Tetsufumi Yamashita

Structural Changes of Collagen Components and Diminution of Nerves in Congenital Ureteropelvic Junction Obstruction

PURPOSE Three-dimensional arrangements of smooth muscle cells, collagenous component and peripheral nerves of congenital ureteropelvic junction (UPJ) obstruction were studied in order to clarify the pathogenetic mechanism of interaction among these neuro-myo-stromal components. MATERIALS AND METHODS The UPJ and upper ureters were obtained from 14 patients with congenital hydronephrosis (7 intrinsic and 4 extrinsic obstruction) and 7 normal controls. Three-dimensional arrangement of each structural component was observed by scanning electron microscopy, and the nerve distribution was analyzed with immunohistochemistry for protein gene product 9.5. RESULTS The UPJ of intrinsic obstruction had structural features as follows. Muscle fascicles were sparse and thin. Each muscle cell was thin in diameter. Intercellular spaces were six to seven times wider than controls. Collagen fibrillar sheaths of smooth muscle cells (pericellular collagen fibrils attached to the basement membrane) were interwoven to form a dense felt-like structure against thin lace-like sheaths in controls. Interstitial collagenous component showed dense and compact structure against loose network of wavy collagen bundles in controls. In the muscular layer, nerve distribution was decreased to about one-third of controls. In contrast, non-stenotic portion of intrinsic UPJ obstruction as well as materials from extrinsic UPJ obstruction showed no structural difference as compared with controls. CONCLUSIONS In the intrinsic obstruction, nerve fibers were depleted in the muscular layers in the ureteric walls, resulting in dysfunction and atrophy of muscle fibers and an increase of collagen fibers in the muscle layers with abnormal accumulation of intercellular and interstitial collagen. These changes may disrupt the mobility of UPJ and lead to both mechanical and functional obstruction.

Experience with one-stage repair of severe proximal hypospadias: operative technique and results.

Our experience with one-stage repair of severe proximal hypospadias in children is reported. The operative technique, which makes one-stage repair of hypospadias and associated bifid scrotum feasible, is described in detail. A 45% chance of secondary repair notwithstanding, we recommend our one-stage repair for all children with severe hypospadias.

Qualitative and quantitative evaluation of renal parenchymal damage by99mTc-DMSA planar and SPECT scintigraphy

The initial99mTc-DMSA studies carried out over a four year period in 229 patients with various heterogenic causes of lower urinary tract abnormalities were reviewed. Anatomical damage to the renal parenchyma was graded by means of planar and SPECT studies into a six group classification proposed by Monsour et al.: grade 0 (normal), I (equivocal), II (single defect), III (more than 2 defects), IV (contracted or small) and V (no visualization). Parenchymal uptake of99mTc-DMSA was quantitated from planar images at 2 hours postinjection by a computer assisted gamma camera method. SPECT studies could enhance the pick-up rate for parenchymal uptake defects by a factor of 1.5 in comparison with planar imaging. The incidence of anatomical damage to the renal parenchyma increased with a high radiological grade for VUR, and renal uptake per injection dose of99mTc-DMSA by the individual kidney significantly decreased in grades III and IV of the anatomical classification.These data revealed that99mTc-DMSA planar is still useful for evaluating gross structural damage and for quantitative evaluation of the kidney with computer assistance. SPECT scintigraphy is more effective in disclosing anatomical damage to the renal parenchyma than planar, although it needs further discussion as to whether SPECT may increase sensitivity with minimal or no adverse affect on specificity.

Impact of Congenital Narrowing of the Bulbar Urethra (Cobb’s Collar) andIts Transurethral Incision in Children

Objectives: We described the clinical manifestation and outcome after transurethral incision (TUI) of a congenital narrowing of the bulbar urethra (Cobb’s collar). Materials and Methods: Over a period of 11 years a total of 74 boys, from 3 months to 16 years old with a mean age of 5 years, were subjected to TUI. A febrile urinary tract infection (UTI) was the most common symptom in 40 cases, enuresis in 15, urinary incontinence in 11, hematuria in 9, antenatally diagnosed dilated urinary tract in 4 and others in 9. Concurrent bladder instability was detected by cystometry in 27/31 boys older than 3 years with suspicious bladder urgency. When the bulbar narrowing was detected by cystourethroscopy under 8 Fr, the lesion was simultaneously incised by using an infantile resectoscope (Olympus 10 Fr with a knife electrode or Storz 10 F with a cold knife). Results: Vesicoureteral refluxes (VURs) occurred in 39 cases (53%) and it was diminished in 11 and improved in 25 after TUI. Of the 40 cases, 38 (95%) were free from UTI after TUI. For enuresis and urinary incontinence, 14/15 and all 11, respectively, thrived after TUI and the anticholinergic supplement. Although 61 cases were primarily cured with no complications, insufficient cutting and recurrence of the stricture required an additional TUI in 13 cases for whom the knife electrode was mostly used. Overall clinical improvement was obtained in 71/74 (93%) cases after TUI. Conclusion: Meticulous cystourethroscopy is indispensable for detecting a clinically significant bulbar narrowing. TUI of the lesion is useful as a primary treatment in the majority of cases even with concurrent VUR and unstable bladder. A cold knife is preferable to electrocautery in incising this fine anterior urethral lesion.

Feasibility of Urodynamic Study (Combined Cystometry and Electromyography of the External Urethral Sphincter) under General Anesthesia in Children

Background To assess the feasibility of urodynamic study under general anesthesia (GA) we performed electromyography of the external urethral sphincter (EUS‐EMG) on 73 children and cystometry (CM) alone on 10 children.

Clinical Features of Vesicoureteral Reflux in Infants and Outcome of Conservative Therapeutic Approach

Objectives: We evaluated the clinical features of vesicoureteral reflux (VUR) detected in infants and the outcome of a conservative therapeutic approach. Methods: Consecutively 67 infants with VUR (55 boys and 12 girls) were enrolled in this study. Of the 67 patients, 34 had primary and 33 had secondary VUR. Underlying abnormalities in secondary VUR were: posterior urethral valve (PUV) in 7; bulbar urethral stenosis (Cobb’s collar) in 16; neurovesical dysfunction (NVD) in 8, and others in 2. Transurethral incision was performed in patients with PUV or Cobb’s collar. NVD was managed with intermittent catheterization. All patients were followed with antibiotic prophylaxis. Results: No significant difference was found in VUR grades between primary and secondary VUR. Spontaneous resolution of VUR was noted in 31% of primary and 54% of secondary VUR (p < 0.02). VUR downgrading including VUR resolution was also noted more often in secondary than in primary VUR (80 vs. 48%; p < 0.01). Conclusions: The distribution of primary and secondary VUR in infants was almost equal in our study. Resolution of reflux is seen more often in secondary than in primary cases. Thus, early detection and proper management of underlying lower urinary tract abnormalities, either structural or functional, are crucial in the treatment of VUR in infants.

Kidney Transplantation in Patients with Neurovesical Dysfunction

Background: Five renal recipients with neurovesical dysfunction (NVD) were retrospectively reviewed focusing on anatomical and urodynamic abnormalities of the lower urinary tract and their management prior to kidney transplantation.

MANAGEMENT AND OUTCOME OF ANTENATALLY DIAGNOSED HYDRONEPHROSIS

From March 1989 to December 1992, we encountered 25 kidneys in 21 patients with a suspicious ureteropelvic junction (UPJ) obstruction detected only on prenatal ultrasound. In all these patients other urological abnormalities were excluded by voiding cystourethrography and other radiological findings. Diuretic renography (DR) was initially performed at an age ranging from 15 days to 32 months in all patients and repeated a total of 39 times. Both the split renal function (SRF) and diuretic drainage half‐time clearance (DT1/2) of radioagent were within their normal ranges in the case of 15 (60%) of the kidneys on initial DR. In these kidneys, there were no aggravated signs on repeated DR. Decreased SRF was found in 3 kidneys (12%) on initial DR. Of these, the renal function spontaneously reverted to normal in 2 cases with bilateral hydronephrosis. Another 1 kidney revealed significant UPJ obstruction assessed by pressure flow study and continuous nephrostomy drainage had brought relief from the obstruction 1 year later. Prolonged DT1/2 with normal SRF was found in 7 (28%) kidneys. The renal function did not deteriorate and the diuretic response improved on repeat DR except for 1 kidney, whose function deteriorated and on which ultimately, pyelo‐plasty was performed at 7 months of age. Prenatally diagnosed hydronephrosis is usually asymptomatic and clinically significant UPJ obstruction should be always verified. Although even today there is still no examination which can detect a definite obstruction, we can identify one as significant by careful repeat examinations and thus avoid unnecessary surgery without causing any renal deterioration.

Kidney Transplantation in a Child with Posterior Urethral Valve from a Hepatitis B Virus-Carrier Mother

The case of a 7-year-old boy with posterior urethral valve (PUV) who underwent successful kidney transplantation for progressive renal failure is reported. He required complex reconstructive surgery for PUV-related disorders, and also specific serological preparation for hepatitis B (HB) as his living donor mother was a proven carrier. By carefully executing the principles of reconstructive surgery and with well-planned seroimmunological preparation, we have demonstrated that successful kidney transplantation can be done from an HB Ag-positive mother to an HB Ag- and HB Ab-negative son, even when his urinary tract is severely dysfunctional due to PUV.

Usefulness of Transurethral Incision as a Primary Treatment of Ureterocele in Children

Seventeen patients (11 girls and 6 boys, with bilateral cases in 4 for a total 21 units), in whom ureterocele was diagnosed at from 5 days to 11 years old, were treated with transurethral incision as a primary treatment. Urinary tract infection was the most common presenting sign in 8 patients. A voiding disturbance was observed in 10 patients. Seven units were diagnosed as intravesical ureteroceles of a single system and 14 units as ectopic ones (12 associated with the duplex system and 2 with a single system). De novo reflux occurred in 12 units, but in 5 units resolved spontaneously. All 5 refluxes in mate units improved, and 2 refluxes in the contralateral ureter also disappeared. The control of infection became easy in all patients except for one with a sphincteric ureterocele. Split renal function on 99mTc-diethylenetriamine pentaacetic acid scintigraphy was prominently improved in 5 systems (35.7%) and normal kidney growth was obtained in 11 systems (78.6%). A total of 13 affected units (68.4%), including 7 units (6 intravesical and 1 ectopic) for which transurethral incision seemed to have been the sole necessary treatment, were saved. We believe that transurethral incision of ureteroceles is a very useful technique as a primary treatment for all types of ureteroceles in children of all ages.