The anastomosis itself is usually accomplished by a continuous suture of fine, nonabsorbable suture material on atraumatic needles. Two angle sutures of 00000 arterial synthetic material are placed with knots tied on the outside (Figure 14). Both the portal vein and the inferior vena cava are very fragile. It is therefore necessary to use the utmost caution during the suturing process to avoid trauma to these vein walls. This caution should apply not only to the surgeon doing the actual suturing but equally, if not more, to the assistant holding the clamps. A very slight shearing force created by shifting the vascular clamps in relation to each other may easily disrupt a partly completed anastomosis. Leaks from the anastomotic site, particularly along the left side of the anastomosis, may be difficult to expose for subsequent resuturing. The anastomosis is completed (Figures 15 and 16) and the occluding clamps are released one at a time to check the adequacy of the suture line. Although the portal vein represents the high-pressure system in this anastomosis, it is usually convenient to release one of the portal clamps first, since these are normally easier to reapply if hemostasis is not satisfactory. After all clamps are released, it is frequently possible to detect the functioning of the shunt by visible turbulence in the vena cava. Palpation of the opening between the two veins by invaginating the anterior wall of the portal vein can also be used to verify the patency of the anastomosis. Repeat measurement of pressure in the portal system will normally show that it has been reduced to about half of its preoperative level.
The completed end-to-side anastomosis is illustrated (Figure 17). This is usually accomplished by dividing the portal vein as close as possible to the liver hilum. It is important not to leave the proximal stump of the portal vein too short, since this is a large vein and under considerable pressure. One should leave room for a double ligature, the second being a transfixation suture ligature with several millimeters of vein cuff to assure adequate control of the hepatic side of the portal ...