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Page 2 of 5 Ribeiro et al. Vessel Plus 2019;3:21 I http://dx.doi.org/10.20517/2574-1209.2018.66

Keywords: Chronic total occlusion complex, percutaneous coronary intervention, right coronary artery, retrograde
approach, moderator band

INTRODUCTION
The use of the retrograde approach has dramatically increased in the last years, not only throug the septal
[1-9]
collaterals and saphenous venous graft , but also via epicardial connections to the chronic total occlusion
[10]
[11]
(CTO) lesion.
We report the case of a right coronary artery (RCA) CTO recanalized using the retrograde approach through
the contralateral channels of a third septal artery connecting with the moderator band artery [Figure 1] that
was connected with the right ventricular branch of the RCA.

CASE REPORT
A 64 year-old male, with hypertension, dyslipidemia, left ventricle dysfunction with 35% ejection fraction,
and known coronary artery disease. A previous percutaneous coronary intervention (PCI) was performed
6 months before revascularizing an extremely calcified left anterior descendent artery with rotational
atherectomy and Impella CP mechanical circulatory support. The patient remained symptomatic due to
RCA CTO [Figure 2] with 24% ischemic burden involving the inferior wall in myocardial scintigraphy.
Therefore, PCI of RCA CTO was indicated.

We started the procedure through double femoral access, trying to perform the anterograde approach. We
tried to reach the intimal plaque and then the distal vessel, first using AL-1 guide catheter 7F in the RCA,
Turnpike spiral microcatheter (Teleflex), Fielder FC guidewire (Asahi Intec.) and Conquest Pro 12 (Asahi
Intec.), however without success. After 15 min, we decided to switch retrograde approach, using EBU 4.0
7F guide catheter in left coronary. We used a Turnpike spiral microcatheter (Teleflex) and a Whisper Light
Support (Abbott) guidewire to access the third septal, where we could navigate into a connection through
the moderator band artery into the right posterior atrioventricular branch. Then, we used the Turnpike
Spiral microcatheter to replace the previous guidewire for a new Sion (Asahi Intec.) guidewire due to the
fragility of this channel. After accessing the RCA [Figure 3], the reverse controlled antegrade and retrograde
tracking technique [Figure 4] was performed and the retrograde guidewire was externalized [RG3 (Asahi
Intec.)]. As we reached the RCA in the middle part of the vessel, we used a double lumen catheter TwinPass
(Teleflex) to introduce a Fielder FC guidewire anterogradely into the distal RCA, and then PCI with 3 DES
Xience Alpine (Abbott) was performed with a good result [Figure 5].

DISCUSSION
The retrograde approach has dramatically increased as an alternative to recanalize complex CTO in case
of anterograde failure. Data from the ERCTO registry showed that retrograde approach was only used in
15% of the CTO procedures . The septal collaterals are the safest and easiest to track to achieve retrograde
[12]
access, but in our case we showed an unusual route of the septal channel that was connected probably with
the moderator band artery . Sadek et al. described this forgotten access, showing that first, the moderator
[13]
[14]
band is a muscle column that courses inferiorly from the right portion of the interventricular septum to the
base of the anterior papillary muscle of the right ventricle. Second, the source of the moderator band artery
lies in the first three septal arteries, most often in the second one; in our case we used the less common third
one. Finally, this artery makes connections with various branches of the RCA, hence representing a real
source of collateral circulation to RCA CTO as we practically demonstrated through this case.