Usefulness of Motor Evoked Potential Measurement and Analysis of Risk Factors for Spinal Cord Ischaemia from 300 Cases of Thoracic Endovascular Aortic Repair.

OBJECTIVE: This study investigated the usefulness of motor evoked potentials (MEPs) for intra-operative monitoring to detect the risk of spinal cord ischaemia (SCI) during thoracic endovascular aortic repair (TEVAR). Risk factors for SCI in TEVAR were also analysed. METHODS: Among 330 TEVARs performed from February 2009 to October 2018, 300 patients underwent intra-operative MEP monitoring. SCI risk groups were extracted based on MEP amplitude changes using a cutoff value of 50%. When the amplitude decreased to < 50% of the pre-operative value, intra-operative mean arterial pressure (MAP) was increased by about 20 mmHg using noradrenaline, whereas MAP was usually controlled to about 80 mmHg during surgery. Other efforts were also made to increase MEP amplitude by increasing cardiac output, correcting anaemia, and finishing the surgery promptly. Based on MEP amplitude data, SCI risk groups were extracted and risk factors for SCI in TEVAR were analysed. RESULTS: A total of 283 non-SCI risk patients and 17 SCI risk patients by MEP monitoring were extracted; only 1.0% developed immediate paraplegia and none developed delayed paraplegia. Bivariable analysis showed significant differences in chronic kidney disease, haemodialysis, artery of Adamkiewicz closure, and stent graft (SG) covered length ≥ 8 vertebral bodies. Logistic regression analysis showed hyperlipidaemia (odds ratio [OR] 3.55, 95% confidence interval [CI] 1.08 - 11.67; p = .037), SG covered length ≥ 8 vertebral bodies (OR 1.35, 95% CI 1.02 - 1.78; p = .034), and haemodialysis (OR 27.78, 95% CI 6.02 - 128.22; p < .001) were the most influential risk factors for SCI in TEVAR. CONCLUSION: MEPs might be a useful monitoring tool to predict SCI in TEVAR. In addition, hyperlipidaemia, SG covered length ≥ 8 vertebral bodies, and haemodialysis represent key risk factors for SCI during TEVAR.

Prognostic value of brachial-ankle pulse wave velocity changes post-transcatheter aortic valve replacement.

Transcatheter aortic valve replacement (TAVR) offers a solution, especially for high-risk aortic stenosis (AS) patients. However, patient outcomes post-TAVR show variability, highlighting the need for reliable prognostic indicators. Brachial-ankle pulse wave velocity (baPWV), a measure of arterial stiffness, may predict outcomes post-TAVR. This study aims to explore baPWV's prognostic value in relation to all-cause mortality post-TAVR. This study prospectively enrolled 212 severe AS patients undergoing TAVR between September 2015 and December 2021, focusing on pre- and post-TAVR baPWV measurements to explore associations with all-cause mortality. Of the 212 patients (119 females, 93 males, mean age 85 years), post-TAVR baPWV increased significantly from 1589 ± 376 to 2010 ± 521 cm/s (p < 0.001). Aortic valve (AV) peak velocity and mean pressure gradient decreased, while AV area increased, indicating procedural success. Despite this, 88% of patients experienced an increase in baPWV, with higher pre-procedure AV peak velocity and mean pressure gradient identified as predictors of increased baPWV post-TAVR. Over 23 months, 29 patients (14%) reached the primary endpoint of all-cause mortality. Notably, changes in baPWV, rather than baseline values, were significantly associated with event-free survival (HR: 0.64 per 1SD increase, p = 0.009). The study highlights the prognostic value of baPWV changes post-TAVR in predicting patient outcomes. Elevated baPWV post-TAVR may reflect a beneficial adaptation to altered hemodynamics, suggesting the need for individualized patient evaluation and the integration of baPWV measurements into clinical practice for improved post-TAVR management.

[Rupture of Artificial Blood Vessel by a Sternal Wire:Report of a Case].

Formation of a pseudoaneurysm due to blood leakage from the anastomotic site of the vascular graft in large-diameter vessels is often seen, but formation of a pseudoaneurysm from the non-anastomotic site is extremely rare. A 68-year-old woman presented with a history of double valve replacement for combined valvular disease at 37 years old and hemiarch replacement for thoracic aortic dilatation at 65 years old. She visited the emergency room with a 2-week history of chest pain. Contrast-enhanced computed tomography (CT) revealed a 5-cm-diameter pseudoaneurysm and extravasation from the ascending aorta, so emergency surgery was performed. Around the ascending aorta area, we confirmed bleeding from a 5-mm dehiscence in the non-anastomotic part of the graft prosthesis, so hemostasis was performed with a cross-stitch mattress suture over a felt strip. Initially, the cause of the pseudoaneurysm was unknown, but re-examination of CT images from after the previous hemiarch replacement confirmed contact between the sternal wire and graft prosthesis. The wire was thus considered to have caused damage and bleeding. The patient was discharged from the hospital with a good postoperative course and is being followed-up in the outpatient department.

[Dynamics Evaluation of Remodeling Operation Using 4-dimentional Computed Tomography].

OBJECTIVES: The extensibility of the aortic root after the remodeling procedure was evaluated using 4-dimentional computed tomography( 4D-CT). PATIENTS AND METHODS: Seventeen patients( 13 males/4 females), mean age 52 years, who had undergone the remodeling procedure in the last 3 years were included. To understand the dynamics of the aortic root after reconstruction, the R-R interval on the electrocardiogram was divided into 10 equal parts, and the percentage change in area of the basal ring/Valsalva sinus/sino-tubular junction (STJ) level was calculated to evaluate the extensibility of the aortic root. For the basal ring, changes in ellipticity and circumference were also compared. RESULTS: Basal ring, Valsalva sinus, and STJ area changes with cardiac cycle were similar to those in the control group. Basal ring showed a regular circle in systole and an oval in diastole, and its circumference was enlarged in systole. CONCLUSIONS: The use of 4D-CT made it possible to evaluate the extensibility of the aortic root after remodeling procedure. In particular, the mobility of the basal ring is large, suggesting that it guarantees the physiological opening and closing of the valve and contributes to its durability.

Early Clinical Outcomes of the Active Seal Technology of the AFX Endovascular Aortic Aneurysm System With the VELA Cuff for Patients With a Conical Proximal Neck.

PURPOSE: To evaluate the efficacy of the Active Seal technology employed in the AFX endovascular aortic aneurysm system (AFX), during endovascular aneurysm repair (EVAR) in patients with abdominal aortic aneurysms (AAAs) having a conical proximal neck. MATERIALS AND METHODS: A retrospective analysis of the EVAR for AAA with a conical proximal neck using the AFX was performed at 17 Japanese hospitals between January 2016 and August 2020. The conical proximal neck was defined as a cone-shaped proximal neck, with more than 10% diameter increase within a 15 mm length at the proximal landing zone. All anatomical analyses were performed in the core laboratory, and cases with parallel walls within the proximal neck adequate for the landing zone were excluded from the study. RESULTS: This study included 53 patients, but only 39 patients (mean age, 76.6 ± 6.7 years; 87.0% males; mean aneurysm diameter, 52.0 ± 8.0 mm) were analyzed after being characterized as having a pure conical neck by the core laboratory. The mean proximal neck diameters at the lower renal artery and proximal edge of the aneurysm were 20.0 ± 2.9 mm and 27.5 ± 4.9 mm, respectively. The mean proximal neck length was 21.5 ± 6.0 mm. Instructions for use violations other than the conical neck were observed in 15 patients (38.5%). The VELA cuff was used in all cases; however, additional proximal cuff was required in 9 more cases (23.1%). The Active Seal technology was able to significantly extend the proximal sealing zone from 21.5 ± 6.0 to 26.0 ± 12.2 mm (p = .047). Thirty-six patients completed the 12-month follow-up (one patient was lost to follow-up, and 2 patients died from causes unrelated to the aneurysm), and there were no type-1a and 3 endoleaks with only one reintervention (2.6%) related to type 1b endoleak in the 12-month period. Furthermore, there was no significant enlargement of the proximal neck diameter at 12 months (at 1 month: 20.6 ± 3.4 mm and at 12 months: 21.3 ± 3.8 mm; p = .420). CONCLUSION: The Active Seal technology of the AFX significantly extended the proximal seal zone and no type-1a endoleak and proximal neck dilation was observed in patients with conical proximal neck at 12 months.

[Pulmonary Artery Transection in Surgery for Coronary Artery Fistula].

Coronary artery fistula is a rare abnormality in the communication between a coronary artery and any of the cardiac chambers or major vessels. At present, there is no standard surgical treatment and the most appropriate method is selected on a case-by-case basis. We report one case of coronary artery fistulae in which pulmonary artery transection was required around the left main trunk (LMT). A 62-year-old man who had coronary artery fistulae with an aneurysm which increased from 12 mm to 16 mm in a two-year span. The fistula was located adjacent to the LMT. A complete aneurysm excision under cardiopulmonary bypass was performed, which required pulmonary artery transection. No postoperative complications occurred. Postoperative coronary computed tomography scan showed intact coronary arteries and complete aneurysm removal.

Successful Endovascular Repair of a Kommerell's Diverticulum and a Right-Sided Aortic Arch.

BACKGROUND: A 57-year-old woman was diagnosed with Kommerell's diverticulum in the setting of a right aortic arch on computed tomography. CASE REPORT: Although asymptomatic, the maximum diameter of the aneurysm was 55 mm; thus, she underwent surgery to prevent rupture of the aneurysm. A bypass was constructed from the left common carotid artery to the left subclavian artery. A stent-graft was deployed from the distal right subclavian artery, and coil embolization of the diverticulum was performed via the left subclavian artery. She was discharged after 12 days of surgery. The postoperative four-month follow up showed a smaller aneurysm. CONCLUSION: Thoracic endovascular aortic repair is feasible and effective for Kommerell's diverticulum.

Retrograde Type A Aortic Dissection after Thoracic Endovascular Aortic Repair for Type B Dissection.

BACKGROUND: A 64-year-old woman presented with dilatation of the distal aortic arch secondary to chronic type B aortic dissection. CASE REPORT: The patient underwent fenestrated thoracic endovascular aortic repair (TEVAR) for closure of the entry site, and reconstruction of the left subclavian artery with a covered stent. On the 40th postoperative day, a retrograde type A aortic dissection (RTAD) was observed on computed tomography and she underwent emergency surgery. The entry tear, related to the proximal bare metal stent, was located in front of the aortic arch. A partial aortic arch replacement was performed. CONCLUSION: Consideration of the risk factors of RTAD is important when performing TEVAR.

[Endovascular Repair of Infected Thoracic Aortic Aneurysm whose Shape Changed during Treatment of Infection].

We report a successful case of infected thoracic aortic aneurysm treated by endovascular repair. An 82-year-old woman, presenting with intermittent back pain and low-grade fever, was transferred with the diagnosis of infected thoracic aortic aneurysm. High inflammatory reaction and a thickened aortic wall around the aneurysm confirmed the diagnosis. We performed infection control first because enhanced computed tomography (CT) scanning revealed aneurysm was a low-density mass, which denied aortic pseudoaneurysm or rupture. After administration of broad-spectrum antibiotics, low-grade fever was relieved and inflammatory reactions were decreased. CT performed on the 11th hospital day showed the low-density mass was decreased in size. However, CT performed on the 35th hospital day revealed penetrating atherosclerotic ulcer( PAU) into the low-density mass, which was consistent with saccular aortic aneurysm. The patient underwent thoracic endovascular aortic repair( TEVAR). Postoperative course was uneventful and she was discharged on 22nd postoperative day. Oral administration of antibiotics was continued for 6 months after discharge. Eight months after TEVAR, CT revealed disappearance of the aneurysm. The patient showed no recurrence of infection at 5 years of follow-up.

Direct visualization of postoperative aortobronchial fistula on computed tomography.

BACKGROUND: Postoperative aortobronchial fistula (ABF) is a rare complication that can occur in 0.3%-5.0% of patients over an extended period of time after thoracic aortic surgery. Direct visualization of the fistula via imaging is rare. AIM: To investigate the relationship between computed tomography (CT) findings and the clinical signs/symptoms of ABF after thoracic aortic surgery. METHODS: Six patients (mean age 71 years, including 4 men and 2 women) with suspected ABF on CT (air around the graft) at our hospital were included in this retrospective study between January 2004 and September 2022. Chest CT findings included direct confirmation of ABF, peri-graft fluid, ring enhancement, dirty fat sign, atelectasis, pulmonary hemorrhage, and bronchodilation, and the clinical course were retrospectively reviewed. The proportion of each type of CT finding was calculated. RESULTS: ABF detection after surgery was found to have a mean and median of 14 and 13 years, respectively. Initial signs and symptoms were asymptomatic in 4 patients, bloody sputum was found in 1 patient, and fever was present in 1 patient. The complications of ABF included graft infection in 2 patients and graft infection with hemoptysis in 2 patients. Of the 6 patients, 3 survived, 2 died, and 1 was lost to follow-up. The locations of the ABFs were as follows: 1 in the ascending aorta; 1 in the aortic arch; 2 in the aortic arch leading to the descending aorta; and 2 in the descending aorta. ABFs were directly confirmed by CT in 4/6 (67%) patients. Peri-graft dirty fat (4/6, 67%) and peri-graft ring enhancement (3/6, 50%) were associated with graft infection, endoleaks and pseudoaneurysms were associated with hemoptysis (2/6, 33%). CONCLUSION: Asymptomatic ABF after thoracic aortic surgery can be confirmed on chest CT. CT is useful for the diagnosis of ABF and its complications.

Three Arterial Ruptures in a Patient with Neurofibromatosis Type 1.

Neurofibromatosis type 1 (NF-1) is a rare disease known to cause vascular fragility. A case of a 59-year-old man with NF who had ruptures in three different arteries within a month is presented. The first rupture occurred in the right renal artery and was treated using a stent graft and embolization coils. The second and third ruptures occurred in an artery that had been compressed by a hematoma formed during the first bleed; both were embolized. In patients with NF-1, blood vessel fragility must be considered in treatment selection, especially when performing surgery or other invasive procedures near the great vessels.

Mitral valve perforation during transcatheter aortic valve replacement.

An 86-year-old female with severe aortic valve stenosis underwent transcatheter aortic valve replacement. A balloon-expandable valve was used, guided by a double-stiff guidewire that successfully straightened the aorta. During valve placement, the balloon shifted. After placement of the prosthetic valve, intraoperative transesophageal echocardiography revealed severe mitral regurgitation from the anterior mitral leaflet. Open conversion was performed immediately. A 5-mm hole was identified in the anterior leaflet, and direct closure was chosen for mitral valve repair. While transcatheter aortic valve replacement has gained popularity for patients with severe aortic stenosis and high operative risk, reports of mitral valve perforation are rare.

Survival and cause of death after aortic arch aneurysm repair.

BACKGROUND: This study aimed to identify differences in prognosis, causes of death, and outcomes between open and endovascular repair for aortic arch aneurysms. METHODS: We retrospectively analyzed the survival status and causes of death determined from the medical records of 124 consecutive elderly patients (age>70 years) with aortic arch aneurysms that were treated between 2010 and 2018 at our hospital. Forty patients (male, N.=30; mean age, 76 years) underwent open repair and 84 (male, N.=68; mean age, 78 years) underwent endovascular repair. RESULTS: Early postoperative complications (10.0% vs. 6.3%; P=0.4) and rates of in-hospital death (2.5% vs. 6.3%; P=0.2) did not significantly differ between open and endovascular repair. Cumulative long-term and event free survival rates at eight years were similar in both groups (78.7% vs. 66.3%, P=0.1 and 66.6% vs. 58.4%; P=0.4, respectively). The causes of death at follow-up after endovascular repair comprised malignancies in 11 (52.4%) patients and cardiopulmonary and cerebral events unrelated to aortic aneurysms in 10 (47.6%). CONCLUSIONS: Early and late outcomes did not statistically differ after both procedures. However, the prevalence of cancer-related death occurring late after arch repair was significantly higher after endovascular repair. The most important observation from this series was that significantly more patients died of malignant disease during follow-up after endovascular repair than open repair.

A three-decade experience of radical open endvenectomy with pericardial patch graft for correction of Budd-Chiari syndrome.

BACKGROUND: We previously reported the value of our operative procedure for Budd-Chiari syndrome (BCS) that comprised reconstruction of the occluded or severely stenosed inferior vena cava (IVC) using an autologous pericardium patch and reopening as many occluded hepatic veins as possible. Here, we present the long-term durability and efficacy of the autologous pericardium patch for reconstruction of the IVC in BCS. METHODS: We retrospectively analyzed a series of 53 consecutive patients (mean age, 48.4 +/- 12.8 years; range, 24-76 years; 34 men) who underwent surgical treatment for BCS at our institution from 1979 to 2008. Patency of the IVC and hepatic veins was examined by venography at discharge. Patients attended an outpatient clinic every 1 or 2 months for follow-up. The reconstructed IVC was evaluated by enhanced computed tomography every 1 or 2 years. RESULTS: Two in-hospital (operative mortality, 3.7%) and 15 late deaths occurred. During a mean follow-up of 7.6 +/- 6.5 years (range, 0.08-24.1 years), the reconstructed IVC became totally obstructed in three patients, of whom two underwent reoperation, and severely stenosed in two patients, who required percutaneous transvenous balloon venoplasty (PTV). The 5- and 10-year patency rates without reoperation or PTV for the reconstructed IVC were 90.5% and 84.3%, respectively. The cumulative 5- and 10-year survival rates were 89.8% and 70.7%, respectively. CONCLUSION: The autologous pericardium patch is effective and durable for reconstructing a diseased IVC in BCS.

Infected thoracoabdominal aortic aneurysms including the major abdominal branches in 4 cases.

We present four cases of infected thoracoabdominal aortic aneurysm (TAAA), including abdominal branches that underwent surgical repair. The mean age of patients at the time of operation was 61+/-18 (range: 39-83) years. The extent of the aneurysm was Crawford type III in 1 case and type IV in the other 3. They all underwent an emergency or urgent operation, which consisted of a debridement of the infected tissue, in situ four-branched Dacron graft replacement, and iodine gauze packing for 48 h followed by omental wrapping of the graft. To prevent postoperative spinal ischemia, intercostal and lumbar arteries were reimplanted under motor-evoked potential (1.25 pairs per patient). There was one (25%) hospital death, but postoperative graft infection did not occur in these present cases during a mean follow-up period of 15+/-43 (1-96) months. Antibiotics were administered intravenously for 8 weeks after the operation, then continued orally for a lifelong period. Postoperatively, paraplegia occurred in one (25%) patient. Our strategy for infected TAAA including major abdominal branches may prevent postoperative graft infection.

Direct reopening of the occluded hepatic veins of Budd-Chiari syndrome: verification of our operative method by the perioperative course of esophageal varices.

OBJECTIVE: A total of 69 patients with Budd-Chiari syndrome (BCS) were operated by direct approach under cardiopulmonary bypass (CPB). To assess the operative procedure, the perioperative course of esophageal varices (EVs) was evaluated. PATIENTS AND METHODS: Of the 69 patients, 59 (22 females) were enrolled in this study because they had complete follow-up data for endoscopic evaluation of EVs. Their mean age was 46.3 ± 13.0 years (range 21-73.3 years). EVs were found in 52 patients. Under partial cardiopulmonary bypass, the inferior vena cava (IVC) was incised. The obstruction of the IVC was excised, and the occluded hepatic veins were reopened. The incised IVC was reconstructed with an auto-pericardial patch. RESULTS: Postoperatively, the repaired IVC was patent in all patients. The average number of patent hepatic veins (HVs) increased from 1.23 ± 0.81 to 2.21 ± 0.97/patient. The pressure gradient between the IVC and right atrium (RA) decreased from 12.4 ± 5.52 to 4.46 ± 3.21 mmHg. The indocyanine green clearance test (ICG) at 15 min decreased from 31.57 ± 17.44 to 22.27 ± 15.23%. EVs had disappeared in 13 patients at discharge and in 6 patients at late postoperative follow-up. CONCLUSION: Our operative procedure for BCS is useful for decreasing portal pressure, which is reflected by disappearance of EVs. Therefore, the high risk of EV rupture could be avoided by reopening the occluded HVs.

Transapical aortic perfusion using a deep hypothermic procedure to prevent dissecting lung injury during re-do thoracoabdominal aortic aneurysm surgery.

BACKGROUND: Avoiding various complications is a challenge during re-do thoracoabdominal aneurysm surgery. CASE PRESENTATION: A 56-year-old man had undergone surgery for type I aortic dissection four times. The residual thoracoabdominal aortic aneurysm that had severe adhesions to lung parenchyma was resected. Since the proximal anastomotic site was buried in lung parenchyma, deep hypothermia was essential to avoid lung dissection and to protect the spinal cord during the proximal anastomosis. The deep hypothermia was induced with bilateral infusion of cardiopulmonary bypass by femoral artery cannulation for the lower body and by transapical cannulation for the upper body because of easy access. There was no hemorrhagic tendency after deep hypothermic bypass. The patient was discharged uneventfully. CONCLUSIONS: For upper body perfusion, transapical aortic cannulation was a simple and effective procedure during left thoracotomy.

Directly measuring spinal cord blood flow and spinal cord perfusion pressure via the collateral network: correlations with changes in systemic blood pressure.

OBJECTIVE: During thoracoabdominal surgery in which segmental arteries are sacrificed over a large area, blood supply routes from collateral networks have received attention as a means of avoiding spinal cord injury. The aim of this study was to investigate spinal cord blood supply through a collateral network by directly measuring spinal cord blood flow and spinal cord perfusion pressure experimentally. METHODS: In beagle dogs (n = 8), the thoracoabdominal aorta and segmental arteries L1-L7 were exposed, and a temporary bypass was created for distal perfusion. Next, a laser blood flow meter was placed on the spinal dura mater in the L5 region to measure the spinal cord blood flow. The following were measured simultaneously when the direct blood supply from segmental arteries L2-L7 to the spinal cord was stopped: mean systemic blood pressure, spinal cord perfusion pressure (blood pressure within the aortic clamp site), and spinal cord blood flow supplied via the collateral network. These variables were then investigated for evidence of correlations. RESULTS: Positive correlations were observed between mean systemic blood pressure and spinal cord blood flow during interruption of segmental artery flow both with (r = 0.844, P < .01) and without (r = 0.834, P < .01) distal aortic perfusion. In addition, we observed significant correlations between spinal cord perfusion pressure and spinal cord blood flow with and without distal perfusion (r = 0.803, P < .001 and r = 0.832, P < .01, respectively), and between mean systemic blood pressure and spinal cord perfusion pressure with and without distal perfusion (r = 0.898, P < .001 and r = 0.837, P < .001, respectively). The spinal cord was perfused from the collateral network from outside the interrupted segmental arteries, and high systemic blood pressure (∼1.33-fold higher) was needed to obtain the preclamping spinal cord blood flow, whereas 1.68-fold higher systemic blood pressure was needed when distal perfusion was halted. CONCLUSIONS: Spinal cord blood flow is positively correlated with mean systemic blood pressure and spinal cord perfusion pressure under spinal cord ischemia caused by clamping a wide range of segmental arteries. In open and endovascular thoracic and thoracoabdominal surgery, elevating mean systemic blood pressure is a simple and effective means of increasing spinal cord blood flow, and measuring spinal cord perfusion pressure seems to be useful for monitoring perioperative spinal cord blood flow.

Selective visceral perfusion during thoracoabdominal aortic aneurysm repair.

PURPOSE: To evaluate the effectiveness of selective visceral perfusion during repair of an thoracoabdominal aortic aneurysm (TAAA), we compared the postoperative renal and hepatic functions (blood urea nitrogen, serum creatinine, total bilirubin, glutamate pyruvate transaminase) between the two groups with and without perfusion. PATIENTS AND METHODS: We operated on 52 patients with TAAA. Among them, the visceral vessels were reconstructed in 22 patients with selective visceral perfusion and in 12 patients without perfusion. The average selective perfusion time was 49.5+/-25.5 min. in the celiac and superior mesenteric arteries and 32.8+/-18.8 min. in the renal arteries. The average perfusion flow rate per each visceral vessel was 155.4+/-97.4 ml/min. RESULTS: There were five hospital deaths. There was no significant difference between the groups in the postoperative value of four factors. The selective perfusion time for vessel reconstruction in the selective visceral perfusion group was significantly longer than the arterial clamp time for vessel reconstruction in the non-perfusion group (49.5+/-25.5 min. vs. 25.6+/-13.4 min.). CONCLUSION: Our selective visceral perfusion method is not only beneficial for organ protection, but also provides us with the necessary time to reimplant the visceral as well as intercostal or lumbar arteries.

Determination of oxidative stress and cardiac dysfunction after ischemia/reperfusion injury in isolated rat hearts.

BACKGROUND: Oxidative stress due to reactive oxygen species (ROS) is thought to play a considerable role in ischemia/reperfusion (I/R) injury that impairs cardiac function. The present study examined oxidative damage in I/R injury and investigated the correlation between oxidative stress and impaired cardiac function after I/R injury of the isolated rat heart. METHODS: Hearts isolated from male Sprague-Dawley rats were mounted on a Langendorff apparatus. Hearts arrested using St. Thomas cardioplegic solution and then they were reperfused. The hearts were divided into three groups depending on the frequency (0-2) of I/R. After I/R, left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP), positive maximum left ventricular developing pressure (max LV dP/dt) and coronary flow (CF) were measured. Creatine kinase (CK) was measured in the coronary effluent and 8-hydroxy-2'deoxyguanosine (8OHdG), a marker of oxidative DNA damage, was measured. Adenosine triphosphate (ATP) was measured from frozen myocardial tissue after experiment. RESULTS: We immunohistochemically demonstrated and quantified levels of 8-OHdG after I/R injury of the heart. The frequency of I/R injury and cardiac dysfunction significantly and negatively correlated. The ATP products were similar among the three groups. The incidence of ventricular arrhythmias was not by affected oxidative stress. CONCLUSION: The frequency of I/R injury had more of an effect on 8-OHdG products and on impaired cardiac function with less myocyte damage than ischemic duration within 30 minutes of ischemia.