Polymorphisms in fibronectin binding protein A of Staphylococcus aureus are associated with infection of cardiovascular devices

Medical implants, like cardiovascular devices, improve the quality of life for countless individuals but may become infected with bacteria like Staphylococcus aureus. Such infections take the form of a biofilm, a structured community of bacterial cells adherent to the surface of a solid substrate. Every biofilm begins with an attractive force or bond between bacterium and substratum. We used atomic force microscopy to probe experimentally forces between a fibronectin-coated surface (i.e., proxy for an implanted cardiac device) and fibronectin-binding receptors on the surface of individual living bacteria from each of 80 clinical isolates of S. aureus. These isolates originated from humans with infected cardiac devices (CDI; n = 26), uninfected cardiac devices (n = 20), and the anterior nares of asymptomatic subjects (n = 34). CDI isolates exhibited a distinct binding-force signature and had specific single amino acid polymorphisms in fibronectin-binding protein A corresponding to E652D, H782Q, and K786N. In silico molecular dynamics simulations demonstrate that residues D652, Q782, and N786 in fibronectin-binding protein A form extra hydrogen bonds with fibronectin, complementing the higher binding force and energy measured by atomic force microscopy for the CDI isolates. This study is significant, because it links pathogenic bacteria biofilms from the length scale of bonds acting across a nanometer-scale space to the clinical presentation of disease at the human dimension.     

Endoscopic palliation of oesophageal carcinoma with Atkinson prosthesis

Abstract To assess the degree of palliation, the associated morbidity and mortality and to compare our results with other published series, we reviewed our use of the Atkinson prosthesis in 100 consecutive patients for the palliation of unresectable oesophageal carcinoma. The group had a mean age of 71.2 ± 2.3 years. All prostheses were placed by the pulsion method. Intubation was successful in 91%. Improvement in swallowing was seen in 82.1%. Major early procedure-related morbidity was high at 23% with 11 perforations (11%). Procedure-related mortality was 12%. Those aged 70 years or more had a 34.5% risk of morbidity and 15.5% risk of dying from the procedure. Late procedure-related complications requiring further endoscopic procedures occurred in 27%. Our 7 day mortality was 14.7% (14 patients) and 31 patients (32.6%) had died within 30 days, usually from the disease itself. Those surviving the procedure (> 7 days) had a mean survival of 105 (range 9–735) days.
We obtained acceptable palliation but with a significant morbidity and mortality. Endoscopic intubation remains a useful palliative treatment for patients with unresectable carcinoma of the oesophagus and cardia.     

彩色多普勒超声对长期血液透析老年患者动静脉内瘘并发症的监测作用

目的 探讨彩色多普勒超声检测老年人长期血液透析动静脉内瘘并发症的临床应用价值.方法 36例血液透析老年患者,其中27例采用自体动静脉瘘,9例因自身血管条件限制,不能建立理想的血管通路,采用人工血管移植建立动静脉瘘,应用彩色多普勒超声检测动静脉内瘘的功能及其并发症的发生情况.结果 36例老年血液透析患者中,26例(72....     

带瓣膜心血管内支架封堵动脉导管未闭的可行性研究

目的 探讨带瓣膜心血管内支架在动脉导管封堵中应用的可行性及其体内特性,以期研制一种用于封堵合并严重肺动脉高压动脉导管未闭的新的治疗系统.方法 小型猪8头,采用聚四氟乙烯人工血管建立降主动脉起始部和肺总动脉之间的动脉导管未闭模型,术中采用带瓣膜心血管内支架行直视下封堵术.术后2 h行超声心动图检查,术后30 d行主动脉逆行造影观察动脉导管未闭的封堵情况.术后30 d处死、解削实验动物,并以电镜检查人工动脉导管主动脉端和肺动脉端的新生内膜组织.结果 1头小型猪在术后6 h因支架移位导致肺动脉栓塞而死亡,另外1头小型猪在术后2 h因呼吸衰竭死亡,其余6头小型猪饲养30 d后处死.术后2 h超声心动图和术后30 d主动脉逆行造影均未见残余分流.术后30 d动脉导管均完全封闭,4例动脉导管的肺动脉端和3例动脉导管的主动脉端被新生内膜完整覆盖.电镜检查显示动脉导管主动脉端和肺动脉端的新生组织均有血管内皮细胞生长.结论 采用带瓣膜心血管内支架能有效封堵动脉导管未闭动物模型,残余分流及支架移位发生率低.新生内膜能够覆盖动脉导管的主动脉端和肺动脉端.     

老年人心脏瓣膜置换手术的临床特点及围手术期处理

目的总结60岁以上心脏瓣膜置换手术387例的临床特点及围手术期处理经验。方法1998年5月至2006年5月共实施心脏瓣膜置换术1116例,60～89岁患者387例（老年组）,其中男178例,女209例,按年龄60～64岁、65～69岁、70～89岁分为3组,手术在体外循环中度低温下行瓣膜置换术,并发严重冠心病者行冠状动脉旁路移植术,并发心血管畸形者行矫治术。分析老年人瓣膜置换手术的临床特点,并以同期13～59岁的729例（非老年组）作比较。结果老年组术后早期（30 d内）发生各种并发症55例,并发症发生率14.2%,高于非老年组的11.2%（P〈0.05）。主要并发症为心包积液、胸腔积液、恶性心律失常、循环衰竭,肾功能衰竭及多脏器功能衰竭。老年组术后早期死亡10例（2.6%）,60～64岁4例、65～69岁3例、70～89岁3例；非老年组死亡31例（4.2%）。早期死亡的主要原因是恶性心律失常、呼吸循环衰竭、肾功能衰竭及多脏器功能衰竭。结论老年人心脏瓣膜置换术并发症发生率高,加强围手术期处理,可降低术后病死率。     

超声心动图评价二尖瓣位机械瓣口远期功能的探讨

目的：应用多普勒超声评价二尖瓣位机械瓣口的远期功能状况。方法：选择100例二尖瓣机械瓣置换术的患者,换瓣时间12～120个月,平均52个月。对比分析术后近期组（1～3年,30例）、中期组（3～5年,35例）和远期组（〉5年,35例）的二尖瓣口面积和最大压差。结果：与近期组比较,术后远期组机械瓣口舒张期跨二尖瓣口峰值血流速度[（1．56±0．20）m／s比（1．78±0．35）m／s]、压力降半时间[（80±0．36）s比（128±0．55）s]均显著增加,二尖瓣有效瓣口面积[（2．75±0．18）cm^2比（1．72±0．45）cm^2]显著减少,P〈0．05或〈0．01;中期组和近期组比较,瓣口功能略有减退,但两者无显著差异（P〉0．05）。结论：二尖瓣机械瓣置换术患者机械瓣口面积有减少趋势。     

经导管主动脉瓣置换器械研制及动物实验方法

目的探讨经导管置入新型带瓣膜球囊扩张支架,置换动物主动脉瓣的可行性和有效性。方法自行设计圆柱状网状支架,使用医用316L不锈钢激光雕刻而成。将新鲜的猪心包经脱细胞等处理后裁剪成人工瓣膜,缝合在不锈钢支架上,制成带瓣膜主动脉支架。手术前将带瓣膜支架压缩至定制的相应大小球囊的预载输送鞘管上。选择健康羊3只,开腹分离腹主动脉,穿刺腹主动脉,建立轨道,X线引导下沿加硬导丝经22F输送鞘管将带瓣膜支架逆行送至主动脉瓣位置,扩张球囊释放支架,置换原主动脉瓣。于手术后即刻观察实验效果。结果 1只实验羊因支架置入位置过低突入左心室造成动物心室颤动后死亡,另2只实验羊经导管瓣膜置换术均获得成功,术后即时影像及解剖结果表明人工主动脉瓣膜置入位置理想,可代替原瓣膜工作。结论经导管置入自制新型带瓣膜球囊扩张支架置换动物主动脉瓣方法可行,效果理想。     

Strut-fracture of a Bjork--Shiley tilting disc valve diagnosed by echocardiography--A case report

A 40-year-old man with Bjork-Shiley valves implanted in theaortic and mitral positions nine months previously presentedwith central chest pain. Shortly after admission he developedclinical features consistent with left ventricular failure.Fracture of the mitral prosthesis was diagnosed by echocardiography.At emergency operation the outlet strut of the mitral valvewas found to be fractured and the disc was in the left ventricle.The patient survived valve re-placement and is in good healthfour years later.     

Viscoelastic Polyurethane Foams for Use as Auxiliary Materials in Orthopedics

One of the essential factors in prostheses is their fitting. To assemble a prosthesis with the residual limb, so-called liners are used. Liners used currently are criticized by users for their lack of comfort, causing excessive sweating and skin irritation. The objective of the work was to develop viscoelastic polyurethane foams for use in limb prostheses. As part of the work, foams were produced with different isocyanate indexes (0.6–0.9) and water content (1, 2 and 3 php). The produced foams were characterized by scanning electron microscopy, computer microtomography, infrared spectroscopy, thermogravimetry and differential scanning calorimetry. Measurements also included apparent density, recovery time, rebound elasticity, permanent deformation, compressive stress value and sweat absorption. The results were discussed in the context of modifying the foam recipe. The performance properties of the foams, such as recovery time, hardness, resilience and sweat absorption, indicate that foams that will be suitable for prosthetic applications are foams with a water content of 2 php produced with an isocyanate index of 0.8 and 0.9.     

In Vitro Two-Dimensional Echocardiographic Imaging of a Stented Porcine Bioprosthetic Valve: The Bent Strut Artifact

Background: Echocardiographic imaging of a stented valve bioprosthesis can reveal apparent inward deflection of one or more struts. It could be assumed that this finding is related to actual strut distortion as opposed to an artifact of off-axis imaging. Objective: To determine whether normal (nondistorted) bioprosthetic struts can appear by artifact to be bent inward on two-dimensional echocardiographic imaging. Methods: A production-quality porcine bioprosthetic aortic valve was imaged in vitro using standard two-dimensional echocardiographic techniques. Apparent strut distortion on echocardiographic imaging was investigated relative to prosthesis orientation to the transducer. Results: The appearance of inward strut distortion was produced when two of three struts were simultaneously imaged, including imaging in an off-axis long axis orientation and from above or below the prosthesis. Conclusion: Apparent inward distortion of bioprosthetic struts can be simulated in vitro using a normal, nondistorted valve, and is common if two struts are simultaneously imaged. A finding of inward distortion of strut tips on in vivo imaging should be used with caution, since the finding may not be representative of actual strut anatomy.     

Exclusion of an isolated iliac artery aneurysm using a bifurcated endograft following failed covered stent exclusion.

Endovascular exclusion with covered stents is an alternative to surgical repair of iliac artery aneurysms (IAAs). We report a case where covered stent implantation failed to exclude an IAA, as demonstrated by persistent endoleak. The aneurysm was successfully excluded with a bifurcated aortoiliac endograft. This option should be considered for endovascular treatment of IAAs.     

70岁及以上患者膝关节表面置换术围手术期并发症的处理及疗效分析

目的 探讨70岁及以上患者膝关节表面置换术围手术期常见并发症的处理及疗效评价。方法 回顾性分析2002年1～12月70岁以上患者109例168个膝行膝关节表面置换术围手术期的临床资料。结果 109例全部安全度过围：手术期，术后早期并发症发生率为31．2％。根据美国膝关节外科学会(HSS)膝评分标准，由术前的26．1分提高到术后出院时的82．0分，功能评分由术前的32．1分提高到术后出院时的89．1分。结论 70岁以上患者虽然并发症较多，围手术期风险大，但如果能重视风险防范，手术熟练，尽量减少不必要的损伤，可以顺利经受手术并获得满意的临床治疗效果。     

Long-term follow-up of stentless prosthesis

BackgroundStentless prostheses have an interesting hemodynamic performance when compared to stented prostheses and are recommended in cases of small aortic annulus.Materials and methodsFrom January 1996 to January 2004, 138 patients suffering from aortic disease, underwent aortic valve replacement.

• •Group A: 93 patients underwent stentless aortic valve implantation [stentless Biocor (Biocor Industria e Pesguisa Ltda, Belo Horizonte, Brazil) and stentless Sorin (Sorin Group, Saluggia, Italy)].
• •Group B: 45 patients underwent stented aortic valve implantation (stented Biocor). Patients were assessed by clinical evaluation and echocardiography after a mean follow up of 124.5 ± 58.2 months.

ResultsThere was a significant difference in terms of time of extracorporeal circulation and aortic cross clamp. The actuarial survival at 4, 8, 12, and 15 years is 77%, 50%, 21%, and 18%, respectively. Freedom from reoperation at 4, 8, 12, and 14 years was 92%, 83%, 73%, and 63%, respectively. Freedom from all events, death, and reoperation at 4, 8, 12, and 14 years was 70%, 39%, 13%, and 8%, respectively. There is no statistical difference among the two groups in terms of actuarial survival, freedom from reoperation, and freedom from re-hospitalization for prosthesis-related causes.DiscussionThere was a significantly higher incidence of pacemaker implantation in Group A and the causes are not known. The rate of freedom from reoperation is high in both groups for the patients who remained alive. There was no statistical difference about prosthesis dysfunction between the two groups. The higher incidence of death in Group A cannot be explained by causes related to the prosthesis because there is no difference in terms of causes of death. Rates of reoperation did not differ between the two groups.ConclusionsThe results obtained with stentless prostheses are encouraging even in long-term follow-up.     

Real time triplane echocardiography in the assessment of the functional area of prosthetic aortic valves: reliability and feasibility

Purpose: Our study is aimed at evaluating the feasibility and reliability of a simple method for the measurement of the functional area of prosthetic aortic valves (EOA). Three-dimensional echocardiography has proven accurate for left ventricular volume, stroke volume, and aortic valve area measurement. We studied the feasibility and reliability of real time simultaneous triplane echocardiography (RT3P) for assessing the EOA with a fast formula based on the principle of continuity equation, in which we replaced Doppler-derived stroke volume (SV) with SV directly measured with RT3P. Methods and results: EOA of prosthetic aortic valves were measured in 23 consecutive patients requiring periodical follow up. EOA was calculated using Doppler continuity equation (DCE) and the RT3P method by replacing Doppler-derived SV with SV measured with real time triplane echocardiography. We compared functional areas obtained with the two methods with the prosthetic area indicated in the manufacturer's specifications and with the mean transprosthetic gradient. Both methods had a good correlation with the area indicated by the manufacturer. RT3P revealed an inverse correlation between functional area and mean gradient that was better than DCE (P = 0.0359). Inter- and intraobserver variability was not different between the two methods. Execution time was significantly shorter for RT3P. Conclusions: RT3P is a simple method that can be performed quite rapidly, and can complement the overall assessment of prosthetic valve function. Further studies can confirm our technique. (Echocardiography 2012;29:34-41).     

二尖瓣位置入GK双叶瓣应用体会——附684例早期临床分析

目的:评估二尖瓣置换术中应用GK瓣的早期疗效。方法:回顾分析2007年1月至2013年6月间,二尖瓣位应用GK瓣的684例患者的临床资料:男性256例,女性428例,年龄(46.70±13.54)岁,病程(13.17±8.29)年;术前心功能分级(NYHA):II级141例,III级369例,IV级174例,其中,再次手术41例,感染性心内膜炎53例,急诊手术75例,合并心房颤动509例。结果:死亡7例,病死率1.02%。早期并发症为:严重低心输出量综合征(低心排)30例,转化为多脏器功能衰竭6例;恶性心律失常11例;呼吸衰竭12例;肾功能严重损害6例。随访6个月至3年,恢复良好,6个月时心脏超声检查心脏功能和二尖瓣跨瓣压差满意。出院1个月后,发生瓣膜血栓1例,该患者合并三尖瓣置换,再次手术见人工三尖瓣和二尖瓣均有血栓,再次置入GK瓣,术后恢复较好;出院后4个月发生瓣周漏1例,再次换瓣手术,恢复好。结论:二尖瓣位应用GK瓣安全,缝合环柔软,入座自然,早期疗效好。     

Echocardiographic features of aortic ball valve prosthesis malfunction

A case of aortic ball valve prosthesis malfunction is described in which the poppet became alternately stuck in the open and closed position. The patient experienced chest pain followed by pulmonary edema and cardiac arrest. Malfunction of prosthetic valve was diagnosed on echocardiogram and cardiopulmonary resuscitation was carried out until a Bjork-Shiley valve could be inserted in place of the faulty prosthesis. At the time of the operation, poppet migration had occurred and the poppet could not be found. Subsequent Bjork-Shiley aortic valve prosthesis dysfunction was suggested by variation in the intensity of the aortic opening sound and in the duration of the systolic ejection period. Fluoroscopy revealed the missing poppet in the left ventricle. Following surgical removal of the poppet, “normal” Bjork-Shiley valve function was restored.     

颅内梭状动脉瘤支架辅助栓塞治疗

目的探讨颅内支架辅助栓塞梭状动脉瘤的方法与疗效。方法对我科2006年1月～2009年6月收治的21例梭状动脉瘤患者行颅内支架辅助栓塞治疗。采用Neuroform支架辅助栓塞治疗12例,采用LEO支架辅助栓塞治疗6例,采用Wingspan支架辅助栓塞治疗1例,采用Neuroform与LEO支架辅助栓塞治疗2例。结果完全栓塞动脉瘤1 7例,部分残留4例。数字减影血管造影随访检查未出现动脉瘤继续扩张1 6例。结论采用颅内支架辅助栓塞的方法治疗梭状动脉瘤是一种安全、有效的方法,可以闭塞梭状动脉瘤或防止梭状动脉瘤继续扩张。