Abdominal Pain in the Roux-en-Y Gastric Bypass Patient

Transcription

1 THE RED SECTION 161 see related editorial on page x Abdominal Pain in the Roux-en-Y Gastric Bypass Patient A l lis on R. S chu lman, M D, M PH 1, 2 and C h r istophe r C. Thompson, MD, MSc, FASGE, FACG AGAF1, 2 Am J Gastroenterol 2018; 113: ; doi: /ajg ; published online 10 October 2017 INTRODUCTION Roux-en-Y gastric bypass (RYGB) is a common bariatric surgical procedure resulting in weight loss and resolution of comorbidities. It involves partitioning of the upper portion of the stomach to create a small gastric pouch, along with diversion of oral intake and biliopancreatic digestive enzymes to the distal small bowel, via creation of a Roux limb ( Figure 1 ). Abdominal pain is common in patients who have undergone RYGB, although existent literature is variably sparse. Numerous studies focus on s such as marginal ulceration, and fewer studies describe other causes ( 1,2 ). In a large retrospective study of 1,429 RYGB patients, over one-third presented with abdominal pain (3 ). This is likely an underestimate as this study was not performed in a closed setting, and oftentimes patients will be admitted to other hospitals or change health-care providers. A standard abdominal pain work-up evaluating potential etiologies unrelated to bariatric surgery should be pursued as appropriate, including but not limited to cardiovascular disease, pancreatitis, appendicitis, functional pain, splenic infarcts or abscesses, pulmonary processes, or vascular evaluation for what would be considered an atypical presentation. These and other rare causes of abdominal pain that are not unique to gastric bypass will not be addressed in this review. A surgery specific work-up should also be pursued, with attention to unique diagnostic strategies and treatment plans. With this in mind, patient history and physical examination are often essential in making a diagnosis, with prioritization of diagnostic studies depending on initial presenting symptoms. Symptoms may be suggestive of a particular diagnosis, but they are seldom pathognomonic. Below, we discuss the most common diagnoses tied to type and location of abdominal pain; however, there is no doubt that there is overlap between symptoms and other diagnoses. We also propose a suggested treatment algorithm ( Figure 2 ) and management strategy ( Table 1 ), although additional studies are underway to solidify the approach. Epigastric pain Ulceration at the gastrojejunal anastomosis, also known as marginal ulceration, is the most common cause of epigastric pain following RYGB ( Figure 3 ). Marginal ulceration occurs in up to 16% of patients, and can develop from weeks to years following surgery (1,2 ). The pain is often described as constant, gnawing, sometimes incapacitating, and may or may not be affected by meals. Additional symptoms, such as nausea, vomiting, lack of appetite, or gastrointestinal bleeding may also be present. Concomitant mid-epigastric pain and anemia strongly suggests the presence of a marginal ulceration, as chronic occult bleeding may cause anemia in as many as 10.2% of patients after RYGB ( 4 ). Physical exam often demonstrates tenderness to palpation in the epigastric region. Marginal ulcerations can be due to several factors. Acid production is important in the formation of marginal ulcerations. The gastric pouch produces a small amount of acid, with larger pouches producing more acid. The jejunum, unlike the duodenum, is susceptible to even small amounts of acid production, as the mucosa does not secrete bicarbonate, and it is not in proximity to bicarbonate-rich pancreatic secretions. Gastrogastric fistula ( Figure 4 ) allow larger amounts of acid to enter the pouch and jejunum from the gastric remnant, amplifying this effect. Another element in the pathophysiology of marginal ulcerations is tissue ischemia. This typically involves small vessel ischemia, such as seen with diabetes and tobacco use. Other contributory factors include inciting medication such as nonsteroidal anti-inflammatory drugs, Helicobacter pylori, and foreign material such as surgical suture. Upper endoscopy is important to diagnose, assess the severity of, and monitor healing of ulceration. Additionally, the diagnostic strategy for H. pylori is different from that in the non-bypass population. The preferred diagnostic studies include fecal antigen, off proton pump inhibitor (PPI) therapy for 2 weeks, and serology, if there is no history of exposure. In our experience, pouch biopsies (rapid urease or histology) and breath tests are less reliable in this patient population, as the majority of the stomach where H. pylori resides is inaccessible, and therefore can yield false-negative results. There are also some unique treatment considerations. PPIs are typically effective in the management of marginal ulcerations, and should be opened or prescribed in soluble form. Owing to rapid 1 Division of Gastroenterology, Hepatology and Endoscopy, Brigham and Women s Hospital, Boston, Massachusetts, USA ; 2 Harvard Medical School, Boston, Massachusetts, USA. Correspondence: Christopher C. Thompson, MD, MSc, FACG, FASGE, AGAF, Division of Gastroenterology, Hepatology and Endoscopy, Brigham and Women s Hospital, 75 Francis Street, ASB II, Boston, Massachusetts 02115, USA. cthompson@hms.harvard.edu 2018 by the American College of Gastroenterology The American Journal of GASTROENTEROLOGY

2 162 THE RED SECTION Roux-en-Y gastric bypass (RYGB) Figure 1. Roux-en-Y gastric bypass anatomy. With permission from P. Jirapinyo and C.C. Thompson. Endoscopic bariatric and metabolic therapy: surgical analogues and mechanisms of action. Clin Gastroenterol Hepatol 2016 Oct 28 (Epub ahead of print); PMID: gastrointestinal transit time after RYGB, this method of administration allows enhanced absorption in the Roux limb and common channel, and significantly decreases time to ulcer healing ( 5 ). Additionally, contributory factors should be addressed including tobacco use, poorly controlled diabetes, and inciting medication use including NSAIDs. Endoscopic removal of foreign material at the gastrojejunal anastomosis is also important ( 6 ). Retained foreign material such as suture not only predisposes patients to marginal ulceration but also can be a cause of epigastric pain in RYGB patients, even in the absence of ulceration. Studies have shown that some patients with visible suture have resolution of pain following endoscopic removal. Furthermore, these patients reported worsening of pain during endoscopic manipulation of suture material while under light sedation. As such, excess suture material should be removed endoscopically when identified with the use of endoscopic scissors, provided the surgery was at least 6 weeks prior ( 6 ). Premature breakdown of staple lines or suture loss can lead to gastrogastric fistula ( Figure 4 ). Gastrogastric fistula can also lead to epigastric pain, which may be accompanied by symptoms of reflux and borborygmi ( 7 ). Oftentimes, gastrogastric fistula can be medically managed with PPI; however, it may warrant closure or surgical revision if symptomatic. Right upper quadrant pain Right upper quadrant pain, particularly within the first 24 months following bariatric surgery, warrants investigation of gallstone disease. The highest risk period for development of this disorder is during the rapid weight loss phase, and decreases to a minimum once the weight has stabilized ( 8 ). Aside from rapid weight loss, postoperative anatomic changes and compromised gallbladder emptying may also play a role in its development. Pain that prolongs beyond 6h may favor choledocholithiasis over biliary colic, and fevers or leukocytosis raise concern for cholangitis. Physical exam demonstrates pain in the right upper quadrant or epigastric region. Elevated bilirubin, alkaline phosphatase, and GGT are all independent predictors of choledocholithiasis. Abdominal ultrasound or magnetic resonance cholangiopancreatography should be performed as a first-line test to evaluate for these s. Endoscopic retrograde cholangiopancreatography is particularly challenging in RYGB anatomy, and oftentimes requires a pediatric colonoscope, spiral overtube, balloon-assisted enteroscope, or a duodenoscope back-loaded onto a guidewire. Additionally, endoscopic ultrasound (EUS)-guided access ( Figure 5 ) and laparoscopic-assisted procedures may have advantages over these techniques ( 9,10 ). Choice of procedure is dependent on local expertise and severity of illness, with acutely ill patients likely benefitting from a percutaneous approach. Patients who are <6 weeks out from surgery should not undergo deep enteroscopy, as the staple lines are vulnerable. Also, if repeat procedures are needed, access through a gastrostomy tube could be preferable. A much less common cause of severe life-threatening right upper quadrant pain following RYGB is non-alcoholic steatohepatitis due to rapid weight loss. Rapid weight loss has been reported to induce hepatic inflammation and exacerbate steatohepatitis; however, the pathophysiology remains poorly understood and pathologic features have not been well characterized ( 11 ). L e ft upper quadrant pain Patients who describe pain that is intermittent, positional, or severe left upper quadrant pain should undergo cross-sectional imaging to evaluate for potential intestinal obstruction such as internal hernia ( Figure 6a ) and intussusception ( Figure 6b ). While the majority of patients with intestinal obstruction following RYGB report pain in the left upper quadrant, other locations are not uncommon ( 12 ). Imaging should ideally be performed when the patient is symptomatic, which increases the sensitivity of detection. The overall incidence ranges widely and depends on the etiology of obstruction. It is often dependent on surgical factors including but not limited to type of surgery performed (open vs. laparoscopic) and orientation of the Roux limb (antecolic vs. retrocolic). Common locations, incidence, imaging findings, and other interesting features are shown in Table 2. Furthermore, owing to the potentially catastrophic risk of a missed diagnosis, surgical exploration remains common in patients with high clinical suspicion of intestinal obstruction. Endoscopy plays little role in management of these s. In patients who report dull, aching pain that is predominantly in the left upper quadrant, s of the remnant stomach should The American Journal of GASTROENTEROLOGY VOLUME 113 FEBRUARY

3 THE RED SECTION 163 Epigastric pain + Abdominal pain in RYGB* + Crosssectional imaging RUQ pain RUQ u/s or MRCP Physical exam LUQ pain Mild to moderate, constant Severe, intermittent Other presentations It is important to keep in mind that the pain location is not without variation for the above s, and quality of pain must be taken into consideration. For instance, severe intermittent abdominal pain typical of small bowel obstruction occurring in a location other than the left upper quadrant still warrants urgent evaluation for obstructive processes. Additionally, pain referred from other locations such as back and kidneys must also be considered. Crosssectional imaging Carnett s sign + Diffuse pain Mild to moderate Breath test with transit time Site-specific work-up Pain referral severe Crosssectional imaging If unresponsive to therapy Evaluate remnant vs. empiric ursodiol + + *Exclude non-gi causes as appropriate Figure 2. Proposed treatment algorithm for abdominal pain in Roux-en-Y gastric bypass. be considered. This is critical in patients who also have unexplained anemia, as adenocarcinoma, mucosa-associated lymphoid tissue, and peptic ulceration have been described in the remnant stomach. A more common that presents with this type of pain is remnant gastropathy, which is likely due to mucosal atrophy owing to the lack of nutrient contact with the gastric mucosa and a chemical irritation due to pooling of bile. Additionally, acid production continues in the remnant stomach without the buffering effects of food. Finally, the pooling of bile due to the proximity of the papilla to the remnant, in addition to a lack of antegrade flow, all contribute to mucosal damage and resultant abdominal pain. Device-assisted enteroscopy with biopsy can be used to make the diagnosis; however, this procedure is technically demanding, invasive, and only performed in a limited number of centers. Cholescintigraphy (99mTc-heapto-iminodiacetic acid scanning), for patients without anemia, may be a less invasive means of identifying patients at risk for remnant gastropathy. 99mTc-heapto-iminodiacetic acid scans allow for a radiolabeled substance to be taken up selectively by hepatocytes and excreted into bile, thereby yielding information about bile flow. Pooling of bile in the remnant stomach yields a positive test and may suggest increase risk for bile acid gastropathy ( 13 ). If this is suspected, treatment with ursodeoxycholic acid, a secondary bile acid, should be considered. This medication alters the composition of bile, halting the caustic damage and allowing the mucosa to heal. Elimination of symptoms and resolution of gastropathy on repeat histologic examination have been demonstrated in small series ( 14 ). D iff use discomfort Small intestinal bacterial overgrowth is a in which bacteria proliferate in the intestine resulting in excessive inflammation, or malabsorption, and may cause diffuse or lower abdominal discomfort. Abdominal bloating and change in bowel habits often accompany these symptoms, and should raise suspicion for this. In fact, change in bowel habits and abdominal distention may be the only symptoms. Hydrogen or methane breath tests are the diagnostic standard. These studies may be fraught with false positives, as there is also faster transit time in RYGB patients. As such, transit time to the colon should be estimated by small bowel follow through, and duration of breath test should be adjusted to this transit time ( 15 ). The mainstay of treatment includes antibiotic therapy, in addition to dietary changes and management of underlying causes by the American College of Gastroenterology The American Journal of GASTROENTEROLOGY

4 164 THE RED SECTION Table 1. Common diagnoses and proposed management strategy for abdominal pain in Roux-en-Y gastric bypass Diagnosis Marginal ulceration Foreign body Gastrogastric fi stula Choledocholithiasis Non-alcoholic steatohepatitis Intestinal obstruction (volvulus, internal hernia, intussusception) Remnant gastropathy SIBO Abdominal wall pain Addiction ment High dose PPI (soluble form)±sucralfate Stop smoking No NSAIDs H. pylori stool antigen or serology Foreign body removal using endoscopic scissors Endoscopic scissors to facilitate removal If asymptomatic: PPI+dietary counseling If symptomatic: closure (endoscopic (<1 cm) vs. surgical) Device-assisted enteroscopy Laparoscopic-assisted ERCP EUS directed ERCP Percutaneous drainge Cholecystectomy Management of acute liver failure including but not limited to hemodynamic support and laboratory testing, infection surveillance and prevention, early enteral feeding, management of encephalopathy, consideration of liver transplant Surgery Endoscopy is not indicated for extraluminal causes of obstruction High dose PPI (soluble form) Ursodiol 500 1,000 mg b.i.d. Confi rm positive test by comparing it to small bowel transit time Two weeks of antibiotics (Rifaximin 500 mg t.i.d.) Dietary changes ment of underlying Trigger point injection Neuroma resection Refer to specialist for counseling ERCP, endoscopic retrograde cholangiopancreatography; EUS, endoscopic ultrasound; NSAID, nonsteroidal anti-inflammatory drug; PPI, proton pump inhibitor; SIBO, small intestinal bacterial overgrowth. Figure 3. Marginal ulceration at the gastrojejunal anastomosis. Figure 4. Gastrogastric fi stula in the pouch of a gastric bypass patient. A common masquerader of all of the above s is abdominal wall pain. This can occur in any location, and often at previously placed trochar sites or at the site of previous incision. As such, evaluation for a Carnett s sign very important in gastric bypass patients. Carnett s sign is elicited by having the patient lie flat on an examination table, and identify the point of maximal abdominal tenderness. This location is then focally compressed with continuous pressure while the patient raises their shoulders or off the examination table, tensing abdominal musculature. If Figure 5. Endoscopic ultrasound (EUS)-guided placement of a lumen apposing metal stent (LAMS) (arrow) to facilitate endoscopic retrograde cholangiopancreatography (ERCP) in a patient with Roux-en-Y gastric bypass anatomy. the focal pain intensifies, this is a positive sign suggesting an abdominal wall syndrome. The most common treatment for abdominal wall pain is trigger point injection, whereby a local The American Journal of GASTROENTEROLOGY VOLUME 113 FEBRUARY

5 THE RED SECTION 165 a b Figure 6. Examples of radiographic fi ndings in patients with intestinal obstruction. Computed tomography demonstrating swirled appearance of mesenteric vessels due to internal hernia ( a ) and target sign due to intussusception ( b ). Table 2. Small bowel obstruction in Roux-en-Y gastric bypass Etiology of obstruction Common locations Overall incidence (%) Imaging findings Other features Adhesions Internal hernia ( Figure 7 ) Ventral incisional hernia Can occur anywhere, often near jejunojejunal anastomosis Defect in transverse mesocolon (67%) Defect at the jejunojejunostomy (21%) Space between transverse mesocolon and Roux limb (Peterson s hernia) (7.5%) Other (4.5%) Laparotomy site Trochar site Abrupt change in bowel caliber without evidence of other causes of obstruction Acute angulation of small bowel loops Asymmetric thickening of small bowel wall 3 16 Swirl sign : swirled appearance and twisting of bowel and mesenteric vessels (Sn: %; Sp: 80 90%) Clustered loops : abnormally clustered otherwise normal appearing loops of small bowel (Sn: 22 33%; Sp: 70 90%) Small-bowel obstruction (Sn: 11 22%; Sp: 11 80%) Mushroom sign : A mushroom shape to the herniated mesenteric root with associated crowding and/ or stretching of the mesenteric vessels (Sn: 0 56%; Sp:100%) Hurricane eye : tubular distal mesenteric fat surrounded by bowel SMA sign : bowel other than duodenum posterior to the superior mesenteric artery Right-sided location of the distal jejunojejunal anastomosis (i.e., right-sided anastomosis) Defect in the abdominal wall External protrusion of bowel loops through defect Dilation of the bowel loops within the hernia Normal/collapsed bowel distal to obstruction Open>laparoscopic Retrocolic>antecolic Bimodal distribution (<2 weeks, >1 year) Laparoscopic>open Retrocolic>antecolic Increased in pregnancy 2 3 years following RYGB Open>laparoscopic Incision length/trochar size Morbid obesity-->increased intraabdominal pressure-->increased risk Volvulus Mesenteric root <1 Swirl sign Days weeks postop Intussusception Stenosis of the jejunojejunostomy Jejunojejunal anastomosis, where the common limb telescopes through the anastomosis Target sign (bowel within bowel and presence of fat density within) Dilated excluded stomach Bowel wall thickening Abnormally reduced or increased bowel wall enhancement Delayed bowel wall enhancement Increased attenuation of the mesentery due to fluid and hemorrhage Pneumatosis intestinalis Mesenteric or portal venous gas Jejunojejunostomy 0.5 Dilated and fl uid-fi lled excluded stomach and biliopancreatic limb to the level of jejunojejunal anastomosis Normal caliber Roux limb Normal/collapsed common channel RYGB, Roux-en-Y gastric bypass; Sn, sensitivity; Sp, specifi city. Distal to proximal telescopic invagination most common) Incidence increases after weight loss Suture line may act as lead point Disordered motility may alter peristalsis Accumulation of intraluminal fluid in excluded segment may force telescopic invagination Months to years following RYGB Days weeks postop Surgical technique 2018 by the American College of Gastroenterology The American Journal of GASTROENTEROLOGY

6 166 THE RED SECTION the work-up strategy, and a thorough understanding of the diagnostic modalities is requisite to optimal care. CONFLICT OF INTEREST Guarantor of the article: Christopher C. Thompson, MD, MSc, FASGE, FACG AGAF. Specific author contributions: Allison R. Schulman drafting of the manuscript; this author has approved the final draft submitted. Christopher C. Thompson editing of the manuscript; this author has approved the final draft submitted. Financial support: None. Potential competing interests: A. Schulman has no personal or financial conflicts of interest to disclose. C.C. Thompson Apollo Endosurgery (Consultant/Research Support); Olympus (Consultant/ Research Support); Boston Scientific (Consultant); Covidien (Consultant, Royalty, Stock). Figure 7. Three potential sites for internal hernia location following Roux-en- Y gastric bypass including the defect in the transverse mesocolon through which the Roux limb passes (white arrow), through the mesenteric defect at the jejunojejunostomy (black arrow) and the space between the transverse mesocolon and the Roux limb known as Peterson s hernia (gray arrow). anesthetic is injected directly into the site of pain, or neuroma resection. A growing number of studies have provided information regarding the frequency of addiction and alcohol consumption, and possible changes in the effects of consuming alcohol following bariatric surgery. Narcotic bowel, withdrawal, and drugseeking behavior can all mimic the above symptomatology. These issues should be included in a detailed patient history. CONCLUSION Abdominal pain is extremely common in patients who have undergone RYGB, and the evaluation has several unique features that should not be overlooked. As gastroenterologists encounter these patients with ever increasing frequency, it is important that we familiarize ourselves with the surgical anatomy and likely complications. Pain quality and location are helpful in directing REFERENCES 1. Coblijn UK, Lagarde SM, de Castro SMM et al. Symptomatic marginal ulcer disease after Roux-en-Y gastric bypass: incidence, risk factors and management. Obes Surg 2015 ;25 : A z ag u r y DE, Abu D ay yeh BK, Gre e nw a lt I T et al. Marginal ulceration after Roux-en-Y gastric bypass surgery: characteristics, risk factors, treatment, and outcomes. Endoscopy 2011 ;43 : Høgestøl IK, Chahal-Kummen M, Eribe I et al. Chronic abdominal pain and symptoms 5 years after gastric bypass for morbid obesity. Obes Surg 2016 ;27 : Avgerinos DV, Llaguna OH, Seigerman M et al. Incidence and risk factors for the development of anemia following gastric bypass surgery. World J Gastroenterol 2010 ;16 : S chu l man A R, C han W W, D e ve r y A et al. Opened proton pump inhibitor capsules reduce time to healing compared with intact capsules for marginal ulceration following Roux-en-Y gastric bypass. Clin Gastroenterol Hepatol 2016 ;15 : e1. 6. Ryou M, Mo g ab g ab O, L aut z DB et al. Endoscopic foreign body removal for treatment of chronic abdominal pain in patients after Roux-en-Y gastric bypass. Surg Obes Relat Dis 2010 ; 6 : Pauli EM, Beshir H, Mathew A. Gastrogastric fistulae following gastric bypass surgery clinical recognition and treatment. Curr Gastroenterol Rep 2014 ; 16 : Karadeniz M, Gorgun M, Kara C. The evaluation of gallstone formation in patients undergoing Roux-en-Y gastric bypass due to morbid obesity. Turkish J Surg 2014 ;30 : Thomp s on C C, Ryou M K, Ku mar N et al. Single-session EUS-guided transgastric ERCP in the gastric bypass patient. Gastrointest Endosc 2014 ;80 : Kedia P, Kumta N, Widmer J et al. Endoscopic ultrasound-directed transgastric ERCP (EDGE) for Roux-en-Y anatomy: a novel technique. Endoscopy 2015 ;47 : Tsai J-H, Ferrell LD, Tan V et al. Aggressive non-alcoholic steatohepatitis following rapid weight loss and/or malnutrition. Mod Pathol 2017 ;30 : Elms L, Moon RC, Varnadore S et al. Causes of small bowel obstruction after Roux-en-Y gastric bypass: a review of 2,395 cases at a single institution. Surg Endosc 2014 ;28 : Schulman AR, Thompson CC. Utility of bile acid scintigraphy in the diagnosis of remnant gastritis in patients with Roux-en-Y gastric bypass. Gastrointest Endosc 2016 ;83 :AB Kumar N, Thompson CC. Ursodiol is effective for treatment of abdominal pain associated with gastritis of the remnant stomach in Roux-en-Y gastric bypass patients. Gastroenterology 2013 ; 144 : S Abidi W, Chan WW, Thompson CC. Breath testing for small intestinal bacterial overgrowth in Roux-en-Y gastric bypass patients: the importance of orocecal transit time. Gastroenterology 2016 ; 150 : S The American Journal of GASTROENTEROLOGY VOLUME 113 FEBRUARY

7 GASTROENTEROLOGY ARTICLE OF THE WEEK April 26, 2018 Schulman AR, Thompson CC. Abdominal pain in the Roux-en-Y gastric bypass patient. Am J Gastroenterol 2018;113: True statements regarding marginal ulcerations include a. Do not respond to PPI b. Tissue ischemia may be a contributing factor c. Bile salt injury plays an important role d. Gastrogastric fistula may be a possible cause True or False 2. Bypass surgery reduces risk of cholelithiasis as patients lose weight. 3. Remnant gastropathy can be a cause of LUQ pain, treatment with ursodeoxycholic acid may help 4. The most common cause of epigastric pain after bypass surgery is marginal ulceration 5. Left upper quadrant pain should raise suspicion for an internal hernia, endoscopy is the diagnostic test of choice 6. Visible suture material at the anastomotic site is normal and does not contribute to pain. 7. H. pylori infection of the gastric pouch is best diagnosed by stool antigen tests and not only gastric pouch biopsies 8. PPI therapy for marginal ulceration should be given as soluble forms or sprinkled on foods