Anaesthetic experience with paediatric interventional cardiology

Anaesthetic and sedation techniques, complications and outcomes were reviewed in 176 children undergoing 184 interventional cardiologic procedures. Techniques included sedation only, and ketamine, inhalational or narcotic anaesthesia. Ketamine infusion was the technique most frequently used. Ketamine was associated with a higher incidence of respiratory complications (P < 0.05) than the other techniques. The higher incidence of hypercarbia (15.6 per cent), which did not affect outcome, may be attributable to the use of supplemental sedatives. The incidence of upper airway obstruction (7.8 per cent) was similar to that of previous studies. Vascular compromise resulted from the procedure in 33 patients, necessitating surgical correction in 16. Cardiac perforation occurred in four cases, causing one death. Pulmonary valve stenosis was most amenable to balloon dilatation and aortic valve stenosis least amenable. Ketamine was the anaesthetic agent preferred by cardiologists for use in the catheterisation suite when general anaesthesia was required. Vigilant monitoring by anaesthetic staff is necessary during the procedure, and avoidance of concomitant narcotics is recommended if a ketamine technique with spontaneous ventilation is used. Les techniques anesthésiques et de sédation ainsi que les complications et les issues ont été revues chez 176 enfants subissant 184 procedures cardiaques. Les techniques ont inctu soil la sédation seulement, soit l’anesthésie à la kétamine, aux agents d’inhalation ou aux narcotiques. La perfusion de kétamine était la technique la plus fréquemment utilisée. La ketamine était associée à une plus grande incidence de complication respiratoire (P < 0.05) comparativement aux autres techniques. La plus grande incidence d’hypercarbie (15.6 pour cent), n’ayant pas affecté l’issue, pourrait être attribuée à l’utilisation additionnelle de sédatifs. L’incidence d’obstruction des voies aériennes supérieures (7.8 pour cent) était similaire aux études préalables. Un problème vasculaire suite à la procédure fut observé chez 33 patients dont 16 ont requis une correction chirurgicale. Une perforation cardiaque est survenue dans quatre cas provoquant le décès d’un seul patient. La sténose de la valve pulmonaire était la procédure la plus susceptible d’être dilatée et la sténose de la valve aortique la moins susceptible. La kétamine était l’agent anesthésique préféré par les cardiologistes lors des cathétérisations quand une anesthésie générate était requise. Une surveillance vigilante par une équipe anesthésique fut nécessaire durant la procedure. Il faut aussi éviter l’administration de narcotiques si la kétamine est administrée en respiration spontanée.

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Presented in part at the Canadian Anaesthetists’ Society annual meeting in Halifax, June 1988.     

组织工程心脏瓣膜研究进展

目前组织工程心脏瓣膜研究已在支架的选材、种子细胞的选择、种子细胞的种植与瓣膜构建方法三个方面取得进展，并已构建出三种代表性组织工程心脏瓣膜。对它们各自的特点进行综述。     

心脏组织工程瓣脉动流培养系统的设计与构建

自行设计和制造平面和三维立体培养室及贮液室等构件,用医用硅胶管连接;转子泵作为动力源,贮液室通气口供给5%CO2 95%空气,恒温水浴箱保持构件37℃恒温,这样组成了种植细胞与生物瓣支架复合体的脉动培养系统,并进行生物力学和生物相容性测试,为心脏组织工程瓣的体外构建提供研究器材。结果显示,该装置密闭性能好,内环境能保持37±1℃、CO2浓度5%±1%、pH值6.8～7.5;流量在0.125～6.0L/min的范围内任意调节;同种瓣膜上的内皮细胞经2周培养后扩增约10倍;瓣膜支架的细菌和霉菌培养均为阴性,说明我们构建的脉动流培养系统能有效地模拟体内脉动流场实现种植细胞在体外的增殖、重塑,为心脏组织工程瓣的体外构建提供了一种新的实验方法。     

Early clinical evaluation of the Cosgrove-Edwards prosthetic heart valve ring

 We discuss the usefulness of the Cosgrove-Edwards ring from our early clinical results from 25 rings in 24 patients who underwent mitral annuloplasty (MAP) or tricuspid annuloplasty (TAP) between June 1999 and December 2000. In the MAP group, the posterior mitral annulus between the anterior and posterior fibrous trigones was reinforced with the prosthetic ring. In the TAP group, the annuli of the anterior and posterior leaflets were splinted with the ring. The prosthetic ring was attached by pledgeted U-sutures. Cardiologists performed echocardiography pre- and postoperatively. Thirteen of the 14 in the MAP group showed mitral valve regurgitation of grade 0 or I. Six of the 11 in the TAP group showed tricuspid regurgitation of grade 0 or I, and 5 patients with regurgitation equal to or greater than grade II who remained in atrial fibrillation postoperatively recovered without further clinical symptoms. No patient has required reoperation during a follow-up period of up to 2 years. Cosgrove-Edwards ring-related complications, such as valve stenosis, ring detachment, and arrhythmia, have been not recognized in these patients. In conclusion, for mitral and tricuspid annuloplasty, the Cosgrove-Edwards prosthetic ring showed excellent early clinical results, particularly in patients maintained in sinus rhythm. Received: November 5, 2001 / Accepted: May 30, 2002 Correspondence to:Y. Misawa     

家猪心脏三尖瓣复合体的形态学观测

目的　观测家猪心脏三尖瓣复合体 ,为家猪心脏研究和心脏移植积累资料。方法　甲醛固定的家猪心脏 35例 ,大体解剖并观测三尖瓣复合体。结果　家猪心脏三尖瓣复合体由瓣环、瓣膜、腱索和乳头肌构成 ,瓣环周长为 70 75± 8 4 5mm ,前瓣、后瓣、隔侧瓣、前隔连合、前后连合、后隔连合的高度分别为 14 5 8±2 6 4、14 16± 2 5 0、12 84± 2 37、6 2 9± 1 97、6 86± 1 0 1、6 5 1± 1 36mm。前隔连合、前后连合、后隔连合的宽度分别为 6 4 0± 1 5 4、6 78± 1 2 3、6 4 3± 1 4 6 ;前乳头肌起始 ,腱索附着于前瓣、后瓣和前后连合的条数分别为 3 0 0± 0 97、3 0 9± 1 0 9、2 4 4± 1 16 ;后乳肌起始 ,腱索附着于后瓣、隔侧瓣和后隔连合的条数分别为 2 6 0± 0 6 9、3 0 9± 1 6 3、1 14± 0 4 3。隔侧乳头肌起始 ,附着于前瓣、隔侧瓣、前隔连合的腱索条数分别为1 71± 0 6 7、2 37± 1 2 6、0 94± 0 4 2。结论　家猪心脏三尖瓣复合体中各结构与人类相似 ,但大小有一定差异。     

Minimally immunogenic decellularized porcine valve provides in situ recellularization as a stentless bioprosthetic valve

Currently used bioprosthetic valves have several limitations such as calcification and functional deterioration, and revitalization through cellular ingrowth is impossible. To overcome these obstacles, we have developed a minimally immunogenic tissue-engineered valve that consists of an unfixed, decellularized porcine valve scaffold capable of being spontaneously revitalized in vivo after implantation. Porcine aortic root tissue was decellularized using detergents such as sodium lauryl sulfate and Triton X-100. The porcine valve was treated very gently and plenty of time was allowed for constituents to diffuse in and out of the matrix. In a preliminary study, a piece of decellularized porcine valve tissue was implanted into the rat subdermal space for 14 and 60 days and the structural integrity and calcification were evaluated. As an in vivo valve replacement model, the decellularized porcine valve was implanted in the pulmonary valve position in dogs and functional and histological evaluation was performed after 1, 2, and 6 months. Histological examination showed that the newly developed detergent treatment effectively removed cellular debris from the porcine aortic tissue. Decellularized porcine valve tissue implanted subdermally in rats showed minimal inflammatory cell infiltration and calcification. In the valve replacement model, spontaneous reendothelialization and repopulation of the medial cells were observed within 2 months, and good valve function without regurgitation was observed by echocardiography up to 6 months. The minimally immunogenic decellularized porcine valve proved effective in mitigating postimplant calcification and provided a suitable matrix for revitalizing prostheses through in situ recellularization, cellular ingrowth, and tissue remodeling.     

Mechanical heart valve prostheses:: identification and evaluation (erratum)

Mechanical heart value prostheses have been in use since the 1950s. Many prostheses have been used for a while and then discontinued. Today, there are a large number and variety of prostheses in use and an even larger variety that are in place in patients. These may be explanted at any time for a number of reasons. It is essential for the practicing pathologist to be able to identify the prosthesis and be aware of some of its reported complications and modes of failure. This article, and a second one on bioprosthetic heart valves, is designed as a ready reference guide to heart valve prostheses, their important identifying features, their common complications, and modes of failure. It should help in the accurate identification of explanted prosthetic valves and more definitive reports. This accuracy of identification as well as tracking of abnormalities noted will, we hope, permit the identification of new failure modes and the recording of causes of failure of new (or even modified) prosthetic heart valves.     

Role of computational fluid mechanics in the analysis of prosthetic heart valve flow

The paper aims to present the strengths and weaknesses of computational fluid mechanics (CFM) compared with existing in vitro haemodynamic techniques such as LDA, hot-wire anemometry and static pressure measurement, and to discuss the application of CFM to the analysis of prosthetic heart valve flow. It presents a brief summary of existing methods used in analysing in vitro heart valve flow (along with CFM), the special problems inherent in each method and the quantities each is capable of giving. The analysis then goes on to present examples of information yielded by CFM. It also contains a brief discussion of the data requirements for the analysis of heart valve performance and the clinical relevance of fluid dynamic occurrences. The conclusion drawn is that CFM has a major role to play in the analysis of prosthetic heart valve flow and design because of the improved availability of data afforded and the increased correlation between CFM and clinical flow regimes, due to the ability to consider realistic models of blood.     

Tumorous deformity of mitral valve leaflet after chordal rupture in a child

A case with tumorous deformity of the posterior mitral valve leaflet after spontaneous chordal rupture in a child is described. A partial rupture in the chordae tendineae of the posterior mitral leaflet was found by echocardiography in a 9-year-old Japanese boy. Tumorous bulging was gradually developed in the leaflet and was surgically excised 5 years later. Multiple nodular tumors were found on the atrial surface of the posterior mitral leaflet. Histological examination revealed that the tumorous bulging consisted of myxomatous materials in which collagen fibrils and very fine elastic fibers were distributed loosely and irregularly. Normal-looking endothelial cells covered the luminal surface of the bulging lesion. Vimentin-positive spindle-shaped mesenchymal cells were scattered in the bulge area. The labeling index of proliferating cell nuclear antigen (PCNA) in these cells was 29.3%. These spindle cells were positive for matrix metalloproteinase (MMP)-1 in the entire bulge area. The cells and matrix were positive for MMP-2 and tissue inhibitor of MMP (TIMP)-1 in the basal area of bulging, but were weakly positive or negative at the surface area. Reactivity for TIMP-2 in the cells in the bulge area was obviously weaker than that in the cells at the spongiosa of the anterior mitral leaflet, which was obtained from the patient at the valve replacement operation 9 months after the initial operation. These findings indicated that the tumorous deformity of the mitral valve was formed by the overgrowth of valve tissue under the stimulation of mitral regurgitation in this child, and the imbalance of MMP and TIMP might play an important role in the bulge formation.