The LINX procedure was developed to address the existing “therapy gap” in the treatment of GERD. The LINX is a simple mechanical device designed to augment the physiologic barrier to reflux by magnetic force. It remedies transient failure of the LES by preventing shortening of its overall length when challenged by gastric distension or dilation [17]. The procedure requires only limited dissection, does not alter the anatomy of the esophageal hiatus, has minimal side effects, and is reversible (Table 15.2).

The device consists of a series of titanium beads with magnetic cores hermetically sealed inside. The beads are interlinked with independent titanium wires to form a flexible and expandable ring. Interestingly, each bead can move independent of the adjacent beads, creating a dynamic implant that mimics the physiological movement of the esophagus without limiting its range of motion (Fig. 15.1). The strength of the magnetic core contained in each bead is calibrated by mass to provide a resisting force that precisely augments the sphincter’s function. For reflux to occur, the intragastric pressure must overcome the resistance to opening of both the patient’s native LES pressure and the magnetic bonds of the device. The device is manufactured in different sizes and is capable of nearly doubling its diameter when all beads are separated. The magnetic attraction force to be counteracted to allow beads separation is independent of the number of beads contained in the device. The LINX device, while augmenting the LES, allows for expansion to accommodate a swallowed bolus or the escape of elevated gastric pressure associated with belching or vomiting. This provides control of reflux without compromising the physiologic function of the LES [18]. The LINX device can be easily removed if necessary, thereby preserving the option for a subsequent fundoplication if necessary. More importantly the LINX device produces little to no persistent side effects and was designed to limit the technical variability that occurs with fundoplication.

The goal was to develop a more standardized and gentler antireflux procedure that is applicable and acceptable to patients with early progressive disease with reproducible outcomes. The principles of implanting the LINX device are proper sizing of the device, proper positioning of the device, and constructing, with limited dissection, a tunnel behind the esophagus and between its posterior wall and the posterior vagus nerve through which the LINX device is passed. The phrenoesophageal ligament is not dissected and the esophageal hiatus is not explored. Guarding the integrity of the phrenoesophageal ligament during LINX implantation is imperative as the ligament functions to maintain the abdominal length of the LES. This is counter to doing a fundoplication where the hiatus is completely dissected out and the LES is enveloped with the gastric fundus to provide a conduit to transmit intra-abdominal pressure around the LES.

The critical benchmark steps of the procedure are listed in Table 15.3. The steps of the procedure are illustrated in Fig. 15.2. Briefly, surgical dissection begins by dividing the peritoneum on the anterior surface of the gastroesophageal junction (GEJ) below the insertion of the inferior leaf of the phrenoesophageal ligament and above the junction of the hepatic branch to the anterior vagus nerve. The lateral surface of the left crus is freed from the posterior fundic wall without dividing any short gastric vessel. The gastro-hepatic ligament is opened above and below the hepatic branch to facilitate the preparation of the retro-esophageal window. Gentle dissection from the right side is made toward the left crus just above the crural decussation to identify the posterior vagus nerve. A tunnel is then created between the vagus and the posterior esophageal wall, and a penrose drain is passed in a left to right direction. The circumference of the esophagus is measured with a proprietary sizer to determine the proper size of the LINX device to be implanted. The sizing tool is a laparoscopic instrument with a soft, circular curved tip actuated by coaxial tubes through a handset. The handset contains a numerical indicator that corresponds with the size range of the LINX device. Alternatively, the original sizing device mimics the LINX implant with special color-coding of each bead to measure the circumference of the esophagus. The sizing tool is placed around the esophagus in the dissected space between the posterior esophageal wall and the posterior vagus nerve bundle. Once the appropriate LINX device has been selected, it is introduced through the posterior tunnel. The opposing ends are then brought to the anterior surface of the esophagus and connected together; this completes the implant procedure.

Preliminary observations suggest that patients with minimal to no hiatal hernia achieve the best results with the LINX augmentation. However, sliding hernias, up to 3 cm in size, can be effectively repaired by approximating the crura with interrupted posterior stitches and then the device can safely be implanted. The decision to proceed with a posterior crural repair depends on the size of the hernia that is found intra-operatively.

Operative time is about half-an-hour. Patients are discharged the same day of surgery or on the first postoperative day under direction to return to a normal diet as quickly as possible and to discontinue use of acid suppression medication immediately. Patients typically return to normal physical activity in less than a week. The most common complaint following the LINX procedure is mild dysphagia that is usually easily tolerated and requires only temporary diet adjustments.

The LINX Reflux Management System has been recently reviewed by the Gastroenterology and Urology Advisory Panel of the FDA. This panel voted unanimously that there was reasonable assurance of safety and effectiveness and that the benefits of treatment outweighed the risks. This information is in the public domain and available at the FDA website. To date the LINX device has been implanted in over 1,000 patients worldwide and the outcomes have confirmed its safety and efficacy [19].

Two initial prospective, multicenter, clinical studies have been conducted under an FDA investigational device exemption to evaluate the LINX System. The first study evaluated 44 patients implanted with the LINX at four study centers in USA and in Europe between February 2007 and October 2008; the short-term, mid-term, and the 4-year results of this study have been previously published [20–22].