This work was supported by a grant from the Swiss Cardiovascular Foundation to RT.

The protocol follows the institutional guidelines of the human research ethics committee.
1. Pre-selection of the Patient
<ol>
	<li>Using the preoperative echocardiography, identify patients with an estimated aortic annulus diameter of less than 20 mm. Be aware that in heavily calcified aortic valves and annuli, the preoperative echocardiography can sometimes be misleading.</li>
	<li>Select from these patients a subgroup with a body surface area greater than 1.6 m2.</li>
	<li>Veri...

<ol>
	<li>Bonow, R. O., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Focused+update+incorporated+into+the+ACC/AHA+2006+guidelines+for+the+management+of+patients+with+valvular+heart+disease:+A+report+of+the+American+College+of+Cardiology/American+Heart+Association+Task+Force+on+Practice+Guidelines+(Writing+Committee+to+Revise+the+1998+Guidelines+for+the+Management+of+Patients+With+Valvular+Heart+Disease):+endorsed+by+the+Society+of+Cardiovascular+Anesthesiologists,+Society+for+Cardiovascular+Angiography+and+Interventions,+and+Society+of+Thoracic+Surgeons.">Focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1998 Guidelines for the Management of Patients With Valvular Heart Disease): endorsed by the Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons.</a> Circulation. 118 (15), e523-e661 (2008).</li><li>Rahimtoola, S. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+problem+of+valve+prosthesis-patient+mismatch.">The problem of valve prosthesis-patient mismatch.</a> Circulation. 58 (1), 20-24 (1978).</li><li>Pibarot, P., Dumesnil, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prosthesis-patient+mismatch:+definition,+clinical+impact,+and+prevention.">Prosthesis-patient mismatch: definition, clinical impact, and prevention.</a> Heart. 92 (8), 1022-1029 (2006).</li><li>Pibarot, P., Dumesnil, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hemodynamic+and+clinical+impact+of+prosthesis-patient+mismatch+in+the+aortic+valve+position+and+its+prevention.">Hemodynamic and clinical impact of prosthesis-patient mismatch in the aortic valve position and its prevention.</a> J. Am. Coll. Cardiol. 36 (4), 1131-1141 (2000).</li><li>Kang, Y. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiac+hypertrophy:+a+risk+factor+for+QT-prolongation+and+cardiac+sudden+death.">Cardiac hypertrophy: a risk factor for QT-prolongation and cardiac sudden death.</a> Toxicol. Pathol. 34 (1), 58-66 (2006).</li><li>Castro, L. J., Arcidi, J. M., Fisher, A. L., Gaudiani, V. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Routine+enlargement+of+the+small+aortic+Root:+a+preventive+strategy+to+minimize+mismatch.">Routine enlargement of the small aortic Root: a preventive strategy to minimize mismatch.</a> Ann. Thorac. Surg. 74 (1), 31-36 (2002).</li><li>Kunihara, T., Schmidt, K., Glombitza, P., Dzindzibadze, V., Lausberg, H., Sch&#228;fers, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Root+replacement+using+stentless+valves+in+the+small+aortic+root:+A+propensity+score+analysis.">Root replacement using stentless valves in the small aortic root: A propensity score analysis.</a> Ann. Thorac. Surg. 82 (4), 1379-1384 (2006).</li><li>Yacoub, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fourteen-year+experience+with+homovital+homografts+for+aortic+valve+replacement.">Fourteen-year experience with homovital homografts for aortic valve replacement.</a> J. Thorac. Cardiovac. Surg. 110 (1), 186-194 (1995).</li><li>Sommers, K. E., David, T. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aortic+valve+replacement+with+patch+enlargement+of+the+aortic+annulus.">Aortic valve replacement with patch enlargement of the aortic annulus.</a> Ann. Thorac. Surg. 63, 1608-1612 (1997).</li><li>El-Hamamsy, I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rate+of+progression+and+functional+significance+of+aortic+root+calcification+after+homograft+versus+freestyle+aortic+root+replacement.">Rate of progression and functional significance of aortic root calcification after homograft versus freestyle aortic root replacement.</a> Circulation. 120 (Suppl 1), S269-S275 (2009).</li><li>Bach, D. S., Kon, N. D., Dumesnil, J. G., Sintek, C. F., Doty, D. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ten-year+outcome+after+aortic+valve+replacement+with+the+Freestyle+stentless+bioprosthesis.">Ten-year outcome after aortic valve replacement with the Freestyle stentless bioprosthesis.</a> Ann. Thorac. Surg. 80 (2), 480-487 (2005).</li><li>Ennker, I. C., Albert, A., Dalladaku, F., Rosendahl, U., Ennker, J., Florath, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Midterm+outcome+after+aortic+root+replacement+with+stentless+porcine+bioprostheses.">Midterm outcome after aortic root replacement with stentless porcine bioprostheses.</a> Eur. J Cardio-thorac. Surg. 40 (2), 429-434 (2011).</li><li>Tavakoli, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Full-root+aortic+valve+replacement+with+stentless+xenograft+achieves+superior+regression+of+left+ventricular+hypertrophy+compared+to+pericardial+stented+aortic+valves.">Full-root aortic valve replacement with stentless xenograft achieves superior regression of left ventricular hypertrophy compared to pericardial stented aortic valves.</a> J. Cardiothorac. Surg. 10, 15 (2015).</li><li>Kon, N. D., Cordell, A. R., Adair, S. M., Dobbins, J. E., Kitzman, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aortic+root+replacement+with+the+Freestyle+stentless+porcine+aortic+root+bioprosthesis.">Aortic root replacement with the Freestyle stentless porcine aortic root bioprosthesis.</a> Ann. Thorac. Surg. 67 (6), 1609-1616 (1999).</li><li>Dapunt, O. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stentless+full-root+bioprosthesis+in+surgery+for+complex+aortic+valve-ascending+aortic+disease:+a+single+center+experience+of+over+300+patients.">Stentless full-root bioprosthesis in surgery for complex aortic valve-ascending aortic disease: a single center experience of over 300 patients.</a> Eur. J. Cardiothorac. Surg. 33 (4), 554-559 (2008).</li><li>Saxena, A., Dinh, D., Smith, J. A., Reid, C. M., Shardey, G., Newcomb, A. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Training+surgeon+status+is+not+associated+with+an+increased+risk+of+early+or+late+mortality+after+isolated+aortic+valve+replacement+surgery.">Training surgeon status is not associated with an increased risk of early or late mortality after isolated aortic valve replacement surgery.</a> Cardiol. J. 21 (2), 183-190 (2014).</li><li>D'Agostino, R. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Society+of+Thoracic+Surgeons+Adult+Cardiac+Surgery+Database:+2016+Update+on+Outcomes+and+Quality.">The Society of Thoracic Surgeons Adult Cardiac Surgery Database: 2016 Update on Outcomes and Quality.</a> Ann. Thorac. Surg. 101 (1), 24-32 (2016).</li><li>Fries, R., Wendler, O., Schieffer, H., Sch&#228;fers, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+rest+and+exercise+hemodynamics+of+23-mm+stentless+versus+23-mm+stented+aortic+bioprostheses.">Comparative rest and exercise hemodynamics of 23-mm stentless versus 23-mm stented aortic bioprostheses.</a> Ann. Thorac. Surg. 69 (3), 817-822 (2000).</li></ol>

The authors have nothing to disclose.

This study reports a detailed description of the surgical technique of full-root aortic valve replacement using stentless aortic xenografts in patients with small aortic roots. Early morbidity and mortality are very low and compare favorably with other reports7. Heavily calcified coronary ostia constitute an anatomical limitation to this technique. Another drawback to this technique is represented by patients with a poor general condition who would not tolerate longer operative times. In these cas...

Biological aortic valve replacement is recommended for patients older than 65 years1. In patients with small aortic roots, the implantation of a stented biological valve substitute based on the labelled size given by the manufacturer might not meet the functional needs. In this situation, Rahimtoola first described the prosthesis-patient mismatch (PPM) as follows: &#34;mismatch can be considered to be present when the effective prosthetic valve area, after insertion into the patient, is less than that of a normal human valve&#34;2. The effective orifice area of the valve prosthesis is to be related to the patient&#39;s body size and, more commonly, to the patient&#39;s body surface area. The hemodynamic consequence of a too-small prosthetic valve is an abnormally high transvalvular gradient3. It has been shown that the relationship between the transvalvular gradient and the effective orifice area indexed to the body surface area (EOAI) is curvilinear and that gradients increase exponentially when the indexed EOA is less than 0.8 to 0.9 cm2/m2. On the basis of this relation, an EOAI less than 0.85 cm2/m2 is generally regarded as the threshold for PPM in the aortic position4. The impact of the PPM on early and late clinical outcomes is controversial. However, it has been reported that PPM negatively affects the regression of left ventricular hypertrophy and thus the normalization of left ventricular function and the alleviation of symptoms4. Persistent left ventricular hypertrophy is associated with an increased risk of arrhythmias and sudden cardiac death5.
It is therefore advisable to avoid PPM as much as possible4. In the case of a predictable PPM for a planned aortic valve replacement with a biological valve substitute, the options are: 1) to accept the PPM resulting from the implantation of a stented pericardial valve when comorbidities of the patient forbid a more technically demanding operative technique to implant a larger prosthesis, 2) to enlarge the aortic root to accommodate a larger stented valve substitute6, or 3) to implant a stentless biological valve7 or homograft8.
Aortic root enlargement has been reported to enhance perioperative bleeding, necessitating a re-sternotomy and increasing early mortality9. Aortic homografts may have excellent hemodynamic profiles and good long-term outcomes when implanted by experienced surgeons8. However, their limited availability and the accelerated rate of calcification make aortic homografts less suitable biological valve substitutes than their counterpart, porcine stentless aortic xenografts10.
The shortage and drawbacks of homografts have prompted the conception and development of alternative biological valve substitutes. To this purpose, stentless aortic xenografts were introduced into clinical practice11. On one hand, thanks to the elimination of the cumbersome sewing ring, stentless aortic xenografts can reproduce the hemodynamic advantages of homografts. On the other hand, as a result of the application of anti-calcification technology, the durability of stentless aortic xenografts has been optimized to match and even exceed the longevity of homografts11. Hemodynamic advantages of stentless aortic xenografts are entirely attained by full-root implantation12. In contrast to subcoronary and root inclusion techniques, full-root implantation places the stentless aortic xenograft on top of the aortic annulus, and not inside it. This fact underlies the rationale to opt for the full-root implantation technique, which grants the implementation of the largest internal functional diameter of the stentless valve substitute. In addition, the preservation of the Valsalva sinuses en-bloc with the valve leaflets favors more physiological opening and closing movements and hence a longer life expectancy of the leaflets. This advantage further contributes to the amelioration of long-term results12.
However, concerns regarding the increased potential for bleeding and for the possible distortion of coronary ostia anastomoses prevent a number of cardiac surgeons from shifting from a classical aortic valve replacement with a stented biological valve to the more technically demanding procedure represented by full-root replacement with stentless aortic xenografts.
Given the potential hemodynamic advantages of stentless aortic xenografts, we have adopted full-root implantation to avoid PPM in patients with small aortic roots necessitating an aortic valve replacement (Table 1). In these patients, the aim is to attain a projected EOAI of greater than 0.85 cm2/m2 for the newly implanted aortic valve. This intention is based on the reports of Pibarot and co-workers showing an unacceptably high transvalvular gradients for valve substitutes having a projected EOAI of less than 0.85 cm2/m2, with the subsequent incomplete relief of symptoms and the persistent risk of adverse outcomes3,4. Following the initial identification of adult patients with an aortic annulus diameter of less than 20 mm on their pre-operative echocardiography, patients are further selected to have a body surface area of greater than 1.6 m2. In this subgroup of patients, the implantation of a 19-mm stented pericardial aortic valve (EOA: 1.28 cm2) would result in a projected EOAI of less than 0.85 cm2/m2. In this protocol, these patients are candidates for the full-root implantation of stentless aortic xenografts. The final decision is made intra-operatively after the removal of the aortic valve. If a 19-mm valve sizer for the stented pericardial aortic valve passes too-tightly through the aortic annulus and the patient is hemodynamically stable and can tolerate a longer operation, the full-root implantation of a stentless aortic xenograft is performed.
For the stentless aortic xenografts, we use two commercially available valve substitutes interchangeably (for details, see the Table of Materials). Both valves are procured from the porcine aortic root bearing the aortic valve. They are prepared using a low-pressure (0-2 mmHg) fixation process, with anti-calcification (e.g., XenoLogiX) treatment for one valve and alpha amino oleic acid (AOA) anti-calcification treatment for the other. In those patients for whom the 19 mm sizer for the stented pericardial valves passes too-tightly through the aortic annulus, the 23 mm sizer for the stentless aortic xenograft fitting well in the aortic annulus denotes that the stentless aortic xenograft size of 23 mm is to be chosen. This protocol describes in detail the technique of full-root implantation of stentless aortic xenografts, with emphasis on the management of the proximal suture line and coronary anastomoses. Limitations of this technique and alternative options are discussed.

<table border="0" cellpadding="0" cellspacing="0" width="761">
	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:368px;">Heart surgery infrastructure:</td>
			<td style="width:163px;"></td>
			<td style="width:151px;"></td>
			<td style="width:80px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Heart Lung Machine</td>
			<td>Stockert</td>
			<td>SIII</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">EOPA 24Fr. arterial cannula</td>
			<td>Medtronic</td>
			<td>77624</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Atrial caval venous cannula 34/48Fr.</td>
			<td>Medtronic</td>
			<td>93448</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">LV vent catheter 17Fr.</td>
			<td>Edwards</td>
			<td>E061</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Antegrade 9Fr. cardioplegia cannula</td>
			<td>Edwards</td>
			<td>AR012V</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Retrograde 14Fr. cardioplegia cannula&#160;</td>
			<td>Edwards</td>
			<td>NPC014&#160;</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Coronary artery ostial cannula 90&#176;</td>
			<td>Medtronic</td>
			<td>30155</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Coronary artery ostial cannula 45&#176;</td>
			<td>Medtronic</td>
			<td>30255</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Valve subsitutes:</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Stentless aortic xenograft Prima Plus 23mm</td>
			<td>Edwards</td>
			<td>2500P-23</td>
			<td>anti-calcification XenoLogiX treatment</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Stentless aortic xenograft Sizer 23mm</td>
			<td>Edwards</td>
			<td>1170</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Stentless aortic xenograft Freestyle 23 mm</td>
			<td>Medtronic</td>
			<td>FR995-23</td>
			<td>alpha amino oleic acid (AOA) anti-calcification treatment</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Stentless aortic xenograft Sizer 23mm</td>
			<td>Medtronic</td>
			<td>7900</td>
			<td></td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Electrocautery</td>
			<td>Covidien</td>
			<td>Force FXTM</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Sutures:</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Polypropylene 4/0</td>
			<td>Ethicon</td>
			<td>8871H</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Polypropylene 5/0</td>
			<td>Ethicon</td>
			<td>8870H</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Polypropylene 6/0</td>
			<td>Ethicon</td>
			<td>EH7400H</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Braided polyesther 2/0 ligature with polybutylate coating&#160;</td>
			<td>Ethicon</td>
			<td>X305H</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Micro knife Sharpoint&#160;</td>
			<td>TYCO Healthcare PTY&#160;</td>
			<td>78-6900</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Drugs:</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Midazolam</td>
			<td>Roche Pharma</td>
			<td>N05CD08</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Rocuronium</td>
			<td>MSD Merck Sharp &#38; Dohme&#160;</td>
			<td>M03AC09</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Propofol</td>
			<td>Fresenius Kabi</td>
			<td>N01AX10</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Fentanil</td>
			<td>Actavis</td>
			<td>N01AH01</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Heparin</td>
			<td>Braun</td>
			<td>B01AB01</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Protamin</td>
			<td>MEDA Pharmaceutical</td>
			<td>V03AB14</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Instruments:</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Cooley vascular aortic clamp</td>
			<td>Delacroix-Chevalier</td>
			<td>DC40810-16</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Dissection forceps Carpentier</td>
			<td>Delacroix-Chevalier</td>
			<td>DC13110-28&#160;</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Scissors Metzenbaum</td>
			<td>Delacroix-Chevalier</td>
			<td>B351751</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Needle holder Ryder</td>
			<td>Delacroix-Chevalier</td>
			<td>DC51130-20&#160;</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Dissection forceps DeBakey</td>
			<td>Delacroix-Chevalier</td>
			<td>DC12000-21&#160;</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Micro needle holder Jacobson</td>
			<td>Delacroix-Chevalier</td>
			<td>DC50002-21&#160;</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Micro scisors Jacobson</td>
			<td>Delacroix-Chevalier</td>
			<td>DC20057-21&#160;</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Lung retractor</td>
			<td>Delacroix-Chevalier</td>
			<td>B803990</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Allis clamp</td>
			<td>Delacroix-Chevalier</td>
			<td>DC45907-25&#160;</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">O&#8217;Shaugnessy Dissector</td>
			<td>Delacroix-Chevalier</td>
			<td>B60650</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">18 blade knife</td>
			<td>Delacroix-Chevalier</td>
			<td>B130180</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Leriche haemostatic clamp</td>
			<td>Delacroix-Chevalier</td>
			<td>B86555</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Data analysis:</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Mann-Whitney and Chi-square tests</td>
			<td>GraphPad</td>
			<td>Prism 7</td>
			<td></td>
		</tr>
	</tbody>
</table>

full-root aortic valve replacement by stentless aortic xenografts in patients with small aortic roots

In patients with small aortic roots who need an aortic valve replacement with biological valve substitutes, the implantation of the stented pericardial valve might not meet the functional needs. The implantation of a too-small stented pericardial valve, leading to an effective orifice area indexed to a body surface area less than 0.85 cm2/m2, is regarded as prosthesis-patient mismatch (PPM). A PPM negatively affects the regression of left ventricular hypertrophy and thus the normalization of left ventricular function and the alleviation of symptoms. Persistent left ventricular hypertrophy is associated with an increased risk of arrhythmias and sudden cardiac death. In the case of predictable PPM, there are three options: 1) accept the PPM resulting from the implantation of a stented pericardial valve when comorbidities of the patient forbid the more technically demanding operative technique of implanting a larger prosthesis, 2) enlarge the aortic root to accommodate a larger stented valve substitute, or 3) implant a stentless biological valve or a homograft. Compared to classical aortic valve replacement with stented pericardial valves, the full-root implantation of stentless aortic xenografts offers the possibility of implanting a 3-4 mm larger valve in a given patient, thus allowing significant reduction in transvalvular gradients. However, a number of cardiac surgeons are reluctant to transform a classical aortic valve replacement with stented pericardial valves into the more technically challenging full-root implantation of stentless aortic xenografts. Given the potential hemodynamic advantages of stentless aortic xenografts, we have adopted full-root implantation to avoid PPM in patients with small aortic roots necessitating an aortic valve replacement. Here, we describe in detail a technique for the full-root implantation of stentless aortic xenografts, with emphasis on the management of the proximal suture line and coronary anastomoses. Limitations of this technique and alternative options are discussed.

Statistical analysis
The values of projected effective orifice area indexed to the body surface area (EOAI, cm2/m2) for implanted stentless aortic xenografts sized 23 mm are expressed as means &#177; SD and compared to the calculated EOAI of stented pericardial valves 4 mm smaller (i.e., 19 mm) using the non-parametric Mann Whitney test. In Table 2, continuous variables are compared using the non-para...

Watch this Scientific Journal Video about Full-root Aortic Valve Replacement by Stentless Aortic Xenografts in Patients with Small Aortic Roots at JoVE.com

Full-root Aortic Valve Replacement by Stentless Aortic Xenografts in Patients with Small Aortic Roots

Full-root aortic valve replacement by stentless aortic xenograft is a viable option in patients with small aortic roots. We describe, a technique for the full-root implantation of stentless aortic xenografts, with emphasis on the management of the proximal suture line and coronary anastomoses, and discuss its limitations and alternative options.

In patients with small aortic roots who need an aortic valve replacement with biological valve substitutes, the implantation of the stented pericardial ...

The overall goal of this surgical procedure is to provide a reliable and reproducible full root implantation of stentless aortic xenografts for patients with small aortic roots undergoing aortic valve replacements. The main advantage of this technique is that it is an excellent option to avoid prosthesis patient mismatch in patients who have a small aortic annulus and who are undergoing an aortic valve replacement. This method can also help answer key questions regarding re-implantation of coronary arteries, such as during aortic root surgery.After surgically accessing the heart through a median sternum and installing a cardiopulmonary bypass, prepare the aortic root for implantation. In summary, use forceps and a number 18 blade to enlarge the aortic opening and transect the aorta with Metzenbaum scissors. Then, verify the presence of the right coronary ostium and the left coronary ostium.Next, excise the right coronary leaflet, the non-coronary leaflet, and the left coronary leaflet. Finish the preparation with a perpendicular incision from the top of the non-coronary Valsalva sinus wall down to its base. Now, start the proximal anastomosis.After placing stay sutures above each aortic commissure, start a suture from the outer aspect of the xenograft to the inner aspect, and pass the stitch into the nadir of the left coronary sinus. Place the next stitch two millimeters to the left of the first. Then, with the aid of an assistant, continue the running suture up to the commissure between the coronary sinuses.Now, start a second suture starting at the aortic annulus two millimeters to the right of the first suture. From the ventricle, pass these stitches outward. Next, place a third suture starting two millimeters to the side of the second suture starting at the sewing ring at the xenograft.Run the suture to the commissure between the right sinus and non-coronary sinus and put both ends of the third suture on traction. Now, place a fourth suture at the commissure between the right and non-coronary sinus and run it to the middle of the non-coronary sinus. Now, run a fifth suture from the middle of the non-coronary sinus to the commissure between the non-coronary sinus and the left coronary sinus.Finally, run the last suture from the end of the fifth suture to the end of the first running suture. Once placed, slowly pull the sixth suture until the graft is tight against the aortic annulus;and then, tie the sutures together. Before proceeding, clean out the region around the proximal suture line and coronary ostia.Inspect the anastomosis for gaps between the bites. Begin the coronary anastomoses by reconnecting the left coronary ostium to the left coronary neo-ostium of the graft. Place the first stitch of a 6/0 polypropylene running suture at the deepest point of the left coronary neo-ostium from the inside out, and pass this stitch to the deepest point of the left coronary ostium from the outside in.Place the second stitch to the right of the first. Now, continue the suture into the left coronary neo-ostium of the graft and then into the left coronary ostium of the patient. Then, tie the two sutures together.Next, using a scalpel, create a right coronary neo-ostium in the graft by excising the ligated right coronary of the graft and enlarging the opening horizontally towards the commissure between the right sinus and the non-coronary sinus of the graft. Then, place a running suture at the left end of the lower ridge of the right coronary ostium. Stitch from the inside out and pass the stitch through the neo-ostium, also at the left end of the lower ridge of the right coronary.Then, pull the tissues together. Pass the second stitch to the right of the first and bring the suture to the middle of the right ridge of the right coronary anastomosis. Now, continue stitching from the left, moving from the outside to the inside of the patient's tissue and from the inside to the outside of the graft tissue.Once the running suture is completed, tie the ends together. Lastly, put two coronary artery ostial cannulas in place, one into the left coronary ostium and the other into the right coronary ostium for repeat antegrade cardioplegia. Begin the distal anastomosis with a 5/0 polypropylene running suture from the left end of the lower rim and continue it to the middle of the right rim.Place stitches at regular two-millimeter intervals from the inside out on the graft tissue and from the outside in on the patient's tissue. Now, continue with the left end of the suture placing equidistant stitches on the anterior aspect of the anastomosis from the outside in on the graft and from the inside out on the patient. Once closed, tie together the suture ends.Now, slowly remove the aortic cross-clamp under gentle aspiration of the left ventricular vent. Then, remove the lung retractor on the right ventricle. The effective orifice area index is determined from the patient's body surface area and can be used to predict prosthesis patient mismatches.In patient's with small aortic roots, a 19-millimeter stented pericardial valve would result in mismatches. However, by implanting stentless aortic xenografts, the EOAI becomes significantly greater;and mismatch problems are not expected. Surgical data of stentless aortic xenograft implantation in small aortic roots was compared with similar data reported for stented pericardial valves.Cross-clamp cardiopulmonary bypass and operative times were all longer using the xenografts;however, 30-day morbidity and mortality measures were equally excellent. While attempting this procedure, it is important to remember to sufficiently mobilize the coronary ostium. Don't forget that full root implantation of stentless aortic xenografts can be extremely delicate and precautions, such as even distribution of tension on the proximal anastomosis by multiple semi-continuous sutures, should always be taken.

full-root-aortic-valve-replacement-stentless-aortic-xenografts

Research

JoVE Journal

Medicine

11.2K ビュー.  University of Zurich. The overall goal of this surgical procedure is to provide a reliable and reproducible full root implantation of stentless aortic xenografts for patients with small aortic roots undergoing aortic valve replacements. The main advantage of this technique is that it is an excellent option to avoid prosthesis patient mismatch in patients who have a small aortic annulus and who are undergoing an aortic valve replacement. This method can also help answer key questions regarding re-implantation of co...