Surgery for Obesity and Related Diseases 12 (2016) 572–576
Conversion from gastric bypass to sleeve gastrectomy for complications
of gastric bypass
Cullen O. Carter, M.D.
, Adolfo Z. Fernandez, M.D., Stephen S. McNatt, M.D.,
Myron S. Powell, M.D.
Department of Surgery, Wake Forest Baptist Health, Winston-Salem, North Carolina
Received June 2, 2015; accepted July 1, 2015
Abstract Background: Complications after gastric bypass (RYGB) are well documented. Reversal of RYGB
is indicated in select cases but can lead to weight gain. Conversion from RYGB to sleeve gas-
trectomy (SG) has been proposed for correction of complications of RYGB without associated
weight gain. However, little is known about outcomes after this procedure.
Objectives: To examine outcomes after conversion from RYGB to SG.
Setting: University hospital.
Methods: A retrospective study of patients who underwent RYGB to SG conversion was
Results: Twelve patients underwent RYGB to SG conversion for refractory marginal ulceration,
stricture, dumping, gastrogastric ﬁstula, hypoglycemia, and failed weight loss. No deaths occurred.
Four patients experienced 7 major complications, including portal vein thrombosis, bleeding, pan-
creatic leak, pulmonary embolus, seroma, anastomotic leak, and stricture. Two required reoperation,
and 6 were readmitted within 30 days. Four required nasoenteric feeding postoperatively because of
prolonged nausea. The complication of RYGB resolved in 11 of 12 patients. At 14.7 months, change
in body mass index for all patients was a decrease of 2.2 kg/m
. In 5 patients with morbid obesity at
conversion, the change in body mass index was a decrease of 6.4 kg/m
at 19 months.
Conclusions: Laparoscopic conversion from RYGB to SG is successful in resolving certain
complications of RYGB and does not result in short-term weight gain. However, conversion has a
high rate of major complications as well as a high rate of readmission and need for supplemental
nutrition. Although conversion to SG may be appropriate in carefully-selected patients, other options
for patients with severe chronic complications after RYGB should be considered. (Surg Obes Relat
Dis 2016;12:572–576.) r2016 American Society for Metabolic and Bariatric Surgery. All rights
Keywords: Gastric bypass; Sleeve gastrectomy; Intractable dumping syndrome; Revisional bariatric surgery; Conversion;
Bariatric surgery; Bariatric complications; Failed weight loss
Laparoscopic Roux-en-Y gastric bypass (RYGB) was the
most common bariatric procedure performed in the United
States from 2004 to 2012, after which sleeve gastrectomy
(SG) became the most common procedure . Despite
excellent weight loss and resolution of co-morbid condi-
tions experienced by most patients, RYGB is known to
cause long-term complications.
Overall, indications for reversal of RYGB are extremely
rare and include intractable nausea, severe dumping syn-
drome, cachexia, psychological issues, chronic pain, recur-
rent anastomotic ulceration, and refractory neuroglycopenia
. Although long-term results of reversal of RYGB are not
1550-7289/r2016 American Society for Metabolic and Bariatric Surgery. All rights reserved.
Correspondence: Cullen O. Carter, M.D., Department of Surgery, 1
Medical Center Boulevard, Winston-Salem, NC 27157, USA.
published in the literature, it is known that most patients who
undergo reversal of other weight loss procedures such as
jejunoileal bypass regain all of the lost weight  and that re-
establishment of normal anatomy in the form of gastrogastric
ﬁstula can lead to signiﬁcant weight gain . Thus, many
patients who experience severe complications of RYGB are
hesitant to undergo reversal to normal anatomy.
Conversion from RYGB to SG has been proposed as a
method for correcting certain complications of RYGB without
associated weight gain. Such a procedure has been described
for correction of retrograde intussusception , weight regain
[6,7], intractable dumping syndrome , cachexia , severe
neuroglycopenia [7,9], and hypocalcemia after inadvertent
parathyroidectomy . Currently, there are 5 series in the
literature describing a total of 27 patients who have undergone
conversion from RYGB to SG. Thus, little is known about the
long-term outcome of the procedure. We hereby report our
experience with conversion from RYGB to SG.
A total of 12 patients who underwent conversion from
RYGB to SG between 2012 and 2014 were identiﬁed. After
Institutional Review Board approval, a retrospective review
was performed to collect patient data. Information regarding
patient demographic characteristics, initial surgeries, reason
for conversion to sleeve, postoperative complications, post-
operative readmissions, need for supplemental enteral
nutrition, and weight were collected.
Patients were placed in the supine position, and laparo-
scopic surgery was attempted in all cases. Four standard
ports suitable for gastric bypass and a port for liver
retraction were placed. Adhesions to the peritoneum and
the left lobe of the liver were lysed as needed. The Roux
limb was identiﬁed and traced to the gastric pouch. Endos-
copy was used to conﬁrm the location of the gastrojejunal
anastomosis. The gastric pouch was divided proximal to the
gastrojejunal anastomosis with an extra-thick (black) staple
load (Ethicon, Somerville, NJ). The Roux limb was
mobilized, stapled proximal to the jejunojejunal anastomo-
sis, and resected. The remnant stomach was then mobilized.
A gastrotomy was made along the greater curvature,
through which a 25-mm EEA circular stapler was intro-
duced. The spike was deployed in the appropriate position
on the proximal lesser curvature of the remnant stomach. It
was mated to a 25-mm anvil, which was placed transorally
using the Orvil device (Covidien, Mansﬁeld, MA). The
circular stapler was then ﬁred, creating a gastrogastrostomy.
A 36F bougie (ViSiGi, Phoenixville, PA) was then passed
transorally, directed through the gastrogastric anastomosis,
and aligned along the lesser curvature of the stomach. The
gastric sleeve was then created by transecting the stomach
along the bougie in the standard fashion with sequential
ﬁrings of a linear stapler, and the specimen was removed.
Endoscopic leak test was performed in all cases. Drains and
jejunal feeding tubes were placed at the discretion of the
If open surgery was required because of severe adhesive
disease, the same steps were followed in an open fashion.
From January 2012 to November 2014, 12 patients
underwent conversion from RYGB to SG. All patients
were female, and 10 of 12 had undergone the original
RYGB at another institution. Three had undergone prior
revision. As shown in Table 1, mean age was 44.4 years
(range 31–54), and the mean body mass index (BMI) before
conversion was 32.2 kg/m
Six patients underwent conversion to SG for refractory
marginal ulceration (MU) with or without associated
stenosis. Patient 1 had undergone 3 years of maximal
medical therapy (proton pump inhibitor and sucralfate)
along with smoking cessation with persistence of MU on
4 diagnostic endoscopies. She eventually developed a
stricture refractory to 2 endoscopic dilation procedures.
Patient 2 experienced epigastric pain, nausea, and vomiting
because of MU as well as stricture refractory to 4 months of
maximal medical therapy, attempts at smoking cessation,
and 3 endoscopic dilations. Patient 5 developed early
circumferential MU that persisted after 2 months of
maximal medical therapy, prompting surgical resection
and revision of the anastomosis. MU recurred soon after
surgical revision and symptoms continued, requiring several
admissions, until conversion to SG was performed 6 months
later. Patient 6 was a smoker who had undergone 3
endoscopic interventions for MU-related upper gastrointes-
tinal bleeding over 4 years at another institution; this patient
was referred for nausea, vomiting, and cachexia because of
continued MU. Her MU did not heal despite 6 months of
maximal medical therapy, supplemental feeding, and
attempts at smoking cessation. Patient 7 developed MU,
which failed to heal despite 2 years of maximal medical
therapy and unsuccessful attempts at smoking cessation.
She ultimately developed a stricture refractory to several
treatments with endoscopic dilation. Patient 12 developed
MU after a revision of RYGB for failed weight loss. This
was treated at another facility with 6 months of medical
therapy, then 3 endoscopic dilations for associated stricture,
followed by surgical revision of gastrojejunal anastomosis.
She developed recurrent MU and underwent conversion to
SG after 5 months of unsuccessful medical treatment.
Two patients underwent conversion to SG after gastro-
gastric ﬁstula (GGF) development. Patient 3 had undergone
remote anastomotic revision for smoking-related MU and
was referred with 8 months of epigastric pain, reﬂux, and
weight gain because of GGF. Patient 8 was referred after
Conversion from Gastric Bypass to Sleeve Gastrectomy / Surgery for Obesity and Related Diseases 12 (2016) 572–576 573
9 months of worsening nausea secondary to GGF with
associated anastomotic stenosis treated with endoscopic
dilation twice. Neither patient with GGF underwent any
attempt at endoscopic closure.
Two patients underwent conversion for hyperinsulinemic
hypoglycemia. Patient 4 presented with 3 years of post-
prandial hypoglycemia that initially improved with dietary
modiﬁcation and alpha-glucosidase inhibitor therapy but
then continued despite these treatment measures. Patient 9
experienced 8 years of gradually more severe postprandial
hypoglycemia associated with poor dietary choices. Dietary
counseling was attempted for 1 year, at which point
conversion was performed for continued frequent hypogly-
cemia. Both patients were admitted for 72-hour fast testing
to rule out endogenous hyperinsulinemia.
Patient 11 underwent conversion to SG for refractory
dumping syndrome, which had been present for several
years but worsened signiﬁcantly over 1 year despite nutri-
tional counseling and medical treatment with octreotide.
Patient 10 presented with weight gain that occurred 10
years after RYGB. Before conversion, she underwent 6
months of a physician-supervised weight-loss program that
did not include prescription medication.
Ten of the 12 procedures were completed laparoscopi-
cally, whereas 2 were converted to open surgery because of
severe adhesive disease. Average surgical time was 262
minutes (range 128–396), and estimated blood loss was 146
mL (range 50–300). All surgeries were technically success-
ful, and the average length of stay was 6.2 days (range
2–18, median 4.5).
A total of 4 patients (25%) experienced 7 signiﬁcant
postoperative complications. These included portal vein
thrombosis (Clavien-Dindo Grade II), bleeding requiring
transfusion (Clavien-Dindo Grade II), pancreatic leak
(Clavien-Dindo Grade IIIb), pulmonary embolus (Clavien-
Dindo Grade IVa), wound seroma (Clavien-Dindo Grade
IIIa), and anastomotic leak resulting in gastrocolic ﬁstula
and anastomotic stenosis treated with endoscopic stenting
(Clavien-Dindo Grade IIIb). Two patients required reoper-
ative intervention within 30 days, the ﬁrst for a pancreatic
leak and the second for a dislodged jejunostomy tube.
Six of the 12 patients (50%) required readmission within
30 days of surgery. The most common indication for
readmission was prolonged nausea and inability to tolerate
an oral diet. Four patients underwent jejunostomy feeding
tube placement at the time of surgery, and of the 8 who did
not, 4 required readmission and prolonged nasoenteric
feeding because of an inability to tolerate an oral diet.
One patient required total parenteral nutrition. All patients
were ultimately able to tolerate an oral diet without need for
supplementation. Of note, evaluation with upper gastro-
intestinal series and endoscopy revealed a structural explan-
ation for nausea in only 1 of the 6 patients readmitted. This
patient was found to have stenosis at the gasto-gastric
Average follow-up was 14.7 months (range 5–38), and
the average change in BMI for all 12 patients was a
decrease of 2.2 kg/m
(range –13.9 to þ12.0 kg/m
Five of 12 patients were class 2 or 3 obese at the time of
conversion (BMI range 36.0–47.9 kg/m
). Only 1 of these
patients gained weight during the follow-up period, and at
an average follow-up of 19 months, these 5 patients saw a
decrease in BMI of 6.4 kg/m
. Percent excess weight loss
was 30.1%, percent total weight loss was 13.0%, and
percent excess BMI lost was 28.7%.
For the 7 patients who were not morbidly obese at the
time of conversion (BMI range 20.1–30.5 kg/m
average change in BMI was þ0.8 kg/m
, and all patients
Indication BMI (kg/m
Current Change F/U
1 40 N MU, GJ strict 26.7 29.7 þ3.0 18 Lap None 3 N Y–J
2 39 N MU, GJ strict,
22.3 21.5 –.8 20 Lap None 4 Y (30) Y–NJ
3 46 Y GGF, smoker 30.0 25.4 –4.8 4 Lap None 2 N N
4 38 N Hypoglycemia 36.0 48.0 þ12.0 15 Lap PVT, seroma 6 Y (21) Y–NJ
5 54 Y MU 25.0 26.7 þ1.7 8 Lap Bleeding 4 N N
6 37 N MU, smoker 20.2 20.4 þ.2 10 Lap None 10 Y (24) Y–J
7 51 N MU, smoker 39.4 19.6 –19.2 38 Open Panc leak,
18 Y (22) Y–J
8 47 N GGF 20.1 28 þ7.9 16 Lap None 2 N Y–J
9 44 N Hypoglycemia 46.7 42.6 –4.1 24 Lap None 5 N N
10 61 N Weight gain 47.9 34.0 –13.9 12 Open None 4 N N
11 31 N Dumping 41.6 35.0 –6.6 6 Lap None 6 Y (16) Y–NJ
12 45 Y MU 30.5 29.0 –1.5 5 Lap Leak, GC
10 Y (20) Y–NJ, TPN
Average 44.4 32.2 30.0 –2.2 14.7 6.2
No. ¼number; BMI ¼body mass index; F/U ¼follow-up; LOS ¼length of stay; Readmit ¼readmission; MU ¼marginal ulcer; Lap ¼laparoscopic;
Panc ¼pancreatic; PVT ¼portal vein thrombus; GGF ¼gastrogastric ﬁstula; NJ ¼nasojejunal; Y ¼yes; N ¼no; GC ¼gastrocolic.
C. O. Carter et al. / Surgery for Obesity and Related Diseases 12 (2016) 572–576574
maintained a healthy BMI of less than 30 kg/m
average follow-up of 11.5 months. No patients were lost to
In this cohort, conversion from RYGB to SG is described
in 12 patients with successful resolution of the complication
prompting revisional surgery and without signiﬁcant weight
gain. High rates of major complication and readmission
were, however, experienced.
As bariatric surgery has become more common, the need
for revisional surgery for both complications of the primary
procedure and for unsuccessful weight loss has grown.
Revisional surgery can be performed without a prohibitive
complication rate . Some complications of RYGB, such
as refractory or recurrent marginal ulceration, intractable
dumping syndrome, and refractory hyperinsulinemic hypo-
glycemia, require reversal of RYGB to normal anatomy.
Although little is documented in the literature regarding
weight gain after reversal of RYGB, it is known that many
patients regain much of the weight they had lost after reversal
of other bariatric procedures, such as jejunoileal bypass and
laparoscopic adjustable gastric banding [3,11].Thus,reversal
to normal anatomy should be undertaken cautiously.
Conversion of RYGB to SG has been proposed as an
alternative to reversal of RYGB to correct the above
complications without resulting in weight gain. Such a
technique has been described by 5 case series in the
literature. In 2010, Simper et al. reported 8 patients who
underwent successful conversion for retrograde intussus-
ception or roux stasis, with complete relief of symptoms in
6. In 2011, Dapri, Cadiere, and Himpens described
4 patients with unsuccessful weight loss after RYGB who
underwent conversion to SG as a ﬁrst step in conversion to
duodenal switch and reported 59.3% excess weight loss
after conversion to SG alone . In 2013, Zurita, Tabari,
and Hong reported 2 patients with resolution of intractable
dumping syndrome after conversion to SG . Also in
2013, Vilallonga, van de Vrande, and Himpens described
10 patients who underwent conversion to SG and 10 who
underwent reversal to normal anatomy for a variety of
indications . Finally, Campos et al. described 3 patients
converted to SG and 2 reversed to normal anatomy, all with
resolution of hyperinsulinemic hypoglycemia or severe
hypocalcemia after inadvertent parathyroidectomy after
Although conversion from RYGB to SG is reported to be
successful in resolving certain complications of RYGB, the
conversion procedure can also result in signiﬁcant perioper-
ative complications. Simper et al. saw signiﬁcant compli-
cations in 5 of 8 patients, including gastric ﬁstula, superior
mesenteric vein thrombosis, bowel obstruction, anastomotic
stricture, and splenic bleeding . Vilallonga et al. reported
3 anastomotic leaks and 1 gastric ulcer in 10 patients .
We similarly report major complications in 4 of 12 patients.
Revisional bariatric surgery is known to have a higher
complication rate than primary bariatric surgery, with up to
21.8–23% morbidity and 1.3% mortality in large series
[12,13]. Anastomotic leak can be seen in 4.2–11% of
patients undergoing revision [14–16]. Thus, the complica-
tion rate of 25% seen in the present series is not unexpected.
The alternative to conversion to SG for most of the patients
described is reversal to normal anatomy, an operation for
which the rate of complication is unknown because it is so
infrequently reported in the literature.
Regarding the technical aspect of conversion from RYGB
to SG, the creation of the gastrogastric anastomosis varies in
published reports. Parikh, Pomp, and Gagner used a circular
stapled gastrogastric anastomosis in conversion from RYGB
to duodenal switch and reported a 25% anastomotic stricture
rate . Dapri et al. and Vilallonga et al. used a hand-sewn
technique for gastrogastrostomy creation, without stricture in
any patient, while Simper et al. reported a 50% stricture rate
using a similar hand-sewn technique [5–7]. Using a circular
stapled anastomosis, we had only 1 patient develop a stricture
requiring dilation. Regarding sleeve creation, Vilallonga et al.
reported 3 leaks in the ﬁrst 5 patients converted to SG using a
standard stapled technique. Thereafter, no leaks occurred by
ﬁrst removing the fundus with a stapled technique and
performing plication of the stomach distal to the gastro-
gastrostomy to avoid ischemic areas lateral to the anastomo-
sis . We experienced 1 leak after a more standard stapling
technique, including stapling the portion of the stomach
distal to the gastrogastrostomy.
The frequent incidence of postoperative nausea and
inability to tolerate an oral diet in the present series was
not reported by other authors. The cause of nausea is
unclear. In 5 of 6 patients readmitted for severe nausea, no
anatomic cause was found on imaging or endoscopy. It is
possible that poor function of the sleeve stomach due to
vagal denervation contributed to these symptoms. Gastro-
esophageal acid and nonacid reﬂux after conversion may
have contributed to these symptoms, and an important
limitation of this study is that patients did not undergo
objective assessment with pH probe and impedance mon-
itoring. These 6 patients required supplemental enteral
nutrition and were only able to tolerate an oral diet after a
period of several weeks. We recommend considering
feeding jejunostomy placement in patients undergoing
conversion from RYGB to SG.
The goal in performing most of the surgeries in this series
was not to induce weight loss but to resolve a speciﬁc
complication related to RYGB without causing weight gain.
However, others have performed conversion from RYGB to
SG for failure of weight loss [6–7], with Vilallonga et al.
reporting a 59% excess weight loss in 4 patients .Inthe
present series, 5 patients had class II or III obesity at the time
of conversion, and the average change in BMI after 19
months was a decrease of 6.4 kg/m
, or 30.1% excess weight
Conversion from Gastric Bypass to Sleeve Gastrectomy / Surgery for Obesity and Related Diseases 12 (2016) 572–576 575
loss. It is important to note that the indication for conversion
to SG in most of these patients was not failed weight loss and
that long-term follow-up is not available. Given the high risk
of complication, we would not recommend conversion from
RYGB to SG for failure of weight loss.
The current report has several limitations. It describes a
small number of patients and is retrospective in nature. The
follow-up was also relatively short at 14.7 months. How-
ever, this series contributes to bring the total number of
reported patients in the literature to 39.
Laparoscopic conversion from RYGB to SG is successful
in resolving certain complications of RYGB and does not
result in short-term weight gain. However, conversion has a
high rate of major complication as well as a high rate of
readmission and need for supplemental nutrition. Although
conversion to SG may be appropriate in carefully-selected
patients, other options for patients with severe chronic
complications after RYGB should be considered.
None of the authors have anything to disclose.
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