Portopulmonary hypertension: Diagnostic advances and caveats

Abstract

Portopulmonary hypertension represents a major risk factor for transplantation; therefore, preoperative detection is crucial. The aims of this study were to determine (1) whether Doppler echocardiography performed at evaluation is a reliable tool for detecting portopulmonary hypertension and (2) the incidence of acquired portopulmonary hypertension profile after evaluation. One hundred sixtyfive patients had Doppler echocardiography and right heart catheterization at evaluation over a 9-year period. All patients had a prospective follow-up, and the results of catheterization at evaluation were compared with those obtained at the time of transplantation. Seventeen of 165 patients met the criteria for portopulmonary hypertension on Doppler echocardiography. Portopulmonary hypertension was confirmed by catheterization in 10 patients and ruled out in 7. There were no false negatives for echocardiography. Mean pulmonary artery pressure was significantly higher during the initial phase of transplantation than at evaluation (17.8 ؎ 4.3 versus 20.3 ؎ 5.5 mm Hg, respectively, P < .0001), and there was no significant correlation between values obtained at these 2 time points. Three patients showed to have acquired portopulmonary hypertension profile although waiting for a graft within time intervals ranging from 2.5 to 5 months. In conclusion, Doppler echocardiography is a highly sensitive tool for detecting portopulmonary hypertension. However, because this technique has a poor positive predictive value, right heart catheterization is recommended for confirming portopulmonary hypertension. In addition, the absence of portopulmonary hypertension at evaluation does not exclude the occasional occurrence of acquired portopulmonary hypertension profile after listing. (Hepatology 2003;37:401-409)

Pulmonary-Hepatic vascular Disorders (PHD)

“…Definition PPHTN can be defined as a PAH associated with portal hypertension, with or without hepatic disease [153][154][155][156]. Diagnosis of PPHTN is based on pulmonary haemodynamic criteria obtained via right heart catheterisation [6,153].…”

“…Diagnosis of PPHTN is based on pulmonary haemodynamic criteria obtained via right heart catheterisation [6,153]. Diagnostic criteria for PAH include a mean pulmonary arterial pressure (Ppa) of w25 (at rest) or w30 mmHg (during exercise), with a mean pulmonary artery occlusion pressure (mPAOP) ofv15 mmHg [153,154,157].…”

“…This increase in Ppa is most commonly caused by increases in Q9 (despite reduced PVR) and/or in blood volume (increased mPAOP) [158,159], without pulmonary vascular remodelling. Less commonly, moderate-to-severe PAH with extensive pulmonary vascular remodelling (increased PVR) develops [6,153,158,160,161]. In order to distinguish between these two forms of PAH, criteria have evolved for the diagnosis of PPHTN (table 4) [162][163][164][165].…”

“…NO, glucagon, vasoactive peptide and substance P) have been measured in the setting of portal hypertension [186][187][188]. In short, investigators have hypothesised that an imbalance of vasoactive substances could reach the pulmonary circulation in abnormally high concentrations due to portosystemic shunts or defective hepatic metabolism, causing the pathological pulmonary vascular lesions seen in PPHTN [6,153].…”

“…Accordingly, pulmonary haemodynamic measurements by right heart catheterisation must be performed in order to confirm the diagnosis [153,156,219]. Lung biopsy is not advised due to increased risk of bleeding.…”