Time Course of Oxidative Stress During Open-Heart Surgery

Oxidative stress and subsequent lipid peroxidation have been suggested as pathogenetically important for postischaemic reperfusion injury. We studied the time-course of oxidative stress in 14 adults undergoing cardiac surgery, evaluating serum levels of lipid peroxidation products—diene conjugates (DC) and basal and Fe-stimulated thio-barbituric acid reactive substances (TBARS, Fe-TEBARS)—as well as markers of blood antioxidant status—serum antioxidative capacity (AOC) and red blood cell glutathione (RBC-GSH) at 6 perioperative time-points. Arterial TBARS were significantly increased 15 minutes after start of cardiopulmonary bypass, 5 minutes after release of aortic cross-clamp and 15 minutes after cessation of bypass, compared with the preoperative levels (respective means 20.8, 38.5, 34.8 vs 7.5 nmol/g protein, p < 0.05). AOC had decreased at these times (means 21.3, 18.1, 23.2 vs 34.9%, p < 0.05). The TBARS changes correlated with AOC decrease (r = 0.30, p < 0.001). Changes in serum DC and RBC-GSH were not statistically significant. All lipid peroxidation parameters had returned to preoperative levels on the following morning, while antioxidative capacity remained suppressed (28.1%, p < 0.05). These data demonstrate a definite time-course of oxidative stress markers in arterial blood during open-heart surgery.     

Dopamine versus Dobutamine after Open-Heart Surgery

The haemodynamic effects of dopamine and dobutamine were compared in a cross-over study of 12 patients in the early postoperative phase after open-heart surgery. The drug infusion rates (dopamine (μg/kg/min) mean 6.5, range 2.8–12, dobutamine (μg/kg/min) mean 7.9, range 4.3–12.3) were adjusted so that the cardiac output increased by 50%. With both drugs this was achieved through simultaneous increases in stroke volume (dopamine + 16%, dobutamine + 9%) and heart rate (dopamine + 31 %, dobutamine + 38%). The systemic vascular resistance did not change with dopamine but decreased significantly (—18%) with dobutamine. Therefore, the systolic and diastolic arterial blood pressures rose significantly more with dopamine than with dobutamine. The left atrial pressure increased with dopamine but was unchanged with dobutamine. The urine output was significantly higher with dopamine than with dobutamine.     

Altered Plasma Antigen Levels of Tissue Factor Pathway Inhibitor During Open-Heart Surgery

r = 0.96, P < 0.0001) which increased significantly after heparin injection (P < 0.0001), and increased further during the bypass period (P < 0.005). The increased free TFPI antigen level during CPB correlated with the duration of bypass (r = 0.65, P = 0.02). When heparin was neutralized by protamine, the free TFPI antigen level decreased immediately, but remained higher than the preoperative level (P < 0.005). These results suggest that plasma TFPI antigen levels increase during CPB. (Received for publication on Dec. 14, 1998; accepted on July 13, 1999)     

Natural Killer Cell Activity After Open-Heart Surgery

We studied the effects of elective open-heart surgery with cardiopulmonary bypass on peripheral blood natural killer (NK) cell activity in 12 patients with heart disease. Separated mononuclear cells from patients and control cells taken from healthy volunteers were incubated in microtiter plates for 24 h with ³H-thymidine-labelled K 562 cells as target cells. In this test system, higher counts per minute (cpm) values represent a greater number of surviving target cells and thus weaker NK activity. Results of cultures prepared from blood samples taken preoperatively were compared with those taken 2, 7 and 14 days postoperatively. NK cell activity was depressed ( P <0.01) for 2 days after surgery. NK cell activity in the control samples did not change significantly. The results show an impairment of NK cell activity immediately after open-heart surgery.     

Cardiac troponin T: A new marker of myocardial tissue damage in bypass surgery

The purpose of this study was to evaluate cardiac troponin T (TnT) in the diagnosis of minor perioperative myocardial tissue damage and small myocardial infarctions during aortocoronary bypass surgery. In 15 patients without enzymatic or electrocardiographic signs of perioperative myocardial ischemia (group 1, uncomplicated bypass surgery), TnT did not exceed 3.55 μg/L. In 3 patients with perioperative non-Q-wave infarctions (group 2), TnT was significantly higher than in group 1 patients. In all 3 patients, TnT peak concentrations exceeded 3.5 μg/L. Thirteen patients (group 3, borderline cases) showed either signs of perioperative myocardial ischemia by creatine kinase isoenzyme MB (CKMB) activity levels (CKMB > 20 U/L on the first postoperative day, 3 patients) or by electrocardiography (new ST-T segment alterations, 10 patients). TnT concentrations were comparable to group 1 patients and indicated uncomplicated bypass surgery in all 3 patients with solely elevated CKMB activities. On the other hand, TnT concentrations in 3 patients with electrocardiographic signs of perioperative myocardial ischemia were significantly higher than in uncomplicated patients (group 1) with peak values exceeding 3.5 μg/L. Thus, TnT indicated perioperative non-Q-wave infarctions not detected by CKMB activity in these 3 patients. These results are in accordance with findings in nonsurgical patients. They suggest a higher sensitivity and specificity of cardiac TnT compared to CKMB activity in the diagnosis of small perioperative myocardial infarctions after bypass surgery.     

Clinical Experience with a New Pulsatile Assist Device (PAD®) During Open-Heart Surgery

Until now, it has not been possible to routinely use counterpulsation during open-heart surgery. A new pulsatile assist device (PAD®) has been developed to convert roller pump flow to pulsatile flow in a simple fashion. In addition, the PAD can be used as an arterial counterpulsator before and after cardiopulmonary bypass (CPB).
The PAD® is inserted in the arterial line close to the aortic root. The device consists of a flexible, valveless balloon through which the arterial blood flows. The balloon is contained within a rigid plastic housing which is connected to a standard intra-aortic balloon pump unit, thereby enabling the blood-filled balloon to be squeezed.
The PAD® was employed in 400 adult patients undergoing open-heart surgery for coronary artery and/or valvular heart disease from 1975 to 1978. Seventy-two percent of these patients were categorized in the New York Heart Association (NYHA) Class III or IV, or had ejection fractions of less than 0.3. The device functioned as a hemodynamically effective counterpulsator before and after CPB. Urinary outputs during CPB were more than doubled on the PAD® when compared to a control group. In addition, during CPB, coronary graft blood flow increased an average of 21.4% with the PAD®. Free plasma hemoglobin levels after CPB were not elevated. Only eight patients (2%) had a perioperative myocardial infarction. Six patients were treated with intra-aortic balloon pumping (IABP) and five survived. Total mortality in this series was eight patients (2%).
It is suggested that the PAD® is a simple and reliable device for both intraoperative counterpulsation and creation of pulsatile CPB. More significantly, use of the PAD® may decrease both the incidence of perioperative myocardial infarction and the need for postoperative IABP.     

Effects of Oxygen on Central Haemodynamics and Va/Q Distribution after Coronary Bypass Surgery

Central haemodynamics and ventilation-perfusion (VA/Q) distribution were studied in 16 patients, 21 h after coronary bypass surgery, during ventilation with FIO2 = 0.3 and 1.0. VA/Q distributions were determined by the multiple inert gas elimination technique. In 15 patients with normal preoperative lung function, there was a significant shunt of 7.5% of cardiac output and perfusion of regions with VA/Q between 0.005-0.1 of 2.4% (FIO2 = 0.3). Mean VA/Q for the Q-distribution was 0.89 with log s.d. of 0.92. Ventilation of regions with VA/Q above 100 was 0.22. After 30 min of ventilation with FIO2 = 1.0, there was a slight increase in cardiac output while pulmonary arterial mean pressure and pulmonary vascular resistance showed slight decreases. There was a marked increase of the shunt in three patients but the increase for the whole group was not significant. Perfusion of regions with low VA/Q (0.005-0.1) increased significantly to 8.7% while the distribution of ventilation remained unchanged. The changes in distribution of Q were probably due to a release of hypoxic vasoconstriction in combination with complete or incomplete alveolar collapse. One patient with obstructive lung disease showed only minor changes in perfusion distribution.     

Effects of Prenalterol on Central Haemodynamics and VA/Q Distribution Early after Open-Heart Surgery

The effects of intravenous injection of prenalterol, a selective β₁,-adrenoceptor agonist, on central haemodynamics and the distribution of ventilation-perfusion (_A/) were assessed in eight patients alter aortic and/or mitral valve replacement. _A/ distributions were determined by the multiple inert gas elimination technique. Administration of prenalterol resulted in a significant increase in cardiac output and heart rate with no changes in mean pulmonary arterial pressure and wedge pressure. There was an insignificant fall in arterial oxygen tension from 14.3 to 12.4 kPa, accompanied by a significant increase in the inert gas shunt from 6.4 to 11.3% of cardiac output, while the configuration of the distributions of perfusion and ventilation on _A/, remained unchanged. The increase in shunt was probably more an effect of the increase in cardiac output than a direct effect of the drug on the pulmonary vascular bed.     

体外循环心脏手术中的意外及并发症

体外循环心脏手术是一个复杂的过程，麻醉，机器及手术环节中常可出现各种意外及并发症，作者报告这类意外及并发症23例次，其中死亡1例，意外中主要是各种插管的脱出及闭塞，。其次是动脉路管道进气，作者分析了这些意外的发生原因并提出处理及预防措施，心脏大血管损伤是最常见者，本组共发生15例次，作者讨论了造成这些损伤的常见原因及预防措施，作者指出，心内手术中发生的心脏大血管损伤均宜在体外循环下进行修补。     

Plasma Colloid Osmotic Pressure During Open-Heart Surgery Using Non-Colloid or Colloid Priming Solution in the Extracorporeal Circuit

Two different priming solutions for the heart-lung machine were compared in 14 patients during aortic valve replacement. Colloid osmotic pressure (COP), and albumin in plasma, blood erythrocyte volume fraction (B-EVF) and arterial oxygen tension (PaO₂) (FIO₂ = 1.0) were followed before, during and after perfusion. The two priming solutions were 2000 ml Ringerdex^® (7 patients) or 1800 ml Ringerdex + 200 ml 20% albumin^® (7 patients). COP and B-EVF were normal before bypass. After 10 min on bypass, when about 1 000 ml of crystalloid cardioplegic solution had been given, COP was reduced by about 50% and B-EVF fell to 23%, indicating a small loss of water from the circulation when compared with in vitro dilution curves. COP was slightly lower in the non-colloid group (p < 0.02). Both COP and B-EVF remained unchanged during perfusion, despite transfusica from the heart-lung machine of a mixture of blood and crystalloid solution with a calculated very low COP (6 mmHg) and B-EVF (15 %). After perfusion the restitution of COP and B-EVF was rapid and parallel. Both returned to normal levels after 2 hours. There was a good correlation between COP and albumin measured in the same plasma samples (r = 0.83, p < 0.001). At one hour after bypass PaO₂ (FIO₂ = 1.0) tended to decrease in the non-colloid group, compared with the preperfusion level. 40 g of albumin was a too small amount of colloid to diminish substantially the reduction of COP during perfusion. The unchanged levels of COP and B-EVF during perfusion, despite further dilution as well as the parallel normalization after perfusion, can only be explained by loss of water from the circulation.     

The Efficacy and Renal Protective Effect of Tolvaptan in Chronic Kidney Disease Patients after Open-Heart Surgery

Purpose: Unlike loop diuretics, tolvaptan is reported to have a renal protective effect. The purpose of this study was to retrospectively assess the efficacy of tolvaptan administration in chronic kidney disease (CKD) patients following open-heart surgery.Methods: From February 2017 to August 2020, 75 patients with preoperative CKD stages IIIb–V were enrolled in this study and were divided into two groups: the control group (n = 30) and the tolvaptan group (n = 45). All patients routinely received conventional diuretics starting from postoperative day (POD) 1. Tolvaptan at 7.5–15 mg/day was administered if the patients had persistent fluid retention or poor response to conventional diuretics.Results: Tolvaptan administration was initiated at a mean of POD 2.9 ± 2.2, and the mean dosing period was 4.1 ± 3.0 days. The mean time to return to the preoperative body weight in the control and tolvaptan groups was similar. However, estimated glomerular filtration rate (eGFR) was significantly increased at the time when body weight reached the preoperative level and at discharge in the tolvaptan group than in the control group.Conclusion: This study demonstrated the renal protective effect of tolvaptan even in advanced CKD patients after open-heart surgery.     

心脏手术脑损伤与脑保护

心脏术后脑损伤主要表现为中风．病理性脑病和神经认知功能障碍。脑栓塞和／或脑低灌注是围术期脑损伤的主要原因。本文从以下几个方面对心脏手术的脑保护进行综述：体外循环装置,升主动脉粥样硬化的管理。减少栓子的措施,体外循环期间血压,血糖．温度的管理,输血指征,药物脑保护和脑监测措施等。     

Early results with the minimally invasive thoracotomy for myocardial revascularization

Objective: We report the early results of the left anterior descending artery revascularization through a minimally invasive thoracotomy, examining the main technical aspects of the operation. Methods: From January 1995 to September 1996, 51 patients underwent myocardial revascularization through a mini-thoracotomy on beating heart without cardiopulmonary bypass. The main indication to operation was limited lesions of the left anterior descending artery with contra-indications or high risk of failure of angioplasty. The position of the patient was the same than traditional surgery; the chest was opened on the fourth left intercostal space; the left internal mammary artery harvested under direct vision; temporary occlusion of the left anterior descending was obtained prevalently using 5–0 poliypropilene sutures; the anastomosis was performed with single or double 7–0 or 8–0 suture. In six patients the chest was closed and a conventional open-heart operation was performed due to internal mammary artery or left anterior descending unsuitability for minimally invasive revascularization. All the patients were submitted after operation to early angiographic control and/or a Doppler study of the mammary flow. Results: There was no intra-operative mortality. One patient had a postoperative myocardial infarction of the anterior-lateral wall of the left ventricle, and died after an emergency open-heart operation. In one case the patient was reopened after a few hours for a bleeding. Three patients showed various degrees of anastomotic stenosis at the angiographic control. Conclusions: Several technical difficulties can play an important role in the operative outcome because a single repeated technical error could not fully explain these heterogeneous observed failures. The technique of myocardial revascularization through a left anterior small thoracotomy might present several critical points, particularly: (1) the harvesting of LIMA, meaning the preservation of integrity of the arterial wall and adequacy of the length; (2) the method of the temporary closure of the LAD during of the anastomosis; (3) the stabilization of the LAD and the surgical technique of the anastomosis; (4) the methods for intraoperative control of the patency of the anastomosis. All points mentioned have been thought in our experience to be causes of early failure.     

Acute Renal Failure and Mortality After Open-Heart Surgery in Infants

Acute renal failure (ARF) is a major complication in infants who undergo cardiac surgery. The aim of this investigation was to identify possible risk factors for ARF and mortality in this patients group. Out of 64 patients, 21 (32.8%) cases developed acute renal failure and overall mortality rate was 25%. The mortality rate was higher in the infants who developed ARF than those who did not (66.7% and 4.7%, respectively, p < 0.05). Also, ARF was positively correlated with mortality (r:0.70, p < 0.0001). The nonsurvivors had lower mean serum albumin than did the survivors (p < 0.05), and serum albumin level was negatively correlated with mortality (r = ? 0.34, p < 0.05). For the patients with serum albumin level < 3.5 g/dL, the unadjusted odds ratio for mortality was 4.3 (CI 95%:1.05 ? 17.86). Total bypass time and aorta clamping time were significantly longer in the nonsurvivor group than in the survivor group (p < 0.05 for both). In conclusion, the significant risk factors for mortality in these patients were development of ARF, low serum albumin level, and long total bypass and aorta clamping times, which may be predictive of poor prognosis.     

A DROP-IN Gamma Probe for Robot-assisted Radioguided Surgery of Lymph Nodes During Radical Prostatectomy

BackgroundThe DROP-IN gamma probe was introduced to overcome the restricted manoeuvrability of traditional laparoscopic gamma probes. Through enhanced manoeuvrability and surgical autonomy, the DROP-IN promotes the implementation of radioguided surgery in the robotic setting.ObjectiveTo confirm the utility and safety profile of the DROP-IN gamma probe and to perform a comparison with the traditional laparoscopic gamma probe and fluorescence guidance.Design, setting, and participantsTwenty-five prostate cancer patients were scheduled for a robot-assisted sentinel lymph node (SN) procedure, extended pelvic lymph node dissection, and prostatectomy at a single European centre.Surgical procedureAfter intraprostatic injection of indocyanine green (ICG)-^99mTc-nanocolloid (n = 12) or ^99mTc-nanocolloid + ICG (n = 13), SN locations were defined using preoperative imaging. Surgical excision of SNs was performed under image guidance using the DROP-IN gamma probe, the traditional laparoscopic gamma probe, and fluorescence imaging.MeasurementsIntraoperative SN detection was assessed for the different modalities and related to anatomical locations. Patient follow-up was included (a median of 18 mo).Results and limitationsOverall, 47 SNs were pursued in vivo by the DROP-IN gamma probe, of which 100% were identified. No adverse events related to its use were observed. In vivo fluorescence imaging identified 91% of these SNs. The laparoscopic gamma probe identified only 76% of these SNs, where the detection inaccuracies appeared to be related to specific anatomical regions.ConclusionsOwing to improved manoeuvrability, the DROP-IN probe yielded improved SN detection rates compared with the traditional gamma probe and fluorescence imaging. These findings underline that the DROP-IN technology provides a valuable tool for radioguided surgery in the robotic setting.Patient summaryRadioguided robot-assisted surgery with the novel DROP-IN gamma probe is feasible and safe. It enables more efficient intraoperative identification of sentinel lymph nodes than can be achieved with a traditional laparoscopic gamma probe. The use of the DROP-IN probe in combination with fluorescence imaging allows for a complementary optical confirmation of node localisations.     

右腋下直小切口在婴儿心脏直视手术中的应用

目的总结右腋下直小切口在婴儿常见先天性心脏病（先心病）心内直视手术中的应用经验。方法回顾性分析解放军第153中心医院2009年4月至2013年4月采用右腋下直小切口施行婴儿心脏直视手术369例患者的临床资料,其中男191例、女178例,年龄3～12（8.2±3.1）个月,体重4.5～11.2（7.8±4.5）kg。行室间隔缺损（VSD）修补术290例,房间隔缺损（ASD）修补术16例,VSD＋ASD修补术34例,VSD修补术＋二尖瓣成形术（MVP）4例,肺动脉瓣狭窄（PVS）交界切开术9例,ASD修补术＋PVS交界切开术6例,部分肺静脉异位引流（PAPVC）4例和部分房室管畸形（PECD）6例均行手术治疗。结果手术死亡6例（1.6%）。术后发生右肺不张3例,右侧气胸2例,肺部感染16例,切口液化12例,Ⅲ°房室传导阻滞1例,脑气栓1例,二次开胸止血3例。术后6个月至1年门诊随访295例,发现VSD残余漏4例,二尖瓣轻度关闭不全2例。结论在婴儿常见先心病直视手术中,采用右腋下直小切口可获得满意的临床效果,但需要严格把握手术适应证,熟练掌握手术要点。