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Updated: Jul 24, 2026

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Protocol for Relative Hydrodynamic Assessment of Tri-leaflet Polymer Valves
Published on: October 17, 2013
大動脈の位置におけるハンコック改変孔生体義肢の血液動力学的評価
F H Levin1, M J Buckley, W G Austen
1Surgical Service, Massachusetts General Hospital Boston, Massachusetts 02114, USA.
Circulation
|September 1, 1978
まとめ
新型モディファイド・オーリフィス (MO) ヘテログラフト義肢は,オーリフィス面積を増やすことで大動脈弁の機能を改善します. 臨床結果は,患者,特に小さな大動脈環を持つ患者の優れた血液動力学性能と安全性を示しています.
科学分野:
- 心血管外科手術についてです.
- バイオマテリアル科学 バイオマテリアル科学
- 義肢バルブの設計について
背景:
- 豚の異種移植は,主動脈の位置において,特に小型の弁のサイズにおいて,しばしば不最適の血動力学的機能を示す.
- 効果的な穴面積の制限は,標準のバイオプロステティックバルブの性能を制限します.
研究 の 目的:
- ヘモダイナミックパフォーマンスを向上させるために設計された新しいモディフィケートオーリフィス (MO) ヘテログラフト義肢を導入し,評価する.
- 大動脈弁の置換を必要とする患者のMO弁の安全性と有効性を評価する.
主な方法:
- MO義肢は,切断された筋肉の小葉が非筋肉の小葉に置き換えられ,有効な内部穴の面積を25〜35%増加させています.
- 試験管内の水力学研究では,標準の豚用および低プロフィール金属義肢に対するMO性能を比較しました.
- MO弁は26人の患者に埋め込まれ,追跡期間は1ヶ月から10ヶ月でした.
主要な成果:
- 実験室内研究では,標準的な豚義肢と比較して,MOバルブの優れた水力性能が示されました.
- 26人の患者の体内では,義肢機能障害や血栓塞栓性イベントは観察されなかった.
- 術内ピークシストリックグラディエントは,標準義肢と比較してMO義肢 (例えば,6.6mm for 21mm) の方が著しく低く,標準義肢 (例えば,14.0mm for 23mm) の方が著しく低い.
結論:
- 改造された穴のヘテログラフト義肢は,標準の豚用バルブよりも水力学的改善を大幅に提供しています.
- MOバルブは,優れた血液動力学性能と,臨床使用において良好な安全性プロファイルを示しています.
- この生体義肢は,小型の大動脈環を持つ患者に適しており,バルブ置換治療の重要な未満たされたニーズに対応しています.
関連する概念動画
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Blood is pumped by the heart into the aorta, the largest artery in the body, and then into increasingly smaller arteries, arterioles, and capillaries. The velocity of blood flow decreases with increased cross-sectional blood vessel area. As blood returns to the heart through venules and veins, its velocity increases. The movement of blood is encouraged by smooth muscle in the vessel walls, the movement of skeletal muscle surrounding the vessels, and one-way valves that prevent backflow.
Pathophysiology of Cardiac Performance
Typical heart performance is influenced by heart rate, rhythm, myocardial contraction, and metabolism or blood flow. The cardiac muscle exhibits distinct electrophysiological features, including pacemaker activity and calcium channel control, which play a vital role in the heart's response to various drugs. The autonomic nervous system, comprising the sympathetic and parasympathetic branches, regulates heart rate. Sympathetic activation increases heart rate, while parasympathetic activation...
Cardiac Output and Stroke Volume
Cardiac output (CO) is an integral aspect of human physiology, reflecting the heart's efficiency and responsiveness to the body's needs. It represents the volume of blood that the left or right ventricle ejects into the aorta or pulmonary trunk each minute. The CO is calculated by multiplying the heart rate (HR)—the number of heartbeats per minute—by the stroke volume (SV)—the amount of blood pumped out with each heartbeat.
In an average resting adult male, the typical cardiac output averages...
In an average resting adult male, the typical cardiac output averages...
Regulation of Stroke Volume
The regulation of stroke volume, which is the amount of blood the heart pumps out during each heartbeat, is critical for maintaining a healthy circulatory system. Stroke volume is influenced by three main factors: preload, contractility, and afterload.
Preload refers to the degree of stretch on the heart before it contracts. It's analogous to the stretching of a rubber band; the more it's stretched, the more forcefully it snaps back. This concept is encapsulated in the Frank-Starling law of the...
Preload refers to the degree of stretch on the heart before it contracts. It's analogous to the stretching of a rubber band; the more it's stretched, the more forcefully it snaps back. This concept is encapsulated in the Frank-Starling law of the...
Cardiac Output I:Effect of Heart Rate on Cardiac Output
Cardiac Output
Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements.
Effect of Heart Rate on Cardiac Output
Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart rate...
Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements.
Effect of Heart Rate on Cardiac Output
Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart rate...
Cardiac Output II: Effect of Stroke Volume on Cardiac Output
Cardiac output (CO), the amount of blood the heart pumps per minute, is a parameter in cardiovascular physiology determined by stroke volume and heart rate. Stroke volume, the amount of blood pushed from one of the ventricles per heartbeat, is influenced by preload, afterload, and contractility.
Preload
Preload refers to the initial elongation of the cardiac myocytes before contraction and is related to the volume of blood filling the heart at the end of diastole, or end-diastolic volume. The...
Preload
Preload refers to the initial elongation of the cardiac myocytes before contraction and is related to the volume of blood filling the heart at the end of diastole, or end-diastolic volume. The...

