Elizabeth Rajan, MD, FASGE from the Mayo Clinic College of Medicine in Rochester, Minnesota, USA describes this New Methods article “Innovative gastric endoscopic muscle biopsy to identify all cell types, including myenteric neurons and interstitial cells of Cajal in patients with idiopathic gastroparesis: a feasibility study (with video).”

The pathophysiology of some gastrointestinal neuromuscular diseases remains largely unknown. This is in part due to the inability to obtain ample deep gastric wall biopsies that include the intermuscular layer of the muscularis propria (MP) to evaluate the enteric nervous system, interstitial cells of Cajal (ICC) and related cells. Currently, we rely on surgical approaches such as laparoscopic wedge biopsy to obtain sufficient tissue samples of the gastric wall.

Presently we obtain mucosa/superficial submucosa via endoscopic biopsy forceps and deeper tissue to include the entire mucosa and submucosa via techniques such as endoscopic mucosal resection (EMR). There is no technique for endoscopic muscle (MP) biopsy. So, the aims of our study were to determine if our innovative gastric endoscopic muscle biopsy (gEMB) technique was safe and effective.

gEMB was studied in 3 patients with idiopathic gastroparesis.

• Safety: There were no procedural adverse events. At 1 month follow-up, repeat EGD showed a scar (n=2) and minimal ulceration with retained clip (n=1), and CT abdomen was unremarkable.  All patients experienced post-procedure pain that required NSAIDs and opioid analgesics.
• Efficacy: Muscularis propria was identified in all samples. Mean sample size was 10 mm. There was a decrease in nerve fibers and loss of ICC in 2 patients which are hallmark features of gastroparesis.
• Mean procedure time: 25 mins

gEMB is safe, effective, and easy to perform. The double resection technique is fundamental to ensure MP is obtained. The “no hole” (close then cut) concept is key to ensure safety. Our ability to acquire large tissue samples allows for both quantitative and qualitative analysis of multiple cell types. Future research may contribute to our knowledge of the pathophysiology of GINMD and other inflammatory and neoplastic conditions, leading to potential targeted and curative therapies and likely challenging current clinical practice.

As endoscopists we now have the ability to sample the entire gastric wall, mucosa to serosa. This technique represents a paradigm shift in endoscopic tissue diagnosis. This is our initial experience and more data is needed to confirm the safety and efficacy of the technique.

Find the article abstract here.

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