LAUSR

The article of Thompson et al. (1) is certainly interesting, because for the first time it tries to stratify the risk of patient safe late-stage SLA in amyotrophic lateral sclerosis (ALS) subjected to endoscopic manoeuvre for percutaneous endoscopic gastrostomy (PEG) insertion. The manoeuvre of PEG placement, although simple, in some patients, as in the case of safe late-stage (SLA), can cause a variety of adverse events. The authors argue that layering the risk through clinical and laboratory parameters on respiratory conditions, makes it possible to obtain a reduction of adverse events, which in their case is mortality. We believe that there are some relevant considerations for understanding the implications of this study. First, we should keep in mind that that recent studies on the subject such as the ProGas study cited by the authors, consider that PEG is a manoeuvre associated with low mortality in SLA patients, even with functional volume capacity (FVC) less than 50% of predicted (2,3). For this reason, in our opinion a ‘risk map drawn up beforehand’, in an arbitrary manner, taking account of the previous studies, might not be accurate in stratifying risk in these patients. Secondly, if we analyse mortality at one month, the highest percentage (even if not significant) is observed in patients with FVC550%. If instead we proceed to observe mortality at six months, it is high in patients with FVC 550%, but if we analyse similarly in groups stratified by risk we see that there is little or no difference amber and red groups (1,2). The confounding factor appears to be the reduction of FVC that in SLA patients is a prognostic factor of mortality independent also from the manoeuvre of PEG insertion. For this reason, it is right to keep in mind (as the authors have done) that these patients could have died from the natural history of the disease and the insertion of PEG is associated with a functional state of risk that could create the adverse event. In our opinion, a chart of risk should be constructed on a large cluster of patients prospectively studied, evaluating additional parameters (there are different experiences in this regard (4)). In this case, it is possible to maintain consideration of other parameters such as the PCF/PEF ratio, which is an index of the glottic functionality; this could have a role in predicting peri-operative risk in these patients. In our opinion, in this type of procedure, mortality is not the unique parameter that we should investigate but also the frequency of the complications. This could allow us to address these patients in respect of modified PEG techniques;it would be useful to investigaterespiratory insufficiency from bronchial encumbrance and inhalation (3,4). For this reason, it is more important to avoid adverse events due to impaired breathing that could compromise the quality of life of the patient; more that mortality, as we have seen and assumed, has its own specific course independent of the insertion of PEG (5,6).