Define pediatric urinary tract infection, also known as urinary tract infection (UTI):
The inflammation caused by the invasion of bacteria into the urinary tract, accounting for 8.5% of urinary tract diseases and causing much more damage to the kidneys than adults. Yu D, Department of Pediatric Surgery, Jinan Children’s Hospital
Often secondary to urinary tract abnormalities, but can also occur in healthy children with normal urinary tracts.
Classification of pediatric urinary tract infections
1. Initial urinary tract infection
2. refractory bacteriuria occurring during the course of treatment
3. Persistent bacterial infections occurring at specific anatomical sites
4. recurrent urinary tract infections
Epidemiological data
Urinary tract infections are second only to upper respiratory tract infections in outpatients.
Children under 10 years of age: approximately 1% of boys and 3% of girls have at least one symptomatic urinary tract infection.
Boys who are uncircumcised are 10 times more likely to have an infection than those who are circumcised.
Epidemiological data
Four routes.
1. episodic: most common, bacteria migrate from the gastrointestinal tract to the paraurethral mucosa and then up to the bladder and kidneys.
2. Hematogenous: Most commonly seen in immunocompromised children or newborns.
3. Direct invasion: occurs in those children with fistulas.
4. Lymphatic
Epidemiological data
Among children with urinary tract infection.
5-10% have urinary tract obstructive disease
21-57% have vesicoureteral reflux
Therefore.
Finding the specific anatomic site where the bacterial infection is present is important to control the infection and prevent recurrence.
Surgically correctable urinary tract infections:
Infected stones
Infections in non-functioning or very poorly functioning renal units
Infection of the ureteral stump after nephrectomy
Rectal vesicovaginal fistula
Vesicovaginal fistula
Infected necrotic renal papillae
Unilateral spongy kidney
Infection of the umbilical ureter
Infection of the urethral diverticulum
A few common sense points :
The bladder is sterile under normal conditions.
The normal unidirectional rapid urine flow is able to flush away bacteria not adhering to the urinary tract and protect it from infection.
Urinary tract infections in children have traditionally been used as an indication of the presence of an anatomical abnormality of the genitourinary system. —-Pediatric Surgery:Sixth edition (2009)
Diagnostic gold standard.
Urine culture. (Note the influence of the urine sampling method. Diagnosis should be made when there is bacterial growth in bladder puncture urine specimens for culture; ordinary retained urine culture should not be based solely on the presence or absence of bacterial growth, but should be done for colony count, with <10,000/ml suggesting contamination, 10,000-100,000/ml suspicious, and >100,000/ml diagnostic. )
Surgical etiology
Urinary tract obstruction
Vesicoureteral reflux
Functional voiding abnormalities
Urinary tract obstruction
Upper urinary tract obstruction: obstruction above the opening of the ureteral bladder. Common causes include obstructive hydronephrosis at the pelvic-ureteral junction, distal ureteral stenosis, ureteral cysts, and ectopic ureteral openings.
Lower urinary tract obstruction: obstruction at and below the bladder outlet. Common causes include neurogenic bladder dysfunction, tumors within and outside the bladder, urethral valves, and traumatic urethral strictures. The discussion focuses on the most common of these, posterior urethral valves.
Upper urinary tract obstruction
Ureteropelvic junction obstruction (UPJO) hydronephrosis:
Upper urinary tract obstruction
Hydronephrosis is the most common cause of hydronephrosis in newborns.
The usual clinical term for hydronephrosis.
The International Fetal Urological Association defines: separation of the collecting system of the kidney more than 0.5 cm before 24 weeks of fetal age and more than 1 cm after 24 weeks and in the neonatal period as the diagnostic criteria for hydronephrosis.
UPJO remains controversial: in almost all cases, the obstruction is incomplete or undetectable. Some define UPJO as “the presence of a ureteropelvic junction that restricts urinary drainage.”
Upper urinary tract obstruction
Hydronephrosis regression.
1. transient hydronephrosis: e.g. mild hydronephrosis found in the fetus, some of which can disappear completely in the first few weeks of life;
2. Hydronephrosis without progressive renal impairment: In addition to mild hydronephrosis, there is no progressive impairment of renal function and no clinical symptoms, which accounts for about 1/3 of congenital hydronephrosis and requires long-term follow-up;
3. Hydrocele with progressive impairment of renal function: UPJ obstruction is more serious, with progressive increase of hydrocele and progressive impairment of renal function.
Upper urinary tract obstruction
Diagnosis: the most commonly used
B ultrasound, nuclein renal scan (ECT), intravenous urography (IVU).
Followed by 3D CTU, MRU.
Upper urinary tract obstruction
Ultrasound: renal collecting system separation 1-2 cm, mild ;
Renal collecting system separation 2-4cm, moderate;
Renal collecting system separation >4cm, severe.
In addition, renal blood flow velocity and blood flow resistance index can be measured. The normal renal blood flow resistance index decreases with age and ranges from 0.85 to 0.62 in children from newborns to 12 years old, and values greater than this indicate the presence of UPJO.
Nuclear renal scan (ECT): renal dynamic image: can understand the fractional renal function, diuretic nephrography can distinguish between functional and organic obstruction; renal static image: mainly used for the visualization of renal parenchyma, mostly used for the examination of poorly functioning kidney and renal scar.
Intravenous urography (IVU): mild to moderate can mostly be visualized, severe fluid accumulation contrast agent is diluted, intestinal pneumatization, when the renal function is severely impaired contrast agent secretion is difficult, the diagnosis is difficult.
Upper urinary tract obstruction
3D CTU: Clearly shows the dilated pelvis and calyces, the site of obstruction and renal function.
MRU: most satisfactory morphology, no X-ray radiation. gd-DTPA-enhanced dynamic MRI to assess renal morphology and function.
Upper urinary tract obstruction
Treatment principles.
Mild hydronephrosis – follow up and observation.
Those with significant evidence of UPJO or progressive renal damage – should be treated surgically. Those who need surgery are not restricted by age.
Severe atrophy of the hydronephrosis kidney, loss of function or combined with severe infection, and normal contralateral kidney – consider hydronephrosis nephrectomy.
Upper urinary tract obstruction
Surgical procedure: Dissecting pyeloureteroplasty (gold standard) (Anderson-Hynes pyeloplasty)
Upper urinary tract obstruction
Laparoscopic pyeloplasty.
Transabdominal approach
Upper urinary tract obstruction
Laparoscopic pyeloplasty.
Upper urinary tract obstruction
Laparoscopic pyeloplasty: Upper urinary tract obstruction
Upper urinary tract obstruction
Laparoscopic pyeloplasty: upper urinary tract obstruction
Upper urinary tract obstruction
Laparoscopic pyeloplasty: Upper urinary tract obstruction
Retroperitoneal
Upper urinary tract obstruction
Laparoscopic pyeloplasty: upper urinary tract obstruction
Upper urinary tract obstruction
Distal ureteral stenosis: vesicoureteral junction obstruction (UVJO)
Upper urinary tract obstruction
Distal ureteral stenosis.
Diagnosis: Ultrasound, IVU, CTU, MRU
Need for surgical treatment: commonly used Cohen procedure
Upper urinary tract obstruction
Upper urinary tract obstruction
Ureteral cyst: cystic dilatation at the end of the ureter, simple type, ectopic type
Ultrasound, IVU, CTU, MRU, cystoscopy
Treatment aims: to relieve obstruction, protect renal function, prevent infection and prevent reflux. The procedures include cystotomy, cystectomy ureteral reimplantation, duplicate nephrectomy and ureterectomy, etc.
Upper urinary tract obstruction
Upper urinary tract obstruction
Ureteral ectopic opening: This is when the ureter does not enter the bladder triangle and opens outside the bladder. It occurs four times more frequently in women than in men.
Diagnosis: Initial suspicion – search for basis – determine the side of the lesion, IVU and ultrasound complement each other, and retrograde imaging is found for ectopic opening.
Note: In boys, because the ectopic opening is proximal to the external sphincter, it is still controlled by the sphincter, and the clinical symptoms are relatively hidden, manifesting as recurrent epididymitis, dilatation of the seminal vesicles and tenderness can be found on anal examination, and the opening in the posterior urethra is feasible for urethroscopy to help diagnosis.
Only surgical treatment is available: ectopic ureteral bladder reimplantation, or removal of duplicated kidney and ureter.
Upper urinary tract obstruction
Ureteral ectopic opening.
Ectopic opening in the posterior vaginal wall
Lower urinary tract obstruction
Posterior urethral valve (PUV): the valve usually starts from the seminal frenulum and goes distally to the proximal border of the lateral membranous urethra.
Diagnosis: there are usually obvious signs of dyspareunia at birth or significant urinary retention with hyperreflexia of the detrusor muscle and markedly decreased bladder compliance, which can cause hydronephrosis in severe cases.
Voiding cystourethrography (VCUG): the best diagnostic method.
Lower urinary tract obstruction
VCUG of PUV.
Lower urinary tract obstruction
Treatment: further understanding of pathophysiology and endoscopic application – early diagnosis and treatment to reduce mortality. 50% → 5%
1. Prenatal intervention: Pulmonary dysplasia and renal failure are the main causes of death in children with posterior urethral valves in the neonatal period. (Posterior urethral valves appear early in embryonic formation, fetal urine is the main source of amniotic fluid in mid to late pregnancy, and low amniotic fluid prevents normal fetal thoracic movement and lung expansion in utero, resulting in pulmonary dysplasia)
Lower urinary tract obstruction
Indications for prenatal intervention: prenatal ultrasound diagnosis of posterior urethral valves, decreased amniotic fluid, and the kidney’s own ability to produce sufficient amniotic fluid as demonstrated by amniotic fluid aspiration.
If the amniotic fluid is reduced and the lungs have developed, labor can be induced early with postpartum monitoring.
Intrauterine treatment is to do bladder amniotic cavity drainage.
Lower urinary tract obstruction
2. The main principles of treatment: correction of hydroelectric imbalance, control of infection, drainage of urine, and release of obstruction.
Catheterization alone
Cystostomy (fistula)
Urethroscopic electrocautery flap
Advanced renal failure – renal transplantation
Vesicoureteral reflux
The cause of vesicoureteral reflux (VUR) is that the ureteral
opening is not near the bladder triangle (trigone)
but rather laterally, so that the
so that the bladder wall’s
anti-reflux mechanism of the bladder wall
The anti-reflux mechanism of the bladder wall does not work.
Vesicoureteral reflux
There are five levels of reflux severity: the more severe the reflux, the more likely it is that urinary tract infection and kidney damage will occur. Some cases of reflux have significant renal insufficiency.
Vesicoureteral reflux
Treatment principles: The first urinary tract infection should be treated completely followed by prophylactic antibiotic therapy.
Young children under one year of age can gradually improve as they grow up due to high bladder pressure and as the pressure decreases.
In general, 2/3 of cases of second degree reflux may heal spontaneously, about half of third degree, and about 1/3 of unilateral fourth degree cases will also heal spontaneously.
Vesicoureteral reflux
Indications for surgery: Only the occurrence of reinfection despite medication is an indication to abandon medication and receive more aggressive treatment.
Bilateral 4th degree or unilateral or bilateral 5th degree reflux and age over one year also favor surgical treatment.
Another relative indication is the attitude of the family. If the parents are unable to cooperate with the medication every night, fever and urine test, and return to the clinic on time, they should select cases of severe reflux (third degree or above) and introduce the advantages and disadvantages of surgery for their reference.
Other treatment methods Injection of hyaluronic acid (Deflux): This drug was approved for use by the Department of Health in Taiwan after 2002. Under anesthesia, an appropriate amount of hyaluronic acid is injected under the ureter to make the opening of the ureter nearly blocked, so as to prevent reflux. Many European countries have been practicing injection therapy for many years and have a success rate of 60% to 80%. However, the injection of hyaluronic acid must be noted that the drug will break down and be absorbed after five years. If the structural abnormality of reflux is not resolved by growth by then, reflux may still occur again.
Vesicoureteral reflux
Puri catheter.
Vesicoureteral reflux
Neurogenic bladder
The causes of neurogenic bladder in children are mostly due to spina bifida or spinal meningeal bulge. The principles of management of other unexplained causes of similar neurogenic bladder symptoms are similar.
Frequent infections of the urinary tract are the most common manifestation.
Neurogenic bladder
Treatment.
Care of neurogenic bladder must begin with careful observation and management right after neonatal spinal surgery.
Clean intermittent catheterization (CIC) should be started if there is hydronephrosis and bladder wall irregularities to avoid urinary tract damage due to infection.
Controlled urinary diversion should be considered in cases of decreased bladder volume and frequent infections. This procedure includes removal of the thickened and infected bladder, bladder enlargement using the bowel, and self-catheterization using the small intestine or cecum as an anti-reflux tube.