A 66-year-old man presented to our department with one day history of intermittent angina. After loading of aspirin 300 mg and clopidogrel 300 mg, coronary angiography (CAG) via left snuffbox approach (Fig. 1 and Fig.2A) demonstrated the severe stenosis in the unprotected left main coronary artery (ULMCA) (Fig. 3A). ULMCA was engaged with a 6 French guiding catheter and intravascular ultrasound (IVUS) demonstrated that a minimal lumen area of 5.1 mm2 (Fig 4A) and distal reference diameter of 5.9 mm. The IVUS assessment led to a 4.0 x 12 mm bioabsorbable polymer everolimus-eluting stent (SYNERGYTM, Boston Scientific, USA) implantation at 16 atmosphere (atm). Postdilation was achieved with a 5.0 x 12 mm noncompliant (NC) balloon at up to 18 atm. Repeated IVUS showed a minimal stent area (MSA) of 7.5 mm2 at the distal portion of stent, but revealed severe malapposition at the same site (Fig. 4B). Significant malapposition led to 2nd postdilation with a 5.0 mm NC balloon at 18 atm by stent boost guidance (Fig 4C). Follow-up IVUS showed markedly improved malapposition and MSA of 17.4mm2 (Fig. 4D). Final CAG showed good distal flow without residual stenosis (Fig. 3B). There was no bleeding complication of sheath remove site on next day (Fig. 2B).
The feasibility of percutaneous coronary intervention (PCI) of ULMCA via distal radial approach, called snuffbox approach, is concerned, even though it has several advantages regarding less bleeding complication and puncture trauma. Our experience highlights the efficacy and safety of snuffbox approach in IVUS-guided PCI for ULMCA.
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Figure 1. Peripheral angiography of left hand demonstrating relevant caliber of distal radial artery compared with conventional puncture site of radial artery (arrow: punctured artery site of left snuffbox approach).
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Figure 2. Inserted 6 French sheath via left snuffbox approach (A) and clear wound of puncture site on next day after removal of sheath (B).
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Figure 3. Diagnostic coronary angiography (CAG) demonstrating severe stenosis in the unprotected left main coronary artery (ULMCA) (arrow in A) and post percutaneous coronary intervention CAG demonstrating successful stenting of the ULMCA (arrow in B).
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Figure 4. (A) Intravascular ultrasound (IVUS) cross-section demonstrating minimal lumen area of 5.1 mm2 and plaque burden of 78%. (B) IVUS after post-stent implantation with postdilation demonstrating minimal stent area (MSA) of 7.5 mm2 and significant malapposition (1.1 mm of distance between both arrowheads). (C) Stent boost imaging demonstrating under-expansion stent before 2nd postdilation (arrowheads in C1) and well-expansion after 2nd postdilatioin (arrowheads in C2). D: Follow-up IVUS demonstrating MSA of 17.4 mm2 without malapposition.
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