Introduction

Sleeve Gastrectomy (SG) is now the most commonly performed bariatric procedure in the world [1]. It was first performed by Hess in 1988 as a component of biliopancreatic diversion-duodenal switch (BPD-DS) procedure which was modified from Scopinaro’s biliopancreatic diversion (BPD) and DeMeester’s duodenal switch (DS) procedure [2,3,4]. With the evolution of laparoscopic surgery in the 1990s, Gagner performed the first laparoscopic SG as a part of BPD-DS in 1999 [5]. In the early part of the twenty-first century, it was popularized as a first-step intervention before BPD or gastric bypass in the super obese and high-risk group of patients [6, 7]. Due to the unexpected good results in terms of weight loss and resolution of comorbidities, coupled with the simplicity of performing the procedure requiring intervention on only the stomach, SG gained status as a stand-alone bariatric procedure [8, 9].

Despite SG being the most commonly performed procedure worldwide, there is a lack of agreement among surgeons regarding its contraindications, preoperative assessment, technical aspects of the procedure such as diameter of the orogastric tube to size the sleeve, distance from the pylorus at the beginning of gastric transection, staple line reinforcement, intraoperative leak test, and postoperative management [10,11,12].

Though there have been previous attempts to build consensus on various aspects of SG [10, 11], these efforts have been hampered somewhat by lack of published scientific data on global variation in practices concerning this procedure. The objective of this study was to understand the variations in perioperative practices concerning SG through a survey of global community of bariatric surgeons on its contraindications, preoperative assessment, intraoperative technical details and postoperative management. It is expected that understanding variations in practice scientifically may pave way for focused studies to identify best practice in the future. A better understanding of the global variations in practices might also improve the quality of future consensus building attempts on this procedure.

Methods

This survey followed the principles of good practice in the conduct and reporting of survey research as recommended by the EQUATOR network guidelines [13]. A 37-item questionnaire-based survey (https://www.surveymonkey.co.uk/r/Mahawar) was conducted encompassing the global community of bariatric and metabolic surgeons. The 37 items in the questionnaire were formulated by the authors based on the existing controversies surrounding the management of patients who undergo SG. Eight bariatric surgeons from 5 continents shared responsibility of circulating the survey within the global bariatric community through emails, social media and personal interaction. The link to the survey was freely shared on social and scientific media (Facebook™, Researchgate™, Twitter™, Whatsapp™ and Linkedn™), and through personal network.

The survey was made live on 02/02/019 and closed for analysis on 29/03/2019. Questions enquired about the responder’s experience with SG, contraindications, preoperative investigations, technical details and postoperative management. Full details of the questionnaire have been provided in Table 1.

Table 1 Survey questionnaire with summary of responses (Edited)
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Analysis was done using descriptive statistics as numbers (percentage) and bar graphs were used for representation where applicable.

Results

Of the 942 surgeons who responded to the survey, 79 did not perform SG and their responses were omitted. The remaining 863 surgeons had performed 5,20,230 SGs till the time of completion of the survey and their responses were included.

Nationality of the Respondents

A total of 67 countries were represented in the survey. Table 2 provides the representation of the respondents in terms of nationality.

Table 2 Country of origin of the survey participants in alphabetical order
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Experience of the Respondents

Approximately, 12.5% (n = 109) surgeons had performed between 1 and 50 SGs, 13% (n = 113) had performed between 51 and 100 SGs, 38% (n = 332) had performed 101–500 SGs while 30% (n = 255) surgeons had performed more than 500 SGs at the time of completion of the survey. The mean experience per surgeon of the entire cohort was 603 procedures.

Absolute Contraindications of SG

A total of 689 (80%) surgeons listed 13 absolute contraindications to SG, while 106 (12%) felt there was no absolute contraindication of SG. The list of absolute contraindications to SG chosen by the participants are enumerated in Table 3.

Table 3 Absolute contraindications to sleeve gastrectomy as reported by the participants of the survey
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Relative Contraindications of SG

A total of 764 (89%) surgeons listed 13 relative contraindications to SG, while 64 (7.4%) felt no relative contraindications of SG. Relative contraindications to SG as listed by the participants are enumerated in Table 4.

Table 4 Relative contraindications to sleeve gastrectomy as reported by the participants of the survey
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Preoperative Assessment

A total of 559 (65%) surgeons reported that they perform routine preoperative Upper Gastro-Intestinal Endoscopy (UGIE) before SG while 275 (32%) did not. A slightly lower number (n = 527; 61%) of surgeons perform routine ultrasound of the abdomen while 330 (38%) did not.

Intraoperative Technical Details

Orogastric tube - An overwhelming 97% (n = 835) surgeons routinely use an orogastric tube to size the sleeve. A wide variation was observed in the size of the orogastric tube used, which has been provided in Fig. 1. Size of 36 Fr was used by maximum number of surgeons (n = 344; 40%).

Fig. 1
figure 1

Size of orogastric tube in sleeve gastrectomy preferred by the participants of the survey (n = 856)

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Distance from the Pylorus at the Beginning of Gastric Transection

Wide variation was also observed in the distance from the pylorus at the beginning of gastric transection while fashioning the sleeve, as enumerated in Fig. 2. Most surgeons prefer to begin the gastric transection at 4–5 cm from pylorus (n = 501; 58%).

Fig. 2
figure 2

Distance from the pylorus at the beginning of gastric transection preferred by the participants of the survey (n = 863)

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Intraoperative Detection and Management of Hiatus Hernia

Routine hiatal dissection to rule out occult hiatus hernia was performed by 24% (n = 204) surgeons, while 623 (72%) surgeons did not. Once encountered with a preoperatively or intraoperatively diagnosed diaphragmatic hernia, posterior crural approximation is preferred by 34% (n = 296) surgeons, anterior crural approximation by 8.2% (n = 71) surgeons, while 26% (n = 221) surgeons perform anterior or posterior crural approximation depending on the anatomy. Approximately 29% (n = 249) surgeons do not routinely approximate the diaphragmatic crura in patients with identified hiatus hernias.

Staple Line Reinforcement

Approximately 54% (n = 467) surgeons routinely use staple line reinforcement while fashioning the sleeve while 43% (n = 369) surgeons do not use routine staple line reinforcement. 334 surgeons (39%) mentioned that they do not use any reinforcement. A total of 502 (58%) surgeons mentioned their choice of staple line reinforcement and a wide variation was observed in their choices as enumerated in Table 5. 18% (n = 154) surgeons routinely anchored the omentum to the sleeve at the end of the procedure while 77% (n = 668) did not.

Table 5 Type of staple line reinforcement in sleeve gastrectomy preferred by the participants of the survey
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Clipping of Short Gastric Vessels

89% (n = 771) do not clip the splenic end of short gastric vessels before dividing it with energy device, while 3.2% (n = 28) clip the short gastric vessels routinely. 61 (7.1%) clip it only when faced with a large vessel.

Intraoperative leak test - 65% (n = 565) surgeons perform routine intraoperative leak test at the end of the procedure, while 11% (n = 96) perform routine intraoperative UGIE. 732 (85%) surgeons mentioned their choice of the leak test method which is enumerated in Table 6.

Table 6 Technique of intraoperative leak test in sleeve gastrectomy preferred by the participants of the survey
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Use of Abdominal Drain

Approximately 65% (n = 558) surgeons do not use an intraabdominal drain routinely after SG, 21% (n = 180) use it for <48 h, while 12.5% (n = 108) leave a drain for >48 h.

Single Incision and Robotic Sleeve Gastrectomy – Approximately 12% (n = 105) perform single incision SG while 10% (n = 86) surgeons perform the procedure robotically.

Postoperative Management

Water Soluble Contrast Study

25% (n = 218) surgeons perform a routine water-soluble contrast study in the early postoperative period while 73% (n = 629) do not. Oral intake is encouraged on the day of surgery by 45.5% (n = 393) surgeons, on the first day after surgery by 41% (n = 353) surgeons, and on the second day after surgery by 6.4% (n = 55) surgeons. A total of 45 (5.2%) surgeons start oral intake only after confirming the absence of leak on a water-soluble contrast study.

Micronutrient Supplementation

Lifelong multivitamin/mineral supplements after SG is recommended by 66% (n = 567) surgeons, iron supplements by 29% (n = 250) surgeons, vitamin D supplements by 41% (n = 346) surgeons, calcium supplements by 38% (n = 324) surgeons, and vitamin B12 supplements by 44% (n = 383) surgeons.

PPI and Gallstone Prophylaxis

Approximately 79% (n = 681) surgeons routinely use PPI prophylaxis after SG, while only 20% (n = 172) use ursodeoxycholic acid for prophylaxis of gall stones.

Revisional Procedure after Sleeve Gastrectomy for Further Weight Loss and Resolution of Comorbidities

For further weight loss and resolution of co-morbidities after SG, the preferred revisional procedure offered to patients is Roux-en-Y gastric bypass (RYGB) by 51% (n = 441) surgeons, one anastomosis gastric bypass (OAGB) by 25% (n = 217) surgeons, single anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) procedure by 10% (n = 87) surgeons, and duodenal switch (DS) by 3.2% (n = 28) surgeons, while only 2.2% (n = 19) surgeons prefer to re-sleeve their patients.

Revisional Procedure after Sleeve Gastrectomy for Gastro-Esophageal Reflux Disease (GERD)

For patients troubled with symptoms of GERD unresponsive to maximal medical therapy, the preferred revisional procedure of choice offered is RYGB by 87% (n = 752) surgeons. Other revisional options offered for GERD are OAGB by 64 (7.4%) surgeons, SADI-S by 7 (0.81%) surgeons and duodenal switch by 1 (0.12%) surgeon.

Discussion

This survey on 863 bariatric and metabolic surgeons from 67 countries with a cumulative experience of 520,230 SGs is the largest survey of surgical community in scientific literature aimed to capture the global practices concerning SG and is expected to identify areas of future research and building of consensus that might help in improving outcomes.

Literature on how SG influences Barrett’s esophagus and GERD is conflicting. Gagner noted that “SG improves symptoms and reduces reflux in most morbidly obese patietns with preoperative reflux. [14]”. Genco et al, on the other hand, published a series of 110 patients and showed an increase GERD symptoms and PPI intake after SG along with newly diagnosed Barrett’s esophagus occurring in 17.2% of patients at a follow up of 58 months [15]. In this survey, 79% surgeons believed Barrett’s esophagus to be an absolute contraindication to SG and 28% believed it to be a relative contraindication. In contrast, only 23% surgeons viewed GERD to be an absolute contraindication while 56% surgeons believed only severe GERD requiring daily PPI therapy to be an absolute contraindication to SG. This survey showed that what constitutes as a relative contraindication to one group of surgeons is an absolute contraindication for another suggesting a lack of clarity due to conflicting literature on the safety of SG in individual groups of patients. More studies comparing different procedures are needed for patients with GORD.

The ASMBS guidelines advocates the use of UGIE preoperatively on a selective basis based on the presence of symptoms [16]. This is in contrast to the observation by another study that found significant findings relevant for SG (hiatus hernia, esophagitis, Barrett’s esophagus, esophageal dysplasia) in 23% patients, of whom only half were symptomatic and the authors concluded that preoperative UGIE was indicated before SG for all patients irrespective of symptoms [17]. Once again, significant variation was observed in this survey with only 65% surgeons advocating routine UGIE before SG.

This survey found wide variation in the diameter of the orogastric tube used to size the sleeve, even though the majority (40%) of surgeons preferred a size of 36 Fr. The International Sleeve Gastrectomy Consensus recommends a 32–36 Fr sized orogastric tube and a distance of 2–6 cm from the pylorus as per their survey based best practice guidelines [10]. A meta-analysis of 9991 patients showed reduced leak rate by increasing the diameter of the bougie (>40 Fr), however, neither the diameter of the bougie nor the distance from pylorus at the beginning of distal section showed any correlation with excess weight loss [18]. This is in contrast to a few studies that showed a higher excess weight loss by reducing the size of the bougie and closing the distance of the first section nearer to the pylorus [19, 20]. Another study showed that increasing the size of the bougie (>38 Fr) was associated with lower leak rate while increasing the distance of the beginning of gastric transection from the pylorus was associated with greater weight loss [21]. This survey showed that 82% surgeons prefer an orogastric tube <40 Fr in diameter while 16% surgeons prefer >40 Fr. 73% surgeons prefer a distance of 3–5 cm from the pylorus at the beginning of gastric transection, while 1.39% prefer a distance of >6 cm. Significant variation among surgeons with regard to the size of orogastric tube and distance of the beginning of gastric transection from the pylorus, as demonstrated in this survey, could be due to conflicting literature and reflects the need for high quality randomized controlled trials on the topic.

The use of reinforcements with the stapling device to construct the sleeve has been a matter of contextual debate among bariatric and metabolic surgeons, with this survey showing 54% surgeons who prefer to reinforce the staple line routinely. Of those who use reinforcements (n = 502), 41% prefer to oversew the staple line with running suture, 30% use Seamguard™ (absorbable polymer membrane), 17% invaginate the staple line with running suture, 15% use Medtronic™ reinforced staples, 5.3% use Peristrips™ (bovine pericardial strips) and 4.6% use fibrin sealant. A systematic review of 30 studies (4881 patients) and a meta-analysis of 791 patients from 8 randomized controlled trials on staple-line reinforcements in SG showed no statistical difference in terms of staple line leak and bleeding, though bleeding tended to reduce with reinforcements [22, 23]. Similar findings were observed by Dapri et al who compared three techniques – non-reinforcement, absorbable membrane, and staple line suture. The study found no difference in staple line leak between the three groups but the use of absorbable membrane reduced bleeding [24]. Contradictory data is obtained from Choi et al who performed a review of 1345 patients and Gagner et al who analyzed 88 articles with 8920 patients [25, 26]. Both of these studies found reduced incidence of staple line leak with reinforcements [25, 26]. A systematic review of 148 studies with 40,653 patients compared the different types of reinforcements and found absorbable polymer membrane to be superior to oversewing, fibrin glue, bovine pericardial strips and no reinforcement in the prevention of staple line leak [27].

Literature shows no correlation between intraoperative leak test with staple line leaks, with most leaks known to occur in patients with negative intraoperative leak test [28,29,30]. Some authors have in fact described a higher likelihood of staple line leak after intraoperative leak test [29, 30]. Contradictory data is obtained from a review of four studies that suggested routine use of methylene blue test intraoperatively [31]. Some studies endorse routine use of leak test using intraoperative endoscopy utilizing air insufflation [32]. Another study on 712 patients showed intraoperative leak test with methylene blue to be a sensitive and effective method for detecting intraoperative leak during SG with the authors suggesting its routine use in all cases [33]. However, no correlation was observed in this study with early postoperative water-soluble contrast study and the authors suggested that the use of routine contrast study in the postoperative period was not indicated unless clinically indicated in selected patients [33]. This survey captured the existing practice of 863 bariatric surgeons and found that 65% surgeons perform routine intraoperative leak test while only 11% surgeons perform routine intraoperative endoscopy in SG. Of those who routinely perform intraoperative leak test (n = 732), dilute methylene blue solution is the preferred choice among 63% surgeons, 11.4% preferred air insufflation using orogastric tube, while 9.4% surgeons prefer to use air insufflation with an endoscope. In contrast, only 25% surgeons perform a contrast study in the early postoperative period for detection of staple line leak routinely. 65% surgeons do not advocate the routine use of intraoperative drain which was found to be in keeping with a review of 353 patients of SG that found no benefit with intraabdominal drains in terms of detection of leak, abscess, bleeding or reoperation due to these complications [34].

A limitation of this study is that in spite of the large number of surgeons who participated from different countries, there is a possibility of missing out on bariatric surgeons who have not participated in the survey. However, the aim of this survey was to get a worldwide snapshot of the prevailing practices concerning SG and the authors believe that this was accomplished based on the large number of participating surgeons from 67 countries. Another limitation is that because of our methodology, we are not able to give an exact response rate but we believe our sample is representative because of the large number of surgeons who participated in the survey from all parts of the world in this very narrow surgical specialty. Certain intraoperative factors like the snugness of the stapler to the orogastric tube and the method of measurement of the distance between the pylorus and beginning of gastric transection were not addressed in this survey.

Finally, authors would like to caution against over interpretation of this data. The purpose of this study is simply to capture global variation and not to identify best practice as that can only be done through adequately designed scientific studies. In that sense, even a variation practiced by the majority may not be the scientifically correct choice and should be examined in future studies. At the same time, knowing the variations might make it easier to design future studies to identify best practice and future attempts at consensus building while we wait for those studies to be conducted.

Conclusion

This study found significant variation among global community of bariatric surgeons with regard to various perioperative practices concerning SG and identifies areas for future research and consensus building.