Two-year results of laparoscopic sleeve gastrectomy and Roux-En-Y Gastric Bypass in patients with morbid obesity

Introduction

Obesity is a serious health problem worldwide. It is associated with a number of comorbidities, including type 2 diabetes mellitus (T2DM) and cardiovascular diseases, primarily arterial hypertension. Bariatric surgery is currently the most effective method of weight loss in patients with morbid obesity [1–4]. Worldwide, the most commonly performed bariatric surgeries are laparoscopic gastro-jejunal junction according to Roux, also known as laparoscopic Roux-En-Y Gastric Bypass (RuGB), and laparoscopic longitudinal gastrectomy also known as laparoscopic sleeve gastrectomy (LSG). Regardless of the fact that RuGB has been considered the gold standard for many years, now LSG is the most commonly performed bariatric procedure worldwide due to a number of advantages, most notably due to its relative technical simplicity. In total, these two surgeries amount to approximately 80% of all bariatric surgeries worldwide [5].

Along with weight loss, bariatric surgery can contribute to achieving remission or improve the course of comorbidities, including hypertension and T2DM. Specifically, a systematic review and meta-analysis of prospective studies by Ricci et al., involving 6587 patients, demonstrated that a 5 kg/m² decrease in body mass index (BMI) corresponded to a 27% reduction in arterial hypertension during 12–24 months of follow-up periods after surgery [6]. A number of researchers confirmed the high effectiveness of RuGB and LSG in terms of T2DM remission, which can reach 60% according to Ching et al. [7–10].

However, weight loss after bariatric surgery may be accompanied by a number of adverse effects, in particular malabsorptive complications and the development of sarcopenia, which can reach 32% according to Voican et al. [11]. The malabsorptive component at RuGB determines a higher frequency of such complications compared to LSG.

The purpose of the study was to compare the long-term results of LSG and RuGB with a fixed restrictive component in patients with morbid obesity by the indices of weight loss and changes in the course of comorbidities, as well as the development of long-term complications, including sarcopenia.

Materials and methods

A retrospective single-center cohort study was conducted based on the results of treatment of patients who underwent LSG and RuGB due to morbid obesity. In the LSG group, the volume of the gastric sleeve was up to 100 ml. In the RuGB group, the volume of the gastric stump was up to 35 ml, the size of the anastomosis was 10–15 mm, and the lengths of the biliopancreatic (BL) and alimentary (AL) loops were 100 and 150 cm, respectively. Using the national bariatric registry and patient medical records, a database was compiled for patients who underwent LSG and RuGB from January 2016 to December 2022 and passed through 24 months of follow-up; the median follow-up period was 38 months.

The selection of patients for the study was carried out in strict accordance with clinical recommendations for the treatment of patients with morbid obesity. Patients were eligible for the study if they had a BMI >40 kg/m², regardless of the presence or absence of comorbidities, or BMI >35 mg/m² in the presence of one or more obesity-associated diseases. All patients included in the study were adults at the time of surgery. Informed voluntary consent for surgery and participation in the study was obtained.

Patients, who refused to undergo control studies for objective and subjective reasons, as well as patients under 18 years of age at the time of surgery, and patients with a history of bariatric surgery were excluded from the study. Besides, patients with early postoperative complications, which emerged during the first 30 days after surgery, were also excluded from the study. In addition, this study did not include patients if they had the following features a year after surgery: a gastric sleeve volume was more than 100 ml or a gastric stump volume was more than 35 ml according to CT volumetry data in the LSG and RuGB groups, respectively, as well as when the size of the gastroenteroanastomosis was more than 15 ml in the second group according to the gastroscopy examination. This made it possible to eliminate the influence of different severity degrees of the restrictive component on the long-term results of surgeries.

The design of this study was as follows: all patients at the preoperative stage underwent a standard prehospital examination, supplemented by bio-impedancemetry (BIM) to detect body composition for the purpose of a detailed analysis of nutritional status. Consultations with specialists, including a therapist, cardiologist, and endocrinologist, were also carried out in order to identify arterial hypertension and T2DM. The study groups did not have statistical differences in terms of laboratory test indices, the prevalence of sarcopenia, arterial hypertension, and T2DM (p>0.05). Further, surgical intervention was performed through two paths, and patients were divided into two groups according to the surgery type. The first group, consisting of 153 patients, underwent LSG surgery; among them, there were 122 (79.7%) women and 31 (20.3%) men with an average age of 58.0±11.1 years and an average BMI of 41.5±4.5 kg/m². The second group consisted of 98 patients who underwent RuGB surgery. This group included 78 (79.6%) women and 20 (20.4%) men with an average age of 57.3±11.4 years and an average BMI of 40.9±3.8 kg/m². The studied groups of patients did not have statistical differences in the average age and BMI (p>0.05).

The features of the studied groups of patients are presented in Table 1.

In the postoperative period, all patients underwent examination at the 3rd, 6th, 12th, and 24th months of postoperative follow-up, which included laboratory tests, in particular tests on protein metabolism indicators, and BIM, as well as repeated consultations with specialists for patients with hypertension and T2DM. Hypertension control was considered to be achieved if blood pressure levels were normal after the discontinuation of antihypertensive therapy, and T2DM remission was recognized if blood glucose levels were normal after the discontinuation of hypoglycemic therapy. All patients, at the 12th month after surgery, underwent fibrogastroscopy with mandatory assessment of the size and condition of the gastroenteroanastomosis in the RuGB group, as well as CT volumetry to determine the volume of the gastric “sleeve” and gastric stump in the corresponding groups. Patients with gastric sleeve and gastric stump volumes exceeding established values were excluded from the study. Data from prehospital and control postoperative examinations of patients were collected into a single database and analyzed using modern methods of statistical analysis.

All surgeries were performed laparoscopically. In the LSG group, a gastric “sleeve” was formed on a 36Fr calibration probe with mandatory strengthening of the staple line with non-absorbable monofilament atraumatic suture material. The volume of the gastric “sleeve” was no more than 100 ml.

In the LSG group, the formation of the gastric stump was also performed around a 36Fr calibration probe using two or three 60 mm long cassettes with mandatory strengthening of the staple line. Further, a manual gastroenteroanastomosis was formed on a 32Fr calibration probe with a 150 cm intestinal loop, followed by the formation of an entero-enteroanastomosis with a 100 cm intestinal loop with the intersection of the intestine between the two anastomoses. Hence, the lengths of AL and BL in the RuGB group were 150 cm and 100 cm, respectively. Thus, in both groups, the restrictive effect was strictly regulated and standardized.

Statistical analysis was carried out using the Statistica SPSS 26.0 software (IBM Statistic, USA).

The compliance of quantitative data with the law of normal distribution was assessed using the Kolmogorov-Smirnov criterion. When a normal distribution was identified, quantitative data were described as the mean value and standard deviation M±SD. In the absence of a normal distribution, the median (Me) and the lower and upper quartiles (Q1 – Q3) were used.

If both samples obeyed the law of normal distribution, the parametric Student’s t-test was applied. If the groups did not follow a normal distribution, the nonparametric Mann-Whitney U test was used for comparative analysis. Differences between the data were considered statistically significant at p≤0.05. The data had no statistically significant differences at p>0.05.

To describe categorical data, absolute values (the number of people) and relative values (frequency of occurrence, percentage, %) were used.

Results

In 24 months after surgery, positive results were obtained in terms of weight loss in both groups. In the LSG group, the average rate of excess weight loss (%EWL) was slightly lower than in the RuGS group (78 ± 2.2 vs. 86.4 ± 2.5, p = 0.001). The average values of reduction in BMI in the LSG and RuGS groups were −11.9±3.8 and −13.2±3.8 kg/m² (p = 0.012), respectively. It should be noted that the share of weight regain had no statistical difference between the examined groups at 24 months of the follow-up period (7 patients (4.6%) in the LSG group and 4 patients (4.1%) in the RuGB group, p=0.268); but the possibility could not be excluded that the differences in this indicator can emerge in later follow-up periods.

The results of this study showed that in the LSG group, remission of hypertension was achieved in 46 (72%) patients, and in the RuGB group this rate amounted to 35 (81%) patients; the difference was statistically significant, p = 0.002. Complete remission of T2DM in the examined groups was revealed in 16 (59%) and 14 (87%) patients for LSG and RuGB groups, respectively; the difference was statistically significant, p = 0.001.

In the LSG group, median levels of total protein and albumin in 24 months after surgery decreased from 72 [ 68;76] g/l to 69 [ 68;73] g/l and from 47 [ 45;49] g/l to 44 [ 41;46] g/l, respectively. Not a single patient in this group had a decrease in protein metabolism below the age norm, and no symptoms of malabsorption were detected. Concurrently, in the RuGB group, a more pronounced decrease in these indicators was revealed: total protein decreased from 72.5 [ 70;78] g/l to 67 [ 65;69] g/l, and albumin dropped from 46 [ 42; 49] g/l to 38 [ 35;43] g/l. Moreover, in this group, 3 (3.1%) patients had a decrease in albumin to 29–32 g/l, and 5 (5.1%) patients had diarrhea with steatorrhea, which resolved spontaneously. The difference between the studied groups was statistically significant, p>0.05. However, it should be noted that the median laboratory indices of protein metabolism remained within age norms in both groups throughout the entire investigation.

In the LSG group, during the 24-month period of follow-up after surgery, sarcopenia progressed in only 5 (3.3%) patients; the difference in this group between follow-up periods was not statistically significant, p = 0.38. Not a single case of severe sarcopenia was identified after LSG in a two-year follow-up period.

In the RuGB group, during the 24-month period of follow-up after surgery, the number of patients with normal skeletal muscle mass index (SMMI) decreased from 79 (80.6%) to 71 (72.5%). The number of patients with moderate sarcopenia increased from 19 (19.4%) to 24 (24.5%); 3 (3%) patients manifested signs of severe sarcopenia according to BIM. Analysis of the patient feature data allowed concluding that the development or progression of sarcopenia in this group was manifested predominantly among elderly patients, as well as among patients with T2DM or initial signs of moderate sarcopenia.

Discussion

The most commonly performed surgeries for morbid obesity are laparoscopic longitudinal gastrectomy, also known as laparoscopic sleeve gastrectomy (LSG), and Roux-en-Y gastro-jejunal junction, also known as laparoscopic Roux-En-Y Gastric Bypass (RuGB). As was already noted above, these two methods in total amounted to about 80% of all bariatric surgeries performed worldwide [5]. The present study demonstrated good long-term results in weight loss in both groups. However, RuGB had a more pronounced and lasting effect, which is certainly associated with the presence of a malabsorptive component of this surgery. Gamba et al. also demonstrated higher rates of weight loss after RuGB compared with LSG in the five-year follow-up period after surgery [12]. A meta-analysis by Hayoz et al., published in 2018, also confirmed the superior effectiveness of RuGB compared with LSG in the context of sustained weight loss and lower rates of weight regain at follow-up periods from 6 to 52 months [13].

With regard to the remission of comorbidities, according to the obtained data, the results of treatment of patients after RuGB were also superior to the results of treatment after LSG. Remission of hypertension in the RuGB group was 81% versus 72% in LSG (p=0.002), and remission of diabetes in the RuGB group was 87% versus 59% in LSG (p=0.001), which is consistent with data from other studies. In particular, meta-analyses by Hayoz et al. and Li et al. confirmed a higher level of remission of the disease for long-term follow-up periods, specifically from 12 to 52 months [13][14].

However, along with greater effectiveness in terms of weight loss and controlling comorbidities, RuGB demonstrated a higher frequency of malabsorptive complications and more pronounced progression of sarcopenia, which was most important for elderly patients, as well as for patients with T2DM and initial signs of sarcopenia. Moreover, the results of BIM revealed progression of sarcopenia in 8 (8.2%) patients, including 3 (3%) patients with severe sarcopenia, while in the LSG group, not a single case of severe sarcopenia was identified during a 24-month follow-up period, and progression of moderate sarcopenia was detected in only 3 (3.3%) patients. In addition, in the RuGB group, 5 (5.1%) patients had signs of malabsorption, namely diarrhea in combination with steatorrhea, which resolved spontaneously, while in the LSG group, no signs of malabsorption were detected in any follow-up period.

It should also be noted that laboratory test data on protein metabolism, namely indices of total protein and albumin, in the majority of patients continued to remain within the age-related norm, while BMI demonstrated a decrease in SMMI. Thus, BIM has proven to be a more sensitive tool for the early detection of protein metabolism disorders.

Analysis of the results obtained revealed that elderly patients, as well as patients suffering from diabetes mellitus and having signs of sarcopenia during the preoperative period, were most susceptible to the development of malabsorptive complications and the development or progression of sarcopenia. Specifically, the average age of patients, which manifested progression of sarcopenia according to BIM data, amounted to 64±3.4 years versus 57.5±10.7 in the general cohort of patients; the difference was statistically significant (p=0.041); 6 patients (66 .7%) of them suffered from T2DM.

Thus, restrictive surgeries are certainly safer for older patients. RuGB demonstrates good results in weight loss and remission of comorbidities; however, in elderly patients, as well as in patients with T2DM, the malabsorptive effect may be accompanied by the development of sarcopenia and dysproteinemia.

Conclusions

RuGB has a more pronounced and lasting effect compared to LSG in terms of weight loss and controlling comorbidities, but it demonstrates a higher incidence of malabsorptive complications and the development of sarcopenia signs.

Bioelectrical impedance analysis is a more sensitive method for assessing the state of protein metabolism in comparison with laboratory methods, which allows using it as a tool for assessing the risk of developing long-term complications.

CT volumetry is an effective method for examining the restrictive effect after bariatric surgery.

For elderly patients, as well as for patients with T2DM and signs of sarcopenia, it is advisable to avoid surgeries with a pronounced malabsorptive effect.