Infected epicardial pacemaker systems

Surgical and Hybrid Lead Extraction

Surgical and hybrid lead extraction has developed considerably over the past several decades. Although transvenous lead extraction is the standard approach to remove infected or malfunctioning cardiac implantable electronic device leads, surgical approaches may be necessary in complex cases not amenable to transvenous lead extraction or in cases that involve concomitant pathologies, such as tricuspid valve regurgitation. We describe our experience with 4 minimally invasive surgical approaches to lead extraction as well as our experience with hybrid open heart surgery and transvenous lead extraction as an option for patients who present with concomitant conditions.

Complete removal as a routine treatment for any cardiovascular implantable electronic device-associated infection

OBJECTIVE

Pacemaker and implantable cardioverter defibrillator lead endocarditis mandates removal of all foreign material. In supposedly limited (pocket) infections, such a radical approach is still controversial. Thus, some patients are potentially exposed to persistent and recurrent infection because of retained material. Procedural risks and the success of eradicating infection were examined if involvement of the complete system was assumed in any cardiovascular implantable electronic device infection and complete removal was thus mandatory.

METHODS

A 12-year experience with 192 consecutive cases of bacterial pacemaker (152) or defibrillator (40) infections is presented. Complete removal of all prosthetic material was always aimed for. This was followed by antibiotic treatment for 4 to 6 weeks under temporary pacing if required, and then the new system was implanted. A total of 104 parameters concerning patient characteristics and operative and postoperative treatment were examined for their influence on outcome.

RESULTS

Infection was eradicated in 92.8% of patients. Recurrence was predominantly caused by failure to remove all prosthetic material (P < .001). If the protocol was strictly followed, infection was eradicated in 97.4% of patients. Conversely, 71.4% of patients with retained material showed recurrence. Further risk factors were poor dental hygiene and evidence of chronic subclinical infection. Morbidity and mortality of the interventional and open procedures were low. Open lead extraction was performed primarily in 34 patients (17.7%) and secondarily in 3 patients (1.9%). Temporary pacing and long-term antibiotic treatment were well tolerated.

CONCLUSIONS

Complete removal of prosthetic material in any cardiovascular implantable electronic device infection is safe and associated with low morbidity and mortality. Success of eradicating infection is high if all system components are removed. Temporary pacing in dependent patients may be performed safely on an outpatient basis.

Extracción de electrodos de marcapasos y desfibrilador mediante técnicas percutáneas

INTRODUCTION AND OBJECTIVES

There is an increasing need for endocardial pacing and defibrillators leads to be removed. However, the procedure can be complex and it is not risk-free. We reviewed our experience between April 1989 and June 2006 with the percutaneous extraction of leads.

METHODS

In total, 314 electrodes were extracted from 187 patients. The leads had been implanted over an average period of 69.16 months (range 0.11-234.6 months, median 60.25 months). Some 115 were atrial leads, 196 were ventricular, and three were in the coronary veins; of these, 78 had been abandoned in the vascular bed.

RESULTS

Indications for removal were infection (26.1%), dysfunction (22.9%), erosion (25%), endocarditis (20.7%), and bacteremia (2.7%). Overall, 58.8% of patients were referred from other departments. In 96.8%, the electrodes were completely removed. Simple traction was used in 23.4%, and countertraction techniques (with and without radiofrequency current support) were used in 60.7%. For abandoned leads, a biopsy clamp was used in combination with countertraction (4.3%) or a femoral approach with a snare (10.1%). A sternotomy was required in three of the 10 patients with remaining electrode fragments. The complication rate was 4.6% (with major complications in 2.5%). Complications were associated with age < 60 years (odds ratio [OR]=5.38, 95% confidence interval [CI] 1.07-27.23), the presence of endocarditis (OR=4.97: 95%CI, 1.04-23.70), and right side implantation (OR=17.09; 95% CI, 2.15-135.70).

CONCLUSIONS

In the majority of cases, pacing and defibrillator leads can be removed without difficulty using modern extraction techniques. However, because there is a risk of complications during extraction, even though it is low, the procedure should be carried out in specialized centers with surgical facilities.

Detailed bacteriologic tests to identify the origin of transvenous pacing system infections indicate a high prevalence of multiple organisms

BACKGROUND

The reported incidence of pacing system-related infections (PSIs) varies widely, and the roles of leads and blood cultures remain poorly defined.

METHODS

Leads and blood cultures were obtained prospectively in 224 patients with suspected PSIs, and the results of cultures of blood and extravascular and intravascular lead fragments were compared.

RESULTS

In 12.3% of the patients, no microorganism was found on the leads. Lead cultures with > or =1 microorganism cultured on the extravascular and intravascular fragments of the leads were found in 88.5% of the positive lead cultures. Infection was caused by Staphylococcus epidermidis and coagulase-negative staphylococci in 66.0% and 29.5%, respectively. Only 33 patients had positive blood cultures according to the Duke criteria with the same microorganism found by lead cultures in 30 cases. Infection was caused by multiple organisms in 39 (25%) patients.

CONCLUSION

(1) Regardless of the clinical presentation, the extravascular and intravascular body of the lead is infected, even when the infection is local. More than one microorganism may be implicated. (2) Bacteriologic analyses must be performed on several segments of each implanted lead. (3) More than 2 positive blood cultures are a reliable clinical criterion for the diagnosis of pacemaker lead-related infection, but blood cultures alone are an insensitive method to identify the cause of infection. (4) Up to 50% of microorganisms isolated in a single blood culture are also recovered in lead cultures.

Laser-assist during extraction of chronically implanted pacemaker and defibrillator leads

BACKGROUND

Extraction of chronically implanted pacing and defibrillator leads has historically been difficult, occasionally requiring open surgical procedures. The purpose of this study was to evaluate the efficacy, safety, and potential need for percutaneous laser-assisted sheath techniques for extraction of chronically implanted leads.

METHODS

From January 1999 to August 2001, 128 consecutive patients underwent extraction of 229 leads (138 pacing, 91 defibrillator) in the operating room 61 +/- 44 (mean +/- standard deviation) months after implantation. Common indications included erosion or pocket infection (41%), lead dysfunction (30%), and sepsis (13%).

RESULTS

Laser techniques were used for 56% +/- 4% (104 of 186) of long-term (implanted for more than 1 year) leads, compared with only 16% +/- 6% (7 of 43) of short-term (implanted for less than 1 year) leads (p < 0.001). For infected leads, laser was used in 53% +/- 5% (49 of 92) with erosion or pocket infections, compared with only 3% +/- 4% (1 of 29) with sepsis (p < 0.001). Extraction was complete in 88%, near complete (retained tip) in 10%, and incomplete in 2%. Two patients required a later percutaneous femoral venous approach to remove mobile retained segments, but no patients required cardiac surgery for extraction. Complications included sternotomy for subclavian vein injury (1), chest tube for caval perforation (1), innominate vein thrombosis (1), and partial clavicle removal for subclavian vein repair (2). There were no procedure-related deaths.

CONCLUSIONS

Laser-assisted lead extraction is safe, but it is best performed in the operating room; it should be available for long-term leads, except when they are grossly infected, producing sepsis. Laser techniques have essentially eliminated the need for open surgical removal of retained leads.

Infection of a retained permanent epicardial pacemaker lead

Infection of a retained permanent epicardial pacemaker lead rarely causes mediastinal infection. A 21-month-old boy who had undergone an arterial switch operation at day 6 of life presented with mediastinal infection 3 months after removal of the generator. Removal of the infected pacemaker leads with the inflammatory granuloma was performed under extracorporeal circulation. The mediastinal infection developed from the retained epicardial pacemaker lead infection.

Removal of infected pacemaker leads with deep hypothermic circulatory arrest and open surgical exploration of the superior vena cava and innominate veins

Despite the use of transvenous methods for extraction of infected leads, failed attempts may result in retained lead fragments. Retained lead fragments may be a focus of continued infection leading to sepsis. We present two patients in which conversion from cardiopulmonary bypass to hypothermic circulatory arrest allowed direct visualization, using venotomies in the superior vena cava and innominate vein to achieve complete removal of retained pacemaker lead fragments. Use of venotomies in the extracardiac venous system is a technical addition to prior descriptions of lead extraction using deep hypothermia and circulatory arrest.

Extraction of pacemaker and implantable cardioverter defibrillator leads

The common reasons for removal of pacing and defibrillator leads are infection, malfunction, or design defects such as fracture of J wires in Teletronics Accufix leads (Telectronics Pacing, Englewood, CO), which impose considerable risk for cardiac morbidity and mortality. Chronically implanted leads are fixed to the myocardium by fibrous tissue. Fibrous scar tissue may also encase the lead along its course. Furthermore, fragility of the lead and its tendency to break when extraction force is applied to overcome resistance imparted by the scar tissue add to the challenge of lead extraction. Thus, the extraction of chronically implanted leads is an important issue. Until a few years ago, the only methods available for the removal of chronically implanted leads were traction on the proximal segment of the lead and cardiac surgery. New techniques were developed to extract the leads by a transvenous approach using locking stylets, sheaths, snares, and retrieval baskets. Lead extraction using intravascular countertraction methods has since evolved as a specialty of its own. Progress has also been made in developing other system, such as Excimer laser energy for lead extraction. In this article, we discuss principles, techniques, and experience with these methods of extraction of chronic pacemaker and defibrillator leads.

Postcardiac surgery infections

Infections following cardiac surgery, although generally uncommon, are associated with difficult management decisions and significant morbidity and mortality. They often present while the patient is either in a critical care unit, or requires CCU management. This review analyzes infections related to median sternotomy wounds, prosthetic heart valves, transvenous permanent pacemakers, automatic implantable cardioverter-defibrillators, and left ventricular assist devices. The diagnosis, microbiology, treatment and outcome of each is also discussed.

Management of infected implantable cardiac defibrillators

BACKGROUND

The implantable cardiac defibrillator (ICD) was introduced clinically in 1980 for the management of ventricular arrhythmias.

METHODS

From January 31, 1989, through May 29, 1996, 329 ICD devices were implanted at Allegheny University Hospital, Hahnemann Division, Philadelphia, Pennsylvania. All device-related infections were examined.

RESULTS

Fifteen patients (5%) experienced infection of the generator component of the ICD. There were 14 male and 1 female patients with a mean age of 62 years (range, 38 to 79 years). All infections involved the generator with or without other component involvement. Complete removal of the system was performed in 7 patients, partial removal in 5, and the entire system was left intact in 3. In 4 patients (27%), further procedures were performed to remove additional infection. Three patients (20%) died during the hospital stay.

CONCLUSIONS

Infection of ICD devices is a devastating event. We favor complete removal of the ICD generator and all the components when possible. Partial removal of the ICD unit (ie, generator only) is reserved for patients in whom the risk of complete removal is too high and infection is confined to the generator only.

A new approach to the management of infected pacemakers

Management of infected pacemakers always presents a problem. This report describes a method of managing infected pacemakers, using the infected unit as a temporary pacer. This method has worked well in four patients.

Intravascular extraction of chronic pacemaker leads: efficacy and follow-up

Extraction of chronic pacemaker leads has been recommended for infections, prevention of venous thrombosis, migration, and possible perforation. Success with constant traction techniques has been variable, and the cost and morbidity of open chest surgical procedures are prohibitive. Efficacy of a new system for lead extraction using intravascular techniques was analyzed. The system (Cook Pacemaker) uses a locking stylet, which is secured at the distal electrode by counterclockwise rotation to reinforce the lead and facilitate traction, and dilator sheaths that are used to free the lead from adhesions in the venous system. In a series of 56 patients (ages 19-88) who presented for lead extraction because of erosion (5), infection (14), lead replacement (35), or other (2), 86 leads were extracted. Thirty-two were atrial leads and 54 ventricular; 23 had active fixation and 63 passive. Average duration of implant was 58 +/- 42 months (range 1-264). Eighty-four leads were totally removed and two partially removed. For these two leads, the distal tip was not removed; in both cases the locking stylet was not secured at the distal electrode due to obstruction within the lead. Two patients developed arm edema following the procedure, which resolved with elevation. One patient developed a subclavian thrombosis, which resolved with warfarin anticoagulation. Four patients have expired due to unrelated causes. In conclusion, this intravascular approach for extraction of chronic leads is effective, and the procedure is safe when performed by experienced personnel.

Surgical removal of infected transvenous pacemaker leads

Infection, though uncommon, can be the most lethal of all potential complications following transvenous pacemaker implantation. Eradication of infection associated with pacemakers requires complete removal of all hardware, including inactive leads. Since 1972, 5,089 patients have had 8,508 pacemaker generators implanted at Montefiore Medical Center. There were 91 infections (1.06%); four of our patients required surgical removal. Nine additional patients were referred for surgical removal of infected transvenous pacemaker leads from other institutions. Surgical methods for removal included use of cardiopulmonary bypass or inflow occlusion. Surgery may be safely used in unstable or elderly patients and should not be reserved as a last resort. This article reviews our surgical experience removing infected pacemaker leads at Montefiore Medical Center.

Infected endocardial pacemaker electrodes: successful open intracardiac removal

The long-term results after open intracardiac removal of infected pacing electrodes are presented.

METHODS

Between 1985 and 1990 open intracardiac removal of 19 infected pacing electrodes was performed in seven patients (six male and one female), with a mean age of 56 years. The indications were: persisting bacteremia in three; generator pocket infection in four; endocarditis in one; and ventricular tachycardia caused by retracted electrodes in one. All electrodes were fixed in the right heart and extraction by closed methods failed. Percutaneous catheter techniques were not applied in these seven patients. In five patients two ventricular electrodes had to be removed, and in two patients a single one. A total of seven atrial electrodes were removed in six patients (one electrode each in five patients; two electrodes in one patient). All atrial and two ventricular electrodes could be removed through a pursestring suture without use of a pump oxygenator. For the removal of ten ventricular electrodes in six patients (two electrodes each in four patients; 1 electrode each in two patients) a right-sided atriotomy was necessary with cardiopulmonary bypass (CPB). Simultaneously, five new pacing systems were implanted.

RESULTS

There were no early or late mortalities. In January 1991, all seven patients are alive and in a mean New York Heart Association Class 1,3 of heart failure after a mean interval of 33 months. In all cases the infection could controlled with a simultaneous antimicrobial chemotherapy and the postoperative period was free of major complications.

CONCLUSION

Open intracardiac removal of retained pacing electrodes with or without use of CPB is a safe procedure without major complications. It is mandatory for all infected pacing electrodes that cannot be extracted by closed methods.

Permanent transvenous pacemaker implantation in forty dogs

Permanent transvenous cardiac pacemakers were implanted in 40 dogs. Electrocardiographic diagnoses included persistent atrial standstill (3 dogs), sick sinus syndrome (8 dogs), and high-grade second-degree or third-degree atrioventricular (AV) block (29 dogs). Thirteen dogs were alive and well 4 to 42 months after pacemaker implantation (mean, 16.9 months). The mean and median survival times of the 26 dogs that died or were euthanatized during the study were 17.9 months and 13 months, respectively. Most of these dogs succumbed to problems unrelated to the arrhythmia and pacemaker implant. One dog was lost to follow-up. Complications associated with permanent transvenous pacemaker implantation included lead dislodgement, infection, hematoma formation, skeletal muscle stimulation, ventricular arrhythmia, migration of the pulse generator, and skin erosion. Lead dislodgement was the most common complication, occurring in 7 of 9 dogs paced using untined electrode leads and in 6 of 30 dogs paced using tined leads. Lead dislodgement did not occur in the only dog paced using an actively fixed endocardial lead. It was concluded that permanent transvenous cardiac pacing is a feasible, less traumatic alternative to epimyocardial pacing in dogs, but that successful use of this technique requires careful implantation technique and anticipation of the potential complications.

Extraction of implanted transvenous pacing leads: a review of a persistent clinical problem

Within a few months of implantation, permanent pacemaker leads become ensheathed in fibrocollagenous tissue. This tissue may anchor the lead so that it is difficult, dangerous, or impossible to remove it. Leads with bulbous or finned tips are particularly resistant to extraction. The risks of applying traction to an entrapped lead include induction of bradycardia or ventricular tachycardia and fibrillation, invagination of the right ventricle, avulsion of the right ventricular myocardium or tricuspid valve, hemopericardium, and cardiac tamponade. Forceful traction may result in uncoiling of the conductor, disruption of the insulation, or complete fracture, leaving an intravascular remnant that may embolize or be a source for thrombosis. Although fixation and abandonment of an inactive chronically implanted lead is frequently appropriate and is known to pose little long-term risk, the retained inactive lead may interact adversely with a new active lead and then increase the risk of venous thrombosis, serve as a potential nidus for infection, or produce spurious electrical sensing signals that may be sensed by the pulse generator. Absolute indications for lead removal are those in which there would be a life-threatening situation if the lead were to remain in situ. In the absence of an absolute indication, the decision to proceed with extraction must be made by weighing the potential for serious morbidity or mortality against risks of the extraction technique. Techniques for lead removal include traction and open cardiotomy operations. When a portion of the lead is intravascular, forceps, snares, baskets, countertraction, or lead-transection devices may be used to retrieve the fragment.

Infections in implantable cardioverter defibrillator patients

Implantable cardioverter defibrillators (ICDs) have been documented as an effective modality in reducing arrhythmic mortality. A serious complication associated with implantation of the device is infection. Few studies have addressed this issue. Two hundred seven patients with refractory ventricular arrhythmias underwent 207 ICD implantations, and 56 subcutaneous generator changes at our institution. Eight patients developed wound infections, four following ICD implantation (4 out of 207 or 1.9%), and four following a generator change (4 out of 56 or 7.1%). Wound cultures most commonly revealed Staphylococcus aureus and Staphylococcus epidermidis. Infections treated with antibiotics alone, or with only generator removal, frequently recurred (four out of five attempts). There were no recurrences following total patch/lead and generator system removal. In five patients, the same generator unit was successfully reimplanted following ethylene oxide sterilization without infection recurrence. We conclude that treatment of device-associated infection generally requires total generator and patch/lead system removal, and that generator units can be successfully reimplanted yielding substantial cost savings.

The salvage of infected cardiac pacemaker pockets using a closed irrigation system

Over a period of 71 months, 19 patients were treated for infected or eroded permanent pacemaker pockets. All cases were treated with local debridement and insertion of a closed irrigation system using a solution of tyloxapol and tobramycin. Successful eradicaiton of the infection, without complete replacement of the pacemaker system, was achieved in all cases.

An unusual complication of a myocardial electrode--apatite mantle on the platinum-iridium spurs

A case of a high excitation threshold that occurred 2 years 5 months after the initial implantation of pacemaker electrodes is described in a girl 4 years 3 months of age. This complication was considered to be due to calcification of the platinum-iridium electrode spurs. The calcified material was shown to be a kind of apatite using the X-ray powder diffraction method. This complication is rare, but it must be kept in mind since battery longevity has markedly improved in recent years.

Management of the infected pacemaker: explantation, sterilization, and reimplantation

From January, 1970, through December, 1984, nineteen infected or eroded pacemaker units were reimplanted in 17 patients. Characteristics of the patients, types of infecting organisms, surgical management, and complications are described. Optimal treatment of the infected generator pocket requires explantation of the generator unit with utilization of the in situ leads for pacing by an external-demand pacemaker unit. The generator unit is sterilized, and new leads are placed with relocation of the pocket. The old leads are then removed. This technique has been used safely and with excellent results for the past fourteen years.

Extraction of an intravascularized pacemaker lead--a new approach to an unusual problem

A new catheter approach to removing an intravascularized, nonfunctional pacemaker lead which was fixed at both distal (right ventricular endocardium) and proximal (brachiocephalic vein/superior vena cava) ends is described. This case also emphasizes the need for removal of an old pacemaker lead that caused bacteremia in a patient with a prosthetic aortic valve even when infection was presumed to be cured.

[Staphylococcus epidermidis causing infections in trauma surgery]

During 27 months at the Tübingen Accident Hospital, Staphylococcus epidermidis could be found in 464 of 1824 bacteriological wound swabs. This normally had to be considered as contamination. However, in at least 69 cases, S. epidermidis alone undoubtedly caused or maintained a fresh or chronic infection of the bone and soft tissue following aseptic orthopedic surgery, whereby the infection was temporarily sustained by S. epidermidis during pathogen change. The findings are demonstrated and compared with the literature.

Recurrent sepsis from retained endocardial electrode in children: successful removal with cardiopulmonary bypass

Infection remains a significant problem in patients undergoing permanent cardiac pacemaker implantation, and removal of all components is usually required. The transvenous system carries minimal morbidity at implantation, but the development of infection is more life-threatening than in the epicardial system. Although the evolution of the tined porous endocardial lead reduced the incidence of wire displacement, the development of a serious infection is still a problem and may require major surgery for removal. We experienced this problem in a 15-month-old child who developed recurrent sepsis. Attempts at removal of the retained tined porous electrode through the neck incision proved dangerous and unsuccessful. Removal was carried out using cardiopulmonary bypass and infection was promptly controlled.