Mitral valve repair with artificial chordae is a widely accepted procedure for the majority of patients with degenerative mitral regurgitation (MR), rendering good long-term results.1Salvador L. Mirone S. Bianchini R. et al.A 20-year experience with mitral valve repair with artificial chordae in 608 patients.J Thorac Cardiovasc Surg. 2008; 135: 1280-1287Abstract Full Text Full Text PDF PubMed Scopus (112) Google Scholar A new technique for the treatment of extensive mitral prolapse/flail is described herein. After median sternotomy, cardiopulmonary bypass is established between the right atrium and the aorta. The pericardium is opened, and the apex is elevated with stay sutures. A purse-string suture is placed onto the posterior aspect of the left ventricular (LV) apex. The LV apex is punctured with the Seldinger technique through the string suture, and an 8F introducer sheath is placed into the LV cavity. After cross-clamping of the aorta and normothermic cardioplegia, the left atrium (LA) is opened in the usual manner. Two double-armed pledgeted 2-0 Prolene sutures (Ethicon, Somerville, NJ) are passed through the prolapsed/flail leaflet segment and traversed through the LV sheath out of the left ventricle. The heart is deaired, the LA is closed, and the aortic crossclamp is removed. A custom-made polymer elastic tube of premeasured length and a 2-mm external profile is advanced over the exteriorized suture arms to contact the target leaflet, thereby securing the suture loops to the leaflet on the beating heart and thus replacing intracardiac knotting (Figure 1A) . The introducer sheath is removed, and the LV entry site is closed with a custom-made polymer occluder placed over the suture arms. The sutures are pulled and released until a good coaptation of the prolapsed/flail segment is achieved on the beating heart with transesophageal echocardiographic (TEE) guidance (Figure 1B). The exteriorized suture lengths are locked with the separate loop knot and secured to the exterior of the myocardial entry site occluder (Figure 2).Figure 2Scheme of the technique. The exteriorized sutures are initially fixated at the desired level, with the preformed loop knot (eg, “bowline”) attached to the occluder. This loop knot does not slip. The additional “stopper” knots cannot slide through the solid occluder.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Between March and December 2007, 6 male patients aged 64 to 73 years with extensive prolapse, flail, or both of the posterior (n = 4) and anterior (n = 2) mitral leaflets underwent mitral repair with the described procedure. All 6 patients had significant heart failure (New York Heart Association class III–IV) caused by severe MR 2 to 6 weeks before surgical intervention. Degenerative mitral disease was present in all, although only 1 patient had concomitant coronary artery disease treated with percutaneous intervention. The mitral annulus and the LA were not significantly enlarged in any of the patients. Informed consent was obtained from each patient. The procedure was approved by the institutional review board. No other interventions were performed during the operation. Cardiopulmonary bypass time ranged from 40 to 70 minutes, and aortic cross-clamp time ranged from 5 to 15 minutes. MR was abolished in 2 patients, reduced to less than grade I in 3 patients, and reduced to grade II in 1 (coronary diseased) patient. Inappropriate leaflet tethering during the procedure resulted in significant residual MR in this patient. No complications occurred. At 6 months' follow-up, MR increased from grade II to grade III in the 1 patient with coronary artery disease, whereas no changes were observed in 5 patients, as seen with TEE analysis. No major events were reported at follow-up. The complexity during insertion of neochordae includes determining chordal length on a nonbeating heart, securing the neochordae to the leaflet, and knot sliding.2Gilinov M. Banbury K.M. Pre-measured artificial chordae for mitral valve repair.Ann Thorac Surg. 2007; 84: 2127-2129Abstract Full Text Full Text PDF PubMed Scopus (28) Google Scholar The technique here described enables a dynamic adjustment of the chordal length on a beating heart controlled by TEE. External fixation of the neochordae on a beating heart under TEE guidance has been used for the tricuspid valve3Baufreton C. Laporte J. Langlais J. Mehreb M. Binuani P. De Brux J.L. Transesophageal echocardiography-guided chordal replacement for tricuspid regurgitation.Ann Thorac Surg. 2004; 77: 1811-1813Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar and also for repair of the prolapsed aortic valve leaflet.4Fattouch K. Sampognaro R. Bianco G. et al.Implantation of Gore-Tex chordae on aortic valve leaflet to treat prolapse using “the chordae technique”: surgical aspects and clinical results.Ann Thorac Surg. 2008; 85: 2019-2024Abstract Full Text Full Text PDF PubMed Scopus (14) Google Scholar Use of the elastic polymer tube that covers the suture loops, longitudinally tightening them to the leaflet, replaces the intracardiac knots. The suture anchorage in the myocardial occluder–type plug contributes to the shock absorption. We used a biocompatible polymer tube, which is used for permanent pacemaker lead insulation and has a well-established safety record. Strong tube attachment to the mitral leaflet and the LV apical endocardium has been reported 10 years after inadvertent pacemaker lead placement through the perforated posterior mitral leaflet.5Konings T.C. Koolbergen D.R. Bouma B.J. et al.Iatrogenic perforation of the posterior mitral valve leaflet: a rare complication of pacemaker lead placement.J Am Soc Echocardiogr. 2008; 21 (512.e5-e7)PubMed Google Scholar The expanded polytetrafluoroethylene sutures were not available at our institution. The long-term intracorporal physical characteristics of the unit composed of 2-0 Prolene suture loops covered with the polymer tube have yet to be investigated. The breaking strength of this unit is about 10 kg. Long-term follow-up and extensive studies are needed to establish the real value of this technique. Its simplicity might enable less experienced centers to perform isolated chordal replacement, especially in patients with acute onset of MR without annulus enlargement.

KRATAK SADRŽAJ Hilo­p erika­ rd je izliv­ a­we li mfe u perika­ rdni pro­st o­ r ko­je mo­že d a­ se ja­ v­ i i ka­o­ k o­m plika­c ija­ po­sle k a­rd io­h irur­ skih interv­ encija­ . Ciq o­v­ o­g a­ ra­d a­ je b­ io­ d a­ kr o­ z prika­ z dv­a­ b­ o­l esnika­ ko­j a­ su h irurski lecena­ u In stitutu za­ k a­rd io­ v­a­ ­ skula­r ne b­ o­l esti Klinicko­ g centra­ S rb­ije u B eo­gra­du uka­že mo­ n a­ sp ecificno­sti d ija­g no­st iko­ v­ a­w a­ i l ecewa­ o­v­o­ g retko­ g, a­ li tesko­ g sta­w a­ . Ko­ d b­ o­l esnika­ sta­r o­ g 63 go­d ine hilo­p erika­ rd je na­st a­o­ u n epo­sre dno­ m po­sto­p era­c io­n o­ m to­ku po­sle im­ pla­n ta­c ije v­e sta­c ke meha­ni cke v­a­lv­u le na­ a­o­ rtno­ j po­z iciji (St. Jude No 21) i mitra­l no­ j po­z iciji (St. Jude No 29). Etio­lo­g ija­ perika­ rdno­ g izliv­a­ je do­ka­za­n a­ b­ o­j ewem „Suda­n o­ m III” uzo­ra­k a­ punk ta­t a­ do­ b­ij eno­ g supksifo­i dno­ m perika­ rdno­ m punkcijo­ m. Uzrok nastanka hiloperikarda bila je lezija ductus thoracicus (grudno­ g v­ o­d a­ ) ko­j a­ je na­sta­la­ pr iliko­ m klemo­ v­ a­w a­ g o­r we su­ pqe v­e ne Kulijev­o­ m klemo­ m. Ko­ d b­ o­l esnika­ je pr imewena­ d ijeta­ b­ o­ga­t a­ tr igliceridima­ sre dwih la­na­c a­, ko­j a­ je do­ v­e la­ d o­ izlecewa­ . To­k o­ m pet go­d ina­ n a­d gleda­w a­ b­ o­l esnika­ n ije b­i lo­ r ecidiv­a­ p erika­ rdno­ g izliv­a­ . Ko­ d b­ o­l esnice sta­re 21 go­di­ nu hilo­p erika­ rd je na­st a­o­ po­sle pa­r cija­l ne perika­rd iekto­m ije zb­o­ g hro­ni cno­ g eksuda­tiv­n o­ g perika­rd itisa­ . Perika­rdi­ o­ce ntezo­ m je do­ b­ij eno­ 650 ml b­ ledo­žu cka­ste te cno­sti s a­ v­i so­kim sa­dr ža­jem ho­l estero­la­ (3,2 mmol/l), triglicerida­ (16,6 mmol/l) i pro­t eina­ (64,7 g/l), sto­ je uka­z iv­ a­l o­ n a­ h ilo­p erika­ rd na­st a­o­ k a­o­ po­sl edica­ l ezije grudno­ g v­o­ da­ to­k o­ m perika­rdi­ ekto­m ije. Primewena­ je d ijeta­ b­ o­ga­t a­ tr igliceridima­ sre dwih la­na­c a­, ko­j a­ n ije do­ v­e la­ d o­ po­ b­o­q sa­w a­ sta­w a­ b­ o­l esnice ni po­sle d v­ o­n edeqne primene (dnev­n a­ s ekrecija­ 250 ­350 ml). Na­ li mfo­gra­mu je u o­ cena­ l ezija­ gru dno­ g v­ o­d a­, v­ero­ v­a­t no­ n a­ niv­o­ u prsqena­ 9 i 10, a­ li b­ ez direktne v­iz ueliza­c ije ekstra­ v­ a­za­c ije ko­n tra­st a­ . Ura­đ ena­ je l iga­t ura­ grudn o­ g v­o­ da­ kr o­ z de­ snu to­ra­ko­to­m iju. Međutim, po­sto­p era­c io­n a­ dnev­n a­ dr ena­ž a­ h ilo­zne te cno­sti se po­ v­e ca­ v­ a­la­ n a­ v­i se o­ d 1000 ml. Ko­ d b­ o­le­ snice je ura­đ ena­ l iga­t ura­ li mfnih putev­a­ pr ema­ m estu ekstra­ v­ a­za­c ije ub­ rizga­n o­ g v­ o­d eno­ g ra­s tv­ o­r a­ m etilensko­ g pla­ v­o­ g to­k o­ m o­ pera­c ije. To­k o­ m jedno­go­d isweg na­d gleda­w a­ n ije b­i lo­ r ecidiv­a­ h ilo­p erika­rd a­ . Po­ka­za­n o­ je d a­ je li mfo­gra­f ija­ t o­ ­ ko­ m o­ pera­c ije izuzetno­ ko­r ista­ n meto­d z a­ usp esno­ h irursko­ l ecewe b­ o­l esnika­ s a­ h ilo­p erika­rd o­ m. Kqucne reci: hilo­perika­rd; limfo­gra­fi ja­; ma­sne kis eline sredwih la­na­ca­; perika­rditis; perika­rdni izliv­; perika­r­ diekto­mi ja­

The posterodorsolateral neostriatum (PDLNS) in pigeons may be an equivalent of the prefrontal cortex (PFC) in mammals. Here we report that lesions of this brain region in pigeons have a detrimental effect on various learned visual discriminations. Pigeons with lesions of the overlying area corticoidea dorsolateralis (CDL) served as controls. Both the postoperative re-learning to criterion of a preoperatively learned simultaneous double visual mirror pattern discrimination and the learning of a simple successive go, no-go discrimination were impaired by the PDLNS lesions. The PDLNS and CDL groups did not differ significantly in the postoperative learning of a reversal of the simultaneous discrimination. The results are discussed in relation to the presumed equivalence between the avian PDNLS and the mammalian PFC.

Hippocampal processing is often crucial for normal spatial learning and memory in both birds and mammals, suggesting a general similarity in avian and mammalian hippocampal function. However, few studies using birds have examined the effect of hippocampal lesions on spatial tasks analogous to those typically used with mammals. Therefore, we examined how hippocampal lesions would affect the performance of pigeons in a dry version of the water maze. Experiment 1 showed that hippocampal-lesioned birds were impaired in acquiring the location of hidden food in the maze. Experiment 2 showed that hippocampal-lesioned birds were not impaired when a single cue indicated the location of hidden food. These results support the notion that avian and mammalian hippocampal functions are quite similar, in terms of the tasks for which their processing is crucial and the tasks for which it is not.

This study further explored functional similarities of mammalian prefrontal cortex and its presumed equivalent in pigeons. Our results show that the performance of delayed alternation of pigeons in an Y-maze is impaired following ablations of the prefrontal equivalent together with the corticoid but not of the corticoid alone. In the same maze, discrimination between vertical and horizontal stripes was unimpaired regardless of the lesion. Our results added the following new information. (1) Corticoid is not essentially involved in mediation of delayed responding. (2) Like monkeys, pigeons take much fewer trials to learn delayed alternation in a maze than in an operant chamber. (3) Lesions of the pigeon equivalent of the prefrontal cortex impair delayed responding also in the new apparatus. (4) These lesions do not impair visual pattern discrimination. Our results do not contradict the hypothesis that the postero-dorso-lateral neostriatum in pigeons is comparable to the prefrontal cortex in mammals.

In unanaesthetized rats, mechanical stimulation of a single vibrissa increased glucose utilization in one cortical column of the somatosensory area and in several spots in the dorsolateral neostriatum, predominantly on the side contralateral to the stimulation. Two or three peaks of glucose utilization unique to the stimulated animals were seen in cross sections throughout a 1.8 mm anteroposterior extent in the dorsolateral striatum. These observations suggest that one cortical column is functionally related to several neostriatal regions. The distributed modularity may be an important characteristic of the basal ganglia system.

The standard current technique for demonstration of cytochrome oxidase (CyOx) provides low-contrast diaminobenzidine (DAB) polymer. In order to enhance the contrast with divalent metalic ions, we have screened a number of buffers and found that Hepes, Mops and cacodylate neither precipitate these ions nor inactivate CyOx in a concentration of 0.1 M. Staining thus obtained shows a broad range of gradations between black and white. With fresh tissue the resulting image is superior to that obtained with the brown DAB product, even if a recommended blue filter or printing on very hard paper are used. The technique is as simple as the one which is currently standard. Fixed tissue, cut either in a cryostat or vibratome, can be stained well when floating but not when mounted on slides. The stained floating tissue can be used for electron microscopy, but has no advantage over the standard method.

Neostriatal afferents from the primary visual cortex in rats were studied using dextran-biotin, biocytin, and Fluoro-Gold. The area V1 was found to project only to a dorsomedial, longitudinal region of neostriatum (NS), bordering on the lateral ventricle and subcortical white matter. The preterminal fibres in the NS form fluffs which increase in number and density in the cases with larger injections. This target region is poorly stained for calbindin and yet belongs to the matrix compartment. The secondary visual areas also project to the dorsomedial NS region but they also innervate the deeper tissue in the same general region. Iontophoresis of Fluoro-Gold into the dorsomedial NS labelled some pyramidal neurones in the fifth layer of the primary visual cortex. The cortical areas that surround the visual cortical complex project to other regions of the NS: the somatosensory cortex to a dorsolateral longitudinal region and the auditory area to the medial half of the caudalmost portion of NS. Thus, major sensory cortical divisions project to non-overlapping NS regions. Since NS in monkeys and cats does not receive afferents from the primary visual cortex and in a number of other species does, we conclude that visual systems in different mammals differ with respect to their projections to NS.

The most extensive development during primate brain evolution involves the cortex of the frontal lobe, especially its prefrontal region. The distribution of neurotransmitter receptors is unknown in this part of the cortex of New World monkeys. The respective distributions of eight different receptors for the transmitters l-glutamate (l-glu and NMDA), γ-amino-butyric acid (GABAA), noradrenaline (α1), acetylcholine (M1 and M2) and serotonin (5-HT1 and 5-HT2) were therefore studied in cortical areas of the frontal lobe of the lissencephalic New World monkey, Callithrix jacchus. The results are compared to earlier data on Old World monkeys in order to obtain insight into evolutionary trends at the level of chemical neuroanatomy. Our results indicate that the density and laminar pattern of some receptors change precisely at the cytoarchitectonic boundaries between different cortical areas, while some other receptors do not exhibit measurable changes. For example, the premotor area 6 can be distinguished from prefrontal areas by its high concentration of adrenergic α1 receptors as labelled with [3H] prazosin, with only the cingulate area 24 showing higher values. In other cases, the receptor distribution changes within a cytoarchitectonically homogeneous area. Thus, area 8 can be subdivided into dorsal and ventral regions on the basis of the distribution of GABAA, muscarinic and serotonin receptors. Comparison of these results in a New World monkey with receptor distributions in other primate species reveals much larger interspecies differences in the areas of the frontal lobe than e.g. in the primary visual cortex. This is interpreted as an indication of extensive changes in the neuro-chemical organisation of this part of the brain during primate brain evolution.

The Tachyglossidae (long- and short-beaked echidnas) are a family of monotremes, confined to Australia and New Guinea, that exhibit striking trigeminal, olfactory and cortical specialisations. Several species of long-beaked echidna (Zaglossus robusta, Zaglossus hacketti, Megalibgwilia ramsayi) were part of the large-bodied (10 kg or more) fauna of Pleistocene Australasia, but only the diminutive (2–7 kg) Tachyglossus aculeatus is widespread today on the Australian mainland. We used high-resolution CT scanning and other osteological techniques to determine whether the remarkable neurological specialisations of modern echidnas were also present in Pleistocene forms or have undergone modification as the Australian climate changed in the transition from the Pleistocene to the Holocene. All the living and extinct echidnas studied have a similar pattern of cortical gyrification that suggests comparable functional topography to the modern short-beaked form. Osteological features related to olfactory, trigeminal, auditory and vestibular specialisation (e.g., foramina and cribriform plate area, osseous labyrinth topography) are also similar in living and extinct species. Our findings indicate that despite differences in diet, habitat and body size, the suite of neurological specialisations in the Tachyglossidae has been remarkably constant: encephalisation, sensory anatomy and specialisation (olfactory, trigeminal, auditory and vestibular), hypoglossal nerve size and cortical topography have all been stable neurological features of the group for at least 300,000 years.

Chronic changes in the thalamic mediodorsal nucleus (MD) after unilateral lesions of the prefrontal cortex were studied with the aid of quantitative light, and electron microscopic immunohistochemistry. Three months after the lesions, although the size of MD ipsilateral to the lesion did not change considerably, the neuronal density was significantly reduced. Conversely, as demonstrated by quantitative electron microscopy, the density of GABA immunostained axon terminals significantly increased in the lesioned side. It is suggested, that as MD does not contain GABA cells, the reactive hyperinnervation of the MD by GABA-containing axons is of extrinsic origin. This finding is also the morphological evidence of the potential of GABA-ergic nerve cells for reactive (induced) axonal sprouting.

The regional and laminar distributions of eight different transmitter-binding sites were measured in the marmoset hippocampus by means of quantitative in vitro receptor autoradiography. Receptors for 5-HT1, l-glutamate, N-methyl-d-aspartate (NMDA) and GABAA were similarly distributed. The highest concentrations of these receptors were found in the pyramidal layer of CA1 and the molecular layer of the dentate gyrus. The 5-HT2 receptors showed the highest concentrations in the oriens layer of CA2. The highest concentrations of muscarinic M1 receptors were seen in the pyramidal layer of CA1. Muscarinic M2 receptors were most densely concentrated in the pyramidal layers of CA1, CA2 and CA3. The noradrenergic α1 receptors were most densely packed in the radiatum-lacunosum-molecular layer of CA2 and the molecular layer of the dentate gyrus. Statistically significant co-distributions of serotoninergic, glutamatergic and GABAergic receptors point to possible interactions between these receptor systems in the same hippocampal regions and layers. Comparisons of marmoset distribution patterns for GABAA, NMDA, l-glutamate and 5-HT1 receptors with those in human hippocampi and those of other primates showed similarities between them. Clear differences in the patterns of α1, M1, M2 and 5-HT2 receptors could be seen between marmoset and human hippocampi, indicating a high degree of species specificity in a presumably “conservative” brain region. More similarities, however, could be found between marmoset and human hippocampi than between those of rat and human brains, especially in relation to 5-HT1 and GABAA receptors and l-glutamate-binding sites. In addition to the functional significance of receptor distribution patterns, such studies represent a valuable tool for the analysis of neurochemical aspects of brain evolution.

Fluorescent somatopetal tracers were used to infiltrate, by diffusion rather than injections, the dorsolateral cortex of one hemisphere in rats. In different ani mals the tracers penetrated into the cortex to different depths. We found several interesting features of the commissural system: first, there were no areas without commissural neurons. At least a few labelled cell bodies were present in a single-cell layer also in ''acallosal'' cortical areas, Secondly, there is a considerable variety of laminar distribution patterns of labelled perikarya in different areas. Thirdly, some cortical fields, which cytoarchitecturally appear uniform, can be subdivided according to different distributions of cell bodies with commissural projections. Fourthly, when only supragranular lay ers were infiltrated, labelled cell bodies were present mainly in the supragranular layers of the contralateral cortex. Infiltration of the first layer alone did not label any neurons in the contralateral cortex but did label neurons in layer VIb ipsilaterally. In the subcortex, the labelled perikarya were found in the structures already known to project directly to the cortex. In rats with the tracer restricted mainly to the supragranular layers, a conspicuously reduced labelling was found in the basal forebrain and the thalamus. In the thalami of those animals, labelled neurons were found only in paralamellar nuclei. The high sensitivity of the tracer used, together with infiltration of the entire dorsolateral cortex, allows us to conclude that probably all sources of innervation of the isocortex in rats have been seen.

Inducibility of NADPH-diaphorase (NADPH-d) or nitric oxide synthase (NOS) has been demonstrated in pyramidal neurones of the hippocampus, but the mechanisms of this induction are not known. The present study aimed to assess the role of anti-inflammatory drugs in injury-induced production of NADPH-d/NOS in CA1 pyramidal neurones. We found that either a steroid, dexamethasone or a non-steroid, indomethacin, prevents induction of these enzymes. We also found that NO is not necessary for the induction. None of the three drugs used had detectable effect on the neurones which contain constitutive NADPH-d/NOS.

The synaptic organisation of neurons in the nucleus medialis dorsalis (MD) was investigate by combined Golgi, and post-embedding gamma-aminobutyric acid (GABA) and/or glutamate (GLU) immunogold methods. The morphological features of the impregnated neurons in the MD (detailed by Kuroda et al. 1992a) were similar to thalamocortical relay cells present in other thalamic nuclei. GABAergic cell bodies could not be found. Distal dendritic branches of gold toned neurons established synaptic contacts with small and medium size glutamate as well as GABA-immunoreactive axonal endings. Large glutamate and GABA-positive axon terminals formed synaptic contacts with proximal dendrites. GABAergic axon terminals exhibited symmetric synaptic contacts and contained pleomorphic vesicles. Glutamate immunoreactive terminals formed asymmetric synapses and contained spheroid vesicles, although, some large glutamate immunoreactive endings contained pleomorphic vesicles. Synaptic glomerulus-like complexes could also be observed with the participation of glutamate-, and GABA-positive large axon terminals synapsing with Golgi impregnated proximal dendrites.

In the postero-dorso-lateral neostriatum (PDLNS) of the pigeon we found a high density of tyrosine hydroxylase and perineuronal nests of fibres labelled with anti-dopamine antibody. These data confirm our earlier indirect evidence that PDLNS receives a dense dopaminergic innervation and therefore can be compared with the mammalian prefrontal cortex.

In the present study we addressed the question whether, within the isocortex, the prefrontal area of the rat is uniquely involved in mediation of delayed alternation. In one group of rats the dorsolateral isocortex, from the dorsomedial shoulder to the dorsal lip of the rhinal sulcus was removed bilaterally in a single surgical session. In these rats delayed alternation in a T-maze was significantly less impaired than in rats with one stage bilateral removal of the medial prefrontal cortex. The prefrontal cortex seems not to depend crucially on isocortical input for its mediation of delayed alternation.