[1743] Pulmonary Arterial Remodeling in End-Stage Liver Disease.

Gregory A Fishbein, Tisha Wang, Rajeev Saggar, Rajan Saggar, Michael Hansen, Michael C Fishbein. David Geffen School of Medicine at UCLA, Los Angeles, CA

Background: Pulmonary arterial remodeling is a well-recognized phenomenon associated with end-stage liver disease (ESLD). Two major pulmonary manifestations of ESLD exist: the hepatopulmonary syndrome and portopulmonary hypertension (POPH). Though both diseases are reported to be of low prevalence, screening for POPH is routine, as POPH is a relative contraindication to orthotopic liver transplantation. Little is known about the pathogenesis of POPH, and there are relatively few detailed quantitative studies of the pulmonary vasculature in ESLD. We reviewed autopsy specimens from 38 patients with ESLD, 11 with known POPH, in order to quantify pulmonary vascular morphology compared to normal controls.
Design: Using trichrome/elastic stained histologic sections, we performed computer-assisted morphometry of pulmonary arteries in 38 patients with ESLD and 12 patients with no known pulmonary or hepatic pathology. Eleven of the patients with ESLD had known POPH. A mean of 75 arteries per patient (range = 22-123) were analyzed, with diameters ranging from 50-1000 micrometers. Using calibrated software, tracings were made of external and internal elastic laminae, and endothelial surfaces, so as to calculate the areas occupied by the intima, media, and lumen of each vessel.

	Cases (males)	Mean Age	No. Arteries
POPH(-) ESLD	27 (18)	52	1907
POPH(+) ESLD	11 (4)	54	827
Control	12 (10)	38	748

Results: Pulmonary arteries in all patients with ESLD exhibited significant intimal thickening compared to controls (p < 0.01), greatest in patients with POPH (p = 0.02). Significant medial atrophy was present in ESLD patients without POPH (p = 0.01). Media area in POPH was not statistically different from controls (p = 0.45). Plexiform or thrombotic lesions were not present in any cases.

	Media Area		Intima Area
	Mean	Std Dev	Mean	Std Dev
ESLD (no POPH)	7968	5069	9500	3680
POPH	10827	6550	11531	8241
Control	12850	6070	5118	2324

Area in square-microns


Conclusions: In this study, pulmonary arterial remodeling occurred in all patients with end-stage liver disease. These patients all exhibited pulmonary arteries with marked intimal thickening, usually accompanied by significant medial atrophy. However, in cases of POPH, the medial area is not significantly different from controls, suggesting the arterial media is either regenerated or spared. Whether the preservation of medial thickness is the cause or effect of pulmonary hypertension is unknown. Nevertheless, our findings suggest that the prevalence of pulmonary vascular pathology in ESLD is greatly underestimated.
Category: Pulmonary

Wednesday, March 2, 2011 9:30 AM

Poster Session V # 274, Wednesday Morning