Sleeve gastrectomy for morbid obesity: weight loss trajectory and failure predictors over a decade

Abstract

Background

Sleeve gastrectomy (SG) is an effective treatment for morbid obesity, promoting weight loss and resolving related comorbidities.

Methods

This prospective, observational study involved 100 patients undergoing SG at Farhat Hached Hospital, Sousse, between February 2009 and December 2019.

Results

Patients had a mean age of 34 ± 9.9 years and a mean BMI of 46.2 ± 7.8 kg/m². Preexisting conditions included type 2 diabetes (16%), hypertension (18%), dyslipidemia (13%), and obstructive sleep apnea (OSA) (29%). Eating disorders were prevalent (98%), notably binge eating (87%). Mortality was 0%, with 12% early morbidity. Maximum of Excess weight loss (EWL) reached 59 ± 19% at 24 months (with a maximum Total Weight Loss (%TWL) of 30 ± 7.9%) but declined to 30% by 10 years. Comorbidity remission rates were significant: 68.7% for diabetes, 27.7% for hypertension, and 46% for dyslipidemia. OSA improved in 86% of cases. The overall success rate (EWL >50%) was 61%, with 39% experiencing insufficient weight loss or regain. Predictors of failure identified through multivariate analysis included hypertension, diabetes, age >40 years, preoperative BMI > 40 kg/m², postoperative dietary lapses, and a sedentary lifestyle.

Conclusions

Our findings demonstrate that sleeve gastrectomy offers substantial initial weight loss, with the maximum Excess Weight Loss (EWL) achieved at 2 years. However, this weight loss diminishes over the long term, with long-term data (up to a decade) requiring cautious interpretation due to high attrition. A comprehensive understanding of factors influencing long-term success is vital for improving patient care.

ARTICLE HIGHLIGHTS

Sleeve Gastrectomy (SG) is a safe and effective bariatric procedure, providing significant initial weight loss and high rates of comorbidity remission, with a low incidence of surgical complications and no mortality in our series.Weight loss diminishes over time, peaking at 2 years post-surgery and showing a progressive decline thereafter.Long-term surgical failure (EWL < 50%) is multifactorial and strongly predicted by pre-operative conditions (hypertension, diabetes, older age, higher initial BMI) and poor post-operative lifestyle habits (dietary noncompliance, sedentary behavior).

1. Introduction

Obesity, recognized as a disease by the World Health Organization (WHO), presents a global public Heath challenge. In 2016, it affected 13% of the world’s adult population [1]. Alarmingly, Tunisia has witnessed a significant rise in obesity prevalence, escalating from 8.7% in 1980 to 25.4% in 2012 [2], and reaching 27.1% by 2016 [3]. The escalating prevalence of obesity is directly correlated with a significant increase in morbidity and premature mortality, resulting in a substantial reduction in life expectancy and a profound deterioration in quality of life among affected individuals. Consequently, the economic burden attributed to obesity-related healthcare expenditures is substantial, underscoring its critical importance as a public health challenge. Effective obesity management necessitates a multidisciplinary intervention strategy complemented by robust patient adherence and engagement. Among the diverse therapeutic modalities for obesity, surgical intervention has consistently demonstrated superior long-term efficacy. In contrast to dietary prescriptions, which frequently show limited sustained success, bariatric surgery offers a more durable solution. Currently, Sleeve Gastrectomy (SG) is the most commonly performed bariatric procedure globally.SG is a restrictive laparoscopic procedure involving the resection of a significant portion of the stomach to create a tube-shaped gastric pouch. Initially, SG was conceptualized as the first stage of a two-stage procedure, such as a duodenal switch, primarily for individuals with super-obesity. However, given its comparable efficacy to other bariatric surgeries and a favorable morbidity and mortality profile, SG has evolved into a standalone definitive procedure. Its widespread global adoption extends beyond mere weight and Body Mass Index (BMI) reduction to include substantial control and remission of obesity-related comorbidities. Motivated by these observations and the growing number of morbidly obese patients undergoing SG in Tunisia, we conducted this study to evaluate the weight loss and metabolic outcomes of sleeve gastrectomy. This prospective study included 100 morbidly obese patients who underwent SG at the General Surgery Department of Farhat Hached University Hospital in Sousse, over a 10-year period from February 2009 to December 2019. The aims of our study were: To evaluate the outcomes of SG in operated patients by assessing: Percent of Excess Weight Loss (EWL), Percent of Total Weight Loss (%TWL) and the evolution of comorbidities, including type 2 diabetes, hypertension, disabling osteoarticular disease, dyslipidemia, and obstructive sleep apnea. We aim also to identify predictors of SG failure.

2. Methods

2.1. Study design and participants

This was a prospective, observational study conducted between February 2009 and December 2019 in the General Surgery Department of Farhat Hached Hospital. The study enrolled 100 consecutive patients who all underwent Sleeve Gastrectomy (SG) for morbid obesity (MO) (Figure 1).

Figure 1.

Flow diagram.

2.2. Selection criteria

Patients were eligible for inclusion in this study if they were between 18 and 60 years old and presented with a Body Mass Index (BMI> 30 kg/m² or a BMI between 35 and 40 kg/m² coupled with at least one obesity-related comorbidity. Crucially, all included patients must have demonstrated a documented failure of at least 6 months of supervised non-surgical weight loss, characterized by either insufficient weight loss or an inability to maintain weight loss. Furthermore, eligible patients were fully informed, willing to undergo surgery, capable of providing informed consent, and committed to long-term postoperative follow-up. Finally, completion of a comprehensive multidisciplinary preoperative assessment was mandatory, and all included individuals were deemed to have an acceptable operative risk. Conversely, patients were excluded from the study if they were unavailable for medium- or long-term follow-up post-discharge, failed to comply with established follow-up protocols, or underwent gastric bypass or re-sleeve gastrectomy during the study’s follow-up period.

2.3. Data collection methods

Data were primarily retrieved from the medical records of patients who underwent surgery. Patient follow-up was achieved through direct consultation at the outpatient surgical clinic. For those unable to attend in-person appointments, telephonic interviews were conducted to ensure comprehensive data acquisition.

2.4. Study variables

2.4.1. Preoperative optimization and intraoperative surgical management

Prior to surgery, patients underwent a standardized preoperative assessment that included comprehensive comorbidity evaluation (e.g., diabetes, hypertension, dyslipidemia, sleep apnea) with specialist management-initiated weeks in advance. This also involved a standard biological workup, hepatic assessment for nonalcoholic steatohepatitis, and consultations with endocrinology, nutrition (dietitian), and psychological/psychiatric services to identify contraindications, manage eating disorders, and optimize overall health. An upper endoscopy screened for Helicobacter pylori (requiring eradication) and other upper gastrointestinal pathologies, while an abdominal ultrasound checked for cholelithiasis, enlarged left liver, or hepatic steatosis. An anesthesiology consultation assessed operative risk and ordered additional cardiac or respiratory evaluations if necessary. Beyond systematic smoking cessation one month pre-surgery, no other specific preoperative preparation was routinely prescribed; however, comorbidities were actively managed to mitigate postoperative risks. All procedures were performed over a 36 French bougie and the gastric resection was initiated 4–6 cm from the pylorus. Staple line reinforcement (using suture imbrication or buttressing material) was consistently applied. Intraoperatively, key parameters recorded included operative duration, detailed surgical technique (e.g., gastric calibration tube, staple details, staple line management), methylene blue leak test results, and the use of intra-abdominal drainage. All intraoperative incidents, including any laparoscopic conversion and the specific management strategies, were thoroughly documented.

2.4.2. Immediate postoperative course

Hospital length of stay and all postoperative complications (categorized as specific or nonspecific) occurring within the first 30 d were meticulously recorded.

2.4.3. Medium- and long-term postoperative follow-up

Postoperative follow-up occurred at 15 d, 1, 2, and 3 months, then quarterly for the first year, and biannually thereafter. Patients were referred to specialists for comorbidity management as needed. At each visit, general condition and functional symptoms were assessed. Weight reevaluation included current weight, weight loss, BMI, and percentage of excess weight loss (%EWL) a crucial metric for bariatric surgery outcomes. We also calculated the Percentage of Total Weight Loss (%TWL), the current reporting norm, defined as %TWL = [({Initial Weight} - {Current Weight})/{Initial Weight}]\100}. %EWL was determined by the following formula: %{EWL} = [({Initial Weight} - {Ideal Weight}) - ({Current Weight} - {Ideal Weight})]/[{Initial Weight} - {Ideal Weight}]. Ideal Weight was derived using the Lorentz formula [5]: {Ideal Weight (kg)} = {Height (cm)} - 100 - ({Height} - 150)/{sex index}. The sex index was set at 4 for males and 2.5 for females. The limitations of using the Lorentz formula for EWL, instead of the standard BMI 25 kg/m², are noted in the Discussion.

2.4.4. Bariatric surgery failure criteria

Bariatric surgery failure (BSF) was defined as a % EWL < 50% AND BMI > 35 kg/m² (Christou et al. modified Reinhold criteria [4,5]). Conversely, surgical success was defined as a % EWL ≥ 50%, regardless of follow-up duration. Unlike some definitions, non-improvement of comorbidities was not considered a criterion for failure in this study.

2.4.5. Metabolic outcome definitions

Remission and Improvement of obesity-related comorbidities were defined using objective, biochemical, and clinical criteria, as adopted from the American Society for Metabolic and Bariatric Surgery (ASMBS) and the American Diabetes Association (ADA) guidelines:

• Type 2 Diabetes Mellitus (T2DM) Remission: Defined as achieving HbA1c < 6.5% and a fasting glucose < 126 mg/dL without the use of anti-diabetic medications (insulin or oral agents) for a minimum duration of six months. Improvement was defined as reduction in medication dosage or HbA1c to between 6.5% and 7.0%.

• Hypertension (HTN) Remission: Defined as blood pressure maintained at < 140/90 mmHg without the use of anti-hypertensive medications for a minimum duration of six months. Improvement was defined as a reduction in the number or dose of anti-hypertensive medications.

• Dyslipidemia Remission: Defined as reaching LDL < 100 mg/dL, Triglycerides} < 150 mg/dL, and HDL > 40 mg/dL (men) or > 50 mg/dL (women) without the use of lipid-lowering agents for a minimum duration of six months.

2.5. Statistical analysis

To address patient attrition, descriptive statistics for longitudinal outcomes (e.g., %EWL and %TWL at each timepoint) utilized available case analysis. All data were entered and analyzed using SPSS software version 25.0 for Windows. For qualitative variables, we calculated frequencies and percentages. For quantitative variables, descriptive statistics included means, standard deviations (SD), medians, and ranges. To compare means, Student’s t-test was used for two independent groups, and one-way ANOVA (Snedecor’s F-test) was employed for comparing more than two means. Pearson’s Chi-squared test was utilized for comparing frequencies. The association between two quantitative variables was assessed using Pearson’s correlation coefficient. For multivariate analysis, a backward stepwise logistic regression was performed. The multivariate analysis utilized baseline, preoperative variables and the last available data for postoperative behavioral factors to minimize bias from long-term missingness. Independent variables with a univariate p-value < 0.2 were initially included. In subsequent steps, variables were removed based on the least significant p-value. This analysis yielded adjusted Odds Ratios (ORs), quantifying the independent effect of each factor. A p-value < 0.05 was considered statistically significant for all tests.

3. Result

3.1. Descriptive study

3.1.1. Patients profiles

Our study included 100 consecutive patients (91 women, 9 men) who underwent sleeve gastrectomy for morbid obesity. The mean age was 35 years (range: 18–58 years), and the mean pre-operative BMI was 46.2 ± 7.8 kg/m² (range: 34–74 kg/m²). A high prevalence of comorbidities was noted. The most frequent were osteoarticular disorders (65%), familial obesity (57%), and obstructive sleep apnea (OSA) (29%). Other common comorbidities included hypertension (18%), type 2 diabetes (16%), and dyslipidemia (13%). Pre-operative dietary habits were characterized by a high incidence of eating disorders (ED), with hyperphagia in 87% of cases, snacking in 51%, and “sweet-eating” in 44% (Table 1).

Table 1.

Table presenting the main characteristics of the population.

	Numbers of patients (N)	Percentage (%)
Demographic data
Gender M/F*	91/9	91/9
Age (Year)
[18–20] ; [21–30] ; [31–40] ; [41–50] ; >50	6; 30; 39; 17; 8	6; 30; 39; 17; 8
BMI*
[30–34,9] ; [35–39,9] ; [40–45,9] ; ≥50	3; 16; 56; 25	3 ;16 ;56 ; 25
Lifestyle Habit
- ED	98	98
Hyperphagia	87	87
Snacking	51	18
“Sweet-eaters” behavior	44	51
- Smoking	18	44
- Sedentary lifestyle	81	81
Co-morbidities:
Osteoarticular disorders	65	65%
Familial obesity	57	57%
OSA*	29	29%
Hypertension	18	18%
Type 2 Diabetes	16	16%
Dyslipidemia	13	13%
Previous medical treatment for obesity	98	98%

^*M/F: Male/Female *BMI:Body Index Mass *ED:Eating disorder *OSA: Obstructive Sleep Apnea.

3.1.2. Surgical outcomes and complications

All surgical procedures were performed laparoscopically, with no conversions to open surgery. The mean operative time was 93 min. The hospital stay had a median duration of 2 d (range: 1–12 d). There were no post-operative deaths. The overall morbidity rate was 12%. Specific complications occurred in 5% of patients and included two cases of early gastric staple line leaks requiring re-operation. Nonspecific complications (7%) included four cases of lower respiratory tract infection. Long-term complications were reported in 27% of patients. One case of a late gastric leak was noted at 44 d post-operatively. Other long-term issues included micronutrient deficiencies (14%), de novo gastroesophageal reflux disease (7%), and symptomatic cholelithiasis (2%) (Table 2).

Table 2.

Surgical outcomes and complications.

	Numbers of patients (N)	Percentage (%)
Mortality	0	0
Operative Morbidity	12	12
Specific complications	5	5
SSI	3	3
Staple line leak	2	2
Nonspecific complications	7	7
Lower respiratory infection	4	4
Functional renal failure	2	2
Infectious colitis	1	1
Follow-up Complications (late)	28	28
Oligoelement deficiency	14	14
Symptomatic GERD*	7	7
Vitamin deficiency	4	4
Cholelithiasis	2	2
Late gastric leak	1	1

SSI*: Surgical site infection GERD*: Gastroesophageal Reflux Disease.

3.1.3. Medium and long-term follow-up

The mean follow-up duration was 10.6 months, ranging from 3 to 60 months. Patient retention decreased over time: 100 patients (100%) were seen at 6 months, but this number dropped to 42 patients at 5 years and only 5 patients at 10 years.

• Weight Loss Evolution

The primary outcome of the study was the assessment of weight loss after Sleeve Gastrectomy (SG), measured by absolute weight, BMI, and percentage of excess weight loss (EWL), and Percentage of Total Weight Loss (%TWL) (Table 3). The mean %EWL was 38 ± 14%at 6 months (Mean %TWL 19.2% ± 5.9%). A stable phase was observed between 18 ±and 24 months, with % EWL peaking at 59 ± 19% at 24 months (Mean % text TWL: 30.0% ± 7.9%). A gradual decline in weight loss was noted thereafter, with mean % EWLvalues of 52 ± 19% at 3 years (Mean %\TWL± 25.8% ±7.2%), 5 ± 21% at 5 years (Mean %TWL: 23.5% ± 7.8%), and 30 ± 20% at 10 years (Mean %TWL: 19.1% ± 5.1%) (Figure 2).

Table 3.

Weight loss over 120 months of follow-up.

Time point	Number of patients	Mean weight (kg)	Mean BMI (kg/m2)	Mean %EWL (%)	Mean %TWL (%)
Preoperative	100	126.1 ± 20.7	46.2 ± 7.8	–	–
6 months	100	102 ± 18.3	37.6 ± 7.5$	38 ± 14	19.2 ± 5.9
12 months	100	89.4 ± 17.5	33 ± 7.3	57 ± 18	29.1 ± 7.1
18 months	80	88.6 ± 17.2	32.6 ± 7	9 ± 19	29.7 ± 7.4
2 years	76	88.3 ± 17.9	32.5 ± 6.9	59 ± 19	30 ± 7.9
3 years	53	93.6 ± 18.2	34.8 ± 7.1	52 ± 19	25.8 ± 7.2
5 years	42	96.6 ± 19.6	36.6 ± 7.7	45 ± 21	23.5 ± 7.8
7 years	26	105.4 ± 20.3	40.2 ± 9.3	35 ± 19	16.5 ± 7.3
8 years	15	108.9 ± 21$	40.5 ± 8.2	33 ± 22	13.7 ± 8.2
9 years	8	103.5 ± 11.9	38.6 ± 5.4	28 ± 27	18 ± 4.5
10 years	5	102 ± 11.9	38.7 ± 6.1	30 ± 20	19.1 ± 5.1

Figure 2.

% of EWL during follow up.

Table 4.

Univariate analysis of predictive factors for failure.

Variable	Failure group (G1)		Success group (G2)
	Numbers of patients (N)	Percentage (%)	Numbers of patients (N)	Percentage (%)	p-value
Age
≤20 years	0	0.0	6	9.8	0.006
21–30 years	10	25.6	20	32.8
31–40 years	12	30.8	27	44.3
41–50 years	11	28.2	6	9.8
>50 years	6	15.4	2	3.3
Gender
Male	3	7.7	6	9.8
Female	36	92.3	55	90.2	0.71
Initial BMI
≤40 kg/m²	14	35.9	35	57.4	0.03
>40 kg/m²	25	64.1	26	42.6
Comorbidities
Diabetes	12	30.8	4	6.6	0.001
Hypertension	15	38.5	3	4.9	0.0001
Dyslipidemia	9	23.1	4	6.6	0.017
Sleep apnea	15	38.5	14	23.0	0.09
Eating Behavior
Snacking	26	66.7	25	41.0	0.012
Postoperative Lifestyle
Dietary deviation	21	53.8	16	26.2%	0.005
Sedentary lifestyle	33	84.6	19	31.1%	0.0001
Physical activity	5	12.8	41	67.2%	0.0001
Total N	39	100	61	100%

• Post-Surgical Comorbidity Outcomes

The surgical intervention led to substantial improvements in a range of obesity-related comorbidities. Type 2 Diabetes showed significant positive results, with 68.7% (11 of 16 patients) achieving complete remission and the remaining 31.2% (5 patients) demonstrating improved glycemic control. Similarly, hypertension outcomes were favorable for 66% (12 of 18 patients), including 27.7% (5 patients) who experienced complete remission. In cases of dyslipidemia, remission was observed in 46% (6 of 13 patients), and an additional 38.4% (5 patients) had improved lipid profiles. For patients with Sleep Apnea Syndrome (SAS), a favorable evolution was noted in 86% (25 of 29 patients), with 73.3% (11 of 15 CPAP users) able to discontinue their device. Furthermore, 90% (27 of 30 patients) with Gastroesophageal Reflux Disease (GERD) reported symptomatic improvement. Finally, 78.4% (51 of 65 patients) with preoperative osteoarticular pain experienced a significant reduction in symptoms (Figure 3).

Figure 3.

Trends in the prevalence of comorbidities over the initial two-year period.

3.1.4. Surgical failure

The overall failure rate was 39% (39/100 patients). The lowest failure rate was observed at 2 years (28.9%), with rates increasing thereafter.

3.2. Analytic study

Based on the provided univariate and multivariate analyses, several factors were identified as significant predictors of failure.

3.2.1. Univariate analysis findings

Univariate analysis, which examines the effect of each variable individually, identified several factors associated with a higher failure rate. Age was a significant predictor, with patients 40 years and older having a higher risk of failure (p = 0.006). A higher preoperative BMI was also strongly associated with failure. Specifically, a BMI greater than 40 kg/m² (p = 0.03), super-obesity with a BMI over 50 kg/m² (p = 0.02), and a BMI cutoff of 45 kg/m² were all found to be significant predictors (Figure 4).

Figure 4.

Optimal BMI Cutoff using ROC Analysis The presence of comorbidities such as diabetes (p = 0.001), hypertension (p = 0.0001), and dyslipidemia (p = 0.017) also significantly increased the risk of failure. Regarding eating habits, “snacking” was the only food-related habit identified as a significant predictor (p = 0.012). Finally, postoperative lifestyle factors, including dietary noncompliance (p = 0.005) and a sedentary lifestyle (p = 0.0001), were strongly linked to failure. Conversely, engaging in physical activity was associated with a positive outcome (p = 0.0001) (Table 4).

3.2.2. Multivariate analysis findings

Multivariate analysis, which assesses the independent predictive power of each factor while controlling for other variables, confirmed a subset of these factors as independent predictors of failure. The strongest independent predictor was hypertension, with an odds ratio of 4.24 (p = 0.0001), indicating a more than fourfold increased risk of failure. This was followed by postoperative dietary deviation (Odds Ratio: 3.28; p = 0.001) and diabetes (Odds Ratio: 2.71; p = 0.002). A postoperative sedentary lifestyle was also confirmed as a strong independent predictor (Odds Ratio: 2.39; p = 0.0001). Patients aged 40 years or older were independently found to be at a higher risk of failure (Odds Ratio: 2.21; p = 0.001), as were those with an initial BMI greater than 40 kg/m² (Odds Ratio: 1.41; p = 0.02). These findings highlight the critical role of both preoperative patient characteristics and postoperative lifestyle adherence in determining the success of the intervention (Table 5).

Table 5.

Multivariate analysis of predictive factors for failure.

	Predictive factors	Failure rate	Odds ratio	95% CI	p-value
Hypertension	No	29.3%	4.24	1.49–12.03	0.0001
	Yes	83.3%
Postoperative dietary deviation	No	28.6%	3.28	1.41–7.67	0.001
	Yes	56.8%
Diabetes	No	32.1%	2.71	1.14–6.42	0.002
	Yes	75%
Postoperative sedentary lifestyle	No	12.5%	2.39	1.65–3.48	0.0001
	Yes	63.5%
Age	<40 years	29.3%	2.21	1.22–3.98	0.001
	≥40 years	68%
Initial BMI	≤40 kg/m²	28.6%	1.41	1.15–1.93	0.02
	>40 kg/m²	49%

4. Discussion

4.1. Epidemiological context and etiological factors of morbid obesity

The rise in obesity is no longer limited to high-income countries, as lifestyle changes contribute to increasing rates in low- and middle-income nations [6]. In Tunisia, for example, the prevalence of obesity is particularly high among women, and has increased from 27.2% in 2005 to 34.1% in 2016 [5]. Several factors contribute to the development of obesity. According to the American Psychiatric Association, eating disorders such as “snacking” and binge eating are critical etiological factors, leading to the overconsumption of high-calorie foods [7]. In our patient series, a sedentary lifestyle, poor eating habits, and eating disorders were identified as the main causes of obesity, mirroring findings in the literature [8]. “Snacking,”, was prevalent in 51% of our patients and poses a significant challenge for long-term surgical success with restrictive procedures like sleeve gastrectomy (SG) [9]. The “yo-yo” effect, a cycle of weight loss and regain, was observed in 59% of patients who had undergone preoperative diets, highlighting the need for comprehensive psychological support alongside dietary interventions [10].

4.2. Bariatric surgery outcomes and postoperative management

Surgical intervention for obesity requires a thorough multidisciplinary evaluation [11]. A preoperative weight loss of 9.5% has been shown to significantly reduce postoperative complications, especially in patients with a BMI > 45.8 kg/m² [10]. The intraoperative management of obese patients is also critical. Anesthetic evaluation must address the increased risk of difficult intubation and compromised cardiovascular and respiratory function [12]. Positioning the patient in a head-up or reverse Trendelenburg position is favored to improve respiratory mechanics and minimize risk [12]. Our study reported a zero-mortality rate, which is consistent with the literature’s rate of less than 1% [13]. The early postoperative complication rate was 5%, a figure comparable to other studies [13]. The most severe early complications are hemorrhage and gastric fistula. We noted a 2% rate of acute/early fistulas and a 1% rate of late fistulas, which is within the literature’s range of 0.5-8% [14]. Long-term complications, such as gastric stenosis, were not observed in our series, though they can occur due to technical issues during surgery [15]. De novo gastroesophageal reflux disease (GERD) was observed in 7% of our patients and was effectively managed with medical treatment [16]. Nutritional deficiencies are a notable postoperative concern, as patients may have preexisting deficits and reduced food intake [16]. This was tragically illustrated by two of our youngest patients who developed Wernicke-Gayet encephalopathy, a severe neurological condition resulting from thiamin (B1) deficiency, following prolonged vomiting [17].

4.3. Impact on weight loss and comorbidity resolution

Sleeve gastrectomy is highly effective for both weight loss and the resolution of comorbidities. Our study’s results show an average excess weight loss (EWL of 57% at one year and 59% at two years, with a corresponding total weight loss (%TWL) of 29.1%and 30% respectively, which is consistent with other studies [18]. However, we, like others, observed a gradual decline in EWL to 45% at five years and 30% after ten years [19]. The surgery demonstrated a powerful effect on obesity-related diseases. Our study’s Type 2 Diabetes (T2DM) remission rate was 68.7%, which is comparable to the 60-80% range reported in meta-analyses for SG [20,21]. The remission rates for hypertension and dyslipidemia were 27.7% and 46% respectively. The relatively lower rate for hypertension, compared to diabetes, is frequently observed in bariatric cohorts and may reflect a distinct underlying pathophysiology or the impact of long-standing disease [22]. The resolution of obstructive sleep apnea (OSA) in 86% of cases underscores the substantial respiratory benefits of SG.

4.4. Predictors of surgical failure and long-term weight recidivism

Despite its initial efficacy, the decline in weight loss, culminating in an %EWL of only 30% at 10 years, emphasizes the challenge of long-term weight maintenance [19]. This long-term weight regain (weight recidivism) is a complex, multifactorial phenomenon. Physiological factors, such as adaptation of the gastric pouch volume or changes in the set-point of body weight regulation, play a role [23]. However, as evidenced by our multivariate analysis, behavioral non-adherence remains the strongest determinant of long-term failure [24].

Our study identified several significant predictors of failure (%EWL} < 50% and BMI > 35 kg/m²: Hypertension, T2DM, age >40 years, preoperative BMI > 40 kg/m², postoperative dietary lapses, and a sedentary lifestyle.

The association between failure and baseline comorbidities (HTN, T2DM) suggests that individuals with greater preoperative metabolic burden may exhibit a blunted response to the metabolic effects of SG or that their disease is more resistant to surgical intervention. Similarly, patients presenting with a higher baseline BMI >40 kg/m²) or greater age (>40 years) have consistently been shown to achieve lower absolute weight loss, making them more susceptible to falling below the success threshold [25,26].

Crucially, our findings underscore the pivotal role of behavioral adherence: postoperative dietary lapses and a sedentary lifestyle were independently associated with failure. This finding reinforces the concept that SG is a tool that requires permanent modification of eating habits and physical activity to ensure sustained success [27].

The provided study offers a robust and comprehensive analysis, effectively contextualizing the study’s findings on sleeve gastrectomy with established literature. The strengths lie in its clear, logical structure, which moves from the epidemiology of morbid obesity to specific surgical outcomes. It provides data-driven arguments by integrating the study’s remission rates for Type 2 Diabetes and Excess Weight Loss (EWL) into the broader scientific discourse. The discussion also offers nuanced insights, explaining the mechanisms behind clinical observations, such as why recent-onset diabetes responds better to surgery and the importance of addressing comorbidities (Table 6)

Table 6.

Weight loss outcomes and remission of major comorbidities reported in the literature at 5 years and beyond following sleeve gastrectomy.

Authors	Y*	Ni* / N* at 5 Y*	Initial BMI (kg/m²)	EWL % 12 M*	EWL % 2 Y*	EWL % 5 Y*	EWL % > 5 Y*	T2DM remission (%)	HTN (%)	Dyslipidemia (%)	oAS (%)
Boza [24]	2012	1000	37.4 ± 4	86.6%	84.1%	–	–	91%	63.5%	84.8%	–
Rawlins[25]	2013	276 / 49	65	56%	70%	85.8%	–	100%	95%	100%	100%
AbdEllatif [26]	2014	1395 / 859	46	53%	61%	61%	57% at 7 years	69%	54%	43%	51%
Boza [27]	2014	161 / 112	34.9	88%	81%	62.9%	64% at 6 years	40%	57.6%	80.7%	–
Casella [28]	2016	182 / 148	45.8 ± 7.4	70.4%	75.8%	70.2%	65.7% at 7 years	83.8%	59.7%	–	75.6%
Pok [29]	2016	667 / 61	37.5 ± 1.4	76%	79.6%	71.7%	70% at 7 years	–	–	–	–
Gadiot [18]	2017	277	44.8 ± 6.7	–	–	–	–	68%	53%	25%	91%
Hoyuela [17]	2017	156 / 51	41.5 ± 7.9	82 ± 18.8	86.1 ± 28.9	60.3 ± 28.9	–	75%	71.7%	–	100%
Chuffart [20]	2017	64 / 41	47 ± 8	49 ± 22%	–	–	41 ± 22% at 6 years	50%	28%	58%	33%
Noel [30]	2017	168 / 146	42.8	81%	–	76%	67% at 8 years	43.4%	59.4%	–	72.4%
Sepúlveda	2017	148 / 148	36 ± 4	93.9%	88.7%	70.6%	51.7% at 7 years	40%	62%	69%	–
Salminen [16]	2018	121 / 98	45.5 ± 6.2	60%	–	49%	–	12%	29%	47%	–
Peterli	2018	107	43.6 ± 5.2	–	–	–	–	61.5%	62.5%	42.6%	45.8%
Misra	2019	284 / 150	44.9 ± 7.9	76.3 ± 25.5%	–	62.4 ± 25.8%	–	71.4%	40.6%	–	100%
Guerreiro	2019	466 / 60 (4 years)	43.9 ± 6.52	72.8 ± 25.3%	68.0 ± 26.1%	53.3 ± 23.8% (4 years)	–	57.9%	35.3%	36.4%	–
El Moussaoui	2020	529	42.9 ± 5.5	77.2 ± 27.2%	77.3 ± 27.2%	–	–	28%	33.5%	40%	32.6%
Our series		100 / 42	46.2 ± 7.8	57 ± 18	59 ± 19	45 ± 21	30 ± 20 at 10 years	68.7%	27.7%	46%	86%

Ni: Initial cohort; N: cohort; M*: Months; Y*: Years; EWL: Excess weight loss; T2DM: Type 2 Diabetes Mellitus; HTN: Hypertension; DL: Dyslipidemia; OAS: Obstructive Apnea Syndrome.

5. The imperative of multidisciplinary care and study limitations

The high rate of preoperative eating disorders (98%, notably binge eating at 87%) highlights the necessity of a robust, mandatory preoperative psychological and nutritional evaluation and optimization protocol [28]. The role of the Multidisciplinary Team (MDT) is paramount, not just for preoperative risk optimization, but for sustained postoperative follow-up [29]. Regular and lifelong follow-up with the MDT(surgeon, dietitian, psychologist, endocrinologist) is critical to promptly address nutritional deficiencies, psychological triggers for eating disorders, and weight regain, thereby mitigating long-term failure [30].

A key limitation of this study is the high attrition rate, particularly beyond five years, which is a common challenge in long-term bariatric surgery research. Only 5 patients were available 10 years. While our data provides a glimpse into the long-term trajectory, the small sample size at later time points limits the generalizability and statistical power of the 7–10 year outcomes. Furthermore, the use of the Lorentz formula for Ideal Weight to calculate %EWL may differ from the currently accepted standard calculation using a target BMI of 25 kg/m². This methodological variability in %EWL calculation across studies should be noted when comparing our success rates with international benchmarks, as shown in Table 6 [4].

Despite these limitations, our study provides valuable long-term data from an African center, confirming that SG is an effective and safe procedure, provided it is supported by a comprehensive, lifelong multidisciplinary care program.

6. Conclusions

Sleeve Gastrectomy (SG) is a highly effective bariatric procedure for morbid obesity, yielding maximum Total Weight Loss (%TWL) of 30% and%EWL of 59% at two years, alongside significant remission of obesity-related comorbidities like Type 2 Diabetes and OSA. Our long-term %EWL of 45% at 5 years is lower than the majority of international reports, and the efficacy is challenged by significant weight recidivism, with %EWL declining to 30% at 10 years in the retained patient cohort. Long-term success is strongly dependent on behavioral factors, as demonstrated by the independent association between postoperative dietary lapses and a sedentary lifestyle with surgical failure. Comprehensive, mandatory, and lifelong follow-up within a robust multidisciplinary framework is essential to address these behavioral and metabolic challenges, optimize patient selection, and ensure the durable success of SG.

Funding Statement

This paper was not funded.

Author contributions

Writing - Review & Editing, AS, FH; Conceptualization, Methodology, Software, AS, MB; Validation, Formal analysis, ZM; Investigation, AL; Resources, Visualization, AS, AE, Supervision, MHM; Writing - Original Draft, SY.

Ethical approval

No ethical approval was needed. In compliance with national law and institutional standards, written informed permission was not needed for participation in this study.

Disclosure statement

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Data availability statement

the datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.