Superior vena caval approach for resecting intracardially extended Ewing sarcoma

Intracardiac extension of Ewing sarcoma is extremely rare. Herein, we report the case of a pediatric patient with mediastinal Ewing sarcoma which extended to right atrium via the azygos vein. Surgical resection was performed through longitudinal incision on anterior surface of the superior vena cava under cardiopulmonary bypass. Resection was feasible because the tumor was sufficiently elastic and non-adherent to the inner surface of the heart. The patient was received chemotherapy and proton beam radiation postoperatively and is doing well with no tumor recurrence for 5 years after surgery.

Pericardial effusion after congenital heart surgery

Objective

Pericardial effusion after cardiac surgery remains an important cause of morbidity and mortality. We describe the risk factors of pericardial effusion after congenital heart surgery through analyzing data from a nationwide, multi-institutional registry.

Methods

The Japan Congenital Cardiovascular Surgery Database, which reflects routine clinical care in Japan, was used for this retrospective cohort study. Multivariable regression analysis was done after univariable comparison of patients with pericardial effusion and no pericardial effusion.

Results

The study enrolled 64,777 patients registered with the Japan Congenital Cardiovascular Surgery Database between 2008 and 2016; 909 of these had postoperative pericardial effusion (1.4%) and were analyzed along with 63,868 patients without pericardial effusion. Univariable analysis found no difference between the groups in terms of gender, early delivery, or preoperative mechanical ventilatory support. In the pericardial effusion group, cardiopulmonary bypass use was lower (58.4% vs 62.1%), whereas the cardiopulmonary bypass time (176.9 vs 139.9 minutes) and aortic crossclamp time (75.1 vs 62.2 minutes) were longer, and 30-day mortality was higher (4.1% vs 2.2%). Multivariable analysis identified trisomy 21 (odds ratio, 1.54), 22q.11 deletion (odds ratio, 2.17), first-time cardiac surgery (odds ratio, 2.01), and blood transfusion (odds ratio, 1.43) as independent risk factors of postoperative pericardial effusion. In contrast, neonates, infants, ventricular septal defect, atrial septal defect, tetralogy of Fallot repair, and arterial switch operation were correlated with a low risk of pericardial effusion development.

Conclusions

The incidence of postoperative pericardial effusion in congenital cardiac surgery was 1.4%. Trisomy 21, 22q.11 deletion, first-time cardiac surgery, and blood transfusion were identified as the principal factors predicting the need for pericardial effusion drainage.

Adult ALCAPA: from histological picture to clinical features

BACKGROUND

Anomalous left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital coronary anomaly that results in high mortality if left untreated. Our aim was to extend our knowledge of the histological, angiographic, and clinical characteristics of ALCAPA in order to deepen our understanding of this rare entity.

CASE PRESENTATION

We were involved in the assessment, treatment, and pathological evaluation of two adult ALCAPA patients who were rescued from ventricular fibrillation and then surgically treated to establish a dual coronary artery system. Histological studies indicated various chronic ischemic changes in the myocardium, patchy fibrosis, and severely thickened arteriolar walls in both ventricles. The first patient is alive and well 11.5 years after surgical correction without any implantable cardioverter defibrillator (ICD) activations. The second patient required re-do surgery 9 months after the initial operation but subsequently died. Histologically, chronic ischemic alteration of the myocardium and thickened arteriolar walls persisted even after surgical correction, and coronary angiography (CAG) showed an extremely slow flow phenomenon even after surgical correction in both patients. The average postoperative opacification rate in the first case was 7.36 + 1.12 (n = 2) in the RCA, 3.81 + 0.51 (n = 3) in the left anterior descending (LAD) artery, and 4.08 + 0.27 (n = 4) in the left circumflex (LCx) artery. The slow flow phenomenon may represent persistent high arteriolar resistance in both ventricles.

CONCLUSIONS

Seldom reported or new findings in adult ALCAPA were identified in two cases. More frequent diagnosis of adult ALCAPA can be expected because of the widespread availability of resuscitation and more advanced diagnostic modalities. Accumulation of pathological and clinical findings and confirmation of the long-term follow-up results after treatment may contribute to expanding our knowledge of this rare entity and establishing optimal treatment.

Predictors of Pericardial Effusion in Patients Undergoing Pulmonary Artery Banding

BACKGROUND

Although pulmonary artery banding (PAB) is a common palliative procedure for pediatric heart malformation, there are concerns of pressure overload and concomitant immune reactions in the right ventricle causing postsurgical complications such as pericardial effusion. At this time, no clear guidelines as to potential risk factors or procedural contraindications have been widely disseminated. Therefore, a study was undertaken to examine wide-ranging factors to find potential biomarkers for postsurgical pericardial effusion formation risk.

METHODS

A retrospective study was conducted on all cardiac surgeries performed over an eight-year period, and the main inclusion criterion was pericardial effusion development after PAB that required surgical drainage. Nine cases were then analyzed against a control group of 45 cases with respect to body measurements, concomitant surgeries, genetic screens, laboratory tests results, and cardiac function parameters.

RESULTS

Trisomy 21 was strongly associated with the development of severe pericardial effusion after PAB, and postoperative serum albumin levels in patients with trisomy 21 were associated with pericardial effusion development. Other parameters showed no significant correlation with pericardial effusion development.

CONCLUSIONS

Our data indicate a strong association between trisomy 21 and pericardial effusion requiring drainage after PAB, which is in line with translational research findings. Pressure overload from PAB may play a role in the formation of severe pericardial effusion that is exacerbated by cardiac structural defects commonly associated with trisomy 21. Surgical teams should therefore use caution and plan to implement drainage in PAB cases, and postoperative serum albumin may serve as a useful biomarker for pericardial effusion formation.

Patency of Saphenous Vein Grafts Using the PAS-Port System During Coronary Artery Bypass Surgery

BACKGROUND

Several proximal anastomosis devices have been developed to shorten the time required for a proximal anastomosis and to avoid aortic cross-/side-clamping during coronary artery bypass grafting. This study retrospectively examined the patency of saphenous vein grafts (SVGs) using the PAS-Port System (Cardia Inc, Redwood City, CA).

METHODS

From 2004 to 2014, 451 patients underwent coronary artery bypass graft operations requiring at least 1 proximal anastomosis using a PAS-Port device. A total of 802 PAS-Port devices were used, and 95.0% (762 of 802) were implanted successfully. Among the successfully implanted anastomoses, 76.8% (585 of 762) were evaluated using coronary angiography or multidimensional computed tomography, or both. The evaluations were performed between postoperative days 4 and 3,182 (mean, 319 ± 624 days). The early (1 to 365 days) and the midterm to long-term (more than 366 days) occlusion rates were examined. A complete postoperative clinical course was recorded for 70.7% of the patients.

RESULTS

Overall, 93.8% (549 of 585) of the device-dependent SVGs were patent. The patency rates of device-dependent SVGs that were 1, 2, 3, 4, 5, 6, 7, and 8 years old were 90.1% ± 1.8%, 87.1% ± 2.3%, 86.1% ± 2.5%, 82.9% ± 3.3%, 80.6% ± 3.9%, 77.2% ± 5.0%, 77.2% ± 5.0%, and 70.2% ± 8.1%, respectively. The longest follow-up period was 3,182 days (8.7 years). The occlusion rate for device-dependent SVGs tended to decrease as the number of patients accumulated.

CONCLUSIONS

The PAS-Port system provided acceptable SVG patency and clinical outcome for the early and midterm to long-term. There may be a learning curve for the use of PAS-Port device that affects the device-dependent SVG patency.

Two adult cases of Bland-White-Garland syndrome with lethal arrhythmia due to coronary steal phenomenon during physical or mental stress

We experienced two adult cases of anomalous origin of the left coronary artery from the pulmonary artery, so-called Bland-White-Garland (BWG) syndrome, that presented with ventricular tachycardia (VT) and ventricular fibrillation during exertion in daily life. They presented to our hospital with syncope due to VT, and recovered following application of an automated external defibrillator with cardiopulmonary resuscitation. We diagnosed BWG syndrome by multi-detector computed tomography angiography and coronary angiography. We analyzed the mechanisms of lethal arrhythmias in relation to myocardial ischemia on exertion. Coronary flow modification and implantable cardioverter defibrillator implantation were performed in order to prevent future lethal arrhythmia due to myocardial ischemia. It is important to be aware of congenital heart disease in ordinary cases. <Learning objective: We experienced two rare cases of patients who were admitted with ventricular tachycardia and ventricular fibrillation who had adult type Bland-White-Garland syndrome during exertion in daily life. It is important to be aware of congenital heart disease in ordinary cases.>.

Abstract P1-15-03: Prevention of letrozole–induced bone loss using risedronate in postmenopausal women with hormone receptor positive breast cancer: A multicenter randomized clinical trial

Background

Prevention of letrozole–induced bone loss using oral risedronate has not been proved in the Japanese women. The aim of this study was to assess the effect of risedronate 17.5mg/week on bone mineral density (BMD) in postmenopausal, early breast cancer patients scheduled to receive adjuvant letrozole.

Patients and Methods

Postmenopausal women with hormone receptor–positive early breast cancer were assigned to one of two strata according to their baseline BMD T-score as being at low and high risk of osteoporosis. Patients with low risk (-2.5 ≤ T score) were randomly assigned to letrozole and risedronate (L+R) or to letrozole alone (L). Patients with high risk (-2.5 &gt; T score) received letrozole and risedronate (L+R). Letrozole was given at a dosage of 2.5 mg/day while oral risedronate was given at 17.5mg/week. The primary end point was the change in lumbar spine (LS) BMD at 12 months. The secondary end points included change in total hip (HP) BMD and bone turnover markers.

Results

In the low risk group (N=103), treatment with L+R resulted in a significant increase in BMD at LS and at HP compared to treatment with L only at 12 months (1.8% vs -2.2%, P &lt; 0.001, and -0.3% vs -2.9%, P = 0.001, respectively). In the L+R group, significant decreases in bone turnover makers, NTX and PINP, were recognized compared with L only at 12months (-11.1% vs. 27.5%, P&lt;0.001, -42.3% vs. 15.2%, P&lt;0.001, respectively). In the high risk group (N=28), treatment with L+R resulted in a significant increase in BMD at LS and prevention of decrease in BMD at HP (3.6%; 95%CI, 1.8% to 5.3%, p=0.003, 0.3%; 95%CI, -1.3% to 1.8%, p=0.47, respectively).

Estimated Percentage Change From Baseline to 6 and 12 Months in Lumbar Spine and Total Hip BMD   From Baseline to 6 MonthsFrom Baseline to 12 MonthsBMD areaRisk GroupTreatmentChange in BMD (%), 95% CIPChange in BMD (%), 95% CIPLumbar spineLow riskL+R1.7 (-1.3 to 4.7)&lt;0.0011.8 (-2.1 to 5.7)&lt;0.001  L-1.6 (-4.3 to 1.1) -2.2 (-5.7 to 1.3)  High riskL+R1.8 (0.4 to 3.2)0.043.6 (1.8 to 5.3)0.003Total hipLow riskL+R-0.2 (-2.7 to 2.3)0.001-0.3 (-3.2 to 2.6)0.001  L-2.2 (-5.4 to 1.0) -2.9 (-7.2 to 1.4)  High riskL+R0.1 (-1.3 to 1.6)0.610.3 (-1.3 to 1.8)0.47BMD: bone mineral density, L: Letrozole, R: risedronate

Four patients (14.3%) improved from osteoporotic region to the osteopenic region with L+R treatment. Letrozole and risedronate were well tolerable and there was no serious adeverse event including osteonecrosis of jaw.

Conclusions

At 12 months, 17.5mg/week risedronate therapy prevented bone loss in postmenopausal women with breast cancer who were receiving adjuvant letrozole, of which results were compatible with previous findings of western populations.

Citation Format: Kadoya T, Masumoto N, Shigematsu H, Emi A, Kajitani K, Kobayashi Y, Funakoshi M, Kawabuchi Y, Ohara M, Matsuura K, Noma M, Sasada T, Okada M. Prevention of letrozole–induced bone loss using risedronate in postmenopausal women with hormone receptor positive breast cancer: A multicenter randomized clinical trial. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-15-03.

Xenopericardial roll graft replacement for infectious pseudoaneurysms and graft infections of the aorta

Background

Which graft material is the optimal graft material for the treatment of infected aortic aneurysms and aortic graft infections is still a matter of controversy. Orthotopic aortic reconstruction with intraoperatively prepared xenopericardial roll grafts without omentopexy was performed as the “initial” operation to treat aortic infection or as a “rescue” operation to treat graft infection. Mid-term outcomes were evaluated.

Methods

Between 2009 and 2013, orthotopic xenopericardial roll graft replacement was performed to treat eight patients (male/female: 6/2; mean age: 69.5 [55–80] yr). Graft material: equine/bovine pericardium: 2/6; type of operation: initial 4/rescue 4; omentopexy 0. Additional operation: esophagectomy 2. Mean follow-up period: 2.6 ± 1.6 (1.1–5.1) years.

Results

Replacement: ascending 3, arch 1 (reconstruction of neck vessels with small xenopericardial roll grafts), descending 3, and thoracoabdominal 1. Pathogens: MRSA 2, MSSA 1, Candida 1, E. coli 1, oral bacillus 1, and culture negative 2. Postoperative local recurrence of infection: 0. Graft-related complications: stenosis 0, calcification 0, non-infectious pseudoaneurysm of anastomosis 2 (surgical repair: 1/TEVAR 1). In-hospital mortality: 2 (MOF: initial 1/rescue 1); Survival rate exclusive of in-hospital deaths (~3 y): 100 %, but one patient died of lung cancer (3.6 yr).

Conclusions

Because xenopericardial roll grafts are not composed of synthetic material, the replacement procedure is simpler and less invasive than the standard procedure. Based on the favorable results obtained, this procedure may have the possibility to serve as an option for the treatment of aortic infections and aortic graft infections not only as a “rescue” treatment but as an “initial” treatment as well.

Electronic supplementary material

The online version of this article (doi:10.1186/s13019-015-0343-5) contains supplementary material, which is available to authorized users.

Airway obstruction by a retropharyngeal hematoma secondary to thoracic aortic aneurysm rupture

Background

Retropharyngeal hematoma is a rare form of pharyngeal pathology and can present as acute airway obstruction. Among the many causes of retropharyngeal hematoma, thoracic aortic rupture is extremely rare.

Methods and results

A 78-year-old female with airway obstruction by a retropharyngeal hematoma secondary to thoracic aortic aneurysm rupture was successfully treated by total aortic arch replacement and open stent-graft insertion.

Conclusion

Rupture of the thoracic aorta should be considered as a rare but important cause of retropharyngeal hematoma and airway obstruction.

Equine pericardial roll graft replacement of infected pseudoaneurysm of the ascending aorta

The standard procedure for treating infected aortic aneurysms is to resect the infected aorta, debridement of the surrounding tissue, in situ graft replacement, and omentopexy. However, the question of which graft material is optimal is still a matter of controversy. We recently treated a patient with an infected ascending aortic aneurysm. Because of previous abdominal surgery, the omentum was unavailable. The ascending aorta was replaced in situ with equine pericardial roll grafts. The patient is alive and well 29 months after the operation.

Equine pericardial roll graft replacement of infected pseudoaneurysm of the aortic arch

Resection of the infected aorta, debridement of the surrounding tissue, in situ graft replacement, and omentopexy is the standard procedure for treating infected aortic aneurysms, but the question of which graft material is optimal is still a matter of controversy. We recently treated a patient with an infected thoracic aortic aneurysm. The aneurysm was located in the proximal aortic arch. Because the patients had previously undergone abdominal surgery, the aortic arch were replaced in situ with a branched equine pericardial roll grafts. The patient is alive and well 23 months after the operation.

In vivo fluorometric assessment of cyclosporine on mitochondrial function during myocardial ischemia and reperfusion

BACKGROUND

Cyclosporine A (CsA) limits myocardial reperfusion injury and preserves mitochondrial integrity, but its influence on mitochondrial function has not been described in vivo. Auto-fluorescence of mitochondrial nicotinamide adenine dinucleotide and flavin adenine dinucleotide correlate with mitochondrial dysfunction. We hypothesized that CsA limits mitochondrial dysfunction and that fluorometry can quantify this influence.

METHODS

Seventeen rabbits were studied: untreated (UnT, n = 7), CsA preinfarction (CsAp, n = 6), and CsA on reperfusion (CsAr, n = 4). Animals underwent 30 minutes of myocardial ischemia and 3 hours reperfusion. Infarct size was determined by staining. Nicotinamide adenine dinucleotide and flavin adenine dinucleotide fluorescence was continually measured in the risk area. The redox ratio was calculated [flavin adenine dinucleotide(f)/(flavin adenine dinucleotide(f) + nicotinamide adenine dinucleotide(f))]. Electron microscopy evaluated mitochondria morphology.

RESULTS

The infarct size by group was 39.1% +/- 1.7% in CsAp, 39.1% +/- 1.7% in CsAr, and 53.4% +/- 1.9% in UnT (p < 0.001). During ischemia, the CsAp group demonstrated less hypoxic reduction, with the redox ratio decreasing to 75.6% +/- 4.1% of baseline. The UnT and CsAr groups deceased to 67.1% +/- 4.0% and 67.2% +/- 3.6%, respectively (p < 0.005). During reperfusion the UnT group redox ratio increased to 1.59 +/- 0.04 times baseline. This increase was blunted in the CsAp (1.17 +/- 0.04, p = 0.026) and CsAr (1.35 +/- 0.02, p = 0.056) groups. Electron microscopy revealed reduced mitochondrial disruption in CsAp (19.7% +/- 7.6%) and CsAr (18.1% +/- 7.1%) rabbits compared with UnT (53.3% +/- 12.5%).

CONCLUSIONS

Fluorometric spectroscopy can be used in vivo to quantitatively assess the time course of CsA's influence on the mitochondrial dysfunction associated with myocardial ischemia and reperfusion.

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.

The elimination of the onchocerciasis vector from the island of Bioko as a result of larviciding by the WHO African Programme for Onchocerciasis Control

The island of Bioko is part of the Republic of Equatorial Guinea and is the only island in the World to have endemic onchocerciasis. The disease is hyperendemic and shows a forest-type epidemiology with low levels of blindness and high levels of skin disease, and the whole population of 68,000 is estimated to be at risk. Control of onchocerciasis began in 1990 using ivermectin and this yielded significant clinical benefits but transmission was not interrupted. Feasibility and preparatory studies carried out between 1995 and 2002 confirmed the probable isolation of the vector on the island, the high vectorial efficiency of the Bioko form of Simulium yahense, the seasonality of river flow, blackfly breeding and biting densities, and the distribution of the vector breeding sites. It was proposed that larviciding should be carried out from January to April, when most of the island's rivers were dry or too low to support Simulium damnosum s.l., and that most rivers would not need to be treated above 500 m altitude because they were too small to support the breeding of S. damnosum s.l. Larviciding (with temephos) would need to be carried out by helicopter (because of problems of access by land), supplemented by ground-based delivery. Insecticide susceptibility trials showed that the Bioko form was highly susceptible to temephos, and insecticide carry was tested in the rivers by assessing the length of river in which S. damnosum s.l. larvae were killed below a temephos dosing point. Regular fly catching points were established in 1999 to provide pre-control biting densities, and to act as monitoring points for control efforts. An environmental impact assessment concluded that the proposed control programme could be expected to do little damage, and a large-scale larviciding trial using ground-based applications of temephos (Abate 20EC) throughout the northern (accessible) part of the island was carried out for five weeks from 12 February 2001. Following this, a first attempt to eliminate the vectors was conducted using helicopter and ground-based applications of temephos from February to May 2003, but this was not successful because some vector populations persisted and subsequently spread throughout the island. A second attempt from January to May 2005 aimed to treat all flowing watercourses and greatly increased the number of treatment points. This led to the successful elimination of the vector. The last biting S. damnosum s.l. was caught in March 2005 and none have been found since then for more than 3 years.

Infarction induced myocardial apoptosis and ARC activation

BACKGROUND

Apoptosis is thought to play a role in infarction induced ventricular remodeling. Apoptosis repressor with caspase recruitment domain (ARC) has been shown to limit cardiomyocytes apoptosis; however, its role in the pathogenesis of heart failure is not established. This study examines the regional and temporal relationships of apoptosis, ARC, and remodeling.

METHODS

Myocardium was harvested from the infarct borderzone and remote regions of the left ventricle (LV) at 2 (n=8), 8 (n=6), and 32 (n=5) wk after MI. Activated ARC was compared with myocardial apoptosis in each region at each time. Both were then compared with the progression of remodeling.

RESULTS

LV systolic volume increased by a factor 1.56±0.06 and 2.09±0.07 at 2 and 8 wk, respectively then stabilized by 32 wk (2.08±0.18). Activated ARC was elevated at 2 wk, diminished at 8 wk, and increased again at 32 wk in both regions. Apoptosis was elevated at 2 wk, and further increased at 8 wk. By 32 wk, apoptosis had diminished significantly.

CONCLUSIONS

In a large animal infarction model, remodeling varied directly with the degree of apoptosis and inversely with ARC activation, suggesting that ARC acts as a natural regulatory phenomenon that limits apoptosis induced ventricular remodeling.

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.

Mild hypothermia to limit myocardial ischemia-reperfusion injury: importance of timing

BACKGROUND

Hypothermia during ischemia has been shown to reduce myocardial reperfusion injury. We sought to establish the cardioprotective effect of very mild total-body hypothermia (<or= 2.5 degrees C) and to determine whether the application of hypothermia at different points during the ischemia-reperfusion period influenced the degree of myocardial salvage.

METHODS

Rabbits were subjected to 30 minutes of myocardial ischemia followed by 3 hours of reperfusion. Twenty-five animals were maintained at normal temperature (39.5 degrees C) throughout the experiment (W-W-W group). All other animals were cooled to reduce left atrial temperature 2.0 degrees C to 2.5 degrees C. Eleven animals reached goal temperature before coronary occlusion (C-C-C group), in 14 animals cooling was initiated at coronary occlusion (W-C0-C group), in 8 animals cooling was initiated 15 minutes after coronary occlusion (W-C15-C group), in 5 animals cooling was initiated 25 minutes after coronary occlusion (W-C25-C group), and in 13 animals cooling was started concurrently with reperfusion (W-W-C group). Infarct size as a percentage of the risk area (I/AR) was determined by a double staining-planimetry technique.

RESULTS

Goal temperature was achieved before reperfusion in the C-C-C and W-C0-C groups but was not achieved until the reperfusion period in the other treatment groups. Infarct size was 59.0 +/- 1.2% in the W-W-W group and was reduced in all cooling groups (C-C-C = 30.4 +/- 4.9%; W-C0-C = 33.4 +/- 5.0%; W-C15-C = 42.4 +/- 1.4%; W-C25-C = 44.1 +/- 2.3%; W-W-C = 50.5 +/- 4.1%). The temperature at reperfusion correlated most strongly with infarct size (r = 0.72, p < 1 x 10(-12)).

CONCLUSIONS

Very mild hypothermia affords a significant cardioprotective effect. Temperature at the time of reperfusion most strongly correlates with the degree of myocardial salvage.

Dermal filler injection: a novel approach for limiting infarct expansion

BACKGROUND

Early infarct expansion after coronary occlusion compromises contractile function in perfused myocardial regions and promotes adverse long-term left ventricular (LV) remodeling. We hypothesized that injection of a tissue-expanding dermal filler material into a myocardial infarction (MI) would attenuate infarct expansion and limit LV remodeling.

METHODS

Fifteen sheep were subjected to an anteroapical MI involving approximately 20% of the LV followed by the injection of 1.3 mL of a calcium hydroxyapatite-based dermal filler into the infarct. Real-time three-dimensional echocardiography was performed at baseline, 30 minutes after MI, and 15 minutes after injection to assess infarct expansion. Sixteen additional sheep were subjected to the same infarction and followed echocardiographically and hemodynamically for 4 weeks after MI to assess chronic remodeling. Eight animals had injection with dermal filler as described above immediately after MI, and 8 animals were injected with an equal amount of saline solution.

RESULTS

All animals exhibited infarct expansion soon after coronary occlusion. The regional ejection fraction of the apex became negative after infarction, consistent with systolic dyskinesia. Injection of the dermal filler converted the apical wall motion from dyskinetic to akinetic and resulted immediately in significant decreases in global, regional, and segmental LV volumes. Chronically, relative to saline control, dermal filler injection significantly reduced LV end-systolic volume (62.2 +/- 3.6 mL versus 44.5 +/- 3.9 mL; p < 0.05) and improved global ejection fraction (0.295 +/- 0.016 versus 0.373 +/- 0.017; p < 0.05) at 4 weeks after infarction.

CONCLUSIONS

Injection of an acellular dermal filler into an MI immediately after coronary occlusion reduces early infarct expansion and limits chronic LV remodeling.

Proton beam therapy interference with implanted cardiac pacemakers

PURPOSE

To investigate the effect of proton beam therapy (PBT) on implanted cardiac pacemaker function.

METHODS AND MATERIALS

After a phantom study confirmed the safety of PBT in patients with cardiac pacemakers, we treated 8 patients with implanted pacemakers using PBT to a total tumor dose of 33-77 gray equivalents (GyE) in dose fractions of 2.2-6.6 GyE. The combined total number of PBT sessions was 127. Although all pulse generators remained outside the treatment field, 4 patients had pacing leads in the radiation field. All patients were monitored by means of electrocardiogram during treatment, and pacemakers were routinely examined before and after PBT.

RESULTS

The phantom study showed no effect of neutron scatter on pacemaker generators. In the study, changes in heart rate occurred three times (2.4%) in 2 patients. However, these patients remained completely asymptomatic throughout the PBT course.

CONCLUSIONS

PBT can result in pacemaker malfunctions that manifest as changes in pulse rate and pulse patterns. Therefore, patients with cardiac pacemakers should be monitored by means of electrocardiogram during PBT.

[Epicardial atrial pacing using an active fixation bipolar endocardial lead in children]

Good performance was observed over 10 years after implantation of bipolar epicardial atrial pacing using an active fixation bipolar endocardial lead in 3 pediatric patients with congenital heart block. The bipolar endocardial lead which was supposed to be fixed transvenously was implanted on the atrial surface by first screwing the lead's helix into the myocardium. The catheter was then laid down on the atrial surface, and both electrodes were wrapped by the atrial tissue. The good performance of this pacing lead seemed to depend on stable positioning of the electrode. This lead is superior to the commercially available, and steroid eluting epicardial bipolar pacing lead, on the point of its small size in head and body, and could be applied to dual chamber pacing in smaller children.

[African programme for onchocerciasis control (APOC): entomological aspects of Onchocerca volvulus transmission by Simulium neavei in the Basin of Sankuru (Eastern Kasai, Democratic Republic of Congo)]

As part of a study to evaluate the long-term impact of community-directed treatment with ivermectin (CDTI), baseline entomological data on the transmission of onchocerciasis in the forest zone of the Eastern Kasai Province were collected from July 1998 to January 1999. Species of the Simulium neavei complex were the only vectors found in the site during the study. Nuisance activity was low with a mean biting rate of only 32.5 bites/man/day. The mean parturity rate was 29.4%, the mean rate of infected females was 14.5% and the mean number of infective Onchocerca larvae per 1000 parous flies was 659. These findings clearly show that the S. neavei population at the study site has high vector capability and constitutes a large microfilarial reservoir. The entomological features found in the study area are consistent with a hyper-endemic zone.