Assertion: isthmus | /r/HasProperty | absent
Facets:
value: congenitally
type: DEGREE
value: in most patients with tof
type: OTHER
value: with absent pulmonary valve
type: OTHER
value: in the single case of tof
type: LOCATION
value: often
type: DEGREE
Source sentences:
text: Isthmus 3 was present in 24 cases (89%) while being absent in the single case of TOF with absent pulmonary valve and in the 2 cases with bioprosthetic pulmonary valves that had been sewn to the region of the VSD patch in the RVOT.
text: However, this isthmus was often absent secondary to a transannular incision or avoidance of RVOT incision altogether, and it is likely that with changes in surgical technique this isthmus will be encountered even less frequently with time.4,6
text: Because isthmus 4 is congenitally absent in most patients with TOF (existing a priori in only ≈20%), this finding is not surprising.25