Objective: The expected types of connections in asplenia or polysplenia are well known. This study was undertaken to ascertain the number of exceptions.
Methods: The connections were assessed in 38 specimens with asplenia and 13 with polysplenia.
Results: There was right atrial appendage isomerism in 95% of cases with asplenia and left isomerism in 77% with polysplenia. A unique patient with asplenia had right-sided juxtaposition of the atrial appendages. The atrial septum did not show lateralization in 84% with asplenia and 92% with polysplenia. Bilateral superior vena cavae were found in 63 with asplenia and in only 23% with polysplenia. The coronary sinus was absent in 95% with asplenia but in only 50% with polysplenia. In polysplenia the suprarenal portion of the IVC was absent in 54% and pulmonary veins connected to ipsilateral atria in 62%. There was total anomalous pulmonary venous connection in 74% with asplenia. Only 4 patients had normal pulmonary venous connections. In the others with connection to the atria, the pulmonary veins united into a common vessel which was often obstructed at the junction with the atrium. Eleven different patterns of systemic venous connections were seen in the asplenia cases plus additional variations with pulmonary venous connections to different sites. Ten patterns of systemic and pulmonary venous connections were seen in the polysplenia cases.
Conclusion: Detailed analysis of these connections is required before surgical treatment could be undertaken.