The use of the holmium laser for treating strictures of the urethra and bladder neck in men

30 patients with strictures of the urethra (n = 19) and bladder cervix (n = 11) received combined treatment including surgical endoscopic correction of the stricture with Ho:YAG laser, pre- and postoperative endourethral radiation with low-energy laser, instillations of collagenase and dimexide solution into the urinary tract. The operation was made by Ho:YAG laser (2.09) microns, 4 J, 15 Hz, 300 mc). Persistent response for 10-12 months was achieved in 93.3% of patients.     

Endoscopic ureterolithotripsy with the holmium laser

One of the clinical and experimental investigations performed in the urological clinic of the Moscow Medical University and Research Institute of Urology aimed at elucidation of Ho-YAG-laser potential in endoscopic lithotripsy (EL). Russian Ho-YAG laser surgical units CTH-10 and LLT-3 with wave length 2.09 mu were employed. The studies showed that the developed laser units satisfied relevant medical and technical requirements. Low depth of laser impulse penetration (0.4 mm) obtained at EL warrants safety of the adjacent tissues which is essential in crushing fixed ureteroliths in the presence of severe inflammation in the ureteral wall. The conclusion is made that Ho-YAG laser EL is an effective treatment of ureteroliths. Further tests for EL efficacy in affections of the upper urinary tracts are advocated to define a proper place of EL in endoscopic urology.     

Self-expanding metallic endoprosthesis in the treatment of recurrent ureteral stenosis

OBJECTIVE: To describe two cases of recurrent fibrotic stricture of the uretero-vesical junction treated with a metallic self-expanding endoprosthesis which has successfully achieved patency of the stenotic area in the medium-term. METHODS: Two cases of difficult ureteral stricture are described. Both cases presented obstruction of the terminal ureter by abundant fibrotic tissue in the bladder wall following radical prostatectomy in one case and TUR in the other for non-infiltrating bladder carcinoma. Several attempts to recover patency by endoscopic resection and placement of a double-J stent in these patients had previously failed. The patients were therefore submitted to resection of the fibrotic area and insertion of a self-expanding endoprosthesis (Wallstent), which was eventually enclosed by fibrous tissue at its vesical portion. Both cases underwent resection again and another endoprosthesis (Memotherm) was inserted to extend the previous prosthesis 1 cm within the bladder lumen. RESULTS/CONCLUSIONS: When the endoprosthesis is placed in the uretero-vesical junction with its tip flush with the bladder wall, it is eventually enclosed by fibrous tissue, which invariably leads to recurrent obstruction. We have found that extending the prosthesis 1 cm within the bladder lumen can overcome the foregoing complication, although the long-term results have as yet to be established.     

Trace elements in egg contents and egg shells of slider turtles (Trachemys scripta) from the Savannah River Site

OBJECTIVES: Stricture of the vesico-urethral anastomosis is a well-known complication after radical prostatectomy. Dilatation, stricture incision or resection have been proposed for endoscopic treatment. METHODS: In a retrospective study of 340 patients with prostatic cancer who underwent a radical retropubic prostatectomy from 1988 until 1996, we looked at the incidence of anastomotic strictures. RESULTS: An anastomotic stricture was found in 24 cases (7%) requiring endoscopic treatment. Based on prospective X-ray studies, we were able to show that the site of stricture is located below the bladder neck musculature in most cases well above the distal urethral sphincter and pelvic floor. No continence problems were encountered following structure resection in a follow-up of 12-72 months determined by a questionnaire and pad test. CONCLUSION: The transurethral resection of anastomotic stricture allows for a rather generous tissue resection, which is preferable to incision or dilatation in our hands.     

Changes in tissue and blood polyamines during N-butyl-N-(4-hydroxybutyl) nitrosamine-induced bladder carcinogenesis in rats

(BACKGROUND): Polyamine are recognized as cell growth factors. We studied in order to determine whether alterations in the levels of tissue and blood polyamines were useful biochemical markers for bladder tumor. (METHODS): The concentrations of three polyamines, diamine, spermidine and spermine, in urinary bladder and blood were determined during N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN)-induced bladder carcinogenesis in male F344 rats. At 5 weeks of age, rats were given 0.05% BBN in the drinking water for 20 weeks. (RESULTS): BBN induced bladder hyperplasia in 4 of 5 rats at 8 weeks, papillomas in 2 of 5 rats at 12 weeks, and transitional cell carcinoma in all the rats by 20 weeks. The levels of total polyamine in both bladder and blood of the rats during 12-20 weeks were significantly higher than those of the control animals given water alone. The elevation of total polyamine was mainly due to the increase of spermidine of the three polyamines, which was coincident with the incidence of bladder tumors. (CONCLUSION): The results indicated that the polyamines are excellent biochemical markers for bladder tumors.     

Experience with the hemi-Kock ileocystoplasty with a continent abdominal stoma

We describe our experience with the hemi-Kock ileocystoplasty with a continent abdominal stoma as an alternative to an indwelling catheter or supravesical diversion in 14 women and 4 men with various problems who could not perform intermittent urethral self-catheterization. The aim of management was also to provide, if possible, a competent urethra for additional access. Mean patient age was 37 years (range 22 to 75) and mean followup was 26 months (range 5 to 58). Preoperative management in the 11 wheelchair dependent women with neurological disease was an indwelling catheter in 7, urethral intermittent catheterization with the patient in the supine position in 3 and diapers in 1. Two women with a nonneurogenic bladder and a grossly incompetent urethra (1 after multiple incontinence and fistula repairs, and 1 after severe obstetrical trauma) wore diapers, while 1 with urinary retention and inability to perform self-catheterization had an indwelling catheter. The 4 men included 2 wheelchair dependent incontinent spinal cord injury patients who could not be managed with condom drainage, 1 with multiple anomalies who had trouble with self-catheterization, and 1 with an impassable postoperative stricture and a suprapubic tube. Surgery included anti-incontinence procedures in 10 patients and bladder neck closure in 3. A total of 15 patients required bladder augmentation in addition to the stoma and 3 had a stoma alone. Postoperative intervention was necessary in 4 women for stomal incontinence and in 2 of these bladder stones were removed simultaneously. One of these women was later treated for recurrent stones cystoscopically through the stoma. Overall, 17 of 18 patients are dry on intermittent stomal catheterization, with 1 lost to followup. We conclude that this procedure is a good alternative in patients with an end stage urethra or who cannot perform urethral catheterization because of physical disability. Establishing urethral continence and maintaining patency leaves a safety valve should the stoma fail. Since the bladder remains as a reservoir no ureteral surgery is necessary.     

Optimal scheduling of interleukin 12 and chemotherapy in the murine MB-49 bladder carcinoma and B16 melanoma

The antitumor activity of interleukin (IL)-12, a naturally occurring cytokine, has been demonstrated in several murine solid tumors. Animals bearing established B16 melanoma or MB-49 bladder carcinoma were used to study the most effective scheduling of recombinant murine IL-12 (rmIL-12), along with systemic chemotherapy. rmIL-12 (0. 45, 4.5, or 45 microgram/kg) was more effective as a single agent when administered to mice bearing the MB-49 bladder carcinoma at the highest dose for 11 doses rather than for 5 doses. In combination with chemotherapy (Adriamycin, cyclophosphamide, or 5-fluorouracil), rmIL-12 administration did not increase the toxicity of the chemotherapy, and there was increased antitumor activity with each rmIL-12-drug combination. Administering rmIL-12 (45 microgram/kg) on days 4-14, along with Adriamycin, cyclophosphamide, or 5-fluorouracil on days 7-11, resulted in 2.2-2.7-fold increases in tumor growth delay, compared with the chemotherapy alone against the primary tumor, and a marked decrease in the number of lung metastases on day 20. Because the B16 melanoma grows more slowly than the MB-49 bladder carcinoma, allowing multiple courses of chemotherapy, cyclophosphamide could be administered. The rmIL-12 (45 microgram/kg)-cyclophosphamide combination regimen that was most effective overlapped 2 days with the terminal portion of the chemotherapy treatment. There was a parallel increase in the response of the primary tumor and metastatic disease to the lungs. Administration of rmIL-12 to animals bearing the MB-49 bladder carcinoma or the B16 melanoma was compatible with coadministration of chemotherapy at full dose without additional toxicity.     

Expression of cell adhesion molecules and vascular endothelial growth factor in experimental choroidal neovascularisation in the rat

AIMS: To investigate the longevity and reproducibility of choroidal neovascularisation (CNV) induced by krypton laser photocoagulation in the rat. The presence of cell adhesion molecules (CAMs) and vascular endothelial growth factor (VEGF) during the development of CNV was also studied. METHODS: 67 pigmented rats underwent retinal photocoagulation by krypton laser. The eyes were examined by either single or serial fluorescein angiography at 3 days, 1, 2-3, 4-5, 7-8, and 12 weeks post photocoagulation. The expression of CAMs (ICAM-1, E-selectin, and CD44) and VEGF post photocoagulation was studied by immunohistochemistry. RESULTS: CNV related fluorescein leakage appeared in 46.4% of 766 laser spots delivered to the 58 eyes that were tested at 2-3 weeks post treatment. The ratio of hyperfluorescent laser sites did not change significantly at 8 weeks post laser. The number of leaky spots was independent of the total number of lesions delivered to each eye (at 2-3 weeks post laser 10-15 spots/eye: 44% and 25-30 spots/eye: 49%; t = 0.7673; p = 0.3903). Nine eyes were followed by serial angiography between 2 and 12 weeks. The laser spots with fluorescein leakage at 2 weeks (51.5%) remained leaky at 12 weeks (51.5%). Histopathologically, macrophage accumulation peaked at 5 days and CNV was firstly observed at 1 week post photocoagulation. ICAM-1, E-selectin, CD44, and VEGF were maximally induced at 3-5 days post laser photocoagulation, and were localised to RPE, choroidal vascular endothelial, and inflammatory cells. VEGF was also detected in intravascular leucocytes at the sites of laser lesions. CONCLUSIONS: These studies demonstrated that krypton laser photocoagulation can be successfully used to produce lesions similar to those of human CNV. The response induced remained present for an extended period of time (12 weeks), thus offering a potential model to screen candidate CNV inhibitory agents. In addition, it is proposed that the expression of ICAM-1, E-selectin, CD44, and VEGF before new vessel formation might be linked to the initiation of CNV.     

Enterocystoplasties: results in 22 children

A study of paediatric enterocystoplasty in 22 children of 1 to 14 years of age (M = 8) during 5 years is presented. The diagnoses were: neurogenic bladder 16 (73%), extrophic bladder 3, urethral valves 1, and complex uropathies 2. The intestinal segments used were: ileum 12 cases, sigmoid 8, and ileocaecal region 2 (non myelodisplastic). During the last years sigmoid have been preferred due to its bigger size. The middle follow up is 3.5 years (R 1-6). The results have been good in: renal function 86%, and upper urinary tract 95%. Bladder capacity was 278% higher, bladder pressure was 82% less, and residual urine was 217% more, than preoperatively. Five children developed 6 complications (23%), and 4 reinterventions were performed (18%). When it is indicated, paediatric enterocystoplasty is a good alternative to urinary diversion, and it is useful to prevent the upper urinary tract deterioration; but a frequent and, all the life long follow up is necessary, due to its possible complications.     

Ureteroileal anastomotic strictures: an innovative approach with metallic stents

PURPOSE: We report our experience with the use of self-expandable metallic stents to bypass anastomotic strictures after ureteroileal urinary diversion. MATERIALS AND METHODS: We evaluated 3 men and 1 woman with invasive bladder carcinoma who underwent radical cystectomy and ileal conduit urinary diversion. Ureteroenteric anastomotic strictures developed after a mean of 16 months. Self-expandable metallic stents were successfully placed (bilaterally in 2) comprising 6 stented ureters that bypassed strictures. Mean patient age was 64 years and mean followup was 12 months. RESULTS: No restenosis was observed in 3 patients during followup. The stricture recurred 1 month after stent placement in the remaining patient and additional intervention was necessary, consisting of placement of a totally coaxial overlapping metal stent. No sepsis or other complication was observed. One patient died of metastatic disease 12 months after stent placement. CONCLUSIONS: We propose the use of metal stents as an adequate, safe and effective alternative treatment for anastomotic strictures after ureteroileal diversion.     

Method for the analysis of the methylphosphonic acid metabolites of sarin and its ethanol-substituted analogue in urine as applied to the victims of the Tokyo sarin disaster

The present study was designed to evaluate the role of the cytokeratin-19 fragment (CYFRA 21-1) as a tumor marker in bladder cancer. The bladder cancer cell line JMSU1 was used in the preclinical study. Subjects comprised 120 healthy volunteers, 20 patients with benign bladder diseases including acute cystitis and bladder stones, 12 patients with chronic renal failure, and 117 patients with histologically confirmed primary bladder cancer. CYFRA 21-1 concentrations were measured by a sandwich enzyme-linked immunosorbent assay. The preclinical study in vitro and in vivo showed that JMSU1 produced and released CYFRA 21-1 in the culture supernants and serum of JMSU1-bearing nude mice. The cutoff level was set at 3.5 ng/ml (mean + 3 SD) by the analysis in the healthy volunteers. Under this condition, sensitivity was 0% in benign bladder diseases, 83% in chronic renal failure, and 41.9% in bladder cancer. Serum CYFRA 21-1 levels increased significantly as tumor stage advanced or tumor grade increased. A serial follow-up study demonstrated that patients with progressive showed a gradual increase in serum CYFRA 21-1 levels while patients who responded to the treatments had a marked decrease in serum CYFRA 21-1 levels. Higher serum CYFRA 21-1 levels were related to poor survival. The present study suggest that serum CYFRA 21-1 is a useful marker to monitor the clinical course of bladder cancer and to provide prognostic information.     

The inhibitory effect of nociceptin on the micturition reflex in anaesthetized rats

1. We have investigated the effect of nociceptin on the micturition reflex evoked by distension or topical application of capsaicin on the urinary bladder of urethane-anaesthetized rats. 2. Nociceptin produced a dose-dependent (3-100 nmol kg(-1) i.v.) transient suppression of the distension-evoked micturition reflex: its effect was not modified by guanethidine (68 micromol kg(-1) s.c.) nor by bilateral cervical vagotomy, alone or in combination, and by naloxone (1.2 micromol kg(-1) i.v.). 3. Nociceptin (100 nmol/kg i.v.) slightly (about 30%) inhibited the contractions of the rat bladder produced by pre- or postganglionic electrical stimulation of the pelvic nerve. 4. Nociceptin almost totally abolished the reflex component of the response to topical capsaicin (1 microg in 50 microl). 5. In the rat isolated bladder, submaximal contractions produced by electrical field stimulation were slightly reduced (25+/-4% inhibition) by 1 microM nociceptin. Nociceptin did not affect the contraction of the rat bladder induced by acetylcholine (10 microM) or ATP (1 mM). 6. These findings indicate that nociceptin exerts a naloxone-resistant suppression of the volume-evoked micturition reflex which involves inhibition of transmitter release from postganglionic bladder nerves. An inhibitory effect on bladder afferent nerves is also suggested.     

Transurethral balloon dilation of the external urinary sphincter: effectiveness in spinal cord-injured men with detrusor-external urethral sphincter dyssynergia

The authors investigated balloon dilation as a minimally invasive alternative to transurethral external sphincterotomy for the treatment of detrusor-external urethral sphincter dyssynergia (DESD). Seventeen spinal cord-injured men with voiding pressures greater than 60 cm H2O underwent balloon dilation of the external sphincter to 90 F at 4 atm of pressure for 10 minutes. The mean voiding pressures before and 12 months after dilation were 83 cm H2O +/- 35 and 37 cm H2O +/- 15, respectively (P = .008). There was a significant decrease in residual urine volume, from 163 mL +/- 162 to 68 mL +/- 59 (P = .05), whereas bladder capacity remained relatively unchanged at 253 mL +/- 181 and 230 mL +/- 97 (P = .30). Complications included one case of postoperative bleeding necessitating transfusion, two treatment failures, and one bulbous urethral stricture. Fourteen of the 17 patients (82%) now void without the aid of an indwelling catheter or alternative therapy. Balloon dilation has no detrimental effect on erectile function and may improve fertility.     

Comparison of the in vitro and in vivo profiles of tolterodine with those of subtype-selective muscarinic receptor antagonists

Tolterodine [(R)-N,N-diisopropyl-3-(2-hydroxy-5-methylphenyl)-3-phenylpropanamine ] is a new potent and competitive muscarinic receptor antagonist developed for the treatment of urinary urge incontinence and other symptoms of overactive bladder. In vivo, tolterodine exhibits functional selectivity for the urinary bladder over salivary glands, a profile that cannot be explained in terms of selectivity for a single muscarinic receptor subtype. The aim of this study was to compare the in vitro and in vivo antimuscarinic profiles of tolterodine with those of muscarinic receptor antagonists with distinct receptor subtype-selectivity profiles: darifenacin [(S)-2-[1-[2-(2,3-dihydrobenzofuran-5-yl)ethyl]-3-pyrrolidinyl]-2,2-d iphenylacetamide; selective for muscarinic M3 receptors]; UH-AH 37 (6-chloro-5,10-dihydro-5-[(1-methyl-4-piperidinyl)acetyl]-11H-dibenzo-[b ,e][1,4]diazepine-11-one; low affinity for muscarinic M2 receptors); and AQ-RA 741 (11-([4-[4-(diethylamino)butyl]-1-piperidinyl]acetyl)-5,11-dihydro-6H-py rido[2,3-b][1,4]benzodiazepine-6-one; high affinity for muscarinic M2 receptors). The in vitro profiles of these compounds were in agreement with previous reports; darifenacin and UH-AH 37 demonstrated selectivity for muscarinic M3/m3 over M2/m2 receptors, while the converse was observed for AQ-RA 741. In vivo, AQ-RA 741 was more potent (1.4-2.7-fold) in inhibiting urinary bladder contraction than salivation in the anaesthetised cat (i.e., a profile similar to that of tolterodine [2.5-3.3-fold]), while darifenacin and UH-AH 37 showed the reverse selectivity profile (0.6-0.8 and 0.4-0.5-fold, respectively). The results confirm that it is possible to separate the antimuscarinic effects on urinary bladder and salivary glands in vivo. The data on UH-AH 37 and darifenacin support the view that a selectivity for muscarinic M3/m3 over M2/m2 receptors may result in a more pronounced effect on salivation than on bladder contraction. The data on AQ-RA 741 may indicate that muscarinic M2/m2 receptors may have a role in bladder contraction.     

Hydroxyzine inhibits neurogenic bladder mast cell activation

OBJECTIVES: Increased numbers of activated mast cells have been documented close to substance P (SP) containing nerve endings in the bladders of patients with interstitial cystitis (IC), a painful, sterile bladder disorder occurring primarily in females. Many of these patients also suffer from allergies, but common antihistamines do not help. In line with the fact that IC symptoms worsen under stress, we recently showed that bladder mast cells could be activated by the stable acetylcholine (Ach) analogue carbachol and by immobilization stress. Preliminary data from open label studies indicated that the heterocyclic histamine-1 receptor antagonist (H-1r alpha) hydroxyzine reduces IC symptoms. We, therefore, investigated whether hydroxyzine could inhibit carbachol-induced bladder mast cell activation. METHODS: Bladder pieces from male Sprague-Dawley rats were perfused with 10(-5) M carbachol, 10(-5) M SP, or 100 microg/ml compound 48/80 (C48/80), with or without preincubation with the designated concentrations of the H-1r alpha. Mast cell activation was assessed by release of exogenous 3H-serotonin and morphological evidence of secretion by light microscopy. RESULTS: Carbachol at 10(-5) M triggered rat bladder mast cell serotonin release which represented a 65% increase over control. Equimolar concentrations of SP caused a 32% increase, while C48/80 had no effect. The heterocyclic piperazine H-1r alpha hydroxyzine reduced carbachol-induced serotonin release by 25% at 10(-6) M and 34% at 10(-5) M, both of which were statistically significant (P < 0.05). On the contrary, the well known H-1r alpha diphenhydramine had no inhibitory effect, while the mixed H-1r alpha and 5-hydroxytryptamine-receptor antagonist (5-HTr alpha) azatadine actually caused an 11% increase. CONCLUSION: Hydroxyzine reduced carbachol-induced serotonin release from rat bladder in vitro through a mechanism which was unrelated to its H-1 receptor antagonistic properties. The ability of hydroxyzine to inhibit bladder mast cell activation by neurogenic stimuli along with its anticholinergic, anxiolytic and analgesic properties, may explain the clinical efficacy of this drug in reducing IC symptoms. Other, nonsedating, hydroxyzine analogues able to inhibit bladder mast cell activation may provide potentially new therapeutic approaches for IC.     

Tumour progression and survival in patients with T1G3 bladder tumours: 15-year outcome

OBJECTIVE: To evaluate tumour progression and survival of patients with T1G3 bladder tumours who were followed for 15 years. PATIENTS AND METHODS: A subset of 48 patients with T1G3 bladder tumours was entered into a randomized trial of transurethral resection (TUR) or TUR plus bacille Calmette-Guèrin (BCG) therapy and followed for a minimum of 15 years. Thirty-nine (81%) patients received one or more courses of BCG. The endpoints of the study were stage progression (defined as muscle invasion of metastasis) and disease-specific survival. RESULTS: Of the 48 patients, 25 (52%) progressed and 15 (31%) died from the disease; 33 patients (69%) survived, including 24 (50%) with an intact bladder. The median progression-free survival time was 151 months. Tumour progression occurred in 35% of the patients within the first 5 years, in 16% after 5-10 years and in 12% of those followed for 10-15 years. Deaths from cancer occurred in 25% of the patients in the first 5 years and in 10% of patients at risk from 5 to 15 years. CONCLUSIONS: Patients with T1G3 bladder tumours who are treated conservatively are at life-long risk of having a muscle-invasive tumour and dying from bladder cancer.     

Distribution of doxorubicin in the bladder wall and regional lymph nodes after bladder submucosal injection of liposomal doxorubicin in the dog

PURPOSE: Liposome-encapsulated doxorubicin (Lip-Dox) has increased therapeutic efficacy and reduced toxicity compared to free doxorubicin (Dox). To assess the utility of Lip-Dox for local control of bladder cancer, we examined the distribution of Dox in the bladder wall and the regional lymph nodes of dogs after bladder submucosal injection of Lip-Dox. MATERIALS AND METHODS: In 8 dogs (group SM), Lip-Dox (2 mg.:1 ml.) was injected into the submucosal layer of each lateral bladder wall by using a flexible cystoscope. The other 8 dogs (group IV) underwent intravenous injection of free Dox (4 mg.). Both groups of animals were sacrificed at 1, 3, 5 or 7 days after the injections. The concentration of Dox was measured in both the mucosal and muscle layers of 5 bladder wall sites and also in the external iliac lymph nodes bilaterally. RESULTS: The Dox-concentration in the lymph nodes of group SM was significantly higher (about 15-100 times) than that of group IV throughout the whole follow-up period. The Dox-concentration in the bladder wall for group SM was significantly higher than that in group IV (about 70-930 times at the lateral walls and 2-830 times at the other sites). CONCLUSION: The present results demonstrate that Lip-Dox injected into the bladder submucosally distributes well, both in the whole bladder wall and in regional lymph nodes and remains at a high concentration in these tissues for at least one week after injection.     

Long-term results of intermittent low-friction self-catheterization in patients with recurrent urethral strictures

OBJECTIVE: To ascertain the duration of intermittent low-friction self-catheterization (ILSC) required to cause stricture stabilization. PATIENTS AND METHODS: Over a 4 year period, 101 patients with a median age of 62 years (range 16-85) with recurrent urethral strictures were recruited to the trial. All the strictures were treated by internal urethrotomy and the patients were then randomized to perform ILSC twice weekly for either 6 months (group 1) or 36 months (group 2). Out-patient follow-up with urinary flow rate was initially at 1 month and then at 3 monthly intervals. Stricture recurrence rates were compared between the two groups. RESULTS: Of 101 patients, seven failed to attend after the first out-patient appointment. A further 21 died of unrelated disease whilst on ILSC (although 13 had been followed up for at least 24 months and so were included in the analysis). The median follow-up was 67 months (range 24-78). Ten patients in group 2, who had suffered from recurrent strictures, refused to stop catheterizing at the appointed time and all remain stricture-free on permanent ILSC. Of the remaining 76 patients, 48 catheterized for 6 months and 28 patients performed ILSC for 12 to 36 months (nine stopped earlier than intended). Forty per cent of patients who stopped at 6 months developed a recurrence compared with 14% who catheterized for more than 12 months (P < 0.05) (chi-square test with Yates' correction). CONCLUSIONS: Our results indicate that ILSC is safe and effective in preventing stricture recurrence in the long term. The recurrence rate of urethral strictures was significantly lower when ILSC was continued for more than 12 months compared with ILSC that was stopped at 6 months. We conclude that catheterization for at least 1 year is required to achieve adequate urethral stabilization.     

Assessment of lung function using forced impulse oscillometry in cystic fibrosis patients

The aim of this study was to evaluate the usefulness of forced impulse oscillometry to measure airway resistance in patients with cystic fibrosis. Thirty-four patients (20 men) with a mean age of 15 +/- 4 years were studied. All patients underwent forced impulse oscillometry, forced spirometry and body plethysmography. Correlations among spirometric, plethysmographic and oscillometric variables were analyzed. We found a statistically significant relation between both forced expiratory volume in one second (FEV1) and total airway resistance (Raw) and the following oscillometric variables: impedance (Zrs), resonance frequency (Fres), resistance to 5 hertz (Rrs5) and reactance to 5 hertz (Xrs5). The measurements that correlated most highly with classical pulmonary function tests were Zrs and Xrs5. Both resistance (Rrs) and reactance (Xrs) of the respiratory system were dependent on frequency. Their correlation with FEV1 and Raw were therefore lower when frequencies above 5 hertz were used. We conclude that airway resistances of cystic fibrosis patients can be adequately estimated by forced impulse oscillometry. This technique is a promising test of pulmonary function in such patients.