Retrograde Percutaneous Re-Anastomosis of Occluded Right Coronary Artery Through a Synthetic Bentall Graft

Abstract

Background

In some Bentall surgeries, a coronary artery is not reimplanted but instead grafted.

Case Summary

A 49-year-old patient who underwent prior Bentall surgery using a synthetic root, mechanical valve, and saphenous vein graft (SVG) to the right coronary artery (RCA) developed non-ST-segment elevation myocardial infarction due to graft failure. We performed retrograde recanalization of the native RCA and created a neo-ostium through the graft using electrosurgery, high-pressure and molding balloons, and stenting without complications.

Discussion

Success was achieved through careful planning using coronary computed tomography angiography and execution using latest available techniques and technology.

Novelty

This is the first reported percutaneous re-anastomosis of a coronary to a synthetic aortic graft.

Take-Home Message

Failure of an SVG attached to a non-reimplanted coronary post Bentall is a challenging clinical situation. We could re-anastomose the RCA to the synthetic Bentall graft using retrograde, electrosurgery, novel balloon techniques, and stenting.

Graphical Abstract

The Bentall procedure is a major cardiac operation that treats disease involving the aortic valve, root, and ascending aorta by replacing these structures with a synthetic graft and prosthetic valve (bioprosthetic or mechanical). Both coronary arteries are typically reimplanted into the new graft, but if this is not possible, a saphenous vein, arterial, or woven polyester (commonly referred as Dacron) graft is used instead.¹

Take-Home Messages

• •Failure of a saphenous vein graft attached to a non-reimplanted coronary post Bentall is a challenging clinical situation.
• •We could re-anastomose the right coronary artery to the synthetic Bentall graft using retrograde, electrosurgery, novel balloon techniques and stenting.

We describe the case of a 49-year-old man with a congenital bicuspid aortic valve who underwent a surgical aortic valve replacement with a St Jude mechanical valve in 1994 (at age 19) for infective endocarditis. Two months later, he underwent reoperation for severe paravalvular aortic insufficiency with a Carbomedics mechanical valve. In addition, he had a saphenous vein graft (SVG) placed to the right coronary artery (RCA), reportedly due to right ventricular dysfunction. In 2016, he developed partial mechanical valve thrombosis treated with systemic fibrinolysis, which improved valve gradients. Due to progressive aortic stenosis and diastolic heart failure, a Bentall procedure was performed in 2020 with a synthetic woven polyester root, often referred as “Dacron,” a mechanical valve, and left coronary reimplantation. The RCA was occluded at the ostium (post coronary artery bypass graft chronic total occlusion [CTO]) and not reimplanted. The SVG to the RCA was documented to be patent prior to the surgery, but repeat vein grafting was nevertheless done, presumably due to the age of the SVG (15 years). His evolution was remarkable for recurrent atrial fibrillation episodes which would require electrical cardioversion, however without angina.

In May 2025, he presented with a non-ST-segment elevation myocardial infarction in a context of fast atrial fibrillation. A computed tomography positron emission tomography myocardial perfusion imaging revealed extensive infero-lateral ischemia. Echocardiography showed normal left ventricle function and a well-functioning mechanical aortic valve. Coronary and graft angiography found an occluded RCA SVG, a healthy left coronary system re-anastomosed to the aortic prosthesis, supplying faint epicardial and septal collaterals (CCO and CC1)² to an RCA CTO. The RCA was retrogradely filled up to 2 or 3 mm from its ostium, which had never been reattached during the Bentall procedure; thus, there was no right-sided ostium for cannulation. Both SVGs were occluded at the aortic origin.

The patient was seen in consultation in June 2025. He had developed crescendo angina, reaching Canadian Cardiovascular Society class 4. Given the patient's 3 prior cardiac surgeries with sternotomies, our options for RCA revascularization were limited: either a fourth operation with an arterial graft to the RCA in a very challenging third redo setting, or a percutaneous attempt using advanced CTO percutaneous coronary intervention (PCI) techniques to connect the isolated RCA to the synthetic aorta.

We presented the options to the patient and his wife, explaining that the proposed procedure would, to our knowledge, be a world first and likely require ElectroCautery-Assisted Re-enTry (E-CART) electrosurgery due to the high resistance encountered when crossing the scar and aortic polyester tissue. Unlike prior cases involving classical Bentall procedures with both coronaries reimplanted at the time of surgery,^3,4 our patient's condition was different, with the RCA that had never been reimplanted, mandating a retrograde approach. Attempting epicardial collateral tracking after an open-heart surgery could raise the risk of dry tamponade,⁵ while creating a new hole in the synthetic graft might lead to bleeding around the prosthesis. We discussed the use of covered stents and our experience with them. Both the patient and his wife consented, accepting the risks for a greatly improved quality of life.

Procedure Planning With Coronary Computed Tomography Angiography

We began with a coronary computed tomography angiography to reconstruct images of the RCA and occluded SVGs in relation to the prosthesis. The RCA ostium appeared tapered and was located a few millimeters from the Dacron prosthesis, although its surrounding tissue was uncertain. The SVGs were occluded at their ostia and anastomosed to the mid-RCA, an uncommon site. On the sagittal view, the proximal CTO cap looks tapered (Figure 1A). On the transverse view, the cap was less defined and divided into 3 branches, suggesting the RCA remnant with the old aortic root might have been pushed by the new Dacron graft (Figure 1B).

Figure 1.

CCTA Prior to the Intervention

(A) Sagittal view. (B) Transverse view. CCTA = coronary computed tomography angiography; RCA = right coronary artery; CTO = chronic total occlusion; SVG = saphenous vein graft.

Complex CTO PCI With the Retrograde Approach

The procedure was done under general anesthesia to avoid patient discomfort from potential ischemia in case we would have to track an epicardial collateral. Anticipating an enlarged aortic root, we used a femoral approach. To preserve one groin for possible veno-arterial extracorporeal membrane oxygenation resuscitation,⁶ we chose ipsilateral dual femoral access with 2 7-F 45-cm sheaths in the right common femoral artery, which was suitable in size and without any disease. Venous access was also secured on the same side for activated clotting time monitoring and potential pacing or cannulation if needed.

Accessing the left coronary was challenging, ultimately requiring an EBU 5 (Medtronic), an unusually long curve. The catheter had a standard length of 100 cm, was not available in a 90-cm version, and was not shortened.⁷ Coronary angiography of the left system revealed faint septal channels (CC0 and CC1)² and RCA filling up to its very proximal segment before a prominent acute marginal/conus branch (Figure 2).

Figure 2.

Angiography of the Left System

(A) EBU 5 positioned in the LM with injection demonstrating faint septal CC (white arrow). (B) Subsequent visualization of septal CCs (white arrows). (C) Identification of the distal cap of the RCA occlusion (black arrow) and RV branch (white arrow). (D) The distal cap of the RCA occlusion (black arrow) and RV branch (white arrow) are depicted. Dashed arrows indicate septal and epicardial CC to the PL and PDA. CC = collateral channel; LM = left main; PDA = posterior descending artery; PL = postero-lateral; RCA = right coronary artery; RV = right ventricular.

The procedure required dedicated specialized equipment (Table 1). Our initial strategy was to pursue a lower-risk septal surfing approach to attempt a retrograde connection to the RCA.⁸ After successfully connecting to the posterior descending artery with a Sion wire, we advanced the Corsair XS Pro to the RCA ostium. A tip injection revealed the distal graft remnant and a tapered RCA CTO about 1 cm from the inner edge of the prosthesis. Multiple wires such Gaia Next 3, Hornet 14, Asato 20, and even an Asato 40 without electrification failed to cross due to resistance from the synthetic tissue and tracking along the outer wall of the prosthesis (Figure 3). We then replaced the retrograde microcatheter for a Mamba Flex 150 cm anticipating electrosurgery (E-CART)⁹ due to concerns that polymer tip microcatheters like the Corsair XS Pro may melt when electrified. For E-CART, we energized an Asato 40 guidewire at cut mode with 50 J, successfully piercing the graft and advancing into the aorta (Figure 4).

Table 1.

Specialized Disposable Equipment Used During This Procedure

Equipment	Manufacturer	Description and Function
Microcatheters
Corsair XS Pro	Asahi Intecc	Highly torquable lower profile microcatheter with a nose cone, often for retrograde CTO PCI
Mamba Flex	Boston Scientific	Low-profile microcatheter without a nose cone, often used in retrograde CTO PCI
Corsair Pro	Asahi Intecc	Larger profile microcatheter with a nose cone, often used antegrade or retrograde
Guidewires
Sion	Asahi Intecc	Non polymer jacketed soft with high torque guidewire, good for CC crossing
Gaia Next 3	Asahi Intecc	Highly torquable slightly tapered 6 g guidewire for tissue tracking
Hornet 14	Boston Scientific	Tapered, 14 g highly penetrative guidewire for puncture of hard tissue
Astato 20	Asahi Intecc	Highly penetrative tapered 20 g guidewire. Peripheral guidewire. Non indicated for coronaries. Used off label
Astato 40	Asahi Intecc	Highly penetrative tapered 40 g guidewire. Peripheral guidewire. Non indicated for coronaries. Used off label
R350	Teleflex	Long 350 cm nitinol guidewire for externalization technique during retrograde CTO PCI
Gladius Mongo	Asahi Intecc	Polymer jacketed guidewire, with 3g tip load, and ability to form a small knuckle
Other catheters
En-Snare 27–35 mm	Meritt	Snare that opens with 3 large loops into the aorta to facilitate catching of a retrograde guidewire for externalization
Balloon catheters
Takeru	Terumo	Low-profile balloon for difficult to cross lesions or tissue
ScoreFlex	OrbusNeich	Balloon with a dual wire scoring system (a nitinol integral wire plus the conventional guidewire), for resistant, fibrotic, or calcified coronary lesions
OPN NC	SIS Medical AG	Double-layered high-pressure balloon, rate burst at 35 atm, that can be inflated to 50 atm
Ostial FLASH	Ostial Corp	Dual-balloon catheter designed for stent expansion and apposition of aorto-ostial lesions. Flares the stent edge against the vessel wall, conforming it to the aortic or coronary root

CC = collateral channel; CTO = chronic total occlusion; PCI = percutaneous coronary intervention.

Visual Summary.

Timeline of the Patient's Medical History and Procedures

Timeline	Age	Events
1994	19	•Endocarditis on a congenital bicuspid aortic valve •Surgical AVR with a St Jude #23 mechanical valve
1995 (2 mo later)	19	•Severe and symptomatic paravalvular regurgitation •Re-do AVR with a #23 Carbomedics mechanical valve •Single-vessel CABG with SVG-RCA due to some right ventricle malperfusion
1995-2016	19-40	•Episodes of fast atrial fibrillation, without angina •Chronically elevated gradients with suspected patient/prosthesis mismatch
2016	40	•Fast atrial fibrillation •Mechanical aortic valve stenosis with a mean gradient of 51 mm Hg on TEE, AVA of 0.38 mm2. LVEF 60%-65% •Fluoroscopy confirming leaflet dysfunction •Fibrinolysis with tPA on with improved mean gradient of 27 mm Hg and restoration of normal function
2017-2019	41-43	•Stable, no symptoms
2020	44	•Progressive increase in aortic valve gradients with DOE •Coronary and graft angiography with normal left main, RCA CTO and patent SVG to RCA
2020 (5 mo later)	44	•Redo-redo sternotomy (third cardiac surgery) for a modified Bentall procedure with •#27 St Jude Regent mechanical valve, #30 Valsalva graft conduit with left main reattachment •#30 woven polyester Gelweave graft prosthesis (commonly referred as “Dacron”) for aortic reconstruction •Redo SVG to RCA (reason unclear, likely due to age of the other graft) •The RCA was not reimplanted
2020-2024	45-48	•Few episodes of fast atrial fibrillation requiring electrical cardioversion, without angina
04-05/2025	49	•Fast atrial fibrillation episode with NSTEMI and chest pain •CT PET perfusion: reversible defect of moderate size affecting the basal mid-inferior and infero-septal segments, consistent with ischemia in the RCA territory. Total perfusion defect 10%-13% •Coronary angiography showed no RCA button, and both SVG-RCA were occluded •CCTA confirmed both SVGs occlusion and showed native RCA stump adjacent to the synthetic root
04-06/2025	49	•Class 3 angina on 3 antianginal medications
06/2025	49	•Retrograde recanalization and percutaneous neo-ostium creation through the woven polyester prosthetic graft, utilizing electrosurgery, balloon techniques, and stenting, without complications •Minor post PCI stroke, with full recovery
09/2025	49	•Successful ablation of atypical flutter
10/2025	49	•Dual-chamber pacemaker for tachy-brady syndrome
11/2025	49	•Fully functional, active, working 5 d/wk, no angina

AVA = aortic valve area; AVR = aortic valve replacement; CCTA = coronary computed tomography angiography; CT PET = computed tomography positron emission tomography; CTO = chronic total occlusion; DOE = dyspnea on exertion; LVEF = left ventricular ejection fraction; NSTEMI = non-ST-segment elevation myocardial infarction; RCA = right coronary artery; SVG = saphenous vein graft; TEE = transesophageal echocardiography; tPA = tissue plasminogen activator; CABG = coronary artery bypass graft; PCI = percutaneous coronary intervention.

Figure 3.

Retrograde Tracking of the RCA

(A) Sion wire tracks the PDA (black arrow) from a Corsair XS Pro microcatheter (white arrow). (B) Microcatheter reaches proximal RCA; tip injection shows a tapered distal cap (white arrow). A pigtail marks the aorta, with <10 mm between the distal cap and Dacron wall (black arrow). (C) Microcatheter advanced to the distal cap (white arrow). (D) Hornet 14 contacts the synthetic wall and tracks outside the aorta (dashed arrow). PDA = posterior descending artery.

Figure 4.

E-CART Through the Dacron Aortic Graft

(A) Retrograde microcatheter is exchanged for a Mamba Flex 150 cm and positioned at the distal cap (white arrow). (B) E-CART is performed with the electrification of an Asato 40 guidewire (electrosurgery) (black arrow). (C and D) The guidewire advances into the ascending aorta (black arrow). Pigtail interaction with the wire confirms position.

Unfortunately, the Mamba Flex could not traverse through the synthetic tissue to follow the wire, and the 100-cm guide length limited the maneuvers. We decided to do a risky maneuver of removing the Asato hoping to be able to track the channel created with electrosurgery (“hole-in-one” technique) with an R350 guidewire (to externalize) but failed. Tip injections from the Mamba demonstrated some aortic wall hematoma. Trials to track the electrosurgery channel with other wires of varying stiffness also failed at this point (Figures 5A to 5C).

Figure 5.

After a Failed Microcatheter Tracking Through the Aortic Wall

(A) The Mamba Flex could not cross the aortic wall; after the risky maneuver of removing the Asato wire, our efforts to track the channel created by electrosurgery with an R350, hoping to be able to externalize, failed. A distal tip injection revealed an aortic wall hematoma (white arrows). (B) The “hole-in-one” technique with a Raider wire inadvertently tracked outside the aortic wall. (C) The Raider wire made an unusual bend into a cavity, raising concern for possible pulmonary artery entry (white question mark). (D) Unable to open the native RCA, we shortened the EBU 5, recrossed the dilated septal channel, and tried but failed to open the SVG with reverse CART using a Corsair Pro (white arrow indicates retrograde gear, the black arrow the antegrade SVG wire). CART = controlled antegrade and retrograde tracking.

We shortened another EBU 5 to 90 cm, removed the retrograde gear, cannulated the left system, and easily crossed back through the dilated septal channel with a Sion wire. Using a regular Corsair Pro 150 cm, we tracked to the distal RCA segment. We briefly tracked an old SVG and attempted opening the graft using retrograde dissection and reentry techniques to ease a future native RCA CTO PCI (an alternative option as we were failing) but also could not connect (Figure 5D).

Ultimately, we redirected the microcatheter to the distal native RCA cap and tried again to track the hole made by the electrified wire with various guidewires, this time successfully with a Gladius Mongo guidewire. We then advanced the Corsair Pro microcatheter into the aorta and, using a 7-F JR 4 catheter and a 27- to 35-mm Ensnare, snared a retrograde R350 guidewire, performed externalization, and guided the JR4 to the aortic wall (Figure 6).

Figure 6.

Surfing and Tracking of the Electrosurgery Connection

(A) Ultimately, the procedure returned to the distal RCA cap, where a Gladius Mongo was used to surf and attempt to follow the channel previously created with electrosurgery (white arrow). (B and C) The wire tracked this connection and entered the aorta (white arrow). (D) Snaring with a 27- to 35-mm Ensnare of a retrograde R350 guidewire and externalization.

At this stage, the team remained cognizant of the potential risk of periaortic bleeding during subsequent interventions. As a precaution, all Papyrus-covered stents (Biotronik) in 3- and 4-mm sizes were made available in the room to facilitate immediate access by the scrub team in the event of a major perforation. The opening of the track started with dilation using a 1.5-mm Takeru balloon, followed by a 2.5-mm semi-compliant balloon. Notably, inflation revealed a waist corresponding to the location of the synthetic aortic wall. Subsequent small-volume contrast injections excluded the presence of any perforation. Attempts at further dilation with a 3.5-mm noncompliant (NC) balloon proved ineffective, as resistance from the wall was not overcome even at 20 atm. Inflation with a 3.0-mm ScoreFlex balloon at 20 atm partially overcame this resistance; however, only a 3.5-mm OPN NC high-pressure balloon inflated to 45 atm could achieve complete expansion (Figure 7).

Figure 7.

Creation of a Neo-Ostium Through the Synthetic Graft

(A) 2.5-mm compliant balloon. (B) 3.5 NC balloon at 20 atm with a persistent waist at the ostium (black arrow). (C) 3.0 mm Scoreflex begins to overcome Dacron resistance (black arrow). (D) OPN NC balloon fully expanded at 45 atm.

Control angiography revealed no evidence of contrast extravasation, likely attributable to the density of the scar tissue adjacent to the aortic wall. Intravascular ultrasound demonstrated vessel structure up to several millimeters from the outer aortic edge. Beyond this region, vessel architecture was undetectable, suggesting a short extra-vascular tracking. More proximally, there was a diminished ultrasonic signal across the synthetic material (Figure 8). Further dilation with a 4.0-mm ScoreFlex resulted in additional expansion. The intervention was finalized with deployment of a 4 × 18-mm Onyx Frontier drug-eluting stent (Medtronic) from the proximal to ostial RCA, without necessitating a covered stent. Final angiography confirmed the absence of perforation. Strut flaring at the neo-ostium was achieved using an Ostial FLASH 4.5-mm balloon, and the ostium was postdilated to 5 mm at high pressure (Figure 9). The final angiographic assessment demonstrated excellent results with TIMI flow grade 3, while intravascular ultrasound confirmed satisfactory neo-ostial expansion (Figure 10).

Figure 8.

Control Angiography and IVUS

(A) Control angiography prior to stent implantation demonstrates TIMI 3 flow. (B) IVUS was used to evaluate vessel size, trauma, and wire position. 1) Distal reference of the vessel appears healthy. 2) Adventitial borders are visible, with the vessel measuring approximately 4 mm. 3) Hematoma is observed from 7 to 11 o'clock, with less defined adventitial borders. 4) No clear vessel structure is seen just distal to the external border of the Dacron synthetic graft, indicating possible extra-vascular tracking. 5) IVUS signal decreases when passing through the neo-ostium. 6) IVUS positioned in the aorta. IVUS = intravascular ultrasound.

Figure 9.

Stenting and Optimization

(A) Additional scoring was performed using a 4.0 mm Scoreflex. (B) A 4 × 18 mm Onyx Frontier stent was deployed from the proximal to the ostial RCA. (C) Strut flaring at the neo-ostium was achieved in the aorta utilizing a 4.5-mm Ostial Flash balloon. (D) Postdilation was conducted to 5 mm at high pressure. Minimal residual waist remains visible. RCA = right coronary artery.

Figure 10.

Final Result

The final angiography shows an excellent result and TIMI 3 flow. IVUS was performed to assess the results. 1) Good stent expansion with clear vessel structures. 2) Larger expansion in the area with uncertain adventitial borders. 3) and 4) Eccentric but adequately expanded ostium. 5) and 6) Stent area increases due to flaring with minimal strut overhang into the Bentall aortic root.

The procedure concluded with closure of both femoral arterial access sites with Perclose Pro-Style sutures (Abbott). Total procedural duration was 5 hours 20 minutes, including 180 minutes of fluoroscopy, with a cumulative radiation dose of 5.8 Gy and a total contrast usage of 260 cc.

One hour after the procedure, the patient experienced temporary left hemiplegia and slurred speech for 10 minutes. A code stroke was activated; CT showed no acute stroke. MRI 2 days later revealed small nonhemorrhagic infarcts in the right parietal lobe, consistent with embolic stroke. He was pretreated with dual anti-platelet therapy, activated clotting time ACT was maintained >350 during the procedure. Echocardiogram noted an unchanged filament on the aortic valve. The patient fully recovered.

After discharge, he presented recurrent atrial fibrillation episodes that were believed to be due to an atypical flutter, successfully ablated in September 2025. He also underwent dual pacemaker implantation following the ablation due to tachy-brady symptoms. He came back for outpatient clinic follow-up in November 2025, reporting being fully active, working 5 days a week without anginal symptoms or dyspnea.

Discussion

This appears to be the first documented case of a nonanastomosed coronary artery following a Bentall procedure being reanastomosed percutaneously. In addition, there are no previously reported cases of a Dacron or other type of woven polyester synthetic graft being pierced with electrified guidewires and then dilated and stented to address tissue recoil. This case involved the use of advanced CTO PCI retrograde techniques, percutaneous electrosurgery, new high-pressure balloon and molding balloon technologies, and imaging to accomplish revascularization in a young, very symptomatic patient.

Interventional cardiologists often use synthetic grafts for vascular access, but transradial techniques have made this less necessary. Penetrating a synthetic femoral graft usually requires a strong 18-gauge needle and dilators before inserting the sheath. In our case, crossing the aortic root into the Bentall lumen relied on blunt 0.014-inch guidewires rather than needles, which proved ineffective; even very stiff peripheral guidewires like Asato 20 and 40, with 20- and 40-g tip load, respectively, could not match the rigidity of a needle and failed to cross the synthetic tissue without electrification. Electrosurgery was needed to pierce the aortic wall and proved again its usefulness in interventional cardiology, this time outside the structural cardiology world.¹⁰

We made 2 notable mistakes. First, we failed to realize the necessity of a 90-cm guide, which nearly led to procedural failure. We should have tried exchanging the guiding catheter for a shortened one using a guidewire extension or attempting the procedure with a different microcatheter, though these options remain technically challenging. Perseverance and electrosurgical techniques ultimately allowed us to complete the procedure. Second, we overlooked the filament image on the mechanical valve before surgery. Although this may have contributed to the patient's minor stroke, identifying it earlier might have prevented this beneficial intervention altogether.

We achieved success through several key steps. First, we used coronary computed tomography angiography to evaluate the RCA's relationship to the aortic graft; a greater distance from the aortic wall may have increased the risk of perforation and bleeding. Second, all covered stent sizes were prepared in advance. Third, our team's experience with electrosurgery in various structural procedures proved valuable. Fourth, while the Mamba catheter could not cross, it remained intact, making it preferable to the less torquable Finecross (Terumo) for E-CART. Fifth, after crossing, we avoided atherectomy therapies due to concerns about synthetic debris embolizing in the aorta, relying instead on balloon-based strategies. We succeeded using an OPN NC balloon at 45 atm to create a neo-ostium, completed tissue modification with scoring balloon technology, and optimized the ostial stent with an Ostial FLASH balloon to flare the struts on the aortic wall, which would facilitate future RCA cannulation if needed.

Our final guidewire track on which balloon dilation was performed involved a short segment outside the RCA architecture in the proximal segment. Fibrotic scar tissue from 3 previous surgeries likely prevented bleeding and supported stent placement, though longer unsupported extra-vascular segments may not behave similarly. Persistent stent waist at the ostium after aggressive ballooning raises concern for potential subsequent recoil, warranting close clinical follow-up. A minor stroke raised concern for wire tip electrosurgical charr embolism, but its timing and the presence of pre-existing aortic valve filaments suggest alternative causes; a filament embolism during wire snaring is possible. The patient fully recovered, with only minor MRI-detected brain defects.

This is the first reported case of retrograde E-CART via a synthetic aortic graft to re-anastomose a likely ligated RCA, presenting as a CTO after a modified Bentall procedure with subsequent SVG to RCA failure. The resistant synthetic tissue required high-pressure ballooning and scoring balloon use before stenting, but no perforation occurred despite some extravascular tracking. Stenting with ostial molding of the struts restored TIMI 3 flow with no significant recoil. The patient remains fully functional and asymptomatic. PCI should be considered over repeat surgery in similar post-Bentall cases when carefully planned.

Funding Support and Author Disclosures

Dr Rinfret serves as a consultant for SIS medical, Shockwave, and Teleflex. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.