Currently, it is believed that about one-third of the adult population in United States is obese, and this percentage is rising. As a result, we are witnessing a concurrent increase in the number of bariatric procedures performed for treating obesity in this country [
The reported incidence of intussusception following gastric bypass surgery is about 0.1–0.3% [
(a) Illustration of intussusception. (b) Target sign: it indicates hyperemia of mucosa, muscularis, and serosa with submucosal edema. The high attenuation of mucosa, muscularis, and serosa is due to contrast enhancement, while the low attenuation of submucosa is believed to result from edema.
(a) Axial view of the CT scan showing intussusception with fat and blood vessels within the lumen of intestine (white arrow—target sign and pneumatosis). (b) Coronal view of the CT scan showing intussusception (white arrow—sausage-shaped thickened bowel wall).
Sagittal view of the CT scan showing intussusception (white arrow—site of intussusception).
Although our ability to detect and treat intussusception following gastric bypass surgery has improved, its etiology remains somewhat unclear. Most people still believe that intussusception is related to dysmotility, which develops secondary to the development of ectopic pacemakers. Other proposed mechanisms include development of new lead points such as sutures or staple lines and focal nodal hyperplasia. However, in the vast majority of cases, no identifiable lead points or aberrations in anatomy are detected [
A comprehensive search was conducted to identify the literature published worldwide including articles, reviews, case reports, and series and abstracts describing intussusception after gastric bypass surgery. We also included patients from our own clinical experience. We included all patients who underwent gastric bypass surgery for weight loss—both open and laparoscopic, confirmed diagnosis of intussusception—either preoperative or postoperative based on pathology. Patients with gastric bypass surgery for reasons other than weight loss, intussusception not associated with weight loss surgery, and diagnosis of intestinal obstruction due to causes other than intussusception were excluded in this review.
The data was extracted using a structured form that included information regarding demographic profile, medical history, weight loss, clinical presentation, radiographic imaging, diagnosis, management, and posttreatment course in these patients (Table
Summary of patient profile.
Patient number | Year of publication | Age | Gender | Initial surgery | Time to presentation (in years) | Diagnosis | Type of intuss. | Operation | Death | Post-op readmit |
---|---|---|---|---|---|---|---|---|---|---|
1 | 1991 | 31 | F | Roux-en-Y | 7 | US | RINT | SBR | No | Yes |
2 | 1996 | 40 | F | Roux-en-Y | 5 | CT scan | INT | SBR | No | No |
3 | 1996 | 35 | F | Roux-en-Y | 3 | CT scan | INT | SBR | No | No |
4 | 1996 | 36 | F | Roux-en-Y | 4 | UGI | INT | SBR | No | No |
5 | 2000 | 40 | F | Roux-en-Y | 5 | CT scan | INT | SBR | No | No |
6 | 2000 | 27 | F | Roux-en-Y | 4 | X-ray | INT | SBR | No | No |
7 | 2004 | 30 | F | Roux-en-Y | 3 | CT scan | RINT | SBR | No | No |
8 | 2004 | 30 | F | Roux-en-Y | 2 | CT scan | RINT | SBR | No | No |
9 | 2004 | 44 | F | Roux-en-Y | 1 | CT scan | AINT | SBR | No | No |
10 | 2004 | 33 | F | Roux-en-Y | 1.5 | CT scan | AINT | SBR | No | No |
11 | 2004 | 47 | F | Roux-en-Y | 2 | CT scan | RINT | SBR | No | No |
12 | 2004 | 36 | F | Roux-en-Y | 5 | UGI | RINT | SBR | No | No |
13 | 2004 | 48 | F | Roux-en-Y | 2 | UGI | RINT | SBR | No | No |
14 | 2004 | 39 | F | Roux-en-Y | 2 | — | RINT | SBR | No | No |
15 | 2004 | 49 | F | Roux-en-Y | 2.5 | CT scan | RINT | SBR | No | No |
16 | 2006 | 48 | F | Roux-en-Y | 1.5 | CT scan | RINT | SBR | No | No |
17 | 2006 | 33 | F | Roux-en-Y | 4 | CT scan | RINT | SBR | No | No |
18 | 2006 | 37 | F | Roux-en-Y | 3 | CT scan | INT | SBR | No | No |
19 | 2007 | 31 | F | Roux-en-Y | 1 | Intra-op | AINT | Reduction | No | No |
20 | 2007 | 44 | F | Roux-en-Y | 2.5 | Intra-op | AINT | Reduction | No | No |
21 | 2007 | 27 | F | Roux-en-Y | 3.5 | Intra-op | AINT | Reduction | No | No |
22 | 2007 | 35 | F | Roux-en-Y | 1 | X-ray | RINT | SBR | No | No |
23 | 2007 | 35 | F | Roux-en-Y | 4 | CT scan | RINT | Reduction | No | No |
24 | 2007 | 27 | F | Roux-en-Y | 3 | X-ray | AINT | Reduction | No | Yes |
25 | 2007 | 28 | F | Roux-en-Y | 1.5 | CT scan | RINT | SBR | No | No |
26 | 2007 | 58 | F | Roux-en-Y | 3 | CT scan | INT | Reduction | No | No |
27 | 2007 | 44 | F | Roux-en-Y | 6 | CT scan | INT | SBR | No | No |
28 | 2007 | 31 | F | Roux-en-Y | 3 | CT scan | RINT | SBR | No | No |
29 | 2008 | 46 | F | Roux-en-Y | 5 | CT scan | RINT | SBR | No | No |
30 | 2008 | 39 | F | Roux-en-Y | 4 | CT scan | RINT | SBR | No | No |
31 | 2008 | 51 | F | Roux-en-Y | 2 | CT scan | RINT | SBR | No | No |
32 | 2008 | 20 | F | Roux-en-Y | 1.58 | — | RINT | SBR | No | No |
33 | 2008 | 20 | F | Roux-en-Y | 1.83 | — | RINT | SBR | No | No |
34 | 2008 | 25 | F | Roux-en-Y | 5 | — | RINT | SBR | No | No |
35 | 2008 | 36 | F | Roux-en-Y | 5.17 | — | RINT | SBR | No | No |
36 | 2008 | 29 | F | Roux-en-Y | 3.25 | — | RINT | SBR | No | No |
37 | 2008 | 41 | F | Roux-en-Y | 4.25 | — | RINT | SBR | No | No |
38 | 2008 | 38 | F | Roux-en-Y | 1.5 | — | RINT | SBR | No | No |
39 | 2008 | 36 | F | Roux-en-Y | 3.83 | — | RINT | SBR | No | No |
40 | 2008 | 32 | F | Roux-en-Y | 4.17 | — | RINT | Reduction | No | No |
41 | 2008 | 29 | F | Roux-en-Y | 1.33 | — | RINT | SBR | No | No |
42 | 2008 | 20 | F | Roux-en-Y | 2.33 | — | RINT | SBR | No | No |
43 | 2008 | 25 | F | Roux-en-Y | 1.58 | — | RINT | SBR | No | Yes |
44 | 2008 | 33 | F | Roux-en-Y | 10 | — | RINT | Reduction | No | Yes |
45 | 2008 | 28 | F | Roux-en-Y | 11.08 | — | RINT | Reduction | No | Yes |
46 | 2008 | 50 | F | Other | 5 | — | RINT | Plication | No | No |
47 | 2008 | 36 | F | Roux-en-Y | 0.67 | — | RINT | Plication | No | No |
48 | 2008 | 41 | F | Roux-en-Y | 5.83 | — | RINT | Plication | No | Yes |
49 | 2008 | 25 | F | Roux-en-Y | 9 | — | RINT | Plication | No | Yes |
50 | 2008 | 34 | F | Roux-en-Y | 9.17 | — | RINT | SBR | No | No |
51 | 2008 | 50 | F | Roux-en-Y | 0.5 | — | RINT | SBR | No | No |
52 | 2008 | 23 | F | Roux-en-Y | 3.67 | — | RINT | SBR | No | No |
53 | 2008 | 25 | F | Roux-en-Y | 2.33 | — | RINT | SBR | No | No |
54 | 2008 | 32 | F | Roux-en-Y | 2.33 | — | RINT | SBR | No | Yes |
55 | 2009 | 60 | F | Roux-en-Y | 4 | CT scan | RINT | SBR | No | No |
56 | 2009 | 25 | F | Roux-en-Y | 5 | CT scan | RINT | Reduction | No | No |
57 | 2009 | 32 | F | Roux-en-Y | 3 | CT scan | RINT | Reduction | No | No |
58 | 2009 | 27 | F | Roux-en-Y | 1.5 | CT scan | AINT | Reduction | No | No |
59 | 2009 | 33 | F | Roux-en-Y | 1 | CT scan | RINT | SBR | No | No |
60 | 2009 | 51 | F | Roux-en-Y | 2 | CT scan | RINT | SBR | No | No |
61 | 2009 | 37 | F | Roux-en-Y | 5 | CT scan | RINT | SBR | No | No |
62 | 2010 | 27 | F | Roux-en-Y | 2 | CT scan | AINT | Reduction | No | No |
63 | 2010 | 42 | F | Roux-en-Y | 0.75 | CT scan | RINT | Reduction | No | No |
64 | 2010 | 25 | F | Roux-en-Y | CT scan | RINT | SBR | No | No | |
65 | 2011 | 36 | F | Roux-en-Y | 3 | CT scan | — | Non-op | No | No |
66 | 2011 | 28 | M | Roux-en-Y | 8 | CT scan | — | Non-op | No | Yes |
67 | 2011 | 29 | F | Roux-en-Y | 6 | CT scan | RINT | Reduction | No | Yes |
68 | 2011 | 31 | F | Roux-en-Y | 8 | CT scan | — | Non-op | No | No |
69 | 2011 | 44 | F | Roux-en-Y | 1 | CT scan | RINT | Reduction | No | Yes |
70 | 2011 | 47 | F | Loop GBP | 11 | CT scan | INT | Rev. loop | No | Yes |
71 | 2011 | 41 | F | Roux-en-Y | 5 | CT scan | RINT | SBR | No | Yes |
Seventy one patients were identified including seven patients from our own series, in 29 studies published worldwide between the years 1991 and 2011. The majority of patients identified were females (
The median time to presentation (from the time of weight loss surgery to development of intussusception) was 36 months (range, 6–133 months). Amongst the patients with data available, the mean excess weight loss was about 145 pounds. Most of the patients presented to the physician with complaints of diffuse abdominal pain, nausea, and vomiting. However, in nearly all patients, the abdomen was described as soft and without obvious peritonitis. A palpable mass was reported in 7 (9.8%) patients only. Amongst the 47 patients with detailed data available regarding imaging, CT scan was diagnostic in 38 (81%) patients. In other patients, the diagnosis was established based on findings from abdominal radiographs (
At the time of initial presentation, 68 (96%) patients underwent surgery, while 3 (4%) patients were treated nonoperatively. Amongst the patients treated operatively, 51 patients (75%) were found to have retrograde intussusception, 8 patients (11.8%) were reported to have antegrade intussusception, and the remaining 9 cases (13.2%) were not specified (Figure
Resected specimen showing intussusception (note position of mesentery and blood vessels).
In the postoperative period, 20 patients developed complications ranging from pain and ileus to obstruction and recurrence (Table
List of complications after initial treatment for intussusception.
Complication | Number of patients |
---|---|
Recurrence with intussusception | 9 |
Pain | 4 |
Ileus | 3 |
Bleeding | 1 |
Marginal ulcer | 1 |
Obstruction due adhesions | 1 |
Intra-abdominal abscess | 1 |
Intussusception in adults is relatively rare however; in patients undergoing gastric bypass surgery, the incidence is believed to be rising. Our analyses pose several questions that need to be answered: what are the risk factors? What is the etiology and why are females more commonly affected as compared to males? And what is the appropriate management of patients presenting with intussusception after gastric bypass surgery? To answer these questions, we looked at the problem in detail.
The overall rate of complications associated with gastric bypass surgery is between 15% and 20% [
The majority of patients identified in our analysis were young with a median age of about 35.5 years. However, since most of the patients developing pathological primary intussusception or complications after gastric bypass surgery are relatively old [
In summary, female gender, a relative young age, and significant excess weight loss after gastric bypass surgery may be considered as potential risk factors for the development of intussusception after gastric bypass surgery.
The etiology for developing intussusception after gastric bypass appears more complex than previously thought. To date, the most widely accepted view has been that the creation of Roux limb disrupts the natural intestinal pacemakers in the duodenum and allows for the formation of ectopic pacemakers or migratory motor complexes in the Roux limb. It is believed that the electric potential generated by these ectopic pacemakers migrates in both the distal as well as the proximal limbs. This creates an area or segment of dysmotility, which according to some authors is responsible for developing intussusception in these patients [
It is our belief that the etiology of intussusception after gastric bypass is multifactorial and occurs due to the combination of the following: (1) disruption of the natural pacemakers. In the process of creating the Roux limb, the distal jejunum is separated from the proximal jejunal pacemaker during transection. This leads to a decreased pacesetter potential in the distal Roux limb and causes activation of the ectopic pacemakers in this limb. These ectopic pacemakers generate new pace-setting potentials that travel in both distal as well as proximal direction, resulting in delayed emptying and stasis of the Roux limb; (2) thinning of the mesentery. Substantial weight loss causes potential thinning of the mesentery around the intestine. This leads to a decreased cushion effect and increased bowel mobility around the roux limb and the jejunojejunostomy site, thereby creating a zone of instability.
The combination of these two factors is believed to increase the risk of telescoping and intussusception and accentuate abnormal waves of dysmotility. This may explain why there is a delay in presentation and why most patients with this condition have lost a substantial amount of weight. Still, more analyses need to be made between patients with substantial weight loss from gastric bypass (Roux-en-Y) and others to determine if rates of intussusception show a statistically significant difference.
The majority of patients presented with nonspecific abdominal symptoms including diffuse abdominal pain, nausea, and vomiting. Interestingly, in nearly all of these patients, the abdomen was found to be soft, nonrigid, and without obvious peritonitis or any palpable mass (seen only in 7 patients). Further, we observed that in our series, most of the patients had nonspecific laboratory findings/values, without any indication or reflection on the underlying pathology in these patients. Since both physical examination and initial laboratory investigations were nonspecific and did not relay the appropriate information on the severity of the underlying pathology to the clinicians, we argued that the onus of diagnosing intussusception was dependent on further radiological investigations.
We found that CT scan was the diagnostic study of choice in majority of patients studied. Most patients were found to have been investigated with more than one radiological investigation; however, the diagnosis was not established until the CT scan was completed. It may therefore be prudent to argue here that the CT scan is not only sensitive, but is also reliable in establishing the diagnosis early, and thus, in potential high-risk patients (females, young age, and significant excess weight loss), CT scan should take precedence over other investigations in diagnosing intussusception.
As regards the treatment, it is clear that surgical intervention is warranted early. However, in deciding how to operate, there is room for discussion. Some authors have suggested that simple reduction without resection is safe, while others have opted to proceed with resection of the bowel to prevent reoccurrence. Obviously, in cases that necessitate resection (bowel ischemia or necrosis), the latter is the treatment of choice. We found in our analysis that the majority of patients required small bowel resection and revision of the anastomosis. Those patients who were initially not treated with resection/revision subsequently developed recurrence and had to be operated again.
Within our clinical experience, we found that the operative technique (open or laparoscopic), length of the limb, or the type of suture material/staplers made no difference in outcome. As long as the patients were treated with resection/revision, they did not develop recurrence. With regards how the revision is done, it is a matter of debate until more information becomes available. We treated our patients both laparoscopically and with open technique. However, because of the limited number of small patients and lack of statistical validation, these findings must be considered in light of clinical experience at this stage.
The diagnosis of intussusception in adults is relatively rare; however, we are noticing an increase in the incidence of this complication in patients who have undergone gastric bypass surgery. At present, the etiology is not very well understood, and most believe that dysmotility due to the development of ectopic pacemaker plays a crucial role in creating an unstable zone that predisposes to telescoping of the bowel. Further, the thinning of mesentery due to excessive weight loss decreases the “cushion effect” and potentially augments the unstable zone. Female gender, relative young age, and loss of significant amount of excess weight loss are potential risk factors for developing intussusception.
The diagnosis is often difficult and not straightforward. This is because the initial physical examination and laboratory investigations are nonspecific. Further, it has been noted that plain X-rays and ultrasound are generally nonconfirmatory and can potentially blur the clinical picture further. Therefore, we propose a low threshhold for multimodality approach using a combination of initial examination, CT scan, and early surgical intervention to aid in diagnosis as well as provide optimal treatment.
We believe that surgical intervention should entail bowel resection and revision of anastomosis as it prevents recurrence. As regards the technique is concerned, we will leave it at the discretion of the individual surgeon.