Ghosh P, Kumar S, Pandey S, Kumar A S, Sinha N
Cardiac Sciences Center, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
Ann Thorac Cardiovasc Surg. 1998 Oct;4(5):251-61.
BACKGROUND & OBJECTIVE: Small aortic annulus is conventionally associated with poor outcome after aortic valve replacement (AVR). Contrarily, several patients have excellent follow-up results after AVR with 19, 20 or 21 size Medtronic Hall (MH) or Sorin Carbocast (SC) prostheses. This disparity prompted a relook at the semantics of a small aortic annulus.
Available survivors of isolated AVR with #19, #20 or #21 prostheses - 13 with 19 SC or 20 MH valves (Group A) and 29 with 21 SC or MH valves (Group B) were studied. Disparity between actually implanted prostheses versus predicted prosthetic size (tissue annulus diameter) was analysed according to nomograms of Rowlatt et al, NIH Plehn, Kishimoto formula and Sievers composite criteria. Preoperative and follow-up echocardiographic assessments were used for hemodynamic and prosthetic function indices.
Both groups were similar in age, height, weight, BSA, BMI, mean NYHA class, CTR, preoperative peak gradient (PG) (92. 0 +/- 29.55 vs 102.88 +/- 33.65), mean gradient (MG) (56.8 +/- 24.6 vs 61.55 +/- 16.56), LVEDD (50.75 +/- 10.92 vs 56.0 +/- 13.5), LVESD (34.37 +/- 13.32 vs 38.52 +/- 13.85) and LVEF (67.5 +/- 12.5 vs 63.9 +/- 14.3). By developmental indices of Rowlatt et al. and NIH, no valve annulus could be designated as narrow. By Sievers composite nomogram all implanted valves were undersized by echocardiographic parameters, in normal range by angiographic criteria and oversized by anatomic autopsy data. Implanted valves in both groups were bigger than Plehn-predicted size (18.16 +/- 1.48 in GrA, 19.46 +/- 1. 10 in GrB). Valve size indices (VSI) (GrA 16.16 +/- 2.85 GrB 14.24 +/- 1.64) and geometric orifice area indices (VAI: valve area index) (GrA 1.50 +/- 0.28 vs 1.41 +/- 0.19) and postoperative rest PG (GrA 47.2 +/- 18.6 GrB 33.8 +/- 9.9) and MG (GrA 27.2 +/- 12.9 vs 19.0 +/- 9.9) were acceptable. LVEDD and LVESD regressed in both groups. LV mass indices regressed from 218.56 +/- 100.85 to 128.17 +/- 27.7 in GrA and 238.94 +/- 102.5 to 134.22 +/- 34.72 in GrB. Performance indices of implanted valves and postoperative aortic valve resistances were correlative.
The size of the implanted prostheses per se does not denote narrowness. Patient-prosthesis mismatch may be considered if predicted prosthesis has VSI <12 mm/m2, VAI <1.31 cm2/m2 or prosthesis orifice diameter <19 mm which may indicate annular enlargement.
传统观念认为，主动脉瓣环较小与主动脉瓣置换术（AVR）后预后不良相关。相反，一些患者在接受19号、20号或21号美敦力霍尔（MH）或索林卡波卡斯特（SC）人工瓣膜置换术后，随访结果良好。这种差异促使人们重新审视小主动脉瓣环的定义。
对接受#19、#20或#21号人工瓣膜置换术的孤立性AVR存活患者进行研究，其中13例植入19号SC或20号MH瓣膜（A组），29例植入21号SC或MH瓣膜（B组）。根据Rowlatt等人的列线图、美国国立卫生研究院（NIH）的Plehn公式、岸本公式和Sievers综合标准，分析实际植入的人工瓣膜与预测的人工瓣膜尺寸（组织瓣环直径）之间的差异。术前和随访时进行超声心动图评估，以获取血流动力学和人工瓣膜功能指标。
两组患者在年龄、身高、体重、体表面积、体重指数、平均纽约心脏协会（NYHA）分级、心胸比率（CTR）、术前峰值梯度（PG）（92.0±29.55对102.88±33.65）、平均梯度（MG）（56.8±24.6对61.55±16.56）、左心室舒张末期内径（LVEDD）（50.75±10.92对56.0±13.5）、左心室收缩末期内径（LVESD）（34.37±13.32对38.5,2±13.85）和左心室射血分数（LVEF）（67.5±12.5对63.9±14.3）方面相似。根据Rowlatt等人及NIH的发育指标，没有瓣环可被认定为狭窄。根据Sievers综合列线图，所有植入瓣膜经超声心动图参数评估均尺寸偏小，经血管造影标准评估在正常范围内，而经解剖尸检数据评估则尺寸偏大。两组植入瓣膜均大于Plehn预测尺寸（A组为18.16±1.48，B组为19.4,6±1.10）。瓣膜尺寸指数（VSI）（A组16.16±2.85，B组14.24±1.64）、几何开口面积指数（VAI：瓣膜面积指数）（A组1.50±0.28对1.41±0.l9）以及术后静息PG（A组47.2±18.6，B组33.8±9.9）和MG（A组27.2±12.9对19.0±9.9）均在可接受范围内。两组患者的LVEDD和LVESD均有所下降。A组左心室质量指数从218.56±100.85降至128.17±27.7，B组从238.94±102.5降至134.22±34.72。植入瓣膜的性能指标与术后主动脉瓣阻力相关。
植入人工瓣膜的尺寸本身并不意味着狭窄。如果预测的人工瓣膜VSI<12mm/m2、VAI<1.31cm2/m2或人工瓣膜开口直径<19mm，可能提示瓣环扩大，此时可考虑患者-人工瓣膜不匹配。
