Figure 3
Build-up around an ICD lead visualized on TEE and fluoroscopy and its consequences during TLE
  1. TEE (2D, ME- bicaval) Segmental thickening of the ICD lead with three binding sites in the RA wall (arrows), additionally a blue arrow points to the binding site and conductor externalization
  2. TEE (2D and 3D, ME - bicaval ) The thickened ICD lead attached to the IAS (arrows)
  3. TEE (2D, ME RV - Inflow) The ICD lead, hyperechoic, thickened, over the TV bound to the lateral atrial wall at the site of externalization (blue arrow)
  4. D1- Evaluation of ICD lead position and venous patency before TLE. D1 – Imaging during TLE – well visible site of externalization (blue arrow), the tip of Byrd’s dilator marked with a black arrow. D3 – significant pulling on the ICD lead during TLE
  5. TEE (2D, bicaval) The moment of pulling on the thickened ICD lead (red arrow) seen on fluoroscopy. D3 – significant pulling on the RA wall and the separation of pericardial layers
  6. The extracted lead with multiple fragments of the connective tissue, the site of externalization and a dilator (black arrow)
The connective tissue on the leads (scar tissue build-up around the lead, fibrous tissue binding sites, accretions) is visible on TEE as lead thickening resulting in the formation of sites at which the leads are bound to one another after being in direct contact over an extended period of time. The imaging of this phenomenon has important implications for the course of the TLE procedure. During the extraction procedure the direct pulling on the wall at the binding site may be too strong and cause inadvertent pulling on and uncontrolled removal of the other lead, risking a tear of the heart wall with cardiac tamponade or hemopericardium as the end result.
The originality of this study is that it explores the impact of TEE assessment before TLE on the course of the procedure. Multivariate analysis showed that lead-to-lead binding sites were the strongest predictive factor which caused a 3-fold increase in the probability of major complications during TLE. The presence of fibrous tissue binding the lead to the atrial wall and tricuspid valve approached the borderline of significance. The presence of binding sites in the RV wall caused a nearly 2-fold increase in the risk of technical difficulties, thus increasing the degree of procedure complexity. The probability of technical difficulty increased also in the presence of excess lead loops, fibrous tissue binding the lead to the RA wall and lead-to-lead binding sites. The presence of binding sites in the tricuspid apparatus and lead-to-lead adhesion on the borderline of statistical significance reduced the chances of complete clinical success. The chances of procedural success were also reduced in relation with the presence of binding sites in the SVC, RA and lead-to-lead adhesions, whereas lead-dependent tricuspid dysfunction approached the borderline of significance.
There are numerous studies [4-7] which on the basis of demographic data (age, sex), clinical information (indications, accompanying diseases, heart sufficiency), information about PM/ICD/CRT devices (number and type of leads) and history of pacemaker therapy (age of leads and route of implantation) show that initial patient assessment may identify the individuals in whom TLE may be more difficult or associated with the occurrence of major complications. Only few studies using scoring systems provide a more precise prediction of the level of procedure difficulty or estimate the true risk [6,7]. A review of the literature shows that so far echocardiographic findings have not been analyzed with respect to prediction of technical difficulties associated with TLE and complications of the procedure. Only one paper demonstrated that low LVEF was a predictor of major complications [6], another paper documented an eventful postoperative course in patients with right ventricular dysfunction [4]. The evidence from another study suggests that information from CT examination may be useful for estimating procedure difficulty [8]. Yet another study implies that accurate Doppler blood flow measurements in the SVC may identify patients with significant lead fibrosis requiring powered sheaths for successful removal. Although numerous papers have emphasized the role of the connective tissue (scar tissue binding the lead to the SVC and heart wall) in estimating procedure complexity and its complications [3,6,7], to the best of our knowledge we are the first to use the information about the degree of connective tissue build-up to predict technical difficulties and risk of major complications associated with TLE.
When developing a risk calculator for prediction of complications (SAFeTy TLE) [7] we found out that lead-to-lead binding site was an extremely important prognostic factor, however other information (S = sum of lead dwell times, A = anemia, Fe = female, T == treatment (previous procedures), Y = young patients) appeared more significant in multivariate analysis. We are of the opinion that all forms of connective tissue response (scar tissue binding the lead to the vein and heart structures, lead-to-lead adhesion) are extremely significant factors that increase procedure complexity and its radiological efficacy, however they do not necessarily translate into major complications at an experienced high volume center. Nevertheless TEE before TLE should become a tool that provides additional information about procedure-related risk.