Iatrogenic phrenic nerve palsy

Abstract

Iatrogenic phrenic nerve injury is an issue that all thoracic surgeons will be called to tackle during their career. Injury of the phrenic nerve leads to paralysis of the hemidiaphragm, which can result in a spectrum of symptom severity from asymptomatic to disabling shortness of breath. It can result from any operation requiring dissection close to its anatomical pathway from the neck to the diaphragm, but is also at risk with interventional procedures within its vicinity, such as cardiac ablation techniques. Injury can range from complete, irreversible transection of the nerve to neuropraxia with temporary nerve dysfunction. Due to this the timing of intervention is individual to each patient. Symptoms may range from mild to severe and from typical to aspecific. Confirmation of diagnosis is accomplished with a combination of static (CXR, CT) and dynamic imaging (ultrasound, fluoroscopy). The presence of other co-morbidities such as obesity, heart conditions or obstructive airways disease potentially contributing to the same symptoms, makes relative contribution of each difficult to ascertain and may increase surgical risks. A careful risk/benefit assessment, as well as the optimisation of these underlying conditions prior to treatment is paramount. Treatment options include minimally invasive diaphragmatic plication as well as nerve repair techniques. We hereby give an overview of the relevant anatomy and aetiology of iatrogenic phrenic nerve injury, as well as of the diagnostic work-up and different therapeutic options, with a focus on diaphragmatic plication, nerve repair and treatment timing.

Right hemidiaphragmatic paralysis after cervical transforaminal epidural steroid injection: illustrative case

“…Phrenic nerve neurotmesis is a complication that can arise after thoracic surgery or as a result of trauma. 14 , 15 Axonotmesis is less severe but involves damage of the myelin sheath, which degrades the continuity of nerve conduction. Although various causes exist for axonotmesis, similar to neurotmesis, the deficit is often irreversible.…”