Aortic valve disease

The upper sternotomy or ministernotomy has been a well-known technique for many years, but it is not a common surgery. It has few pitfalls and not many secrets, but many benefits. Despite these factors, a minimally invasive approach is not routinely adopted. The ministernotomy finished at the third or fourth right Intercostal spaces can result in one of the pitfalls at the right mammary artery. The authors prefer to clip and section the artery. Some others prefer to respect the mammary. The point of this technique is that one must open the right pleura, and if the mammary bleeds, it can result in some blood loss. One of the tips is to put in the venous cannula as a chest tube. This can expand the operating field with less cannulae in the area, and remove the right atrium from the aortic root.

References

1. Aris A, Cámara ML, Montiel J, Delgado LJ, Galán J, Litvan H. Ministernotomy versus median sternotomy for aortic valve replacement: a prospective, randomized study. Ann Thorac Surg. 1999; 67:1583-1587.
2. Bonacchi M, Prifti E, Giunti G, Frati G, Sani G. Does ministernotomy improve postoperative outcome in aortic valve operation? A prospective randomized study. Ann Thorac Surg. 2002; 73:460-465.
3. Filip G, Bryndza MA , et al. Ministernotomy or sternotomy in isolated aortic valve replacement? Early results. Kardiochir Torakochirurgia Pol. 2018 Dec;15(4):213-218.

E. Murat Tuzcu of Cleveland Clinic Abu Dhabi in the United Arab Emirates and Ourania Preventza of Baylor College of Medicine in Houston, Texas, discuss valve-in-valve transcatheter aortic valve replacement versus redo surgical aortic valve replacement.

This debate was presented at the Heart Valve Society (HVS) Annual Meeting 2019 in Sitges, Spain, and is presented here with permission from HVS. For more information on upcoming events, please visit the HVS website.

Aortic valve reconstruction with glutaraldehyde-treated autologous pericardium has been demonstrated by Ozaki and colleagues to have good midterm results with less transvalvular gradient, less than mild aortic regurgitation, and 96.2% freedom from reoperation. The Ozaki technique uses an original template for each cusp designed by Ozaki, and the leaflets are trimmed according to the template size (1).

Inspired by the work of Ozaki et al for using glutaraldehyde-treated autologous pericardium and associated midterm results, the authors have developed a simple formula for the making of neo–aortic leaflets with 0.6% glutaraldehyde-treated autologous pericardium.

The patient was a 17-year-old girl with symptoms of dyspnea on exertion for one year, New York Heart Association class III symptoms, and a history of rheumatic fever two years previously. Echocardiography showed thickened, small, and retracted aortic leaflets with central coaptation defect and severe aortic regurgitation, vena contract of 7 mm, a dilated left ventricle, and normal left ventricular function. After examining the aortic valve, the authors decided to replace the diseased leaflets with 0.6% glutaraldehyde-treated autologous pericardial leaflets.

After excising the diseased aortic leaflets, the base of each cusp attachment to the annulus was measured with silk thread. The aortic annulus was measured with the aortic valve sizer. The authors converted the aortic valve sizer diameter directly into millimeters, and used it as a marker for the neocusp measurement. The valve-sizer diameter was used as the height and width of the neocusp free margin, and the silk thread was kept on the pericardium in an arc shape to fashion the neocusp as shown in the video. All three neocusps were created in this manner and then sutured to the respective cusp annulus with a 5-0 polypropylene suture in a continuous manner, and the suture was brought out at the commissure level. The suturing technique for the central part of the cusp to the annulus was in a 2:1 ratio, that is, 4 mm on the pericardium and 2 mm on the annulus. This created a nice puckering of the pericardium in the central part. For the ascending part of the annulus, the suturing was performed in a 1:1 ratio, that is, 2 mm on the pericardium and 2 mm on the annulus, and then the sutures were brought out at the commissure level. This was repeated for all three cusps. The sutures of the adjacent cusp were tied at the commissure level. Fine adjustments were made at the commissure level for any undulation or prolapse.

The postoperative echocardiography of this patient showed good coaptation, with the coaptation height of 9.4 mm, no residual aortic regurgitation, and aortic valve orifice area of 3.4 cm². The patient was extubated after eight hours of ventilation and discharged from the hospital on postoperative day seven. Follow-up echocardiography at one month and at six months showed no aortic regurgitation, coaptation height of 1 cm, and good aortic valve orifice area.

The authors propose that this new technique of aortic valve repair with all cusp replacement using glutaraldehyde-treated autologous pericardium is durable, simple, reproducible, and economical, and it awaits midterm and long-term results.

Reference

1. Ozaki S, Kawase I, Yamashita H, et al. A total of 404 cases of aortic valve reconstruction with glutaraldehyde-treated autologous pericardium. J Thorac Cardiovasc Surg. 2014 Jan;147(1):301-306.

The authors present a video showing their technique of totally endoscopic aortic valve replacement with a bovine pericardial valve (Trifecta GT, Abbott), performed for an 81-year-old patient with severe aortic stenosis and moderate aortic regurgitation. The patient was heavily symptomatic in class III and had a EuroSCORE II of 2.36. The patient was positioned supine on the operating table, with his right shoulder elevated by 30 degrees. Double lumen ventilation was also used.

The operation was performed through a 3 cm working incision in the second intercostal space parasternally, with two 10 mm ports in the second and fifth intercostal spaces in the anterior axillary line. The extra small Alexis wound protector was used in the working incision. A 3D 30-degree Karl Storz endoscope was inserted in the second intercostal port and the whole of the procedure was done under stereoscopic vision. The fifth intercostal port was used for the right-hand instruments during the opening of the pericardium and for the left atrial vent while the aorta was cross-clamped.

Three pericardial retraction sutures where used to retract the pericardium and the heart towards the endoscope (the sutures were externalized in the first, third, and seventh intercostal spaces in the middle axillary line).

The Chitwood cross-clamp was inserted through a separate hole in the first intercostal space, anterior and superior to the endoscope. On femoro-femoral cardiopulmonary bypass, the aorta was cross-clamped and Custodiol cardioplegia was used to arrest the heart. Half of the dose was given in the aortic root and the other half directly in the coronary ostia (due to the aortic regurgitation), after performing a transverse aortotomy 3 cm above the right coronary ostium. The heavily calcified valve was excised using long-shafted instruments, and the annulus was sized. A 23 mm Trifecta GT (Abbott) bovine pericardial prosthesis was inserted using 2/0 Ethibond sutures secured with the COR-KNOT® automated suture-fastening device. In order to facilitate the placement of the annular sutures, the authors used a self-expanded iron net to increase the volume of the aortic root.

The aortotomy was closed in two layers, the heart was de-aired, and the cross-clamp was removed. Postoperative transesophageal echocardiography confirmed a normally functioning prosthesis. The patient was extubated a couple of hours later and had an uneventful recovery.

Additional Resources

1. Pitsis A, Tsotsolis N, Nikoloudakis N, et al. Totally endoscopic redo tricuspid valve repair. CTSNet. June 2019. doi: 10.25373/ctsnet.8199260.
2. Pitsis A, Nikoloudakis N, Tsotsolis N, et al. Totally endoscopic bileaflet mitral valve repair with preformed chordae loops. CTSNet. March 2019. doi: 10.25373/ctsnet.7837853.

Dr Antonios Pitsis serves as a Proctor for Abbott.

Sir Magdi Yacoub of the Imperial College London in the UK and Patrick Serruys of the Thoraxcenter Erasmus University in Rotterdam, Netherlands, discuss the use of tissue-engineered valves versus endogenous tissue restoration. 

This debate was presented at the Heart Valve Society (HVS) Annual Meeting 2019 in Sitges, Spain, and is presented here with permission from HVS. For more information on upcoming events, please visit the HVS website.