Surgical Experience of Ascending Aorta and Aortic Valve Replacement in Patient with Calcified Aorta

BACKGROUND: The conventional method of aortic cross-clamping is very difficult and increases the risk of cerebral infarct due to embolism of the calcified aorta in these patients. Accordingly, we analyzed our experience with 11 cases of ascending aorta and aortic valve replacement with hypothermic circulatory arrest. MATERIALS AND METHODS: From January 2002 to December 2009, 11 patients had ascending aorta and aortic valve replacement with hypothermic arrest at our hospital. We performed a retrospective study. RESULTS: There were 5 males and 6 females, with a mean age of 68 years (range, 44 to 82 years). Eight patients had aortic stenosis, and 3 patients had aortic regurgitation. An aortic cannula was inserted into the right axillary artery in 3 patients and ascending aorta in 6 patients. Two patients with aortic regurgitation had a remote access perfusion catheter inserted though the right femoral artery. The mean cardiopulmonary bypass time was 180 minutes (range, 110 to 306 minutes) and mean hypothermic circulatory arrest time was 30 minutes (range, 20 to 48 minutes). The mean rectal temperature during hypothermic circulatory arrest was 21degrees C (range, 19degrees C to 23degrees C). No patient had any new onset of cerebral infarct or cardiovascular accident after surgery. There was no hospital mortality. Early complications occurred in 1 patient who needed reoperation due to postoperative bleeding. Late complications occurred in 1 patient who underwent a Bentall operation due to prosthetic valve endocarditis. The mean follow-up duration was 32 months (range, 1 month to 8 years) and 1 patient died suddenly due to unknown causes after 5 years. CONCLUSION: Patients with a calcified aorta can be safely treated with a technique based on aorta and aortic valve replacement under hypothermic circulatory arrest.

Surgical Correction of Total Anomalous Pulmonary Venous Connection without Total Circulatory Arrest / 대한흉부외과학회지

BACKGROUND: Circulatory arrest under deep hypothermia is an important auxiliary means for surgical correction of total anomalous pulmonary venous connection (TAPVC). However, cardiac operations under deep hypothermic circulatory arrest are associated with the risk of post-arrest neurologic abnormalities. The purpose of this study is to evaluate the results of the surgical correction of total anomalous pulmonary venous connection without the total circulatory arrest. MATERIAL AND METHOD: Between April 2000 and October 2004, hospital records of 10 patients were reviewed retrospectively. RESULT: The locations for abnormal anatomical connections were supracardiac in 7 cases, cardiac in 1 case, and infracardiac in 2 cases. The mean cardiopulmonary bypass time and aorta cross clamp time were 116.8+/-40.7 and 69.5+/-24.1 minutes. There was no surgical mortality. Postoperative complications were post-repair pulmonary venous stenosis in 1 case, pneumonia in 1, pneumothorax in 1, wound infection in 1, and diaphragmatic paralysis in 1. All patients without pulmonary venous stenosis were in NYHA class I at mean follow-up of 16.6 months (3~49 months) CONCLUSION: We could obtain excellent results by repair without the total circulatory arrest for total anomalous pulmonary venous connection.

The Thracoabdominal Aortic Replacement Using Deep Hypothermic Circulatory Arrest Technique / 대한흉부외과학회지

BACKGROUND: Thoracoabdominal aortic replacement is an extensive operation that opens both the pleural cavity and abdominal cavity, which has high mortality and morbidity rate. The authors have reported 9 cases of the thoracoabdominal aortic replacement in 2001. Since 2003 we have applied the deep hypothermic circulatory arrest to the Crawford type I and II thoracoabdominal aortic replacement. Therefore, we analysed the effect of the changes in operative techniques. MATERIAL AND METHOD: Between 1996 and 2005, we have performed 20 cases of thoracoabdominal aortic replacement. The underlying diseases were 8 cases of atherosclerotic aneurysm with 4 cases of ruptured aneurysm and 12 cases of aortic dissection with 10 cases of a previous operations. According to Crawford classification, there were 2 cases of type I, 7 cases of type II, 1 case of type III, 7 cases of type IV, and 3 cases of type V. We compaired the results of the patients who underwent thoracoabdmoninal replacement before 2001 which already has been reported and after then. RESULT: Before 2001 we have performed 9 cases of thoracoabdominal replacement and 5 patients were died of the operation. All three patients with type I and II were died. There was no case of thoracoabdominal replacement between 2001 and 2002, but after 2003 we have performed 11 cases of thoracoabdominal replacement which involved 1 case of type I, 5 cases of type II, 1 case of type III, 2 cases of type IV and 2 cases of type V. There was no mortality and no fetal complications. CONCLUSION: The deep hypothermic circulatory arrest is a safe method of extended thoracoabdominal aortic replacement.

Analysis of Neurological Complications on Antegrade Versus Retrograde Cerebral Perfusion in the Surgical Treatment of Aortic Dissection / 대한흉부외과학회지

BACKGROUND: In the surgical treatment of aortic dissection, aortic arch replacement under total circulatory arrest is often performed after careful inspection to determine the severity of disease progression. Under circulatory arrest, antegrade or retrograde cerebral perfusion is required for brain protection. Recently, antegrade cerebral perfusion has been used more, because of the limitation of retrograde cerebral perfusion. This study is to compare these two methods especially in the respect to neurological complications. MATERIAL AND METHOD: Forty patients with aortic dissection involving aortic arch from May 2000 to May 2004 were enrolled in this study, and the methods of operation, clinical recovery, and neurological complications were retrospectively reviewed. RESULT: In the ACP (antegrade cerebral perfusion) group, axillary artery cannulation was performed in 10 out of 15 cases. In the RCP (retrograde cerebral perfusion) group, femoral artery Cannulation was performed in 24 out of 25 cases. The average esophageal and rectal temperature under total circulatory arrest was 17.2oC and 22.8oC in the group A, and 16.0oC and 19.7oC in the group B, respectively. Higher temperature in the ACP group may have brought the shorter operation and cardiopulmonary bypass time. However, the length of period for postoperative clinical recovery and admission duration did not show any statistically significant differences. Eleven out of the total 15 cases in the ACP group and thirteen out of the total 25 cases in the RCP group showed neurological complication but did not show statistically significant difference. In each group, there were 5 cases with permanent neurological complications. All 5 cases in the ACP group showed some improvements that enabled routine exercise. However all 5 cases in RCP group did not show significant improvements. CONCLUSION: The Antegrade cerebral perfusion, which maintains orthordromic circulation, brings moderate degree of hypothermia and, therefore, shortens the operation time and cardiopulmonary bypass time. We concluded that Antegrade cerebral perfusion is safe and can be used widely under total circulatory arrest.

Norwood Procedure on Beating Heart / 대한흉부외과학회지

Modified Norwood procedure with maintaining cardiac beat was done in a 30-day-old neonate. Procedure was done with regional perfusion of innominate and coronary artery. Postoperative course was uneventful. Second-stage operation (bi-directional cavopulmonary shunt) was done 4 months later. The diameter of ascending aorta was more than 5 mm, Norwood procedure can be done in beating hearts.

Repair of Acute Aortic Arch Dissection with Hypothermic Circulatory Arrest and Retrograde Cerebral Perfusion / 대한흉부외과학회지

BACKGROUND: Acute thoracic aortic dissections involving the aortic arch differ in diagnosis, surgical procedures, and operative results compared to those that do not involve the aortic arch. In general cerebral perfusion under deep hypothermic circulatory arrest (HCA) is performed during the repair of the aortic arch dissection. Here, we report our surgical results of the aortic arch dissection repair using retrograde cerebral perfusion (RCP) and its safety. MATERIAL AND METHOD: Between January 1996 and June 2002, 22 consecutive patients with aortic arch dissection underwent aortic arch repair. In 20 of them RCP was performed under HCA. RCP was done through superior vena cava in 19 patients and by systemic retrograde venous perfusion in 1, in whom it was difficult to reach the SVC. When the patient's rectal temperature reached 16 to 18oC, systemic circulation was arrested, and the amount of RCP amount was 481.1+/-292.9 ml/min with perfusion pressure of 20~30 mm Hg. RESULT: There were two in-hospital deaths (4.5%) and one late death (9.1%). Mean circulatory arrest time (RCP time) was 54.0+/-13.4 minutes (range, 7 to 145 minutes). RCP time has no correlation with the appearance of consciousness, recovery of orientation, or ventilator weaning time (p=0.35, 0.86, and 0.92, respectively). Ventilator weaning was faster in patients with earlier recovery of consciousness and orientation (r=0.850, r=926; p=0.000, respectively). RCP of more than 70 minutes did not affect the appearance of consciousness, recovery of orientation, ventilator weaning time, exercise time, or hospital stay (p= 0.42, 0.57, 0.60, 0.83, and 0.51, respectively). CONCLUSION: Retrograde cerebral perfusion time under hypothermic circulatory arrest during repair of aortic arch dissection may not affect recovery of orientation, ventilator weaning time, neurologic complications, and postoperative recovery.

The Significance of Electroencephalography in the Hypothermic Circulatory Arrest in Human / 대한흉부외과학회지

BACKGROUND: Hypothermia protects the brain by suppressing the cerebral metabolism and it is performed well enough before the total circulatory arrest(TCA) in the operation of aortic disease. Generally, TCA has been performed depending on the rectal or nasopharyngeal temperatures; however, there is no definite range of optimal temperature for TCA or an objective indicator determining the temperature for safe TCA. In this study, we tried to determine the optimal range of temperature for safe hypothermic circulatory arrest by using the intraoperative electroencephalogram(EEG), and studied the role of EEG as an indicator of optimal hypothermia. MATERIAL AND METHOD: Between March, 1999 and August 31, 2000, 27 patients underwent graft replacement of the part of thoracic aorta using hypothermia and TCA with intraoperative EEG. The rectal and nasopharyngeal temperatures were monitored continuously from the time of anesthetic induction and the EEG was recorded with a ten-channel portable electroencephalography from the time of anesthetic induction to electrocerebral silence(ECS). RESULT: On ECS, the rectal and nasopharyngeal temperatures were not consistent but variable(rectal 11degree C -25degree C, nasopharynx 7.7degree C -23degree C). The correlation between two temperatures was not significant(p=0.171). The cooling time from the start of cardiopulmonary bypass to ECS was also variable(25-127min), but correlated with the body surface area(p=0.027). CONCLUSION: We have found that ECS appeared at various body temperatures, and thus, the use of rectal or nasopharyngeal temperature were not useful in identifying ECS. Conclusively, we can not fully assure cerebral protection during hypothermic circulatory arrest in regards to the body temperatures, and therefore, the intraoperative EEG is one of the necessary methods for determining the range of optimal hypothermia for safe circulatory arrest.

Clinical Application of Compressed Spectral Array During Deep Hypothermia / 대한흉부외과학회지

Profound hypothermia protects cerebral function during total circulatory arrest(TCA) in the surgical treatment of a variety of cardiac and aortic diseases. Despite its importance, there is no ideal technique to monitor the brain injury from ischemia. Since 1994, we have developed compressed spectral array(CSA) of electroencephalography(EEG) and monitored cerebral activity to reduce ischemic injury. The purposes of this study are to analyse the efficacy of CSA and to establish objective criteria to consistently identify the safe level of temperature and arrest time. We studied 6 patients with aortic dissection(AD, n=3) or aortic arch aneurysm(n=3, ruptured in 2). Body temperatures from rectum and esophagus and the EEG were monitored continuously during cooling and rewarming period. TCA with cerebral ischemia was performed in 3 patients and TCA with selective cerebral perfusion was performed in 3 patients. Total ischemic time was 30, 36 and 56 minutes respectively for TCA group and selective perfusion time was 41, 56 and 92 minutes respectively for selective perfusion group. The rectal temperatures for flat EEG were between 16.1 and 22.1 degrees C (mean:18.4+/-2.0); the esophageal temperatures between 12.7 and 16.4 degrees C(mean : 14.7+/-1.6). The temperatures at which EEG reappeared 5~15.4 degrees C for esophagus. There was no neurological deficit and no surgical mortality in this series. In summary, the electrical cerebral activity reappeared within 23 minutes at the temperature less than 16degrees C for rectum. It seemed that 15 degrees C of esophageal temperature was not safe for 30 minutes of TCA and continuous monitoring the EEG with CSA to identify the electrocerebral silence was useful.

Early Results in Surgical Treatment of Thoracic Aortic Aneurysm / 대한흉부외과학회지

This study represents an attempt to present an analysis of early surgical results in 15 cases of aortic surgery conducted at Chonnam University Hospital between February 1994 to August 1995. The subject, 9 males and 6 females, ranged in age from 32 to 73 years with a mean age of 55.07+/-11.76 years. The patients were treated for dissecting aortic aneurysm in nine, atherosclerotic aneurysm in 4, and traumatic aortic aneurysm in two. There were 9 cases of median sternotomy, 4 cases of posterolateral thoracotomy, and 2 cases of thoracoabdominal incision. Graft replacement of ascending aorta and/or partial or total aortic arch were performed in 9 patients, descending aorta and/or thoracoabdominal aorta in 3 and total aorta in 1. Two traumatic aortic aneurysms were closed directly. Associate procedures were resuspension of aortic valve in three patients and elephant trunk procedure, coronary reimplantation and aortic valve replacement in one patient. Nine patients underwent operation for ascending aorta and/or aortic arch with retrograde cerebral perfusion during deep hypothermia and circulatory arrest. Perfusion pressure was maintained below 25 mmHg and the mean duration of circulatory arrest was 56.67+/-29.25 minutes. Three patients underwent graft replacement of desending thoracic and thoracoabdominal aorta during deep hypothermia and circulatory arrest. Three patients died of traumatic bile peritonitis, multioragn failure, and rupture of residual dissecting aortic aneurysm by malignant hypertension. Postoperative complications included reoperation for bleeding in 4 patients, temporary confusion in 3, pulmonary complication in 3, and pericardial effusion in 1.

Steroid Effect on the Brain Protection During Open Heart Surgery Using Hypothermic Circulatory Arrest in the Rabbit Cardiopulmonary bypass Model / 대한흉부외과학회지

INTRODUCTION: The use of rabbits as a cardiopulmonary bypass(CPB) animal model is extremely difficult mainly due to technical problems. On the other hand, deep hypothermic circulatory arrest(CA) is used to facilitate surgical repair in a variety of cardiac diseases. Although steroids are generally known to be effective in the treatment of cerebral edema, the protective effects of steroids on the brain during CA are not conclusively established. Objectives of this study are twofold: the establishment of CPB technique in rabbits and the evaluation of preventive effect of steroid on the development of brain edema during CA. MATERIAL AND METHODS: Fifteen New Zealand white rabbits(average body weight 3.5kg) were divided into three experimental groups; control CA group(n=5), CA with Trendelenberg position group(n=5), and CA with Trendelenberg position + steroid(methylprednisolone 30 mg/kg) administration group(n=5). After anesthetic induction and tracheostomy, a median sternotomy was performed. An aortic cannula(3.3mm) and a venous ncannula(14 Fr) were inserted, respectively in the ascending aorta and the right atrium. The CPB circuit consisted of a roller pump and a bubble oxygenator. Priming volume of the circuit was approximately 450ml with 120~150ml of blood. CPB was initiated at a flow rate of 80~85ml/kg/min. Ten min after the start of CPB, CA was established with duration of 40min at 20 degrees C of rectal temperature. After CA, CPB was restarted with 20min period of rewarming. Ten min after weaning, the animal was sacrificed. One-to-2g portions of the following tissues were rapidly dissected and water contents were examined and compared among groups: brain, cervical spinal cord, kidney, duodenum, lung, heart, liver, spleen, pancreas, stomach. Statistical significances were analyzed by Kruskal-Wallis nonparametric test. RESULTS: CPB with CA was successfully performed in all cases. Flow rate of 60-100 ml/kg/min was able to be maintained throughout CPB. During CPB, no significant metabolic acidosis was detected and aortic pressure ranged between 35-55 mmHg. After weaning from CPB, all hearts resumed normal beating spontaneously. There were no statistically significant differences in the water contents of tissues including brain among the three experimental groups. CONCLUSION: These results indicate (1) CPB can be reliably administered in rabbits if proper technique is used, (2) the effect of steroid on the protection of brain edema related to Trendelenburg position during CA is not established within the scope of this experiment.

Safety of Aprotinin Under Hypothermic Circulatory Arrest / 대한흉부외과학회지

It was reported that use of aprotinin in elderly patients undergoing hypothermic circulatory arrest was associated with an increased risk of renal dysfunction, and myocardial infarction as a result of intravascular coagulation. We reviewed 20 patients who received high-dose aprotinin under deep hypothermic circulatory arrest with(NP group, n=11) or without selective cerebral perfusion(SP group, n=9). The activated clotting time was exceeded 750 seconds in all but 1 patient. After opening aortic arch, retrograde low flow perfusion was maintained through femoral artery to prevent air embolization to the visceral arteries. Four patients among 20 died during hospitalization due to bleeding, coronary artery dissection, pulmonary hemorrhage and multiple cerebral infarction. Postoperatively, cerebrovascular accidents occurred in two patients; one with preoperative carotid artery dissection and the other with unknown multiple cerebral infarction. In conclusion, use of aprotinin in young patients undergoing hypothermic circulatory arrest did not increase the risk of renal dysfunction or intravascular coagulation if ACT during circulatory arrest is maintained to exceed 750 seconds with low-flow perfusion.