Marginal ulcer: Difference between revisions

(Created page with "'''Marginal ulcer''' (also called stomal ulcer or anastomotic ulcer) is a mucosal ulceration that develops at or near a surgical gastroenteric anastomosis, most commonly on the jejunal side of the gastrojejunostomy after Roux-en-Y gastric bypass (RYGB).<ref>Coblijn UK, Goucham AB, Lagarde SM, Kuiken SD, van Wagensveld BA. Development of ulcer disease after Roux-en-Y gastric bypass, incidence, risk factors, and patient presentation: a systematic review. ''Obes Surg''....")
 
(Formatting: moved intro to Background bullets, removed excessive bold from bullet lead-ins)
 
Line 1: Line 1:
'''Marginal ulcer''' (also called stomal ulcer or anastomotic ulcer) is a mucosal ulceration that develops at or near a surgical gastroenteric anastomosis, most commonly on the jejunal side of the gastrojejunostomy after [[Roux-en-Y gastric bypass]] (RYGB).<ref>Coblijn UK, Goucham AB, Lagarde SM, Kuiken SD, van Wagensveld BA. Development of ulcer disease after Roux-en-Y gastric bypass, incidence, risk factors, and patient presentation: a systematic review. ''Obes Surg''. 2014;24(2):299-309.</ref> It is the most common late complication of RYGB and may present to the emergency department with pain, [[GI bleeding]], or perforation.
==Background==
*Marginal ulcer (also called stomal ulcer or anastomotic ulcer) is a mucosal ulceration that develops at or near a surgical gastroenteric anastomosis, most commonly on the jejunal side of the gastrojejunostomy after [[Roux-en-Y gastric bypass]] (RYGB).<ref>Coblijn UK, Goucham AB, Lagarde SM, Kuiken SD, van Wagensveld BA.
*Development of ulcer disease after Roux-en-Y gastric bypass, incidence, risk factors, and patient presentation: a systematic review. ''Obes Surg''. 2014;24(2):299-309.</ref>
*It is the most common late complication of RYGB and may present to the emergency department with pain, [[GI bleeding]], or perforation.
 


==Background==
* Incidence ranges from 0.6% to 25% following RYGB, with a mean prevalence of approximately 4.6%<ref>Azagury DE, Abu Dayyeh BK, Greenwalt IT, Thompson CC. Marginal ulceration after Roux-en-Y gastric bypass surgery: characteristics, risk factors, treatment, and outcomes. ''Endoscopy''. 2011;43(11):950-954.</ref>
* Incidence ranges from 0.6% to 25% following RYGB, with a mean prevalence of approximately 4.6%<ref>Azagury DE, Abu Dayyeh BK, Greenwalt IT, Thompson CC. Marginal ulceration after Roux-en-Y gastric bypass surgery: characteristics, risk factors, treatment, and outcomes. ''Endoscopy''. 2011;43(11):950-954.</ref>
* Typically presents a median of 1-2 years after surgery, but can occur from weeks to >10 years postoperatively
* Typically presents a median of 1-2 years after surgery, but can occur from weeks to >10 years postoperatively
* Ulcers are located on the anastomosis (~50%) or the jejunal mucosa (~40%)
* Ulcers are located on the anastomosis (~50%) or the jejunal mucosa (~40%)
* Pathophysiology is multifactorial:
* Pathophysiology is multifactorial:
** '''Acid exposure''' — jejunal mucosa lacks protective buffering mechanisms against gastric acid
** Acid exposure — jejunal mucosa lacks protective buffering mechanisms against gastric acid
** '''Ischemia''' — tension on the anastomosis, compromised local blood supply
** Ischemia — tension on the anastomosis, compromised local blood supply
** '''Large gastric pouch''' — greater parietal cell mass increases acid production<ref>Edholm D, Ottosson J, Sundbom M. Importance of pouch size in laparoscopic Roux-en-Y gastric bypass: a cohort study of 14,168 patients. ''Surg Endosc''. 2016;30(5):2011-2015.</ref>
** Large gastric pouch — greater parietal cell mass increases acid production<ref>Edholm D, Ottosson J, Sundbom M. Importance of pouch size in laparoscopic Roux-en-Y gastric bypass: a cohort study of 14,168 patients. ''Surg Endosc''. 2016;30(5):2011-2015.</ref>
** '''Foreign body reaction''' — non-absorbable suture material or exposed staples at the anastomosis
** Foreign body reaction — non-absorbable suture material or exposed staples at the anastomosis
** '''Gastrogastric fistula''' — allows acid from the excluded gastric remnant to reach the pouch
** Gastrogastric fistula — allows acid from the excluded gastric remnant to reach the pouch
* Risk factors (by meta-analysis):<ref>Liang Y, Wang C, Yang L, et al. Nonsurgical risk factors for marginal ulcer following Roux-en-Y gastric bypass for obesity: a systematic review and meta-analysis of 14 cohort studies. ''Int J Surg''. 2024;110(3):1793-1799.</ref>
* Risk factors (by meta-analysis):<ref>Liang Y, Wang C, Yang L, et al. Nonsurgical risk factors for marginal ulcer following Roux-en-Y gastric bypass for obesity: a systematic review and meta-analysis of 14 cohort studies. ''Int J Surg''. 2024;110(3):1793-1799.</ref>
** '''[[Helicobacter pylori]]''' infection (OR 4.97)
** [[Helicobacter pylori]] infection (OR 4.97)
** '''Smoking''' (OR 2.50)
** Smoking (OR 2.50)
** '''Diabetes mellitus''' (OR 1.80)
** Diabetes mellitus (OR 1.80)
** [[NSAID]] / [[aspirin]] use
** [[NSAID]] / [[aspirin]] use
** [[Corticosteroid]] use
** [[Corticosteroid]] use
Line 22: Line 25:


==Clinical Features==
==Clinical Features==
* '''Epigastric or periumbilical pain''' (most common, ~63%)<ref>Azagury DE, Abu Dayyeh BK, Greenwalt IT, Thompson CC. Marginal ulceration after Roux-en-Y gastric bypass surgery: characteristics, risk factors, treatment, and outcomes. ''Endoscopy''. 2011;43(11):950-954.</ref>
* Epigastric or periumbilical pain (most common, ~63%)<ref>Azagury DE, Abu Dayyeh BK, Greenwalt IT, Thompson CC. Marginal ulceration after Roux-en-Y gastric bypass surgery: characteristics, risk factors, treatment, and outcomes. ''Endoscopy''. 2011;43(11):950-954.</ref>
** Often postprandial, may mimic pre-bypass [[peptic ulcer disease]]
** Often postprandial, may mimic pre-bypass [[peptic ulcer disease]]
* Nausea and vomiting
* Nausea and vomiting
Line 29: Line 32:
** [[Melena]], [[hematemesis]], or occult blood loss with iron deficiency [[anemia]]
** [[Melena]], [[hematemesis]], or occult blood loss with iron deficiency [[anemia]]
* [[Dysphagia]] (if associated anastomotic stricture)
* [[Dysphagia]] (if associated anastomotic stricture)
* '''Complicated presentations:'''
* Complicated presentations:
** '''Perforation''' — acute-onset severe abdominal pain, peritoneal signs, [[sepsis]]
** Perforation — acute-onset severe abdominal pain, peritoneal signs, [[sepsis]]
*** May present with left shoulder pain (diaphragmatic irritation)
*** May present with left shoulder pain (diaphragmatic irritation)
** '''Hemorrhage''' — [[Hemorrhagic shock|hemodynamic instability]], [[hematemesis]], [[hematochezia]]
** Hemorrhage — [[Hemorrhagic shock|hemodynamic instability]], [[hematemesis]], [[hematochezia]]
** '''Stricture''' — progressive [[dysphagia]], vomiting, inability to tolerate oral intake
** Stricture — progressive [[dysphagia]], vomiting, inability to tolerate oral intake
** '''Gastrogastric fistula''' — chronic symptoms, weight regain
** Gastrogastric fistula — chronic symptoms, weight regain
* Up to 28% of patients may be '''asymptomatic''' (discovered incidentally on surveillance endoscopy)
* Up to 28% of patients may be '''asymptomatic''' (discovered incidentally on surveillance endoscopy)


Line 53: Line 56:


===Workup===
===Workup===
* '''Labs:'''
* Labs:
** [[CBC]] — anemia (chronic blood loss), leukocytosis (perforation/infection)
** [[CBC]] — anemia (chronic blood loss), leukocytosis (perforation/infection)
** [[BMP]] — electrolyte abnormalities from vomiting or poor oral intake
** [[BMP]] — electrolyte abnormalities from vomiting or poor oral intake
Line 61: Line 64:
** [[H. pylori]] testing (stool antigen or urea breath test preferred over serology post-bypass)
** [[H. pylori]] testing (stool antigen or urea breath test preferred over serology post-bypass)
** [[Iron studies]] — if chronic anemia
** [[Iron studies]] — if chronic anemia
* '''Imaging:'''
* Imaging:
** '''CT abdomen/pelvis with IV contrast''' — study of choice in the ED for suspected complications<ref>Meissnitzer MW, Stättner S, Gmeiner D, et al. Imaging features of marginal ulcers on multidetector CT. ''Clin Radiol''. 2023;78(2):e178-e185.</ref>
** CT abdomen/pelvis with IV contrast — study of choice in the ED for suspected complications<ref>Meissnitzer MW, Stättner S, Gmeiner D, et al. Imaging features of marginal ulcers on multidetector CT. ''Clin Radiol''. 2023;78(2):e178-e185.</ref>
*** May show: wall thickening at the gastrojejunostomy, periananastomotic fat stranding, extraluminal air (perforation), extraluminal fluid, oral contrast leak
*** May show: wall thickening at the gastrojejunostomy, periananastomotic fat stranding, extraluminal air (perforation), extraluminal fluid, oral contrast leak
*** CT also evaluates for [[internal hernia]], [[small bowel obstruction]], and [[abscess]]
*** CT also evaluates for [[internal hernia]], [[small bowel obstruction]], and [[abscess]]
** Upright CXR or left lateral decubitus — may show free air under diaphragm if perforation
** Upright CXR or left lateral decubitus — may show free air under diaphragm if perforation
** '''UGI fluoroscopy with water-soluble contrast''' — can confirm contained perforation vs free leak
** UGI fluoroscopy with water-soluble contrast — can confirm contained perforation vs free leak
* '''EGD (esophagogastroduodenoscopy):'''
* EGD (esophagogastroduodenoscopy):
** Gold standard for diagnosis
** Gold standard for diagnosis
** Directly visualizes ulcer at or near gastrojejunostomy
** Directly visualizes ulcer at or near gastrojejunostomy
Line 84: Line 87:


===Medical management (uncomplicated)===
===Medical management (uncomplicated)===
* '''[[Proton pump inhibitor]] (PPI)''' — mainstay of treatment<ref>Pyke O, Yang J, Cohn T, et al. Marginal ulcer continues to be a major source of morbidity over time following gastric bypass. ''Surg Endosc''. 2019;33(10):3451-3456.</ref>
* [[Proton pump inhibitor]] (PPI) — mainstay of treatment<ref>Pyke O, Yang J, Cohn T, et al. Marginal ulcer continues to be a major source of morbidity over time following gastric bypass. ''Surg Endosc''. 2019;33(10):3451-3456.</ref>
** High-dose PPI (e.g., [[omeprazole]] 40 mg BID or [[pantoprazole]] 40 mg BID)
** High-dose PPI (e.g., [[omeprazole]] 40 mg BID or [[pantoprazole]] 40 mg BID)
** Duration: minimum 8-12 weeks; many patients require long-term or indefinite PPI
** Duration: minimum 8-12 weeks; many patients require long-term or indefinite PPI
* '''[[Sucralfate]]''' 1 g QID (mucosal protectant, adjunct to PPI)
* [[Sucralfate]] 1 g QID (mucosal protectant, adjunct to PPI)
* '''Risk factor modification:'''
* Risk factor modification:
** Smoking cessation (critical)
** Smoking cessation (critical)
** Discontinue [[NSAID|NSAIDs]], [[aspirin]] (if possible; discuss with prescribing physician)
** Discontinue [[NSAID|NSAIDs]], [[aspirin]] (if possible; discuss with prescribing physician)
Line 109: Line 112:
* NPO, IV fluid resuscitation, broad-spectrum [[antibiotics]]
* NPO, IV fluid resuscitation, broad-spectrum [[antibiotics]]
* IV PPI
* IV PPI
* '''Surgical options:'''<ref>Wendling MR, Linn JG, Keplinger KM, et al. Omental patch repair effectively treats perforated marginal ulcer following Roux-en-Y gastric bypass. ''Surg Endosc''. 2013;27(2):384-389.</ref>
* Surgical options:<ref>Wendling MR, Linn JG, Keplinger KM, et al. Omental patch repair effectively treats perforated marginal ulcer following Roux-en-Y gastric bypass. ''Surg Endosc''. 2013;27(2):384-389.</ref>
** Omental (Graham) patch repair — most common initial approach
** Omental (Graham) patch repair — most common initial approach
** Anastomotic revision with resection of ulcer bed
** Anastomotic revision with resection of ulcer bed
** Gastric bypass reversal (complex, reserved for refractory cases)
** Gastric bypass reversal (complex, reserved for refractory cases)
* Laparoscopic approach preferred if patient is hemodynamically stable and presents within 24 hours
* Laparoscopic approach preferred if patient is hemodynamically stable and presents within 24 hours
* '''Contained perforation''' in select hemodynamically stable patients with minimal symptoms may be considered for non-operative management with NPO, IV antibiotics, and IV PPI (emerging evidence)<ref>Pope R, English W, Walden RL, et al. Non-operative approach to contained perforated marginal ulcers: a systematic review and case series. ''Am Surg''. 2024;90(3):471-477.</ref>
* Contained perforation in select hemodynamically stable patients with minimal symptoms may be considered for non-operative management with NPO, IV antibiotics, and IV PPI (emerging evidence)<ref>Pope R, English W, Walden RL, et al. Non-operative approach to contained perforated marginal ulcers: a systematic review and case series. ''Am Surg''. 2024;90(3):471-477.</ref>


===Stricture===
===Stricture===
Line 122: Line 125:


==Disposition==
==Disposition==
* '''Admit''' if:
* Admit if:
** Signs of perforation or peritonitis → emergent surgical consultation
** Signs of perforation or peritonitis → emergent surgical consultation
** Hemodynamically significant [[GI bleeding]]
** Hemodynamically significant [[GI bleeding]]
Line 128: Line 131:
** Severe pain requiring IV analgesia
** Severe pain requiring IV analgesia
** Concern for sepsis or abscess
** Concern for sepsis or abscess
* '''Discharge''' may be appropriate if:
* Discharge may be appropriate if:
** Mild symptoms with stable vital signs
** Mild symptoms with stable vital signs
** Tolerating oral intake
** Tolerating oral intake
** Reliable follow-up arranged (PPI prescription, outpatient EGD referral, bariatric surgery follow-up)
** Reliable follow-up arranged (PPI prescription, outpatient EGD referral, bariatric surgery follow-up)
** Clear return precautions given: worsening pain, vomiting, bloody or tarry stools, fever, lightheadedness
** Clear return precautions given: worsening pain, vomiting, bloody or tarry stools, fever, lightheadedness
* '''Recurrence''' rate is high (~30% or more), especially if risk factors are not addressed<ref>Coblijn UK, Lagarde SM, de Castro SM, Kuiken SD, van Wagensveld BA. Symptomatic marginal ulcer disease after Roux-en-Y gastric bypass: incidence, risk factors and management. ''Obes Surg''. 2015;25(5):805-811.</ref>
* Recurrence rate is high (~30% or more), especially if risk factors are not addressed<ref>Coblijn UK, Lagarde SM, de Castro SM, Kuiken SD, van Wagensveld BA. Symptomatic marginal ulcer disease after Roux-en-Y gastric bypass: incidence, risk factors and management. ''Obes Surg''. 2015;25(5):805-811.</ref>
* Approximately 9% of patients ultimately require surgical revision despite medical therapy
* Approximately 9% of patients ultimately require surgical revision despite medical therapy
* Endoscopic surveillance is recommended given high recurrence rate
* Endoscopic surveillance is recommended given high recurrence rate

Latest revision as of 15:53, 19 March 2026

Background

  • Marginal ulcer (also called stomal ulcer or anastomotic ulcer) is a mucosal ulceration that develops at or near a surgical gastroenteric anastomosis, most commonly on the jejunal side of the gastrojejunostomy after Roux-en-Y gastric bypass (RYGB).[1]
  • It is the most common late complication of RYGB and may present to the emergency department with pain, GI bleeding, or perforation.


  • Incidence ranges from 0.6% to 25% following RYGB, with a mean prevalence of approximately 4.6%[2]
  • Typically presents a median of 1-2 years after surgery, but can occur from weeks to >10 years postoperatively
  • Ulcers are located on the anastomosis (~50%) or the jejunal mucosa (~40%)
  • Pathophysiology is multifactorial:
    • Acid exposure — jejunal mucosa lacks protective buffering mechanisms against gastric acid
    • Ischemia — tension on the anastomosis, compromised local blood supply
    • Large gastric pouch — greater parietal cell mass increases acid production[3]
    • Foreign body reaction — non-absorbable suture material or exposed staples at the anastomosis
    • Gastrogastric fistula — allows acid from the excluded gastric remnant to reach the pouch
  • Risk factors (by meta-analysis):[4]

Clinical Features

  • Epigastric or periumbilical pain (most common, ~63%)[5]
  • Nausea and vomiting
  • Reduced oral intake / early satiety
  • GI bleeding (~24%)
  • Dysphagia (if associated anastomotic stricture)
  • Complicated presentations:
    • Perforation — acute-onset severe abdominal pain, peritoneal signs, sepsis
      • May present with left shoulder pain (diaphragmatic irritation)
    • Hemorrhage — hemodynamic instability, hematemesis, hematochezia
    • Stricture — progressive dysphagia, vomiting, inability to tolerate oral intake
    • Gastrogastric fistula — chronic symptoms, weight regain
  • Up to 28% of patients may be asymptomatic (discovered incidentally on surveillance endoscopy)

Differential Diagnosis

Diffuse Abdominal pain

Evaluation

Workup

  • Labs:
    • CBC — anemia (chronic blood loss), leukocytosis (perforation/infection)
    • BMP — electrolyte abnormalities from vomiting or poor oral intake
    • Lipase — rule out pancreatitis
    • Lactate — if concern for perforation or ischemia
    • Type and screen — if GI bleeding
    • H. pylori testing (stool antigen or urea breath test preferred over serology post-bypass)
    • Iron studies — if chronic anemia
  • Imaging:
    • CT abdomen/pelvis with IV contrast — study of choice in the ED for suspected complications[6]
      • May show: wall thickening at the gastrojejunostomy, periananastomotic fat stranding, extraluminal air (perforation), extraluminal fluid, oral contrast leak
      • CT also evaluates for internal hernia, small bowel obstruction, and abscess
    • Upright CXR or left lateral decubitus — may show free air under diaphragm if perforation
    • UGI fluoroscopy with water-soluble contrast — can confirm contained perforation vs free leak
  • EGD (esophagogastroduodenoscopy):
    • Gold standard for diagnosis
    • Directly visualizes ulcer at or near gastrojejunostomy
    • Evaluates for exposed suture/staple material, gastrogastric fistula, stricture
    • Allows biopsy (rule out malignancy, test for H. pylori)
    • Enables therapeutic intervention (hemostasis, dilation)
    • May not be immediately available in the ED setting

Diagnosis

  • Suspect in any post-bariatric surgery patient presenting with epigastric pain, GI bleeding, or signs of perforation
  • Definitive diagnosis by EGD with direct visualization of ulcer at the gastrojejunal anastomosis
  • CT findings suggestive but not diagnostic; primarily used to identify complications (perforation, abscess, obstruction)
  • Visible suture material or staples at the ulcer base is a characteristic finding

Management

Medical management (uncomplicated)

  • Proton pump inhibitor (PPI) — mainstay of treatment[7]
    • High-dose PPI (e.g., omeprazole 40 mg BID or pantoprazole 40 mg BID)
    • Duration: minimum 8-12 weeks; many patients require long-term or indefinite PPI
  • Sucralfate 1 g QID (mucosal protectant, adjunct to PPI)
  • Risk factor modification:
    • Smoking cessation (critical)
    • Discontinue NSAIDs, aspirin (if possible; discuss with prescribing physician)
    • Limit alcohol
    • H. pylori eradication if positive[8]
    • Optimize glycemic control in diabetics
    • Discontinue or minimize corticosteroids
  • Endoscopic removal of exposed foreign material (sutures, staples) if identified

GI bleeding

  • Standard approach to Upper GI bleed
  • Aggressive resuscitation, blood transfusion as needed
  • IV PPI (e.g., pantoprazole 80 mg bolus then 8 mg/hr drip)
  • Urgent EGD for diagnosis and hemostasis (clips, epinephrine injection, thermal therapy)
  • Consult surgery if hemodynamically unstable or endoscopy fails to achieve hemostasis
  • See Upper GI bleed

Perforation

  • Surgical emergency in most cases
  • NPO, IV fluid resuscitation, broad-spectrum antibiotics
  • IV PPI
  • Surgical options:[9]
    • Omental (Graham) patch repair — most common initial approach
    • Anastomotic revision with resection of ulcer bed
    • Gastric bypass reversal (complex, reserved for refractory cases)
  • Laparoscopic approach preferred if patient is hemodynamically stable and presents within 24 hours
  • Contained perforation in select hemodynamically stable patients with minimal symptoms may be considered for non-operative management with NPO, IV antibiotics, and IV PPI (emerging evidence)[10]

Stricture

  • Endoscopic balloon dilation (may require serial dilations)
  • Continue PPI therapy
  • Surgical revision if refractory

Disposition

  • Admit if:
    • Signs of perforation or peritonitis → emergent surgical consultation
    • Hemodynamically significant GI bleeding
    • Inability to tolerate oral intake
    • Severe pain requiring IV analgesia
    • Concern for sepsis or abscess
  • Discharge may be appropriate if:
    • Mild symptoms with stable vital signs
    • Tolerating oral intake
    • Reliable follow-up arranged (PPI prescription, outpatient EGD referral, bariatric surgery follow-up)
    • Clear return precautions given: worsening pain, vomiting, bloody or tarry stools, fever, lightheadedness
  • Recurrence rate is high (~30% or more), especially if risk factors are not addressed[11]
  • Approximately 9% of patients ultimately require surgical revision despite medical therapy
  • Endoscopic surveillance is recommended given high recurrence rate

See Also

External Links

References

  1. Coblijn UK, Goucham AB, Lagarde SM, Kuiken SD, van Wagensveld BA.
    • Development of ulcer disease after Roux-en-Y gastric bypass, incidence, risk factors, and patient presentation: a systematic review. Obes Surg. 2014;24(2):299-309.
  2. Azagury DE, Abu Dayyeh BK, Greenwalt IT, Thompson CC. Marginal ulceration after Roux-en-Y gastric bypass surgery: characteristics, risk factors, treatment, and outcomes. Endoscopy. 2011;43(11):950-954.
  3. Edholm D, Ottosson J, Sundbom M. Importance of pouch size in laparoscopic Roux-en-Y gastric bypass: a cohort study of 14,168 patients. Surg Endosc. 2016;30(5):2011-2015.
  4. Liang Y, Wang C, Yang L, et al. Nonsurgical risk factors for marginal ulcer following Roux-en-Y gastric bypass for obesity: a systematic review and meta-analysis of 14 cohort studies. Int J Surg. 2024;110(3):1793-1799.
  5. Azagury DE, Abu Dayyeh BK, Greenwalt IT, Thompson CC. Marginal ulceration after Roux-en-Y gastric bypass surgery: characteristics, risk factors, treatment, and outcomes. Endoscopy. 2011;43(11):950-954.
  6. Meissnitzer MW, Stättner S, Gmeiner D, et al. Imaging features of marginal ulcers on multidetector CT. Clin Radiol. 2023;78(2):e178-e185.
  7. Pyke O, Yang J, Cohn T, et al. Marginal ulcer continues to be a major source of morbidity over time following gastric bypass. Surg Endosc. 2019;33(10):3451-3456.
  8. Schulman AR, Abougergi MS, Thompson CC. H. pylori as a predictor of marginal ulceration: a nationwide analysis. Obesity (Silver Spring). 2017;25(3):522-526.
  9. Wendling MR, Linn JG, Keplinger KM, et al. Omental patch repair effectively treats perforated marginal ulcer following Roux-en-Y gastric bypass. Surg Endosc. 2013;27(2):384-389.
  10. Pope R, English W, Walden RL, et al. Non-operative approach to contained perforated marginal ulcers: a systematic review and case series. Am Surg. 2024;90(3):471-477.
  11. Coblijn UK, Lagarde SM, de Castro SM, Kuiken SD, van Wagensveld BA. Symptomatic marginal ulcer disease after Roux-en-Y gastric bypass: incidence, risk factors and management. Obes Surg. 2015;25(5):805-811.