自体心包跨环补片在右心室流出道重建中的应用

目的　探讨自体心包同时扩大肺动脉瓣环与瓣膜的跨环补片技术在右心室流出道(RVOT)重建术中的应用效果。方法　 2 5例肺动脉发育较差的先天性心脏病病人在行心室矫治和RVOT重建术中 ,按跨环补片手术方法 ,13例为自体心包同时扩大肺动脉瓣环与瓣膜的跨环补片组 (试验组 ) ;12例同期行常用的心包带瓣或不带瓣跨环补片组 (对照组 )。比较两组手术前、后主要临床及随访资料。结果　两组无手术死亡和再手术病例。术毕测右心室与左心室收缩压比值及右房压力 ,术后观察多巴胺用量及肺动脉瓣反流等指标 ,两组比较差异均有显著性 (P <0 0 5 ,P <0 0 1) ,试验组明显优于对照组。结论　采用自体心包同时扩大肺动脉瓣环与瓣膜的跨环补片技术重建RVOT ,可取得满意的防止肺动脉瓣反流的早期手术疗效。操作简单、取材方便、易于掌握 ,可作为RVOT重建术的很好补充 ,有一定的应用价值 ,但瓣膜功能远期效果有待于进一步观察。     

法洛四联症合并异常冠状动脉的外科治疗

目的 总结法洛四联症(TOF)合并异常冠状动脉完全矫治手术的经验.方法 自1993年3月至2006年4月对22例TOF合并异常冠状动脉的患者施行完全矫治手术,其中经右室前壁小切口径路切除右心室流出道(RVOT)内肥厚的隔束、壁束以及纤维狭窄环,并修补室间隔缺损(VSD)5例;经右心房径路疏通RVOT、修补VSD17例,其中跨肺动脉瓣环补片加宽RVOT 7例,用自体心包外管道重建RVOT 3例,同种带瓣血管重建RVOT 1例,肺动脉前壁血管片反折缝合于RVOT上缘,外用带单瓣的牛心包补片缝合,将RVOT重建为外通道2例;其余患者均经右心房-肺动脉径路解除RVOT狭窄.结果 术后早期因冠状动脉损伤死亡1例.1例误将发自右冠状动脉(RCA)的附前降支当作增粗的圆锥支予以切断,导致停体外循环困难,将左乳内动脉与该血管吻合后停机成功,其余患者均顺利恢复.术后早期右心室-肺动脉压差(△P)平均为23.4mmHg,△P＞20mmHg者9例.随访18例,平均随访13.2个月,失访3例.△P＞20mmHg者7例,其余患者△P均＜20mmHg.结论 经右心房径路修补VSD并疏通RVOT使手术更加安全,RVOT的重建方式应根据异常冠状动脉的类型等具体解剖情况来决定.     

法洛四联症矫治术中自体心包梯形补片加宽右心室流出道35例

1997年1月～2005年9月，我们在法洛四联症（TOF）矫治术中采用自体心包梯形补片加宽右心室流出道35例，取得了满意效果。     

Gore-Tex片作单瓣重建右心室流出道的早、中期疗效

目的评价0.1mm厚的Gore-Tex片作肺动脉单瓣重建右心室流出道(RVOT)的早中期临床效果。方法2002年6月至2006年7月,对48例合并肺动脉狭窄或闭锁的先天性心脏病患者施行矫治手术,术中采用0.1mm厚的Gore-Tex片作肺动脉单瓣的Dacron血管片重建RVOT,其中包括法洛四联症合并肺动脉狭窄33例、型肺动脉闭锁8例、肺动脉瓣缺如3例,右心室双出口合并肺动脉狭窄2例,永存动脉干1例,完全型大动脉错位、室间隔缺损、肺动脉狭窄1例。结果本组无手术死亡。术后血氧饱和度达1.00,右心室/左心室收缩压比值0.22~0.65,右心室与左、右肺动脉压差<10mm Hg。所有患者(100%)均随访3~48个月,无死亡和并发症。彩色多普勒超声心动图检查提示:无肺动脉狭窄,肺动脉瓣轻度反流13例,中度反流5例,Gore-Tex膜具有活动功能40例。结论采用0.1mm厚的Gore-Tex片作单瓣重建RVOT,其早中期临床结果显示有较满意的血流动力学效果。     

法洛四联症矫治术后远期肺动脉瓣关闭不全的治疗进展

随着外科、麻醉、灌注及围术期处理技术的不断发展,法洛四联症(TOF)行常规矫治手术的手术死亡率低于2%～3%,而远期预后越来越受到关注,其中远期肺动脉瓣反流是困扰心脏外科医师和影响患者预后的重要因素;由此带来的右心室扩张、右心室功能不全、致死性心律失常等直接影响患者的生存质量和术后远期生存率。目前,对肺动脉瓣反流的治疗方法包括肺动脉瓣置换术(PVR)、介入治疗、镶嵌治疗等,PVR是治疗肺动脉瓣反流的主要方法,该方法能明显改善患者的心功能和临床症状,延长患者的生存时间;介入治疗因不需要行再次开胸手术,减少了手术创伤和手术风险,而且能改善右心室压力、肺动脉瓣反流程度,使许多患者受益。我们对TOF矫治术后远期肺动脉瓣反流的病理生理改变、PVR的手术指征、肺动脉瓣反流临床治疗进展和早期防治进行综述。     

法洛四联症合并冠状动脉畸形的外科治疗

目的总结法洛四联症(TOF)合并冠状动脉畸形(ACA)手术治疗经验,探讨ACA的诊断,右心室流出道(RVOT)疏通手术方式的选择及其效果。方法回顾性分析2004年1月至2010年1月武汉亚洲心脏病医院手术矫治TOF合并ACA 29例,其中男18例,女11例;年龄7岁(5个月～33岁),体重18(5～51)kg。术前动脉血氧饱和度65%～91%。所有患者均行完全矫治手术。1例经右心房疏通RVOT,修补室间隔缺损;3例经右心房疏通RVOT,修补室间隔缺损,用自体心包片加宽主肺动脉;3例行肺动脉移位术(REV),5例患者采取"双通道"手术;11例采取冠状动脉下方、上方或者两边切口疏通,补片加宽的方法("单片"或"双片"法);6例行冠状动脉移植术后行跨瓣环补片重建RVOT。结果体外循环时间78(65～102)min,主动脉阻断时间50(40～82)min,手术时间150(126～178)min。手术未出现死亡以及严重冠状动脉损伤。术后2例因出血行二次开胸止血;2例出现低心排血量,强心药物支持后治愈。随访51(21～83)个月,随访过程中无死亡。所有患者术后心功能(NYHA)分级均为Ⅰ级,心脏射血分数均正常,心电图未提示心肌缺血,动脉血氧饱和度恢复至96%～99%。术后早期RVOT压差(△P)为19(8～38)mm Hg,术后随访患者无△P增加。结论对于TOF合并ACA患者,术前通过64排螺旋CT(64-MSCT)检查可以明确ACA诊断,术中根据冠状动脉情况选择合适的流出道疏通方法,手术效果良好。     

法洛四联症根治术后肺动脉瓣置换术

目的　讨论法洛四联症 (TOF)术后肺动脉瓣关闭不全的外科治疗时机和方法。　方法　 5例 TOF患者行根治术后发生严重肺动脉瓣关闭不全 ,选用液氮保存的同种带瓣肺动脉行肺动脉瓣置换术 (PVR) ,并同期分别行三尖瓣成形术 (TVP)、右心室流出道 (RVOT)成形术、VSD残余漏修补术或 RVOT疏通。　结果　 1例术后早期因进行性右心功能衰竭死亡 ;余 4例均恢复良好 ,无严重心律失常 ;分别随访 3个月～ 4年 ,心功能为 ～ 级。　结论　早期 PVR能明显改善右心功能 ;采用同种带瓣肺动脉手术简便 ,早期效果满意。     

食管超声心动图评价围术期儿童法洛四联症的右室流出道

目的 运用经食管超声心动图（TEE）对儿童法洛四联症（TOF）的右室流出道（RVOT）情况进行围术期评价。方法 32例TOF病儿体外循环前后分别进行TEE检查，年龄4个月～15岁8个月，平均4．0岁。结果 术前32例均TEE诊断为TOF。31例行根治术，1例行B-T分流术。RVOT扩大补片15例；跨肺动脉瓣环补片（TAP）16例，包括4例切除肺动脉瓣，2例带瓣移植物重建RVOT。术后TEE诊断RVOT残余梗阻5例（16．1％），与是否采用TAP无关（X^2=1．115，P=0．291）。肺动脉反流（PR）16例（51．6％），采用TAP比扩大补片术后更易出现PR（X^2=14．212，P=0．000）。保留原肺动脉瓣可减轻术后PR程度（X^2=5．915，P=0．015）。带瓣移植物重建RVOT可减少术后PR（X^2=8．163，P=0．004）。结论 术前TEE可明确诊断TOF，术后TEE可评价不同手术方法对于RVOT的效果。     

人同种心包补片在法洛四联症分期手术中的应用

目的比较人同种心包补片和G ore-tex补片在法洛四联症(tetra logy of F a llot,TOF)分期手术中扩大右心室流出道(righ t ven tricu lar ou tflow tract,RVOT)的效果。方法28例已行一期手术再行分期手术的TOF患者,按不同的二期或三期手术时间分为两组,G ore-tex组:13例,以G ore-tex补片扩大RVOT;人同种心包补片组:15例,以深低温冷冻保存的人同种心包补片扩大RVOT。比较两组术后临床结果和随访结果。结果G ore-tex补片组术中死亡1例(7.7%),人同种心包补片组术后早期死亡1例(6.7%)。人同种心包补片组住ICU时间、呼吸机使用时间和心包腔引流量均少于G ore-tex补片组(P<0.01)。所有患者均获得随访,随访时间0.8~4.5年,超声心动图检查提示G ore-tex补片组患者术后RVOT水平残余梗阻的比率高于人同种心包补片组(P<0.01),胸部X线片未发现钙化影。结论人同种心包组织致密,缝合后不易渗血,止血方便;且具有良好的弹性和顺应性,有助于降低术后RVOT水平的残余梗阻发生,可作为补片材料在心脏外科手术中应用。     

小儿法乐四联症跨瓣环补片重建右心室流出道

作者采用跨瓣环补片重建右室流出的方法对５２例小儿法乐四联症进行手术治疗，并随访４７例生存者，发现术后近，远期右室流出道无梗阻发生。大部分患者术后一年肺动脉瓣在有定程度关闭不全，但随生存时间延长肺动脉瓣返流不断好转，为此，作者对跨越瓣环补片重建右室流出道的适应证，补片材料选择及肺动脉瓣加宽的标准进行了分析，强调跨越瓣环补片应正确掌握适应证，补片材料以自体心包为优选。     

A new right ventricular assist device for right ventricular support.

Right ventricular support by mechanical devices for postcardiotomy right heart failure is still associated with a high mortality. We report on the first use of a new paracardiac microaxial blood pump for postcardiotomy right heart failure in two patients undergoing emergency coronary artery bypass grafting (the first patient for a myocardial infarction complicated by a left ventricular wall rupture, the second patient for a dissection of the right coronary artery after an interventional procedure).     

Acute right ventricular failure is caused by inadequate right ventricular hypothermia

The hypothesis of this study was that inadequate right ventricular hypothermia contributes to the right ventricular dysfunction occasionally observed after cardiac operations. Dogs were placed on cardiopulmonary bypass, and 60 minute periods of hypothermic myocardial ischemia were imposed. Left ventricular temperature was always maintained at 15 degrees C and right ventricular temperatures were maintained at 15 degrees C (Group I, n = 8), 25 degrees C (Group II, n = 8), and 35 degrees C (Group III, n = 8). These temperatures were produced by infusion of hypothermic crystalloid cardioplegic solution and appropriate topical cooling and heating of the left and right ventricles, respectively. Multiple indices of ventricular function were obtained 15, 30, 45, and 60 minutes after bypass and compared to prebypass control values. In all Group I animals (left ventricular temperature = 15 degrees C, right ventricular temperature = 15 degrees C), postischemic indices of right ventricular function were not different from control values (p = NS). In Group II (left ventricular temperature = 15 degrees C, right ventricular temperature = 25 degrees C), two animals died 30 and 45 minutes after bypass, respectively, of right ventricular failure. In the other six animals in Group II, all indices of right ventricular function were significantly reduced (p less than 0.05) except for right ventricular systolic pressure. In Group III (left ventricular temperature = 15 degrees C, right ventricular temperature = 35 degrees C), two animals could not be weaned from cardiopulmonary bypass because of right ventricular akinesia. Six animals were weaned from bypass, but two died 15 minutes, one died 30 minutes, and one 45 minutes after bypass. Two animals lived 60 minutes, but all indices of right ventricular function were decreased. Failure to maintain right ventricular temperatures below 25 degrees C during 1 hour of cardiac ischemia in the dog can result in fatal right ventricular failure.     

Concurrent left and right ventricular hypertrophy in dog models of right ventricular overload

In two pressure and volume overload models of canine right ventricular hypertrophy, we have demonstrated significant hypertrophy of both the left and the right ventricles. The extent of hypertrophy was correlated positively to the extent of the increase in plasma epinephrine in both volume and pressure overload models. Attenuation or ablation of plasma epinephrine through the administration of propranolol, a beta-adrenergic blocker, or by denervation of the adrenal medulla prevented the hypertrophy process. No hemodynamic parameter was altered consistently in a parallel manner to hypertrophy. This is the first report of concurrent right and left ventricular hypertrophy in response to pressure or volume overload of the right ventricle. These studies further implicate epinephrine as a major trophic hormone of the heart.     

Experimental acute right ventricular failure and right ventricular assist in the dog

We describe a technique for the production of acute progressive right ventricular failure in experimental animals that mimics the hemodynamic characteristics of right ventricular failure found in some patients being weaned from extracorporeal circulation after surgical repair of left ventricular abnormalities. The technique combines three alterations of right ventricular state: excision of the tricuspid valve, ventriculotomy, and ligation of the right coronary artery. Seven control dogs died within 3 hours after this intervention. Death was due to low cardiac output as a result of low left atrial and pulmonary arterial pressures. Right atrial pressure was high. Use of a right ventricular assist device in an additional seven dogs to pump blood from the right atrium to the pulmonary artery confirmed good preservation of left ventricular function by reestablishing adequate left ventricular filling pressure. All seven dogs survived for more than 3 hours. The validity of the technique in restricting failure principally to the right ventricle was thus demonstrated.     

Usefulness of right ventricular tissue Doppler imaging for diagnosis of right ventricular myocardial infarction

Background

Right ventricular myocardial infarction (RVMI) is a complication of acute inferior myocardial infarction and sometimes causes severe hemodynamic disturbance. It is therefore important to promptly detect RVMI and assess the severity of right ventricular (RV) dysfunction. Tissue Doppler imaging (TDI) is a useful method to assess left ventricular function and RV function. In this study, we investigated the possibility of diagnosing RVMI using tricuspid annular velocity determined by TDI.

Methods

Thirty consecutive patients with first acute inferior myocardial infarction were studied. The diagnosis of RVMI was based on an ST-segment elevation of at least 0.1 mV in lead V4R. The patients were classified into 12 patients with RVMI (the RVMI group) and 18 patients without RVMI (non-RVMI group). All patients underwent two-dimensional echocardiography, pulsed Doppler and TDI, and coronary angiography within 48 h after onset of myocardial infarction. Tricuspid inflow velocity was recorded by pulsed Doppler and early diastolic tricuspid inflow velocity (TVE) was measured. Peak early diastolic velocity of the tricuspid annulus (TVe’) at the RV free wall was recorded using TDI. The ratio of TVE to TVe’ (TVE/TVe’) was calculated.

Results

TVe’ was significantly lower in the RVMI group compared to that in the non-RVMI group (5.9 ± 1.3 vs. 9.1 ± 3.1; p = 0.0025). On the basis of a TVe’ cutoff value of less than 8.3 cm/s, RVMI was diagnosed with 100 % sensitivity and 61 % specificity.

Conclusions

The early diastolic tricuspid annular velocity determined by TDI is a noninvasive and sensitive index for diagnosing RVMI.     

Arrhythmogenic right ventricular dysplasia

Arrhythmogenic right ventricular dysplasia (ARVD) is a new form of cardiomyopathy probably more frequent than commonly reported. The incidence is unknown. ARVD is a heart muscle disorder of unknown cause that is characterised pathologically by fibro-fatty replacement of the right ventricular myocardium. It is a rare but important cause of sudden cardiac death in young, otherwise healthy persons. The right ventricle should be extensively sampled histologically in all cases of sudden unexpected death, especially those that are exercise related. The disease is often familial (about 30%) with an autosomal dominant inheritance.     

The use of right ventricular support with a centrifugal pump in a case with right ventricular failure due to intraoperative right ventricular infarction

The patient was 67-year-old woman with mitral valve restenosis and regurgitation, tricuspid insufficiency, and left atrial dilatation who underwent mitral valve replacement, tricuspid valvuloplasty, and left atrial plication. The patient developed right ventricular (RV) failure due to RV infarction when she was weaned from cardiopulmonary bypass (CPB). Therefore, CPB was resumed to be followed by intra-aorta balloon pumping (IABP). However, complete response was not obtained. Thus, right ventricular support was performed using a centrifugal pump, and the patient could be weaned from CPB. Three days after surgery, the right ventricular support was discontinued, and IABP was removed 7 days after surgery without marked changes in hemodynamics. Although RV failure due to RV infarction is a serious intraoperative complication, favorable results were obtained by combination therapy with IABP and right ventricular support using a centrifugal pump in our patient.