The EXCOR® Adult system is comprised of the following components, which are optimally harmonized with one another and have proven successful in practice:
Our EXCOR® cannulae are made by hand from medical grade silicone. In order to optimally supply patients, the cannula range includes various types and sizes of cannulae with the following features:
The EXCOR® Adult range includes blood pumps of various sizes, which are optimally suited for patients’ needs. Our blood pumps boast the following features:
The driving unit Ikus is designed specifically for stationary use with the EXCOR® blood pumps. As a high-performing all-rounder, the Ikus covers all areas of application:
The mobilization of young patients is important to their well-being. For adolescents with a weight starting at approximately 40 to 50 kg, the use of blood pumps starting at 60 ml can be considered. A battery-supplied Excor driving unit can be used with these blood pumps. It allows for free mobility over a space of several hours.
The cannulae of the paracorporeal EXCOR® VAD are diverted below the rib cage and through the thorax. Depending on the form of therapy, up to four individual wounds will form around the cannula transcutaneous exit sites and must be cared for, as per antiseptic standards, throughout the entire course of therapy. The more thorough the wound care, the lower the risk of wound healing disorders.
The dressing assists not only with sterile wound closure. It is also used to immobilize the cannulae in the transcutaneous exit site, whereby the wound healing is supported. In addition, the dressing has a strain-relieving effect on the cannulae. This also fosters the healing process.
In the earlier postoperative phase, the change of wound dressing is conducted daily. If healing progresses normally, the interval for changing dressings can be expanded to twice a week. If the appearance of the transcutaneous exit site changes (e.g. circumferential skin reddening, skin secretions, etc.), wound care will be adapted accordingly.
During the patient's stay in the hospital, nursing personnel will be in charge of wound care. If the patient is transferred, e.g. to a rehab clinic, this responsibility will pass on to the personnel at the new facility. If a patient on EXCOR® VAD is discharged to home, wound care can be assumed by the patient – if there is a willingness to do so – or by an outpatient nurse.
Anticoagulation therapy continues to be a challenge for VAD patients: Coagulation must be managed by medication in such a manner that no deposits are formed in the VAD, and no severe bleeding complications are experienced by the patient.
Anticoagulation therapy is initiated 24 hours after implantation, at the earliest, with administration of heparin. If possible, a switch should be made to oral therapy with vitamin-K-antagonists as early as possible. The antiaggregation therapy is conducted with a combination of acetylsalicylic acid (ASA) and Dipyridamole and Clopidogrel, if required.
The choice and dosage of medications administered postoperatively is closely monitored. The monitoring includes thrombelastography (e.g. Rotem®) as well as control of platelet function with the aid of aggregometry (e.g. Multiplate™). Anticoagulation is PTT- and/or INR-controlled.
The blood circulation is mechanically supported by a VAD. This means that the blood comes into contact with non-biological surfaces such as silicone or metal. The blood reacts to such contact as it does with an open wound: It coagulates, whereby the artificial surface is covered with a biological one. In order to prevent this, the patient receives a medication-based anticoagulation therapy. The blood is analyzed at regular intervals in order to control whether the platelet inhibition is effective.
Regular control of the EXCOR® blood pump and of the visible portion of the cannulae is equally important. This control is conducted several times a day with the aid of a mirror and a flashlight. The blood-carrying portion of the blood pump can be inspected through the transparent polyurethane housing. If small fibrin deposits are observed during the pump control, the anticoagulation therapy is adjusted. If a thrombus-like formation is already present, the blood pump is replaced.
The membrane, which alternates continuously between pump filling and pump emptying, can be easily identified through the also-transparent housing for the air side of the blood pump. It is possible to tell, based on the membrane movement, whether the drive parameters have been optimally set or whether optimization is necessary.
The EXCOR® VAD is a pneumatic ventricular assist device. A triple-layer membrane serves to delimit the blood and air sides of the blood pump. The membrane is curved and can be set in motion through alternating pressures. The pressures originate from a driving system and are channeled into the pump via a tube. If positive pressure is applied on the membrane, it displaces the blood out of the blood chamber and back into the patient's circulation. With a negative pull, the blood pump fills again with blood. Valves in the inflow and outflow stubs ensure that the blood can only circulate in one direction. The blood pumps differ in the size of their stroke volumes, i.e. the volume of blood displaced with each stroke. The pump rate setting determines how often the membrane moves in one minute. The rate should be chosen in such a way that the resulting blood flow meets the patient's requirements.
With a stable hemodynamic status and a blood pump size of at least 60 ml, adolescent and adult patients can use the Excor mobile driving unit during the postoperative course of therapy. Secured onto a caddy, the system has the size of a carry-on suitcase and can be used in both interior and exterior environments. If clinically justifiable, patients on Excor mobile can be discharged to rehabilitation and further on to their home environments. With the four exchangeable batteries it is possible to pursue activities independently of a mains power supply.
"The filling and emptying pressures of Excor mobile adjust during operation in accordance with the changing hemodynamic conditions, within the limits specified by the hospital. Safety is of utmost importance, especially among outpatient VAD patients. Thanks to the system's modular design, individual components can be replaced in cases of fault.
*CARMEDA® is a trademark of Carmeda AB