Intermittent Circulatory Arrest Research Articles

Can regional cerebral oxygen saturation monitoring during circulatory arrest time predict postoperative neurological dysfunction in patients undergoing surgical pulmonary thromboendarterectomy? Useful index for short- and long-term outcomes.

A hypothermic circulatory arrest is usually used to correct thoracic aorta pathologies. The emergency treatment of acute type A aortic dissection and elective repair of aortic arch pathologies are the most common indications for using hypothermic circulatory arrest. A hypothermic circulatory arrest can also be used for surgical pulmonary thromboendarterectomy in patients with chronic thromboembolic pulmonary hypertension. Intervals with total circulatory arrest offer a clear surgical field for thrombus and emboli removal from the pulmonary artery branches. The price to pay for intermittent circulatory arrest during pulmonary thromboendarterectomy is postoperative neurological dysfunction due to brain hypothermia and hypoperfusion. A noninvasive method for cerebral monitoring during cardiac surgery is real-time regional cerebral oxygen saturation (rSO2 ). Liu et al. report that continuous monitoring of rSO2 during surgical pulmonary thromboendarterectomy may reduce the long cerebral hypoperfusion time and prevent postoperative neurological dysfunction.

A Case Report of Pulmonary Thromboendarterectomy for Chronic Thromboembolism in a Patient with Protein C Deficiency

The patient was a 41-year-old female with chronic thromboembolism. She was admitted to an affiliated hospital with exertional dyspnea, leg swelling, and hemoptysis, and she was treated medically with tissue plasminogen activator and warfarin therapy. When transferred to our hospital, she was oxygen-dependent with severe dyspnea. A pulmonary arteriogram showed occlusion and stenosis of the pulmonary arteries. Cardiac catheterization revealed marked pulmonary hypertension. The lung perfusion scintigram showedmultiple defects in the right and left lungs. Preoperative laboratory data showed a markedly decreased protein C antigen level. Magnetic resonance angiography showed that a myoma uteri compressed the pelvic vein and that she had deep vein occlusion of the left leg. After the administration of an epoprostenol infusion and the insertion of an inferior vena cava filter, she underwent an operation. Under deep hypothermia, the bilateral pulmonary artery was opened and an endarterectomy was performed during intermittent circulatory arrest. After surgery, her pulmonary vascular resistance was in the normal range. Her New York Heart Association functional classification changed from class IV to class I. She has been in good condition for 7 years since the surgery.

慢性血栓塞栓性肺高血圧症における超低体温間歇的循環停止法の成績

慢性血栓塞栓性肺高血圧症における超低体温間歇的循環停止法の成績

Japanese Single-Center Experience of Surgery for Chronic Thromboembolic Pulmonary Hypertension

We review the outcome of surgery for chronic thromboembolic pulmonary hypertension (CTEPH). Between 1995 and 2004, 88 patients underwent surgery for CTEPH. Mean pulmonary artery pressure and pulmonary vascular resistance were 46 mm Hg (range, 23 to 70 mm Hg) and 986 dynes.sec(-1).cm(-5) (298 to 2,231 dynes.sec(-1).cm(-5)). The pulmonary artery lesion was proximally located in 51 patients, subsegmental in 34 patients, and peripheral in 3 patients. Pulmonary endarterectomy was performed using cycles of 15-minute intermittent circulatory arrest followed by 10-minute reperfusion at 16 degrees C to 18 degrees C. The median durations of circulatory arrest, cardiopulmonary bypass, and surgery were 58, 217, and 355 minutes, respectively. Percutaneous extracorporeal membrane oxygenation was used in 8 patients (9.1%) who had difficulty being weaning from cardiopulmonary bypass. Three recent patients for whom this was performed promptly were weaned and survived. There were 7 hospital deaths (8.0%, including 6 30-day deaths) from pulmonary bleeding in 2 patients, residual pulmonary hypertension in 3, rupture of bulla in 1, and empyema in 1. In the 81 survivors, mean pulmonary artery pressure and pulmonary vascular resistance fell significantly after surgery (p < 0.0001, each case). Age more than 60 years was a risk factor for hospital mortality on multivariate analysis. Although distal pulmonary artery disease including subsegmental and peripheral lesions was not a significant risk factor for mortality, it did influence patient recovery: the frequency of percutaneous extracorporeal membrane oxygenation was higher and hemodynamic improvement less pronounced in patients with distal disease. The actuarial survival rate was 90.7% at 3 years and 86.4% at 5 years. None of the patients have suffered recurrence. The event-free rate was 97.1% at 3 years and 93.5% at 5 years. Of the 68 patients surviving for more than 1 year after surgery, 67.6% were successfully weaned from home oxygen therapy and 13.2% required only occasional use of oxygen. Pulmonary endarterectomy can be safely performed with relatively low mortality and favorable prognosis with long-term survival, although it should be performed carefully for patients with distal disease.

Two Cases of Chronic Pulmonary Thromboembolism Saved by Postoperative Use of a Percutaneous Cardiopulmonary Support Device

We performed pulmonary thromboendarterectomy under deep hypothermic intermittent circulatory arrest in 18 patients with chronic pulmonary thromboembolism from August 2001 to January 2004. In some of these cases, reperfusion pulmonary edema prevented a satisfactory improvement in hemodynamic data soon after the surgery. Here we report two cases of chronic pulmonary thromboembolism in which we successfully prevented postoperative persistent pulmonary hypertension and hypoxia caused by severe reperfusion pulmonary edema by the use of a percutaneous cardiopulmonary support device.

Pulmonary thromboendarterectomy for chronic pulmonary thromboembolism in protein C deficiency

Pulmonary thromboendarterectomy was performed on a patient with chronic pulmonary thromboembolism showing thrombophilia. The patient was a 56-year-old female with the above condition complicated by congenital protein C deficiency. She was admitted to our hospital with severe dyspnea accompanied by right ventricular failure. A pulmonary arteriogram showed occlusion and stenosis from lobar to segmental arteries. Cardiac catheterization showed marked pulmonary hypertension. A lung perfusion scintigram revealed multiple defects in the right and left lungs. After the insertion of an inferior vena cava filter, she was operated on. Following a median sternotomy, thromboendarterectomy of the bilateral pulmonary arteries was performed using deep hypothermia and intermittent circulatory arrest. Circulatory arrest was employed in three periods totaling up to 36 minutes. After surgery, she had improvements in pulmonary hypertension and pulmonary vascular resistance. She maintained improved lung functions, and remained in the New York Heart Association functional class I for more than two years and eight months after surgery.

Pulmonary thromboendarterectomy for thromboembolic pulmonary hypertension

Pulmonary artery thromboendarterectomy (PTE) is a surgical procedure that offers the only cure for chronic thromboembolic pulmonary hypertension (TPH), a progressive form of secondary pulmonary hypertension. Current estimates indicate that 1% to 5% of patients who survive a pulmonary embolus will develop chronic TPH with progressively worsening pulmonary hypertension and right-sided heart failure. This bilateral procedure is performed through a sternotomy incision using cardiopulmonary bypass, profound hypothermia, and intermittent circulatory arrest with antegrade cerebral perfusion. As an alternative to lung transplantation, PTE offers patients with chronic TPH an improved quality of life.

Surgical treatment for chronic thromboembolic pulmonary hypertension under profound hypothermia and circulatory arrest in 24 patients.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a serious disease that induces hypoxemia and pulmonary hypertension, eventually leading to respiratory failure and right heart failure. We evaluated the results of surgical treatment in patients undergoing circulatory arrest under profound hypothermia. Between February 1995 and June 1999, 24 cases of CTEPH were surgically treated. The age of patients (11 males and 13 females) ranged from 21 to 71 years (mean 49+/-15 years). Because of hypoxemia, severe pulmonary hypertension (mean pulmonary artery pressure 45+/-7 mmHg ), and low cardiac output, the functional class of these patients was New York Heart Association (NYHA) III or IV. Following a median sternotomy, profound hypothermia was induced using cardiopulmonary bypass, and pulmonary thromboendarterectomy in the bilateral pulmonary arteries was performed under intermittent circulatory arrest. Surgery was performed emergently in four patients. Of these 24 patients, 2 of 20 patients who underwent elective surgery and 3 of 4 patients who underwent emergent surgery died in the hospital. Symptoms of CTEPH markedly improved in 18 patients who survived the surgery. Pulmonary arterial pressure was decreased to 16+/-6 mmHg, and cardiac output was increased. When CTEPH is resistant to medical treatment, surgical treatment is useful. When surgical indications are carefully selected, pulmonary thromboendarterectomy using intermittent circulatory arrest under profound hypothermia is quite effective for treating CTEPH.

Operation for chronic pulmonary thromboembolism accompanied by thrombophilia in 8 patients

Background. Medical therapy for chronic pulmonary thromboembolism is limited, and surgical treatment has become more frequent recently. We have performed pulmonary thromboendarterectomy on 8 patients with chronic pulmonary thromboembolism accompanied by thrombophilia.Methods. The patients were 6 men and 2 women aged 21 to 56 years (mean, 35 years). Five patients had antiphospholipid syndrome, 2 had protein C deficiency, and 1 had congenital antithrombin III deficiency. The preoperative condition was New York Heart Association functional class III in 5 and class IV in 3. Hypoxemia, marked pulmonary hypertension (mean pulmonary artery pressure, 47 ± 6.7 mm Hg), and low cardiac output were observed in all patients. After a median sternotomy, deep hypothermia was induced using a cardiopulmonary bypass, and pulmonary thromboendarterectomy in the bilateral pulmonary arteries was performed under intermittent circulatory arrest.Results. There were no operative deaths. Long-term respiratory management was needed postoperatively by 3 patients. In the remaining 5 patients, no reperfusion injury was observed. The arterial blood oxygen concentration improved, and the mean pulmonary pressure decreased to 16 ± 5.5 mm Hg. The cardiac output also increased, and New York Heart Association functional class improved to I in 4 and II in 4 patients.Conclusions. Pulmonary thromboendarterectomy under deep hypothermic intermittent circulatory arrest was effective for chronic pulmonary thromboembolism accompanied by thrombophilia for which medical treatment is of limited value.

Prolongation of total permissible circulatory arrest duration by deep hypothermic intermittent circulatory arrest

Objective: We determined whether the duration of permissible circulatory arrest could be prolonged by deep hypothermic intermittent circulatory arrest. Methods: Twenty-five beagles were cooled on bypass to 18° C to initiate deep hypothermia that was maintained for 3 hours. Five protocols were then studied: group 1, uninterrupted bypass during hypothermia; group 2, arrest for 40 minutes during hypothermia; group 3, arrest for 60 minutes during hypothermia; group 4, arrest for 80 minutes during hypothermia; and group 5, intermittent circulatory arrest, consisting of six cycles of 20 minutes of arrest followed by 10 minutes of systemic recirculation during hypothermia (total, 120 minutes of arrest). The oxyhemoglobin concentration in the brain was measured with near infrared spectrophotometry. Results: In groups 2, 3, and 4, the oxyhemoglobin concentration in the brain decreased continuously after arrest, finally reaching a plateau after 24.9 ± 1.2 minutes. This finding suggested that the available cerebral oxyhemoglobin was depleted. In contrast, the available cerebral oxyhemoglobin was not depleted during hypothermic intermittent arrest in group 5. The mitochondrial respiratory control index was significantly lower in group 4 than in the other groups ( p < 0.05). However, there were no significant differences in the respiratory control index for groups 1, 2, 3, and 5. Moreover, the formation of brain edema was significantly lower in group 5 than in the other groups ( p < 0.05). Conclusions: These results indicate that deep hypothermic intermittent arrest can increase the duration of total permissible circulatory arrest and will be a useful modality when prolonged arrest is anticipated. (J Thorac Cardiovasc Surg 1998;116:163-70)

Deep hypothermic intermittent circulatory arrest--an adjunct technique for operations on aneurysms involving the aortic arch.

Aneurysms involving the aortic arch were repaired in 12 patients using a technique known as deep hypothermic intermittent circulatory arrest (DHICA). This technique consists of repeated cycles of 20 min of circulatory arrest and 10 min of cerebral and systemic reperfusion. Aneurysms were of the following types: 2 true atherosclerotic aneurysm, 8 aortic dissections, and 2 traumatic aneurysm. There were 2 operative deaths caused by coagulopathy as a result of hepatic failure and difficulty with left ventricular venting. The frequency of circulatory arrest ranged from 2 to 5 cycles, and total circulatory arrest ranged from 20 to 71 min (mean 43.6 min). The lowest tympanic temperature ranged from 17.7 to 19.2 degrees C. No permanent cerebral complications occurred in 10 patients. We believe that this adjunct technique offers excellent results in the surgical treatment of aneurysms involving the aortic arch.

Hypothermic intermittent circulatory arrest for aortic arch replacement

Hypothermic intermittent circulatory arrest for aortic arch replacement

Thromboembolic Obstruction of the Pulmonary Artery Treated by Endarterectomy

Endarterectomy of a totally occluded right pulmonary artery by median sternotomy with cardiopulmonary bypass and intermittent circulatory arrest is described. The nature of the thrombus encountered and brisk backbleeding from the endarterectomized vessels predicted the functional improvement seen in the patient postoperatively. Reperfusion edema, which often complicates pulmonary artery thromboendarterectomy, was not observed. Preoperative assessment, postoperative management, and technical aspects of the operative procedure used in treating patients with thromboembolic obstruction of the pulmonary arteries are discussed.

Surgical Treatment for Chronic Thromboembolic Pulmonary Hypertension Under Profound Hypothermia and Circulatory Arrest in 24 Patients

AbstractBackground: Chronic thromboembolic pulmonary hypertension (CTEPH) is a serious disease that induces hypoxemia and pulmonary hypertension, eventually leading to respiratory failure and right heart failure. We evaluated the results of surgical treatment in patients undergoing circulatory arrest under profound hypothermia. Methods: Between February 1995 and June 1999, 24 cases of CTEPH were surgically treated. The age of patients (11 males and 13 females) ranged from 21 to 71 years (mean 49 ± 15 years). Because of hypoxemia, severe pulmonary hypertension (mean pulmonary artery pressure 45 & 7 mmHg 1, and low cardiac output, the functional class of these patients was New York Heart Association (NYHA) 111 or IV. Following a median sternotomy, profound hypothermia was induced using cardiopulmonary bypass, and pulmonary thromboendarterectomy in the bilateral pulmonary arteries was performed under intermittent circulatory arrest. Surgery was performed emergently in four patients. Results: Of these 24 patients, 2 of 20 patients who underwent elective surgery and 3 of 4 patients who underwent emergent surgery died in the hospital. Symptoms of CTEPH markedly improved in 18 patients who survived the surgery. Pulmonary arterial pressure was decreased to 16 ± 6 mmHg, and cardiac output was increased. Conclusions: When CTEPH is resistant to medical treatment, surgical treatment is useful. When surgical indications are carefully selected, pulmonary thromboendarterectomy using intermittent circulatory arrest under profound hypothermia is quite effective for treating CTEPH.

Surgical management of chronic pulmonary embolism Surgical treatment and late results

Failure of pulmonary emboli to undergo fibrinolytic resolution generates a small but significant patient population progressively disabled by hypoxemia, chronic pulmonary hypertension, and eventual right heart failure. Medical management of these patients has not been effective. In the few patients treated surgically, no clear picture has emerged regarding the most effective surgical approach or the late results. Four male patients with chronic pulmonary embolism were managed operatively. Extrapericardial dissection, cardiopulmonary bypass, deep hypothermia, and intermittent circulatory arrest were utilized to perform pulmonary thromboendarterectomy. All patients, ages 30 to 65 years, had had severe dyspnea with minimal exertion for 1 to 20 years. Angiograms showed 50% to 75% of the pulmonary vasculature to be occluded, with frequent involvement of the segmental arteries. Preoperative pulmonary pressures varied from 60/33 to 74/24 mm Hg. Pulmonary vascular resistance values ranged from 450 to 750 dynes-sec-cm-5. All patients survived the operative procedure. The eldest patient died 3 weeks postoperatively following an acute posteroseptal myocardial infarction. The remaining patients had a 20 to 50 mm Hg decrease in pulmonary systolic pressure with a 50% to 75% reduction in pulmonary vascular resistance. Neither static nor dynamic lung volumes were changed appreciably. Follow-up angiograms in all patients confirmed significant increase in pulmonary perfusion. Each patient had improvement in functional capacity; one is completely asymptomatic. The primary advantage of the surgical approach described is the more complete removal of distally located thrombofibrotic material. The late results suggest that this surgical approach should be considered in the management of patients disabled by chronic pulmonary embolism.