Endoscopic Approaches to Gastroparesis

Renato V. Soares and Lee L. Swanstrom

Disclosures

Curr Opin Gastroenterol. 2015;31(5):368-373. 

In This Article

Endoscopic, Surgical and Hybrid Approaches

Jejunostomy/Gastrostomy

Enteral feedings may be necessary for patients with advanced gastroparesis and inability to maintain nutritional status with oral diet. The proximal jejunum is the preferred site for delivering the diet, since the noncontractile stomach is bypassed.[1] Permanent jejunostomy should be performed only after the function of the small bowel has been assessed, because these patients may have small bowel dysfunctions as well, therefore requiring total parenteral nutrition (TPN). In a series with 6-year follow-up, 21% of the patients required jejunal enteral support or total parenteral nutrition for at least some period.[9] A venting gastrostomy tube can drain gastric fluid and gas, thus improving symptoms of persistent belching and fullness.[30]

Gastric Electric Stimulation (Gastric Neurostimulation)

The Enterra Therapy System (Medtronic Inc., Dublin, Ireland) is composed of a small implantable electrical generator and two electrodes that are placed within the gastric wall.[31] The gastric neurostimulation (GNS) consists of high-frequency/low-energy electrical pulses. The physiologic mechanism in which the electrical stimulation improves patient symptoms is unclear. About 50–90% of the patients have some improvement with GNS in surgical series, with morbidity rates of 7–14%.[31–36] In order to better select the patient for a permanent GNS, thus avoiding potential high costs and morbidity, Ayinala et al.[37] described an endoscopic technique for temporary GNS. In this procedure, cardiac pacemaker leads were implanted into the gastric wall from the mucosal side and fixed with endoscopic clips. The correspondent wire was exteriorized through the nose (EndoStim) or through a percutaneous endoscopic gastrostomy tube (PEGStim) and externally attached to the Enterra system. The same neurostimulation parameters as for the permanent GES can be used. The temporary electrodes can be left in place from 3 up to 14 days while the patient is being evaluated. In case of improvement, a surgical implantation of the Enterra device is indicated. Ayinala et al. made a comparison of the effectiveness of the temporary GNS and the permanent GNS, and concluded that the two arrangements had the same effect. Other authors have reported the use of temporary GNS. For example, Jayanthi et al.[33] implanted the temporary device in 51 patients, and 77% had a favorable response. Of these 35 patients, 31 had the permanent GNS device, with 71% of more than 50% symptom improvement at 1-month follow-up.

Gastric Resections

Surgical resection (total or near-total gastrectomy) is a radical surgical resource in the treatment of gastroparesis, and is usually reserved for patients with severe chronic symptoms despite other treatments. The precise role and extent of gastric resection in patients with gastroparesis is debated. Recently, our group reported a series of 35 cases of laparoscopic gastric resections (6 total and 29 near-total gastrectomies) in patients with gastric failure. In this series, 46% of the patients had a previous pyloroplasty and 54% had a previous fundoplication. Good symptomatic outcomes for abdominal pain (70% improvement/resolution), nausea and belching (78% improvement/resolution) were obtained. Six patients (17%) had a leak, but no mortality occurred.[17] Speicher et al.[16] reported follow-up of 29 patients who had a completion gastrectomy for postsurgical gastric atony. The authors found significant improvements in abdominal pain, vomiting and nausea, and 78% satisfaction with surgery. The complication rate in this series was 36% (7% leak). There are no studies comparing gastric resections with other methods of treatment of gastroparesis.

Surgical/Hybrid Pyloroplasty

Gastric antral hypomotility[38] and pyloric dysfunction[39,40] have been demonstrated in patients with idiopathic and diabetic nausea and vomiting. Thus, it is reasonable to postulate that therapies aiming to eliminate the pyloric barrier may improve symptoms in patients with gastroparesis. Surgical pyloroplasty (Heinecke-Mikulicz) for gastric drainage was first described in the 19th century[41] and remains a useful surgical tool in the treatment of refractory disease. This technique can be performed safely laparoscopically. Recently, our group presented a series of 28 patients who had laparoscopic pyloroplasty (26 patients) or laparoscopic-assisted endoscopic pyloroplasty using an endoscopic flexible stapler (2 patients). There were no leaks in this series. At 3-month follow-up, 14 patients had a gastric emptying scintigraphy, which was normal in 10 patients (71%). Significant improvements on symptoms of nausea, bloating and abdominal pain were also noted.[42] Toro et al.[43] operated 50 patients with laparoscopic pyloroplasty. In this study, there was an 82% improvement in symptoms. The median preoperative T1/2 scintigraphy was 180 ± 73 min and postoperative T1/2 was 60 ± 23 min (P < 0.001).

These good results and low procedural morbidity have made laparoscopic pyloroplasty our primary recommendation for patients failing conservative and medical management. In cases where there is no improvement after a pyloroplasty, other procedures may be subsequently offered, including a gastrojejunostomy, gastrectomy or gastric electric stimulation (GNS).

Endoscopic Pyloroplasty (Per-oral Pyloromyotomy)

After the introduction in clinical practice of the per-oral endoscopic myotomy (POEM procedure) for achalasia, it was hypothesized that an analogous procedure, using a mucosal incision and submucosal tunneling, could be used to access the pyloric ring and surgically divide the pylorus. A POP could have the same efficacy of a surgical pyloroplasty while being less invasive. An endoscopic pyloromyotomy for infants with congenital hypertrophic pyloric stenosis has been described.[44,45] In the pediatric group, however, there is no submucosal tunnel and the technique comprises two incisions from the mucosal surface into the anterior and posterior walls of the pylorus.

Kawai et al.[46] in 2012 performed an animal study to determine the feasibility of POP. In the experiment, the authors describe a decrease on the median pyloric resting pressure, from 16.5 to 8.4 mmHg at 14 days after POP. In the following year, Khashab et al.[18] reported the first human case of POP in a 27-year-old female diabetic patient with gastroparesis. The procedure was completed uneventfully and the patient had a good clinical outcome.[18]

In 2014, Shlomovitz et al.[47] published a series of seven patients who underwent POP for refractory gastroparesis. The procedure was technically successful in all of them. There were concomitant laparoscopic procedures performed in six patients, which allowed the POP to be done under laparoscopic observation. The remaining patient had a POP without laparoscopy. There were two postoperative complications: one patient that was not taking the proton pump inhibitor regimen had a bleeding duodenal ulcer treated endoscopically. Another patient had nosocomial pneumonia. Six patients reported improvement in their symptoms during 6 months of follow-up. Among the five patients who had follow-up scintigraphy, the exam was normal in four (80%). The only patient in the series who did not improve had a laparoscopic pyloroplasty after 7 months, which also failed to relieve her symptoms. The preoperative work-up for a POP procedure includes upper endoscopy and a gastric emptying study. Ambulatory esophageal pH study and esophageal manometry are also performed in case of concomitant GERD symptoms.[47]

Routine antibiotic prophylaxis, as well as steroids (8 mg Decadron) to prevent mucosal swelling, is recommended. Briefly, the operative steps are the following: the submucosal plane is elevated at the mucosotomy site. A 2-cm mucosal incision is performed 3–5 cm proximal to the pylorus, in the anterior wall of the gastric antrum. Endoscopic submucosal tunneling progresses up to the pylorus, and the descending duodenal mucosa can be seen (Fig. 1). The myotomy is started just before the pyloric ring and extends about 2 cm in length. No attempt is made to selectively divide only the circular muscular layer.[47]

Figure 1.

Submucosal view of pyloric musculature during the per-oral pyloromyotomy (POP) procedure.

Another case of POP done in Brazil[19] was published in a patient with post fundoplication gastroparesis, with success. POP has also been employed to treat postesophagectomy vomiting due to delayed gastric emptying.[48]

Endoscopic Stent Placement

There have been a few anecdotal reports on the use of transpyloric totally covered metal stents in patients with gastroparesis. Although reporting initial good results,[49] the high migration rate seems to be a weakness of this modality.[19,49] Also, it is likely that complications from the stent may ensue in the long term.

Botulin Toxin Injection

Botulin toxin inhibits neuromuscular transmission. Injection of Botox in the pyloric muscle could have the effect of relaxing the sphincter and been described as a treatment for gastroparesis. In the early 2000s, a few uncontrolled studies demonstrated mild improvements of symptoms and gastric emptying studies[50,51] in patients with gastroparesis after four quadrant pyloric injections of 80–200 UI of Botox. However, two placebo-controlled trials demonstrated no difference in symptoms compared to placebo.[52,53] Another downside is the known short-term effect of Botox paralysis in the gastrointestinal tract. Botulin toxin is generally no longer recommended for treatment of gastroparesis.[7]

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