Targeting the pylorus in gastroparesis: From physiology to endoscopic pyloromyotomy

Efficacy of gastric per-oral endoscopic myotomy remains similar after failure of interventional techniques in refractory gastroparesis

BACKGROUND AND AIMS

Gastric per-oral endoscopic myotomy (G-POEM) is a new therapeutic option for the treatment of refractory gastroparesis. However, the outcome of G-POEM after the failure of gastric electrical stimulation (GES) or other pylorus-targeting therapies has been poorly reported.

METHODS

Data were collected from patients referred for G-POEM for refractory gastroparesis. The efficacy in patients with previous interventional techniques was compared to patients naïve to instrumental technique. The primary endpoint was the 6-month clinical success rate, defined as at least a 1-point decrease in the Gastroparesis Cardinal Symptom Index (GCSI).

RESULTS

Among 48 patients referred for G-POEM, 32 patients had previous instrumental treatments (66%): 15 (31%) had GES, and 17 (35%) had pyloric endoscopic dilation or toxin injection. The technical success rate was 100%. At 6 months, clinical success was achieved in 25/48 patients (52%) and the GCSI decreased from 3.38 (2.94-3.95) to 2.25 (1.11-3.36) (p < 0.001). The 6-month success rate was similar in patients with or without previous instrumental treatment (50.0% vs 56.3%; p = 0.41). The complication rate was also similar in the two groups (6.3% vs 12.5%; p = 0.59), with only one severe adverse event. The only predictive factor for success at 6 months was a higher body mass index (OR = 1.14 [1.01-1.32]; p = 0.05).

CONCLUSION

G-POEM is safe and remains effective after GES or previous pyloric treatment failure, with 50% efficacy at 6 months. The therapeutic strategy in refractory gastroparesis remains to be defined.

Disorders of gastric motility

Gastroparesis is a disorder of delayed gastric emptying with associated symptoms of postprandial fullness, early satiety, nausea, vomiting, bloating, and abdominal pain. Functional dyspepsia is an upper gastrointestinal disorder of gut-brain interaction that presents with similar symptoms but is defined according to symptom patterns rather than gastric motor dysfunction. Although delayed gastric emptying is a defining feature of gastroparesis, other aspects of gastric neuromuscular dysfunction, such as gastric accommodation and visceral hypersensitivity might contribute to symptoms. Similarly, although functional dyspepsia is not defined by impaired gastric emptying, disordered gastric motility might underlie pathogenesis in some patients with functional dyspepsia. In the last decade, it has been increasingly recognised that these two disorders might represent varying presentations along a common continuum of neuromuscular dysfunction, although with differentiating features with respect to outcomes, diagnosis, and treatments. In this Review, an overview of gastroparesis and functional dyspepsia from the perspective of gastric motility is provided, discussing what is distinct and what is shared between these disorders.

EndoFLIP evaluation of the pylorus during minimal invasive Ivor-Levis esophagectomy

BACKGROUND/AIMS

During esophagectomy for malignancy, the anterior and posterior branches of the vagus nerve are transected in order to achieve surgical radicality. This leads to loss of central nervous system-control of the pylorus which may lead to delayed gastric emptying. We aimed to investigate the feasibility of the EndoFLIP technique for assessment of pyloric biomechanical properties in patients undergoing esophagectomy.

METHODS

A feasibility study in six patients undergoing surgery was conducted. EndoFLIP measurements were carried out preoperative (Pre-op), after surgical resection (Post-op) and following prophylactic balloon dilatation of the pylorus (Post-dil). By measuring the cross-sectional area and pressure of the pylorus the pyloric compliance and the incremental pressure-strain elastic modulus (Ep) were calculated.

RESULTS

Placing the catheter in the pyloric region was successfully achieved in all six patients. No complications were observed. Resection of the esophagus increased the incremental pyloric elastic modulus (Ep) from 0.59 ± 0.18 kPa to 0.99 ± 0.34 kPa (p = 0.03). After dilatation, the Ep was reduced to 0.53 ± 0.23 kPa (p = 0.04), which was close to Pre-op (p = 0.62). The pyloric compliance showed a similar pattern as that found for Ep.

CONCLUSION

The EndoFLIP system holds promise for assessment of biomechanics of the pyloric region in patients undergoing esophagectomy for cancer.

Gastric and sacral electrical stimulation for motility disorders-A clinical perspective

BACKGROUND

Electrical stimulation of the gut has been investigated in recent decades with a view to treating various gastro-intestinal motility disorders including, among others, gastric electrical stimulation to relieve nausea and vomiting associated with gastroparesis and sacral neuromodulation to treat fecal incontinence and/or constipation. Although their symptomatic efficacy has been ascertained by randomized controlled trials, their mechanisms of action are not fully understood.

PURPOSE

This review summarizes the past year's literature on the mechanisms of action of gut electrical stimulation therapies, including their impact on the gut-brain axis.

Physiological characterization of gastric emptying using high-resolution antropyloroduodenal manometry

Delayed gastric emptying (GE) has been associated with antral and pyloric dysmotility. We aimed to characterize differences in the antral, duodenal, and pyloric motility profiles associated with delayed GE, using high-resolution antropyloroduodenal manometry (HR-ADM). Patients referred for HR-ADM for dyspeptic symptoms performed a concurrent GE breath test (NCT01519180 and NCT04918329). HR-ADM involved 36 sensors 1 cm apart, placed across the pylorus. Interdigestive and postprandial periods were identified. Antral, pyloric, and duodenal motor profiles were analyzed recording the frequency, amplitude, and propagative nature of contractions for each period. Plots of patients with normal and delayed GE were compared. Sixty patients underwent both HR-ADM and GE tests. Twenty-five and 35 patients had delayed and normal GE, respectively. Antral and duodenal motor profiles were not different between the two groups during the interdigestive period. During the postprandial period, a lower frequency of antral contractions was associated with delayed GE (2.22 vs. 1.39 contractions/min; P = 0.002), but no difference in mean contraction amplitude was observed. The pyloric region was identified in all the patients and pylorospasms, defined as 3 min of repeated isolated pyloric contractions, were more frequent in patients with delayed GE (32.0% vs. 5.7%; P = 0.02) during the postprandial period. No difference in duodenal contraction profiles was observed. Manometric profile alterations were observed in 72% of the patients with delayed GE, with 56% having a low frequency of antral contractions. Using HR-ADM, patients with delayed GE displayed different postprandial antropyloric motility as compared with patients with normal GE.NEW & NOTEWORTHY High-resolution antropyloroduodenal manometry (HR-ADM) allows precise characterization of antral, pyloric, and duodenal motility, although its association with gastric emptying (GE) has been poorly investigated. Concurrent HR-ADM with GE measurement showed a lower frequency of antral postprandial contractions and an increased frequency of postprandial pylorospasms in patients with delayed GE. HR-ADM could, therefore, be useful in the future to better select patients for treatments targeting the pylorus.

Use of endolumenal functional lumen imaging probe in investigating paediatric gastrointestinal motility disorders

Investigating gastrointestinal (GI) motility disorders relies on diagnostic tools to assess muscular contractions, peristalsis propagation and the integrity and coordination of various sphincters. Manometries are the gold standard to study the GI motor function but it is increasingly acknowledged that manometries do not provide a complete picture in relation to sphincters competencies and muscle fibrosis. Endolumenal functional lumen imaging probe (EndoFLIP) an emerging technology, uses impedance planimetry to measure hollow organs cross sectional area, distensibility and compliance. It has been successfully used as a complementary tool in the assessment of the upper and lower oesophageal sphincters, oesophageal body, the pylorus and the anal canal. In this article, we aim to review the uses of EndoFLIP as a tool to investigate GI motility disorders with a special focus on paediatric practice. The majority of EndoFLIP studies were conducted in adult patients but the uptake of the technology in paediatrics is increasing. EndoFLIP can provide a useful complementary data to the existing GI motility investigation in both children and adults.

Paradoxical association between dyspepsia and autoimmune chronic atrophic gastritis: Insights into mechanisms, pathophysiology, and treatment options

BACKGROUND

Autoimmune gastritis (AIG) is a progressive, chronic, immune-mediated inflammatory disease characterized by the destruction of gastric parietal cells leading to hypo/anacidity and loss of intrinsic factor. Gastrointestinal symptoms such as dyspepsia and early satiety are very common, being second in terms of frequency only to anemia, which is the most typical feature of AIG.

AIM

To address both well-established and more innovative information and knowledge about this challenging disorder.

METHODS

An extensive bibliographical search was performed in PubMed to identify guidelines and primary literature (retrospective and prospective studies, systematic reviews, case series) published in the last 10 years.

RESULTS

A total of 125 records were reviewed and 80 were defined as fulfilling the criteria.

CONCLUSION

AIG can cause a range of clinical manifestations, including dyspepsia. The pathophysiology of dyspepsia in AIG is complex and involves changes in acid secretion, gastric motility, hormone signaling, and gut microbiota, among other factors. Managing dyspeptic symptoms of AIG is challenging and there are no specific therapies targeting dyspepsia in AIG. While proton pump inhibitors are commonly used to treat dyspepsia and gastroesophageal reflux disease, they may not be appropriate for AIG. Prokinetic agents, antidepressant drugs, and non-pharmacological treatments may be of help, even if not adequately evidence-based supported. A multidisciplinary approach for the management of dyspepsia in AIG is recommended, and further research is needed to develop and validate more effective therapies for dyspepsia.