Coronary artery stent dislodgement and aortic dissection in a patient with a severely calcified lesion in the proximal right coronary artery

Abstract

In atherosclerosis progression, calcium deposition may have an impact on the natural history of coronary atherosclerosis, and the amount of calcium may affect the success rate of percutaneous coronary intervention (PCI). Coronary stent dislodgement does not commonly occur in the modern PCI era; however, it may lead to fatal death. If it occurs, retrieval of a dislodged stent can be performed either surgically or percutaneously using a variety of retrieval techniques, including inflating a catheter balloon distal to the undeployed stent, twirling 2 wires around the stent, a loop snare, or forceps. Here, we report a rare case that coronary artery stent dislodgement and aortic dissection simultaneously occurred during PCI for a severely calcified lesion in the proximal right coronary artery with shepherd’s crook morphology. The situation was successfully rectified by using balloons to deploy the stent, as well as by applying an additional stent and minimizing the contrast used to treat aortic dissection.

Learning objective: During percutaneous coronary intervention (PCI), stent dislodgement and aortic dissection are extremely rare, but life-threatening complications. In this rare case of simultaneous stent dislodgement in the coronary artery and aortic dissection during PCI for a severely calcified lesion in the right coronary artery with shepherd’s crook morphology, the situation was successfully rectified by using balloons to retrieve and deploy the stent, as well as by applying an additional stent and minimizing the contrast used to treat aortic dissection.

Introduction

Atherosclerosis progression involves inflammation and immune responses in all layers of the arterial wall [1], in which calcified coronary lesions can occur [2]. Calcium deposition impacts the natural history of coronary atherosclerosis, and the amount of calcium may affect the success rate of percutaneous coronary intervention (PCI) [3]. Here, we report a complicated case of severely calcified lesion in the proximal right coronary artery, which caused coronary artery stent dislodgement and aortic dissection.

Case report

An 84-year-old man, who had chronic heart failure, an abdominal aortic aneurysm, hypertension, and chronic kidney disease, was admitted to our hospital due to exacerbation of his chronic heart failure. Chest radiography showed cardiomegaly and pulmonary congestion (Fig. 1A-), and electrocardiography demonstrated low voltage and V1-3 leads revealed poor R wave progression (Fig. 1A-). Cardiac ultrasonography revealed dilation of the left atrium and ventricle, indicating the presence of pulmonary hypertension (estimated systolic pulmonary arterial pressure, 45 mmHg).

Fig. 1.

Chest X-ray, electrocardiogram, abdominal computed tomography scan (A-) Chest radiography examination showed cardiomegaly and congestion. (A-) These immediately improved after the patient received adaptive support ventilation and treatment with diuretics. Electrocardiogram shows low voltage and V1-3 leads revealed poor R wave progression (A-).

Abdominal computed tomography upon admission showed a significant increase in the size of the patient’s abdominal aortic aneurysm from 48 mm (B-) to 54 mm (B-) in 3 months (arrows).

He was treated by adaptive support ventilation (ASV) with intravenous administration of human atrial natriuretic polypeptide (0.05 μg/kg/min), and intravenous administration of furosemide (40 mg/day). His dyspnea improved immediately after ASV treatment (Fig. 1A-). Abdominal computed tomography (CT) scan showed a significant increase of abdominal aortic aneurysm (48–54 mm in three months, Fig. 1B- ). We therefore decided to perform aortic replacement, following improvement of the patient’s cardiac failure symptoms.

Prior to surgery, we performed coronary angiography, which indicated single vessel disease of 90% stenosis in proximal right coronary artery (RCA) (Fig. 2A-). There were no significant stenoses in left anterior descending (LAD) and left circumflex (LCX) arteries (Fig. 2A-). We considered that the RCA stenosis should be revascularized, because the surgery for abdominal aortic aneurysm would be highly invasive. Therefore, we decided to perform PCI using a bare metal stent (BMS). A 6 French 0.75-in. short tip Amplatz left type guiding catheter (Launcher SAL 0.75, Medtronic Inc., Dublin, Ireland) and guidewire (Sion Blue, ASAHI Intec., Nagoya, Japan) were inserted into the RCA, and we performed intravascular ultrasound (IVUS). IVUS revealed circumferential severe calcification (Fig. 2A-). Thus, we predilated the target lesion by a non-compliant balloon (Hiryu Plus 2.5 × 12 mm, Terumo Inc., Tokyo, Japan). IVUS-guided PCI with BMS (Integrity 4.0 × 22 mm, Medtronic Inc.) placement was then attempted; however, the stent was not able to go through the severely calcified lesion. When we tried to retrieve the stent into the guiding catheter, the stent was dislodged near the target lesion in the coronary artery. Then, we retained the guidewire, and advanced a second guidewire external and distal to the dislodged stent, and subsequently twisted the two guidewires several times to allow their distal ends to intermingle. However, we were not able to trap the dislodged stent (Fig. 2B-). Next, we attempted to retrieve the dislodged stent into the guiding catheter by dilating the distal portion of the stent using a 1.0 mm × 10 mm small balloon (IKAZUCHI Zero, KANEKA Inc., Osaka, Japan) and by manipulating the wire. However, we could not retrieve the stent, although it moved to the proximal portion of RCA (Segment 1). Finally, we placed the dislodged stent in the proximal portion of RCA after dilatation with a 4.0 × 15 mm balloon (NC Euphora, Medtronic Inc.) (Fig. 2B-).

Fig. 2.

Coronary angiography Coronary angiography showed single-vessel disease with 90% stenosis in segment 1 of right coronary artery (A-, arrow). The left anterior descending artery and left circumflex artery were patent (A-). Intravascular ultrasound detected circumferential severe calcification (A-). The stent was dislodged near the target lesion in the coronary artery. At first, we advanced a second guide wire external and distal to the dislodged stent, and subsequently twisted the two guide wires several times to allow their distal ends to intermingle. However, we could not trap the dislodged stent (B-, arrow). Place of the dislodged stent in the proximal portion of RCA segment 1 after dilatation with a 4.0 × 15 mm balloon (NC Euphora, Medtronic Inc.) (B-).

Immediately after this procedure, we observed the retention of contrast agent in the right coronary cusp, which indicated aortic dissection caused by the guiding catheter (Fig. 3A-). We remodeled by promptly placing a stent (Integrity 4.0 × 15 mm) in the RCA ostium entry site (Fig. 3A-). After this procedure, we added plain old balloon angioplasty (POBA) and we were able to place the BMS (Integrity 4.0 × 12 mm) in the target lesion and complete the procedure successfully. The post-procedure CT scan indicated that the local aortic dissection lesion was barely visible (Fig. 3B-). We also performed contrast-enhanced CT scan on the following day and a week after the PCI, which showed a partial Valsalva dissection; however, there was no evidence of progression (Fig. 3B-). The patient had a favorable clinical course and was discharged in ambulatory condition. A month later, he underwent a surgical replacement of aneurysm using synthetic graft.

Fig. 3.

Coronary angiography, chest computed tomography scan Retention of contrast agent in the right coronary cusp was observed, which showed an aortic dissection caused by the guiding catheter (A-, arrow). Repaired aortic dissection by promptly placing a stent (Integrity 4.0 × 15 mm, Medtronic Inc.) in the RCA ostium entry site while minimizing the use of contrast (A-). The post-percutaneous coronary intervention procedure computed tomography scan indicated that the local aortic dissection lesion was barely visible (B-). Contrast-enhanced computed tomography was also performed the following day and a week after the procedure. Although a partial Valsalva dissection was observed (B-, arrow), there was no evidence of its progression.

Discussion

Coronary stent dislodgement does not commonly occur in the modern PCI era, which may lead to fatal death [4], [5]. The prevalence of stent dislodgement has been reported to be highest in the left main coronary artery and LAD, and lower in LCX and RCA [6]. Risk factors for stent dislodgement include severe coronary angulations, coronary tortuosity, diffuse long lesions, and calcified coronary arteries [7], in which the present case presented a severely calcified lesion in the proximal RCA. Retrieval of a dislodged stent can be performed either surgically or percutaneously using a variety of retrieval techniques, including inflating a catheter balloon distal to the undeployed stent, twirling 2 wires around the stent, a loop snare, or forceps. We were able to pass a small balloon through the center of our dislodged stent, and then deploy the stent with successively larger balloons. If failed, we would have tried to crash the dislodged stent by using a large size balloon or new stent.

Localized dissection of the sinus of Valsalva is another extremely rare complication that may occur during PCI, and can lead to serious conditions such as dissection of the ascending aorta. Dissection of the sinus of Valsalva and aortic wall following coronary artery dissection induced by a guiding catheter or guidewire has been previously reported, and the rate is 0.04%, according to their experience [8].

However, the precise mechanism of this unusual complication remains unclear. Vigorous hand injection of the contrast medium, subintimal passage of guidewires, and inadvertent handling of the guiding catheter have been proposed as possible mechanisms of iatrogenic coronary and aortic dissection during PCI [9]. The present case also involved a severely calcified lesion in the proximal RCA with shepherd’s crook morphology.

If aortic dissection occurs, sealing the entry port of the coronary dissection with a stent can be also effective to prevent the progression of dissection [10]. In the present case, we implanted a stent in the ostium of the right coronary artery by minimizing the contrast, which might prevent the progression into the ascending aorta. Gentle manipulation of the guiding catheter was therefore imperative not only in the coronary artery, but also in the sinus of Valsalva.

In summary, we describe for the first time a rare case that coronary artery stent dislodgement and aortic dissection simultaneously occurred during PCI for a severely calcified lesion in the proximal RCA with shepherd’s crook morphology. The situation was successfully rectified by using balloons to retrieve and deploy the stent, as well as by applying an additional stent and minimizing the contrast used to treat aortic dissection.

Conflict of interest

None.