Superficial Thickness Suturing

A subsequent iteration of the EndoCinch, the RESTORe endoscopic suturing device (Davol) was used to perform the first endoscopic sleeve gastroplasty. RESTORe could perform deeper-thickness suturing than the EndoCinch and did not need to be removed and reinserted for suture reloading. ESG was performed in the TRIM trial, with placement of an average of 6 plications to approximate the anterior and posterior walls of the stomach. The prospective TRIM trial performed at 2 centers included 18 subjects. The subjects lost 27.7% ± 21.9% of their excess weight (11.0 ± 10 kg). Waist circumference decreased by 12.6 ± 9.5 cm. However, endoscopic follow-up found that suture placement was not durable.

Full-Thickness Suturing

The OverStitch (Apollo Endosurgery, Austin, TX) has made full-thickness endoscopic suturing possible. The device can rapidly place full-thickness sutures in several configurations, including interrupted and running stitches. It can be reloaded without removal and reinsertion. The device has an actuating handle, which attaches to the endoscope handle, and a needle driver, which attaches to the endoscope tip. At this time, a double channel endoscope is required. One channel is used for a suture anchor catheter, and the other can be used for a tissue helix. The helix is a catheter with a retractable corkscrew tip, which can be used to securely grasp tissue and bring it into the working area of the OverStitch. After the stitches have been placed, the suture is tightened and secured with a combined suture-cutting catheter and cinch tag placement device. The device has been approved by the FDA for tissue apposition and has been used for a variety of gastrointestinal procedures. A comparison of full-thickness suturing with superficial thickness suturing showed greater efficacy (weight loss after gastric bypass revision) using the same technique, suggesting that full-thickness suturing may be associated with greater durability.

A standardized full-thickness ESG technique was developed in an international multicenter fashion starting in April 2012. Multiple iterations of the procedure were evaluated for feasibility, safety, and efficacy at centers in India, Panama, and the Dominican Republic, followed by the United States and Spain. Obese patients who did not respond to diet and lifestyle modification were included, and patients with prior gastric surgery, eating disorders, bleeding disorders, psychiatric disease, and gastrointestinal disease were excluded.

Procedure Development

The initial 5 human cases in India evaluated the safety and feasibility of several stitch patterns to optimize efficiency. Argon plasma coagulation was used to create dotted lines from the gastroesophageal junction to the antrum in a longitudinal fashion—one along the anterior wall and one along the posterior wall, toward the greater curvature side of the midline. Running stitches were created in a triangular fashion, including 6 to 12 tissue acquisitions each. The suturing was started in the fundus, which required working in retroflexion. After each stitch, the endoscope was rotated and moved distally to start the next stitch. The lumen toward the greater curvature was excluded. The tissue helix was used for tissue acquisition in some stitches, but suction was used to bring tissue into the device in others. Because of the challenge of working in retroflexion and use of suction to acquire tissue, procedure time was 3.5 ± 0.5 hours. There was no free intraperitoneal air on chest radiograph, and there were no reported significant adverse events during the procedure or during the follow-up period.

The second phase of procedure development started with the final technique refined in the first stage, and assessed time efficiency in 22 patients. The longitudinal argon plasma coagulation lines were eliminated because they did not remain in a consistent position after suturing began. Because free air had not been seen on chest x-ray during the first phase, the tissue helix was used for each stitch placement to ensure full-thickness stitches. The suturing was initiated in the antrum and moved proximally to the fundus, which eliminated the need for cumbersome retroflexed suturing for much of the procedure. Additionally, this allowed the fundus to be pulled downward. Rather than using up to 12 stitches per suture, 6 stitches were used (at most) before securing the stitches. This action reduced complexity, and the risk of stitch release from tissue caused by high suture tension. During the second phase, it was noted that full-thickness suture placement resulted in free air on chest radiograph; insufflation was modified to use carbon dioxide. A subset of patients was operated on using only interrupted stitches, which resulted in durable stitch placement but was time consuming. However, this technique was incorporated to add to sleeve durability, and a row of interrupted stitches was placed medially to the suture line after the sleeve was created.

The third phase was performed in the Dominican Republic, the United States, and Spain to assess the efficacy of the final technique in 77 patients with a body mass index (BMI) of 36.1 ± 0.6 kg/m ² . Nausea and epigastric pain were routinely reported, as well as transient epigastric pain, in the postoperative period. No significant adverse events were reported to the prospective registry. Patients at some centers were admitted for 24 hours after the procedure, whereas others were discharged home on the same day. Preliminary data showed weight loss of 17.9 ± 1.3 kg, or 17.4 ± 1.1% total weight loss (TWL), at 12 months.

Procedure Technique

At most centers, ESG is currently performed using the standardized technique created in the procedure development process. General anesthesia with endotracheal intubation is necessary. An esophageal overtube should be used to protect the oropharynx and esophagus. The use of a cephalosporin antibiotic for prophylaxis is advisable. The patient should be placed in a partial left lateral/supine position. Because of long procedure times, intraoperative venous thromboembolism prophylaxis should be considered. Preoperative and postoperative antiemetics can reduce nausea. In its current and most broadly applied form, full-thickness ESG is performed by placing a series of running stitches, each made of 6 stitch placements in a 2-triangle configuration. A triangular stitch is placed from the anterior gastric wall to the greater curvature to the posterior gastric wall, and a second triangle is placed before the suture is cinched and secured. These stitches are placed in a series, beginning in the antrum, and moving proximally to the fundus. This stitch pattern excludes the gastric lumen along the greater curvature and shortens the stomach, resulting in the creation of a tubular sleeve along the lesser curvature. The suture line along the lateral sleeve is reinforced with multiple interrupted stitches. Routine use of the helix is recommended to aid full-thickness stitch placement and to avoid injury to structures adjacent to the stomach. The procedure entails long operating times and requires familiarity with torquing the endoscope, avoidance of crossed sutures in the setting of multiple running stitch placements, and management of suture tension to avoid suture pull-through.

Clinical Results

Over time, published series show the safety and efficacy of ESG.

• •
  

  A series of 10 patients with mean BMI of 45.2 kg/m ² reported 6-month TWL of 33.0 kg, equivalent to 30% excess weight loss (EWL). There was a significant improvement in postprandial glucose, with a 36% decrease in area under the curve.

  
  
• •
  

  A prospective study of 25 subjects with average BMI of 38.5 ± 4.6 kg/m ² reported TWL of 18.7 ± 10.7% after 12 months. In the setting of multidisciplinary follow-up, the number of visits to a nutritionist and psychologist was a predictor of superior weight loss results, underscoring the importance of clinical follow-up after the procedure. In one case, the procedure was endoscopically revised to restore gastric plication.

  
  
• •
  

  An international multicenter series including 126 patients with average BMI of 36.2 kg/m ² reported BMI decrease to 29.8 ± 1.4 kg/m ² after 12 months. Weight decreased from 101.6 ± 2.3 kg to 81.8 ± 3.8 kg/m ² after 12 months. No serious adverse events were reported.

  
  
• •
  

  A prospective study including 25 subjects with average BMI of 35.5 kg/m ² reported 3 serious adverse events: perigastric inflammatory serous fluid collection, pulmonary embolism, and pneumoperitoneum with pneumothorax. At 12 months, EWL was 54 ± 40% (n = 10) and 45 ± 41% at 20 months (n = 8). A detailed analysis of motility and neurohormonal changes was performed in 4 patients: after 3 months, ESG decreased the caloric intake required to achieve maximum satiety by 59%, meal duration decreased from 35.2 ± 9.9 minutes to 11.5 ± 2.3 minutes, and fasting and postprandial ghrelin levels decreased by 29.4%. Insulin sensitivity also increased significantly.

  
  
• •
  

  A multicenter series of 242 patients (including patients reported in other series) reported 19.8% TWL after 18 months. There was a serious adverse event rate of 2%, with report of a perigastric fluid collection treated with percutaneous drainage and antibiotics, self-limited hemorrhage from splenic laceration, pulmonary embolism, and pneumoperitoneum/pneumothorax.

  
  
• •
  

  ESG has been endoscopically revised to address a plateau in weight loss. A case report described a 60-year-old woman with baseline BMI of 33.5 kg/m ² who reached BMI of 26.5 kg/m ² and 21% TWL 1 year after ESG. However, her weight loss subsided. She had an endoscopy, which showed prior gastroplasty with loosened sutures. Two layers of running stitches were placed to approximate opposing gastric walls. A gentamicin lavage was performed to prevent infection, and she was discharged home on the same day. One month later, she had an additional 8% TWL, reaching BMI of 24.4% and 27% TWL.

  
  
• •
  

  Other adverse events have been reported, including a case report describing onset of abdominal pain and vomiting 12 days after ESG. Computed tomography scan showed a 3.3 × 2.9 × 3.7 cm fundic fluid collection along the greater curvature, consistent with a perigastric collection. The patient was given antibiotics—a dose of intravenous ertapenem followed by oral ciprofloxacin, 500 mg twice daily, and metronidazole, 400 mg 3 times daily for 7 days. The collection resolved on follow-up imaging.

Mechanism

ESG (and the preceding vertical gastroplasty) are often analogized to surgical sleeve gastrectomy. However, ESG differs in important ways. Whereas sleeve gastrectomy permanently alters the stomach with excision of gastric tissue, ESG remodels its shape. ESG is less invasive, but sleeve gastrectomy excises ghrelin-producing tissue. Whereas sleeve gastrectomy is permanent, ESG may be reversible, and its durability is being studied. Therefore, ESG is not necessarily an analogue of sleeve gastrectomy. This fact was underscored when the mechanism of ESG was studied by Abu Dayyeh and colleagues. ESG seems to slow gastric emptying, whereas sleeve gastrectomy speeds it. Further investigation of the mechanism, neurohormonal effects, and subsequent change in comorbidities is ongoing. There is potential for ESG to be combined with endoscopic small bowel interventions, medications, or other technologies with complimentary mechanisms to potentiate the effect of ESG.