Pediatric pacemaker infections: twenty years of experience

Case report demonstrating novel approaches for leadless pacemaker implantation in the single ventricle heart

Background

The congenital heart disease population can provide a unique set of challenges during pacemaker implant, including the necessity of transvenous leads in a young group of patients. In this case report we demonstrate how leadless pacemakers may be used as an option in patients with Fontan circulation.

Case Summary

We present two cases of novel use of the Abbott AVEIR™ leadless pacemaker, including the first reported in person trans-baffle delivery of this device and implantation into a single ventricle heart. Our cases are a 30-year-old male with single ventricle physiology and Fontan circulation, found incidentally to have complete heart block (CHB) and a 48-year-old female with a Fontan circulation who had CHB and a history of syncope. These cases demonstrate a variety of venous access routes and add to the existing data of leadless pacemaker implantation in single ventricle physiology. The very long battery life of these devices make them ideal for patients with difficult venous access with bradycardia pacing requirement with low pacing burden.

Discussion

Leadless pacemakers offer a valuable alternative to transvenous pacing leads for providing bradycardia pacing support in this patient population.

Epicardial Versus Endocardial Pacing in Paediatric Patients with Atrioventricular Block or Sinus Node Dysfunction: A Systematic Review and Meta-analysis

Pacing indications in children are clearly defined, but whether an epicardial (EPI) or an endocardial (ENDO) pacemaker performs better remains to be elucidated. This systematic review and meta-analysis aimed to directly compare the incidence of pacemaker (PM) lead-related complications, mortality, hemothorax and venous occlusion between EPI and ENDO in children with atrioventricular block (AVB) or sinus node dysfunction (SND). Literature search was conducted in MEDLINE (via PubMed), Scopus by ELSEVIER, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, and OpenGrey databases until June 25, 2022. Random-effects meta-analyses were performed to assess the pacing method's effect on lead failure, threshold rise, post-implantation infection and battery depletion and secondarily on all-cause mortality, hemothorax and venous occlusion. Several sensitivity analyses were also performed. Of 22 studies initially retrieved, 18 were deemed eligible for systematic review and 15 for meta-analysis. Of 1348 pediatric patients that underwent EPI or ENDO implantation, 542 (40.2%) had a diagnosis of congenital heart disease (CHD). EPI was significantly associated with higher possibility of PM-lead failure [pooled odds ratio (pOR) 3.00, 95% confidence interval (CI) 2.05-4.39; I2 = 0%]; while possibility for threshold rise, post-implantation infection and battery depletion did not differ between the PM types. Regarding the secondary outcome, the mortality rates between EPI and ENDO did not differ. In sensitivity analyses the results were consistent results between the two PM types. The findings suggest that EPI may be associated with increased PM-lead failure compared to ENDO while threshold rise, infection, battery depletion and mortality rates did not differ.

Leadless Pacemakers in Patients with Congenital Heart Disease

Transcatheter leadless pacemakers have benefits in congenital heart disease because they eliminate the risks of lead malfunction, venous occlusions, and pocket complications. This newest pacemaker's utility in this population has been limited by the large sheath and delivery system, need for atrioventricular synchronous pacing, lack of explantation options, and possible lack of adequate access to the subpulmonary ventricle. With careful planning, leadless pacing can be successfully performed in these patients. Consideration of nonfemoral access, alternative implant sites to avoid myocardial scar or prosthetic material, anticoagulation for patients with persistent intracardiac shunts or systemic ventricular implantation, and operator experience are critical.

Leadless pacemaker implantation for pediatric patients through internal jugular vein approach: A case series of under 30 kg

BACKGROUND

We demonstrate a case series of 8 pediatric patients, all under 30 kg, who had leadless pacemaker implants via the internal jugular vein.

METHODS

A retrospective review of pediatric leadless pacing placement via the internal jugular vein at the University of Minnesota Masonic Children's Hospital and UC Davis Medical Center from 2018 through 2021 was performed. Rationales for pacing, demographics of patients, pacing thresholds, and longevity of devices were recorded.

RESULTS

Eight internal jugular pacemaker insertions were performed successfully in patients weighing between 10.9 kg and 29 kg. Five patients had Micra implantation via the right internal jugular vein, whereas 3 patients had insertion via the left internal jugular vein. No surgical cut-downs were performed. No venous complications occurred. Up to 3 years of follow-up were noted.

CONCLUSION

Leadless pacemaker implantation, via left or right internal jugular veins, is feasible without surgical cutdown in patients <30 kg.

Mucormycosis: An Uncommon Cutaneous Infection at Permanent Pacemaker-Implanted Site in a Very Low-Birthweight Baby

Permanent pacemaker implantation in low birthweight (LBW) babies with congenital complete heart block is extremely challenging due to a paucity of appropriate pulse generator placement pocket sites. The development of infection following an implantation procedure can pose a life-threatening risk to the patients. With more patients in the younger group receiving these devices than ever before and the rate of infection increasing rapidly, a closer look at the burden of infection and its impact on outcome of these patients is warranted. We report mucormycosis infection at the abdominal pacemaker pocket site of an infant requiring pacemaker explantation and re-insertion into the intrapleural space.

Local device infection successfully treated without pacemaker removal in a neonate: a case report

AIMS

Local device infection is a serious complication, especially in neonates. Complete device removal is the gold standard treatment for cardiac device infection; however, in selected cases alternative strategies could be adopted. We describe a case of a 14-day-old neonate, weighing 2.5kg, who had undergone epicardial double chamber pacemaker implantation for a congenital complete atrioventricular block. The generator pocket was created in the epigastric area below the rectus abdominis. At six days after implantation, pocket infection was found; blood cultures and the transoesophageal echocardiogram were normal. Due to the low weight of the neonate, and the limited possibility of finding a new comfortable site for housing the generator far from the infected area, we opted for a conservative strategy. We successfully applied a combination of antibiotic therapy, a vacuum-assisted wound closure system (KCI, Germany) for 40 days, and then skin transfer flap from the right flank without device removal. At one-year follow-up there were no local or systemic signs of infection.

Impact of the axillary approach on epicardial pacing lead durability in children

BACKGROUND

To avoid lead failure and pocket infection in neonates/infants requiring pacemakers, we used the axillary approach of placing the generator in the axilla and the leads in the intrathoracic space. We describe the technical details of the axillary approach and evaluate the efficacy of this method.

METHODS

We assessed 21 patients (7 males) weighing ≤8.0 kg who underwent epicardial pacemaker implantation with the axillary approach between 2004 and 2018. The axillary approach entails (1) positioning the pacemaker generator in the axilla to avoid local skin/pocket complications due to tissue compression by the generator and (2) making a double loop in the pleural space to reduce stress on the pacemaker leads caused by somatic growth. This approach can be combined with median sternotomy for simultaneous intracardiac repair.

RESULTS

The patients' median age at pacemaker implantation was 6.0 months; 16 (76%) patients were aged <12 months. The median body weight was 4.5 kg (interquartile range: 3.0-7.0). In all five patients requiring simultaneous cardiac repair, a median sternotomy was performed to access the heart. Sixteen patients required only pacemaker implantation: left thoracotomy was performed in 10 patients, right thoracotomy in 5, and subxiphoid approach in 1. The 5- and 10-year freedom from pacemaker-related adverse events was 89.4% and 79.5%, respectively.

CONCLUSIONS

The axillary approach using intrathoracic double-loop routing of leads to position the generator in the axilla for pacemaker implantation can be a valuable alternative for neonates/infants weighing ≤8 kg with or without complex congenital heart disease.

Surveillance Cultures and Infection in 230 Pacemaker and Defibrillator Generator Changes in Pediatric and Adult Congenital Patients

BACKGROUND

Postoperative infections can occur during surgical replacement of pulse generators for pacemakers and implantable cardioverter-defibrillators. The incidence of infection is poorly documented in children and patients with adult congenital heart disease. The utility of surveillance cultures obtained from device pocket swabs is unknown in this group.

METHODS

We reviewed surgical replacements of cardiovascular implantable pulse generators from 2010 to 2017. Two cohorts were defined. In a surveillance cohort (123 patients), aerobic and anaerobic culture swabs of the device pocket were obtained at the time of generator change. In a nonsurveillance cohort (107 patients), generator change occurred without obtaining cultures.

RESULTS

During 230 generator changes (mean patient age 19 years; 77% with structural congenital heart disease), two clinical infections occurred at the surgical site (0.9% incidence). Neither infection occurred in the surveillance cohort. Cultures were positive in 12 (9.8%) of 123 patients in the surveillance cohort, but 11 of 12 were likely contaminants and none were subsequently associated with clinical disease. There was no association between clinical infection or positive surveillance cultures and the location of pulse generator, the presence of other concurrent surgeries, or a history of prior pocket infection.

CONCLUSIONS

Clinical infection was rare after pulse generator change in children and young adults. No cases required reintervention on the pocket. Surveillance cultures did not improve clinical care. These data extend current recommendations that surveillance cultures are not required during generator change to the pediatric and young adult population.

A Minimally Invasive Approach for Placing Sew-On Epicardial Leads in the Child

Traditionally, pacing leads are placed transvenously, although smaller pediatric patients who require permanent pacemakers may benefit from delaying tranvenous lead placement until they are larger. Alternative, minimally invasive atrioventricular pacing options have not previously existed for this patient population, leaving many of these children with large sternotomies or thoracotomies. Using three port sites and an adjustable shaft dual-needle suturing device, we placed a steroid-eluting, sew-on epicardial lead on the right atrium of a 9-year-old patient. This is one of the earliest reported cases of a minimally invasive technique for sew-on epicardial lead placement on the atrium of a child. Although based on a single case, we believe that this approach is safe, reliable, and reproducible and that it can be used to place leads on any aspect of the heart. Adoption of this technique will allow for earlier atrioventricular pacing, which may decrease the incidence of pacemaker syndrome, and thus improve overall outcomes in this patient population.

Effect of pocket irrigation with antimicrobial on prevention of pacemaker pocket infection: a meta-analysis

Background

The presence of cardiac implantable electronic devices (CIEDs) pocket infection is difficult to treat, causing serious clinical outcomes, but little is known for prevention. Results from some studies suggested that pocket irrigation could reduce infection while others showed conflicting results. We pooled the effects of pocket irrigations on the prevention of pocket infection by meta-analysis methods.

Method

Relevant studies published before June, 2017 were retrieved mainly by the computer-based search of PubMed, Cochrane, EMBASE, Web of Science, Chinese BioMedical, Global Health and BIOSIS Previews databases. Estimations of relative ratios (RRs) and 95% confidence intervals (95% CIs) were pooled. Subgroup analyses according to potential key factors affecting the effects were conducted, which was confirmed by meta-regression. Sensitivity analysis and test for publication bias were also performed.

Results

We identified 10 studies providing data of 5467 patients receiving CIEDs implantations. Pooled infection rates were 1.48 and 3.49% respectively for medication and saline irrigation groups. Meta-analysis showed that medication irrigation conferred protection to pocket infection (RR = 0.44, 95% CI: 0.31-0.63). Subgroup analysis showed that antibiotics, rather than non-antibiotics (antiseptics) exerting the protection. The first and second lines antibiotics against staphylococcus aureus, which is the main pathogen for pocket infection, were both effective (RR = 0.42, 95% CI: 0.24-0.75 and RR = 0.34, 95% CI: 0.20-0.58 respectively for first line and second line therapies). Meta-regression revealed that region and class of irrigation medication completely explained the variance among studies and implied that effects of region were masked by medication types. Sensitivity analysis did not showed any significant change of the result and publication bias were not statistical significance.

Conclusion

Pocket irrigation with antibiotics were effective for reducing pocket infection and should be encouraged in CIEDs implantation.

Strategies to prevent infections associated with cardiovascular implantable electronic devices

INTRODUCTION

Infections involving cardiovascular implantable electronic devices (CIED) are associated with high morbidity and mortality and substantial financial cost. In the past two decades, the rate of CIED infections has increased disproportionate to the number of devices implanted, likely due to aging patient population with multiple comorbidities. Microbial contamination of the generator pocket and or leads by skin flora at the time of implantation is a major mechanism for early CIED infections. Due to resistance to host immune cells and antibiotics caused by biofilm formation, complete removal of the device generator and leads is required to achieve cure. Areas covered: In this manuscript, we review the published literature regarding epidemiology, risk factors, and pathogenesis of CIED infections with primary focus on the preventative strategies to reduce the incidence of device infections. Expert commentary: Strict adherence to infection control measures at the time of CIED implantation is critical in reducing the risk of device infection while adjunctive strategies such as use of antimicrobial envelopes might help in certain high-risk individuals. Technological advances in device manufacturing with availability of subcutaneous devices without transvenous leads and self-contained intracardiac devices without leads and generator show promise with lower risk of infection.

Late Outcome and Predictors of Adverse Events Related to the Implantation of a Permanent Pacemaker in Patients with Isolated Congenital Atrioventricular Block

Isolated congenital atrioventricular block (ICAVB) is a rare, and pacemaker implantation is the only effective treatment. We sought to identify the predictive factors of adverse events related to pacemaker implantation in ICAVB. This is a cohort study of patients diagnosed with ICAVB who underwent pacemaker implantation from 1980 to 2014 in a single center. During the studied period, a total of 647 patients underwent implantation of their first permanent cardiac pacemaker before 30 years of age. Of these, only 62 (9.5 %) were diagnosed with ICAVB. This condition was diagnosed in utero in 15 (24.2 %) cases, 5 (8.1 %) in the neonatal period, 32 (51.6 %) during childhood, and 10 (16.1 %) during adolescence and young adulthood. The presence of autoantibodies (anti-Ro/SSA) was observed in 41 % of mothers who underwent serological evaluation. Age at the time of the initial pacemaker implant was 9.8 ± 9 years. During a mean follow-up time of 15 years, 1 (1.7 %) death occurred due to infectious endocarditis. Complications related to pacemaker implant were reported in 24 patients (38.7 %). The number of complications was significantly higher in the group with an epimyocardial implantation site (HR 6; CI 2.45-14.95). Ventricular dysfunction occurred in 6 (11.7 %) patients; however, we were not able to identify any predictors of it. Our results showed a low mortality rate after permanent therapy. However, these patients exhibited high morbidity related to the pacemaker system, and the epimyocardial implant site was an independent predictor of complications. Predictors of left ventricular dysfunction were not found in the present study.

A Review of Surgical Atrioventricular Block with Emphasis in Patients with Single Ventricle Physiology

We perceived an increased incidence of surgical atrioventricular (AV) block in patients with single ventricle physiology undergoing two ventricle rehabilitation for hypoplastic left heart syndrome compared to the overall incidence of surgical AV block for our institution. Retrospective investigation of our center's data revealed a statistically significant increase in the incidence of surgical AV block in the single ventricle population and two ventricle rehabilitation population compared to the two ventricle population. Here we review the literature with respect to historic definitions, incidence, risk factors, pre- and post-op management, current indications for pacemaker placement and added cost and comorbidity associated with surgical AV block. We then offer possible strategies for decreasing the incidence of surgical AV block within both the single and two ventricle populations.

Prevention of infections in cardiovascular implantable electronic devices beyond the antibiotic agent

The increase in incidence/prevalence of infections of implantable pacemakers and defibrillators (implantable cardioverter defibrillator, ICD) is outweighing that of the implanting procedures, mainly favored by the changes in patient profile. Despite the high impact on patient's outcome and related costs for healthcare systems, we lack specific evidence on the preventive measures with the exception of antibiotic prophylaxis. The aim of this study is to focus on common approaches to pacemaker/ICD implantation to identify the practical preventive strategies and choices that can (potentially) impact on the occurrence of this feared complication. After a brief introduction on clinical presentation, pathogenesis, and risk factors, we will present the results from a survey on the preventive strategies adopted by different operators from the 25 centers of the Emilia Romagna region in the northern Italy (4.4 million inhabitants). These data will provide the basis for reviewing available literature on this topic and identifying the gray areas. The last part of the article will cover the available evidence about pacemaker/ICD implantation, focusing on prophylaxis of pacemaker/ICD infection as a 'continuum' starting before the surgical procedure (from indications to patient preparation), which follows during (operator, room, and techniques) and after the procedure (patient and device follow-up). We will conclude by evaluating the relationship between adherence to the available evidence and the volume of procedures of the implanting centers or operators' experience according to the results of our survey.

Cardiac pacing in paediatric patients with congenital heart defects: transvenous or epicardial?

AIMS

Cardiac pacing is a difficult technique in children, particularly in patients with congenital heart defects (CHDs). Few studies to date have addressed this topic.

METHODS AND RESULTS

We performed a retrospective analysis of the results of a single centre. Between 1982 and 2008, 287 patients with CHD, median age of 5 years (25-75%, 1-11) underwent cardiac pacing for sinus node dysfunction (SND) and atrioventricular block (AVB); 97% of patients underwent at least one heart surgery. Endocardial systems (Endo) were implanted in 117 patients, epicardial systems (Epi) in 170, with 595 leads (228 Endo, 367 Epi). Endocardial systems showed a significantly older age group with more frequent SND; Epi a younger age group, with more frequent AVB, greater number of surgical interventions. Perioperative complications were mortality 0.6% (Epi), pericardial effusion 0.6% (Epi), and haemothorax 3.4% (Endo). The median follow-up is 5 (2-10) years: the pacing system failed in 29% of patients, 13% Endo, and 40% Epi (P < 0.0001). Multivariate analysis showed a significantly higher risk of failure for Epi, a lower implant age, greater the number of leads implanted. The risk of malfunction of the leads increases significantly for Epi and the younger age when implanted. The steroid-eluting leads have a lower risk of malfunction (P = 0.05), steroid-eluting Endo leads provide significantly better outcomes than Epi.

CONCLUSION

Cardiac pacing in paediatric patients with CHD shows satisfactory results in the long term. Endocardial systems show significantly better results than Epi systems. A younger age when implanted is a risk factor for complications at follow-up.

Pacing device therapy in infants and children: a review

The number of pediatric pacemakers implanted is still relatively small. Children requiring pacing therapy have characteristics that are distinct from those of adults, including physical size, somatic growth, and cardiac anomalies. Considering these features, long-term follow-up of pediatric pacemaker implantation is necessary. Selection of appropriate generators, pacing modes, pacing sites, and leads is important. Generally, epicardial leads are commonly used in small infants. On the other hand, the use of endocardial leads in children is increasing worldwide because of their benefits over epicardial leads, such as minimal invasiveness, lower pacing threshold, and longer generator longevity. Endocardial leads are not suitable for patients with intracardiac shunts because of the high risk of systemic thrombosis. Venous occlusion is another significant problem with endocardial leads. With the increase in the number of pacing device implantations, the incidence of infection from such devices is also increasing. Complete device removal is sometimes recommended to treat device infection, but experience in the removal of endocardial leads in children is still scarce. This article gives an overview of pacing therapy in the pediatric population, including discussions on new pacing systems, such as remote monitoring systems, magnetic imaging compliant pacemaker systems, and leadless pacing devices.

Long-term outcome of transvenous bipolar atrial leads implanted in children and young adults with congenital heart disease

AIMS

Atrial leads are often implanted in paediatric patients needing a pacemaker (PM). The aim of this study is the evaluation of their outcome in young patients.

METHODS AND RESULTS

We evaluated transvenous atrial leads outcome in children and young adults from a single centre, with a retrospective analysis. A P< 0.05 was considered significant. Between 1992 and 2008, 110 patients, 75 with congenital heart defects (d-transposition of great arteries status/post, s/p, Mustard 41%, atrioventricular septal defect 11%, tetralogy 9%, ventricular septal defect 8%), aged 13.3 ± 5.3 years, underwent PM implantation with bipolar atrial transvenous leads for sinus node dysfunction (50%), atrioventricular block (38%), cardiomyopathies, and primary ventricular arrhythmias (12%). Leads are steroid-eluting (98%), tined (59%), screw-in (41%), polyurethane-insulated (72%), silicone-insulated (28%), and have been positioned by transcutaneous puncture of subclavian vein into right atrial appendage/remnant (RAA, 50%), right atrial free wall/septum (25%), left atrium (s/p Mustard, 25%). Follow-up duration is 6.4 ± 4.8 (range 0.1-18) years. At multivariate analysis, younger age at implant was a risk factor for lead failure (4 leads, 3.5%) (P= 0.03); 16 leads (14%) dislodged post-implantation and 12 were successfully repositioned, the others extracted or abandoned. Dislocation occurred more frequently with screw-in leads (P= 0.03) positioned outside RAA (P= 0.02). Atrial threshold showed a small but significant increase, 0.002 V/month (P< 0.001), impedance showed a decrease (0.6 Ω/month, P< 0.001), P-wave showed no significant difference.

CONCLUSIONS

Transvenous bipolar atrial leads have good long-term results in young patients, with a very low rate of lead failure. Older age at implant can further reduce this rate. Lead dislodgement is frequent in the post-operative period.

A single institution experience with pacemaker implantation in a pediatric population over 25 years

BACKGROUND

With the development of new technical devices and software more appropriate for pediatric patients, pacemaker implantations in children and young adults have increased over time. It is necessary to monitor the mid- and long-term consequences. The decision for the implantation of a cardiovertor defibrillator (ICD) in children remains challenging despite technical improvements.

OBJECTIVE

To assess the safety of pacemaker implantation in children, to review old and new indications, and to point out changes of management over time.

PATIENTS AND METHODS

Between 1984 and 2009, 181 patients required the implantation of a pacemaker or an ICD device at the Heart and Diabetes Centre in Bad Oeynhausen, Germany. Their charts have been reviewed pro- and retrospectively for indications, complications, longevity of the device, and the natural course.

RESULTS

Indications have been high-degree atrioventricular block in 65% (postoperative 55%) and sinus node dysfunction in 24% (postoperative 90%), including three patients with vasovagally mediated significant bradycardia. Eleven percent required the implantation of an ICD device secondary to significant ventricular arrhythmias. The indication was class II in one-third of all patients. Complications requiring revision occurred in six patients (3.3%); one of them required removal of the device due to an infection. Ten patients died, but none related to pacemaker implantation.

CONCLUSION

Pacemaker implantation even in young pediatric patients is generally safe. No complication led to the death of a patient. The number of class II indications has been increasing. The future aim is to improve pediatric algorithms and to prevent unnecessary pacing.

Axillary versus infraclavicular placement for endocardial heart rhythm devices in patients with pediatric and congenital heart disease

Our objective was to evaluate the implant and mid-term outcomes of transvenous pacemaker or internal cardioverter-defibrillator placement by alternative axillary approaches compared to the infraclavicular approach in a pediatric and congenital heart disease population. We conducted a retrospective review of all patients with new endocardial heart rhythm devices placed at 4 pediatric arrhythmia centers. A total of 317 patients were included, 63 had undergone a 2-incision axillary approach, 51 a retropectoral axillary approach, and 203 an infraclavicular approach. Congenital heart disease was present in 62% of the patients. The patients with the 2-incision axillary approach were younger and smaller. The patients with the retropectoral axillary approach were less likely to have undergone previous cardiac surgery and were more likely to have had an internal cardioverter-defibrillator placed. The duration of follow-up was 2.4 ± 1.9 years for the 2-incision axillary, 2.6 ± 2.6 years for retropectoral axillary, and 3.5 ± 1.4 years for the infraclavicular technique (p = 0.01). No differences were seen in implant characteristics, lead longevity, implant complications, lead fractures or dislodgements, inappropriate internal cardioverter-defibrillator discharges, or device infections among the 3 groups. In conclusion, our data support that the outcomes of axillary approaches are comparable to the infraclavicular approach for endocardial heart rhythm device placement and that axillary approaches should be considered a viable option in patients with pediatric and congenital heart disease.

Update on cardiovascular implantable electronic device infections and their management: a scientific statement from the American Heart Association

Despite improvements in cardiovascular implantable electronic device (CIED) design, application of timely infection control practices, and administration of antibiotic prophylaxis at the time of device placement, CIED infections continue to occur and can be life-threatening. This has prompted the study of all aspects of CIED infections. Recognizing the recent advances in our understanding of the epidemiology, risk factors, microbiology, management, and prevention of CIED infections, the American Heart Association commissioned this scientific statement to educate clinicians about CIED infections, provide explicit recommendations for the care of patients with suspected or established CIED infections, and highlight areas of needed research.

Interventions using foreign material to treat congenital heart disease in children increase the risk for infective endocarditis

BACKGROUND

Congenital heart disease (CHD) is a risk factor for infective endocarditis (IE). We aimed to assess the impact of cardiac interventions on the frequency and microbial profile of IE in children with CHD.

METHODS

Episodes of IE were analyzed in children aged < or =18 years with CHD between 1995 and 2005 with respect to cardiac surgery or catheter interventions with or without implantation of foreign material.

RESULTS

Diagnosis of IE was made in 14 (0.36%) of 3826 children with CHD including native IE in 6 and postinterventional IE in 8 patients. During the period 3029 cardiac interventions (1944 surgeries; 1085 catheters) were performed; foreign material was implanted in 1360 interventions (1139 surgeries; 221 catheters) including all 8 patients with postinterventional IE. Cardiac intervention by itself did not change the risk for IE compared with no intervention. The risk of IE after implantation of foreign material was higher than following intervention without implantation (odds ratio, 21.0; 95% confidence interval, 1.2-365; P < 0.05). Pacemaker implantation was associated with the highest risk for IE (odds ratio, 11.0; 95% confidence interval, 2.6-46.5; P < 0.001). Staphylococci were the most frequently isolated organisms in foreign material-associated IE.

CONCLUSIONS

Cardiac intervention in children with CHD does not increase the risk for IE. Postinterventional IE in children with CHD is strongly linked to implantation of foreign material, especially of pacemaker.

Pacemakers and implantable cardioverter-defibrillators in pediatric patients

The use of pacemakers and implantable cardioverter-defibrillators (ICDs) in infants, children, and patients with congenital heart disease presents unique challenges and considerations. They include uncommon indications for device implantation, innovative approaches to lead implantation and configuration, and age-dependent and disease-specific aspects of device programming. In this review, the current indications for pacemaker and ICD implantation in young patients are discussed, followed by consideration of the approaches to lead and device placement in very small patients and those with complex congenital heart disease, in whom unique problems may be encountered. The limitations of programmability of current pacemakers and ICDs when used in young patients are discussed, followed by an analysis of long-term device follow-up and potential late complications.

Fever of unknown origin, infection of subcutaneous devices, brain abscesses and endocarditis

The term 'fever of unknown origin' includes a wide range of conditions that often remain undiagnosed. The possibility of an infection must be promptly diagnosed in order to begin appropriate therapy. Imaging with radiopharmaceuticals, computed tomography, magnetic resonance imaging and ultrasound are the most commonly applied techniques, usually performed in addition to blood tests, biopsies or tissue cultures when required. The lack of comparative studies investigating the accuracy of each radiopharmaceutical for the study of fever of unknown origin was the incentive to perform a meta-analysis of peer articles published between 1981 and 2004 (33 papers) describing the use of nuclear medicine imaging for this purpose. Furthermore, infection of subcutaneous devices, brain abscesses and endocarditis must be considered amongst the causes of fevers of unknown origin. Reviews of 23, 10 and 10 papers, respectively (from 1976 to 2005), were performed on these specific topics. The results may be a useful guide for the choice of the optimal radiopharmaceutical(s) and diagnostic strategy to be applied in each clinical condition and for different aims.

Deep brain stimulation for Parkinson's disease: Surgical issues

Numerous factors need to be taken into account when implanting deep brain stimulation (DBS) systems into patients with Parkinson's disease. The surgical procedure itself can be divided into immediate preoperative, intraoperative, and immediate postoperative phases. Preoperative considerations include medication withdrawal issues, stereotactic equipment choices, imaging modalities, and targeting strategy. Intraoperative considerations focus on methods for physiological confirmation of a given target for DBS electrode deployment. Terms such as microelectrode recording, microstimulation, and macrostimulation will be defined to clarify inconsistencies in the literature. Advantages and disadvantages of each technique will be addressed. Furthermore, operative decisions such as staging, choice of electrode and implantable pulse generator, and methods of device fixation will be outlined. Postoperative issues include imaging considerations, including magnetic resonance safety, device-device interactions, and immediate surgical complications pertaining to the DBS procedure. This report outlines answers to a series of questions developed to address all aspects of the DBS surgical procedure and decision-making with a systematic overview of the literature (until mid-2004) and by the expert opinion of the authors. This is a report from the Consensus on Deep Brain Stimulation for Parkinson's Disease, a project commissioned by the Congress of Neurological Surgeons and the Movement Disorder Society. It outlines answers to a series of questions developed to address all surgical aspects of deep brain stimulation.

The Impact of Povidone-Iodine Pocket Irrigation Use on Pacemaker and Defibrillator Infections

BACKGROUND

Infection is a devastating complication of permanent pacemakers (PMs) implantable cardioverter defibrillators (ICDs). Many implanting physicians commonly use povidone-iodine solution to irrigate the device pocket before implanting the device. We sought to assess if such a measure would alter the rate of infection.

METHODS

A total of 2,564 consecutive patients who received implantable PM or ICD devices between 1994 and 2002 were studied. Povidone-iodine was used for pocket irrigation in 53% and saline in 47%. A total of 18 (0.7%) patients developed pocket infections with 0.7% (10/1,359) in povidone-iodine (group I) and 0.6% (8/1,205) in saline (group II) pocket irrigation (p = ns). Groups I and II were studied for various clinical and demographic variables described in the results section.

RESULTS

There was no statistical difference in the baseline demographic and clinical characteristics between groups I and II, respectively. ICDs were most frequently infected than PMs (56% vs 44%). Most (83%) of the devices were dual chamber. Reopening of the pocket for either lead or generator replacement had a higher incidence of infection than new implants (61% vs 39%). There was no difference in the use of preimplantation antibiotic prophylaxis. Late (61%) and deep pocket infections (78%) were more common than early (39%) and superficial infections (22%). Blood cultures were positive in 67% and Staphylococcus aureus was the common most pathogen (50%). The mean duration of antibiotics use after the diagnosis of device infection was 35 +/- 23 days with 72% requiring device explantation. The device was reimplanted on the contralateral side in 56% cases. One patient in each group died due to device infection and related complications. No significant allergy to iodine was seen in either group.

CONCLUSION

Povidone-iodine irrigation of the subcutaneous pocket did not alter the rates of pocket infection after pacemaker/defibrillator implantation.

Chronic Pseudomonas Infections of Cochlear Implants

OBJECTIVE

To discuss chronic, refractory Pseudomonas infections of cochlear implants and their management.

DESIGN

Retrospective case series.

SETTING

Two university-based cochlear implant programs.

PATIENTS

Twenty-eight-year-old (Case 1) and 4-year-old (Case 2), different devices.

INTERVENTIONS

Medical and surgical management.

MAIN OUTCOME MEASURES

Clinical course.

RESULTS

Both patients had delayed presentations, 4 months and 3 years postimplantation, respectively, with fluctuating scalp edema and pain resistant to multiple courses of oral antibiotics. Infections began as localized granulation and progressed to complete encasement of both devices with rubbery, poorly vascularized tissue. In each case, two different strains of multiresistant Pseudomonas aeruginosa were cultured. Infections progressed despite local debridement and targeted antipseudomonal antibiotic coverage, and sensitive organisms continued to appear in cultures of refractory granulation tissue. Both patients underwent partial explantation, with the electrode array left in the cochlea, then received 2 to 3 more months of further medical therapy and observation and then were reimplanted successfully with new devices. Both have shown excellent performance and no sign of recurrent infection.

CONCLUSIONS

Infections of cochlear implants are uncommon, and cases of successful conservative management without device explantation have been reported. However, our experience and the implanted device literature suggest that chronic Pseudomonas infections may represent a distinct clinical entity, likely to fail protracted therapy and ultimately require device removal. Fortunately, successful reimplantation is possible.

Port-A-Cath infections in children with cancer

Implanted subcutaneous (s.c.) central venous port accesses including Port-A-Cath (PAC) facilitate the administration of chemotherapy or blood products and are frequently used in children with cancer. The incidence of PAC-related infections was determined in 155 consecutive paediatric cancer patients with PAC followed for a total of 134,773 days (median, 738; range, 25-2080). Overall, 48 bloodstream infections occurred in 26 patients. 12 (25%) of these infections and 3 local infections at the insertion site were treatment-resistant and demanded removal of the PAC. Coagulase-negative staphylococci were involved in 12 of these 15 episodes. The rate of clearly PAC-related infections in this so far largest reported series was 0.11 episodes per 1000 PAC days, one of the lowest in the literature. Although catheter-related infections demanded PAC removal in 8% of our patients, the long periods PAC were in use and their benefits argue for continued PAC use in the paediatric cancer population.

Efficacy of prophylactic epicardial pacing leads in children and young adults

BACKGROUND

Epicardial pacemakers are often required in children and young adults who cannot undergo a transvenous system because of patient size, vascular barriers, or significant residual intracardiac shunts. Prophylactic epicardial pacing leads, placed at the time of concomitant congenital heart surgery, may reduce a late thoracotomy or sternotomy. The efficacy of prophylactic epicardial leads in the pediatric population is unknown.

METHODS

A retrospective review of the cardiovascular surgery and pacemaker databases at The Children's Hospital of Philadelphia identified all patients less than or equal to 21 years of age, who underwent placement of an epicardial pacing lead between January 1, 1990 and December 31, 2002. Prophylactic epicardial pacing leads placed at the time of a concomitant congenital heart procedure were compared to standard epicardial leads that were connected to a simultaneous programable generator. Pacing and sensing threshold data were obtained in prophylactic epicardial leads at the time of lead retrieval and 6 month follow-up and compared to standard epicardial pacing leads.

RESULTS

Twenty-two (13 ventricular, 9 atrial) prophylactic epicardial pacing leads were retrieved in 13 patients at a median of 252 days (7 days to 3.98 years) from the time of initial implant and compared to 256 (164 ventricular, 92 atrial) standard epicardial leads placed in 142 patients. Nineteen (86%) prophylactic epicardial leads had acceptable pacing and sensing thresholds at lead retrieval. Only 1 patient with atrial and ventricular leads had poor pacing and sensing at retrieval and required a redo-sternotomy for placement of new atrial and ventricular epicardial pacing leads. For the remaining atrial (n = 7) and ventricular (n = 12) prophylactic epicardial leads, there was no significant difference in pacing (atrial, 1.59 +/- 1.1 microJ; ventricular, 1.98 +/- 1.9 microJ) or sensing (atrial, 3.6 +/- 1.8 mV; ventricular, 13.8 +/- 4.4 mV) compared to standard pacing (atrial, 2.1 +/- 1.8 microJ; ventricular, 1.9 +/- 3.4 microJ) and sensing (atrial, 3.3 +/- 1.7 mV; ventricular, 11.3 +/- 5.3 mV) epicardial leads. Six-month follow-up pacing and sensing thresholds were not significantly different between the prophylactic and standard epicardial pacing leads.

CONCLUSIONS

Prophylactic epicardial pacing leads can be successfully placed and retrieved in a subset of children and young adults who will likely require pacing at a later date. Prophylactic leads have comparable pacing and sensing qualities at lead retrieval and short-term follow-up compared to standard epicardial leads. Consideration for prophylactic epicardial pacing leads will likely reduce the need for a late thoracotomy or sternotomy.

Vagal nerve stimulator pocket infections

Vagal nerve stimulator pocket infections are uncommon but can cause considerable morbidity. We describe 3 children from our institution and 8 others previously reported with infection after vagal nerve stimulator implantation for seizure control. Infection was suppressed but recurred despite appropriate antimicrobial therapy when the device remained in situ. Device removal was required in all patients to achieve cure.

Indications and techniques of pediatric cardiac pacing

There are special challenges associated with the use of transvenous pacemakers in children. For example, a child's chest cavity or vascular dimensions could be too small to host the generator and leads available or required. If leads are implanted, they may stretch as the child grows. This increases the risk that the leads will later dislodge or fracture. Moreover, children requiring pacemakers often have coexisting congenital heart defects and the structural abnormalities of those could hinder easy placement of the pacing system. This article will first review the indications for permanent pacing in children and will then describe the unique challenges associated with such use.