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.
With the development of radiologic intervention, the treatments of aortic dissection are getting more and more diversified. In recent years, Debakey Ⅲ and DebakeyⅠaortic dissection has been usually treated with endovascular graft exclusion, or combined surgical and endovascular treatment. It is therefore more important to evaluate the aorta and its complications after interventional treatments. Because multidetector-row computed tomography (MDCT) has advantages, such as short examination time, high spatial resolution, and simple operation, this modality has become a first choice of non-invasive methods for the follow-up of aortic diseases after the intervention. Now the MDCT presentations and their anatomic-pathologic features of aortic dissection after endovascular graft exclusion or combined surgical and endovascular treatment are reviewed in this article.
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.
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 compare the early compl ications of carotid stenting (CAS) and carotid endarterectomy (CEA) in treatment of carotid artery stenosis. Methods Between January 2005 and December 2007, 63 patients with carotid artery stenosis were treated with CEA in 36 cases (CEA group) and with CAS in 27 cases (CAS group). There were 42 males and 21 females with an average age of 67.5 years (range, 52-79 years). The locations were the left side in 28 cases and the rightside in 35 cases. The carotid stenosis was 60%-95% (mean, 79%). The major cl inical symptoms were stroke and transient ischemic attack. The cranial CT showed old cerebral infarction in 24 cases, lacunar infarction in 22 cases, and no obvious abnormal change in 17 cases. The encephalon, heart, and local compl ications were compared between 2 groups within 7 days after operation. Results In CEA group, encephalon compl ications occurred in 3 cases (8.3%), heart compl ications in 2 cases (5.6%), and local compl ications in 5 cases (13.9%); while in CAS group, encephalon compl ications occurred in 8 cases (29.6%), heart compl ications in 1 case (3.7%), and local compl ications in 3 cases (11.1%). The encephalon compl ication ratio of CAS group was significantly higher than that of CEA group (χ2=4.855, P=0.028); and there was no significant difference in other compl ications ratios between 2 groups (P gt; 0.05). Conclusion CEA is the first choice to treat carotid artery stenosis.
Objective To evaluate the effect of niti-alloy urethral stent on the prevention of urethrocutaneous fistula and urethral stricture in hypospadias repair. Methods From January 2001 to December 2004, niti-alloy urethral stents were applied to repair congenital hypospadias in 63 patients. Among 63 patients, 49( 19 cases of proximal hypospadias, 22 cases of penoscrotal hypospadias and 8 casesof perineoscrotal hypospadias) received one-stage surgical managements of urethral reconstruction, and 10 underwent postoperative fistular repairs and 4 received repeated urethral reconstruction because of urethral stricture after hypospadias repair. Results All patients gained healing by first intention without fistula or urethral stricture. The stents were left indwelling in the neourethra for 2 months to 3 months to prevent stricture. The longest indwelling period was about 1 year. No dysuria or other discomfort occurred during this period. Conclusion Niti-alloy urethral stent can effectively prevent the postoperative urethrocutaneous fistula and urethral stricture after hypospadias repair.
ObjectiveThis study was aimed to evaluate the clinical efficacy of mechanical thrombectomy using the AngioJet System for the treatment of lower extremity acute arterial embolism and thrombosis.MethodsThe clinical data of 20 patients with acute lower extremity arterial embolism and thrombosis admitted to the Department of Vascular Surgery in the People’s Hospital in Gansu Province where the author worked from September 2016 to March 2017, were retrospectively analyzed. All patients were treated with the AngioJet mechanical thrombectomy system. Clinical data of the patients were retrospectively collected. The clinical efficacy of AngioJet mechanical thrombectomy wasanalyzed.ResultsEighteen (90.0%) of the 20 patients successfully completed the mechanical thrombectomy by using the AngioJet System. The mean time for hospital stay and operation was (4.2±1.4) d and (1.3±0.4) h, respectively. The average doses of urokinase and heparin during operation were (35.80±12.30) ×104 U and (45.10±8.30) mg, respectively. Two patients received a complementary treatment of incision for removing the thrombus. Two patients received catheter-directed thrombolysis after the mechanical thrombectomy, 5 patients received bare-metal stent implantation after balloon expansion. Clinical success was in 16 cases. According to the Cooley standard, 10 patients were in excellent condition,6 in good condition, 2 in fair condition, and 2 in poor condition. There were 2 cases of distal arterial embolization,2 cases of antecardial discomfort of bradycardia, and 4 cases of bleeding at the puncture point, but no serious bleeding complications such as gastrointestinal and intracranial hemorrhage occurred. A total of 16 patients presented myoglobinuria during and after operation. All patients were followed up for 6–12 months. The results of ultrasound examination showed that the artery was patency in 15 cases. One patient died of myocardial infarction in 9 months after surgery,2 patients developed lower extremity ischemia symptoms again after surgery, and 2 patients had lower extremity ulcer caused by lower extremity ischemia symptoms. During the follow-up period, no lower limb necrosis, amputation, and death occurred in the remaining patients.ConclusionsThe AngioJet mechanical thrombectomy system is safe and effective. Combined with the use of catheter-directed thrombolysis and stent implantation, the AngioJet mechanical thrombectomy could lead to quick recovery of the perfusion of the lower extremity and improve the limb salvage rates, exhibiting excellent clinical value.
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 explore the current research status of endovascular treatment for isolated superior mesenteric artery dissection (ISMAD) so as to provide a reference for vascular surgeons and patients in selecting treatment methods. MethodThe recent domestic and international literature on the endovascular treatment for ISMAD was collected and summarized. ResultsThe current endovascular treatment methods for ISMAD mainly included catheter-directed thrombolysis and stent placement. For the ISMAD patients with true intraluminal thrombus formation, true luminal occlusion, and partial embolization of branch vessels, the catheter-directed thrombolysis was performed by continuously pumping urokinase locally to dissolve thrombus and improve distal blood supply. The stent placement mainly included two main types: bare stent placement and covered stent placement, both aiming to promote true lumen recanalization, false lumen thrombosis, and vascular remodeling through mechanical support and blood flow redirection. The bare stents had unique advantages such as being well-developed, offering a wide range of options, and having stable performance. However, covered stents were superior to bare stents in terms of mid-term patency rate and in-stent restenosis. ConclusionsWith the development of technology, endovascular treatment has become an indispensable method for ISMAD patients. Extensive multicenter cases reports from both domestic and international studies have supported the safety and efficacy of endovascular treatment. Catheter-directed thrombolysis and stent placement (bare stent and covered stent) offer targeted solutions for various types of ISMAD patients, providing more minimally invasive and effective treatment.
Autologous blood patch pleurodesis (ABPP) was first proposed in 1987. Now it is mainly used to treat intractable pneumothorax and persistent air leakage after pneumonectomy, and also used to treat pneumothorax in children and other rare secondary pneumothorax. Persistent air leakage and pneumothorax of various causes are essentially alveolar pleural fistula. It can usually be treated by closed thoracic drainage, continuous negative pressure suction and surgery. Pleurodesis is a safe and effective alternative to surgery for patients who have failed conventional conservative treatment and can not receive operations. Compared with other pleurodesis adhesives, autologous blood (ABPP) is safer and more effective, and it is simple, painless, cheap and easy to be accepted by patients. But in the domestic and foreign researches in recent years, many details of ABPP treatment have not been standardized. For further research and popularization of ABPP, this article reviews the detailed regulations, efficacy and safety of this technology.