Missing data represent a general problem in many scientific fields, especially in medical survival analysis. Dealing with censored data, interpolation method is one of important methods. However, most of the interpolation methods replace the censored data with the exact data, which will distort the real distribution of the censored data and reduce the probability of the real data falling into the interpolation data. In order to solve this problem, we in this paper propose a nonparametric method of estimating the survival function of right-censored and interval-censored data and compare its performance to SC (self-consistent) algorithm. Comparing to the average interpolation and the nearest neighbor interpolation method, the proposed method in this paper replaces the right-censored data with the interval-censored data, and greatly improves the probability of the real data falling into imputation interval. Then it bases on the empirical distribution theory to estimate the survival function of right-censored and interval-censored data. The results of numerical examples and a real breast cancer data set demonstrated that the proposed method had higher accuracy and better robustness for the different proportion of the censored data. This paper provides a good method to compare the clinical treatments performance with estimation of the survival data of the patients. This provides some help to the medical survival data analysis.
Objective To systematically review the effectiveness and safety of coronary artery bypass grafting (CABG) versus percutaneous coronary stent implantation (PCI) in the treatment of patients with unprotected left main coronary artery disease (ULMCA). Methods Databases including The Cochrane Library (Issue 2, 2012), PubMed, EMbase, CBM, CNKI, WanFang Data and VIP were electronically searched from inception to September 2012 for randomized controlled trials on the effectiveness and safety of coronary artery bypass grafting (CABG) versus percutaneous coronary stent implantation (PCI) for ULMCA; References of the included studies were also retrieved. Two reviewers independently screened literature according to the inclusion and exclusion criteria, extracted data, and assessed the methodological quality of the included studies. Then, meta-analysis was performed using RevMan 5.0. Results Four studies were included involving 1 611 cases, of which, 802 cases are in the CABG group, while 809 cases were in the PCI group. The results of meta-analysis showed that: comparing with PCI, CABG significantly reduced the postoperative repeat revascularization rate (OR=0.45, 95%CI 0.31 to 0.66, Plt;0.000 1), but there was no significant difference between the two groups in reducing the myocardial infarction incidence (OR=1.28, 95%CI 0.47 to 3.48, P=0.63), mortality rate (OR=1.36, 95%CI 0.80 to 2.34, P=0.26), and the incidence of major adverse cardio-cerebral vascular events (OR=0.92, 95%CI 0.66 to 1.28, P=0.61). Conclusion This study indicates that CABG is superior to PCI in reducing postoperative rate of target vessel revascularization. But CABG and PCI are alike in reducing myocardial infarction incidence, mortality rate, and the incidence of major adverse cardio-cerebral vascular events. Due to the limited quantity and quality of the included studies, the above conclusion needs to be verified by more high quality RCTs.
Objective To make an individualized treatment plan concerning a newborn with meconium aspiration syndrome combined with persistent pulmonary hypertension. Methods Based on the clinical questions raised by a newborn with meconium aspiration syndrome combined with persistent pulmonary hypertension, we searched The Cochrane Library (Issue 3, 2009), MEDLINE (1980 to June 2009), ACP Journal Club (1991 to June 2009), and Chinese Journal Fulltext Database (1994 to June 2009) for systematic reviews, randomized controlled trials (RCTs) and case-control studies. The quality of the included studies was assessed. Results A total of 9 RCTs, 1 health economic evaluation, 1 meta analysis, and 2 systematic reviews were considered eligible. The evidence indicated that the use of ECMO in infants of PPHN had shown a decreased risk of death, but not cost-saving from a societal perspective; iNO treatment could improve the PaO2 and resulted in a reduction in the incidence of requirement for ECMO; there were not randomized controlled trials regarding the treatment of PPHN by hyperventilation, high-frequency ventilation, alkali infusion, pulmonary vasodilators (magnesium sulfate, tolazoline, prostaglandin or prostacyclin, milrinone), surfactant therapy; oral sildenafil could lower oxygenation index (OI) and result in a reduction in the incidence of death. The individualized treatment plans of oral sildenafil were developed based on the available evidence, existing conditions of the hospital, and the values of children with families. After 1 month of treatment, the FiO2 returned to normal and symptoms were alleviated. Conclusion The treatment efficacies and the survival rates in meconium aspiration syndrome combined with PPHN have been improved by determining an individualized treatment plan according to evidence-based methods.
Objective To investigate the effect of implanting uncovered self-expandable metal stent for treatment of distal malignant biliary obstruction through endoscope. Methods The effect of therapy about implanting uncovered self-expandable metal stents to 16 patients who had unsectable malignant tumors companing with obstructive jaundice through endoscope was reviewed. Results Fifteen of the studied patients were implanted uncovered self-expandable metal stents successfully (94%), for their internal drainage were patent. At the seventh and fourteenth day after implantation, liver function and B-ultrasound were rechecked. Compared to the data before operation, total bilirubin, direct bilirubin and transaminase declined respectively (P＜0.01). And the diameter of the total biliary duct became shorter (P＜0.01). Six of them returned to the normal level in three weeks. Early adverse events (in seven days) included mild acute pancreatitis (one case) and acute cholangitis (one case). Mean survival and patency of drainage were 186.93 days (54 to 426 days) and 156 days (51 to 426 days) respectively. All of them, 3 cases occured obstruction of stents (20%). Conclusion Implantation of uncovered selfexpandable metal stent through endoscope is an ideal therapy for distal malignant biliary obstruction.
ObjectiveTo summarize our experience in treating highrisk carotid stenosis. MethodsWe retrospectively analyzed the clinical characteristics, treatment, and outcomes of 24 patients with highrisk carotid stenosis in our department from January 2001 with emphasis on the application of carotid stents and shunting tubes. ResultsAll patients were successfully treated, with 11 patients undergoing carotid angioplasty and stenting (CAS) and 13 patients receiving carotid endarterectomy (CEA) and shunting. No death, stroke, and ischemic neurological deficit occurred in 30 days postoperatively. ConclusionSelective application of CAS and shunting in CEA can effectively reduce complications and improve therapeutic effects in patients with highrisk carotid stenosis.
We had performed transjugular intrahepatic portosystemic stent shunt (TIPSS) in one hundred and three patients with advanced liver cirrhosis and portal hypertension from July,1993 to January, 1995. TIPSS was carried out successfully in ninty-eight out of 103 cases and the technical success rate was 95.2%. Acute variceal bleeding was immediatly controlled and portal pressure reduced by an average of 1.36±0.02 kPa after TIPSS. The disappearance of gastric cornoary and esophageal varices, the shrinkage of spleen and the reduction of ascite were observed . Three patients died of acute liver failure and one died of variceal redbleeding within 30 days of treatment. Mild encephalohthy was obserbed in 10 cases with TIPSS. At follow-up of 1～22 months, variceal rebleeding and ascite were observed in 6 patients and stenosis of shunt was evident is 12.5% of cases by the subsequent doppler sonography. According to this result, TIPSS is an effective method for the treatment of portal hypertension.
Objective To investigate the correlation between persistent wheezing and positive result of sputum fungal culture in patients with chronic obstructive pulmonary disease ( COPD) . Methods The COPD patients who hospitalized in the respiratory department of Shanghai First People’s Hospital, Zhongshan Hospital and Huadong Hospital fromJanuary 2005 to December 2007 were analyzed retrospectively. Results Thirty-five cases were enrolled in the persistent wheezing group and 43 cases in the non-wheezing group. In the wheezing group, sputumfungal culture revealed positive yield in 32 cases while Aspergillus were isolated in 12 cases. In the non-wheezing group, sputum fungal culture revealed only 11 cases positive, and none of which were Aspergillus positive. Aspergillus distributions in the two groups were significantly different( P lt;0. 05) . There was also significant difference in the positive result of sputum fungal culture ( 91. 4% vs 25. 6%, P lt;0. 01) , while there was no significant difference in positive result of bacterial culture( 28. 6% vs 39. 5%, P gt; 0. 05) . In the wheezing group, the patients with antifungal treatment showed better prognosis than those without antifungal treatment( 81. 0% vs 36. 4% , P lt;0. 05) . Conclusion The persistent wheezing in the patients with COPD is correlated with the fungi, especially Aspergillus airway colonization.
Objective To investigate the feasibility and therapeutic efficacy of inverted Y-shaped self-expandable metal airway stent for complex airway diseases ( stenosis or fistula) .Methods According to the particular anatomic structure and the pathological changes of complex airway diseases, the inverted Y-shaped self-expandable metal airway stent was designed. 10 stents were implanted in 10 cases of airway complex diseases under the guidance of interventional fibroscopy and fluoroscopy. Results The inverted Y-shaped stents were placed successfully with immediate relief of the symptoms. 100% of the patients were able to be weaned fromoxygen therapy completely. Dyspnea grade improved significantly fromⅢ-Ⅳ to 0-Ⅱ,and oxygen saturation elevated from ( 85 ±5) % in inspiring high concentration oxygen to ( 95 ±3) % in breathing ambient air ( t = - 7. 352, P lt;0. 05) . Breathlessness in 2 cases with tracheoesophageal fistula was relieved after inserting covered airway stent without bucking while foodintaking after fasting 24 hours.Conclusion The placement of inverted Y-shaped self-expandable metal airway stent is a feasible and safetreatment for complex airway disease such as stenosis or fistula.
Objective To investigate clinical outcomes of one-stage repair for patients with persistent truncus arter-iosus who missed optimal timing of surgery. Methods We retrospectively analyzed clinical data of 12 patients with persistent truncus arteriosus who had missed optimal timing of surgery and were admitted to Wuhan Asia Heart Hospital between June 2003 and August 2011. There were 7 male patients and 5 female patients with their median age of 4.5 （0.6-14.0）years and median body weight of 23 （6-36）kg. All the patients underwent one-stage surgical repair. There were 9 patients with Van Praagh type A1，2 patients with type A2，and 1 patient with type A4 persistent truncus arteriosus. There were 2 patients with anomalous origin of coronary artery，2 patients with moderate truncal valve insufficiency，and 3 patients with moderate tricuspid valve insufficiency which required concomitant surgical repair. All the patients received preoperative right heart catheterization which showed severe pulmonary hypertension. The median pulmonary-systemic blood flow ratio （Qp/Qs ratio） was 2.42 （1.50-5.26），and median pulmonary vascular resistance was 8.1 （4-12） Wood units. All the patients showed a positive pulmonary vasodilator response to oxygen. Right ventricular outflow tract （RVOT） reconstruction was achieved using a valved conduit in 7 patients and a valved patch in 5 patients. Results There was no in-hospital death in this group. Three patients had transient pulmonary hypertensive crisis during postoperative intensive care and were healed after proper treatment. Early postoperative pulmonary artery pressure monitoring in all the patients showed that main pulm-onary artery systolic pressure/radial artery systolic pressure was 0.48±0.12. All the 12 patients were followed up for 48（12-91）months. There were 10 patients with New York Heart Association （NYHA） classⅠand 2 patients with NYHA classⅡ during follow-up. One patient received reoperation for residual ventricular septal defect and right ventricular failure.Two patients required long-term medication treatment for high pulmonary vascular resistance and right ventricular failure. The latest echocardiography during follow-up showed that average pressure gradient across RVOT was 21 （16-42） mm Hg in patients with valved conduit for RVOT reconstruction and 18 （10-28） mm Hg in patients with valved patch for RVOT reconstruction. None of the patients required reoperation for RVOT obstruction. Pulmonary regurgitation was less than moderate degree in all the patients. Two patients with anomalous origin of coronary artery didn’t have symptoms or electrocardiogram changes of myocardial ischemia during follow-up. Conclusion For patients with persistent truncus arteriosus who missed optimal timing of surgery， one-stage repair can achieve good early and intermediate clinical outcomes，but long-term follow-up is needed to observe truncal valve regurgitation and right ventricular function.
Abstract： Objective To analyze the mid-term outcomes after correction of type Ⅰ and type Ⅱ persistent truncus arteriosus in all patients operated in our institution over the past 5 years. Methods Between May 2006 and October 2010, 17 patients, mean age 4.7（ 0.7-19.0）years, underwent repair of truncus arteriosus（ type Ⅰ in 13 and type Ⅱ in 4） in Fu Wai Cardiovascular Hospital. Some other concomitant cardiovascular malformations included truncal valve regurgitation, partial anomalous pulmonary venous connection, mitral regurgitation and atrial septal defect. Their average pulmonary vascular resistance was （4.4±2.2） Wood units detected by cardiac catheterization before operation. Repair with reconstruction of the right ventricular to pulmonary artery continuity was performed using a valved conduit in all 17 patients （aortic homografts in 3, pulmonary homografts in 2, and bovine jugular vein in 12 patients）. Survivors were followed up for assessment of residual heart lesions. Results The early mortality was 5.8% （1/17）. The mean cardiopulmonary bypass time was （165±52） min, mean aortic cross-clamping time was （114±29） min, and mean postoperative ventilation time was （106±148） h. Two patients had pleural effusion after surgery, 2 patients underwent tracheostomy, and other patients recovered uneventfully. The surviving 16 patients were followed up for 0.6-5.0 years. All patients were alive with their original conduit during follow-up. No patient required re-operation for conduit dysfunction after correction. Conclusion Truncus arteriosus remains a challenging congenital heart disease. For patients with type Ⅰ and type Ⅱ persistent truncus arteriosus who have missed their best age for correction, cardiac catheterization should be routinely examined, and the operation should be performed if the pulmonary vascular resistance is under 8 Wood units before operation. Although the short- and mid-term results of surgery are good, more observations are needed to assess its long-term effect.