Spontaneous Intestinal Perforation and Neonatal Necrotizing Enterocolitis: Two Distinct Clinicopathological Entities
G De Hertogh, P Van Eyken, K Geboes. UZ KUL, Leuven, Belgium
Background: Intestinal obstruction and perforation are serious problems in the premature neonate. They can be due to mechanical factors or necrotizing enterocolitis (NEC). Often, no apparent cause can be identified clinically. This is referred to as spontaneous intestinal perforation (SIP). The histological changes in SIP are at present poorly characterized and its pathogenesis is unknown. To this end, we performed a detailed comparison of the clinical and histological features of SIP and NEC.
Design: Clinical files and biopsy material from all neonates treated surgically for NEC (n = 25) or SIP (n = 40) in the period 19912008 were reviewed. Biopsies were also stained for alpha-smooth muscle actin, S100 protein, c-kit protein and Cathepsin D.
Results: SIP patients had more often been exposed to antenatal corticosteroids. They had a lower birth weight and were more commonly treated with dexamethasone in the early neonatal period. Occult or frank blood in the stools and systemic symptoms were more common in NEC. The histological evaluation showed a segmental absence of the intestinal musculature (SAM) in dilated bowel segments or close to a perforation in all SIP cases, and in none of the NEC samples. SAM typically affected the circular muscle layer. Gaps in this structure were filled with connective tissue similar to that found in the normal submucosa. The architecture and composition of the myenteric plexus were always preserved.
Conclusions: In our series, segmental absence of the intestinal musculature was specific for SIP and moreover present in all such cases. A compilation of previous publications showed a much lower frequency (14%). The reason for this discrepancy may be that SAM can be very localized and requires diligent searching. On the basis of the histological characteristics of SAM, we believe that it occurs before birth. A short period of localized ischemia in a zone of SAM might be sufficient to cause spontaneous bowel perforation in the neonate.
Monday, March 9, 2009 1:00 PM
Poster Session II # 212, Monday Afternoon