Presentation
History of open heart operation (CABG) since 3 months, currently presents with dyspnea
Patient Data
Elevation of the left diaphragmatic copula reaching DV6/7 level. It is associated with relaxation atelectasis of the left lower lobe with preserved vascular and bronchiolar tree distribution. No pathological underlying pulmonary process could be noted. No evidence of diaphragmatic defects or hernia. Normal position of the right diaphragmatic copula.
Sternotomy sutures are noted.
Case Discussion
Elevation of the left diaphragmatic copula, mostly related to diaphragmatic etiology rather than pulmonary etiology. The possibility of diaphragmatic paralysis is considered. Elevation of hemidiaphragm is a radiological finding seen in conditions such as diaphragmatic eventration, lobar lung collapse, subphrenic mass or abscess and phrenic nerve paralysis.
In this case, the patient developed dyspnea after open heart surgery. So, iatrogenic etiology related to surgery is strongly suggested. Injury to the phrenic nerve during cardiac surgery is one of the recognized complications. It is more common on the left side. Possibilities of phrenic nerve injury during cardiac surgery include 1:
- the ice cold slush used for myocardial protection (most common) 2
- dissecting or using diathermy near its course
- dissecting near the area of internal thoracic artery pedicle
- at re-operations, where there is adhesion between the lung and the pericardium
- during placement of central vein catheter
- during pericardiectomy for constrictive pericarditis
- injury to pericardiophrenic artery
Patients with diaphragmatic palsy may improve if operative etiology is known. Otherwise, surgical plication of the hemidiaphragm is warranted in symptomatic non-improving cases.