Pneumatic reduction of intussusception using carbon dioxide

Pneumatic reduction using air has recently become popular for the initial non-surgical managment of intussusception. Since carbon dioxide (CO₂) is rapidly absorbed from body surfaces, it should theoretically result in less cramping and distension following reduction. We reviewed our recent experience with the pneumatic reduction of intussusception using CO₂ in 26 children. In 22 of these the intussusception was reduced (85%). There was one perforation with CO₂; the patient did not suffer any postoperative complications. Five additional children who had been treated unsuccessfully with barium had intussusception subsequently reduced with CO₂. Following CO₂ reduction, most children were fed within hours, and there were no instances of significant abdominal distension or cramping. We conclude that pneumatic reduction of intussusception using CO₂ is safe and effective, and has the theoretical advantage of more rapid absorption from the gastrointestinal tract than air.     

Intestinal intussusception survey about diagnostic and nonsurgical therapeutic procedures

Objective. To provide an overview of the diagnostic and therapeutic procedures performed by European paediatric radiologists in the management of intussusception. Materials and methods. A postal survey was sent to the European members of ESPR. Items surveyed included diagnostic imaging procedures (plain films, US, contrast enema [CE]), contrast medium used (barium, iodine, air, saline solution), and imaging technique used for monitoring during reduction (films, fluoroscopy, US). Multiple answers were possible. Other data, including contraindications, maximum pressure, pressure and irradiation monitoring, presence of a surgeon, sedation, number and duration of attempts, and hospitalisation were also obtained and analysed. Results. There were 204 respondents (60.2 %). Regarding diagnosis, 72.5 % of respondents used plain radiographs, 93 % US, and 34 % CE. Reduction was performed using air (55 %), a barium suspension (32 %), iodinated contrast medium (24 %), or a saline solution (10 %). Reduction was monitored using fluoroscopy alone (46 %), fluoroscopy and radiographs (49.5 %), US alone (9.5 %), or a combination of radiology and US (18 %). Pressure was monitored by 81 % of respondents. Most respondents (82.4 %) used a maximum pressure between 100 and 120 mm Hg. Conclusions. US is widely used for diagnosing intussusception. For treatment, contrast medium and air reduction are used almost equally. A large number of radiologists are now performing intussusception reduction using US monitoring. Received: 27 September 1998 Accepted: 15 January 1999     

Sonographic guidance of air enema for intussusception reduction in children

Background. Fluoroscopically guided air reduction of intussusception is a well-accepted technique. There are only two previous reports in which US has been used to monitor pneumatic reduction. Objective. To assess the ability of US to monitor the success of air reduction of intussusception. Materials and methods. Sonographically guided air-enema reduction of intussusception in 199 children. In phase I (11 children), the success or failure of reduction was confirmed by fluoroscopy. In phase II (188 children), complete reduction was confirmed by clinical improvement of the child and repeat sonography 1 h later showing no persistent intussusception. Results. In phase I, fluoroscopy confirmed the accuracy of US in all 11 children. In phase II, the success rate of initial reduction was 95 %. Following successful reduction, US repeated 1 h later showed no recurrence of intussusception in 92 %. In ten (5 %) of 188, initial reduction was unsuccessful; fluoroscopically guided air reduction successfully reduced only three of these ten failures. Conclusions. Air enema guided by US is a practical and reliable technique for the reduction of intussusception. Received: 26 April 1999 Accepted: 10 October 1999     

Enema reduction of intussusception with a small dose of iopamidol may have advantages over barium

Barium enema (B-enema) has been the standard method for hydrostatic reduction of intussusception, although recently air enema has been used due to the lower risk when perforation occurs. Recently, we have administered a small dose of iopamidol during enema reduction (I-enema) in children with intussusception. From November 1989 to December 1993, we treated 50 children with intussusception at Kiyama Hospital. Barium was used in the first half of the period, and iopamidol in the second half. Reduction was successful in 22 of 24 patients with barium (92%) and 23 of 26 with iopamidol (88%); 25 children had the ileocolic type and 25 the ileoileocolic (-cecal) type of intussusception. Operations were carried out in 3 patients from each group. I-enema avoids some of the drawbacks of barium and air enemas. It is a new method of enema reduction, as a contrast medium is injected first. It is possible to obtain a good image of the advanced portion with a small dose of contrast medium, which is important for treatment. For institutions performing B-enemas, I-enemas can be performed easily with the same equipment and technique. It causes less contamination upon leakage than a B-enema, and also has less influence on the intestinal membrane with very few risks if perforation occurs. Better images are obtained than with air. A large dose of contrast medium is not needed, thereby reducing medical expenses to a minimum. Iopamidol can be used safely for enema reduction of intussusception with an expected high success rate.     

Pediatric musculoskeletal computed radiography

Background. In conventional radiography, a film-screen system serves as the X-ray detector and the film also functions as an archival and display medium. Unlike film-screen radiography, these functions are uncoupled in computed radiography (CR). CR uses conventional radiographic equipment to expose an image on a storage phosphor plate instead of a film-screen combination. Objective. To review the basic concepts of CR and to provide a background for discussion of specific musculoskeletal applications of CR in children. Materials and methods. Various aspects of musculoskeletal CR in children are presented based on our 4 years' experience and a review of the literature. Results. A greater amount of scatter capture occurs with storage phosphor CR than with a film-screen system in the 70- to 120-kVp range. This is attributed to a lower K-absorption edge of barium in the barium fluorohalide (BaFBr) compound used in the imaging plate. A significant reduction of scatter to primary radiation, improvement in bony trabecular sharpness, and improvement in line pair resolution can be achieved in pediatric musculoskeletal imaging using an air gap without an increase in the skin entrance dose as compared to the non-grid table top technique. With CR, in addition to proper radiographic exposure technique, one needs to preprogram and select the optimal processing technique for each anatomic region, projection and age group of the child. Conclusion. The main advantages of CR in pediatric musculoskeletal imaging consist of a reduction in radiation dose for many applications, improved contrast resolution, near elimination of repeat radiographs related to exposure errors, and digital processing capabilities for image enhancement, storage, retrieval, display and transmission. The current limitations of CR include the moderately high start-up cost, the long learning curve to produce optimal films, and the reduced spatial resolution. Received: 10 May 1996 Accepted: 19 November 1996     

Air reduction of intussusception.

AIM: To show that intussusception in children is reducible in most cases, using air. METHODS: Initially we used a barium enema to treat paediatric intussusception. Now we use an air enema. We consider the latter reduction technique to be the method of choice in the treatment of intussusception in childhood. RESULTS: Over a period of 21 years, we have treated 151 patients presenting with intussusception. In a group of 130 children treated with barium enema we managed to reduce the intussusception in 110 cases (84.6 %). We used air pressure to treat a second group of 21 children; the success rate in this group was 100 %. CONCLUSIONS: In order to avoid a surgical operation this technique must become more generally known. We are of the opinion that if the method is applied correctly, it is almost always possible to correct intussusception using air.     

Ultrasound features of intussusception predicting outcome of air enema

Objective. To examine features identified on US which predict success or failure of air-enema reduction of intussusception. Materials and methods. A retrospective study of 117 consecutive episodes of intussusception, presenting for US over a 6-year period. The specific features examined were: free fluid within the peritoneum, small-bowel obstruction, colonic wall thickness, and fluid trapped between the colon and the intussusceptum. Results. The overall reduction rate, irrespective of US features, over the 6-year period was 72 %. Reduction rates were significantly higher with the absence of free fluid, trapped fluid, or small-bowel obstruction (93 %). The presence of trapped fluid predicted an unfavourable outcome, with a significantly lower success rate (25 %). Colonic wall thickness did not predict outcome; in successful reductions, mean wall thickness was 7.2 mm and in failed reductions 7.6 mm. Conclusions. Where free fluid, small-bowel obstruction, and trapped fluid are absent, almost 100 % success with air-enema reduction should be achievable. Where trapped fluid is present, air enema should be performed cautiously to avoid perforation caused by overvigorous attempts at pneumatic reduction of an incarcerated intussusception. Received: 5 August 1998 Accepted: 15 February 1999     

Radiological evidence of bowel obstruction in intussusception

Several criteria have been proposed to identify patients likely to be at risk from barium reduction of intussusception, those with a high probability of having a pathological lead point, and those in whom an enema is unlikely to be successful. Signs of peritonitis and septicaemia are regarded as absolute contraindications to attempted barium reduction of intussusception, but as yet the radiological appearance of small bowel obstruction per se has not been substantiated as a contraindication. The presence of small bowel obstruction indicates that therapeutic reduction is less likely to be successful than in patients with normal or nonspecific plain radiographs (31% vs 57%) but is not in itself an indication that the examination would be unsafe. Patients with small bowel obstruction are acceptable risks for safe and successful therapeutic enemas, provided there is no clinical evidence of gangrenous bowel. Offprint requests to: J. de Campo     

Are hydrostatic and pneumatic methods of intussusception reduction comparable?

The hydrostatic pressures and flow rates of barium sulphate and water soluble contrast in concentrations representative of those used for intussusception reduction were measured. The change of height with discharge of fluid from the filled kit was also assessed. A group of experienced paediatric radiologists and radiographers significantly underestimated the height to which contrast should be placed for intussusception reduction. The results indicate that baseline hydrostatic reduction pressures tend to be less and maximum pressures significantly less than those presently advocated for pneumatic reduction. This disparity may account for the apparent improvement in intussusception reduction rates reported for air enema when compared with barium enema. Intraluminal pressure monitoring during contrast enema would aid control of intussusception reduction but hydrostatic reduction would still be at a disadvantage because of lower flow rates. Where hydrostatic reduction is performed, the contrast density and height used should be set to give known pressure, according to local guidelines.     

Intussusception: recurrence following gas (oxygen) enema reduction

Over a 38-month period, prospective data were collected on all episodes of intussusception treated at the Royal Children's Hospital, Melbourne. There were 170 initial episodes for which a gas enema was performed, 127 of which were reduced successfully. Recurence occured in 10 patients following initial successful gas enema reduction, a recurrence rate of 7.9%, which compares with a recurrence rate of 8.9% with barium (P = 0.896). We conclude that the gas enema does not have a higher rate of recurrence than barium and that there is no evidence of a significant incidence of incomplete reduction unrecognised at the time of gas enema. Correspondence to: S. W. Beasley     

Air reduction of an intussusception caused by a pathologic lead point in an infant

Lead points that are the cause of an ileocolic intussusception are rare in infants [1], as is successful reduction using barium [2]. Air reduction of an intussusception with a pathologic lead point has not been previously reported. We report a case of an infant with an ileocolic intussusception secondary to a duplication cyst that was successfully reduced with air. The pathologic lead point was recognized at the time of reduction and confirmed with water-soluble contrast. Air is both a diagnostic and therapeutic contrast agent.     

Is barium enema reduction safe and effective in patients with a long duration of intussusception?

The aim of this study was to determine whether barium enema reduction (BER) is safe and effective in patients with a long duration of intussusception. Over the last 17 years, 104 patients were admitted to our hospital with a diagnosis of intussusception. All except 1 with peritonitis underwent BER primarily. Of the 103 intussusceptions treated primarily by BER, 84 (82%) were reduced by the enema alone, whereas 19 (18%) underwent surgical reduction. There were no differences in mean duration of disease between the patients with successful and failed enema reduction (successful: 15 ± 14 h; failures: 14 ± 11 h, P = 0.6). The success rate of BER was 85% within 12 h of symptoms, 76% for 12–24 h, and 71% for more than 24 h. Of 8 cases with a second trial, 4 (50%) were reduced by repeated barium enema. There were no deaths and no intestinal perforations. The success rate of more than 70% even in patients with a long duration of intussusception suggests that BER is safe and effective regardless of the duration of the disease. Accepted: 4 September 1998     

Multipolypoid intussusceptum: A distinctive appearance of ileoileocolic intussusception at the ileocecal valve

Objective. To determine whether ileoileocolic intussusception can be diagnosed by a distinctive appearance during pneumatic reduction.Materials and methods. We reviewed the clinical, pathologic, and imaging findings of 11 patients with ileoileocolic intussusceptions seen in our hospital between January 1989 and July 1994. The patients ranged in age from 4 months to 4 years and 2 months. We specifically evaluated the appearance of these intussusceptions on air enemas performed in nine of these patients. Another 22 air enemas of all patients with surgically proven ileocolic intussusception seen during the same time period were also reviewed for comparison.Results. In seven of the nine patients with ileoileocolic intussusception who had air enemas, the intussusceptum clearly had two or more separate polypoid components once it was reduced to the cecum. This distinctive appearance was not seen until the intussusceptum was tethered at the ileocecal valve. The intussusceptum was also reduced to the cecum in 19 patients from the control group with ileocolic intussusception. In contrast to the ileoileocolic intussusceptums, these intussusceptums were either smoothly marginated (16 patients) or slightly lobular (three patients).Conclusion. In most patients with ileoileocolic intussusception, the intussusceptum has two or more polypoid components at the level of the ileocecal valve which are easily distinguished from the smoothly marginated or slightly lobular intussusceptum seen with ileocolic intussusception.     

Adding a custom made pressure release valve during air enema for intussusception: A new technique

Background:

Non-surgical reduction remains the first line treatment of choice for intussusception. The major complication of air enema reduction is bowel perforation. The authors developed a custom made pressure release valve to be added to portable insufflation devices, delivering air at pressures accepted as safe for effective reduction of intussusception in children under fluoroscopic guidance. The aim of this study was to develop a custom made pressure release valve that is suitable for the insufflation devices used for air enema reduction of intussusception and to put this valve into regular clinical practice.

Materials and Methods:

An adjustable, custom made pressure release valve was assembled by the authors using readily available components. The valve was coupled to a simple air enema insufflation device. The device was used for the trial of reduction of intussusception in a prospective study that included 132 patients.

Results:

The success rate for air enema reduction with the new device was 88.2%. The mean pressure required to achieve complete reduction was 100 mmHg. The insufflation pressure never exceeded the preset value (120 mmHg). Of the successful cases, 58.3% were reduced from the first attempt while 36.1% required a second insufflation. Only 5.55% required a third insufflation to complete the reduction. In cases with unsuccessful pneumatic reduction attempt (18.1%), surgical treatment was required. Surgery ranged from simple reduction to resection with a primary end to end anastomosis. No complications from air enema were recorded.

Conclusions:

The authors recommend adding pressure release valves to ensure safety by avoiding pressure overshoot during the procedure.Key words: Air enema, intussusception, pneumatic, pressure release, reduction, safety, valve     

Experimental study of mortality and morbidity of contrast media and standardized fecal dose in the peritoneal cavity

Background. The use of radiographic contrast media in the setting of possible bowel ischemia and potential perforation is known to be associated with increased clinical risk. However, there is a lack of controlled studies using a standard native fecal load to define and compare the intrinsic mortality and morbidity among options of contrast media currently available to the radiologist. We have compared the mortality and gross and histopathologic morbidity of a standard intraperitoneal native fecal dose in the guinea pig, using barium, two iodinated media, saline and air.¶Materials and methods. The study was performed on adult Hartley guinea pigs. A standard native fecal solution with a colony count of 10⁸ aerobes and 2 × 10⁷ anaerobes was prepared, and the LD₅₀ of intraperitoneal injection of the solution was determined. The standard solution at the LD₅₀ dose was then used to compare the mortality and morbidity when commercial barium sulfate (18 % w/v), Conray 30 (iothalamate meglumine 30 %), 1:1 dilution of Conray 30 with sterile water, termed Conray “15” (iothalamate meglumine 15 %), saline and air, were added to the intraperitoneal injection of the fecal solution in five groups of 20 animals each. Mortality and acute (96 h) and chronic (30 days) gross and histopathology were assessed and graded according to a standard system and analyzed statistically.¶Results. Barium was significantly more deleterious than the dilute water-soluble iodinated media, saline and air. Mortality occurred within 24 h in the barium group and within the initial 48 h in all groups as follows: barium 19/20 (95 %); Conray 30 16/20 (80 %); Conray “15”¶7/20 (35 %); saline 0; air 0. Acute gross and histopathology showed extensive grade 4 lesions in 19/19 barium animals; less severe lesions were present in a lesser percentage of the animals in the other four groups. Entirely chronic lesions were present only in the single surviving barium animal and were non-significant (<400 μm) or absent in the other four groups.¶Conclusions. In our study, barium incurred the most significant deleterious short and long-term effects in the setting of fecal peritonitis. Dilute water-soluble media offer a much greater margin of safety. Saline under sonographic guidance is less deleterious than any of the positive radiographic contrast media. However, in our study, air was the safest contrast medium in the setting of peritoneal soiling.     

Radiation dose reduction in pediatric CT

The relationship between image noise and radiation dose was investigated in computed tomography (CT) images of a pediatric abdomen phantom. A protocol which provided a minimum absorbed dose consistent with acceptable image noise criteria was determined for a fourth generation CT scanner. It was found that pediatric abdominal CT scans could maintain diagnostic quality with at least a 50% reduction in dose from the manufacturers' suggested protocol.     

Intussusception reduced by barium enema. Outcome and short-term follow-up

A retrospective study was performed of 88 consecutive cases of intussusception that occurred during a 3-year period. Forty-eight patients experienced hydrostatic reduction of intussusception with barium enema and 40 patients required surgical correction of intussusception when barium enema reduction was unsuccessful. Patients with fever or duration of symptoms greater than 24 hours, or ileo-ileocolic type of intussusception had a significantly greater rate of unsuccessful hydrostatic reduction (p less than 0.001). Of 48 cases of intussusception hydrostatically reduced by barium enema, 47 patients received repeat physical examination after reduction, 45 having normal findings. Oral feeding was tolerated in these 47 patients within 12 hours after reduction. All 41 hospitalized patients were discharged within 24 hours of reduction without developing complication; of seven non-hospitalized patients, six reported no complications during the initial 24 hour post-reduction period. The single complication that occurred was recurrence of intussusception (ileo-ileocolic type) in a patient 6 hours after initial reduction; this was the only case in which neither post-reduction physical examination nor trial of feeding had been performed. Children with intussusception hydrostatically reduced by barium enema are at low risk for complication during the subsequent 24 hour post-reduction period. When the pre-reduction course has been relatively uncomplicated, the post-reduction physical examination does not reveal abnormalities, and the patient is able to tolerate oral feeding, close outpatient monitoring appears to be safe.     

Perforation during attempted intussusception reduction in children —a comparison of perforation with barium and air

This paper compares the effects on patients of perforation with barium and with air during attempted intussusception reduction by reviewing the clinical, radiological, surgical and pathological findings and sequelae in seven children who received barium and seven who received air. In both groups perforation occurred in infants under 6 months of age (with one exception) with a long duration of symptoms. All patients with barium enema required resection of bowel whereas only four with air enema required resection. Anesthetic times were longer in those patients with barium perforation in whom the intussusception did not move and there was a large leak. The patients with perforation due to air had a shorter hospital stay with decreased morbidity compared to those with perforation due to barium. Perforation occurred through areas of transmural necrosis in a minority of patients in each group. Perforations through normal bowel and shear injury (with air enema) indicate that increased pressure during the examination is an important factor in some patients. Because perforation with air is so much easier to deal with surgically and the children do better clinically, there is a tendency for some to consider perforation with air an inconsequential situation. However, a potential rare complication with this technique is tension pneumoperitoneum. Keeping this in mind, we continue to use air as the contrast of choice because the procedure in our hands is a safe, quicker and easier technique and we have achieved a substantial improvement in reduction rates. Overall reported perforation rates with air enema compare favourably with those due to barium enema.     

Musculoskeletal computed radiography in children: scatter reduction and improvement in bony trabecular sharpness using air gap placement of the imaging plate

The effect of various air gaps on computed radiographic musculoskeletal images was investigated using a knee phantom. Scatter to primary radiation ratios were measured using the beam stop method at air gaps ranging from 0 to 30 in. (0–762-mm). Bony trabecular sharpness, line pair resolution, quantum mottle and visualization of low-contrast beads in the soft tissues were evaluated. A significant reduction of scatter to primary radiation ratio, from a value of almost 1 at table top to about 0.4 at 10-in. (254-mm) air gap and about 0.2 at 25-in. (635-mm) air gap placement of the computed radiography (CR) imaging plate, was obtained. A progressive improvement in bony trabecular sharpness and line pair resolution, compared with the table top and Bucky images was observed on 10-in. (254-mm) through 25-in. (635-mm) air gap images. Sharpness of the bony trabeculae and line pair resolution were best on the 25-in. (635-mm) air gap images. The skin entrance radiation dose does not have to be increased for air gap digital radiography. The radiographic noise or quantum mottle is highest on the Bucky image, higher on air gap images and minimal on the table top images, despite a high scatter to primary radiation ratio at the table top. The lower quantum mottle on the table top images allowed for maximal visualization of low contrast densities in the soft tissues. Air gap radiography further improves musculoskeletal computed imaging by reducing the scatter to primary radiation ratio without an increase in the skin entrance dose. For significant reduction of the scatter to primary radiation ratio and best evaluation of line pair spatial resolution and bony trabeculae, a 25-in. (635-mm) air gap with digital radiography would be optimal. For evaluation of low contrast densities in the soft tissues, table top placement would be the technique of choice. Received: 29 December 1995 Accepted: 27 March 1996     

A multihospital survey of radiation exposure and image quality in pediatric fluoroscopy

Background. Traditionally, pediatric radiologists have been advocates of fluoroscopy systems that provide diagnostic images at the lowest possible radiation dose to the pediatric patient. Manufacturers of fluoroscopic equipment vary as to their claims of “low radiation“ exposures.¶Objectives. To obtain comparative data on radiation exposure and image quality from four pediatric hospitals, across variants of fluoroscopic equipment (such as pulsed versus continuous fluoroscopy).¶Materials and methods. Images were acquired from phantoms that simulated the size of a 3-year-old child. Phantom results, both stationary and rotating dynamic, were evaluated for radiation exposure and for image resolution of high- and low-contrast objects.¶Results. Radiation exposure from the four fluoro units varied widely; the lowest-dose selectable fluoro mode produced exposures varying between 34 and 590 mrads/min among the four fluoro units, and the highest-dose selectable fluoro mode produced 540–2230 mrads/min. The lowest radiation exposures were produced by pulsed fluoro units, and the very lowest radiation exposure was produced by a fluoroscope that had been especially optimized for pediatric imaging. There was only a small variation in image quality among the hospitals for visualization of stationary objects. A wide variability was noted for detection of objects on the moving phantom.¶Conclusions. The variability in the number of detected objects was considerably smaller than the variability in radiation exposure. Pulsed fluoroscopy provides improved resolution for moving objects. Optimization of one hospital's fluoroscope especially for pediatric imaging produced the best ratio of image quality to radiation exposure.