Cone Repair in an Adult Patient with Type-C Ebstein's Anomaly
Ebstein’s anomaly is a rare malformation involving the tricuspid valve and the right ventricle (1). The main features are: (a) failure of leaflets delamination; (b) atrialization of part of the right ventricle; (c) apicalization of the functional tricuspid anulus; (d) interatrial shunt. Natural history is burdened by a high mortality rate, reaching 50 percent at approximately fifty years of age (2). The indication for surgical repair depends on the presence of symptoms such as cyanosis, reduced exercise capacity, arrhythmias, and embolism.
Surgical repair of Ebstein’s anomaly has a long history, and several techniques have been adopted in recent decades (3,4). The cone repair is a recently introduced technique that has provided good early and midterm results (5). Furthermore, this technique has proved to be reliable, reproducible, and standardizable and has changed the face of the surgical approach to this pathology. The short video above aims to show a step-by-step cone repair of a type-C Ebstein’s anomaly in an adult patient.
Case Description
The patient is a fifty-nine-year-old female with Ebstein’s anomaly. She had experienced worsening symptoms over the last year consisting of asthenia and dyspnea. Until that point, she had led a normal life, including a pregnancy at twenty-nine years of age. In 2017, she suffered her first episode of atrial fibrillation, which became persistent in the following six months. A functional NYHA class III was described. She started oral therapy with amiodaron 200 mg qod, apixaban 10 mg bid, furosemide 25 mg bid, ramipril 2.5 mg qod, and bisoprolol 1.25 od. A surgical plan was scheduled.
At admission, an electrocardiogram (EKG) showed atrial fibrillation and right bundle branch block (RBB) with QRS duration of 160 msec. The echocardiographic examination evidenced severe displacement of all tricuspid leaflets and a severe atrialization of the right ventricle. The anterior leaflet showed multiple attachments to the anterior right ventricular wall. Furthermore, the coaptation plan was oriented toward the right ventricular outflow tract. A patent foramen ovale was present. At a cardiac catheterization, the mean right ventricular and pulmonary artery pressures were 12 and 11 mmHg, respectively. The coronary arteries were unobstructed. The patient underwent a successful cone repair, as shown in the video above. While her postoperative hospital stay was uneventful, the post-operative echocardiographic examination showed trivial residual tricuspid regurgitation. At discharge, the chest Xray was nearly normal, and the EKG showed sinus rhythm with RBB. At a thirteen months follow-up, the tricuspid coaptation was high with trivial regurgitation. A significative reduction of the right ventricle and a more balanced volume between right and left ventricles were described. Actual oxygen saturation was 96 percent.
Surgical Procedure
The operation was conducted under full median sternotomy. To start, a bicaval cannulation was adopted. Under moderate hypothermic circulation, the heart was arrested using cold crystalloid cardioplegia.
The right atrium was opened through an incision parallel to the atrioventricular groove. Careful attention was posed to avoid injury of the right coronary artery. After valve inspection, the anterior and posterior leaflets were detached, starting at the level of anteroseptal commissure toward the posteroseptal commissure. Once both leaflets were detached from the anulus, a surgical delamination was started. Both leaflets were delaminated completely until primary chordae were found. All possible attachments were removed, and multiple fenestrations became evident. Small fenestrations were directly closed using 6-0 Prolene sutures. Similarly, a large fenestration of the posterior leaflet was closed using a patch of fresh autologous pericardium, also sutured with 6-0 Prolene.
Next, right ventricle plication was performed starting at the apex and proceeding toward the tricuspid anatomic anulus. Concerning possible damage to the right posterior descending artery, the suture was anchored to the endocardial fibrous tissueand secured using two strips of heterologous pericardium. A further suture was placed to reduce the tricuspid anulus.
Once the right ventricle was addressed, the cone was created. Since the septal leaflet was diminutive, it was left in place. The commissure between anterior and posterior leaflets was sutured. Then the septal portion of the posterior leaflet was sutured to the septal portion of the anterior leaflet. All sutures were placed using the intertwined technique to prevent any purse-string effects on the leaflet tissue.
Finally, the cone was reattached to the anulus using four different 5-0 Prolene sutures to divide the anulus in four quadrants. As before, intertwined sutures were adopted. A hydrodynamic test using saline was performed with temporary closure of the pulmonary trunk; the test proved satisfactory. The atrial septum was replaced using a 3.5 mm fenestrated heterologous pericardial patch. The right atrium was then closed.
Discussion
This approach was chosen because of the severe unbalanced size between left-sided and right-sided heart chambers. Furthermore, the fenestration could be easily closed by a device in the catheterization lab. After aortic unclamping, the heart started beating in sinus rhythm.
References
1. Schiebler GL, Gravenstein JS, Van Mierop LH. Ebstein’s anomaly of the tricuspid valve. Translation of original description with comments. Am J Cardiol 1968; 22:867-73
2. Attie F, Rosas M, Rijlaarsdam M et al. The adult patient with Ebstein’s anomaly. Outcome in 72 unoperated patients. (Medicine (Baltimore) 2000; 79(1):27-36
3. Danielson GK, Maloney JD, Devloo RA. Surgical repair of Ebstein’s anomaly. Mayo Clin Proc. 1979;54(3): 185-92
4. Carpentier A, Chauvaud S, Macé L, et al. A new reconstructive operation for Ebstein’s anomaly of the tricuspid valve. J Thorac Cardiovasc Surg 1988;96(1): 92-101
5. da Silva JP, Baumgratz JF, da Fonseca L, et al. The cone reconstruction of the tricuspid valve in Ebstein’s anomaly. The operation: early and midterm results. J Thorac Cardiovasc Surg 2007;133(1): 215-23