Following a few cases of heterotaxy syndrome with polysplenia in adults diagnosed in our hospital,
we have performed a bibliographic review of the evidence in order to identify the principal radiological findings of altered anatomy in situs anomalies and associated diseases.
LUNGS AND BRONCHI
Associated with the syndrome of heterotaxia with asplenia,
the literature describes a strong association with the presence of right isomerism.
This implies that the patient has trilobulated lungs with bilateral minor fissures and bronchi in epiarterial situation with a short course.
Nevertheless,
in the syndrome of heterotaxia with polysplenia,
the association with left isomerism is described with lungs bilobed bilaterally and bronchi in hypoarterial situation with a long course.
Nobody of our patients had this characteristic disposition.
They had right trilobed (Fig. 3) and left bilobed lungs (Fig. 4),
with the bronchi in normal disposition (Fig. 5).
HEART
Patients with asplenia-associated heterotaxia syndrome have a very high mortality rate due to frequent and severe associated cardiac malformations,
such as the common atrioventricular canal,
the univentricular heart and the transposition of large vessels.
All of them tend to present with anomalous pulmonary venous drainage.
In patients with polysplenia,
cardiac malformations are less frequent and milder.
Patients with left isomerism present morphologically left atrial appendages (long and narrow) and receive pulmonary veins.
INFERIOR VENA CAVA
The most frequent alteration found associated to the syndrome of heterotaxy with polysplenia is the interruption of the inferior vena cava (IVC) with continuation through the azygos vein or hemiazygos (Fig. 6 and Fig. 7),
as well as short intrahepatic segment of the IVC (Fig. 8).
The infrahepatic portion of the IVC has been described in normal,
left or even duplicated position.
AORTA
Aorta is in its normal position in most of the cases.
Despite,
cases have been described in which it is located to the right of the midline when it coexists with a duplicated IVC.
SPLEEN
The absence of spleen in the syndrome of heterotaxy with asplenia causes high mortality before the first year of life due to its greater association with severe congenital heart disease and decreased immunological activity.
On the other hand,
in polysplenia heterotaxy,
we found different multiple sizes and rounded spleens (called "splenules") or a small lobed spleen,
located generally close to the stomach and adjacent to the greater curvature (Fig. 9 and Fig. 10).
It can be located in the right or left hypochondrium.
This anatomical association of the spleen with the stomach is due to the fact that the splenic tissue originates in the dorsal mesogastrium.
LIVER:
As much in polysplenia or asplenia,
midline liver is a very common finding.
However,
it appears more frequently in patients with asplenia.
We found in our patients midline liver (Fig. 11 and Fig. 12) and hepatic artery originated in the superior mesenteric artery as a variant of normality (Fig. 13).
PANCREAS:
Regarding the majority of cases of patients with heterotaxy described in the literature,
the pancreas is truncated or incomplete with the absence of the tail and/or body because of partial agenesis of the dorsal pancreas (Fig. 14).
GASTROINTESTINAL TRACT
Intestinal malrotation is a common discovery in heterotaxy syndrome.
The stomach may be in a normal or mirror location.
Regarding the small bowel and colon,
different degrees of intestinal malrotation could be observed.
The most common finding described is the small bowel to the right of the midline and the colon to the left (Fig. 15).
The preduodenal position of the portal vein has been described in the literature,
which might cause intestinal obstruction.
TREATMENT AND PROGNOSIS
The management of adults with polysplenia is generally palliative and symptom-specific.
Most adult patients with heterotaxy syndrome with polysplenia do not present any specific symptoms and are incidentally diagnosed.
The existence of associated anomalies such as a preduodenal portal vein,
intestinal malrotation or vascular anomalies can condition the surgery.
Its awareness is important and priority to avoid complications in interventional procedures.