The LiVac laparoscopic liver retractor system (LiVac retractor) is a straightforward and easy-to-use surgical instrument. This is demonstrated by successful application in each of the first ten patients in a research study published by the National Library of Medicine. The retractor does not fundamentally alter the techniques required for the procedures for which it was used. However, it does result in fewer incisions. The LiVac retractor) is composed of a soft silicone ring connected to suction tubing and connected to a controlled suction source. Suction tubing runs parallel to existing ports.

In-Depth to the Clinical Study

Most retractors used in laparoscopic gallbladder or stomach procedures apply an upward force to the liver or gallbladder's undersurface, with the majority requiring an additional skin incision. But with the LiVac retractor, when suction is applied between the liver and diaphragm, a vacuum is created within the ring, which maintains in apposition. After a successful proof-of-concept animal study, a clinical study was conducted to evaluate the retractor's performance and safety in humans.

In single-port cholecystectomy, the liver was retracted without suturing the gallbladder. The technique involved placing intercostal sutures or using a hand-held grasper, which increases hand clashing. As the liver was retracted during reduced-port and single-port cholecystectomy with the LiVac retractor, the plane between the liver and gallbladder opens up during dissection. Using a LiVac retractor enables a method of concentrating on directing the laparoscope with one hand free to easily adjust the orientation of the angled scope, potentially improving exposure.

The currently available liver retractor devices in the market pose a certain degree of risk of liver injury. For decades, the Nathanson retractor has been widely used and has been shown to cause liver congestion by compressing the liver parenchyma and associated vasculature. The Nathanson retractor is a robust retractor constructed of steel and secured to an external frame. And it has been associated with liver hematoma, hepatic necrosis, and atrophy.

Because the LiVac retractor is the only one that attaches to the superior surface and does not press against the liver parenchyma, no tissue or vessels are compressed. Hand-held retractors have the advantage of maneuverability, but they require an appropriately skilled assistant and are susceptible to fatigue.

Moreover, the assistant determines the amount of force applied to the liver by hand-held retractors, not the surgeon. Internal retraction requires clamps or hooks to secure two sites, with the band, suture, or rod between these two points of fixation pushing up against the liver linearly. Nonetheless, the liver tends to drape on either side of the retractor.

As the diaphragm and liver are drawn into the ring under a vacuum, they conform to the internal contours of the LiVac retractor. The surface embossing visible as the LiVac retractor was released flattened out entirely within minutes, and there was no bleeding or serosal laceration.

Additionally, all patients had a routine liver ultrasound on Day 1 postoperative, and insignificant AST changes were noted. The device draws only a limited tissue depth into it, limiting the depth of associated hemorrhagic changes. These findings corroborated previous animal testing in which liver histology was obtained. In a study involving two sheep recovered and then killed on postoperative day 5, histological evidence of trauma was limited to the serosa, with normal liver parenchyma underneath.

Similarly, in porcine testing in which the liver was retracted in the exact location for 97 minutes at 400 mmHg and immediately resected, the pathologist reported that histological evidence of trauma in the liver resected immediately post-procedure did not extend beyond 1–2 mm beyond the capsular surface. As a result, the safety of the LiVac retractor has been demonstrated to be comparable to, if not superior to, existing methods.

Conclusion

The LiVac retractor successfully retracted the liver without causing clinically significant trauma and may be used in a wide variety of multi- or single-port laparoscopic upper abdominal surgery. Due to the absence of a separate incision, using the LiVac retractor in multi-port surgery reduces the number of incisions.