Influence of the Size of the Gastric Antrum After Sleeve Gastrectomy on Weight Loss in Bariatric Surgery
Phase: NA
Conditions: Bariatric Surgery Candidate
Sponsor: Azienda Sanitaria Locale Napoli 2 Nord

Title: Does Antrum Size Matter in Sleeve Gstrectomy?      Versione 6.0.   21/10/2014 
 
Study Protocol 
 
Study Protocol 
 
“Does Antrum Size Matter in Sleeve Gastrectomy?   
 

Title: Does Antrum Size Matter in Sleeve Gstrectomy?      Versione 6.0.   21/10/2014 
 
Study Protocol 
 
 
Study Protocol 
 
“Does Antrum Size Matter in Sleeve Gastrectomy?  ” 
 
 
BACKGROUND 
 
 
Laparoscopic sleeve gastrectomy (LSG) is currently the most frequent primary bariatric procedure 
performed worldwide. LSG is safe and effective in terms of excess weight loss. It is a powerful metabolic 
operation that activates significant hormonal pathways that lead to changes in eating behavior, glycemic 
control and intestinal functions. LSG can be a faster procedure for its technical aspects (any need for 
intestinal anastomosis, being limited to the stomach transection). The most frequent and sometimes 
dangerous complications are leaking, hemorrhage, splenic injury, stenosis and Gastroesophageal Reflux 
Disease (GERD)(1). Despite its established efficacy and safety, dispute still exists on optimal operative 
technique for LSG: bougie size, distance of resection margin from the pylorus, the shape of section at the 
gastroesophageal junction, staple line reinforcement and intraoperative leak testing are among the most 
controversial issues (2). Indeed, different Authors have adopted a resection distance from the pylorus 
between 2 and 6–7 cm with various reasons (3). In favor of resections more distant to the pylorus, Authors 
argue that it seems to improve gastric emptying, prevent distal stenosis and reduce intraluminal pressure, 
potentially leading to a lower incidence of fistula and/or reflux. On the other hand, resections close to the 
pylorus seems to reduce more the gastric distensibility and increase intragastric pressure, potentially 
leading to a better satiation with less oral intake (4, 5). However, only few studies have investigated the 
differences between these two approaches (3). Thus, the primary aim of this randomized monocentric 
study is to evaluate variations in percentage of excess weight loss  (%EWL) at 1 and 2 years follow-up after 
LSG in subject with a gastric resection starting from 2 cm from the pylorus (wide antrectomy) compared to 
those with a gastric resection starting from 6 cm from the pylorus (small antrectomy). Secondary aim-
points are represented by evaluation of differences in morbidity, mortality, tolerance to food, incidence of 
reflux symptoms and GERD Health-Related Quality-of-Life (GERD-HRQL) score between the two groups. 
. 
Material and Methods  
This study was conducted from January 2015 to November 2017 in the Department of General and 
Emergency Surgery of "A. Rizzoli" Hospital in Lacco Ameno (Naples, Italy). All the procedures were 

Title: Does Antrum Size Matter in Sleeve Gstrectomy?      Versione 6.0.   21/10/2014 
 
Study Protocol 
performed by the same surgeon. Morbid obesity was preoperatively diagnosed according to the 
International Federation for Surgery of Obesity (IFSO) guidelines (1). Patients were randomized into 2 
groups: Group A (dissection starts at 2 cm proximally to the pylorus and continued along the greater 
curvature to the left crus) and Group B (dissection starts at 6 cm proximally to the pylorus and continued 
along the greater curvature to the left crus). Results were obtained at 1 and 2 years follow-up.  
Pre-operative evaluation 
Preoperative evaluation included anthropometric measurements (height in cm, weight in kg, Body Mass 
Index(BMI) in kg/m2), comorbidity evaluation [Glycated Hemoglobin(A1c), C-peptide, stimulated C-peptide, 
Electrocardiography (ECG), echocardiography, lower limbs US color-doppler study, thyroid function profile].  
All patients were evaluated for the presence/absence of GERD before surgery. All patients were surveyed 
about the presence of heartburn and/or regurgitation with a specific questionnaire GERD HRQL 
questionnaire (6). Each of the 10 questions were rated from 0 (absence of symptoms) to 5 (severe 
symptoms) for a total score that may range from 0 to 50. Symptoms were defined as absent when patients 
reported a GERD-HRQL score of 0, mild from 1 to 15, moderate from 16 to 24, and severe from 25 to 50. 
Patients with GERD-HRQL score >16 was considered positive for GERD;(7). Atypical symptoms were also 
recorded. All patients underwent upper endoscopy (UE) after 20 days proton pump inhibitors (PPIs) or H2 
blockers off, with Helicobacter Pylori(HP) test. When present, HP was eradicated according to Maastricht 
consensus(8). At UE, esophagitis presence was graded according Los Angeles Classification (9). PPI 
assumption and symptoms relief was also measured. In case of atypical symptoms and PPI refractoriness,  
pH-monitoring was indicated to confirm or exclude GERD diagnosis. 
2.2 Study Design 
The study is designed as a randomized controlled trial. Primary outcome was the evaluation of %EWL 
between 2 groups. Secondary outcomes were evaluation of morbidity, mortality, incidence of reflux 
symptoms and Quality of Life score between the Groups.From January 2015 to November 2017, a series of 
218 consecutive patients suffering from morbid obesity and scheduled for LSG were included; informed 
consent was obtained from each participant before surgery.  
Inclusion criteria were morbid obesity defined as BMI 40 kg/m2 and age between 25–50 years old. 
Obesity-related comorbidities included Type 2 Mellitus Diabetes (T2MD), hypertension, hyperlipidemia, 
bronchial asthma, osteoarthritis and degenerative joint disease.  
 
 

Title: Does Antrum Size Matter in Sleeve Gstrectomy?      Versione 6.0.   21/10/2014 
 
Study Protocol 
Exclusion criteria 
Patients with previous bariatric surgical procedures, endocrine disorders causing obesity (as 
hypothyroidism and Cushing disease), pregnancy or lactation, psychiatric illness, or recent diagnosis of 
malignancy, inflammatory bowel disease, Barrett ́s esophagus, and GERD with esophagitis  scored as or 
greater than grade B, a large hiatal hernia (>3 cm) were excluded from the study. In case of absence or 
grade A esophagitis, GERD was also considered as severe with GERD-HRQL> 30 and when interfering with 
daily activities or inducing dietary restriction despite, also these were excluded.  
One hundred-fifty patients were considered eligible and randomized in two Group (Group A n = 75, Group 
B n=75). All patients underwent elective laparoscopic LSG. In the case of conversion to open surgery, 
patients were excluded. Details of enrollment procedure are shown in Fig. 1.   
Randomization 
Participants were randomly assigned to one of the two groups using computer-generated permuted blocks 
(www.randomization.com). Outpatient clinic controls were done by surgeons/surgical residents/GP blinded 
for the groups. Patients were randomized into 2 groups based on the distance to pylorus of resection: 
Group A (n=75)  at 2 cm, Group B(n=75) at 6 cm. Results were obtained at 1 and 2 years follow-up. The 
randomization 
scheme 
was 
generated 
using 
the 
web 
site 
Randomization.com 
⟨http://www.randomization.com⟩.  
Blinding Process  
Patients, care providers, staff collecting data, and those assessing the endpoints were all blinded to 
treatment allocation. Patients were blinded to the surgical procedure performed until the final assessment 
of the study endpoints. Because the blinding of the operating surgeons was not feasible, they were not 
involved in the data collection and outcome assessment. Physicians in charge of patients’ management 
were not involved in the operating room and were blinded to the surgical procedure. Data were collected 
and analyzed by physicians who were not involved in the patient’s management during the whole RCT. For 
all patients enrolled in the study, a detailed letter of the protocol was sent to general practitioners, with a 
detailed calendar of clinical and/or instrumental follow-up data to be performed at the bariatric surgery 
center.  
 
 
 

Title: Does Antrum Size Matter in Sleeve Gstrectomy?      Versione 6.0.   21/10/2014 
 
Study Protocol 
Surgical Technique  
The patient is placed in a split leg position with the surgeon located in between the patient’s legs. Closed 
pneumoperitoneum was established using our standard technique of Veres needle insufflation in Palmer 
site and optical insertion of a 12-mm port at a supraumbilical site (10-15 cm from umbilicus) Two further 
15-mm and 12-mm ports were placed respectively in the left and right ipocondrum as working ports. A 
subxiphoid track was created using a 5-mm port for placement of a liver retractor. CO2 is insufflated up to 
15 mmHg. In patients with higher body mass index who have severe visceral obesity, additional trocars can 
be added for retraction of the omentum or big fatty livers, to optimize the exposure to reach the left crus. 
Once the left crus is reached, an optimal exposure of the hiatus is mandatory to find incidental hiatal 
hernias and a complete dissection of the left crus performed to prevent retained fundus. The greater 
omentum was opened close to the stomach wall in some part in between the fundus and the antrum to 
have greater curvature completely detached from the stomach; this dissection starts at 2 cm proximal to 
the pylorus and continued along the greater curvature to the left crus in Group A with Blunt Tip (Medtronic 
Inc., Dublin, Ireland), and  at 6  cm proximal to the pylorus in Group B. Posterior adhesions if present, were 
carefully divided. The left gastrophrenic ligament was divided to expose the angle of His to identify the 
complete hiatus and fundus. A bougie was positioned before starting resection of the stomach. We use a 
36Fr bougie The starting point from the pylorus to begin the gastrectomy was 2 cm in Group A and 6  cm in 
Group B. To perform gastrectomy, we used a Medtronic Tri-Staple® SIGNA (Medtronic Inc., Dublin, Ireland) 
with GORE®SEAMGUARD® Bioabsorbable Staple Line Reinforcement. we have chosen cartridges Black at the 
antrum level and finished with a purple cartridge. We always checked the posterior wall before firing. Once 
we have reached the proximal stomach, the stapler has to be positioned 1 cm lateral to the left of the angle 
of His to avoid inclusion of esophageal tissue. Methylene blue test is performed routinely. 
 
2.5 Post-operative evaluation  
All patients were actively clinical followed up regularly at 3, 6, 12 and 24, included GERD-HRQL. UE was 
performed in all patients at 12 or 24 months. Significant vomiting and food intolerance were evaluated at 6, 
12 and 24 months follow-up. Vomiting was considered significant when occurring at least three times a 
week and food intolerance was defined as vomiting occurring almost each day. Esophageal biopsies were 
performed only in case of esophagitis ³ B (9). 

Title: Does Antrum Size Matter in Sleeve Gstrectomy?      Versione 6.0.   21/10/2014 
 
Study Protocol 
Weight loss parameters were recorded at 3, 6, 12 and 24 months after the LSG : BMI (in kg/m2), %EWL and 
percentage total weight loss %TWL from baseline. The secondary endpoints were GERD and esophagitis 
studied with Upper endoscoy and GERD score 
 
2.6 Statistical Analysis  
Statistical analysis was performed using Graphpad Quick Calcs (GraphPad version 6.04 for Windows, 
GraphPad Software, La Jolla California USA). Baseline comparisons were performed using chi-square tests 
and T-tests. Continuous variables are expressed as mean ± standard deviation (SD). Differences between 
preoperative and postoperative parameters were compared by Wilcoxon paired rank test. For all tests, a 
two-sided p<0.05 was considered statistically significant. 
 
Sample size 
THIS IS A CONTROLLED RANDOMIZED STUDY OF BINARY NON-INFERIORITY OUTCOME IN PARALLEL 
GROUPS. IF THERE IS TRULY NO DIFFERENCE BETWEEN THE STANDARD AND EXPERIMENTAL 
TREATMENT, THEN 138 PATIENTS ARE REQUIRED TO BE 90% SURE THAT THE LOWER LIMIT OF A ONE-
SIDED 95% CONFIDENCE INTERVAL (OR EQUIVALENTLY A 90% TWO-SIDED CONFIDENCE INTERVAL) 
WILL BE ABOVE THE NON-INFERIORITY LIMIT OF -10. SAMPLE SIZE WAS CALCULATED WITH SEALED 
ENVELOPE LTD. 2012.  
 
 
 
Appendix 2  
Chief Investigator: Pizza Francesco, MD, PhD – UOC Chirurgia Generale – Ospedale A. Rizzoli  –
Lacco ameno napoli.francesco.pizza@aslnapoli2nord.it;  cellulare: 3338275449. 
 
 

Title: Does Antrum Size Matter in Sleeve Gstrectomy?      Versione 6.0.   21/10/2014 
 
Study Protocol 
 
 
 
 
 
 

 
Title: Title: Does Antrum Size Matter in Sleeve Gstrectomy?      Versione 6.0.   18/11/2018 
 
Results 
Results summarized in the table: 
 
Table 1 :Preoperative demographics data 
Table 2: Weight, Body mass index, and the percentage of  excess body weight loss and the     
  Percentage Total Weight loss of the two groups at follow-up 3-6-12-24-months 
Table 3: GERD Health-Related Quality-of-Life (GERD-HRQL)  Score preoperative and     
             postoperative scores follow-up 3-6-12-24 months 
 
Table 4: Endoscopy Preoperative and at 1 and 2 years follow-up into two Groups 
 
 
 

 
Title: Title: Does Antrum Size Matter in Sleeve Gstrectomy?      Versione 6.0.   18/11/2018 
 
Results 
Table 1 Preoperative demographics data 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
BMI body mass index, %EWL percentage excess weight loss, %TWL percentage total weight loss, Type 2 Mellitus Diabetes (T2MD) 
 
 
Table 2: Weight, Body mass index, and the percentage of  excess body weight loss and the Percentage Total 
Weight loss of the two groups at follow-up  
 
 
Patients 
Total 
Group A (n=75) 
Group B(n=75) 
Age 
33.6 ± 14 
32.2 ± 8 
34.2 ± 9 
Male 
39% 
35% 
38% 
Female 
61% 
63% 
62% 
Height 
151.2 ± 22 
150.1 ± 23 
152.8 ± 33 
Weight kg 
121.9 ± 21.7 
124.5 ± 26.7 
125.3 ± 23.5 
BMI 
44.23 ± 6.32 
43 ± 8 (40–57) 
44 ± 4(40–55) 
ASA(I-II)(%) 
65% 
64% 
66% 
ASA(III-IV)(%) 
35% 
36% 
34% 
T2MD(%) 
12(8.%) 
7(9.3%) 
5(6.6%) 
Chronic obstructive 
pulmonary disease(%) 
7(4.6%) 
2(2.6%) 
3(4%) 
Heart Ischemia 
1 
0 
0 
Hypertension(%) 
95(63%) 
55(73.3%) 
40(53.4%) 
Patients 
3 months follow-up 
145/150 
p 
6 months follow-up 
141/150 
p 
12 months follow-up 
136/150 
p 
24 months follow-up 
131/150 
p 
 
Group A 
(n=72) 
Group 
B(n=73) 
p>0.05 
Group 
A(n=70) 
Group 
B(n=71) 
P<0.05 
Group 
A(n=67) 
Group 
B(n=69) 
p 
Group 
A(n=65) 
Group 
B(n=66) 
p>0.05 
BMI 
30.9 ± 5.32 
34.7 ± 4.18 
P<0.05 
26.13 ± 7.32 
31.06 ± 3.12 
P<0.05 
24.2 ± 3.4 
27.5 ± 4.3 
P<0.05 
25.2 ± 4.4 
26.2 ± 3.3 
p>0.05 
EBWL%  
40.9 ± 8.1 
31.60± 8.7 
P<0.05 
54.1±11.3 
48.20±12.5 
P<0.05 
63.7±14.1 
59.6±12.5 
P<0.05 
62.8±13.1 
61.6±10.5 
p>0.05 

 
Title: Title: Does Antrum Size Matter in Sleeve Gstrectomy?      Versione 6.0.   18/11/2018 
 
Results 
 
Table 3 GERD Health-Related Quality-of-Life (GERD-HRQL)  Score preoperative and     
             postoperative scores  
 
Patients 
Preoperative 
150/150 
3 months follow-up 
145/150 
 
6 months follow-up 
141/150 
 
12 months follow-up 
136/150 
 
24 months follow-up 
131/150 
 
 
Group A 
(n=75) 
Group 
B(n=75) 
Group A 
(n=72) 
Group 
B(n=73) 
p>0.05 
Group 
A(n=70) 
Group 
B(n=71) 
P<0.05 
Group 
A(n=67) 
Group 
B(n=69) 
P<0.05 
Group 
A(n=65) 
Group 
B(n=66) 
p>0.05 
GERD HRQL 
Score<15 
 
 
38(52.7%) 
57(78%) 
P<0.05 
36(51.4%) 
56(78.8%) 
P<0.05 
47(70.4%) 
55(79.7%) 
P<0.05 
49(75.3%) 
55(83.3%) 
P<0.05 
GERD HRQL 
Score >16<30 
7(9.3%) 
9(12%) 
29(40%) 
15(20.5%) 
P<0.05 
30(42.8%) 
14(19.7%) 
P<0.05 
16(23.8%) 
13(18.8%) 
P>0.05 
14(21.5%) 
10(15.1%) 
P>0.05 
GERD HRQL 
Score >31 
- 
- 
5(6.9%) 
1(1.3%) 
P<0.05 
4(5.7%) 
1(1.4%) 
P<0.05 
4(5.9%) 
1(1.4%) 
P<0.05 
1(1.5%) 
0 
P<0.05 
Significant 
Vomit 
- 
- 
11(15,3%) 
3(4.1%) 
P<0.05 
6(8.6%) 
2(2.8%) 
P<0.05 
6(8.9%) 
2(2.9%) 
P<0.05 
2(3.1%) 
1(1.5%) 
P<0.05 
Intolerance to 
food 
- 
- 
2(2.7%) 
0 
P<0.05 
1(1.4%) 
0 
p>0.05 
0 
0 
p>0.05 
0 
0 
p>0.05 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
Title: Title: Does Antrum Size Matter in Sleeve Gstrectomy?      Versione 6.0.   18/11/2018 
 
Results 
 
 
Table 4: Endoscopy Preoperative and at 1 and 2 years follow-up into two Groups 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Preoperative 
Patients  
150 
1 year follow-up  
Patients 108/150(72%) 
2 years follow-up 
Patients 105/150(70%) 
 
Group A 
75 
Group B 
75 
Group A 
53 
Group B 
55 
Group A 
52 
Group B 
53 
Esophagitis 
 
 
 
 
 
 
A 
4(5.3%) 
5(6.7%) 
9(16.9%) 
7(12.7%) 
5(9.6%) 
5(9.4%) 
B 
- 
- 
11(20.7%) 
5(9%) 
9(17.3%) 
3(5.6%) 
C 
- 
- 
2(3.8%) 
0 
1(1.9%) 
0 
D 
- 
- 
 
 
 
 
Esophageal 
biopsy 
 
 
 
 
 
 
Metaplasia 
- 
- 
0 
0 
0 
0 
Helicobacter 
Pylori 
9(12%) 
7(9.3%) 
 
 
 
 
Hiatal Hernia< 
5 cm 
1(1.3%) 
2(2.7%) 
- 
- 
- 
- 

 
Title: Title: Does Antrum Size Matter in Sleeve Gstrectomy?      Versione 6.0.   18/11/2018 
 
Results 
 
 
 
Figure 1 Diagram of Patients eliaibility  
 
Flow Diagram 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Assessed for eligibility (n=  218) 
Excluded  (n=   68) 
¨   Not meeting inclusion criteria (n=33  ) 
¨   Declined to participate (n=  35) 
Lost to follow-up (give reasons) (n=3 ) 
Group A (Experimental Group) 
Allocated to intervention (n=  75) 
¨ Received allocated intervention (n=75  ) 
Lost to follow-up (give reasons) (n= 2) 
Group B (Control Group) 
Allocated to intervention (n=75) 
¨ Received allocated intervention (n=75) 
Allocation 
Randomized (n=150  ) 
Enrollment 
Allocated to intervention (n=150  ) 
¨ Received allocated intervention (n= 150 ) 
¨ Did not receive allocated intervention (give reasons) (n= 0 ) 
Analysed  (n=71) 
Lost to follow-up  (n= 2 ) 
At 6 months 
At 3 months Follow-
Analysed  (n= 73) 
Analysed  (n= 72) 
Analysed  (n=  70) 
Lost to follow-up  (n=2) 
Analysis 
Analysis 
Lost to follow-up  (n=3  ) 
At 12 months Follow-Up  
Lost to follow-up  (n=2  ) 
Analysis 
Analysed  (n=  69) 
Analysed  (n=  67) 
Lost to follow-up  (n=2  ) 
At 24 months Follow-Up  
l
i
Lost to follow-up  (n=3  ) 

 
Title: Title: Does Antrum Size Matter in Sleeve Gstrectomy?      Versione 6.0.   18/11/2018 
 
Results