In medicine, a driveline is a thin cable that connects an implanted heart pump to an external power source and controller. It exits through a small wound in the abdomen and is the only part of a left ventricular assist device (LVAD) that crosses from inside the body to outside. For the roughly 50,000 people worldwide living with these heart pumps, the driveline is a lifeline, but also the component that demands the most daily attention.
What a Driveline Does
An LVAD is a mechanical pump implanted in the chest to help a weakened heart move blood. The pump itself sits inside the body, but it needs electricity to run and a computer to monitor its performance. The driveline solves both problems. It contains duplicate sets of three conductors: two carry power and a ground connection, while the third transmits data between the pump and the external controller. That controller, which most patients carry in a small bag or wear on a belt, processes pump performance data and connects to battery packs that keep the device running around the clock.
No current wireless technology can deliver enough power to run an LVAD reliably. Metallic wires conduct electricity roughly a million times more efficiently than the best flexible electronics or hydrogel-based alternatives being tested in labs. For now, a physical cable through the skin remains the only proven commercial solution.
How the Driveline Is Placed
The driveline has two segments. The pump cable runs from the LVAD inside the chest, through the abdominal tissue, to a point where it exits the skin. The modular cable picks up from there and connects to the external controller. During surgery, the internal portion is tunneled under the tissue of the abdomen before emerging through a small incision called the exit site.
Surgeons have refined this tunneling process over time. A technique called the “double tunnel” routes the cable along a longer, C-shaped path beneath a layer of tough connective tissue called fascia, rather than taking a short, straight route. In studies comparing the two approaches, the longer tunnel produced fewer infections. It also gives surgeons more options if an infection does develop at the exit site, because the infected area can be separated from the rest of the cable path and treated independently.
Why Infection Is the Biggest Risk
Because the driveline permanently passes through the skin, it creates an opening that bacteria can exploit. Driveline infection is the most common serious complication of living with an LVAD. In a recent study of patients with the latest fully magnetically levitated pump, the cumulative infection rate was 2.8% at six months, 5.6% at one year, and 8.5% at two years.
Infections are classified as either uncomplicated or complicated. An uncomplicated infection stays local: redness, tenderness, or drainage at the exit site, sometimes with a positive wound culture, but no fever, no bacteria in the bloodstream, and no deeper abscess. These typically improve with antibiotics. A complicated infection is more serious and involves one or more warning signs: fever, chills, abscess formation visible on imaging, bacteria in the blood, drug-resistant organisms, or signs that infection has spread along the cable’s path or onto the device itself.
Daily Exit Site Care
Preventing infection depends heavily on how well the exit site is maintained, and that responsibility falls largely on patients and their caregivers. Dressing changes follow a structured routine, though protocols vary somewhat between hospitals. The general process involves washing hands thoroughly for 20 to 30 seconds with soap and water, putting on clean gloves to remove the old dressing, then switching to sterile gloves before touching the exit site.
The skin around the exit site and the driveline itself are cleaned with an antiseptic solution, typically chlorhexidine. Best practice calls for scrubbing in a back-and-forth motion for at least 30 seconds, then letting the area dry completely for another 30 seconds before applying a new dressing. An antimicrobial disc or silver-based pad is often placed directly over the exit site, followed by a transparent adhesive dressing that lets caregivers monitor the skin without removing the bandage. Throughout the entire process, the driveline must be held carefully to avoid pulling or tugging on the wound.
Securing the Driveline to Prevent Trauma
Tugging or jerking the cable is a known risk factor for infection, so patients use adhesive anchoring devices to hold the driveline against their abdomen. These anchors absorb accidental pulls before the force reaches the exit site. In a 2023 lab study that applied a standard pulling force to a simulated driveline setup, every anchoring device reduced the force transmitted to the exit site compared to using no anchor at all. The best-performing devices cut the force reaching the wound by roughly 65 to 75 percent.
Beyond adhesive anchors, most patients wear a belt, holster, or vest system that holds the controller and batteries while keeping the cable secure and out of the way. Managing the driveline becomes part of daily life: tucking the cable safely when dressing, protecting it during sleep, and being mindful of it during physical activity. Showering requires waterproof dressing covers, and submerging in water (baths, pools, lakes) is generally off limits because of the infection risk at the exit site.
Living With a Driveline
For patients, the driveline is the most visible and tangible part of having an LVAD. It connects to a controller that must be carried at all times, along with backup batteries. The equipment adds a few pounds of weight and requires some planning, especially for travel or overnight stays. Power must always be available, whether from battery packs (which typically last several hours each) or a plug-in power unit at home.
The psychological adjustment matters too. Having a cable exit the body permanently changes how people think about clothing, intimacy, exercise, and even sleeping positions. Support from LVAD coordinators and peer networks of other patients helps many people adapt. Most patients eventually develop a routine that lets them work, exercise moderately, and travel with reasonable confidence.
Efforts to Eliminate the Driveline
Researchers are actively working on ways to power heart pumps without a cable through the skin. The most promising approach is transcutaneous energy transfer, which uses electromagnetic coils to send power wirelessly through intact skin. One recent design pairs an external magnet-driven pump with an internal backup battery, wirelessly recharged at low power to avoid the heat buildup that has plagued earlier wireless systems. That system completed a seven-day bench test, but the researchers noted it still needs to be made smaller before animal testing can begin.
Eliminating the driveline would remove the primary source of LVAD infections and significantly simplify daily life for patients. But the engineering challenges are substantial. The pump needs a continuous, reliable power supply, and any wireless system must work safely through varying thicknesses of skin and tissue without generating dangerous heat. Until those problems are solved, the physical driveline remains an essential, if imperfect, bridge between a mechanical heart pump and the outside world.