Recurrent intussusception in infants

AIM

Clinical features to identify infants at increased risk of recurrence after a primary episode of intussusception (IS) are poorly defined.

METHODS

Prospective study of the clinical presentation, treatment and outcome in infants <2 years presenting with acute IS to the National Hospital of Pediatrics, Hanoi, over a 14-month period (1 November 2002 to 31 December 2003). A retrospective review of medical records was performed to verify complete patient ascertainment.

RESULTS

Five hundred ninety-eight children were recruited, including 513 (86%) with a primary episode only and 53 (9%) with ≥1 recurrent episodes. Another 32 (5%) infants presented with recurrent IS, but the primary episode of IS occurred outside the study period. Estimated recurrence risk at 6 months following a primary episode was 14%. A pathological lead point was rare in primary (n= 1) and recurrent IS (n= 1). Most infants were successfully treated with enema reduction.

CONCLUSIONS

This study describes the natural history of recurrent IS in infants and may assist in interpreting data from post-marketing surveillance following introduction of rotavirus vaccines.

Accuracy of ultrasonography for the diagnosis of intussusception in infants in Vietnam

BACKGROUND

Intussusception (IS) is the most common cause of acute bowel obstruction in infants and young children. Ultrasonography is being increasingly used as the primary investigation for the diagnosis of IS and to guide air or hydrostatic enema reduction. However the accuracy of ultrasonography outside tertiary care settings in developed countries has not been assessed, particularly in Asia where the incidence of IS based on sonographic diagnosis has been reported as the highest in the world.

OBJECTIVE

The aim of this study was to evaluate the accuracy of ultrasonography in the diagnosis of acute IS in infants less than 2 years of age in a paediatric hospital in Vietnam.

MATERIALS AND METHODS

A prospective study was conducted at the National Hospital for Paediatrics, Hanoi, Vietnam, over a 14-month period recruiting patients <2 years of age with IS. Abdominal ultrasonography was performed on each patient and the accuracy of the diagnosis was evaluated against the final diagnosis provided by air enema and/or surgery.

RESULTS

A total of 640 infants <2 years of age presented with clinical symptoms and signs of IS. The diagnosis was confirmed in 533 patients via air enema or surgery. Abdominal ultrasonography was 97.5% (466/478) sensitive and 99% (106/107) specific in the detection of IS.

CONCLUSION

Ultrasonography is an accurate, safe and valuable clinical tool in the diagnosis of IS. The use of ultrasonography as a primary investigation for patients with suspected IS prevents unnecessary radiological or surgical procedures being performed, and reduces radiation exposure while maintaining a high level of diagnostic accuracy. These results validate the use of ultrasonography for the diagnosis of IS in a developing country setting.

Risk factors for intussusception in infants in Vietnam and Australia: adenovirus implicated, but not rotavirus

OBJECTIVE

This study aimed to investigate risk factors for the development of intussusception in infants in a developing country with a suspected high incidence and in a developed country with a low incidence.

STUDY DESIGN

A prospective case-control study of infants <2 years of age with idiopathic intussusception confirmed by air enema or surgery was conducted at the National Hospital of Paediatrics (NHP), Vietnam (n = 533) and the Royal Children's Hospital (RCH), Australia (n = 51). Diagnosis was validated in a subset (84% NHP; 67% RCH) by an independent blinded radiologist. Risk factor assessment was performed using a standardized questionnaire. Stool specimens were assayed for bacterial, viral, and parasitic agents.

RESULTS

The incidence of intussusception in Vietnam was 302/100,000 in infants <1 year of age (95% CI: 258-352), substantially higher than in Australia (71/100,000). A strong association with adenovirus infection was observed at both sites (cases positive at NHP: 34%, OR 8.2; cases positive at RCH: 40%, OR 44). No association was identified between intussusception and rotavirus, other enteric pathogens, oral polio vaccine, feeding practices, or living conditions.

CONCLUSIONS

The incidence of intussusception in infants was markedly higher in Vietnam than in Australia. A strong association between adenovirus infection and intussusception was identified at both sites suggesting that adenovirus may play a role in the etiology of intussusception.

Intussusception: trends in clinical presentation and management

BACKGROUND

The association of a rotavirus vaccine and intussusception has renewed interest in understanding the incidence, clinical presentation and outcome of intussusception.

METHODS

A retrospective chart review of all patients diagnosed with intussusception at Royal Children's Hospital, Melbourne over a 6.5-year period (1 January 1995-30 June 2001) was conducted using patients identified by a medical record database (ICD-9-CM code 560.0 1993-1997; ICD-10-CM code 56.1 1998-2001). Patient profile, clinical presentation, diagnosis methods, treatment and outcome were analyzed and compared to data previously reported on children with intussusception at the same hospital during 1962-1968.

RESULTS

The hospitalization rate for primary idiopathic intussusception increased marginally from 0.19 to 0.27 per 1000 live births during the period 1962-1968 to 1995-2001. Most patients (80%) were <12 months of age (median age 7 months, range 2-72 months). The combination of abdominal pain, lethargy and vomiting was reported in 78% of infants. Air enema confirmed the diagnosis of intussusception in 186 of 191 cases (97%) and air reduction was successful in most cases (82%). Factors associated with increased risk of intestinal resection included abdominal distension (32%), bowel obstruction on abdominal X-ray (27%) and hypovolemic shock (40%). No mortality was observed in the present study.

CONCLUSIONS

Over the past 40 years at Royal Children's Hospital, Melbourne the hospitalization rate due to primary idiopathic intussusception has marginally increased from 0.19 to 0.27 per 1000 live births. Diagnosis and treatment using air enema has been highly successful, resulting in a reduction in patients requiring surgery and reduced hospital stays.

mRNA levels of dipeptidyl peptidase IV decrease during intestinal adaptation

BACKGROUND

Glucagon-like peptide 2 (GLP-2) has recently been shown to be a potent enterotrophic factor that may mediate mucosal hyperplasia during intestinal adaptation. The intestinal brush-border protease dipeptidyl peptidase IV (DPP IV) cleaves GLP-2 to an inactive form. It has been postulated that DPP IV activity limits the enterotrophic activity of GLP-2 in rats and humans. Massive small bowel resection (MSBR) in rats is an animal model of intestinal adaptation that has been used successfully to characterize factors involved in the modulation of adaptation.

METHODS

Total RNA was extracted from normal terminal ileum or terminal ileum post-MSBR from Sprague-Dawley rats which were sacrificed 2, 4, and 7 days postresection. A partial rat DPP IV clone was isolated by reverse transcription polymerase chain reaction, and Northern blot analysis of rat DPP IV mRNA levels in normal small bowel and small bowel post-MSBR was performed.

RESULTS

Within normal small bowel, DPP IV mRNA levels were greatest in the terminal ileum; levels in the duodenum and jejunum were approximately 50% of those in the terminal ileum. DPP IV mRNA levels decreased in terminal ileum post-MSBR 2, 4, and 7 days after resection.

CONCLUSION

The decreased DPPIV gene expression suggests a novel mechanism by which the effects on mucosal growth of GLP-2 may be further enhanced, and further that GLP-2 may be a more useful therapeutic agent in humans than currently anticipated.