Urinary tract infections in children. An update.

Urinary tract infection is a common and frequently recurring condition in children. The susceptibility of the host, the presence of urinary tract abnormalities, and the virulence of the urinary pathogens are of primary importance in the development of the infection. Renal parenchymal scarring, hypertension, and renal insufficiency are well-established complications of the infection in children. To reduce the risk of renal damage, diagnosis and treatment must be prompt. The diagnosis demands radiologic evaluation of the urinary tract in all boys, all children younger than 5 years, all patients with voiding dysfunction, and school-aged girls with recurrent infection to identify those patients with vesicoureteral reflux, obstruction, or other urinary tract abnormalities. Both voiding cystourethrography and renal ultrasonography are the initial examinations to use to determine the next appropriate study. Children with vesicoureteral reflux or with recurrent urinary tract infections should receive prophylactic antibiotic therapy and should be observed closely to prevent renal scarring.

Primary vesicoureteral reflux in blacks with posterior urethral valves: does it occur?

Primary vesicoureteral reflux (VUR) is thought to be largely independent of obstruction. Therefore, in patients with urethral obstruction due to posterior urethral valves (PUV) the occurrence of VUR is coincidental. In addition, primary VUR is reported to be uncommon in black children. If these two premises are correct, then primary VUR should be rare in black males with PUV. To test this hypothesis, we reviewed the medical records and radiographs of 43 males with PUV. Twenty-one of the 37 non-black males with PUV had VUR, of which 67% was primary and 33% was secondary. Three of the six blacks with PUV had VUR of which all was secondary. Thus, blacks with PUV lend credence to the theory that primary VUR is not caused by obstruction and support the observation that primary VUR is rare in black children, even those with PUV.

Stability of coil emboli: an in vitro study.

Gianturco stainless steel coils were discharged into clear plastic tubes of varying sizes and subjected to pulsatile flow in order to study their behavior in a controlled, in vitro environment. When coils are too small for a given vessel, they tend to migrate distally or even proximally. Coils that are too large tend not to reform completely, limiting their cross-sectional area and potentially affecting their occlusive potential. Thus, each coil was tested in tubes of varying sizes and evaluated with regard to positional stability and extent of reformation.

Kinked catheters: radiographic appearance of functionally significant bends.

Several nonangiographic catheters commonly used in children were bent and kinked, radiographed, and perfused at different rates to identify appearances that corresponded to significant alterations in flow dynamics. Radiographic signs of catheter kinking (i.e., focal buckling) depended on the severity of bending and the angle of the radiographic beam relative to the plane of the bend. One or more straight lines appeared at the site of buckling; catheters that were not kinked did not demonstrate straight lines. Other signs were distortion of the round catheter lumen and bulging of the catheter material. Distortions short of sharp kinking did not compromise flow except in very small catheters.

Plain abdominal radiographs in children with inflammatory bowel disease.

The value of plain abdominal radiography in children with inflammatory bowel disease (IBD) has not been ascertained. We reviewed the scout radiographs prior to first barium examination in 100 children with IBD [53 Crohn, 47 ulcerative colitis (UC) and scout films prior to excretory urography in 50 patients who had no clinical evidence of intestinal disease (controls)]. The films were reviewed without clinical information, and the abnormalities on each film scored according to severity and location. Criteria included: mural thickening, dilatation and mucosal abnormalities of the small bowel and colon, as well as abnormal quantity and/or distribution of feces in the colon. Eighty percent (40/50) of the films in the control group were interpreted as normal. Abnormalities suggestive of IBD were present in 73% of the IBD group (76% Crohn and 72% UC). Thirty-one percent of the films in the IBD group had a moderately abnormal score (greater than or equal to 3) or markedly abnormal score (greater than or equal to 5) at presentation. The most reliable radiographic findings were: mucosal abnormality in the colon and small bowel and an abnormal stool pattern (feces completely absent or only present in one colonic segment). The clinical presentation of IBD in childhood is often vague and nonspecific. Abnormalities in plain films of the abdomen are common in these patients and may be helpful in suggesting the presence and, to a great degree, the severity of disease in these children.

Progressive thoracic aortic dilatation after aortic valve replacement.

Aneurysms of the ascending aorta developed after aortic valve replacement for chronic aortic insufficiency in four cases. Two of the aneurysms were complicated by dissection; one patient died. Rheumatic disease has become a less common cause of pure aortic regurgitation, and a number of etiologies primarily involving the wall of the aorta are now recognized. Although appropriately timed aortic valve replacement can prevent the irreversible left ventricular depression associated with chronic aortic insufficiency, careful evaluation of the thoracic aorta on serial postoperative chest radiographs is warranted, because the underlying pathologic process may proceed in the aortic wall with eventual aneurysm formation.