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Radiofrequency ablation of rabbit liver in vivo: effect of the pringle maneuver on pathologic changes in liver surrounding the ablation zone.

Kim SK, Lim HK, Ryu JA, Choi D, Lee WJ, Lee JY, Lee JH, Sung YM, Cho EY, Hong SM, Kim JS - Korean J Radiol (2004 Oct-Dec)

Bottom Line: Radiofrequency ablation was performed in the groups with (n=12 rabbits) and without (n=12 rabbits) the Pringle maneuver.None of the above changes was found in the livers ablated without the Pringle maneuver.On the microscopic findings, centrilobular congestion, sinusoidal congestion, sinusoidal platelet and neutrophilic adhesion, and hepatocyte vacuolar and ballooning changes in liver ablated with Pringle maneuver showed more significant changes than in those livers ablated without the Pringle maneuver (p < 0.05) Radiofrequency ablation with the Pringle maneuver created more severe pathologic changes in the portal vein, bile ducts and liver parenchyma surrounding the ablation zone compared with RF ablation without the Pringle maneuver.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Kangnam-gu, Seoul, Korea.

ABSTRACT

Objective: We wished to evaluate the effect of the Pringle maneuver (occlusion of both the hepatic artery and portal vein) on the pathologic changes in the hepatic vessels, bile ducts and liver parenchyma surrounding the ablation zone in rabbit livers.

Materials and methods: Radiofrequency (RF) ablation zones were created in the livers of 24 rabbits in vivo by using a 50-W, 480-kHz monopolar RF generator and a 15-gauge expandable electrode with four sharp prongs for 7 mins. The tips of the electrodes were placed in the liver parenchyma near the porta hepatis with the distal 1 cm of their prongs deployed. Radiofrequency ablation was performed in the groups with (n=12 rabbits) and without (n=12 rabbits) the Pringle maneuver. Three animals of each group were sacrificed immediately, three days (the acute phase), seven days (the early subacute phase) and two weeks (the late subacute phase) after RF ablation. The ablation zones were excised and serial pathologic changes in the hepatic vessels, bile ducts and liver parenchyma surrounding the ablation zone were evaluated.

Results: With the Pringle maneuver, portal vein thrombosis was found in three cases (in the immediate [n=2] and acute phase [n=1]), bile duct dilatation adjacent to the ablation zone was found in one case (in the late subacute phase [n=1]), infarction adjacent to the ablation zone was found in three cases (in the early subacute [n=2] and late subacute [n=1] phases). None of the above changes was found in the livers ablated without the Pringle maneuver. On the microscopic findings, centrilobular congestion, sinusoidal congestion, sinusoidal platelet and neutrophilic adhesion, and hepatocyte vacuolar and ballooning changes in liver ablated with Pringle maneuver showed more significant changes than in those livers ablated without the Pringle maneuver (p < 0.05)

Conclusion: Radiofrequency ablation with the Pringle maneuver created more severe pathologic changes in the portal vein, bile ducts and liver parenchyma surrounding the ablation zone compared with RF ablation without the Pringle maneuver. Therefore, we suggest that RF ablation with the Pringle maneuver should be performed with great caution in order to avoid unwanted thermal injury.

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Microphotographs (H & E, ×400) of resected specimens obtained immediately after radiofrequency ablation. The microphotograph of the liver specimen ablated with the Pringle maneuver (B) shows mild proliferation of bile duct epithelium (arrows), whereas it is normal (arrows) in the liver ablated without the Pringle maneuver (A).
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Figure 6: Microphotographs (H & E, ×400) of resected specimens obtained immediately after radiofrequency ablation. The microphotograph of the liver specimen ablated with the Pringle maneuver (B) shows mild proliferation of bile duct epithelium (arrows), whereas it is normal (arrows) in the liver ablated without the Pringle maneuver (A).

Mentions: The mean grades of the microscopic variables surrounding the ablation zones created in the rabbit livers with and without the Pringle maneuver are summarized in Table 2. Centrilobular congestion, sinusoidal congestion, sinusoidal platelet and neutrophilic adhesion, and hepatocyte vacuolar and ballooning changes in livers ablated with the Pringle maneuver showed more significant changes than those changes observed in livers ablated without the Pringle maneuver (p < 0.05) (Fig. 5). The bile duct epithelium was mildly proliferated in two cases of livers ablated with the Pringle maneuver (Fig. 6), while the bile duct epithelium was normal in livers ablated without the Pringle maneuver. The mean grade of centrilobular necrosis between the two groups was similar, but the extent of centrilobular necrosis in livers ablated with the Pringle maneuver was significantly larger than that in the livers ablated without the Pringle maneuver (p < 0.05).


Radiofrequency ablation of rabbit liver in vivo: effect of the pringle maneuver on pathologic changes in liver surrounding the ablation zone.

Kim SK, Lim HK, Ryu JA, Choi D, Lee WJ, Lee JY, Lee JH, Sung YM, Cho EY, Hong SM, Kim JS - Korean J Radiol (2004 Oct-Dec)

Microphotographs (H & E, ×400) of resected specimens obtained immediately after radiofrequency ablation. The microphotograph of the liver specimen ablated with the Pringle maneuver (B) shows mild proliferation of bile duct epithelium (arrows), whereas it is normal (arrows) in the liver ablated without the Pringle maneuver (A).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2698168&req=5

Figure 6: Microphotographs (H & E, ×400) of resected specimens obtained immediately after radiofrequency ablation. The microphotograph of the liver specimen ablated with the Pringle maneuver (B) shows mild proliferation of bile duct epithelium (arrows), whereas it is normal (arrows) in the liver ablated without the Pringle maneuver (A).
Mentions: The mean grades of the microscopic variables surrounding the ablation zones created in the rabbit livers with and without the Pringle maneuver are summarized in Table 2. Centrilobular congestion, sinusoidal congestion, sinusoidal platelet and neutrophilic adhesion, and hepatocyte vacuolar and ballooning changes in livers ablated with the Pringle maneuver showed more significant changes than those changes observed in livers ablated without the Pringle maneuver (p < 0.05) (Fig. 5). The bile duct epithelium was mildly proliferated in two cases of livers ablated with the Pringle maneuver (Fig. 6), while the bile duct epithelium was normal in livers ablated without the Pringle maneuver. The mean grade of centrilobular necrosis between the two groups was similar, but the extent of centrilobular necrosis in livers ablated with the Pringle maneuver was significantly larger than that in the livers ablated without the Pringle maneuver (p < 0.05).

Bottom Line: Radiofrequency ablation was performed in the groups with (n=12 rabbits) and without (n=12 rabbits) the Pringle maneuver.None of the above changes was found in the livers ablated without the Pringle maneuver.On the microscopic findings, centrilobular congestion, sinusoidal congestion, sinusoidal platelet and neutrophilic adhesion, and hepatocyte vacuolar and ballooning changes in liver ablated with Pringle maneuver showed more significant changes than in those livers ablated without the Pringle maneuver (p < 0.05) Radiofrequency ablation with the Pringle maneuver created more severe pathologic changes in the portal vein, bile ducts and liver parenchyma surrounding the ablation zone compared with RF ablation without the Pringle maneuver.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Kangnam-gu, Seoul, Korea.

ABSTRACT

Objective: We wished to evaluate the effect of the Pringle maneuver (occlusion of both the hepatic artery and portal vein) on the pathologic changes in the hepatic vessels, bile ducts and liver parenchyma surrounding the ablation zone in rabbit livers.

Materials and methods: Radiofrequency (RF) ablation zones were created in the livers of 24 rabbits in vivo by using a 50-W, 480-kHz monopolar RF generator and a 15-gauge expandable electrode with four sharp prongs for 7 mins. The tips of the electrodes were placed in the liver parenchyma near the porta hepatis with the distal 1 cm of their prongs deployed. Radiofrequency ablation was performed in the groups with (n=12 rabbits) and without (n=12 rabbits) the Pringle maneuver. Three animals of each group were sacrificed immediately, three days (the acute phase), seven days (the early subacute phase) and two weeks (the late subacute phase) after RF ablation. The ablation zones were excised and serial pathologic changes in the hepatic vessels, bile ducts and liver parenchyma surrounding the ablation zone were evaluated.

Results: With the Pringle maneuver, portal vein thrombosis was found in three cases (in the immediate [n=2] and acute phase [n=1]), bile duct dilatation adjacent to the ablation zone was found in one case (in the late subacute phase [n=1]), infarction adjacent to the ablation zone was found in three cases (in the early subacute [n=2] and late subacute [n=1] phases). None of the above changes was found in the livers ablated without the Pringle maneuver. On the microscopic findings, centrilobular congestion, sinusoidal congestion, sinusoidal platelet and neutrophilic adhesion, and hepatocyte vacuolar and ballooning changes in liver ablated with Pringle maneuver showed more significant changes than in those livers ablated without the Pringle maneuver (p < 0.05)

Conclusion: Radiofrequency ablation with the Pringle maneuver created more severe pathologic changes in the portal vein, bile ducts and liver parenchyma surrounding the ablation zone compared with RF ablation without the Pringle maneuver. Therefore, we suggest that RF ablation with the Pringle maneuver should be performed with great caution in order to avoid unwanted thermal injury.

Show MeSH
Related in: MedlinePlus