【膀胱输尿管返流】
膀胱输尿管返流(Vesicoureteral Reflux、VUR)是尿从膀胱到输尿管或肾的异常地反向性地流动。尿液的正常运行是从肾脏进经由输尿管到膀胱。
==症状和病征==
出生前胎儿的膀胱输尿管反流的症状可能以"产前肾积水"、输尿管异常扩大、或泌尿道感染或则"急性肾盂肾炎(pyelonephritis)"之症状出现。
新生儿可能昏昏欲睡(Lethargy)乏力地成长，而婴幼儿及年幼的孩子呈现的典型症状为发热、尿痛(dysuria)、多尿症、恶臭尿(malodorous urine)及消化作用(GIT)等症状，但只有当尿路感染才会呈现VUR的初期症状。
==病因==
健康的个体上输尿管会倾斜地进入膀胱及在粘膜下运行一段距离。因此、除了在输尿管的肌肉附著外，而这有助于在后侧安全地支住它们。所有这些特点都产生"阀门似的效果"、在尿液的存储及排尿期间能闭塞住输尿管的开口。在人与VUR，这种机制发生故障时，与尿所得逆行流。
哈尔迪卡尔氏综合征(Hardikar syndrome)具有膀胱输尿管返流、肾积水、唇颚裂、肠梗阻(Bowel obstruction)及其它的症状。
===原发性VUR===
Insufficient submucosal length of the ureter relative to its diameter causes inadequacy of the valvular mechanism. This is precipitated by a congenital defect/lack of longitudinal muscle of the intravesical ureter resulting in an ureterovesicular junction (UVJ) anomaly.
===继发性VUR===
In this category the valvular mechanism is intact and healthy to start with but becomes overwhelmed by raised vesicular pressures associated with obstruction, which distorts the ureterovesical junction. The obstructions may be anatomical or functional. Secondary VUR can be further divided into anatomical and functional groups as follows:
解剖性：后尿道瓣膜；尿道、或"尿道外口狭窄"(meatal stenosis)。
可能时这些病因会在外科手术时进行处理。
功能性：膀胱不稳定、神经源性膀胱及非神经源性性膀胱。
Urinary tract infections may cause reflux due to the elevated pressures associated with inflammation.
Resolution of functional VUR will usually occur if the precipitating cause is treated and resolved. Medical and/or surgical treatment may be indicated.
==膀胱输尿管返流的国际分类==
*第I级 - 回流到非扩张的输尿管。
*第II级 – 无扩张的回流入肾盂肾盏。
*第III级 – mild/moderate dilatation of the ureter, renal pelvis and calyces with minimal blunting of the fornices
*第IV级 – dilation of the renal pelvis and calyces with moderate ureteral tortuosity
*第V级 – gross dilatation of the ureter, pelvis and calyces; ureteral tortuosity; loss of papillary impressions
The younger the age of the patient and the lower the grade at presentation the higher the chance of spontaneous resolution. Most (approx. 85%) of grade I & II cases of VUR will resolve spontaneously. Approximately 50% of grade III cases and a lower percentage of higher grades will also resolve spontaneously.
==诊断==
VCUG呈现双边第三级膀胱输尿管返流。
以下的过程可用于诊断VUR：
*核膀胱造影术(cystogram)(RNC)。
*透视(Fluoroscopic)排泄性膀胱尿道造影照片(voiding cystourethrogram)(VCUG)
*超声膀胱造影(Ultrasonic cystography)
*腹部超声波诊断。
An abdominal ultrasound might suggest the presence of VUR if ureteral dilatation is present; however, in many circumstances of VUR of low to moderate severity, the sonogram may be completely normal, thus providing insufficient utility as a single diagnostic test in the evaluation of children suspected of having VUR, such as those presenting with prenatal hydronephrosis or urinary tract infection (UTI).
VCUG is the method of choice for grading and initial workup, while RNC is preferred for subsequent evaluations as there is less exposure to radiation. A high index of suspicion should be attached to any case a where a child presents with a urinary tract infection, and anatomical causes should be excluded. A VCUG and abdominal ultrasound should be performed in these cases
Early diagnosis in children is crucial as studies have shown that the children with VUR who present with a UTI and associated acute pyelonephritis are more likely to develop permanent renal cortical scarring than those children without VUR, with an odds ratio of 2.8. Thus VUR not only increases the frequency of UTI's, but also the risk of damage to upper urinary structures.
==治疗==
The goal of treatment is to minimize infections, as it is infections that cause renal scarring and not the vesicoureteral reflux.   Minimizing infections is primarily done by prophylactic antibiotics in newborns and infants who are not potty trained.  However in children who are older, physicians and parents should focus on bowel and bladder management.  Children who hold their bladder or who are constipated have a greater number of infections than children who void on a regular schedule.  When medical management fails to prevent recurrent urinary tract infections, or if the kidneys show progressive renal scaring then surgical interventions may be necessary. Medical management is recommended in children with Grade I-III VUR as most cases will resolve spontaneously. A trial of medical treatment is indicated in patients with Grade IV VUR especially in younger patients or those with unilateral disease. Of the patients with Grade V VUR only infants are trialled on a medical approach before surgery is indicated, in older patients surgery is the only option.-->
===内镜下注射===
Endoscopic injection involves applying a gel around the ureteral opening to create a valve function and stop urine from flowing back up the ureter. The gel consists of two types of sugar-based molecules called dextranomer and hyaluronic acid. Trade names for this combination include Deflux and Zuidex. Both constituents are well-known from previous uses in medicine. They are also biocompatible, which means that they do not cause significant reactions within the body. In fact, hyaluronic acid is produced and found naturally within the body.
===医疗===
Medical treatment entails low dose antibiotic prophylaxis until resolution of VUR occurs. Antibiotics are administered nightly at half the normal therapeutic dose. The specific antibiotics used differ with the age of the patient and include:
*阿莫西林或氨苄青霉素 - 婴儿年龄小于6周。
*复方新诺明(增效磺胺甲基异恶唑) - 6周〜2个月。
经过2个月以下的抗生素都适合：
*呋喃妥因 {5–7 毫克/公斤/24小时}
*萘啶酸(Nalidixic acid)
*复方新诺明
*甲氧芐氨嘧啶(Trimethoprim)
*头孢菌素
Urine cultures are performed 3 monthly to exclude breakthrough infection. Annual radiological investigations are likewise indicated. Good perineal hygiene, and timed and double voiding are also important aspects of medical treatment. Bladder dysfunction is treated with the administration of anticholinergics.
===手术治疗===
A surgical approach is necessary in cases where a breakthrough infection results despite prophylaxis, or there is non-compliance with the prophylaxis. Similarly if the VUR is severe (Grade IV & V), there are pyelonephritic changes or congenital abnormalities. Other reasons necessitating surgical intervention are failure of renal growth, formation of new scars, renal deterioration and VUR in girls approaching puberty.
There are three types of surgical procedure available for the treatment of VUR: endoscopic (STING/HIT procedures); laparoscopic; and open procedures (Cohen procedure, Leadbetter-Politano procedure).
==流行病学==
据估计、VUR存在于人口超过10％以上。
Younger children are more prone to VUR because of the relative shortness of the submucosal ureters. This susceptibility decreases with age as the length of the ureters increases as the children grow. In children under the age of 1 year with a urinary tract infection, 70% will have VUR. This number decreases to 15% by the age of 12. Although VUR is more common in males antenatally, in later life there is a definite female preponderance with 85% of cases being female.
==以后发展==
美国泌尿协会(American Urological Association)建议持续监测膀胱输尿管返流的患儿、直至异常解决或不再有临床显著病征。The recommendations are for annual evaluation of blood pressure, height, weight, analysis of the urine, and kidney ultrasound.