Surgical Treatment for the Individual Patient

Fig. 30.1

Roux-en-Y gastric bypass, gastrojejunostomy

../images/473262_1_En_30_Chapter/473262_1_En_30_Fig2_HTML.png — Fig. 30.2

Roux-en-Y gastric bypass, jejuno-jejunostomy

Sleeve Gastrectomy

The sleeve gastrectomy is a purely restrictive procedure, although resection of the fundus of the stomach might decrease temporarily ghrelin levels, one of the hormones involved in the regulation of the appetite. The operation includes removal of approximately three-fourth of stomach, with the subsequent reduction in gastric volume (Fig. 30.3). The first SG was performed in 2000, by Michel Gagner in New York. This operation emerged as an attempt in decreasing complications after duodenal switch in super–super-obese patients. The SG was designed as a first step of a two-stage procedure, which included a SG followed by a RYGB. The idea was to complete the second step of the procedure once the patient had lost enough weight in order to decrease the risk of complications [3]. Years later, the American Society for Metabolic and Bariatric Surgery (ASMBS) recognized SG as a primary bariatric procedure, due to its effectiveness and safety already demonstrated during several consensuses [4–6].

../images/473262_1_En_30_Chapter/473262_1_En_30_Fig3_HTML.png — Fig. 30.3

Sleeve gastrectomy

Classification of Obesity

Body mass index (BMI) calculation is the most utilized method to diagnose and classify obesity. BMI results from the ratio between weight (kg) and height (m²). Obesity is categorized as follows:

Obesity Class I: BMI 30–34.9 kg/m²
Obesity Class II: BMI 35–39.9 kg/m²
Obesity Class III: BMI ≥40 kg/m²

Selection Criteria

According to the NHI consensus, patients with BMI >40 kg/m² or between 35 and 40 with comorbidities such as type 2 diabetes, cardiovascular disease, or physical alterations that interfere with normal life are considered candidates for bariatric surgery [7]. Patients should be motivated and well informed, and they must understand benefits and risks of surgery.

Results

So far, both procedures have been briefly introduced, and selection criteria have been exposed. Advantages and disadvantages according to published results will be discussed next.

Effect on Type 2 Diabetes

One of the most classic publications approaching this topic is the STAMPEDE trial . In this study, 150 obese patients with type 2 diabetes were randomized to either medical or surgical treatment. Surgical treatment comprised SG and RYGB ; patients were followed-up for 5 years. Primary outcome was HbA1c ≤6, with or without diabetes medications. At the end of the trial, 5.3% of the patients in the medical treatment (MT) group, 28.6% in the RYGB, and 23.4% in the SG group were able to achieve this goal. The statistical analysis showed that there was no difference between both surgical procedures; however, the difference was evident after comparison between MT versus RYGB (p = 0.01) and MT versus SG (p = 0.03).

The key part came after analyzing the need for any type of medication for type 2 diabetes control. Almost half of the patients (45%) in the RYGB group were not taking any medications. Remarkably, this number decreased to 25% in the SG group (p <0.05). This means that type 2 diabetes was better controlled, with fewer medications after RYGB than after SG [8].

An interesting meta-analysis including five randomized controlled trials (RTC), with 396 patients (RYGB = 196 and SG = 200), was performed by Li et al. Remission was defined as fasting plasma glucose levels <126 mg/dL with HbA1c <6.5% without oral medications or insulin. Authors concluded that both procedures were effective in the treatment of type 2 diabetes. However, the remission rate was much higher in the RYGB group (p = 0.001) [9].

Conversely, the following two studies did not find any statistically significant difference. Peterli conducted a randomized multicenter study in Switzerland, analyzing results from 217 patients who were appointed either to SG (n = 107) or RYGB (n = 110). At 5-year follow-up, complete remission was observed in 61.5% of the patients of the SG group versus 67.9% in the RYGB group (p = NS) [10].

Similarly, the SLEEVEPASS randomized Clinical Trial performed in Finland included 238 patients who were assigned to undergo either SG or RYGB. At 5-year follow-up, complete remission of diabetes was observed in 12% of patients undergoing SG and 25% of patients after RYGB (p = NS). No differences were found either in fasting plasma glucose or HA1c levels among both procedures at the same follow-up period. Authors attributed this disparity respect to other studies to possible differences in preoperative diabetes duration [11].

Weight Loss

Schauer et al. also compared weight loss among groups. Change in BMI from baseline was −5, −23, and −18 for MT, RYGB, and SG, respectively. Statistical analysis showed significant differences among all comparisons (surgical vs. MT p <0.05 and RYGB vs. SG p = 0.01), being RYGB the best treatment option in terms of weight loss [8].

The following data comes from an attractive meta-analysis of 14 comparative studies (RYGB vs. SG), with 5264 patients. There were 2782 RGYB (53%) and 2482 SG (47%). The primary end point was to compare mid- (3–5 years) and long-term (>5 years) weight loss between both procedures. Authors did not find any difference in weight loss at midterm follow-up. However, RYGB patients presented a clear superior weight loss in the long run (p <0.05) [12].

Furthermore, the study from Finland found superiority of RYGB over SG in terms of weight loss. At 5-year follow-up, mean excess weight loss (EWL) for SG was 49%, whereas that number scaled up to 57% for the RYGB group. Authors concluded that there was not equivalence, based on their predefined margins of equivalence [11].

Contrariwise, Peterli et al. did not find any statistically significant difference in percentage excess BMI loss for SG compared with RYGB (61.1 vs. 68.3%, p = NS) at 5-year follow-up. Moreover, they found no difference in the proportion of patients being able to reach a percentage excess BMI loss greater than 50% at 5 years (68.3% in the SG group vs. 76% in the RYGB group, p = NS) [10].

The subsequent numbers come from our own experience, not published yet. A total of 2839 patients were operated. There were 2383 (84%) RYGB and 456 SG (16%). Interestingly, SG showed superior weight loss at 3 months. After that period of time, RYGB demonstrated better results steadily. At 6-year follow-up, the percentage of EWL was 61% for RYGB and 55% for the SG group (p <0.05); %EWL at every point in time are shown in Fig. 30.4.

../images/473262_1_En_30_Chapter/473262_1_En_30_Fig4_HTML.png — Fig. 30.4

% Estimated weight loss (EWL) : Roux-en-Y gastric bypass (RGYB) vs. sleeve gastrectomy (SG)

Complications

Zellmer et al. published a remarkable meta-analysis that included 84 articles comparing risks associated to both procedures. The study involved 11,000 RYGB and 5000 SG. Leak, bleeding, deep venous thrombosis (DVT), pulmonary embolism (PE) , stomal stenosis/stricture, reoperation, and mortality rates were investigated. Complication rate was higher for RYGB in every category, except for leaks. Nevertheless, statistical analysis showed significance only for bleeding and stomal stenosis/stricture (Table 30.1). They concluded that there is a generalized misconception about lesser risk after SG. They recommended choosing the operation based on individual patients’ characteristics and institutional experience, instead of basing the decision only on risks associated with the procedure [13].

Table 30.1

Complication rate ; comparison between RYGB and SG [11]

Complication (%)	RYGB	SG	p
Leak	1.9	2.3	NS
Bleeding	3.1	2	0.001
DVT/pulmonary embolism	0.7	0.6	NS
Stomal stenosis/stricture	3.4	1.3	0.001
Reoperation	4.4	3.4	NS
Mortality	0.4	0.2	NS

DVT deep venous thrombosis, RYGB Roux-en-Y gastric bypass, SG sleeve gastrectomy

Conversely, Kumar et al. investigated about 30-day complication rate using the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) data registry . This database included 150,000 operations performed across the USA and Canada during 2015. They found that leak rate and morbidity and mortality rates were significantly higher for RYGB than for SG (Table 30.2). Again, they concluded that in spite of this, RYGB should not be abandoned and that the short-term complications needed to be weighed against differences in the mid- and long-term outcomes [14].

Table 30.2

Complication rate; comparison between RYGB and SG [12]

Complication (%)	RYGB	SG	p
Leak	1.5	0.7	<0.001
Comorbidities	11.6	5.7	<0.001
Mortality	0.2	0.1	<0.001

RYGB Roux-en-Y gastric bypass, SG sleeve gastrectomy

Authors from the SM-BOSS (Swiss Multicenter Bypass or Sleeve Study) did not observe any statistical significant difference in either early (SG, 0.9% vs. RYGB, 4.5%, p = NS) or late complications (SG, 14.9% vs. RYGB, 17.3%, p = NS) occurrence among the two procedures. Also, the need for reoperation or endoscopic revision was evaluated. Again, no difference was found between both operations. De Novo GERD or worsening of preexisting GERD was the most frequent cause of reoperation after SG, while insufficient weight loss was the second one. Instead, the most common reason for reoperation after RYGB was internal hernia. Of note, they explained that closure of mesenteric defects was not mandatory during the trial, so the incidence of internal hernias could have been reduced by adding that step to the operation [10].

The group conducting the SLEEVEPASS trial did not detect any differences in terms of early or late complications either. Specifically, late complications were reported in 19% of cases after SG and 26% of patients after RYGB (p = NS). Remarkably, their observations were concurrent with those coming from the Swiss study. The most frequent cause of reoperation after SG was intractable GERD, while internal hernia was the most common after RYGB. Again, mesenteric defects were not closed during this trial [11].

Outcomes coming from our experience were also analyzed in terms of complications (Gorodner V, Matucci A, Grigaites A. (2018), data unpublished yet). Complication rate was 9% for RYGB and 5% for SG (p <0.05). It is worth mentioning that when complications were divided into mild and severe; the difference remained significant only for mild complications (Table 30.3).

Table 30.3

Complication rate; comparison between RYGB and SG (our experience, Gorodner V, Matucci A, Grigaites A. (2018), data unpublished)

	RYGB (2383)	Reoperation	LSG (456)	Reoperation	p
Severe complications
Leak	4 (0.1%)	4	–	–	–
Intra-abdominal bleeding	20 (0.8%)	8	10 (2%)	6	–
GI bleeding	24 (1%)	3	1 (0.2%)	–	–
Internal hernia	36 (1.5%)	36	–	–	–
SBO	9 (0.4%)	9	–	–	–
SBO + intestinal necrosis	2 (0.08%)	2	–	–	–
Portal-splenic thrombosis	1 (0.04%)	–
Pulmonary embolism	–		1 (0.2%)	–
Total severe	96 (4%)	62	12 (2.6%)	6	NS
Mild complications
Abdominal pain	7 (0.3%)	4	–	–	–
Pneumonia	3 (0.1%)		3 (0.6%)	–	–
Stenosis G-J	67 (2.8%)		–	–	–
Wound infection	24 (1%)		7 (1.5%)	–	–
Ulcer	23 (1%)		–	–	–
Pancreatitis	1 (0.04%)		–	–	–
Total mild	125 (5%)	4	10 (2%)	–	0.007