DK2985_C000 1..28 - AlSharqia Echo Club

482 Transesophageal EchocardiographyDoppler imaging of the tricuspid valve (TV) annulus (6).Right ventricular systolic dysfunction has also beenshown to be associated with an abnormal hepatic venoussystolic (S) wave (7). The use of a pulmonary artery catheter(PAC) for continuous pulmonary artery pressuremeasurement in conjunction with TEE is useful in thissetting. The need for pharmacological support, ventilatorymanagement and cardiopulmonary bypass (CPB) can thusbe safely planned. In the authors’ experience, the need forCPB varies from ,2% for emphysema patients, 30% inpatients with pulmonary fibrosis, to its systematic use inPPH patients.II.ROLE OF TEE DURING THE PROCEDUREDuring the procedure, TEE can be used to evaluate left andright systolic and diastolic function, to rule out the presenceof an unexpected patent foramen ovale with aright-to-left shunt (8), to verify the integrity of the pulmonaryvascular anastomoses (Fig. 21.1) and to exclude significantair embolus (1). The appearance of continuousair emboli observed by TEE at the end of a lung transplantationshould prompt re-examination of the bronchial anastomosisintegrity (9) (Fig. 21.2). Although the need forCPB varies greatly, all lung transplantations are performedwith CPB on standby. In the absence of a formal indicationfor CPB such as the presence of PPH or an Eisenmenger’ssyndrome, surgeons have yet to agree on whether or notCPB should be routinely used (10,11). The need for CPBis difficult to establish preoperatively as reported by deHoyos et al. (12) and Triantafillou et al. (13). In thesetwo studies, parameters such as preoperative PaO 2 , meanpulmonary artery pressure and pulmonary vascular resistancewere not found to be reliable predictive indicators forthe use of CPB. Intraoperatively however, the hemodynamiceffects of pulmonary artery clamping as evaluatedby TEE are extremely useful in establishing the need forCPB: echocardiographic signs of low cardiac output(CO) or severe right ventricular dysfunction such asright atrial and ventricular dilatation with paradoxicalseptal motion (Fig. 21.3) and reduced systolic excursionof the tricuspid annulus (see Chapter 9) help to determineprecisely the need for circulatory support.Using a 5.0 MHz biplane or multiplane TEE probe, astandard examination, including Doppler flow measurements,is performed in both the transverse and longitudinalplanes. The examination should be repeated intraoperativelyonce the anastomoses have been completed. Thepresence of an arterial or pulmonary vein stenosisFigure 21.1 Pulmonary vascular anastomosis. (A, B) Right pulmonary artery (RPA) anastomosis in a 45-year-old man after lung transplantation,viewed through the upper mid-esophageal view at 08. (C) Intraoperative left pulmonary artery anastomosis in a 55-year-oldwoman undergoing single left pulmonary transplantation. (D) After completing the anastomosis, the pericardium is closed. (Ao, aorta;MPA, main pulmonary artery; TRPA, transplanted right pulmonary artery).