Effectiveness of percutaneous endoscopic gastrostomy in amyotrophic lateral sclerosis

Slow vital capacity as a useful indicator of the prognosis after percutaneous endoscopic gastrostomy in patients with amyotrophic lateral sclerosis

OBJECTIVES

Forced vital capacity (FVC) is recommended as a respiratory function test in patients with amyotrophic lateral sclerosis (ALS). However, in ALS associated with orofacial palsy, FVC may be an unreliable test. Slow vital capacity (SVC) is an easier and more reliable test even in cases with bulbar symptoms. However, it remains unclear whether respiratory function tests using SVC and FVC are associated with prognosis after percutaneous endoscopic gastrostomy (PEG) placement. This study aimed to confirm whether both SVC and FVC are related to prognosis after PEG placement in patients with ALS.

MATERIALS AND METHODS

We conducted this retrospective observational cohort study of 69 consecutive patients diagnosed with sporadic ALS who underwent PEG placement between July 2007 and February 2020. We analyzed the association with mortality 6 months after PEG placement and evaluated long-term prognosis.

RESULTS

Forty-four patients met the inclusion criteria. In cases with decreased SVC (p < .01) and FVC (p < .01), a significant difference was observed in mortality 6 months after PEG placement, with an optimal cut-off of SVC ≤57.4% (sensitivity, 0.828; specificity, 0.867) and FVC ≤57.3% (sensitivity, 0.828; specificity, 0.867). Multivariate analysis showed that onset age ≥ 65 years (p < .05), SVC ≤57.4% (p < .01), and FVC ≤57.3% (p < .01) were associated with survival after PEG placement.

CONCLUSIONS

SVC, like FVC, is an important prognostic factor after PEG placement in patients with ALS, and there is a possibility that evaluation using SVC can complement respiratory function testing even in cases where the evaluation of FVC is limited.

Reduction of Sniff Nasal Inspiratory Pressure (SNIP) as an Early Indicator of the Need of Enteral Nutrition in Patients with Amyotrophic Lateral Sclerosis

Percutaneous endoscopic gastrostomy (PEG) is the standard procedure for feeding severely dysphagic patients with amyotrophic lateral sclerosis (ALS). It is associated with prolonged survival and improvement in quality of life. Nasal inspiratory pressure during a sniff (SNIP) is a respiratory test used extensively in ALS for the assessment of inspiratory muscle strength. In this study, we aimed to investigate the role of SNIP at baseline to predict PEG placement in ALS. Data from a clinical incident cohort of 179 ALS cases attending the multidisciplinary ALS unit of the University of Bari between April 2006 and December 2012 were retrospectively analysed. At baseline, patients underwent detailed neurological, nutritional and respiratory assessments, including measurements of SNIP and forced vital capacity (FVC). Patients were therefore followed up approximately every three to six months until they were able to attend the centre. The censoring date for the survival analysis was 15 April 2014, with PEG placement as the main outcome. Cox proportional hazard regression models were used to examine the association between SNIP and PEG placement, adjusted for possible confounders. During the follow-up period, 75 participants (42%) received PEG implant. PEG placement was more frequent (57% vs. 31%; p = 0.001) and earlier (after 11.6 ± 14.0 months from the first visit, vs. 23.3 ± 15.5 months; p < 0.0001) in the group of patients with baseline SNIP ≤ 40 cm H₂O. Baseline SNIP was a predictor of PEG placement even after correction for multiple potential confounders (HR 0.98; 95% CI: 0.96–0.99; p = 0.02). To conclude, the present study showed that SNIP at baseline is an early indicator of disease progression and therefore of the need for enteral nutrition in ALS.

Percutaneous gastrostomy in amyotrophic lateral sclerosis: a review

Amyotrophic lateral sclerosis (ALS) causes dysphagia and consequent poor nutrition. Sometimes enteral feeding is offered. Percutaneous endoscopic gastrostomy (PEG) is currently the technique of choice for enteral nutrition of these patients. This systematic review addresses the role of PEG and other enteral feeding techniques in maintaining ALS patients' survival and quality of life and in identifying prognostic factors for survival, in order to optimize their usefulness. We also evaluated the mortality of enteral feeding in the first 30 days after each procedure and its complications. Studies were retrieved from Pubmed, Google Scholar, and Cochrane databases, using the relevant keywords, and by hand search. The inclusion criteria were prospective and retrospective designs of studies of people with clinically diagnosed ALS in whom gastrostomy or nasogastric enteral feeding were used in management, published in English. Studies with sample sizes <40, or which focused on a specific gastrostomy technique utilizing less than 30 subjects were excluded in order to avoid small sample bias. We conclude that PEG is safe and probably prolongs survival in non-malnourished ALS patients. However, older age at onset, marked loss of weight or reduced body mass index from symptomatic onset, and marked respiratory dysfunction negatively influence the outcome after PEG insertion. The currently available evidence does not meaningfully address the impact of PEG on quality of life in ALS. The literature about other enteral feeding techniques is insufficient for reliable conclusions. The optimum time for PEG insertion and preferences for specific gastrostomy techniques also require more investigation.

Gastrointestinal motility disorders in neurologic disease

The extrinsic and autonomic nervous system intricately controls the major functions of the gastrointestinal tract through the enteric nervous system; these include motor, secretory, sensory, storage, and excretory functions. Disorders of the nervous system affecting gastrointestinal tract function manifest primarily as abnormalities in motor (rather than secretory) functions. Common gastrointestinal symptoms in neurologic disorders include sialorrhea, dysphagia, gastroparesis, intestinal pseudo-obstruction, constipation, diarrhea, and fecal incontinence. Diseases of the entire neural axis ranging from the cerebral hemispheres to the peripheral autonomic nerves can result in gastrointestinal motility disorders. The most common neurologic diseases affecting gastrointestinal function are stroke, parkinsonism, multiple sclerosis, and diabetic neuropathy. Diagnosis involves identification of the neurologic disease and its distribution, and documentation of segmental gut dysfunction, typically using noninvasive imaging, transit measurements, or intraluminal measurements of pressure activity and coordination of motility. Apart from treatment of the underlying neurologic disease, management focuses on restoration of normal hydration and nutrition and pharmacologic treatment of the gut neuromuscular disorder.