Pocket Management to Prevent Infection

Introduction

Implantable cardioverter-defibrillators (ICDs) continue to be implanted in an expanding patient base. Moreover, a number of devices are now being replaced at increasing rates as early generation devices reach their elective replacement intervals. Unfortunately, this has resulted in a marked increase in device-related infections. In fact, the rate of device-related infections has grown at twice the rate of device implantations.¹ Careful attention to patient and procedural characteristics is warranted to minimize this risk at time of device replacement.

Case Description

The patient is a 53-year-old man with history of a bicuspid aortic valve that was replaced in 1999. He was implanted with a traditional left-sided prepectoral ICD due to recurrent ventricular fibrillation at that time. In 2003 he developed endocarditis, which necessitated redo aortic valve replacement and complete ICD extraction, and a dual-chamber ICD was implanted in the right prepectoral region. He subsequently experienced multiple right ventricular defibrillator lead failures, resulting in a new lead being placed in 2006 and another in July 2015. The malfunctioning leads were capped and abandoned by the operator. In September 2015, the patient presented with device erosion (Figures 1 and 2). As a result, the patient was referred for device and lead extraction. At the time of extraction, it became clear that no capsulectomy was ever performed during the patient’s prior procedures. A thick posterior capsule was completely excised, revealing healthy tissue below. The 3 right ventricular leads and right atrial lead were all successfully extracted. However, the patient’s skin was too necrotic to allow for primary closure, so it was packed. He was referred to plastic surgery for evaluation for a possible skin flap at a later date.

Discussion

Approximately 400,000 patients receive ICDs every year in the U.S., and more than 3 million patients in the U.S. currently have ICDs.² Unfortunately, device leads have a failure rate from 0.3% per year upwards to 2% per year in recalled and/or advisory leads. The REPLACE trial³ has shown us that major complication rates may approach 14% when a lead revision occurs at the time of device replacement, including an infection rate of 1.1% to 1.4%. The risk of complication increases with the number of leads in the patient, a defibrillator versus pacemaker replacement, and whether there are underlying medical and cardiovascular co-morbidities. 

This case exemplifies several issues with device and lead management. Risk factors for device erosion include increased pressure on the overlying skin due to minimal subcutaneous fat, repeat invasion of the device pocket, increased hardware in the pocket, or patient manipulation of the device. In this patient, multiple abandoned defibrillator leads resulted in increased bulk in the device pocket. This, coupled with excessive capsule growth, likely resulted in increased pressure on the overlying skin, which was already stretched taut over the device. Over time, the device eroded through the skin. Interventions that could have prevented this device erosion include extraction of the abandoned leads, resulting in debulking of the pocket, and a capsulectomy at the time of device change and/or revision. Furthermore, submuscular placement should have been considered in a situation where there was very thin, overlying skin.

Pocket management is especially important in preventing device erosion. An eroded device is considered infected given its exposure to the external environment. A portion of these will result in endovascular infection and endocarditis. Importantly, the risk of morbidity and mortality with device infections resulting in endocarditis can be as high as 60%.⁴ 

Conclusion

Careful management of the device pocket and abandoned leads can prevent device erosion and potential intravascular infection. Partial posterior or complete capsulectomy should be considered in order to debulk the pocket as well as allow healthy tissue to contact device and leads to minimize infection. Extraction of abandoned leads should be considered to debulk the device pocket as well as decrease risk of intravascular infection or stenosis.

Disclosure: The author has no conflicts of interest to report regarding the content herein.

References

1. Voigt A, Shalaby A, Saba S. Rising rates of cardiac rhythm management device infections in the United States: 1996 through 2003. J Am Coll Cardiol. 2006;48(3):590-591.
2. Buch E, Boyle NG, Belott PH. Pacemaker and defibrillator lead extraction. Circulation. 2011;123:e378-380.
3. Poole JE, Gleva MJ, Mela T, et al. Complication rates associated with pacemaker or implantable cardioverter-defibrillator generator replacements and upgrade procedures: results from the REPLACE registry. Circulation. 2010;122:1553-1561.
4. Sohail MR, Uslan DZ, Khan AH, et al. Management and outcome of permanent pacemaker and implantable cardioverter-defibrillator infections. J Am Coll Cardiol. 2007;49(18):1851-1859.