Case report

The patient was a 3-year-old male weighing 16 kilograms, diagnosed with transposition of the great arteries, ventricular septal defect, and left ventricular outflow tract obstruction. The ventricular septal defect was remote and restrictive. In his history, there was a modified Blalock–Taussig shunt that was performed through median sternotomy with a 4-millimetre expanded polytetrafluoroethylene graft when he was 3 months old. Despite the fact that echocardiography and angiography confirmed the functioning shunt, the room-air oxygen saturation was 65%. In addition, cardiac catheterisation indicated unusual coronary pattern: the right coronary artery originated from the left anterior descending artery (Fig 1) and normal origin circumflex coronary artery. Most probably due to post-stenotic dilatation, the main pulmonary artery and both branches were large and revealed a McGoon value above 2.

Figure 1

The cardiac catheterisation showing the right coronary artery originating from the left anterior descending artery. RCA = right coronary artery; LAD = left anterior descending coronary artery.

Surgical technique

The heart was accessed through median sternotomy. There were extensive adhesions, and care was taken to free the heart and vascular structures from these adhesions. Cardiopulmonary bypass was initiated with cannulation of the distal ascending aorta and superior and inferior caval veins. Cardioprotection was achieved with moderate hypothermia (28 degrees Celcius) and cold intermittent antegrade blood cardioplegia. The modified Blalock–Taussig shunt was ligated. The pulmonary arteries were large. Despite the fact that the coronary anatomy was identified before the surgery with cardiac catheterisation, the right coronary artery was accidentally injured during the aortic root preparation from the right ventricle (Fig 2) because of extensive adhesions that occurred after his first operation. The right coronary artery was anastomosed end to end with an 8.0 polyprolene suture. Repair of the right coronary artery was easy because of the large size of the artery in accordance with the child's age, as well as cyanotic status of the patient – that is, in cyanotic congenital cardiac disorders, the coronary arteries are enlarged. The circumflex coronary artery was not removed as a button, but was prepared free from the right ventricular wall to facilitate aortic translocation. The aortic root was completely dissected, leaving the left anterior descending coronary artery together with right coronary artery as a button. The pulmonary artery was dissected. The left ventricular outflow tract was hypoplastic with an annulus size of 4–5 millimetres (Fig 3). A “V”-shaped dacron patch was used to reconstruct the new outflow tract and close the ventricular septal defect (Fig 4). The left ventricular outflow tract was enlarged by incising the infundibular septum and trimming the hypertrophied muscle bands at the left ventricular outflow tract. Lecompte manoeuvre was performed. The aortic root containing the circumflex coronary artery was translocated with posterior rotation to the remodelled left ventricular outflow tract. The detached left anterior descending coronary artery was then reimplanted to the most suitable location on the translocated aorta. Despite the fact that pre-operative calculations indicated a conduit size of 16 millimetres for the reconstruction of the right venrtricular outflow tract, a Contegra valved conduit with a size of 14 millimetres was used to provide pulmonary flow due to the close anatomy of the right coronary artery crossing the right ventricular outflow tract to prevent right coronary artery distention and myocardial ischaemia.

Figure 2

The right coronary artery was accidentally injured during the aortic root preparation. RCA = right coronary artery.

Figure 3

Figure showing the pathology. RVOT = right ventricular outflow tract; LVOT = left ventricular outflow tract; VSD = ventricular septal defect.

Figure 4

A “V”-shaped dacron patch was used to reconstruct the new outflow tract and close the ventricular septal defect. LVOT = left ventricular outflow tract; VSD = ventricular septal defect.

The cardiopulmonary bypass and aortic cross-clamp times were 185 and 142 minutes, respectively. The patient experienced Wenkebach Type 2-like rhythm disturbances, and therefore we instituted ventricular pacing perioperatively. He was weaned off cardiopulmonary bypass with moderate dose inotropic support – 5 micrograms per kilogram per minute Dopamine, and 0.05 microgram per kilogram per minute Adrenalin. We did not come across coronary artery-related ischaemia symptoms, which might have resulted from the right coronary artery, thus confirming the successful repair of the injured right coronary artery. At post-operative echocardiography, the right ventricular outflow tract indicated a maximum of 20-millimetre mercury gradient through the Contegra and minimal aortic valve insufficiency. The patient was transferred to the intensive care unit and was extubated on the fourth post-operative day. The rhythm problem ceased spontaneously on the third day. The post-operative course was uneventful and he was discharged on day 10 without any problems. He was at New York Heart Association Functional Class I, and was symptom free in the follow-up period, with 100% oxygen saturation at room air for more than 8 months, without signs and symptoms of coronary ischaemia.

Comment

Transposition of the great arteries, ventricular septal defect, and left ventricular outflow tract obstruction pathology has long been treated with different techniques. Among them, since its first introduction in 1969, the Rastelli procedure is indisputably the most common method with long-term follow-up results.Reference Sayin, Ugurlucan, Saltik, Sungur and Tireli^2–Reference Kreutzer, De Vive and Oppido⁹ The procedure has evolved over time with contributions from different authors for better outcomes.Reference Alsoufi, Awan and Al-Omrani¹⁰ However, long-term follow-up results of the Rastelli procedure have shown the unfeasibility of the method due to considerable rates of reoperations, rhythm disturbances, and low 20-year survival rate.Reference Morell, Jacobs and Quintessenza^4–Reference Kreutzer, De Vive and Oppido⁹

In 1982, as an alternative to the Rastelli procedure, a new technique, the Réparation à l'Etage ventriculaire procedure, was introduced by Lecompte et alReference Lecompte, Neveux and Leca¹¹ In this method, the right ventricular outflow tract is reconstructed by directly anastomosing the pulmonary artery to the right ventricular outflow tract, and hence left valveless and without using a prosthetic conduit.Reference Alsoufi, Awan and Al-Omrani¹⁰ Metras repair is a modification of Réparation à l'Etage ventriculaire in which the pulmonary artery is still left valveless and connected to the right ventricle, but with an elongation segment obtained from the autologous aorta.Reference Metras, Kreitmann and Riberi¹² Valveless right ventricular outflow tract reconstructions may provide longer reoperation-free interval; however, inevitably, these patients will require a reintervention for the valveless pulmonary artery and right ventricular functions in the long run.

In 1984, Nikaidoh announced the latest technique for the treatment of this particular group of patients.Reference Nikaidoh¹ The method is a combination of the Ross, Konno, and Jatene procedures.Reference Morell, Jacobs and Quintessenza⁴ It provides anatomical alignment of the aorta over the left ventricle and better haemodynamic and physiologic performance at the left and right ventricular outflow tracts. The native aortic valve is transferred to the systemic circulation with anatomical alignment, and therefore it is believed that the longevity of the procedure will be better.Reference Hu, Liu and Li⁵

Modifications of Nikaidoh differ from the original technique mainly on the basis of the type of the coronary transfers. In the original technique, aortic root is transferred en bloc to the left ventricular outflow tract, whereas in the modified techniques either left or right coronary artery or both are detached and reimplanted following aortic translocation to prevent coronary insufficiency.Reference Sayin, Ugurlucan, Saltik, Sungur and Tireli^2–Reference Morell, Jacobs and Quintessenza^4, Reference Ugurlucan and Tireli¹³

It is well known that the Rastelli, Réparation à l'Etage ventriculaire, or Metras operations do not require coronary transfer. However, during the Nikaidoh-type repairs, the coronary arteries are transferred either en bloc or separately. It has been accepted as a risk factor for increased mortality and morbidity in the conventional arterial switch operations, and thus some authors propose unusual coronary anatomy as a contraindication for the Nikaidoh procedure.Reference Delgado-Pecellín, García-Hernández, Hosseinpour and Gerard Hazekamp^3, Reference Morell, Jacobs and Quintessenza⁴ The reasons are mainly due to the high risk and aggressive nature of the Nikaidoh and its modifications. In the literature, only Hu et alReference Hu, Liu and Li⁵ presented cases of two patients with coronary anomalies who underwent Nikaidoh procedures; however, the authors did not explain their techniques in these two particular cases in detail. As can be seen in the history of the Jatene procedures, increasing experience will eventually cease the high-risk nature of challenging coronary anatomy during the Nikaidoh operations.

The Nikaidoh procedure may include some limitations, and our case clearly shows why some authors considered coronary anomalies as relative contraindications to the Nikaidoh.Reference Delgado-Pecellín, García-Hernández, Hosseinpour and Gerard Hazekamp^3, Reference Morell, Jacobs and Quintessenza⁴ The coronary pattern should be extensively evaluated in the pre-operative period, as well as during the surgery. Our patient was 3 years old; however, if the patient was much smaller or even a neonate, repair of the injured coronary artery would not have been as easy or successful, and the procedure may have ended up with catastrophic results. However, Nikaidoh-type repairs are very rarely indicated in neonates or small children. In children with challenging coronary anatomies, such as intramural coronary course, one must not hesitate to proceed with alternative techniques such as Rastelli or Réparation à l'Etage ventriculaire procedures even though the Nikaidoh procedure was planned in the pre-operative period.

In the presented case, although a conduit size of 16 millimetres was required, a 14-millimetre-sized Contegra valved conduit was used for the right ventricular outflow tract reconstruction because of the close anatomy of the right coronary artery to the right ventricular outflow tract. This did not lead to low oxygen saturation because the child was not very small. It also provided distension-free right coronary artery and prevented myocardial ischaemia. Thus, the child has been at New York Heart Association Functional Class I, without signs and symptoms of coronary ischaemia, with 100% oxygen saturation at room air.