Abstract
The retrograde approach is an effective therapeutic strategy for chronic total occlusion (CTO) intervention. In CTO cases, the retrograde approach from the opposite coronary artery is not always applicable. In certain left anterior descending (LAD) CTO cases, the distal LAD is filled from the septal channel where it is supplied by the proximal septal route. We report two LAD CTO cases of percutaneous coronary intervention (PCI) conducted with a wire from the proximal septal branch to the distal septal channel using the retrograde approach.
1
Introduction
Previous reports demonstrate that successful recanalization of CTO has clinical benefits for improvement of angina, left ventricular function, and mortality . Despite advances in technology, percutaneous revascularization of CTO remains technically challenging. The procedural success rate of the antegrade approach was about 60–80% . To improve the success rate of CTO procedures, the retrograde approach has been introduced . There are several types of collateral channel used for the retrograde approach. Particularly, a septal perforator of applicable size is used to deliver a balloon to the distal of the CTO . There are some other channels used for the retrograde approach: conus branch route, atrial branch route, diagonal route, and apical route for collateral channel in LAD CTO lesions. Occasionally, the proximal septal branch diverges small channels which connect to the distal septal branch that links to the distal of the CTO. Such a septal–septal channel has a possibility for retrograde approach, if the flexion is small. We report two successful LAD CTO cases that used this channel which has no good collateral channel from RCA.
2
Case 1
A 76-year-old male visited our hospital presenting with chest pain. The initial electrocardiogram revealed ST-segment elevation in the inferior leads and was diagnosed with acute myocardial infarction of the inferior wall. Emergency angiogram revealed mid right coronary artery (RCA) occlusion and proximal LAD occlusion. Left ventriculography showed akinesis of the inferior wall and normal antero-septal wall motion with ejection fraction of 36.4%. RCA was judged as a culprit lesion and LAD was judged as CTO. Primary drug-eluting stent (Cypher 3.5×33mm; Cordis) implantation was performed for the RCA lesion following thrombus aspiration (TVAC 6F; NIPRO, Japan) and distal protection (Guard Wire; Medtronic). RCA lesion was improved from 100% to 0% with TIMI 3 grade flow. Angiogram showed the LAD distal was filled by rentrop grade 3 collaterals ( Fig. 1 ). Peak CK level was 1293 U/l, and treatment for the LAD CTO lesion was scheduled for 10 days later. An intra-aortic balloon pump was inserted before the procedure. We used an 8F XB3.5 Bright Tip (Cordis) guiding catheter with a side hole to intubate the left main stem from the femoral artery. Firstly, an antegrade approach was conducted. The proximal edge of CTO was just after the septal branch where it was confirmed by intravascular ultrasound. Initial wire system was a Miracle 3g (Asahi Intec, Japan) with a TRANSIT catheter (Cordis); the wire did not reach the distal true lumen. A parallel wire technique by using a Conquest Pro (Asahi Intec) also failed to pick up the distal true lumen ( Fig. 2 A ). The wire picked up a small septal branch in the middle of the CTO ( Fig. 2 B); therefore, the side branch technique, which expands a septal branch and connects with a distal true lumen, was attempted by using a small balloon (Ryujin OTW 1.25 mm; Terumo, Japan); however, the connection could not be made ( Fig. 2 C). At this point, wiring by the antegrade approach was abandoned and treatment was shifted to that from the retrograde approach. Septal perforators from RCA or epicardial channel were not found with the retrograde approach. LAD CTO distal was filled from the proximal large septal branch connected to the distal septal branch. Therefore, wiring by the retrograde approach by using the septal–septal channel was adopted. A Pilot 50 wire (Abott) with a TRANSIT catheter (Cordis) was used for the septal–septal channel selection. The wire was advanced into the septal branch, passed the connection, and preceded to the distal septal branch retrogradely ( Fig. 3 A ). Then the wire was entered into the CTO from the distal and reached the proximal entrance of the CTO ( Fig. 3 B). The fibrous cap of the proximal entrance of the CTO was hard which led the wire from the retrograde to slid into the subintimal space. Thus, with the use of this approach from both directions, the subintimal space was expanded by using a 2.5-mm balloon (OTTIMO ROSSO; Kaneka, Japan) on the proximal wire ( Fig. 3 C). Then the retrograde wire passed through the dissected channel to the proximal true lumen by means of the reverse-controlled antegrade and retrograde subintimal tracking (CART) technique. Retrogradely, the LAD was expanded by a 2.5-mm balloon ( Fig. 4 A ). Antegrade flow was obtained and an antegrade wire was introduced to the distal LAD ( Fig. 4 B). Two sirolimus-eluting stents (Cypher 3.0×33 mm, 3.0×33mm; Cordis) were implanted and the final angiogram showed TIMI 3 grade flow ( Fig. 5 A and B).
2
Case 1
A 76-year-old male visited our hospital presenting with chest pain. The initial electrocardiogram revealed ST-segment elevation in the inferior leads and was diagnosed with acute myocardial infarction of the inferior wall. Emergency angiogram revealed mid right coronary artery (RCA) occlusion and proximal LAD occlusion. Left ventriculography showed akinesis of the inferior wall and normal antero-septal wall motion with ejection fraction of 36.4%. RCA was judged as a culprit lesion and LAD was judged as CTO. Primary drug-eluting stent (Cypher 3.5×33mm; Cordis) implantation was performed for the RCA lesion following thrombus aspiration (TVAC 6F; NIPRO, Japan) and distal protection (Guard Wire; Medtronic). RCA lesion was improved from 100% to 0% with TIMI 3 grade flow. Angiogram showed the LAD distal was filled by rentrop grade 3 collaterals ( Fig. 1 ). Peak CK level was 1293 U/l, and treatment for the LAD CTO lesion was scheduled for 10 days later. An intra-aortic balloon pump was inserted before the procedure. We used an 8F XB3.5 Bright Tip (Cordis) guiding catheter with a side hole to intubate the left main stem from the femoral artery. Firstly, an antegrade approach was conducted. The proximal edge of CTO was just after the septal branch where it was confirmed by intravascular ultrasound. Initial wire system was a Miracle 3g (Asahi Intec, Japan) with a TRANSIT catheter (Cordis); the wire did not reach the distal true lumen. A parallel wire technique by using a Conquest Pro (Asahi Intec) also failed to pick up the distal true lumen ( Fig. 2 A ). The wire picked up a small septal branch in the middle of the CTO ( Fig. 2 B); therefore, the side branch technique, which expands a septal branch and connects with a distal true lumen, was attempted by using a small balloon (Ryujin OTW 1.25 mm; Terumo, Japan); however, the connection could not be made ( Fig. 2 C). At this point, wiring by the antegrade approach was abandoned and treatment was shifted to that from the retrograde approach. Septal perforators from RCA or epicardial channel were not found with the retrograde approach. LAD CTO distal was filled from the proximal large septal branch connected to the distal septal branch. Therefore, wiring by the retrograde approach by using the septal–septal channel was adopted. A Pilot 50 wire (Abott) with a TRANSIT catheter (Cordis) was used for the septal–septal channel selection. The wire was advanced into the septal branch, passed the connection, and preceded to the distal septal branch retrogradely ( Fig. 3 A ). Then the wire was entered into the CTO from the distal and reached the proximal entrance of the CTO ( Fig. 3 B). The fibrous cap of the proximal entrance of the CTO was hard which led the wire from the retrograde to slid into the subintimal space. Thus, with the use of this approach from both directions, the subintimal space was expanded by using a 2.5-mm balloon (OTTIMO ROSSO; Kaneka, Japan) on the proximal wire ( Fig. 3 C). Then the retrograde wire passed through the dissected channel to the proximal true lumen by means of the reverse-controlled antegrade and retrograde subintimal tracking (CART) technique. Retrogradely, the LAD was expanded by a 2.5-mm balloon ( Fig. 4 A ). Antegrade flow was obtained and an antegrade wire was introduced to the distal LAD ( Fig. 4 B). Two sirolimus-eluting stents (Cypher 3.0×33 mm, 3.0×33mm; Cordis) were implanted and the final angiogram showed TIMI 3 grade flow ( Fig. 5 A and B).
