Aspiration Thrombectomy With 6 French GuideLiner to Prevent Distal Embolization: Three Case Examples

Aspiration thrombectomy in percutaneous coronary interventions (PCI) is an established method used with the hope of avoiding distal embolization and decreasing incidence of a no-reflow phenomenon, which portends a poorer prognosis. Previous trials have had conflicting results (i.e., TAPAS, TASTE, and TOTAL) with meta-analysis suggesting an increased risk of stroke that was confirmed by the TOTAL trial. However, the mechanism of stroke is unclear, given that stroke incidence continued between 30-180 days after PCI, which cannot easily be explained.¹ All previous trials in regards to manual thrombectomy used approved aspiration catheters (i.e., Export [Medtronic], Pronto [Teleflex]). Our technique of using the GuideLiner (GL) catheter (Teleflex) for manual aspiration thrombectomy has been described in a previous article.² Here we describe an additional three cases that were successful with this technique. 

Case 1

A 70-year-old male without prior cardiac history presented with new-onset angina and a non ST-elevation myocardial infarction (NSTEMI). Angiography showed subtotal occlusion of a proximal right coronary artery (RCA) with a large thrombus burden and Thrombolysis in Myocardial Infarction (TIMI) 2 flow (Figure 1). A 6 French (Fr) Amplatz left (AL) 0.75 catheter and a 6 Fr GuideLiner were selected for support with a Balanced Middleweight (BMW) coronary wire (Abbott Vascular). The GuideLiner was carefully advanced to the proximal part of thrombus and aspiration with a 50 cc syringe via a Y connector through the side port was performed with partial success. Next, a compliant balloon (Trek Rx 2.0 x 12 mm [Abbott Vascular]) was inflated to 18 atmospheres (atm) at the site of the stenosis/thrombus. Another aspiration attempt through the GuideLiner was successful. A Resolute stent (3.5 x 18 mm) (Medtronic) was deployed at 22 atm with good expansion. A follow-up angiogram (Figure 2) after aspiration thrombectomy and stent deployment revealed TIMI-3 flow with no evidence of the thrombus and good distal flow. The patient was started on optimal medical therapy, including continuation of a glycoprotein (GP) IIb/IIIa inhibitor. The patient did well post PCI and was discharged the next day in stable condition. 

Case 2

A 47-year-old male without prior cardiac history presented with an inferior ST-elevation myocardial infarction (STEMI) and received thrombolytics at an outside facility. Upon transfer to our facility, he was taken immediately to the cath lab due to continued angina and ST elevations. Angiography revealed a large distal RCA thrombus proximal to the bifurcation with TIMI-2 flow (Figure 3). Through a 6 Fr Judkins right (JR) 4.0 guide catheter and a 6 Fr GuideLiner, a Runthrough NS coronary wire (Terumo) was advanced to the distal RCA branch. The GuideLiner was carefully advanced to the distal RCA at the site of the thrombus and aspiration was attempted using a 50 cc syringe, but with only partial success. A stent (Xience 4.0 x 18 mm [Abbott Vascular]) was deployed at 20 atm proximal to the RCA bifurcation, with full expansion, but persistent thrombus in the stented segment. The GuideLiner once again was carefully advanced to the thrombus and after second aspiration attempt, there was complete clearance of the thrombus (Figure 4). TIMI-3 flow with no evidence of distal embolization was noted. The patient was started on optimal medical therapy, including continuation of a GP IIb/IIIa inhibitor, and was discharged 3 days later without any complications. 

Case 3

A 51-year-old male without prior cardiac history presented with chest pain that started 24 hours prior that was persistent and varying in intensity. He was still having intermittent chest pain when he was evaluated in the emergency department. An electrocardiogram showed inferior Q waves without ST elevation. Initial troponin was 19 ng/mL. He was taken to the cath lab with a concern for post infarct angina. Angiography revealed a large RCA with multiple large thrombi in the proximal to mid RCA (Figure 5A). Using a 6 Fr Amplatz left (AL) 0.75 catheter, and a 6 Fr GuideLiner, aspiration thrombectomy was attempted with little success. A 2.0 x 30 mm compliant balloon was inflated at the site of the thrombus to try to disintegrate the thrombus. A second attempt with aspiration thrombectomy through the GuideLiner showed marked improvement in thrombus burden, but persistent ulceration of the proximal RCA (Figure 5B). At this point, it was felt that the best possible reduction of thrombus burden had been achieved and a stent was deployed (Resolute Onyx 4.5 x 30 mm, inflated at 26 atm). Remarkably, after stent deployment, there was no evidence of thrombus or distal embolization. A second stent was placed from the mid to distal RCA (Resolute Onyx 4.5 x 26 mm inflated at 26 atm) due to severe luminal irregularities, with the final result in Figure 5C. Multiple thrombi were visualized on the filtered blood that was suctioned with the 50 cc syringe (Figure 7). A GP IIb/IIIa inhibitor was administered post operatively. The patient was started on optimal medical therapy and was discharged 3 days post-op without any complications. 

Discussion

Aspiration thrombectomy was previously a routine recommendation for STEMI; however, recent trials have challenged this approach, showing that despite improvement of dynamic ST changes and prevention of distal embolization, there was no improvement in clinical outcomes and stroke rates were higher.¹ However, in a meta-analysis by Elgendy et al, the increase in stroke was not statistically significant.³ The increased stroke rates were also noted after more than 1 month from the aspiration thrombectomy, meaning they could not be explained by the procedure itself.¹ Although we only present three cases here with good results, it is difficult to ignore the benefits of aspiration thrombectomy in the prevention of no-reflow phenomenon and the adverse outcomes that it may entail. 

Our technique of aspiration thrombectomy with a 6 Fr GuideLiner is unique in that it accommodates a larger inner cross-sectional area (1.48 mm²) when compared to the dedicated coronary thrombectomy devices on the market (Export Aspiration and Pronto V3 Extraction catheter), as shown in Table 1. Poiseuille’s law tells us that flow is proportional to the cubed root of radius (if pressure remains constant), thus a small increase in radius will be exponentially magnified.² Table 1 shows the comparison of inner lumen diameter, cross-sectional area, and functional cross-sectional area (when taking into consideration the cross-sectional area occupied by the coronary wire, which is approximately 0.102 mm² for a standard .014-inch [0.36 mm] wire). The inner radius of a 6 Fr GuideLiner is 0.71 mm, whereas the inner radius of the Export Aspiration catheter is 0.51 mm. The difference translates to an approximate 6.7 times magnitude increase of flow in favor of the 6 Fr GuideLiner when a coronary wire is in the catheter, as compared to the Export catheter. Theoretically, the 6 Fr GuideLiner will have a much larger advantage for aspirating larger thrombi due to the vast increase in flow. Figure 7 is a close-up comparison between the two common extraction catheters (Export Aspiration and Pronto V3 Extraction catheter) for visualization. The dedicated thrombectomy catheters do have a beveled tip, but we believe that the catheter’s effectiveness in aspirating thrombi mainly arises from the size of the catheter. The straight tip of the GuideLiner may actually be beneficial, as it can more easily conform to the vessel, and in fact, Rioufol et al has shown in a bench study that straight-tip outperform beveled-tip catheters.⁴ In our third case, the RCA was large enough that we could have used an 8 Fr guide and an 8 Fr GuideLiner with an inner diameter of 1.80 mm. However, we felt it was not necessary to upsize to a larger catheter for the sole purpose of aspiration thrombectomy. 

Cases 2 and 3 revealed a large thrombus burden that even a GuideLiner could not aspirate initially. We were left with the option of direct stenting the lesion and “cutting” the thrombus with stent struts to help in its disintegration. Indeed, stenting post GuideLiner aspiration was very successful in these two cases. Looking at the TOTAL trial, aspiration thrombectomy would not have met the criteria for a clinical benefit; however, all three cases presented here had an unusually large thrombus burden; thus, we could not ignore the risk of embolization. We were able to fully retrieve the thrombi in each of the three cases. 

The versatility of a GuideLiner allows safe use of this device for aspiration thrombectomy. Since most PCIs today are done with a 6 Fr catheter, this technique can be used without increasing the size of the access site. The GuideLiner tip to base (at site of wire exchange) is 25 cm, and our recommendation is that at the very least, the base should be in the guide, so that during suction, the thrombi will stay within the GuideLiner and transition to the guide. Therefore, at most, a 20 cm extension into the coronary artery for aspiration thrombectomy would probably be considered safe. This allows plenty of length to reach even the most distal coronary arteries, as evidenced by our second case, a GuideLiner was used to extract a thrombus in the distal RCA. The Export and Pronto catheters are also rapid exchange; however, they do not have a length requirement, due to a separate rail built into the catheters for the coronary wire. We would recommend matching the GuideLiner Fr size with the catheter Fr size (i.e., a 6 Fr GuideLiner with a 6 Fr guide and a 7 Fr GL with a 7 Fr guide). Using a smaller GuideLiner Fr size (i.e., a 5.5 Fr GuideLiner with a 6 Fr guide) may not prove as effective, as the size discrepancy of the GuideLiner when it sits in the guide may cause flow during aspiration to be dispersed within the GuideLiner and within the guide itself.

While we present what is a currently an off-label use of a GuideLiner catheter, we hope to see the technique of GuideLiner aspiration thrombectomy become an indicated use for this device. A future trial with this technique may prove rewarding. 

Conclusion

Manual aspiration thrombectomy with the GuideLiner technique is a safe and effective method in carefully selected patients with a large thrombus burden. Stenting can improve thrombectomy success in cases of inadequate reduction in thrombus burden, despite aggressive manual aspiration with the GuideLiner technique.  

References

1. Jolly SS, Cairns JA, Yusuf S, et al. Randomized trial of primary PCI with or without routine manual thrombectomy. N Engl J Med. 2015; 372(15): 1389-1398. doi:10.1056/NEJMoa1415098.
2. Stys AT, Stys TP, Rajpurohit N, Khan MA. A novel application of GuideLiner catheter for thrombectomy in acute myocardial infarction: a case series. J Invasive Cardiol. 2013; 25(11): 620-624.
3. Elgendy IY, Huo T, Bhatt DL, Bavry AA. Is aspiration thrombectomy beneficial in patients undergoing primary percutaneous coronary intervention? Meta-analysis of randomized trials. Circ Cardiovasc Interv. 2015; 8(7): e002258. doi:10.1161/CIRCINTERVENTIONS.114.002258.
4. Rioufol G, Collin B, Vincent-Martin M, et al. Large tube section is the key to successful coronary thrombus aspiration: findings of a standardized bench test. Catheter Cardiovasc Interv. 2006; 67(2): 254-257. doi:10.1002/ccd.20471.

¹Cardiovascular Disease Fellow, Division of Cardiology, Sanford School of Medicine, Sioux Falls, South Dakota; ²Internal Medicine Resident, Division of Internal Medicine, Sanford School of Medicine, Sioux Falls, South Dakota; ³Professor of Medicine, Division of Cardiology, Sanford School of Medicine, Sioux Falls, South Dakota

Disclosures: The authors report no financial relationships or conflicts of interest regarding the content herein.

The authors can be contacted via Jimmy Yee, MD, at jyee315@yahoo.com.