We report intraoperative transesophageal echocardiographic (TEE) findings in a 69-year-old woman with severe aortic stenosis (AS) undergoing aortic valve replacement (AVR) using autologous pericardium.
A probe was inserted under general anesthesia for TEE, which revealed normal ventricular systolic function, but thickening and heavy calcification of the aortic valve (AV) leaflets, restricting their opening (Video 1, see Supplemental Digital Content 1, http://links.lww.com/AA/A495). Continuous wave Doppler in the deep transgastric long-axis (TG LAX) view confirmed severe AS (maximum velocity and mean pressure gradient across the AV, 445 cm/s and 48.5 mm Hg, respectively; estimated area of AV, 0.41 cm2 by continuity equation).
The pericardium was excised, treated with 0.6% glutaraldehyde solution, and rinsed with physiologic saline solution. The native AV leaflets were excised under cardiopulmonary bypass (CPB) with aortic cross-clamp. The distance between each commissure was measured with a custom-designed apparatus (Fig. 1A). New leaflets corresponding to the measured values were cut from the glutaraldehyde-treated autologous pericardium (Fig. 1B). Finally, the annular margin of the pericardial leaflet was directly sutured to the native aortic wall (Fig. 2). The patient was weaned from CPB uneventfully. Postsurgical TEE revealed that the coaptation length of the new AV cusps was 10.9 mm (Fig. 3A), full opening of the AV (Video 2, see Supplemental Digital Content 2, http://links.lww.com/AA/A496) (Fig. 3B), and centrally directed trivial regurgitation (Video 3, see Supplemental Digital Content 3, http://links.lww.com/AA/A497); the mean pressure gradient across the AV was 2.03 mm Hg. Duration of aortic cross-clamp and CPB was 109 and 157 minutes, respectively. The patient was discharged and her condition remains satisfactory.
The standard treatment for AV disease is AVR, usually with prosthetic valves. However, AV repair is performed in selected patients, particularly those with aortic insufficiency (AI). Kim et al.1 reported AV repair for AI caused by a redundant cusp and summarized the mechanisms of AI and potential procedures. The evaluation of AV repair with TEE has been reviewed.2
Ozaki et al.3 and Kawase et al.4 reported satisfactory results for a novel method of autologous pericardial AVR for AS or AI arising from infective endocarditis, prosthetic valve endocarditis, annuloaortic ectasia, or bicuspid or quadricuspid AV.
In AVR with autologous pericardium, preoperative TEE is used to determine the location and degree of aortic wall and annulus calcification, presence of abscess cavities, and number of AV cusps. The preoperative measurement of the distance between each commissure and aortic root diameter is not mandatory with this approach, because they can be determined by direct observation.
Any aortic wall and annular calcification and aortic annulus abscesses should be carefully removed to avoid postoperative paravalvular regurgitation. To avoid obstruction of coronary arteries by implanted autologous pericardium, the location of the coronary artery ostium should be carefully determined in midesophageal short-axis view with color flow Doppler, especially with bicuspid or unicuspid AV, which tend to arise from an anomalous origin in such cases. If the bicuspid AV has a raphe, it is reconstructed as a trileaflet AV, assuming the raphe as the commissure line; if there is no raphe, the AV leaflets are reconstructed as a trileaflet AV, while avoiding interference with the coronary artery ostium.
To evaluate the success of AVR, we performed TEE to ascertain the morphologic features of the pericardial AVR. The midesophageal AV short-axis view revealed full opening of the implanted pericardial leaflets in systole and no interference with the coronary artery ostium by color flow Doppler imaging; the midesophageal AV LAX view revealed that coaptation length exceeded 10 mm, with the bottom of the coaptation zone above the ventriculoaortic junction during diastole. In comparison with a native AV (typical length, 3.2 ± 0.8 mm in adult population),5 an increase in cusp height may occur with autologous pericardial AVR, resulting in an increase in coaptation length in excess of 10 mm and distal extension as far as the sinotubular junction;3,4 moreover, the distal edge of the implanted AV leaflet moves outward close to the aortic wall, because autologous pericardium is more pliable than a native AV leaflet. However, prolapse of the base of the implanted AV leaflets below the ventriculoaortic junction in such cases is not a major concern unless more than trivial regurgitation is observed.
Paravalvular regurgitation is a potential complication caused by dehiscence of AV leaflets from the native aortic wall; the absence of paravalvular regurgitation was confirmed by color flow Doppler imaging. Finally, deep TG LAX and/or deep TG view were used again to determine whether there was any regional wall motion abnormality due to coronary artery obstruction or AV regurgitation and the mean transvalvular pressure gradient (<10 mm Hg from our experience).
Unlike with a stentless AVR, the pericardial AVR leaflets are sewn directly to the native aortic wall without any supporting structures. There is no space between the porcine root and aortic wall, typically seen as an echolucency, resulting in less chance of annular instability. If stentless AVR is performed, especially involving subcoronary or root inclusion technique, valve dehiscence and hematoma may occur between the native and porcine aortic walls, and size mismatch between the native aortic sinotubular junction and stentless AV can cause tethering or prolapse of the implant, which may be detected by color flow Doppler imaging. Furthermore, unlike the Ross procedure, which involves excision of an intact pulmonary valve for reimplantation in the aortic position, pericardial AVR does not carry the risk of postoperative pulmonary artery narrowing. Differentiation of postoperative TEE images among various types of AV surgery is summarized in Table 1.
We have reported intraoperative TEE of a novel AVR technique using autologous glutaraldehyde-treated pericardium. Postoperative TEE of autologous pericardial AVR reveals the distinctive increase in coaptation length and lack of supporting structures as acoustic shadowing, reverberation, and echolucency between the native and implanted AV.
We believe that intraoperative TEE imaging of AV surgery has an important role in evaluation of the success of this procedure.
Name: Hiroshi Inoue, MD.
Contribution: This author helped with anesthetic management, transesophageal echocardiography, and image acquisition, and helped prepare the manuscript.
Name: Jun Ito, MD.
Contribution: This author helped prepare the manuscript.
Name: Hiroaki Uchida, MD.
Contribution: This author helped prepare the manuscript.
This manuscript was handled by: Martin J. London, MD.
1. Kim TY, Alfirevic A, Wallence LK. Transesophageal echography for tricuspid aortic valve repair. Anesth Analg. 2010;110:370–2
2. Van Dyck MJ, Watremez C, Boodhwani M, Vanoverschelde JL, El Khoury G. Transesophageal echocardiographic evaluation during aortic valve repair surgery. Anesth Analg. 2010;111:59–70
3. Ozaki S, Kawase I, Yamashita H, Uchida S, Nozawa Y, Matsuyama T, Takatoh M, Hagiwara S. Aortic valve reconstruction using self-developed aortic valve plasty system in aortic valve disease. Interact Cardiovasc Thorac Surg. 2011;12:550–3
4. Kawase I, Ozaki S, Yamashita H, Uchida S, Nozawa Y, Matsuyama T, Takatoh M, Hagiwara S. Original aortic valve plasty with autologous pericardium for quadricuspid valve. Ann Thorac Surg. 2011;91:1598–9
5. Hasegawa J, Kitamura S, Kawata T, Kawachi K, Niwaya K. Echocardiographic characteristics of the cryopreserved allograft aortic valve replacement assessed by intraoperative transoesophageal echocardiography. Cardiovasc Surg. 1996;4:293–8
Clinician’s Key Teaching Points
By Kent H. Rehfeldt, MD, Roman M. Sniecinski, MD, and Martin J. London, MD
- Creation of a new aortic valve (AV) using autologous glutaraldehyde-treated pericardium is a unique alternative to traditional AV replacement using a tissue prosthesis. The pericardial valve leaflets are sewn directly to the aortic wall without the use of a sewing ring or other supporting structures. Consequently, mean transvalvular gradients are lower, potentially even more so than stentless AV prostheses.
- Although aortic root diameter and the distances between commissures are measured directly by the surgeon, intraoperative transesophageal echocardiographic imaging of the aortic root in long- and short-axis is critical for the procedure. Annular calcification or abscesses must be identified and removed before pericardial leaflet insertion to prevent subsequent paravalvular regurgitation. The location of the coronary ostia should also be identified using color Doppler and the presence of anomalous coronary arteries should be described to the surgeon.
- In this case, the coaptation zone between the autologous pericardial leaflets exceeded 10 mm, a common finding with this technique, which produces greater cusp height and a coaptation point that may extend to the sinotubular junction. There is a potential for obstruction of the coronary ostia, and careful assessment of regional wall motion abnormalities is warranted. The greater pliability of autologous pericardium can also result in diastolic prolapse of the base of the leaflets beyond the ventriculoaortic junction, although such prolapse is not concerning if only trivial regurgitation is present.
- The lack of a sewing ring or rigid support structures reduce acoustic shadowing after autologous pericardial valve insertion, and the results are similar to the echocardiographic appearance of a stentless bioprosthetic valve. Further studies may be warranted to determine whether this technique offers the same durability and long-term results as traditional AV replacement.