Disintegration of Large Gastric Lactobezoars by <i>N</i>‐acetylcysteine

Abstract

A gastric lactobezoar is a freely floating mass in the lumen of the stomach composed of undigested milk and mucous secretions. In infants and small toddlers it is the most common type of bezoar as compared with other bezoar types such as tricho-, phyto-, mixed food, or medication bezoars (1). The etiopathogenetic factors implicated are inadequate milk composition, and disturbed gastric emptying, which impedes food fragmentation as well as abnormal secretion of gastric acid, pepsin, and mucus. Bezoar formation has been reported with every type of milk, including human breast milk (2,3), cow's milk, and cow's milk- or soy-based commercial infant formulas (4,5). Gastric lactobezoars may grow to considerable sizes. With a high index of suspicion, diagnosis can be easily made by plain or contrast radiography and, provided an experienced examiner, also by ultrasonography. Successful treatment measures include discontinuation of oral feeding, intravenous fluids, and gastric lavage (4,6). However, despite these therapies, in a few published cases lactobezoars did not disintegrate as expected and caused serious complications such as persistent gastric outlet obstruction or gastric perforation (7–12). We here describe 3 patients with large gastric lactobezoars that did not readily dissolve with the standard treatment of nil per mouth and intravenous fluids. Having in mind serious complications reported in the literature (8–10), we looked for options other than endoscopy or surgery to quickly disintegrate lactobezoars resistant to the established standard therapy. N-Acetylcysteine (ACC) has been known as an effective bronchial mucolytic agent for a long time and was successfully used for the treatment of a mixed food bezoar in an adult (13). We report for the first time the use of intragastric ACC for the rapid dissolution of large gastric lactobezoars in 3 female toddlers. METHODS Clinical data were obtained retrospectively from the patient's hospital charts. Methods of lactobezoar visualization included ultrasound of the abdomen and abdominal plain and double-contrast radiography of the upper gastrointestinal tract using a nonionic water-soluble medium (Jopamiro 200, Brucco, Italy) combined with air insufflation via a nasogastric tube. Administration of ACC was performed after written informed consent from the parents and followed the method reported by Schlang (13): we gave 10 mg · kg−1 · dose−1 of ACC in 50 mL of physiologic saline via a nasogastric tube. After 6 hours gastric fluid was aspirated. If milk curds were still present, then additional doses of ACC were administered every 6 hours. The treatment was terminated when no milk curds were visible in the gastric aspirate, and an ultrasound scan confirmed the complete dissolution of the lactobezoar. CASE DESCRIPTIONS The patients' clinical data are summarized in Table 1. Each of the 3 girls was born at term after an uneventful pregnancy. Each had been initially breast-fed but was given large amounts of cow's milk within 1 to 3 months before admission to the hospital. All of the patients presented with pallor, tachycardia, and were found to have iron deficiency anemia (Table 1). Patient 1 showed impressive generalized edema and hypovolemia, whereas the other 2 girls were dehydrated due to emesis, and in 1 case also to diarrhea. The presence of a gastric lactobezoar was demonstrated in all 3 girls by ultrasound (Fig. 1, showing the lactobezoar in patient 1) and confirmed by double-contrast radiography in patient 1 (Fig. 2). The gastric lactobezoars resolved after 8 intragastric administrations of 10 mg · kg−1 · dose−1 ACC in patients 1 and 2 and after only 5 courses in patient 3. The dissolution of the lactobezoars (Fig. 3A, patient 1 as an example) was confirmed by ultrasound (Fig. 3B) and by the aspiration of clear, milk curd–free gastric juice in all of the 3 patients.TABLE 1: Clinical data from 3 patients with gastric lactobezoarFIGURE 1: Transverse ultrasound scan of the upper left abdomen shows a distended stomach filled with a lactobezoar, that is, a mass of low echogenicity (arrows) containing multiple interspersed spots of high echogenicity indicating immobile trapped air (arrowheads).FIGURE 2: Double-contrast examination of the stomach. The lactobezoar mass filling the gastric fundus and corpus is outlined by arrows.FIGURE 3: Transverse scans of the gastric fundus. (A) the lactobezoar (low echogenicity) touches the gastric wall (arrows): fixed echogenic signals within the lactobezoar represent trapped air (arrowheads). (B) Same gastric area after 48-hour course of ACC: fluid with multiple small mobile echogenic gas bubbles indicates dissolution of the lactobezoar.DISCUSSION We have demonstrated in 3 female toddlers that lactobezoars resistant to the standard treatment of nil per mouth and intravenous fluids can be quickly dissolved by intragastric ACC. These patients had been predominantly fed with cow's milk, and milk curds were seen in their gastric aspirates before giving ACC, confirming the nature of the bezoars as lactobezoars. Given the reported complications of gastric lactobezoars (6,8–10,12) it seemed prudent to disintegrate these dense agglomerations of milk and mucus as soon as possible. Of the 76 patients with lactobezoars found in the literature, 37 had shown signs of at least intermittent gastric outlet obstruction, 12 subjects were reported to be severely dehydrated, and 8 patients failed to thrive. In 7 patients lactobezoars led to gastric perforation whereby at least 2 of them were known to have died from this complication. With standard treatment a widely varying duration of lactobezoar disintegration of up to several weeks (6,8,10,12,14) has been reported, which may have been too long to avoid gastric perforation (6,8–10). Surgery or endoscopic disintegration was performed in 9 patients, and at least 2 patients died (9,10). ACC, in analogy to its well-known effect on bronchial mucus, is thought to exert its mucolytic activity on gastric lactobezoars by attacking disulfide bonds between mucopolysaccharide fibers. It is largely a nontoxic drug with few side effects (15). In adults, ACC has been shown to be effective for the disintegration of gastric mixed or phytobezoars (13,16). To the best of our knowledge, the use of the drug for gastric lactobezoars in children has hitherto not been reported. In the 3 patients described in this article, ACC was administered via nasogastric tube at a dose of 10 mg/kg every 6 hours and led, within no more than 48 hours, to successful disintegration of large lactobezoars that had resisted the standard therapy before. We therefore regard ACC as a reasonable option for the treatment of large lactobezoars in the case of failure of conventional therapy after 72 hours and before endoscopic or surgical removal is considered.