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On 01.07.21,the patient had an ST-segment elevation MI. CAG was urgently performed: LAD -stenosis in the middle segment 80%, OM-2 - acute occlusion in the proximalthird; RCA - CTO in the proximal segment. Performed mechanical recanalizationand stenting of the VTK.Despitereceiving optimal drug therapy, the patient retains a stress angina clinic atthe level of functional class 2

Clinical bloodtest: RBC - 5.4 10 in 12 tbsp. / l; HGB - 145 g / l;  MCV – 79.6  cubic meters; PLT - 307 10 in 9 st. / l; MPV –9.7 cubic meters; Leukocytes – 10.4 10 in 9 tbsp. / l; Segmented neutrophils,%- 55%; Lymphocytes,% - 21%; Monocytes,% - 9%; Eosinophils,% - 13%; Basophils,%- 1%; Erythrocyte sedimentation rate - 4 mm / h;Biochemicalblood test: Potassium - 4.49 mmol / l; Glucose - 5.82 mmol / L; GFR (MDRD) M - 76ml / min / 1.73m2; Serum creatinine – 91.9 μmol / l.

Coronary bloodsupply type: right.LM: with uneven contoursLAD:  with unevencontours, stenotic at the mouth by 30-40%.CxA: with uneven contours throughout.RCA: with uneven contours, occluded in the proximal segment,the post-occlusion section is well filled along the intersystem collaterals.

A guidingcatheter is placed in the ostium of the LM. The second guiding catheterwas placed in the ostium of the RCA.  Numerous attempts of antegrade recanalization failed. It was decided toperform retrograde recanalization of RCA. The coronary guidewire was insertedinto the distal segment of the LAD. The second coronary guidewire supported bya Corsair microcatheter was inserted through the septal branch into the distalthird of the PDA. Escalation to a stiffer guidewire was performed. Subintimalretrogradely, the guidewire was inserted into the proximal segment of the RCA and the guidewire was externalized into the guide catheter using Reverse CART technique. However, due to pronounced spasm in the LCA, it was impossible toexternalize the microcatheter into the antegrade guide catheter. It was decidedto perform recanalization using the tip-in technique using a Corsair microcatheter along the retrograde guidewire. The microcatheter was successfully inserted into the distal segment of the RCA. The antegrade guidewire was replaced. The microcatheter was removed. Balloon catheter 2.0x30mm was used for predilation at the occlusion site in the proximal andmiddle segments of the RCA, with pressure up to 14 atm. A satisfactory bloodflow through the artery was obtained. DES 2.75x44mm and DES 2.75x39mm stentswere implanted in the distal, middle and proximal segments of the RCA, pressureup to 16 atm. 

When choosing tactics for recanalization of CTO, several prognostic scales should be used (J-CTO, PROGRESS CTO, etc.) Antegrade progress of CTO recanalization is important, even when performing retrograde recanalization. Recanalization of CTO should be performed by experienced surgeons. The operating room should be equipped not only with instruments aimed at recanalization, but also at eliminating possible intraoperative complications. A second catheter for contralateral control before antegrade recanalization is recommended.