[The muscle compressing the ureter and its role in the closure mechanism of the ureteral-bladder segment].
The authors indicate an important role of the locking mechanism of the vesicoureteral segment in the prevention of the retrograde regurgitation of urine into the upper urinary tracts, namely vesicoureteral reflux. They pay special attention to the fact that the knowledge of the structure of the terminal part of the ureter helps select certain appliances preventing the development of the reflux. However, the known data fail to satisfy the clinicians and explain the appearance of the reflux in some cases. Therefore, the authors have undertaken an original morphological investigation of the terminal part of the ureter, observing the vesicoureteral complexes of 32 human cadavers. Micropreparation of the vesicoureteral segments was performed with the use of a 2.5-4X binocular magnifier. The study revealed a muscle previously undepicted. Regarding it as the ureter-pressing one, the authors designated it as "musculus appressor ureteris". Formed by the muscular fibres of the detrusor and situated 1-2 cm more proximal than the ostium ureteris, it arches through the submucosal segment of the ureter and is connected with the musculature of the urinary bladder on the both sides of the ureter. Its width is about 6-8 mm and its thickness is 1.5-2 mm. The authors explain its function and role by the locking system of the vesicoureteral segment, which is proved by the development of the reflux in case the ureteral ostium and the above muscle are dissected. The authors emphasize the fact that it is necessary to extremely accurately cut the anterior wall of the terminal part of the ureter.
Iu A
IuA
Pytel'
A Z
AZ
Vinarov
V Ia
VIa
Bocharov
D006801:Humans; D009130:Muscle, Smooth / Q000033:anatomy & histology* / Q000502:physiology; D014513:Ureter / Q000033:anatomy & histology / Q000502:physiology; D001743:Urinary Bladder / Q000033:anatomy & histology* / Q000502:physiology; D014718:Vesico-Ureteral Reflux / Q000209:etiology / Q000473:pathology
Myshtsa, prizhimaiushchaia mochetochnik, i ee rol' v zamykatel'nom mekhanizme mochetochnikovo-puzyrnogo segmenta.