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Best Practice Corner

Complex Lead Extraction

Saad Rasheed MD1, Jennie Ngai MD1

  1. Department of Anesthesiology, Perioperative Care, and Pain Medicine, NYU Langone Medical Center
Background

Lead extraction is defined by the Heart Rhythm Society as the removal of a pacemaker or implantable cardioverter defibrillator (ICD) lead that has been in place for more than 1 year, requires specialized equipment to remove, or is removed from a route other than via the implant vein. This differs from a lead explant, which is defined as a lead removal that only requires the use of simple traction techniques.1 The increasing number of implanted pacemakers and ICDs has led to an increasing need for lead extractions. Despite this increase in performed cases, definitive anesthetic guidelines for the procedure have yet to be published.

The most common indication for lead extraction is infection. Other potential reasons for extraction include occlusion of the venous system, a lead that poses a threat to the patient, abandoned leads, chronic pain, need for radiation therapy, or need for placement of an MRI compatible device. Lead extraction initially was performed via open heart surgery or prolonged traction using a weight and pulley. Modern transvenous extraction techniques have since been developed. The simplest of these techniques involves traction and rotational force to eventually free the lead. Such techniques are rarely successful in older leads that have developed fibrosis. In these cases, a locking stylet is placed into the lead and then a sheath is placed over the lead and used to free the lead from adhesions as it is advanced to the lead tip. The sheath then provides counter-traction by bracing the myocardium when the lead is removed from the heart tissue. Specialized sheaths also can dissect as they are passed over the lead via radiofrequency ablation, mechanical rotation, or laser. Occasionally, a femoral approach is utilized to snare and retrieve leads, either as a primary approach or when a lead has broken into one or more fragments.2 Certain characteristics of the patient, lead, and extraction technique have been found to be associated with an increased complication risk. An increased implant duration of the oldest lead, female gender, removal of an ICD lead, and the use of laser extraction technique are all associated with an increased difficulty of extraction and/or risk of complication. Leads that have been place for more than 1 year typically develop adhesions. ICD leads are larger in diameter, and defibrillator coils typically stimulate a larger degree of fibrosis, especially in the area of the superior vena cava. In each case, extraction becomes more difficult and the risk of perforation and bleeding is increased.1

Complications

The most feared and potentially catastrophic complication of lead extraction is a myocardial or vascular tear. A tear of the atrial or ventricular myocardium can result in cardiac tamponade, which often can be relieved by a pericardiocentesis. If pericardiocentesis does not relieve the tamponade, or the bleeding does not stop rapidly, a cardiothoracic surgeon must perform a sternotomy to repair the injury. This possible necessity is why a cardiothoracic surgeon must be immediately available, if not the primary operator of the lead extraction, and also one reason why performing a transesophageal echocardiogram during the procedure is so useful.

A potentially more lethal vascular complication is a tear of the superior vena cava (SVC). Such tears are much more likely during the extraction of dual-coil ICD leads, as the proximal coil in these devices is positioned against the SVC. A tear of the SVC can lead to rapid and massive blood loss, and repair of this structure can prove to be difficult to impossible, even with the necessary personnel in the operating room. Recently, there has been development of a “rescue” balloon to assist in management of SVC tears. This balloon is long and compliant, and placed over a guidewire that has been previously placed into the internal jugular vein via a femoral venous access. In the case of a tear, the balloon is advanced to the SVC and inflated, thereby tamponading the flow of blood and allowing more time for the cardiac surgeon to perform the sternotomy and repair the vessel.

Tricuspid valve damage is another relatively common complication of lead extraction. During placement, the lead can either perforate the valve or become adherent to it with resultant fibrosis. Extraction of such a placed lead can tear the valve. Use of an extraction sheath also can cause a defect in one of the valve leaflets. Fortunately, the damage is rarely significant enough to require surgical intervention.

Another possible complication is the embolus of air, clot, or vegetation. Air emboli can occur if a lead is removed while a sheath is still in the vessel, allowing air to enter the central venous circulation. Depending on the amount of embolus, there may be a significant drop in cardiac output requiring supportive measures and catheter placement to aspirate the entrained air. Trauma to the venous system, most likely from the sheath, also can cause blood clots in the pulmonary vasculature. Vegetations or thrombi on the lead also may lead to pulmonary embolic events. Although no absolute limits have been determined, it is commonly accepted that the presence of vegetations and clots that are as large, or larger, than the pulmonary artery may necessitate an alternative method of lead extraction, such as open heart surgery.3

Intraoperative Management

At our institution, lead extractions are performed in a hybrid operating room, allowing for fluoroscopic examination by the operator during extraction. General endotracheal anesthesia is employed to facilitate continuous transesophageal echocardiography (TEE) and in case emergent chest exploration or cardiopulmonary bypass initiation is required. Large bore intravenous access is obtained in case massive resuscitation is required, and an arterial line is placed for continuous hemodynamic monitoring. In addition, the cardiologist provides the anesthesia team with an additional access via an extension from his femoral cannulation, which is essential in the event of an SVC tear and hemorrhage into the pleural space. The entire chest is sterilely prepared, and a cardiothoracic surgeon is immediately available in the event that an emergency sternotomy is required. A cardiac anesthesiologist performs a transesophageal echocardiogram.

The arterial line and TEE allow for quick identification and investigation of blood pressure decreases. Common, less concerning, and quickly reversible causes of hypotension include the effects of anesthetic agents, decreased left ventricular filling due to inversion of the right ventricle, and increased vagal output due to sheath manipulation and traction on the myocardium. The more concerning cause of hypotension is blood loss from cardiac or vascular tearing. Rapid identification of this cause of hypotension, as well as the determination of its severity by TEE, allows for quick decision making regarding the need for pericardiocentesis and/or surgical intervention. Such quick decision making can be the difference between life and death, as it has been reported that delays in open access to the heart of more than 5 to 10 minutes increases the likelihood of a fatal outcome in the event of a major cardiac or vascular injury.1 The ability to rule out such serious complications also is invaluable, preventing unnecessary surgical exploration and premature case termination. Communication between the anesthesiologist and person performing the extraction regarding changes in blood pressure is critical, so that the cause may be determined and appropriate interventions taken.4,5

Conclusion

Lead extraction is an increasingly common procedure that often is performed without complication. But the possibility, however low, of major morbidity and mortality necessitates proper preparation. We believe our current practice helps to properly assess and deal with these potential complications.

References
  1. Endo Y, O'mara JE, Weiner S, et al. Clinical utility of intraprocedural transesophageal echocardiography during transvenous lead extraction. AM Soc Echo. 2008;21(7):861-867. doi:10.1016/j.echo.2008.01.006.
  2. Love CJ. Update on indications, techniques, and complications of cardiac implantable device lead extraction. Curr Treat Options Cardio Med. 2012;14(5):565-570. doi:10.1007/s11936-012-0200-y.
  3. Love CJ, Kennergren C. Complications and errors made in lead extraction. Cardiac Electrophys Clin. 2014;6(2):355-360. doi:10.1016/j.ccep.2014.03.003.
  4. Oestreich BA, Ahlgren B, Seres T, et al. Use of transesophageal echocardiography to improve the safety of transvenous lead extraction. JACC: Clinical Electrophysiology. 2015;1(5):442-448. doi:10.1016/j.jacep.2015.07.007.
  5. Wilkoff BL, Love CJ, Byrd CL, et al. Transvenous lead extraction: Heart rhythm society expert consensus on facilities, training, indications, and patient management. Heart Rhythm. 2009;6(7):1085-1104. doi:10.1016/j.hrthm.2009.05.020.