Treatment of gastroparesis

The addition of pyloroplasty as a new surgical approach to enhance effectiveness of gastric electrical stimulation therapy in patients with gastroparesis

BACKGROUND

Improvement of gastroparesis (GP) symptoms has been documented in patients treated with gastric electrical stimulation (GES), but acceleration of gastric emptying (GET) is unpredictable. The aim of our study was to evaluate the advantage of adding surgical pyloroplasty (PP) to GES for improvement of GET and control of symptoms in diabetes mellitus (DM), idiopathic (ID), and postvagotomy (P-V) GP.

METHODS

A total of 49 (17 - DM, 9 - ID, 23 - P-V) consecutive GP patients: 38 female; mean age 42 (21-73 years); mean weight 158 lbs (102-245), underwent GES implantation, and 26 (53%) additionally received PP. Total Symptoms Score, 4-h GET, adverse events (AEs), and days of hospitalizations were captured at baseline and at the last visit.

KEY RESULTS

The mean follow-up was 7 months. Total Symptoms Score in patients who received Enterra and PP or GES alone significantly improved compared to their baseline scores (P < 0.001). GET improved by 64% at 4 h (P < 0.001) in patients with Enterra and PP, compared to 7% observed after GES therapy alone (ns). The most impressive acceleration of GET was seen in the P-V group, who received both therapies (P = 0.004) and 8 (60%) of them normalized GET. No AEs accompanied the addition of PP to the Enterra surgery.

CONCLUSIONS & INFERENCES

(i) In drug-refractory GP the addition of PP to GES substantially accelerated GET; (ii) The GET response in P-V group was the most impressive; (iii) Significant symptom reductions were achieved by both procedures; and (iv) PP added to GES may sustain better long-term symptoms control particularly in the P-V setting.

Comparative gastric motility study of Enterra ™ Therapy and neural gastric electrical stimulation in an acute canine model

BACKGROUND

Gastric electrical stimulation (GES) is an avenue for treating gastroparesis and obesity by controlling gastric motility using electrically mediated gastric contractions. Neural gastrointestinal electrical stimulation (NGES) is a GES modality capable of producing strong lumen-occluding local gastric contractions. Conversely, Enterra ™ Therapy, a commercial implantable gastric electrical stimulator, has been utilized to treat symptoms of gastroparesis, but its nominal electrical parameters are not capable of generating lumen-occluding contractions. However, comparative studies between these two stimulation modalities are lacking.

METHODS

Strain gauge transducers complemented by endoscopic monitoring have been utilized to register gastric contractions invoked with NGES and Enterra neurostimulators in four acute dogs. Mucosal and serosal electrode implantations, 'nominal' and 'maximum' electrical parameters, and longitudinal and transverse electrode placements have been tested with each neurostimulator type.

KEY RESULTS

Strong lumen-occluding, circumferential contractions were induced with a wide variety of NGES parameters utilizing both transverse and longitudinal electrode configurations from the serosal side of the stomach. Similarly, local gastric contractions were observed with the Enterra neurostimulator programmed at its 'maximum' electrical parameters but only when utilizing transverse serosal electrode implantation. Under 'maximum' electrical parameters Enterra was not capable of producing registerable gastric contractions with longitudinally implanted serosal electrodes. Mucosal electrode implantations did not result in GES-invoked gastric contractions in both stimulation modalities.

CONCLUSIONS & INFERENCES

Enterra Therapy is capable of producing gastric contractions under 'maximum' parameters and transverse electrode configuration. Neural gastrointestinal electrical stimulation produces stronger, lumen-occluding contractions under a wider range of electrode configurations and parameters.

Prokinetic therapy: What can be measured by gastric scintigraphy?

OBJECTIVE

To evaluate whether gastric scintigraphy with quantitative analysis of gastric peristalsis may be a useful tool for documenting the effects of prokinetic therapy.

METHODS

Gastric emptying was determined in eight patients with insulin dependent diabetes mellitus (IDDM) and nine patients with progressive systemic sclerosis (PSS) after ingestion of a semi-solid test meal. Fourier analysis of condensed images was used to evaluate contraction amplitudes of the entire stomach, as well as frequency and velocity of gastric contractions. Patients were studied twice, first under baseline conditions and then after 4 weeks of continuous oral prokinetic therapy with cisapride (10 mg t.i.d.). Findings were compared with data derived from 15 healthy controls.

RESULTS

At baseline conditions IDDM and PSS patients exhibited reduced gastric peristalsis and delayed emptying compared to controls. After 4 weeks of prokinetic treatment, gastric contraction amplitudes increased significantly, especially in the gastric corpus and the proximal stomach, associated with a slight improvement of gastric emptying. Changes in frequency and velocity of gastric contractions during prokinetic treatment correlated with the improvement of gastric motility and emptying.

CONCLUSIONS

Prokinetic therapy with cisapride stimulates gastric motility, and could be non-invasively monitored by scintigraphy. This radionuclide technique provides a number of relevant parameters of gastric function, such as gastric emptying, contraction amplitudes, frequency and velocity of gastric contractions, which give crucial insights into the mechanisms of action of prokinetic drugs.

Current pharmacological treatment of gastroparesis

The aetiology of gastroparesis differs between children and adults. During childhood, gastroparesis is quite rare, and is mostly seen in preterm infants, with either immaturity of the gastrointestinal tract, or when allergic to cow's milk protein. Acute, delayed gastric emptying may be observed following viral infections. In adults, most patients with gastroparesis are either idiopathic or of diabetic origin. As a consequence, approaches in the treatment of children and adults differ. Metoclopramide, domperidone, cisapride and erythromycin have all been studied. Evidence for benefit is strongest for the latter two drugs, although most studies have methodological shortcomings. From a paediatric perspective, it seems astonishing that more trials with erythromycin analogues have not been performed, as the few data available suggests that these analogues are more powerful, without the side effects of long-term, low-dose administration of antibiotics. Gastric electrical stimulation seems the most promising therapeutic option available at present.