Surgical treatment of complete aortic dislocation with ventricular septal defect and left ventricular outflow tract obstruction

  Complete transposition of the great arteries with ventricular septal defect and left ventricular outflow tract obstruction (TGA/VSD, LVOTO) is a pathology of complete transposition of the great arteries with conus septal defect and poorly aligned ventricular septal defect resulting in subvalvular pulmonary stenosis. VSD (LVOTO) is a complex cardiac malformation based on the pathology of complete transposition of great arteries (TGA) with posterior displacement of the conical septum and poorly aligned ventricular septal defect, resulting in subvalvular stenosis of the pulmonary artery. Because of the presence of LV outflow tract obstruction, traditional aortic switch operation (ASO) is generally not possible in these patients. Over the years, several generations of cardiac surgeons have tirelessly explored and improved the surgical approach and created various surgical methods to cure this malformation, including the Rastelli, REV, Yamagishi, Ross-Konno switch, and Nikaidoh surgeries. However, the possibility of completely relieving the left ventricular outflow tract obstruction and how to reconstruct the biventricular outflow tract continue to plague cardiac surgeons. Therefore, in today’s rapid development of pediatric cardiac surgery, TGA/VSD and LVOTO are called the only remaining ultimate challenges in TGA surgical treatment. The author is now reviewing the surgical methods, their respective advantages and disadvantages of the above mentioned procedures in order to share with colleagues and better apply them in clinical practice.  The Rastelli procedure was born in 1968 at the Mayo Clinic, and the untimely death of Dr. Rastelli has given this procedure a sad and mysterious tone. The main points of this procedure are: LVOT reconstruction is accomplished by creating an intracardiac tunnel with a patch between the VSD and the opening of the ascending aorta, and RVOT reconstruction is accomplished by connecting the right ventriculotomy to the distal common pulmonary artery. The relative simplicity of the procedure has made the Rastelli procedure the traditional standard of care for this type of malformation in most cardiac centers today. The early mortality rates of the Rastelli procedure reported by Boston Children’s Hospital and Mayo Clinic Hospital in the United States in recent years were 6.9% and 4%, respectively, and the mortality rate of this procedure in China has also decreased to about 7-10% in recent years. However, the intermediate and long-term outcomes after Rastelli surgery are surprisingly disappointing. The non-growing external canal used for the procedure began to suffer early to mid-postoperative fate, and the calcified and distorted external canal not only injured the fragile right heart, but also increased the 15-year secondary surgery rate to 80%. The long-term survival of patients after surgery is also worrisome, with a 20-year survival rate of only about 50%, with most deaths caused by sudden death due to sudden arrhythmias and left heart failure. Studies have shown that restenosis of the intracardiac tunnel and nonphysiological blood flow in the left ventricular outflow tract are responsible for malignant arrhythmias and left heart failure.  REV procedure This procedure was first used in 1980 by Lecompte et al. to correct double outlet right ventricle (DORV), and was subsequently used for TGA/VSD, LVOTO as well. The main pulmonary artery and ascending aorta are crossed over (Lecompte operation) and the posterior wall of the main pulmonary artery is anastomosed to the superior edge of the right ventricular incision to form the posterior wall of the new right ventricular outflow tract, and the anterior wall is enlarged with a patch (pericardium, bullous jugular vein, etc.) to reconstruct the RVOT.The advent of the REV procedure was once a glimmer of hope. The problem of RVOT obstruction was solved, but the problem of regurgitation followed. Follow-up studies have shown that severe pulmonary artery regurgitation occurs in the long term after REV surgery without exception, increasing right ventricular preload, leading to right heart remodeling and failure, and greatly reducing the patient’s activity tolerance and quality of life. Also, intracardiac tunneling for REV surgery has been shown to be associated with the development of arrhythmias in patients in the distant postoperative period.  Nikaidoh procedure In 1984, Nikaidoh et al. first used this procedure to correct TGA/VSD, and LVOTO was successful. This procedure was inspired by the Konno-Rastan strategy for the management of small aortic root valve replacement, which involves cutting off the aorta with the annulus and the autologous coronary artery and grafting it as a whole to the original location of the pulmonary annulus; enlarging the VSD by cutting the conical septum and closing the VSD with continuous sutures, thereby simultaneously Finally, the posterior wall of the main pulmonary artery is sutured directly to the superior edge of the right ventricular incision, and the anterior wall is enlarged with a pericardial patch. The classical Nikaidoh procedure does not have the Lecomte operation and coronary artery reimplantation, so its patient selection is limited by the position of the alignment of the two great arteries and the variability of the coronary artery opening. To address this, Morell and del Nido have made several improvements to the procedure, including 1) crossover of the ascending aorta and main pulmonary artery using the Lecompte operation, 2) reconstruction of the right ventricular outflow tract using a homogeneous valved conduit to alleviate postoperative pulmonary regurgitation, and 3) complete coronary artery reimplantation to avoid postoperative coronary events.The greatest advantage of the Nikaidoh class of procedures advantage is that there is no abnormal intracardiac tunnel between the left ventricle and the aorta, and the hemodynamics of the LVOT is closer to that of a normal heart, fundamentally avoiding the distant arrhythmias that can be caused by the Rastelli and REV procedures. However, it is “made in the left heart and lost in the right ventricle”. In the classical Nikaidoh, the right ventricular outflow tract was reconstructed using an autologous pericardium, and due to the absence of a pulmonary valve, postoperative regurgitation was massive and right ventricular function was severely impaired. Although the right ventricular outflow tract was later reconstructed by Morell and del Nido using the same type of valve-bearing vessel, the reconstructed tissue was still non-growing and therefore faced the same problem of external ductal failure and obstruction. In addition, the modified Nikaidoh procedure disrupts the aortic sinotubular junction and subaortic valve geometry due to the opening of the cone septum and complete coronary reimplantation, making the likelihood of moderate or greater aortic regurgitation much higher postoperatively. A comprehensive evaluation of the midterm outcomes of the Nikaidoh procedure was performed by del Nido et al. at Boston Children’s Hospital, USA, who noted that the midterm postoperative mortality, left and right ventricular outflow tract obstruction rates, and reoperation rates were significantly lower after the Nikaidoh procedure than the Rastelli and REV procedures; however, the higher incidence of aortic regurgitation after the Nikaidoh procedure suggests that its improvement is still needed.  The Yamagishi and Ross-Konno Switch procedures are similar to the Nikaidoh procedure in terms of surgical strategy, but there is no major breakthrough. The number of patients who have undergone these procedures is small, experience is limited, and there is a lack of medium- and long-term follow-up data, so they are still not the mainstream procedures for the treatment of TGA/VSD and LVOTO.  The Nikaidoh procedure effectively relieves the left ventricular outflow tract obstruction, but regurgitation of the right ventricular outflow tract and aortic regurgitation are still risk factors for long-term prognosis. For this reason, the cardiac surgeons at Fulbright Hospital made a pioneering exploration and proposed the Double Root Translocation (DRT), a fully anatomical biventricular correction of TGA/VSD, LVOTO. The core concept is the transposition of the two major arterial roots in pursuit of a patent biventricular outflow tract without reflux. The left ventricular outflow tract obstruction is further relieved after left ventriculotomy, thus eliminating the need for further cone septotomy in the vast majority of patients. The new aortic root sits firmly on the myocardial left ventricular outflow tract, the subaortic valve structure and left heart function are maximally protected, and the morphology and hemodynamics of the left ventricular outflow tract are almost completely normal. At the same time, the coronary artery was selectively reimplanted to preserve the geometry of the aortic sinotubular junction. 2) To ensure a patent right ventricular outflow tract without regurgitation: the pulmonary root was first reconstructed with a single valve patch (homograft) to ensure good performance of the pulmonary valve leaflet and leaflets, then the necessary shaping of the right ventricular outflow tract opening was performed to ensure good three-dimensional morphology of the RVOT, and finally the newly constructed pulmonary root was transposed Finally, the new pulmonary artery root was transposed and anastomosed to the RVOT opening to complete the reconstruction of the RVOT. These two innovations maximize the efficacy of the aortic and pulmonary valves and effectively improve their regurgitation. At the same time, the potential growth of the autologous pulmonary valve meets the needs of the child’s growth and development. The DRT procedure pioneered by Fu Wai Hospital has been invited to speak at the annual meeting of the American Association of Thoracic and Cardiovascular Surgery (AATS) for three consecutive years, and its surgical technique has also been invited to be published in the American journal Atlas of Cardiothoracic Surgical Techniques, which has received high attention and praise from international colleagues. At the 2009 AATS annual meeting, I reported the mid-term follow-up results of Rastelli, REV and DRT procedures in patients with TGA/VSD and LVOTS at Fu Wai Hospital under the title of “The fate of biventricular outflow tract”. However, the DRT procedure is more effective in relieving left ventricular outflow tract obstruction, less incidence of aortic and pulmonary regurgitation, and a more patent right ventricular outflow tract; however, the long extracorporeal circulation time of the DRT procedure places higher demands on the procedure, including anesthesia, myocardial protection, and postoperative monitoring. In the era of evidence-based medicine, the author’s report provides the largest group of international patient follow-up data for the treatment of TGA/VSD,LVOTO, which has attracted much attention from international colleagues.  Prospects The establishment of normal cardiac anatomy through surgical procedures is the aim of surgical treatment of precordial disease. When we look at the development of surgical treatment of TGA/VSD and LVOTO from a historical perspective, we cannot help but feel that the last 50 years of surgical treatment of TGA/VSD and LVOTO have been a great success. One cannot help but feel deeply that its development over the last 50 years has been amazing. It has overcome one difficulty after another, opened one forbidden area after another, and created one dozen miracles after another. This amazing development mainly relies on the deepening of the basic theoretical research of cardiac surgery, the gradual solution of the basic problems related to cardiac surgery, and the active application of recent new technologies. The surgical treatment of TGA/VSD, LVOTO still leaves much to be desired, and cardiac surgeons and physicians in related specialties are still facing serious challenges. We hope that more physicians who are interested in the study of complex precordial disease will work together to seize the opportunities given by the rapid development of technology in this era and continue to overcome the ultimate challenge of this complex precordial heart.