New Developments in Prokinetic Therapy for Gastric Motility Disorders

Prokinetic agents amplify and coordinate the gastrointestinal muscular contractions to facilitate the transit of intra-luminal content. Following the institution of dietary recommendations, prokinetics are the first medications whose goal is to improve gastric emptying and relieve symptoms of gastroparesis. The recommended use of metoclopramide, the only currently approved medication for gastroparesis in the United States, is for a duration of less than 3 months, due to the risk of reversible or irreversible extrapyramidal tremors. Domperidone, a dopamine D2 receptor antagonist, is available for prescription through the FDA’s program for Expanded Access to Investigational Drugs. Macrolides are used off label and are associated with tachyphylaxis and variable duration of efficacy. Aprepitant relieves some symptoms of gastroparesis. There are newer agents in the pipeline targeting diverse gastric (fundic, antral and pyloric) motor functions, including novel serotonergic 5-HT4 agonists, dopaminergic D2/3 antagonists, neurokinin NK1 antagonists, and ghrelin agonist. Novel targets with potential to improve gastric motor functions include the pylorus, macrophage/inflammatory function, oxidative stress, and neurogenesis. In the current review, we discuss the use of pharmacological approaches with potential to enhance motor functions in the management of gastroparesis.

Ingestible transiently anchoring electronics for microstimulation and conductive signaling

Ingestible electronic devices enable noninvasive evaluation and diagnosis of pathologies in the gastrointestinal (GI) tract but generally cannot therapeutically interact with the tissue wall. Here, we report the development of an orally administered electrical stimulation device characterized in ex vivo human tissue and in in vivo swine models, which transiently anchored itself to the stomach by autonomously inserting electrically conductive, hooked probes. The probes provided stimulation to the tissue via timed electrical pulses that could be used as a treatment for gastric motility disorders. To demonstrate interaction with stomach muscle tissue, we used the electrical stimulation to induce acute muscular contractions. Pulses conductively signaled the probes’ successful anchoring and detachment events to a parenterally placed device. The ability to anchor into and electrically interact with targeted GI tissues controlled by the enteric nervous system introduces opportunities to treat a multitude of associated pathologies.

Microwave Ablation: A Potential Minimally Invasive Solution for Gastric Motility Disorders

Many gastric motility disorders, including gastroparesis, are caused by dysrhythmias occurring in the stomach musculature. Microwave ablation (MWA) offers potential as a minimally invasive endoscopic approach for targeted thermal destruction of the gastric musculature to disrupt irregular electrical rhythm within the stomach wall. An experimental study was conducted in a gel phantom to analyze the transient heating profile of a water-cooled 2.45 GHz MWA antenna enclosed within a PET balloon. Fiber-optic temperature sensors were used to collect temperature data at distances 1.5–7.5 mm from the balloon surface. Ablation profiles were also characterized in ex vivo porcine skeletal muscle. With 20 W applied power and cooling water temperature of 5 °C, temperature measured at 3.5 mm from the balloon surface exceeded the temperature at 1.5 mm from the balloon surface by 3 °C. In ex vivo tissue, for 40 W applied power, tissue within 2 mm of the balloon surface remained unablated. With adequate cooling and power, it may be feasible to thermally spare tissue within 2 mm of the MWA balloon applicator.

Tube Gastropexy for the Management of Gastric Dilatation Volvulus in a Dog

Gastric Dilatation Volvulus (GDV) is an acute condition with mortality rate of 20% to 45% in treated animals, (Evans and Adams, 2010). Dogs fed a large volume of food per meal were at increased risk of developing GDV, (Raghavan et al., 2004). Male gender, being under weight, eating rapidly, gastric motility disorders, stress are the predisposing factors for GDV, (Raghavan et al., 2006). This report describes the successful medical and surgical management of GDV and splenic torsion in a GermanSheperd Dog.