Antegrade cerebral protection in thoracic aortic surgery: lessons from the past decade

Prolonged deep hypothermic circulatory arrest (DHCA) adversely affects outcome and quality of life in thoracic aortic surgery. Several techniques of antegrade cerebral perfusion are routinely used: bilateral selective antegrade cerebral protection (SACP) by introducing catheters in the innominate and left carotid artery, unilateral perfusion through the right axillary antegrade cerebral perfusion (RAACP) or a combination of right axillary perfusion with an additional catheter in the left carotid artery (RAACCP), resulting also in bilateral perfusion. The aim of the present study was to analyse the impact of the different approaches on the quality of life (QoL).

Protecção Cerebral na Cirurgia do Arco Aórtico

In this paper the authors proceed to a revision of the three main methods employed for cerebral protection in aortic arch surgery, namely the deep hypothermia and total circulatory arrest, the retrograde cerebral perfusion and the selective anterograde cerebral perfusion. After a deep analysis on their advantages and disadvantages, they proposed the utilization of an association of methods (integrated approach) that has proved to be extremely well succeed in their clinical practice, specially in high-risks patients.

Impact of Endovascular Technique in Vascular Surgery Training at a Large University Hospital in Brazil

OBJECTIVES: The aim of this study was to determine the impact of endovascular surgery versus open vascular technique training in a Brazilian teaching service. DESIGN: Cross-sectional study. SETTING: Hospital das Clinicas-Faculty of Medicine University of Sao Paulo, a tertiary institutional hospital Brazil. PARTICIPANTS: We reviewed 1,040 arterial operations performed during 2 distinct time periods: January 1995 to December 1996, and January 2006 to December 2007. Based on the disease treated, the procedures were classified into the following 5 groups: abdominal aortic aneurysms (AAA), aorto-iliac obstructive disease (Al), obstructive disease of the femoropoplitealtibial segment (FP), carotid disease (C), and others (0). The operations were also divided into an endovascular surgery (ES) group and an open surgery (OS) group. We compared the number of open and endovascular procedures for each arterial disease group during both periods. RESULTS: During the 2006-2007 period, 654 patients were treated surgically, whereas over the 1995-1996 period, 386 arterial operations were performed. A. significant increase in endovascular procedures (p < 0.001) was found from the 1995-1996 period to the 2006-201)7 period (35 vs 351, respectively) in all groups, whereas open surgery showed a slight increase in the number of procedures in the AAA and 0 groups only. In the 1995-1996 period, OS was the primary surgical method for all groups, but in the 2006-2007 time frame, OS was performed more frequently than ES only in the AAA and 0 groups. Considering all vascular disease groups, OS was the technique used in 90.9% (351 of 386) of the operations during 1995-1996, whereas in 2006-2007, OS was performed in only 46.3% (303 of 654) of the procedures. CONCLUSIONS: The increase in the number of ES observed over the past decade has had little impact on OS procedures performed at our medical center, not bringing harm to open surgical training. (J Surg 68:19-23. (C) 2011 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.)

Angioplasty and Stent Placement in Symptomatic Internal Carotid Occlusion

PURPOSE: To report a series of patients with symptomatic internal carotid artery (ICA) occlusion treated with angioplasty and stents. MATERIALS AND METHODS: From a consecutive series of 50 patients experiencing neurologic ischemic symptoms and shown by conventional ultrasonography (US) to have a total ICA occlusion, 16 patients (ages 45-79 years; mean, 63 y; 10 men) were selected between August 2006 to September 2008 to be treated with angioplasty based on discovery of an open ICA distal to the occlusion through contrast-enhanced echo Doppler imaging and/or multislice contrast computed tomography (CT). Angioplasty and stent placement were performed under cerebral protection. Follow-up duplex imaging was performed at 14 days and 3 months and every 6 months thereafter and CT follow-up was performed at 2-9 months; the mean follow-up period was 9.9 months. RESULTS: Lesion crossing and stent placement was successful in 13 of 16 patients. There were no deaths, conversions, cardiac complications, or major strokes. One patient had a transient mild hemiparesis in the upper limb, with total recovery in 3 months. At follow-up, all 13 patients with a good initial result remained with patent arterial lumens and resolution of neurologic ischemic symptoms. After 2-9 months, ICAs with a ""string sign"" had calibers close or equal to those of normal arteries. CONCLUSIONS: Angioplasty with stent placement is an effective treatment with a low morbidity rate for selected patients who continue to experience neurologic ischemic symptoms despite US findings of total occlusion of the ICA.

Changes in Perfusion-Weighted Magnetic Resonance Imaging after Carotid Angioplasty with Stent

Carotid artery stenosis due to arteriosclerosis increases the risk of cerebral ischemia via embolic phenomena or reduced blood flow. The changes in cerebral perfusion that may occur after treatment are not clearly understood. This study evaluated the changes in cerebral microcirculation following carotid angioplasty with stenting (CAS) under cerebral protection with filters using ultrafast gradient echo (GRE) perfusion weighted imaging (PWI) with magnetic resonance imaging (MRI). Prospectively, 21 cervical carotid stenosis patients, mean age 69.95 years, underwent MRI 12 h before and 72 h after CAS. PWI parameters were collected for statistical analysis: cerebral blood volume (CB V), mean transit time (MTT) and time to peak (TTP). Statistical analysis was applied to absolute parameters and to values normalized against those from the contralateral parenchyma. The main finding of this study was improved hemodynamics for the normalized data after CAS, shown by reduced MTT (p<0.001) and TTP (p=0.019) in the territory fed by the middle cerebral artery ipsilateral to the CAS. Absolute data showed increased blood volume in the cerebral hemispheres after CAS, which was more accentuated on the stent side (p=0.016) than the contralateral side (p=0.029). Early improvements in cerebral perfusion, mainly seen in the normalized data, were clearly demonstrated in the timing parameters - TTP & MTT - after CAS.

Bilateral carotid endarterectomy combined with myocardial revascularization during the same surgical act

The best surgical approach for the treatment of patients with severe cerebral artery disease and simultaneous serious coronary artery disease still remains controversial. In this report we present a case of a 72-year-old female patient admitted to the hospital with unstable angina. Triple coronary artery obstructive disease and severe bilateral carotid artery stenosis were diagnosed. A combined, simultaneous surgical procedure was performed. After total circulatory by-pass with a membrane oxygenator, the patient's body temperature was lowered to 32°C. During the cool-down period, three proximal anastomoses of segments of autologous saphenous veins were performed in the ascending aorta. Immediately afterwards, bilateral carotid endarterectomy was performed, followed by three distal anastomoses to coronary arteries. The patient showed a satisfactory post-operative outcome. It was concluded that the combination of moderate hypothermia, hemodilution with appropriate hemodynamic control, as used in this patient, was an effective method of cerebral protection. The simultaneous approach of carotid endarterectomy and coronary artery by-pass surgery should be seen as a safe option for the treatment of this type of patient.

Canulacion arterial axilar versus femoral para cirugía del arco aórtico

Objetivo: Determinar si la canulación arterial axilar para perfusión selectiva anterograda cerebral (PSAC) con hipotermia moderada reduce la morbilidad, mortalidad y el pronóstico neurológico en pacientes llevados a cirugía del arco aórtico. Pacientes y métodos: Se hace una revisión retrospectiva de 2 cohortes de pacientes a quienes se les realizo cirugía del arco aórtico urgente o electiva, para comparar dos técnicas de canulación arterial diferente; la canulación axilar para perfusión selectiva anterograda cerebral con hipotermia moderada y la canulación femoral con hipotermia profunda, en un periodo de tiempo comprendido entre Diciembre del 2002 y Agosto del 2008 en el servicio de cirugía cardiovascular de la Fundación Cardioinfantil Instituto de Cardiología. Resultados: 68 pacientes, 50 hombres y 18 mujeres fueron llevados a cirugía de arco aórtico 19 pacientes (27%) con diagnóstico de aneurisma de aorta ascendente y arco aórtico y 49 pacientes (72%) con disección aortica tipo A aguda o crónica. A 55 pacientes (80.9%) se les hizo canulación axilar y a 13 pacientes (19,1%) se les hizo canulación femoral. No se encontraron diferencias en las variables preoperatorias entre los dos grupos. La mortalidad global fue de 13,2% (9 pacientes), todas las muertes se presentaron en pacientes con diagnóstico de disección aortica tipo A. El 55% de los pacientes (38/68) se operaron de urgencia. No se presentaron diferencias estadísticamente significativas en la mortalidad entre el grupo de canulación axilar, 8 muertes (14,5%) y el grupo de canulación femoral 1 muerte (7,7%) con (p=0.5). No se encontraron diferencias en la incidencia de déficit neurológico permanente entre los dos grupos, presentándose solamente dos pacientes con accidente cerebrovascular ambos en el grupo de canulación axilar (P=0.48). Conclusiones: la canulación axilar con perfusión cerebral selectiva anterograda en hipotermia moderada representa un método seguro de protección cerebral, con una mortalidad aceptable y una incidencia baja de complicaciones neurológicas permanentes, no encontramos diferencias en la mortalidad o la aparición de eventos neurológicos, cuando se comparo con la técnica de canulación arterial femoral. No se presentaron complicaciones asociadas al sitio de canulación en ninguno de los dos grupos.

Huge ruptured and infected pseudoaneurysm of the ascending aorta and aortic arch with erosion of sternum after previous cardiac surgery

A 77-year-old woman underwent aortic valve replacement and coronary bypass grafting in 2007 in the Emirates. Evolution was uneventful until December 2011. After repeated episodes of unspecific infections, a computed tomographic scan showed a large pseudoaneurysm of the distal ascending aorta. The site of aortic rupture was closed with a Gore-Tex patch and a Staphylococcus aureus infection treated appropriately. Two months later, a small cutaneous lesion on the cranial part of the sternotomy started bleeding. Computed tomographic scan demonstrated recurrence of a false aneurysm with erosion of the sternum and a large subcutaneous hematoma caused by the fistula. The patient was transferred to our institution. The challenges of this case included safe surgical approach (sternotomy, cannulation, perfusion, cerebral protection) as well as complete removal and extensive debridement of the infected material and reconstruction of the aortic arch. Using fully biological material, reconstruction of the ascending aorta and proximal arch was successfully performed.

Arterial access through the right subclavian artery in surgery of the aortic arch improves neurologic outcome and mid-term quality of life

BACKGROUND: We have shown that selective antegrade cerebral perfusion improves mid-term quality of life in patients undergoing surgical repair for acute type A aortic dissection and aortic aneurysms. The aim of the study was to assess the impact of continuous cerebral perfusion through the right subclavian artery on immediate outcome and quality of life. METHODS: Perioperative data of 567 consecutive patients who underwent surgery of the aortic arch using deep hypothermic circulatory arrest have been analyzed. Patients were divided into three groups, according to the management of cerebral protection. Three hundred eighty-seven patients (68.3%) had deep hypothermic circulatory arrest with pharmacologic protection with pentothal only, 91 (16.0%) had selective antegrade cerebral perfusion and pentothal, and 89 (15.7%) had continuous cerebral perfusion through the right subclavian artery and pentothal. All in-hospital data were assessed, and quality of life was analyzed prospectively 2.4 +/- 1.2 years after surgery with the Short Form-36 Health Survey Questionnaire. RESULTS: Major perioperative cerebrovascular injuries were observed in 1.1% of the patients with continuous cerebral perfusion through the right subclavian artery, compared with 9.8% with selective antegrade cerebral perfusion (p < 0.001) and 6.5% in the group with no antegrade cerebral perfusion (p = 0.007). Average quality of life after an arrest time between 30 and 50 minutes with continuous cerebral perfusion through the right subclavian artery was significantly better than selective antegrade cerebral perfusion (90.2 +/- 12.1 versus 74.4 +/- 40.7; p = 0.015). CONCLUSIONS: Continuous cerebral perfusion through the right subclavian artery improves considerably perioperative brain protection during deep hypothermic circulatory arrest. Irreversible perioperative neurologic complications can be significantly reduced and duration of deep hypothermic circulatory arrest can be extended up to 50 minutes without impairment in quality of life.

Current trends in cannulation and neuroprotection during surgery of the aortic arch in Europe†‡

OBJECTIVES To conduct a survey across European cardiac centres to evaluate the methods used for cerebral protection during aortic surgery involving the aortic arch. METHODS All European centres were contacted and surgeons were requested to fill out a short, comprehensive questionnaire on an internet-based platform. One-third of more than 400 contacted centres completed the survey correctly. RESULTS The most preferred site for arterial cannulation is the subclavian-axillary, both in acute and chronic presentation. The femoral artery is still frequently used in the acute condition, while the ascending aorta is a frequent second choice in the case of chronic presentation. Bilateral antegrade brain perfusion is chosen by the majority of centres (2/3 of cases), while retrograde perfusion or circulatory arrest is very seldom used and almost exclusively in acute clinical presentation. The same pumping system of the cardio pulmonary bypass is most of the time used for selective cerebral perfusion, and the perfusate temperature is usually maintained between 22 and 26°C. One-third of the centres use lower temperatures. Perfusate flow and pressure are fairly consistent among centres in the range of 10-15 ml/kg and 60 mmHg, respectively. In 60% of cases, barbiturates are added for cerebral protection, while visceral perfusion still receives little attention. Regarding cerebral monitoring, there is a general tendency to use near-infrared spectroscopy associated with bilateral radial pressure measurement. CONCLUSIONS These data represent a snapshot of the strategies used for cerebral protection during major aortic surgery in current practice, and may serve as a reference for standardization and refinement of different approaches.

Protezione cerebrale nella chirurgia dell'arco aortico

Negli ultimi decenni, l’outcome dei pazienti sottoposti a chirurgia dell’aorta toracica è migliorato grazie ai progressi ottenuti nella gestione della circolazione extracorporea, della protezione miocardica e cerebrale e del monitoraggio intra- e postoperatorio dei pazienti. Malgrado questo però, la chirurgia dell’arco aortico è ancora gravata da una significativa mortalità e morbilità dovute principalmente alle complicanze neurologiche conseguenti all’interruzione temporanea della circolazione cerebrale. Nel presente studio sono stati analizzati 364 pazienti trattati per sostituzione dell’arco aortico con l’ausilio della perfusione cerebrale selettiva anterograda, presso l’Unità Operativa di Cardiochirurgia dell’Ospedale di Sant’Orsola di Bologna dal 1° gennaio 2015 al 31 maggio 2020.Le disfunzioni neurologiche permanenti sono state diagnosticate in 33 dei 364 pazienti (9.1%) operati, utilizzando la perfusione cerebrale selettiva anterograda come tecnica di perfusione cerebrale. Pertanto abbiamo confrontato due gruppi di pazienti: un gruppo di 33 pazienti con deficit permanenti con il resto dei pazienti (331) che non aveva alcun deficit. Tra le variabili intraoperatorie, i tipi di cannulazione arteriosa, in particolare la cannulazione dell’arteria femorale (109 [32.9%] vs 17 [51.5%], p-value=0.032) e dell’aorta ascendente (56 [16.9%] vs 0, p-value=0.010), presentano delle differenze statisticamente significative tra i due gruppi. Per quanto riguarda la perfusione cerebrale selettiva anterograda, i valori del flusso medio (899.63 ± 214.12 vs 952.52 ± 160.72, p-value=0.051) presentano una differenza statisticamente significativa tra i due campioni. All’analisi multivariata, la dissezione aortica di tipo A (p = 0.010), la cannulazione femorale (p = 0.033) e l’arresto di circolo totale (p = 0.046) si confermano dei fattori di rischio statisticamente significativi per l’insorgenza di disfunzioni neurologiche permanenti

Disclosing Carbon Monoxide Protection in Cerebral Ischemia: Insights into the cellular mechanisms

Dissertation presented to obtain the PhD degree in Biochemistry, Neurosciences

Chronic ethanol exposure and withdrawal influence NMDA receptor subunit and splice variant mRNA expression in the rat cerebral cortex

Chronic ethanol exposure and subsequent withdrawal are known to change NMDA receptor activity. This study examined the effects of chronic ethanol administration and withdrawal on the expression of several NMDA receptor subunit and splice variant mRNAs in the rat cerebral cortex. Ethanol dependence was induced by ethanol vapour exposure. To delineate between seizure-induced changes in expression during withdrawal and those due to withdrawal per se, another group of naive rats was treated with pentylenetetrazol (PTZ) injection (30 mg/kg, i.p.). RNA samples from the cortices of chronically treated and withdrawing animals were compared to those from pairfed controls. Changes in NMDA receptor mRNA expression were determined using ribonuclease protection assays targetting the NR2A, -2B, -2C and NR1-pan subunits as well as the three alternatively spliced NR1 inserts (NR1-pan describes all the known NR1 splice variants generated from the 5' insert and the two 3' inserts). The ratio of NR1 mRNA incorporating the 5' insert vs, that lacking it was decreased during ethanol exposure and up to 48 h after withdrawal. NR2B mRNA expression was elevated during exposure, but returned to control levels 18 h after withdrawal. Levels of NR2A, NR2C, NR1-pan and both 3' NR1 insert mRNAs from the ethanol-treated groups did not alter compared with the pair-fed control group. No changes in the level of any NMDA receptor subunit mRNA was detected in the PTZ-treated animals. These data support the hypothesis that changes in NMDA receptor subunit composition may underlie a neuronal adaptation to the chronic ethanol-inhibition and may therefore be important in the precipitation of withdrawal hyperactivity. (C) 1999 Elsevier Science B.V. All rights reserved.