Cardioplegia For Myocardial Protection Research Articles

Del Nido versus HTK cardioplegia for myocardial protection during adult complex valve surgery: a retrospective study

BackgroundHistidine-tryptophan-ketoglutarate (HTK) and del Nido (DN) cardioplegia are intracellular-type and extracellular-type solution respectively, both can provide a long period of myocardial protection with single-dose infusion, but studies comparing the two are rare for adult cardiac surgery. This study aims to evaluate whether DN is suitable for cardioplegia in complex and high-risk valve surgery with long-term cardiac ischemia when compared with HTK.MethodsThe perioperative records of adult patients infused with DN/HTK as a cardioplegic solution who underwent complex valve surgery with an expected myocardial ischaemic duration longer than 90 min between Oct 2018 and Oct 2019 were analysed retrospectively.ResultsOf the 160 patients who received DN/HTK and underwent complex valve surgery, we propensity matched 73 pairs. Both groups achieved satisfactory cardiac arrest effects, and no significant difference was found in their cTnI and CK-MB levels within 12 to 72 h postoperatively. The DN group had a higher rate of return to spontaneous rhythm (0.88 v 0.52, P < 0.001), a lower frequency of postoperative severe arrythmias (12% v 26%, P = 0.036), a higher postoperative stroke volume (65 v 59 ml, P = 0.011) and a higher cardiac output (6.0 v 4.9 L/min, P = 0.007) as evaluated by echocardiography, fewer transfusions and shorter ICU stays (both P < 0.05). The two groups had similar inotrope usage and similar incidences of low cardiac output, morbidities and mortality. Subgroup analysis showed that when the aortic clamping time was greater than 120 min, the advantages of DN were weakened.ConclusionsDN can be safely applied to complex valve surgery, and it has a similar myocardial protection effect as HTK. Further prospective studies are required to verify these retrospective findings.Trial registration retrospectively registered.

English

BACKGROUND The del Nido cardioplegia was devised and introduced as a single dose cardioplegia for myocardial protection in congenital heart surgery by Petro del Nido and team. The most commonly used cardioplegia in adult cardiac surgery was multidose blood cardioplegia which has to be repeated every 25 to 30 minutes to maintain cardiac arrest. For this, the surgery has to be interrupted leading to prolonged cardiopulmonary bypass and aortic cross clamp time. With promising results of del Nido cardioplegia in adult cardiac surgery, more and more centres adopted this single dose cardioplegia in adult cardiac surgery. We retrospectively analysed the safety and efficacy of del Nido cardioplegia and compared them with those of conventional blood cardioplegia in isolated coronary artery bypass surgery. METHODS We have been using multidose conventional blood cardioplegia (CBCP) solution for all our cardiac surgeries. We changed the cardioplegia protocol to single dose del Nido cardioplegia (DNCP) solution in October 2016. We collected the preoperative, intraoperative and post-operative data of 100 patients in each group, who underwent elective isolated coronary artery bypass surgery. RESULTS The baseline demographic features, pre- and post-operative cardiac function, number of coronary arteries involved, and comorbidities were similar in both groups. There was a statistically significant reduction in cardiopulmonary bypass time (77.16 ± 13.13 minutes vs. 121.69 ± 28.18 minutes, P-value &lt; .00001) and aortic cross clamp time (57.71 ± 10.6 minutes vs. 77.26 ± 20.29 minutes, p value &lt; .00001) in the DNCP group. The total dose of cardioplegia solution required was significantly less in DNCP group (1000 mL vs. 2393.56 ± 592.42 mL, P-value &lt; .00001). The mean post-operative hospital stay in DNCP group was 7.87 ± 1.25 days as compared to 12.49 ± 1.29 days in CBCP group with a P-value &lt; .00001. CONCLUSIONS The del Nido cardioplegia solution is associated with shorter cardiopulmonary bypass and aortic cross clamp time, less volume of cardioplegia solution and shorter mean hospital stay. The del Nido cardioplegia can be used in adult cardiac surgery with the same safety of conventional blood cardioplegia in adult isolated coronary artery bypass surgery. KEYWORDS Del Nido Cardioplegia, Isolated Coronary Artery Bypass Surgery, Myocardial Protection, Cardiopulmonary Bypass Time, Aortic Cross Clamp Time

Comparison of del Nido's cardioplegia with St. Thomas's cardioplegia for myocardial protection in adult open-heart surgery

Objective: The del Nido cardioplegia solution provides a long period of arrest with single dose as compare to St. Thomas cardioplegia solution. In our study we compared outcomes of del Nido and St. Thomas cardioplegia in adult open cardiac surgeries. Methods: Sixty patients were studied between January 2017 to December 2017. Out of which 30 patients were operated on St. Thomas cardioplegia and 30 patients were on del Nido cardioplegia solution. Outcome was compared in both group in relation to demographic, cardiac enzymes level, cardiopulmonary bypass data and post operative results. Results: Total cardiopulmonary bypass time (111.27 ± 40.791 vs. 131.77 ± 37.97, P = 0.049), Aortic cross clamp time (71.67 ± 27.68 vs. 87.00 ± 30.95, P = 0.048), Time taken for return of cardiac contraction after de-clamping the aorta (2.40 ±1.453 vs. 3.67 ± 1.971, P = 0.006), dose of cardioplegia required (1361.67 ± 362.388 vs. 2716.67 ± 927.021, P=0.001) repetition of Cardioplegia needed (1.37±0.490 vs. 4.07±1.437, P=0.001), time to wean off from bypass (21.93±4.934 vs. 32.67±10.535 , P=0.001) and intraoperative cardioversion requirement (p=0.001) were significantly lower in del Nido group as compared to St. Thomas group. Postoperative PRO BNP level (2269.8 ±2098.97 pg/mL vs. 10220.0 ± 8343.62 pg/mL, P= 0.001) was significantly lower in the DN group. While troponin T levels (P= 0.314), CPK-MB level (P=0.111) were comparable in between groups. Conclusion: Del Nido cardiplegia is associated with lower bypass and cross clamp time, less dose and repetition of cardioplegia and early return of cardiac activity as compared to ST Thomas solution. There is better myocardial protection with del Nido cardioplegia as assessed with less increase in PRO BNP level.

Is the custodiol effective as blood cardioplegia for myocardial protection in adult cardiac surgery?

Is the custodiol effective as blood cardioplegia for myocardial protection in adult cardiac surgery?

CHOICE OF MANAGEMENT METHOD OF MYOCARDIAL REVASCULARIZATION IN PATIENTS WITH LOW LEFT VENTRICULAR EJECTION FRACTION (&lt;35 %): A RANDOMIZED PROSPECTIVE STUDY

Purpose. Make a comparative assessment of supportive methods of myocardial revascularization in ischemic heart disease patients with low left ventricular ejection fraction (<35 %) conducted under CPB with cardioplegic cardiac arrest and on a beating heart combined with intraoperative use of IABP or levosimendan. Materials and methods. The study included 90 patients with coronary artery disease and left ventricular ejection fraction <35 %, which was performed CABG under normothermic CPB. Patients were randomized into 4 groups: IABP+CP (CPB with cardioplegia and IABP) (n=30), IABP+CPB (beating heart on a parallel CBP and IABP) (n=14), LS+CP (CBP with cardioplegia and levosimendan) (n=30), LS+CBP (beating heart on a parallel CBP and IABP) (n=16). The primary endpoint wastroponinI.Hemodynamic parameters, the markers of myocardial damage and heart failure, postoperative complications, length of ICU stay, length of hospital stay was evaluated. Results. In LS+CP and LS+CBP groups was revealed reduction in blood pressure (p=0.002 and p=0.013 respectively) and increase in heart rate (p=0.0008 and p=0.0002 respectively) before CBP in comparison with IABP. The average area under the curve (AUC) of troponin I concentration in LS+CP group was less than in IABP+CP group: 11.75 (6.28–13.29) ng/ml vs 24.43 (12.52–27.88) ng/ml, p=0.013. In LS+CP group was revealed decrease in length of ICU stay (2 (2–3) days) compared with IABP+CP group (4 (3–4) days, p=0.0002) and IABP+CBP group (4 (3–6) days, p=0.0008). Preoperative BNP concentration ≥203 pg/mL was a predictor of necessity for inotropic support with sensitivity 60 % (95 % CI 47.1–72.0) and specificity 93.75 % (95 % CI 69.8–99.8) (AUC 0.728; p=0.0001). Preoperative NTproBNP concentration ≥8.24 fmol/L was a predictor of necessity for inotropic support in the postoperative period with sensitivity 77.78 % (95 % CI 64.4–88.0) and specificity 66.67 % (95 % CI 38.4–88.2) (AUC 0.745; p=0.0012). In singlefactor regression analysis the independent effect on necessity for inotropic support in the early postoperative period exert the concentration of preoperative BNP (OR=1.01; 95 % CI 1.001–1.014; p=0.033). Belonging to LS+CP group reduces the risk of ICU stay for more than 3 days on 72 % (OR=0.28; 95 % CI 0.09–0.82; p=0.021). In multivariate regression analysis, a risk factor for 30-day mortality was the concentration of troponin I on the second postoperative day (OR=1.15; 95 % CI 1.03–1.27; p=0.010) and the preoperative concentration NTproBNP was a risk factor for the 1 year mortality (OR=1.02; 95 % CI 1.001–1.032; p=0.006). 6 hours CPK level after CBP was a predictor of atrial fibrillation development in the early postoperative period (OR=1.003; 95 % CI 1.001–1.005; p=0.003) and prolonged hospital stay for more than 14 days (OR=0.996; 95 % CI: 0.994–0.999; p=0.007) Conclusion. CABG on a beating heart under CPB in ischemic heart disease patients with low left ventricular ejection fraction (regardless of the hemodynamic support method) does not lead to significant decrease in serum concentration of Troponin I in the postoperative period. Intraoperative levosimendan infusion together with cardioplegic cardiac arrest improves early postoperative period, which is expressed in significant reduction in ICU stay. Thus, the most preferred method to support myocardial revascularization in ischemic heart disease patients with low left ventricular ejection fraction is combination of a standard methodology for CABG with cardioplegic myocardial protection accompanied by intraoperative infusion of levosimendan. Key words: cardiopulmonary bypass; coronary artery bypass surgery; beating heart; IABP; levosimendan.

The efficacy of custodiol as blood cardioplegia for myocardial protection in adult cardiac surgery

Custodiol cardioplegia is attractive method of myocardial protection, as a single dose provides a long period of preservation. Despite widespread use in Europe, the available data confirming its efficacy is little compared with conventional methods of cardioplegia. Custodiol solution is administered in a single-dose, allowing the operation to be done continuously. This is an advantage over other cardioplegic solutions that may have to be re administered every 20-30 minutes.

Coronary artery bypass surgery without cardioplegia: hospital results in 8515 patients

Cardioplegic myocardial protection is used in most cardiac surgical procedures. However, other alternatives have proved useful. We analysed the perioperative results in a large series of patients undergoing coronary artery bypass (CABG) using cardiopulmonary bypass (CPB) and non-cardioplegic methods. From January 1992 to October 2013, 8515 consecutive patients underwent isolated CABG with CPB without cardioplegia, under hypothermic ventricular fibrillation and/or an empty beating heart. The mean age was 61.9 ± 9.5 years, 12.4% were women, 26.3% diabetic, 64% hypertensive; and 9.6% had peripheral vascular disease, 7.8% cerebrovascular disease and 54.3% previous acute myocardial infarction (AMI). One-third of patients were in Canadian Cardiovascular Society Class III/IV. Three-vessel disease was present in 76.5% of the cases and 10.9% had moderate/severe left ventricle (LV) dysfunction (ejection fraction <40%). A multivariate analysis was made of risk factors associated to in-hospital mortality and three major morbidity complications [cerebrovascular accident, mediastinitis and acute kidney injury (AKI)], as well as for prolonged hospital stay. The mean CPB time was 58.2 ± 20.7 min. The mean number of grafts per patient was 2.7 ± 0.8 (arterial: 1.2 ± 0.5). The left internal thoracic artery (ITA) was used in 99.4% of patients and both ITAs in 23.1%. The in-hospital mortality rate was 0.7% (61 patients), inotropic support was required in 6.6% and mechanical support in 0.8, and 2.0% were re-explored for bleeding and 1.3% for sternal complications (mediastinitis, 0.8%). AKI, the majority transient, occurred in 1595 patients (18.9%). The incidence rates of stroke/transient ischemic attack (TIA) and acute myocardial infarction (AMI) were 2.6 and 2.5%, respectively, and atrial fibrillation/flutter occurred in 22.6% of cases. Age, LV dysfunction, non-elective surgery, previous cardiac surgery, peripheral vascular disease and CPB time were independent risk factors for mortality and major morbidity. The mean hospital stay was 7.2 ± 5.7 days. Isolated CABG with CPB using non-cardioplegic methods proved very safe, with low mortality and morbidity. These methods are simple and expeditious and remain as very useful alternative techniques of myocardial preservation.

Carotid Doppler Flow After Cardiopulmonary Bypass and Mild Hypothermia in Neonatal Piglets

Although the mechanisms of neurological disorders after cardiac surgery in neonates are still not fully understood, alterations in blood flow after cardiopulmonary bypass (CPB) may lead to cerebral injury. The aim of the study was the analysis of flow changes in the carotid artery of neonatal piglets after CPB. Ten neonatal piglets (younger than 7 days) were connected to the CPB and further management underwent three steps: (i) cooling to 32°C core temperature within 30 min; (ii) cardiac arrest under cardioplegic myocardial protection for 90 min; and (iii) rewarming to 37°C after cross-clamp release (60 min of reperfusion). In summary, piglets were separated from CPB after a total duration time of 180 min. The blood flow was measured in the left carotid artery by an ultrasonic flow probe before CPB (baseline), immediately after CPB, 30 min, and 60 min after CPB. Additionally, the pulsatility index and the resistance index were calculated and compared. Finally, the relation of the carotid artery flow data with the corresponding pressure data at each time point was compared. After termination of CPB, the carotid artery mean flow was reduced from 28.34 ± 13.79 mL/min at baseline to 20.91 ± 10.61 mL/min and remained reduced 30 and 60 min after CPB termination (19.71 ± 11.11 and 17.64 ± 15.31 mL/min, respectively). Both the pulsatility and the resistance index were reduced immediately after CPB termination and increased thereafter. Nevertheless, values did not reach statistical significance. In conclusion, the carotid Doppler flow immediately after CPB and mild hypothermia in neonatal piglets was lower than before CPB due to reduced vascular resistance. Additionally, the pressure-flow relation revealed that immediately after CPB, a higher pressure is required to obtain adequate flow.

Cold blood vs. warm blood cardioplegia in patients with acute coronary syndrome undergoing coronary artery bypass grafting

Objective: Patients with acute coronary syndrome (ACS) undergoing urgent on-pump coronary artery bypass grafting (CABG) are at increased risk for myocardial ischemia/reperfusion injury, but the optimal cardioplegic strategy remains uncertain. This study compared the cardioprotective effects of intermittent warm (IWC) versus cold blood cardioplegia (ICC) in this high-risk cohort. Methods: All patients with acute coronary syndrome (ACS) and urgent indication for on-pump coronary artery bypass grafting (CABG) were prospectively enrolled into the study. Applied cardioplegic strategy (ICC/IWC) was left at the discretion of the surgeon. Groups were compared with regard to the release of markers for myocardial injury (CK-MB, cTnT) and clinical outcomes, including in-hospital mortality and major adverse cardiac events (MACE). Results: From April to September 2010 a total of 65 patients with ACS underwent urgent CABG in our institution. Mean patients age was 67.6±9.8 years. IWC was used in 20 patients (30.8%) while ICC was applied in 45 patients (69.2%). Demographics, intraoperative data (CPB time, cross-clamp time, number of grafts) did not differ between groups. Pre- and postoperative levels of myocardial injury markers (CK-MB, cTnT) were similar in both groups (p=ns). Overall in-hospital mortality was 12.3% (8/65) with a MACE rate of 21.5% (14/65) without intergroup differences. Conclusion: Urgent CABG for ACS is associated to an increased postoperative mortality and morbidity. Our preliminary analysis in this small patients cohort fails to reveal relevant benefits of either cold or warm blood cardioplegia for myocardial protection in this high-risk patients cohort.

Comparison of warm versus cold blood cardioplegia for myocardial protection in patients with prolonged aortic cross-clamp times during isolated CABG and aortic valve surgery

Comparison of warm versus cold blood cardioplegia for myocardial protection in patients with prolonged aortic cross-clamp times during isolated CABG and aortic valve surgery

Postconditioning the Human Heart with Adenosine in Heart Valve Replacement Surgery

The effect of adenosine postconditioning on myocardial protection in cardiac surgery remains uncertain. The present study evaluated the safety, feasibility, and beneficial effect of adenosine postconditioning as an adjunct to predominantly used cold-blood cardioplegic myocardial protection method in the setting of heart valve replacement operations. Sixty patients with rheumatic heart valve disease undergoing heart valve replacement operations were randomized to an adenosine (1.5 mg/kg) or saline (as control) bolus injection through an arterial catheter immediately after the aorta cross-clamp was removed. The surgical indications were similar in both groups, and heart valve replacement was successful in all patients. The extubation time and postoperative hospital time were similar in both groups. Compared with the control group, however, the inotrope scores in the intensive care unit (ICU) were much lower (p < 0.01), and the ICU time was significantly shorter (p < 0.05) in adenosine group. More important, cardiac troponin I release was less in the adenosine group, especially at 12 and 24 hours after reperfusion (p < 0.01), and total cardiac troponin I release estimated with the area under curve was also significantly reduced during the first 24 hours after reperfusion (p < 0.01). A 1.5-mg/kg bolus administration of adenosine through an arterial catheter immediately after the aorta cross-clamp is removed is feasible and well tolerated in patients undergoing heart valve replacement. An adenosine postconditioning adjunct to high potassium cold blood myocardial protection is related to less troponin I release, less inotropic drug use, and shorter ICU stay.

Acute ascending aortic dissection complicating open heart surgery: cerebral perfusion defines the outcome

This retrospective study was designed to assess the risks of acute ascending aorta dissection (AAD) as a rare but potentially fatal complication of open heart surgery. Among 8624 cardiac surgical procedures under cardiopulmonary bypass (CPB) and cardioplegic myocardial protection from 1978 to 1997, 10 patients (0.12%) presented with a secondary or so called 'iatrogenic' AAD. There were seven men and three women, mean age 64 +/- 9 years, ranging from 47 to 79. The original procedures involved five coronary artery bypass grafts (CABG), one repeat CABG, one aortic valve replacement (AVR), one AVR and CABG, one mitral valvuloplasty (MVP) and CABG and one ascending aorta replacement. We retrospectively analyzed their hospital records. Group I consisted of seven patients with AAD intraoperatively and group II consisted of three patients who developed acute AAD 8-32 days after cardiac surgery. In group I, treatment consisted of the original procedure, plus grafting of the ascending aorta in six patients and closed plication and aortic wrapping in one. In group II, two patients received a dacron graft and one patient developed lethal tamponnade due to aortic rupture before surgery. Postoperatively, six patients responded well and three died (33%), two patients from group I on the 2nd postoperative day with severe post-anoxic encephalopathy, and one from group II with severe peroperative cardiogenic shock. Preventing AAD with the appropriate means remains standard practice in cardiac surgery. If AAD occurs, it requires prompt diagnosis and interposition graft to allow a better prognosis. Intraoperative AAD happens at the beginning of CPB jeopardizing perfusion of the supra-aortic arteries.

Antegrade-Retrograde Cardioplegia for Myocardial Protection during Coronary Artery Bypass Graft Surgery

This prospective randomized clinical study was designed to assess and compare the use of combined antegrade-retrograde cardioplegia versus antegrade cardioplegia in providing adequate myocardial preservation during coronary artery bypass graft surgery. Fifty patients undergoing elective coronary artery bypass grafting were randomly divided into 2 groups according to the route of cardioplegic delivery: group A (25 patients) received antegrade cold crystalloid cardioplegia; group B (25 patients) received combined antegrade-retrograde cold crystalloid cardioplegia. The groups were compared by clinical and electrocardiographic criteria and biochemical markers of ischemic myocardial damage. There was a highly significant statistical difference between the groups in terms of spontaneous recovery of sinus rhythm (40% of patients in group A versus 96% in group B). The use of direct current shock to restore sinus rhythm was higher in group A (60%) compared with group B (4%). Low cardiac output occurred in 20% of patients in group A and in 16% of patients in group B but this difference was not statistically significant. No bundle-branch block was found in group B whereas the incidence was 8% in group A. Significantly higher levels of biochemical markers of myocardial damage were obtained in group A at 10 minutes, 4 hours, and 12 hours after declamping. These results indicate that combined antegrade-retrograde cardioplegia is superior to antegrade cardioplegia for myocardial protection during coronary artery bypass graft surgery.

Ischemic preconditioning as an adjunct to crystalloid or blood cardioplegia for myocardial protection in routine coronary surgery.

Experimental preconditioning is commonly regarded as a powerful protective phenomenon in case of subsequent ischemia. However, little is known about the applicability of preconditioning as an adjunct to cardioplegic myocardial protection in routine coronary surgery. For this reason, a prospective clinical study (611995 to 4/1996) was initiated to evaluate normothermic ischemic preconditioning prior to crystalloid or cold blood cardioplegic arrest. Preconditioning was performed in two cycles of 5 min ischemia and 10 min reperfusion. Four groups of 7 patients each were compared regarding release of troponin T, creatine kinase-myocardial isoform (CK-MB), lactate, and total CK in coronary sinus effluents over a 12-hour period. In the absence of perioperative myocardial infarction, there were no significant differences in these ischemic and metabolic parameters. Unexpectedly, the heed of postoperative pharmacological inotropic support was greater after preconditioning. These results may indicate that ischemic preconditioning as an adjunct to cardioplegic arrest may be associated with impairment of left-ventricular contractility, thus even exerting potentially detrimental functional effects. Overall, the proven beneficial effects of experimental preconditioning seem not to be directly transferable into the clinical settings.

Parasternal Approach for Minimally Invasive Aortic Valve Surgery

Aortic valve replacement for the stenotic or regurgitant aortic valve has been one of the major advances of medical science in the 20th century. Patients who have severe pressure gradients between the left ventricle and the aorta, or who have severely dilated hearts due to massive aortic regurgitation, are treated by insertion of a reliable mechanical or bioprosthetic device to relieve these hemodynamic abnormalities. This technique has saved hundreds of thousands of lives since the first successful aortic valve replacements by Harken et al,' and Starr et a12 in 1960. Since 1960, valve devices, incisions, and surgical techniques have evolved to the extent that, by the early 1990s, the risk of aortic valve replacement in patients without coronary disease was under 3% in most large centers in the world that do aortic valve replacement .3 The complete median sternotomy became the standard incision for aortic valve replacement in the late 1960s. This incision is flexible and relatively painless because it is a midline incision. It allows maximal exposure of all parts of the cardiac structure, and most importantly, enables physicians to effectively remove air from intracardiac structures. As interest in minimizing surgical trauma has increased, minimally invasive incisions for cardiac surgery are receiving increasing attention. The evolution of minimally invasive surgery in all surgical specialties began with Fogarty's conversion of the vastly complicated aortoiliac embolectomy to a balloon catheter technique via the groin vessels in the early 1960s. In orthopaedics, endoscopy for joint operations replaced open operations about 15 years ago. Approximately 10 to 15 years ago in general surgery, laparoscopic colocystectomy became the treatment of choice, replacing the open colocystectomy. In the last 5 years, the use of video-assisted thoracic surgery has been enormously important in redefining general thoracic surgical procedures to a much less invasive type of surgery for many pulmonary lesions. Minimally invasive cardiac surgery began with the use of techniques for the so-called direct-access coronary bypass, off cardiopulmonary bypass, performed through small incisions, primarily using the left anterior descending coronary artery and applied directly to it. At the same time, Port-Access systems, popularized by Heartport, Inc, Redwood City, CA,5 were developed to afford a minimally invasive incision for a coronary artery bypass graft that had the advantages of cardiopulmonary bypass, aortic cross-clamping by endoclamp, and cardioplegia for myocardial protection. Finally, the use of minimally invasive direct access incisions for cardiac valve surgery were developed in the early part of 1996, when investigators believed that small incisions, accessing only those chambers or vessels where the valve surgery would take place and aided by femoro-femoral bypass, would be an advantage for patients undergoing cardiac valve surgery without combined coronary These approaches have been extended widely, and include a Port-Access system9 for mitral but not aortic valve replacement.

Minimal-Access Surgery for Congenital Heart Defects

Improved results with lower operative mortality and morbidity for corrective surgery for many congenital cardiac defects has stimulated a renewed interest in the use of surgical approaches other than a full midline sternotomy. In an effort to decrease pain and discomfort, shorten the recovery period, and improve the cosmetic result, several alternative approaches have been proposed and implemented, with varying results. Anterior thoracotomy in the inframammary area has been the most widely used incision and is most applicable to females patients past puberty, in whom the extent of breast tissue can be assessed more accurately. Complications with this approach including phrenic nerve injury and breast and chest wall deformities have been reported, although most reports describe satisfactory cosmetic results. We have used a midline approach limiting the incision over the xyphoid process either without a sternal incision (infants) or with division of the lower segment (patients younger than 3 to 4 years) with cephalad retraction to expose the heart and great vessels. From May 1996 to June 1997, 54 children had repair of a secundum-type atrial septal defect using a transxyphoid or ministernotomy approach. In 29, arterial cannulation was performed through the ascending aorta, and in 25 via the femoral artery. There were no instances in which conversion to full sternotomy was required, and complete repair with comparable ischemic and bypass time to full sternotomy was achieved in all patients. We have also used the same technique for repair of other congenital cardiac lesions, including ventricular septal defect and partial or complete atrioventricular canal defects, and in selected infants with tetralogy of Fallot. With this approach, cardioplegia for myocardial protection and left ventricular venting to prevent distention and to remove air from the heart can be used routinely. The adaptability of this technique to various cardiac defects and the ability to extend the incision if necessary make it an attractive alternative to other approaches for minimal-access cardiac surgery for congenital defects. Copyright 1998 by W.B. Saunders Company

Surgical treatment of aortic arch aneurysms using selective cerebral perfusion. Experience with 100 patients.

Hundred consecutive patients were operated on for aortic arch aneurysms between January 1986 and October 1993. All operations were performed with the aid of extracorporeal circulation, blood cardioplegia for myocardial protection, and selective cerebral perfusion (SCP) for protection of cerebral ischemia during aortic arch repair. Forty-four patients (44%) had an emergency operation because of frank or impending rupture of aneurysms or acute aortic dissection. Eighty-three patients (83%) underwent total arch replacement, and 54 had concomitant procedures including aortic valve resuspension, aortic valve replacement (AVR), composite graft replacement and coronary artery bypass grafting (CABG). The overall early (30-day) mortality rate was 16%. Multivariate analysis revealed, as significant risk factors, preoperative cardiopulmonary resuscitation, renal-mesenteric ischemia due to acute dissection, previous ascending aorta/arch operation and preoperative stroke. Of the 71 (71%) patients who were free of these risk factors, only one (1.4%) died. One patient (1%), who was preoperatively in shock state, had a distinct stroke. The present data suggest that SCP is a useful method for aortic arch aneurysm operation requiring complex repair of the aortic arch.

5′-Nucleotidase Inhibition Enhances Postischemic Myocardial Performance

Adenosine methylene diphosphate (AMPCP), a 5′-nucleotidase inhibitor, was evaluated as an adjunct to cold crystalloid cardioplegic myocardial protection. Cardiopulmonary bypass (CPB) was instituted at 28°C in two groups of mongrel dogs (each, n = 6). Myocardial ischemia was induced for 150 min by aortic cross clamping. Crystalloid cardioplegia (4°C) was infused into the aortic root at 15 ml/kg/20 min in the control group (CP). The experimental group (CP + AMPCP) received identical doses of cardioplegia supplemented with 250 μM AMPCP. While on CPB, the mean arterial pressure was 70 mm Hg and the myocardial temperature ranged from 16 to 22°C. Hemodynamic parameters were recorded prior to institution of CPB and at 15 and 45 min following the termination of CPB. Starling curves were constructed for cardiac index (CI), mean arterial pressure (MAP), mean left ventricular pressure (LVP), + dP/dt and - dP/dt at each time point for left atrial pressures between 5 and 12.5 mm Hg. The area under each curve was calculated and expressed as a percentage of prebypass values. Statistical analysis was performed with Student's two-tailed t test. The data demonstrate that although recovery of CI, MAP, heart rate, and LVP was similar in both groups, statistically significant improvement in recovery of myocardial compliance (- dP/dt) and systolic function (+ dP/dt) was seen with AMPCP. The addition of the 5′-nucleotidase inhibitor, AMPCP, to cold crystalloid cardioplegia enhances postischemic myocardial performance in vivo and may be useful during prolonged periods of global myocardial ischemia.

A prospective randomised study of continuous warm versus intermittent cold blood cardioplegia for coronary artery surgery: preliminary report

Between October 1991 and March 1993, 281 consecutive patients underwent non-emergency isolated coronary artery surgery under the care of one surgeon (A.R.). They were prospectively randomised to receive either intermittent cold (Group I-144 patients) or continuous warm (Group II-137 patients) blood cardioplegia for myocardial protection. There were no significant differences in clinical outcome between the two groups, as judged by operative mortality, rates of peri-operative myocardial infarction, blood loss, need for circulatory support, post-operative neurological deficit, or duration of intensive care or hospital stay. However, sinus rhythm returned spontaneously with greater frequency (91.2% vs 45.8%, P < 0.001) in Group II patients. There was greater transmyocardial oxidative stress in Group I patients, as evidenced by a significant rise in oxidised glutathione in coronary sinus blood on myocardial reperfusion. Also, the serum CKMb isoenzyme level 2 h post-operatively was significantly raised in Group I patients, although this difference had disappeared by the day after surgery. In conclusion this preliminary report suggests that continuous warm blood cardioplegia provides comparable myocardial protection to that achieved with standard hypothermic techniques in patients undergoing coronary artery surgery.

Surgical Treatment of Acute Aortic Dissection: Efficacy of Retrograde Cardioplegia for Myocardial Protection

The operative morbidity and mortality of patients with Stanford type A acute aortic dissection undergoing urgent operation using retrograde cardioplegia for myocardial protection were evaluated to assess the efficacy of such surgery. A total of 18 patients (12 men and six women, 19-71 years of age) were operated on 9-137 h after onset of dissection using cardiopulmonary bypass with deep hypothermia and retrograde cardioplegia. Graft replacement was performed in ten patients, primary anastomosis in three, and Cabrol and Bentall operations in five. All patients were weaned from cardiopulmonary bypass, but four died in hospital (mortality rate 22%). Thirteen patients were in good health at follow-up ranging from 3 to 98 months, and the remaining patient died from rectal cancer 5 months after surgery. It is concluded that urgent operation of patients with Stanford type A acute aortic dissection can be performed with reasonable operative and excellent follow-up results. Retrograde cardioplegia is an easy and reliable method of myocardial protection to repair the fragile aortic wall.