肺灌注显像评价全腔肺动脉吻合术后肺血分布

The significance of radionuclide lung perfusion imaging in assessment of the pulmonary blood flow distribution after total cavopulmonary connection

目的 探讨肺灌注显像评价全腔肺动脉吻合术后肺血分布的价值。方法 19例全腔肺动脉吻合术后的患者 ,根据上下腔静脉与肺动脉连接的方式分为 3组。第 1组 (6例 ) :上下腔静脉对称地与右肺动脉端侧吻合 ;第 2组 (10例 ) :下腔静脉通过心外管道或心内隧道与主肺动脉端端吻合 ;第 3组 (3例 ) :下腔静脉与主肺动脉端端吻合 ,左右上腔静脉与左右肺动脉端侧吻合。患者术后均接受肺灌注显像 ,根据显像结果 ,定性和定量分析上、下腔静脉血及全部肺血在左右肺内的分布特征。结果 第 1组 :上下腔静脉血均匀地回流至左右肺 ,全部静脉血均匀地分布到左右肺 ;第 2组 :大多数或全部上腔静脉血回流到右肺 ,极少数回流到左肺 ;大多数或全部下腔静脉血回流到左肺 ;全部肺血主要分布到左肺 ;第 3组 :右上腔静脉血全部回流至右肺 ;左上腔静脉血全部回流至左肺 ;下腔静脉血液多数分布至左肺 ,少数分布至右肺。结论 不同方式的全腔肺动脉吻合术可导致不同的肺血分布 ;肺灌注显像是一种简单、准确。

Objective To evaluate the value of radionuclide lung perfusion imaging in assessment of the pulmonary blood flow distribution after total cavopulmonary connection (TCPC). Methods Nineteen consecutive patients with age ranging from 5～21 years who survived TCPC underwent radionuclide lung perfusion imaging. According to the radionuclide counts in left and right lungs to analysis the distribution of blood flow from superior vena cava (SVC) and inferior vena cava (IVC) and the whole pulmonary blood flow in both lungs. On the base of the anastomosis between IVC and pulmonary artery, all patients were divided into three groups. GroupⅠ( n =6): Patients after TCPC with the anastomosis of SVC and IVC directly opposites each other on the right pulmonary artery (RPA) with '+'imaging . GroupⅡ( n =10): Patients after the TCPC with the IVC connected to the main pulmonary artery (MPA) by extracardiac conduit or intraatrial lateral tunnel. Group Ⅲ ( n =3): Patients after the TCPC with the IVC connected to the main pulmonary artery (MPA) by extracardiac conduit with bilateral bidirectional cavopulmonary connection (BCPC). Results GroupⅠ: The flow from the SVC and IVC were mixed in the middle of the junction and turn toward the right and left lungs driving evenly in halves [SVC: (49±4.2)% to right lung, (51±4.2)% to left lung , t=0.113, P> 0.05; IVC: (48±3.7)% to the left lung, (52±3.7)% to the right lung, t=0.29, P >0.05] ; the whole pulmonary blood flow went to both lungs dividing evenly in halves [(51±3.9)% to right lung,(49±3.9)% to left lung, t =0.131, P >0.05]. GroupⅡ:The flow proportion of the IVC to left lung was greater than that to the right lung, the blood flow went dominantly or completely to the left lung [(87±3.2)% to the left, (13±3.2)% to the right, t=8.22, P< 0.01]; the flow proportion of the SVC to right lung was greater than that to the left lung , the blood flow went dominantly or completely to the right lung [(85±3.0)% to the right, (15±3.0)% to the left, t=6.84, P< 0.01]; and the whole pulmonary blood flow went dominantly to left lung[(61±3.1)% to the left, (39±3.1)% to the right, P <0.05]. GroupⅢ: The flow from right SVC to right lung by 100% (right lung vs. left lung, P <0.01) and that from left SVC to left lung by 100% (right lung vs. left lung, P <0.01), the flow from IVC went dominantly to left lung and a small part went to right lung [(60±4.5)% to the left, (40±4.5)% to the right, P >0.05]. Conclusions Different designs of TCPC can result in different pulmonary blood distribution; radionuclide lung perfusion is a convenient, non-invasive, accurate and reproducible method, which allows quantitative analysis.