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At least 19 recordsLinked to original sources
PubMed1994

Repeated arterial infusion chemotherapy for inoperable hepatocellular carcinoma using an implantable drug delivery system.

Arterial infusion chemotherapy has become one of the major treatments for malignant tumors. Since 1988, we have attempted repeated arterial infusion of anticancer drugs using an implantable drug delivery system in 68 patients who had inoperable hepatocellular carcinoma (HCC). Most of our patients could not undergo transcatheter arterial embolization (TAE) because of extreme tumor extension and/or accompanying advanced liver cirrhosis. In most patients we implanted a 5-F catheter via the femoral artery nonsurgically and connected it to a subcutaneously implanted drug delivery system without any difficulty. The treatment consisted of weekly or biweekly intrahepatic one-shot administration of anticancer drugs. As one therapeutic regimen, epirubicin was given alone. Other regimens consisted of combined chemotherapy using two or more of the following drugs: mitomycin C. Adriamycin, 5-fluorouracil, cisplatin, and epirubicin. In some cases, these drugs mixed with Lipiodol were given for targeting and slow release in the liver. The response rate (CR+PR) of the cases was 25.0%. The median survival period was 389.9 days. The 6-month, 1-year, and 2-year survival rates were 75%, 45%, and 17%, respectively. There was no severe side effect or complication except arterial occlusion that precluded further infusion chemotherapy. We think that the implantable drug delivery system will contribute not only to improved therapeutic efficacy for inoperable HCC but also to an improved quality of life for the patients.

Adult↗
PubMed1982

Long-term intravenous infusion of antiarrhythmic drugs using a totally implanted drug delivery system.

In vitro and in vivo testing was performed to establish the feasibility of a totally implantable pump system to deliver antiarrhythmic agents. In vitro flow characteristics suggested predictable day to day delivery with acceptably small variations in flow with changes in reservoir volume or temperature. During 3 months of in vitro testing, procainamide and bretylium were found suitable for long-term delivery. Delivery of lidocaine was limited by high viscosity and corrosion of steel elements within the pump. The pump was implanted in a subcutaneous pocket in four dogs. Procainamide (0.5 g/ml), delivered at 4 ml/day (70 mg/kg body weight per day), provided a mean steady state drug concentration of 5.3 micrograms/ml. Bretylium (50 mg/ml), delivered at 8 ml/day (13 mg/kg per day), provided a steady state concentration of 0.8 micrograms/ml (range 0.4 to 1.4). Long-term intravenous administration of therapeutic doses of bretylium and procainamide with this delivery system has been demonstrated in dogs and appears to be feasible in human subjects.

Animals↗
PubMed1993

Tissue response to bioerodible, subcutaneous drug implants: a possible determinant of drug absorption kinetics.

The fibrous tissue compartments that develop in response to the subcutaneous implantation of bioerodible heat-fused rods of norethindrone and cholesterol (85 and 15%, respectively) were studied by light and electron microscopy at various intervals after implantation to determine whether the biological inflammatory response may play a role in drug absorption. Thirty-five regularly menstruating, sterilized (tubal ligation), healthy females each received four Annuelle rods. The microanatomy of seven of the largest implants (135 mg norethindrone) was studied. A dense fibrous biological compartment was found to surround each rod. By light microscopy no abnormal tissue response was revealed. Scanning and transmission electron microscopy showed that the surfaces of the rods were covered by a cellular matrix of mononuclear cells. The fibrous compartment was composed of a loose cellular bed immediately surrounding the norethindrone rod, a dense fibrous connective tissue envelope containing blood and lymphatic vessels, and an outer fatty connective tissue layer. Transmission electron microscopy confirmed that the cellular tissue immediately surrounding the rods was composed mainly of lipid laden macrophages. Norethindrone levels in tissue capsules at 3 and 10.5 months were 0.05 and 8.4% by weight, respectively. These observations suggest that the local inflammatory response plays a role in the active processing of this delivery system. This picture is qualitatively different from the general view of the fibrous capsule as a simple rate limiting membrane. The effects observed in this study suggest that a more complex, functional biological system develops in response to the subcutaneous introduction of a drug delivery device.

Absorption↗
PubMed1994

Technical note: radiological insertion of an implantable drug delivery system.

A fully implantable drug delivery system has been shown to overcome many of the problems of long-term venous access. Traditionally these have required surgical implantation but we describe a simple, cost-effective and successful technique for the percutaneous insertion of an implantable vascular device (Vascuport, Ohmeda) in the angiography suite under local anaesthesia. It was successful in all 19 patients in whom it was attempted, with only one minor complication. We recommend that the procedure should be performed in X-ray departments using screening and conventional guidewire techniques.

Anesthesia, Local↗
PubMed1994

Pain relief mediated by implantable drug delivery devices.

Various totally implantable drug delivery systems from single access ports to micropumps are now available for administration of repeated boluses, and continuous or programmable infusions. In this respect, emphasis is given to a relatively cheap, totally implantable system for self-administering intraspinal opiates in the treatment of cancer pain. The SECOR pump system, developed by Cordis, consists of a dual pump with refill port and safety valve. The volume of the pliable reservoir is 12 ml and refill is accomplished with a 25-G needle. The bolus delivered with each transcutaneous activation of the pumps is 0.1 ml. Clinical results demonstrated that this patient-controlled drug delivery system is safe and provides excellent pain relief associated with terminal cancer. A possible advantage of this drug delivery system over continuous infusion pumps is that patients can elect to have the morphine delivered only when they feel pain. Thus pain relief would be maximized and tolerance build-up would be minimized.

Analgesia, Epidural↗
PubMed1984

Cancer pain relief using chronic morphine infusion. Early experience with a programmable implanted drug pump.

Fourteen patients were implanted with drug pumps to provide chronic epidural or intrathecal morphine to relieve pain due to cancer. A new programmable pump was used in seven of the patients and a constant infusion device was used in the other seven patients. Results, judged by subjective pain reports (on a 0 to 10 scale), decrease in oral narcotics, and change in activity level, were excellent in eight patients, good in five patients, and poor in one patient. The programmable device has the obvious advantage of being able to vary dose according to patient need and requires less frequent refilling. Four programmable pump failures occurred, two requiring replacement.

Adult↗
PubMed1986

Antibiotics delivered by an implantable drug pump. A new application for treating osteomyelitis.

Osteomyelitis is usually treated with wide surgical debridement and prolonged intravenous antibiotics. The advent of the implantable drug pump has led us to evaluate this therapeutic modality for the treatment of osteomyelitis. We have previously shown that amikacin retains microbiologic activity in an implantable drug pump over a six-week period when incubated at 37 degrees C. We have also demonstrated in rabbits that high local levels and low systemic levels of antibiotic can be achieved using an implantable drug pump as a delivery system and that this method can be used to sterilize infected wounds. This method was applied in the treatment of osteomyelitis in 14 patients whose duration of symptoms ranged from one month to 22 years. In 13 patients, active drainage had been present for more than six months, and all patients had undergone one or more attempts at eradication of their infection. Prior therapy included surgical debridement alone (one patient), one or more attempts at debridement and extended intravenous antibiotic therapy (13 patients), debridement and local flap procedures (four patients), and extended oral antibiotic therapy (two patients). The bones involved were the tibia (six patients), femur (four patients), and elbow, shoulder, hip, and radius (one patient each). Intra-operative cultures indicated that the infecting organism was Staphylococcus aureus alone (seven patients), S. aureus in combination with gram-negative bacteria (five patients), or gram-negative organisms alone (two patients). Debridement and pump implantation were performed in one stage. On an outpatient basis, the pumps were filled with amikacin in a concentration determined by each patient's serum level. Duration of therapy was based upon cessation of drainage and erythrocyte sedimentation rate. During therapy, serum amikacin levels ranged from less than 2.5 micrograms/ml to 8.2 micrograms/ml. The amikacin concentration in the wound drainage was always greater than the upper limits of what could be measured (greater than 55 micrograms/ml to greater than 5,000 micrograms/ml). There were no cases of ototoxicity and one case of minimal renal toxicity (posttreatment creatinine clearance of 66 ml per minute; normal equal to 70 ml per minute). Length of therapy ranged from 32 to 140 days (mean equal to 63 days). Length of hospitalization ranged from five to 52 days (mean equal to 24 days). Drainage in all patients stopped during therapy, but resumed in three patients after pump removal--in two patients, for brief periods of time, and in one patient, it continues. Twelve patients have posttreatment erythrocyte sedimentation rates less than or equal to 20 mm per hour.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1992

Seventy-two patients' experience with an implantable drug delivery system for chemotherapy or total parenteral nutrition.

An implantable drug delivery system will play an important role for patients who need chemotherapy or prolonged total parenteral nutrition in the future. We implanted 72 injection capsules in 74 patients who were undergoing aggressive chemotherapy or total parenteral nutrition programs. These capsules were implanted in different positions, including central access in 67 cases, peritoneal cavity in 1, hepatic artery in 2, portal vein in 1 and intrathecal space in 1. The actual median functional survival of the injection capsules was 12.3 months (range, 2 months to 4 years). The total cumulative puncture numbers were 1651 (range, 5 to 153; median 23). There was no unsuccessful instance in infusion or injection. To date, 27 patients still survive. The complication rate was about 7% including 1 sepsis, 1 skin infection, 1 catheter thrombosis, 1 dislodgement of reservoir and 1 catheter-reservoir disengagement, which were all corrected by a secondary operation without mortality. Patency of the Port-A-Cath system was maintained using a regular flushing schedule once every 30 days. The results of this study suggest that the implantable drug delivery system can provide a safe and reliable method for venous access or even arterious access in patients requiring intermittent or prolonged intravenous therapy.

Adolescent↗
PubMed1998

Therapeutic applications of implantable drug delivery systems.

In the past, drugs were frequently administered orally, as liquids or in powder forms. To avoid problems incurred through the utilization of the oral route of drug administration, new dosage forms containing the drug(s) were introduced. As time progressed, there was a need for delivery systems that could maintain a steady release of drug to the specific site of action. Therefore, drug delivery systems were developed to optimize the therapeutic properties of drug products and render them more safe, effective, and reliable. Implantable drug delivery systems (IDDS) are an example of such systems available for therapeutic use. The application of currently available implantable drug delivery systems is the main focus of this review. IDDS can be classified into three major categories: biodegradable or nonbiodegradable implants, implantable pump systems, and the newest atypical class of implants. Biodegradable and nonbiodegradable implants are available as monolithic systems or reservoir systems. The release kinetics of drugs from such systems depend on both the solubility and diffusion coefficient of the drug in the polymer, the drug load, as well as the in vivo degradation rate of the polymer, especially, in the case of the biodegradable systems. Controlled release of drug from the implantable pump is generally achieved utilizing the microtechnology of electronic systems and remote-controlled flow rate manipulation through the maintenance of a constant pressure difference. The third atypical class includes those which have been recently developed such as ceramic hydroxyapatite antibiotic systems used in the treatment of bone infections, intraocular implants for the treatment of glaucoma, and transurethral implants utilized in the treatment of impotence. The major advantages of these systems include targeted local delivery of drugs at a constant rate, less drug required to treat the disease state, minimization of possible side effects, and enhanced efficacy of treatment. Also, these forms of delivery systems are capable of protecting drugs which are unstable in vivo and that would normally require a frequent dosing intervals. Due to the development of such sustained release formulations, it is now possible to administer unstable drugs once a week to once a year that in the past required frequent daily dosing. Preliminary studies using these systems have shown superior effectiveness over conventional methods of treatment. However, one limitation of these newly developed drug delivery systems is the fact that their cost-to-benefit ratio (cost/benefit) is too high which restricts their use over conventional dosage forms. Hopefully, in the future, new implantable systems can be developed at a lower cost, thereby minimizing the cost-to-benefit ratio and therefore, be used extensively in standard therapeutic practice. Some of the most recently discovered implants are in the early developmental stages and more rigorous clinical testing is required prior to their use in standard practice.

Animals↗
PubMed1992

[Intra-arterial infusion chemotherapy for hepatocellular carcinoma using an implantable drug delivery system].

Intra-arterial chemotherapy and chemoembolization using implantable drug delivery system were performed in sixty-one cases of unresectable hepatocellular carcinoma (HCC). The following results were obtained. (1) The follow-up period was 253 days, and the administrations numbered 13.9 times on average. (2) Response rate was 31.1%. (3) AFP decreased in 80% cases, and PIVKA-II in 83.3% cases. (4) Tumor thrombus in the portal vein disappeared in 4 of 40 cases(10%). (5) Free-CDDP continued for 60 minutes after injection of cisplatin-phosphatidyl-choline-Lipiodol (CPL), and the response rate was 47%. (6) The survival rates were 56% in one year, 25% in two years, and 20% for three years. These results were significantly higher than those of one shot therapy. It is suggested that good therapeutic effects can be obtained by the implantable drug delivery system, and CPL was a useful anticancer agent for the therapy.

Biomarkers↗
PubMedDate not supplied

Portable data acquisition and control apparatus for implanted drug infusion pump interrogation.

Now that implantable drug infusion pumps are well established clinically, methods for diagnosing suspected pump failures are needed. The authors previously constructed a benchtop data acquisition and control apparatus to assist our work in developing new pump technology. Although this device is technically capable of in vivo pump monitoring, it is cumbersome. Thus, they recently created a portable interrogation unit with more limited features. This portable pump interrogation apparatus consists of a 32 bit MS-DOS labtop computer, data acquisition software, an analog/ASCII interface, a pressure transducer, and appropriate fluid conduits. Communication between the device and the implanted pump is via a percutaneous needle puncture of the drug reservoir refill septum. This procedure is identical to that employed in a standard pump refill. Pump performance is evaluated by incrementally filling the pump reservoir while simultaneously measuring reservoir pressure. The resulting data are presented on the computer screen as a plot of pressure versus volume that quickly and simply either eliminates or confirms the reservoir pressure source as a failure mode. Diagnostic runs are saved on file for archival purposes. Their benchtop apparatus has been a valuable and reliable tool over many years of use. The authors believe that their portable apparatus will be equally beneficial.

Data Collection↗