Introduction

Single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) is a safe and effective technique that has shown good short- and mid-term weight control and associated medical problems remission for patients with a body mass index (BMI) > 45 kg/m2 minimizing the risk of insufficient weight loss or weight regain in the long term [1,2,3,4,5,6]. Classic complications of hypoabsorptive procedures like hypoproteinemia and persistent diarrhea have been described with the 200-cm common limb SADI-S; but their incidence dropped with the 250-cm and 300-cm SADI-S [6, 7]. The omega reconstruction of SADIS, despite the preserving of pylorus, leads to a hypothetical risk of biliary reflux which continues to be one of the main arguments against this technique. Most series report this complication as anecdotical or even absent [1,2,3,4,5,6,7]; however, most of these studies do not perform an objective and systematical evaluation of the incidence of biliary reflux symptoms and do not consider its influence on patients’ quality of life (QOL).

In our previous experience with SADI-S technique, a 6.5% rate of symptomatic gastroesophageal reflux disease (GERD) was found, with not a single case of persistent diarrhea or hypoalbuminemia [7,8,9]. However, data was retrospectively obtained from standard follow-up and not confirmed by validated tests. Besides, an objective information about QOL was not reported.

During the COVID-19 pandemic, most of the presential follow-up visits were replaced by telephone consultations. This inconvenience allowed the healthcare professionals to explore different strategies to improve the accuracy of patient’s evaluation. Telemedicine became a complementary and feasible help to obtain objective information about patients’ current state [10].

The aim of this study was to analyze patient-reported symptoms, specifically GERD symptoms, depositional habit, and QOL following SADI-S, using telemedicine and validated tests. As a secondary aim, the influence of factors such as weight loss, associated medical problems remission, GERD symptoms, or depositional habit on patients’ QOL was evaluated. Finally, we compared the information obtained by telematic tests with that reported in the medical history derived from patients’ last presential visit.

Material and Methods

Study Design, Patients, and Data Source

A prospective unicentric cross-sectional study was conducted including all patients submitted to SADI-S, either directly or as a two-step procedure, in the bariatric and metabolic surgical unit of the University Hospital of Bellvitge from May 2014 to September 2019. To obtain a baseline control group, we included 67 patients who fulfilled indication criteria and had previously signed the informed consent to undergo SADI-S in the following 4 months. Patients who were exitus or had needed a revisional surgery after SADI-S before the study had started were excluded. To evaluate the chronological evolution of study variables, patients were divided in four groups: pre-SADIS, < 2 years, 2–3 years, and > 3 years after surgery.

Patients were contacted by telephone and were informed about the study. Those who accepted to participate received an email with a link to a telematic questionnaire composed by validated tests. Patients who did not respond to the questionnaire after a month were sent another email as a reminder. Finally, in case they had not yet responded to the survey, patients were recontacted by phone.

Data obtained telematically were integrated into our prospectively maintained database. Besides, the information gathered telematically in patients submitted to SADI-S was compared with its presence in patients’ clinical history derived from last presential visit.

Study Outcomes and Definitions

Primary outcomes were SF-36 physical and mental component scores (PCS and MCS), percentage of patients with a GERD-Q score ≥ 8, daily depositional frequency, and stool constitution determined by Bristol stool chart.

The SF-36 test is a validated questionnaire that consists of 36 multiple choice questions included in eight dimensions of QOL that can be factor-analyzed and reduced in two summary components: Physical Component Summary (PCS) and Mental Component Summary (MCS) [11]. Using these results, a substudy dividing the whole cohort of patients in two different groups considering a cut-off point of 50 for both PCS and MCS was performed compared with the average Spanish population (mean = 50, standard deviation = 10) [12, 13]. The GERD-Q test was used to assess GERD symptoms [14]. A GERD-Q score > 8 has been established as the cut-off score with greater sensitivity and specificity for the diagnosis of esophagitis [15] and exclude functional pyrosis [16]. Bristol questionnaire was used to identify patients with altered bowel movements being Bristol ≤ 2 for constipation and Bristol ≥ 5 for diarrhea [17].

Secondary outcomes were adequate weight control, expressed as proportion of patients with excess weight lost (EWL%) ≥ 50%; and BMI < 35 kg/m2; and remission of associated medical problems, such as type 2 diabetes (T2D), hypertension (HTN), dyslipidemia (DLP), and obstructive sleep apnea (OSA). EWL% was calculated taking as reference an ideal BMI of 25 kg/m2. Remission of associated medical problems was defined as complete withdrawal of all specific treatment by the treating physician.

Statistical Analysis

Continuous variables were expressed as mean and standard deviation. Categorical variables were described as its absolute value and percentage. To evaluate differences between groups parametric tests as χ2 for categorical variables and analysis of variance or Student’s t for continuous variables depending on the number of comparison groups were used. McNemar’s test was used to compare the grade of information gathered telematically with the last report in patients’ history. A p-value < 0.05 was considered significant. Statistics were analyzed with Stata Statistics Version 16 computer software.

Results

A total of 301 patients fulfilled the inclusion criteria: 234 submitted to SADI-S, and 67 recruited to undergo SADI-S in the following 4 months. After withdrawing 8 patients with exclusion criteria and 10 patients lost to follow-up, 283 patients were contacted telephonically in a two-step process that lasted 3 months. The number of patients who finally answered the telematic tests was 246 (86.9%) (Fig. 1).

Fig. 1
figure 1

Flowchart of patients’ selection

Full size image

Baseline Characteristics

Table 1 shows preoperative demographic and clinical data of the study population, depending on the moment of evaluation before or after surgery. Patients’ age, gender, BMI, and obesity associated medical problems were similar between groups.

Table 1 Preoperative clinical characteristics of patients depending on moment of evaluation
Full size table

Weight Loss and Obesity Associated Medical Problems

Postoperative weight-related outcomes depending on moment of evaluation are described in Table 2.

Table 2 Weight control and obesity associated medical problems depending on moment of evaluation
Full size table

Baseline mean BMI was 50.8 kg/m2 and 30.0 kg/m2, 31.1 kg/m2, and 32.7 kg/m2 at < 2-, 2–3-, and > 3-year follow-up, respectively (p < 0.001) (Figs. 2 and 3). Mean EWL% also exhibited significant differences depending on moment of follow-up: 82.0%, 75.5%, and 70.0% at < 2-, 2–3-, and > 3-year follow-up, respectively (p = 0.003). These weight control differences are illustrated in Fig. 4.

Fig. 2
figure 2

Weight control (BMI and EWL%) depending on moment of evaluation

Full size image
Fig. 3
figure 3

Self-reported symptoms depending on moment of evaluation

Full size image
Fig. 4
figure 4

Physical and mental quality of life depending on moment of evaluation

Full size image

Patients with > 3-year follow-up presented remission of 84.6% T2D, 75.0% HTN, 76.9% DLP, and 88.9% OSA, with significant control of all associated medical problems. There were significant differences regarding supplementation needs between groups, with up to 67.4% of patients with > 3-year follow-up requiring oral supplementation.

Patient-Reported Outcomes

As shown in Fig. 2, 17.9% of patients in the baseline group had a GERD-Q score ≥ 8. After SADI-S, this percentage increased over time (18.8% vs 26.9% vs 30.2%, respectively), although no statistical difference was reached (p = 0.320).

As for depositional habit, 10.5% patients in the baseline group before surgery had a history of chronic diarrhea or loose stools (Bristol ≥ 5) and 6.0% constipation (Bristol ≤ 2). After SADIS, the percentage of patients with loose stools was progressively higher (17.4% vs 25.4% vs 30.2%, p = 0.043). The incidence of constipation remained steady over time (14.5% vs 13.4% vs 14.0.%, p = 0.386). The average number of bowel moments per day after SADI-S was 1.4, with no statistical differences between groups (1.3 vs 1.7 vs 1.3, p = 0.112).

Quality of Life

Figure 3 displays both physical and mental components of QOL before and after surgery. Baseline group of patients presented a PCS = 34.3 and MCS = 44.7, worse than the Spanish population mean (PCS and MCS = 50). Patients submitted to SADI-S with a follow-up of less than 2 years presented an improvement both in physical and mental condition compared to the baseline group (PCS = 51.3, and MCS = 49.4). Patients with 2–3-year follow-up showed a slight decrease of both PCS and a MCS (49.6 and 46.3, respectively). Following the trend, patients with > 3-year follow-up showed a PCS = 48.3 and MCS = 41.9, being these differences statistically significant (PCS p = 0.000; MCS p = 0.022).

As shown in Tables 3 and 4, there was a significant association between effective weight control and physical and mental QOL: in PCS ≥ 50 group, a higher proportion of patients had achieved a satisfactory weight loss, compared with the group of patients with PCS < 50 (BMI < 35 kg/m2 75.6% vs 38.3%, respectively, p < 0.001). The mean BMI of patients with PCS ≥ 50 was 31.9 kg/m2, compared with 41.7 kg/m2 in the PCS < 50 group (p < 0.001). Similarly, in the MCS ≥ 50 group, there were more patients with a BMI < 35 kg/m2 than the MCS < 50 group (66.7% vs 48.7%, p = 0.004). In the PCS < 50 group, 27.8% of patients had a score of GERD-Q ≥ 8 in comparison to 20.6% in the PCS ≥ 50 group, although no statistical significance was reached (p = 0.186). This non-significant association GERD symptoms and QOL could also be seen in the mental component (MCS < 50: 26.5% vs MCS ≥ 50: 21.7%; p = 0.380). No significant associations were found either between QOL and depositional habit or obesity associated medical problems, except for dyslipidemia (DLP) and mental health status: 28.2% of patients with MCS < 50 suffered from DLP in comparison with 16.3% in the MCS ≥ 50 group (p = 0.024).

Table 3 Physical quality of life of patients submitted to SADI-S
Full size table
Table 4 Mental quality of life of patients submitted to SADI-S
Full size table

Grade of Information Gathering

As shown in Table 5, response rate to the telematics tests was 82.9%, similar to the compliance rate of the cohort in its last presential visit (86.1%).

Table 5 Grade of information gathering depending on type of medical interview
Full size table

Telematic follow-up offered a more systemic and detailed information: in the last presential visit, only 13.9% of patients had complete data regarding weight evolution, remission of associated medical problems, GERD symptoms, and depositional habit in comparison with the 82.9% of patients with telematic follow-up (p < 0.001).

Discussion

This prospective cross-sectional study performed with telematic tests in a cohort of 246 patients with morbid obesity before and after SADI-S found a progressive increase in the rate of patients suffering from GERD symptoms and loose stools, up to 30% at 3 years. Besides, physical and mental QOL experienced a soft progressive decrease with follow-up, after an initial substantial postoperative amelioration, being the main conditioning of this factor the loss of efficacy of weight control.

Patient-Reported Outcomes

GERD Symptoms

Prevalence of GERD symptoms after SADI-S is a controverted topic with limited information, mainly due to the lack of reported data with objective and validated questionnaires such as GERD-Q. There are several methods to diagnose GERD symptoms in a bariatric patient: by the symptomatology deliberately referred by the patient or the prescriptions of proton pump inhibitors/antacids; by asking systematically through objective and validated questionnaires such as GERD-Q; and by endoscopic and/or impedance-pH monitoring. Even though endoscopic evaluation is the gold standard to diagnose GERD, the difficulty to perform a systematic evaluation to every patient often relegates it to a second step. GERD-Q test is an efficient method to monitor GERD symptoms with a sensibility of 65% and specificity of 71% in patients without acid-suppressive therapy (cut-off score ≥ 8) [14, 18, 19]. By answering the GERD-Q test, we were able to objectively evaluate the proportion of patients submitted to SADI-S with high probability of suffering symptom-defined GERD.

In our study, patients with a more extended follow-up presented a higher proportion of GERD-Q score ≥ 8 (30.2% in SADI-S > 3 years). The long-term follow-up study by Sánchez-Pernaute et al. [6] described 14% of cases with grade A esophagitis and 8.3% with grade C or D. However, no systematic GERD symptoms questionnaires were provided, and an upper gastrointestinal endoscopy was performed in only 22% of patients. The sleeve gastrectomy shape and high-pressure might be responsible for the presence of acid GERD [20,21,22]. However, the loop configuration of SADI-S could lead to an additional bile reflux risk, which has been associated with a carcinogenic effect [23,24,25]. As mentioned by Yashkov et al., both the distance of the duodenal transection from the pylorus and the initial pyloric insufficiency could potentially be correlated with bile reflux [26]. In a previous report of our group, 3 patients were found to have bile reflux confirmed by impedance-pH monitoring, 2 of them requiring revisional surgery to duodenal switch [8]. The meta-analysis of 2029 patients submitted to SADI-S conducted by Portela et al. concluded that bile reflux has not been demonstrated to have a negative impact after SADI-S [27]. However, the mean follow-up of patients in the study was 10.3 months. In the present study, GERD symptoms increased with time after surgery. Systematic surveillance with objective suggesting symptoms testing and esophagogastroduodenoscopy may be necessary to exclude bile reflux after SADI-S.

Depositional Habit

There is limited data about depositional habit and stool composition of patients submitted to SADI-S, being limited to no specific information or the average number of bowel movements per day in the majority of studies. We decided to incorporate Bristol stool chart as a form to assess bowel habit after bariatric procedures in order to establish a more objective evaluation [28]. Although we did not observe statistical differences in the number of stool frequency per day after SADI-S, we did find differences in consistency, according to the Bristol stool chart. The prevalence of patients with chronic diarrhea or loose stools (Bristol ≥ 5) was higher in the group of patients with longer follow-up.

Even though patients with a longer follow-up presented a higher need for oral supplementation, there were no cases of intractable diarrhea or hypoalbuminemia in the present study. Other series reported a higher average number of daily bowel movements (ranging from 2.1 to 4.2) and an incidence of revisional surgeries due to malabsortive complications up to 10% [6, 29, 30]. These results are probably due to the fact that these studies included patients submitted to SADI-S with a 200-cm or 250-cm common limb length, while the patients in the present cohort had a 300-cm common limb length.

Quality of Life

Obesity is associated with serious metabolic morbidities and a reduced QOL [31]. Patients with severe obesity present a significant improvement in QOL after bariatric surgery [32,33,34,35,36,37]. In our study, prior to SADI-S, patients exhibited poor results regarding their health status (PCS = 34.3, MCS = 44.7) with a significant improvement 2 years after surgery (PCS = 51.3, MCS = 49.4) that was maintained but not so evident in patients with > 3-year follow-up (PCS = 48.3, MCS = 41.9). These results consisted with a cross-sectional study by Marceau et al., which described an improvement of QOL in severely obese patients submitted to biliopancreatic diversion with duodenal switch (BPDDS) in comparison with a group of patients prior to the same surgical procedure [35]. Aasprang et al. found an early enhancement of both PCS and MCS after surgery but a significant decline at 5 years after BPDDS [36]. Canetti et al. reported that even though patients had a successful weight reduction after BPDDS, their mental health worsened significantly after 10-year follow-up [38]. This deterioration of mental health might be potentially related to patients’ unfulfilled expectations on their physical appearance after weight loss in some cases or to the weight regain that occurred in the long-term in other patients. Both physical and mental QOL were associated with weight control in the present study. Patients with lower QOL scores presented mainly after > 3 years follow-up, being this poorer result in relation with weight regain. Our findings are consistent with the Swedish Obese Subjects study, a 10 year follow-up study which concluded that deterioration of health-related QOL scores corresponded with weight regain after bariatric surgery [37].

In addition, the presence of GERD symptoms could also have a relevant impact in the postoperative QOL after SADI-S. GERD symptoms incidence after SADI-S is still unknown, but there is increasing interest in analyzing its role in the omega-reconstruction techniques. In the present study, we found a higher but not significant proportion of GERD-Q ≥ 8 in the group of patients with poorer QOL scores. These results are consisted with the conclusions of Choi et al., a large cross-sectional study which demonstrated that the levels of anxiety and depression were higher in subjects with GERD symptoms than in controls [39]. Furthermore, Yang et al. reported a lower QOL score, measured using the SF-36 questionnaire, in patients suffering from GERD symptoms in comparison with healthy controls [40].

Information Gathering

The present study detected a poorer registration of patient-reported symptoms in presential visits compared with telematic controls. Variables such as GERD symptoms, depositional habit, or QOL were not systematically reflected in patients’ medical history after a presential appointment and therefore may be underestimated. This fact could probably be explained by the elevated number of patients examined in a bariatric surgeon’s visit. Telematic questionnaires could allow a more objective and systematic evaluation of QOL and postoperative symptoms.

Strengths and Limitations

The main limitation of this observational study is the absence of a prospective individual follow-up of patients. However, it is accepted that a cross-sectional study can be an adequate design to interpret the health status and patient-reported symptomatology in different evolution moments [35, 41]. Besides, the homogeneous groups were a representative sample of the cohort of patients submitted to SADI-S which allowed to analyze a chronological evolution of symptoms and QOL before and after surgery [7, 8]. Moreover, the use of an endoscopic procedure for the diagnosis of GERD could have been a great complimentary tool to the GERD-Q test.

One of the strengths of this study is the number of patients (246) and the good response rate to our telematic tests (86.9%). The use of validated tests such as SF-36, GERD-Q, or Bristol stool chart allowed an objective evaluation of self-reported symptoms.

Conclusion

This single-institution cross-sectional study demonstrated that weight control is the main factor related to long-term QOL after SADI-S. Incidence of GERD symptoms and loose stools was up to 30% in patients with > 3 years follow-up. Monitoring postoperative patient-related symptoms with validated objective tests seems a feasible and useful resource for the long-term follow-up of patients submitted to SADI-S.