Case Report J Clin Ultrasound 24:326-328, JulyiAugust 1996

CCC 0091-27511961060326-03 0 1996 by John Wiley & Sons, Inc.

Intestinal Ascariasis as a Cause of Bowel Obstruction in Two Patients:

Sonographic Diagnosis

Abdulhakim CoSkun, MD,* Nevzat Ozean, MD,* Ahmet Candan Durak, MD,* ismet Tolu, MD,* Mustafa Giileq, MD,* and Ciineyt Turan, MD'F

Ascaris lumbricoides, the most widespread and common of all helmints, has been seen in native populations at many locations throughout the world.' Clinical manifestations are divided into two groups: (1) those produced by the migration of larvae, i.e., respiratory manifestations' and (2) those produced by the adult worms. Intestinal ob- struction may develop as a complication of intes- tinal ascariasis when a mass of worms obstructs the lumen of the small bowel.'

The diagnosis of ascariasis in the intestinal system has become possible through the use of ultrasonography (US).3 We present two typical cases of roundworm infestation complicated with bowel obstruction.

CASE REPORTS

Case 1

A 5-year-old girl was admitted with the com- plaints of vomiting, acute colicky abdominal pain, and constipation which had begun 15 hours ear- lier. There was no previous episode of symptoms and no history of parasites. The physical exami- nation revealed rebound tenderness in the right lower quadrant. An abdominal radiogram showed air-fluid levels. A preliminary diagnosis of ileus was established, and an US examination was re- quested to clarify the etiology.

US revealed numerous, typical tubular, inter- wined structures in dilated intestinal segments in the right paraumblical region. These structures had two parallel echogenic bands with a central sonoluscent line in a coiled pattern and small tar- get views exhibiting slow curling movements.

They were very long and 0.3 cm to 0.6 cm wide. There was minimal fluid accumulation in the lower quadrants, and the appendix could not be seen. These findings were suggestive of an ascaris ball giving rise t o intestinal obstruction (Fig- ure 1).

Laparatomy, performed on the same day be- cause of the acute intestinal obstruction, revealed the jejunum, ileum, and cecum filled with round- worms. There was secondary accumulation of free fluid. Ileotomy was performed, and many of the roundworms were removed. After 5 days, the pa- tient was discharged.

Case 2

A 21-month-old boy was admitted with pain and diarrhea which he had been experiencing for 1 week. He had defecated a few roundworms prior to his hospital admission. The physical examina- tion revealed abdominal distention, guarding, and tenderness. Plain abdominal films were nor- mal. Partial obstruction was suggested clinically and a sonographic examination was requested to assist in the differential diagnosis.

Using real-time ultrasonography, findings similar to those in case 1 were seen, especially in the left lumbar region with some jejunal seg- ments (Figure 2). The diagnosis of ascariasis was made and the patient was treated with mebenda- zole. During the follow-up, the patient defecated a significant number of roundworms and his clini- cal symptoms disappeared. The patient was dis- charged.

DISCUSSION From the *Departments of Radiology and Pediatric Surgery, Hospital of Erciyes University, Medical Faculty, 38039 Kay- seri, Turkey.

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Ascariasis is one of the largest human intestinal infestation, particularly in children, and has a

JOURNAL OF CLINICAL ULTRASOUND

BOWEL OBSTRUCTION BY INTESTINAL ASCARIS

FIGURE 1. Ultrasound showed numerous, long, tubular structures longitudinally (arrows) and small target views transaxially (arrow- heads) in the right paraumbilical region. This suggested the tangled mass of roundworms.

world-wide distribution with the highest inci- dence in the Far East, Latin America and Af- r i ~ a . l , ~ , * These worms are typically tubular in shape with bilaterally symmetric bodies contain- ing an intestinal tract and a large body cavity. The adults vary in size.'P2 Infection is the result of oral ingestion of embryonated eggs derived from contaminated vegetables, water, or soil.

The second stage larvae inside the eggs hatch in the duodenum and penetrate the wall to reach the bloodstream, whence they are carried to the lungs. The larvae leave the blood circulation in the lungs, where they penetrate the alveolar wall and return to the intestine, via the trachea and esophagus. In the ileum they become adults whose eggs leave the body by the fecal route. Adult worms live mainly in the intestines, most commonly in the jejunum and middle ileum, but are notorius for their propensity to migrate through orifices and d u ~ t s . ' , ~ , ~ , ~ Wandering roundworms reaching abnormal foci provoke acute symptoms. These ectopic locations of round- worms may give rise to difficult diagnostic prob- lems.2 Some of them include: ileus, perforation of the bowel, acute appendicitis, gastric and duode- nal trauma, blockage of ampulla of Vater or the common bile duct, entry into the gall bladder, and the parenchyma of the liver.','

Intestinal obstruction is one of the serious com- plications of Ascaris infection resulting from me- chanical obstruction by a tangled mass of writh-

VOL. 24, NO. 6, JULYiAUGUST 1996

ing W O F ~ S . ~ ' ~ The presentation is similar to acute intestinal obstruction with vomiting, abdominal distention, and acute colicky pain.2 Patients may pass worms in vomitus or in stool during an at- tack which provides an important clue to the di- a g n ~ s i s . ~ , ~ Because the symptoms may simulate acute appendicitis and other causes of acute ab- domen, the diagnosis may be difficult, especially if there is no history of as~ar ias i s .~

The diagnosis is established on clinical grounds, but in suspicious cases roentgeno- graphic features may be important. In roentgen- ograms, air-fluid levels and occasionally a ball of roundworms may be seen. The appearance of as- caris in barium studies, as a filling defect within the barium column, is well known. On delayed views, filling of the alimentary tract with the roundworms may be seen.3

Recently, ultrasonography has offered a sim- ple, rapid, reliable approach which has facilitated the diagnosis of roundworm o b s t r u ~ t i o n . ~ ~ ~ * ' ~ ~ However, there are very few case reports in the literature about sonographic visualization of worms in the in t e~ t ine .~ Sonographic findings in- clude numerous, long, echogenic, tubular struc- tures that contain two parallel outer lines repre- senting outer walls, with a central sonolucent line representing the digestive tract of the worm. Transaxially the individual worm exhibits a small target view with an outer echogenic, circu- lar body and a central, sonolucent dot-like diges- tive tract. Slow, erratic, non-directional and curl-

FIGURE 2. Ultrasound revealed tubular structures (arrows and be- tween two plus signs) as two echogenic bands with central sonotus- cent line in the right upper hypochondrium similar to that in Figure 1.

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CASE REPORT: COSKUN

ing movements of worms are seen. The typical tubular appearance with active movements, char- acteristic of roundworms, makes the diagnosis easy .5,8,9

In conclusion, we emphasize that US is a useful technique in the identification of this parasite in the intestinal system. Although, in most cases, the diagnosis can be established clinically with- out any other examination technique, in some cases, US may show intestinal roundworms to be the cause of the bowel obstruction and clarify the e t i ~ l o g y . ~ The sonographic features of round- worms must be known by radiologists, especially in developing countries.

1.

2.

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Faust EC, Russel PF, Jung RC: Craig and Faust’s Clinical Parasitology, ed 8. Lea & Febiger, Philadel- phia, 1970, pp 335-343. Adel AFM: Intestinal nematodes (roundworms). In Mandell GL, Douglas RC, Benett JE, eds: Principles

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Gabaldon A, Mofidi C, Morishta K, et al: Control of ascariasis (report of an WHO Committee). World Health Organization Technical Report Series 379:6, 1967. Khuroo MS, Zargar SA, Yatoo GN, et al: Sono- graphic findings in gallbladder ascariasis. J Clin Ultrasound 20:587-591, 1992. Tolu 1, Giileq M, $ahin M: Ultrasonographic obser- vation of ascariasis in the choledochus. Turs J Resc Med Sci 9:327-329, 1991. Kiiqiikaydin M, Okur H, Iqer M, et al: Intestinal complications of Ascaris lumbricoides in children. Erciyes Medical Journal 11:484-489, 1989. Aslam M, Dore SP, Verbanck J J , et al: Ultrasono- graphic diagnosis of hepatobiliary ascariasis. J Ul- trasound Med 12573-576, 1993. Peck RJ: Ultrasonography of intestinal ascaris. J Clin Ultrasound 18:741-743, 1990.

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