Procedure of CARVAR

CARVAR is a surgical procedure that is developed to preserve both the aortic root and the aortic valve. CARVAR can treat all kinds of aortic root and valve disease, not only isolated aortic valve diseases but also combined aortic root and valve disease such as aortic aneurysm and dissection. CARVAR is the abbreviations for Comprehensive Aortic Root and Valve Repair. The primary goal of CARVAR procedure is to reconstruct the patient's aortic root and valve of appropriate size and shape, preserving the patient's native frame of aortic root and valve as enough as possible, instead of resection and replacement. Indications of CARVAR? Aortic valve repair has been considered as the challenging area in the cardiac surgery. But CARVAR procedure provides the uniform standard modality in treating various types of aortic root and valve diseases, preserving the native aortic root and valve structure as much as possible, because it restores not only aortic root cage, but also reconstructs the aortic leaflets.CARVAR procedure using the Rootcon® and Leafcon® series can be applied to the following cases 1) Isolated aortic valve disease Isolated aortic regurgitation is a good indication and aortic stenosis can also be indicated, even though severe calcification and leaflet distortion are present. - Aortic Valve Insufficiency - Aortic Valve Stenosis - Annulo-Aortic Ectasia (including Marfan Syndrome) 2) Combined aortic root and valve disease  Regardless of its causative and initiating disease, once the aortic root or valve is involved pathologically, both aortic root and valve are supposed to be all diseased as time passes. Diseases such as aortic aneurysm, annuloaortic ectasia, aortic dissection belong to this category. CARVAR technique also can be successfully applied to these cases. - Aortic Aneurysm (ascending aorta, descending aorta) - Aortic Dissection - Infective Endocarditis 3) Prosthetic valve failure at the aortic position Conditions with present artificial heart valve can be indicated for CARVAR, if the patient's aortic root has been preserved. - Other aortic valve diseases CARVAR procedure is largely composed of 3 surgical steps. 1. retention of appropriate aortic annulus size 2. restoration of appropriate sinotubular junction size 3. reconstruction of aortic valve leaflets  Depending on the patient's pathologic condition, all or some of the above surgical steps are performed. For example, in most cases for aortic regurgitation, step 1 is not needed. But in most cases for aortic stenosis or aortic valve leaflet prolapsed, step 2 and 3 should be performed. In most cases for aortic dissection and ascending aortic aneurysm, step 2 and ascending aorta replacement are enough to do. 1. Peri-root dissection The aortic root should be first dissected and freely mobilized with complete resection of fatty tissue attatched to the aortic root and its neighboring structures before aortotomy. If the coronary arteris are "high take -off" type, sub-coronary dissection is recommended.

2. Aortotomy If the ascending aorta is hugely dilated like in the annuloaortic ectasia, ascending aortic aneurysm and aortic dissection, the ascending aorta is transected. But if the ascending aorta is not dilated or slightly to moderately dilated, the ascending aorta is incisied partially and anteriorly. The level of aortotomy is usually 7~10㎜ above the sinotubular junction. If the coronary arteries take off high, then the level of aortotomy is 7~10㎜ above the origin of coronary arteries.

3. Annulus diameter measurement The annulus diameter is measured with the Annulus Sizer 011 series. The aortic annulus is composed of fibrous annulus and muscular annulus. First, measure the length of muscular annulus. When the muscular annulus is measured, measure the circumferential length from the commissure between noncoronary leaflet and right coronary leaflet to the mid-point of left coronary leaflet (Fig. 4). Next, measure the opposite fibrous annulus in the similar manner and compare it with the length of muscular annulus. Then, make the length of muscular annulus as a reference because the ratio of the length of fibrous versus muscular part is approximately 1:1 in the normal condition (Fig. 5).

If the muscular annulus is dilated and ejection fraction (EF) is less than 30%, it may be attributed to a kind of cardiomyopathy. Consider a cardiac transplantation instead of CARVAR procedure.)

4. STJ diameter measurement and determination of ideal STJ diameter. The STJ diameter is measured with the Sciencity STJ Sizer 012 series. There can be two situations: (1) aortic leaflets look like normal and (2) aortic leaflets are deteriorated like in the calcified aortic stenosis. When the aortic leaflets look like normal, 3 leaflets are pulled together by a single stitch (Frater's stitch) that is passed through the 3 nodules of Aranti (center of leaflet margin), and measure the leaflet surface (Fig. 6). If STJ diameter is measured in the aortic aneurysm and dissection, the level of STJ is determined just above the level of commissures. When the aortic leaflets are deteriorated, cut them to open the commissural fusion and remove the calcifed mass sufficient enough to mobilize the leaflets and then measure the STJ diameter in the manner that sizer can be passed without resistance (Fig. 7). Select the one as large as possible of these diameters, considering that the ratio of Annulus/STJ diameter is normally within the range 1.0 ~1.2.

5. Annulus reduction (Annuloplasty) If the fibrous annulus is not dilated, this procedure is not needed (Table 1). But if the annulus part is dilated larger than muscular part by 2㎜ more, reduce it to the length of muscular annulus. Also in all Marfan patients (annuloaortic ectasia), the fibrous annulus have to be always reduced. The same numbered strip as the length of muscular annulus measured is selected. For example, if the length of muscular annulus is measured 30㎜, then select the Rootcon® Annulus In 30 strip. After peeling off the lid of the package, remove the strip with its holder and separate the strip from the holder. Six 4-0 polypropylene double-armed sutures are evenly placed on the Rootcon® Annulus In 30 strip and then passed through the aortic annulus wall and come out of the aortic root, so that 2 suture in left coronary leaflet and 4 suture in noncoronary leaflet are approximately placed. Then, select the +6 numbered Annulus Out strip, that is, 36 and call for Annulus Out strip 36 and remove the strip with its holder from package and place the above sutures in order sequence on the Annulus Out strip 36. After separating the Annulus Out 36 strip from its holder, pull out all 6 sutures and push down the Annulus Out 36 strip and make alignment with the Annulus In 30 strip and tie tightly (Fig. 8).

6. Aortic leaflet reconstruction If aortic valve leaflets are normal, skip this step (Table 1). But when the aortic valve leaflets are distorted and diseased, resect the aortic leaflets. Often the subaortic membrane over the muscular annulus can be present in severe aortic stenosis. Then resect it at the same time. When the aortic leaflets are resected, decide the resection type or range among the following 3 methods, depending on the scope of the disease involvement. 1) Complete resection down to the annulus 2) Partial resection to 2~3㎜ away from the annulus 3) Leaflet extension without resection of diseased leaflet Resect all 3 leaflets, rather than leaving 1 or 2 leaflets. New leaflets are reconstructed with bovine or glutaraldehyde-fixed autologous pericardium. It is very convenient to use the template (Leafcon®) for designing the pericardial patch. When template is used, select the same numbered template as the number of STJ diameter measured and the same type of template as the resection type performed. There are provided 3 types of template in concordance with resection type, C-Leafcon®, P-Leafcon®, and E-Leafcon® for each size (Fig. 9). For example, if the diameter of STJ was determined as 28㎜ and leaflets were partially resected, select the #28 P-type template(P-Leafcon® 28) among 3 types of template.

Then place the bovine or glutaraldehyde-fixed autologous pericardium between the plates of selected template and cut the pericardium along the margin of the template with the scissors. (See the User’s manual of Leafcon® Set) Attach the cut pericardial cusp to the remnant of the aortic leaflet with continuous 5-0 polypropylene sutures (Fig. 10).

7. Commissure reduction (Commissuroplasty) After new leaflets are reconstructed, commissuroplasty is added in the following manner in order to compress or reduce a commissural gap and subcommissural triangle. Three 4-0 pledget-reinforced mattress sutures are placed through the adjacent edges of the newly reconstructed pericardial leaflets at each commissural level. These sutures can be externalized outside the aorta and secured (Fig. 11).

8. STJ reduction STJ reduction should be always carried out in CARVAR procedure. But only when the aortic stenosis without STJ dilatation (STJ diameter <24㎜) is corrected, STJ reduction is done enoughly with the outer strip (STJ Out) without inner ring (STJ In) (Table 1). Otherwise, both of inner and outer ring or strip are together used. The size selection of STJ inner ring (STJ In) is automatically determined by the diameter of STJ measured. When the size of STJ outer ring or strip is selected, it is determined as the +6 numbered STJ outer ring in the usual cases but if the aortic root is huge-dilated or involved by dissection, select the +8 numbered STJ outer ring (STJ Out) or open STJ outer strip (STJ Out Strip 40). Also, when the aorta is partially incised, it is convenient to use the open STJ Out Strip 40. For example, if the diameter of STJ is measured 28㎜, select the same numbered STJ In 28. Then, select +6 ~ +8 numbered STJ Out Ring, that is STJ Out Ring 34 or 36. Normally STJ ring or strip is located 5mm above the ostia of coronary artery. But if the coronary artery is highly taken off just like in the huge aortic aneurysm, STJ reduction should be performed in the sub-coronary position. When STJ is reduced, there can be 2 types of situations: (1) complete transection of ascending aorta and (2) anterior partial incision of ascending aorta. When the asceding aorta is completely transected, inner ring is inserted with three 4-0 double-armed orientaional mattress sutures which pass through the aortic wall from the inner ring. (There are 3 equidistant vertical marks for alignment with commissures and another 3 mid-way marks between them on the ring) Next, another three 4-0 mattress mid-way sutures are placed between the orientational sutures. Additional two 4-0 mattress sutures are placed mid-way between each orientational and mid-way sutures. These sutures in due order are passed through the outer ring or strip and tied (Fig. 12 and 13). When the ascending aorta is anteriorly and partially incised, outer strip is first placed behind the dissected aortic root and 3 orientational sutures are first placed from the inner ring through the aortic wall to the outer strip and tied. Again, 3 mid-way mattress sutures encompassing the inner ring, aortic wall and outer strip are placed mid-way between the orientational sutures and tied. In the regular order, 12 additional sutures are placed between them in the same manner and tied (Fig. 14)

9. New leaflets coaptation sutures 5-0 polypropylene sutures are passed over and over the adjacent pericardial new leaflets near the each commissural region and externalized outside the aorta and tied to make the new commissures (Fig. 15).

10. Removal of the product  Evaluation on the implanted device after operation can be achieved by Transesophageal Echocardiography or Multi-Channel CT or Magnetic Resonance Imaging.If the implants are wrongly located, or if the implant is displaced after operation, implants can be removed through the previous route and reimplanted or replaced with other new implant. When endocarditis occurs in the aortic root before neo-intima is created by endothelialization process, implanted ring and/or strip are easy to be removed. Simply cut the knot of sutures on the ring/strip and take them out. However, when endocarditis occurs after endothelialization is completed, neo-intima has to be surgically opened to remove the encapsulated ring/strip. The other processes are same. Advantage of CARVAR Technically Easy and Safe In comparison with the conventional prosthetic aortic valve replacement technique, this standardized CARVAR technique helps surgeon operate in comfort. Minimizes Functional Impairment of Aortic RootCARVAR Set (Rootcon® series and Leafcon® series) can preserve the function of Aortic Root without prosthetic aortic valve replacement. Obviates Anticoagulation Anticoagulant is unnecessary; no danger of blood clots. Preserves Hemodynamics (Reduces Progression of Aortic Valve Regurgitation)CARVAR Set (Rootcon® series and Leafcon® series) ensures the normal function of cardiac valve and whereby it leads to ideal blood pressure and blood flow. Improves Quality of Life Quick recovery from surgical operation and low rate of recurrence ensure active and energetic life. Tissue Compatibility: reduces the threat of endocarditisAs CARVAR Set (Rootcon® series and Leafcon® series) is made of Dacron in form of flexible bands and strips, it can endure repetitive contraction and relaxation of aorta and does not give any stress on the tissues.