Hepatocellular Carcinoma: Targeted Therapy and Multidisciplinary P27

15 Vascular Resection for Hepatocellular Carcinoma 245 a b c Fig. 15.2 (a) Hepatocellular carcinoma (HCC) extending from the posterior branch of the right portal vein into the main right portal vein and into the main portal vein. (b) Resection specimen demonstrating tumor extending down from the posterior branch of the portal vein (PV) to the main right portal vein with tumor adherence to the vein wall. (c) Patient side of Fig. 15.2b with the left portal vein anastomosed to the main portal vein. The left hepatic duct and bile duct have been elevated and rotated to the left to provide access to the portal vein but do not require division. MHV = middle hepatic vein have been described for HCC tumor thrombi, they are rarely necessary and offer no survival advantage to thrombectomy as described above as long as the whole thrombus is extracted [6]. If thrombectomy alone can be achieved with no residual tumor on the vein wall then resection can be avoided. In the rare case that both hep-atic artery and portal vein require reconstruction they can be performed alternately, maintaining flow through one vessel while reconstructing the other. 246 R.D. Kim and A.W. Hemming Hepatic Vein and IVC Involvement Similar to their effects on hilar vessels, large HCC lesions involving the hepatic veins or retrohepatic vena cava by external compression rarely invade the vessels walls. However, hepatic veins are more likely to require resection and reconstruc-tion since they are thin walled and lack the protective Glissonian extensions that envelop hilar vessels. In addition, tumors centrally involving hepatic veins that also drain peripheral uninvolved segments may need reconstruction in order to maintain outflow in parenchyma preserving resections. One example is the reconstruction of a right hepatic vein in order to resect a tumor in segments 7 and 8 while preserving the outflow to segment 6 (Fig. 15.3a, b). a b Fig. 15.3 (a) Resection of tumor in segment 7 or 8 may require sacrifice of the right hepatic vein and preservation of venous outflow to segment 6 by reconstructing the right hepatic vein may be required if significant alternative venous outflow does not exist. (b) Resection of segment 7, part of 8 and 5 for HCC in a cirrhotic liver. The right hepatic vein has been reconstructed using 8 mm ringed Gortex since no inferior hepatic vein was present. Notice the significant volume of liver that segment 6 represents in this case Hepatocellular cancer may also cause tumor thrombi in the hepatic veins in 11–23% (Fig. 15.4a–c) [37, 38], the IVC in 9–26% [37–39], and further extend into the right atrium in 2.4% to 6.3% of cases [37, 38, 40]. Although rare, there have been 87 case reports of HCC with intracavitary cardiac involvement [39]. In these extreme cases, complications may include heart failure, tricuspid stenosis or insufficiency, ventricular outflow tract obstruction, ball valve thrombus syndrome, sudden cardiac death, secondary Budd–Chiari syndrome, pulmonary embolism, and pulmonary metastasis [39]. We have in rare cases resected HCC with extension of tumor into the right atrium under cardiopulmonary bypass with hypothermic arrest. This is obviously an extreme measure that really cannot be considered curative although it is life prolonging in some cases. There are a number of options for reconstructing the resected vasculature. Hepatic veins can bereconstructed using autologous vein graft fromsuch sitesas the 15 Vascular Resection for Hepatocellular Carcinoma 247 a b c d Fig. 15.4 (a) MR imaging of HCC with tumor thrombus in the right hepatic vein extending into the IVC. (b) Intraoperative picture of resection of patient in Fig. 15.4a. The liver has been divided centrally back to the retrohepatic inferior vena cava (RHIVC). The suprahepatic cava (SHC) has been controlled above the tumor extension by opening the pericardium from below and encircling the intrapericardial inferior vena cava at its junction with the right atrium(RA). The middle hepatic vein (MHV) has been divided at its origin using a vascular stapler. Notice the right hepatic vein (RHV) is distended and is enlarged much more than usual. (c) The resection specimen from 4b. Notice the right hepatic vein (RHV) is filled with loosely adherent tumor (HCC) and that the right hepatic vein orifice has been distended with tumor. (d) The completed resection from 4b. The right hepatic vein (RHV) orifice was enlarged further at the time of tumor removal and extended down the IVC requiring closure and tangential repair of the inferior vena cava. SIVC = suprahepatic inferior vena cava, RA = right atrium saphenous, left renal, or gonadal veins [41, 42]. For longer reconstructions of hep-atic veins cadaveric vein grafts may be used. For broad defects of the IVC, cadaveric vein or bovine pericardium patches may be used [43]. Replacement of the IVC has been described using woven Dacron [44]; however, expanded PTFE [45–48] has become the synthetic graft of choice (Fig. 15.5a–c). A number of recent case series have been published regarding combined liver and hepatic vein/vena cava resections for HCC. The number of cases ranged from 2 to 29 per report, with a total of 59 patients who underwent resections of the IVC. More 248 R.D. Kim and A.W. Hemming a b c Fig. 15.5 (a) Three-dimensional CT of HCC involving inferior vena cava (IVC). (b) Three-dimensional CT of HCC from Fig. 15.5a that demonstrates that there is enough space below the hepatic veins to allow clamp placement on the inferior vena cava (IVC) but maintain outflow through the hepatic veins during caval flow interruption. (c) Ringed Gortex graft being sewn in place in patient from Fig. 15.5b. Notice that the right lobe (plus middle vein) has been removed from the field with caval clamps placed below the left hepatic vein, allowing continued perfusion of the remnant liver while replacing the IVC. In this case the tumor was not truly invading the IVC wall but could not be separated from the IVC with risk of either tearing the IVC or rupturing the tumor recent data suggest that HCC involving the hepatic veins or IVC rarely requires vas-cular resections to achieve complete tumor thrombectomy [49]. However, tumors centrally involving hepatic veins that also drain peripheral uninvolved segments may need reconstruction in order to maintain outflow in parenchyma preserving resections. Strategies to Achieve Vascular Control During Complex HCC Resections Total Vascular Isolation Tumors involving the retrohepatic IVC or the hepatic veins as they enter the IVC require a variety of techniques to establish inflow and outflow control to minimize 15 Vascular Resection for Hepatocellular Carcinoma 249 blood loss. In total vascular isolation, control of the portal hepatic (inflow) and the suprahepatic and infrahepatic IVC (outflow) is established to minimize bleeding from the hepatic artery, portal vein, and hepatic veins. Some evidence suggests that hepatic venous back-diffusion may minimize ischemic injury and that total vascular isolation increases the degree of ischemic liver injury [50]. However, the majority of the hepatic parenchymal division can usually be performed without total vascular isolation, and IVC clamping can be reserved for the relatively short time period that is required to resect and reconstruct the inferior vena cava or hepatic veins. In one series of five patients with HCC extending into the IVC which required combined liver and IVC resections, total vascular isolation was used with ischemic times rang-ing from 40 to 90 min, the IVC exclusion time ranged from 25 to 90 min, and the average blood loss was 6,500 ± 1,732 mL [43]. For total vascular isolation as much mobilization of the liver off of the vena cava is performed as possible without encroaching on tumor planes prior to hepatic parenchymal transection. In some cases, however, the bulky nature of the tumor inhibits the ability to rotate the liver safely and a primary anterior approach to the IVC can be taken with little or no mobilization of the liver off of the IVC. The approach to vena caval resection depends on the extent and location of tumor involvement. If the portion of vena cava involved with tumor is below the hepatic veins then the parenchyma of the liver can be divided exposing the retro-hepatic IVC. The parenchymal transection can be performed with inflow occlusion (Pringle maneuver); however, if possible the parenchymal division is done main-taining hepatic perfusion. Central venous pressure is kept at or below 5 cm H2O during parenchymal transection to minimize blood loss. Once the IVC is exposed, portal inflow occlusion is released if utilized, the patient volume loaded, and clamps placed above and below the area of tumor involvement. The portion of liver and involved IVC is then removed allowing improved access for reconstruction of the IVC. The placing of clamps on the IVC below the hepatic veins allows continued perfusion of the liver and minimizes the hepatic ischemic time. In cases where tumor involvement does not allow placement of clamps below the hepatic veins there were two different approaches. If there is only IVC and/or hepatic vein involvement the hepatic parenchyma can be divided back to the IVC, the patient volume loaded and then clamps are placed sequentially on the infrahep-atic IVC, the porta hepatis and then above the hepatic veins with the liver and IVC removed en bloc. If hepatic vein repair or reconstruction is required, the remaining in situ portion of the liver is rotated up out of the patient allowing repair or reim-plantation of the hepatic veins to be done under excellent visualization. This can be done under normothermic conditions if expected reconstruction time is short or the remnant liver can be cold perfused using the in situ technique (described below). In patients with involvement of IVC, hepatic veins, and portal structures and it may be the only possibility of obtaining tumor-free margins would be to use ex vivo resection techniques. In these patients minimal mobilization of the liver off of the IVC is attempted in situ. The suprahepatic IVC is mobilized with the phrenic veins divided and the intrapericardial portion of the IVC lowered. It is fre-quently necessary to open the pericardium from below to obtain adequate length ... - tailieumienphi.vn