Occlusion of patent ductus arteriosus Porstmann 1967
In 1967, Porstmann performed the first successful closure of a patent ductus arteriosus (PDA) without opening the chest. The technique was applied in China in 1983, and Rashkind et al. successfully closed the PDA by delivering an umbrella patch through the venous route in 1977, Cambier used a spring steel ring to seal the PDA in 1992, Masura et al. started to use the Amplatzer sealer to treat the PDA in 1997, and the Amplatzer technique was introduced in China in 1998. At present, the Amplatzer method and the controlled spring bolus method are commonly used at home and abroad. Indications I. Amplatzer method (a) left-to-right shunt does not combine with the heart malformation requiring surgery PDA; PDA narrowest diameter ≥ 2.0mm; age: usually ≥ 6 months, weight ≥ 4kg. (b) post-surgical residual shunt; diameter ≥ 14mm PDA is often combined with more severe pulmonary hypertension, its operation is difficult, low success rate, many complications, should be cautious. At present, the domestic PDA blocker or Amplatzer myocardial septal defect blocker can help to block the larger diameter PDA. In PDA with severe pulmonary hypertension, right heart catheterization should be routinely performed before blocking. If the pulmonary circulation flow/body circulation flow (QP/QS) is >1.3; femoral artery oxygen saturation is >90 %; occlusion can be considered for treatment. If the pulmonary artery pressure decreases (more than 30 mmHg or 20% of the original pressure), the aortic pressure does not decrease and the oxygen saturation of the femoral artery increases, and the patient has no adverse reaction, and the imaging shows no or only a small amount of residual shunt, the blocker can be released. However, care should be taken to avoid stenosis of the descending aortic arch and left pulmonary artery caused by oversized blocker; in addition, the operation should be gentle, and once it is unsuccessful, the blocker should be retrieved smoothly into the sheath to prevent damage to the PDA and the occurrence of pulmonary artery entrapment. If the pulmonary artery pressure increases instead of decreasing after the trial blocking, or the heart rate slows down, the aortic pressure decreases, and the patient feels chest tightness, shortness of breath, chest pain, dizziness or even syncope and other adverse reactions, the blocking device should be retrieved immediately. Then closely observe the condition and deal with it as appropriate. PDA in elderly patients
Although the pulmonary artery pressure is lower than the aortic pressure before blocking, the oxygen saturation of ascending aorta and femoral artery may be lower than normal (which cannot be explained by the right-to-left shunt caused by PDA with severe pulmonary hypertension). Even if the oxygen saturation of the femoral artery does not return to normal after experimental occlusion, permanent occlusion can be performed at this time if the pulmonary artery pressure decreases satisfactorily and the patient has no adverse reactions, although close follow-up should be performed. In both cases, clinical experience is limited and more cases need to be accumulated to further evaluate the long-term effects. For PDA combined with other interventional cardiovascular malformations, interventional treatment can be performed concurrently or in stages as appropriate. For PDA
For PDA combined with other malformations that are not suitable for intervention but temporarily unsuitable or do not require surgery (such as mild aortic valve lesions or small coronary artery fistulas in children), PDA occlusion can be performed first, and the combined malformations should be followed up and observed, and surgical treatment or interventional treatment should be performed at a later stage as appropriate. Controlled spring embolization method (a)
PDA with left-to-right shunt without combined cardiac malformation requiring surgery; narrowest diameter of PDA (single Cook embolus ≥ 2.0mm; single pfm embolus ≥ 3mm). Age: usually ≥ 6 months and weight ≥ 4 kg. (ii) Post-surgical residual shunt.