Ding Yuan

Systematic Review and Meta-Analysis of the Relationship between EPHX1 Polymorphisms and Colorectal Cancer Risk

Background Microsomal epoxide hydrolase (EPHX1) plays an important role in both the activation and detoxification of PAHs, which are carcinogens found in cooked meat and tobacco smoking. Polymorphisms at exons 3 and 4 of the EPHX1 gene have been reported to be associated with variations in EPHX1 activity. The aim of this study is to quantitatively summarize the relationship between EPHX1 polymorphisms and colorectal cancer (CRC) risk. Methods Two investigators independently searched the Medline, Embase, CNKI, and Chinese Biomedicine Databases for studies published before June 2012. Summary odds ratios (ORs) and 95% confidence intervals (CIs) for EPHX1 Tyr113His (rs1051740) and His139Arg (rs2234922) polymorphisms and CRC were calculated in a fixed-effects model and a random-effects model when appropriate. Results This meta-analysis yielded 14 case-control studies, which included 13 studies for Tyr113His (6395 cases and 7893 controls) and 13 studies for His139Arg polymorphisms (5375 cases and 6962 controls). Overall, the pooled results indicated that EPHX1 Tyr113His polymorphism was not associated with CRC risk; while the His139Arg polymorphism was significantly associated with decreased CRC risk (Arg/His vs. His/His, OR = 0.90, 95%CI = 0.83–0.98; dominant model, OR = 0.92, 95%CI = 0.85–0.99). The statistically significant association between EPHX1 His139Arg polymorphism and CRC was observed among Caucasians and population-based case-control studies. This association showed little heterogeneity and remained consistently strong when analyses were limited to studies in which genotype frequencies were in Hardy–Weinberg equilibrium, or limited to studies with matched controls. When cumulative meta-analyses of the two associations were conducted by studies’ publication time, the results were persistent and robust. Conclusion This meta-analysis suggests that EPHX1 Tyr113His polymorphism may be not associated with CRC development; while the EPHX1 His139Arg polymorphism may have a potential protective effect on CRC.

Estimation of Standard Liver Volume for Liver Transplantation in the Chinese Population

INTRODUCTION The accurate assessment of standard liver volume (SLV) is necessary for the safety of both the donor and the recipient in living donor liver transplantation. However, the accuracy of SLV formulas relates to cohorts or races. This study examined the accuracy of a simple linear formula versus previous formulas of SLV for Chinese adults. METHODS Among 112 patients with normal liver, we created a new formula for SLV with stepwise regression analysis using the following variables: age, gender, body weight, body height, body mass index, and body surface area. The agreement between the actual liver volume (LV) and calculated LV using various formulas was prospectively evaluated among 63 living donors by paired-sample students t-test and Lins concordance correlation coefficient. RESULTS A new formula was developed SLV (mL) = 949.7 x BSA (m(2)) - 48.3 x age - 247.4 where age was counted as 1 for those <40, 2 if 41-60, and 3 if >60 years old. The calculated LV using our formula showed no significant difference from the actual LV using the paired-samples students t-test (P = .653). Lins concordance correlation coefficient showed substantial agreement between estimated LV using our formula and actual LV. Furthermore, this study also observed an almost perfect agreement between our formula and the Yoshizumi et al formula. CONCLUSION Our formula, which accurately estimated LV among Chinese adults, may be applicable to adults of other ethnicitis.

Risk factors associated with early and late HAT after adult liver transplantation

AIM To identify risk factors that might contribute to hepatic artery thrombosis (HAT) after liver transplantation (LT). METHODS The perioperative and follow-up data of a total of 744 liver transplants, performed from February 1999 to July 2010, were retrospectively reviewed. HAT developed in 20 patients (2.7%). HAT was classified as early (occurring in fewer than 30 d post LT) or late (occurring more than 30 d post LT). Early HAT developed in 14 patients (1.9%). Late HAT developed in 6 patients (0.8%). Risk factors associated with HAT were analysed using the χ(2) test for univariate analysis and logistic regression for multivariate analysis. RESULTS Lack of ABO compatibility, recipient/donor weight ratio ≥ 1.15, complex arterial reconstruction, duration time of hepatic artery anastomosis > 80 min, duration time of operation > 10 h, dual grafts, number of units of blood received intraoperatively ≥ 7, number of units of fresh frozen plasma (FFP) received intraoperatively ≥ 6, postoperative blood transfusion and postoperative FFP use were significantly associated with early HAT in the univariate analysis (P < 0.1). After logistic regression, independent risk factors associated with early HAT were recipient/donor weight ratio ≥ 1.15 (OR = 4.499), duration of hepatic artery anastomosis > 80 min (OR = 5.429), number of units of blood received intraoperatively ≥ 7 (OR = 4.059) and postoperative blood transfusion (OR = 6.898). Graft type (whole/living-donor/split), duration of operation > 10 h, retransplantation, rejection reaction, recipients with diabetes preoperatively and recipients with a high level of blood glucose or diabetes postoperatively were significantly associated with late HAT in the univariate analysis (P < 0.1). After logistic regression, the independent risk factors associated with early HAT were duration of operation > 10 h (OR = 6.394), retransplantation (OR = 21.793) and rejection reactions (OR = 16.936). CONCLUSION Early detection of these risk factors, strict surveillance protocols by Doppler ultrasound and prophylactic anticoagulation for recipients at risk might be determined prospectively.

Body Mass Index Evaluating Donor Hepatic Steatosis in Living Donor Liver Transplantation

INTRODUCTION Evaluation of graft hepatic steatosis is important for the safety of the donor and the recipient in living donor liver transplantation. It is necessary to establish a noninvasive evaluation method to avoid performing a liver biopsy for donor safety. The aim of this study was to identify independent factors that correlated with hepatic steatosis to create a noninvasive method to evaluate hepatic steatosis. METHODS We retrospectively collected data from 105 living donors. No prisoners were used to obtain the grafts, all of which underwent postoperative histological evaluation for hepatic steatosis. Preoperative clinical and biochemical variables were examined with univariate analyses, and filtered variables further examined with ordinal regression analysis. RESULTS Eighty (76.2%) donors showed no hepatic steatosis, 15 (14.3%), mild steatosis, and 10 (9.5%), moderate steatosis. In ordinal stepwise regression analysis, body mass index (BMI; P = .000) was the only independent factor that correlated with the grade of hepatic steatosis. Preoperative biochemical parameters were not significantly correlated with hepatic steatosis. A regression model based on BMI was created to evaluate hepatic steatosis grade. Furthermore, individuals with a BMI > 27.5 were most likely to show moderate steatosis, and those with BMI < 23 likely to display no or mild steatosis. CONCLUSION BMI can help to identify the grade of hepatic steatosis among living donors. BMI is also useful to select living donors for a preoperative liver biopsy before liver transplantation.

Tumour cryoablation combined with palliative bypass surgery in the treatment of unresectable pancreatic cancer: a retrospective study of 142 patients

Background Although cryosurgery has been proved to be an effective treatment to extend the survival time of unresectable liver cancer patients and improve their quality of life, few surgeons actually treat unresectable pancreatic cancer with this method because of its safety risks. This study aims to evaluate the safety and efficacy of cryosurgical ablation in the treatment for unresectable pancreatic cancer. Methods A retrospective study was conducted on 142 patients who underwent palliative bypass with cryoablation (PBC group: 68) or without cryoablation (PB group: 74) for unresectable pancreatic cancer from 1995 to 2002. The morbidity and 5 year survival rates of the two groups were compared. Carbohydrate antigen 19–9 (CA19-9) level and tumour size were evaluated in PBC group. Results There was no significant difference in the rate of overall complications between the two groups (p=0.809), except for a higher delayed gastric emptying rate observed in the PBC group (36.8% vs 16.2%, p=0.005). In the PBC group, the median preoperative CA19-9 concentration decreased from 690 U/ml to 56 U/ml (p=0.000). CT scan results of 55 patients indicated that tumour mass shrinkage occurred in 36 of them, from 4.3 cm to 2.4 cm (pre-ablation to 3 months after ablation). Kaplan–Meier analysis showed no significant difference in 5 year survival rates between the two groups (p=0.124). Conclusions Cryosurgery combined with palliative bypass surgery can be considered a safe and effective treatment for unresectable pancreatic cancer. Though this technique remains only palliative, it may be further employed to improve advanced stage pancreatic cancer.

Risk factors of biliary complications following liver transplantation: retrospective analysis of a single centre

Background: Despite improvements that have been achieved in surgical techniques and organ preservation, biliary complications remain one of the most serious morbidities following liver transplantation. However, factors related to biliary complications after liver transplantation are not completely understood. The objective of this study was to identify retrospectively possible risk factors of biliary complications following liver transplantation. Methods: Data on 279 patients who underwent liver transplantation between January 1999 and November 2005 were collected retrospectively. Selected variables from preoperative, intraoperative and postoperative data were first analysed using univariate logistic regression. Filtered factors with p<0.1 in the first step were further investigated to identify factors independently associated with biliary complications following liver transplantation. Results: The overall incidence of biliary complications was 22.6%. Multivariate regression revealed that biliary cirrhosis (p = 0.038), anhepatic phase time (p = 0.04), and incidence of hepatic artery abnormality (p = 0.001) after transplantation were factors that were significantly related to biliary complications. Use of a T tube for biliary reconstruction and living grafts were not associated with biliary complications following liver transplantation. Conclusion: This study suggests that further technical refinement—namely, shortening the anhepatic phase duration, shielding the hepatic artery, and refining biliary duct reconstruction—can reduce the incidence of biliary complications following liver transplantation.

Adult-to-adult living donor liver transplantation for acute liver failure in China

AIM To investigate the long-term outcome of recipients and donors of adult-to-adult living-donor liver transplantation (AALDLT) for acute liver failure (ALF). METHODS Between January 2005 and March 2010, 170 living donor liver transplantations were performed at West China Hospital of Sichuan University. All living liver donor was voluntary and provided informed consent. Twenty ALF patients underwent AALDLT for rapid deterioration of liver function. ALF was defined based on the criteria of the American Association for the Study of Liver Diseases, including evidence of coagulation abnormality [international normalized ratio (INR) ≥ 1.5] and degree of mental alteration without pre-existing cirrhosis and with an illness of < 26 wk duration. We reviewed the clinical indications, operative procedure and prognosis of AALDTL performed on patients with ALF and corresponding living donors. The potential factors of recipient with ALF and corresponding donor outcome were respectively investigated using multivariate analysis. Survival rates after operation were analyzed using the Kaplan-Meier method. Receiver operator characteristic (ROC) curve analysis was undertaken to identify the threshold of potential risk factors. RESULTS The causes of ALF were hepatitis B (n = 18), drug-induced (n = 1) and indeterminate (n = 1). The score of the model for end-stage liver disease was 37.1 ± 8.6, and the waiting duration of recipients was 5 ± 4 d. The graft types included right lobe (n = 17) and dual graft (n = 3). The mean graft weight was 623.3 ± 111.3 g, which corresponded to graft-to-recipient weight ratio of 0.95% ± 0.14%. The segment Vor VIII hepatic vein was reconstructed in 11 right-lobe grafts. The 1-year and 3-year recipients survival and graft survival rates were 65% (13 of 20). Postoperative results of total bilirubin, INR and creatinine showed obvious improvements in the survived patients. However, the creatinine level of the deaths was increased postoperatively and became more aggravated compared with the level of the survived recipients. Multivariate analysis showed that waiting duration was independently correlated with increased mortality (P = 0.014). Furthermore, ROC curve revealed the cut-off value of waiting time was 5 d (P = 0.011, area under the curve = 0.791) for determining the mortality. The short-term creatinine level with different recipients waiting duration was described. The recipients with waiting duration ≥ 5 d showed the worse renal function and higher mortality than those with waiting duration < 5 d (66.7% vs 9.1%, P = 0.017). In addition, all donors had no residual morbidity. Furthermore, univariate analysis did not show that short assessment time induced the high morbidity (P = 0.573). CONCLUSION Timely AALDLT for patients with ALF greatly improves the recipient survival. However, further systemic review is needed to investigate the optimal treatment strategy for ALF.

Precise treatment of aortic aneurysm by three-dimensional printing and simulation before endovascular intervention

In this study, three-dimensional printing (3Dp) models and simulation surgeries (SSs) were applied in two challenging aortic cases. The first was an abdominal aortic aneurysm with a complex neck, and the second was a thoracic aortic dissection aneurysm (TADA) with an angled arch. In order to avoid unpredictable obstacles and difficulties, we made optimal surgical plans by using 3D models and virtual simulations. Based on preoperative evaluation system, the surgical plans seemed more reasonable and time-saving.

New Prognostic Model for Adult-to-Adult Living Donor Liver Transplant Recipients

Adult-to-adult living donor liver transplantation (A-A LDLT) is an effective therapeutic modality to treat patients with end-stage liver disease. The aims of this study were to identify recipient characteristics of A-A LDLT seeking to determine variables that affected patient survival. We retrospectively examined a cohort of 154 consecutive A-A LDLT recipients with end-stage liver disease in our center over 4 years. All donors volunteered to give their partial livers with written consent. There were no organs from prisoners and no prisoner subjects. The overall survivals at 1, 2, 3, 6, 12, 24, 36, and 48 months were 93.5%, 90.9%, 88.9%, 86.3%, 80%, 65.6%, 63.8%, and 63.8%, respectively. About 31 pre- and intraoperative factors were analyzed to identify correlations with posttransplant survival using the Cox proportional-hazards regression model. Recipient age, serum creatinine concentration, intraoperative blood loss, and graft-to-recipient weight ratio were significant predictors of survival after transplantation. The prognostic index model, which was calculated by combining these four prognostic values with their regression coefficients, showed a c-statistic of 0.706 (95% confidence interval [CI] = 0.621-0.792) compared with the Model for End-stage Liver Disease value of 0.546 (95% CI = 0.350-0.558). There was a significant difference between the predictions achieved with the two models (P = .012). In conclusion, selecting younger recipients, better pretransplant renal condition, reduced intraoperative blood loss, and graft-to-recipient size match appeared to be advantageous to achieve better survivals among patients undergoing A-A LDLT.

Prevalence and risk factors of type II endoleaks after endovascular aneurysm repair: A meta-analysis

Objectives This systematic review and meta-analysis aims to determine the current evidence on risk factors for type II endoleaks after endovascular aneurysm repair (EVAR). Materials and methods A systematic literature search was carried out for studies that evaluated the association of demographic, co-morbidity, and other patient-determined factors with the onset of type II endoleaks. Pooled prevalence of type II endoleaks after EVAR was updated. Results Among the 504 studies screened, 45 studies with a total of 36,588 participants were included in this review. The pooled prevalence of type II endoleaks after EVAR was 22% [95% confidence interval (CI), 19%–25%]. The main factors consistently associated with type II endoleaks included age [pooled odds ratio (OR), 0.37; 95% CI, 0.31–0.43; P<0.001], smoking (pooled OR, 0.71; 95% CI, 0.55–0.92; P<0.001), patent inferior mesenteric artery (pooled OR, 1.98; 95% CI, 1.06–3.71; P = 0.012), maximum aneurysm diameter (pooled OR, 0.23; 95% CI, 0.17–0.30; P<0.001), and number of patent lumbar arteries (pooled OR, 3.07; 95% CI, 2.81–3.33; P<0.001). Sex, diabetes, hypertension, anticoagulants, antiplatelet, hyperlipidemia, chronic renal insufficiency, types of graft material, and chronic obstructive pulmonary diseases (COPD) did not show any association with the onset of type II endoleaks. Conclusions Clinicians can use the identified risk factors to detect and manage patients at risk of developing type II endoleaks after EVAR. However, further studies are needed to analyze a number of potential risk factors.