Jacek L. Mostwin

Female Stress Urinary Incontinence Clinical Guidelines Panel Summary Report on Surgical Management of Female Stress Urinary Incontinence

PURPOSE The American Urological Association convened the Female Stress Urinary Incontinence Clinical Guidelines Panel to analyze the literature regarding surgical procedures for treating stress urinary incontinence in the otherwise healthy female subject and to make practice recommendations based on the treatment outcomes data. MATERIALS AND METHODS The panel searched the MEDLINE data base for all articles through 1993 on surgical treatment of female stress urinary incontinence. Outcomes data were extracted from articles accepted after panel review. The data were then meta-analyzed to produce outcome estimates for alternative surgical procedures. RESULTS The data indicate that after 48 months retropubic suspensions and slings appear to be more efficacious than transvaginal suspensions, and also more efficacious than anterior repairs. The literature suggests higher complication rates when synthetic materials are used for slings. CONCLUSIONS The panel found sufficient acceptable long-term outcomes data (longer than 48 months) to conclude that surgical treatment of female stress urinary incontinence is effective, offering a long-term cure in a significant percentage of women. The evidence supports surgery as initial therapy and as a secondary form of therapy after failure of other treatments for stress urinary incontinence. Retropubic suspensions and slings are the most efficacious procedures for long-term success (based on cure/dry rates). However, in the panels opinion retropubic suspensions and sling procedures are associated with slightly higher complication rates, including longer convalescence and postoperative voiding dysfunction.

The rat as a model for the study of penile erection

A model has been developed for the study of penile erection in the Sprague-Dawley rat. Anatomical dissections demonstrate a bilateral ganglion lateral to the prostate called the major pelvic ganglion. This ganglion receives input from the pelvic and hypogastric nerves and innervates the pelvic viscera. A large fiber from the major pelvic ganglion courses along the urethra and innervates the corpus cavernosum, the cavernous nerve. In 40 animals, electrical stimulation of either the cavernous nerve or the pelvic nerve resulted in reproducible repetitive tumescence of the corpora cavernosum. Following ablation of the cavernous nerve, electrical stimulation failed to produce erections. Standard mating behavior tests of mounting, intromission and ejaculation in 38 rats showed that surgical ablation of the cavernous nerve resulted in a decrease in the rate of intromissions and ejaculations compared with sham operated controls. Present models for the study of erection have been limited to the dog, monkey and cat. The rat model presented here offers several advantages over these existing models: 1) the cavernous nerve is easily identified, 2) electrical stimulation is easily accomplished and reproducible, 3) behavioral and neurophysiological studies are possible, and 4) animal purchase, housing, and maintenance costs are low. These advantages make this model a uniquely useful tool in the further study of penile erection.

In situ anatomical study of the male urethral sphincteric complex: Relevance to continence preservation following major pelvic surgery

PURPOSE We describe a correlative gross anatomical and histological study of the human male urethral sphincteric complex using methods that delineate skeletal, muscular and fascial components. MATERIALS AND METHODS Pelves of 6 fresh frozen male cadavers were sectioned as 4 mm. tissue blocks in planes sagittal and perpendicular to the axis of the prostatomembranous urethra from the bladder neck to the bulb of the corpus spongiosum. Sections were photographed and prepared in situ for histological staining (hematoxylin and eosin, Massons trichrome and phosphotungstic acid hematoxylin). RESULTS The structure of the male urethral sphincteric complex was demonstrated to include the cylindrical rhabdosphincter surrounding the prostatomembranous urethra and a fascial framework, principally consisting of the ventral subpubic fascia and medial fascia of the levator ani musculature. The histological appearance of the rhabdosphincter at its dorsal aspect suggested a suburethral musculofascial plate. Rhabdosphincteric muscle fibers were oriented in vertical and ventrolateral directions with attachments to the subpubic fascia and the medial fascia of the levator ani. CONCLUSIONS The structural components and their relationships suggest mechanisms whereby the complex is suspended and stabilized within the deep pelvis, and achieves urethral closure. Our study furthers an understanding of the anatomical basis for male urinary continence and micturition, and is expected to have primary importance in the effort to preserve urinary function following major pelvic surgery.

The Guinea Pig as a Model of Gradual Urethral Obstruction

We developed a new model of partial urethral obstruction using the guinea pig. We placed jewelers jump rings loosely around the proximal urethra of immature guinea pigs and allowed the obstruction to develop gradually as the animal grew. After four or eight weeks of obstruction, we studied the filling and emptying characteristics of the bladder during continuous repetitive cycling under urethane anesthesia. Following this examination, bladders were removed and weighed. Wet weight was compared to urodynamic findings. We identified four abnormal urodynamic patterns: high pressure voiding, instability, poor compliance and decompensation. All obstructed bladders showed weight gain associated with muscle hypertrophy, but the degree of weight gain was different for each of the various urodynamic categories. High pressure voiding was associated with the least weight gain, whereas instability and decompensation showed the most weight gain. The results are consistent with a thesis that partial urethral outlet obstruction in the guinea pig gives rise to several distinct forms of abnormal voiding characterized by high pressure in the early stages, and progressing to more advanced forms of dysfunction characterized by instability and decompensation in the later stages.

Local Recurrence and Survival Following Nerve-Sparing Radical Cystoprostatectomy

From March 1982 through July 1988, 76 men underwent nerve-sparing radical cystoprostatectomy for carcinoma of the bladder at our hospital. Of the 76 patients 2 (2.6%) had positive surgical margins (dome of the bladder and left ureter) and neither had positive margins at the site of nerve-sparing modifications. Of 3 patients (3.9%) who had local recurrence none had positive surgical margins. The 5-year actuarial local recurrence rate is 7.5%. Thirteen of 76 patients (17%) died of transitional cell carcinoma and 7 (9%) died of other causes, while 53 (70%) are alive without evidence of disease with a mean followup of 38.4 months. The 5-year actuarial survival rates are 64% over-all, 68% without disease and 78% disease-specific. Of the 42 evaluable men who underwent cystoprostatectomy alone 27 (64%) are potent, compared to 2 of the 12 men (17%) who also underwent urethrectomy. We conclude that the nerve-sparing modifications do not compromise cancer control, that local recurrence and survival rates are at least comparable to those achieved with standard radical cystoprostatectomy, and that it is possible to preserve potency in most men undergoing this procedure.

Electrical and mechanical responses of guinea‐pig bladder muscle to nerve stimulation

1 The electrical and mechanical responses to transmural stimulation of intrinsic nerves have been recorded from smooth muscle strips dissected from the dome of the guinea‐pig bladder, by use of intracellular microelectrodes, and conventional tension recording techniques. 2 Stimulation of intrinsic nerves evoked action potentials in all cells studied. Hyperpolarization of the cells by extracellular current injection revealed subthreshold excitatory junction potentials (e.j.ps) in about a quarter of the cells studied. 3 Action potentials could still be evoked in the presence of atropine and neostigmine, but were abolished after desensitization of the cells to α,β‐methylene ATP, a stable analogue of ATP. 4 In the presence of neostigmine, the evoked action potential was followed by a slow depolarization of the membrane. The mechanical response increased in amplitude and duration. 5 The contractile response to transmural nerve stimulation was reduced but not abolished in the presence of either atropine or desensitizing doses of α,β‐methylene ATP. Atropine was more effective at high frequencies of stimulation (≥ 30 Hz), and α,β‐methylene ATP at low frequencies (≤ 15 Hz). In combination the drugs abolished the response. 6 The results suggest that the mechanical response to excitatory nerve stimulation is biphasic. The early transient reponse is elicited by e.j.ps and evoked spikes, is resistant to atropine, but sensitive to desensitization of purinoceptors. The late response is mediated through muscarinic receptors, involves little membrane depolarization, and is unaffected by desensitization of purinoceptors. These responses are analogous to the responses seen in rabbit bladder, and in the sympathetically innervated rat tail artery and guinea‐pig vas deferens.

Receptor Operated Intracellular Calcium Stores in the Smooth Muscle of the Guinea Pig Bladder

Study of the in vitro behavior of strips of guinea pig bladder and taenia coli demonstrated that: Both bladder and taenia temporarily retain their ability to contract in Ca-free solutions, but the magnitude of this response decays with time. Carbachol is capable of producing contraction in Ca-free solution for a longer period of time than K depolarisation. Once lost, the ability of carbachol (but not K) to contract the tissues in Ca-free solution can be temporarily restored by a brief application of high Ca. The size of the carbachol contraction in Ca-free solution is reduced in Na-free solution, suggesting that membrane-bound Ca may not play a major role in this response. In depolarised bladder exposed to nifedipine 2 X 10(-7) M, carbachol can only elicit 1 large contraction, suggesting depletion of an intracellular source. It is concluded that whereas the response of the bladder to depolarisation depends primarily on extracellular Ca, the response to carbachol may also involve release of stored Ca and that the bladder, like other smooth muscles, appears to contain agonist-releasable intracellular Ca stores.

Transesophageal Echocardiography in Renal Cell Carcinoma: An Accurate Diagnostic Technique for Intracaval Neoplastic Extension

Between 4 and 10% of patients with renal cell carcinoma have tumor involving the inferior vena cava and many of these patients have suprahepatic extension. In patients with intracaval neoplastic extension precise definition of the superior aspect of the tumor thrombus is critical. Transabdominal ultrasonography, computerized tomography (CT), magnetic resonance imaging (MRI) and inferior venacavography are all currently used to evaluate the inferior vena cava in these patients. Intraoperative transesophageal echocardiography was used to image the inferior vena cava in 5 patients with renal cell carcinoma and intracaval neoplastic extension. In each patient transesophageal echocardiography correctly revealed the superior extent of tumor thrombus. In 3 patients tumor thrombus was found at a higher level by transesophageal echocardiography than by CT, MRI and inferior venacavography. In all patients tumor imaging by transesophageal echocardiography correlated well with the gross appearance and extent of tumor found at operation. Echocardiography also documented the absence of residual gross tumor after resection. Transesophageal echocardiography was also useful to assess left ventricular function. Although each of these patients had a pulmonary artery catheter as well transesophageal echocardiography can be useful in situations when right atrial tumor thrombus prevents right heart catheterization. This small series demonstrates that intraoperative transesophageal echocardiography can accurately evaluate the extent of tumor thrombus and provides a means to assess myocardial function complementary to the pulmonary artery catheter.

The action potential of guinea pig bladder smooth muscle

The smooth muscle of the guinea pig bladder demonstrates in vitro spontaneous electrical activity in the form of action potentials which are associated with contraction. The action potential frequency is highly voltage-sensitive. The relative contributions of Na, Ca and K to the action potential elicited by depolarizing current have been studied using intracellular microelectrodes. In solutions in which NaCl is replaced by sucrose, the membrane hyperpolarizes and the rate of rise and after-hyperpolarization of the elicited action potential is increased. The amplitude is unaffected. In Ca-deficient solutions, the membrane depolarizes, the rate of rise and amplitude of the action potential is reduced, and the after-hyperpolarization is decreased. Nifedipine reduces amplitude and rate of rise but does not affect after-hyperpolarization. In the presence of the K-channel antagonist TEA, the duration of the action potential is prolonged, but the amplitude and rate of rise are unaffected. After-hyperpolarization is not reduced. It is concluded that the action potential of guinea pig bladder muscle, like many other smooth muscles studied, is Ca-based. Repolarization depends on changes in K conductance. The after-hyperpolarization is voltage-sensitive.

Cyst of the ejaculatory duct/urogenital sinus.

We report a case of a midline cyst involving both ejaculatory ducts and seminal vesicles. There have been only 3 previous reports in the literature of ejaculatory duct cysts, 1 of which was iatrogenic, and all have been unilateral. However, several cases have been reported of cysts arising from the müllerian duct or seminal vesicle, in which the described anatomy is essentially identical to our case. It is proposed that midline retroprostatic/retrovesical cysts that communicate with both wolffian systems be classified as urogenital sinus cysts.