Neurologic deficit in patients at high risk with thoracoabdominal aortic aneurysms: the role of cerebral spinal fluid drainage and distal aortic perfusion

PURPOSE

This prospective study evaluated the possible prevention of postoperative neurologic deficit in patients at high risk with thoracoabdominal aortic aneurysms (TAAA), types I and II, by use of perioperative cerebrospinal fluid drainage and distal aortic perfusion.

METHODS

Between September 18, 1992, and August 8, 1993, 45 consecutive patients underwent TAAA repair (14 type I, 31 type II). Thirty-six were men and nine were women. The median age was 63 years (range 28 to 88). Twenty-four of 45 patients (53%) had dissection and 17 of 45 (38%) had prior proximal aortic replacement. All patients underwent perioperative cerebrospinal fluid drainage and distal aortic perfusion. Median aortic clamping time was 42 minutes. Thirty-five of 45 patients (78%) underwent intercostal artery reattachment.

RESULTS

The 30-day survival rate was 96% (43 of 45 patients). Early neurologic deficit occurred in two of 45 patients (4%), and late neurologic deficit also occurred in two of 45 patients (4%). We compared the neurologic deficit of our current group of 45 patients with the data of a previously unpublished study of 112 patients also from this center. Total neurologic deficit for the current group was four of 45 (9%) versus the previous group of 35 of 112 (31%) with a p value of 0.0034 (Pearson chi-square test). Neurologic deficit for patients with type I TAAA was 0 of 14 (0%) versus 15 of 73 (21%) (p = 0.062); for patients with type II TAAA 4 of 31 (13%) versus 20 of 39 (51%) (p = 0.0008). In patients with aortic dissection, neurologic deficit was 3 of 24 (12%) versus 9 of 32 (28%) (p = 0.0304); no dissection was 1 of 21 (5%) versus 26 of 80 (32%) (p = 0.011). For aortic clamp times less than 45 minutes, neurologic deficit was 1 of 24 (4%) versus 14 of 68 (21%) (p = 0.061); for aortic clamp times equal to or greater than 45 minutes, neurologic deficit was 3 of 21 (14%) versus 21 of 44 (48%) (p = 0.0090).

CONCLUSION

Neurologic deficit in patients treated for types I and II TAAA was reduced significantly by perioperative cerebral spinal fluid drainage and distal aortic perfusion.

Palmitoylethanolamide controls reactive gliosis and exerts neuroprotective functions in a rat model of Alzheimer's disease

Given the complex heterogeneity of pathological changes occurring in Alzheimer's disease (AD), any therapeutic effort absolutely requires a multi-targeted approach, because attempts addressing only a single event may result ineffective. Palmitoylethanolamide (PEA), a naturally occurring lipid amide between palmitic acid and ethanolamine, seems to be a compound able to fulfill the criteria of a multi-factorial therapeutic approach. Here, we describe the anti-inflammatory and neuroprotective activities of systemic administration of PEA in adult male rats given intrahippocampal injection of beta amyloid 1-42 (Aβ 1-42). Moreover, to investigate the molecular mechanisms responsible for the effects induced by PEA, we co-administered PEA with the GW6471, an antagonist of peroxisome proliferator-activated receptor-α (PPAR-α). We found that Aβ 1-42 infusion results in severe changes of biochemical markers related to reactive gliosis, amyloidogenesis, and tau protein hyperphosphorylation. Interestingly, PEA was able to restore the Aβ 1-42-induced alterations through PPAR-α involvement. In addition, results from the Morris water maze task highlighted a mild cognitive deficit during the reversal learning phase of the behavioral study. Similarly to the biochemical data, also mnestic deficits were reduced by PEA treatment. These data disclose novel findings about the therapeutic potential of PEA, and suggest novel strategies that hopefully could have the potential not just to alleviate the symptoms but also to modify disease progression.

Superoxide dismutase content and microsomal lipid composition of tumours with different growth rates

The content of cytosolic superoxide dismutase has been determined in Morris hepatomas 3924A (fast-growing) and 44 (slow-growing) and in ascites tumour cells (Novikoff hepatoma and Ehrlich-Lettré). The enzyme is decreased in all the tumours examined. The lowest amounts were found in the tumours with the fastest growth rates. Measurements of the lipid composition and fluidity of microsomal membranes isolated from Morris hepatomas show that also these parameters are changed in relation to the growth rate. The lipid to protein ratio and the degree of fatty acid unsaturation decrease gradually from rat liver to hepatoma 44 and 3924A microsomes. The different lipid composition is reflected also by differences in the physical environment of the bilayer, as indicated by data obtained with spin-labeled fatty acids. It is proposed that the changes in the membrane lipid composition and organization are consequent to the decrease in the protective effect of cytosolic superoxide dismutase against the O2- induced lipid peroxidation.

In vivo and in vitro binding of 1,2-dibromoethane and 1,2-dichloroethane to macromolecules in rat and mouse organs

The comparative interaction of equimolar amounts of 1,2-dichloroethane and 1,2-dibromoethane with rat and mouse nucleic acids was studied in both in vivo (liver, lung, kidney and stomach) and in vitro (liver microsomal and/or cytosolic fractions) systems. In vivo, liver and kidney DNA showed the highest labeling, whereas the binding to lung DNA was barely detectable. Dibromoethane was more highly reactive than dichloroethane in both species. With dichloroethane, mouse DNA labeling was higher than rat DNA labeling whatever the organ considered: the opposite was seen for the bioactivation of dibromoethane. RNA and protein labelings were higher than DNA labeling, with no particular pattern in terms of organ or species involvement. In vitro, in addition to a low chemical reactivity towards nucleic acids shown by haloethanes per se, both compounds were bioactivated by either liver microsomes and cytosolic fractions to reactive forms capable of binding to DNA and polynucleotides. UV irradiation did not photoactivate dibromoethane and dichloroethane. The in vitro interaction with DNA mediated by enzymatic fractions was PB-inducible (one order of magnitude, using rat microsomes). In vitro bioactivation of haloethanes was mainly performed by microsomes in the case of dichloroethane and by cytosolic fractions in the case of dibromoethane. When microsomes plus cytosol were used, rat enzymes were more efficient than mouse enzymes in inducing a dibromoethane-DNA interaction: the opposite situation occurred for dichloroethane-DNA interaction, and this is in agreement with the in vivo pattern. In the presence of both metabolic pathways, addition or synergism occurred. Dibromoethane was always more reactive than dichloroethane. An indication of the presence of a microsomal GSH transferase was achieved for the activation of dibromoethane. No preferential binding in vitro to a specific polynucleotide was found. Polynucleotide labeling was higher than (or equal to) DNA binding. The labeling of microsomal RNA and proteins and of cytosolic proteins was many times lower than that of DNA or polynucleotides. The in vivo and in vitro data reported above give an unequivocal indication of the relative reactivity of the haloethanes examined with liver macromolecules from the two species and agree, on the whole, with the relative genotoxicity (DNA repair induction ability, mutagenicity and carcinogenicity) of the chemicals.

Retrograde cerebral perfusion during profound hypothermia and circulatory arrest in pigs

The purpose of this study was to evaluate the use of retrograde cerebral perfusion via the superior vena cava during profound hypothermia and circulatory arrest (CA) in pigs. In three groups of 5 pigs each, group A (control) underwent cardiopulmonary bypass and normothermic CA for 1 hour, group B underwent cardiopulmonary bypass, profound hypothermia, and CA (15 degrees C nasopharyngeal) for 1 hour, and group C underwent the same procedure as group B plus retrograde cerebral perfusion. In group A none awoke. In group B, 2 of 5 did not awake and 3 of 5 awoke unable to stand, 2 with perceptive hind limb movement and 1 moving all extremities. In group C all awoke, 4 of 5 able to stand and 1 of 5 unable to stand but moving all limbs. In neurologic evaluation group B had significantly lower Tarlov scores than group C (p = 0.0090). Group B mean wake-up time, plus or minus standard error of the mean, was 124.6 +/- 4.6 minutes versus 29.2 +/- 5.1 in group C (p = 0.0090). In group B late phase CA cerebral blood flow dropped 30.9% +/- 4.8%, but in group C it rose 24.7% +/- 9.3% (p = 0.0007, pooled variance t test, two-tailed). In group B late phase CA brain oxygenation decreased 46.0% +/- 13.9% but it increased 26.1% +/- 5.4% in group C (p = 0.0013). This difference was reduced somewhat during rewarming (B, -21.2% +/- 14.9%; C, 16.4% +/- 4.7%; p = 0.043). Group B rewarming jugular venous O2 saturation was 30.8% +/- 2.5% versus 56.0% +/- 4.4% in group C (p = 0.0011). We conclude that in pigs retrograde cerebral perfusion combined with profound hypothermia during CA significantly reduces neurologic dysfunction, providing superior brain protection.

Long-term results and outcomes of crossover axilloaxillary bypass grafting: A 24-year experience

OBJECTIVE

The outcome of crossover axilloaxillary bypass grafting in patients with stenosis or occlusion of the innominate or subclavian arteries was investigated.

METHODS

The study was designed as a retrospective clinical study in a university hospital setting with 61 patients as the basis of the study. Fifty-eight patients (95.1%) had at least two risk factors or associated medical illnesses for atherosclerosis, and 35 patients (57.4%) had concomitant carotid artery stenosis that necessitated a staged procedure in 12 patients (19.7%). The patients underwent a total of 63 crossover axilloaxillary bypass grafting procedures. Demographics, risk factors and associated medical illnesses, preoperative symptoms and angiographic data, blood flow inversion in the vertebral artery, concomitant carotid artery disease, graft shape, caliber and material, and intraoperative and postoperative complications were studied to assess the specific influence in determining the outcome.

RESULTS

One postoperative death (1.6%), four early graft thromboses (6.2%), and six minor complications (9. 8%) occurred. The overall mortality and morbidity rates were 1.6% and 16.1%, respectively. During the follow-up period (mean, 97.3 +/- 7.9 months), we observed five graft thromboses (8.3%). Primary and secondary patency rates at 5 and 10 years were 86.5% and 82.8% and 88.1% and 84.3%, respectively. Overall, two patients (3.3%) had recurrence of upper limb symptoms and none had recurrence of symptoms in the carotid or vertebrobasilar territory. The 5-year and 10-year symptom-free interval rates were 97.7% and 93.5%, respectively. Nine patients (15%) died of unrelated causes. The 5-year and 10-year survival rates were 93.2% and 67.3%, respectively. Multivariate analysis showed that no specific variables exerted an influence in the short-term and long-term results and the outcome.

CONCLUSION

The optimal outcome of axilloaxillary bypass grafting supports its use as the most valuable surgical alternative to transthoracic anatomic reconstructions for innominate lesion, long stenosis of the subclavian artery, and short subclavian artery stenosis associated with ispilateral carotid artery lesions.

The Different Genotoxicity of P-Dichlorobenzene in Mouse and Rat: Measurement of the in Vivo and in Vitro Covalent Interaction with Nucleic Acids

Twenty-two hours after i.p. injection to male Wistar rats and BALB/c mice para-dichlorobenzene (p-DCB) is bound covalently to DNA from liver, kidney, lung and stomach of mice but not of rats. DNA adducts in mouse liver are repaired in seventy-two hours. The covalent binding index value, calculated on the labelling of mouse liver DNA, classifies p-DCB as a weak initiator with an oncogenic activity lower than that of chlorobenzene. The labelling of RNA and proteins from the different organs of both species is, however, low. In vitro interaction with calf thymus DNA mediated by mouse and rat microsomes from liver and lung did occur. Binding extent was strongly reduced by addition of 2-diethylaminoethyl-2,2-diphenylvalerate hydrochloride (SKF 525-A) to the microsomal standard incubation mixture, whereas it was enhanced by adding GSH. Cytosolic fractions from kidney and lung were able to induce binding of p-DCB to DNA to a lower extent with respect to microsome-mediated binding. These results indicate that microsomal mixed function oxidase system and microsomal GSH-transferases can be involved in overall activating metabolism whereas cytosolic GSH-transferases play a minor role. This study, which is a part of a structure-activity relationship approach on benzene and its haloderivatives, provides the first evidence of genotoxicity of p-DCB in mammalian cell. It allows to partly explain variations of susceptibility of different species to hepatocarcinogenesis and of hepatotoxicity of different isomers.

Benzene adducts with rat nucleic acids and proteins: dose-response relationship after treatment in vivo

The dose-response relationship of the benzene covalent interaction with biological macromolecules from rat organs was studied. The administered dose range was 3.6 x 10(7) starting from the highest dosage employed, 486 mg/kg, which is oncogenic for rodents, and included low and very low dosages. The present study was initially performed with tritium-labeled benzene, administered by IP injection. In order to exclude the possibility that part of the detected radioactivity was due to tritium incorporated into DNA from metabolic processes, 14C-benzene was then also used following a similar experimental design. By HPLC analysis, a single adduct from benzene-treated DNA was detected; adduct identification will be attempted in the near future. Linear dose-response relationship was observed within most of the range of explored doses. Linearity was particularly evident within low and very low dosages. Saturation of benzene metabolism did occur at the highest dosages for most of the assayed macromolecules and organs, especially in rat liver. This finding could be considered as indicative of the dose-response relationship of tumor induction and could be used in risk assessment.

Hey surgeons! It is time to lead and be a champion in preventing and managing surgical infections!

Appropriate measures of infection prevention and management are integral to optimal clinical practice and standards of care. Among surgeons, these measures are often over-looked. However, surgeons are at the forefront in preventing and managing infections. Surgeons are responsible for many of the processes of healthcare that impact the risk for surgical site infections and play a key role in their prevention. Surgeons are also at the forefront in managing patients with infections, who often need prompt source control and appropriate antibiotic therapy, and are directly responsible for their outcome. In this context, the direct leadership of surgeons in infection prevention and management is of utmost importance. In order to disseminate worldwide this message, the editorial has been translated into 9 different languages (Arabic, Chinese, French, German, Italian, Portuguese, Spanish, Russian, and Turkish).

Spinal cord protection during aortic cross clamping: retrograde venous spinal cord perfusion, distal aortic perfusion, and cerebrospinal fluid drainage

OBJECTIVE

We investigated retrograde venous spinal cord perfusion (RVP), with the established adjuncts cerebrospinal fluid drainage (CSFD), and distal aortic perfusion (DAP) in the canine model. We then examined the clinical feasibility of RVP, DAP, and CSFD.

DESIGN

Canine study: Twenty dogs were randomized to four treatment groups. All animals underwent 60 min of complete aortic cross-clamp. Group 1 was the control and received only aortic cross-clamp; group 2 DAP and CSFD; group 3 DAP, CSFD, and RVP; and group 4 CSFD plus RVP. Human study: Five patients underwent aortic graft replacement of the descending or thoracoabdominal aorta, while receiving CSFD, DAP, and RVP.

RESULTS

Canine study: All animals in groups 1 and 4 awoke paralyzed. One animal each in groups 2 and 3 were paraparetic, with the remaining dogs neurologically intact. Groups 2 and 3 differed from groups 1 and 4 at p < 0.0001. Human study: No mortality or permanent complications were observed in this group.

CONCLUSION

While RVP did not reduce neurologic injury, neither did it increase morbidity. In humans the method is technically feasible and free from major problems. Further animal studies and randomized trials are underway at our center.

Lipid-F1 nucleohistone interactions

High concentrations of phospholipids determine destabilization of F1 histone-DNA complex at the weight ratios, histone:DNA, 0.8:1 and 1:1, but low concentrations cause only negligible destabilization. Cholesterol at high weight ratios has little effect on nucleohistone stability. Only linolenic acid of the fatty acids used reproduces similar changes in the thermal stability of F1 histone-DNA complex as phospholipids. The type of interaction of phospholipids with the F1 histone-DNA complex is analyzed, and the involvement of phospholipids in DNA replication in vivo is discussed.

Chloroform Bioactivation Leading to Nucleic Acids Binding

Chloroform was bound covalently to DNA, RNA and proteins of rat and mouse organs in vivo after i.p. injection. Covalent Binding Index values of rat and mouse liver DNA classify chloroform as a weak initiator. Labelings of RNA and proteins from various organs of both species were higher than that of DNA. In an in vitro cell-free system, chloroform was bioactivated by cytochrome P450-dependent microsomal fractions, by cytosolic GSH-transferases from rat and mouse liver, and particularly by the latter enzymes from mouse lung. This observation suggests that GSH plays a role In the binding of chloroform metabolites to DNA. The presence of both microsomal and cytosolic enzymatic systems in the standard incubation mixture generally led to an additive or synergistic bioactivating effect for rat and mouse, respectively.

In Vivo and in Vitro Interaction of 1,2-Dichlorobenzene with Nucleic Acids and Proteins of Mice and Rats

Twenty-two hours after i.p. injection into male Wistar rats and BALB/c mice, 1,2-dichlorobenzene (1,2-DCB) was covalently bound to DNA, RNA, and proteins of liver, kidney, lung and stomach. The covalent binding index to liver DNA was typical of carcinogens classified as weak initiators. The enzyme-mediated in vitro interaction of 1,2-DCB with calf thymus DNA of synthetic polyribonucleotides was carried out by a microsomal mixed-function oxidase system and microsomal GSH-transferases, which seemed to be effective only in liver and lung of rat and mouse. Cytosolic GSH-transferases played a minor role in 1,2-DCB bioactivation. The latter finding provides the first evidence of 1,2-DCB genotoxicity in mammalian cells. The type of halide, the number of halosubstituents and their spatial disposition on the benzene ring are the major determinants of halobenzenes activability to intermediate(s) capable of interacting covalently with DNA and other macromolecules in biologic systems.

Initiating activity of 1,1,2,2-tetrachloroethane in two-stage BALB/c 3T3 cell transformation

By using in vitro two-stage BALB/c 3T3 cell transformation assay, we have tested the effect of promoting treatment with tetradecanoylphorbol acetate (TPA) on transformation induced by 1,1,2,2-tetrachloroethane (1,1,2,2-TTCE). Cells were treated with subeffective or transforming concentrations of 1,1,2,2-TTCE in the presence of an S9-mix activating system, followed by TPA promoting treatment. The transforming activity of 1,1,2,2-TTCE is evident only by reseeding confluent cells and allowing additional rounds of cell replications in the amplification test. Treatment with TPA leads to a marked transformation yield in all plates scored even at the lowest assayed dosage of 1,1,2,2-TTCE, without performing amplification of transformation.

Covalent binding of 1,1,1,2-tetrachloroethane to nucleic acids as evidence of genotoxic activity

Twenty-two hours after ip administration to male Wistar rats and BALB/c mice, 1,1,1,2-tetrachloroethane (1,1,1,2-TTCE) is bound covalently to DNA, RNA, and proteins of liver, lung, kidney, and stomach. The in vivo reactivity leads to binding values to DNA generally higher in mouse organs than in rat organs. The covalent binding index (CBI) values (82 in mouse liver DNA and 40 in rat liver DNA) classify 1,1,1,2-TTCE as a weak to moderate initiator. Both microsomal and cytosolic enzymatic systems from rat and mouse organs are capable of bioactivating 1,1,1,2-TTCE in vitro. Liver fractions are the most effective. When the activating systems are simultaneously present in the incubation mixture a synergistic effect is observed. Unlike the related chemical 1,1,2,2-tetrachloroethane (1,1,2,2-TTCE), which is bioactivated only through an oxidative route, 1,1,1,2-TTCE metabolism is carried on by oxidative and reductive pathways, both dependent on cytochrome P-450. 1,1,1,2-TTCE is also bioactivated by microsomal GSH-transferases from liver and lung. These data further confirm that correlations exist between structure and genotoxic activity of halocompounds.

Common carotid artery endovascular clamping for neuroprotection during carotid stenting: Flow-gate system as an innovative treatment approach

OBJECTIVES

We here report our clinical experience in CAS management through common carotid artery endovascular clamping with FlowGate2 system.

METHODS

Forty-five patients were enrolled with de novo asymptomatic internal carotid artery stenosis ≥70%. Cerebral protection during the stenting procedure was achieved using a unique endovascular clamping technique developed in our Institution which includes: (a) the occlusion of the common carotid artery only, through inflatable balloons integrated in the FlowGate2 Balloon Guide Catheter system; (b) flow inversion connecting catheter to 16 G blood cannula previously placed in arm vein; (c) after the placement of the stent, the flow inversion is maintained for 30 s to allow debris washout. The related primary end-point was the rate of Diffusion-weighted imaging magnetic resonance (DWI) micro-embolic scattering of infarction. The patient's clinical and the neurological status were assessed prior, during and after intervention, at discharge.

RESULTS

Transient clamping intolerance was observed in two patients (2/45; 4%). One minor stroke (1/45; 2%) occurred 8 hr the procedure with DWI ipsilateral micro-embolic lesions. No major strokes or deaths were observed at 3 months follow-up. DWI demonstrated ipsilateral micro-embolic scattering of infarction, in one asymptomatic patient. In all patients, no worst changes in NIHSS scale assessment were recorded at 1, 3, and 6 months.

CONCLUSIONS

Our data confirmed the efficacy of FlowGate2 in terms of neuroprotection during CAS. To our knowledge, these are the first published data on this innovative approach developed in our institution. A large controlled trial is ongoing to confirm preliminary evidences.

The covalent interaction of 1,4-dibromobenzene with rat and mouse nucleic acids: in vivo and in vitro studies

1,4-Dibromobenzene (1,4-DBB) was covalently bound to DNA from liver, kidney, lung and stomach of mice after intraperitoneal administration. The covalent binding index (CBI) value (23 in mouse liver) was typical of weak initiators. On the contrary, no interaction with DNA from rat organs was observed (CBI detection limit: 1.3-2.6). The in vitro interaction of 1,4-DBB with calf thymus DNA was mediated mainly by microsomes, especially those from liver of both species and from mouse lung. Mouse subcellular fractions were more active then rat subcellular fractions. Unlike liver cytosol, subcellular cytosolic fractions from lung, kidney and stomach were capable of bioactivating 1,4-DBB, although to a lesser extent than liver microsomes. Both cytochrome P-450 and GSH-transferases are involved in 1,4-DBB bioactivation.

1,2-Dibromoethane as an initiating agent for cell transformation

The two-stage transformation assay increases the sensitivity of cells to chemicals and permits detection of carcinogens acting as initiating agents. 1,2-Dibromoethane, a representative halogenated aliphatic, has been tested in the two-stage BALB/c 3T3 cells transformation test at dosage from 16 microM to 128 microM. This dose range is much lower than those previously found efficient in transforming BALB/c 3T3 cells. Apart from the lowest dose, which induced borderline effects, all the other assayed dosages appeared to induce heritable changes in the target cells. The initiated cells were revealed as fully transformed foci both in the combination with a chronic promoting treatment and also by allowing cells to perform more rounds of cell replication. The results clearly show that 1,2-dibromoethane can act as an initiator of cell transformation.

Isolated popliteal artery lesion due to giant cell vasculitis post COVID-19 mRNA vaccine and COVID-19 asymptomatic infection

OBJECTIVE

Giant cell arteritis (GCA) is a rare granulomatous vasculitis, affecting medium and large vessels, usually in old patients. The incidence of GCA has been higher during current COVID-19 pandemia and COVID-19 is recognized for its immune dysregulation. Lower limbs involvement is uncommon but can be limb threatening, resulting in limb loss.

METHOD

A 43-year-old man presented with a sudden pain in his right calf and foot associated with pallor and hypothermia, and there was objective evidence of ischemia. Symptoms began few days after he received the first dose of a COVID-19 mRNA vaccine and COVID-19 asymptomatic infection 20 days after vaccination. He had no history of any signs of claudication pre-COVID or limb trauma and was very fit.Enhanced computed tomography and magnetic resonance imaging (MRI)suggest diagnosis of popliteal artery cystic adventitial disease. We resected the affected popliteal artery with interposition using a right great saphenous vein graft, through a posterior approach. On the fourth postoperative day, he was discharged.Histopathological examination revealed patchy intramural inflammatory infiltrates composed of lymphocytes and rare multinucleated giant cells at the internal lamina and adventitia consistent with a diagnosis of GCA.

CONCLUSION AND RESULT

Our case represents the first reported case of isolated popliteal GCA following vaccination with a COVID-19 mRNA vaccine and COVID-19 infection. We propose that the upregulated immune response to the vaccine acted as a trigger for GCA in this patient with predisposing risk factors and recurrent and repetitive microtrauma in popliteal fossa (the patient is a professional runner). Our case suggests the need for further studies about real world incidence of GCA associated vaccination and COVID-19 infection. Currently, data is limited regarding this relationship. We continue to encourage COVID-19 vaccination, even in elderly patients because the benefits of vaccination far outweigh any theoretical risk of immune dysregulation following administration.