Discussion
The present case demonstrates that surgical epicardial LV lead implantation could troubleshoot patients with limited and barely acceptable LV pacing region transvenously which can progress myocardial damage. Furthermore, to the best of our knowledge, this is the first case report of an epicardial LV lead that was surgically implanted to troubleshoot LV lead fracture.
The use of cardiac implantable electronic devices (CIED) as nonpharmacological treatments has increased dramatically in the past decade 7. Of the many possible complications following CIED implantation, lead fracture is one of the serious mechanical issues. Some studies have shown that the incidence of CIED lead fracture is 1–4% 8, 9. There are various causes of lead fractures, such as subclavian crush syndrome caused by continuous compression of the lead between the clavicle and first rib; failure of the lead itself; and flexibility of the lead—where bending within a short radius of curvature exerts high stress on the metal components of the lead 10, 11. In the present case, the subclavian crush syndrome was possibly associated with the LV and atrial lead fractures because both leads had been implanted via a left subclavian veinous puncture and the fracture was detected in the subclavian region. A recent study showed that CIED implantation via subclavian veinous punctures is associated with a higher risk of lead failure compared with cephalic vein cutdowns or axillary veinous punctures12. Therefore, a cephalic vein cutdown or axillary veinous puncture can be considered to reduce the risk of LV lead failure in CRT patients and avoid further CRT breakdown and worsening of HF.
LV lead fracture can be addressed via the new LV lead reimplantation after the fractured LV lead extraction, or surgical epicardial LV lead implantation. Although there are few data pertaining to LV lead extraction for LV lead fracture, researchers have shown that subsequent reimplantation after the LV lead extraction is feasible ‘under local anaesthesia or sedation’ even with tools that are used in angioplasty in cases of CS adherences or veinous occlusions as necessary 13. Due to its invasiveness, the new LV lead reimplantation after the fractured LV lead extraction can be the primary option to address the LV lead fracture of CRT as compared to surgical epicardial LV lead implantation. However, poor pacing threshold due to LV remodeling, anatomical abnormalities, persistent diaphragmatic twitching due to unwanted phrenic nerve stimulation, CS adherence after the lead extraction may cause an implantation failure when adopting the transvenous approach13, 14. Therefore, all necessary precautions should be observed through continuous monitoring for these complications.
Surgical implantation of an epicardial LV lead is an alternative option to transvenous LV lead reimplantation. This can be performed with concomitant open-heart surgery or by performing less invasive left-lateral mini-thoracotomy. An advantage of surgical implantation is direct access to the lateral LV wall 15, 16. Direct visualisation of the region of interest greatly helps in achieving optimal lead positioning regardless of the anatomy of the coronary vein. Previous studies have shown that epicardial LV lead implantation results in lower LV lead-related complication rates and positive long-term clinical performance and durability, compared with transvenous LV lead implantations 15, 16. Therefore, surgical epicardial LV lead implantation, although more invasive than transvenous procedure, can be feasible, at least in selected patients like the patient in the present case 17.
The advantages of surgical epicardial LV lead implantation for correcting LV lead fracture, as compared to transvenous LV lead reimplantation after LV lead extraction, necessitates further investigation. However, surgical epicardial LV lead implantation may be favourable, particularly for those with difficulty of transvenous LV lead replacement due to LV remodeling and anatomical limitation and for those who are not expected to inhibit LV remodeling and hospitalisation due to HF. As shown in this case report, poor pacing threshold due to LV remodeling and diaphragmatic twitching of the entire LV lateral wall inhibited a successful transvenous implantation of the LV lead into the suitable region. In such case, surgical epicardial LV lead implantation can troubleshoot LV lead fracture of CRT.