Senning procedure for transposition of the great arteries

Pulsed Doppler evaluation of pulmonary venous flow was performed in three groups of patients who had undergone either a Mustard or Senning procedure. Group I consisted of 43 patients in sinus rhythm who had undergone the Mustard procedure 9 months or more before the Doppler examination and 16 who were evaluated immediately after surgery. Group II consisted of 12 patients in sinus rhythm who had undergone the Senning procedure 9 months or more before the Doppler evaluation. Group III consisted of eight patients with mid baffle obstruction of the pulmonary venous atrium and seven with isolated stenosis of the pulmonary vein of which all but one had previously had associated mid baffle obstruction. In those without obstruction, the pulmonary venous flow pattern mirrored the left atrial pressure trace, with peak forward flow occurring during the x and y descent. Obstruction produced a specific high-velocity turbulent pattern, whether at the mid baffle or pulmonary venous level. This technique provides reliable noninvasive information about pulmonary venous flow after the Mustard or Senning procedure. Circulation 73, No. 4, 765-774, 1986. INTERATRIAL REROUTING of pulmonary and systemic venous blood by the Mustard or Senning procedure is still the most common operation for patients with simple transposition of the great arteries. In the former the pericardium is used to form the baffle, while in the latter the native atrial tissue is used.' The theoretical advantages of the Senning procedure is that it preserves normal atrial function and growth of the pathways.t Both procedures may be complicated by systemic or pulmonary venous obstruction (PVO), and more rarely by isolated stenosis of the pulmonary veins.'-"1 Unless PVO is severe, clinical recognition is difficult and diagnosis necessitates cardiac catheterization.' 1-7 Recently cross-sectional echocardiography has been From the Department of Pediatrics, Division of Cardiology and Cardiovascular Surgery, The Hospital for Sick Children, Toronto, Ontario, the Montreal Children's Hospital, Quebec, and the Ottawa Children's Hospital, Ontario. Dr. Gow was supported by the Ontario Heart Foundation, grant No. 9511. Address for correspondence: Jeffrey Smallhom, M.D., Department of Cardiology, The Hospital for Sick Children, 555 University Ave., Toronto, Ontario M5G 1X8, Canada. Received July 22, 1985; revision accepted Dec. 5, 1985. Vol. 73, No. 4, April 1986 used to assess the midportion of the pulmonary venous atrium after the Senning procedure.'8' 9 However, problems may occur in the older patient in whom a reliable window is absent. Furthermore, this technique does not identify those patients with stenosis of the pulmonary veins.11 The left atrium acts as a reservoir for pulmonary venous return and augments left ventricular filling during atrial contraction. Pulmonary venous flow measured experimentally appears to mirror left atrial pressure events, particularly the slope of the x and y descent.2'22 More recently it has been possible to assess pulmonary venous flow by pulsed Doppler echocardiography.2324 The purpose of this study was to compare pressure and flow profiles in patients who have undergone the Mustard Senning procedure with normal subjects and those with PVO either at mid baffle or pulmonary venous level. Materials and methods Three groups of patients were studied. Group I consisted of 59 patients who had undergone the Mustard procedure and were evaluated at the Hospital for Sick Children. In 43, the surgery had been performed more than 9 months before the study. In