Reconstruction of artery wall in experimental giant aneurysms.

AIM: This study describes five experimental techniques for the surgical treatment of giant aneurysms based on the resection of the aneurysm sac and reconstruction of the arterial wall. METHODS: The aneurysm was realized with a venous graft implanted with end-to-side anastomosis on the common carotid artery on 50 rabbits (with each technique realized in 10 rabbits). The first two experimental techniques (A and B) involve the reconstruction of the artery wall by a synthetic dural patch and by direct suture reinforced by a venous patch, respectively. In the model C a collateral branch arising from the aneurysm is resected and reimplanted on the parent artery after aneurysm resection. In the experimental model D the arterial defect is closed by a venous patch surrounding the whole arterial wall and sutured with the aid of fibrin glue. In the model E clamping of the parent artery proximal to the aneurysm site and termino-lateral anastomosis with the contralateral artery lead to the thrombosis of the aneurysm fulled only by refluent flow. RESULTS AND CONCLUSION: The venous pouch experimental models are useful to realize giant aneurysms. The above described techniques allow to realize the reconstruction of the arterial wall without stenosis and shortening the clamping time.

Quantification of thyroxine and 3,5,3'-triiodo-thyronine in human and animal hearts by a novel liquid chromatography-tandem mass spectrometry method.

Assaying tissue T3 and T4 would provide important information in experimental and clinical investigations. A novel method to determine tissue T3 and T4 by HPLC coupled to mass spectrometry is described. The major difference vs. previously described methods lies in the addition of a derivatization step, that is, to convert T3 and T4 into the corresponding butyl esters. The yield of esterification was Ì´ 100% for T3 and 80% for T4. The assay was linear (r>0.99) in the range of 0.2-50 ng/ml, accuracy was in the order of 70-75%, and the minimum tissue amount needed was in the order of 50 mg, that is, about one order of magnitude lower than observed with the same equipment (AB Sciex API 4000 triple quadrupole mass spectrometer) if derivatization was omitted. The method allowed detection of T3 and T4 in human left ventricle biopsies yielding concentrations of 1.51±0.16 and 5.94±0.63 pmol/g, respectively. In rats treated with different dosages of exogenous T3 or T4, good correlations (r>0.90) between plasma and myocardial T3 and T4 concentrations were observed, although in specific subsets different plasma T4 concentrations were not associated with different tissue content in T4. We conclude that this method could provide a novel insight into the relationship between plasma and tissue thyroid hormone levels.

Intracranial hypertension due to meningioma of the unique transverse sinus.

We describe a 28-year-old woman with intracranial hypertension due to a meningioma invading the unique transverse sinus (with absent contralateral sinus). Clinical remission and normalization of orbital echography were obtained by resection of the intradural tumor and peeling of the dural attachment. In such cases, resection and reconstruction of the involved sinus segment is at high risk of venous infarction. Endovascular stenting of the obstructed sinus is a valid alternative when the stenosis is not remarkable. Single tumor removal may lead to partial sinus decompression and increased venous flow, resulting in long-term clinical remission.

Fusiform aneurysm of the proximal anterior cerebral artery (A1).

OBJECTIVE: Fusiform aneurysms of the A1 segment of the anterior cerebral artery (ACA) are exceptional, with only 15 reported cases. This article presents an additional case treated by microsurgical trapping. The aim is to discuss the treatment of these aneurysms based on the aneurysm morphology and the anatomy of the ACA complex. CASE REPORT: A 52-year-old woman with subarachnoid hemorrhage (Hunt-Hess grade II) showed an aneurysm of the proximal part of the A1 segment of the left ACA involving the whole circumference of the arterial wall on computerized tomography angiography and digital angiography. There was good collateral blood flow from the right ACA to the distal left ACA. A left pterional craniotomy allowed us to expose a large aneurysm of the proximal part of the A1 segment; the artery entered into the aneurysm sac and could not be identified at the level of the aneurysm. Trapping of the aneurysm was performed with a distal clip placed just before the origin of the artery of Heubner. No neurological deficits were observed postoperatively. CONCLUSION: Clipping of fusiform aneurysms of the A1 segment using an encircling clip is the treatment of choice but, more often, this is impossible. Trapping of the aneurysm with preservation of the perforating branches (mainly the Heubner artery) may be easily performed when collateral blood flow from the contralateral ACA is sufficient.

Spheno-orbital meningiomas: surgical approaches and outcome according to the intraorbital tumor extent.

OBJECT: This study proposes a topographical classification of spheno-orbital meningiomas. Its aim was to define whether the different intraorbital localizations require different surgical approaches and have different recurrence rates and outcomes. MATERIAL AND METHODS: Sixty patients with spheno-orbital meningiomas operated upon between 1983 and 2003 were reviewed. Four types were identified according to the extent of intraorbital tumor invasion: I: lateral or superolateral (15 cases); II: medial and inferomedial (8 cases); III: orbital apex (25 cases); IV: diffuse (12 cases). Three surgical approaches were used: lateral orbitotomy (15 cases with lateral or superolateral tumors), supraorbital-pterional approach (42 cases, including all 8 inferomedial cases, all 25 orbital apex cases, and 9 of 12 diffuse tumors), and a fronto-temporal-orbitozygomatic approach (only 3 cases with diffuse meningiomas and large-scale tumor invasion in the infratemporal fossa and cavernous sinus). RESULTS: Tumor removal was complete (Simpson grades I and II) in 40 cases, and incomplete in 20 (33.3%). There were two postoperative deaths (3.3%). A sufficient clinical follow-up was obtained in 52 cases. The clinical outcome was excellent in 26 patients (50%), good in 16 (30.8%), moderate in 6 (11.5%), and poor in 4 (7.7%). Twenty-two of 52 patients (42.3%) had tumor recurrence; however, 44 (84.6%) achieved tumor control after surgery alone through two or more operations. The recurrence rate was correlated with the Simpson grade of resection and the intraorbital tumor location. Significantly higher rates of recurrence were recorded for the orbital apex type (50%) and diffuse forms (60%), than for the inferomedial (28.5%) and superolateral forms (23%). CONCLUSIONS: Spheno-orbital meningiomas may be classified according to the location and extent of the intraorbital tumor invasion. The different localizations may require different surgical approaches, with different chances of complete removal. The location and extent of the intraorbital tumor results in different recurrence rates, lower for superolateral and inferomedial forms than for orbital apex and diffuse forms.

Local versus diffuse recurrences of meningiomas: factors correlated to the extent of the recurrence.

OBJECTIVE: The aim of this study is to evaluate the factors correlated with the different patterns (local, peripheral and diffuse) of meningioma recurrence. MATERIAL AND METHODS: 55 patients with benign (WHO I) meningiomas which recurred after seemingly complete removal were reviewed; 40 (Group I) had local or peripheral recurrences (< 3 cm from the initial dural attachment) and 15 (Group II) had distant and diffuse recurrences. Patient age and sex, tumor location, interval of recurrence, tumor shape, type of brain-tumor interface, histological subtype, mitotic index (MI) and progesterone receptor (PR) expression of the initial tumor, histological WHO Grade of the recurrent tumor and patient outcome were analyzed and correlated with the pattern of recurrence. RESULTS: Flat-shaped meningiomas with large dural attachment showed a significantly higher rate of diffuse recurrences than round tumors, whereas the brain-tumor interface and the tumor location were not relevant (excepting the lack of convexity meningiomas in the group of diffuse tumors). There were no significant differences of histology, MI and PR expression of the initial tumor and histological grade of the recurrent tumor between the two groups. CONCLUSIONS: The different patterns of meningioma recurrences (local, peripheral, diffuse) are not correlated with the tumor location and histology and do not represent a different biological tumor progression. We agree that most unexpected extensive recurrences result from a more extensive microscopic dural involvement.

Microsurgical repair of the facial nerve.

OBJECTIVE: To report a series of 18 patients who underwent microsurgical repair of the facial nerve using different techniques and to discuss the indications and results of facial reinnervation procedures. METHODS: Eighteen patients with post-surgical facial palsy underwent facial reinnervation using different techniques.'These included classic hypoglossal-facial anastomosis in 13 cases, one-stage hemihypoglossal-intratemporal facial nerve anastomosis and translabyrinthine removal of residual intra-canalar acoustic schwannoma in 3, hemihypoglossal-facial nerve anastomosis in one, and neurotization of facial muscles through a nerve graft in one. RESULTS: The facial muscle function improved in all patients, up to grade III in 7 cases (39 %), grade IV in 9 (50 %) and grade V in 2 (11 %). The tongue atrophy was minimal in 70.5 %, moderate in 17.5 % and severe in 12 %. The outcome was better in younger patients (less than 40 years of age) and in those with a lesser grade of preoperative facial impairment. CONCLUSIONS: The classic hypoglossal-facial anastomosis is the technique of choice in most cases. The use of the intratemporal facial nerve is indicated when removal of an intra-canalar residual schwannoma must also be performed. The neurotization of the facial muscles through a nerve graft may be used when there is no distal trunk of the facial nerve available for the anastomosis.

Schwannomas of the brachial plexus--diagnostic and surgical problems.

OBJECTIVE: This paper reports four cases of schwannomas of the brachial plexus operated upon with good outcome and discusses the CT and MRI findings and the best surgical treatment of these lesions. DESIGN: All patients had large schwannomas (more than 4 cm in diameter) presenting as painless masses in the supraclavear region, explored by CT and MRI. A homogeneous mass, hypo-isointense in T1- and hyperintense in T2-weighted images, with well-defined margins, is in favor of a schwannoma. The nerve of origin, external to the tumor mass, may be defined on MRI. INTERVENTION: All patients have been operated upon using microsurgical technique: enucleation of the tumor content, piecemal removal of the capsule, identification and preservation of the neural elements were the main goals of the operation in all cases. OUTCOME: Postoperatively, one patient experienced transient deficit of the deltoid muscle (two weeks). Actually, all four patients are symptom-free with no tumor recurrence, 6 months to 7 years after the operation. CONCLUSIONS: A correct preoperative diagnosis of schwannoma of the brachial plexus may be obtained by MRI, which shows a rather typical aspect; on the other hand, needle aspiration histology and open biopsies should be avoided. The microsurgical treatment with preservation of the neural structures, as for schwannomas of the cranial and spinal nerves, results in good outcome without recurrences.

1,4-Dihydropyridine calcium channel blockers inhibit plasma and LDL oxidation and formation of oxidation-specific epitopes in the arterial wall and prolong survival in stroke-prone spontaneously hypertensive rats.

BACKGROUND AND PURPOSE: Calcium-channel blockers (CCBs) reduce systolic blood pressure and stroke-related mortality in stroke-prone spontaneously hypertensive rats (SPSHR). Brain ischemia is associated with loss of intracellular antioxidants. Increased formation of oxygen radicals and oxidation of LDL may enhance arterial vasoconstriction by various mechanisms. CCBs that also exert antioxidative properties in vitro may therefore be particularly useful. To investigate such antioxidant effects in vivo, we determined several parameters of LDL oxidation in SPSHR treated with two 1,4-dihydropyridine-type (1,4-DHP) CCBs of different lipophilic properties and compared them with antioxidant-treated and untreated controls. We also tested whether these drugs decrease the formation of oxidation-specific epitopes in arteries. METHODS: Five groups of 9 to 14 SPSHR each (aged 8 weeks) were treated with 80 mg/kg body wt per day nifedipine, 1 mg or 0.3 mg/kg body wt per day lacidipine, vitamin E (100 IU/d), or carrier for 5 weeks. A group of Wistar-Kyoto rats was used as normotensive control. Plasma samples were taken, and LDL was isolated by ultracentrifugation. Then LDL was exposed to oxygen radicals generated by xanthine/xanthine oxidase reaction (2 mmol/L xanthine+100 mU/mL xanthine oxidase), and several parameters of oxidation were determined. The presence of native apolipoprotein B and oxidation-specific epitopes in the carotid and middle cerebral arteries was determined immunocytochemically. RESULTS: 1,4-DHP CCBs completely prevented mortality. Normotensive Wistar-Kyoto rats showed less oxidation than control SPSHR. Plasma lipoperoxide levels were 0.87+/-0.27 micromol/L in control SPSHR, 0.69+/-0.19 and 0.63+/-0.20 micromol/L in the groups treated with 0.3 and 1 mg lacidipine, respectively, and 0.68+/-0.23 micromol/L in nifedipine-treated animals (P<0.05 versus control SPSHR for all values). Both CCBs significantly decreased formation of conjugated dienes and prolonged the lag time in LDL exposed to oxygen radicals. Similarly, lipoperoxides and malondialdehyde were significantly reduced (P<0.05). Reduced relative electrophoretic mobility and increased trinitrobenzenesulfonic acid reactivity of LDL from treated rats (P<0.01) also indicated that fewer lysine residues of apolipoprotein B were oxidatively modified in the presence of 1,4-DHP CCBs. Finally, these drugs reduced the intimal presence of apolipoprotein B and oxidized LDL (oxidation-specific epitopes) in carotid and middle cerebral arteries. CONCLUSIONS: In the SPSHR model, 1,4-DHP CCBs reduce plasma and LDL oxidation and formation of oxidation-specific epitopes and prolong survival independently of blood pressure modifications. Our results support the concept that the in vivo protective effect of these drugs on cerebral ischemia and stroke may in part result from inhibition of oxidative processes.

Evidence of exercise-induced myocardial ischemia in patients with primary aldosteronism: the Cross-sectional Primary Aldosteronism and Heart Italian Multicenter Study.

BACKGROUND: Primary aldosteronism (PA) is a disease associated with hypersecretion of aldosterone caused by an aldosterone-producing adrenal adenoma, bilateral adrenal hyperplasia, and, although rarely, by adrenal carcinoma. Arterial hypertension induces several cardiovascular alterations that yield a high cardiovascular risk. It has been shown that reduced myocardial perfusion at rest, assessed by thallium-201 myocardial scintigraphy, was greater in PA than in essential hypertension (EH). However, it is still unknown whether reduced myocardial perfusion at rest and/or regional function abnormalities are present during exercise-induced myocardial stress. PURPOSE: We addressed the impact of PA on myocardial ischemia and sought to identify signs of exercise-induced myocardial ischemia (assessed by MIBI-SPECT and echocardiography) in patients with PA compared to patients with EH. Patients with consistent signs of myocardial ischemia on all of the tests were studied by coronary arteriography. PATIENTS: We studied 72 patients with PA and an age/sex-matched group of 72 patients with EH enrolled in the cross-sectional Primary Aldosteronism and Heart Italian Multicenter Study (PAHIMS). METHODS: Regional function was detected from echocardiographic measurement of wall motion done at baseline and immediately after exercise. Myocardial perfusion was evaluated by SPECT imaging after injecting 99mTc-MIBI with the same-day protocol using the rest-stress sequence. RESULTS: Although the conditions of arterial pressure, duration of hypertension, and target organ damage were equivalent, the patients with PA had greater incidence of both reversible perfusion defects and abnormalities of regional function. Moreover, multiple regression analysis showed that the high plasma aldosterone level was highly predictive for SPECT ischemic score and wall motion index, suggesting that PA contributes to cardiovascular risk over and above that associated with ventricular hypertrophy. Exercise-induced myocardial ischemia in PA was not segmental but widely distributed suggesting that this phenomenon was not related to abnormal coronary perfusion. Accordingly, of the 38 patients with PA who underwent coronarography, there was no presence of significant coronary atherosclerotic lesions in 30 (78.9%) of the patients. CONCLUSIONS: The PAHIMS observed more exercise-induced moderate myocardial ischemic defects (co-detected by SPECT and echocardiograms and not segmental but widely allocated) in patients with PA than in patients with EH. This phenomenon occurred in a greater percentage of patients with PA without significant coronary lesions (78.95%, n = 38), which supports the possible presence of small-vessel intramyocardial disease.

Microsurgical nervous reconstruction using autografts: a two-year follow-up.

BACKGROUND: To analyze factors influencing surgical results after microsurgical reconstruction of injured nerves. METHODS: We report a series of 32 cases of microsurgical nerve reconstruction after traumatizing lesions using nervous autografts. The series comprises 8 reconstructions of radial nerve, 8 of median nerve, 6 of ulnar, and 10 of sciatic nerve. Motor and sensitive deficits have been evaluated preoperatively using a standard grading. RESULTS: A useful sensory recovery has been obtained in radial nerve, as well as in median and ulnar nerve reconstruction. Good results regarding the motor recovery have been obtained in superior limb nerve reconstruction. Sciatic nerve reconstruction showed the worse results. CONCLUSIONS: There is a big discrepance between superior limb vs inferior limb results. A more than 10 cm gap has a negative influence on the progression of regenerating axons, especially in median and ulnar nerves.

Anomalous meningeal branches of the ophthalmic artery feeding meningiomas of the brain convexity.

Many anomalies may involve the ophthalmic and middle meningeal arteries, because of the close relationship of their development. The system of the ophthalmic artery may supply the dural convexity by the middle meningeal artery of ophthalmic origin, the anterior branch of the middle meningeal artery or an accessory meningeal artery. The development and the anatomic arrangement of these anomalous vessels are discussed. Three cases of meningiomas of the brain convexity supplied by anomalous meningeal arteries arising from the ophthalmic artery are described. In one case internal carotid angiography showed an anomalous anterior branch of the middle meningeal artery arising from the ophthalmic artery, whereas the maxillary artery provided only the posterior branch of the middle meningeal artery. In two cases the middle meningeal artery system was normal, but the ophthalmic artery provided an accessory meningeal artery supplying the meningioma. Whereas an ophthalmic origin of the middle meningeal artery is rather common, the angiographic finding of an accessory meningeal artery or an anterior branch of the middle meningeal artery arising from the ophthalmic arterial system is exceptional. The preoperative embolization of dural lesions supplied by anomalous meningeal vessels of ophthalmic origin is dangerous because of the risk of embolization into the ophthalmic circle.

The oculomotor nuclear complex in humans. Microanatomy and clinical significance.

This study has been performed to define better the anatomical structure of the oculomotor nuclear complex and its neuronal components. The oculomotor nuclear complex was examined in fixed and serially sectioned midbrains from 12 adult subjects free from neurological diseases. The complex included the somatic portion, (formed by multipolar motor neurons), and the parasympathetic portion, (formed by oval or fusiform preganglionic cells), on each side of the median raphe. The somatic portion consisted of the lateral somatic cell column and the caudal central nucleus. The somatic column measured from 0.2 x 0.1 mm to 3.4 x 1.4 mm (X = 2.4 x 1.2 mm) in transverse section. It was divided into the principal, intrafascicular and extrafascicular parts. The principal part was subdivided into the dorsal, intermediate and ventral portions. Isolated multipolar neurons were also found in the periaqueductal gray matter, the interstitial nucleus of Cajal, the Edinger-Westphal nucleus and the fibre bundles of the oculomotor nerve. These cells most likely represent the displaced motor neurons of the oculomotor nerve. The caudal central nucleus was 0.8 x 0.6 mm in size. The Edinger-Westphal nucleus consisted of the rostral, ventral and dorsal parts; the longest rostrocaudal diameter of this nucleus measured 7.1 mm. The anatomical data of our study are relevant clinically and allow explanation of the neurologic signs following complete or partial lesions of the oculomotor nuclear complex.

Territories of the perforating (lenticulostriate) branches of the middle cerebral artery.

The territories of the central branches of the middle cerebral artery (MCA) were examined in 21 injected human brains. It was noted that these central arteries supplied: the caudate nucleus (dorsolateral half of the rostral part of its head; the entire caudal part of the head; the body and rostral portion of the tail in some cases), the putamen (dorsolateral part of its rostral portion, the remainder of the putamen, except the most caudal part occasionally), the globus pallidus (the entire lateral segment, except the ventrorostral and, sometimes, the most caudal part), the basal forebrain (lateral parts of the basal nucleus of Meynert and the nucleus of the diagonal band, as well as fiber bundles in this region), the internal capsule (dorsal and ventrocaudal part of the anterior limb, dorsal part of the genu, dorsal and ventrorostral part of the posterior limb), the corona radiata (a narrow strip close to the internal capsule) and the cerebral cortex (the caudal orbitofrontal cortex occasionally). The presented data may have certain neuroradiologic, neurologic and neurosurgical significance.

Multicentrical growth of meningiomas: "spatial" or "temporal" phenomenon.

Small nodules of neoplastic cells protruding from the arachnoidal layer surrounding an intracranial meningioma, completely independent from the tumor mass, have been observed in three patients who underwent primary surgery. The high rate of recurrence for meningiomas after a seemingly total excision has been many times reported, and related to histological subtypes, tumor site, and hormonal influence. In the past meningotheliomatous cell aggregates protruding from the inner surface of the dura mater at a distance of 3 cm from the insertion of globoid meningiomas have been described, and the concept of "localized dural multifocality" emphasized. Probably this concept has to be enlarged to consider meningioma as a "neoplastic disease" with different grade of expression. The presence of unidentified macroscopic or microscopic clusters of neoplastic cells, lying around, more or less close to, the line of insertion of lesion, could render any attempt to gain a "radical" excision useless.

Light and laser scanning microscopy analysis of hydroxyapatite used in periodontal osseous defects in man: evidence of a different resorption pattern in bone and soft tissues.

Hydroxyapatite (HA) is a highly biocompatible material that recently has been shown to undergo biodegradation. The mechanisms of this phenomenon are unclear, and humoral and cellular events have been thought to be implicated. In the present study HA particles were put into infraosseous defects on teeth that were to be extracted for prosthetic reasons and then retrieved after a 1-year period. The specimens were processed with the cutting grinding system. Results show a very sharp difference of the biodegradation processes, related to the tissues that surround the HA particles. HA in tight contact with mineralized bone showed no evidence of degradation or resorption, while on the contrary, in the areas where bone loose connective tissue was present, it was possible to observe HA crystals detached and scattered in cells cytoplasm or extracellular fluids. This dissolution and resorption phenomenon were observed also by Laser Scanning Microscope (LSM) in fluorescent mode. These differences in degrees of degradation between bone and loose connective tissue could be due to the small amount of interstitial fluid present in mineralized bone and the greater flow of fluid through connective tissue.

[Complications of trans-sphenoidal surgery of the sellar lesions]. / Complicazioni della chirurgia transfenoidale delle lesioni sellari.

Trans-sphenoidal surgery has a very low rate of complications despite a series of apparently negative anatomo-topographical factors. Complications may be either mechanical or functional, transitory or permanent. The most important complications are: hematoma of the focus, sub-arachnoid hemorrhage, empty sella, liquoral fistula, opto-chiasmatic lesions, arterial lesions, lesions of the cavernous sinus, parenchymal damage, nasal and paranasal mechanical lesions, insipid diabetes, hypopituitarism. The overall mortality rate is 0.4-1% and is always associated with predisposing factors, such as previous treatment, voluminous extrasellar growth, concomitant causes of disease; the most frequent causes of death are: hemorrhagic phenomena in the extrasellar portion of large size adenomas; vascular lesions involving the intracavernous carotid artery; and hypothalamic lesions. The frequency of major complications is in the region of 2.3%. Predisposing factors are: volume, consistency, invasiveness, previous treatment, intratumoral necrotic-hemorrhagic phenomena, age. Surgery is only indicated for some of the above complications, including hematoma of the focus, acute postoperative empty sella, rhinoliquorrhea resistent to conservative treatment, excessive filling of the sellar cavity. All the other possible complications are results or functional alterations which must be treated medically, even if a specific therapy only exists for some (such as early hypotonic polyuria). The series of patients reported here refers to the period 1978-1989 and accounts for a total of 259 trans-sphenoidal operations performed in 245 patients. Of the secondary operations, 6 were due to postoperative complications (hematoma of the focus in 2 cases, rhinoliquorrhea in 2 cases; empty sella and hemorrhagic infarction of a large suprasellar site in the 2 remaining cases). There were 2 deaths related to direct mechanical complications (both caused by hemorrhagic infarction of large tumoural residues and the surrounding cerebral parenchyma). Complications which did not require re-operating were observed in 11 further cases: 6 cases of persistent rhinoliquorrhea which required protracted spinal drainage; 2 cases of deterioration of previous visual deficits unrelated to either hematoma of the focus or empty sella but caused by trauma to optic structures, either directly or on a vascular basis; 3 cases of dyplopia due to oculomotory deficiency. In terms of hypophyseal function, the ex-novo onset of postoperative pan-hypopituitarism and insipid diabetes was only observed in one case.(ABSTRACT TRUNCATED AT 400 WORDS)

Action of glucomannans on complaints in patients affected with chronic constipation: a multicentric clinical evaluation.

Chronic constipation is a very frequent disease in western countries but fibres can often solve the problem. In the present study, authors tested the efficacy and the acceptability of glucomannans, hydrophylic carbohydrates with a high degree of viscosity, in 93 patients affected with chronic constipation. The multicentric, open and non-controlled study was divided into an initial phase (treatment with 1g of glucomannans t.i.d. for 1 month) and a maintenance phase (1g b.i.d. for one month). We evaluated both objective parameters (number of days per week with bowel movements and number of enemas) and abdominal symptoms. After one month all assessed parameters showed a statistically significant improvement lasting through the second month. Glucomannans were well accepted and devoid of relevant side-effects. In conclusion, considering their efficacy and tolerability, they can be proposed as an ideal therapeutic tool in the management of chronic constipation symptoms.

Hemodilution and revascularization for early treatment of stroke: an experimental trial.

A new experimental trial to investigate the usefulness of early therapeutic measures in case of acute I.V.D. has been performed, on the basis of a previous already reported experience. A combined treatment consisting of hemodilution and revascularization starting 16 hours after the onset of cerebral ischemia was tested. The study was performed in a population of 20 New Zealand male rabbits in which an acute cerebral ischemia was achieved by means of extracranial ligation of both common carotid artery and of one vertebral artery. The animals were divided into two groups. 1st group: no treatment; 2nd group: revascularization + hemodilution. Better results were observed in treated group considering either CBF rates or histological changes.

Vascular microsurgical anastomosis in hypercholesterolemic rats: an experimental study.

Patency of vascular microanastomosis was examined in aging (6 months) and hypercholesterolemic rats, reproducing conditions similar to those occurring in human pathology. Results have been compared with those achieved in normocholesterolemic, younger (aging less than 8 weeks) rats.