Wernicke Encephalopathy in Adolescents After Bariatric Surgery: Case Report and Review

Thank you for your thoughtful commentary. While we agree with most of your discussion, especially your conclusion that adolescent bariatric surgery should be performed in multidisciplinary adolescent centers, there are a few points that we would like to emphasize.
First, most bariatric procedures done in adolescents in the United States and worldwide today are sleeve gastrectomies (SG), rather than Roux-en-Y (RYGB) procedures. Although there is limited statistical data in adolescents, this transition from bypass to sleeve procedures seems to be mirroring that of the adult population. While 37% of weight reduction surgery in 2011 was RYGB and 18% was SG, by 2015 only 23% were bypass procedures and 54% were SG(1).
Theoretically, the risk of Wernicke encephalopathy (WE) should be higher after RYGB compared with SG, a restrictive procedure in which the stomach volume is reduced without bypassing the duodenum. There are, however, several reported cases of both adolescent and adult patients developing WE after SG(2,3,4,5). A recent case series demonstrated that preoperative thiamine (Vitamin B1) levels in seven patients who underwent SG fell significantly post-operatively, though only two of these patients developed WE(2). The risk factors for developing WE after RYGB and SG appear similar and include nausea, vomiting, and medication non-compliance. Additionally, the limited reports on WE after SG demonstrate a similar time from surgery to first presentation and variable weight loss at presentation. Thus, impaired absorption of thiamine can occur even in the absence of significant post-operative weight loss(3). Lastly, the significant challenge some adult patients have with medication and dietary compliance underscores the even larger barriers that adolescents face post-operatively(3,4,5).
We believe that the most important points of this paper involve prevention and early recognition of this easily treatable condition. Thiamine supplementation should be used in all adolescent patients before and after bariatric surgery. Furthermore, members of the bariatric team as well as the adolescent and their family should be aware of the symptoms of WE and the need for immediate treatment. Anecdotally, adolescents appear to be at greater risk of post-operative WE than adults. Prevention remains the best therapy for WE in weight loss surgery patients both adolescents and adults.

References

1. American Society for Metabolic and Bariatric Surgery. (July, 2016). Estimates of bariatric surgery numbers, 2011-2015. Retrieved from https://asmbs.org/resources/estimate-of-bariatric-surgery-numbers.
2. Tabbara M, Carandina S, Bossi M, Plliand C, Genser L, Barrat C. Rare neurological complications after sleeve gastrectomy. Obes Surg. 2016;26(12):2843-2848.
3. Samanta D. Dry beriberi preceded Wernicke’s encephalopathy: thiamine deficiency after laparoscopic sleeve gastrectomy. J Pediatr Neurosci. 2015;10(3):297-299.
4. Makarewicz W, Kaska L, Kobiela J, et al. Wernicke’s syndrome after sleeve gastrectomy. Obes Surg. 2007;17(5):704-706.
5. Kröll D, Laimer M, Borbély YM, Laederach K, Candinas D, Nett PC. Wernicke encephalopathy: a future problem even after sleeve gastrectomy? A systematic literature review. Obes Surg. 2016;26(1):205-212.

We read with great interest the recent article by Armstrong-Javors et al.(1) published in the December 2016 issue of the Pediatrics which describes a case of Wernicke encephalopathy (WE) 2 months after Roux-en-Y gastric bypass (RYGB). The authors report a rare case of WE resulting from thiamine deficiency in a 15-year-old Caucasian girl who underwent RYGB. According to the manuscript, WE was suspected due to the progressive neurologic symptoms (nystagmus, irritability, ataxia) and frequent vomiting. The aforementioned case is very important because it reports not only a rare but also an acute complication after Bariatric surgery with notably increased mortality and morbidity. Furthermore, this review revealed that the overwhelming majority of the cases of WE after bariatric surgery occurred during the recent years. There are three solid reasons for the aforementioned increase.
Firstly, adolescent obesity has dramatically increased worldwide in recent decades and the prevention strategies for obesity are failing. Due to the fact that pharmacological and behavioural treatment options had mainly poor results in the treatment of obesity, bariatric surgery emerges as alternative treatment option . Bariatric surgery in adult population has proved effective with superior outcomes in terms of weight loss and remission of obesity-associated comorbidities, however, long-term results and complications post bariatric surgery in obese adolescents are not yet available. According to Armstrong-Javors et al.(1) there are only 9 definitive adolescent cases of WE after bariatric surgery reported in the literature. Our review of the literature revealed that there is also a dramatic increase of the published cases of WE after bariatric procedures in adult population during the recent years (2, 3). Due to the fact that bariatric surgery in pediatric patients is used increasingly during the last years, there is a consequential rise of complications, mainly, severe micronutrient deficiency, protein-calorie malnutrition, gastrointestinal obstruction and pulmonary embolism.
Secondly, RYGB is the most commonly performed procedure in obese adolescents in the United States, and the risk of severe micronutrient deficiencies after malabsorbitive procedures such as RYGB is significantly higher than restrictive bariatric procedures such as sleeve gastrectomy and laparoscopic adjustable gastric band. The RYGB reduces the absorption of thiamine mainly because it bypasses duodenum and more than 30 cm of jejunum beyond the ligament of Treitz. Moreover, small intestinal bacterial overgrowth due to altered gut ecology, is associated with the development of thiamine deficiency and WE(4). Last but not least, the majority of patients undergoing bariatric procedures does not receive adequate and appropriate nutrition supplements, not only after but and before the operation, including the supplementation of vitamin B1, and for this reason is more likely to develop WE(5).
Overall, bariatric surgery in adolescents should be offered only within authorized adolescent obesity prevention programs, provided by interdisciplinary adolescent obesity teams, and only by specialist centers, so as to minimize detrimental complications and improve outcomes. Furthermore, patients and family should be informed and educated about the risks and benefits, expected complications, potential eating behaviour changes, careful nutritional follow-up and lifelong requirement for multivitamin supplementation.

References

1. Armstrong-Javors A, Pratt J, Kharasch S. Wernicke Encephalopathy in Adolescents After Bariatric Surgery: Case Report and Review. Pediatrics. 2016;138(6):e20161039.
2. Athanasiou A, Moris D, Davakis S, Spartalis E. Wernicke Encephalopathy after Restrictive Bariatric Surgery: A Significant Increase of a Rare Complication. Am Surg. 2016;82(12):374-5.
3. Athanasiou A, Angelou A, Diamantis T. Wernicke's encephalopathy after sleeve gastrectomy. Where do we stand today? A reappraisal: Surg Obes Relat Dis. 2014 May-Jun;10(3):563. doi: 10.1016/j.soard.2014.01.028. Epub 2014 Jan 30.
4. Lakhani SV, Shah HN, Alexander K, Finelli FC, Kirkpatrick JR, Koch TR. Small intestinal bacterial overgrowth and thiamine deficiency after Roux-en-Y gastric bypass surgery in obese patients. Nutrition research. 2008;28(5):293-8.
5. Inge TH, Krebs NF, Garcia VF, Skelton JA, Guice KS, Strauss RS, et al. Bariatric surgery for severely overweight adolescents: concerns and recommendations. Pediatrics. 2004;114(1):217-23.