[1717] Histopathological Features of Hepatic Venous Outflow Obstruction in Transplant Liver Biopsies

Wei Xiong, Paul E Swanson, Matthew M Yeh. University of Washington, Seattle, WA

Background: Hepatic venous outflow obstruction (HVOO) is a clinically significant complication of orthotopic liver transplantation. Because its histological features often overlap with other conditions, definitive diagnosis is occasionally problematic, in part because these features have not been systematically evaluated in the context of radiologic findings. We analyzed histopathological changes in liver allograft biopsies from patients with concurrent radiological evidence of HVOO.
Design: 28 post-transplant orthotopic liver allograft biopsies with clinical suspicion for hepatic venous outflow obstruction and with no histological evidence of rejection were selected for study. 15 cases had imaging evidence of HVOO (HVOO group) while 13 cases did not (control group). Clinical and laboratory data were also reviewed.
Results: 97% of imaging proven HVOO cases occurred within the first year post transplant (median=16 weeks; range 1-104 weeks). The most common clinical presentation included ascites and elevated LFTs. Perivenular hepatocyte dropout and perivenular congestion were present in the vast majority of HVOO cases (100% and 80%, respectively) but only in 23% (p=0.001) and 30% (p=0.02) of controls, respectively. Perivenular fibrosis was significantly more frequent in HVOO compared to controls (93% and 46%, respectively; p=0.01). Diffuse sinusoidal dilation was more commonly seen in HVOO but this feature did not reach statistical significance. Perivenular collapse and edema were observed only in HVOO, but were not commonly identified (13 %).

Histologic features of HVOO
 Perivenular dropoutPerivenular congestionSinusoidal dilation (>focal)Perivenular fibrosisHepatocytic atrophyPerivenular edemaPerivenular inflammation
HVOO (n=15)15 (100%)12 (80%)8 (53%)14 (93%)6 (40%)2 (13%)2 (13%)
Control (n=13)3 (23%)4 (30%)2 (15%)6 (46%)5 (38%)00
P value0.00010.02000.05460.01081.00000.48410.4841



Conclusions: Based on systematic review of histological features associated with imaging proven hepatic venous outflow obstruction (HVOO) in allograft liver biopsies, we conclude that the most reliable among them are perivenular hepatocyte dropout, perivenular sinusoidal congestion and perivenular fibrosis. Perivenular collapse and edema, though specific, are not sensitive markers of HVOO. These findings may aid in the identification and proper management of patients with HVOO.
Category: Liver

Monday, March 4, 2013 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 264, Monday Morning

 

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