Persistence of Mammary Artery Branches and Blood Supply to the Left Anterior Descending Artery

Background. Partial harvesting of the left internal mammary artery (LIMA) is a widespread technique used during minimally invasive coronary operations performed through a left anterior small thoracotomy. The influence of persisting LIMA branches was investigated to evaluate their effect on the blood flow of the left anterior descending artery.

Methods. Thirty patients, 15 with totally (group A) and 15 with partially (group B) harvested LIMAs, were evaluated. All the patients underwent postoperative angiography, during which a flow map of the LIMA was performed. The average peak velocity and the diastolic-to-systolic peak velocity ratio were recorded. The LIMA graft flow pattern was recorded in the proximal and distal thirds of the artery. Intramammary adenosine (12 to 14 μg) was injected and the average peak velocities before and after injection were calculated.

Results. The average peak velocity was similar in both groups in the proximal and distal thirds of the LIMA (25 ± 7 and 26 ± 5 cm/sec, respectively, in group A versus 27 ± 5 and 25 ± 5 cm/sec, respectively in group B; p = NS). The diastolic-to-systolic peak velocity ratio was similar proximally (0.78 ± 0.3 in group A versus 0.69 ± 0.3 cm/s in group B; p = NS), but not distally (1.72 ± 0.1 in group A versus 0.97 ± 0.3 in group B; p < 0.0005). The LIMA graft flow reserve was similar both proximally and distally (2.6 ± 0.6 and 2.5 ± 0.3 cm/s, respectively, in group A versus 2.6 ± 0.5 and 2.6 ± 0.3 cm/s, respectively, in group B; p = NS).

Conclusions. The persistence of LIMA branches does not influence the blood flow of the left anterior descending artery after acute adenosine-induced myocardial hyperemia. If a left anterior small thoracotomy is used in left anterior descending artery direct revascularization, complete LIMA harvesting is not mandatory and depends on the personal preference of the surgeon.     

Frequency dependence of complex moduli of brain tissue using a fractional Zener model

Brain tissue exhibits viscoelastic behaviour. If loading times are substantially short, static tests are not sufficient to determine the complete viscoelastic behaviour of the material, and dynamic test methods are more appropriate. The concept of complex modulus of elasticity is a powerful tool for characterizing the frequency domain behaviour of viscoelastic materials. On the other hand, it is well known that classical viscoelastic models can be generalized by means of fractional calculus to describe more complex viscoelastic behaviour of materials. In this paper, the fractional Zener model is investigated in order to describe the dynamic behaviour of brain tissue. The model is fitted to experimental data of oscillatory shear tests of bovine brain tissue to verify its behaviour and to obtain the material parameters.     

Dopamine-induced migrating myoelectrical complex-like activity in human duodenum

The effect of dopamine on human gastric and small intestinal interdigestive motility was investigated in 12 subjects. Intestinal motility was recorded by means of a four-lumen polyvinyl probe with four open tips located 15 cm apart, continuously perfused with distilled water. In each subject during the same study, after recording two consecutive spontaneous phase III of migrating myoelectrical complexes and when a phase II appeared, dopamine was infused intravenously twice in a dose of 5 g/kg/min for 15 min with an interval of 20 min between each infusion. In six subjects, the second dopamine infusion was preceded by a treatment with sulpiride (10 mg, intravenously, as bolus) or domperidone (10 mg, intravenously, as bolus), each considered a highly selective dopamine antagonist. The results show that dopamine stimulates duodenal motility producing a pattern similar to that observed in phase III of spontaneously occurring migrating myoelectrical complexes. The second dopamine infusion reproduced in all cases the same pattern of motility as observed during the first infusion. Sulpiride and domperidone prevented the effect of dopamine in all cases. It is therefore suggested that dopamine-induced duodenal motility may involve specific dopaminergic receptors.     

Mitral valve repair for dilated cardiomyopathy: predictive role of right ventricular dysfunction.

AIMS: To evaluate the impact of right ventricular (RV) dysfunction on early and mid-term outcome of patients with ischaemic or dilated cardiomyopathy (DCM) undergoing mitral valve annuloplasty. METHODS AND RESULTS: From January 1997 to December 2005, 111 patients with DCM (89 ischaemic, 22 non-ischaemic) were enrolled in this retrospective study. Mean age was 67 +/- 10 years. Average pre-operative NYHA class was 3.0 +/- 0.6. Tricuspid annular plane systolic excursion (TAPSE), tricuspid annular pleak systolic velocity (TAPSV), and RV fractional area change were considered as an index of RV function. A strong relationship between TAPSE and TAPSV were found (r = 0.76). Thirty-day mortality was 10.8%. Five-year survival and possibility to be alive in NYHA classes I-II were 66.5 +/- 5.0 and 59.5 +/- 5.0%. TAPSE, TAPSV, and MV coaptation depth (MVCD) were found to be risk factors for worse early and mid-term outcome; functional class impaired mid-term outcome. ROC analysis identified TAPSE < or = 12 mm, TAPSV < or = 10 cm/s, and MVCD>10 mm as predictive cut-offs. CONCLUSION: Pre-operative assessment of some echocardiographic parameters (TAPSE, TAPSV) is very easy, low cost, and provides accurate information on RV function. A good pre-operative clinical compensation has to be necessarily reached before the operation. MVCD should be evaluated to decide surgical strategy (repair or replace).     

First time myocardial revascularization in patients younger than 70 years. Single versus double internal mammary artery.

BACKGROUND: We evaluated the early and late outcomes of bilateral internal mammary artery (BIMA) grafting, with or without saphenous vein grafts (SVGs), compared to single internal mammary artery and SVGs in patients < 70 years undergoing first myocardial revascularization. METHODS: From September 1986 to December 1999, 1389 patients underwent first myocardial revascularization using the left internal mammary artery (LIMA) to the left anterior descending artery and SVGs (n = 480) or BIMA (one internal mammary artery on the left anterior descending artery) with or without SVGs (n = 909). Propensity score analysis was used to select 952 (476 of each group) patients with the same preoperative and operative characteristics. Thirty-day outcome and 10-year freedom from all-cause death, cardiac death, acute myocardial infarction (AMI), AMI in a grafted area, redo/percutaneous transluminal coronary angioplasty (PTCA), redo/PTCA in a grafted artery, cardiac events and any events, were evaluated. Follow-up ranged from 3.5 to 16.8 years (mean 8.8+/-4.0 years). RESULTS: Thirty-day mortality was 2.9% in the LIMA group and 1.9% in the BIMA group, p = NS; the BIMA group showed a better 10-year freedom from all-cause death (92.4+/-2.1 vs 87.5+/-3.5%, p = 0.0216), cardiac death (97.4+/-0.9 vs 91.9+/-1.4%, p = 0.0042), AMI (98.7+/-0.5 vs 94.2+/-1.2%, p = 0.0034), AMI in a grafted area (98.9+/-0.5 vs 94.7+/-1.3%, p = 0.0017), cardiac events (95.4+/-1.2 vs 86.8+/-1.8%, p = 0.0026) and any events (88.8+/-2.2 vs 80.7+/-2.1%, p = 0.0124). Cox analysis confirmed that LIMA + SVGs was a risk factor independent of lower freedom from all the above-mentioned events. CONCLUSIONS: Double mammary artery in patients < 70 years who had a first time myocardial revascularization gives a better clinical outcome even 10 years after the operation.     

Aza-CGP37157-lipoic hybrids designed as novel Nrf2-inducers and antioxidants exert neuroprotection against oxidative stress and show neuroinflammation inhibitory properties

Two multitarget hybrids, derived from an aza-analogue of CGP37157, a mitochondrial Na⁺/Ca²⁺ exchanger antagonist, and lipoic acid were designed in order to combine in a single molecule the antioxidant and Nrf2 induction properties of lipoic acid and the neuroprotective activity of CGP37157. The hybrid derivatives showed Nrf2 induction and radical scavenging properties, leading to a good neuroprotective profile against oxidative stress, together with an interesting antineuroinflammatory activity. The results obtained show differences in activity depending on the configuration of the chiral center of LA.     

The surgical treatment of cerebrospinal fistula: Qualitative and quantitative analysis of indications and results

Cerebrospinal fistula might occur in different ways. CSF closure techniques have undergone significant evolution that has led to the consolidation of the transnasal endoscopic approach. Despite the existence of multiple publications, meaningful information is still lacking in clinical practice and the literature about the ideal method, material, and timing for repair of CSF. The purpose of this review was to summarize the success rate of endoscopic CSF leak repair as well as whether specific techniques or materials influence the primary success rate through a review of the latest advancements in endoscopic CSF management published in the past 10 years. The principles of multilayer reconstructions and the routine use of vascularized flaps in expanded endonasal surgery have reduced postoperative CSF leaks' failure rates between 5% and 10% (4% in this meta‐analysis). Effective endoscopic anterior skull base (ASB) closure may be achieved by multiple reconstructive techniques, which should be tailored case by case according to the patient and defect conditions.     

Plasma exchange in chronic inflammatory demyelinating polyneuropathies

Chronic Inflammatory Demyelinating Polyneuropathies (CIDP) are characterized by demyelination of peripheral nerves with mononuclear cell infiltrates, electrical conduction slowing or block and elevated cerebrospinal fluid protein with no cells. An immune mediated pathogenesis has been suggested. Immune suppressive therapy, as well as plasmapheresis and intravenous immunoglobulins have been used with variable success. Our objective was to review our results of plasma exchange in this disease in 20 patients with very different underlying diseases, none of them eligible for the Canadian CIDP plasmapheresis study, and define certain guidelines of predictability for the effectiveness of plasma exchange. Five patients had monoclonal gammopathies of unknown significance, two had lung cancer, one breast cancer, one hairy cell leukemia and later carcinoma of the pancreas; two had hepato-splenomegaly and hemolytic anemia; nine were idiopathic (two with autoimmune markers). Plasmapheresis varied from 4 to 31 plasma volumes and procedures with a median of 12, always with 5% albumin. Two excellent responses, one very good, two moderate transient and 12 had no change in clinical or conduction status. Best response occurred in paraproteinemias. Thus immune modulation with plasma exchange may be useful in CIDPs with paraproteinemias and autoimmune manifestations.