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Utility of barium studies for patients with recurrent weight gain after Roux-en-Y gastric bypass
Clinical Radiology 70 (2015) 67e73
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Utility of barium studies for patients with recurrent weight gain after Roux-en-Y gastric bypass B. Wang a, M.S. Levine a, *, S.E. Rubesin a, N.N. Williams b, K. Dumon b, S. Raper b a b
Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA
art icl e i nformat ion Article history: Received 17 July 2014 Received in revised form 20 September 2014 Accepted 24 September 2014
AIM: To determine the utility of barium studies for detecting abnormalities responsible for recurrent weight gain after gastric bypass surgery. METHODS: A computerized search identified 42 patients who had undergone barium studies for recurrent weight gain after gastric bypass and 42 controls. The images were reviewed to determine the frequency of staple-line breakdown and measure the length/width of the pouch and gastrojejunal anastomosis. A large pouch exceeded 6 cm in length or 5 cm in width and a wide anastomosis exceeded 2 cm. Records were reviewed for the amount of recurrent weight gain and subsequent weight loss after additional treatment. RESULTS: Staple-line breakdown was present in 6/42 patients (14%) with recurrent weight gain. When measurements were obtained, 13/35 patients (37%) with recurrent weight gain had a large pouch, three (9%) had a wide anastomosis, and four (11%) had both, whereas 22/42 controls (52%) had a large pouch, one (2%) had a wide anastomosis, and two (5%) had both. Ten patients (24%) with recurrent weight gain underwent staple-line repair (n ¼ 3) or pouch/ anastomosis revision (n ¼ 7). These 10 patients had a mean weight loss of 38.1 lbs versus a mean loss of 8.6 lbs in 19 patients managed medically. CONCLUSION: Only 14% of patients with recurrent weight gain after gastric bypass had staple-line breakdown, whereas 57% had a large pouch, wide anastomosis, or both. Not all patients with abnormal anatomy had recurrent weight gain, but those who did were more likely to benefit from surgical intervention than from medical management. Ó 2014 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.
Introduction Roux-en-Y gastric bypass (RYGB) has become the most popular form of bariatric surgery, accounting for 65% of all
* Guarantor and correspondent: M.S. Levine, Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA. Tel.: þ1 215 662 6908; fax: þ1 215 662 7263. E-mail address: [email protected] (M.S. Levine).
weight-loss procedures performed worldwide.1 Weight loss in RYGB is caused by a restrictive effect from the creation of a small gastric pouch and, to a lesser degree, by a malabsorptive effect from surgical bypass of part of the jejunum.2 RYGB is an effective procedure for treatment of obesity, resulting in mean excess body weight loss of 62%3 and resolution of concomitant diabetes in 84% of patients.4 Nevertheless, this procedure is associated with serious complications, including perforation, anastomotic and jejunal ulcers and strictures, adhesions, internal
http://dx.doi.org/10.1016/j.crad.2014.09.018 0009-9260/Ó 2014 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.
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hernias, and small bowel obstruction.5 Barium studies and CT are valuable imaging tests for detecting these complications.6e9 Another long-term problem after RYGB is recurrent weight gain, which has been reported in 20e50% of patients who undergo this form of surgery.10e13 In one study, the average amount of recurrent weight gain after RYGB was 19.4 lbs.11 Recurrent weight gain in these patients has been attributed to a variety of factors, including dietary habits, socioeconomic status, and psychiatric illness.14e16 Recurrent weight gain also results from anatomical disruption of the gastric staple line, producing a gastrogastric fistula (GGF) that eliminates the restrictive effect of the pouch.17e19 When this complication is detected at endoscopy or upper gastrointestinal (GI) barium studies, the fistula can be repaired surgically to induce further weight loss.17,18 Enlargement of the pouch and widening of the gastrojejunal anastomosis (GJA) are other surgically correctible anatomical abnormalities that cause recurrent weight gain after RYGB.20e22 In some patients with a wide GJA, endoscopic administration of sodium morrhuate to the anastomotic region can shrink the anastomosis and restore the restrictive effect of the pouch, leading to renewed weight loss without need for additional surgery.23 Although upper GI barium studies are often performed to assess the integrity of the gastric staple line in patients with recurrent weight gain after RYGB, the role of this imaging test for detecting not only a GGF but also a large gastric pouch or wide GJA as potential causes of recurrent weight gain has not been adequately addressed in the radiology literature. The purpose of the present investigation, therefore, was to determine the utility of barium studies for detecting various anatomical abnormalities (including a GGF, large gastric pouch, and wide GJA) associated with recurrent weight gain after RYGB, and the implications for patient management.
Materials and methods Institutional review board approval The institutional review board approved all aspects of this retrospective study and did not require informed consent from any patients whose radiographic images or medical records were included in the study. This investigation was also compliant with the Health Insurance Portability and Accountability Act (HIPAA).
Patient population A computerized search of the radiology database identified all upper GI barium studies performed on patients for recurrent weight gain after RYGB during a 7 year period from January 2006 to December 2012. The latter date was used to allow time for adequate clinical follow-up. Patients were included in the study group if surgical records confirmed that RYGB had been performed and if medical records provided adequate clinical information about recurrent weight gain. Using these inclusion criteria, the
study group consisted of 42 patients who underwent upper GI barium studies for recurrent weight gain after RYGB. A separate search of the radiology database was performed to generate a control group of 42 patients in whom upper GI barium studies had been obtained after RYGB for reasons other than recurrent weight gain during the same time period. Patients were selected for the control group on a random basis and were included only if surgical records confirmed that RYGB has been performed; if medical records confirmed that these patients did not have recurrent weight gain; and if these patients did not have GGFs, leaks, ulcers, or strictures at the GJA that could affect anastomotic width or gastric pouch size. Computerized medical records were reviewed by one author to determine baseline demographic information (including age and gender) and body mass index (BMI) for the study and control groups before RYGB, as well as the percentage of excess body weight loss at the time of the patient’s lowest recorded weight after RYGB, and the BMI and percentage of excess body weight loss at the time of the barium examination for the study and control groups.
Examination technique All 85 patients in the study and control groups underwent single-contrast upper GI barium examinations, using a 50% (w/v) low-density barium suspension. All of the radiographic examinations were performed with digital fluoroscopic equipment (Sireskop SD; Siemens, Munich, Germany). All of the barium studies were performed by or under the direct supervision of one of three experienced attending GI radiologists and all were interpreted by the attending radiologists. The post-surgical anatomy was assessed on barium studies by following the head of the barium column at fluoroscopy as it passed from the oesophagus into the gastric pouch and then from the pouch into the Roux limb via the GJA. This technique enabled detection of staple-line breakdown with the development of a GGF, characterized by passage of barium from the gastric pouch across the disrupted portion of the staple line into the excluded stomach. Early fluoroscopic evaluation of the staple line was essential, as barium can occasionally reflux into the excluded stomach via the biliopancreatic limb later in the examination, erroneously suggesting staple-line breakdown. In patients with an anteriorly located GJA, steep oblique or even lateral views were required to prevent overlap between the gastric pouch and jejunum and visualize the GJA in profile.
Image interpretation All 84 barium examinations in the study (n ¼ 42) and control (n ¼ 42) groups were randomly interspersed and reviewed in a blinded fashion in consensus by two experienced GI attending radiologists who had no knowledge of the indications for the barium studies or subsequent patient management. In all patients, the dimensions (i.e., length and width) of the gastric pouch and diameter of the GJA
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were measured in centimetres. All measurements were obtained on images in which the gastric pouch and GJA were maximally distended. The volume of the gastric pouch was also determined by multiplying pouch width times pouch length in centimetres squared. In 54 (64%) of the 84 patients, the fluoroscopist obtained a single spot image of a 12.5 mm barium tablet placed alongside the patient at the same field of view as a reference standard to correct for radiographic magnification. In the remaining 30 patients (36%), the L4 vertebral body height (L4VBH) was used as an alternate reference standard to correct for magnification on the images. This reference standard was established by measuring the L4VBH in patients in whom a barium tablet had been employed. When the known diameter of the barium tablet was used to correct for radiographic magnification, the mean L4VBH was 2.5 cm. This figure is comparable to the mean L4VBH of 2.7 cm in an earlier study in which radiographic magnification of the L4 vertebral body was determined for normal adults.24 Thus, for the purposes of the present study, an L4VBH of 2.5 cm was used as the reference standard to correct for radiographic magnification in the 30 patients in whom a barium tablet had not been employed. The degree of magnification can also be affected by the height of the fluoroscopy tower above the table, but comparison of the images from individual studies showed no gross differences in the size of the visualized lumbar vertebral bodies. Thus, the position of the fluoroscopy tower did not appear to be a major factor in the degree of magnification for the patient cohort. For the purposes of the study, a large gastric pouch was defined as a pouch exceeding 6 cm in length or 5 cm in width, and a wide GJA was defined as an anastomosis with a diameter greater than 2 cm. These threshold numbers have been used in previous studies as parameters for a large gastric pouch or wide GJA.21,22,25 A control patient with a normal-sized gastric pouch and GJA is illustrated in Fig 1. All of the barium studies were also reviewed for the presence or absence of gastric staple-line breakdown and the development of a GGF. The six patients with a GGF were excluded from analysis of pouch size and GJA diameter, as the GGF was presumed to be responsible for recurrent weight gain in these patients. Moreover, decompression of the gastric pouch in patients with a fistula made evaluation of pouch size and GJA diameter unreliable because of difficulty distending the pouch. One patient with recurrent weight gain had an anastomotic ulcer, and this patient was also excluded from analysis of pouch size and GJA diameter, as oedema and spasm at the anastomosis likely affected the anastomotic calibre in this patient.
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Figure 1 A 45-year-old woman without recurrent weight gain after RYGB (i.e., control patient). Frontal spot image from a single-contrast upper GI barium study shows a normal-sized GJA (arrows) with a diameter of 1 cm and a normal-sized gastric pouch with a length of 4 cm and width of 2 cm.
staple line in three patients with a GGF and revision of the pouch/anastomosis in seven, including five with a large gastric pouch and/or wide GJA and two with a normal-sized pouch and normal-calibre GJA but a short Roux limb. Revision of the pouch/anastomosis was performed using a surgical stapler to create a smaller pouch with a volume of about 20 ml or a smaller GJA with a width of 1 cm or less. Adequate clinical follow-up (i.e., the final weight of the patients at their last physician visit after treatment) was available for all 10 patients who underwent surgery and for 19 (59%) of 32 who underwent medical weight-loss programmes. Based on a study by Magro et al.,11 successful weight loss was defined as greater than 20 lb at the time of the last physician visit after surgery or medical weight-loss programmes. Medical records were reviewed to determine the percentage of excess body weight loss at the time of the barium study versus the time of the last physician visit after repeat surgical intervention or additional medical weight-loss programmes. The mean length of clinical follow-up was 1.4 years (range 0.4e3.1 years) years for patients who underwent surgery and 1.4 years (range 0.1e5.2 years) for patients who underwent medical weight-loss programmes.
Statistical analysis Surgical revision and follow-up A review of medical records revealed that 10 (24%) of 42 patients with recurrent weight gain after RYGB underwent surgical intervention and the remaining 32 (76%) underwent medical weight-loss programmes. Surgery consisted of an open laparotomy with repair of a disrupted gastric
The data were analysed using Microsoft Excel 2007. Baseline characteristics were compared using Student’s ttest (Table 1). Student’s t-test was used to compare mean values for pouch length, width, and volume and GJA diameter for the study and control groups (Table 2). Differences in the frequency of anatomic abnormalities after
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RYGB (including staple-line breakdown, a large gastric pouch, and a wide GJA) were also compared for the study and control groups, using Fisher’s exact test on 2 2 contingency tables of the variables of interest. Finally, Fisher’s exact test and Student’s t-test were used to compare differences in the final weight loss status and percentage of EWL, respectively, at the time of the barium studies and at the time of the last physician visit. A p-value less than 0.05 was considered to be statistically significant.
Results
Table 2 Comparison of pouch size (including length, width, and volume) and gastrojejunal anastomotic diameter in patients with recurrent weight gain after Roux-en-Y gastric bypass (n ¼ 35) versus control patients (n ¼ 42).a Rec Wt Gain Pouch width, cm Pouch length, cm Pouch volume, cm2 GJA diameter, cm
3.2 6.0 20.1 1.4
1.2 1.8 11.2 0.7
Controls 3.0 6.5 21.4 1.2
1.2 2.6 15.3 0.5
p-Value 0.203 0.171 0.336 0.149
Rec Wt Gain, recurrent weight gain; GJA, gastrojejunal anastomosis. a Seven patients in the group with recurrent weight gain were excluded because of gastrogastric fistulas (n ¼ 6) or an anastomotic ulcer (n ¼ 1).
the disrupted portion of the staple line into the excluded stomach (Fig 2).
Patient characteristics and clinical presentation The study group consisted of seven men (17%) and 35 women (83%), with a mean age of 48 years (range 26e70 years), whereas the control group consisted of 10 men (23%) and 32 women (77%), with a mean age of 45.8 years (range 28e71 years). The mean amount of recurrent weight gain in the study group was 61.9 lbs (range 8e220 lbs). As shown in Table 1, the mean age, male-to-female ratio, pre-RYGB body mass index (BMI), and initial weight loss after RYGB were comparable for patients with and without recurrent weight gain. Patients with recurrent weight gain had a significantly longer mean duration from the time of RYGB to the time of the barium study than patients in the control group (6.2 versus 3.8 years; p ¼ 0.0013). While patients in the study group all underwent barium studies for recurrent weight gain, the indications for barium studies in the control group included abdominal pain in 27 patients, reflux symptoms in four, iron-deficiency anaemia in three, nausea in two, dysphagia in two, and other clinical signs or symptoms in the remaining four.
Findings on upper GI barium studies
Gastric pouch size and GJA diameter Mean gastric pouch size (including length, width, and volume) and GJA diameter for 35 patients with recurrent weight gain after RYGB and 42 control patients are summarized in Table 2. [Seven patients with recurrent weight gain were excluded from this part of the analysis because of GGFs (n ¼ 6) or anastomotic ulcers (n ¼ 1).] Twenty (57%) of 35 patients with recurrent weight gain after RYGB had a large gastric pouch and/or wide GJA on barium studies (Figs 3 and 4) versus 25 (59%) of 42 control patients (p ¼ 1.00; Fig. 5), so the two groups had a comparable frequency of large gastric pouches and wide GJAs on barium studies (Table 3).
Surgical versus medical intervention and final weight status Ten (24%) of the 42 patients with recurrent weight gain after RYGB underwent surgical intervention. The surgery consisted of repair of the gastric staple line in three patients with a GGF and revision of the gastric pouch/GJA in the
Gastrogastric fistulas Breakdown of the gastric staple line and associated GGFs were present in six (14%) of 42 patients with recurrent weight gain after RYGB. In all six patients, the GGFs were characterized by focal breakdown of the staple line, with passage of ingested barium from the gastric pouch across Table 1 Summary of patient characteristics in 42 patients with recurrent weight gain after Roux-en-Y gastric bypass versus 42 control patients. Variable
Rec Wt Gain
Age, years Male, % Female, % BMI before RYGB % EWLa BMI at UGI % EWL at UGI Time to UGI
48.0 17 83 53.2 59.6% 43.8 30.4% 6.2 yrs
9.8
11.6 20.2 10.8 18.7 3.0
Controls 45.6 21 79 54.1 57.8% 35.5 57.8% 3.8 yrs
p-Value
10.6
11.1 17.7 7.2 17.7 3.0
0.275
0.729 0.676 <0.001 <0.001 0.0011
No. Pts, number of patients; Rec Wt Gain, recurrent weight gain; BMI, body mass index; RYGB, Roux-en-Y gastric bypass; EWL, excess body weight loss; UGI, upper gastrointestinal barium study. a At time of patient’s lowest recorded weight after RYGB.
Figure 2 A 52-year-old woman with recurrent weight gain after RYGB. Frontal spot image from a single-contrast upper GI barium study shows focal breakdown of the staple line, with passage of ingested barium from the gastric pouch (large white arrow) across the disrupted portion of the staple line (small white arrow) into the excluded stomach (black arrows).
B. Wang et al. / Clinical Radiology 70 (2015) 67e73
Figure 3 A 55-year-old woman with recurrent weight gain after RYGB. Steep left posterior oblique spot image from a single-contrast upper GI barium study shows a wide GJA with a diameter of 2.6 cm (arrows) and a somewhat enlarged gastric pouch with a length of 6.8 cm and width of 5.4 cm.
remaining seven, including two with a large gastric pouch and normal-calibre GJA, two with a large pouch and wide GJA, one with a normalize-sized pouch and wide GJA, and two with a normal-sized pouch and normal GJA but a short Roux limb. The remaining 32 patients (76%) with recurrent weight gain underwent medical weight-loss programmes without additional surgery. The 10 patients who underwent surgical intervention had a mean weight loss of 38.1 lbs and a mean excess body weight loss of 46.5% at their last physician visit. When the three patients who underwent surgical repair of a disrupted gastric staple line were excluded, the remaining seven still had a mean weight loss of 37.6 lbs and a mean excess body weight of 47.7%. In contrast, the 19 patients with adequate clinical follow-up who underwent medical weight-loss programmes had a mean weight loss of 8.6 lbs and a mean excess body weight loss of 31.5%, respectively.
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Figure 5 A 59-year-old man without recurrent weight gain after RYGB (i.e., control patient). Steep right posterior oblique spot image from a single-contrast upper GI barium study shows a normal-sized GJA with a diameter of 1.2 cm (arrows) and a markedly enlarged gastric pouch with a length of 11 cm and width of 4 cm. The absence of recurrent weight gain in such patients presumably reflects the ability of some individuals to maintain current eating habits even when the restrictive effect of the gastric pouch is lost.
Therefore, the patients treated surgically had significantly greater weight loss than those treated medically (p < 0.001). These findings are summarized in Table 4. When successful weight loss is defined as greater than 20 lbs at final follow-up [11], nine (90%) of 10 patients who underwent surgical intervention had a satisfactory outcome versus only four (21%) of 19 who underwent medical weight-loss programmes (p ¼ 0.0004). Furthermore, the one patient treated surgically who failed to lose more than 20 lbs had no evidence of a large gastric pouch or wide GJA on barium study.
Discussion RYGB has become the reference standard for bariatric surgery, producing sustained weight loss in the majority of patients with obesity.1 Nevertheless, recurrent weight gain remains a serious problem for as many as 20e50% of Table 3 Number of patients with a large gastric pouch, wide gastrojejunal anastomosis, both, or neither in group with recurrent weight gain after Roux-en-Y gastric bypass (n ¼ 35) versus control group (n ¼ 42).a
Figure 4 A 45-year-old woman with recurrent weight gain after RYGB. Steep right posterior oblique spot image from a single-contrast upper GI barium study shows a wide GJA with a diameter (arrows) of 2.8 cm and a somewhat enlarged gastric pouch with a length of 6.5 cm and width of 5.8 cm.
Large pouch Wide GJA Both Large pouch, wide GJA, or both Neither
Rec Wt Gain
Controls
p-Value
13 3 4 20
22 1 2 25
0.251 0.325 0.402 1.00
15
17
Rec Wt Gain, recurrent weight gain, GJA, gastrojejunal anastomosis. a Seven patients in the group with recurrent weight gain were excluded because of gastrogastric fistulas (n ¼ 6) or an anastomotic ulcer (n ¼ 1).
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Table 4 Comparison of final weight loss status in 10 patients who underwent surgical intervention versus 29 patients treated with medical weight-loss programmes for recurrent weight gain after Roux-en-Y gastric bypass. Surgery Final Wt Loss (lbs) % EWL at UGI % EWL at F/U
38.1 *37.6 28.3 *28.4 46.5 *47.8
15.0 15.2 14.9 20.3 13.1 9.0
Weight-loss programme
p-Value
8.6 18.0
<0.001 <0.001 0.999 0.999 0.028 0.026
28.4 20.3 31.5 21.7
Wt, weight, EWL, excess body weight loss; F/U, follow-up. Excluding three patients who underwent surgical repair of a gastrogastric fistula.
*
patients who undergo RYGB.10e13 Both endoscopy and barium studies may be performed to detect anatomical causes of recurrent weight gain after this form of surgery.26 Breakdown of the staple line between the gastric pouch and the excluded portion of the stomach is a wellrecognized anatomical cause of recurrent weight gain after RYGB.17e19 This complication can be detected on barium studies when ingested barium traverses the disrupted portion of the staple line and enters the excluded stomach, producing a GGF (Fig 2).19,26 In the present study, breakdown of the gastric staple line was found in only six (14%) of 42 patients who had barium studies for recurrent weight gain after RYGB. Previous studies have also found that disruption of the gastric staple line is an unusual complication of RYGB, occurring in only 1.2e3.5% of patients who undergo this surgery.18,19 Despite emphasis on radiological or endoscopic detection of a GGF, staple-line breakdown is therefore a relatively uncommon cause of recurrent weight gain after RYGB. In the absence of a GGF (n ¼ 6) or anastomotic ulcer (n ¼ 1), 20 (57%) of the remaining 35 patients with recurrent weight gain after RYGB in the present study had a large gastric pouch (n ¼ 13), a wide GJA (n ¼ 3), or both (n ¼ 4) on barium studies (Figs 3 and 4). These findings are not surprising, as stretching and enlargement of the pouch over time gradually eliminate the restrictive effect that originally caused early satiety and weight loss.20 Similarly, widening of the GJA permits rapid emptying of ingested solids from the pouch, undermining the restrictive effect of the pouch.20 In earlier studies from the surgery literature, a large gastric pouch or wide GJA was found at endoscopy in about 70% of patients with recurrent weight gain after RYGB.21,22 To the authors’ knowledge, however, such anatomical alterations have not been documented previously in the radiology literature as predisposing factors for recurrent weight gain after RYGB. Radiologists who perform barium studies should therefore be aware of the importance of assessing pouch size and GJA diameter as potential causes of recurrent weight gain in this setting. In the present study, surgical repair of a GGF or reduction of pouch size and/or GJA diameter in patients with a large gastric pouch or wide GJA was an effective form of treatment for recurrent weight gain after RYGB. Nine (90%) of 10 patients who underwent surgical intervention had
successful weight loss (defined as weight loss greater than 20 lbs) versus only four (21%) of 19 who underwent medical weight-loss programmes (p ¼ 0.0005). Furthermore, the one patient treated surgically who failed to lose more than 20 lbs had no evidence of a large gastric pouch or wide GJA on barium studies. The benefit of this surgery in patients with successful weight loss almost certainly resulted from reduction of pouch size and/or GJA width, restoring the restrictive effect of the pouch. Previous studies have also shown that surgical reduction of pouch size27,28 and surgical or endoscopic reduction of GJA diameter20e22,29 can lead to successful weight loss in patients with a large gastric pouch or wide GJA after RYGB. Nevertheless, future studies with longer follow-up after surgical revision of the gastric pouch or GJA are needed to determine the long-term benefit of this approach. Despite the satisfactory outcome of patients with recurrent weight gain after RYGB who underwent surgical revision of the pouch/anastomosis, control patients had a frequency of large gastric pouches and/or wide GJAs that was comparable to that of patients with recurrent weight gain after RYGB (Fig 5). This finding is most likely related to varying patient responses to changes in pouch size or GJA width. Successful weight loss after RYGB is caused by the restrictive effect of the gastric pouch that forces these patients to modify their behaviour by ingesting smaller volumes of food. As suggested by the present data, some patients apparently avoid gaining weight after the pouch enlarges or GJA widens by maintaining their altered eating habits even when the restrictive effect of the pouch is lost. In contrast, other patients are unable to maintain their altered eating habits after the gastric pouch enlarges or GJA widens, eliminating the restrictive effect of the pouch, so these individuals increase their food intake, leading to recurrent weight gain. In other words, a large gastric pouch or wide GJA predisposes patients to recurrent weight gain after RYGB, but whether or not they experience this weight gain depends on their ability to maintain previously learned behavioural patterns and eat less even after the restrictive effect of the gastric pouch is lost. Whatever the explanation, the findings of the present study indicate that many patients with a large gastric pouch or wide GJA will not suffer from recurrent weight gain. Thus, there is no need for surgical revision of a large pouch or wide GJA in patients with sustained weight loss after RYGB. As in the present study, however, other patients with a large gastric pouch or wide GJA do experience recurrent weight gain, and these individuals are significantly more likely to benefit from surgical reduction of pouch size or GJA width than from medical weight-loss programmes (90% versus 21%, p ¼ 0.0004). Thus, barium studies have considerable value in patients with recurrent weight gain after RYGB to determine whether they will benefit from additional surgery because of a large gastric pouch or wide GJA. The present investigation has the inherent limitations of a retrospective study, including selection and interpretation bias. Another limitation of the study is the variable size of the pouch and diameter of the GJA, depending on their
B. Wang et al. / Clinical Radiology 70 (2015) 67e73
degree of distention. An attempt was made to minimize this variation by obtaining measurements on images in which the gastric pouch and GJA were maximally distended. Because the data for patient weights were collected retrospectively, the results may be less uniform than data collected in a prospective and more consistent manner. Patients with recurrent weight gain also had a significantly longer mean duration from the time of RYGB to the time of the barium study than patients in the control group (6.2 versus 3.8 years), and this greater time interval could have increased the likelihood of recurrent weight gain independent of pouch size or GJA width. Finally, an attempt was made to account for radiographic magnification using the known dimensions of a barium tablet in the majority of patients and the measured/expected L4VBH in the remaining patients, but this magnification created another potential source of error. Because of these limitations, a prospective study may be helpful for further elucidating the importance of pouch size and GJA diameter as potential causes of recurrent weight gain after RYGB. In summary, the present study indicates that breakdown of the gastric staple line accounts for only a small percentage of patients with recurrent weight gain after RYGB. Instead, a large pouch, wide GJA, or both are responsible for recurrent weight gain in the majority of cases. Although many patients with a large pouch or wide GJA may not have recurrent weight gain, those who do are significantly more likely to benefit from surgical reduction of pouch size and/ or GJA width than from medical weight-loss programmes. Thus, pouch size and GJA width should routinely be assessed on barium studies performed for recurrent weight gain after RYGB to facilitate management of these individuals.
Acknowledgements Drs Levine and Rubesin are consultants for Bracco Diagnostics, Inc.
References 1. Buchwald H, Williams SE. Bariatric surgery worldwide 2003. Obes Surg 2004;14:1157e64. 2. Cummings DE, Overduin J, Foster-Schubert KE. Gastric bypass for obesity: mechanisms of weight loss and diabetes resolution. J Clin Endocrinol Metab 2004;89:2608e15. 3. Buchwald H, Avidor Y, Braunwald E, et al. Bariatric surgery: a systematic review and meta-analysis. JAMA 2004;292:1724e8. 4. Buchwald H, Estok R, Fahrbach K, et al. Weight and type 2 diabetes after bariatric surgery: systematic review and meta-analysis. Am J Med 2009;122:248e56. 5. Patel S, Szomstein S, Rosenthal RJ. Reasons and outcomes of reoperative bariatric surgery for failed and complicated procedures (excluding adjustable gastric banding). Obes Surg 2011;21:1209e19. 6. Yu J, Turner MA, Cho SR, et al. Normal anatomy and complications after gastric bypass surgery: helical CT findings. Radiology 2004;231:753e60.
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7. Carucci LR, Turner MA, Yu J. Imaging evaluation following Roux-en-Y gastric bypass surgery for morbid obesity. Radiol Clin North Am 2007;45:247e60. 8. Chandler RC, Srinivas G, Chintapalli KN, et al. Imaging in bariatric surgery: a guide to postsurgical anatomy and common complications. AJR 2008;190:122e35. 9. Levine MS, Carucci LR. Imaging of bariatric surgery: normal anatomy and postoperative complications. Radiology 2014;270:327e41. 10. Christou NV, Look D, Maclean LD. Weight gain after short- and longlimb gastric bypass in patients followed for longer than 10 years. Ann Surg 2006;244:734e40. 11. Magro DO, Geloneze B, Delfini R, et al. Long-term weight regain after gastric bypass: a 5-year prospective study. Obes Surg 2008;18:648e51. 12. Meguid MM, Glade MJ, Middleton FA. Weight regain after Roux-en-Y: a significant 20% complication related to PYY. Nutrition 2008;24:832e42. 13. Brolin RE, Kenler HA, Gorman JH, et al. Long-limb gastric bypass in the superobese: a prospective randomized study. Ann Surg 1992;215:387e95. 14. Perugini RA, Mason R, Czerniach DR, et al. Predictors of complication and suboptimal weight loss after laparoscopic Roux-en-Y gastric bypass: a series of 188 patients. Arch Surg 2003;138:541e6. 15. Odom J, Zalesin KC, Washington TL, et al. Behavioral predictors of weight regain after bariatric surgery. Obes Surg 2010;20:349e56. 16. Rutledge T, Groesz LM, Savu M. Psychiatric factors and weight loss patterns following gastric bypass surgery in a veteran population. Obes Surg 2011;21:29e35. 17. Halverson JD, Koehler RE. Gastric bypass: analysis of weight loss and factors determining success. Surgery 1981;90:446e55. 18. Carrodeguas L, Szomstein S, Soto F, et al. Management of gastrogastric fistulas after divided Roux-en-Y gastric bypass surgery for morbid obesity: analysis of 1,292 consecutive patients and review of literature. Surg Obes Relat Dis 2005;1:467e74. 19. Carucci LR, Conklin RC, Turner MA. Roux-en-Y gastric bypass surgery for morbid obesity: evaluation of leak into excluded stomach with upper gastrointestinal examination. Radiology 2008;248:504e10. 20. Dayyeh BKA, Lautz DB, Thompson CC. Gastrojejunal stoma diameter predicts weight regain after Roux-en-Y gastric bypass. Clin Gastroenterol Hepatol 2011;9:228e33. 21. Heneghan HM, Yimcharoen P, Brethauer SA, et al. Influence of pouch and stoma size on weight loss after gastric bypass. Surg Obes Relat Dis 2012;8:408e15. 22. Yimcharoen P, Heneghan HM, Singh M, et al. Endoscopic findings and outcomes of revisional procedures for patients with weight recidivism after gastric bypass. Surg Endosc 2011;25:3345e52. 23. Catalano MF, Rudic G, Anderson AJ, et al. Weight gain after bariatric surgery as a result of a large gastric stoma: endotherapy with sodium morrhuate may prevent the need for surgical revision. Gastrointest Endosc 2007;66:240e5. 24. Gilad I, Nissan M. Sagittal radiographic measurements of the cervical and lumbar vertebrae in normal adults. Br J Radiol 1985;58:1031e4. 25. Carucci LR, Turner MA. Radiologic evaluation following Roux-en-Y gastric bypass surgery for morbid obesity. Eur J Radiol 2005;53:353e65. 26. Brethauer SA, Nfonsam V, Sherman V, et al. Endoscopy and upper gastrointestinal contrast studies are complementary in evaluation of weight regain after bariatric surgery. Surg Obes Relat Dis 2006;2:643e8. 27. Fobi MAL. Surgical treatment of obesity: a review. J Natl Med Assoc 2004;96:61e75. 28. Powers MA, Pappas TN. Physiologic approaches to the control of obesity. Ann Surg 1989;209:255e60. 29. Mullady DK, Lautz DB, Thompson CC. Treatment of weight regain after gastric bypass surgery when using a new endoscopic platform: initial experience and early outcomes (with video). Gastrointest Endosc 2009;70:440e4.
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Utility of barium studies for patients with recurrent weight gain after Roux-en-Y gastric bypass B. Wang a, M.S. Levine a, *, S.E. Rubesin a, N.N. Williams b, K. Dumon b, S. Raper b a b
Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA
art icl e i nformat ion Article history: Received 17 July 2014 Received in revised form 20 September 2014 Accepted 24 September 2014
AIM: To determine the utility of barium studies for detecting abnormalities responsible for recurrent weight gain after gastric bypass surgery. METHODS: A computerized search identified 42 patients who had undergone barium studies for recurrent weight gain after gastric bypass and 42 controls. The images were reviewed to determine the frequency of staple-line breakdown and measure the length/width of the pouch and gastrojejunal anastomosis. A large pouch exceeded 6 cm in length or 5 cm in width and a wide anastomosis exceeded 2 cm. Records were reviewed for the amount of recurrent weight gain and subsequent weight loss after additional treatment. RESULTS: Staple-line breakdown was present in 6/42 patients (14%) with recurrent weight gain. When measurements were obtained, 13/35 patients (37%) with recurrent weight gain had a large pouch, three (9%) had a wide anastomosis, and four (11%) had both, whereas 22/42 controls (52%) had a large pouch, one (2%) had a wide anastomosis, and two (5%) had both. Ten patients (24%) with recurrent weight gain underwent staple-line repair (n ¼ 3) or pouch/ anastomosis revision (n ¼ 7). These 10 patients had a mean weight loss of 38.1 lbs versus a mean loss of 8.6 lbs in 19 patients managed medically. CONCLUSION: Only 14% of patients with recurrent weight gain after gastric bypass had staple-line breakdown, whereas 57% had a large pouch, wide anastomosis, or both. Not all patients with abnormal anatomy had recurrent weight gain, but those who did were more likely to benefit from surgical intervention than from medical management. Ó 2014 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.
Introduction Roux-en-Y gastric bypass (RYGB) has become the most popular form of bariatric surgery, accounting for 65% of all
* Guarantor and correspondent: M.S. Levine, Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA. Tel.: þ1 215 662 6908; fax: þ1 215 662 7263. E-mail address: [email protected] (M.S. Levine).
weight-loss procedures performed worldwide.1 Weight loss in RYGB is caused by a restrictive effect from the creation of a small gastric pouch and, to a lesser degree, by a malabsorptive effect from surgical bypass of part of the jejunum.2 RYGB is an effective procedure for treatment of obesity, resulting in mean excess body weight loss of 62%3 and resolution of concomitant diabetes in 84% of patients.4 Nevertheless, this procedure is associated with serious complications, including perforation, anastomotic and jejunal ulcers and strictures, adhesions, internal
http://dx.doi.org/10.1016/j.crad.2014.09.018 0009-9260/Ó 2014 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.
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hernias, and small bowel obstruction.5 Barium studies and CT are valuable imaging tests for detecting these complications.6e9 Another long-term problem after RYGB is recurrent weight gain, which has been reported in 20e50% of patients who undergo this form of surgery.10e13 In one study, the average amount of recurrent weight gain after RYGB was 19.4 lbs.11 Recurrent weight gain in these patients has been attributed to a variety of factors, including dietary habits, socioeconomic status, and psychiatric illness.14e16 Recurrent weight gain also results from anatomical disruption of the gastric staple line, producing a gastrogastric fistula (GGF) that eliminates the restrictive effect of the pouch.17e19 When this complication is detected at endoscopy or upper gastrointestinal (GI) barium studies, the fistula can be repaired surgically to induce further weight loss.17,18 Enlargement of the pouch and widening of the gastrojejunal anastomosis (GJA) are other surgically correctible anatomical abnormalities that cause recurrent weight gain after RYGB.20e22 In some patients with a wide GJA, endoscopic administration of sodium morrhuate to the anastomotic region can shrink the anastomosis and restore the restrictive effect of the pouch, leading to renewed weight loss without need for additional surgery.23 Although upper GI barium studies are often performed to assess the integrity of the gastric staple line in patients with recurrent weight gain after RYGB, the role of this imaging test for detecting not only a GGF but also a large gastric pouch or wide GJA as potential causes of recurrent weight gain has not been adequately addressed in the radiology literature. The purpose of the present investigation, therefore, was to determine the utility of barium studies for detecting various anatomical abnormalities (including a GGF, large gastric pouch, and wide GJA) associated with recurrent weight gain after RYGB, and the implications for patient management.
Materials and methods Institutional review board approval The institutional review board approved all aspects of this retrospective study and did not require informed consent from any patients whose radiographic images or medical records were included in the study. This investigation was also compliant with the Health Insurance Portability and Accountability Act (HIPAA).
Patient population A computerized search of the radiology database identified all upper GI barium studies performed on patients for recurrent weight gain after RYGB during a 7 year period from January 2006 to December 2012. The latter date was used to allow time for adequate clinical follow-up. Patients were included in the study group if surgical records confirmed that RYGB had been performed and if medical records provided adequate clinical information about recurrent weight gain. Using these inclusion criteria, the
study group consisted of 42 patients who underwent upper GI barium studies for recurrent weight gain after RYGB. A separate search of the radiology database was performed to generate a control group of 42 patients in whom upper GI barium studies had been obtained after RYGB for reasons other than recurrent weight gain during the same time period. Patients were selected for the control group on a random basis and were included only if surgical records confirmed that RYGB has been performed; if medical records confirmed that these patients did not have recurrent weight gain; and if these patients did not have GGFs, leaks, ulcers, or strictures at the GJA that could affect anastomotic width or gastric pouch size. Computerized medical records were reviewed by one author to determine baseline demographic information (including age and gender) and body mass index (BMI) for the study and control groups before RYGB, as well as the percentage of excess body weight loss at the time of the patient’s lowest recorded weight after RYGB, and the BMI and percentage of excess body weight loss at the time of the barium examination for the study and control groups.
Examination technique All 85 patients in the study and control groups underwent single-contrast upper GI barium examinations, using a 50% (w/v) low-density barium suspension. All of the radiographic examinations were performed with digital fluoroscopic equipment (Sireskop SD; Siemens, Munich, Germany). All of the barium studies were performed by or under the direct supervision of one of three experienced attending GI radiologists and all were interpreted by the attending radiologists. The post-surgical anatomy was assessed on barium studies by following the head of the barium column at fluoroscopy as it passed from the oesophagus into the gastric pouch and then from the pouch into the Roux limb via the GJA. This technique enabled detection of staple-line breakdown with the development of a GGF, characterized by passage of barium from the gastric pouch across the disrupted portion of the staple line into the excluded stomach. Early fluoroscopic evaluation of the staple line was essential, as barium can occasionally reflux into the excluded stomach via the biliopancreatic limb later in the examination, erroneously suggesting staple-line breakdown. In patients with an anteriorly located GJA, steep oblique or even lateral views were required to prevent overlap between the gastric pouch and jejunum and visualize the GJA in profile.
Image interpretation All 84 barium examinations in the study (n ¼ 42) and control (n ¼ 42) groups were randomly interspersed and reviewed in a blinded fashion in consensus by two experienced GI attending radiologists who had no knowledge of the indications for the barium studies or subsequent patient management. In all patients, the dimensions (i.e., length and width) of the gastric pouch and diameter of the GJA
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were measured in centimetres. All measurements were obtained on images in which the gastric pouch and GJA were maximally distended. The volume of the gastric pouch was also determined by multiplying pouch width times pouch length in centimetres squared. In 54 (64%) of the 84 patients, the fluoroscopist obtained a single spot image of a 12.5 mm barium tablet placed alongside the patient at the same field of view as a reference standard to correct for radiographic magnification. In the remaining 30 patients (36%), the L4 vertebral body height (L4VBH) was used as an alternate reference standard to correct for magnification on the images. This reference standard was established by measuring the L4VBH in patients in whom a barium tablet had been employed. When the known diameter of the barium tablet was used to correct for radiographic magnification, the mean L4VBH was 2.5 cm. This figure is comparable to the mean L4VBH of 2.7 cm in an earlier study in which radiographic magnification of the L4 vertebral body was determined for normal adults.24 Thus, for the purposes of the present study, an L4VBH of 2.5 cm was used as the reference standard to correct for radiographic magnification in the 30 patients in whom a barium tablet had not been employed. The degree of magnification can also be affected by the height of the fluoroscopy tower above the table, but comparison of the images from individual studies showed no gross differences in the size of the visualized lumbar vertebral bodies. Thus, the position of the fluoroscopy tower did not appear to be a major factor in the degree of magnification for the patient cohort. For the purposes of the study, a large gastric pouch was defined as a pouch exceeding 6 cm in length or 5 cm in width, and a wide GJA was defined as an anastomosis with a diameter greater than 2 cm. These threshold numbers have been used in previous studies as parameters for a large gastric pouch or wide GJA.21,22,25 A control patient with a normal-sized gastric pouch and GJA is illustrated in Fig 1. All of the barium studies were also reviewed for the presence or absence of gastric staple-line breakdown and the development of a GGF. The six patients with a GGF were excluded from analysis of pouch size and GJA diameter, as the GGF was presumed to be responsible for recurrent weight gain in these patients. Moreover, decompression of the gastric pouch in patients with a fistula made evaluation of pouch size and GJA diameter unreliable because of difficulty distending the pouch. One patient with recurrent weight gain had an anastomotic ulcer, and this patient was also excluded from analysis of pouch size and GJA diameter, as oedema and spasm at the anastomosis likely affected the anastomotic calibre in this patient.
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Figure 1 A 45-year-old woman without recurrent weight gain after RYGB (i.e., control patient). Frontal spot image from a single-contrast upper GI barium study shows a normal-sized GJA (arrows) with a diameter of 1 cm and a normal-sized gastric pouch with a length of 4 cm and width of 2 cm.
staple line in three patients with a GGF and revision of the pouch/anastomosis in seven, including five with a large gastric pouch and/or wide GJA and two with a normal-sized pouch and normal-calibre GJA but a short Roux limb. Revision of the pouch/anastomosis was performed using a surgical stapler to create a smaller pouch with a volume of about 20 ml or a smaller GJA with a width of 1 cm or less. Adequate clinical follow-up (i.e., the final weight of the patients at their last physician visit after treatment) was available for all 10 patients who underwent surgery and for 19 (59%) of 32 who underwent medical weight-loss programmes. Based on a study by Magro et al.,11 successful weight loss was defined as greater than 20 lb at the time of the last physician visit after surgery or medical weight-loss programmes. Medical records were reviewed to determine the percentage of excess body weight loss at the time of the barium study versus the time of the last physician visit after repeat surgical intervention or additional medical weight-loss programmes. The mean length of clinical follow-up was 1.4 years (range 0.4e3.1 years) years for patients who underwent surgery and 1.4 years (range 0.1e5.2 years) for patients who underwent medical weight-loss programmes.
Statistical analysis Surgical revision and follow-up A review of medical records revealed that 10 (24%) of 42 patients with recurrent weight gain after RYGB underwent surgical intervention and the remaining 32 (76%) underwent medical weight-loss programmes. Surgery consisted of an open laparotomy with repair of a disrupted gastric
The data were analysed using Microsoft Excel 2007. Baseline characteristics were compared using Student’s ttest (Table 1). Student’s t-test was used to compare mean values for pouch length, width, and volume and GJA diameter for the study and control groups (Table 2). Differences in the frequency of anatomic abnormalities after
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RYGB (including staple-line breakdown, a large gastric pouch, and a wide GJA) were also compared for the study and control groups, using Fisher’s exact test on 2 2 contingency tables of the variables of interest. Finally, Fisher’s exact test and Student’s t-test were used to compare differences in the final weight loss status and percentage of EWL, respectively, at the time of the barium studies and at the time of the last physician visit. A p-value less than 0.05 was considered to be statistically significant.
Results
Table 2 Comparison of pouch size (including length, width, and volume) and gastrojejunal anastomotic diameter in patients with recurrent weight gain after Roux-en-Y gastric bypass (n ¼ 35) versus control patients (n ¼ 42).a Rec Wt Gain Pouch width, cm Pouch length, cm Pouch volume, cm2 GJA diameter, cm
3.2 6.0 20.1 1.4
1.2 1.8 11.2 0.7
Controls 3.0 6.5 21.4 1.2
1.2 2.6 15.3 0.5
p-Value 0.203 0.171 0.336 0.149
Rec Wt Gain, recurrent weight gain; GJA, gastrojejunal anastomosis. a Seven patients in the group with recurrent weight gain were excluded because of gastrogastric fistulas (n ¼ 6) or an anastomotic ulcer (n ¼ 1).
the disrupted portion of the staple line into the excluded stomach (Fig 2).
Patient characteristics and clinical presentation The study group consisted of seven men (17%) and 35 women (83%), with a mean age of 48 years (range 26e70 years), whereas the control group consisted of 10 men (23%) and 32 women (77%), with a mean age of 45.8 years (range 28e71 years). The mean amount of recurrent weight gain in the study group was 61.9 lbs (range 8e220 lbs). As shown in Table 1, the mean age, male-to-female ratio, pre-RYGB body mass index (BMI), and initial weight loss after RYGB were comparable for patients with and without recurrent weight gain. Patients with recurrent weight gain had a significantly longer mean duration from the time of RYGB to the time of the barium study than patients in the control group (6.2 versus 3.8 years; p ¼ 0.0013). While patients in the study group all underwent barium studies for recurrent weight gain, the indications for barium studies in the control group included abdominal pain in 27 patients, reflux symptoms in four, iron-deficiency anaemia in three, nausea in two, dysphagia in two, and other clinical signs or symptoms in the remaining four.
Findings on upper GI barium studies
Gastric pouch size and GJA diameter Mean gastric pouch size (including length, width, and volume) and GJA diameter for 35 patients with recurrent weight gain after RYGB and 42 control patients are summarized in Table 2. [Seven patients with recurrent weight gain were excluded from this part of the analysis because of GGFs (n ¼ 6) or anastomotic ulcers (n ¼ 1).] Twenty (57%) of 35 patients with recurrent weight gain after RYGB had a large gastric pouch and/or wide GJA on barium studies (Figs 3 and 4) versus 25 (59%) of 42 control patients (p ¼ 1.00; Fig. 5), so the two groups had a comparable frequency of large gastric pouches and wide GJAs on barium studies (Table 3).
Surgical versus medical intervention and final weight status Ten (24%) of the 42 patients with recurrent weight gain after RYGB underwent surgical intervention. The surgery consisted of repair of the gastric staple line in three patients with a GGF and revision of the gastric pouch/GJA in the
Gastrogastric fistulas Breakdown of the gastric staple line and associated GGFs were present in six (14%) of 42 patients with recurrent weight gain after RYGB. In all six patients, the GGFs were characterized by focal breakdown of the staple line, with passage of ingested barium from the gastric pouch across Table 1 Summary of patient characteristics in 42 patients with recurrent weight gain after Roux-en-Y gastric bypass versus 42 control patients. Variable
Rec Wt Gain
Age, years Male, % Female, % BMI before RYGB % EWLa BMI at UGI % EWL at UGI Time to UGI
48.0 17 83 53.2 59.6% 43.8 30.4% 6.2 yrs
9.8
11.6 20.2 10.8 18.7 3.0
Controls 45.6 21 79 54.1 57.8% 35.5 57.8% 3.8 yrs
p-Value
10.6
11.1 17.7 7.2 17.7 3.0
0.275
0.729 0.676 <0.001 <0.001 0.0011
No. Pts, number of patients; Rec Wt Gain, recurrent weight gain; BMI, body mass index; RYGB, Roux-en-Y gastric bypass; EWL, excess body weight loss; UGI, upper gastrointestinal barium study. a At time of patient’s lowest recorded weight after RYGB.
Figure 2 A 52-year-old woman with recurrent weight gain after RYGB. Frontal spot image from a single-contrast upper GI barium study shows focal breakdown of the staple line, with passage of ingested barium from the gastric pouch (large white arrow) across the disrupted portion of the staple line (small white arrow) into the excluded stomach (black arrows).
B. Wang et al. / Clinical Radiology 70 (2015) 67e73
Figure 3 A 55-year-old woman with recurrent weight gain after RYGB. Steep left posterior oblique spot image from a single-contrast upper GI barium study shows a wide GJA with a diameter of 2.6 cm (arrows) and a somewhat enlarged gastric pouch with a length of 6.8 cm and width of 5.4 cm.
remaining seven, including two with a large gastric pouch and normal-calibre GJA, two with a large pouch and wide GJA, one with a normalize-sized pouch and wide GJA, and two with a normal-sized pouch and normal GJA but a short Roux limb. The remaining 32 patients (76%) with recurrent weight gain underwent medical weight-loss programmes without additional surgery. The 10 patients who underwent surgical intervention had a mean weight loss of 38.1 lbs and a mean excess body weight loss of 46.5% at their last physician visit. When the three patients who underwent surgical repair of a disrupted gastric staple line were excluded, the remaining seven still had a mean weight loss of 37.6 lbs and a mean excess body weight of 47.7%. In contrast, the 19 patients with adequate clinical follow-up who underwent medical weight-loss programmes had a mean weight loss of 8.6 lbs and a mean excess body weight loss of 31.5%, respectively.
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Figure 5 A 59-year-old man without recurrent weight gain after RYGB (i.e., control patient). Steep right posterior oblique spot image from a single-contrast upper GI barium study shows a normal-sized GJA with a diameter of 1.2 cm (arrows) and a markedly enlarged gastric pouch with a length of 11 cm and width of 4 cm. The absence of recurrent weight gain in such patients presumably reflects the ability of some individuals to maintain current eating habits even when the restrictive effect of the gastric pouch is lost.
Therefore, the patients treated surgically had significantly greater weight loss than those treated medically (p < 0.001). These findings are summarized in Table 4. When successful weight loss is defined as greater than 20 lbs at final follow-up [11], nine (90%) of 10 patients who underwent surgical intervention had a satisfactory outcome versus only four (21%) of 19 who underwent medical weight-loss programmes (p ¼ 0.0004). Furthermore, the one patient treated surgically who failed to lose more than 20 lbs had no evidence of a large gastric pouch or wide GJA on barium study.
Discussion RYGB has become the reference standard for bariatric surgery, producing sustained weight loss in the majority of patients with obesity.1 Nevertheless, recurrent weight gain remains a serious problem for as many as 20e50% of Table 3 Number of patients with a large gastric pouch, wide gastrojejunal anastomosis, both, or neither in group with recurrent weight gain after Roux-en-Y gastric bypass (n ¼ 35) versus control group (n ¼ 42).a
Figure 4 A 45-year-old woman with recurrent weight gain after RYGB. Steep right posterior oblique spot image from a single-contrast upper GI barium study shows a wide GJA with a diameter (arrows) of 2.8 cm and a somewhat enlarged gastric pouch with a length of 6.5 cm and width of 5.8 cm.
Large pouch Wide GJA Both Large pouch, wide GJA, or both Neither
Rec Wt Gain
Controls
p-Value
13 3 4 20
22 1 2 25
0.251 0.325 0.402 1.00
15
17
Rec Wt Gain, recurrent weight gain, GJA, gastrojejunal anastomosis. a Seven patients in the group with recurrent weight gain were excluded because of gastrogastric fistulas (n ¼ 6) or an anastomotic ulcer (n ¼ 1).
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Table 4 Comparison of final weight loss status in 10 patients who underwent surgical intervention versus 29 patients treated with medical weight-loss programmes for recurrent weight gain after Roux-en-Y gastric bypass. Surgery Final Wt Loss (lbs) % EWL at UGI % EWL at F/U
38.1 *37.6 28.3 *28.4 46.5 *47.8
15.0 15.2 14.9 20.3 13.1 9.0
Weight-loss programme
p-Value
8.6 18.0
<0.001 <0.001 0.999 0.999 0.028 0.026
28.4 20.3 31.5 21.7
Wt, weight, EWL, excess body weight loss; F/U, follow-up. Excluding three patients who underwent surgical repair of a gastrogastric fistula.
*
patients who undergo RYGB.10e13 Both endoscopy and barium studies may be performed to detect anatomical causes of recurrent weight gain after this form of surgery.26 Breakdown of the staple line between the gastric pouch and the excluded portion of the stomach is a wellrecognized anatomical cause of recurrent weight gain after RYGB.17e19 This complication can be detected on barium studies when ingested barium traverses the disrupted portion of the staple line and enters the excluded stomach, producing a GGF (Fig 2).19,26 In the present study, breakdown of the gastric staple line was found in only six (14%) of 42 patients who had barium studies for recurrent weight gain after RYGB. Previous studies have also found that disruption of the gastric staple line is an unusual complication of RYGB, occurring in only 1.2e3.5% of patients who undergo this surgery.18,19 Despite emphasis on radiological or endoscopic detection of a GGF, staple-line breakdown is therefore a relatively uncommon cause of recurrent weight gain after RYGB. In the absence of a GGF (n ¼ 6) or anastomotic ulcer (n ¼ 1), 20 (57%) of the remaining 35 patients with recurrent weight gain after RYGB in the present study had a large gastric pouch (n ¼ 13), a wide GJA (n ¼ 3), or both (n ¼ 4) on barium studies (Figs 3 and 4). These findings are not surprising, as stretching and enlargement of the pouch over time gradually eliminate the restrictive effect that originally caused early satiety and weight loss.20 Similarly, widening of the GJA permits rapid emptying of ingested solids from the pouch, undermining the restrictive effect of the pouch.20 In earlier studies from the surgery literature, a large gastric pouch or wide GJA was found at endoscopy in about 70% of patients with recurrent weight gain after RYGB.21,22 To the authors’ knowledge, however, such anatomical alterations have not been documented previously in the radiology literature as predisposing factors for recurrent weight gain after RYGB. Radiologists who perform barium studies should therefore be aware of the importance of assessing pouch size and GJA diameter as potential causes of recurrent weight gain in this setting. In the present study, surgical repair of a GGF or reduction of pouch size and/or GJA diameter in patients with a large gastric pouch or wide GJA was an effective form of treatment for recurrent weight gain after RYGB. Nine (90%) of 10 patients who underwent surgical intervention had
successful weight loss (defined as weight loss greater than 20 lbs) versus only four (21%) of 19 who underwent medical weight-loss programmes (p ¼ 0.0005). Furthermore, the one patient treated surgically who failed to lose more than 20 lbs had no evidence of a large gastric pouch or wide GJA on barium studies. The benefit of this surgery in patients with successful weight loss almost certainly resulted from reduction of pouch size and/or GJA width, restoring the restrictive effect of the pouch. Previous studies have also shown that surgical reduction of pouch size27,28 and surgical or endoscopic reduction of GJA diameter20e22,29 can lead to successful weight loss in patients with a large gastric pouch or wide GJA after RYGB. Nevertheless, future studies with longer follow-up after surgical revision of the gastric pouch or GJA are needed to determine the long-term benefit of this approach. Despite the satisfactory outcome of patients with recurrent weight gain after RYGB who underwent surgical revision of the pouch/anastomosis, control patients had a frequency of large gastric pouches and/or wide GJAs that was comparable to that of patients with recurrent weight gain after RYGB (Fig 5). This finding is most likely related to varying patient responses to changes in pouch size or GJA width. Successful weight loss after RYGB is caused by the restrictive effect of the gastric pouch that forces these patients to modify their behaviour by ingesting smaller volumes of food. As suggested by the present data, some patients apparently avoid gaining weight after the pouch enlarges or GJA widens by maintaining their altered eating habits even when the restrictive effect of the pouch is lost. In contrast, other patients are unable to maintain their altered eating habits after the gastric pouch enlarges or GJA widens, eliminating the restrictive effect of the pouch, so these individuals increase their food intake, leading to recurrent weight gain. In other words, a large gastric pouch or wide GJA predisposes patients to recurrent weight gain after RYGB, but whether or not they experience this weight gain depends on their ability to maintain previously learned behavioural patterns and eat less even after the restrictive effect of the gastric pouch is lost. Whatever the explanation, the findings of the present study indicate that many patients with a large gastric pouch or wide GJA will not suffer from recurrent weight gain. Thus, there is no need for surgical revision of a large pouch or wide GJA in patients with sustained weight loss after RYGB. As in the present study, however, other patients with a large gastric pouch or wide GJA do experience recurrent weight gain, and these individuals are significantly more likely to benefit from surgical reduction of pouch size or GJA width than from medical weight-loss programmes (90% versus 21%, p ¼ 0.0004). Thus, barium studies have considerable value in patients with recurrent weight gain after RYGB to determine whether they will benefit from additional surgery because of a large gastric pouch or wide GJA. The present investigation has the inherent limitations of a retrospective study, including selection and interpretation bias. Another limitation of the study is the variable size of the pouch and diameter of the GJA, depending on their
B. Wang et al. / Clinical Radiology 70 (2015) 67e73
degree of distention. An attempt was made to minimize this variation by obtaining measurements on images in which the gastric pouch and GJA were maximally distended. Because the data for patient weights were collected retrospectively, the results may be less uniform than data collected in a prospective and more consistent manner. Patients with recurrent weight gain also had a significantly longer mean duration from the time of RYGB to the time of the barium study than patients in the control group (6.2 versus 3.8 years), and this greater time interval could have increased the likelihood of recurrent weight gain independent of pouch size or GJA width. Finally, an attempt was made to account for radiographic magnification using the known dimensions of a barium tablet in the majority of patients and the measured/expected L4VBH in the remaining patients, but this magnification created another potential source of error. Because of these limitations, a prospective study may be helpful for further elucidating the importance of pouch size and GJA diameter as potential causes of recurrent weight gain after RYGB. In summary, the present study indicates that breakdown of the gastric staple line accounts for only a small percentage of patients with recurrent weight gain after RYGB. Instead, a large pouch, wide GJA, or both are responsible for recurrent weight gain in the majority of cases. Although many patients with a large pouch or wide GJA may not have recurrent weight gain, those who do are significantly more likely to benefit from surgical reduction of pouch size and/ or GJA width than from medical weight-loss programmes. Thus, pouch size and GJA width should routinely be assessed on barium studies performed for recurrent weight gain after RYGB to facilitate management of these individuals.
Acknowledgements Drs Levine and Rubesin are consultants for Bracco Diagnostics, Inc.
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