Takanori Yamaguchi

Standard method for diagnosing dilatation of the renal pelvis and ureter discovered in the fetus, neonate or infant

With the increased use of ultrasonography in prenatal diagnosis in the field of obstetrics, and with more neonates and young children receiving abdominal ultrasonographic examinations, the discovery of various congenital anomalies has also increased. Many congenital anomalies of the kidneys and urinary tract are easily discovered by ultrasonographic examination because fluid is retained in the dilated urinary tract. These account for about 50% of the congenital anomalies discovered in this period. The number of reports of the dilatation of the renal pelvis and ureter (hydronephrosis and hydronephroureterosis, respectively, referred together as HN hereafter) in particular are increasing, and there is growing concern regarding their management. Ultrasonography and diuretic renography are the most commonly used procedures for the diagnosis of dilatation of the upper urinary tract, but methods of diagnosis and evaluation have not been standardized. The Japanese Society of Pediatric Urology (JSPU), which handles the management of HN, has realized that it is necessary to standardize the methods of description in ultrasonography and the methodology of performing diuretic renography so that the natural course, therapeutic strategy and therapeutic results can be discussed on common terms. In response, JSPU, mainly its Academic Committee, have prepared the following protocol. Since HN is a continuous entity from fetal to neonatal and infant stages, it is important to call upon not only JSPU but also the related societies to join in sharing this standardized methodology. The protocol proposed by JSPU aims to provide a standard method to: (i) describe and evaluate HN; (ii) be used widely in institutions with pediatric urology cases; (iii) eliminate as much of the variability among institutions or doctors performing the examination as is possible; and (iv) to be used universally. It is not for recommending the therapeutic regimen or method to be selected. In regard to the terminology used to describe the various degrees of dilatation of the renal pelvis and ureter, the terms hydronephrosis and hydronephroureterosis refer to these entities, generalizing their morphological characteristics and are sometimes used synonymously. In some opinions, they are used only if the dilatation of the urinary tract is judged to be pathological; and shows variability with the discipline. As a result of this situation, in the guidelines we present, we use the term dilatation of the renal pelvis and ureter.

Yoke technique for severe proximal hypospadias

UNLABELLED PROPOSED: Various techniques have so far been reported for the repair of hypospadias, however, a one-stage procedure for the repair of severe proximal hypospadias still remains difficult to perform. We recently have begun to use the Yoke hypospadias repair technique for the treatment of severe proximal hypospadias. PATIENTS AND METHODS As the chief surgeon, I performed a one-stage hypospadias repair on 40 proximal hypospadiac patients with severe fibrous chordee between July 1992 and December 2004. During the early period, eleven patients underwent urethroplasty by the Transverse Preputial Island Flap techinique (TPIF). Next, 10 patients underwent One-stage Urethroplasty with Parameatal Foreskin flap technique (OUPF IV). Finally, the most recent 19 had their hypospadias repaired by the Yoke technique. RESULTS With the TPIF technique in the early periods, only 6 out of 11 patients underwent a successful repair (54.5%). With the OUPF IV technique, the success rate was only 60.0% (6 out of 10 cases). In contrast, 17 out of 19 cases treated by the Yoke technique in the most recent period had a successful repair, although proximal urethrocutaneous fistula and urethral stenosis occurred in one patient, respectively. A relatively high success rate was therefore obtained using the Yoke technique for the repair of severe proximal hypospadias. CONCLUSION The Yoke techniques for the repair of hypospadias is therefore considered to be a safe and effective technique for the repair of proximal hypospadias because of the continuous skin flap of the ventral urethral plate and the prepuce with a blood supply from the circumferential vascular pedicle. We consider this technique to be very useful for the treatment of severe proximal hypospadias.

[The effects of autonomic agonists on the female rabbits urethra--in vitro isovolumetric and isometric study].

To investigate the characteristics of adrenoceptors of the proximal urethra in female rabbits, we performed the in vitro isovolumetric urethral pressure study and isometric study with three parts of muscle strips of the proximal urethra (whole layers, inner layers and outer layers). Both alpha-1 and alpha-2 agonist caused dose dependent response in in vitro isovolumetric pressure study as well as in vivo study. However, the response of alpha-2 agonist in in vitro was small in magnitude compared to in vivo study, suggesting the influence of permeability of drugs from serosa to mucosa in in vitro whole urethra study. The response of the strips of inner layers to alpha-1 agonist is almost the same as that of outer layers and whole layers, while the response of inner layers to alpha-2 agonist is almost twice as that of other layers. These findings are suggestive of predominance of alpha-2 adrenoceptors mediating contractions in the inner layers of the proximal urethra in female rabbits. Alpha-2 adrenoceptors which probably are distributed in mucosal and submucosal layers may have an important role in the mechanism of urinary continence in female rabbits.