Posterior urethral valves in patients with Down syndrome

Renal and urological anomalies in Down syndrome (DS) have received little attention compared with the nephrourological findings described in other chromosomal abnormalities. Renal hypoplasia, hydroureteronephrosis, ureterovesical and ureteropelvic junction obstruction, and vesicoureteral reflux, but not posterior urethral valves, have been associated with DS. We report the occurrence of posterior urethral valves in three male infants with DS at a single institution. All had multiple urological procedures for correction or palliation of obstruction. Children with DS may have an increased risk for developing posterior urethral valves and obstructive uropathy. Furthermore, they may also develop chronic renal failure secondary to posterior urethral valves. Therefore, we suggests that infants with DS be screened with ultrasonography for renal and urological abnormalities early in life and, if abnormal, a contrast voiding cystourethrogram be performed to rule out posterior urethral valves or other bladder or urethral abnormalities. A review of the renal and urological anomalies in DS reported in the literature since 1960 is presented.     

Long-term results of surgically treated traumatic rectourethral fistulas

OBJECTIVE: Rectourethral fistulas are uncommon, usually iatrogenic injuries that are demanding to treat. We present the challenging problems involving the treatment of rectourethral fistulas caused by war wounds. MATERIALS AND METHODS: In the period 1991-1996, during the war in Croatia and Bosnia, six patients with rectourethral fistulas caused by war injuries were operated in our institution by the same surgeon. All patients were young males with a mean age of 24.6 years. In all patients, double diversion (diversion colostomy and cystostomy) was performed at the time of the injury in military hospitals. In three patients, multiple unsuccessful operations were performed in other institutions to close rectourethral fistula. We found urethrocystography and proctoscopy as the most reliable diagnostic studies and performed them in all patients. In first three patients, we performed transanal repair with anterior rectal wall advancement flap. Because it failed in all three patients, we performed York-Mason trans-sphincteric approach and anterior rectal wall advancement flap after which rectourethral fistula closed in all patients. Because of the satisfactory results, we performed the same procedure in other three patients. RESULTS: In all patients rectourethral fistula healed 2 months after the operation. Closure of diverting colostomy was performed after urethrocystography and proctoscopy proved that the rectourethral fistula has healed. There were no operative deaths and no major complications. Urethral stenosis developed in one patient and was successfully managed by dilatation. CONCLUSION: We believe that York-Mason trans-sphincteric approach offers straightforward access through healthy tissues and good fistula visualization. Anterior rectal wall advancement flap can easily be performed and offer good chances for definitive closure of the rectourethral fistula.     

尿道损伤46例临床分析

本文报道尿道损伤46例,占同期泌尿系损伤的70%。分析尿道损伤手术术式和疗效,以尿道对端吻合最好.尿道会师牵引术亦有其优点。     

脱细胞尿道及其海绵体基质制备的实验研究

目的 探索脱细胞尿道及其海绵体基质的制备方法。方法取健康壮年兔完整尿道及其海绵体组织，以Triton-X100与NH3H2O联合提取法进行脱细胞处理。标本做HE染色，组织学观察分析脱细胞效果。结果脱细胞处理11天后，成功获得脱细胞及其海绵体基质，所得基质外观良好。HE染色观察无细胞存在。弹力纤维排列规整，间隙较大，结构无破坏。结论利用Triton-X100与NH3H2O联合提取法可成功制备完整无细胞尿道及其海绵体基质，为尿道再造修复提供崭新思路。     

女性控尿解剖学机制的MRI研究

目的探讨女性控尿的解剖学机制在MRI（磁共振成像）的表现和观察方法。方法对20例正常控尿的成年女性进行MRI扫描，采用八通道体部线圈、快束自旋回波（FSE）扫描序列进行扫描，采集静息时盆腔横断面、矢状面和冠状面影像。结果MRI显示，女性的尿道分三层结构，与病理学对照，由内向外依次为黏膜及黏膜下组织、肌肉、外膜组织，但无法区分平滑肌与括约肌；与控尿有关的盆底肌肉也能够清楚显示。结论MRI能够清楚观察到女性控尿的有关解剖结构，是观察女性控尿解剖结构的较理想影像方法。     

Neurotransmitter release evoked by α-latrotoxin in the smooth muscle of the female pig urethra

Neuronal regulation of smooth muscle tone in the female pig urethra has mainly been studied in vitro using electrical field stimulation (EFS) of nerves. Excitatory control is considered to be exerted by released noradrenaline, whereas inhibitory control is non-adrenergic non-cholinergic (NANC), and mediated by nitric oxide (NO), and an as yet unidentified agent. We investigated the functional and morphological effects of α-latrotoxin (αLTX), a spider neurotoxin believed to cause massive release of vesicle-stored neurotransmitters, on spontaneously developed urethral smooth muscle tone. The effects were compared to those of EFS and high potassium. In the presence of the NO-synthesis inhibitor N^ω-nitro-L-arginine (L-NOARG: 0.3 mM) both αLTX and EFS evoked contractions. After treatment with scopolamine and phentolamine, no contraction was observed, and under these conditions αLTX and EFS induced relaxation. At low frequencies (<12 Hz), the EFS-induced relaxations were rapid, whereas at higher frequencies (>12 Hz), they were biphasic, consisting of a rapid first phase followed by a more long-lasting second phase. L-NOARG abolished the relaxations at low frequencies, as well as the first phase of the biphasic relaxation. The second phase was not affected by treatment with L-NOARG, but 0.1 μM ω-conotoxin GVIA, blocker of N-type voltage-operated calcium- channels (VOCCs), markedly reduced or abolished the response. In the presence of L-NOARG or ω-conotoxin GVIA, the αLTX-induced relaxation was significantly decreased, and the combination of L-NOARG and ω-conotoxin GVIA further reduced or abolished the relaxation. In preparationstreated with tetrodotoxin or scorpion venom, believed to inactivate nerves by acting on sodium channels, αLTX and EFS had no effects. αLTX-induced relaxation was not associated with changes in cyclic GMP or cyclic AMP content. High (80 mM) potassium solution induced a triphasic response of the preparation. A transient relaxation was followed by a restoration of tone, and then by a persistent relaxation. The persistent relaxation was slightly reduced by scorpion venom or L-NOARG, but reduced by 50% by a combination of L-NOARG and ω-conotoxin GVIA. Ultrastructural analysis of the urethral circular smooth muscle layer revealed a moderate amount of nerve profiles supplying the smooth muscle. In control preparations, the nerve profiles contained both small synaptic vesicles and large dense core vesicles. αLTX caused a major loss of both types of vesicle. The present data suggest that αLTX has the ability to release not only adrenergic and cholinergic transmitters, but also NANC mediators of relaxation, including NO, from nerve terminals in the urethra. Received: 13 January 1997 / Accepted: 17 April 1997     

后尿道损伤的早期,亚早期手术治疗

１９７３－１９９４年５月共收治骨盆骨折所致的后尿道断裂５４例，其中行早期尿道吻合３３例，亚早期尿道吻合９例，占７７．８％（４２．５４），均取得满意效果，尿道断早期组织弹性好，无粘连，无瘢痕，可以达到解剖对位。手术同时可以清除血肿及外渗尿液，减少感染及狭窄机会，对合并休克的病人在休克纠正后，处理其他复合伤的同时急尽早行尿道对端吻合术。对伤严重的的病人经抢救休克处理复合伤，生命指标平稳后行亚早期手术仍     

Responses of sacral visceral afferents from the lower urinary tract,colon and anus to mechanical stimulation

The discharge characteristics of sacral visceral afferents supplying the urinary bladder, urethra, colon and anus to mechanical stimuli were analyzed in the anaesthetized cat. The stimuli used were passive distension (urinary bladder, colon), isovolumetric contraction (urinary bladder), movements of the urethral catheter and mechanical shearing stimuli (mucosal skin of the anal canal). (1) In total 245 afferent units which projected in the pelvic nerve were isolated from the sacral dorsal roots. From one of the following organs, urinary bladder, colon, urethra and anus 117 afferent units were activated. By these stimuli from the bladder, urethra and anus 122 afferent units could not be activated, and as far as tested also not from the colon; in 6 afferent units the classification was unclear. (2) Afferent units from the urinary bladder and the colon responded consistently to passive distension of the respective organ. The units from the urinary bladder showed graded responses at intraluminal pressures of about 10–70 mm Hg and responded also to isovolumetric contractions of the organ. The thresholds of the units from the bladder to passive distension and contraction varied from about 5 to 20 mm Hg intravesical pressure. (3) The afferent units from the urethra and the anus did not react or showed some weak phasic and irregular responses to distension and contraction applied to the urinary bladder or to distension of the colon. They were consistently excited by low threshold mechanical stimulation of the urethra and anus, respectively. (4) The axons from the bladder, urethra and anus were presumably myelinated (conduction velocity above 2 m/s) and conducted at 10.3±6.1 m/s (n=34, mean±SD), 26.3±9.3 m/s (n=13) and 9.5±5.1 m/s (n=37), respectively. The axons from the colon conducted at about 0.5 to 16 m/s (n=20), 13 of them conducting at less than 2 m/s. About 75% of the axons which could not be activated by mechanical stimulation of the visceral organs were presumably unmyelinated (conduction velocity below 2 m/s). (5) Some ongoing activity was found in 9 out of 26 afferent units from the anus but, with one exception, the afferent units from the bladder, urethra and colon were silent. (6) It is concluded that the pelvic afferent units from the urinary bladder, urethra, colon and anus consist of distinct populations with characteristic response patterns. There is no indication from this investigation that the urinary bladder is supplied by sacral afferents which are only recruited at high intravesical pressures during passive distension and isovolumetric contractions and which are possibly associated with pain.Supported by the Deutsche Forschungsgemeinschaft     

Denervation supersensitivity of the urethra to α-adrenergics in the chronic neurogenic bladder

Summary The response of the urethral pressure profile to the administration of various autonomic drugs was compared between a group of eight patients with chronic neurogenic bladder as evidenced by denervation supersensitivity to besacholine^R and a group of 10 control subjects. A supersensitive response to the administration of an -stimulant with a rise of maximum urethral pressure of 10 mmHg or more above the control urethral pressure was uniformly observed in the urethra of patients with chronically denervated bladders. Mechanisms of supersensitivity are postulated and the significance of -adrenergic innervation of the urethra are stressed. These results appear to add pharmacological evidence of -adrenergic predominance in the urethra which is now believed to be dually innervated.     

Crede法排尿与持续导尿对尿路感染和尿道功能影响的研究

目的研究Crede法排尿(间歇人工辅助排尿)与持续导尿对继发尿路感染和远期尿道功能的影响.方法76例神经源性膀胱功能障碍者分别采用Crede法排尿和留置导尿,定期尿液培养进行尿路感染率比较;导尿时间达4～6个月后配合膀胱尿路造影(VCUG)及尿流动力学检查观测尿液返流情况、膀胱颈形态变化和尿道功能指标.结果Crede法排尿组和持续导尿组其尿路感染、尿液返流率分别为16.6%、17.9%和35.1%、40.5%,差异有显著性意义(P＜0.05);VCUG及尿流动力学检查提示持续导尿较C rede法排尿明显损害膀胱颈形态和远期尿道功能.结论对丧失自主排尿功能但无严重意识障碍者宜尽可能减少留置导尿的应用范围和时间,采用Crede法排尿对控制尿路感染、维护和促进排尿功能恢复具有重要意义.