SS–22 Stent-Balloon System Dislodgement and IntraGuiding Catheter Stent Deformation in a Calcified Proximal RCA Lesion: A Rare Primary PCI Complication

Abstract

Introduction and Aim: During primary percutaneous coronary intervention (PCI), calcified coronary lesions can cause difficulty in balloon and stent delivery, leading to rare but severe mechanical complications. Stent-balloon system dislodgement (detachment), balloon rupture/ perforation, and stent deformation within the guiding catheter are extremely rare complications, yet their management is critical. In this case report, we present the dislodgement of a stent-balloon system in a calcified proximal right coronary artery (RCA) lesion and the successful, safe retrieval of the entire system.

Case Report: A 60-year-old male patient presented to the emergency department with typical chest pain ongoing for 30 minutes. His past medical history was unremarkable except for smoking. The initial electrocardiogram (ECG) demonstrated findings consistent with inferior ST-segment elevation myocardial infarction (STEMI), and the patient was urgently transferred to the catheterization laboratory. Coronary angiography was performed using a JR4 guiding catheter to selectively visualize the right coronary artery (RCA). Stenoses of 70% in the proximal segment and 99% in the mid-segment of the RCA were identified. The lesion was crossed with a soft workhorse coronary wire, and predilatation was performed using a 2.0×15 mm PTCA balloon. Subsequently, attempt was made to advance a 3.5×21 mm drug-eluting stent (DES) to the lesion; however, significant resistance was encountered due to the heavily calcified proximal segment. To increase support, a second coronary wire (buddy wire) was placed, and additional predilatation was performed using a 2.5×15 mm PTCA balloon. With this extra support, the stent was advanced to the target lesion area. When attempt was made to inflate the stent balloon, it was observed that the stent failed to expand and contrast extravasation occurred from the balloon system. Suspecting balloon perforation and system failure, retrieval of the stent was attempted. However, the proximal portion of the stent became caught at the tip of the guiding catheter, preventing complete retraction into the catheter. Consequently, the stent-balloon system was retracted in a controlled manner up to the tip of the guiding catheter, and the entire assembly (guiding catheter, wire, balloon, and stent) was retrieved en bloc from the body. Ex vivo examination revealed that the proximal portion of the stent had detached/dislodged from the delivery balloon, the balloon had suffered perforation, and the stent had deformed the tip of the guiding catheter (Fig. 1). The RCA was re-cannulated using a new guiding catheter and a new coronary wire. After re-crossing the lesion, sequential balloon dilatations were performed, and a new drug-eluting stent was successfully implanted. Final angiography demonstrated restored TIMI-3 flow, and the procedure was completed without further complications.

Discussion: Calcified coronary lesions represent one of the most challenging anatomical factors impeding stent delivery. During stent passage through highly resistant segments or in the setting of inadequate lesion preparation, increased mechanical stress can cause stent deformation, balloon perforation, and, rarely, stent-balloon system dislodgement. In this case, severe resistance encountered in the calcified proximal RCA segment exerted excessive mechanical load on the device assembly. The subsequent balloon perforation and stent detachment are among the rarely reported complications. The critical aspect of this case was the controlled withdrawal of the entire stent system without allowing it to embolize freely within the coronary circulation. Thanks to this approach, a potentially fatal complication was successfully prevented.

Conclusion: Adequate lesion preparation and the utilization of appropriate support strategies are of paramount importance in reducing device-related complications in calcified coronary lesions. In rare complications such as stent-balloon system dislodgement, controlled retrieval of the system followed by re-intervention using an alternative strategy can ensure a safe clinical outcome.