Hypothermic Low-flow Perfusion Research Articles

Reducing risk in infant cardiopulmonary bypass: The use of a miniaturized circuit and a crystalloid prime improves cardiopulmonary function and increases cerebral blood flow

Advances in perfusion strategies have played an important role in improving outcomes following repair of complex congenital heart defects. The influence of cooling strategy, temperature, duration of circulatory arrest, and specific method of cerebral perfusion on neurologic morbidity have been extensively characterized. Similarly, the ability of pharmacologic agents to modulate the post-cardiopulmonary bypass (CPB) inflammatory response has been previously elucidated in both the laboratory and clinical arena. However, modification of the circuit and priming components have received comparably less attention. We recently showed that employment of a miniaturized circuit and a bloodless prime reduce inflammation and have salutary effects on cardiopulmonary function following hypothermic low-flow perfusion (HLF), and that this circuit may also improve cerebral protection following both deep hypothermic circulatory arrest and HLF. The current report, therefore, reviews current strategies utilized to minimize post-CPB inflammation and highlights the empirical evidence from our laboratory demonstrating the beneficial role of a miniaturized extracorporeal circuit in this context.

Surgical-closure of patent ductus arteriosus under deep hypothermic low-flow perfusion cardiopulmonary dypass

目的 探讨深低温低流量体外循环下动脉导管缝扎术的手术方法和效果.方法 86例粗大的动脉导管、成人动脉导管或动脉导管合并其他心内畸形的病人,采用体外循环下降温至21℃,低流量下缝扎动脉导管.结果手术死亡2例,死亡原因为术后低心排和肺动脉高压危象,存活84例无脑栓塞、肾功能衰竭或其他神经系统并发症发生,随访12～50个月无复发再通.结论深低温低流量下动脉导管缝扎术对于粗大动脉导管、成人动脉病人是一种安全、可靠的手术方法。

Mediastinal false aneurysm after thoracic aortic surgery

Background. Postoperative mediastinal false aneurysm is associated with a substantial morbidity and mortality. Surgical treatment is mandatory, although the individual approach varies according to the type of pathologic process, infection status, and site of origin of the aneurysm. Methods. Between April 1993 and February 1999, we treated 10 patients, aged 25 to 73 years, with anastomotic mediastinal false aneurysm originating from the proximal thoracic aorta. Nine had undergone prior operations on the ascending aorta (7, type A dissection repair; 1, aortitis; 1, root abscess) with a Dacron conduit (n = 5) or valved conduit (n = 4). The last patient had undergone valve replacement for excavating aortic root sepsis. False aneurysms were detected from 2 to 70 months after the most recent operation. Three patients had positive tissue cultures. The surgical procedure was direct suture repair of the disrupted anastomosis in 5, root or ascending aortic replacement with an aortic homograft in 4, and Dacron graft interposition in 1. Hypothermic low-flow perfusion with or without circulatory arrest was used in all patients. Results. There was one hospital death caused by staphylococcal mediastinitis. A false aneurysm recurred after direct suture repair in 2 patients with underlying type A dissection or aortitis. This resulted in one late death. One patient experienced a neurologic event during removal of an infected vascular graft. All 8 surviving patients are alive and well after a mean follow-up of 2 years. Three patients with mycotic false aneurysms remain free from infection after aortic homograft replacement. Conclusions. Mediastinal false aneurysms are surgically taxing. Low-flow hypothermic perfusion with or without circulatory arrest allows safe reentry. Radical surgery provides a satisfactory outcome in infected patients. Local repair of suture dehiscence in pathologic tissues may predispose to recurrence. We suspect that excessive use of formalin in gelatin-resorcin-formol glue may predispose to tissue necrosis.

31P-NMR study of cardiac preservation: St. Thomas' Hospital cardioplegic solution versus UW preservation solution

Ex vivo cardiac preservation was evaluated by measuring the catabolism of high-energy phosphate (ATP and creatine phosphate, CrP) using 31P-NMR spectroscopy. After cardioplegic arrest St. Thomas' Hospital cardioplegic solution (group A), and University of Wisconsin (UW) preservation solution (group B) were tested. The hearts were mounted in the 4.7 T horizontal bore magnet of the NMR spectrometer and were continuously perfused with the test solution under 25 cm H2O pressure for 6 h at 10 degrees C. Peak heights of the beta-phosphate of ATP and CrP were measured and expressed as percentages of the initial value. For both group A and group B. ATP declined less rapidly during preservation than CrP. In group A, ATP remained constant for 60 min while CrP decreased from the onset of preservation. After 6 h of preservation 28.3% of ATP and 24.5% of CrP remained (group A). On the other hand, in group B, levels of both ATP and CrP remained much more stable: CrP did not decrease during the first 3 h of preservation, while ATP started to decrease after 5 h. At the end of preservation 76.1% of ATP and 71.5% of CrP were still present. We conclude that UW solution is superior to St. Thomas' Hospital solution for the preservation of high-energy phosphates during 6 h cardiac preservation with continuous hypothermic low-flow perfusion.

31P-NMR study of cardiac preservation: St. Thomas' Hospital cardioplegic solution versus UW preservation solution

Abstract. Ex vivo cardiac preservation was evaluated by measuring the catabolism of high-energy phosphate (ATP and creatine phosphate, CrP) using 31P-NMR spectroscopy. After cardioplegic arrest St. Thomas' Hospital cardioplegic solution (group A), and University of Wisconsin (UW) preservation solution (group B) were tested. The hearts were mounted in the 4.7 T horizontal bore magnet of the NMR spectrometer and were continuously perfused with the test solution under 25 cm H2O pressure for 6 h at 10°C. Peak heights of the β-phosphate of ATP and CrP were measured and expressed as percentages of the initial value. For both group A and group B, ATP declined less rapidly during preservation than CrP. In group A, ATP remained constant for 60 min while CrP decreased from the onset of preservation. After 6 h of preservation 28.3% of ATP and 24.5% of CrP remained (group A). On the other hand, in group B, levels of both ATP and CrP remained much more stable: CrP did not decrease during the first 3 h of preservation, while ATP started to decrease after 5 h. At the end of preservation 76.1% of ATP and 71.5% of CrP were still present. We conclude that UW solution is superior to St. Thomas' Hospital solution for the preservation of high-energy phosphates during 6 h cardiac preservation with continuous hypothermic low-flow perfusion.

Hypothermic preservation of the rat heart: Comparison of immersion and low-flow perfusion methods: Contribution of 31P-NMR spectroscopy

Comparison of rat heart preservation by simple storage in a cardioplegic solution at 4 °C (6 hr for group I; 15 hr for group II) and by hypothermic low-flow perfusion of the same solution (0.3 ml min−1, 15 hr: group III) was performed by measuring biochemical and functional parameters and by collecting 31P-NMR Spectroscopy data. When compared to control values, adenine nucleotide levels remained unchanged in group I hearts, while glycogen was 45% hydrolyzed and lactate level increased by 700%. Extension of heart immersion to 15 hr (group II) led to breakdown of ATP (− 77%), of the sum of adenine nucleotides (− 27%), and of glycogen (− 77%), whereas lactate accumulation reached 900% of the control value. Functional recovery, measured at the end of a 60-min reperfusion was less than 10% in group II hearts when compared to group I hearts. This dramatic development was completely avoided by hypothermic low-flow perfusion (group III). 31P-NMR data showed that phosphocreatine was completely degraded in all groups of preserved hearts. Low-flow perfusion limited cellular acidosis. The ATPPi (Pi = inorganic phosphate) ratio calculated from NMR data was lower for group II hearts (0.04 ± 0.01, n = 6) than for group I hearts (0.29 ± 0.12; n = 6) or group III hearts (0.19 ± 0.09; n = 6) and could constitute a convenient bioenergetic index to predict the capability of the heart to recover satisfactory contractility following a preservation period.

234 術中心筋温ならびに術後血清CPK・LDHアイソザイムの変動からみた超低体温・低流量灌流法の評価

234 術中心筋温ならびに術後血清CPK・LDHアイソザイムの変動からみた超低体温・低流量灌流法の評価

B-29 術後早期の血清LDHおよびCPKアイソザイムの変動からみた超低体温低流量灌流法の検討

B-29 術後早期の血清LDHおよびCPKアイソザイムの変動からみた超低体温低流量灌流法の検討

主題 I-3 乳児開心術の問題点

主題 I-3 乳児開心術の問題点

The effect of different storage methods on the subsequent biochemical performance of perfused canine livers

Canine livers were stored in 4 different ways prior to an evaluation by a normothermic dilute blood test perfusion. The storage modalities were hypothermia alone, hypothermic low-flow perfusion with Tis-U-Sol, hypothermic low-flow perfusion with cryoprecipitated plasma and normothermic perfusion with dilute blood. In a subsequent normothermic dilute blood test perfusion, glucose production was found to correlate with the perfusion characteristics of the liver. Storage with cryoprecipitated plasma resulted in organs which demonstrated the most satisfactory perfusion, and which yielded the highest glucose levels. The values of these parameters were similar to those seen in unstored livers. Clearance of bromsulphthalein by the livers stored in different ways was not a satisfactory indicator of damage produced by the storage.