Prepectoral Region Research Articles

CASE PRESENTATION: A COMPLEX CLINICAL SCENARIO IN A 43–YEAR–OLD MALE WITH DEVICE–RELATED COMPLICATIONS

Abstract A 43 yo male presented with an exposed pocket of his ICD in the right prepectoral and axillary region, along with total exposure of the lead electrodes up to the fixation sleeves.The patient, a known carrier of double–outlet right ventricle, underwent surgical correction. At the age of one, he received a dual–chamber pacemaker in the left prepectoral region due to AVB. Due to recurrent sustained ventricular tachycardias an ICD was implanted in the right prepectoral region, with removal of the left–sided pacemaker and concurrent abandonment of the ventricular pacing lead. In October 2019, he was admitted for a recurrence of pocket erosion.Device extraction was proposed but declined by the patient. Subsequently, he was referred to our institution for device removal. After heart team discussion, the patient was offered a transvenous lead extraction, with potential cardiothoracic surgical intervention if transvenous extraction proved to be challenging.An attempt was made to extract the leads using a transvenous approach. The procedure proceeded without complications, and the leads were released from adhesions up to the superior vena cava. However, there was an adhesion point at this location that was not overcome by mechanical dilation.Due to this limitation, a few days later, a cardiothoracic surgical intervention was performed to complete the lead wires‘ extraction using an invasive approach. In this context, a cardiac resynchronization device CRT–P was reimplanted in the left prepectoral region with epicardial electrodes. The patient underwent submuscular subclavian implantation of a SCID.The patient presented with a new pocket erosion of the CRT–P.Considering the high infection risk, It was therefore decided to implant a leadless device following electroanatomic mapping of the right ventricle, as there were surgical patches in the septal region. This approach aimed to identify the optimal anchoring site for the device. Subsequently, he will go extraction of the generator of the CRT–P.The decision to forgo biventricular stimulation was made, because of the elevated infectious risk.Complications associated with implantable devices pose an increasingly significant challenge in managing young patients with cardiac arrhythmias. Only through an integrated approach and proactive sharing of knowledge and expertise can we significantly improve clinical outcomes and the quality of life for this increasingly relevant population.

Pacemaker in patients undergoing mammography: A limitation for breast cancer diagnosis?

A pacemaker may affect the utility of a mammogram in several ways. The aim of this study is to summarize our institution's experience with mammograms among patients with a cardiac pacemaker, focusing on the diagnostic workup among patients with a newly diagnosed ipsilateral breast cancer. A retrospective search of all mammography reports between January 2011 and April 2021 was conducted for identifying cases of patients with a pacemaker. Demographic and clinical characteristics as well as mammography-derived quality parameters and findings were categorized and statistically compared. The incidence of pacemaker concurrence in mammographic examination, although apparently slightly under-documented, accounted for 0.33% of cases. Population mean age was 71.7 years, and most patients (79%) had a left-sided pacemaker. The pacemaker was much more likely to be projected on the medio-lateral-oblique (96%) than on the cranio-caudal view (10%), on the axilla rather than the breast, and on the retro-pectoral rather than the pre-pectoral region (P < 0.001 for all). Compression force decreased by up to 23.0% (P < 0.001) and breast thickness increased by up to 9.5% (P < 0.001) for the ipsilateral vs. the contralateral side. Among 11 patients with newly diagnosed ipsilateral breast cancer, the pacemaker partially projected on the tumour region in two cases, and significantly obscured the tumour in another two. Although rare, the coexistence of a pacemaker in patients undergoing mammography is associated with reduced image quality due to suboptimal breast visualization and reduced compression, and as a result, this may eventually lead to decreased diagnostic efficacy.

Balanced Steady-State Free Precession Cine MR Imaging in the Presence of Cardiac Devices: Value of Interleaved Radial Linear Combination Acquisition With Partial Dephasing.

Balanced steady-state free precession (bSSFP) is important in cardiac MRI but suffers from off-resonance artifacts. The interpretation-limiting artifacts in patients with cardiac implants remain an unsolved issue. To develop an interleaved radial linear combination bSSFP (lcSSFP) method with partial dephasing (PD) for improved cardiac cine imaging when implanted cardiovascular devices are present. Prospective. Flow phantom adjacent to a pacemaker and 10 healthy volunteers (mean age ± standard deviation: 31.9 ± 2.9 years, 4 females) with a cardioverter-defibrillator (ICD) positioned extracorporeally at the left chest in the prepectoral region. A 3-T, 1) Cartesian bSSFP, 2) Cartesian gradient echo (GRE), 3) Cartesian lcSSFP, and 4) radial lcSSFP cine sequences. Flow artifacts mitigation using PD was validated with phantom experiments. Undersampled radial lcSSFP with interleaving across phase-cyclings and cardiac phases (RLC-SSFP), combined with PD, was then employed for achieving improved quality of cine images from left ventricular short-axis view. The image quality in the presence of cardiac devices was qualitatively assessed by three independent raters (1=worst, 5=best), regarding five criteria (banding artifacts, streak artifacts, flow artifacts, cavity visibility, and overall image quality). Wilcoxon rank-sum test for the five criteria between Cartesian bSSFP cine and RLC-SSFP with PD. Fleiss kappa test for inter-reader agreement. A P value < 0.05 was considered statistically significant. Based on simulations and phantom experiments, 60 projections per phase cycling and 1/6 PD were chosen. The in vivo experiments demonstrated significantly reduced banding artifacts (4.8 ± 0.4 vs. 2.7 ± 0.7), fewer streak artifacts (3.7 ± 0.6 vs. 2.6 ± 0.7) and flow artifacts (4.4 ± 0.4 vs. 3.7 ± 0.6), therefore improved cavity visibility (4.1 ± 0.4 vs. 2.9 ± 0.9) and overall quality (4.0 ± 0.4 vs. 2.7 ± 0.7). RLC-SSFP method with PD may improve cine image quality in subjects with cardiac devices. 2. Stage 1.

How to perform extrathoracic venous access for cardiac implantable electronic device placement: Detailed description of techniques

Venous access is needed for implantation of cardiac implantable electronic devices (CIEDs) with endocardial leads. Extrathoracic venous access in the prepectoral region has become the standard of care for CIED implantation because of lower risks for pneumothorax and likely less lead malfunction due to subclavian crush syndrome. The most common extrathoracic venous access sites in the pectoral region are extrathoracic subclavian vein access, axillary vein access, and cephalic vein access. This review provides a detailed description of the anatomy, technical considerations, and relative advantages and disadvantages of each of these extrathoracic venous access sites.

Long-term results of conservative treatment of pacemaker pocket site infections.

The increasing frequency of cardiac device use has led to an increase in complication rates. The standard treatment for cardiac device-related infections is removal of the entire pacemaker system and reimplantation from the contralateral side after systemic antibiotherapy. The efficacy of various conservative treatments has been established for many years, but there is conflicting information in the literature regarding long-term efficacy. Our study investigated the long-term efficacy of conservative treatment in patients with pacemaker pocket site infection. In this retrospective study, according to the exclusion criteria, 132 patients were included. Patients were divided into conservative and standard treatment groups. Conservative treatment was considered to be opening the pacemaker pocket capsule, removing all infected and necrotic tissue, cleaning the capsule, and embedding the battery in the prepectoral region in the subpectoral muscle region. The follow-up time was 36 ±12.96 months in the conservative treatment group and 39.6 ±10.8 months in the standard treatment group. During this period, no re-infection at the pacemaker pocket site was observed in either group. Examination of the swab cultures of the patients' pacemaker wounds revealed negative culture results in 15 patients (15 out of 60) in the conservative treatment group. In the standard treatment group, 60 patients (60 out of 72) were culture-negative. This difference was statistically significant (p = 0.04). After a rigorous evaluation, conservative treatment is considered effective and safe in the long term in patients with device pocket site infection.

616 Endocardial lead placement guided by high resolution voltage mapping in a patient with recurrent failure of transvenous pacing system

Abstract Methods and results A 58 years-old man was admitted to our intensive care unit for syncope due to inconstant capture of epicardial ventricular lead. His cardiovascular history began 20 years before when he underwent single chamber pacemaker implantation with insertion of a passive fixation ventricular lead for symptomatic complete atrio ventricular block (AVB). Electrical parameters were good at implantation. However, during follow-up a gradual and progressive increase of pacing threshold occurred, with no changes in impedance values, finally leading to complete loss of ventricular capture. Hence, 2 years later, the lead was extracted and a new transvenous ventricular lead was placed in septal position. All electrical parameters were optimal at the end of the procedure. However, in the following months threshold values gradually increased as previously observed. The referring clinicians decided to surgically extract both the device and transvenous lead and to implant an epicardial ventricular lead connected to an abdominal generator. The pacemaker worked properly for about 17 years until he was transferred to our institution with evidence of inconstant lead capture at maximum pacing outputs. A temporary transvenous pacemaker was immediately inserted. Clinical examination, laboratory exams, and echocardiography were normal. Cardiac magnetic resonance (MRI) was not feasible due to the epicardial lead. Thus, in order to obtain cardiac substrate characterization, we decided to perform high density multielectrode voltage mapping of the right ventricular endocardium with HD Grid multielectrode mapping catheter (HD Grid mapping catheter sensor enabled, Abbott Technologies, Minneapolis, MN). Electroanatomic voltage map allows distinction of areas of healthy myocardium (&amp;gt;1.5 mV) from scar tissue (&amp;lt;0.5 mV). Unexpectedly, voltage mapping highlighted no scar zones, showing a globally normal endomyocardial surface. Therefore, a new endocavitary pacemaker was inserted in right prepectoral region and an active fixation right ventricular lead was placed on mid-ventricular septum. A backup pacing lead was placed in a more apical position in an area of endocardial healthy myocardium. Post-procedural sensing, impedance and capture threshold were optimal (0.3 V × 0.4 ms for mid-septal lead and 0.3 × 0.4 ms for the other one). At 1 month follow-up mid-septal lead’s threshold was slightly increased (1.0 V × 0.4 ms) and further increase was observed at 3-month outpatient visit (1.75 V × 0.4 ms). Capture threshold of the other lead and other parameters were stable. The patient received remote monitoring for home surveillance of the implanted system. Home monitoring shows a trend toward a progressive increase of pacing threshold of the mid-septal lead and stable value of the other electrode. Conclusions The present report suggests an innovative use of high-density mapping with HD Grid catheter to characterize endocardial right ventricular myocardium in a patient with contraindication to cardiac MRI and recurrent failure of previous implanted pacing systems for unknown reason and to guide effective lead placement in areas of normal endocardial voltage. Combined use of telemedicine and high-resolution mapping technique allowed us to avoid unnecessary high risk reintervention for novel epicardial lead placement.

Baseline incision characteristics and early scar maturation indices following cardiac device implantation.

AimsDermatologic evaluation for cardiac implantable electronic devices (CIEDs) has not been established. We sought to ascertain baseline wound scar features using quantifiable surgical tools and scar scales on post‐CIED patients.MethodsA single‐center, prospective observational case‐control study was performed where 92 study subjects (40 healthy volunteers and 52 post‐CIED patients) completed the study. Durometer was used to quantify skin pliability before CIED placement, postprocedure, and 2 weeks postprocedure. Higher durometer readings signified reduced skin pliability. Durometer readings were compared to the patients’ contralateral pectoral skin and to a healthy volunteer's cohort skin within the prepectoral region. Patient wounds were observed and graded using the Patient Observer Scar Assessment Scale (POSAS) and Manchester Scar Scale (MSS).ResultsBaseline pectoral skin pliability readings were similar in healthy volunteers and CIED patient population. In comparison to preprocedural measurements, surgical site skin pliability decreased in postprocedural and 2 weeks follow‐up time points (P‐value .004 and <.001, respectively). The increases in durometer readings were higher in the older population (age >75 over time, P = .008). POSAS evaluations showed on average a thin painless hypopigmented scar with moderate stiffness. MSS scar evaluation showed a palpable scar with slight contour differences and color mismatch and appeared to be slightly better in the African American population. There was no difference in scar characteristics with preprocedural use of antiplatelet or anticoagulation or staple closure or gender.ConclusionsSerial measurements could be of value for development of new strategies for cosmesis and improved wound healing.

Strategies to Promote Long-Term Cardiac Implant Site Health.

In the past several decades there has been a continuous growth in the field of cardiac implantable electronic devices (CIED) implantation procedures as well as their technological development. CIEDs utilize transvenous leads that are introduced into the heart via the axillary, subclavian, or cephalic veins, as well as a devices generator that is implanted in a subcutaneous pocket, typically in the pre-pectoral region. Despite this significant improvement, complication rates range from 1-6% with current implant tools and techniques. In this review we will discuss the three central parts of the CIED implantation procedure, their impact on implantation site, infections, and possibilities for its prevention.

External closed-circuit cooling system for management of patients after device implantation: A feasibility study

BackgroundIn the first 24h after pacemaker or implantable cardioverter/defibrillator (ICD) implantation or replacement, the occurrence of hematoma and pain in the surgically treated region is not infrequent and may result in re-intervention and/or more severe complications, such as infections. Currently, the post-implant phase management is very empiric. The aim of this study was to test the clinical applicability and usefulness of an external close-circuit cooling system for the management of the early post-implant period in patients with high risk of hematoma due to anticoagulant and/or antiplatelet therapy. MethodsWe studied 135 patients (78M; 71±11years) with high risk of hematoma occurrence after pace-maker (63 patients) or ICD (72 patients) implantation or replacement. Immediately after the intervention, a closed-circuit cooling system (CAREPACE™ system, Zamar, Italy) was externally applied on the pre-pectoral region to each patient and maintained for 24h. The system has a compressive pad and a refrigerating circuit in which non-toxic glycolic fluid is pumped. The fluid temperature was set and kept at 5°C for the whole period. ResultsThe compressive and cooling effect of the system was well tolerated by all the patients at the temperature set. Four patients complained of noise due to machine operation, but in none the treatment was interrupted. The average length of hospital stay was 2.8±0.4days. No clinically significant hematoma was observed at discharge and after one month follow-up visit. ConclusionsThis new system can be used for the management of the early phase after device implantation or replacement and appears clinically useful and well tolerated. Further studies on a larger scale are needed to test the potential reduction of post-intervention complications and the cost-effectiveness of this device.

Evaluation of Interaction between a Spinal Cord Stimulator and Implanted CardioverterDefibrillator in a Swine Model

Background: Spinal cord stimulators (SCS) have been used for many years to treat a myriad of chronic pain conditions using electrical signals to diminish the perception of a painful stimulus. Because of the electrical nature of the devices, there is a concern about the potential for electromagnetic interaction between the device and lifesaving cardiac implantable cardiovertersdefibrillators (ICVD). Objective: The purpose of this study was to use a swine model to evaluate the potential for interaction between an implanted SCS and ICVD using the closest possible proximity, highest stimulation settings, and most sensitive ICVD settings. Methods: A pig was anesthetized and subsequently an ICVD and ICVD lead (Cogni 100-D and Endotak Reliance®, Boston Scientific, Natick, MA) were placed into the right prepectoral region and the right ventricle, respectively. An SCS (50 cm linear ST Precision Plu octad electrode lead [Boston Scientific, Valencia, CA] with 3 mm wide contacts spaced one mm apart) was implanted using fluoroscopic guidance into the posterior epidural space. Remote interrogation and programming of the ICVD were performed while the SCS lead was placed in as close proximity as possible, using fluoroscopy to guide the final position of the SCS electrode. After confirming that both systems were working, appropriately 9 stimulating configurations of varying current, pulse width, and frequency, including maximal settings, were delivered through the SCS. The effects on the ICVD were recorded at 2 sensitivity settings. Results: None of the tested SCS configurations caused interference with the proper functioning of the ICVD. Limitations: The anatomical proximity of the posterior epidural space and right ventricle of the swine is different from humans. While the entire pacer, including generator, was imbedded in a subcutaneous pocket, an implantable pulse generator for the SCS was not implanted, which did not allow us to study if any damage or a resetting of settings had occurred to the generator. Only one manufacturer was used in this study. Also, this study was performed in an anesthetized pig and the anatomical positions remained static. Realistically, changes in position of the devices would occur in patients who perform activities of daily living, and this can potentially shorten the distance between the 2 leads causing adverse interaction. Conclusion: This study clearly demonstrated the feasibility of the 2 devices coexisting and functioning appropriately in an animal model using an ICVD and SCS donated by Boston Scientific. Further studies are needed to elucidate restrictions, optimal settings and parameters in a human setting. Key words: Spinal cord stimulator, interaction, implantable cardioverter defibrillator, pacemaker, swine model, cross-talk.

Use of oxidized regenerated cellulose to prevent pocket hematomas after cardiac electronic device implantation in patients on anticoagulants or dual antiplatelet therapy

Up to 30% of patients remain on anticoagulants or antiplatelet agents at the time of implantation of cardiac electronic devices [1]. The use of clopidogrel alone, dual antiplatelet therapy (DAPT) or intravenous heparin significantly increases the risk of hematoma post device implantation [2–4]. Then again, withholding anticoagulants or antiplatet therapy peri-operatively may result in thromboembolic complications. Surgicel® FibrillarTM Hemostat (Ethicon Inc. USA) is a form of oxidized regenerated cellulose (ORC), a plant-based topical hemostatic agent that is used adjunctively in surgical procedures to help control capillary, venous and small arterial hemorrhage when conventional methods of hemostasis are impractical [5,6]. It is fully absorbablewithin 14 days and has in-vitro bactericidal properties [6,7]. We describe a pilot series of 42 patients who received Surgicel® FibrillarTM Hemostat during implantation of cardiac pacemakers or defibrillators whilst remaining on anticoagulants or DAPT. We aim to assess the safety and efficacy of ORC in prevention of pocket hematomas in this group of individuals at high risk of bleeding complications postimplant. In our institution, patients on antiplatelet therapy or warfarin remain on these medications when they undergo implantation of cardiac pacemakers or defibrillators. The international normalized ratio (INR) is titrated to less than 3. A pocket hematoma is defined as a palpable mass that protrudes N2 cm (minor hematoma) or N4 cm (significant hematoma). Between 1 April 2012 and 31 January 2013, we identified 42 patients onwarfarin or DAPT inwhom implantation of cardiac electronic devices was indicated (See Table 1). Their mean age was 68 ± 8 years, 28 were males. Eighteen patients were onwarfarinwith a mean INR of 2.5 ± 0.2 peri-operatively. Of these 18 patients, 3 were on both warfarin and clopidogrel 75 mg daily. Twenty-four patients were on DAPT consisting of aspirin 100 mg and clopidogrel 75 mg daily. Each patient received 1 dose of intravenous cephazolin 1 h prior to the procedure. During implantation, a subcutaneous pocket was created in the pre-pectoral region with the use of electrocautery. All visible bleeding sites, especially arterial ones, were meticulously cauterized. Vascular access was obtained through subclavian or axillary venous punctures under fluoroscopy guidance. Each lead was implanted via a separate venous puncture. Following placement of the pulse generator in the pocket, Surgicel® FibrillarTM Hemostat was peeled off in the desired amount and the pieces fitted into the pocket, above and to the sides of the pulse generator. The wound was then closed in 2 layers with absorbable sutures and a sterile dressing applied. Each patient was prescribed a 1-week course of oral cephalexin post-implant. They were examined daily until hospital discharge and they returned for outpatient follow-up on Day 7 and 1 month postimplant for wound inspection and device check. Subsequent follow-up was at 3 to 6 monthly intervals. There was no case of pocket hematoma or infection with a mean follow-up period of 6 ±2.3 months. Despite the continued use of warfarin and DAPT peri-operatively, none of our patients developed pocket hematoma or infection. ORC appeared to be safe and effective in prevention of bleeding complications in high-risk individuals during device implantation. In the setting of anticogulation or DAPT, capillary or venous ooze is common. Conventional methods to achieve hemostasis may prove ineffective, especially in the confined areas of the subcutaneous pocket. The benefit of topical hemostatic agents in such settings is controversial. Milic et al. reported that the administration of fibrin sealant in patients on anticoagulation eliminated post-operative pocket hematomas after pacemaker implantation [8]. Recently, Ohlow et al. published data showing that the use of D-Stat HemostatTM (Vascular Solutions Inc. USA) tended towards a higher incidence of pocket hematoma requiring evacuation and pocket infections [9]. ORC is ready for use straight out of the packaging. It can be cut or peeled into customized sizes and fitted into the subcutaneous pocket. It provides a matrix for platelet adhesion and aggregation by melting into bleeding tissue, thereby serving as a hemostatic adjunct in the control of capillary, venous and small arterial hemorrhage. It is fully absorbed from the sites of implantation within 1 to 2 weeks with no tissue reaction. In-vitro studies highlight its bactericidal properties [7]. Given such features, ORC may potentially be suitable as a topical hemostat during cardiac electronic device implantation. Our study is limited by its small sample size and non-randomized design with no control arm. Large randomized trials comparing ORC versus standard care are necessary to fully evaluate the effectiveness and

Percutaneous Epicardial Defibrillation Coil Implantation

Received December 8, 2009; revision accepted February 9, 2010. A 70-year-old African American female with known history of nonischemic cardiomyopathy (ejection fraction, 15%) was referred for BiVentricular implantable cardioverter-defibrillator (BiV-ICD) implantation for primary prevention. Because of a previous left mastectomy for breast cancer and occlusion of the left subclavian axillary venous system, a right-sided prepectoral implant was chosen for this patient. The procedure included a right-sided prepectoral BiV-ICD implantation, implantation of a right atrial appendage active fixation lead, a single-coil active fixation right ventricular lead, and a left ventricular coronary sinus lead. During the routine testing of the ICD, the defibrillation threshold (DFT) was >35 J, requiring external cardioversion. A second DFT testing performed thereafter with a polarity modification was also >35 J. The patient was subsequently treated with sotalol 80 mg bid for 1 week and the DFT was repeated but was still refractory (>35 J). Hence, alternate options were entertained. Although a left-sided subcutaneous coil array was considered, it was abandoned because the coil extension had to cross the midline of the chest. However, a percutaneous epicardial defibrillation coil implantation was considered (Figure 1A). Figure 1. A, Anteroposterior chest radiograph showing the BiV-ICD generator in the right prepectoral region with the defibrillation coil (halo) in the pericardial space. B, Subxyphoid approach (arrow) to access the pericardial space. Note …

Computed Tomography angiographic demonstration of collateral circulation in superior vena cava syndrome

2 r vena Surg This 63-year-old man had a dual-chamber perman acemaker (PPM) placed in the right prepectoral posi or sick sinus syndrome in 1997. After a failed lead re n 2000, both the atrial and ventricular leads were cu bandoned in the right subclavian vein. A second pa eads was then inserted through the right subclavian v he pacemaker pocket then became infected, leading xplant of the device and 1 lead, leaving 3 leads in th ubclavian vein. A new dual-chamber PPM was then pl n the left prepectoral region through the left subcla ein. In 2005, the patient sought treatment at our ho or edema of the head and bilateral upper extremities resyncope when bending forward. Chest x-ray at adm ion confirmed the presence of 5 pacemaker leads. A ated computed tomography (CT) angiography of the ax was performed on a Biograph 16 scanner (Siem orp, New York, NY) after 75 mL of contrast injection

Rib Perforation From a Right Ventricular Pacemaker Lead

A 50-year-old man was admitted to a community hospital for high fever. Seven years earlier, he had been in a motor vehicle accident and a cervical spine injury had resulted in quadriplegia and ventilator dependence. During that hospitalization, he was noted to have long sinus pauses that were thought to be vagally mediated, and a single-chamber pacemaker was implanted to hasten his recovery, with an active fixation pacing lead placed at the right ventricular apex (Figure 1A through 1C). His bradycardia spells subsequently disappeared, and minimal pacing was needed. Figure 1. Serial chest radiographs showing the pacemaker lead position at the time of implantation (A), at initial hospital discharge (B), 7 months after implantation (C), and at the current admission (D). The position of the lead tip is designated by an arrow, and the lead tip is clearly located outside the rib cage (D). Because of spiking fevers, leukocytosis, and methicillin-resistent Staphylococcus aureus growing from blood cultures; a …

Prevalence of Venous Obstruction in Permanent Endovenous Pacing in Newborns and Infants: Follow‐Up Study

We examined the prevalence of venous obstruction in 12 newborns and infants with permanent endovenous ventricular pacing, clinically, and by ultrasonographic assessment of hemodynamics (spontaneity, phasicity, velocity, and turbulence of flow) and morphologic parameters (compressibility, wall thickness, and thrombus presence). All implantations of single ventricular unipolar endovenous steroid leads, were performed via cephalic vein, and pacemakers were placed in subcutaneous pocket in right prepectoral region. After the vascular surgeon has carefully examined all children for presence of venous collaterals in the chest wall, morphologic and hemodynamic parameters of the subclavian, axillary, and internal jugular veins, were assessed by linear-array color Doppler. Lead capacity (LC) was calculated for each patient. Mean age of patients at implant was 6.2 months (range 1 day-12 months), mean weight 6.5 kg (range 2.25-10 kg), and mean height 60.9 cm (range 48-78 cm). Mean LC was 1.99 (range 1.14-3.07). Total follow-up was 1023 and mean follow-up 85.2 pacing months (range 3-156). No clinical signs of venous obstruction were observed. Mild stenosis (20%) of subclavian vein was found by color Doppler in 2/12 patients. Both had adequate lead diameter for body surface. Permanent endovenous pacing is a feasible procedure, even in children of body weight less than 10 kg, with quite acceptable impact on venous system patency.

Reconstruction secondaire des moignons d'amputation au-dessus du coude. À propos de cinq cas cliniques

The authors report a serie of five patients with five stumps above the elbow who needed a secondary reconstruction to allow or facilitate a prosthesis. They used in the first case an expansion of the latissimus dorsi flap and of the axillary and prepectoral region in order to free the stump of the humerus sutured on the thorax. In the second case, a free parascapular flap covered an unstable scar of the clavicula after a scapulothoracic amputation. In the third case, the transfer of a free flap of fibula associated with a pedicled latissimus dorsi flap had allowed the elongation of the stump of the humerus. In the two last cases, a latissimus dorsi flap pedicled in one and free in the second one had allowed to preserved the length of the humerus for prosthesis. The technical choices are eclectic and different in every case. The purpose is to obtain an efficient trophicity and a thickness that can support the prosthesis and if possible a stump long enough to improve the adaptation of the prosthesis. The five operated patients were able to be apparated, reducing in this way their daily functional difficulties.

Right side implant of the unipolar single lead defibrillation system.

The active can defibrillator has been designed for implantation in the left prepectoral region. Whether this system can be successfully implanted on the right side is unknown. We describe six cases in which placement of the unipolar single lead defibrillation system was successfully attempted in the right prepectoral region due to impediments on the left side. The mean age of the patients was 62 +/- 12 years. Five patients had ischemic heart disease and one idiopathic dilated cardiomyopathy. The endocardial defibrillation electrode was placed in the right ventricle through the right subclavian vein and positioned at the apex in two patients and in the septal position in four patients. Defibrillation threshold testing was performed using a step-up/step-down protocol beginning at 12 J with 3-J increments or decrements. Defibrillation threshold was defined as the lowest energy of the first shock able to terminate ventricular fibrillation. The generator models used were the Medtronic 7218C in 1 patient, the Medtronic 7219C in 3 patients, and the Ventritex Cadet 115 AC in 2 patients. The mean defibrillation threshold was 15 +/- 3 J. The defibrillation thresholds were retested at 1, 3, and 6 months, and showed no significant change in five patients but decreased from 15 J to 12 J in one patient. The presence of impediments on the left side should not preclude attempts to place the unipolar active can system in the right prepectoral region.

Consistent Subcutaneous Prepectoral Implantation of a New Implantable Cardioverter Defibrillator

To describe the use of a new implantable cardioverter defibrillator (ICD) that can be placed in the prepectoral region rather than implanted in the abdominal wall. We report the experience of placement of this new ICD in the prepectoral region in 13 patients from Sept. 28, 1993, through Jan. 10, 1994, at the Mayo Clinic. Thirteen consecutive patients offered this new ICD underwent placement of transvenous defibrillation leads, and the pulse generator was placed in a pocket formed in the subcutaneous, prepectoral space. Testing ensured a defibrillation threshold of 24 J or less. In all 13 patients, the pulse generator could be placed in the subcutaneous, prepectoral space. In all except one patient, acceptable defibrillation thresholds were achieved by using lead systems placed totally transvenously. Only one patient required placement of a subcutaneous patch. All but two patients were dismissed from the hospital within 3 days after the ICD implantation. Consistent subcutaneous, prepectoral placement of this new ICD pulse generator is possible. Because the entire procedure can be performed in the pacemaker implantation room, the potential exists for decreasing the duration of the hospitalization and associated costs.

Gynecomastia: Treatment by Liposuction Subcutaneous Mastectomy

Gynecomastia is a common finding in both adolescents and mature adult males. The previous surgical techniques of direct subcutaneous mastectomy were associated with high frequency of complications and unsatisfactory aesthetic results. Application of liposuction techniques to the prepectoral region has provided an effective and safe technique for reliably contouring and reducing the prepectoral region. The technique described in this article includes proper placement of the incision, the injection of low-dose Xylocaine and epinephrine, and the utilization of three different types of cannulas to significantly reduce the tissue mound. The author has operated upon 60 patients utilizing this technique without having a single operative complication.

Rate Modulation by Arm Movements of the Respiratory Dependent Rate Responsive Pacemaker

The rate response to arm movements of the respiratory dependent rate responsive pacemaker (RDP3, Biotec) was assessed in four patients implanted with this pacemaker. The pacemaker was implanted in the left prepectoral region and the auxiliary impedance measuring electrode positioned subcutaneously over the right second intercostal space with its tip lateral to the mid-clavicular line. The lower rate of the pacemaker was programmed to 75 bpm. While holding the breath, swinging arm movements (30 times) resulted in rate acceleration. The peak rate was faster when the arm on the side of the auxiliary electrode was swung (mean +/- SEM, 117 +/- 8 compared to 130 +/- 5 bpm, P less than 0.5). The mean rate response of the subjects to brief treadmill exercise (Bruce stage I) performed with both hands holding the support rails, swinging the right arm only, swinging left arm only and swinging both arms were 108, 140, 135 and 128 bpm respectively. Impedance measurement confirmed the significant influence of arm movements on thoracic "impedance" changes, which was mainly caused by electrode motion artifacts affecting the two electrode measuring system. This effect was dependent on the relative positions of the impedance measuring electrodes (i.e., between the pacemaker casing the auxiliary lead). Subsequently the auxiliary lead of the respiratory pacemaker (MB-1, and Biorate) was implanted in the lower part of the chest on the right sternal edge in another patient. Rate acceleration was only observed when the arm on the side of the pacemaker was swung. As arm movements often accompany physical activities, pacing rate can be affected and should be considered when programming this pacemaker.