All patients with symptomatic cardiac AL amyloidosis had poo
All 4 patients with symptomatic cardiac AL amyloidosis had poor prognoses. The median survival period for these 4 patients was 12.3 months (minimum=4 months, maximum=28 months) (Table 1). The patient in Case 2, whose BNP level was the highest of the 4 patients, had the shortest survival period. However, careful consideration is required to determine whether there is a correlation between the BNP level at the time of diagnosis of cardiac amyloidosis and the survival period. Considering the standard guidelines for ICD implantation in preventing arrhythmia-associated CSD, patients with poor prognoses should perhaps be excluded from for ICD implantation .
Conflict of interest
Introduction Devices for cardiac arrhythmia, such as pacemakers, implantable cardioverter defibrillators (ICD), and cardiac resynchronization therapy (CRT), involve inserting leads into the cardiac chambers via veins. In patients in whom these devices have been implanted, the leads often adhere to the vascular wall, and their extraction (e.g., to treat infection) can be very difficult. If the lead is pulled excessively, fatal complications (e.g., vascular injury and perforation) may develop, eventually requiring open surgery and extraction of the lead by cardiopulumonary bypass . Worldwide, many cases have extracted leads using an excimer laser sheath and have met with favorable results. However, the incidence of serious complications, such as cardiac tamponade and hemothroax, has not been low, indicating the necessity of care in using this technique [2,3]. The risk of vascular injury with this technique is particularly high when the pacemaker lead to be extracted adheres strongly to the superior vena cava (SVC), because there is a steep curve between the subclavian vein and the SVC. Immediate detection of SVC injury at its onset is difficult using intraoperative transesophageal echocardiography (TEE) alone. If a thoracoscope is used during this technique, it can detect complications soon after development, allowing for immediate action.
Case report The patient was a 29-year-old male who had been diagnosed with transposition of the great Phos-tag with an intact ventricular septum. At the age of 6 months, he underwent a Senning operation. At the age of 1 year, he developed atrioventricular block. At the age of 7 years, the patient was diagnosed with sinus node dysfunction and underwent pacemaker implantation via the left subclavian vein. The implanted pacemaker was later removed due to infection. At the age of 10 years, a dual-chamber (DDD) pacemaker was implanted via the right subclavian vein. At the age of 25 years, the generator was extracted because of a lead fracture, and a new pacemaker was implanted via the left side. The two leads, which had been inserted via the right side, could not be extracted (Fig. 1). Thus, the stump of the fractured lead was capped and kept buried in the subcutaneous pocket. Later, the patient developed pain of the right precordium, cramping of the major pectoral muscle, and non-sustained ventricular tachycardia, suggesting physical stimulation of the left ventricle (functional right ventricle) by the residual lead. Preoperative computed tomography (CT) scans revealed intense adhesion of the lead to the SVC (Fig. 2). Therefore, we planned to perform surgery for lead extraction using a laser sheath while monitoring the thoracic cavity with a thoracoscope in order to directly observe the SVC during application of the sheath and to detect any injury to the SVC. In addition, we planned to use intraoperative TEE for detecting cardiac tamponade. Under general anesthesia, a thoracoscope port of 10mm in length was placed in the third intercostal space with the patient lying on his left side. We attempted to extract the leads while monitoring the area in the vicinity of the SVC. In order to immediately respond to any emergencies, such as vascular injury, a 4-Fr sheath had been inserted in advance via both the right femoral artery and vein for prompt establishment of extracorporeal circulation. An excimer laser generator (CVX-300®, Spectranetics Inc., Colorado Springs, CO, USA) and a laser sheath (SLSII, Spectranetics Inc., Colorado Springs, CO, USA) were used for the operation. A locking device (LLD) was inserted into the lead as a stylet. We were able to observe the excimer laser sheath as it was advanced inside the SVC through the thoracoscope. The atrial lead was easily extracted. The ventricular lead could mostly be extracted, but its tip of 2cm in length remained in the junction between the right subclavian vein and the SVC. No injury of the SVC was observed thoracoscopically (Fig. 3). Intraoperative TEE revealed no pericardial fluid pooling. After the operation, we attempted to extract the remaining tip of the lead in the subcalvian vein using a basket catheter inserted via the right femoral vein, but this approach failed. The residual lead seemed to be locked or adhered to the vein and was unlikely to be dislocated. Thus, the patient was followed with the residual lead left in place. The postoperative course was uneventful, and the subjective symptoms seen preoperatively subsided. The patient was discharged from the hospital on the fifth postoperative day.