Objective By comparing the efficacy and complication rates of the 8-mm-tip cryoablation catheter with the normal electrode ablation catheter in the treatment of atrioventricular nodal reentrant tachycardia,this study investigated the efficacy and feasibility of ablation with the 8-mm-tip cryoablation catheter.Methods This is a retrospective case-control study including 122 patients with AVNRT treated with CRYO (n =56) using an 8-mm-tip cryoablation catheter or RF ablation (n =66) from June 2014 to May 2016.The procedure success rate,the recurrence rate,atrioventricular block incidence,procedure time and the difference between the X-ray fluoroscopy dose were compared between the 2 groups.Results The procedure success rate was comparable between the 2 groups(100％ for CRYO vs.98.5％ for RF,P ＞0.999)and no AVB was found in both groups.The CRYO group needed shorter procedural time [(66.29±4.72)min vs.(70.00 ± 7.50) min,P =0.001] and less X-ray exposure [(674.14 ± 126.12) mSv vs.(837.52 ± 138.38) mSv,P ＞ 0.001] than the RF group.Conclusions 8-mm-tip cryoablation catheter cryoablation for atrioventricular nodal reentrant tachycardia is as safe and effective as compared to conventional radiofrequency ablation with potential advantages.

Objective To evaluate the histocompatibility of novel manufactured xenogenic tendon matrix materials by an animal experimental study.Methods The study was conducted on 15 dogs,weighing 10-13 kg.The prepared xenogenic tendon matrix materials were implanted into the bilateral area of spine in dogs subcutaneously (experimental group),and the implantation of silicon served as control group.The animals were killed 14,30,60 days after surgery and the specimens were processed in laboratory to receive gross and histology observation.The histological sections were stained with hematoxylin-eosin and analyzed by light microscopy.Scores were assigned to the inflammatory process and statistically compared by two related samples with non-parametric test.Results All dogs survived well during the embedded test.There was no tissue necrosis,effusion or inflammation at all implantation sites in both groups during the test.The xenogenic implant materials promoted slight to moderate inflammation process after 14 days,with no statistically significant difference compared to the control.However,after 30 days,there was a regression of inflammation.After 60 days,it was observed the presence of well-organized connective tissue,and few inflammatory cells.Score evaluation of inflammation response at different time after operation of two groups showed no statistically significant difference (P＞0.05).Conclusions The new xenogenic tendon matrix materials are considered biocompatible with subcutaneous tissue.

Objective The stress reaction in double-balloon enteroscopy was investigated,the influencing factors and intervention countermeasures were studied.Methods Cardiovascular effects and physiological reactions of 60 double-balloon enteroscopy patients were surveyed.The patients were divided into 2 groups according to the cardiovascular effects to underwent single factor analysis of related factors.Results The incidence of physiological reactions was 68.3%,the incidence of cardiovascular reactions was 56.7%.Evident difference existed in blood pressure,heart rate and blood oxygen saturation rate before,during and after examination.The grouping analysis showed cardiovascular effects were influenced by many kinds of factors.Conclusions Different degrees of the stress reactions in double-balloon enteroscopy might appear.The influencing factors included the enteroscopy mode and time,gender,age,mood,and physician operation experience.The stress reactions might be reduced by taking the corresponding intervention measures according to the influencing factors.