PMC9411943_01
Sagittal computed tomography images from the late post-contrast series of cases 1. (A,B) Segmental caudal vena cava aplasia (asterisk) and portosystemic shunt (arrow) were observed. Dorsal computed tomography images from the late post-contrast series of cases 1. (C) The white arrow head indicates caudal portion of the shunt.
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F1
CT scanner (Alexion, TSX-034A, Canon Medical Systems Europe B.V., Zoetermeer, Netherlands) with the patient anesthetized to diagnose and evaluate PSS. CT revealed segmental CVC aplasia (right lateral cavo-right-azygos shunt) and a porto-azygos shunt (Figure 1).
Case 1. Volume-rendered three-dimensional (3D) projection of the computed tomography (CT) angiography study (A). Surface-rendered 3D projection of the CT angiography study (B). Illustrations of vascular anomaly (C). 3D printed vascular model (areas marked in transparent red color indicate shunt) (D).
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F2
The left gastric branch of portal vein could be identified more clearly through surface rendering, and the blood vessels were separated to facilitate 3D printing (Figures 2A,B). Based on 3D rendering, the structure was clearly identified by illustration of blood vessels and surrounding organs (Figure 2C). Patient-specific 3D vascular models (Figure 2D) were printed using a resin 3D printer (Pixel One, Zerone, Gyeonggi, Korea), and dental surgical guide resin (SG-100, Graphy, Seoul, Korea) was used.
The surgical procedure for case 1. Approach the diaphragm to secure visibility around the shunt (white arrow) (A). The band of cellophane was placed around the shunt with minimal dissection (B,C). The band was placed in contact with the wall of the shunt without decreasing the diameter of the shunt. Vascular clips were used to secure the band in place (D).
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A porto-azygos shunt from the right azygos vein of the thoracic cavity to the abdominal cavity was found near the diaphragm, and cellophane banding (3 mm wide triple-layer bands) was performed with minimal dissection around the shunt (Figure 3).
Preoperative volume-rendered three-dimensional (3D) images in case 1 (A,C,E). Postoperative volume-rendered 3D images in case 1 revealed complete occlusion of the shunt (white arrow indicates surgical clip) (B,D,F). The transparent green area represents the shunt (s). The transparent purple area represents the right azygos vein (a) and the transparent blue area represents the portal vein (p), respectively.
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F4
There were no specific clinical symptoms, such as seizures post-surgery, and a CT scan 8 months after surgery revealed a completely occluded shunt (Figure 4).
PMC9411943_02
Sagittal computed tomography images from the late post-contrast series of cases 2. (A,B) Segmental caudal vena cava aplasia (asterisk) and portosystemic shunt (arrow) were observed. Dorsal computed tomography images from the late post-contrast series of cases 2. (C) The white arrow head indicates caudal portion of the shunt.
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F5
CT scan was performed. CT revealed segmental CVC aplasia (dorsal cavo-right-azygos shunt) and a porto-azygos shunt (Figure 5).
Case 2. Volume-rendered three-dimensional (3D) projection of the computed tomography (CT) angiography study (A). Surface-rendered 3D projection of the CT angiography study (B). Illustrations of vascular anomaly (C). 3D printed vascular model (areas marked in transparent red color indicate shunt) (D).
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F6
The 3D modeling provided visual confirmation of the absence of abnormal blood flow to the abdominal organs, except for the shunt (Figures 6A,B). Based on 3D rendering, the structure was clearly identified by illustration of blood vessels and surrounding organs (Figure 6C). Patient-specific 3D vascular models (Figure 6D) were printed using a resin 3D printer, and a dental surgical guide resin was used.
The surgical procedure for case 2. Approach between the kidneys to secure visibility around the shunt (white arrow) (A). The dissection performed was sufficient to place an ameroid constrictor (B). The constrictor was placed around the shunt (C,D).
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F7
A porto-azygos shunt was found between the kidneys, and an ameroid constrictor (5 mm internal diameter ring) was placed with dissection around the shunt (Figure 7).