poster situs inversus
TRANSCRIPT
SITUS INVERSUS ASSOCIATED WITH COMPLEX VENOUS ANATOMY; A RARE ASSOCIATION
Syed Muzzammil Wasti, Sohail Amin, Sibtain Raza, S. Shafqat-ul-Islam, Syed Mahmood
Karachi X Rays & U/S / CT Scan Centre
INTRODUCTIONSitus Inversus literally means mirror image arrangement of the
Situs Solitus. It is a rare condition with a frequency of 0.01%. If it
is found to be associated with dextrocardia and chance of
congenital heart diseases is 3-5 %. Levocardia is an extremely
rare association. But when Situs Inversus is associated with
Levocardia, chance of congenital heart diseases rises to 95 %1.
Since Situs Inversus has numerous associated anomalies, so most
of the patients come to clinical and imaging attention because of
congenital heart disease, immune deficiency, or bowel obstruction
related to malrotation2.
It may also result in atypical presentation of typical diseases
leading to misdiagnosis.
Establishing a good understanding of multiple anatomic
variations, anomalies, associations and differences in clinical
manifestations of disease process is of paramount importance.
CASE REPORTA 14 years old young male presented with a history of lower
backache, mild dysuria and supra-pubic pain for the last 01 year.
It was not associated with fever, increased frequency, urgency or
hesitancy. This patient had a history of congenital cardiac
anomalies which were known to him. He however denied any
history of previous hospitalization. There were no other known co-
morbid. Overall growth pattern, milestones and secondary sexual
characteristics were well developed.
His previous ultrasound abdomen revealed Situs Inversus which
was known to the patient as well.
The imaging was performed on 16 slicer CT-Scanner. The scan
revealed Dextro-cardia, Situs Inversus along with ectopic right
kidney which was fused with the left kidney at its lower pole (Fig I
& II). In addition to that ectopic right kidney was also malrotated,
extending to the midline and laid anterior to the Aorta and IVC
(Fig III). Slight malrotation of left kidney was also noted with
associated left pelvi-utreteric junction narrowing leading to
dilatation and ballooning of left renal pelvis. Striated nephrogram
and duplex type of collecting system was noted on right side with
dilatation of both moieties. Renal pelvis of both moieties showed
abrupt tapering most likely due to pelvi-utreteric junction
narrowing. No contrast was seen in right ureter and it was seen to
be dilated up to the uretero-vesical junction. Vascular anatomy
(Fig IV) raised the possibility of having double IVC (seen to be
uniting at infra-hepatic level). Rest of the scan was unremarkable
a) Situs Inversus along with ectopic right kidney, two IVC are seen, one anterior to aorta on this image and other on left side
DISCUSSIONAnomalies related to Situs are quite unusual or even very rare at
times. Situs Inversus is considered as the most common form
which is seen only in 0.01% of the whole population1.
Establishing a good understanding of these variations certainly
becomes helpful to avoid complications in surgical or
interventional procedures2.
Situs Inversus either have an associated Dextrocardia or
Levocardia. Situs Inversus is relatively common with the former
one and is seen to have transposition of cardiac apex, spleen,
stomach, and aorta on the right and the liver and IVC on the left.
Cardiac diseases occur in 3-5% of cases3. Having an associated
Levocardia is exceedingly rare and almost all cases have cardiac
anomalies4. Congenital heart disease occurs in less than 1% of
individuals with situs solitus5.
Spectrum of manifestations varies greatly among those who
present in early life than those who present late.
Unusual clinical manifestations and confusing pictures due to
abnormal locations of spleen, gall bladder and appendix may
present as diagnostic dilemma7.
For appropriate recognition and characterization of visceral
anatomy, Sonography8, Computed Tomography (CT), and
Magnetic Resonance (MR) imaging have greatly enhanced the
diagnostic abilities9.
Situs Inversus has been found to be associated with various
vascular anomalies and variations. Interruption of IVC with
Azygous or Hemiazygous continuation is also seen in association
with polysplenia 10, 11, 12. The infra hepatic IVC may be right
sided, left sided or duplicated. However, IVC interruption with
Azygous continuation in asplenia syndrome is very rare13.
Ipsilateral location of the aorta and IVC has been reported to be a
consistent finding in asplenia14. Applegate et al 15 noted that the
aorta and IVC were ipsilateral in only six patients
c) Ectopic right kidney fused with the left kidney at its lower pole, large right paravertebral vein also seen
b) Ectopic right kidney was also malrotated, IVC are seen to join at the level of renal hilum on this CT image
REFERENCES
1 Dahnert W. CVS Disorders. In: Dahnert W, ed. Radiology Review
Manual. 5th edition. Lippincott, Williams and Wilkins. 2003; pp. 582
2 Moller JH, Nakib A, Anderson RC, Edwards JE. Congenital heart
disease associated with polysplenia, a developmental complex of
bilateral "left-sidedness". Circulation 1967; 36:789-799.
3 Applegate KE, Goske MJ, Pierce G, Murphy D. Situs revisited:
imaging of the heterotaxy syndrome. Radiographics 1999;19:837-852
4 Tegtmeyer CJ, Hust FS, Keats TE. Arteriographic manifestations of
abdominal situs inversus. AJR Am J Roentgenol 1975; 125:427-430
5 Tonkin IL. The definition of cardiac malpositions with
echocardiography and computed tomography. In: Friedman WF,
Higgins CB, eds. Pediatric cardiac imaging. Philadelphia, Pa:
Saunders, 1984; 157-187
6 Tonkin IL. The definition of cardiac malpositions with
echocardiography and computed tomography. In: Friedman WF,
Higgins CB, eds. Pediatric cardiac imaging. Philadelphia, Pa:
Saunders, 1984; 157-187.
d) Sagittal reformatted image showing fused kidneys with hydronephrosis
SUMMARY OF IMAGING FINDINGS1. Situs Inversus with Dextrocardia
2. Crossed Fused Ectopia of Right Kidney with duplex collecting
system
3. Bilateral Pelvi-Utreteric Junction narrowing
4. Double IVC (seen to be uniting at renal hilum level)