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Objective: To determine whether muscle precursor cells (MPCs) harvested from limb skeletal muscle can enhance the regeneration process of the striated urethral sphincter after injury., Material and Methods: Striated urethral sphincters of male mice were injured by an injection of a myotoxic substance (notexin). In the experimental group, 2 days after injury, MPCs were enzymatically harvested from striated muscles of the lower limbs and labelled with PKH 26, then immediately re-injected into the injured urethral sphincter of the same animal. In the control group, saline buffer was injected instead of MPCs. Animals were killed 7 days or 1 month after injury and the sphincters removed for histological study (the presence of PKH 26-labelled myofibres, measurement of myofibre diameter and total number of myofibres)., Results: MPC autografting accelerated sphincter muscle repair, as shown by a higher myofibre diameter (P = 0.03) and number (P = 0.01) in the experimental group than in the controls at 7 days. One month after their injection MPCs were still detectable in the regenerating sphincters and participated in the formation of new myofibres., Conclusion: This study provides the experimental basis for a new therapeutic approach to urethral sphincter insufficiency after surgical or obstetrical injury, based on MPC autografting.

The muscle changes related to pelvic floor disorders are poorly understood. We conducted an anatomical and histological study of the perineum of the normal mouse and of a transgenic mouse strain deficient in urokinase-type plasminogen activator (uPA-/-) that was previously reported to develop a high incidence of rectal prolapse. We could clearly identify the iliococcygeus (ILC) and pubococcygeus (PC) muscles and anal (SPA) and urethral (SPU) sphincters in male and female mice. The bulbocavernosus (BC), ischiocavernosus (ISC) and levator ani (LA) muscles could be found only in male mice. Histochemical analysis of the pelvic floor muscles revealed a majority of type IIA fibres. Rectal prolapses were observed only in male uPA-/- mice. The most obvious finding was an irreducible evagination of the rectal mucosa and a swelling of the entire perineal region corresponding to an irreducible hernia of the seminal vesicles through the pelvic outlet. The hernia caused stretching and thinning of the ISC, BC and LA. Myopathic damage, with degenerated and centronucleated myofibres, were observed in these muscles. The PC, ILC, SPA and SPU were not affected. This study provides an original description of a model of pelvic floor disorder and illustrates the differences existing between the perineum of humans and that of a quadruped species. In spite of these differences, the histopathologic changes observed in the pelvic floor muscles of uPA-/- mice with rectal prolapse suggest that prolonged muscular stretching causes a primary myopathic injury. This should be taken into account in the evaluation of pelvic floor disorders.

Lumboscopy provides an approach to the retroperitoneum for the majority of upper urinary tract operations. The technique involves a knowledge of specific anatomical landmarks that differ from those in classical open surgery, because of the inferior approach to the renal pedicle with the kidney initially mobilized in a ventral and cranial position. An anatomical study was conducted on five cadavers, using images from surgical operations, in order to describe the vascular elements of the retroperitoneal spaces as they are approached during lumboscopy, as well as to define specific anatomical landmarks. Identification of psoas major is crucial as it is then possible to locate the renal pedicle opposite and the area of the great vessels medially. During dissection of the renal pedicle the renal vein and its branches are the first elements to be approached. On the left side the distal portion of the renal vein can be confused with a reno-hemi-azygo-lumbar trunk, due to the initial ventral mobilization of the kidney stretching it. Because of the inferior view of the renal pedicle the reno-hemi-azygo-lumbar trunk can obscure part of the renal artery and may be confused with the renal vein. On the right side initial identification of the inferior vena cava on the medial aspect of psoas major facilitates identification of the gonadal, renal and suprarenal veins all located in the same plane.

Objectives: The measurement of the pudendal nerve terminal motor latency (PNTML) is used to assess anal sphincter innervation. In healthy subjects, we studied the influence of age on PNTML and the advantage of a new intra-rectal stimulator., Methods: PNTML was determined in a first series of 40 normal subjects, aged 21-75 years, using a standard St. Mark's electrode, and in a second series of 20 normal subjects over 50 years, using a new intra-rectal monopolar stimulator that did not require finger insertion through the anal canal., Results: In the first series, PNTML ranged from 1.8 to 5.6 ms (mean+/-SD 2.94+/-0.8 ms) and correlated positively with the age of the subjects (P=0.01, Spearman test). In the second series, PNTML ranged from 2.2 to 5.4 ms (3.7+/-0.9 ms) and was similar to that of the subjects over 50 years of the first series (3.5+/-0.4 ms) (P=0.35, Mann-Whitney U test)., Conclusions: This study showed significant effects of age on PNTML. This should encourage every examiner to establish age-stratified reference values of PNTML for older age groups. In addition, we showed the advantage of using a new type of intra-rectal stimulator to reduce the patient's discomfort by avoiding finger insertion to stimulate the pudendal nerve.

Purpose: To determine the occurrence of penile small nerve fiber damage following transurethral resection of the prostate (TURP) for benign prostatic hypertrophy (BPH)., Materials and Methods: Penile nerve function was evaluated in 18 consecutive patients prior to and one month after TURP for BPH. To test nerve fibers of small diameter, the penile warm and cold sensory thresholds were measured by means of a Peltier-based device, as well as the penile sympathetic skin potentials obtained following electrical stimulation at the wrist. To test nerve fibers of large diameter, the pudendal nerve somatosensory evoked potentials (pSEPs) and the penile vibratory thresholds were recorded. Clinical erectile function was quantified using a standardized questionnaire (erectile dysfunction symptom score, EDSS). Urinary handicap was assessed by the measurement of maximum flow rate (MFR) at uroflowmetry and by a standardized questionnaire (AUA symptom score, AUASS)., Results: Penile warm threshold (+7.8 vs +6.3C, p = 0.005), cold threshold (-8.5 vs -5.7C, p = 0.003) and vibratory threshold (9.3 vs 7.9 microm., p = 0.03) were significantly higher after than prior to TURP. The amplitude of pSEPs tended to decrease (1.7 versus 2.3 microV, p = 0.06), whereas the remaining neurophysiological parameters were unchanged. Clinical assessment by EDSS demonstrated a significant postoperative erectile function impairment (20.2 vs 17.5, p = 0.04), whereas mictional function improved (MFR: 19 vs 8.8 ml./s and AUASS: 4.9 versus 15.1, p < 0.0001)., Conclusions: This study highlights the occurrence of penile small nerve fiber damage following TURP and supports the hypothesis of neurogenic damage as the primary cause of post-operative erectile dysfunction.