magnet-assisted laparoscopic surgery requires two sets of instruments and devices.

The first one comprises those specifically designed for magnet-assisted laparoscopic surgery as the Thomas grasper™ (IMANLAP Ltd, Buenos Aires, Argentina), the internal magnetic grasper, the external magnet, the Dominguez articulating self-retaining arm, and the Williams grasper™ (IMANLAP Ltd, Buenos Aires, Argentina) (Table 15.1).

The internal magnetic grasper (IMANLAP Ltd) can be reusable—environmentally friendly—or disposable (Fig. 15.1). By covering the intracorporeal magnet with biocompatible plastic, attractions between the instruments and the magnet are impeded. Moreover this material prevents the alligator clamp from transmitting electricity to the abdominal wall and enables the use of monopolar hook even in those cases in which the electrocautery device is leaning on the alligator clamp. This new version of the internal magnetic grasper ensures its sterilization with ethylene dioxide and is far more practical as there is no need to disassemble it for cleansing.

With the aim of achieving an effective surgical manipulation of the target organ, flexible control of its application point is essential. Fixation of the internal magnetic grasper (IMANLAP Ltd) was consequently improved by linking the alligator clamp to the magnet via a flexible connector. This results in softer retraction movements as the distance between the barycenter of the magnet and the application point is reduced.

The Thomas grasper™ (IMANLAP Ltd) handles the jaws of the alligator clamp intracorporeally. It was specially designed to be unaffected by electromagnetic fields and with the necessary strength to open and close the alligator clamp. The force needed for these maneuvers is substantially greater than that required for any other routine endosurgical grasping action, what explains the reason why the internal magnetic grasper (IMANLAP Ltd) is held tightly at the application site and rarely becomes loose, being a safe and effective retraction tool. If by chance, the internal magnetic grasper is released, it can be rapid and easily managed with the Thomas grasper™ and attached where it corresponds.

The external magnet (IMANLAP Ltd) frees surgical assistants for other tasks and can enable the main surgeon to operate alone whenever coupled to the Dominguez articulating self-retaining arm fixed to the operating table. Since the external magnet can be easily engaged and disengaged from the arm, it is possible to use it manually when dynamic magnetic retraction is needed. However, when static magnetic retraction is required, the external magnet can always be re-engaged to the arm without difficulty (Fig. 15.2).

The second set comprises already existing instruments and devices as a single 12-mm trocar (any brand is suitable) to accommodate the 11.83-mm internal magnetic grasper (IMANLAP Ltd) or the SILS™ port (Covidien, New Haven, CT, USA) for operations requiring more extensive dissection or intraabdominal suturing. We recommend the use of a 10-mm, 27-cm, 0° laparoscope, with a 6-mm working channel (Karl Storz-Endoskope, Tuttlingen, Germany) because it allows surgeons to operate and drive the camera simultaneously (the camera headlight is coupled to a different and independent line) (Fig. 15.3). Commercially available 42-cm, 5-mm instruments (irrigation/aspiration devices, dissectors, graspers, scissors, forceps, harmonic scalpels, staplers, needle holders, etc), can be perfectly accommodated. The Thomas grasper™ (IMANLAP Ltd) and the 5-mm Hem-o-Lok clip applier (Weck Teleflex, Research Triangle Park, NC, USA) have been lengthened up to 45-cm, to enhance reach and to allow extra maneurability within the body cavity (Fig. 15.4). Regular transumbilical instruments with exaggerated curves or roticulating tips are impractical for magnet-assisted laparoscopic surgery because they transmit little torque and their movements are counteractive. We therefore prefer to use a 5-mm, gently curved non-roticulating grasper (Karl Storz-Endoskope).

The absolute constrainments are pregnancy and pacemaker patients.

The relative constrainments are:

Transumbilical Cholecystectomy with Magnetic Retraction, or in other words, magnet-assisted laparoscopic surgery of the gallbladder is founded on reproducing the classic laparoscopic cholecystectomy, with an optimum vision and exposition of the triangle of Calot. Before describing the technique, it must be pointed out that the technique can also be used as a complement in classic laparoscopic cholecystectomy since it clearly does not replace videosurgery but adds a surgical variant to the so called reduced port surgeries [11]. Additionally it makes possible the retraction of key structures without the need for needles, sutures and retractors permitting minimization of the number of access ports, incisions, and eventually staff.

General anesthesia is used in the same fashion as for a laparoscopic cholecystectomy. The patient’s umbilicus is infiltrated with local anaesthesia (bupivacaine) to facilitate an equilibrated analgesia. A single 1.5-cm umbilical incision for a 12-mm port is performed. Even though in the beginning, we used to create the 12/14-mm Hg pneumoperitoneum using a Veress needle, we nowadays prefer the Hasson’s technique, which is safe and recommendable since many years ago, and because it is the best alternative in those occasions in which a good exposition of the umbilical aponeurosis is indispensable for the extraction of surgical specimens.

The patient is placed in a reverse Trendenlenburg’s position slightly rotated to the left. Initially the surgeon would stand up between the legs with the assistant aside and the scrub nurse opposite to the assistant (French position). Nowadays we use the American position with the monitor placed at the head of the operating table (Fig. 15.5).

The approach is transumbilical in all patients. The umbilical stem is never removed to accomplish an excellent cosmetic result. The laparoscope is introduced through the 12-mm trocar. Once the first internal magnetic grasper (IMANLAP Ltd) is progressed into the abdominal cavity, it is manipulated under direct vision with the Thomas grasper™ (IMANLAP Ltd). The latter enables the surgeon to maneuver the alligator clamp (onward, from behind, laterally and from its tip) to further orient it towards the gallbladder whereas the magnet faces the parietal peritoneum.

The external magnet (IMANLAP Ltd) attached to the articulating self-retaining arm, is drawn near the patient’s skin to generate a magnetic field across the abdominal wall that allows the mobilization of the internal magnetic grasper (IMANLAP Ltd) in all directions to suit the surgeon’s need. The jaws of the alligator clamp are opened with the Thomas grasper™ (IMANLAP Ltd) and fastened tightly to the gallbladder’s fundus or Hartmann’s pouch. By moving the external magnet in the direction of the axilla, the liver is lifted cephalad exposing the gallbladder, which is retracted over the liver edge toward the patient’s right shoulder (Fig. 15.6). By repositioning the external magnet on the abdominal wall, the intraabdominal magnet moves to provide further traction. Because the magnet is not fixed at any level, it can freely cruise around the peritoneal cavity, extending the surgeon’s reach without the need for additional ports. Next, the laparoscope is removed and another internal magnetic grasper is inserted in the same way as the first one. This 2° internal magnetic grasper is placed in the infundibulum and managed by another external magnet to expose the triangle of Calot for its dissection (Fig. 15.7a) at first and for the cholecystectomy next (Fig. 15.7b, c).

Once the surgical field is exposed, each 5-mm diameter instrument can be passed through the laparoscope’s 6-mm working channel for the cystic duct and vessels dissection, ligation and section, the cholangiography (whenever necessary), and the gallbladder dissection in the usual way that traditional laparoscopic cholecystectomy is performed. The cystic duct is sealed with a proximal medium sized Hem-o-lok polymer clip using the Hem-o-lock ligation applier, size M-L (Weck Teleflex) (Fig. 15.7a). The gallbladder is dissected at its base using an insulated hook. Finally, both internal magnetic grasper (IMANLAP Ltd) are released using the Thomas grasper™ (IMANLAP Ltd) and removed through the umbilical 12-mm trocar. The gallbladder is withdrawn under direct vision.