Segmental clamp and distal perfusion technique for reducing myocardial ischemia during coronary onlay grafting on a beating heart.

We present a segmental clamp with distal perfusion technique to reduce myocardial ischemia during onlay grafting, on a beating heart. After a proximal coronary arteriotomy for 2-3 cm, the distal artery is perfused through a cannula, with femoral arterial blood (distal perfusion with external shunt). During proximal and distal coronary snare clamping with distal perfusion, onlay anastomosis is performed, from the heel toward the point of cannula insertion. We then move the proximal clamp to the onlay area and open the graft, to get early proximal coronary reperfusion. The arteriotomy is extended, and this procedure is repeated to achieve complete beating heart onlay anastomosis. We safely performed this procedure on the beating heart off-pump or on-pump in 95 patients with no perioperative myocardial infarction, no intraoperative hemodynamic deterioration, no 30-day mortality. This technique reduces regional myocardial ischemic and secures the safety for onlay grafting on the beating heart.

[Aortic Valve Replacement Concomitant with Right and Left Ventricular Outflow Tract Repair Eight Years after Arterial Switch Operation for Double Outlet Right Ventricle;Report of a Case].

We report a case of successful aortic valve replacement and relief of right and left ventricular outflow tract obstruction 8 years after an arterial switch operation for double outlet right ventricle. Since the surgical access to the ascending aorta was limited because of the anatomical feature and the adhesion after the arterial switch operation, arterial infusion site for cardiopulmonary bypass was secured at the right common carotid artery ahead of the sternal re-entry. After cardiopulmonary bypass was established, the right pulmonary artery was divided and then dissection of the ascending aorta was completed to secure the space for aortic valve replacement. A discrete membrane of the left ventricular outflow and muscle bands of the right ventricular outflow were completely resected. The right pulmonary artery was reconstructed by interpose of a prosthetic graft. Our experience would provide a technical option how to handle complex late complications after the arterial switch operation.

Nontraditional placement of an implantable cardioverter-defibrillator in a heterotaxy patient after the completion of total cavopulmonary connection.

A 15-year-old boy with heterotaxy syndrome developed a prolonged QT interval and intractable torsade de pointes after the administration of sodium channel blockers for atrial tachyarrhythmia. Although this situation called for the placement of an implantable cardioverter-defibrillator, a conventional transvenous approach was not available since the patient had previously undergone a nonfenestrated extracardiac total cavopulmonary connection. We were urged to carry out the surgical placement of an epicardial lead for an implantable cardioverter-defibrillator using a single coil transvenous shock lead through re-do midline sternotomy. Here we describe the details of this nontraditional surgical procedure for the placement of a lead for an implantable cardioverter-defibrillator in a case without venous access into the heart.

Surgical removal of infected pacemaker leads without cardiopulmonary bypass after failed extraction using the Excimer Laser Sheath Extraction System.

With the growing number of cardiac pacemakers and internal cardioverter defibrillator implantations, problems with endocardial lead infection have been increasing. The newly developed Excimer Laser Sheath Lead Extraction System has been recognized as being highly useful for removing chronic infected leads. However, serious bleeding complications are a concern when this system is used. Here we report our experience with a 67-year-old man who was diagnosed with pacemaker endocarditis. Initially, lead removal was attempted using the Excimer Laser Sheath Extraction System, though this was abandoned because of severe adhesion of the leads and the junction of the supra vena cava (SVC) with the right atrium. Surgical removal of the leads was performed without using cardiopulmonary bypass and the leads were removed without any complications. During surgery, we found there was a silent perforation of the innominate vein brought about by the Excimer Laser Sheath System. Also, the junction of the SVC with the right atrium was thought to be an area potentially at high risk of perforation, because of a lack of surrounding tissue. It is our opinion that those who carry out procedures with the Excimer Laser Sheath System should understand the potential risk of perforation based on cardiac anatomy and should be prepared for lethal bleeding complications. Also, for emergent situations, we believe that close backup by a cardiovascular surgical team should be considered essential for performing the Excimer Laser Sheath Lead Extraction safely.

Staged repair of pentalogy of Cantrell with ectopia cordis and ventricular septal defect.

Pentalogy of Cantrell is a rare congenital anomaly characterized by a combination of severe defects in the middle of the chest and abdomen including intracardiac defects. Survival rate after cardiac surgery is extremely low. We present a successful staged complete repair of an omphalocele, a ventricular septal defect and a sternal defect in a case of pentalogy of Cantrell.

Surgical repair for rupture of a chronic traumatic thoracic aneurysm 14 years after injury: report of a case.

Traumatic thoracic aortic injury is a lethal condition. Because its mortality rate is extremely high in the acute phase, these patients rarely survive long enough for a chronic aneurysm to develop. We herein report a case of surgical repair for a ruptured chronic traumatic thoracic aneurysm. A 32-year-old man, who had been involved in a traffic accident 14 years earlier, was diagnosed with a rupture of a chronic traumatic thoracic aneurysm. Preoperative computed tomography showed that the ruptured aneurysm arose from the aortic isthmus and was accompanied by multiple daughter lesions. He underwent an aorta graft replacement with reconstruction of the left subclavian artery using both a median sternotomy and a left thoracotomy. The surgery was successful and the postoperative course was uneventful. Chronic traumatic thoracic aneurysm is usually a single lesion, and cases with daughter aneurysms have rarely been reported. We include a review of the previous literature and also discuss the etiology of this condition.

Midterm Performance of the Autologous Adventitial Overlay Method in Aortic Surgery.

BACKGROUND: We developed an adventitial overlay method for reinforcing aortic anastomoses. This study evaluated the midterm morphological and clinical outcomes of this method. METHODS: We harvested and prepared adventitia from a resected aneurysm or dissected aortic wall and performed aortic repair using the adventitial overlay method. At the midterm follow-up, we examined the differences among overlay, inversion, and felt-sandwich (FS) methods by evaluating the morphology of the anastomosis using computed tomography (CT) scans. Moreover, we performed macroscopic evaluation of one patient who required a second operation. RESULTS: Between May 2009 and April 2020, 160 consecutive patients (104 males, 56 females; mean age, 68.6 ± 11; range, 39-88 years) underwent thoracic aortic surgery. The overlay technique was successfully performed in 84 cases. The anastomosis sites of the overlay method maintained their morphology without any clinical complications. The inner diameter ratio of anastomosis/graft was measured using CT, which revealed that the overlay method was not significantly different from inversion and was significantly larger than the FS method. There was no anastomotic stenosis in the proximal or distal overlay anastomosis. Only one patient required a second operation for an enlarged aneurysm of the distal false lumen. We observed that the proximal overlaid adventitia was smoothly attached to the native lumen and was macroscopically indistinguishable from the original intima. CONCLUSIONS: This study showed the midterm stability of the overlay technique. The midterm outcome was clinically acceptable. No anastomotic stenosis or pseudoaneurysm formation in either the true aortic aneurysm or dissection cases was observed.

Single dose GLP-1-Tf ameliorates myocardial ischemia/reperfusion injury.

BACKGROUND: Glucagon-like peptide-1 (GLP-1) has insulinomimetic, insulinotropic, and antiapoptotic properties that may make it a useful adjunct to reperfusion therapy for myocardial infarction (MI); however, GLP-1 has a short plasma half-life. Fusion of GLP-1 to human transferrin (GLP-1-Tf) significantly prolongs drug half-life. MATERIALS AND METHODS: We tested the ability of single dose GLP-1-Tf to limit myocardial ischemia (30 min)/reperfusion (180 min) injury in rabbits. Nineteen animals were untreated controls. The pre-ischemic group (n=10) was given 10mg/kg of GLP-1-Tf 12 h before ischemia. Immediately after reperfusion, the post-ischemic group (n=10) received GLP-1-Tf (10 mg/kg) and the Tf group (n=4) received transferrin alone. RESULTS: Infarct size as a percentage of the area at risk was 59.1% ± 1.3%, 45.7% ± 1.9%, 44.1% ± 3.3%, 59.7% ± 2.0% in the control group, pre-ischemic group, post-ischemic group, and Tf group, respectively (P<0.05 for both GLP-1-Tf treatments group versus control). GLP-1-Tf reduced the apoptotic index from 4.67% ± 0.40% in the control group to 3.15% ± 0.46% in the pre-ischemic group and to 2.66% ± 0.40% in the post-ischemic group (P<0.05 for both GLP-1-Tf treatments versus control). The size of the wall motion abnormality and ejection fraction was significantly improved in the post-ischemic group relative to the control group. Serum GLP-1 levels were 239.8 ± 25.7 µg/mL in the post-ischemic group, 27.9 ± 5.8 µg/mL in the pre-ischemic group, and undetectable in the control group. CONCLUSION: GLP-1-Tf limits myocardial reperfusion injury whether given prior to the onset of ischemia or given at reperfusion. GLP-1-Tf may also limit myocardial stunning at high serum levels of the drug.

Utility of Ultrasonographic Assessment of Distal Femoral Arterial Flow during Minimally Invasive Valve Surgery.

PURPOSE: To evaluate the utility of ultrasonographic assessment of blood flow to the lower limb below the cannulation site in minimally invasive cardiac surgery (MICS). METHODS: Twenty-two patients who underwent ultrasonographic assessment in MICS were reviewed retrospectively. In all patients, the right femoral artery was used for arterial cannulation. Ultrasonographic assessment was performed using a 15-MHz ultrasonography small probe, and regional oxygen saturation was monitored by near-infrared spectroscopy (NIRS). RESULTS: The mean flow velocity at the distal side of the cannulation site was 46.2 ± 25.4 cm/s. In six patients, a >40% decreased from baseline regional oxygen saturation was observed. In five of the six patients, the flow velocity was very slow, and spontaneous echo contrast was also observed in three cases. Their regional oxygen saturation was improved rapidly after distal leg perfusion. In the remaining case, the flow velocity was not decreased. In another one case, the stenosis at the cannulation site was detected after decannulation and repaired immediately. No limb ischemic complications were observed in this series. CONCLUSION: Ultrasonographic assessment combined with the NIRS monitoring is useful to prevent lower limb ischemic complications after femoral arterial cannulation in MICS.

Sex-related resistance to myocardial ischemia-reperfusion injury is associated with high constitutive ARC expression.

The female sex has been associated with improved myocardial salvage after ischemia and reperfusion (I/R). Estrogen, specifically 17beta-estradiol, has been demonstrated to mediate this phenomenon by limiting cardiomyocyte apoptosis. We sought to quantitatively assess the effect of sex, ovarian hormone loss, and I/R on myocardial Bax, Bcl-2, and apoptosis repressor with caspase recruitment domain (ARC) expression. Male (n = 48), female (n = 26), and oophorectomized female (n = 20) rabbits underwent 30 min of regional ischemia and 3 h of reperfusion. The myocardial area at risk and infarct size were determined using a double-staining technique and planimetry. In situ oligo ligation was used to assess apoptotic cell death. Western blot analysis was used to determine proapoptotic (Bax) and antiapoptotic (Bcl-2 and ARC) protein levels in all three ischemic groups and, additionally, in three nonischemic groups. Infarct size (43.7 +/- 3.2%) and apoptotic cell death (0.51 +/- 0.10%) were significantly attenuated in females compared with males (56.4 +/- 1.6%, P < 0.01, and 4.29 +/- 0.95%, P < 0.01) and oophorectomized females (55.7 +/- 3.4%, P < 0.05, and 4.36 +/- 0.51%, P < 0.01). Females expressed significantly higher baseline ARC levels (3.62 +/- 0.29) compared with males (1.78 +/- 0.18, P < 0.01) and oophorectomized females (1.08 +/- 0.26, P < 0.01). Males expressed a significantly higher baseline Bax-to-Bcl-2 ratio (4.32 +/- 0.99) compared with females (0.65 +/- 0.13, P < 0.01) and oophorectomized females (0.42 +/- 0.10, P < 0.01). I/R significantly reduced Bax-to-Bcl-2 ratios in males. In all other groups, ARC levels and Bax-to-Bcl-2 ratios did not significantly change. These results support the conclusion that in females, endogenous estrogen limits I/R-induced cardiomyocyte apoptosis by producing a baseline antiapoptotic profile, which is associated with estrogen-dependent high constitutive myocardial ARC expression.

A modification of extended aortic arch anastomosis augmented with subclavian flap aortoplasty for interrupted or hypoplastic aortic arch.

BACKGROUND: Surgical repair for hypoplastic aortic arch in neonates carries a substantial risk of recurrent obstruction. Simple arch anastomosis is not always a solution in cases of extended arch hypoplasia. We present our modified technique of extended aortic arch anastomosis augmented with subclavian flap aortoplasty. METHOD: We describe two neonates: interrupted aortic arch and transverse arch hypoplasia associated with aortic coarctation, who underwent a modification of extended aortic arch anastomosis augmented with subclavian flap aortoplasty. RESULTS: The patients recovered without any pressure gradient at the anastomotic site. Postoperative aortography showed no arch obstruction and they successfully underwent second stage repair. CONCLUSION: Our technique provides extensive augmentation of the aortic arch with a tension-free, wide and non-circumferential suture line which preserves potential for growth. The technique described may avoid persistent or repeat arch obstruction.

Intimal regeneration after coronary endarterectomy and onlay grafting in coronary artery bypass grafting.

OBJECTIVES: Coronary onlay grafting, with or without endarterectomy, has been widely used for the treatment of diffuse lesions. Recent studies have demonstrated excellent long-term patency and favorable remodeling of onlay anastomosis; however, the underlying mechanisms remain unknown. Here, we describe the mechanism of intimal regeneration based on postmortem pathological evaluation of a patient who had undergone onlay grafting with coronary endarterectomy. METHODS: The onlay anastomosis was analyzed using a combination of immunohistological stainings, namely, H&E, vimentin, α-SMA, factor VIII, and Ki-67, to identify the source and mechanism of intimal regeneration after onlay grafting with endarterectomy. RESULTS: Our results suggest that the regenerated endothelium derives from the smooth muscle cells of the endarterectomized media of the coronary artery and that it circumferentially covers the internal lumen of the arterial graft. CONCLUSIONS: Intimal regeneration, derived from the smooth muscle cells of the endarterectomized coronary artery that proliferate toward the graft lumen, may be a key mechanism that underlies the observed favorable remodeling after onlay grafting during coronary endarterectomy.

Fluorescence spectroscopy and imaging of myocardial apoptosis.

Fluorometry is used to detect intrinsic flavoprotein (FP) and nicotinamide adenine dinucleotide (NADH) signals in an open-chest rabbit model of myocardial ischemia-reperfusion injury. Myocyte apoptosis has been shown clinically to contribute to infarct size following reperfusion of ischemic myocardium. A noninvasive means of assessing apoptosis in this setting would aid in the treatment of subsequent ventricular remodeling. We show that in vivo fluorometry can be useful in apoptosis detection in open-chest surgeries. Specific changes in myocardial redox states have been shown to indicate the presence of apoptosis. Two main mitochondrial intrinsic fluorophores, NADH and FP signals, were measured during normoxia, ischemia, and reperfusion experimental protocol. Ischemia was induced by occlusion of the largest branch of the circumflex coronary artery and fluorescence signals are collected by applying two different fluorescence techniques: in vivo fluorometry and postmortem cryoimaging. The first technique was employed to detect FP and NADH signals in vivo and the latter technique uses freeze trapping and low-temperature fluorescence imaging. The heart is snap frozen while still in the chest cavity to make a "snapshot" of the metabolic state of the tissue. After freezing, the ischemic area and its surrounding border zone were excised and the sample was embedded in a frozen buffer for cryoscanning. These two data sets, in vivo fluorometry and low-temperature redox scanning, show consistent extreme oxidation of the mitochondrial redox states (higher redox ratio) suggesting the initiation of apoptosis following reperfusion. This represents the first attempt to assess myocyte apoptosis in the beating heart.

Mid-Term Outcomes of a Modification of Extended Aortic Arch Anastomosis with Pulmonary Artery Banding in Single Ventricle Neonates with Hypoplastic Transverse Arch.

PURPOSE: There is less certainty regarding the best strategy for treating neonates with functional single ventricle (SV) and hypoplastic aortic arch. We have applied a modified extended aortic arch anastomosis (EAAA) and main pulmonary artery banding (PAB) as an initial palliation in neonates with transverse arch hypoplasia and assessed the mid-term outcomes. METHODS: In total, 10 neonates with functional SV and extensive hypoplasia or interruption of the arch underwent a modified EAAA (extended arch anastomosis with a subclavian flap) concomitant with main PAB through a thoracotomy without cardiopulmonary bypass. Patient age and weight ranged from 4 to 14 days and 2.3 to 3.8 kg, respectively. RESULTS: There were no hospital deaths although there were two late deaths. Gradients across the arch were 0 to 7 mmHg at postoperative day 1 and no arch reoperations were required. Two patients required balloon aortoplasty. Nine underwent bidirectional cavopulmonary shunt and two of them needed concomitant Damus-Kaye-Stansel (DKS) anastomosis. Six have completed Fontan. CONCLUSION: Our modification of EAAA with main PAB for SV neonates may benefit a certain population with transverse arch hypoplasia as an option to be considered. Patients with the potential for developing outflow obstruction may be best managed with an initial DKS-type palliation.

Cardiac resynchronization therapy in a patient with a failing systemic right ventricle.

Systemic right ventricular dysfunction is 1 of the late complications of the atrial switch operation for transposition of the great arteries. It has been reported that cardiac resynchronization therapy (CRT) for the failing systemic right ventricle (RV) improves symptoms and systolic function. However, patient selection for CRT in congenital heart disease is still challenging because the clinical standard for CRT in these patients is not established. We describe a case of successful implantation of a CRT device for a failing systemic RV aided by multimodality imaging and cardiac hemodynamic studies.

Cardiopulmonary bypass induces recruitment of bone marrow-derived leukocytes to the lungs in monkeys.

BACKGROUND: A bone marrow (BM) response induced by cardiopulmonary bypass (CPB) as a systemic inflammatory reaction has previously been postulated but not clarified. Newly released polymorphonuclear leukocytes (PMNs) and monocytes from the BM are known to be immature, indicating their greater potential to damage tissue. The present study aimed to examine the kinetics of BM-derived leukocytes associated with CPB in a nonhuman primate model. METHODS: Normothermic CPB was performed in cynomolgus monkeys for 2 hours through a median sternotomy. Leukocyte precursors were labeled in the BM of the monkeys in vivo by an intravenous injection of 5-bromo-2'-deoxyuridine (BrdU), and their release into the circulation and recruitment to the lungs after operation with or without CPB (control group) were monitored over time by flow cytometry. RESULTS: In normal-state monkeys, the calculated transit time of BrdU-labeled PMNs (PMNBrdU) through the BM was 143.6±4.5 hours and that of monocytes was 100.9±7.6 hours. CPB caused a rapid release of PMNs and monocytes from the BM, shortened their transit through the BM to 92.0±4.1 and 60.3±2.9 hours, respectively, and further induced their increased appearance in the alveolar spaces, with a significant increase in both interleukin (IL)-6 and IL-8 levels in the bronchoalveolar lavage fluid (BALF) 24 hours after CPB. CONCLUSIONS: CPB accelerated the release of PMNs and monocytes from the BM and their recruitment to the lungs in our monkey model, indicating that this model is relevant for monitoring the kinetics of BM-derived leukocytes in humans.

Effects of landiolol hydrochloride on intractable tachyarrhythmia after pediatric cardiac surgery.

BACKGROUND: While ß-blockers can be effective in controlling tachyarrhythmias after pediatric cardiac surgery, a negative inotropic influence sometimes complicates their use. Landiolol hydrochloride is a novel, ultra-short-acting ß-blocker recently developed in Japan. The drug has higher ß1:ß2 selectivity ratio and a less negative inotropic effect. This study retrospectively evaluates the efficacy and safety of landiolol in the management of tachyarrhythmias after pediatric cardiac surgery. METHODS: A retrospective analysis was performed on 312 consecutive patients undergoing surgery for congenital heart disease. Twelve patients were treated with landiolol for critical tachyarrhythmia. The mean age of patients was 28.7 ± 10.6 months. Five junctional ectopic tachycardia, 2 atrial flutters, 1 paroxysmal supraventricular tachycardia, 1 atrial fibrillation, 1 atrioventricular reciprocating tachycardia with Wolff-Parkinson-White syndrome and 2 excessive sinus tachycardia were treated. RESULTS: The mean loading and maintenance doses were 11.3 ± 4.0 and 6.8 ± 0.9 µg/kg per minute, respectively. Rate control was achieved in all patients. Landiolol reduced the heart rate from 169.7 ± 11.4 to 127.7 ± 7.5 beats per minute (p < 0.05) while blood pressure did not significantly change. Tachyarrhythmias were converted to sinus rhythm in 70.0% of the cases and the average time needed to achieve heart rate reduction was 2.3 ± 0.5 hours. CONCLUSIONS: Landiolol was efficacious in treating tachyarrhythmia in pediatric cardiac surgery. The desired negative chronotropic effect was achieved without significant hemodynamic compromise. The ultra-short half-life of landiolol provided rapid dose manipulation. This study suggests that landiolol is a promising option for the management of postoperative tachyarrhythmias in pediatric patients.

Appropriate route selection for extracardiac total cavopulmonary connection in apicocaval juxtaposition.

BACKGROUND: A malpositioned heart with apicocaval juxtaposition may complicate the management of patients with functional single ventricles when total cavopulmonary connection is performed. We reviewed our experience with extracardiac total cavopulmonary connection in patients with apicocaval juxtaposition with a special focus on route selection and outcomes. METHODS: Of 68 patients who underwent extracardiac total cavopulmonary connection at our hospitals, 10 patients with apicocaval juxtaposition were included in this study. The mean follow-up was 40 ± 28 months. Patient demographics were compared with data on patients without apicocaval juxtaposition. RESULTS: The age at operation was 8 ± 7 years. We carefully chose conduit routes to create satisfactory fluid dynamics. The conduit was placed between the inferior vena cava and the ipsilateral pulmonary artery in 2 patients, and the conduit crossed midline in 8 patients. The mean postoperative pulmonary artery pressure was 13 ± 2 mm Hg. The surgical and postoperative data were not significantly different when compared with the patients without apicocaval juxtaposition. There were no conduit-related early or late complications except for 1 patient who had poor ventricular function. CONCLUSIONS: Extracardiac total cavopulmonary connection in apicocaval juxtaposition can be carried out with favorable midterm outcomes. The route between the inferior vena cava and the contralateral pulmonary artery should be the primary choice when the relevant pulmonary artery is in good shape. Care must be taken in regard to critical conduit oppression by the ventricle in cases with large ventricular volume or poor ventricular function.

Staged Fontan operation for children with heterotaxy syndrome, bilateral ductus arteriosus, and nonconfluent pulmonary artery.

We report two cases of successful Fontan operation in children with heterotaxy syndrome associated with univentricular physiology and absent and nonconfluent central pulmonary arteries with both distal pulmonary arteries directly connected to the ipsilateral ductus arteriosus. After unilateral systemic-pulmonary shunt, the central pulmonary artery was reconstructed with a polytetrafluoroethylene prosthetic graft concomitantly with bidirectional cavopulmonary shunt. Finally, extracardiac total cavopulmonary connection was performed as an off-pump procedure. Children with bilateral ductus arteriosus and a nonconfluent pulmonary artery with univentricular physiology present a particular challenge in regard to completing Fontan operations. Careful attention should be directed at ensuring balanced growth of the bilateral distal pulmonary arteries. When planning reconstruction of the central pulmonary artery with a prosthesis, late reconstruction may be beneficial, as it enables utilization of a larger-caliber graft, obviating the need for replacement during a subsequent Fontan operation.

Erythropoietin enhances arterioles more significantly than it does capillaries in an infarcted rat heart model.

Erythropoietin (Epo) is a hormone which regulates erythrocyte production. It has recently become known that Epo enhances angiogenesis. However, since shear stress is an initiator of arteriogenesis, this increase with Epo may be due to increased shear stress from erythrocytosis. To clarify this, we compared the effects of Epo on both angiogenesis and arteriogenesis. Myocardial infarction was induced by LAD ligation in Wistar rats (Epo, G-CSF and control). Epo (1,000 IU/kg) was administered immediately after ligation of the LAD. G-CSF was administered at 100 microg/kg/day for 5 days after the coronary ligation. Four weeks later, coronary angiography was performed using synchrotron radiation coronary micro-angiography with a Langendorff apparatus. The number of vessels was investigated by microscopy. The numbers of capillaries and arterioles (> 100 microm in diameter) were measured. Microscopical examination: Capillary density in the twilight zone was 95 +/- 19 in the control group, 126 +/- 24 in the G-CSF group, and 142 +/- 32 in the EPO group (control versus Epo: P < 0.005, control versus G-CSF: P < 0.05). Arteriole numbers were 4.3 +/- 0.2 in the control group, 6.9 +/- 1.0 in the G-CSF, and 11.8 +/- 0.6 in the Epo group (control versus Epo: P < 0.00001, G-CSF versus Epo: P < 0.00001, control versus G-CSF: P < 0.00001). The ratios of arterioles and capillaries were 0.048 +/- 0.013 in the control group, 0.057 +/- 0.016 in the G-CSF group, and 0.088 +/- 0.019 in the Epo group (control versus Epo: P < 0.0005, G-CSF versus Epo: P < 0.05). Angiography: The number of crossing arterioles in the 2 mm lattice was 5.4 +/- 1.7 in the Epo group and 3.8 +/-0.4 in the control group (P < 0.05). The gray scale values for the evaluation of capillaries was 128 +/- 3.7 and 119 +/- 2.1 in the Epo and control groups, respectively (P < 0.00005). Epo enhanced arterioles more significantly than it did capillaries in this infarcted rat heart model.