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.
ObjectiveThe aim of this current meta-analysis is to evaluate the efficacy and safety of selective surgery after colonic stenting versus emergency surgery for acute obstructive colorectal cancer.MethodsThe studies published from January 1, 2000 to July 31, 2018 were searched from Pubmed, Embase, Cochrane Library, CNKI, Wanfang database, and VIP database. RevMan 5.3 software was used for data analysis.ResultsA total of 21 studies were included in this meta-analysis. Compared to emergency surgery, selective surgery after colonic stenting had significant lower mortality rate [OR=0.44, 95% CI was (0.26, 0.73), P<0.05], permanent stoma rate [OR=0.46, 95% CI was (0.23, 0.94), P<0.05], complication rate [OR=0.47, 95% CI was (0.35, 0.63), P<0.05], and wound infection rate [OR=0.40, 95% CI was (0.25, 0.65), P<0.05）], but had significant higher primary anastomosis rate [OR=3.30, 95% CI was (2.47, 4.41), P<0.05] and laparoscopic surgery rate [OR=12.55, 95% CI was (3.64, 43.25), P<0.05]. But there was no significant differences between the two groups as to anastomotic leak rate [OR=0.86, 95% CI was (0.48, 1.55), P>0.05].ConclusionsSelective surgery after colonic stenting can be identified in a reduced incidence of mortality rate, complication rate, permanent stoma rate, and wound infection rate, and also can increase primary anastomosis rate and laparoscopic surgery rate. Thus, for acute obstructive colorectal cancer, selective surgery after colonic stenting is better than emergency surgery.
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.
Objective-To apply self-pulmonary tissue flap to reconstruct esophagus directly or with alloy stent in this research. Methods Twenty-four dogs were divided into two groups, middle bronchus was ligated to prepare pulmonaryflap and incised, a 4 to 6 cm long and 1/2 to 2/3 perimeter defect was made in esophageal wall. Esophagus defect was repaired only with pulmonary flap (experimental group) and with pulmonary flap having self-expanded stent inside (control group). The gross appearance, histological apearance and barium X-ray films were observed at 2,4,6,8,10 and 12 weeks after operation. Results Two dogs died of anatomotic leak in experimental group, three dogs died of anatomotic leak and two dogs died of perforation of ulcer in control group. The growth of esophagus epithelium was observed from periphery area to central area after 8 to 10 weeks of operation. In pulmonary flap mass fibrous tissue proliferated and fibroblasts were active, but no necrosis occurred. Barium X-ray ofregenerated esophagus showed that mild stenosis and weakened peristalisis were observed in the middle of resophagus replacement, and that no obstruction, leakage, and dilation above anastomotic stoma occurred. Conclusion Pulmonary tissue flap can well support the mucosa crawl in the defect of esophagus. It is necessary to find a more suitable and satisfied stent for repairing segmental defect.
ObjectiveTo systematically evaluate the outcomes of drug-eluting balloon (DEB) in treating coronary artery in-stent restenosis (ISR) by using meta-analysis and trial sequential analysis (TSA). MethodsWe searched PubMed, EMbase, The Cochrane Library（Issue 4, 2016）, CNKI, CBM, VIP and WanFang Data to collect randomized controlled trials (RCTs) regarding the treatment of ISR by DEB from inception to April 2016. After two reviewers independently screened citations, extracted data and assessed the bias risk of included studies, we carried out meta-analysis and TSA analysis by using RevMan 5.3 version and TSA v0.9 respectively. ResultsA total of 10 RCTs involving 1909 patients were included. Seven-hundred and forty-seven patients were included with regard to the comparison between DEB and POBA, 1162 patients were recruited to compare DEB and drug-eluting stents (DES). The results of meta-analysis revealed that DEB was associated with decreased mortality (OR=0.36, 95%CI 0.14 to 0.93, P=0.04), compared with that of plain old balloon angioplasty (POBA). And TSA showed that cumulative Z-curve strode the conventional threshold value but not the TSA threshold value which suggested a false positive result of meta-analysis. In comparison with that of POBA, DEB had a lower incidence of target lesion revascularization (TLR) (OR=0.16, 95%CI 0.07 to 0.38, P＜0.01). And the result of TSA displayed that the cumulative Z-curve strode both the conventional and TSA threshold value which validated the result of meta-analysis. Besides, the results of meta-analysis showed that there were no significant differences in mortality (OR=0.84, 95%CI 0.41 to 1.72, P=0.63) and TLR (OR=1.55, 95%CI 0.76 to 3.16, P=0.22) between DEB and DES. However, the result of TSA revealed that the cumulative Z-curve did not strode both the conventional and TSA threshold value, and the included sample size less was than required information size which suggested that the reliability of the meta-analysis needed more studies to confirm. While the subgroup analysis of EES revealed that DEB had a higher incidence of TLR than that of DEB (OR=3.37, 95%CI 1.59 to 7.15, P＜0.01). And the result of TSA displayed that the cumulative Z-curve strode both the conventional and TSA threshold value which validated the result of meta-analysis. ConclusionCurrent evidence shows, EES is superior to DEB in decreasing the incidence of TLR in patients with ISR, while DEB is superior to POBA. However, the comparison of DEB and other strategies on reducing of mortality in patients with ISR still needed more studies to prove.
ObjectiveTo evaluate the effectiveness of covered Cheatham-platinum (CP) stent for treatment of coarctation of aorta (CoA). MethodsBetween January 2007 and September 2013, 15 patients (16 lesions) with CoA underwent covered CP stent implantation, and the clinical data were analyzed retrospectively. Of 15 cases, 8 were male and 7 were female, aged 13-56 years (mean, 27.7 years). Fifteen lesions located beyond the origin of the left subdavian artery, and 1 lesion located between the origin of the left common carotid artery and the origin of the left subdavian artery. Proper covered CP stent and balloon-in-balloon (BIB) catheter were selected according to the data of computed tomography angiography or digital subtraction angiography examination. Under fluoroscopic guidance, the covered CP stent was placed at lesion accurately by expanding the inner balloon and the outer balloon sequentially. The variation of the systolic pressure gradient across the lesion and the stenosis extent of the aorta before and after the procedure were recorded. ResultsFifteen patients were all treated by covered CP stent implantation successfully. The systolic pressure gradient across the lesion decreased from (58.1±19.5) mm Hg (1 mm Hg=0.133 kPa) at preoperation to (6.2±5.6) mm Hg at immediate after CP stent implantation, and the stenosis extent of the aorta decreased from 73.8%±12.8% at preoperation to 16.7%±5.6% at immediate after CP stent implantation, all showing significant difference (t=12.483, P=0.000; t=15.631, P=0.000). All puncture points healed well with no aortic dissection, pseudoaneurysm, or obvious subcutaneous hematoma. All the patients could walk moderately within 48 hours after procedure. The average hospitalization time was 11.1 days (range, 6-18 days). During a mean follow-up of 29.7 months (range, 1-81 months), the symptom of dizziness and exercise tolerance were improved obviously, and the systolic pressures gradient between upper and lower extremity was below 20 mm Hg. The systolic and diastolic pressures at last follow-up were significantly improved when compared with preoperative values (t=7.725, P=0.000; t=3.651, P=0.000). According to radiography, the location and shape of the stent were good, and no aortic dissection, aneurysm, or recoarctation occurred. ConclusionAccording to the initial and midterm results, the covered CP stent is an effective treatment for CoA in adolescents and adults with a low rate of complication. However, long-term results still require further follow-up.
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 explore the efficacy of using a single branch stent-graft to treat primary intramural hematoma located at the distal arch or descending aorta in Stanford A type aortic intramural hematoma. MethodsFrom July 2020 to November 2022, 10 patients with primary intramural hematoma of Stanford A type aortic intramural hematoma were treated with endovascular repair using a single branch stent-graft in the Department of Cardiovascular Surgery at The University of Hong Kong-Shenzhen Hospital. There were 9 males and 1 female, aged from 32 to 66 years, with a mean age of (47.0±10.4) years. All patients had intramural hematoma involving the ascending aorta and aortic arch, diagnosed as type A intramural hematoma, with the tear located in the descending aorta. Among them, 6 patients were complicated by ulceration of the descending aorta with intramural hematoma, and 4 patients had changes of the descending aortic dissection. All patients underwent endovascular stent repair, with 8 patients undergoing emergency surgery (≤14 days) and 2 patients undergoing subacute surgery (15 days to 3 months). Results There were no neurological complications, paraplegia, stent fracture or displacement, or limb or visceral ischemia during the perioperative period in all patients. One patient had continuous chest pain after surgery, and the stent had a new tear at the proximal end, requiring ascending aorta and partial arch replacement. As of the latest follow-up, all patients had obvious absorption or complete absorption of the intramural hematoma in the ascending aorta and aortic arch compared with before the operation. ConclusionSingle branch stent-graft treatment of retrograde ascending aortic intramural hematoma is safe and effective, with good short-term results.
Objective To evaluate the value of Ureteral Stent Placement before Extracorporeal Shock Wave Lithotripsy (ESWL). Methods We searched the Cochrane Central Register of Controlled Trials (Issue 4, 2010), MEDLINE (OVID 1950 to April 2010), EMbase (1979 to April 2010), CBM (1978 to April 2010), CNKI (1979 to April 2010), and VIP (1989 to April 2010), and manually searched journals as well. All the randomized controlled trials (RCTs) of treating ureteral stone with ESWL after stent placement were included. We evaluated the risk of the bias of the included RCTs according to the Cochrane Handbook for Systematic Reviews of Interventions Version 5.0.1. The Cochrane Collaboration’s software RevMan 5.0 was used for meta-analysis. Results Three RCTs with C-level evidence involving 319 ureteral stone patients were identified. The results of meta-analyses showed that: a) Effect of treatment: The ureteral stent placement before ESWL did not take better effects in aspects of the complete clearance rate (WMD= 1.10, 95%CI 0.87 to 1.38), the quantity of lithotripsy (WMD= 0.43, 95%CI –?1.05 to 0.19), the frequency of shock wave (WMD= 0.00, 95%CI –?0.25 to 0.25), and the power of shock wave (WMD= 0.20, 95%CI –?0.05 to 0.46); and b) Postoperative complications: The ureteral stent placement were prone to cause dysuria (RR= 2.30, 95%CI 1.62 to 3.26), microscopic hematuria (RR= 2.66, 95%CI 1.97 to 3.58), gross hematuria (RR= 6.50, 95%CI 1.50 to 28.15), pyuria (RR= 1.78, 95%CI 1.44 to 2.21), positive urine culture (RR= 2.13, 95%CI 1.71 to 2.64), and suprapubic pain (RR= 3.10, 95%CI 1.59 to 6.04). Conclusions Ureteral stent placement before ESWL is inadvisable. Multi-factors which lead to bias affected the authenticity of our review, such as low-quality and small amount of RCTs. Further large-scale trials are required.
Objective To evaluate the clinical efficacy and safety of endovascular therapy for spontaneous isolated superior mesenteric artery dissection (SISMAD). Methods The clinical data of 17 patients with SISMAD, who were treated at author's hospital during the period from March 2009 to May 2016, were retrospectively analyzed. According to the Sakamoto angiographic classification, patients were divided into typeⅠ (n=3), typeⅡ (n=5), and type Ⅲ (n=9). Three patients with type Ⅰ were treated with conservative treatment first, and then 2 were treated with endovascular therapy as the poor reaction. The other patients were treated with endovascular treatment right a way. Results Conservative treatment was success in 1 case, 16 patients were treated with endovascular treatment, the technical success rate was 100%, one stent was used in 11 patients and two stents were used in 5 patients, and the blood in the true lumen of superior mesenteric artery (SMA) restored, no major complications occurred. Seventeen patients were followed-up for 3-36 months (mean of 19 months) and the followed-up rate was 100%, no abdominal pain occurred in 17 cases, CTA showed that no dissecting aneurysm was observed and the stents were patent of SMA. Conclusion Interventional therapy is a safe and effective method for SISMAD.