PORTAL HYPERTENSION
p o re
A t i n y o p e n i n g , u s u a l l y i n t h e s k i n .
p o rp h y ria
A n y o f a g r o u p o f r a r e , o f t e n i n h e r i t e d
d i s o r d e r s c a u s e d b y t h e a c c u m u l a t i o n o f
s u b s t a n c e s c a l l e d p o r p h y r i n s .
CAUSES
P o r p h y r i n s a r e c h e m i c a l s f o r m
e d i n t h e
b o d y d u r i n g t h e m a n u f a c t u r e o f h a e m
( a c o m
p o n e n t o f
h a e m o g lo b in ,
t h e o x y -
g e n - c a r r y i n g
p i g m e n t
i n
r e d
b l o o d
c e l l s ) . A b l o c k i n t h i s p r o c e s s c a u s e s a
b u i l d u p o f p o r p h y r i n s , w h i c h c a n a c t a s
a p o i s o n . S u c h b l o c k s m a y r e s u l t f r o m
v a r i o u s g e n e t i c
e n zy m e
d e f i c i e n c i e s . P o r -
p h y r i a m a y a l s o b e d u e t o p o i s o n i n g .
TYPES AND SYMPTOMS
T h e r e a r e s i x t y p e s o f p o r p h y r i a , e a c h o f
w h i c h h a s d i f f e r e n t s y m p t o m s . S u f f e r e r s
o f t e n h a v e a r a s h o r b l i s t e r i n g b r o u g h t o n
b y
s u n l i g h t ,
a n d
m a y
h a v e
a b d o m i n a l
p a i n a n d n e r v o u s s y s t e m d i s t u r b a n c e s d u e
t o t h e e f f e c t s o f c e r t a i n d r u g s o r a l c o h o l .
Acute intermittent porphyria
T h i s
f o r m
u s u a l l y
a p p e a r s
i n
e a r l y
a d u l t h o o d ,
c a u s i n g a b d o m i n a l p a i n , a n d o f t e n l i m b
c r a m p s , m u s c l e w e a k n e s s , a n d p s y c h i -
a t r i c
d i s t u r b a n c e s . T h e
p a t i e n t ’s
u r i n e
t u r n s r e d w h e n l e f t t o s t a n d .
B a rb itu ra te
d r u g s , p h e n y t o in , o ra l c o n tra c e p t iv e s ,
a n d
c e r t a i n o t h e r d r u g s p r e c i p i t a t e a t t a c k s .
Variegate porphyria
T h i s
c o n d i t i o n
h a s
s i m i l a r e f f e c t s t o a c u t e i n t e r m i t t e n t p o r -
p h y r i a , a n d m a y b e c a u s e d b y t h e s a m e
d r u g s . A n a d d i t i o n a l s y m p t o m i s b l i s t e r -
i n g o n s k i n t h a t i s e x p o s e d t o s u n l i g h t .
Hereditary coproporphyria
T h i s f o r m a l s o
h a s s i m i l a r e f f e c t s t o a c u t e i n t e r m i t t e n t
p o r p h y r i a ,
a n d
m a y
c a u s e
a d d i t i o n a l
s k i n s y m p t o m s .
Protoporphyria
I n t h i s f o r m o f p o r p h y r i a ,
m i l d s k i n s y m p t o m s a p p e a r a f t e r e x p o -
s u r e t o s u n l i g h t .
Porphyria cutanea tarda
T h i s
c o n d i t i o n
c a u s e s b l i s t e r i n g o f s k i n t h a t i s e x p o s e d
t o t h e s u n , b u t w i t h n o d i s t u r b a n c e s o f
t h e
d i g e s t i v e
o r
n e r v o u s
s y s t e m s .
W
o u n d s a r e s l o w t o h e a l , a n d u r i n e i s
s o m e t i m e s p i n k o r b r o w n . M a n y c a s e s
a r e p r e c i p i t a t e d b y l i v e r d i s e a s e .
Congenital erythropoietic porphyria
T h i s
i s t h e r a r e s t a n d m o s t s e r i o u s f o r m o f
p o r p h y r i a . I t c a u s e s r e d d i s c o l o r a t i o n o f
u r i n e a n d t e e t h , e x c e s s i v e h a i r g r o w t h ,
s e v e r e
s k i n
b l i s t e r i n g
a n d
u l c e r a t i o n ,
a n d
h a e m o l y t i c
a n a e m ia .
D e a t h
m a y
o c c u r i n c h i l d h o o d .
DIAGNOSIS AND TREATMENT
D i a g n o s i s i s m a d e f r o m a b n o r m a l l e v e l s
o f p o r p h y r i n s i n t h e u r i n e a n d f a e c e s .
T r e a t m e n t
o f
p o r p h y r i a
i s
d i f f i c u l t .
A v o i d i n g s u n l i g h t a n d / o r p r e c i p i t a t i n g
d r u g s
i s t h e m o s t i m p o r t a n t m e a s u r e .
A c u t e i n t e r m i t t e n t p o r p h y r i a , h e r e d i t a r y
c o p r o p o r p h y r i a a n d v a r i e g a t e p o r p h y r i a
m a y b e h e l p e d b y t h e a d m i n i s t r a t i o n o f
g lu c o s e
o r
h e m i n
( a
s u b s t a n c e
t h a t
i s
c h e m i c a l l y
r e l a t e d t o
h a e m ) .
C a s e s
o f
p o r p h y r i a c u t a n e a t a r d a m a y s o m e t i m e s
b e h e l p e d b y
v e n e s e c t io n
( w i t h d r a w i n g
b l o o d f r o m a v e i n ) .
p o rta l h y p e rte n s io n
I n c r e a s e d b l o o d p r e s s u r e i n t h e p o r t a l
v e i n ,
w h i c h
c a r r i e s
b l o o d
f r o m
t h e
s t o m a c h ,
i n t e s t i n e s , a n d s p l e e n t o t h e
l i v e r . T h e
p r e s s u r e
c a u s e s
o e s o p h a g e a l
v a ric e s
( w i d e n e d v e i n s i n t h e o e s o p h a -
g u s ) ,
w h i c h
m a y
r u p t u r e
a n d
c a u s e
i n t e r n a l b l e e d i n g .
I n a d d i t i o n ,
f l u i d i s
f o r c e d
o u t
o f
t h e
o v e r l o a d e d
p o r t a l
v e i n , r e s u l t i n g i n
a s c ite s
( a c c u m u l a t i o n
o f f l u i d i n t h e a b d o m e n ) .
CAUSES
T h e
m o s t
c o m
m o n
c a u s e
o f
p o r t a l
h y p e r t e n s i o n i s
c ir r h o s is
o f t h e l i v e r , i n
w h i c h a r e a s o f s c a r t i s s u e i n t h e l i v e r
o b s t r u c t t h e p o r t a l v e i n . A n o t h e r p o s s i -
b l e c a u s e i s
t h ro m b o s is
( a b n o r m a l b l o o d
c l o t t i n g ) d u e t o n a r r o w i n g o f t h e p o r t a l
v e i n . T h e n a r r o w i n g m a y b e
c o n g e n it a l
( p r e s e n t
f r o m
b i r t h ) ,
a p p e a r
s h o r t l y
a f t e r b i r t h , o r d e v e l o p l a t e r i n l i f e ( d u e
t o c o m p r e s s i o n o f t h e v e i n b y e n l a r g e d
ly m p h n o d e s ,
o r t o i n f l a m m a t i o n r e s u l t -
i n g f r o m a n i n f e c t i o n ) . I n t r o p i c a l a r e a s ,
a c o m
m o n c a u s e i s d i s e a s e t h a t c a u s e s
t h e s p l e e n t o e n l a r g e a n d r e s u l t s i n a n
i n c r e a s e d b l o o d f l o w
f r o m
t h e
s p l e e n
t h r o u g h t h e p o r t a l v e i n .
A r a r e c a u s e o f p o r t a l h y p e r t e n s i o n i s
a n
a b n o r m a l
c o n n e c t i o n
t h a t
o c c u r s
b e t w e e n t h e p o r t a l v e i n a n d a n a r t e r y
( s e e
a rt e rio v e n o u s f is t u la );
t h i s
t y p e
i s
u s u a l l y t h e r e s u l t o f i n j u r y
SYMPTOMS
S y m p t o m s m a y o n l y a p p e a r o n c e c o m
-
p l i c a t i o n s
h a v e
d e v e l o p e d .
R u p t u r e d
o e s o p h a g e a l
v a r i c e s
l e a d
t o
m a s s i v e ,
r e c u r r e n t v o m i t i n g
o f b l o o d a n d p r o -
d u c e
b l a c k
f a e c e s
(m e la e n a ).
A s c i t e s
r e s u l t s i n a b d o m i n a l s w e l l i n g a n d d i s -
c o m f o r t ,
a n d
s o m e t i m e s
d i f f i c u l t y
i n
b r e a t h i n g . I n a d d i t i o n , t h e v e i n s t h a t a r e
s i t u a t e d j u s t u n d e r t h e s k i n o f t h e a b d o -
m e n m a y b e v i s i b l y s w o l l e n .
DIAGNOSIS
D i a g n o s i s
i s
u s u a l l y
m a d e
f r o m
t h e
s y m p t o m s a n d s i g n s .
D o p p le r u lt ra s o u n d
s c a n n in g
m a y b e u s e d t o a s s e s s t h e p r e s -
s u r e i n t h e p o r t a l v e i n .
TREATMENT
V a r i o u s t r e a t m e n t s m a y b e u s e d t o r e d u c e
b l o o d p r e s s u r e a n d t o s t o p b l e e d i n g o r
p r e v e n t
f u r t h e r
b l e e d i n g .
F o r
e x a m p l e ,
r u p t u r e d b l o o d v e s s e l s m a y b e t r e a t e d b y
s c l e r o t h e r a p y ,
i n
w h i c h
a
c h e m i c a l
i s
PORTAL HYPERTENSION
The most common cause of portal hypertension is cirrhosis of the liver or some
other obstruction to the blood flow through the liver. The portal vein becomes
congested with blood, with the result that back pressure develops through the
system of veins that join the portal vein.
Oesophageal varices
The back pressure may
cause oesophageal veins
to widen and rupture.
Enlarged
spleen
Normal action
of portal vein
The vein carries nutrient-
rich blood from the
abdominal organs to the
liver for processing.
Features of portal hypertension
The portal vein becomes congested, the
pressure in it rises, fluid is forced out into
the abdomen, and veins that supply the
portal vein are widened and may rupture.
■ j J r
From stomach
From intestines
P
619
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