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Do not throw away anything from the pig.
No full textAmong the surgical sciences, paediatric cardiac surgery is one of the closest to the concept of reconstruction. Despite the common use of the verb ‘to recycle’ in the third millennium, this notion cannot always be applied to our field and a multitude of materials, patches and conduits have to be used, often leading to rejection, aneurysm formation, calcification and stenosis.
Moreover, our population is very particular for the potential of growing inherent to the age of patients. For these reasons we are forced to use materials that can give the best results in short-term follow-up but that cannot remain effective in the longer term.
The opportunity to use living materials, growing patches or valves, opens up exciting possibilities—opens up incredible possibilities for our patients.
The extracellular matrix (ECM) is the naturally-occurring bioscaffold that surrounds cells in almost all tissues and organ structures. It is an acellular biomaterial that is gradually remodelled, leaving behind organized and healthy tissue. When implanted as a patch, the ECM acts as a scaffold into which the patient's cells migrate and integrate until it is gradually replaced. ECMs originating from various organs have been tested and good results reported.
Among the types available, the CorMatrixTM patch (CorMatrix®, Alpharetta, Georgia, USA), which is derived from porcine small intestinal submucosa extracellular matrix (SIS-ECM), is one of the most promising options among those commercially available.
In this issue of the Journal [1], Witt and colleagues report their experience in the use of the SIS-ECM CorMatrix patch in 37 paediatric patients. Their patient population was divided into four groups, depending on the implant location: septal defect patching, vascular patching, outflow tract patching or valve reconstruction.
There were four deaths (10.8%) at a follow-up time of 411 ± 225 days (range 62–757 days), with no death attributed to the implanted SIS-ECM, even though, in one patient with coronary ostial stenosis after supravalvular aortic patch enlargement, the suspicion of a relationship is legitimate.
The best results were reported in the septal closure group. Unfortunately, a septal closure can be accomplished perfectly with many other cheaper materials and the potential of SIS-ECM is probably greatly reduced in this situation. In adult patients, where the extent of the patch is bigger, SIS-ECM is probably justified and could provide better results in terms of the possibility of restoring suitable cardiac muscle.
In pulmonary or aortic enlargement plasty, the growth potential of SIS-ECM is interesting. In Witt's experience [1], vascular patching accounted for more than 50% of SIS-ECM patch applications (26 locations), with just one re-operation for pulmonary artery residual stenosis. No aneurysm formation was reported when used for aortoplasty [1].
This promising experience confirms that of others. Indeed, Padalino implanted SIS-ECM patch on the abdominal aorta in 15 rats [2]. Graft re-population was demonstrated as early as 15 days after implantation, while it was almost completely remodelled 180 days after implantation. No significant graft aneurysmatic dilation or detachment was present. The new aortic wall presented with an intima incorporating an endothelial lining, a media with smooth muscle cells and an adventitia containing vessels and fibroblasts [2].
The same encouraging results were not obtained in the clinical experience by McCready, who reported seven episodes of patch aneurysm among 76 patients who had undergone patch angioplasty of the carotid artery following endoarterectomy [3]. The patch used in this latter study was another SIS-ECM product (Surgisis® by Cook Surgical, Bloomington, IN, USA) that was thinner than CorMatrix. However, aneurysmal dilation of the graft patch has been described when the CorMatrix was used in carotid patch angioplasty.
As regards right ventricular outflow tract (RVOT) reconstruction, Witt reported on six patients with one re-operation. In three patients, a unicusp SIS-ECM valve was created but, unfortunately, one patient died from low cardiac output and the other two showed moderate-to-severe valve incompetence.
School reported four unicusp valves implanted in pulmonary outflow tract reconstruction with three of them competent at an average follow-up of 9 months: too short to be of significance [4]. Quarti reported 26 cases treated with SIS-ECM patch reconstruction, nine of which were cusp extension valvular repairs: five aortic, two tricuspid, one mitral and one pulmonary valve. At a mean follow-up of 12.5 months no patients had undergone re-operation and no more than mild incompetence was evident [5].
A large variability of results is evident among all the reported experiences. An interesting experimental study by Tottey confirms that differences exist in the composition, structure and mechanical properties of SIS-ECM prepared from tissues harvested from animals of different ages. In their conclusion, SIS-ECMs harvested from pigs aged 12 weeks are suitable for withstanding substantial mechanical loading after in vivo implantation and remodelling into load-bearing or force-generating tissues, while animals aged >52 weeks will yield scaffolds that may persist longer after in vivo implantation [6].
The interactions between the CorMatrix patch and the surrounding tissues can also be affected by the implantation techniques, the suture materials and other factors, potentially explaining the extreme variability of the results.
In our experience in Bologna, the SIS-ECM CorMatrix patch was used in 19 locations on 16 patients (septal patch in 6; pulmonary artery patch enlargement in 5; valve reconstruction in 5 [3 aortic, 1 mitral and 1 tricuspid]; Senning procedure as part of double switch operation in 2 and aortic arch reconstruction in 1). All patients are alive at a mean follow-up of 15 months. One patient underwent re-operation for recurrent incompetence 24 months after repair of a dysplastic aortic valve. The explanted patch appeared pliable and without any calcification.
Our impression is that the SIS-ECM CorMatrix patch is very useful in pulmonary artery enlargement and valve cusp extension by reason of its pliability and thinness, whilst it is probably not necessary for septal closure. Since clinical studies so far have limited follow-up, it is not possible to confirm the ability of the patch to regenerate normal tissue in anatomical and functional terms, although this has been demonstrated in experimental studies. However, the absence of calcific degeneration is encouraging and sufficiently important to recommend its use.
If the material proves capable of allowing for growth, previously unimagined possibilities will open up, forever solving all the problems related to the use of non-living materials
Tetralogy of Fallot with coronary-to-pulmonary artery fistula: a diagnostic snare.
No full textAn 11-month-old infant, moderately cyanotic, with diagnosis of tetralogy of Fallot underwent corrective surgery. At echocardiographic evaluation, a subatretic right ventricular outflow tract without aortopulmonary collateral arteries, confluent pulmonary arteries and normal coronary pattern were evidenced. During operation, an undiagnosed large coronary-to-pulmonary artery fistula was disclosed. Because of the large variety of aortopulmonary collateral arteries that can be associated with this pathology, further imaging study is mandatory when oxygen saturation does not match the right ventricular outflow tract obstruction severity
Neonatal aortic arch surgery
No full textSurgical repair of the aortic arch is entailed in the neonatal period of patients with: hypoplastic left heart syndrome, interrupted aortic arch, hypoplastic aortic arch and complex aortic coarctation. Aortic arch surgery requires a period of circulatory arrest and deep hypothermia. Cerebral selective perfusion has recently been introduced as an alternative to circulatory arrest with the aim of reducing mortality and neurological complications. Moreover, the arch reconstruction phase can be safely performed under moderate hypothermia and with cerebral and myocardial perfusion (on beating heart), thus, completely avoiding cerebral ischemia and completely avoiding or drastically reducing myocardial ischemi
Neonatal coarctation repair using extended end-to-end anastomosis
No full textAortic coarctation without associated intracardiac lesions, with or without posterior arch hypoplasia referred as simple coarctation, is safely and effectively repaired via left posterolateral thoracotomy, whereas median sternotomy and cardiopulmonary bypass are necessary for aortic arch reconstruction in case of complete aortic arch hypoplasia, or coarctation with associated cardiac lesions. There is a wide variety of techniques currently proposed to repair neonatal coarctation, all reported associated with very low operative mortality, nevertheless which one would be the best technique in terms of minimal rate of residual or recurrent obstruction or late complications is still under debate
Pulmonary artery debanding.
No full textPulmonary artery banding is a simple palliative surgical procedure for congenital heart defects with left-to-right shunt or complete mixing and pulmonary over-circulation. Even though indication for pulmonary artery banding has been sensibly reduced, since early reparative surgery has been proved superior to palliation and a staged approach, an increasing support for pulmonary banding has been raised in the last two decades by new indications such as left ventricular retraining, in the late arterial switch operation for complete transposition of the great arteries or before the double-switch operation in congenitally corrected transposition. Along with the increasing interest raised by the new indications and the consequently more diffuse use of banding, debanding has become an important surgical issue. Debanding is usually performed several months after palliation along with the repair of the cardiac malformations; otherwise, it can be done progressively or partially to further delay surgery and let the patient grow. Occasionally, after pulmonary artery banding, a spontaneous resolution of the underlying cardiac malformation can occur; however, a debanding procedure is in any case necessar
Left main coronary artery stenosis secondary to severe pulmonary artery dilation.
No full textA 45-year-old lady with dyspnea and occasional precordial chest pain was diagnosed with a huge sinus venosus atrial septal defect and partial anomalous pulmonary venous return. Preoperative coronary angiography disclosed severe main stem stenosis, considered secondary to compression by the dilated pulmonary trunk. Atrial septal defect closure and pulmonary artery reduction plasty were performed. The left main coronary artery appeared completely patent. The postoperative course was uneventful, and the patient was asymptomatic on follow-u
Ross-kabbani operation in an infant with mitral valve dysplasia.
Full text linkBackground. Mitral valve replacement can be very difficult to obtain in infants because the valve annulus diameter can be smaller than the available prosthesis. Case Report. We describe the case of a 2-month-old female weighing 3.5 kg affected by mitral valve dysplasia leading to severe valve stenosis. Despite full medication, the clinical conditions were critical and surgery was undertaken. The mitral valve was unsuitable for repair and the orifice of mitral anulus was 12 mm, too small for a mechanical prosthesis. Therefore, a Ross-Kabbani operation was undertaken, replacing the mitral valve with the pulmonary autograft and reconstructing the right ventricular outflow tract with an etherograft. Results. The postoperative course was uneventful and the clinical conditions are good at 4-month follow-up. Conclusion. The Ross-Kabbani operation can be an interesting alternative to mitral valve replacement in infants when valve repair is not achievable and there is little space for an intra-annular mechanical prosthesis implant
Results of the modified Fontan procedure are not related to age at operation.
No full textObjective: The modified Fontan procedure represents the final stage for the palliation of hearts with single-ventricle physiology. Different opinions exist regarding the optimal timing of the operation, with most centres advocating early intervention. By contrast, over the past decade, we have progressively increased the age at Fontan operation with the aim to potentially delay the onset of late Fontan failure, and to possibly use larger extracardiac conduits. We retrospectively reviewed our surgical experience with Fontan operation, to understand the impact of this strategy on morbidity and mortality. Methods: Between 1990 and 2008, 65 patients underwent a modified Fontan operation at our institution (extracardiac conduit in 52 and lateral tunnel in 13). The median age at operation in our series was 7.3 years (range: 2.2-15.8 years) and this value was used to divide the study cohort into two groups. Group A (n=28) included patients with an age at Fontan operation 7 years of age. Preoperative characteristics, intra-operative data and short- and medium-term results were assessed. Results: No differences in baseline characteristics, morbidity and mortality were evident between groups. Hospital mortality was 0% in group A and 5.4% (2/37) in group B (p=0.5). Prolonged pleural effusions were present in eight patients in group A (29%) and seven in group B (19%, p=0.39). After a mean follow-up of 5.7+/-5.4 years (range: 0.3-18 years), the overall mortality of group A (1/28) was similar to that of group B (2/37) (3.6% vs 5.4%, p=0.999). The incidence of arrhythmias, protein-losing enteropathy, Fontan take down and re-operation were not different between the two groups. Conclusions: The modified Fontan operation can be performed safely in older patients without affecting operative and medium-term follow-up results. Postponing the extracardiac Fontan operation may have the advantage of the use of a larger conduit. Copyright © 2009 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved
Sinus node dysfunction after partial anomalous pulmonary venous connection repair.
No full textAbstract
OBJECTIVE:
Repair of partial anomalous pulmonary venous connection to superior vena cava using an internal patch has been described as a potential cause of obstruction at the systemic or pulmonary vein level and of sinus node dysfunction. Our experience with this operation was reviewed.
METHODS:
From 1991 to 2011, 59 patients with a diagnosis of partial anomalous pulmonary venous connection to superior vena cava underwent surgical repair with intracardiac patch rerouting alone (45 patients) or with associated superior vena cava patch enlargement (14 patients). Follow-up evaluation was performed, including electrocardiogram, echocardiogram, electrocardiogram Holter monitor recording, and exercise stress test.
RESULTS:
There were no early or late deaths and no reoperations at a mean follow-up of 46 ± 45 months. All patients were asymptomatic in New York Heart Association class I. Echocardiographic evaluation excluded any obstruction at the pulmonary or systemic vein level. At follow-up, 55 patients (93%) presented sinus rhythm and were free from antiarrhythmic medications, 2 patients (3%) presented atrial fibrillation, 1 patient (2%) presented atrial fibrillation and asymptomatic sinus node dysfunction, and 1 patient (2%) presented ectopic atrial rhythm. Electrocardiogram Holter recording demonstrated sinus node dysfunction in 6 of 34 patients (18%). Exercise stress test showed chronotropic incompetence in 8 of 27 patients (30%): All except 1 patient presented sinus rhythm at basal electrocardiogram, and only 4 patients had some evidence of sinus node dysfunction on electrocardiogram Holter recording.
CONCLUSIONS:
Intracardiac repair of partial anomalous pulmonary venous connection can be performed with good results at medium-term follow-up. The rate of sinus node dysfunction or other arrhythmias and obstruction at pulmonary or systemic vein level is comparable to other techniques. Exercise stress test evaluation is the best way to detect asymptomatic sinus node dysfunction
Risultati e complicanze dell'impianto di pacemaker definitivo in pazienti pediatrici con blocco atrioventricolare congenito ed acquisito[Results and complications of permanent pacing in pediatric patients with congenital or acquired atrioventricular block]
No full textBackground. Currently there is no evidence to prefer an endocardial or epicardial approach for pacing in pediatric patients. This analysis was aimed at defining the complications of pacemaker implantation in a pediatric population with atrioventricular block according to a strategy of choosing an epicardial system for patients 10 kg. Methods. This is a retrospective study performed on 27 patients, with and without congenital heart disease, implanted with a permanent pacemaker because of idiopathic or acquired atrioventricular block at our Pediatric Cardiology and Cardiac Surgery Unit of S. Orsola-Malpighi Hospital in Bologna (Italy) between 1981 and 2010. Patients were divided into two groups: 70% of the population (group A) was implanted with an epicardial system, 30% (group B) with an endocardial system. Results. After a mean follow-up of 14 years (17 ± 8 years for group A, 7 ± 5 years for group B), the most frequent complications were lead failure (44%) and infection (18%). Both were more common in the epicardial system group: lead failure rate 53% in group A vs 25% in group B (p=0.0001); infection rate 26% in group A vs 0% in group B (p=0.0001); rate of system revision or implantation of a new electrode 42% in group A vs 12% in group B (p=0.0001). Conclusions. The present study demonstrates a high complication rate in patients undergoing an epicardial pacing system implantation. However, in patients <10 kg the epicardial system allows subclavian venous access protection for endocardial system implantation after somatic growth, avoiding high-risk procedures of system revision or lead extraction and subclavian vein occlusion in the long term
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