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 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.
Objective
To evaluate the short- and middle-term outcomes of surgical treatment for distal aortic arch lesions using stented elephant trunk implantation combined with transposition of left subclavian artery to left common carotid artery.
Methods
The clinical data of 14 patients with distal aortic arch lesions undergoing stented elephant trunk procedure with left subclavain artery transposition under hypothermic cardiopulmonary bypass (CPB) with antegrade selective cerebral perfusion from May 2009 to November 2015 in our hospital were retrospectively reviewed. All of them were males with a mean age of 52±14 years ranging from 20 to 69 years. Hypertension was observed in nine patients, coronary artery disease in five and prior cerebral infarction in one. History of percutaneous coronary intervention was noted in one patient, history of Bentall operation in one, ligation of patent ductus arteriosus in one and endovascular aneurysm repair in one.
Results
There was no hospital death. Concomitant procedures included coronary artery bypass grafting in two patients and plasty of the ascending aorta replacement in one. Mean duration of mechanical ventilation and ICU stay was 21±7 h and 43±19 h, respectively. All patients survived and were discharged. One patient was lost to follow-up and no patient died during the follow-up. Postoperative computed tomography revealed good patency of the anastomotic site between the left subclavian artery and the left common carotid artery.
Conclusion
Stented elephant trunk procedure with left subclavain artery transposition obtains satisfactory surgical results in patients with distal aortic arch lesions.
ObjectivesTo evaluate the efficacy and safety of four antiplatelet regimens after coronary drug-eluting stents by network meta-analysis.MethodsPubMed, The Cochrane Library, EMbase and Web of Science databases were electronically searched to collect randomized controlled trials (RCTs) of the comparison of different antiplatelet regimens after coronary drug-eluting stenting from inception to December 31st, 2019. Two reviewers independently screened literature, extracted data and assessed risk bias of included studies. Network meta-analysis was then performed by using Gemtc14.3 software, Stata16.0 software and RevMan5.3 software.ResultsA total of 23 RCTs involving 45 837 patients were included. The results of network meta-analysis showed that: in terms of prevention of myocardial infarction (MI) recurrence, the aspirin monotherapy after short-term dual antiplatelet therapy was inferior to the triple antiplatelet therapy (OR=2.13, 95%CI 1.08 to 4.03). In terms of reducing the incidence of ischemic compound events, the triple antiplatelet therapy was superior to the standard dual antiplatelet therapy (OR=0.53, 95%CI 0.39 to 0.72), the aspirin monotherapy after short-term dual antiplatelet therapy (OR=0.49, 95%CI 0.35 to 0.69) and the P2Y12 inhibitor monotherapy after short-term dual antiplatelet therapy (OR=0.51, 95%CI 0.35 to 0.73). There was no statistically significant difference among the four interventions in reducing the rate of in-stent thrombosis and all-cause mortality (P>0.05). In terms of safety, the bleeding rate of aspirin monotherapy after short-term dual antiplatelet therapy was lower than that of standard dual antiplatelet therapy (OR=0.70, 95%CI 0.55 to 0.86) and triple antiplatelet therapy (OR=0.58, 95%CI 0.36 to 0.90), and the bleeding rate of P2Y12 inhibitor monotherapy after short-term dual antiplatelet therapy was also lower than that of standard dual antiplatelet therapy (OR=0.51, 95%CI 0.39 to 0.65) and triple antiplatelet therapy (OR=0.43, 95%CI 0.26 to 0.67). The probability ranking diagram showed that: in terms of the recurrence rate of MI, the rate of in-stent thrombosis and the incidence of ischemic compound events, triple antiplatelet therapy was the lowest and aspirin monotherapy after short-term dual antiplatelet therapy was the highest. However, in terms of all-cause mortality and bleeding rate, aspirin or P2Y12 inhibitor monotherapy after short-term dual antiplatelet therapy was the lowest and triple antiplatelet therapy was the highest.ConclusionsThe available evidence suggests that when the risk of ischemia is low, we should choose aspirin or P2Y12 inhibitor monotherapy after short-term dual antiplatelet therapy, and P2Y12 inhibitor monotherapy may have a lower risk of ischemia and bleeding. When the risk of ischemia is high and bleeding is low, the triple or standard dual antiplatelet therapy should be selected, and the efficacy of triple antiplatelet therapy is superior, while the safety may be inferior.
Objective To assess the safety and effectiveness of direct stenting (DS) versus conventional stenting (CS) with predilation in clinical practice. Methods Such databases as PubMed, EMbase, The Cochrane Library (Issue 3, 2011), CBM, VIP and CNKI were searched from the date of their establishment to April 2011, to collect the randomized controlled trials (RCTs) on DS vs. CS. The quality of RCTs was critically appraised, and the data were extracted and cross-checked by two reviewers independently. Meta-analyses were conducted using RevMan 5.0 software. Results A total of 24 RCTs involving 6 666 patients were included. The results of Meta-analyses showed that DS took shorter operative time compared with CS (MD=–3.36, 95%CI –4.41 to –2.30, Plt;0.000 01) with acute gain (luminal diameter) during operation (MD=–0.01, 95%CI –0.04 to 0.02, P=0.64). But there were no significant differences in the incidence of major adverse cardiac events during six-month follow-up (OR=0.89, 95%CI 0.69 to 1.14, P=0.35) and restenosis (OR=1.02, 95%CI 0.82 to 1.26, P=0.88). Conclusion Current evidence shows that DS is not superior to CS. This conclusion still needs to be further proved by well-designed and large scale RCTs with longer follow-up duration.
ObjectiveTo assess whether expanding the landing zone of frozen elephant trunk (FET) increases the risk of spinal cord injury in patients with acute type A aortic dissection. MethodsPatients with acute type A aortic dissection who were treated in Guangdong Provincial People’s Hospital from 2017 to 2020 were collected. They were divided into two groups according to the landing zone of FET by the image diagnosis of postoperative chest X-ray or total aorta CT angiography, including a Th9 group which defined as below the eighth thoracic vertebral level, and a Th8 group which was defined as above or equal to the eighth thoracic vertebral level. Using the propensity score matching (PSM) method, the preoperative and intraoperative data of two groups were matched with a 1∶2 ratio. The prognosis of the two groups after PSM was analyzed. Results Before PSM, 573 patients were collected, including 58 patients in the Th9 group and 515 patients in the Th8 group. After PSM, 174 patients were collected, including 58 patients in the Th9 group (46 males and 12 females, with an average age of 47.91±9.92 years), and 116 patients in the Th8 group (93 males and 23 females, with an average age of 48.01±9.53 years). There were 8 patients of postoperative spinal cord injury in the two groups after PSM, including 5 (4.31%) patients in the Th8 group and 3 (5.17%) patients in the Th9 group (P=0.738). In the Th8 group, 2 patients had postoperative transient paresis and recovered spontaneously after symptomatic treatment, and 1 patient had postoperative paraplegia with cerebrospinal fluid drainage. After 3 days, the muscle strength of both lower limbs gradually recovered after treatment. There was no statistical difference in complications between the two groups (P＞0.05). ConclusionExpanding the landing zone of FET does not increase the risk of spinal cord injury in patients with acute type A aortic dissection. However, the sample size is limited, and in the future, multicenter large-scale sample size studies are still needed for verification
Objective To introduce the technique of esophageal intraluminal stenting and assess its effect on the prevention of development of stenosis in patients with esophageal burns. Methods Thirty-three patients were admitted less than 3 weeks after ingestion of caustic agents. The second-or third-degree injuries were confirmed by esophogoscopy in all cases, but one with esophageal perforation at admission. Esophageal stenting was performed in all patients and these stents were kept in place for 4 to 6 months. Results There was no death in the series. All patients had a normal intake of food after removal of the stents, and stricture was not found on barium swallow test. Follow-up from 1 to 60 months five cases developed esophageal stenosis from 2 to 3 months after extracting the stents. One of them responded to esophageal bougienage, the remaining 4 patients required esophageal reconstruction and took a normal diet postoperatively. The other 28 patients have a normal diet after the stent removal. Conclusion The esophageal intraluminal stenting is able to prevent the formation of stricture in the aftermath of esophageal burns and its effect will be enhanced plus administering isoniazid.
Currently, transcatheter intervention has emerged as a first-line treatment for coarctation of the aortic. Due to the radiation exposure associated with catheter interventional therapy, there are numerous restrictions, which harms both patients and medical personnel and is dependent on sizable radiation apparatus. Here, we report for the first time a case of echo-guiding percutaneous aortic stent implantation for a 27 years female patient of reproductive age. After discharge, the patient's aortic coarctation pressure decreased to 18 mm Hg, and the surgical results were satisfactory.
ObjectiveTo summarize the feasibility and effectiveness of endovascular treatment for vertebral artery stenosis ectopic originating from the aortic arch. MethodThe clinical data of 5 patients with vertebral artery stenosis ectopic originating from aortic arch admitted to Xuanwu Hospital of Capital Medical University from January 2020 to May 2023 were retrospectively analyzed. ResultsAll 5 patients underwent magnetic resonance angiography and CT angiography before treatment. The vertebral arteries of all patients originated from the aortic arch and were severe stenosis, with a median diameter of 1.3 mm (range, 1.1–1.5 mm) by CT angiography. All 5 patients were successfully treated with endovascular intervention. The operation time was 37–45 min, with a median of 39 min. There were no complications of vertebral artery rupture, embolism or occlusion, cerebral infarction, plaque abscission, hematoma at puncture site, pseudoaneurysm, postoperative hemorrhage, or perioperative pulmonary infection. The patients were followed-up for 13–30 months, with a median follow-up time of 20 months. The blood vessels of 5 patients remained unobstructed and no clinically significant vascular restenosis occurred. ConclusionsBased on the experiences of 5 cases of vertebral artery stenosis ectopic originating from the aortic arch, it is safe and effective to choose endovascular treatment for severe symptomatic vertebral artery stenosis. Especially, it is necessary to evaluate the stenosis degree of vertebral artery using CT angiography before treatment.
Central venous stenosis is a common complication following long-term dialysis catheter placement in dialysis patients. Generally, percutaneous angioplasty is the treatment of choice, and venous stent implantation should be considered in different situations. However, the venous stent migrating into right atrium is a rare but fatal complication. We presented a patient whose superior vena cava stents migrated into right atrium, resulting in acute tamponade, and exploratory thoracotomy was proceeded.
