Distal Left Anterior Descending Coronary Artery Obstruction: A Rare Complication of Transapical Aortic Valve Implantation

ABSTRACT: Apical complications are considered the “Achilles’ heel” of transapical aortic valve implantation, in which laceration and hemorrhage are potentially fatal. We describe the case of a rare complication of the transapical aortic valve implantation procedure, where after apical closure, tension on a distal coronary segment resulted in flow obstruction. Clinicians should be alert to the possibility of distal left anterior descending artery obstruction when ischemia following a transapical procedure is suspected. The exact location of sheath insertion during “transapical” aortic valve implantation is usually apicolateral. A more apical insertion should be avoided since the apex is a relatively weak region and there could be an increased risk of coronary avulsion or apical ventricular septal defect. Nevertheless, a too-lateral insertion could diminish the sheath orientation toward the left ventricular outflow tract and the sheath could also be entrapped with mitral valve chordae. Surgeons should be aware of these factors when deciding on the exact sheath insertion site during tranaspical procedures.

J INVASIVE CARDIOL 2011;23(12):E281-E283

Key words: aortic stenosis, apical complications, TAVI

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Percutaneous treatment of aortic stenosis holds promise for providing symptomatic relief and probably longevity for patients who are ineligible for surgery. Preliminary studies show that transcatheter aortic valve implantation (TAVI) is both feasible and effective in the short and medium term in elderly patients with aortic stenosis.^1-3 However, TAVI is a complex invasive procedure with many possible adverse events. Apical complications are considered the “Achilles’ heel” of transapical procedures, in which apical laceration and hemorrhage are potentially fatal.

Case Report. An 88-year-old woman with severe symptomatic aortic valve stenosis, chronic obstructive pulmonary disease, and peripheral vascular disease was considered at high risk for conventional valve replacement surgery. Her calculated logistic EuroSCORE was 18.3% and Society of Thoracic Surgeons (STS) score was 9.2%. She was therefore evaluated for TAVI. Echocardiography revealed good left ventricular systolic function (ejection fraction, 60%), an aortic valve area of 0.7 cm², and valve gradients of 74/49 (peak/mean) mm Hg. The aortic valve annulus measured 21 mm. The patient had mild mitral regurgitation and mild pulmonary hypertension of 40 mm Hg. Coronary catheterization showed nonsignificant coronary artery disease (Figure 1A) and iliofemoral vessels were less than 5-mm wide and therefore incompatible with transfemoral valve delivery.

The patient underwent transapical implantation of an Edwards-XT valve (Edwards Lifesciences) under general anesthesia and transesophageal echocardiography imaging. An anterolateral thoracotomy was performed to gain access to the left ventricular apicolateral region, and several reinforced purse-string sutures were placed around the ventricular apex. Apical puncture was followed by antegrade placement of first a soft and later a superstiff guidewire across the stenotic aortic valve. A 24 Fr Ascendra II delivery system was inserted through the heart apex. Balloon valvuloplasty was performed with a 20 mm valve balloon under brief rapid ventricular pacing using a temporary pacemaker. Subsequently, the 23 mm Edwards-XT valve was implanted under rapid pacing (Figure 1B). The prosthetic valve position was confirmed to be accurate. Aortography revealed only a minimal paravalvular leak (Figure 1C), and echocardiography showed a decrease in valve gradients to 11/6 mm Hg. There was no change in left ventricular function.

The apex was closed using Prolene 2-0 sutures and pledgets. Immediately after that, the electrocardiographic tracing showed ST-segment elevation in the inferior leads (Figure 2B). This pattern had not been present before valve implantation (Figure 2A). The patient was hemodynamically stable, although echocardiography revealed a new inferoapical wall motion abnormality. On aortography, the coronary artery ostia were patent. Selective injection into the right coronary artery revealed a small nondominant vessel with no significant coronary obstruction (Figure 1D). Injection into the left coronary system revealed a flow obstruction in the distal left anterior descending (LAD) coronary artery, near the apex, in a segment that was curved and mildly laterally deviated (Figure 1E). The LAD was wrapped around the apex and was supplying the posterior septum. The flow obstruction had not been present before the procedure (Figure 1A). Visual inspection of the cardiac apex indicated that the apical LAD obstruction was most probably a result of tension from the purse-string sutures. Nevertheless, the vessel segment was clearly not wrapped by a suture. We decided that the safest approach would be percutaneous coronary intervention at the point of the vessel obstruction. We performed balloon angioplasty with a 2.0 x 12 mm Maverick balloon (Figure 1F) and subsequently implanted a 2.5 x 25 mm PROKinetic stent (Figure 1G). The angiographic result was excellent (Figure 1H), and the ST-segment elevation and wall motion abnormality resolved (Figure 2C). The patient was discharged home 7 days after the procedure in excellent condition.

Discussion. Our case illustrates a rare complication of transapical procedures where a distal LAD flow obstruction appeared after apical closure. There are several potential etiologies for this flow obstruction: secondary to a surgical suture, apical tension or edema, coronary embolism, spasm or in-situ thrombosis. After careful inspection, it seemed that in our case tension on a distal coronary segment was the cause of obstruction. To our knowledge, this finding has not been described in the medical literature.

There are many reports of ischemic complications of TAVI.^4-6 Most were related to coronary ostia obstruction, which usually readily appears after aortography. Our case should alert clinicians to the possibility of distal LAD coronary artery obstruction when an ischemic complication is suspected following a transapical procedure. It is possible that specific coronary anatomical patterns pose a higher risk of this complication; for example, when the distal LAD segment has a lateral curvature. Patients should be evaluated for this pattern during screening for transapical procedures. If present, operators should probably perform a more lateral ventricular puncture.

The exact location of sheath insertion during transapical TAVI is usually apicolateral. A more apical insertion should be avoided since the apex is a relatively weak region and there could be an increased risk of coronary avulsion or apical ventricular septal defect. Nevertheless, a too-lateral insertion could diminish the sheath orientation toward the left ventricular outflow tract and the sheath could also be entrapped with mitral valve chordae. Surgeons should be aware of these factors when deciding on the exact sheath insertion site during tranaspical TAVI.

References

1. Webb JG, Chandavimol M, Thompson CR, et al. Percutaneous aortic valve implantation retrograde from the femoral artery. Circulation. 2006;113(6):842-850.
2. Grube E, Schuler G, Buellesfeld L, et al. Percutaneous aortic valve replacement for severe aortic stenosis in high-risk patients using the second- and current third- generation self-expanding CoreValve prosthesis device: success and 30-day clinical outcome. J Am Coll Cardiol. 2007;50(1):69-76.
3. Leon M, Smith C, Mack M, et al. Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery. N Engl J Med. 2010;363(17):1597-1607.
4. Masson JB, Kovac J, Schuler G, et al. Transcatheter aortic valve implantation: review of the nature, management, and avoidance of procedural complications. JACC Cardiovasc Interv. 2009;2(9):811-820. 
5. Kapadia SR, Svensson L, Tuzcu EM. Successful percutaneous management of left main trunk occlusion during percutaneous aortic valve replacement. Catheter Cardiovasc Interv. 2009;73(7):966-972.
6. Stabile E, Sorropago G, Cioppa A, et al. Acute left main obstructions following TAVI. EuroIntervention. 2010;6(1):100-105.

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From the Departments of ¹Cardiology and ²Cardiothoracic Surgery, Rabin Medical Center, Petach Tikva, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.
Manuscript submitted April 14, 2011, provisional acceptance given June 3, 2011, final version accepted June 6, 2011.
Address for correspondence: Dr. Ran Kornowski, Department of Cardiology, Rabin Medical Center, Petach Tikva 49100, Israel. Email: rkornowski@clalit.org.il