Gastric Endoscopic Myotomy Showing Promise for Gastroparesis

Caroline Helwick

May 25, 2016

SAN DIEGO — Gastric peroral endoscopic myotomy (G-POEM) can be used to effectively treat the vast majority of patients with gastroparesis refractory to conventional therapy, two new studies show.

Gastroparesis is a chronic, often disabling, disorder that affects about 4% of the population. It can be a complication of diabetes or surgery, but in about one-third of cases, it is idiopathic. Medical treatment frequently fails.

G-POEM is modeled on the natural orifice endoscopic POEM for the treatment of achalasia. The procedural principles of the two techniques — such as mucosal entry, tunneling, myotomy (including pyloromyotomy), and closure of mucosal entry — are similar.

Results from the first study, on 30 patients with gastroparesis treated with G-POEM, were presented here at Digestive Disease Week 2016 by Mouen Khashab, MD, from the Johns Hopkins Hospital in Baltimore.

All 30 patients had symptoms refractory to medical therapy, including onabotulinumtoxinA (Botox) injection and transpyloric stenting. Nausea and vomiting affected 25 (83%) patients, weight loss affected 27 (90%) patients (average loss, 10% of body weight), and delayed gastric emptying affected 11 (37%) patients.

Response Rate Exceeds 85% in Two Early Studies

For the 30 patients, mean duration of the G-POEM procedure was 72 minutes, and mean hospital stay was 3.3 days.

At mean follow-up of 5.5 months (range, 3.0 - 30.0 months), 26 (86%) patients had achieved a clinical response, defined as improvement in gastroparetic symptoms without recurrent hospitalization. Of the four patients who did not respond to G-POEM, two had diabetes, one had gastroparesis of idiopathic origin, and one was postsurgical.

"These responses were sustained, and there were no further hospitalizations," Dr Khashab reported.

Of the 17 patients who underwent repeat gastroesophageal scintigraphy, eight (47%) showed normalization of gastric emptying and six (35%) showed improvement.

"G-POEM concomitantly results in normalization of gastric emptying in a significant proportion of treated patients," he said.

Adverse events occurred in two (6.7%) patients: one developed pneumoperitoneum and the other developed prepyloric ulcer.

"We had two minor complications, but these 30 procedures were performed by very experienced endoscopists at tertiary centers," he explained. "G-POEM is more technically challenging than esophageal POEM, as the location is more distal."

On the basis of these "amazing results," Dr Khashab told Medscape Medical News, "we are starting a multicenter prospective trial in the United States, South America, and Asia, recruiting about 50 patients. This will be definitive."

First European Prospective Study

Results from the second study, on nine patients with gastroparesis treated with G-POEM, were presented by Jean-Michel Gonzalez, MD, from Aix-Marseille University, North Hospital, in France.

"Endoscopic pyloromyotomy with the G-POEM technique is feasible, reproducible, and safe," Dr Gonzalez said. "This approach seems effective clinically in terms of quality of life and specific symptoms, which was confirmed by the scintigraphic evaluation in our study."

All nine of the study patients were refractory to conventional treatment — including gastric electrical stimulation in two patients — for at least 6 months, had severe symptoms, had been hospitalized at least twice in the previous 6 months, and had disturbed gastric emptying.

Mean procedural time was 48 minutes. There were no peri- or postoperative complications, and all patients could eat 2 days after surgery and were discharged by day 5.

Clinical efficacy was very high; 85% of the patients had improved significantly after 1 month. One of the failures was a recurrence at 2 months in a diabetic patient with renal insufficiency.

Gastroparesis Cardinal Symptom Index (CGSI) score decreased from 3.5 before the procedure to 0.9 at 1 month (P < .001) and 1.1 at 3 months (P < .001). Improvements were also significant for nausea, vomiting, abdominal pain, gastric fullness, and early satiety at 3 months (P <.001 for all), but not for anorexia.

Time to half gastric emptying was significantly better after the procedure than before (133 vs 222 minutes; P < .001). Improved quality of life was reported by 63% of patients.

Table. Gastric Emptying

Mean Residual Percentage Before G-POEM, % After G-POEM, % P Value
At 2 hours 76 40 <.001
At 4 hours 44 19 NS

 

Dr Gonzalez acknowledged that long-term follow-up is needed for these patients, as are prospective studies, which his group has initiated.

Dr Khashab said G-POEM can be considered not only for patients with recurrent hospitalizations, but also "for any patient with nausea and vomiting that significantly affects their quality of life, even without hospitalization."

Although some patients respond to simple medical therapy, metoclopramide carries a black-box warning for tardive dyskinesia "and is only marginally effective," and antiemetics provide only symptomatic relief, Dr Khashab pointed out. Before attempting G-POEM, endoscopists should be skilled at esophageal POEM, he added.

Dr Gonzalez offered a few procedural tips: "Start at the 5 o'clock position from the pylorus, keep checking your direction, and stop at the pyloric arch."

Dr John Vargo

These results come from small case series, but they show "intriguingly positive results" in terms of symptomatic response and gastric emptying tests, said John Vargo, MD, from the Cleveland Clinic's Digestive Disease and Surgery Institute.

"G-POEM is definitely something we have to look at," Dr Vargo Medscape Medical News. "For these patients, pharmacologic treatments are imperfect; medications have many different side effects. We do have another avenue with gastric pacing, but again, this approach is in its infancy."

"I'm hopeful G-POEM will help these very sick people who have a very challenged quality of life," he said. "It's good to see these results, and I look forward to longer follow-up and a larger series of patients."

Dr Khashab, Dr Gonzalez, and Dr Vargo have disclosed no relevant financial relationships.

Digestive Disease Week (DDW) 2016: Abstracts Mo2015 and 715. Presented May 23, 2016.

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