MTACCr. Such a simple measure of peritoneal permeability is, however, most convenient for serial monitoring and can be useful to detect early loss of ultrafiltration or solute clearance.