Easy Implantation Research Articles

Central venous access port devices (cvapds) for cancer patients placed by medical oncologist at the oncology day hospital (odh). A prospective study

8247 Background: To assess the efficacy, safety and indications of ambulatory CVAPDs implanted by medical Oncologist at ODH. Methods: A prospective study of cancer pts who requiring during the evolution of their disease a CVAPDs. Ports were implanted via subclavian vein to out-patients at the ODH bed under local anaesthesia, without fluoroscopic guidance, by the Medical Oncologists. Chest radiography was performed after the implantation. Results: One hundred forty consecutive cancer patients received implantable ports (Healthport®) at the ODH between January 2001 and October 2003. ECOG: 0 (14 pts), 1 (99 pts), 2 (25 pts), 3 (2 pts). Median age was 58.5 years (range 29–82). 78 were male. Diagnostic: 65 pts (46.4%) had colo-rectal cancer, 18 pts (12.8%) gastric cancer, 14 pts (10%) breast cancer, 8 pts (5,7%) lung cancer 6 pts (4,2%) esophagous cancer, 5 pts (3.5%) head and neck cancer and 24 pts (17,14%) other cancers such as ovary, bladder, sarcomas… Complications: \(\underline{\mathrm{During\ device\ insertion\ (15{\%})}}\): arterial puncture 6, local hematomas 4, insertion difficulty 6, local irritation 3, and pneumothorax < 5% 2 pts. \(\underline{\mathrm{Mechanical\ (5,7{\%})}}\): catheter tip malposition 3, thrombosis 3, drug extravasation 1, flexura catheter 1. \(\underline{\mathrm{Device-related\ infections\ (4,2{\%})}}\): Subcutaneous port pocket infections 3, phlebitis 1, and port-related bacteremia by coagulasa-negative Staphylococcus aureus in 2. \(\underline{\mathrm{Device\ was\ removal\ in}}\) 7 occasions (5%), 3 due to thrombosis and 3 due to infection and 1 due to patient's request after end of treatment. One patient died of documented Staphylococcus aureus infection despite device was removed. Conclusions: CVAPDs implanted by oncologist in out-patients is safe, efficient (no room surgery is required and hospitalization can be avoided) and confortable for the patients. Very few serious complications during the insertion and during chemotherapy administration were observed. Removal was due to thrombosis in 3 patients and infection in 2. Patients, as well as hospital staff were satisfed about the easy implantation of these devices No significant financial relationships to disclose.

New Periurethral Bulking Agent for Stress Urinary Incontinence: Modified Technique and Early Results

Durasphere (Carbon Medical Technologies, St. Paul, Minnesota) is a newly approved injectable agent for stress urinary incontinence. Proven and potential advantages include nonimmunogenicity, tissue nonreactivity, efficacy at low injectable volume and durability. A concern regarding use is difficulty involved with application. A modified technique for easier implantation of this agent is described and early results are reported. The surgical technique follows the standard technique for transurethral implantation of bulking agents. Steps modified to allow easier implantation of Durasphere beads include a single needle stick at the 4 o'clock position, hydrodissection with 1.5 ml 1% lidocaine into the submucosa, gradual withdrawal/advancement or rotation of the needle tip after resistance is noted and holding the needle in position for an additional 10 seconds after proper coaptation is achieved to prevent the beads from leaking out of the needle puncture site. Patient charts were retrospectively reviewed. Patient perception of treatment outcomes, a 24-hour pad test and a voiding diary were obtained and analyzed. The strict criteria of the Groutz-Blaivas score were applied as an additional measure of outcome. Of 70 patients 46 (65.7%) for whom full contact information was available responded. Patient age was 46 to 83 years (mean 69.4). A history of a failed prior anti-incontinence procedure was recorded in 15 patients (32.6%) and coexisting symptoms of urge incontinence or urodynamically proven detrusor instability was evident in 29 (63%) and 5 (10.8%), respectively. Bulking agent was delivered at 1 to 3 sessions (mean 1.52) 1 to 3 months apart with 2 to 6 ml (3.2 ml) injected per session. Excellent or good coaptation was achieved in 92% of injections. At a followup of up to 18 months (mean 9.4) 6 (13%), 24 (52.2%) and 16 (34.7%) patients considered themselves cured or improved, or treatment to have failed, respectively. Of the 36 patients who completed a 24-hour pad test 18 (50%), 2 (5.5%) and 16 (44.4%) had a urine loss of 8 or less, 9 to 20 and greater than 20 gm, respectively. Results of the voiding diary and the Groutz-Blaivas score are provided. The modified technique of Durasphere injection allows easy implantation with good coaptation in the majority of patients. Early results are encouraging. Further research may reveal whether the improved delivery techniques translate into improved outcomes with more durable results compared with other approved bulking agents.

Recent advances in implantable cardioverter defibrillator systems.

The usefulness of the implantable cardioverter defibrillator (ICD) for the prevention of sudden cardiac death caused by ventricular tachyarrhythmias has been proven by several international randomized multi-center clinical trials. Recent advances in medical technologies, such as size reduction and the functional improvements of the device, have resulted in relatively easy implantation. As a result, the number of ICD recipients has been rapidly increasing and the indications for ICD implantation have been expanding. Dual chamber ICDs offer improved tachyarrhythmia detection algorithms such as discrimination of supraventricular arrhythmias. In Europe and the United States, biventricular ICDs are now available for the treatment of congestive heart failure associated with ventricular tachyarrhythmias. Although the incidence of inappropriate shock by ICDs is decreasing, inappropriate discharges of ICDs and a declining quality of life are still problems.

Palliative treatment of malignant esophageal stenosis: the role of self-expanding stent endoscopic implantation.

Endoscopic tube implantations were carried out in 40 patients with malignant stenosis of the esophagus and gastric cardia using self-expanding metallic stents. The indications for endoscopic intubation were the advanced stage of the tumor in 27 cases and risk factors that made resection inadvisable in 13 cases. In three patients, it proved impossible to implant a stent endoscopically because we were not able to pass the guide wire through the stenosis, whereas correct stent placement was achieved in 37 cases. Functional results were good in 33 patients, but four patients did not show any improvement of symptoms. Complications occurred in nine patients (24.3%): two bleedings, three neoplastic obstructions, one food obstruction, and three distal dislodgements of the prosthesis were observed, but could be readily corrected. No deaths occurred. The median survival time was 151 days (range 25-545 days). This study suggests that endoscopic placement of metallic self-expanding stents is safe and is to be preferred to plastic stents for easier implantation and lower morbidity.

Atrial sensing performance of a single-lead VDD pacing system during physical activities

This study was undertaken to evaluate the atrial sensing performance of a single-lead atrial synchronous-ventricular pacing system during various physical activities on late follow-up. Fourteen patients (mean age 55 ± 17 years) with a third-degree or high-degree atrioventricular block and normal sinus node function were treated with the single-lead Thera VDD (Medtronic, Inc, Minneapolis, MN) pacemaker system. Mean P-wave amplitude at implantation was 3.2 ± 1.3 mV. To assess the VDD system performance, P-wave amplitudes during various physical maneuvers (supine, sitting, deep breathing, standing, and exercise; respectively) were measured and atrial sensing was evaluated at a mean follow-up of 11 ± 4 months. During deep breathing, minimum and maximum P-wave amplitudes (0.8 ± 0.7, 1.2 ± 1.0 mV, respectively) were found to be significantly lower than the standing position (minimum, 1.1 ± 0.9, maximum, 1.4 ± ± 1.1 mV P =.02 in both). No significant difference was found during other physical maneuvers. During the testing maneuvers, atrial undersensing was observed in 8 patients (57%) at the nominal atrial sensitivity of 0.5 mV. After increasing the atrial sensitivity (0.25 mV), no sensing failure was observed in these patients. It has been concluded that Medtronic Thera VDD system is a safe and reliable device with an easy implantation technique providing effective atrioventricular synchronization. The sensing problems, which may occur on late follow-up, can be corrected successfully by reprogramming. To achieve an optimal atrial sensing function in patients with a single-lead VDD pacing, we recommend that the atrial sensing capability should be examined in various physical maneuvers.

Technologic advances in implantable cardioverter defibrillators.

Multiple technologic advances in the implantable cardioverter defibrillator (ICD) have resulted in smaller size, easier implantation, and improved detection, therapy, and stored diagnostic information. Advanced dual-chamber ICDs are currently available that allow dual-chamber rate-responsive pacing with mode switching, enhanced detection algorithms, antitachycardia pacing, low-energy cardioversion, high-energy shocks, and extensive diagnostics. Based on improvements in lead systems and improved energy waveforms, almost all devices are being implanted with nonthoracotomy leads in the pectoralis area. The results of recent clinical trials have expanded indications for the ICD for primary and secondary prevention of sudden cardiac death. With advances in capacitor and battery technology coupled with improved lead systems and waveform resulting in lower defibrillation thresholds, it is likely that lower-output, smaller devices will be developed. In the future, ICDs may have expanded indications and may incorporate physiologic sensors to access hemodynamic significance of arrhythmias and algorithms for prediction and prevention of cardiac arrhythmias.

Anterior cervical fusion with the Orion locking plate system.

This study was conducted to evaluate an anterior cervical fusion plate system, the Orion locking plate, regarding its surgical handling, hardware-related failures, and short-term and long-term results. A comprehensive evaluation of the implant in a broad range of patients with cervical spine diseases. Locking plates are the most recent devices for achieving anterior cervical spinal fusion and offer considerable advantages such as faster and easier implantation and fewer implant-related failures than older plate systems. Ninety-six patients were investigated. All underwent anterior cervical plate fusion as a component of the surgical treatment for symptomatic degenerative cervical spinal disease or for vertebral destruction caused by trauma, tumor, or inflammation. Besides plate fixation, 6 of the 96 patients had a combined ventrodorsal fusion. In 28 cases, one or more vertebral bodies were removed and replaced with titanium place-holders. The remaining 62 patients were first treated by intervertebral inlay placement, and the fused segments were subsequently plated. Neurologic signs and symptoms were evaluated before and after surgery and during a follow-up period of at least 1 year. The rate of neurologic improvement was highest in radiculopathy patients and lowest in patients with severe myelopathy. In all cases, control radiographs demonstrated a solid bony fusion. Clinical deterioration after surgery was seen in four cases of severe myelopathy in which considerable neurologic deficits existed before surgery, possible because of rapid decompression of the cord and associated microvascular alterations. In two of these cases, there was long-term improvement. Additional general complications caused by surgical retraction included temporary swallowing disturbance in seven patients and a large wound hematoma in one. Hardware failures were encountered in three cases, all of them caused by improper implantation technique and not material failure, per se. In the study group, the Orion locking plate was easy to use, failure-free if properly implanted, safe for the patient and supported solid bony fusion in every case.

A Histological Study on Tissue Responses to Titanium Implantation in Rat Maxilla: The Process of Epithelial Regeneration and Bone Reaction

The present study aimed to establish a titanium implantation model using rat maxillae as well as demonstrate the chronological tissue responses to implantation. Pure titanium implants were inserted in the upper first molar extraction sites of Wistar rats 1 month after tooth extraction. The animals were sacrificed at 1 to 30 days postimplantation, and prepared tissue specimens were processed for light microscopy. The removal of implants from tissue blocks was done using 2 methods: mechanical removal or a cryofracture technique. In the early stages, peri-implant tissues showed severe damage to the oral epithelium and collagen bundles with significant inflammatory cell infiltration. The peri-implant epithelium grew apically along the implant by 10 days postimplantation, and regenerated to show a similar feature of junctional epithelium seen in normal rats at 15 days postimplantation, at which time no signs of inflammation were observed. The regenerated collagen bundles in the connective tissue were arranged circumferentially to the implants in the horizontal sections. New bone formation first appeared around the implants at 5 days postimplantation, covering the entire perimeter of implants by 30 days postimplantation. Scanning electron microscopic observations of the surface texture of the removed implants suggest the probability of an adhesive mechanism between the implants and the peri-implant epithelium and/or the alveolar bone. These findings indicate that this experimental model is useful for detailed analysis of peri-implant tissue because of its easy implantation procedure.

Long-Term Clinical Experience With a Steroid-Eluting Active Fixation Ventricular Electrode in Children

In this study, the first study performed in pediatric patients, we assessed the safety and efficacy of a steroid-eluting active fixation ventricular electrode in 18 children. Our study shows that steroid-eluting active fixation leads are safe and effective in children, and suggests that these leads with their easy implantation and low chronic threshold values may be considered as the first choice in this age group.

Experiments with an optical converter

A non-holographic optical converter of easy implantation is presented. In the write-in process an input image is encoded in a photorefractive crystal as modulation of birefringence. The stored input is displayed in the read-out process through coherent or incoherent illumination. Several experimental results which illustrate both conversion modes are presented. Possible applications are discussed.Resumen. Se presentará un convertidor óptico no holográfico de simple implementación. En el proceso de registro una imagen es almacenada en un cristal fotorrefractivo como modulación de la birrefringencia. La imagen registrada es leída por medio de una iluminación coherente o incoherente. Se presentarán varios resultados experimentales que ilustran ambos modos de conversión. Asimismo son discuidas posibles aplicaciones.

An original technique of brachytherapy for T1 T2 carcinomas of the mobile tongue

Twenty-four patients with T1 or T2 (17 T1 NO, 7 T2 NO not exceeding 3 cm) epidermoid carcinomas from the middle third of the mobile tongue benefit from brachytherapy with “cavaliers-legos” consisting of guide-gutters that are inserted in a rigid support (legos) and covered with a lead plate. Several advantages can be advocated with this technique: easy implantation even with local anaesthetic, no risk of bleeding, good parallelism between Iridium wires, protection of the mandible with the lead plate. Local control was achieved in 22 24 patients (92%). Four patients (16%) developed soft tissue necrosis but only one required surgical intervention and no mandibular necrosis was seen.

A motor integrated regenerative pump as the actuator of an electrohydraulic totally implantable artificial heart.

The authors have developed a new actuator to drive an electrohydraulic totally implantable artificial heart. The basic concept of this artificial heart is that the blood pumps are implanted in the thorax and an actuator is placed separately in the abdominal region. The actuator is a regenerative pump that pumps fluids against high pressures and is thin enough for easy implantation. The rotor-magnet of the brushless DC motor is mounted on the impeller of the pump to miniaturize the actuator and reduce the number of moving parts. The height, diameter, and weight of the actuator are 32.5 mm, 73 mm, and 360 g, respectively. A pair of oil ports is connected to the left and right blood pumps with mesh reinforced tubes filled with silicone oil. The blood pumps are alternately driven by bidirectional rotation of the motor. Performance of the system was evaluated in in vitro and in vivo experiments. Maximum output of the right heart was 6.7 L/min in both experiments. Systemic circulation was well maintained in acute animal experiments using 49 and 50 kg goats. The feasibility of the actuator was confirmed.

A simple and compact total artificial heart for temporary use.

Thromboembolism and anatomic fit are the major issues to be addressed in the design of a heart replacement device for total circulatory support. In an attempt to overcome these problems, a simple 70 mm3 displacement pusher plate, low pressure, pneumatically driven TAH was developed for temporary use. For optimal anatomic fit, easy implantation, and better flow patterns, the 5.7 X 10.7 cm total artificial heart (1) TAH was made of two essentially flat pumps integrated into a single unit. This single package approach avoids the dead space that occurs between the two pieces of conventional TAH and thus minimizes overall volume. It was designed to be positioned in the pericardial sac in a fashion similar to the natural ventricles and, based upon previous anatomic studies, fit in the average sized adult patient. In contrast to conventional free diaphragm pumps, the diaphragms of this TAH are supported by pusher plates that have a unique guide mechanism at the center to ensure a linear-controlled diaphragm motion and consequent uniform blood flow distribution. The guide of each pusher plate nests into the other, resulting in minimal thickness of the package. By using a simple displacement transducer, reliable output monitoring, with the possibility of selection of various pumping modes and adjustment of stroke volume, is possible. The authors anticipate this efficient and practical TAH to be a suitable temporary heart replacement device.

A Simple and Compact Total Artificial Heart for Temporary Use

Thromboembolism and anatomic fit are the major issues to be addressed in the design of a heart replacement device for total circulatory support. In an attempt to overcome these problems, a simple 70 mm3 displacement pusher plate, low pressure, pneumatically driven TAH was developed for temporary use. For optimal anatomic fit, easy implantation, and better flow patterns, the 5.7 ± 10.7 cm total artificial heart (1) TAH was made of two essentially flat pumps integrated into a single unit. This single package approach avoids the dead space that occurs between the two pieces of conventional TAH and thus minimizes overall volume. It was designed to be positioned in the pericardial sac in a fashion similar to the natural ventricles and, based upon previous anatomic studies, fit in the average sized adult patient. In contrast to conventional free diaphragm pumps, the diaphragms of this TAH are supported by pusher plates that have a unique guide mechanism at the center to ensure a linear-controlled diaphragm motion and consequent uniform blood flow distribution. The guide of each pusher plate nests into the other, resulting in minimal thickness of the package. By using a simple displacement transducer, reliable output monitoring, with the possibility of selection of various pumping modes and adjustment of stroke volume, i s possible. The authors anticipate this efficient and practical TAH to be a suitable temporary heart replacement device.

Two-stage technique for implantation of inflatable penile prosthesis in pelvic cancer surgery

A two-stage technique for implantation of an inflatable penile prosthesis has been developed for patients undergoing radical pelvic cancer surgery. Over the past five years, this method has been utilized in 147 men undergoing radical cystectomies or prostatectomies. The technique involves implanting the reservoir and pump of the prosthesis at the time of the radical cancer operation when the lateral neurovascular bundles of erection are being sacrificed. The reservoir and pump are permanently connected, and the cylinder tubns from the pump are temporarily connected and placed in the subcutaneous tissue overlying the pubis. During a second procedure, usually six to twelve weeks later, the cylinders are implanted infrapubically and connected to the easily located pump tubing. The advantages are several. (1) The pump and reservoir are easily implanted during the pelvic surgery while importantly not adding significantly to the operative time or morbidity of the primary procedure. (2) The reservoir is easily positioned in the pelvis. (3) The scrotum with its contained pump already will be healed when the entire prosthesis is connected, bypassing the initial scrotal pain and edema. (4) Psychologically the patients feel relieved that their erectile dysfunction is being treated immediately. This two-stage technique appears to maximize the gain of early and easy implantation while minimizing the potential problems of concomitant surgery.

Implantation of a New Semiautomatic Artificial Genitourinary Sphincter: Experience With Primary Activation and Deactivation in 47 Patients

AS 742 is a new semiautomatic artificial genitourinary sphincter that has been used at the clinic for the last 2½ years in the management of urinary incontinence. Compared to the previous model the simplified design provides for much easier implantation, more reliable function related to cuff pressures and to cuff configuration, and more flexibility in the selection of the site for cuff placement. In addition, this new device has enabled the development and use of a new concept of primary and secondary activation. A total of 47 patients (41 male and 6 female subjects) has undergone implantation of the AS 742. Of the 42 patients who had primary activation 34 experienced continence without further surgical revision. The remaining 5 patients who primarily had deactivated devices subsequently had the devices activated and the patients are dry. Of the 8 patients with initial failures 2 had infection and 6 had primary cuff erosion of the urethra. In 4 of the 8 patients the cuff was replaced, and the device was deactivated and then activated after 3 to 4 months. All 4 of these patients are continent. Followup for these patients has ranged from 6 to 30 months. Over-all, 43 of the 47 patients are continent.