Pulse Generator Replacement Research Articles

Frequency of pacemaker malfunction associated with monopolar electrosurgery during pulse generator replacement or upgrade surgery

The aim of this study is to investigate the frequency of electrosurgery-related pacemaker malfunction. A retrospective study was conducted to investigate electrosurgery-related pacemaker malfunction in consecutive patients undergoing pulse generator (PG) replacement or upgrade from two large hospitals in Minneapolis, MN between January 2011 and January 2014. The occurrence of this pacemaker malfunction was then studied by using MAUDE database for all four major device vendors. A total of 1398 consecutive patients from 2 large tertiary referral centers in Minneapolis, MN undergoing PG replacement or upgrade surgery were retrospectively studied. Four patients (0.3% of all patients), all with pacemakers from St Jude Medical (2.8%, 4 of 142) had output failure or inappropriately low pacing rate below 30bpm during electrosurgery, despite being programmed in an asynchronous mode. During the same period, 1174 cases of pacemaker malfunctions were reported on the same models in MAUDE database, 37 of which (3.2%) were electrosurgery-related. Twenty-four cases (65%) had output failure or inappropriate low pacing rate. The distribution of adverse events was loss of pacing (59.5%), reversion to backup pacing (32.4%), inappropriate low pacing rate (5.4%), and ventricular fibrillation (2.7%). The majority of these (78.5%) occurred during PG replacement at ERI or upgrade surgery. No electrosurgery-related malfunction was found in MAUDE database on 862 pacemaker malfunction cases during the same period from other vendors. Electrosurgery during PG replacement or upgrade surgery can trigger output failure or inappropriate low pacing rate in certain models of modern pacemakers. Cautions should be taken for pacemaker-dependent patients.

Erratum to: Is capsulectomy a feasible and useful measure in internal pulse generator replacement procedures? A technical note on the use of the PEAK PlasmaBlade™.

Erratum to: Is capsulectomy a feasible and useful measure in internal pulse generator replacement procedures? A technical note on the use of the PEAK PlasmaBlade™.

Early Experience with the VerciseTM DBS System in the Treatment of Dystonic Tremor

Six cases of dystonic tremor were treated with the VerciseTM deep brain stimulation(DBS)system, which has the multiple independent current control(MICC)technology. The mean preoperative score of Burke-Fahn-Marsden dystonia rating scale was 16.2±9.4, which was reduced to 6.1±4.6 at 5 months postoperatively. A 65-year-old male presented an intractable dystonic tremor of the jaw, neck, and shoulders due to tardive syndrome. He experienced the successful tremor relief after unipolar DBS in the globus pallidus internus(GPi)with VerciseTM but complained of dysarthria. Steering the current ventrally induced nausea without alleviating dysarthria, while steering the current dorsally alleviated dysarthria but a further dorsal current induced mandibular dyskinesia. The current steering with MICC enabled the simulation field in GPi with successful balance, maximizing tremor suppression, and minimizing the adverse effects. In a second case, 61-year-old male in whom cervical dystonia with rotatory tremor had been successfully treated with interleaving stimulation of GPi-DBS had needed to repeat the replacement of a non-rechargeable pulse generator in only 15-month interval. After the substitution of VerciseTM, the interleaving stimulation of 9.5mA in total was replaced by 8.5mA with the current steering of MICC, while the patient's symptomatic control was unchanged. The microlesion effects after lead implantation are unclear and therapeutic effects are often delayed in cases of dystonia;therefore, the submaximal stimulation intensities must be frequently applied in the early phase following the implantation of DBS. A fine current steering of VerciseTM DBS is very useful in both, the early and late phases of GPi-DBS for dystonic syndrome.

Surgical Replacement of Implantable Pulse Generators in Deep Brain Stimulation: Adverse Events and Risk Factors in a Multicenter Cohort

Background: Deep brain stimulation (DBS) is a growing treatment modality, and most DBS systems require replacement of the implantable pulse generator (IPG) every few years. The literature regarding the potential impact of adverse events of IPG replacement on the longevity of DBS treatments is rather scarce. Objective: To investigate the incidence of adverse events, including postoperative infections, associated with IPG replacements in a multicenter cohort. Methods: The medical records of 808 patients from one Australian and five Swedish DBS centers with a total of 1,293 IPG replacements were audited. A logistic regression model was used to ascertain the influence of possible predictors on the incidence of adverse events. Results: The overall incidence of major infections was 2.3% per procedure, 3.7% per patient and 1.7% per replaced IPG. For 28 of 30 patients this resulted in partial or complete DBS system removal. There was an increased risk of infection for males (OR 3.6, p = 0.026), and the risk of infection increased with the number of prior IPG replacements (OR 1.6, p < 0.005). Conclusions: The risk of postoperative infection with DBS IPG replacement increases with the number of previous procedures. There is a need to reduce the frequency of IPG replacements.

Changing of the guard: reducing infection when replacing neural pacemakers.

OBJECTIVE Infection of deep brain stimulation (DBS) hardware has a significant impact on patient morbidity. Previous experience suggests that infection rates appear to be higher after implantable pulse generator (IPG) replacement surgery than after the de novo DBS procedure. In this study the authors examine the effect of a change in practice during DBS IPG replacements at their institution. METHODS Starting in January 2012, patient screening for methicillin-resistant Staphylococcus aureus (MRSA) and, and where necessary, eradication was performed prior to elective DBS IPG change. Moreover, topical vancomycin was placed in the IPG pocket during surgery. The authors then prospectively examined the infection rate in patients undergoing DBS IPG replacement at their center over a 3-year period with at least 9 months of follow-up. RESULTS The total incidence of infection in this prospective consecutive series of 101 IPG replacement procedures was 0%, with a mean follow-up duration of 24 ± 11 months. This was significantly lower than the authors' previously published historical control group, prior to implementing the change in practice, where the infection rate for IPG replacement was 8.5% (8/94 procedures; p = 0.003). CONCLUSIONS This study suggests that a change in clinical practice can significantly lower infection rates in patients undergoing DBS IPG replacement. These simple measures can minimize unnecessary surgery, loss of benefit from chronic stimulation, and costly hardware replacement, further improving the cost efficacy of DBS therapies.

Is capsulectomy a feasible and useful measure in internal pulse generator replacement procedures? A technical note on the use of the PEAK PlasmaBlade(TM).

Implantable pulse generator (IPG) replacement is considered a simple procedure, but in case of extension cable damage or IPG pocket infection, it can dramatically affect a patient's quality of life. Higher risk of infection has been reported after IPG replacement procedures rather than after primary deep brain stimulation lead implantation, and some authors suggested that the IPG pocket capsule could play a pivotal role in causing it. In this technical note we present a capsulectomy technique adopted in IPG replacement procedures. Between July and October 2015, we carried out ten outpatient IPG replacement procedures at the chest and abdomen under local anesthesia for battery depletion using the PEAK PlasmaBlade(TM). All patients were followed for at least 2months to rule out any hardware malfunction and infection. All ten procedures were uneventful. No extension cable damage occurred. No IPG pocket infection occurred, also not in the follow-up. Mean surgical time was 30min. Complete capsulectomy is not feasible with basic surgical instruments, and the PEAK PlasmaBlade(TM) pencil appears to be a helpful tool in carrying out the procedure.

Ampere Hour as a Predictor of Cardiac Resynchronization Defibrillator Pulse Generator Battery Longevity: A Multicenter Study.

Cardiac resynchronization defibrillator (CRT-D) devices improve survival for New York Heart Association classes II-IV systolic heart failure patients with QRS > 120 ms and left ventricular ejection fraction < 35%. A limitation of 100% CRT pacing is excess battery depletion and pulse generator (PG) replacement compared to VVI or dual-chamber systems. Ampere hour (Ah) measures PG battery capacity and may predict CRT-D device longevity. We performed a multicenter retrospective study of all CRT-D devices implanted at our centers from August 1, 2008 to December 31, 2010. Analysis was performed for survival to elective replacement indicator (ERI) between 1.0 Ah, 1.4 Ah, and 2.0 Ah devices, per manufacturers' specifications. One thousand three hundred and two patients were studied through December 31, 2014. Patients were followed for an average of 3.0 ± 1.3 years (794 1.0 Ah, 322 2.0 Ah, and 186 1.4 Ah devices under study). CRT-D generator ERI occurred in 13.5% of 1.0 Ah systems (107 out of 794), versus 3.8% in 1.4 Ah (seven out of 186), and 0.3% in 2.0 Ah devices (one out of 322) over mean follow-up of 3.0 years. Odds ratio (OR) for reaching ERI with 1.0 Ah device versus 1.4 Ah or 2.0 Ah was 9.73, P < 0.0001. Univariate predictors for ERI included 1.0 Ah device and LV pacing output >3V @ 1 ms (OR: 3.74, P < 0.001). LV impedance >1,000 ohms predicted improved device survival (OR: 0.38, P = 0.0025). CRT-D battery capacity measured by Ah is a strong predictor of survival to ERI for modern systems. Further study on cost and morbidity associated with early PG change in 1.0 Ah systems is warranted.

Patients with long-term permanent pacemakers have a high prevalence of left ventricular dysfunction.

Patients with right ventricular pacemakers are at increased risk of left ventricular systolic dysfunction (LVSD). We aimed to establish the prevalence, degree and associations of LVSD in patients with long-term right ventricular pacemakers listed for pulse generator replacement (PGR). All patients listed for PGR at Leeds General Infirmary were invited to attend for an assessment during which we recorded medical history, symptomatic status, medical therapy, date and indication of first implantation, the percentage of right ventricular pacing (% RVP) and an echocardiogram. We collected data on 491 patients. A left ventricular ejection fraction less than 50% was observed in 40% of our cohort, however, this was much higher (59%) in those with more than 80% RVP than in those with less than 80% RVP (22%) (P < 0.0001). Multivariable analysis revealed % RVP, (but not complete heart block at baseline), serum creatinine and previous myocardial infarction to be independently related to the presence of LVSD. A model combining % RVP and previous myocardial infarction has a c-statistic of 0.74 for predicting LVSD. After a mean follow-up time of 668 days, 56 patients (12%) were dead or had been hospitalized for heart failure. In multivariable analysis, previous myocardial infarction and high % RVP were independently associated with a worse survival. Patients with right ventricular pacemakers have a high prevalence of LVSD, and this is greater in those exposed to more RVP. Those with LVSD and high amounts of RVP are at higher risk of hospitalization or death. Simple variables can identify those patients who might benefit from a more comprehensive review.

Internal Pulse Generators in Deep Brain Stimulation: Rechargeable or Not?

Deep brain stimulation (DBS) is a cost-effective strategy for the treatment of different neurologic disorders. However, DBS procedures are associated with high costs of implantation and replacement of the internal pulse generator (IPG). Different manufacturers propose the use of rechargeable IPGs. The objective of this study is to compare the implantation costs of nonrechargeable IPGs versus the estimated costs of rechargeable IPGs in different categories of patients to evaluate if an economic advantage for the health care system could be derived. The study looked at 149 patients who underwent a surgical procedure for IPG replacement. In a hypothetical scenario, rechargeable IPGs were implanted instead of nonrechargeable IPGs at the time of DBS system implantation. Another scenario was outlined in a perspective period of time, corresponding to the patients' life expectancy. Costs were calculated, and inferential analysis was performed. A savings of €234,194, including the cost of management of complications, was calculated during a follow-up period of 7.9 years. In a comprehensive life expectancy period of 47 years, a savings of €5,918,188 would be obtained (P < 0.05). Long-term group data point out that a relevant savings would be expected from implantation of rechargeable IPGs in dystonic patients (P < 0.05) and patients with Parkinson disease (P < 0.05), and a savings isprojected to occur in other categories of patients (P < 0.05). Implantation of rechargeable IPGs presents clinical advantages compared with nonrechargeable devices. A huge economic savings can be realized with the implantation of rechargeable IPGs in categories of patients implanted with IPGs for DBS.

Vagus nerve stimulation and late-onset bradycardia and asystole: Case report

Vagus nerve stimulation (VNS) therapy is approved in the United States by the FDA in 1997 for medically refractory partial epilepsy in patients of ages 12 years and above. The most common stimulation-associated side effects are voice alteration, hoarseness, throat and neck pain, headache, cough, and dyspnea. Four patients with VNS had late-onset bradycardia and asystole, attributed to VNS stimulation. Their ages were 13, 17, 47, and 55. Cardiac symptoms were noted after 2.33–9 years postimplantation [1–4]. Three cases had symptoms correlated with stimulation, monitored by electrocardiogram [1,2,4]. This new case report highlights cardiac syncope with very similar clinical presentation as previous four cases, and raises the concern for cardiac symptoms, even many years after VNS implantation.

Pacing and Sensing of Human Heart for over 31 Years with the Same Apparatus (Generator and Lead).

Several patients receive a permanent pacemaker in a relatively young age, with multiple subsequent reoperations for pacemaker replacement. Pulse generator replacement is an invasive procedure, associated with the risk of various complications, mainly infection and skin erosion. A case of an extremely long-lasting pacemaker with a totally uneventful longevity period over 31 years is presented. The explanation for this quite rare pacemaker longevity (possibly unique) is analyzed and discussed.

The Gulf Implantable Cardioverter-defibrillator Registry: Rationale, Methodology, and Implementation.

Background:The implantable cardioverter-defibrillator (ICD) is effective in the prevention of sudden cardiac death in high-risk patients. Little is known about ICD use in the Arabian Gulf. We designed a study to describe the characteristics and outcomes of patients receiving ICDs in the Arab Gulf region.Methods:Gulf ICD is a prospective, multi-center, multinational, and observational study. All adult patients 18 years or older, receiving a de novo ICD implant and willing to sign a consent form will be eligible. Data on baseline characteristics, ICD indication, procedure and programing, in-hospital, and 1-year outcomes will be collected. Target enrollment is 1500 patients, which will provide adequate precision across a wide range of expected event rates.Results:Fifteen centers in six countries are enrolling patients (Saudi Arabia, United Arab Emirates, Kuwait, Oman, Bahrain, and Qatar). Two-thirds of the centers have dedicated electrophysiology laboratories, and in almost all centers ICDs are implanted exclusively by electrophysiologists. Nearly three-quarters of the centers reported annual ICD implant volumes of ≤150 devices, and pulse generator replacements constitute <30% of implants in the majority of centers. Enrollment started in December 2013, and accrual rate increased as more centers entered the study reaching an average of 98 patients per month.Conclusions:Gulf ICD is the first prospective, observational, multi-center, and multinational study of the characteristics and, the outcomes of patients receiving ICDs in the Arab Gulf region. The study will provide valuable insights into the utilization of and outcomes related to ICD therapy in the Gulf region.

Management of Cardiovascular Implantable Electronic Devices Infections in High-Risk Patients.

The incidence of infection following implantation of cardiovascular implantable electronic devices (CIEDs) is increasing, as is the number of pulse generator replacements and upgrades. The rate of infections is rising faster than the rate of device implantation, mainly due to the increasing age and number of comorbidities of patients receiving the devices. Patients with a CIED infection usually require hospitalisation, multiple consultations, prolonged intravenous antibiotics and, in the majority of cases, CIED explantation and replacement. A significant proportion die of their infection. CIED infection therefore represents a substantial health and economic burden, and management of infections is critical. Numerous risk factors have been identified including host, procedure and device-related factors. Established strategies for preventing CIED infections include intravenous antibiotics and aseptic techniques. The TYRX™ Absorbable Antibacterial Envelope offers potential as an effective method to reduce CIED infections. Several studies have found a statistically significant association between antibacterial envelope use and reduced incidence of CIED infection in high-risk patients. A prospective, randomised trial to further evaluate this potentially important strategy for CIED infection prophylaxis is underway.

How to avoid trivial mistakes during IPG replacement in patients treated with DBS for movement disorders: technical note from 13-years experience

Purpose: Recent data suggest how adverse events occur more frequently after Implantable Pulse Generator (IPG) replacement than during the deep electrode positioning in patients treated with Deep Brain Stimulation (DBS). For instance, erroneous extension adjustment to change in laterality and inaccurate lead connection represent problems, which strongly affect patients’ outcome. We analyzed our data after 13 years of IPG replacement. Materials and Methods: We treated 107 patients (83 PD and 24 Dystonia) with DBS in 13 years. The Dual Channel IPGs replaced during this period were 91. 25 patients needed more than one replacement, especially among the dystonic population. During surgery, we temporarily marked in all the cases the right extension lead before the disconnection from the exhausted IPG. Good impedances were intraoperatively checked in all the cases. Results: Our surgical technique allowed us to avoid any erroneous change in laterality or abnormal impedances due to a suboptimal connection to the IPG. The mean duration of the operation was 25 min and a quick postoperative restart of DBS was possible in all the cases. Stability of symptoms after IPG replacement was achieved in all the patients, with an accurate clinical management within the first 48–72 postoperative hours. Conclusion: Our surgical and postoperative management demonstrates how to avoid some important adverse events with some easy steps, without any discomfort for the patients in terms of duration of surgery or longer hospitalization. Thus, stability of symptoms after the IPG replacement may be easily guaranteed during the first postoperative period.

Increasing Infection Rate in Multiple Implanted Pulse Generator Changes in Movement Disorder Patients Treated with Deep Brain Stimulation

Background: Deep brain stimulation has been performed at the Department of Neurosurgery, Aarhus University Hospital (AUH), for 16 years. The risk of infection related to implantable pulse generator (IPG) replacement constitutes a weakness in the long-term DBS treatment. Object: The aim of this study is to investigate the association between risk of infection and number of IPG replacements. Methods: All patients who underwent IPG replacement at the AUH from June 1996 until September 2012 were included in the study, and their medical records were systematically reviewed. The data was analyzed using Fisher's exact test on contingency tables. Results: 220 procedures of IPG replacement were completed on 105 patients who suffered from various movement disorders. Up to 5 IPG changes were registered in a single patient. Thirteen patients incurred infection requiring surgical intervention. Testing for risk of infection associated with number of IPG changes, this study found significantly different infection rates (p = 0.0052). In the groups with 3 and 4 IPG changes, infection rates reached over 20%. Conclusion: This study found significantly different rates of infection related to the number of IPG changes. Further investigation and resources should be directed towards improving the lifespan of IPGs.

Ampere Hour (Ah) as a Predictor of CRT ICD Pulse Generator Battery Longevity. A Multi-Center Study

CRT-D devices offer survival benefit in select NYHA class II-IV systolic heart failure patients with QRS >120ms and LVEF <35%. A limitation of 100% CRT pacing is excess battery drain, and earlier pulse generator (PG) replacement for CRT systems. CRT-D pulse generator change is associated with significant infection risk, morbidity, and cost. Ampere-hour or Ah measures residual PG battery capacity and may predict device longevity.

Replacement of a deep brain stimulation implantable pulse generator with a rechargeable device

Aim In the present study, we report on the technical hiccups encountered while replacing the implantable pulse generator (IPG) for deep brain stimulation with a new rechargeable device. Patients and Methods Two dystonia patients suffered from inefficient recharging after replacement of the IPG to the rechargeable device. After identifying the problem, we employed a surgical technique on the third patient. Results The problem was the small size of the new device. The device had a freedom-of-transverse translation and a rocking movement inside the pocket. This unstable positioning lengthened the recharging time in these two patients. By fixing the device on to the adaptor and obliterating the lateral space, the third patient encountered no recharging problems. Conclusion Based on the findings of this study, IPG should be fixed on a flat subcutaneous plane and obliterate the lateral space to avoid the problem.

Evaluation of high-perimeter electrode designs for deep brain stimulation

Objective. Deep brain stimulation (DBS) is an effective treatment for movement disorders and a promising therapy for treating epilepsy and psychiatric disorders. Despite its clinical success, complications including infections and mis-programing following surgical replacement of the battery-powered implantable pulse generator adversely impact the safety profile of this therapy. We sought to decrease power consumption and extend battery life by modifying the electrode geometry to increase stimulation efficiency. The specific goal of this study was to determine whether electrode contact perimeter or area had a greater effect on increasing stimulation efficiency. Approach. Finite-element method (FEM) models of eight prototype electrode designs were used to calculate the electrode access resistance, and the FEM models were coupled with cable models of passing axons to quantify stimulation efficiency. We also measured in vitro the electrical properties of the prototype electrode designs and measured in vivo the stimulation efficiency following acute implantation in anesthetized cats. Main results. Area had a greater effect than perimeter on altering the electrode access resistance; electrode (access or dynamic) resistance alone did not predict stimulation efficiency because efficiency was dependent on the shape of the potential distribution in the tissue; and, quantitative assessment of stimulation efficiency required consideration of the effects of the electrode–tissue interface impedance. Significance. These results advance understanding of the features of electrode geometry that are important for designing the next generation of efficient DBS electrodes.

Investigation of Deep Brain Stimulation Mechanisms During Implantable Pulse Generator Replacement Surgery

Direct testing of deep brain stimulation (DBS) mechanisms in humans is needed to assess therapy and to understand stimulation effects. We developed an innovative paradigm for investigation of DBS on human movement disorders. Temporary connection to the DBS electrode during implantable pulse generator (IPG) replacement permitted analysis of novel patterns of stimulation on motor symptoms, which could enhance efficacy and improve battery life. Patients enrolled in this prospective, Institutional Review Board-approved study underwent IPG replacement using local (monitored) anesthesia. Following device explant, the DBS electrode was connected to an external, isolated electrical stimulator using a sterile adapter cable. Different temporal patterns of stimulation were delivered while quantifying upper-extremity tremor (tri-axial accelerometry) or bradykinesia (finger-tapping). Upon experiment completion, the new IPG was implanted. Among 159 IPG replacements from 2005 to 2011, 56 patients agreed to the research study (16 essential tremor [ET], 31 Parkinson's disease [PD], 5 mixed ET/PD tremor, 3 multiple sclerosis, 1 tremor/myoclonus). Surgical procedures were extended by 42 ± 8.2 min in 37 patients completing the study. Motor symptoms varied with stimulation pattern, with some patterns showing improved tremor or bradykinesia control. No postoperative infections or complications were observed in the 159 patients. IPG replacement occurs when the DBS/brain interface is stable and patients demonstrate symptom reduction with known stimulation parameters. Conducting research at this time point avoids DBS implant issues, including temporary microlesion effects, fluctuating electrode impedances, and technical limitations of contemporary IPGs, providing advantageous conditions to conduct translational DBS research with minimal additional risk to research subjects.

Integrity failure in Riata and Riata ST defibrillator leads: An ongoing problem

Riata and Riata ST silicone defibrillation leads are prone to externalization of conductors due to inside-out abrasion in the high-voltage system, causing structural damage which may be accompanied by electrical failure. These situations are easily detected by fluoroscopy or radiology and by inspection of intracardiac electrograms and/or measurement of impedance. However, older pulse generators do not automatically perform all the measurements needed to assess the integrity of the high-voltage electrical system, nor do they have patient notifier alerts in case of dysfunction.The authors describe the case of a patient in whom structural damage was detected on fluoroscopy during pulse generator replacement. They discuss the best strategy in these patients, considering current knowledge of this dysfunction.