Waterjetting 17e - Liposuction and other medical uses

One of the advantages of using high-pressure waterjet streams as a cutting or cleaning tool is that, unlike more mechanical devices, there is much less need to apply additional force through the tool in order for it to work. This was one of the considerable advantages that waterjetting had when it was first introduced, and married with robotic arms in cutting different materials. Early robots had little arm strength – it was a major constraint in the design of new equipment since we had to recognize that, for example, in order for the arm to keep its precision and accuracy we could apply no more than ten or twenty pounds of thrust through the nozzle. This limit was overcome when the power was applied from a jet at 50,000 psi pressure, over a very small nozzle diameter and meant that the combination of robot controlled manipulators and jet nozzles could cut complex shapes in materials ranging from shoe leather through carpet, through automobile and aircraft components.

That advantage remains as tool size is shrinking and waterjets are gaining an increasing role in the medical part of the waterjet market. I had mentioned, in previous posts, how waterjet systems are increasing being used to debride wounds, remove cancers and help expose blood vessels in liver surgery. But with the small sizes of nozzles that are now available, it is also possible for jets to be transmitted through the small tools used in laparoscopic (keyhole) surgery. As a result surgeries can be smaller in scale, less traumatic to the patient and faster to heal because of the smaller footprint of the surgery. In liver surgery, as an example, the increasing use of waterjets in resection has reduced the amount of transfusion liquid required by more than 75%.

Tool sizes have continued to shrink, and thus it is now possible to use the jets in surgeries beyond those that we originally envisioned. For example there have been a number of studies over the years on the use of waterjets to cut bone. One of the problems in hip, knee and other joint replacement surgeries is that the faces of the cuts need to be quite precisely aligned in order for the prosthesis to fit into place. With surgeons using a common saw to cut through the bone, the cut can deviate from that clean alignment. Further the saw can generate heat that can damage the bone and tissue along the cut line. High pressure jets both cool and help align the cut to minimize misalignment of the cut line.

Other tissues are more easily cut, and waterjets are being used more extensively in tumor removal and in cutting the ligaments that hold organs, such as the gall bladder or prostate in place, making endoscopic surgeries easier.

Other body tissue can also be removed. As I have updated the range of applications for waterjets in the medical field over the years it is only now that I am finding references to the use of waterjets in liposuction. Waterjet Assisted Liposuction (WAL) has been described as:

Using a fan-shaped laminar jet, the body-jet® simultaneously irrigates and aspirates fatty tissue. The gentle separation of fat cells from connective tissue minimizes trauma to the patient. At the same time, significantly less infiltration fluid is needed with the WAL procedure as compared to traditional methods, helping to reduce exposure to tumescent fluid, minimize swelling, allow real-time precise contouring, and dramatically shorten procedure times.

Other sites provide similar comments:

Body-Jet Water Liposuction relies on the power of highly concentrated water to gently dislodge and remove fat cells from the body. Using water-jet technology, fat is removed from the body with significantly less force than older liposuction techniques. The power of the water-jet detaches fat cells from their surrounding tissues, allowing the suction cannula to move freely. This limits the possibility of trauma to surrounding tissues, including skin, muscles, nerves, blood vessels, and septal attachments. . . . . . Because the process is so gentle, Body-Jet Water Liposuction is typically performed as an out-patient procedure under local anesthesia. On average, the entire procedure takes between 30 to 45 minutes for each part of the body that is treated. The majority of body-jet water liposuction patients find that they can return to their regular activities immediately following the procedure. In fact, Body-Jet Water Liposuction has been called “lunch break lipo” because most patients are able to have the procedure performed and immediately resume regular activities.

There is a video about the procedure here .

As I mentioned earlier in regard to back surgery the small amount of damage outside of the region where the jet is cutting means that many of these procedures can be carried out as outpatient surgery with the patient being able to leave without hospitalization. Further because the jet works by discriminately removing the desired tissue without damage to surrounding hard tissue, and it can reach “around corners” to flush out cavities it has been reported, for back surgeries:

In treating spines, where the disc is removed before carrying out spinal fusion the waterjet was able to get out some 96% more of the soft tissue that was achieved by conventional means.

More refined applications, such as in breaking up blood clots in thrombectomy have also now been developed, The technique appears to be more widely tested in Europe than in the United States at the moment. It has been approved for use in the United States.

Each year in the U.S., approximately 600,000 patients are diagnosed with deep vein thrombosis. Complications range from severe pain and limitation of mobility, to limb loss and even death. Moreover, 200,000 people die from pulmonary embolism (PE) each year, which occurs when venous thrombus migrates to the lungs and blocks blood flow. . . . . . The FDA's clearance of AngioJet thrombectomy . . . . . gives doctors a powerful tool to restore flow to blocked veins. Patients may benefit from faster resolution of leg pain and reduced risk of complications.

There are, in short, increasing applications for high-pressure waterjets in the medical field, and the advantages which the tool brings to cutting in more mundane applications seem also to carry over into surgical applications. It has only, however, been after smaller and more precise tools have been developed that this set of applications has evolved, and it will be interesting to see how much longer the list grows in the years to come.