15.3 Coronary & Peripheral Atherectomy

Coronary & Peripheral Atherectomy

ARRT Cardiac-Interventional Procedures 2.A.3–A.4 list atherectomy for both coronary and peripheral arteries. The outline names four types: directional, rotational, laser, and orbital. The same Focus of Questions still applies: anatomy and pathophysiology, indications, contraindications, imaging, access, ultrasound, equipment, complications, and closure. If 15.1 is crack-and-displace and 15.2 is scaffold, this section is debulk and modify — usually because calcium will not let a balloon expand.

Quick Answer: Four devices, one unifying idea: calcium modification (plus selected thrombus, in-stent restenosis, and undilatable lesions). Rotational (Rotablator-class): diamond burr, teaching 140–180 thousand rpm, saline (NS) flush, RCA bradycardia, no-reflow, stuck burr. Orbital (Diamondback-class): crown orbits, crown-to-artery ratio near 1:1, calcium and some peripheral plaque. Directional: cutter and nosecone, larger lumen, perforation. Laser (ELCA): teaching 308 nm excimer, saline flush, not contrast — contrast plus laser makes bubbles and dissection.

Anatomy, pathophysiology, indications, contraindications

Heavy calcium — concentric rings, nodular calcium, or a calcified nodule that dog-boned every balloon in 15.1 — is the pathophysiology that unifies these devices. Fibrotic plaque, some in-stent restenosis (ISR), and selected thrombus (especially laser) are additional targets. Indication: a lesion that will not dilate, will not let a stent expand, or will embolize if you simply crush it, in coronary or peripheral territory. Contraindications are device-specific but share a theme: a dissection already present (rotational and orbital can extend it), inability to pass a dedicated wire, a perforation you have not sealed, and — for laser — a setup that still has contrast in the field. Severe tortuosity and a burr or crown that is oversized for the vessel raise entrapment and perforation risk. Atherectomy is not a substitute for DAPT planning once a stent goes in afterward.

Imaging, access, ultrasound, and shared equipment discipline

Imaging. Cine or DSA shows the calcium bloom and the residual waist. IVUS/OCT (and peripheral IVUS) confirm calcium arc and whether a stent is still underexpanded after ablation. Fluoro watches burr or crown motion; a stalled rotational burr is an emergency, not a pause to inject. Access is the same radial/femoral (coronary) or femoral (many peripheral) sticks as 15.1–15.2, but larger burrs and some peripheral directional devices need larger guides or sheaths (teaching 7 Fr class for bigger rotational burrs). Ultrasound still guides the stick and finds the hematoma after a large sheath. Temporary pacing capability belongs in the room for rotational work in the RCA (and some dominant LCx) because microparticles provoke bradycardia and AV block. The flush bag is equipment: rotational systems need continuous normal saline (often with a lubricant and heparin per lab protocol); laser needs a saline infusion through the catheter. Contrast does not belong in those flush lines.

Closure is unchanged in principle — manual compression or a vascular closure device — but the sheath may be larger, anticoagulation is on, and a groin complication after rotational no-reflow care is easy to miss if the team is watching only the coronary screen.

Rotational atherectomy (Rotablator-class)

A diamond-coated burr spins over a dedicated wire and uses differential cutting: hard calcium is ablated into microparticles; elastic tissue deflects. Teaching speed is about 140–180 thousand rpm (lab protocols often live in the 140–160 thousand range and treat 180 thousand as a ceiling, not a cruise setting). Keep the NS flush running; a dry burr heats and binds. Advance with short pecks, not a long bury. Hallmarks: bradycardia especially in the RCA, no-reflow from microvascular debris, and a burr stuck in the lesion if you stall at high speed without flush. A stuck burr is not a hard yank — notify the operator, maintain flush if possible, and follow the lab’s retrieval sequence (including low-speed dynaglide-style withdrawal on some platforms). Have atropine, pacing, and no-reflow drugs (adenosine, nitroprusside, nicardipine as ordered) ready before the first run.

Orbital atherectomy (Diamondback-class)

An eccentric crown sands as it orbits, typically bidirectional. Teaching crown-to-artery ratio is near 1:1 (contrast rotational teaching of a smaller burr-to-artery ratio, often discussed around 0.5–0.7). Orbital devices treat coronary calcium and some peripheral plaque (including calcified SFA disease on peripheral platforms). Slow flow and spasm still occur; a crown that is too large for a small distal vessel can still perforate. The technologist’s job is crown size, speed setting, saline, and watching for a sudden contrast extra-luminal puff.

Directional atherectomy

Directional coronary atherectomy (DCA) is largely historical in modern coronary labs. Peripheral directional devices (cutter window, apposition balloon or housing, nosecone that stores shavings) are still used to debulk eccentric plaque and leave a larger lumen without a stent. The cutter must face plaque, not a thin wall or a branch ostium. Hallmark complication: perforation (and distal embolization if the nosecone overfills). This is not the same device as a rotational burr and it is not a 308 nm laser.

Laser atherectomy (ELCA-class)

Excimer laser coronary atherectomy (ELCA) and peripheral laser platforms use a teaching 308 nm ultraviolet excimer pulse. Photochemical, photothermal, and photomechanical effects vaporize plaque, ISR tissue, some thrombus, and undilatable lesions. Saline flush, not contrast. Contrast in the field plus laser energy creates large vapor bubbles that dissect (or perforate) the vessel. The technologist’s trap is a manifold that still has contrast when the laser foot pedal goes down. Train the injection: saline on, contrast off, then lase. Laser is not the first-line calcium burr, but it is on the ARRT four-type list for a reason — ISR, thrombus, and undilatable lesions are fair game.

Worked case

An undilatable, heavily calcified mid-RCA will not accept an NC balloon. The team sets up rotational atherectomy: dedicated wire, NS flush confirmed, pacing pads on, atropine drawn. Burr speed in the teaching 140–180 thousand rpm band. After the first run the patient has a long pause — expected RCA bradycardia territory, not a mystery. Later the angiogram shows sluggish distal flow without a new conduit occlusion: treat no-reflow, do not bury a larger burr. If instead the operator chose laser and someone injected a contrast cine during lasing, expect vapor-bubble dissection. Directional cutting of a thin SFA wall is how you get a perforation that then needs a balloon and possibly a covered stent from 15.2.

Exam traps

• Four types for both coronary and peripheral: directional, rotational, laser, orbital.
• Rotational: 140–180k rpm teaching, NS flush, RCA bradycardia, no-reflow, stuck burr.
• Laser: 308 nm, saline not contrast.
• Directional ≠ Rotablator ≠ laser.
• Calcium modification is the unifying indication, not “thrombus-only devices.”