The Buddy Balloon for Transcatheter Aortic Valve Replacement: Insights From Computed Tomographic Assessment of the Aortic Valvular Complex

Abstract: Transcatheter aortic valve replacement (TAVR) is a procedure whose technique and devices are evolving rapidly, facilitating increased safety and efficacy. However, there remain challenging cases. Considering the concept of crossing a bulky prosthesis through a calcified and narrowed aortic valve, it seems not unexpected that some of these procedures have difficulty. This is in fact rare, but can occur and demands special techniques, since the commercially available balloon-expandable prosthesis and its iterations are not retrievable when inserted into the body. The buddy-balloon technique for TAVR has a similar rationale. Sheiban et al reported the buddy-balloon technique as a solution to failed aortic valve crossing, but it is not widely used, particularly in many lower-volume centers starting to perform TAVR. We report two cases that were effectively treated with the help of this technique. 

J INVASIVE CARDIOL 2013;25(9):468-470

Key words: buddy-balloon technique, TAVR

__________________________

Transcatheter aortic valve replacement (TAVR) is a procedure whose technique and devices are evolving rapidly, facilitating increased safety and efficacy. However, there remain challenging cases. Considering the concept of crossing a bulky prosthesis through a calcified and narrowed aortic valve, it seems not unexpected that some of these procedures have difficulty. This is in fact rare,¹ but can occur and demands special techniques, since the commercially available balloon-expandable prosthesis and its iterations are not retrievable when inserted into the body. The buddy-wire technique is used during percutaneous coronary intervention (PCI) for lesions with severe calcium, marked tortuosities, or sharp bends. The concept of this technique is reducing the tortuosities and providing a smooth rail to the other device.² The buddy-balloon technique for TAVR has a similar rationale. Sheiban et al reported the buddy-balloon technique³ as a solution to failed aortic valve crossing, but it is not widely used, particularly in many lower-volume centers starting to perform TAVR. We report two cases that were effectively treated with the help of this technique. We also sought, through a detailed analysis of the aortic valvular complex with computed tomography (CT) to further understand anatomic reasons for failure of the delivery catheter system to cross the native aortic valve. The commissural fusion between the right coronary cusp (RCC) and the non-coronary cusp (NCC) appears to be an important factor.

Case 1

Clinical presentation. The first patient was an 88-year-old male with severe calcific aortic valve stenosis and New York Heart Association (NYHA) class III to IV congestive heart failure symptoms who was referred for TAVR. His past medical history was coronary artery disease and status post previous multiple PCI, peripheral vascular disease, and status post endovascular repair of abdominal aortic aneurysm, hypertension, dyslipidemia, permanent pacemaker, insulin-dependent diabetes, and hepatocellular carcinoma. His transthoracic echocardiogram (TTE) showed an aortic valve area (AVA) of 0.7 cm² with peak and mean pressure gradients of 74 mm Hg and 46 mm Hg, respectively, and ejection fraction (EF) of 67%. The predicted operative mortality for surgical aortic valve replacement based on the Society of Thoracic Surgeons database (STS score) was calculated to be 9.5%. He was evaluated by a multidisciplinary heart team, deemed inoperable, and approved for TAVR. Informed consent was obtained prior to the procedure.

Procedural details. The procedure was performed under general anesthesia with trasesophageal echocardiogram (TEE) and fluoroscopy guidance. After using a modified Seldinger technique with micropuncture kits to both femoral arteries and right femoral vein, positioning of a temporary pacing wire in right ventricular apex was performed. A 24 Fr sheath was successfully inserted into the right femoral artery. Then, an Amplatz-1 catheter and a straight wire were used to cross the aortic valve retrogradely via the right femoral artery and was exchanged for an Amplatz Extra-Stiff wire (Cook Medical, Inc) in the left ventricular apex. We predilated with a 22 x 5 mm Z-med II balloon (B. Braun Medical, Inc). He was deemed suitable for a 26 mm Edwards SAPIEN valve (Edwards Lifesciences) based on echocardiogram and contrast-CT sizing. We tried to insert a RetroFlex transfemoral delivery system (Edwards Lifesciences) across the aortic valve, but it was difficult to pass. 

Then, the buddy-balloon technique was employed. An Amplatz-1 catheter was advanced through a 7 Fr sheath in the left femoral artery and crossed the aortic valve with a straight wire. Another Amplatz Extra-Stiff wire was exchanged and positioned in the left ventricular apex. A 10 x 4 mm Z-med balloon was positioned across the aortic valve. This was inflated and at the same time redirected angulation of the transcatheter valve delivery system and this enabled crossing of the aortic valve. The valve was then deployed with rapid pacing. 

It was well positioned and TEE showed only mild paravalvular leak. Hemodynamics were improved from peak-to-peak gradient of 33 mm Hg and AVA of 0.82 cm² to 4 mm Hg and 1.51 cm², respectively. Catheters and sheaths were removed and good hemostasis was achieved. The patient was extubated in the catheter laboratory. He tolerated the procedure very well. 

Case 2

Clinical presentation. This patient was an 87-year-old female with severe calcific aortic stenosis and NYHA class III to IV who was referred for TAVR. Her past medical history was coronary artery disease with a non-Q wave myocardial infarction 4 years ago, hypertension, hyperlipidemia, asthma, sleep apnea syndrome on continuous positive airway pressure, chronic ataxia, pulmonary fibrosis, and severe degenerative disk disease, with multiple back surgeries. Her TTE showed an AVA of 0.9 cm² with peak and mean pressure gradient of 67 mm Hg and 56 mm Hg, respectively, and ejection fraction of 65%. The STS score was calculated to be 5.0%. She was evaluated by a heart team, deemed inoperable, and approved for TAVR. Informed consent was obtained prior to the procedure.

Procedural details. The setting of the procedure was the same as the previous case. A 6 Fr sheath was inserted into both femoral arteries using a modified Seldinger technique with micropuncture kits. Positioning of a temporary pacing wire in the right ventricular apex was performed via left femoral vein. A 22 Fr sheath was successfully inserted into the right femoral artery. Then, an Amplatz-1 catheter and a straight wire were used to cross the aortic valve retrogradely via the right femoral artery and was exchanged for an Amplatz Extra-Stiff wire in the left ventricular apex. Predilation was performed with an 18 x 5 mm Z-med 2 balloon. She was deemed suitable for a 23 mm Edwards SAPIEN valve according to echocardiogram and contrast-CT sizing. We tried to insert the Retroflex 3 delivery system across the aortic valve, but it was difficult to pass.

The buddy-balloon technique was employed again. The left femoral artery sheath was upsized to a 7 Fr long sheath. We advanced an Amplatz-1 through it and then crossed the aortic valve with a straight wire. Then, another Amplatz Extra-Stiff wire was exchanged and positioned in the left ventricular apex. A 10 x 4 mm Z-med balloon was positioned across the aortic valve. This was inflated and facilitated crossing of the delivery system by changing the orientation of the valve and the delivery system. The valve was deployed with rapid pacing. 

It was well positioned and TEE showed only mild paravalvular leak. Hemodynamics improved from peak-to-peak gradient of 45 mm Hg to only 2 mm Hg. Catheters and sheath were then removed and good hemostasis was achieved. The patient was extubated in the catheter laboratory. She also tolerated the procedure well. 

Discussion

TAVR is an evolving technique with established safety and efficacy for inoperable or high-risk patients with severe aortic stenosis.^4,5 An increase in its usage means that there will be an associated increase in complex cases encountered. Knowledge of advanced techniques is required to avoid failure. We experienced two cases where the prosthesis did not cross the native aortic valve and the buddy-balloon technique was used to address this problem. This technique is not new,^3,6 but requires contingency planning for additional access and specialized equipment.

Moreover, the reasons for difficulty in crossing the valve are often unclear. Possible reasons are a bulky native leaflet and an unfavorable angle of approach caused by aortic tortuosity compounded by outward push by incoming crimped bioprosthesis.¹ Preprocedural CT scans of presented cases were retrospectively reviewed and they showed leaflet calcification (Figures 1A and 1C) and aortic angulation⁷ (Figure 2) to an extent that was similar to other typical cases. Calcium measurement by Structural Heart 5.1 software (3 mensio Medical Imaging BV, using a 450 Hounsfield Unit threshold of detection) was within the range of the mean ± standard deviation (SD); calcium volume and mass in non-contrast CT of aortic valve from nadir to tip in case 1 were 694.8 mm³ and 406.6 mg and those in case 2 were 267.8 mm³ and 124.6 mg, respectively. At our facility, the means ± SD of 162 available consecutive non-contrast CTs are 500.9 ± 390.6 mm³ for volume and 286.76 ± 241.6 mg for calcium mass. We sought a further reason for failure to cross the native valve. Considering each leaflet, the left coronary cusp (LCC) or NCC generally contain more calcium than the RCC.^8,9 However, in the two presented cases there was extensive commissural fusion between the RCC and NCC with associated calcium (Figures 1A and 1C). This appears to be an important mechanism increasing the difficulty of the delivery catheter crossing. There is a clear rationale for this: the wires and catheters in the transfemoral approach tend to have a bias for the outer line of the aortic arch and root and therefore pass between the RCC and NCC. With the buddy-balloon technique, the additional balloon occupies the commissure between the RCC and NCC and keeps the prosthesis away from the fused commissure (Figures 1B and 1D), enabling the native valve to be crossed.

Conclusion

The buddy-balloon technique is an essential contingency plan maneuver for TAVR operators. Extensive commissural fusion between RCC and NCC, particularly when associated with heavy calcification, should alert physicians that this approach may be necessary. 

References

1. Van Mieghem NM, Tzikas A, Nuis RJ, Schultz C, de Jaegere PP, Serruys PW. How should I treat a staggering TAVI procedure? EuroIntervention. 2010;6(3):418-423.
2. Vijayvergiya R, Swamy AJ, Grover A. Buddy wire technique: a simple technique for treating calcified lesion during percutaneous coronary intervention: a case report. J Invasive Cardiol. 2006;18(4):E129-E130.
3. Sheiban I, Infantino V, Bollati M. Buddy ballon to deliver a percutaneous aortic valve device: a percutaneous shoehorn? Catheter Cardiovasc Interv. 2009;74(5):805-807.
4. Leon MB, Smith CR, Mack M, et al; the PARTNER Trial Investigators. Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery. N Engl J Med. 2010;363(17):1597-1607.
5. Smith CR, Leon MB, Mack MJ, et al; the PARTNER Trial Investigators. Transcatheter versus surgical aortic-valve replacement in high-risk patients. N Engl J Med. 2011;364(23):2187-2198. 
6. Balkin J, Silberman S, Almagor Y. Buddy balloon for TAVI. Catheter Cardiovasc Interv. 2010 Jun 14 (Epub ahead of print).
7. Gurvitch R, Wood DA, Leipsic J, et al. Multislice computed tomography for prediction of optimal angiographic deployment projections during transcatheter aortic valve implantation. JACC Cardiovasc Interv. 2010;3(11):1157-1165.
8. Haensig M, Lehmkuhl L, Rastan AJ, et al. Aortic valve calcium scoring is a predictor of significant paravalvular aortic insufficiency in transapical-aortic valve implantation. Eur J Cardiothorac Surg. 2012;41(6):1234-1240; discussion 1240-1241 (Epub 2012 Jan 12).
9. Schultz C, Rossi A, van Mieghem N, et al. Aortic annulus dimensions and leaflet calcification from MSCT predict the need for balloon post-dilation after TAVI with the Medtronic CoreValve prosthesis. EuroIntervention. 2011;7(5):564-572.

____________________________

From the Cedars-Sinai Medical Center, Heart Institute, Los Angeles, California.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Jilaihawi and Dr Makkar are consultants for Edwards LifeSciences. Dr Okuyama reports no conflicts of interest.

Manuscript submitted December 11, 2012 and accepted January 2, 2013.

Address for correspondence: Raj R. Makkar, MD, 8631 W. Third Street, Suite 121 E, Los Angeles, CA 90048. Email makkarr@cshs.org