A study using 2011-2012 data from the National Health and Nutrition Examination Survey found that 35% of US adults aged 20 years or older were obese.¹ In 2010, 6.6% of the US adult population were morbidly obese.² Obesity and morbid obesity have a multitude of negative health effects.³ 

Although nonsurgical approaches to weight loss, including lifestyle modification and medications, are effective, none have proven to be as successful as surgical methods.⁴ Of the various surgical procedures, laparoscopic adjustable gastric banding (LAGB) has been the most commonly used and least invasive. Benefits include a shorter recovery, smaller surgical scars, a lower complication rate, and potential reversibility. 

In 1993, the first LAGB was performed in Europe, and, in 2001, the technique was brought to the United States.⁵ It has subsequently been shown that LAGB produces an average weight reduction of 15.9% when measured 3 years after LAGB placement.⁶ 

Although the procedure has proven benefits, potential complications include infection, mechanical obstruction, chronic abdominal pain, gastroesophogeal reflux disease, gastric ulceration, and erosion of the band into a hollow viscus (usually the stomach).⁷ When erosion occurs, the device must be surgically removed and any damage repaired. 

The rate of erosion is relatively low at 1.5% to 3.4%.^8,9 A retrospective review of 865 patients over 6 years detected band erosion at a nominal average rate of 1.96%, with incidences decreasing further with increased surgeon experience.¹⁰ In this study,¹⁰ the vast majority of band erosions occurred early, with 55% occurring within the first year and 90% occurring within the first 2 years. Incidences of erosion of the band into the small bowel and colon are rarely reported in the literature.^11-14 In all of these cases, the patient was either symptomatic or exhibited lack of weight loss. 

We present a case of asymptomatic LAGB erosion in which both the band and the tubing eroded into the stomach and colon, and the tubing further eroded out of and back into the colon several times. Beyond the rarity of the nature of the erosion itself, we discuss several other features of the case that make it especially atypical. 

A 60-year-old woman with a body mass index of 27.6 and a history of hypertension, type 2 diabetes mellitus, and distant LAGB placement 6 years earlier presented to the emergency department for evaluation after a foreign body was noted in the colon on a routine colonoscopy and confirmed on computed tomographic scan. She had a history of LAGB port infection approximately 4 years earlier but had been asymptomatic since. Her body mass index had declined appropriately after placement of the LAGB. At presentation, she denied having any symptoms and had normal abdominal examination findings. 

Non–contrast-enhanced computed tomographic scans of the abdomen and pelvis performed on the day of colonoscopy and emergency department evaluation revealed that the LAGB was in the lumen of the stomach and, furthermore, that the inflation catheter was adjacent to and possibly within the descending colon (Figure). 

The patient was taken to the operating room for surgical removal of the device. On direct examination, the LAGB was found in the lumen of the stomach. Within the lumen of the colon, the tubing was noted to both originate from and extend back into the stomach. The device appeared to have eroded into the stomach, with the tubing extending into the bowel, traversing the colonic wall several times, and then returning to the stomach. 

Definitive surgical repair included open laparotomy, lysis of adhesions, gastrostomy with LAGB removal and gastrostomy closure, limited resection of the transverse colon with primary reanastamosis, and removal of the subcutaneous LAGB port. The patient's postoperative course was unremarkable. 

There are several recognized mechanisms for LAGB erosion. The first is early erosion of the gastric wall, occurring soon after initial LAGB insertion.¹⁵ The second involves chronic, recurrent microperforation and infection precipitated by the shearing forces exerted on the stomach wall secondary to physiologic movement of the gastric wall and diaphragm.¹⁶ Several factors, such as chronic overfilling of the LAGB, can contribute to these shearing forces. A third mechanism involves the immune response precipitating chronic inflammation at the interface of the LAGB and the gastric mucosa, eventually causing fibrosis, contraction of the tissue, and subsequent erosion.^17-19 Most authorities suggest a multifactorial cause of LAGB erosion.²⁰ The extent of scar tissue formation and adhesions seen during the current patient's operation strongly suggested a chronic inflammatory process as the primary cause. 

Several features of this case are noteworthy. First, whereas most cases of LAGB erosion are detected within the first 2 years of placement, this case provides an example of an erosion detected after 6 years.¹⁰ Second, erosions into the small bowel and colon are exceedingly rare. Third, in all such reported cases,^11-14 the patient was either symptomatic or exhibited a lack of weight loss; the current patient, however, was completely asymptomatic despite an episode of port infection 4 years earlier, and she had lost a reasonable amount of weight since the procedure. 

Gastroduodenoscopy is the criterion standard diagnostic test for LAGB erosion in symptomatic patients. It is not currently recommended for asymptomatic patients. The current case demonstrates that the initial erosion of an LAGB into the stomach can be followed by further distal migration of the tubing and extensive subsequent colonic erosion without obvious symptoms or signs and without a lack of weight loss. Studies designed to specify the prevalence of asymptomatic LAGB erosion in patients with erosion risk factors could be helpful in identifying a subpopulation of patients that would benefit from increased surveillance and a lower threshold for diagnostic evaluation.