Anderson W A, Ilkowski D A, Eldredge J, Cha R, Chen C, Waters D, Mahan V L, Anolik G, Laub G W, Fernandez J, McGrath L B
Deborah Heart and Lung Center, Department of Cardiovascular and Thoracic Surgery, New Jersey, USA.
J Heart Valve Dis. 1996 Nov;5 Suppl 3:S329-35.
The selection of an appropriate size aortic valve substitute with respect to patient size and life-style, in the presence of a small aortic root, is problematic, and a decision to enlarge the aortic annulus is often arbitrary. An aortic valve substitute-patient mismatch may place an excessive load on the left ventricle resulting in residual left ventricular mass with attendant patient morbidity and mortality. The aim of this study was to assess the adequacy of the Medtronic Hall valve in the small aortic root using ultrafast computed tomography analysis of left ventricular mass.
In 13 patients the smallest Medtronic Hall valves (size 20 and 21; measured internal orifice area of 2.01 cm2 for both) were used to replace the native aortic valve. All patients had aortic stenosis, and left ventricular hypertrophy was established by echocardiography. The mean body surface area was 1.8 +/- 0.2 m2 (range 1.50-2.06 m2) and the mean weight was 75 +/- 15 Kg (range 50-97 Kg). The mean preoperative New York Heart Association functional class was 3.54 +/- 0.5.
There was no operative or late mortality. At a mean follow up of 22 months after aortic valve replacement, the mean left ventricular mass index was 89 +/- 11.4 g/m2 (normal left ventricular mass index by ultrafast computed tomography = 97 +/- 14 g/m2) and mean New York Heart Association functional class was 1.6 +/- 0.8 (p (Binomial) = 0.0001 compared to preoperative). Doppler echocardiogram demonstrated a mean gradient across the prosthetic valve of 17 +/- 7 mmHg. There was no trend towards greater left ventricular mass index in patients with greater body surface area or weight. In no patient was the aortic annulus enlarged.
Trends from this preliminary data suggest that implanting the smallest Medtronic-Hall aortic valves (sizes 20 and 21) results in normal left ventricular mass following aortic valve replacement in patients up to a body surface area of 2.06 m2 and provides support for the notion that an aortic annulus enlarging procedure was not necessary in this group of patients.
在主动脉根部较小的情况下，根据患者体型和生活方式选择合适尺寸的主动脉瓣置换物存在问题，决定扩大主动脉瓣环往往具有随意性。主动脉瓣置换物与患者不匹配可能会给左心室带来过重负担，导致左心室残余质量增加，进而引发患者发病和死亡。本研究的目的是通过对左心室质量进行超快速计算机断层扫描分析，评估美敦力霍尔瓣膜在小主动脉根部的适用性。
13例患者使用了最小尺寸的美敦力霍尔瓣膜（型号20和21；两者测量的内孔面积均为2.01平方厘米）来置换自身主动脉瓣。所有患者均患有主动脉瓣狭窄，且经超声心动图确诊为左心室肥厚。平均体表面积为1.8±0.2平方米（范围为1.50 - 2.06平方米），平均体重为75±15千克（范围为50 - 97千克）。术前纽约心脏协会心功能分级平均为3.54±0.5级。
无手术或晚期死亡病例。主动脉瓣置换术后平均随访22个月，左心室质量指数平均为89±11.4克/平方米（超快速计算机断层扫描的正常左心室质量指数为97±14克/平方米），纽约心脏协会心功能分级平均为1.6±0.8级（与术前相比，二项式p值 = 0.0001）。多普勒超声心动图显示人工瓣膜两端的平均压差为17±7毫米汞柱。体表面积或体重较大的患者中，左心室质量指数没有增大的趋势。所有患者均未扩大主动脉瓣环。
这些初步数据表明，植入最小尺寸的美敦力 - 霍尔主动脉瓣膜（型号20和21）可使体表面积达2.06平方米的患者在主动脉瓣置换术后左心室质量正常，这支持了在该组患者中无需进行主动脉瓣环扩大手术的观点。
