Surgery Which of the following should contraindicate performance of the Fontan procedure? A Patient age of 25 years. B Severe mitral insufficiency. C Left ventricular end-diastolic pressure of 18 mm. Hg. D Right pulmonary aery stenosis 💡 Explanation Which of the following should contraindicate performance of the Fontan procedure? ✓ Correct Answer: C. Left ventricular end-diastolic pressure of 18 mm. Hg.