Langenbeck's Archives of Surgery (2023) 408:10 https://doi.org/10.1007/s00423-022-02736-w RESEARCH Severity of post‑Roux‑en‑Y gastric bypass dumping syndrome and weight loss outcomes: is there any correlation? Mohammad Kermansaravi1,2 · Shahab ShahabiShahmiri1,2 · Ramon Vilallonga3 · Barmak Gholizadeh1,4 · Amir Hossein DavarpanahJazi1 · Yeganeh Farsi4 · Rohollah Valizadeh1,5 · Masoud Rezvani6 Received: 21 April 2022 / Accepted: 19 October 2022 / Published online: 6 January 2023 © The Author(s) 2023 Abstract Purpose The present research was conducted to evaluate the effect of the severity of dumping syndrome (DS) on weight loss outcomes after Roux-en-Y gastric bypass (RYGB) in patients with class III obesity. Methods The present retrospective cohort study used the dumping symptom rating scale (DSRS) to evaluate the severity of DS and its correlation with weight loss outcomes in 207 patients 1 year after their RYGB. The patients were assigned to group A with mild-to-moderate DS or group B with severe DS. Results The mean age of the patients was 42.18 ± 10.46 years and their mean preoperative BMI 42.74 ± 5.59 kg/m2. The total weight loss percentage (%TWL) in group B was insignificantly higher than that in group A, but besides that was not significantly different in the two groups. Conclusion The present findings suggested insignificant relationships between the presence and severity of DS after RYGB and adequate postoperative weight loss. Keywords RYGB · Dumping syndrome · Weight loss · Gastric bypass · Bariatric surgery Purpose Roux-en-Y gastric bypass (RYGB) is currently one of the most frequent bariatric surgeries performed worldwide [1]. Dumping syndrome (DS) potentially occurring within the * Mohammad Kermansaravi first 3 months of RYGB is characterized by unpleasant gas- mkermansaravi@yahoo.com; Kermansaravi.m@iums.ac.ir trointestinal symptoms, including abdominal pain, nausea * Ramon Vilallonga and diarrhea, and vasomotor symptoms such as palpitation, vilallongapuy@gmail.com hypotension, sweating, dizziness, fatigue, and flushing [2, 3]. 1 Department of Surgery, Minimally Invasive Surgery DS is categorized as early and late with different etiologies. Research Center, Division of Minimally Invasive Early DS mostly occurring 10–30 min after meals through and Bariatric Surgery, School of Medicine, Rasool-E Akram rapid emptying of hyperosmolar ingestion into the jejunum Hospital, Iran University of Medical Sciences, Tehran, Iran is caused by the absence of the pylorus in the alimentary 2 Iran National Center of Excellence for Minimally Invasive tract [4]. Late DS occurring 1–3 h after meals due to high- Surgery Education, Iran University of Medical Sciences, insulin response after ingestion of high carbohydrate meals Tehran, Iran emerges as postprandial hypoglycemia [5]. 3 Obesity and Metabolic Surgery Unit, Vall Hebron Campus Severe DS can theoretically cause the patient to avoid Hospital, Barcelona, Spain high-fat or high-carbohydrate foods, which is in line with 4 Department of General Surgery, Shahid Modarres Hospital, dieticians’ nutritional orders, helps with weight loss and pre- Shahid Beheshti University of Medical Sciences, Tehran, Iran vents weight regain after RYGB [6–8]. Given the rarely con- 5 ducted studies on the effects of DS on weight loss outcomes Urmia University of Medical Sciences, Urmia, Iran after bariatric procedures [7, 8], the present study aimed at 6 Department of Surgery, Davis Hwy, Inova Fair Oaks Hospital, 14904 JeffersonSuite 205, Woodbridge, VA, USA 13 Vol.:(0123456789) 10 Page 2 of 6 Langenbeck's Archives of Surgery (2023) 408:10 evaluating correlations between DS severity and weight loss discharged within the first day after the surgery. All the outcomes 1 year after RYGB. patients were followed-up 10 days and 1, 3, 6, and 12 months after the surgery by the surgical, nutritionist, and multi-dis- ciplinary team members. Methods Statistical analysis Design and setting The data were analyzed in SPSS-21 at a P < 0.05 signifi- This retrospective cohort study recruited 207 patients under- cance level. After confirming the distribution normality going primary RYGB at Rasool-e-Akram Hospital, Tehran, of the variables using the Kolmogorov–Smirnov test, the Iran, from January 2019 to August 2020. The inclusion crite- relationships of the main factors with the outcomes were ria comprised a minimum age of 18 years and BMI > 40 kg/ investigated using the independent t test and linear regres- m2 or BMI > 35 kg/M2 and obesity-related comorbidities. sion. The data were expressed as descriptive statistics, i.e., The data extracted from the Iran National Obesity Surgery frequency and percentage, or mean ± SD. Database (INOSD) [9] included comorbidities and demo- graphic and anthropometric information. Symptoms of DS were recorded through phone interviews with eligible candi- Results dates using the early dumping symptom rating scale (DSRS) within 1 year after the operation [10]. The exclusion criteria The mean age of the patients was 42.18 ± 10.46 years, their consisted of revisional and conversional RYGB and history mean preoperative BMI 42.74 ± 5.59 kg/m 2 and 89.4% of upper gastrointestinal surgeries. Out of the 11 items in (n = 185) were female. Table 1 presents baseline variables, the DSRS, nine relate to the symptoms emerging within i.e., diabetes mellitus (T2DM), obstructive sleep apnea 10–30 min after meals, one relates to the symptoms emerg- (OSA), cardiovascular disease (CVD), gastroesophageal ing after drinking during meals, and one to the symptoms reflux disease (GERD), hypertension (HTN), and dyslipi- after very sweet drinks. The severity of each symptom in demia (DLP). the previous week was rated on a 7-point scale ranging from Table 2 shows the difference for TWL% in the groups A 1 “no trouble at all” to 7 “very severe problems.” The fre- and B regarding the severity of the measured items. These quency of dumping symptoms within the previous 2 weeks TWL% were not significantly different (P > 0.05) but fatigue was also measured on a 6-point scale ranging from 1 “no and cramp. trouble at all” to 6 “several times a day.” In terms of sever- Table 3 shows differences in %TWL between groups A ity, the patients with “no trouble at all,” “minor inconven- and B by the frequency of the measured items. Although ience,” “mild trouble,” or “moderate trouble” were assigned %TWL was insignificantly different (P > 0.05), nausea to group A and those with “quite severe problems,” “severe or vomiting and cold sweats were significantly different problems,” or “very severe problems” to group B. In terms between the two groups. of frequency, the patients with “no trouble at all,” “less than once a week,” “once a week,” or “a few times a week” were allocated to group A (less than once a day) and those with Table 1  Demographic and clinical characteristics of the studied “once a day” or “several times a day” to group B (at least patients once a day). Variable Value Surgical technique Age, mean ± SD (range), year 42.18 ± 10.46 (21–72) Female sex, no. (%) 185 (89.4) An experienced surgical team performed long laparoscopic Pre-op BMI, mean ± SD (range), kg/m2 42.74 ± 5.59 (31.08–55.68) biliopancreatic RYGB in the French position. After creat- T2DM, no. (%) 38 (18.4) ing a 6-cm slim gastric pouch with about 40–60 ml volume, OSA, no. (%) 81 (39.1) a posterior gastro-jejunostomy was created with a 30-mm CVD, no. (%) 4 (1.9) linear endo-stapler about 125 cm after the ligament of Treitz HTN, no. (%) 47 (22.7) (long BP). A 45-mm jejuno-jejunal anastomosis was then DLP, no. (%) 61 (29.5) created using the linear endo-stapler and a 75-cm Roux limb. GERD, no. (%) 55 (26.57) Both Petersen and jejuno-jejunal defects were closed with BMI body mass index, SD standard deviation, T2DM type 2 diabetes non-absorbable sutures at the end of the operation. mellitus, OSA obstructive sleep apnea, CVD cardiovascular disease, Enhanced recovery after surgery (ERAS) protocol was GERD gastroesophageal reflux disease, HTN hypertension, DLP dys- applied to all the included patients and their majority was lipidemia. 13 Langenbeck's Archives of Surgery (2023) 408:10 Page 3 of 6 10 Table 2  Comparison of TWL% Item %TWL P value by the severity of the dumping syndrome Mean ± SD Fatigue 10–30 min after meals Group A 33.06 ± 1.20 0.017 Group B 32.52 ± 1.49 Palpitations 10–30 min after meals Group A 32.90 ± 1.30 0.276 Group B 33.13 ± 1.22 Sweating/flushing 10–30 min after meals Group A 32.91 ± 1.26 0.367 Group B 33.11 ± 1.37 Cold sweats/paleness Group A 33.00 ± 1.20 0.145 Group B 32.62 ± 1.71 Need to lie down for a while Group A 32.97 ± 1.21 0.694 Group B 32.89 ± 1.46 Diarrhea 10–30 min after meals Group A 32.96 ± 1.30 0.831 Group B 32.90 ± 1.20 Nausea/vomiting 10–30 min after meals Group A 38.94 ± 1.22 0.777 Group B 33.00 ± 1.53 Stomach cramps 10–30 min after meals Group A 33.05 ± 1.21 0.023 Group B 32.53 ± 1.52 Fainting esteem/shaking 10–30 min after meals Group A 32.99 ± 1.22 0.438 Group B 32.78 ± 1.63 Pain/vomiting after drinking fluids in moderate amount Group A 33.03 ± 1.26 0.320 Group B 32.86 ± 1.30 Sudden abdominal problems, faint, or fatigue after drinking Group A 32.96 ± 1.22 0.921 heavily sweetened fluids Group B 32.94 ± 1.37 *Group A: mild to moderate, **Group B: severe Table 4  Comparing %TWL by the severity of DS Severity N Mean ± SD P value Table 3  Comparing %TWL by the DS frequency %TWL Mild-moderate (11–44) 187 32.95 ± 1.29 0.959 Item %TWL P value Severe (more than 44) 20 32.96 ± 1.16 Mean ± SD Fatigue Group A 33.00 ± 1.19 0.052 Table 5  Comparing %TWL by the frequency of DS Group B 32.39 ± 1.97 Palpitations Group A 32.98 ± 1.29 0.104 Frequency N Mean ± SD P value Group B 32.27 ± 0.81 %TWL Mild-to-moderate (9–27) 193 32.95 ± 1.29 0.929 Sweating/flushing Group A 32.97 ± 1.29 0.331 Severe (more than 27) 14 32.98 ± 1.15 Group B 32.54 ± 0.85 Cold sweats/paleness Group A 33.00 ± 1.20 0.001 Group B 31.26 ± 2.43 Tables 4 and 5 show insignificant differences in %TWL Need to lie down Group A 32.98 ± 1.18 0.357 between the two groups by the severity and frequency of Group B 32.73 ± 1.94 DS (P > 0.05), it should be noted that both Tables 4 and Diarrhea Group A 32.95 ± 1.28 0.679 5 included 207 patients (187 + 20 patients = 207 in Table 4 Group B 33.17 ± 1.59 and 193 + 14 = 207 patients in Table 5), but the difference Nausea/vomiting Group A 33.00 ± 1.20 0.009 in the “mild-to-moderate” and “severe” groups is related Group B 31.80 ± 2.45 to the assessment of the DS in terms of “severity” or “fre- Stomach cramps Group A 32.96 ± 1.30 0.603 quency,” e.g., severe score in Table 4 is more than 44 but Group B 32.72 ± 0.79 in Table 5 is more than 27 indeed type of scoring is differ- Fainting/shaking Group A 32.96 ± 1.12 0.854 ent so it is rational to have different patients in each group. Group B 32.91 ± 1.68 Eleven severity items scored 1–7 (total score = 11–77) were 13 10 Page 4 of 6 Langenbeck's Archives of Surgery (2023) 408:10 considered mild-to-moderate (11–44) or severe (more than the patients included had intractable DS which could require 44). Nine frequency items scored 1–6 (total score = 9–54) reversal to normal anatomy or sleeve gastrectomy. were also considered mild-to-moderate (9–27) or severe According to the DSRS self-assessment questionnaire, (more than 27). we measured the severity and frequency of nine dumping According to Table 6, gender, age, DS, and comorbidities symptoms. In our study, as explained, subjects were classi- such as T2DM, DLP, HTN, and OSA at 1-year follow-up fied based on the results of the DSRS questionnaire into two were not correlated with %TWL. Intractable DS was not groups: mild to moderate and severe dumping syndrome. observed in any of the patients, which required reversal to The incidence of severe DS in our study population follow- normal anatomy or sleeve, and all the patients were treated ing LRYGB was 20 cases (10%) while the other 187 cases with conservative managements including diet modifications (90%) complained of mild to moderate dumping syndrome. and medical treatment. Similarly, in Laurenius et al.’s study among 129 patients post-LRYGB, 12% reported severe dumping problems based on the DSRS questionnaire [10]. The DS was thought to induce changes in food preference, Discussion as initially, it was considered as a useful characteristic of the RYGB to “teach” patients to avoid calorie-dense foods and Dumping syndrome is a well-known sequel of Roux-en-Y thus consume fewer calories. However, an unlikely explana- gastric bypass (RYGB). Studies have reported a prevalence tion as most patients with severe dumping still reports that of DS ranging from 3 to 80% after LRYGB [4, 5, 11–13]. DS they have learned to consume only small quantities that do can also be seen after non-anastomotic bariatric procedures, not cause negative visceral symptoms or consume sweets at such as sleeve gastrectomy (SG). DS after SG may occur in night before bedtime. up to 40% of patients [4, 5, 11–13]. The present study did not find relationships between DS In summary, our study showed that the mean age and and weight loss. In addition to the insignificantly-higher pre-op BMI of the patients were 42.18 ± 10.46 years and %TWL in group B (severe DS) than in group A (mild-to- 42.74 ± 5.59 kg/m2, respectively. Study groups of “mild moderate), the difference between the two groups was insig- to moderate” and “severe” were not significantly different nificant in terms of %TWL at one-year follow-up by the (P > 0.05) regarding %TWL but fatigue and cramp. Regard- severity and frequency of each measured dumping symptom. ing frequency of “less than 1 time per day” and “once and Given the lack of differences in the eating habit of the two more than 1 time per day,” %TWL was not significantly groups, the patients might have resumed their preoperative different (P > 0.05) but nausea vomiting feelings and cold diet. sweats. It should be noted that severity with 11 questions Several published studies could not show any significant ranging from 1 to 7 (minimum total score, 11; maximum association between dumping and concomitant weight loss. total score, 77) was divided into mild to moderate (score, A study by Banerjee et al. recruiting 50 patients undergo- 11–44) and severe (more than 44). The frequency with 9 ing RYGB [13] found higher decreases in the mean BMI questions ranging from 1 to 6 (minimum total score, 9; max- in the patients without DS compared to in those with DS imum total score, 54) was divided into mild to moderate 1 year (18.5 versus 14.4) and 2 years (17.8 versus 13.7) (score, 9–27) and severe (more than 27). None of the comor- after the RYGB. In contrast, in Looveren et al. study on 100 bidities such as T2DM, dyslipidemia, HTN, and sleep apnea consecutive patients who underwent revisional RYGB, due at 1-year follow-up, gender, and age as well as dumping syn- to inadequate weight loss or band intolerance after laparo- dromes were correlated with the changes of %TWL. None of scopic adjustable gastric banding (LAGB), fifty-five patients Table 6  Predictive factors for Variable Non-standardized Standard- t P value %TWL obtained using linear coefficient ized coef- regression ficient B Std. error Beta Age To predict %TWL 0.012 0.014 0.110 0.832 0.409 Gender To predict %TWL − 0.843 0.424 − 0.248 − 1.988 0.052 T2DM at 1-year follow-up To predict %TWL 0.158 0.484 0.044 0.327 0.745 Dyslipidemia at 1-year follow-up To predict %TWL − 0.606 0.358 − 0.227 − 1.693 0.096 Hypertension at 1-year follow-up To predict %TWL 0.022 0.468 0.007 0.047 0.962 OSA at 1-year follow-up To predict %TWL 0.951 0.848 0.140 1.121 0.267 1 34 Langenbeck's Archives of Surgery (2023) 408:10 Page 5 of 6 10 (59.1%) suffered from dumping. Based on the findings in REC.1400.684). Written informed consent was obtained from all the their patient group, we suggest that dumping helps patients participants, and ethical issues, including plagiarism, data fabrication, and double publication, were completely observed by the authors. achieve sustainable weight loss. Therefore, dumping can be regarded as a positive sequel rather than a complication [8]. Consent for publication All the authors reviewed and approved the A study by Laurenius et al. on early dumping found final version of the articles and agreed to its publication. patients to consider DS a shield against over-consumption despite their unpleasant symptoms [14–17]. Few studies on Conflict of interest The authors declare no competing interests. late DS also reported associations between the symptoms of Open Access This article is licensed under a Creative Commons Attri- post-bariatric hypoglycemia and weight regain [7, 15, 18]. bution 4.0 International License, which permits use, sharing, adapta- Different degrees of DS were observed in all the present tion, distribution and reproduction in any medium or format, as long study patients after RYGB. Mild-to-moderate DS might have as you give appropriate credit to the original author(s) and the source, been, however, under-reported in the absence of specific provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are screening tools. included in the article's Creative Commons licence, unless indicated The present study limitations comprised failure to per- otherwise in a credit line to the material. If material is not included in form objective tests to confirm DS given the limitation of the article's Creative Commons licence and your intended use is not using questionnaires. This study relied on patients’ phone- permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a interview self-reports in the DSRS to diagnose DS. In copy of this licence, visit http://​creat​iveco​mmons.​org/​licen​ses/​by/4.​0/. addition, DSRS does not differentiate between early and late dumping syndromes, but is rather screening for early dumping symptoms. As the best predictor of overall health, long-term weight loss and weight maintenance, dietary hab- References its were not investigated. It is well known that the dietary habits of an individual are the best predictors of their overall 1. Munoz-Flores F, Rodriguez-Quintero JH, Pechman D, Creange health and long-term weight loss and weight maintenance. 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