Biomedical subjects

F Colombo

Publications and source records attributed to F Colombo.

At least 55 records · Page 3Linked to original sources

PubMed1994

Linear accelerator radiosurgery of cerebral arteriovenous malformations: current status.

228 patients affected by cerebral arteriovenous malformations (AVMs) underwent linear accelerator radiosurgery. Follow-up ranges from 1 to 100 months (mean 42 months). Complete angiographic obliteration was achieved in 47% of treated patients at one year and 80% at 2 years. 17 haemorrhages were observed after treatment and 6 patients died from them. No bleeding took place after complete angiographic obliteration. 11 patients suffered for radionecrosis. In 6 patients complete recovery was obtained with corticoid medication. The aim of this study is to present our results and to evaluate the effect of irradiation on the risk of bleeding after radiosurgery. Patients were considered at risk in the time lapse after irradiation and before angiographic obliteration or other definitive treatment or death. Patients were followed from the date of radiosurgery and the number of haemorrhages were recorded every six months. In our series the bleeding risk in patients harbouring incompletely obliterated AVMs decreases from 8% in the first year after radiosurgery to 0% starting from the 24th month of the follow-up.

Adolescent↗

PubMed1994

Antihypertensive efficacy and tolerability of different drug regimens in isolated systolic hypertension in the elderly.

The pharmacological treatment, mainly based on diuretics, of isolated systolic hypertension (ISH) has recently been shown to reduce the risk of stroke and coronary heart disease in the elderly. The purpose of this study was to compare the antihypertensive effect and tolerability of different drug regimens in elderly subjects with ISH (systolic blood pressure--SBP-- > or = 160 mmHg and diastolic blood pressure--DBP-- < 90 mmHg). A multicentre, randomized, controlled open trial was planned in the general practice setting. Four widely used treatment schedules were tested: hydrochlorothiazide 25 mg plus amiloride 2.5 mg (H+Am), nifedipine slow release 20 mg (N), atenolol 50 mg (At) and atenolol 25 mg plus chlorthalidone 6.25 mg (At+C). After a baseline evaluation, 308 patients (76.3% female, mean age 75.3 +/- 7.1 years) were randomized and followed up for 6 months. After 3 months the drug dosage was doubled if the systolic blood pressure goal (SBP < 160 mmHg and SBP reduction of at least 20 mmHg) had not been reached. Ninety-four subjects (30.5%) presented contraindications to beta-blockers. At the 3rd- and 6th-month visits all treatment groups, except At, showed a significant reduction in SBP compared to the control group; DBP showed no significant reduction in any group at any time. At the end of the follow-up the percentage of hypertensives who had reached the BP goal was 14.6% in the control group, 52.9% in H+Am, 54.8% in N, 28.6% in At and 52.2% in At+C.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1994

Treatment of primary or metastatic pleural effusion with intracavitary cytosine arabinoside and cisplatin. A phase II study.

Thirty-three patients with microscopically verified primary or metastatic malignant pleural effusion were studied: 7 had malignant mesothelioma and 26 metastatic pleural disease. The treatment was based on biochemical and clinical studies which show a synergy between cytosine-arabinoside (Ara-C) and cisplatin. These drugs were instilled in the pleural cavity at the dose of 100 mg for Ara-C and 100 mg/m2 for cisplatin. The cavity was drained after 4 h. If it was possible, the treatment was repeated weekly for 3 times and, after a 6-week rest, it could be started again with the same schedule. The overall response rate (complete plus partial remissions) was 74%. Toxicity was mild or moderate. We conclude that the combination of Ara-C and cisplatin is well tolerated and produces a high response rate in the treatment of malignant pleural effusions.

Adult↗

PubMed1994

Brain stem and motor evoked responses in "locked-in" syndrome.

A patient suffering for an ischemic "locked-in" syndrome following a subarachnoid hemorrhage, was evaluated with brain stem acoustic evoked potentials (BAEPs), short latency somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs). Neuroradiological findings failed to reveal any lesion in the brain stem, while a transcranial Doppler showed increased flow velocity upon the basilar artery, suggesting vascular spasm. BAEPs were normal and SEPs showed to be slightly impaired while MEPs upon magnetic cortical stimulation were heavily deranged. Neurophysiological investigations appeared remarkable for the early diagnosis of the disease, when neuro-radiological findings were still negative.

Adult↗

PubMed1994

[Island flap in the surgical treatment of hypospadias].

Surgery of hypospadias represents an interesting field of innovatory ideas. Many methods may be suitable and many modifications can be performed. There is no one method for all kinds of hypospadias. It is necessary to find the right method for each patient. The result often depends upon the experience of the surgeon with a particular method. The choice between straightening and urethroplasty in one or two stages depends on cost-benefit ratio and evolution at distance of the straightening must be taken into account as well tissue consumption imposed by the urethroplasty, with one stage straightening that makes reintervention very difficult. In the latter case, a multi-stage operation will be necessary with flaps for urethroplasty after the straightening, or, in a more developed penis, a shortening operation according to Nesbit. With two-stage method, in case of relapsed curvature, this can easily be treated, if tissue is available. For a good result of urethroplasty the ability of surgeon, a constant calibration of the canal, plenty of elastic tissue for the neo-urethra, care not to suture on these planes, are highly important. In our opinion Duplay's method observes these requisites. Two-stages surgery allows easy correction of any eventual relapsing incurvature, with no problems for the following urethroplasty. One-stage surgery allows the problems to be resolved in a single surgical Step, but involves the risk of tissue consumption and proximal stricture.

Follow-Up Studies↗

PubMed1994

Human biodistribution, dosimetry and clinical use of technetium(III)-99m-Q12.

UNLABELLED: Technetium(III)-99m-Q12, trans-(1,2-bis(dihydro-2,2,5,5-tetramethyl- 3(2H)furanone-4-methyleneimino)ethane)bis(tris(3-methoxy-1-propyl) - phosphine)technetium(III)-99m, is a nonreducible complex of Tc(III) which is herein evaluated as a myocardial perfusion imaging agent. METHODS: The biodistribution and dosimetry of 99mTc-Q12 were assessed in 10 normal volunteers, while its potential clinical use was evaluated in 70 patients. RESULTS: Safety parameters measured up to 24 hr postinjection demonstrate no clinically significant drug-related adverse reactions. Technetium(III)-99m-Q12 exhibits good heart uptake (2.2% injected dose at 1 hr postinjection under resting conditions) and no detectable myocardial washout or redistribution up to 5 hr postinjection. The biodistribution is characterized by very rapid hepatobiliary clearance which allows effective myocardial imaging at times as short as 15 min postinjection. Blood and plasma clearances and myocardial uptake are rapid, while lung uptake is minimal. The heart-to-lung and heart-to-liver ratios are higher at stress than at rest, independent of the time elapsed between injection and image acquisition, and independent of whether the patient is fasted or fed after tracer administration. A preliminary correlation shows that 46/47 patients with angiographically demonstrated CAD also have perfusion defects demonstrated by 99mTc-Q12. CONCLUSIONS: On the basis of the studies reported herein, 99mTc-Q12 appears to be a promising myocardial perfusion imaging agent.

Adult↗

PubMed1994

[NPT: nocturnal penile tumescence test].

The recording of the variations of penile tumescence and rigidity during nocturnal unconscious erections that usually occur with the REM phases of sleep, has been considered the diagnostic tool of choice in the workup of erectile disturbances for a number of years. Such a success is partly due to its absence of invasiveness. Moreover this test was believed to allow to differentiate between the psychogenic and organic origin of impotence. As some authors have recently reported, anxiety state (common among patients who undergo invasive andrological procedure in the office) can at times influence the content of the dream state, thus negatively affecting the spontaneous nocturnal erections. Besides, sleep disturbances such as apnea and motor agitation can also induce erroneous interpretations of NPT graphs. Further, dysfunctions at the level of the cortex and the spine still allow the occurrence of nocturnal tumescence but determine an erectile deficit in the awake state. Clinically, all this poses new questions about the effectiveness of the NPT test in the study of the origin of impotence. The diagnostic methods, despite its world-wide diffusion, remains, under certain aspects, obscure: the operative details and, above all, its interpretative criteria. All this impedes the achievement of uniformity in the evaluation of the results obtained thanks to this test (e.g. the number and duration of erectile episodes, the interpretation of tumescence on its own, of the basal-apical dissociation, of the erectile episodes occurring immediately before waking, and of those of short duration).

Aged↗

PubMed1994

[The cavernosometry].

The recent clinical and experimental research innovations in Andrology make possible the following classification of impotence: "Failure to initiate" "Failure to store" "Failure to fill" The last aspect, including veno-occlusive dysfunction, is continuously reevaluated by andrologic studies. The main diagnostic procedure of this complex problem, in constant evolution, is represented by cavernometry. Recently, but with full success, we are utilizing direct radioisotopic penogram in video sexy stimulation: in preselection function but probably in future with substitutive function of the more invasive and traditional cavernometry. In spite of this methodologic progress the findings of cavernometry are in continuous discussion as in tumultuous evolution, in anatomo-physiological environment, is the intracavernous district that, for many aspects, necessity of ulterior histochemical, pharmacodynamic and neurophysiological acknowledgements.

Diagnosis, Differential↗

PubMed1994

Modified corporopexy as a new approach to the treatment of congenital rotation of the penis.

Congenital anomalies of the penis expressed in various forms of flexures can be associated with a rotation of the shaft. An asymmetrical insertion of the suspensory ligament on the dorsal surface of the tunica albuginea often accounts for corporal rotation. This distorts the spatial relationship between the corpora cavernosa and the pubic bone. The two corpora may overlap and the shaft is partially rotated. For the surgical treatment of these defects we proposed (1989) a technique of contrarotation of the tunica albuginea which was later abandoned because it was too invasive. We developed a technique based on the ipsilateral re-suspension of the suspensory ligament of the penis between the tunica of the lower corpus and the pubic symphysis to restore the true axis. The neurovascular adnexa, the corpora cavernosa, and the corpus spongiosum remain untouched.

Adolescent↗

PubMed1994

[Erectile complications after radical surgery for penile plastic induration].

The radical surgical option we propose for Peyronie's disease consists in removing the sclero-hyalinotic focus of disease and replacing it by an autologous dermal graft taken from the upper outer thigh area. Between 1981 and 1991, we operated 335 patients with IPP, 152 of whom underwent plaque excision and dermal graft. All could be assessed at two-year follow-up. Two main complications were observed: mild penile flexure due to scar retraction of the graft (35% of cases), and partial erectile deficit with decreased corporal rigidity (17% of cases). The degree of the graft retraction is linked to the individual's histologic response. A mild deviation of the penis can occur some months after surgery and is not a relapse flexure due to disease progression (as it should have evolutive characteristics) but is mere scar retraction and will spontaneously regress. As the patient will date the onset of a postoperative erectile deficit from the time of the operation, it is advisable to assess preoperatively the erectile ability of all patients. Furthermore, an impaired erectile response could result from hypoaesthesia of the glans, post-surgical stress, and fibrosis of the erectile tissue. A retrospective assessment of radical surgery cases involving plaque excision and dermal graft lead us to propose this option where precise indications apply, providing the presence of other alterations of the erectile function are pre-operatively assessed.

Cicatrix↗

PubMed1994

[Realities and limitations of the diagnosis of erectile impotence: radical urethro-prostato-cystectomy as a human experimentalmodel].

Veno-occlusive dysfunction (formerly called "venous leakage") is a clinical-radiographic manifestation of a multi-aetiology syndrome, the pathogenesis of which is to be sought in intrinsic damage to the erectile tissue. It has been attributed to psycho-neurogenic, neurovascular and local--physical factors. The unsatisfactory results of the various surgical techniques proposed (venous ligatures, crural plication, corporopexy) can be explained by the formation of vicarious venous circles, a phenomenon which occurs regardless of the type of procedure adopted and which is the direct consequence of the alteration of the occlusive mechanisms intrinsic to the erectile tissue. At the Urological Institute of the University of Milan, a study has been carried out with the aim of experimentally assessing these aetiopathogenetic hypotheses. 48 sexually potent patients were selected from those scheduled for extensive surgical procedures on account of malignant pathologies of the pelvic cavity (urethro-prostato-cystectomy, radical prostatectomy). The protocol included a series of examinations before and after the operation (at three months): computerised recording of nocturnal erections (NPT test, three consecutive nights), dynamic penile Doppler velocimetry, dynamic cavernosometry/graphy, examination of bulbocavernosus reflex. The goal of the study was to evaluate the haemodynamic consequences of the massive venous ligatures effected during these operations (periprostatic plexus, deep dorsal vein, spongio-cavernous connections). There were 28 cases of radical prostatectomy and 20 cases of radical urethro-prostato-cystectomy. Among the cases of radical prostatectomy, the extrafascial retropubic technique was used for 14 patients, the monolateral nerve-sparing procedure was applied for 10 patients (stage B1) and the transperineal approach was used for 4 patients (the most recent).(ABSTRACT TRUNCATED AT 250 WORDS)

Collateral Circulation↗

PubMed1994

[Erectile function and ablative surgery of penile tumors].

The Authors try to show the possibility to combine radical excision with minimal invasiveness in the surgery of penile cancer. The focal point of every therapeutic decision is correct clinical staging. Unfortunately there's some confusion in the two international staging systems (TNM and Jackson's classification). In fact it's not clear the anatomical difference between epithelioma of the glans infiltrating corpus spongiosum and subcoronary epithelioma of the shaft infiltrating the corpora cavernosa. It's obvious that the infiltration of the corpora cavernosa is a far more aggressive oncological manifestation than that of tumour infiltrating the corpus spongiosum. So we consider Jackson's classification more congenial. In terms of surgery this anatomical independence makes it easy to consider the corpora cavernosa as a distinct entity, so they remain perfectly functional when separated from the glandulo-spongio-urethral unit with its vasculo-nervous bundle. This makes conservation of the erectile function, when clinical staging show us that the tumour is not infiltrating the corpora cavernosa. The Authors show their results, which seem to be rather good.

Humans↗

PubMed1994

[Large cutaneous penile flap in the tubular reconstruction of the urethra in complex recurrent and extensive bulbar-membranous strictures].

The surgical treatment of choice for bulbar-membranous urethral strictures should remove the stricture and achieve an end-to-end anastomosis between two spatulated surfaces to achieve better patency (Turner-Warwick technique [13]). When this is not possible because of recurrence, complex or longer strictures the problem is to choose between various candidate tissue types susceptible of forming a dependable neourethra. With this in view, we have used over the last twenty years a wide range of urethroplastic operating techniques using of scrotal skin [4], bladder mucosa free grafts [3], and dermo-epidermal free mesh grafts [10]. We achieved a significant improvement of the postoperative results with a procedure originally proposed by Quartey [9]. A well vascularised flap is dissected from the whole dorsal penile skin, drawn as far as the perineum and pulled laterally to the cavernous bodies to form the neourethra. We can thus depend on suitable and viable tissue of up to 13 cm in length. A large scalped area of skin is corrected by covering the surface of the penis with a free epidermal mesh graft. Between February 1989 and December 1991, 28 patients with relapsed bulbar-membranous complex urethral strictures underwent urethroplasty with a penile-skin flap. Normal urethro-cystographic imaging and urinary flowmetry figures showed at a three-month follow-up. All patients reported satisfactory micturition and no fistula occurred. Erectile deficiency was not reported.

Adult↗

PubMed1994

Linear accelerator radiosurgery of cerebral arteriovenous malformations: an update.

One hundred eighty patients affected by cerebral arteriovenous malformations (AVMs) underwent radiosurgical treatment in our department. One hundred fifty-three patients have been treated with complete irradiation of the entire AVM nidus. In 27 patients (with large and/or three-dimensional irregular target volumes), only part of the nidus was covered with a dose adequate for obliteration. Follow-up ranged from 88 to 1 months (mean, 43.1 mo). Angiographic control was performed at 12, 24, and 36 months until complete obliteration was attained. The complete obliteration rate was 46% at 1 year and 80% at 2 years. We observed 15 hemorrhages after treatment, and five patients died from them. No bleeding took place after complete angiographic obliteration. The aim of this study is to evaluate the effect of irradiation on bleeding risk after radiosurgery and before complete obliteration. Inclusive parameters of patients considered at risk were as follows: 1) all patients in the time lapse between irradiation and demonstrated complete angiographic obliteration; 2) all patients in the time lapse between irradiation and definitive treatment either by surgery or embolization; and 3) all patients in the time lapse between irradiation and death. These groups include all irradiated patients who still had incompletely obliterated AVMs. They were stratified starting from 0 time (the date of radiosurgery), and the hemorrhages were evaluated every 6 months. In totally irradiated cases, the bleeding risk decreased from 4.8% in the first 6 months after radiosurgery to 0% starting from the 12th month of the follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1993

Time dependence of residual tissue viability after myocardial infarction assessed by [18F]fluorodeoxyglucose and positron emission tomography.

Areas of myocardial infarction may retain glycolytic activity and this finding is indicative of tissue viability and predictive of functional recovery after revascularization. In order to assess the relation between the time elapsed from the occurrence of acute myocardial infarction and persistence of myocardial metabolic activity in the infarcted tissue, we prospectively studied 65 patients with previous myocardial infarction diagnosed clinically and by electrocardiographic (Q wave) and enzymatic criteria. All patients underwent coronary angiography and contrast left ventriculography, evaluation of regional myocardial glucose metabolism (in the fasting state) by positron emission tomography (PET) with 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG), and assessment of myocardial perfusion by single photon emission computed tomography (SPECT) with technetium-99m methoxyisobutyl isonitrile (99mTc-MIBI). Based on the regional metabolic and perfusion findings, patients were divided into 2 groups, depending on the absence (group 1, 26 patients) or presence (group 2, 39 patients) of [18F]FDG uptake in the underperfused regions. Areas of underperfusion at rest, consistent with the clinically identified myocardial infarction site, were observed in all patients. Severity of coronary artery disease, presence of collaterals, number of hypocontractile segments, and wall motion score did not differ significantly in the 2 groups. The time elapsed from the infarction was significantly greater (1,860 +/- 1,333 days) in group 1 than in group 2 (92 +/- 115 days; p < 0.0001). Exercise caused an increase in severity and/or extent of resting perfusion abnormalities in a greater proportion of patients of group 1 (53% vs 23%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

Analysis of dosimetric measurements in linac radiosurgery calibration.

The aim of this paper is to analyse the dosimetric parameters of a linear accelerator used in radiosurgery treatments. The influence of these parameters on the resulting dose distribution are basic for delivering the predefined dose to the vascular or oncological target volume. Several dosimetric methods have been used to define the output factors for small fields. The thimble and the Markus chambers, TLD and film dosimetry are investigated; all these dosimetric systems give reliable and almost similar results if used in the correct way. In the determination of tissue maximum ratio (TMR) the response curves obtained by ionometric and film dosimetry were investigated. For TMR determination the use of the Markus chamber and the correction factors to be applied as a result of the small dimension of the field were also investigated.

Calibration↗

PubMed1993

From radiotherapy to stereotactic radiosurgery: physical and dosimetrical considerations.

The aim of this presentation is to analyse the mechanical and dosimetrical parameters of the linear accelerator used in stereotactic radiosurgery. The use of the thimble and Markus chambers, TL and film in small field dosimetry are investigated. To determine the optimal irradiation technique and dose distribution, the dose volume to healthy tissue is considered.

Humans↗

PubMed1993

Is there still an avoidable fraction of post-operative thromboembolic complications with heparin prophylaxis? The results of a case-control surveillance. Collaborative Group on Heparin Prophylaxis in Surgery (S.E.P.E.C.).

A case-control multicenter study was set up in 68 general and specialistic wards in Italian regional hospitals in order to assess whether underuse of heparin prophylaxis may account for at least a fraction of the thromboembolic events still occurring in surgical patients. 100 cases with clinically relevant thromboembolic or hemorrhagic events occurring during hospitalization for major surgery and 200 controls were identified. Controls were selected among patients not presenting any of the events under study during the same period of observation and were matched with cases for age, sex, and type of surgery. The results of the study suggest that heparin use in routine conditions of care closely reflects the "consensus" knowledge, patients at higher risk (specifically orthopedic surgical patients, those with varicose veins or with preoperative bed rest longer than 3 days) being treated more frequently with heparin. Absence of heparin prophylaxis does not appear to represent a specific risk factor for the occurrence of index events (OR 0.73, 95% CI = 0.42-1.26). Despite the higher rates of heparin exposure, the presence of varicose veins is associated with a statistically significant increase in the risk of postoperative complications (OR 2.23, 95% CI = 1.07-4.65). This study indicates that among known pre- and peri-operative risk factors only varicose veins may be unprotected by the current prophylaxis practice.

Adult↗