体外循环下小儿肌部室间隔缺损的镶嵌治疗

目的 探讨镶嵌模式(hybrid procedure)治疗小儿肌部室间隔缺损(Mvsd)的手术方法及临床应用.方法 2006年1月至2010年6月,在体外循环心内直视手术下采用手术及封堵相结合的镶嵌技术矫治小儿Mvsd 45例,其中男20例,女25例;年龄52天～12岁;体重3～32 kg.7例为单个Mvsd,38例为多发性VSD.同时合并大血管错位(D-TGA)1例、法洛四联症(TOF)2例、肺动脉狭窄(PS)3例、动脉导管未闭(PDA)6例、房间隔缺损(ASD)6例、主动脉缩窄1例.均在心脏停跳后直视下将导引钢丝经三尖瓣孔自心脏右室面穿过VSD至左室面,直视下置入导引器,然后送入封堵器,完成Mvsd封堵.多发性VSD 38例,予自体心包片修补膜周部等较大的VSD,心内其他畸形同期完成矫治.结果 42例置入单枚封堵器(直径4～10 mm)、3例置入双枚封堵器(直径4～7 mm).手术经过顺利,术前左室射血分数(EF)均在正常范围,术后1天小于8月龄组EF均值低于正常,大于8月龄组EF正常,两者差异有统计学意义.术后常规每天给予5 mg/kg肠溶阿司匹林3～6个月.术后随访超声检查示封堵器位置无偏移,无残余分流,无二尖瓣、主动脉瓣反流、Ⅲ度传导阻滞及新发心律失常等.术后因重症感染放弃治疗1例,无远期死亡病例.结论 体外循环下镶嵌技术治疗小儿 Mvsd明显降低了围手术期并发症及病死率,简化了手术过程,降低了手术风险,是一种安全、有效的方法.

Abstract：

Objective To summarize the technique and clinical experience of hybrid procedure under cardiopulmonary bypass (CPB) in children with muscular ventricular septal defect (mVSD). Methods From January 2006 to June 2010, 45 cases of mVSD underwent hybrid procedure with CPB. mVSDs were closed with devices under direct vision in 45 cases. Of them, there were 20 males and 25 females. They ranged from 52 days to 12 years [mean (2.05 ±2.48) year] in age and from 3 to 30 kg [(11.93 ±7.70)kg] in body weight. Preoperatively, most of children were highly susceptible to respiratory tract infections. The hybrid approach was used in all patients with CPB under the guidance of transesophageal echocardiography (TEE). The diameter of mVSDs ranged from 2 to 7 mm under TEE. Of 45 cases, 40 patients had increased rates of pulmonary blood flow. 29 patients had left axis deviation and 12 cases had sinus arrhythmia on electrocardiography (ECG). 19 had other congenital heart lesions, including transposition of great arteries in 1 case, tetralogy of Fallot in 2, pulmonary artery stenosis in 3, patent ductus arteriosus in 6, atrial septal defects in 6) and aorta coactation in 1. The quantity of VSDs were from 1 to 7 (single, in 7; two, in 24 case; three, in 8 case; four, in 5 case and seven, in lease. 37 patients were combined with pulmonary hypertension in our cohort. 38 patients with another large VSD and 19 with other congenital heart lesions were required surgical repair at sometime. Results The hybrid procedures were undertaken in all 45 cases of this cohort. All cases were successful and no deaths occurred during operation. A total of 48 devices were implanted in 45 patients, including single devices in 42 cases (device size ranged from 4 to 10 mm) and two devices in 3 cases (device size ranged from 4 -7 mm). The average time on CPB was (58.28 ±20.70) min , while aortic crossclamp time was(34. 94 ± 14.75) min. In addition, the time on mechanical ventilation postoperatively ranged from 2 hours to 6 days. Compared to the older children, 20 infante aged less than 8 monhad a significant difference in cardiac function in the early postoperative period. One infant was given up treatment because of serious infection. Anather cases recovered with the use of supportive treatment, such as using vasoactive agents, digoxin, inhaling nitric oxide, diuresis, and so on. The enteric-coated aspirin was given at dose of 5 mg ? kg -1. day -1 for a period of 3 to 6 months as usual postoperatively. All patients attended follow-up at 1 week, 1 month, 3 months, 6 months, 1 year and 2 years post-procedure. No major complications were encountered during this period. All cases were no instance of migration of any of the devices, residual shunt, aortic regurgitation, atrioventricular valve dysfunction, Ⅲo atrial-ventricular conduction block, new arrhythmia, and so on. There are no death in long-term follow-up. Conclusion Hybrid procedure is safe and effective for the closure of congenital heart defects in children.     

Comparative Study of the Effect on Clinical Outcome of the Use of an Open Circuit and the Use of a Closed Circuit in Cardiopulmonary Bypass for a Graft Replacement of the Descending Thoracic or Thoracoabdominal Aorta

Purpose. We studied the benefits of reduced systemic heparinization in a heparin-coated cardiopulmonary bypass (CPB) system for graft replacement of the descending thoracic (TA) or thoracoabdominal aorta (TAA). Methods. Fifty-five patients were assigned to two groups: one group in which closed CPB circuits with reduced heparinization by elimination of the hard shell reservoir were used (group A, n = 36) and one group in which open circuits with full heparinization were used (group B, n = 19). Results. The transfusion requirement tended to be greater as the duration of CPB increased, even in group A. The incidences of renal dysfunction in two groups were not significantly different. Only the incidence of pulmonary dysfunction was significantly higher in group B. A reduction of systemic heparinization had no benefit for perioperative bleeding. In the TAA operation, the total amount of hemorrhaging in group A was greater than that in group B, but the difference was not significant. Conclusions. No beneficial effects of the use of heparin-coated CPB circuits on the amount of perioperative bleeding and postoperative organ damage, including renal dysfunction, were found in this study. However, our findings suggest that it may be better to avoid the use of closed CPB circuits in operations with a prolonged duration of CPB, such as a TAA operation.     

经食管超声心动描记术在先天性心脏病镶嵌治疗中的应用

目的观察TEE在非体外循环下先天性心脏病镶嵌治疗中的临床应用价值。方法回顾性分析167例TTE初筛拟行先天性心脏病镶嵌治疗的患者,术前TEE检查进一步筛选患者,指导选择适当封堵器,术中TEE监测引导置入封堵器并评价其疗效。结果本组167例中,24例房间隔缺损(ASD)和121例室间隔缺损(VSD)成功完成镶嵌治疗,1例ASD和5例VSD术后即刻TEE可见一丝残余分流,术后3个月复查1例ASD和4例VSD残余分流消失,1例VSD右心室流出道血流速度稍加快,1例VSD术前无主动脉瓣反流,术后出现轻-中度反流。3例ASD和9例VSD镶嵌治疗不顺利,转体外循环。对1例ASD和2例VSD由于缺口过小而放弃治疗。7例VSD合并主动脉瓣脱垂直接放弃镶嵌治疗,转修补术。结论在非体外循环下先天性心脏病的镶嵌治疗中,TEE能为选择适应证和封堵器提供技术支持,实时监测指导及评价手术,降低手术风险,提高手术成功率。     

The effect of hematocrit on cerebral blood flow velocity in neonates and infants undergoing deep hypothermic cardiopulmonary bypass.

Varying degrees of hemodilution are used during deep hypothermic cardiopulmonary bypass. However, the optimal hematocrit (Hct) level to ensure adequate oxygen delivery without impairing microcirculatory flow is not known. In this prospective, randomized study, cerebral blood flow velocity in the middle cerebral artery was measured using transcranial Doppler sonography in 35 neonates and infants undergoing surgery with deep hypothermic cardiopulmonary bypass. Patients were randomized to low Hct (aiming for 20%) or high Hct (aiming for 30%) during cooling on cardiopulmonary bypass (CPB). Systolic (V(s)), mean (Vm), and diastolic (Vd) cerebral blood flow velocity, as well as pulsatility index (PI = [V(s) - Vd]/Vm) and resistance index (RI = [V(s) - Vd]/V(s)) were recorded at six time points: postinduction, at cannulation, after 10 min cooling on CPB, rewarmed to 35 degrees C on CPB, immediately off CPB, and at skin closure. Vm was significantly lower in the high Hct group compared with that in the low Hct group during cooling (P < 0.01). Postinduction, the high Hct group demonstrated significantly lower Vd immediately off CPB (P < 0.01) and significantly lower Vm and V(s) at skin closure (P < 0.001). We conclude that there is an inverse relation between hematocrit and cerebral blood flow velocity during deep hypothermic cardiopulmonary bypass in neonates and infants. Implications: There is an inverse relation between hematocrit and cerebral blood flow velocity during deep hypothermic cardiopulmonary bypass in neonates and infants. Further studies correlating Hct and cerebral blood flow velocity with cerebral metabolic rate and neurologic outcome are necessary to determine the optimal Hct during deep hypothermic cardiopulmonary bypass.     

Single-stage unifocalization and correction with median sternotomy in complex pulmonary atresia

OBJECTIVE: This study assessed the surgical and post-operative outcome of single-stage complete unifocalization and repair procedure in patients with complex pulmonary atresia. METHODS: From 1999 to 2001, we performed complete unifocalization and correction in 10 patients with complex pulmonary atresia. Their ages ranged from 10 months to 17 years. All patients were evaluated with pulmonary angiography and divided into two groups according to the development of native pulmonary arteries. Group I patients had hypoplastic pulmonary arteries and MAPCAs and Group II patients had only MAPCAs without native pulmonary arteries. With median sternotomy, all MAPCAs were prepared and anastomozed to native pulmonary arteries in group I patients or on a pericardial roll in group II patients without using cardiopulmonary bypass. Right ventricle to pulmonary arterial continuity was established with a valved conduit under CPB. VSD was closed in two patients. RESULTS: Eight patients had complete repair without VSD closure. They were followed periodically with pulmonary angiography. Two patients developed congestive heart failure. One of them was reoperated and VSD was closed. The other patient died because of untractable congestive heart failure. The decision for VSD closure was made in two patients due to suitable pulmonary arterial vascular tree. However, one of them had to be reoperated and VSD patch was removed. This patient died because of sepsis on the postoperative 26th day. We are following the rest of the patients with echocardiography and pulmonary angiography. CONCLUSION: Single stage complete unifocalization and repair should be the treatment of choice in patients with complex pulmonary atresia. This procedure provides a significant development in neopulmonary arterial system. However, the accurate criterias for VSD closure are still controversial. After the operation, these patients had to be followed closely with echocardiography and pulmonary angiography because of the absolute risk of congestive heart failure in patients with VSD left open.     

The short term effects of cardiopulmonary bypass on neurologic function in children and young adults.

OBJECTIVE: Cognitive deficits are common in adults following surgery utilizing cardiopulmonary bypass (CPB). A previous retrospective study suggested that surgical closure of an ASD in children was associated with neurologic injury, while transcather therapy was not. In a prospective study, we sought to determine whether neurologic deficits occur following repair of non-complex congenital heart lesions in school-age children and young adults. METHODS: Inclusion criteria were: age between 5 and 20 years, cardiac surgery utilizing CPB without deep hypothermic circulatory arrest, and no prior cardiac surgery. Patients underwent psychometric testing 1-3 days prior to surgery and re-evaluation 7-18 days after surgery. In order to determine the test/re-test effect an age-matched cohort of children undergoing transcather closure of ASD under general anesthesia was also evaluated. The primary outcome measures were verbal and picture memory. Additional psychometric tests included: computerized performance test (CPT) and Digit Span (DS). Forty-one patients were enrolled, 29 undergoing surgery with CPB and 12 controls. Surgical procedures included ASD closure (n=13), VSD closure (n=10), resection of sub-aortic stenosis (n=3), mitral valvuloplasty (n=3). Mild hypothermia was used in all cases. The mean duration of CPB was 54+/-22 min. RESULTS: There was no significant difference in any of the psychometric test scores between subjects undergoing surgery with CPB or controls. CONCLUSIONS: There are no marked adverse neurologic effects of CPB in school-age children and young adults undergoing non-complex open-heart surgery. These data are important in counseling patients and families and should be considered in the debate as to the relative merits of transcather versus open-heart repair of various heart lesions.     

Effects of Modified Ultrafiltration on Coagulation Factors in Pediatric Cardiac Surgery

Purpose. Modified ultrafiltration (MUF) after cardiopulmonary bypass (CPB) in children has been reported to reduce the need for postoperative blood transfusion and minimize postoperative blood loss. This study was undertaken to quantify the effects of MUF on coagulation factors in pediatric patients. Methods. Seven children scheduled to undergo open-heart surgery for congenital heart defects were studied. CPB cir-cuits were primed with crystalloid solutions and no blood transfusions were performed. Hematocrit, platelet count, total plasma proteins, albumin, fibrinogen, prothrombin, factor VII, factor IX, and factor X were measured preoperatively, at the termination of cardiopulmonary bypass, and at the end of modified ultrafiltration. Results. MUF was associated with significant (P < 0.05) increases in hematocrit (17.6% ± 1.6% to 21.6% ± 2.4%), platelet count 11.1 ± 2.5 to 12.8 ± 2.4 × 10⁴/mm³), total plasma proteins (2.7 ± 0.3 to 3.4 ± 0.4 g/dl), and albumin (1.6 ± 0.2 to 2.1 ± 0.2 g/dl). Fibrinogen, prothrombin, and factor VII also increased significantly (P < 0.05) during MUF, but factor IX and factor X did not change. Conclusion. We conclude that MUF attenuates the dilutional coagulopathy that occurs during CPB in children. There were slight improvements in the coagulation factors when MUF was employed. Received: October 5, 2000 / Accepted: September 11, 2001     

Totally endoscopic computer-enhanced atrial septal defect closure in six patients

BACKGROUND: Totally endoscopic procedures have been introduced into cardiac surgery with the application of telemanipulating robotic systems. We report 6 cases of closed-chest atrial septal defect (ASD) closure using a robotic device. METHODS: After deflating the right lung, the endoscopic camera and two robotic arms were inserted into the right hemithorax through 8-mm ports. An accessory port was placed for blood suction and for introduction of ancillary endoscopic instruments. After femoral-femoral cannulation for cardiopulmonary bypass (CPB), aortic occlusion, and cardioplegia delivery, the intracardiac correction was carried out in 5 patients with an ostium secundum ASD and in 1 patient with a patent foramen ovale (PFO) and atrial septal aneurysm (ASA). The ASDs were closed with a continuous braided polyester suture. The PFO closure with septal aneurysm plication was carried out with interrupted stiches. RESULTS: Mean CPB and cross-clamp times were 106 +/- 22 and 67 +/- 13 minutes, respectively. Extubation was carried out within the seventh postoperative hour. All patients returned to normal function within the first postoperative week. CONCLUSIONS: Totally endoscopic ASD closure can be carried out safely using robotic techniques with rapid postoperative recovery and an excellent cosmetic result.     

Risikofaktoren bei Patienten mit zweizeitigem Thoraxverschluss nach Korrektur eines angeborenen Herzfehlers

Background

Primary sternal closure after cardiac operations in infants with congenital heart defects can lead to hemodynamic instability due to cardiac dilation and increased inotrope dependency. The alternative comprises secondary sternal closure (SSC).

Patients and methods

We performed a retrospective study on 43 neonates and infants, who were operated for congenital heart defects with the use of cardiopulmonary bypass (CPB) in our clinic between January 1994 and September 2003. In these infants SSC was indicated. The age difference at the time of operation was 48.4 months (0.03 months to 48.43 months), the weight difference varied from 1.0 kg to 12.8 kg (median 3.7 kg). The average operation time was 377.9 min (45 min to 670 min), during which CPB was used on average for 221.1 min (31 min to 521 min). In 34 (79 %) infants the sternum was left open primarily, while in the other 9 (21 %) patients the thorax was reopened secondarily on the same day as the operation. In order to makeshift close the thorax, an EPIGARD^® membrane was used in 31 cases (72.1 %) and in the other 12 patients (27.9 %) a SILASTIC^® membrane was used.

Results

6 patients (14 %) died before SSC. In the other three the thorax was closed secondarily; however they succumbed postoperatively to multi-organ failure. In three patients superficial thoracic wound infections occurred. There was no correlation detected between weight, CPB time and mortality. We found a positive correlation between epinephrine- dose 60 minutes after the end of CPB and the interval to final sternal closure. The central venous pressure (CVP) of the 9 patients who died were between 9 and 20 cm H₂O (median =15 cm H₂O). The CVP of the 34 survivors was between 2 and 28 cm H₂O (median = 10 cm H₂O), p<0.007. 77.8 % of patients who had deceased had an oxygen partial pressure below normal 60 minutes after the end of CPB. In addition, the median of 39.1 mmHg was much lower compared to the survivors (median = 199 mmHg).

Conclusion

SSC is not a routine procedure and is associated with a low infection risk. Higher epinephrine dependency 60 minutes after the end of CPB prolongs the time until final sternal closure. Patients with a CVP over 15 cm H₂O 30 minutes after CPB and with oxygen partial pressure below 95 mmHg at 60 minutes after CPB have a worse postoperative prognosis.     

Recombinant Factor VIIa in Pediatric Cardiac Surgery

ObjectivesRecombinant activated factor VIIa (rVIIa) is used off-label for refractory bleeding after cardiac surgery. This study reviewed the indications, usage rates, and complications of rVIIa.DesignA retrospective case-control observational study.SettingA single quaternary pediatric hospital.ParticipantsAll children undergoing cardiac surgery with cardiopulmonary bypass over a three-year period.InterventionsAdministration of rVIIa as rescue therapy for refractory bleeding after weaning from cardiopulmonary bypass.Measurements and Main ResultsOnethousand, five hundred fifteen cardiopulmonary bypass procedures were reviewed. Patients receiving rVIIa were each matched to two control patients by age, procedure type, and bypass time. Data collected included weight, crossclamp time, anticoagulant and antifibrinolytic dose, return to the operating room for bleeding, thrombotic events, and extracorporeal membrane oxygenation (ECMO) circuit interventions.Forty-two patients received rVIIa (2.8%). Major systemic thrombotic complications were observed in 19% (controls 12.5%) of patients; 80% of recombinant factor VIIa patients requiring postoperative ECMO had interventions for circuit thrombosis (controls 31.25%); 4.76% of rVIIa recipients required reexploration for intractable bleeding (controls 1.39%).ConclusionsThis study added to understanding regarding the use of recombinant factor VIIa in pediatric cardiac surgery and reported increased thrombotic complications, especially for children who progress to ECMO. Prospective studies to better understand the pathophysiology of coagulopathy and hemorrhage in pediatric cardiac surgery and the role of hemostatic agents, such as rVIIa, are required.     

Closure of adult patent ductus arteriosus under cardiopulmonary bypass by using foley balloon catheter

BACKGROUND: The wall of patent ductus arteriosus (PDA) in adults is usually fragile and may be associated with calcification. METHOD: We present a 43-year-old female patient who underwent successful ductal closure operation under cardiopulmonary bypass (CPB) via a transpulmonary route. RESULTS: The operation was uneventful and the patient was discharged from the hospital on the 4th postoperative day. CONCLUSION: Transpulmonary route for the closure of the PDA by using CPB is a safe and acceptable approach in adult patients.     

Changes in respiratory mechanics during cardiac surgery

We investigated the role of cardiopulmonary bypass (CPB) in compromised lung function associated with cardiac surgery. Low-frequency respiratory impedance (Zrs) was measured in patients undergoing cardiac surgery with (n = 30; CPB group) or without (n = 29; off-pump coronary artery bypass [OPCAB] group) CPB. Another group of CPB patients received dopamine (DA) (n = 12; CPB-DA group). Extravascular lung water was determined in five CPB subjects. Zrs was measured before skin incision and after chest closure. Airway resistance and inertance and tissue damping and elastance were determined from Zrs data. Airway resistance increased in the CPB group (74.9% +/- 20.8%; P < 0.05), whereas it did not change in the OPCAB group (11.8% +/- 7.9%; not significant) and even decreased in the CPB-DA patients (-40.6% +/- 9.2%; P < 0.05). Tissue damping increased in the CPB and OPCAB groups, whereas it remained constant in the CPB-DA patients. Significant increases in elastance were observed in all groups. There was no difference in extravascular lung water before and after CPB, suggesting that edema did not develop. These results indicate a significant and heterogeneous airway narrowing during CPB, which was counteracted by the administration of DA. The mild deterioration in tissue mechanics, reflecting partial closure of the airways, may be a consequence of the anesthesia itself. IMPLICATIONS: We observed that cardiopulmonary bypass deteriorates lung function by inducing a heterogeneous airway constriction, whereas no such effects were observed in patients undergoing cardiac surgery without bypass. The impairment in parenchymal mechanics, which was obtained in both groups, may result from peripheral airway closure and/or be a consequence of mediator release.     

Endotoxemia in coronary artery bypass surgery: a comparison of the off-pump technique and conventional cardiopulmonary bypass

OBJECTIVES: The endotoxemia associated with cardiac surgery is thought to be dominantly influenced by the use of cardiopulmonary bypass. The objectives of this study were to assess the relative contribution of cardiopulmonary bypass on endotoxemia apart from cardiac surgical access and to improve our understanding of the potential benefits of off-pump procedures. METHODS: Thirty patients undergoing coronary artery bypass grafting were followed up prospectively. The patients were divided into 2 equal groups: those who underwent bypass grafting through a sternotomy incision without cardiopulmonary bypass (off-pump group) and those who underwent bypass grafting through a sternotomy incision with cardiopulmonary bypass (CPB group). Blood sampling for endotoxin, lactate, and cardiac index measurements were performed during the following time points: (1) after sternotomy; (2) during the coronary occlusion period in the off-pump group and during aortic clamping in the CPB group; (3) after removal of the coronary occlusion sutures in the off-pump group and after removal of the aortic clamp in the CPB group; (4) 30 minutes after the completion of all distal anastomoses in the off-pump group and immediately after weaning from cardiopulmonary bypass in the CPB group; (5) 1 hour postoperatively; and (6) 12 hours postoperatively. RESULTS: Endotoxin and lactate levels were significantly (P <.05) lower in the off-pump group at all sampling time points, except after sternotomy. CONCLUSIONS: In conclusion, this study has shown that endotoxemia during coronary artery bypass surgery seems mainly to be associated with cardiopulmonary bypass procedure. The relatively lower endotoxin levels observed in off-pump surgery might contribute to improved postoperative recovery.     

Cardiopulmonary bypass in surgery for interrupted aortic arch

Interrupted aortic arch is a complicated congenital heart defect. Because of its anatomic features, the conventional cardiopulmonary bypass (CPB) procedure is not suitable for the surgery of this type of lesion. Thus, we conducted a retrospective study of CPB in surgery for the disease. Ten patients with interrupted aortic arch underwent surgery by one of three different CPB methods, including profound hypothermia with circulatory arrest in four cases, profound hypothermia with low flow rate in five cases, and normothermia in one case. In profound hypothermic CPB, both ascending aorta and main pulmonary artery were cannulated. Through these two cannulas, the flow was pumped to the upper and lower body separately to cool down the body temperature. After cooling, the main pulmonary artery cannula was removed and interrupted aortic arch was corrected either under low flow rate perfusion or under circulatory arrest. After this, the other intracardiac lesions were repaired under conventional CPB. At the end of CPB, one patient demonstrated third-degree atria-ventricular block and required reinstituting CPB and a second procedure to repair the ventricular septal defect (VSD). In the intensive care unit, one patient developed lung infection and dyspnea after extubation that required intubation and mechanical ventilation for another several days. Another patient required 3 days of peritoneal dialysis caused by low cardiac output, hyperkalemia, and oliguria. All patients survived. The mechanical ventilation times were from 8 hours to 8 days and stays in the intensive care unit were from 4 to 12 days. Profound hypothermic cardiopulmonary bypass either with low flow rate or with circulatory arrest is equally the preferable choice for the surgery of interrupted aortic arch.     

Renal function and cardiopulmonary bypass in pediatric cardiac surgical patients

We studied prospectively the perioperative changes of renal function in nine children undergoing cardiac surgery with cardiopulmonary bypass (CPB). Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured with inulin and ¹³¹I-hippuran clearances before CPB, during hypo and normothermic CPB, following sternal closure and 1 h postoperatively. Urinary alpha glutathione S-transferase (alpha GS-T) was measured pre- and postoperatively as a marker for tubular cellular damage. Plasma and urine creatinine and electrolytes were measured. Free water, osmolal and creatinine clearances, as well as fractional excretion of sodium (FeNa) and potassium transtubular gradient (TTKG) were calculated. GFR was normal before and after surgery. ERPF was low before and after surgery; it increased significantly immediately after CPB. Filtration fraction (FF) was abnormally elevated before and after surgery; however, a significant decrease during normothermic CPB and sternal closure was found. Alpha GS-T presented a moderate, but nonsignificant increase postoperatively. FeNa also increased in this period, but not significantly. Creatinine, osmolal, free water clearances, as well as TTKG, were normal in all patients pre- and postoperatively. We conclude that there is no evidence of clinically significant deterioration of renal function in children undergoing repair of cardiac lesions under CPB. Minor increases of alpha GS-T in urine postoperatively did not confirm cellular tubular damage. There was no tubular dysfunction at that time.Supported by grant 1030645 from FONDECYT.     

Changes in hemostasis during pediatric heart surgery: impact of a biocompatible heparin-coated perfusion system

BACKGROUND: This study describes the response in hemostasis during open-heart surgery with cardiopulmonary bypass (CPB) in children (<== 10 kg) and tests the hypothesis that the use of a biocompatible perfusion system, in comparison with a conventional system, causes less hemostatic activation. METHODS: Prospective, randomized, controlled clinical study. Forty consecutive children <== 10 kg were included and divided into two groups: group bioc. (n = 19) treated with a fully heparin-coated system, centrifugal pump, and a closed circuit, and group conv. (n = 21) treated with an uncoated system, roller pump, and a hard shell venous reservoir. Concentrations of plasma thrombin-antithrombin (TAT), D-dimer, tissue plasminogen activator antigen (t-PA ag), and the complex consisting of tissue plasminogen activator and its inhibitor plasminogen activator inhibitor-1 (t-PA-PAI-1) were measured. RESULTS: The biochemical variables measured increased significantly in both groups during the study period. There was less activation of fibrinolysis during cardiopulmonary bypass (t-PA ag: p = 0.009) in patients treated with the biocompatible perfusion system than in patients treated with the conventional system. A trend in favor of the biocompatible system based on the D-dimer and TAT data (p = 0.07 for both measurements) was observed but no significant intergroup differences regarding these variables or t-PA-PAI-1 were found. CONCLUSIONS: Open-heart surgery with cardiopulmonary bypass in children (<== 10 kg) causes transient activation of the coagulation and fibrinolytic systems. This study demonstrates that the use of a biocompatible perfusion system results in a lower extent of activation of fibrinolysis during CPB than the use of a conventional system.     

Hypothermia During Cardiopulmonary Bypass Increases Need for Inotropic Support but Does Not Impact Inflammation in Children Undergoing Surgical Ventricular Septal Defect Closure

Minimizing the systemic inflammatory response caused by cardiopulmonary bypass is a major concern. It has been suggested that the perfusion temperature affects the inflammatory response. The aim of this prospective study was to compare the effects of moderate hypothermia (32°C) and normothermia (36°C) during cardiopulmonary bypass on markers of the inflammatory response and clinical outcomes (time on ventilator) after surgical closure of ventricular septal defects. During surgical closure of ventricular septal defects under cardiopulmonary bypass, 20 children (median age 4.9 months, range 2.3–38 months; median weight 7.2 kg, range 5.2–11.7 kg) were randomized to a perfusion temperature of either 32°C (Group 1, n = 10) or 36°C (Group 2, n = 10). The clinical data and blood samples were collected before cardiopulmonary bypass, directly after aortic cross‐clamp release, and 4 and 24 h after weaning from cardiopulmonary bypass. Time on ventilation as primary outcome did not differ between the two groups. Other clinical outcome parameters like fluid balance or length of stay in the intensive care were also similar in the two groups. Compared with Group 2, Group 1 needed significantly higher and longer inotropic support (P < 0.001). In Group 1, two infants had junctional ectopic tachycardia, and another had a pulmonary hypertensive crisis. Perfusion temperature did not influence cytokine release, organ injury, or coagulation. Cardiopulmonary bypass temperature does not influence time on ventilation or inflammatory marker release. However, in the present study, with a small patient cohort, patients operated under hypothermic bypass needed higher and longer inotropic support. The use of hypothermic cardiopulmonary bypass in infants and children should be approached with care.     

Coronary reoperations: recurrence of angina and clinical outcome with and without cardiopulmonary bypass

BACKGROUND: We compared our experience of minimal tissue dissection and target vessel revascularization without cardiopulmonary bypass (CPB) with the standard procedure of total dissection of the heart and complete revascularization with CPB in patients who had elective reoperative coronary artery bypass grafting (redo-CABG). METHODS: We analyzed recurrence of angina and clinical outcome in 118 patients who had elective redo-CABG between January 1995 and April 2002. Seventy-four patients had redo-CABG with CPB, and 44 patients had redo-CABG without CPB. RESULTS: Perioperative outcome was comparable with regard to morbidity and mortality rates. At follow-up, the mean Canadian Cardiovascular Society score was 1.3 +/- 0.6 in patients who had redo-CABG with CPB and 1.7 +/- 0.8 in patients who had redo-CABG without CPB (p = 0.02). At follow-up, patients who had redo-CABG without CPB had a higher rate of recurrence of angina (log rank = 0.001) and higher use of nitrates (p = 0.015). Target vessel revascularization was an independent predictor of recurrence of angina in younger patients (< 75 years; p = 0.012) but not in the elderly (> or = 75 years; p = 0.142). CONCLUSIONS: In elective redo-CABG patients, minimal tissue dissection and target vessel revascularization without cardiopulmonary bypass did not add significant benefit with regard to perioperative morbidity and mortality. The unsatisfactory relief of symptoms does not seem to justify target vessel revascularization by a less invasive approach. Therefore, this technique should be offered exclusively to patients at high risk with complete revascularization using CPB, such as the elderly.     

动脉导管未闭疑合并畸形采用胸骨正中切口手术的报告

对５４例ＰＤＡ合并或疑合并畸形者采用胸骨正中切口手术，术前常规备体外循环（ＣＰＢ）。术前１４例疑合并心内畸形者中４例证实合并心内畸形，在ＣＰＢ下进行了心内畸形修复。３例术前合并重度肺动脉高压，术中发现ＰＤＡ形状异常，在ＣＰＢ下经肺动脉切口作了ＰＤＡ内口缝合。另１例ＰＤＡ重度肺动脉高压分离时破裂大出血，即在ＣＰＢ下切断缝合挽救了患者生命。采用仰卧位胸骨正中切口，术前备ＣＰＢ，有利术中合并畸形处理及手术安全。     

Nitric oxide provides myocardial protection when added to the cardiopulmonary bypass circuit during cardiac surgery: Randomized trial

ObjectivesThe aim of this pilot study was to elucidate the effects of exogenous nitric oxide (NO) supply to the extracorporeal circulation circuit for cardioprotection against ischemia–reperfusion injury during coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB).MethodsA total of 60 patients with coronary artery disease scheduled for CABG with CPB were enrolled in a prospective randomized study. Patients were allocated randomly to receive treatment according to standard or modified CPB protocol where 40-ppm NO was added to the CPB circuit during cardiac surgery. The primary endpoint was the measurement of cardiac troponin I (cTnI). The secondary end points consisted in the measurements of creatine kinase-muscle/brain fraction (CK-MB) and vasoactive inotropic score (VIS).ResultsNO delivered into the CPB circuit had a cardioprotective effect. The level of cTnI was significantly lower in NO-treated group compared with the control group 6 hours after surgery: 1.79 ± 0.39 ng/mL versus 2.41 ± 0.55 ng/mL, respectively (P = .001). The CK-MB value was significantly lower in NO-treated group compared with the control group 24 hours after surgery: 47.69 ± 8.08 U/L versus 62.25 ± 9.78 U/L, respectively (P = .001); and the VIS was significantly lower in the NO-treated group 6 hours after the intervention.ConclusionsNO supply to the CPB circuit during CABG exerted a cardioprotective effect and was associated with lower levels of VIS and cardiospecific blood markers cTnI and CK-MB.