Anastomotic Leak Test Using Indocyanine Green During Laparoscopic Roux-en-y Gastric Bypass
Conditions: Obesity, Morbid, Surgery, Leak, Anastomotic
Sponsor: University of Foggia

 
1 
ANASTOMOTIC LEAK TEST USING INDOCYANINE 
GREEN DURING LAPAROSCOPIC ROUX-EN-Y GASTRIC 
BYPASS 
 
RUNNING HEADS: Indocyanine green test for evaluation of perfusion of gastro-
jejunal anastomosis during laparoscopic Roux-en-Y Gastric Bypass 
 
NCT Number: not available  
 
Date of document: 20/07/2022  
 
 
 
 
ABSTRACT 
 
BACKGROUND: Indocyanine green (ICG) can be injected into the human bloodstream 
and it allows us to show stomach vascularity in real time. The aim of our study is to observe 
the preliminary results of the application of indocyanine green fluorescence (IGF) during 
laparoscopic Roux-en-Y Gastric Bypass (RYGB in our center and how the perfusion of 
the gastro-jejunal anastomosis affects the onset of fistula. 
MATERIALS AND METHODS: 30 consecutive patients underwent RYGB with ICG 
fluorescence angiography at our center from January 2020 to December 2021. 5 ml of 
ICG were then injected intravenously to identify the blood supply of the stomach and the 
gastro-jejunal anastomosis. 

 
2 
RESULTS: In the RYGB tested with ICG, we all have adequate perfusion but despite this 
a methylene blue test was positive and allowed us to reinforce the suture of the gastro-
jejunal anastomosis. 
CONCLUSION: Intraoperative ICG testing during laparoscopic RYGB may be helpful 
in determining which patients are at an increased risk for leakage but multiple factors 
concur to the pathophysiology and the incidence of gastric fistula not only the perfusion. 
 
 
 
 
 
 
 
 
 
 
 
Key words: laparoscopic Roux-en-Y gastric bypass, Indocyanine green test, anastomotic 
fistula, gastro-jejunal leak. 
INTRODUCTION 
 
Morbid obesity has become a major global health threat that leads to severe morbidity 
including diabetes, hypertension, obstructive sleep apnea, degenerative joint dis- ease and 
cardiovascular diseases [1].  
Bariatric surgery is recognized as the most effective treatment for morbid obesity, 
maintaining a stable weight reduction in the long term and reducing comorbidities, with a 
favorable impact on mortality [2-4]. 
Gastric Bypass is a common operation for weight loss in patients with severe obesity. The 
procedure was developed in the 1960s by Drs. Mason and Ito who observed significant 
weight loss in a patient undergoing partial gastrectomy for peptic ulcer disease. 

 
3 
As expected, any increase in the frequency of a procedure usually unveils a significant 
number of related complications. Most of the complications of bariatric surgery are usually 
observed in the postoperative period. 
Ninety-day mortality is very low (less than 0.5%). The morbidity of the procedure is 
classified into early complications and late complications. [5] 
Early complications (0-30 days): 
• Venous thromboembolism (VTE) 
• Anastomotic leak 
• Infection 
• Intestinal blockage 
• Stenosis Gastro-Jejunal 
Late complications 
• Intestinal blockage 
• Dumping syndrome 
• Marginal ulcer 
• Gastrointestinal fistula 
• Gallstones 
• Incisional hernia 
• Nutritional deficiencies 
More information on complications after gastrectomy is beyond the scope of this review 
article. These are very complex pathological processes with specific etiologies, 
pathophysiology and treatments. 
Gastric fistulas are the most common complication observed after gastric sleeve surgery. 
A meta-analysis of almost 10,000 sleeve gastrectomies conducted by Parikh et al. revealed 
that 2.2% of these procedures were posteriorly complicated by fistula development. In 
regards to Roux-en-Y gastric bypass (RYGB), anastomotic leaks are their most common 
complications with an incidence of 0-8% [6,7]. 
Indocyanine green fluorescence angiography (AF) (ICG) is an emerging technology that 
has been used in an attempt to reduce the incidence of anastomotic leaks. ICG is a water-

 
4 
soluble tricarbocyanine dye that remains in the intravascular compartment until excretion 
and has a plasma half-life of between 3 and 5 minutes [8]. Importantly, the ICG absorbs 
light at a wavelength of excitation between 750 and 800 nm while emitting light at emission 
wavelengths greater than 830 nm or more [9]. Using near-infrared imaging systems, 
vascular perfusion to the gastro-jejunal anastomosis can be assessed intraoperatively, 
allowing surgeons to anastomose a well perfused bowel or to reshape a poorly perfused 
anastomosis. 5 ml of ICG were then injected intravenously to identify the blood supply 
of the stomach and the gastro-jejunal anastomosis. 
The aim of our study is to observe the preliminary results of the application of indocyanine 
green fluorescence (IGF) during laparoscopic Roux-en-Y Gastric Bypass (RYGB in our 
center and how the perfusion of the gastro-jejunal anastomosis affects the onset of fistula. 
 
MATERIALS AND METHODS 
 
30 consecutive patients underwent RYGB with ICG fluorescence angiography at our 
center from January 2020 to December 2021. 
During the period of interest, 10 male and 20 female patients underwent RYGB by the 
same surgical team with the same standardized technique. 
The mean age was 43.6 in the male group and 37.6 in the female group (mean 39.18). 
The mean preoperative BMI was roughly the same in the two groups (45.16 in the male 
group vs 45.06) (in the female group). 
At least one major comorbidity was found in all patients: the most represented was 
hypertension (19 patients, 63.33%), followed by diabetes (6 patients, 20%), COPD and / 
or OSAS (4 patients, 12 , 3%) and osteoarthritis (1 patient, 3.33%). 
Five patients had previous sleeve gastrectomy surgeries. 
Adequate perfusion was defined as “the direct and clear visualization of the fluorescence 
along the gastric tube, relative to the excised specimen, after an estimated time of 150-180 
s after i.v. administration injection "(FIGURE 1a-1b). 
In case of inadequate perfusion, our expected options were binding reinforcement with 
fibrin glue or with sutures. 

 
5 
A methylene blue test is routinely performed after fluorescence. 
The procedure ended with the placement of an intra-abdominal drain along the suture 
line. 
On the second postoperative day, a routine swallow test with Gastrografin is performed. 
After the Gastrografin swallow test, if negative, patients were given a liquid diet for 1 day, 
then a semi-liquid diet and were discharged on the third postoperative day. 
Our follow-up was performed routinely with blood tests and clinical examination at 3-6-
12 months. 
 
Figure 1a: Evaluation of perfusion of gastro-jejunal by using Indocyanine green test 
Figure 1b: Intraoperative picture of the gastro-jejunal 
 
RESULTS 
 
The procedure was performed in all patients without ICG-related adverse events. 
Blood supply was rated "satisfactory and adequate" in all patients. 
The mean operative time was 123 min. No conversion to laparotomy was performed. 
Despite this, the methylene blue test was positive in only one patient, a suture 
reinforcement of the gastro-jejunal anastomosis was performed with Vycril stitches. 
Routine swallowing of Gastrografin on the second postoperative day was negative for 
leaks in all patients. 
No patient showed signs or symptoms of leaks at the gastro-jejunal anastomosis. 
Analyzing our database, we performed 26 RYGBs without ICG tests from 2017 to 2019; 
the total number of leakage was 0 and our leakage rate was 0%. 
In the RYGB tested with ICG, we all have adequate perfusion but despite this a methylene 
blue test was positive and allowed us to reinforce the suture of the gastro-jejunal 
anastomosis. 
Furthermore, our main objective was to evaluate whether this method could adequately 
estimate the ischemia of the gastro-jejunal anastomosis and help in the prevention of 
leakage: this is so far not confirmed by our preliminary results (the only case with 
methylene blue test positive was adequately perfused with the ICG test). 

 
6 
 
DISCUSSION 
 
Anastomotic leaks following RYGB can be caused by a number of factors including those 
compromising healing such as mechanical tension and ischemia [10] but are also associated 
with other factors such as BMI, age and the postoperative course [11]. 
The reported incidence of gastro-jejunal leakages after LRYGB has been reported to range 
between 1 and 3% [12-13]. 
The diagnosis of gastrointestinal leak after bariatric surgery can be challenging. The 
patient’s presentation varies according to the type and timing of the leak and the patient’s 
systemic inflammatory response. Patients with morbid obesity may show uncertain 
presentations, leading to late diagnosis and potentially catastrophic consequences. 
There is still uncertainty about the pathophysiology of anastomotic leak after RYGB : the 
cause may vary from person to person. It may be caused by a problem with the tool or 
materials used to close the anastomosis during surgery. It may be because of problems 
with the blood flow in the area after surgery. Or it may be linked to other reasons for poor 
wound healing, such as diabetes or smoking [14-17]. 
The use of routine intraoperative methylene blue leak testing is still discussed as it may be 
useful for identifying suture line rupture but not for identifying areas at increased risk of 
subsequent leakage [18-20]. 
Recently, much interest has been focused on the possibility of assessing blood supply 
during surgery with the use of ICG fluorescence angiography, which is a real-time, 
inexpensive and feasible method of establishing vascularity in an area. [21-24]. It has been 
fully and positively approved in most laparoscopic procedures [25-27] but there is still little 
literature on its usefulness in the bariatric procedure. 
Therefore, our aim was to evaluate whether intraoperative ICG fluorescence angiography 
could lead to estimating the ischemic area [28]. 
From the first data, we did not find any ischemic segmental area at the gastro-jejunal 
anastomosis, despite a patient with a positive methylene blue test [29-30]. 
 

 
7 
CONCLUSIONS 
 
Although all patients underwent to the ICG test during RYGB showed optimal perfusion, 
one patient was positive to the intraoperative methylene blue test and this allowed us to 
reinforce the anastomosis with sutures. This information has led us to believe that multiple 
factors contribute to the pathophysiology and incidence of gastric fistula in the context of 
the RYGB operation. Therefore, intraoperative ICG testing may be helpful in determining 
which patients are at an increased risk for leakage, and if adjunctive measure is needed 
intraoperatively, but further testing is needed to determine if ICG will predict leakage due 
to ischemia. 
 
 
 
 
 
REFERENCES 
 
1. Younis F, Shnell M, Gluck N, Abu-Abeid S, Eldar S, Fishman S. Endoscopic 
treatment of early leaks and strictures after laparoscopic one anastomosis gastric 
bypass. BMC Surg. 2020 Feb 21;20(1):33. doi: 10.1186/s12893-020-0686-2. PMID: 
32085769; PMCID: PMC7035723. 
2. Buchwald H, Avidor Y, Braunwald E, Jensen MD, Pories W, Fahrbach K, et al. 
Bariatric surgery:a systematic review and meta-analysis. JAMA. 2004;292(14):1724-
37. 
3. Christou NV, Sampalis JS, Liberman M, Look D, Auger S, McLean AP, et al. 
Surgery decreases long-term mortality, morbidity, and health care use in morbidly 
obese patients. Ann Surg. 2004;240(3):416-23; discussion 423-4. 
4. Sjostrom L, Narbro K, Sjostrom CD, Karason K, Larsson B, Wedel H, et al. Effects 
of bariatric surgery on mortality in Swedish obese subjects. N Engl J Med. 
2007;357(8):741-52. 

 
8 
5. Peterli R, Wölnerhanssen BK, Peters T, Vetter D, Kröll D, Borbély Y, Schultes B, 
Beglinger C, Drewe J, Schiesser M, Nett P, Bueter M. Effect of Laparoscopic Sleeve 
Gastrectomy vs Laparoscopic Roux-en-Y Gastric Bypass on Weight Loss in 
Patients With Morbid Obesity: The SM-BOSS Randomized Clinical Trial. JAMA. 
2018 Jan 16;319(3):255-265. doi: 10.1001/jama.2017.20897. PMID: 29340679; 
PMCID: PMC5833546. 
6. Surgical strategies that may decrease leak after laparoscopic sleeve gastrectomy: a 
systematic review and meta-analysis of 9991 cases. Parikh M, Issa R, McCrillis A, 
Saunders 
JK, 
Ude-Welcome 
A, 
Gagner 
M. Ann 
Surg. 2013;257:231–
237. [PubMed] [Google Scholar] 
7. Diagnosis and management of the postoperative surgical and medical 
complications of bariatric surgery. Montravers P, Augustin P, Zappella N, et 
al.  Anaesth Crit Care Pain Med. 2015;34:45–52. [PubMed] [Google Scholar] 
8. Keller DS, Ishizawa T, Cohen R, Chand M. Indocyanine green fluorescence im- 
aging in colorectal surgery: overview, applications, and future directions. Lancet 
Gastroenterol Hepatol. 2017;2:757e766.  
9. Alander JT, Kaartinen I, Laakso A, et al. A review of indocyanine green fluo- 
rescent imaging in surgery. Int J Biomed Imaging. 2012;2012:940585.  
10. Gonzalez R, Nelson LG, Gallagher SF, et al. Anastomotic leaks after laparoscopic 
gastric bypass. Obes Surg. 2004;14:1299–307. 
11. Ballesta C, Berindoague R, Cabrera M, et al. Management of anastomotic leaks after 
laparoscopic Roux-en-Y gastric bypass. Obes Surg. 2008;18:623–30.  
12. Singhal R, Tahrani AA, Ludwig C, Mahawar K; GENEVA collaborators. Global 
30-day outcomes after bariatric surgery during the COVID-19 pandemic 
(GENEVA): an international cohort study. Lancet Diabetes Endocrinol. 2021 
Jan;9(1):7-9. doi: 10.1016/S2213-8587(20)30375-2. Epub 2020 Nov 27. PMID: 
33253631; PMCID: PMC7832244. 
13. Flum DR, Belle SH, King WC, et al: Periop- erative safety in the longitudinal 
assessment of bariatric surgery. N Engl J Med 2009;361: 445–454.  

 
9 
14. Alizadeh RF, Li S, Inaba C, Penalosa P, Hinojosa MW, Smith BR, Stamos MJ, 
Nguyen NT. Risk Factors for Gastrointestinal Leak after Bariatric Surgery: 
MBASQIP Analysis. J Am Coll Surg. 2018 Jul;227(1):135-141. doi: 
10.1016/j.jamcollsurg.2018.03.030. Epub 2018 Mar 30. PMID: 29605723. 
15. Tartaglia N, Pavone G, Di Lascia A, Vovola F, Maddalena F, Fersini A, 
Pacilli M, Ambrosi A. Robotic voluminous paraesophageal hernia repair: a 
case report and review of the literature. J Med Case Rep. 2020 Feb 4;14(1):25. 
doi: 10.1186/s13256-020-2347-6. PMID: 32019608; PMCID: PMC6998085. 
16. Pacilli M, Tartaglia N, Gerundo A, Pavone G, Fersini A, Ambrosi A. Energy Based 
Vessel Sealing Devices in Thyroid Surgery: A Systematic Review to Clarify the 
Relationship with Recurrent Laryngeal Nerve Injuries. Medicina (Kaunas). 2020 
Nov 27;56(12):651. doi: 10.3390/medicina56120651. PMID: 33260912; PMCID: 
PMC7760641 
17. Tartaglia N., Pavone G., Petruzzelli F., Di Lascia A., Vovola F., Maddalena F., 
Cianci P., Fersini A., Pacilli M., Ambrosi A. Robotic sleeve gastrectomy vs 
laparoscopic sleeve gastrectomy: our preliminary experience and a literature review. 
Clinical and Experimental Surgery. Petrovsky Journal. 2020; 8 (4): 7–15. DOI: 
https://doi.org/10.33029/2308- 1198-2020-8-4-7-15 
18. Singhal R, Ludwig C, Rudge G, Gkoutos GV, Tahrani A, Mahawar K; GENEVA 
Collaborators, et al. 30-Day Morbidity and Mortality of Bariatric Surgery During 
the COVID-19 Pandemic: a Multinational Cohort Study of 7704 Patients from 42 
Countries. Obes Surg. 2021 Oct;31(10):4272-4288. doi: 10.1007/s11695-021-
05493-9. Epub 2021 Jul 30. PMID: 34328624; PMCID: PMC8323543. 
19. Tartaglia N, Pavone G, Lizzi V, Vovola F, Tricarico F, Pacilli M, Ambrosi A. How 
emergency surgery has changed during the COVID-19 pandemic: A cohort study. 
Ann Med Surg (Lond). 2020 Dec 5;60:686-689. doi: 10.1016/j.amsu.2020.12.001. 
PMID: 33312562; PMCID: PMC7719013. 
20. Benedix F, Benedix DD, Knoll C et al. Are there risk factors that in- crease the rate 
of staple line leakage in patients undergoing primary sleeve gastrectomy for morbid 
obesity? ObesSurg 2014; 24: 1610– 1616  

 
10 
21. Sakran N, Goitein D, Raziel A, et al. Gastric leaks after sleeve gastrectomy: a 
multicenter experience with 2,834 patients. SurgEndosc. 2013;27(1):240–5. 
https://doi.org/10.1007/s00464-012- 2426-x  
22. Benedix F, Benedix DD, Knoll C, et al. Are there risk factors that increase the rate 
of staple line leakage in patients undergoing pri- mary sleeve gastrectomy for 
morbid obesity? ObesSurg. 2014;24(10):1610–6.  
23. Lacedonia D, Tartaglia N, Scioscia G, Soccio P, Pavone G, Moriondo G, Gallo C, 
Foschino Barbaro MP, Ambrosi A. Different Expression of Micro-RNA in the 
Subcutaneous and Visceral Adipose Tissue of Obese Subjects. Rejuvenation Res. 
2022 Apr;25(2):89-94. doi: 10.1089/rej.2022.0004. PMID: 35293246. 
24. Singhal R, Cardoso VR, Wiggins T, Super J, Ludwig C, Gkoutos GV, Mahawar K; 
GENEVA Collaborators. 30-day morbidity and mortality of sleeve gastrectomy, 
Roux-en-Y gastric bypass and one anastomosis gastric bypass: a propensity score-
matched analysis of the GENEVA data. Int J Obes (Lond). 2022 Apr;46(4):750-
757. doi: 10.1038/s41366-021-01048-1. Epub 2021 Dec 15. PMID: 34912046; 
PMCID: PMC8671878. 
25. Delle Monache S, Calgani A, Sanità P, et al. Adipose-derived stem cells sustain 
prolonged angiogenesis through leptin secretion. GrowthFactors. 2016;34(3–4):87–
96. https://doi.org/10.1080/ 08977194.2016.1191481.  
26. Cobianchi L, Dal Mas F, Massaro M, Fugazzola P, Coccolini F, Kluger Y, 
Leppäniemi A, Moore EE, Sartelli M, Angelos P, Catena F, Ansaloni L; Team 
Dynamics Study Group. Team dynamics in emergency surgery teams: results from 
a first international survey. World J Emerg Surg. 2021 Sep 16;16(1):47. doi: 
10.1186/s13017-021-00389-6. Erratum in: World J Emerg Surg. 2021 Nov 
1;16(1):55. PMID: 34530891; PMCID: PMC8443910. 
27. Tartaglia N, Di Lascia A, Cianci P, Fersini A, Pacilli M, Pavone G, Ambrosi A. 
Hemoperitoneum caused by spontaneous rupture of hepatocellular carcinoma in 
noncirrhotic liver. A case report and systematic review. Open Med (Wars). 2020 
Aug 3;15(1):739-744. doi: 10.1515/med-2020-0202. PMID: 33336031; PMCID: 
PMC7712383. 

 
11 
28. Singhal R, Wiggins T, Super J, Alqahtani A, Nadler EP, Ludwig C, Tahrani A, 
Mahawar K; GENEVA Collaborative. 30-Day morbidity and mortality of bariatric 
metabolic surgery in adolescence during the COVID-19 pandemic - The GENEVA 
study. Pediatr Obes. 2021 Dec;16(12):e12832. doi: 10.1111/ijpo.12832. Epub 2021 
Jul 8. PMID: 34240553. 
29. Cianci P, Tartaglia N, Altamura A, Di Lascia A, Fersini A, Neri V, Ambrosi A. 
Cervical Esophagotomy for Foreign Body Extraction: A Case Report and 
Extensive Literature Review of the Last 20 Years. Am J Case Rep. 2018 Apr 
5;19:400-405. 
doi: 
10.12659/ajcr.908373. 
PMID: 
29618719; 
PMCID: 
PMC5900799. 
30. Tartaglia N, Iadarola R, Di Lascia A, Cianci P, Fersini A, Ambrosi A. What is the 
treatment of tracheal lesions associated with traditional thyroidectomy? Case report 
and systematic review. World J Emerg Surg. 2018 Mar 23;13:15. doi: 
10.1186/s13017-018-0175-4. PMID: 29588652; PMCID: PMC5865337. 
 
 
Provenance and peer review 
Not commissioned, externally peer-reviewed