[Urethral implantation of collagen in the treatment of urinary incontinence. Comparison of transurethral and periurethral approach]. / Impianto uretrale di collagene nel trattamento dell'incontinenza urinaria. Confronto tra accesso transuretrale e periuretrale.

BACKGROUND: In mini-invasive surgery for the treatment of urinary incontinence injectable substances such as politef, autologous fat or bovine collagen, which can increase urethral resistance or support the sphincteric one are particularly used. It's a simple procedure in which patients may undergo local anesthesia, in short time and in "day hospital" regimen. Collagen, used as an injectable bulking agent, is the gold standard for this surgical technique because of complete biocompatibility, no evidences of adverse immunogenic effects, foreign-body reaction, migration of injected material, and because of higher fluidity which allows the use of thin needles compared to Politef (polytetrafluoroethylene) where an injection device is requested. Bovine collagen is partially reabsorbed within 24-36 months and a reinjection is often necessary. Although autologous fat is cheaper than bovine collagen, its injection shows more difficulties due to the need of higher needle diameter and time to store and prepare the material to inject. METHODS: The results obtained by two different approaches: transurethral injection of collagen and periurethral injection of collagen have been studied. A total of 48 patients underwent collagen injection for treatment of urinary incontinence: 24 treated by transurethral approach and 24 by periurethral approach. Follow-up at 6, 12, 24 months after treatment includes: objective exam, PAD test, functional evaluation, complete urodynamic evaluation (uroflow, cystomanometry, LPP, pressure/flow study, UPP). RESULTS: No clinical differences between peri/trans-urethral approach were found although collagen injection via transurethral technique need fewer material, reducing cost of treatment: an efficacy of treatment in 80% of patients and restoration of a complete urinary continence in 50% of patients was obtained. Although no clinical differences were demonstrated between the two different sites of injection, transurethral approach can be used similarly in both sexes even if without a modified resector as "injection device" it's more difficult to inject collagen in the right position, at the level of bladder neck submucosa. Perineal approach, exclusive of female sex, realizes the procedure without bleeding of urethral mucosa and no waste of collagen, though a longer period of training by surgeon is requested. After four years of experience the authors agreed that with an adequate injection device (modified resector), transurethral approach should be preferred, thus depending on the possibility to inject collagen in a correct position, just under bladder neck mucosa, which is possible to manage with this technique, in order to reduce reabsorption process of collagen and to obtain a longer efficacy of treatment reducing the number of reinjection and of course the cost of treatment. Collagen injection should be considered within an integrated therapeutical picture together with topic and systemic pharmacotherapy, physiotherapy, not excluding surgery techniques such as implantation of an artificial sphincter device in man or a sling procedure in woman. CONCLUSIONS: The urethral collagen injection for the treatment of urinary incontinence is a safe, durable and valid technique to improve urinary continence through a non obstructive effect increasing urethral resistance. Performed under local anesthesia this procedure allows the treatment of patients who may not be candidates suitable for general anesthesia and conventional surgery.

[Assessment of renal function using low doses of paramagnetic contrast media]. / Valutazione della funzionalità renale mediante impiego di basse dosi di mezzo di contrasto paramagnetico.

Dynamic MR techniques with Gd-DTPA bolus administration can be used to study renal perfusion and function. In previous studies, the concentration of Gd-DTPA injected was never lower than 0.1 mmol/kg: as a result, depending on the magnetic susceptibility effect, renal signal intensity reduced in the early phases, right after contrast agent injection. To prevent signal intensity from reducing in the early phases, in our study we used a concentration of 0.05 mmol/kg. Qualitative and quantitative evaluations were performed. Seven healthy subjects and 14 patients with different degrees of renal insufficiency were enrolled in the study. All exams were performed using an 0.5-T magnet (Philips Gyroscan T5, II), with 15 mT/m gradient power. Signal intensity measurements at the cortical, external medullary and internal medullary levels, allowed the drawing of curves typical of each degree of renal insufficiency which correlated well with nuclear medicine (scintigraphy) findings. The qualitative evaluation provided results comparable with scintigraphic findings in all 7 normal subjects, in 3 of 4 cases of moderate renal insufficiency, in all 7 cases of moderate/severe renal insufficiency and in the only case of severe renal insufficiency. To conclude, this trial demonstrates the feasibility of MR studies of renal function, which provide morphological and functional pieces of information. Low concentration Gd-DTPA is decisive to avoid the magnetic susceptibility artifacts observed in previous studies.

[Magnetic resonance pyelography: optimization of the technic and the preliminary results]. / Pielografia con Risonanza Magnetica: ottimizzazione della tecnica e risultati preliminari.

Magnetic resonance pyelography (MRP) is a new noninvasive method which demonstrates dilated urinary tracts with no need of contrast agent injection. This study was aimed at technique optimization, using new fast sequences with high intrinsic contrast, to demonstrate the urinary tract in obstructive uropathy patients. Twelve consecutive patients and 4 healthy volunteers were included in this prospective study; all the exams were performed with a high gradient power 0.5-T unit using T2- weighted turbo SE sequences, acquired three-dimensionally on the coronal plane. Obstructive uropathy was caused in 9 patients by neoplastic lesions, in 2 by postoperative strictures and in 1 by inflammatory tissue. In all patients MRP depicted the dilated urinary tract optimally, with good morphological detailing and the accurate assessment of both level and cause of obstruction. In the healthy volunteers, the absence of dilatation did not permit the complete visualization of the urinary tract. To conclude, MRP is a new technique which permits high-quality imaging of the urinary tract. Further studies are needed to assess its actual potentials and clinical role.

Nitric oxide synthases in normal and benign hyperplastic human prostate: immunohistochemistry and molecular biology.

The expression of nitric oxide synthase (NOS) isoforms has been investigated in normal (three subjects) and benign hyperplastic prostate (ten patients) by immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR). The inducible NOS (iNOS or NOS-2) is not detected in normal prostate, while it is expressed in the prostate of all benign prostatic hyperplasia (BPH) patients, even in the absence of prostatitis or systemic signs of an inflammatory condition. This suggests that sex hormones may be involved in iNOS induction and that there may be a role for NO in the pathogenesis of BPH. Constitutive NOSs (nNOS and eNOS) are expressed in both normal and hyperplastic prostate and are co-expressed in epithelial cells. eNOS, however, is present mainly in the basal layer cells; nNOS seems abundantly expressed in the more superficial cells of the affected prostate. This indicates that the switching between the two constitutive isoforms may be part of the usual process of cell differentiation from the basal to the secretory layer of the epithelium.