Entrapment of OFDI Catheter
Dr. Yu-ho CHAN
Pok Oi Hospital, Hong Kong
A 68-year-old gentlemen with history of diabetes was admitted for anterior ST elevation myocardial infarction. Patient was brought to the cath lab after initial success of thrombolytic therapy. Coronary angiogram showed diffuse proximal to mid LAD stenosis up to 90% (Movie 1) and proximal RCA 90 % stenosis. PCI to LAD using an XB 3.5 guide from right radial approach was planned. Pre-procedural OFDI was performed for lesion assessment and stenting optimization. After predilation, two overlapping drug eluted stent (3.0/18, 2.25/38) were implanted. Further high pressure postdilation were performed using non-complaint 3.5/ 2.5 balloon and satisfactory angiogram result was achieved (Movie 2). Post stenting OFDI was done and showed satisfactory stent expansion and apposition. However, resistant was found during removal of OFDI catheter and further retrieval resulted in trapped OFDI catheter in mid LAD stent. Deformation of the stent was also noticed (Movie 3). Further retrieval was stopped as it will make future stent deformation. Simple maneuver were tried including pushing the OFDI catheter forward followed by rotation (Figure 1), advancing a balloon along the guidewire proximal to the trapped OFDI catheter and push forward (Figure 2). They were proven to be unsuccessful. OFDI catheter was then dissembled by disconnecting the transparent port and removing the soft inner wire (Figure 3). The catheter can then be straightened up by inserting the stiff distal end part of Terumo wire and advancing it to the tip of the catheter (Figure 4). After the straightening, the trapped catheter can be pushed forward to relieve the entrapment but it was unsuccessful again. The OFDI catheter was then cut over the proximal shaft and daughter catheter (either 5Fr ST01 or guide extensor) was inserted over the remaining shaft/guidewire (Figure 5). The daughter catheter can provide strong support and free the trapped OFDI catheter (Figure 6). However, lots of resistance was felt and it failed to advance deep into the vessel. After the initial failure, extra access was obtained via the femoral route and another guiding catheter was advanced close to the left main. LAD was carefully wired with another floppy guidewire (Movie 4) followed by low pressure balloon inflation using a 1.5 semi-compliant balloon to free the trapped device (Figure 7). The OFDI catheter was then pushed and rotated to free the entrapment. The catheter was finally able to be retrieved (Movie 5). The damaged part of the stent/mid LAD was further dilated with high pressure non-compliant 3.5 balloon and stented with 2.75/28 DES. Satisfactory angiogram was achieved. The patient remained stable throughout the procedure (Movie 6). The patient was discharged uneventfully and 9-month angiographic follow-up showed no significant ISR (Movie 7).
The case illustrated various startegies of removing a trapped OFDI device. Similar techniques may be used to release trapped device with a guidewire exit port and a short monorail segment distally. The reason of a trapped OFDI is multifactorial and include inadequate stent expansion/ apposition and guidewire bias. Exhaustive methods can be tried before considering open heart surgery.
May I ask why was it trapped? Any advise to prevent this from happening? Thank you.
The reason of trapping in this case is multifactorial as mentioned in the discussion. More important factor in this case can be due to wire bias.
It is always more important to prevent complication before it occurs. The key is to remove all these imaging catheter with short monorail segment slowly and make sure there is no resistant. Once gross stent deformation or major entanglement occurred, it would be very difficult to retrieve the device like in our case.
Thanks for the question.
This is also because OFDI is a monorail system. The exit port of the wire can get caught occasionlly. The system is similar to Bonston IVUS. In this case the OFDI catheter was passed over a relative shape edge of the vessel or stent while removing. We thought that the catheter was caught unnoticed.
The catheter is a monorail system. The distal part of the catheter is relatively soft and there is a small indentation over the wire exit port. While removing the catheter, in this case, the exit port was caught by part of stent covering the shape angle of the vessel. The catheter was in fact passed over the relatively sharp edge of the vessel as showned by finaly OFDI image. In order to avoid this kind of complication, the most important step is to remove the system slowly. Once we feel any resistance , we should stop pulling immediately and try to push forward in order to relieve the trapping.