David versus Goliath: how to tackle coronary anomalies in D-TGA

A retrospective observational study analyzing outcomes following arterial switch surgery with coronary translocation using the modified Yacoub pouch technique in 14 neonates with D-transposition of the great arteries (D-TGA) and anomalous coronary patterns (single coronary ostium and intramural course).

D-transposition of the great arteries (D-TGA) is among the most common cyanotic congenital heart defects, accounting for one-fifth of this subgroup and with an incidence of approximately 3-5% of all cardiac malformations. It involves ventriculo-arterial discordance due to a failure in the rotation of the conotruncal septum during embryonic development. It is typically 2-3 times more frequent in males. According to published series, coronary pattern anomalies may occur in up to one-third of cases and significantly influence the complexity of surgical repair. The arterial switch operation, or Jatene procedure, is the standard corrective technique, with the transfer of coronary buttons being the most critical step, directly affecting the postoperative course and prognosis. Certain series have shown that specific coronary anomalies are associated with a higher risk of coronary events in the postoperative period, as well as the need for ECMO and early mortality.

To understand normal coronary patterns in D-TGA, we rely on the Leiden Convention system. This approach imagines the observer viewing the pulmonary artery from the aorta at the non-coronary sinus. The adjacent sinus to the right of the pulmonary artery is labeled sinus 1, and the sinus to the left is sinus 2. The normal and most frequent pattern involves the left anterior descending and circumflex arteries originating from sinus 1, and the right coronary artery from sinus 2. Any deviation from this pattern is considered abnormal.

There is a wide range of coronary anomalies. Patterns associated with higher surgical risk include those with an intramural course of a coronary artery and those with multiple arteries originating from the same sinus, regardless of whether they arise from a single ostium or multiple ostia. In cases of coronary anomalies, alternative techniques exist to facilitate coronary translocation, reducing the risk of kinking, stenosis, or over-stretching.

Earlier this year, the Leiden group published an article on an alternative technique for single coronary ostium cases in D-TGA. This involves a modification of the traditional Yacoub aortocoronary pouch technique, adding a pericardial patch as a “roof” to the coronary button, creating a pouch that promotes better coronary flow and reduces the risk of external compression. The study is a single-center retrospective analysis of short- and mid-term outcomes of this technique in patients with D-TGA and a single coronary ostium with an intramural course.

The study includes 14 cases performed using this technique among 516 patients undergoing arterial switch surgery for TGA between January 1977 and April 2022. The two most frequent anomalous patterns were both coronary arteries arising from sinus 2 with an intramural course of the left trunk (11 patients) and, in 2 cases, both coronary arteries also originating from sinus 2 but with the right coronary artery being intramural. Seven patients had an intact ventricular septum (50%), five had intact septum (35.7%), and two had Taussig-Bing anomaly (14.3%).

Mortality was observed in 21.4% (3 patients), all related to intraoperative or immediate postoperative infarctions, with failure to recover adequate ventricular function or electrical activity. The remaining patients are alive at follow-up (9.1 years) without ischemic, arrhythmic, or clinical events (e.g., exercise intolerance), nor have they required surgical intervention for coronary ischemic events. All exhibit preserved ventricular function, and no stenosis or compression of the coronary arteries has been observed in follow-up scans.

Despite being a retrospective single-center study with a heterogeneous patient population and data collected over different eras (thus not always having access to newer surgical techniques discussed below), the authors conclude that the modified Yacoub pouch technique appears to be a useful option for arterial switch cases in patients with D-TGA and a single coronary ostium with an intramural course, with acceptable short- and mid-term outcomes.

COMMENTARY

Traditional techniques for coronary transfer during arterial switch surgery are primarily the coronary button and the trap-door technique (a “J”-shaped incision in the neo-aorta and apposition of the coronary button at this level). However, these are not always suitable for anomalous coronary patterns, especially intramural coronaries, multiple ostia in the same sinus, juxta-commissural ostia, etc. Below, we describe some coronary translocation techniques for these complex cases, which, although requiring experienced hands, have significantly improved the prognosis of these children:

  • Yacoub pouch: Anastomosis of the upper edge of the coronary button to the lower edge of the transected neo-aorta.
  • Coronary unroofing followed by translocation using the button technique.
  • Expanded trap-door with pericardial patches.
  • In situ translocation: Creation of an aortopulmonary window, completing the anastomosis with a portion of the distal aorta.

In summary, coronary ischemic events in neonates are among the most feared complications, and for good reason: it is extremely challenging to revascularize a coronary artery in such small patients. The consequences are often devastating and frequently lead to the patient’s death. In arterial switch surgery, where coronary manipulation is significant, the surgeon’s precision and experience are critical, especially in the case of coronary anomalies. These anomalies not only are less frequent but also carry a higher risk of complications (kinking, torsion, stenosis, etc.) once transferred.

As shown, these patterns are often associated with worse prognoses and postoperative outcomes in most series. Indeed, in our own series at La Paz Hospital, anomalous coronary patterns were significantly associated with increased hospital morbidity and the need for ECMO in the immediate postoperative period. However, unlike other series, we did not find a significant association with increased hospital mortality. The technique used at our center for anomalous coronary patterns, in addition to the trap-door and coronary button, was the Yacoub aortocoronary pouch in 3 of our 46 patients with coronary anomalies (intramural coronary artery).

The existence of so many techniques for coronary translocation in anomalous patterns reflects the importance of this step in arterial switch surgery. This underscores the value of different groups sharing their experiences with the surgical community to minimize ischemic events in these patients as much as possible. Although these techniques seem to help these patients achieve good short- and mid-term outcomes, multicenter and long-term studies are necessary to better understand the evolution of these patients.

REFERENCE:

Van den Eynde J, van der Palen RLF, Knobbe I, Straver B, Stöger L, Ricciardi G, et al. Outcomes of the modified Yacoub aortocoronary flap technique for ‘non-separable’ single sinus coronary arteries with intramural course in the neonatal arterial switch operation. Eur J Cardiothorac Surg. 2023 May 2;63(5):ezad029. doi: 10.1093/ejcts/ezad029.

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