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.