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Hypoxemia and Liver Cirrhosis (Hepatopulmonary Syndrome) in Eight Patients: Comparison of the Central and Peripheral Pulmonary Vasculature1

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To evaluate the pulmonary vasculature in patients with hepatopulmonary syndrome. Conventional computed tomographic (CT) scans in eight patients with hepatopulmonary syndrome were retrospectively evaluated to compare the diameters of the pulmonary trunk, right and left main pulmonary arteries, and peripheral pulmonary vasculature in the right posterior basal segment with those in eight healthy subjects and in four patients with normoxemic cirrhosis. With thin-section CT, the ratio of segmental arterial diameter to adjacent bronchial diameter in the right lower lobe in four patients with hepatopulmonary syndrome was compared with that in four patients with normoxemic cirrhosis. In patients with hepatopulmonary syndrome, the peripheral pulmonary vasculature was significantly dilated compared with that in control subjects and in patients with normoxemic cirrhosis (P = .002); however, the central pulmonary arteries were not significantly dilated (P > .05). At thin-section CT, the ratio of segmental arterial diameter to adjacent bronchial diameter was significantly greater than that in patients with normoxemic cirrhosis (P < .05). In patients with hepatopulmonary syndrome, the peripheral pulmonary vasculature is significantly dilated. Dilatation of the peripheral pulmonary vasculature may be helpful in the diagnosis of hepatopulmonary syndrome.
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Ki-Nam Lee, MD
Ha-Jong Lee, MD
Woo Won Shin, MD
W. Richard Webb, MD
Hypoxemia and Liver Cirrhosis
(Hepatopulmonary Syndrome)
in Eight Patients: Comparison
of the Central and Peripheral
Pulmonary Vasculature
1
PURPOSE: To evaluate the pulmonary vasculature in patients with hepatopulmo-
nary syndrome.
MATERIALS AND METHODS: Conventional computed tomographic (CT) scans in
eight patients with hepatopulmonary syndrome were retrospectively evaluated to
compare the diameters of the pulmonary trunk, right and left main pulmonary
arteries, and peripheral pulmonary vasculature in the right posterior basal segment
with those in eight healthy subjects and in four patients with normoxemic cirrhosis.
With thin-section CT, the ratio of segmental arterial diameter to adjacent bronchial
diameter in the right lower lobe in four patients with hepatopulmonary syndrome
was compared with that in four patients with normoxemiccirrhosis.
RESULTS: In patients with hepatopulmonary syndrome, the peripheral pulmonary
vasculature was significantly dilated compared with that in control subjects and in
patients with normoxemic cirrhosis (P .002); however, the central pulmonary
arteries were not significantly dilated (P .05). At thin-section CT, the ratio of
segmental arterial diameter to adjacent bronchial diameter was significantly greater
than that in patients with normoxemic cirrhosis (P .05).
CONCLUSION: In patientswithhepatopulmonary syndrome, the peripheral pulmo-
nary vasculature is significantly dilated. Dilatation of the peripheral pulmonary
vasculature may be helpful inthe diagnosis of hepatopulmonary syndrome.
Hepatopulmonary syndrome is defined as the triad of hepatic dysfunction, intrapulmo-
nary vascular dilatation, and abnormal arterial oxygenation (hypoxemia) (1–5). It may also
result in dyspnea, platypnea, and orthopnea (1,4). Clinical hepatopulmonary syndrome
manifests with progressive dyspnea andhypoxemia in patients with cirrhosis (6).
Radiographic findings in patients with hepatopulmonary syndrome may include
bibasilar nodular or reticular opacities on chest radiographs, dilated peripheral lung vessels
at conventional computed tomography (CT), and peripheral arteriolar dilatation at
pulmonary angiography (7). However, to our knowledge, a comprehensive description of
both the central and peripheral arterial diameters in patients with hepatopulmonary
syndrome has not been reported. Therefore, we undertook a retrospective review of the
conventionalCTstudiesineightpatientswithhepatopulmonarysyndrometoevaluatethe
diameters of the central and peripheral pulmonary vesselsandto compare them with those
ineighthealthysubjectsandthoseinfourpatientswithnormoxemiccirrhosis(ie,cirrhosis
without hypoxemia). We also compared the ratio of segmental arterial diameter to
bronchial diameter, which was measured by using thin-section CT, in four patients with
hepatopulmonary syndrome and in four patients with normoxemicliver cirrhosis.
MATERIALS AND METHODS
We reviewed the CT scans obtained in 12 patients who had liver cirrhosis, hypoxemia
(partial pressure of oxygen less than 70 mm Hg at arterial blood gas analysis), and dyspnea
Index terms:
Computed tomography (CT),
68.1211, 68.12118
Liver, diseases, 761.794
Lung, CT, 68.1211, 68.12118
Pulmonary arteries, abnormalities,
564.1551
Pulmonary arteries, CT, 564.1211,
564.12118
Radiology 1999; 211:549–553
1
From the Departments of Diagnostic
Radiology (K.N.L., H.J.L.) and Internal
Medicine (W.W.S.), Dong-A University
College of Medicine, 3-1 Ga, Tong-
daesin-Dong, Seo-Ku, Pusan 602-103,
Korea, and the Department of Radiol-
ogy, University of California San Fran-
cisco, Calif (W.R.W.). Received Febru-
ary 16, 1998; revision requested April
16; final revision received September
14; accepted October 28. Address
reprint requests to K.N.L.
r RSNA, 1999
Author contributions:
Guarantor of integrity of entire study,
K.N.L.; study concepts and design,
K.N.L.; definition of intellectual con-
tent, K.N.L., W.W.S.; literature re-
search, K.N.L., W.W.S.; clinical studies,
W.W.S., K.N.L., H.J.L.; experimental
studies, K.N.L.,H.J.L.;data acquisition,
K.N.L., H.J.L.; data analysis, K.N.L.,
W.R.W.; statistical analysis, H.J.L.;
manuscriptpreparation,K.N.L.;manu-
script editing, K.N.L., W.R.W.; manu-
script review, W.R.W.
549
and who underwent a CT examination of
the thorax at our institution between Au-
gust 1993 and December 1996. Four of the
12patientshadpulmonarytuberculosis(n
3) or bronchogenic carcinoma(n 1); these
patients were excluded from the study be-
cause other combined lung disease might
influence dyspnea or hypoxemia. There-
fore,thestudygroupincludedeightpatients
(five men, three women; age range, 54–70
years;mean age SD, 63.5 years 5.3).
To provide a control group, we ran-
domly selected eight healthy individuals
(four men and four women older than 54
years; age range, 54–66 years; mean age,
59.6 years 4.4) who had undergone
conventional CT. In addition, we re-
viewed the CT scans obtained in four
patients (all men aged 55–64 years; mean
age, 59.5 years 3.7) who had liver
cirrhosis without hypoxemia or dyspnea
between August 1996 and December 1996.
These patients underwent both conven-
tionalCTand thin-sectionCTofthethorax.
We reviewed the clinical and labora-
tory data on the eight patients with hepa-
topulmonary syndrome, eight control
subjects, and four patients with normox-
emic liver cirrhosis (Table 1). The present
study was based on a retrospective analy-
sis of their CT scans. The scans were
obtained with use of a Highlight scanner
(GE Medical Systems, Milwaukee, Wis)
with the patient in the supine position at
full inspiration. Mediastinal window set-
tings (level, 30 HU; width, 450 HU) were
used to measure the diameters of the
central pulmonary arteries (ie, main pul-
monary trunk and both right and left
main pulmonary arteries). The lung win-
dow settings (level, 600 HU; width,
1,500 HU) were used to measure the
peripheral pulmonary vasculature.
The diameters of the pulmonary trunk
at the level above the pulmonic valve, of
the right main pulmonary artery between
the anterior wall of the right main bron-
chus and posterior wall of the superior
vena cava, and of the left main pulmo-
nary artery at the level above the left
main bronchus were measured (8,9) with
a Vernier caliper (millimeters, with two
decimals) by consensus between two of
TABLE 1
Clinical and Laboratory Data at or near CT Measurements of the Central and Peripheral Pulmonary Vascular Diameters
in Patients with Hepatopulmonary Syndrome, Healthy Subjects, and Patients with Normoxemic Cirrhosis
Subject
No./Age
(y)/Sex
PaO
2
at
ABGA
(mm Hg)
Total
Bilirubin
Level
(mg/dL)*
Serum
Albumin
Level
(g/dL)
AST Level
(U/L)
ALT Level
(U/L)
Pulmonary
Trunk
Diameter
(mm)
Central Right
Main PA
Diameter
(mm)
Left Main
PA Diameter
(mm)
Peripheral Right
Basal PA
Diameter
(mm)
With HPS
1/65/F 69 2.5 2.8 237 82 39.2 18.0 19.8 7.0
2/70/M 60 3.0 3.0 30 28 29.8 16.0 15.2 6.5
3/61/M 64 0.7 3.6 47 27 29.4 15.6 19.8 6.0
4/64/M 48 1.3 2.3 62 49 33.1 18.9 19.8 10.1
5/54/M 62 2.8 3.7 44 24 33.6 21.6 21.9 7.5
6/67/F 67 1.3 2.6 314 166 36.1 24.1 21.4 5.7
7/59/M 63 2.0 2.5 60 15 25.7 15.7 17.1 6.3
8/68/F 40 1.5 2.2 74 33 35.9 16.4 24.0 9.6
Healthy
9/56/M NA 1.2 4.3 14 13 28.8 16.0 17.9 4.8
10/57/F NA 0.3 4.5 16 12 30.0 19.0 20.9 4.4
11/66/F NA 0.4 4.3 21 23 28.6 15.8 17.2 4.0
12/63/M NA 0.9 4.2 17 20 31.2 18.8 22.2 5.0
13/56/F NA 0.4 4.6 22 27 25.2 15.2 12.8 5.2
14/54/F NA 0.6 4.6 17 14 28.2 17.2 18.8 5.8
15/64/M NA 0.7 4.6 32 32 29.0 14.8 16.2 5.5
16/61/M NA 0.7 4.2 16 13 25.0 13.0 12.0 5.2
With NC
17/59/M 116 5.2 3.2 35 9 30.4 18.7 21.8 3.8
18/60/M 114 3.8 2.9 194 39 28.0 17.0 21.2 3.8
19/64/M 94 8.3 1.9 82 29 28.8 17.3 21.9 4.8
20/55/M 111 1.8 4.5 329 240 23.2 17.1 18.3 3.6
Note.—CT examinations were performed with patients in the supine position and breathing room air. ABGA arterial blood gas analysis, ALT alanine
transaminase, AST aspartate transaminase, HPS hepatopulmonary syndrome, NA not applicable, NC normoxemic cirrhosis, PA pulmonary
artery, PaO
2
partial pressure ofarterial oxygen.
* For SI unit conversion (µmol/L), multiply by 17.1.
For SI unit conversion (g/L),multiply by 10.
TABLE 2
Mean Diameters of the Pulmonary Vasculature in Eight Patients with
Hepatopulmonary Syndrome, Eight Healthy Subjects, and Four Patients
with Normoxemic Cirrhosis
Vasculature
Patients with
Hepatopulmonary
Syndrome
Healthy Control
Subjects
Patients with
Normoxemic
Cirrhosis
Central
Pulmonary trunk 32.9 4.4 28.3 2.2 27.6 3.1
Right main pulmonary artery 18.3 3.1 16.2 2.0 17.5 0.8
Left main pulmonary artery 19.9 2.8 17.3 3.6 20.8 1.7
Peripheral
Right basal pulmonary vessels 7.3 1.6 5.0 0.6 4.0 0.4
Note.—Data are the mean (mm)SD.
550 Radiology May 1999 Lee et al
the authors (K.N.L., H.J.L.). To determine
the peripheral pulmonary vessel size,
three to five pulmonary arteries in the
basalrightlowerlobes, within 2 cm of the
pleural surface, were measured with con-
ventional CT, and their diameters were
averaged. This location was chosen to
avoid cardiac pulsation artifacts.
We correlated the peripheral pulmo-
nary vascular diameter with the partial
pressure of arterial oxygen, total bilirubin
level,andserum albuminlevelin patients
with hepatopulmonary syndrome. The
intervalbetweenthe CT examinationand
laboratory study ranged from 1 to 3 days.
Eight thin-section CT scans were ob-
tainedin fourpatients withhepatopulmo-
nary syndrome and in four patients with
normoxemic cirrhosis (bone algorithm
window width/window level, 700 HU/
1,500 HU). We calculated the ratio of
the diameter of the segmental artery to
the luminal diameter of its accompany-
ing bronchus in the basal segments of the
right lower lobe (n 24, 12 segmental
arteries and 12 bronchi in each patient
with hepatopulmonary syndrome and
normoxemic cirrhosis).
Pulmonaryangiographywas performed
in one patient with hepatopulmonary
syndrome to evaluate whether dilated
peripheral pulmonary vessels represented
pulmonary arterioles or dilated arteriove-
nous connections.
Statistical Analyses
Statisticalanalyses wereperformed with
SAS software (SAS Institute, Cary, NC) on
a minicomputer. The difference in the
meandiameters ofthecentral andperiph-
eral pulmonary vessels between groups
was tested according to the Kruskal-
Wallis test. The correlation coefficients
were calculated with linear regression
analysis.
RESULTS
The diameters of the pulmonary trunk,
right and left main pulmonary arteries,
and peripheral vessels of the basal right
lower lobes in the patients with hepato-
pulmonary syndrome, healthy subjects,
and patients with liver cirrhosis without
hypoxemia or dyspnea are listed in Table
1. The mean diameters of the pulmonary
trunk and right main pulmonary arteries
in the patients with hepatopulmonary
syndrome were slightly larger than were
those in the healthy subjects and the
patients with normoxemic cirrhosis, but
thesedifferences were notsignificant(P
.05) (Table 2). However, the diameters of
the right basal peripheral vessels were
significantly larger in patients with hepa-
topulmonary syndrome compared with
those in the healthy subjects (P .05)
(Fig 1) and in the patients with liver
cirrhosis without hypoxemia or dyspnea
(P .002)
In the patients with hepatopulmonary
syndrome, the diameters of the periph-
eralpulmonaryvesselswere inverselycor-
relatedwiththepartial pressure of arterial
oxygen (r ⫽⫺0.907, P .002); this was
also true when the patients with hepato-
pulmonarysyndromeand thosewithnor-
moxemic cirrhosis were considered to-
gether (r ⫽⫺0.91, P .001) (Fig 2).
a. b.
Figure 1. CT scans of the right lower lobe. (a) CT scan obtained in a 64-year-old man with
hepatopulmonary syndrome shows tortuous dilated peripheral vessels (arrows) 2 cm from the pleura.
The vessels were measured by using a Vernier caliper. (b) CT scan obtained in a 63-year-old man, a
healthycontrol subject, nearthesamelevel as inashowssmallerperipheralpulmonary vessels(arrows).
Figure 2. Correlation of peripheral pulmonary vessel diameter and
partialpressureof arterial oxygen ineightpatientswithhepatopulmo-
nary syndrome and four patients with normoxemic cirrhosis. The
peripheral pulmonary vessel diameter correlated significantly and
inversely with the partial pressure of arterial oxygen (PaO
2
)(r
0.91, P .001).ABGA arterial blood gasanalysis.
Volume 211 Number 2 Central and Peripheral Pulmonary Vasculature in Hepatopulmonary Syndrome 551
However, the correlation of peripheral
pulmonaryvesseldiameter toserumalbu-
min level and total bilirubin level was not
significant (P .05). The diameter of the
main pulmonary artery did not correlate
significantlywith thebilirubinlevel,albu-
min level, or partial pressure of arterial
oxygen in patients with hepatopulmo-
nary syndrome or in the combined group
of patients with hepatopulmonary syn-
drome and patients with normoxemic
cirrhosis (all P .05).
At thin-section CT, the mean diameters
of the right basal segmental arteries and
adjacent bronchi were 7.6 mm and 3.8
mm, respectively, in the patients with
hepatopulmonarysyndrome,and 4.7mm
and 4.3 mm, respectively, in the patients
with normoxemic liver cirrhosis (Fig 3).
The ratio of segmental arterial diameter
to bronchial diameter was 2.0 0.2 in
the patients with hepatopulmonary syn-
drome and 1.2 0.2 in the patients with
normoxemic liver cirrhosis; this differ-
ence was significant (P .05) (Table 3).
The pulmonary angiogram obtained in
one patient with hepatopulmonary syn-
drome showed peripheral vessel dilata-
tion and tortuosity (Fig 4).
DISCUSSION
Hepatopulmonary syndrome represents a
combination of liver dysfunction, intra-
pulmonary vascular dilatation, and hy-
poxemia (1–6). The radiologic manifesta-
tions of this disease have been recently
reviewed by McAdams et al (7). CT find-
ings of hepatopulmonary syndrome in-
clude distal vascular dilatation associated
with an abnormally large number of vis-
ible terminal vessel branches, which are
always concentrated in the lower lung
zones. Although the pathogenesis of vas-
cular dilatation is unknown, some inves-
tigators(10–12) have suggestedthatnitric
oxide associated with portal hyperten-
sion might influence the autoregulation
of the peripheral pulmonary vasculature,
withthe resultbeingvasodilatation. Some
have reported that in patients with liver
cirrhosis and portal hypertension, in-
creased nitric oxide in exhaled gas in-
duced the decrease in pulmonary vascu-
lar tone, which accounted for increased
pulmonary blood flow (12). Arterial hy-
poxemia in patients with hepatopulmo-
nary syndrome is thought to occur be-
cause of ventilation-perfusion mismatch,
limitations in oxygen diffusion due to
vascular dilatation (ie, diffusion-perfu-
sion impairment), and, in some patients,
intrapulmonary shunt through dilated
vascular malformations (10,12,13).
In the present study, the peripheral
pulmonary vessels in the patients with
hypoxemic liver cirrhosis were signifi-
cantly dilated compared with these ves-
sels in the healthy subjects and patients
with cirrhosis who were not hypoxemic.
The diameters of the central pulmonary
trunk and right pulmonary artery in the
patients with hepatopulmonary syn-
Figure 4. Pulmonary angiogram obtained in
a 68-year-old woman with hepatopulmonary
syndrome shows dilated and tortuous periph-
eral pulmonary arteries (arrows) but no evi-
dence of arteriovenous shunting.
TABLE 3
Diameters of the Basal Segmental
Artery and Adjacent Bronchus, and
Their Ratio, in Four Patients with
Hepatopulmonary Syndrome, and
Four Patients with Normoxemic
Cirrhosis at Thin-Section CT
Patients with
Hepato-
pulmonary
Syndrome
Patients with
Normoxemic
Cirrhosis
Segmental artery* 7.6 0.8 4.7 1.7
Segmental bron-
chus* 3.8 0.6 4.3 1.8
Ratio of seg-
mental artery
to segmental
bronchus
2.0 0.2 1.2 0.2
* Numbers are the mean (SD) diameters
(mm) of the segmental artery and internal
lumen of the segmental bronchus.
The difference in the ratios of mean seg-
mental arterial diameter to mean bronchial
diameter is statistically significant (P .05).
a. b.
Figure 3. Thin-section CT scans of the right lower lobe. (a) CT scan obtained in a 68-year-old
woman with hepatopulmonary syndrome. The right basal segmental pulmonary arteries are
dilated. The ratio of the diameter of the segmental arteries (arrows) to the diameter of the
accompanying bronchi (arrowheads) is increased compared with that in a 64-year-old man with
normoxemic liver cirrhosis, whose CT scan is shown in b. Minimal pulmonary edema is likely to
result in a slight increase in apparent arterial diameter. Even considering some peribronchial
cuffing, the size of the arteries is clearly increased relative to that of the adjacent bronchi. (b) CT
scan obtained in a 64-year-old man with normoxemic liver cirrhosis. The peripheral pulmonary
arteries (arrows) are proportionally smaller than those ina. The vessels appear to be slightly larger
than the adjacent bronchi (arrowheads). The ratio of basal segmental arterial diameter to
bronchial diameter was 1.2, which was the average ratio in the patients with normoxemic
cirrhosis in the present study.
552 Radiology May 1999 Lee et al
drome were slightly larger, on average,
than were those in the healthy subjects
and patients with normoxemic cirrhosis,
but the differences were not significant
(P .05), and the left pulmonary artery
did not show similar enlargement. Fur-
thermore, the diameter of the main pul-
monary artery did not correlate with the
partial pressure of arterial oxygen.
Kuriyama et al (9) reported the mean
diameters of the pulmonary trunk and
right and left main pulmonary arteries to
be 24.2 mm 2.2, 15.3 mm 2.9, and
13.0 mm 2.0, respectively, in healthy
subjects and that the diameter of pulmo-
nary arteries increased with age. In our
study, the mean diameters of the pulmo-
nary trunk and right and left pulmonary
arteries in the healthy subjects were 28.3
mm 2.2, 16.2 mm 2.0, and 17.3
mm 3.6 mm, respectively, which are
slightly larger than the diameters re-
ported by Kuriyama et al and in a study
performed by O’Callaghanet al (14).This
may relate to the fact that the patients in
our study were older than those exam-
ined in these two studies.
On thin-section CT scans, the diameter
of an artery and its neighboring bronchus
should be approximately equal, although
vessels may appear slightly larger than
their accompanying bronchi, particularly
in dependent lung regions (15). In the
present study, the ratio of segmental arte-
rial diameter to bronchial diameter in
patients with normoxemic cirrhosis was
1.2 0.2; however, inpatientswithhepa-
topulmonary syndrome, the ratio was
2.0 0.2. It seems clear that hepatopul-
monary syndrome is related to pulmo-
nary vasodilatation.
Although our conclusions are some-
what limited because of the small num-
bers of patients with hepatopulmonary
syndrome and with normoxemic cirrho-
sis who were examined by using thin-
section CT, hepatopulmonary syndrome
is relatively uncommon, with an occur-
rence rate of approximately 15% in pa-
tients with end-stage liver disease(12).
In conclusion, in patients with liver
cirrhosis and hypoxemia, or hepatopul-
monarysyndrome,the peripheral pulmo-
nary vasculature is significantly dilated
compared with that in healthy subjects
and in patients with normoxemic liver
cirrhosis.Dilatationofthe peripheral pul-
monary vessels correlates significantly
with the partial pressure of arterial oxy-
gen but not with the total bilirubin level
or serum albumin level. Detection of di-
lated segmental pulmonary vessels, di-
lated peripheral pulmonary vessels, or
both, may also be helpful in the diagnosis
of hepatopulmonary syndrome in pa-
tients with chronic liver disease.
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Volume 211 Number 2 Central and Peripheral Pulmonary Vasculature in Hepatopulmonary Syndrome 553
... Initial data from a small study with only 10 patients reported that multiple dilated vessels with increased numbers of visible terminal branches that extend to the pleura indicate a diagnosis of HPS [7]. Two subsequent studies in individuals with cirrhosis and HPS reported an increased CT diameter of the peripheral pulmonary vasculature compared with both healthy controls and patients with normoxemic cirrhosis [8,9]. In contrast, another study reported evidence of peripheral pulmonary artery dilatation on CT in patients with liver disease compared with healthy controls, but no differences between patients with liver disease with or without HPS [10]. ...
... The mean ABRs in our and other studies [7][8][9][10] are within the normal range reported for healthy patients (0.98; 95% CI: 0.7, 1.26) [17]. Moreover, consistent with previous reports [10], ABR and PaO 2 were not correlated. ...
... Two previous studies [8,9] demonstrated higher ABRs in patients with HPS compared with those with cirrhosis without HPS. Koksal et al. [8] reported a weak negative correlation (r = -0.64; ...
Article
Full-text available
Purpose Hepatopulmonary syndrome (HPS) is defined as an arterial oxygenation defect induced by intrapulmonary vascular dilatations associated with hepatic disease. This study aimed to assess the prevalence of type 1 and 2 pulmonary vascular abnormalities on chest computed tomography (CT) in patients with cirrhosis and HPS and to characterize intra- and interobserver reliability. Materials and methods Two thoracic radiologists retrospectively evaluated chest CT scans from 38 cirrhosis patients with HPS. They classified the pulmonary vascular abnormalities as type 1 (multiple dilated distal pulmonary arteries), type 2(nodular dilatation or individual pulmonary arterial malformation), or absence of abnormality. Furthermore, they measured the diameters of the central pulmonary arteries and subsegmental pulmonary arteries and bronchi. We analyzed the prevalence, intraobserver reliability, and interobserver reliability of abnormal CT findings related to HPS, and the correlation of these findings with partial arterial oxygen pressure (PaO2). Results The overall prevalence of pulmonary vascular abnormalities was 28.9% (95% confidence intervals: 15.4%, 45.9%). Moreover, 26.3% of patients had type 1 abnormality (13.4%, 43.1%) and 2.6% of patients had type 2 abnormality (0.0%, 13.8%). The intraobserver reliability kappa value was 0.666 (0.40, 0.91) and the interobserver kappa value was 0.443 (0.12, 0.77). There was no correlation between pulmonary vascular abnormalities on CT and PaO2 values. Conclusions The prevalence of pulmonary vascular abnormalities on chest CT of patients with cirrhosis and HPS is low and not correlated with PaO2. These findings question the usefulness of chest CT for the evaluation of patients with cirrhosis and HPS.
... Bien que les mécanismes exacts impliqués dans la physiopathologie du SHP ne soient pas encore clairement élucidés, l'accumulation d'observations, essentiellement expérimentales, apporte des éléments suggérant l'implication d'un dysfonctionnement de l'endothélium vasculaire pulmonaire associé à des mécanismes inflammatoires systémiques et locaux provoqués par l'exposition de la circulation pulmonaire à des effluents issus de la circulation porte et non filtrés par le foie (Fig. 2). Au cours du développement du SHP humain ou expérimental, l'altération progressive des échanges gazeux est associée à un déséquilibre des facteurs vasoconstricteurs et vasodilatateurs, en faveur d'une vasodilatation exagérée des artérioles pulmonaires ainsi que des capillaires pulmonaires [6]. L'étude histologique de prélèvements autopsiques de patients a également permis de mettre en évidence la présence d'un remodelage vasculaire plus ou moins prononcé de ces microvaisseaux avec l'identification de shunts anatomiques artério-veineux pulmonaires et de dilations de vaisseaux sous-pleuraux [7]. ...
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... [38] Management guidelines • Role of medical therapy • In patients with HPS and severe hypoxaemia, long-term oxygen therapy is recommended • TIPS has not been shown to play a role; however, coil embolisation has proven to temporarily increase arterial oxygenation. [39,40] • Role of liver transplantation • A PaO2 <60 mm hg is considered for transplantation, reversing or significant improvement is seen in >85% of patients with HPS [41] • Regularly assessing the degree of hypoxaemia may make LT easier before very severe hypoxaemia develops • Nonetheless, inhaled nitric oxide, extracorporeal membrane oxygenator, non-invasive ventilation, increases oxygenation immediately after liver transplantation. [42][43][44] Hepatorenal syndrome-acute kidney injury Definition and presentation HRS has been defined as 'functional renal failure induced by intrarenal vasoconstriction that occurs in individuals with end-stage liver disease, acute liver failure, or alcoholic hepatitis' for a long time. ...
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To review current knowledge about the hepatopulmonary syndrome, including definition and clinical features, methods for diagnosing it, pathophysiologic mechanisms of the associated vascular dilatations, and considerations in treatment, with emphasis on potential reversibility of the syndrome after liver transplantation. The MEDLINE database from January 1986 to December 1993 and bibliographies of selected articles. Case studies and series reporting results from patients with the hepatopulmonary syndrome were reviewed. Clinical reviews and animal studies relevant to the hepatopulmonary syndrome were examined. Outcomes, including survival and the frequency of reversibility of the hepatopulmonary syndrome, were extracted from available clinical reports. Mild hypoxemia is multifactorial and occurs in approximately one third of all patients with chronic liver disease. The hepatopulmonary syndrome is one cause of hypoxemia that may also cause dyspnea, platypnea, and orthopnea. Intrapulmonary vascular dilatations and the resulting right-to-left intrapulmonary shunt are characteristic of the syndrome. Pharmacologic treatment with almitrine bismesylate, somatostatin analog, and indomethacin and treatment with plasmapheresis have been disappointing. The underlying cause and the predictors of reversibility of the hepatopulmonary syndrome remain unknown, but it has recently been shown that such reversibility is possible and that contrast-enhanced echocardiography appears to be the most sensitive diagnostic test for detecting intrapulmonary vascular dilatations. In the context of persisting uncertainty about the cause and treatment of the hepatopulmonary syndrome, future studies must focus on better understanding the pathophysiology of the hepatopulmonary syndrome, predicting reversibility after liver transplantation, and identifying other treatment options.
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We retrospectively studied 22 patients with hepatopulmonary syndrome (HPS) evaluated at the Mayo Medical Center from 1984 to 1991. All patients had hepatic cirrhosis with clinical evidence of portal hypertension; 13 (59 percent) had severe hypoxemia while breathing room air in the supine position (PaO2 < 60 mm Hg), and 14 of 16 (88 percent) had orthodeoxia breathing room air. On the basis of angiographic observations, we defined type 1 and type 2 patterns of pulmonary vascular abnormalities in HPS. Response to 100 percent oxygen and therapeutic regimens may differ in the angiographic patterns. Substantial deterioration in PaO2 associated with clinically stable hepatic dysfunction was documented in five of seven patients studied with sequential arterial blood gas testing; four subsequently died within 48 months. Overall mortality was 41 percent, occurring a mean of 2.5 years after diagnosis. In 7 of the 22 patients, we prospectively studied the effect of somatostatin analogue given subcutaneously for 4 consecutive days. No significant improvement in PaO2 was documented while breathing room air or 100 percent oxygen (p < 0.05). We conclude that in selected patients with clinically stable hepatic dysfunction and deteriorating oxygenation, the prognosis is poor. Our data in combination with recent surgical reports suggest that liver transplantation may be the treatment of choice in patients with HPS and worsening oxygenation.