Intussusception: indications for ultrasonography and an explanation of the doughnut and pseudokidney signs

Intussusception: the accuracy of ultrasound-guided saline enema and the usefulness of a delayed attempt at reduction

BACKGROUND/PURPOSE

The aim of this study was to evaluate the therapeutic value of ultrasound (US)-guided saline enema for intussusception and the usefulness of a delayed attempt after at least 30 minutes when reduction has not been complete.

METHODS

One hundred ninety-five cases of intussusception were diagnosed with ultrasonography. US-guided saline hydrostatic reduction was performed in 194 with an additional attempt after at least 30 minutes in those cases in which only partial resolution had been achieved. The method was changed (the volume of the reservoir bag and the caliber of the catheter were increased) so we analyze two different periods; 85 cases are included in the first period and 110 in the second.

RESULTS

The global rate of successful reduction was 81.9% (159 of 194 cases), and it raised to 88.2% (97 of 110 cases) in the second period. In 15.5% cases (30 of 194) reduction was achieved in a delayed attempt at least 30 minutes after the initial partial resolution. The rate of recurrence was 9.7%. No perforation was seen.

CONCLUSIONS

The accuracy of US-guided saline enema in achieving intussusception reduction is high, similar to other methods, avoiding radiation exposure. A delayed attempt after a period of rest increases the rate of reductions.

Intussusception in children: current concepts in diagnosis and enema reduction

Intussusception cannot be reliably ruled out with clinical examination and plain radiography. However, a contrast material enema study and ultrasonography (US) allow definitive diagnosis of intussusception. The components of an intussusception produce characteristic appearances on US scans. These appearances include the multiple concentric ring sign and crescent-in-doughnut sign on axial scans and the sandwich sign and hayfork sign on longitudinal scans. Indicators of ischemia and irreducibility are trapped fluid at US and absence of blood flow at Doppler imaging. The aim of enema therapy is to reduce the greatest number of intussusceptions without producing perforation. Barium, water-soluble contrast media, water, electrolyte solutions, or air may be used with radiographic or US guidance. The differences in reduction and perforation rates between the various types of enemas are probably due more to perforations that occurred before enema therapy and the pressure exerted within the colon than to the contrast material used. The pressure within the colon is more constant with hydrostatic reduction than with air reduction; this fact may explain the lower risk of perforation with hydrostatic reduction. Radiation exposure is lower with air enema therapy than with barium enema therapy and is absent in US-guided enema therapy.

Ultrasonographic and clinical predictors of intussusception

OBJECTIVE

The objective of this study was to determine the positive and negative clinical predictors of intussusception and the correlation of ultrasonography and air enema in establishing this diagnosis.

STUDY DESIGN

This was a prospective descriptive cohort study.

SETTING

This study was performed in a tertiary care pediatric emergency department.

PARTICIPANTS

Eighty-eight of 245 candidates were assessed for clinical predictors of intussusception. All 245 cases were examined for correlation between ultrasonography and air enema.

INTERVENTIONS

A questionnaire, ultrasonography, and air enema were used.

RESULTS

Thirty-five of the 88 patients assessed for clinical predictors were positive for intussusception. Significant positive predictors were right upper quadrant abdominal mass (positive predictive value [PPV] 94%), gross blood in stool (PPV 80%), blood on rectal examination (PPV 78%), the triad of intermittent abdominal pain, vomiting, and right upper quadrant abdominal mass (PPV 93%, p = 0.0001), and the triad with occult or gross blood per rectum (PPV 100%, p = not significant). Significant negative predictors were a combination of > or = 3 of 10 clinically significant negative features (negative predictive value 77%, p = 0.035). Of the total 245 cases, intussusception (as confirmed by doughnut, target, or pseudokidney sign) was ruled out by ultrasonography in 97.4%. Alternate ultrasound findings comprised 27% of negative cases.

CONCLUSIONS

Excellent positive predictors of intussusception were identified prospectively. Although no reliable negative predictors were found, patients at low risk may be screened by ultrasonography.

Abdominal ultrasonography

This article focuses on ultrasonographic examinations of the abdomen and important intra-abdominal pathology. The liver and biliary tree are discussed first, followed by the use of ultrasonography in diagnosing appendicitis, ascites, and bowel obstruction. Pyloric stenosis and intussusception, important pediatric intra-abdominal problems, are also discussed.

Ileoileocolic intussusception in children: diagnosis and significance

The ileoileocolic type of childhood intussusception is difficult to diagnose pre-operatively and is associated with increased morbidity. This study describes the clinical and imaging features of 10 consecutive ileoileocolic intussusceptions diagnosed ultrasonically in 10 patients over a 36 month period. Ultrasound-guided hydrostatic reduction using Hartmann's solution was attempted in all 10 patients. Clinical and imaging features were compared with those of 28 ileocolic intussusceptions in 25 patients diagnosed and treated using the same methods during the same period. Most of the clinical and plain radiographic features of the patients with the ileoileocolic and ileocolic types of intussusception were similar. The two types of intussusception had the classical doughnut or pseudokidney, or both, signs on pre-reduction ultrasound scans. During the reduction process, when surrounded by fluid within the caecal lumen, the ileoileocolic type of intussusception had a typical complex appearance due to frond-like loops of intussuscepted small bowel. This finding was present in all cases. The hydrostatic reduction rate was only 10% (1/10) for ileoileocolic intussusception, compared with 92.9% (26/28) for the ileocolic type. All unsuccessfully-reduced cases underwent surgery, with surgical confirmation of the intussusception type in all cases. Only one patient was found to have a lead point, caused by a Meckel's diverticulum. In conclusion, the diagnosis of ileoileocolic intussusception can be made pre-operatively and these patients require surgical management.

Controversies in abdominal imaging

Technologic improvement in ultrasound equipment, together with new clinical information, has altered the imaging of the abdomen in infants. Improvements in ultrasound equipment have allowed this to become the diagnostic test of choice for hypertrophic pyloric stenosis. Barium upper gastrointestinal radiography still remains the diagnostic test of choice for malrotation. New technologies for reduction of intussusception include air reduction and saline enemas with ultrasound monitoring. Controversies surrounding the different technologies and imaging strategies are discussed.

The diagnosis and management of adult intussusception

BACKGROUND

While intussusception is relatively common in children, it is a rare clinical entity in adults, where the condition is almost always secondary to a definable lesion.

DATA SOURCES

Thirteen cases of intussusception occurring in individuals older than 16 were encountered at our institute between 1981 and 1994.

RESULTS

Presenting signs/symptoms included recurrent bowel obstruction, intermittent pain, and red blood per rectum. Correct preoperative diagnosis was made in six patients using colonoscopy, flexible sigmoidoscopy, upper gastrointestinal (GI) series and computed tomography (CT). At surgery the lead point was identified in the small intestine in eight cases, in the colon in four cases, and one small intestinal intussusception was considered idiopathic. Twelve patients underwent laparotomy and one patient was both diagnosed and treated by colonoscopy alone.

CONCLUSIONS

Adult intussusception is an unusual cause of bowel obstruction. The likelihood of neoplasia, particularly in the colon as a cause, is high. Operative management is thus almost always necessary.

Hydrostatic reduction of intussusception under US guidance

The current nonoperative management of ileocolic intussusception includes hydrostatic and pneumatic reduction, both performed under fluoroscopic monitoring. Recently, a new technique--ultrasound-guided reduction--replaced the conventional approach in our institution. Over a 20-month period, 46 intussusceptions were diagnosed sonographically in 40 patients. In all cases, reduction was attempted under ultrasound guidance by means of a normal saline enema. In 42 cases (91%) reduction was successful and only four patients had to be operated (two resections, two manual reductions). Complications did not occur. This technique permits distinct visualization of the entire process, providing a clear and detailed echogram of the fluid-filled large and small intestine. We established the following definite criteria of reduction: disappearance of the target, demonstration of the ileocecal valve, visualization of the fluid reflux, and fluid filling of small bowel loops. The presented technique for the reduction of intussusception without radiation exposure is reliable and safe, and appears to be one of the most promising methods for the nonoperative treatment of ileocolic intussusception.

Ultrasound-guided water enema: an alternative method of nonoperative treatment for childhood intussusception

Ultrasound-guided water enema (USWE) reduction was performed in 115 patients with intussusception, which was diagnosed by ultrasound between April 1988 and August 1992 at Keimyung University Dongsan Medical Center. The overall rate of successful reduction was 80.9%. The rate was 91.0% for patients with symptoms of < or = 24 hours' duration, and 61.1% for patients with symptoms of more than 24 hours' duration (P < .001). Six patients had recurrence during the study period (recurrence rate, 5.2%). There was no perforation or other complications during and after the water enema reduction. The authors conclude that (1) USWE reduction for childhood intussusception has a higher rate of successful reduction and a lower rate of recurrence than does barium enema and (2) USWE is safe and may be an alternative method in the nonoperative treatment of intussusception.

Ultrasonography is accurate enough for the diagnosis of intussusception

For more than 10 years the authors have been using ultrasonography to confirm clinically suspected intussusception without performing a contrast enema. The aim of this study is to review this diagnostic policy. Between 1980 and 1989, 163 children who, on clinical examination and plain abdominal radiographs were suspected of having intussusception, underwent ultrasonography to confirm the diagnosis. In 33 children, ultrasonography did not show intussusception; of the remaining 130 children, intussusception was diagnosed in 128. In two children in whom intussusception was noted subsequently, the diagnosis was not established on ultrasound. Thus, ultrasonography had a sensitivity of 98.5% and a specificity of 100% in the diagnosis of intussusception. It is a quick, simple, noninvasive method to diagnose intussusception, with high accuracy. The role of contrast enema is limited to therapeutic application.

Pneumatic reduction of intussusception: clinical experience and factors affecting outcome

Between 1987 and 1992, 54 patients (32 male, 22 female) underwent 62 attempts at pneumatic reduction of intussusception. The mean age at presentation was 12.5 months (range 2.5 to 4 years 4 months). A retrospective review of all cases was performed to identify success rate and factors affecting it. Successful reduction was achieved in 46 cases (74%). One case was complicated by perforation and four cases (7%) by early recurrence. Patients with failed pneumatic reduction were more likely than those with successful reduction to have: (1) long duration of symptoms; (2) bleeding per rectum; (3) small bowel obstruction. Among the 16 cases of failed reduction, surgical findings were: five cases of ileo-ileo-colic intussusception, one with ileo-ileal, one with perforated ischaemic colon during air enema and one whose intussusception was found to be reduced at surgery. Three patients had lead points: Meckel's diverticula in two and a pinworm in one. Resection was required in three cases for non-viable bowel and in another two for the Meckel's diverticula. Pneumatic reduction of intussusception offers a high success rate with few complications. Performing an air enema earlier in the course of the disease may increase the chance of successful reduction.

Small bowel obstruction in children: review of 10 years experience

Small bowel obstruction, excluding postoperative adhesive ileus, in patients > 1 month old treated between June 1982 and May 1992 at Gunma Children's Hospital Medical Center is reviewed. There were 32 patients, 22 boys and 10 girls, whose ages ranged from 1 month to 6 years (median 9 months). Intussusception was the most frequent cause of obstruction and was seen in 17 patients (53.1%). Causative lesions were identified in five patients, and were ileal duplication cysts in four and Meckel's diverticulum in one. Incarcerated inguinal hernia and mesenteric cysts resulted in bowel obstruction in six and three patients, respectively. Other causes included mesodiverticular band, ileal volvulus without malrotation, abnormal adhesion of omentum, abnormal band, vitelline duct remnant and trapping in a mesenteric defect. As for the age distribution, there was no significant correlation between the causes of obstruction and the age of patients. Ultrasonography was useful in differential diagnosis, and this modality should therefore be used in every patient with signs of small bowel obstruction.

Roundworm obstruction: sonographic diagnosis

We describe the sonographic findings in five pediatric patients with roundworm obstruction. All patients were referred with a clinical diagnosis of acute appendicitis. On ultrasonography (US), an individual worm, when viewed along its longitudinal axis, appeared as a hypoechoic tubular structure with well-defined, echogenic walls. Frequently, the individual body segments could be distinctly visualized. The alimentary canal of the worm was seen either as a single central echogenic line (when in a collapsed state) or as two parallel hyperechoic bands with a hypoechoic center (when distended). When examined transaxially, the individual worm resembled a target with its circular, echogenic body wall and its central dot-like alimentary canal. On prolonged scanning, the worms always showed curling movements. In two patients, a bolus of worms mixed with fecal matter and air produced an unusual appearance of a complex, echogenic mass (helminthoma). Although, an individual worm occasionally resembled an inflamed appendix, visualization of the alimentary canal and individual body segments along with its curling movements helped establish the correct diagnosis. All patients promptly responded to a hypertonic saline enema and no patient was subjected to surgery. Sonographic findings in roundworm obstruction are fairly characteristics to advocate the routine use of sonography for diagnosing this entity.

Peritoneal fluid in children with intussusception: its sonographic detection and relationship to successful reduction

A retrospective review of the abdominal/pelvic ultrasound (US) examinations in 21 consecutive children with intussusception proven on barium enema was performed to determine what is the incidence of US detected peritoneal fluid in this population and to see if the rate of reduction was different in this subset. Twelve of the 21 children (57%) had free fluid demonstrated with US. Eight of these 12 (67%) had successful reduction. Six of the nine children (67%) without free fluid were also successfully reduced.

Paediatric intussusception

Intussusception is one of the commonest causes of intestinal obstruction in infants and accounts for about 700 hospital admissions each year in England and Wales. Improved results of treatment have followed recent technological developments, which include ultrasonographic imaging and pneumatic reduction techniques. Most intussusceptions can be reduced successfully without the need for operation but close cooperation between surgeon and radiologist is essential. Mortality and morbidity rates from the condition have progressively declined in recent decades but avoidable deaths still occur.

Clinical application of ultrasonography in the diagnosis of intussusception

Sixty-five consecutive patients seen in a pediatric emergency department, in whom the diagnosis of intussusception was considered, had an ultrasound examination of the abdomen before a barium enema. The mean age of the patients was 1.7 years (range 2 weeks to 5 years). Intussusception was detected by ultrasonography in all 20 cases proved by barium enema. There were three false-positive ultrasound results (sensitivity = 100%, confidence interval (Cl) = 86% to 100%; specificity = 93%, Cl = 86% to 96%). Normal findings on ultrasonography correlated with a negative barium enema results in 42 of 42 cases (negative predictive value = 100%, Cl = 94% to 100%). No intussusception was missed by ultrasonography. To determine which patients would most benefit from ultrasonography, we divided patients into either a high-risk group (81% with intussusception) or a low-risk group (14% with intussusception) on the basis of clinical symptoms (p less than 0.01). If each high-risk child had a barium enema and each low-risk child had an ultrasound study as their initial diagnostic test, 89% of the patients in this study would have undergone only one examination. We conclude that ultrasonography can be used as a rapid, sensitive screening procedure in the diagnosis or exclusion of childhood intussusception. Children considered at low risk of having intussusception on the basis of clinical symptoms should initially have an ultrasound examination; patients at high risk should have an immediate barium enema.

Ultrasound of intussusception with lead points

Ultrasonography of 4 cases of intussusception in children with proven lead points were reviewed retrospectively. The lead points were due to lymphosarcoma, inverted Meckel's diverticulum, jejunal polyps and an inverted appendiceal stump. The lead points form a complex mass in the centre of the intussusception in both transverse and longitudinal sections, distinct from primary intussusception. The presence of such ultrasonographic findings are suggestive of secondary intussusception with a lead point and surgical reduction rather than hydrostatic reduction should be considered.

Unusual cases of intussusception

Intussusception occurs most commonly in the first five years of life and is classically associated with intense intermittent abdominal pain, vomiting, bloody mucoid diarrhea, and a palpable abdominal mass. These cardinal findings are frequently not present, however, particularly outside the usual age range. The emergency physician must therefore be vigilant in considering intussusception as a potential cause for intestinal obstruction in all patients, if ischemic complications are to be avoided. We present three cases of "unusual" intussusception, and provide a review of this entity and a guide to its consideration and work-up in the emergency department.

Ultrasonographic detection of free peritoneal fluid in uncomplicated intussusception

Two cases of intussusception with free peritoneal fluid detected by ultrasound are presented. In neither of these cases was the fluid associated with perforation or intestinal compromise. After assessing the findings in these patients, we believe that small amounts of fluid may well be present in uncomplicated intussusception. Furthermore, we feel that its presence should not constitute a contraindication to nonsurgical reduction if no associated clinical findings to suggest perforation or intestinal compromise are present.

Diagnostic value of ultrasound in children with recurrent abdominal pain

In order to investigate the diagnostic value of ultrasound in children with recurrent abdominal pain and to estimate the clinical relevance of rare organic causes of abdominal pain in these patients, we prospectively examined 93 children aged between 5.5 and 12 years by means of abdominal ultrasound. In 3 patients (3.2%) an anatomic abnormality was detected, which could not account for the abdominal pain. We conclude that many organic abnormalities, that could be diagnosed by ultrasound, are clinically irrelevant as a cause of recurrent abdominal pain in children and therefore ultrasound does not significantly contribute to the diagnosis. However, ultrasound can still play a role in the work-up of children with recurrent abdominal pain in avoiding unnecessary radiologic X-ray procedures.

Ultrasound findings in post-operative jejunojejunal intussusception

The case is reported of an 11-year-old boy, who developed bowel obstruction after surgical exploration of a kidney transplant. An ultrasound study showed a jejunojejunal intussusception.

Documentation of spontaneous reduction of childhood intussusception by ultrasound

Spontaneous reduction of a presumed ileo-colonic intussusception was demonstrated by ultrasound examination followed by a barium enema. No premedication or anesthetic had been given to the child. This case illustrates the possible natural history of intussusception rarely confirmed by imaging studies. Intussusception is the most common abdominal emergency of early childhood. Diagnosis and therapy is usually performed with a contrast enema. If unsuccessful, surgical reduction is indicated. We wish to report a case of spontaneous reduction of a presumed ileocolonic intussusception. This was initially diagnosed by ultrasound examination, but had spontaneously reduced by the time a barium enema was performed.

Echogenic focus in the gastrointestinal wall as a sign of ulceration

An ultrasound study carried out on 22 patients with ulcerated gastrointestinal lesions (20 adenocarcinomas and 2 peptic ulcers) showed, in all cases, an echogenic focus (EF) that was situated in the gastrointestinal wall. In order to find out the histopathologic significance of this focus and its location, an examination was made "in vitro" of 8 surgical specimens obtained from gastrectomies--6 from peptic and 2 from malignant ulcers. The specimens were immersed in a water bath using a 5-MHz transducer. A common finding in all the specimens was an EF similar to that seen in the clinical study and situated behind the crater of the ulcer. In this location the histopathologic findings demonstrated necrotic and inflammatory material in both the benign and malignant lesions.

Intussusception. A case that suggests a new cardinal symptom--lethargy

Intussusception is an uncommon condition, but it is the most frequent cause of bowel obstruction in infants and children aged 3 months to 5 years. If undiagnosed, it can result in bowel necrosis, perforation, and even death. Four cardinal signs and symptoms (abdominal pain, rectal bleeding, vomiting, and abdominal mass) are described in patients with intussusception, but these manifestations are not always present and their absence may lead to misdiagnosis. Lethargy might be considered a fifth cardinal symptom. As demonstrated in this case, lethargy may be a significant presenting feature in an infant with no history of abdominal pain, and in association with the other cardinal symptoms, it may be an early indication of a significant illness such as intussusception. Awareness of this association may result in an earlier diagnosis and an improved outcome in patients with intussusception.

Carcinoma of the colon: diagnosis by ultrasound and enema

Carcinoma of the colon presenting before puberty is rare and few cases have been recorded in radiological literature. The symptomatology is usually vague but may be similar to the classical presentation of adults. The barium enema will also show the same constricting lesions. Two cases are reported, in one of which the initial diagnosis was made by ultrasound.

Ultrasonic diagnosis of duodenal diaphragm

A case of duodenal diaphragm diagnosed by ultrasound is presented. The case was associated with situs inversus.