Gastrostomy in Amyotrophic Lateral Sclerosis: Timing Enhances Survival

Recognizing the optimal timing for gastrostomy in patients with amyotrophic lateral sclerosis (ALS) continues to pose a significant clinical challenge. Multiple factors influencing this decision-making process have contributed to consequential procedural delays, including the intended clinical benefits that this procedure will provide the patient, and whether these benefits are fully understood or eventually achieved. Practice consensus recommends discussions regarding gastrostomy occurring in the earliest stages of the disease process, with follow-up conversations taking place at regular clinic intervals.1, 2 Multiple studies have attempted to address the various underlying patient and caregiver concerns regarding this procedure,3-6 some of which include psychosocial factors, the development of post gastrostomy abdominal pain, risk of site infection, and limitations of swimming and other physical activities.7 The intended clinical benefits of gastrostomy have focused on mitigating the risk of choking and aspiration, reducing mealtime anxiety and subsequent caregiver burden, achieving appropriate caloric/protein/fluid intake, maintaining healthy social interactions during the mealtime experience, and improving overall quality of life.8, 9 Inevitably, malnutrition secondary to motor neuron disease (MND) remains a significant clinical concern. Factors contributing to progressive weight loss are myriad, including patient difficulties preparing food, loss of appetite or enjoyment while eating, secondary depression or dementia, shortness of breath while eating, progressive dysphagia with advanced sialorrhea, an underlying increased metabolic rate associated with ALS, and progressive mastication muscle weakness, all resulting in decreased caloric intake which ultimately leads to terminal disease progression. In an attempt to further understand and address many of these clinical issues, the 2015 ProGas study10 determined that gastrostomy prior to a 10% loss in body weight, from the time of diagnosis until time of procedure, resulted in an overall improved survival compared to those who experienced a more substantial weight loss. This study concluded that patients with MND derived the greatest benefit from enteral feedings prior to the development of substantial weight loss. Preliminary results from the follow up PostGas study11 indicated nutritional outcomes were found to vary among individuals post gastrostomy, higher caloric and protein intake may prevent further weight loss post gastrostomy, and stressed the importance of closely monitoring nutritional/fluid intake while utilizing the gastrostomy on a daily basis. This study additionally identified malnutrition and weight loss as contributors to increased disability with reduced survival, proposing every means of maintaining adequate nutrition and weight gain following gastrostomy be employed. Recently, the detrimental clinical impact regarding the time of gastrostomy recommendation versus the time of actual placement was evaluated.12 In this retrospective study, gastrostomy recommendation occurred on average 22 months post symptom onset, yet tube placement was not performed until 8 months later. During this delay, a reduction of the ALS Functional Rating Scale-Revised (ALSFRS-R) by 1.7 points per month was reported, compared to 0.6 points per month decline following tube insertion, identifying an accelerated trajectory of decline. The authors' overall conclusions were to emphasize the importance of initiating gastrostomy discussion with the patient and caregivers much earlier in the disease course. In a recent issue of Muscle and Nerve, Yang and colleagues have focused on more clearly defining the predictors of mortality post gastrostomy in MND patients.13 They recognized that little data exists assessing mortality beyond 30 days following gastrostomy placement, and therefore performed a retrospective study from a single site involving 94 MND patients, assessing mortality at 30, 90, and 180 days post gastrostomy. In this study, the median time from diagnosis to gastrostomy was 227 days, identifying no mortality attributed to the actual gastrostomy procedure. Their findings revealed that a lower forced vital capacity (FVC) and greater percentage of weight loss from diagnosis to time of procedure were observed in those who died 30 days post gastrostomy. Older age, male sex, lower FVC and greater weight loss were predictors of mortality at 90 days; however, only older age and greater weight loss were mortality predictors at 180 days. No significant survival difference was noted between patients with bulbar versus limb onset. The authors determined that mortality at 90 and 180 days post gastrostomy procedure was primarily influenced by the percent of weight loss from time of diagnosis to the time of gastrostomy placement, encouraging the importance of initiating early and continuous nutritional care and support in these patients. They further emphasized that gastrostomy placement prior to substantial weight loss may reduce the risk of cachexia associated mortality. In addition, FVC was found to be a significant predictor of mortality at 90 days, and therefore this measure should be included when identifying the appropriate timing of gastrostomy discussion with the patient and their caregivers. This study highlights several key and instructive points, including the importance of clinical decision-making predicated upon the available objective data within the current literature, as lack of evidence breeds indecision. In order to facilitate timely decision-making, dietary/nutritional assessment and evaluation should remain standard practice in all ALS clinics, initially occurring with the patient's first ALS evaluation and including routine visits thereafter.14, 15 It would also appear appropriate to redefine the overall projected clinical purpose and intent of gastrostomy, continuing to educate all parties involved that this procedure should now be considered a means of active supportive intervention, positively influencing the disease trajectory. The importance of maintaining ideal body weight earlier in the disease process has now been recognized in multiple clinical studies2, 12, 13 as essential in achieving prolonged patient survival. Evidence to date further suggests gastrostomy may indeed represent a recognized treatment modality for ALS patients and should now be viewed as achieving a similar impact as other accepted clinical modalities, potentially comparable to the benefits achieved from noninvasive ventilation (NIV) or care in a multidisciplinary ALS clinic. As we strive in our ALS population to encourage adequate and regular NIV usage and device tolerance, the daily and consistent use of the gastrostomy should also be closely monitored in clinic, in order to attain its desired clinical benefit. This could be achieved with weekly body weight measurements at home, or with routine home calorie counts, encouraging timely updates to healthcare providers via caregivers should weight loss ensue. Additionally, evidence-based nutrition guidelines in ALS do exist, including the recommended maintenance of body mass index (BMI) following diagnosis between 25 and 35 kg/m2, with optimization of caloric intake if BMI falls below 25 kg/m2. These guidelines should reinforce the importance of initiating and maintaining dietary/nutritional participation within ALS clinics,1 or through readily available referral networks. In summary, dietary and nutritional management strategies should be standardized early in the disease course, emphasizing a high calorie/protein diet and advocating timely gastrostomy discussions upon recognizing substantial premorbid body weight loss. Introducing the discussion of gastrostomy prior to severe respiratory compromise has also been resolutely encouraged. Initiating earlier gastrostomy discussions with older patients and those with rapidly declining respiratory parameters should now be routine. Ultimately, it must still be recognized that gastrostomy is a major clinical and personal decision, which should involve shared decision-making between the medical team, patient and caregivers, always being respectful of the patient's ultimate wishes. The acquired empirical clinical data to date confirms that the initial discussion of gastrostomy should begin promptly following the ALS diagnosis and continued throughout regular intervals, thereby maximally optimizing all clinically achievable benefits for our patients. Gary L. Pattee: Conceptualization; formal analysis; investigation; methodology; project administration; supervision; writing – original draft; writing – review and editing. The author declares no conflicts of interest. I confirm that I have read the Journal's position on issues involved in ethical publication and affirm that this report is consistent with those guidelines. N/A.