Period Of Aortic Cross-clamping Research Articles

Are severe mitral annular calcification still a contraindication to open surgery?

Abstract Background Mitral annular calcifications are considered a contraindication to open mitral valve repair/replacement, being associated with a significant risk of rupture of the atrioventricular groove or prosthesis detachment/paraprosthetic leak. Recently a scoring system has been proposed, to quantify the severity of MAC and predict the success of transcatheter valve in MAC implantation. Objective We present a series of consecutive patients with MAC undergoing sugical mitral valve replacement in recent years. Patients and methods 82 consecutive patients with MAC underwent open surgical correction from January 2019 at our centre. This was a complex cohort of patients with a high surgical risk profile (STS 5.3±3.2). The degree of MAC was moderate in 60 and severe in 22. Annular decalcification was required in 16 patients, and patch reconstruction of the AV groove in 4. The main predictor of the need for annular decalcification and reconstruction was the depth of calcium infiltration in the ventricular wall at CT. At intraoperative TEE only one patient had a significant paraprosthetic leak, that was repaired during a second short period of aortic cross-clamping. 30 days mortality was 1.2% (one patient), and 87% of patients were alive and well at one year. Comment The presence of significant mitral annular calcificaion per se should not be considered a contraindication to open mitral valve surgery. The depth of the calcifications in the ventricular wall, as measured at CT 3D multiplanar reconstructions is the best predictor of the need to decalcify/reconstruct the AV groove. Detailed imaging analysis is crucial for the success of the procedure. Funding Acknowledgement Type of funding sources: None.

Mitochondrial Oxygenation During Cardiopulmonary Bypass: A Pilot Study.

ObjectiveAdequate oxygenation is essential for the preservation of organ function during cardiac surgery and cardiopulmonary bypass (CPB). Both hypoxia and hyperoxia result in undesired outcomes, and a narrow window for optimal oxygenation exists. Current perioperative monitoring techniques are not always sufficient to monitor adequate oxygenation. The non-invasive COMET® monitor could be a tool to monitor oxygenation by measuring the cutaneous mitochondrial oxygen tension (mitoPO2). This pilot study examines the feasibility of cutaneous mitoPO2 measurements during cardiothoracic procedures. Cutaneous mitoPO2 will be compared to tissue oxygenation (StO2) as measured by near-infrared spectroscopy.Design and MethodThis single-center observational study examined 41 cardiac surgery patients requiring CPB. Preoperatively, patients received a 5-aminolevulinic acid plaster on the upper arm to enable mitoPO2 measurements. After induction of anesthesia, both cutaneous mitoPO2 and StO2 were measured throughout the procedure. The patients were observed until discharge for the development of acute kidney insufficiency (AKI).ResultsCutaneous mitoPO2 was successfully measured in all patients and was 63.5 [40.0–74.8] mmHg at the surgery start and decreased significantly (p < 0.01) to 36.4 [18.4–56.0] mmHg by the end of the CPB run. StO2 at the surgery start was 80.5 [76.8–84.3]% and did not change significantly. Cross-clamping of the aorta and the switch to non-pulsatile flow resulted in a median cutaneous mitoPO2 decrease of 7 mmHg (p < 0.01). The cessation of the aortic cross-clamping period resulted in an increase of 4 mmHg (p < 0.01). Totally, four patients developed AKI and had a lower preoperative eGFR of 52 vs. 81 ml/min in the non-AKI group. The AKI group spent 32% of the operation time with a cutaneous mitoPO2 value under 20 mmHg as compared to 8% in the non-AKI group.ConclusionThis pilot study illustrated the feasibility of measuring cutaneous mitoPO2 using the COMET® monitor during cardiothoracic procedures. Moreover, in contrast to StO2, mitoPO2 decreased significantly with the increasing CPB run time. Cutaneous mitoPO2 also significantly decreased during the aortic cross-clamping period and increased upon the release of the clamp, but StO2 did not. This emphasized the sensitivity of cutaneous mitoPO2 to detect circulatory and microvascular changes.

İzole Koroner Arter Baypas Cerrahisinde Aortik Kros Klemp Sırasında Çıkan İdrar Miktarı: Postoperatif Akut Böbrek Hasarının Bir Göstergesidir.

İzole Koroner Arter Baypas Cerrahisinde Aortik Kros Klemp Sırasında Çıkan İdrar Miktarı: Postoperatif Akut Böbrek Hasarının Bir Göstergesidir.

Dynamics of Cognitive Functions and Proinflammatory Cytokines in Different Variants of Coronary Artery Bypass Surgery

Purpose of the study: to evaluate the parameters of cognitive potential and systemic proinflammatory response during direct myocardial revascularization surgery on a beating heart and under conditions of various types of extracorporeal circulation (classical cardiopulmonary bypass and minimized extracorporeal circuit).Materials and methods. A total of 205 patients aged 41–76 years (56.16±2.91 years) were examined. All patients were screened by the Montreal Cognitive Assessment and underwent contrast-enhanced CT perfusion imaging of the brain. The concentrations of tumor necrosis factor, interleukins-6 and 8, and neuron specific enolase were measured in the perioperative period. Surgery in all patients was performed under general balanced anesthesia based on sevoflurane. All patients were randomly divided into three groups: the patients after off-pump surgery; the patients after surgery with classical cardiopulmonary bypass; the patients after surgery with a minimized extracorporeal circuit. Off-pump surgery was performed using a tissue stabilizer. Cardiopulmonary bypass using membrane oxygenators was performed in a nonpulsatile regimen with a perfusion index of 2.4 l/(min•m2) under moderate hypothermia (34–35°C). Protection of the myocardium during the period of aortic cross-clamping was carried out by pharmacological cold cardioplegia.Results. Seven days after surgery, the lowest Montreal Cognitive Assessment scoring was found in a group of patients operated using the classical cardiopulmonary bypass. In this group, the decline was almost 23 % (P=0.0202) compared with the baseline. In the same group, the increase in the level of neuron specific enolase reached 43.19% (P=0.0047). One day after surgery, the highest values (P&lt;0.05) of tumor necrosis factor, interleukin-6 and interleukin-8 were found in the group of patients who underwent surgery with the classical cardiopulmonary bypass. Cortisol levels 24 hours after surgery also increased in all groups, but the smallest increase was recorded in the group of patients undergoing the off-pump surgery.Conclusion. Off-pump surgery or the use of the minimized extracorporeal circuit with biocompatible coating, centrifugal pump in the absence of blood contact with air minimally affects the cognitive potential of patients, reduces manifestations of the systemic inflammatory response, which, in turn, reduces a number of postoperative complications and improves the results of treatment.

Sutureless, rapid deployment valves and stented bioprosthesis in aortic valve replacement: recommendations of an International Expert Consensus Panel.

After a panel process, recommendations on the use of sutureless and rapid deployment valves in aortic valve replacement were given with special respect as an alternative to stented valves. Thirty-one international experts in both sutureless, rapid deployment valves and stented bioprostheses constituted the panel. After a thorough literature review, evidence-based recommendations were rated in a three-step modified Delphi approach by the experts. Literature research could identify 67 clinical trials, 4 guidelines and 10 systematic reviews for detailed text analysis to obtain a total of 28 recommendations. After rating by the experts, 12 recommendations were identified and degree of consensus for each was determined. Proctoring and education are necessary for the introduction of sutureless valves on an institutional basis as well as for the individual training of surgeons. Sutureless and rapid deployment should be considered as the valve prosthesis of first choice for isolated procedures in patients with comorbidities, old age, delicate aortic wall conditions such as calcified root, porcelain aorta or prior implantation of aortic homograft and stentless valves as well as for concomitant procedures and small aortic roots to reduce cross-clamp time. Intraoperative transoesophageal echocardiography is highly recommended, and in case of right anterior thoracotomy, preoperative computer tomography is strongly recommended. Suitable annular sizes are 19-27 mm. There is a contraindication for bicuspid valves only for Type 0 and for annular abscess or destruction due to infective endocarditis. Careful but complete decalcification of the aortic root is recommended to avoid paravalvular leakage; extensive decalcification should be avoided not to create annular defects. Proximal anastomoses of concomitant coronary artery bypass grafting should be placed during a single aortic cross-clamp period or alternatively with careful side clamping. Available evidence suggests that the use of sutureless and rapid deployment valve is associated with (can translate into) reduced early complications such as prolonged ventilation, blood transfusion, atrial fibrillation, pleural effusions and renal replacement therapy, respectively, and may result in reduced intensive care unit and hospital stay in comparison with traditional valves. The international experts recommend various benefits of sutureless and rapid deployment technology, which may represent a helpful tool in aortic valve replacement for patients requiring a biological valve. However, further evidence will be needed to reaffirm the benefit of sutureless and rapid deployment valves.

A New Surgical Approach to Scimitar Syndrome

A wide variety of surgical strategies has been described to treat scimitar syndrome. However, the incidence of pathway obstruction remains high. An alternative approach is described, in which the pulmonary venous return is widely connected to the left atrium through a tunnel constructed with the in-situ pericardium.

Effects of intraoperative external head cooling on short-term cognitive function in patients after coronary artery bypass graft surgery

The aim of study was to assess the effects of an intraoperative external head-cooling technique on cognitive dysfunction in the early postoperative period (at the 10th day) in patients after coronary artery bypass graft (CABG) surgery. Patients in Group H (n=25) were cooled with CPB and the intraoperative, external head-cooling technique, patients in Group C (n=25) were cooled only with cardiopulmonary bypass (CPB) to achieve mild hypothermia (33 - 34 °C). Cognitive function was analyzed before the operation and after the surgery using the Mini Mental State Examination (MMSE), the Modified Visual Reproduction Test from the Wechsler Memory Scale, Trail Making (A/B), WAIS--Digit Span (WDS) and WAIS Digit Symbol Substitution Test (WDSST). The incidence of cognitive impairment at the 10th day after the surgery was 36% (n=9) in Group H and 64% (n=16) in Group C (p=0.048). The temperature during the aortic cross-clamp period was associated with a lower rate of cognitive dysfunction (p=0.05, r(2)=0.09). The intraoperative, external head-cooling technique during the aortic cross-clamp period has a neuroprotective effect and leads to less short-term cognitive function impairment after CABG surgery.

The Effects of Pulsatile Cardiopulmonary Bypass on Acute Kidney Injury

Protective effect of pulsatile flow cardiopulmonary bypass (CPB) on the occurrence of acute renal injury is still a matter of debate. The objective of this study was to compare the effects of pulsatile and non-pulsatile cardiopulmonary bypass on kidneys using Urinary neutrophil gelatinase-associated lipocalin (NGAL) and interleukin-18 (IL-18) as the markers of renal injury. 85 consecutive patients with normal preoperative renal function were prospectively enrolled in the study. Pulsatile perfusion (Group P) and non-pulsatile perfusion (Group NP) was used in 42 and 43 of the patients, respectively, during aortic cross-clamping period. NGAL and IL-18 were analyzed using ELISA in urine samples obtained preoperatively, and at 2, 12, and 24 h after CPB. There was no significant difference between the groups in terms of perioperative renal function tests. IL-18 levels measured at 12 h after CPB were significantly lower in Group P, compared to Group NP (p<0.05). Urinary NGAL levels measured at 2 and 12 h were higher in Group NP; however, the difference was insignificant. In the subgroup of patients with a cross clamp time ≥45 minutes (pulsatile CPB, group P1, n = 33; non-pulsatile CPB, group NP1, n = 33), IL-18 levels measured at 12 hours after CPB were significantly lower in Group P1. Urinary NGAL concentrations measured at 2 and 12 hours in Group P1 were also significantly lower than that in Group NP1 (p = 0.048 and 0.043, respectively). Low IL-18 and NGAL levels found in the pulsatile perfusion group might suggest the use of pulsatile flow resulted in better kidney protection.

Management of mitral regurgitation during left ventricular reconstruction for ischemic heart failure

Remodeling of the left ventricle (LV) in ischemic cardiomyopathy frequently leads to functional mitral regurgitation (MR). The indication for correcting MR in patients undergoing LV reconstruction (LVR) is unclear. In this study, we evaluated our strategy of correcting MR≥grade 2+ by restrictive mitral annuloplasty (RMA) during LVR. We studied 92 consecutive patients (76 men, mean age 61±10 years) who underwent LVR for ischemic heart failure (IHF). RMA was performed in all patients with MR≥grade 2+ on preoperative echocardiography and in patients who showed increased MR to ≥grade 2+ immediately after LVR. Patients were attributed to a RMA and no-RMA group, depending on whether or not concomitant RMA had been performed. Mean clinical and structured echocardiographic follow-up was 47±20 months and was 100% complete. In 38 out of 40 patients (95%) with preoperative MR≥grade 2+, concomitant RMA was planned and performed. In 17 out of 52 patients (33%) with MR<grade 2+ preoperatively, MR increased after LVR to ≥grade 2+ leading to additional RMA during a second period of aortic cross-clamping. Early mortality in the RMA group (n=55) was 12.7% and survival at 36 months 78.2±11.2%. Early mortality in the no-RMA group (n=37) was 5.4% and survival at 36 months 81.1±12.8%. Patients in the RMA group had significantly more reduced LV function with greater LV dimensions and volumes preoperatively. Echocardiography demonstrated sustained improvement in LVEF with reduction of LV volumes in both patient groups. Recurrence of MR at late follow-up was observed in 2 patients (1 patient per group). Patients with IHF eligible for LV reconstruction have MR≥grade 2+ in 44% of cases. In one-third of IHF patients with MR<grade 2+ preoperatively, MR increases to ≥grade 2+ after LVR. Concomitant mitral valve repair for MR≥grade 2+, on either preoperative echocardiography or immediately after LVR, results in favorable late clinical and echocardiographic outcome that proved to be similar to patients without concomitant mitral valve repair, despite more advanced disease.

Myocardial energy metabolism and functional recovery in coronary bypass surgery: A comparative study between continuous retrograde warm and mild hypothermic blood cardioplegia

The optimal temperature for delivery of continuous retrograde blood cardioplegia is not known. Twenty-two patients admitted to the hospital for elective coronary artery bypass grafting were randomized into the warm (37°) and mild hypothermic (28°C) cardioplegia groups. Changes in myocardial energy metabolism during cardiopulmonary bypass, postoperative efflux of the creatine kinase MB isoform (CK-MB), functional hemodynamic recovery, and postoperative complications were followed. During aortic cross-clamp, the average oxygen consumption was higher in the warm than in the mild hypothermic group (3.4±0.4 vs 2.4±0.3 ml/minute,p=0.06), as was the average transcardiac (outflow-inflow) pCO2-difference (1.1±0.1 vs 0.7±0.1 kPa,p=0.02). The average transcardiac pH-difference during aortic cross-clamp was lower in the warm group (−0.08±0.01 vs −0.06±0.01 U,p=0.02), reflecting more profound tissue acidosis. In accordance with this, warm hearts produced more lactate, especially towards the end of the aortic cross-clamp period (p=0.001). The net efflux of adenosine and its degradation products was more prominent during warm than during mild hypothermic cardioplegia (p=0.016), indicating less degradation of high energy adenylates in the hypothermic group. The functional hemodynamic recovery during the first postoperative day was similar in both patient groups, although the myocardial injury estimated as postoperative leakage of CK-MB was less extensive in the hypothermic group (p=0.011). There were no major differences in the postoperative complications between the study groups. We conclude that continuous retrograde mild hypothermic blood cardioplegia offers better myocardial protection during coronary bypass surgery than does continuous retrograde warm cardioplegia. The clinical significance of this should be tested in a larger series of patients, especially those with recent myocardial infarction, unstable angina, or severely depressed left ventricular function.

Continuous warm blood cardioplegia: A randomized prospective clinical comparison

Seventy-eight patients undergoing isolated coronary artery bypass grafting (CABG) were randomized to receive one of two myocardial preservation techniques. Control patients (C) (n=38) had myocardial protection by moderate systemic hypothermia, topical cold saline, and myocardial arrest with antegrade dilute blood/cold potassium cardioplegia with subsequent intermittent retrograde solution every 10–15 minutes during the period of aortic cross-clamping. The experimental group (warm blood, WB) (n=40) had myocardial protection at systemic normothermia, myocardial arrest with antegrade high potassium, and warm blood cardioplegia with subsequent continuous retrograde low potassium warm blood cardioplegia throughout aortic cross-clamping. The two groups were similar preoperatively. After aortic declamping, all WB patients developed a spontaneous rhythm. Only three (7.5%) required intraoperative defibrillation compared with 23 (61%) C patients,p<0.0001. The cross-clamp time per graft was greater with WB,p=0.003. The postoperative need for inotropes, cardiac pacing, incidence of ventricular dysrhythmia, chest tube drainage, and hospital stay did not differ between groups. Perioperative myocardial infarction occurred in 2 WB and 0 C patients (p=0.25). Mortality was not different between groups (WB=1, C=2,p=0.89). It is possible to perform CABG with continuous warm blood cardioplegia with low morbidity and mortality. However, no clear advantage was demonstrated over standard techniques that allow the technical ease of a bloodless field. The metabolic and physiologic significance of spontaneous resumption of sinus rhythm upon aortic declamping remains to be elucidated.

Myocardial Protection in Patients Undergoing Coronary Artery Bypass Grafting Surgery Using Minimized Extracorporeal Circulation in Combination With Volatile Anesthetic

The minimized extracorporeal circulation (ECC) is a safe alternative for coronary artery bypass grafting (CABG) and allows a reduction of the negative effects associated with conventional extracorporeal circulation. Experimental and clinical data indicate that the anesthetic regime might influence the ischemia-reperfusion injury in CABG surgery. The aim of our retrospective study was to investigate the cardioprotective effects of two different minimized ECC systems in combination with two different anesthetic concepts and to determine the impact on oxygen consumption during aortic cross-clamping (ACC). Data of 1,182 patients who underwent elective isolated CABG with minimized ECC from January 1, 2003, to December 31, 2008, were enrolled in a retrospective manner. Patients were allocated either to sevoflurane-based volatile anesthesia using PRECiSe system (SEVO group) or to propofol-based intravenous anesthesia using MECC system (PROP group). Postoperatively, the SEVO group showed lower concentrations of myocardial fraction of creatine kinase compared with the PROP group (p < 0.001). During the period of ACC, the values of systemic vascular resistance (SVR) were higher in SEVO group (p < 0.005). Also, the SEVO group showed lower oxygen consumption at each time point ACC (p < 0.0001). In conclusion, PRECiSe system using a microporous capillary oxygenator in combination with sevoflurane-based volatile anesthetic regimen seem to provide lower postoperative myocardial cell damage and to allow improved perfusion with higher SVRs and lower oxygen consumption during ACC.

Pulsatile Flow Improves Cerebral Blood Flow in Pediatric Cardiopulmonary Bypass

The objective of this study was to evaluate the effect of pulsatile flow on cerebral blood flow (CBF) in infants with the use of a mild hypothermic cardiopulmonary bypass (CPB). Thirty infants scheduled for open heart surgery were randomized to the pulsatile group (Group P, n = 15) and nonpulsatile group (Group NP, n = 15). In Group P, pulsatile perfusion was applied during the aortic cross-clamping period, whereas nonpulsatile perfusion was used in Group NP. The systolic peak velocity (Vs), the end of diastolic velocity (Vd), the mean velocity (Vm), and the pulsatility index (PI) and the resistance index (RI) of the middle cerebral artery were measured by a transcranial Doppler (TCD) ultrasound after anesthesia (T1; baseline), at the beginning of CPB (T2), 10 min after aortic cross-clamping (T3), 3 min after declamping (T4), at the cessation of CPB (T5), and at the end of the operation (T6). During T3 and T4, the Vs in Group P was significantly higher than in Group NP. However, there were no statistically significant differences between Vd and Vm. The PI and RI in Group P were also higher than those in Group NP (both P < 0.05). During T5, Vd and Vm were higher in Group P (P < 0.05), whereas there was no difference in Vs. Additionally, PI and RI in Group P were significantly lower than those in Group NP (P < 0.05). However, there was no difference during T6. Pulsatile perfusion may increase CBF and decrease cerebral vascular resistance in the early period after mild hypothermic CPB.

Cold blood cardioplegia reduces the increase in cardiac enzyme levels compared with cold crystalloid cardioplegia in patients undergoing aortic valve replacement for isolated aortic stenosis

Cardiac arrest during cardiac surgery is most commonly induced by cold blood or cold crystalloid cardioplegia. The results from clinical studies are divergent regarding which of the 2 solutions provides better myocardial protection. This might be explained by several factors. Both heterogeneity in disease for the included patients and the fact that most studies are retrospective in design and that patients with coronary artery disease with different degrees of myocardial ischemia are included might explain these findings. To circumvent these potentially confounding factors, we included in a prospective randomized study only patients undergoing aortic valve replacement for aortic stenosis without other significant cardiac disease. Patients were randomized to antegrade cold crystalloid or cold blood cardioplegia. Eighty patients with aortic stenosis undergoing aortic valve replacement without significant coronary artery stenosis or other significant concomitant heart valve disease were included in the study. They were randomized to either antegrade cold blood or cold crystalloid cardioplegic solution delivered through the coronary ostia every 20 minutes throughout the period of aortic crossclamping. Maximum postoperative creatine kinase isoenzyme MB and troponin-T levels, well-established markers of myocardial damage, were compared between the 2 groups. Both maximum postoperative creatine kinase isoenzyme MB and troponin-T levels were significantly higher by approximately 100% in the cohort of patients receiving crystalloid compared with blood cardioplegia. Only in the group of patients receiving cold crystalloid cardioplegia was there a positive correlation between cardiac enzyme levels and crossclamp time. Antegrade cold blood cardioplegia provides better myocardial protection than cold crystalloid cardioplegia in patients undergoing aortic valve replacement.

Blood Cardioplegia with N-Acetylcysteine May Reduce Coronary Endothelial Activation and Myocardial Oxidative Stress

The aim of this prospective study was to compare the efficacy of intermittent antegrade blood cardioplegia with or without n-acetylcysteine (NAC) in reducing myocardial oxidative stress and coronary endothelial activation. Twenty patients undergoing elective isolated coronary artery bypass graft surgery were randomly assigned to receive intermittent antegrade blood cardioplegia (32 degrees C-34 degrees C) with (NAC group) or without (control group) 300 mg of NAC. For these 2 groups we compared clinical outcome, hemodynamic evolution, systemic plasmatic levels of troponin I, and plasma concentrations of malondialdehyde (MDA) and soluble vascular adhesion molecule 1 (sVCAM-1) from coronary sinus blood samples. Patient demographic characteristics and operative and postoperative data findings in both groups were similar. There was no hospital mortality. Comparing the plasma levels of MDA 10 min after the aortic cross-clamping and of sVCAM-1 30 min after the aortic cross-clamping period with the levels obtained before the aortic clamping period, we observed increases of both markers, but the increase was significant only in the control group (P= .039 and P= .064 for MDA; P= .004 and P= .064 for sVCAM-1). In both groups there was a significant increase of the systemic serum levels of troponin I compared with the levels observed before cardiopulmonary bypass (P< .001), but the differences between the groups were not significant (P= .570). Our investigation showed that NAC as an additive to blood cardioplegia in patients undergoing on-pump coronary artery bypass graft surgery may reduce oxidative stress and the resultant coronary endothelial activation.

The current strategy of repair of tetralogy of Fallot in children and adults

The strategies of repair of tetralogy of Fallot change with the age of patients. In children older than 4 years and adults, the optimal strategy may be to use different method of reconstruction of the right ventricular outflow tract from those followed in younger children, so as to avoid, or reduce, the pulmonary insufficiency that is increasingly known to compromise right ventricular function. From April, 2001, through May, 2008, we undertook complete repair in 312 patients, 180 male and 132 female, with a mean age of 11.3 years +/-0.4 years, and a range from 4 to 48 years, with typical clinical and morphological features of tetralogy of Fallot, including 42 patients with the ventriculo-arterial connection of double outlet right ventricle. The operation was performed under moderate hypothermia using blood cardioplegia. The ventricular septal defect was closed with a Dacron patch. When it was considered necessary to resect the musculature within the right ventricular outflow tract, or perform pulmonary valvotomy, we sought to preserve the function of the pulmonary valve by protecting as far as possible the native leaflets, or creating a folded monocusp of autologous pericardium. The repair was achieved completely through right atrium in 192, through the right ventricular outflow tract in 83, and through the right atrium, the outflow tract, and the pulmonary trunk in 36 patients. A transjunctional patch was inserted in 169 patients, non-valved in all but 9. There were no differences regarding the periods of aortic cross-clamping or cardiopulmonary bypass. Of the patients, 5 died (1.6%), with no influence noted for the transjunctional patch. Of those having a non-valved patch inserted, three-tenths had pulmonary regurgitation of various degree, while those having a valved patch had minimal pulmonary insufficiency and good right ventricular function postoperatively, this being maintained after follow-up of 8 to 24-months. Based on our experience, we suggest that the current strategy of repair of tetralogy of Fallot in older children and adults should be based on minimizing the insertion of transjunctional patches, this being indicated only in those with very small ventriculo-pulmonary junctions. If such a patch is necessary, then steps should be taken to preserve the function of the pulmonary valve.

Cerebral regional oxygenation during aortic coarctation repair in pediatric population

During repair of aortic coarctation, clamping of the transverse aortic arch proximal to the left common carotid artery occludes blood flow to the left carotid and vertebral arteries. The objective of the present study is to determine whether blood flow through the right carotid and vertebral arteries provides adequate cerebral blood flow during aortic cross-clamping, as assessed by near-infrared spectroscopy. In 11 consecutive children undergoing aortic coarctation repair through a standard posterolateral thoracotomy, regional cerebral oxygen saturation (cSO(2)) was measured using near-infrared spectroscopy. Six patients underwent an extended end-to-end repair, in which the aortic cross-clamp was placed in between the innominate and left common carotid arteries (extended repair group). Five patients underwent a standard end-to-end repair in which the cross-clamp was clamp placed between the left common carotid and subclavian arteries (standard repair group). After aortic clamping, there was a significant decrease in cSO(2) in the extended repair group, whereas the cSO(2) increased in the standard repair group (-9.2+/-12.2 vs 6.0+/-5.1%, extended vs standard repair groups, p=0.03). In the extended repair group, the cSO(2) decreased linearly during the aortic cross-clamping period (r(S)=-0.842, p<0.001), while in the standard repair group, the cSO(2) increased during the same time period (r(S)=0.786, p<0.001). Regression analysis identified the site of aortic cross-clamping as the sole independently significant variable explaining changes in the cSO(2) during aortic cross-clamping (p<0.03), whereas neither age nor duration of aortic cross-clamping was statistically significant. There were no postoperative neurological impairments in either group of patients. During aortic coarctation repair, aortic cross-clamping proximal, as compared to distal, to the left carotid artery is associated with significantly decreased regional cerebral oxygen saturation, as measured by near-infrared spectroscopy. Although no short-term clinical impairments were identified, long-term follow-up in a larger cohort is needed to study the effects of unbalanced cerebral oxygenation during clamping of the transverse arch. These data suggest that cerebral saturation monitoring is warranted, and may be indicative of cerebral hypoperfusion.

Management of Infants with Coarctation and Ventricular Septal Defect

The management of patients with aortic coarctation and ventricular septal defect (VSD) remains controversial. A 2-stage repair uses staged coarctation repair +/- pulmonary artery banding followed by VSD closure with 2 separate operations. This has the advantage of a straightforward coarctation repair (except in the case of proximal arch hypoplasia) and a simpler VSD closure at a later date. A subset of patients will have spontaneous VSD closure that obviates the need for subsequent operation. Disadvantages include a period of palliation between operations and the complications of a pulmonary band. A single-stage approach involves simultaneous coarctation repair and VSD closure on cardiopulmonary bypass with circulatory arrest or regional perfusion during coarctation repair. This has the advantages of complete repair in infancy without palliation and the ability to deal with proximal arch hypoplasia. Disadvantages include a technically more challenging operation and the need for circulatory arrest or regional cerebral perfusion. Some series have suggested a higher risk for recoarctation. An alternative method involves coarctation repair without cardiopulmonary bypass through a thoracotomy followed by VSD closure during the same operation (1 stage, 2 incisions). This affords excellent clinical results with complete repair in infancy. One can avoid prolonged periods of aortic cross clamping, cardiopulmonary bypass, and circulatory arrest/regional perfusion. Compared with the other strategies, there are decreased total intensive care unit and hospital stays.

Comparison of two different extracorporeal circuits on cerebral embolization during cardiopulmonary bypass in children

To compare the effect of two different extracorporeal circuits on the counts of high-intensity transient signals (HITS) during pediatric cardiopulmonary bypass (CPB). Transcranial Doppler was used to detect HITS associated with extracorporeal sources during the period of aortic crossclamping in the middle cerebral artery of children undergoing CPB. Based on body size, children were assigned one of two extracorporeal circuits (A or B). Circuit A included a D-705 oxygenator and associated reservoir, and circuit B included a Lilliput oxygenator and reservoir. Patients were further classified into two groups according to the complexity of surgical repair: single simple lesions or multiple complex lesions. We studied 109 pediatric patients. Surgery for multiple complex lesions was associated with longer periods of aortic crossclamping and CPB (p < 0.0001). The median count of extracorporeal HITS was 12 (25th, 75th percentiles: 3, 51). The type of extracorporeal circuit (p = 0.012) and the complexity of surgical repair (p < 0.0001) had an effect on the HITS counts. The use of circuit A was associated with higher HITS counts during surgery for multiple complex lesions compared to single simple lesions (p < 0.0001). Conversely, no differences were found with the use of circuit B between these two surgical groups (p > 0.25). During surgery for multiple complex lesions, patients treated with circuit A showed higher HITS counts than those with circuit B (p < 0.01), but there were no circuit-related differences in HITS counts (p = 0.30) during single simple lesions. Variations in the design characteristics of extracorporeal circuits can increase cerebral emboli during CPB in children. This may be related to the reduced ability of some circuits to remove emboli during long periods of CPB for complex congenital heart-surgery.

Total Laparoscopic Aortic Surgery Versus Minimal Access Techniques: Review Of More Than 600 Patients

In the following paper we describe our experience with a large number of patients in which either a laparoscopic assisted procedure or a total laparoscopic operation was performed. From 1996 until 2005 a total number of 638 aortic patients were operated on using a total laparoscopic or a laparoscopic assisted approach. A total laparoscopic operation was accomplished in 236 cases. A laparoscopic assisted aortic operation was performed in 402 patients. In aneurysm patients a tube graft was more frequently implanted. Thirty-day mortality was significantly higher in patients with a total laparoscopic abdominal aortic aneurysm repair (3.0%) compared to a laparoscopic assisted procedure (1.8%). There was no significant difference in mortality in patients with occlusive disease and a total laparoscopic aortofemoral bypass versus a laparoscopically assisted operation. The same tendency could be observed when analyzing the incidence of major perioperative complications. Again we found no significant difference in patients with occlusive disease yet more severe complications directly related to the operation in patients with a total laparoscopic aneurysm repair. There was a significantly increased complication rate in total laparoscopic aortoiliac repair with a bifurcated prosthesis compared to a tube graft repair: a tendency we could not observe in aneurysm patients with a laparoscopic assisted operation. Our data also show that there is a lot of room for technical improvements such as stapling devices or special grafts to reduce total operating times as well as the period of aortic crossclamping. The routine use of a minilaparotomy can hardly be a solution considering the technical drawbacks such as impaired vision and long term complications like ventral hernias. Compared to open surgery the midterm results of laparoscopic aortic procedures are promising. The time has come to prove that good results can be obtained in more than a few specialized centers.