Right Ventricular Outflow Reconstruction Using a Polytetrafluoroethylene Conduit With Bulging Sinuses and Tricuspid Fan-shaped Polytetrafluoroethylene Valve  Masaaki Yamagishi, MD, PhD  Operative Techniques in Thoracic and Cardiovascular Surgery  Volume 21, Issue 3, Pages 211-229 (September 2016) DOI: 10.1053/j.optechstcvs.2017.05.002 Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 1 Construction of bulging sinuses. (A) Fluid dynamically, vortex flow occurs along the inner wall of a blood vessel with a sinus. The vortex can be expected to improve the valve's closing motion. (B) The image shows the method used to construct bulging sinuses in an ePTFE graft to improve the function of the fan-shaped valve. First, the ePTFE graft is inserted into a stainless-steel outer cylinder, and compressed air is used to expand a portion of the graft in 3 directions to create the sinuses. At the same time, an industrial dryer is used to heat the graft with hot air at 330°C and solidify the sinus shape of the expanded portions of the ePTFE graft. (C) The ePTFE graft with bulging sinuses is turned inside out to hand-suture the valve to the inner surface of the graft. Operative Techniques in Thoracic and Cardiovascular Surgery 2016 21, 211-229DOI: (10.1053/j.optechstcvs.2017.05.002) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 2 Construction of the fan-shaped valve. (A) The image shows the basic shape of the fan-shaped valve. The length of the lower edge of the valve (a-a′) is equal to the conduit diameter × 3.14/3. The lengths are shown by conduit size in the Table. The length of the upper edge of the valve leaflet (b-b′) that made the leaflets fan-shaped is determined automatically by fitting them to the format shown in the diagram (angle formed by a-b and a′-b′, 34°). Large geometric and effective heights are obtained by giving the free margin of the valve an arched shape. (B) In the case of a tricuspid valve, a 0.1-mm-thick ePTFE membrane (W.L. Gore & Associates, Inc) is cut out with the 3 leaflets connected. A similar paper stencil can also be constructed. As indicated in the figure, drawing guidelines (dotted lines) facilitate stencil construction. Operative Techniques in Thoracic and Cardiovascular Surgery 2016 21, 211-229DOI: (10.1053/j.optechstcvs.2017.05.002) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 3 Suturing of leaflets to the inside-out graft. The graft with bulging sinuses is turned inside out. A cutout 0.1-mm-thick ePTFE membrane is wrapped around the inside-out graft at the position of the sinuses. The lower edge of the leaflet (a) is matched with the lower edge of the bulging sinus (a′). Operative Techniques in Thoracic and Cardiovascular Surgery 2016 21, 211-229DOI: (10.1053/j.optechstcvs.2017.05.002) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 4 Suturing of leaflets (1). The leaflets (cutout 0.1-mm-thick ePTFE membrane) are sutured to the inner surface of the inside-out graft. First, the 2 ends of the wrapped valve are brought together and sutured vertically to the flat area between sinuses using running sutures. The lower edges of the leaflets are positioned at the lower edges of the sinuses. Gore-Tex CV-6 sutures are used for grafts 18 mm in size and larger. CV-7 sutures are used for small-caliber grafts of 16 mm and less. When placing the sutures, care is needed to ensure that the suture needle does not penetrate the full thickness of the graft. Penetrating the full thickness would result in bleeding from needle holes. Suturing can be facilitated by inserting an inner cylinder matching the size of the graft into the graft as a support. Operative Techniques in Thoracic and Cardiovascular Surgery 2016 21, 211-229DOI: (10.1053/j.optechstcvs.2017.05.002) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 5 Suturing of leaflets (2). (A) Next, the other 2 junctions are stitched vertically. A half-back stitch is used for this portion. The suture material used is the Gore-Tex CV-6 or CV-7 suture. (B) Finally, running sutures are used to similarly suture the lower margins of the 3 leaflets to the graft. Reinforcing sutures must be used at the junctions. The sutures are ligated at the inner surface of the graft. After suturing of the leaflets is completed, the graft is returned to the right-side out position. The finished valved conduit is sterilized by hydrogen peroxide low-temperature plasma sterilization (STERRAD, Johnson & Johnson, New Brunswick, NJ) and stored. Operative Techniques in Thoracic and Cardiovascular Surgery 2016 21, 211-229DOI: (10.1053/j.optechstcvs.2017.05.002) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 6 Severing the distal end of the graft and anastomosis to the pulmonary artery. Fluid dynamically, because the flow rate is high on the greater curvature side, it is important to position 1 valve on that side to prevent PR to the greatest extent possible. The distal end of the greater curvature side is severed obliquely so that 1 valve is on the greater curvature side and that side is slightly longer. The length (D) of the lesser curvature side is the distance from the upper edge of the right ventricular outlet to the lower edge of the pulmonary artery (PA) bifurcation orifice. If the sinuses and valve are placed near the original pulmonary valve annulus, which is near the RVOT, there is a risk that the sinuses and the body of the conduit will be compressed and flattened by the sternum. Consequently, the ePTFE valve has to be positioned slightly to the PA side of the original annulus. If the conduit is too short, there is a risk of compressing the left coronary artery, which lies posterior to the RVOT. If it is too long, there is a risk that it will compress the PA bifurcation and result in stenosis at the anastomosis of the PA and conduit. Therefore, a conduit length appropriate for the cardiac morphology should be used. In practice, the length (D) of the lesser curvature is determined after PA anastomosis is performed. Operative Techniques in Thoracic and Cardiovascular Surgery 2016 21, 211-229DOI: (10.1053/j.optechstcvs.2017.05.002) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 7 PA anastomosis of the conduit. Because the Gore-Tex conduit is harder than a homograft or bovine jugular vein graft (Contegra), a special technique must be used to anastomose it with the native PA. If stenosis is present in the left and the right pulmonary arteries, augmentation is performed using autologous pericardium or a cutout ePTFE graft patch. If the difference between the calibers of the PA and conduit is large, turbulent blood flow may occur at the anastomosis and give rise to decreased blood flow energy and stenosis caused by intimal proliferation. Consequently, if stenosis is present near the PA bifurcation, it should be augmented to the greatest extent possible. (A) Conduit anastomosis starts from the anastomosis of the PA side. First, U-shaped Gore-Tex CV-6 sutures are placed and ligated on the lesser curvature of the conduit and the lower edge of the PA orifice. Although the anastomosis can also begin with parachute suturing, because the conduit and native PA differ in hardness, caution is necessary when joining the conduit and PA in a patient with a fragile PA wall to avoid ruptures in the sutured portion of the PA. Fine adjustments are necessary to match the diameter of the conduit opening with that of the native PA orifice. Because the aorta lies to the right of the PA orifice in patients with normal great vessels, there is a limit to how much the native PA can be opened and augmented to the right. Consequently, the anastomosis can also be started from the right edge, as shown in (B). In this case, the PA orifice can easily be augmented by making an incision toward the left PA. Operative Techniques in Thoracic and Cardiovascular Surgery 2016 21, 211-229DOI: (10.1053/j.optechstcvs.2017.05.002) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 8 Anastomosis of the conduit with the right ventricle (1). (A) Determining anastomosis locations on the lesser curvature of the conduit. The locations on the conduit that correspond to the upper edge (a), upper-right edge (b), and upper-left edge (c) of the RVOT orifice are marked a′, b′, and c′. If the distance between the lowest point of the conduit-PA anastomosis (a″) and point a′ (lesser curvature of conduit) is too short, the LCA, which lies posteriorly, may be compressed. If this distance is too long, the PA bifurcation may be compressed, resulting in anastomotic stenosis. Consequently, care is required in determining the distance between a″ and a′ on the lesser curvature of the conduit. LCA, left coronary artery; RVOT, right ventricular outflow tract. (B) Excising the lesser curvature of the conduit (RV anastomosis end). An arch-shaped excision is made along a line connecting points b′, a′, and c′, and parallel incisions are made from points b′ and c′ along the long axis of the conduit (b′-b″, c′-c″). The lower surface of the conduit is excised in a U shape. Excision is easier with a scalpel than with scissors. Operative Techniques in Thoracic and Cardiovascular Surgery 2016 21, 211-229DOI: (10.1053/j.optechstcvs.2017.05.002) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 9 Anastomosis of the conduit with the right ventricle (2). (A) Anastomosis of the proximal stump of the conduit with the upper edge of the right ventricular outflow orifice. The lower edge of the proximal stump of the conduit (b′-a′-c′) is sutured to the upper edge of the right ventricular outflow orifice using running ePTFE sutures (Gore-Tex CV-5 suture). We prefer to use Gore-Tex sutures whose diameter has a 1:1 relation to the diameter of the needle. If the gauge of the needle is larger than that of the suture material, as in the case of monofilament sutures, there is a risk of bleeding from the conduit through the needle holes. Hemostasis may be difficult with bleeding from the needle holes of an ePTFE conduit. (B) Anastomosis of the conduit with the lower edge of the RVOT orifice anastomosis is continued so that approximately the upper one-third of the entire orifice is anastomosed (to points e and e′ in the figure). At this point, the location on the greater curvature of the conduit (d′) that corresponds to the lower point of the RVOT (d) is determined. Because there is a risk that the conduit will become flattened if the greater curvature is short, it is important to give the greater curvature a small amount of extra length so that it has a natural bulge. Operative Techniques in Thoracic and Cardiovascular Surgery 2016 21, 211-229DOI: (10.1053/j.optechstcvs.2017.05.002) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 10 Anastomosis of the conduit with the right ventricle (3). (A) Trimming the conduit. The incision line for the lower edge of the conduit (e-d′-e′) is determined according to point d′. (B) Trimming the conduit. The excess portion of the conduit is severed along the incision line (e-d′-e′). Operative Techniques in Thoracic and Cardiovascular Surgery 2016 21, 211-229DOI: (10.1053/j.optechstcvs.2017.05.002) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 11 Anastomosis of the conduit with the right ventricle (4). (A) Conduit anastomosis. The conduit opening is anastomosed with the lower half of the RVOT orifice. To accommodate the caliber difference for the remainder, the proportion of the inter-suture width used for the RVOT to that used for the conduit is approximately 1:1.5, making the distance slightly larger on the conduit side. (B) Conduit anastomosis completion. Because the remaining conduit edge is trimmed after the parallel incisions are made in the lesser curvature of the conduit and it is sutured through e-e′, the conduit width at e-e′ is somewhat broad, resulting in a bulge effect. The trimming enables the natural shape to be maintained without additional suturing of excess conduit to the RV stump. After anastomosis completion, fibrin glue is rubbed into the anastomosis to prevent bleeding from the needle holes. Operative Techniques in Thoracic and Cardiovascular Surgery 2016 21, 211-229DOI: (10.1053/j.optechstcvs.2017.05.002) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 12 Patient body weights and conduit sizes. Indicates the conduit diameters that have been used and the body weights of the patients. Operative Techniques in Thoracic and Cardiovascular Surgery 2016 21, 211-229DOI: (10.1053/j.optechstcvs.2017.05.002) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 13 (A) Pulmonary regurgitation. (B) Conduit stenosis. Operative Techniques in Thoracic and Cardiovascular Surgery 2016 21, 211-229DOI: (10.1053/j.optechstcvs.2017.05.002) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 14 Reoperation-free rates. Operative Techniques in Thoracic and Cardiovascular Surgery 2016 21, 211-229DOI: (10.1053/j.optechstcvs.2017.05.002) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 15 Reoperation-free rates in patients under 10 kg. Operative Techniques in Thoracic and Cardiovascular Surgery 2016 21, 211-229DOI: (10.1053/j.optechstcvs.2017.05.002) Copyright © 2017 Elsevier Inc. Terms and Conditions