Fine Tilt Tuning of a Laparoscopic Camera by Local Magnetic Actuation: Two-Port Nephrectomy Experience on Human Cadavers

Background. The magnetic surgical camera is an emerging technology having the potential to improve visualization without taking up port site space. However, tilting the point of view downward/upward can be done only by constantly applying a pressure on the abdomen. This study aims to test the hypothesis that the novel concept of local magnetic actuation (LMA) is able to increase the tilt range available for a magnetic camera without the need for deforming the abdominal wall. The hypothesis that 2-port laparoscopic nephrectomy in fresh tissue human cadavers could be performed by using the LMA camera is also tested. Methods. First, the 2 cameras were separately inserted, anchored, and moved inside the inflated abdomen. Tilting angles were quantified by image analysis while intra-abdominal pressure changes were monitored. Then, 5 two-port nephrectomies were performed by using the LMA camera while collecting quantitative outcomes. Results. The magnetic camera required a constant pressure on the magnetic handle to achieve an average +/- 20 degrees tilt from the horizontal position, with an average of 7 mm Hg loss of intra-abdominal pressure. The LMA camera allowed for 75 degrees of tilt from the horizontal position with a resolution of +/- 1 degrees, without any need to deform the abdomen. All the nephrectomies were completed successfully within an average time of 11 minutes. Conclusion. LMA is an effective strategy to provide magnetic cameras with wide-range and high-resolution vertical motion without the need to deform the abdominal wall.