Expeimental Study on Pulmonary Function and Lung Growth after Living-Donor Lobar Lung Transplantation

实验一：为了解决供体短缺的问题，活体肺移植取得了令人满意的结果。小移植物的使用有潜在的问题，因为它可能会导致肺动脉高压，导致肺水肿。这项研究的目的是评估小移植物对早期肺功能的影响，并确定可接受的大小差异的预测因素。选用17对不同供受体(D/R)大小的杂种犬。测量体重、身高、胸围和肺重作为尺寸参数。在不使用体外循环的情况下，将右中、下、心叶作为受体的右肺移植，左下叶作为左肺移植。于再灌注后6h测定受者肺功能。D/R体重比与1h平均肺动脉压呈显著负相关(r=-0.594；p=…超过0.025)。D/R体重比与6h动脉血氧分压(PaO_2)呈显著正相关(r=0.704；p=0.007)。其余三个大小参数与术后肺功能无明显相关性。所有8名D/R体重比为&GT；1.2的受试者在6小时评估期内全部存活，6小时后PaO2超过500毫米汞。D/R重量比是犬活体-供体肺叶移植模型中早期肺功能的重要预测指标。实验2：对于婴幼儿，器官移植受到供体和受者大小差异的限制。为了解决这一问题，使用活体亲属捐赠者的超大移植物可能会扩大捐赠者的人才库。这项实验研究的目的是评估过大的移植物对早期肺功能的影响，并确定一个可接受的大小差异的指标。14只体重不匹配的犬在非体外循环的情况下进行了双侧肺叶移植手术。实验动物分为两组：I组(n=7)供受体肺体积比2.85；II组(n=7)供受体肺体积比2.85。分别在关胸前、关胸后和撤机后测量受者的肺功能。II组封胸后肺血管阻力和气道压力显著升高(1493±195dynes Sec.cm-5和14.4±0.9 mm Hgvs2784±140dyn.sec.cm-5和23.4±1.2 mmHg，p&lt；0.001)。拔除呼吸机后，I组所有受试者Pa02和PaCO2分别为239 mm Hg和76 mm Hg，II组均为Pa02和169 mm Hg。除1只外，I组供受体胸围比均小于1.3。可接受的超大移植物可提供足够的肺功能，尽管过度超大移植物在关闭胸腔后会造成严重的肺功能损害。胸围提供了一个有用的大小匹配标准，当超大移植物在这个犬实验模型中使用。较少

Experiment 1: In an effort to address the donor shortage issue, living-donor lobar lung transplants have been performed with satisfactory results. The use of small grafts is potentially problematic because it could cause high pulmonary artery pressure resulting in lung edema. The purpose of this study was to evaluate the effect of small grafts on early pulmonary function and to identify the predictor for acceptable size discrepancy. Seventeen pairs of mongrel dog with various donor/recipient (D/R) sizes were used. Body weight, height, chest circumference and lung weight were measured as size parameters. Right middle, lower and cardiac lobes were implanted as a right lung of the recipient and left lower lobe was implanted as a left lung without using cardiopulmonary bypass. Pulmonary function of the recipient was measured for 6 hours after reperfusion. A significant negative correlation was found between D/R body weight ratio and mean pulmonary artery pressure at one hour (r=-0.594 ; p= … More 0.025). A significant correlation was found between D/R body weight ratio and arterial oxygen tension (Pa02) at 6 hours (r=0.704 ; p=0.007). There was no significant correlation between the other three size parameters and postoperative pulmonary function. All 8 recipients with D/R body weight ratio > 1.2 survived the 6-hour assessment period and their PaO2 exceeded 500 mmHg at 6 hours. D/R weight ratio is an important predictor of early pulmonary function in a canine living-donor lobar lung transplant model.Experiment 2 : For infants and small children, organ transplantation is limited by the size discrepancy between donor and recipient. To address this problem, the use of over-sized grafts from living-related donors could potentially expand the donor pool. The aim of this experimental study was to evaluate the effect of over-sized grafts on early pulmonary function and to identify an indicator for an acceptable size discrepancy. Fourteen bilateral lobar lung allotransplant operations were performed without cardiopulmonary bypass in weight mis-matched pairs of dogs. Animals were divided into two groups : Group I (n=7), Donor/Recipient lung volume ratio < 2.85 ; Group II (n=7), Donor/Recipient lung volume ratio > 2.85. Pulmonary function of the recipient was measured before chest closure, after chest closure, and after the ventilator was removed. Pulmonary vascular resistance and airway pressure significantly increased in group II after, chest closure (1493±195 dynes sec.cm-5 and 14.4± 0.9 mmHg versus 2784±140 dynes.sec.cm-5 and 23.4±1.2 mmHg, p<0.001). After the ventilator was removed, all recipients in group I showed Pa02 > 239 mmHg and PaC02 < 76 mmHg, whereas all recipients in group II showed Pa02 <116 mmHg and PaCO2 > 169 mmHg. The Donor/recipient chest circumference ratio was less than 1.3 in all but one dog in group I. Acceptable over-sized grafts provide adequate pulmonary function, although excessively over-sized grafts cause significant impairment in pulmonary function after the chest closure. Chest circumference provides a useful size match criteria when over-sized grafts are used in this canine experimental model. Less