二尖瓣置换合并射频迷宫术的体外循环管理

目的探讨二尖瓣置换合并射频迷宫术的体外循环 (CPB)方法。方法 :76例风湿性心脏二尖瓣病变合并房颤患者实施瓣膜置换时 ,采用心内直视射频消融迷宫术对其合并的心房纤颤予以治疗。先期的 13例 (A组 )患者在CPB转流阻闭升主动脉后进行射频消融术和二尖瓣置换 ;后期 6 3例 (B组 )采用阻断上下腔静脉后先射频消融右心房 ,再行二尖瓣置换和左房射频消融。结果 :A组 13例患者CPB转流 (10 4± 2 5 )min ,主动脉阻断 (6 1± 11)min。B组 6 3例患者CPB转流 (81± 19)min ,主动脉阻断 (47± 11)min ;应用冷晶体心肌保护患者开放升主动脉后心脏自动复跳率 5 5 .9% ,应用冷血心肌保护患者心脏自动复跳率 71.4 %。术后恢复窦性心律 6 4例 ,占 84 .2 %。结论 :在二尖瓣置换合并射频迷宫术的体外循环中阻闭升主动脉前先射频消融左房可以明显缩短体外循环时间和主动脉阻断时间 ;应用冷血心肌保护液可以加强心肌保护效果且射频消融迷宫术治疗顽固性房颤效果明显     

Effects of chlorpromazine as a systemic vasodilator during cardiopulmonary bypass in neonates

OBJECTIVES: Vasodilator use during cardiopulmonary bypass is important in pediatric cardiac surgery, but the full range of their effects on hemodynamics remains to be clarified. We studied the effects of chlorpromazine, a potent alpha-blocking agent, in neonates. METHODS: Subjects were 60 neonates undergoing arterial switch operations for complete transposition of the great arteries with an intact ventricular septum. Of these, 37 received 2.1 to 6.5 mg/kg of chlorpromazine during cardiopulmonary bypass (CPZ group) and 23 received no vasodilator (control group). We then compared hemodynamic parameters between groups during and early after surgery. RESULTS: The systemic vascular resistance index and mean arterial pressure during cardiopulmonary bypass were significantly lower in the CPZ group (p < 0.05), but systolic pressure 15 minutes after cessation of cardiopulmonary bypass did not differ between groups. The rise in peripheral temperature during rewarming after hypothermia was significantly higher and the acid-base status 40 minutes after cardiopulmonary bypass less acidotic in the CPZ group. Urine output during cardiopulmonary bypass was higher in the CPZ group. CONCLUSIONS: Chlorpromazine effectively counteracts systemic vasoconstriction induced by cardiopulmonary bypass without serious side effects in neonatal cardiac surgery.     

体外循环期间应用乌司他丁对肾功能影响的临床研究

目的　探讨体外循环 (CPB)中应用乌司他丁 (UTI)对机体肾脏的影响。方法　择期CPB下心内直视术 40例 (ASAⅡ～Ⅲ级 )分为 2组 :乌司他丁组 (U组 ,n =2 0 ) ,于麻醉后、CPB开始前将UTI 2 0万U溶于 2 0ml 0 9%生理盐水中静脉注射 (约 10min) ;若CPB时间超过 4h ,可在CPB开始 4h后追加 1次 ,剂量方法同前。对照组 (C组 ,n =2 0 )不用UTI。分别于麻醉前及CPB结束 3h后检测血Bun、Cr及尿NAG、RBP、α1-MG、γ -GTP ,统计尿量并计算排尿量 /输液量。结果　麻醉前 :两组病人间血Bun、Cr和尿NAG、RBP、α1-MG、γ -GTP及排尿量均无显著性差异 (P >0 0 5 )。CPB结束后 :⑴两组病人其尿γ -GTP、NAG均分别高于麻醉前( P <0 0 5 ) ,但U组二者均分别低于C组 ( P <0 0 5 )。⑵两组病人其尿RBP、α1-MG均分别明显高于麻醉前 ( P <0 0 1) ,但U组二者分别低于C组 (P <0 0 5 )。⑶两组病人其排尿量均明显多于麻醉前 (P <0 0 1) ,但U组高于C组 (P <0 0 5 )。⑷U组病人其排尿量 /输液量高于C组 (P <0 0 5 )。结论　UTI对CPB下心内直视病人的肾脏功能有较强的保护作用     

Cardiac rehabilitation and return to work after coronary artery bypass surgery

The work situation of 66 male patients who underwent elective coronary artery bypass surgery (CABS) and who had been randomly allocated to receive cardiac rehabilitation (group R) was compared with the work situation of 59 similar patients allocated to receive only standard care (group H). The follow-up time was one year. The proportions of subjects working in groups R and H were 26% and 20% (p=ns) before the CABS, 45% and 34% (p=ns) 6 months and 56% and 38% (p=ns) 12 months after the CABS, repectively. The increase in proportion of subjects who worked was significant in both groups at both 6 and 12 months after the CABS (p<0.05 for all changes). The increases were not significantly different between the whole groups, but in patients younger than 55 years of age, return to work was more frequent in group R than in group H (at 12 months 60% vs. 35%, p for the difference in change=0.02). Stepwise logistic regression analysis of the factors influencing return to work showed that a patient's judgement of his own working capacity as good 6 months after CABS (odds ratio (OR) 8.5, confidence interval (CI) 2.3–32.0), functional class 16 months after the CABS (OR 6.7, CI 1.8–24.5), his desire to work (OR 6.4, CI 1.6–26.0) and absence from work of less than 3 months before the CABS (OR 4.9, CI 1.2–20.2) were significant positive predictors of return to work 1 year after the CABS.     

Minimally Invasive Axillary– Coronary Artery Bypass

Axillary artery-to-coronary artery bypass using reversed saphenous vein provides a simple method of applying the minimally invasive coronary bypass grafting procedure when the internal thoracic artery is not an adequate conduit. Although this may allow extended use of the minimally invasive coronary bypass procedure, the long-term patency of this technique is unknown.     

Improvement of oxygen metabolic reserve after extracranial-intracranial bypass surgery in patients with severe haemodynamic insufficiency

Summary The effectiveness of extracranial-intracranial arterial bypass (EC-IC bypass) surgery on impaired haemodynamic status was studied in 12 patients with reduced regional cerebral perfusion pressure (rCPP) and elevated regional oxygen extraction fraction (rOEF) in the area distal to the symptomatic arterial lesion. Postoperative positron emission tomography (PET) study demonstrated a statistically significant decrease of rOEF in the operated hemispheres with disappearance of the pre-operative interhemispheric rOEF difference. Regional cerebral blood flow (rCBF) and regional cerebral oxygen metabolism (rCMRO2) were also increased in the operated hemispheres with disappearance of the pre-operative interhemispheric differences. Regional CBF/regional cerebral blood volume (rCBV) ratios of the symptomatic hemispheres were increased after surgery, but were still lower than in the contralateral hemispheres. We conclude that EC-IC bypass surgery improves impaired cerebral oxygen metabolic reserve.     

Normothermic cardiopulmonary bypass: effect on the incidence of persistent postoperative neurological dysfunction following coronary artery bypass graft surgery

We retrospectively reviewed the records of 250 consecutive patients undergoing coronary artery bypass graft surgery (CABG) from January 1994 through January 1996 to determine the incidence of persistent postoperative neurological dysfunction after CABG and to compare normothermic and moderate hypothermic cardiopulmonary bypass (CPB). Normothermic CPB was used in 128 patients (36°–37°C) and hypothermic CPB (27°–28°C) in 122 patients. Postoperative neurological dysfunction included focal motor deficits, delayed recovery of consciousness (>24h) after surgery, and seizures within 1 week postoperatively. Persistent neurological dysfunction was diagnosed if complete resolution had not occurred within 10 days of surgery. The incidence of persistent postoperative neurological dysfunction was 4.1% in the hypothermic CPB group and 2.3% in the normothermic CPB group. There were no statistically significant differences between the two groups (P=NS). These results suggest that normothermic CPB did not increase the incidence of persistent postoperative neurological dysfunction compared to hypothermic CPB.     

Modified Ultrafiltration Attenuates Dilutional Coagulopathy in Pediatric Open Heart Operations

Background. Extreme hemodilution caused by relatively large prime volumes required for cardiopulmonary bypass in infants causes a dilutional coagulopathy, characterized by low concentrations of fibrinogen and other circulating coagulation factors. Modified ultrafiltration results in hemoconcentration and is associated with decreases in postoperative bleeding and transfusion requirements in children. This study was undertaken to quantify the effect of modified ultrafiltration on concentrations of fibrinogen, plasma proteins, and platelets in infants and small children.

Methods. Twenty patients less than 15 kg were studied. Cardiopulmonary bypass circuits were primed with crystalloid solutions. Red blood cells were added during cardiopulmonary bypass for hematocrits less than 15%. Colloid solutions were not administered. Concentrations of fibrinogen, plasma proteins, and platelets, and hematocrit were measured before cardiopulmonary bypass, before modified ultrafiltration, and after modified ultrafiltration.

Results. Modified ultrafiltration was associated with significant (p < 0.001) increases in hematocrit (19% ± 6% to 31% ± 9%), fibrinogen (65 ± 29 to 101 ± 45 mg/dL), and total plasma proteins (2.7 ± 0.3 to 4.9 ± 0.7 g/dL), but no change (p = 0.129) in platelet count.

Conclusions. We conclude that modified ultrafiltration significantly attenuates the dilutional coagulopathy associated with cardiopulmonary bypass in infants.     

多处钻孔治疗颅底动脉闭塞征临床研究

目的 评价多处钻孔法治疗颅底动脉闭塞征(Moyamoya病)的可行性。方法 对20例Moyamoya病患者行多处钻孔及联合双侧颈动脉外膜剥脱术。钻孔位置依据DSA及ECT所示的缺血区而定。结果 本组除1例视力障碍者临床症状无明显改善外，余19例临床症状均有较明显的改善，部分病例术后原血流减少部位血供均有比较明显的改善。有效率达95％，无死亡病例，无感染及切口愈合不良等并发症发生。结论 多处钻孔法具有操作简单、新生血管出现较早等优点，可单独用于临床或作为直接血行重建术的补充疗法。     

Closed-Chest Cardiopulmonary Bypass and Cardioplegia: Basis for Less Invasive Cardiac Surgery

Background. We developed a method of closed-chest cardiopulmonary bypass to arrest and protect the heart with cardioplegic solution. This method was used in 54 dogs and the results were retrospectively analyzed.

Methods. Bypass cannulas were placed in the right femoral vessels. A balloon occlusion catheter was passed via the left femoral artery and positioned in the ascending aorta. A pulmonary artery vent was placed via the jugular vein. In 17 of the dogs retrograde cardioplegia was provided with a percutaneous coronary sinus catheter.

Results. Cardiopulmonary bypass time was 111 ± 27 minutes (mean ± standard deviation) and cardiac arrest time was 66 ± 21 minutes. Preoperative cardiac outputs were 2.9 ± 0.70 L/min and postoperative outputs were 2.9 ± 0.65 L/min (p = not significant). Twenty-one-French and 23F femoral arterial cannulas that allowed coaxial placement of the ascending aortic balloon catheter were tested in 3 male calves. Line pressures were higher, but not clinically limiting, with the balloon catheter placed coaxially.

Conclusions. Adequate cardiopulmonary bypass and cardioplegia can be achieved in the dog without opening the chest, facilitating less invasive cardiac operations. A human clinical trial is in progress.