CIRUGIA DE NORWOOD PDF
▫La cirugía busca minimizar los factores de riesgo que acechan al Norwood estadio I Fontan atriopulmonar: Conexión de AD con TP para q sangre de. The Fontan procedure or Fontan–Kreutzer procedure is a palliative surgical procedure used in from their existing blood supply (e.g. a shunt created during a Norwood procedure, a patent ductus arteriosus, etc.). Leval, Marc R de ( ). d Servicio de Cirugía Cardiovascular, Hospital Infantil Universitario Virgen del Between October and June , 42 children underwent the Norwood.
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The hypoplasic left heart syndrome is a serious congenital cardiopathy that leads to surgery in the first days of life. The treatment is palliative and it is made in several stages, of which the intervention of Norwood noewood is the first. It fe to make the right ventricle act like a systemic ventricle, connecting the trunk of the pulmonary artery to the aorta.
The pulmonary flow is attained through a fistula between the aorta and the pulmonary artery. Although the results ciruiga in the last years have improved, 2,3 it continues to have jorwood high mortality. The main problem of this intervention is the hemodynamic instability; in order to try and avoid it, in year the modification of Shunji Sano, 4 consisting of the substitution of the fistula for a non-valvulated tube introduced between the right ventricle and the pulmonary artery.
In our hospital, the first Norwood intervention was made in5 and in we incorporated the Sano modification, based on the good results obtained in others centers. The study was planned as prospective, descriptive, and observational, to be carried out in the period between October and June Among the anatomical characteristics of the cardiopathy we emphasized that the average diameter of the norwod aorta was 3.
The intervention was made citugia an mean age of The first 30 patients group 1 underwent the classic 1 Norwood technique, receiving a modified Blalock-Taussig fistula of different diameters, and in the other 12 group 2 the Sano 4 variant was used.
The P 50 of the ECC time, aortic clamping and circulatory shutdown was of The PICU treatment initiated in the operating room was continued, with the objective to optimize cardiac output and to reduce to the systemic nowrood pulmonary vascular resistance to the maximum. In most of our patients, nitric oxide was suspended on the third day, and ventilatory support was suspended between the third and ninth day. Norwooe and analgesia were obtained with midazolam and fentanyl, and we only resorted to the neuromuscular paralysis with vecuronium in children whose sternal closure was deferred.
The process of weaning off the respirator began once the child was hemodynamicaly stable and when the thorax had been closed, in children with deferred closure. We used pressure support ventilatory modalities to facilitate spontaneous breathing and digestive tolerance.
We initiated enteral nutrition through a transpyloric tube on the second postsurgical day, preferentially with hydrolyzed maternal milk or proteins. In the analytical control we measured arterial and venous blood gases, oxygen saturation SO 2 by noninvasive, and continuous pulse-oxymetry and the carbon dioxide CO 2 nnorwood capnography.
We made an immediate postsurgical heart ultrasound to evaluate ventricular function, the size of the auricular defect, the competence of the tricuspid valve, and the flow through the fistula, or the ventriculopulmonary tube.
Hospital mortality, firugia by intrasurgical and postsurgical mortality was analyzed before discharge. In addition, groups 1 and 2 were compared in relation to mortality, intrasurgical, and postsurgical. In addition, the relation between hospital mortality and cardiac anatomy, surgical technique, surgical times, and deferred sternum closure were studied. With the same objective, postsurgical hemodynamic and respiratory variables were analyzed Table 1gathered by means of a standardized protocol and included in a database.
Tissue oxygen extraction EtO 2 measures the oxygen consumption by waves, so that when tissue perfusion is jeopardized, it slows blood flow and increases its extraction, lowering the S v O 2 and increasing the venous PCO 2. The tissue oxygen extraction and venous pCO 2 allow the determination of cardiac output. This fact produces an increase of the dead space, which is translated in a difficulty to exhale carbon dioxide. Its measurement evaluates in an indirect nogwood the pulmonary flow and allows identifying children with a jeopardized pulmonary flow.
The fraction of the pulmonary dead space is considered normal if between 0. The successive determinations of the variables previously mentioned were done in the following sequence: We analyzed, additionally, late mortality and the patients who underwent a second and third procedures, that is the Glenn and Fontan procedures, were classified.
The degree of function of survivors was determined during their last check-up in the outpatient clinic of cardiology. Descriptive statistic of the qualitative variables was done, using absolute and relative frequencies. Some cirugiw the quantitative variables did not follow a normal distribution test of Kolmogorov-Smirnovreason for which they were described nkrwood a mean interquartile range. The association between the quantitative variables was done using the Spearman rank coefficient.
All the analyses were made with SPSS software, version A P value less than. Global hospital mortality was The age and the weight of the children at the moment of the intervention did not have a significant statistical relationship with mortality Table 3. In relation to the cardiac anatomy, hospital mortality was These differences, which relate the cardiac anatomy to hospital mortality, although spectacular, did not have statistical meaning.
We did not find significant differences either between mortality in PICU and the surgical technique used. The one obtained in group 1 was In relation to the surgical times, only the time of ECC was associated significantly with mortality, so that it was greater in those that died in the operating room Table 6 and in PICU Table 3.
The time of aortic clamping only was significant when we compared it with the surgical technique, so that it was superior in children of group 1 Table 7. Mortality in the PICU was also greater, although the differences in this case were not significant Table 3. As far as the postsurgical monitorization in the PICU, there were no nowood differences between the groups of survivors and deceased in the following variables: Two cases had respiratory insufficiency that cirufia weaning off ventilation difficult, finding a dynamic obstruction of the left main bronchus by means of fibrobronchoscopy.
The study of the airways by means of computerized tomography CT with three-dimensional reconstruction and magnetic resonance MR demonstrated that it was produced by an extrinsic compression of the neoaorta.
The surgical technique used in them to reconstruct the aortic arc was the terminoterminal suture without aortic graft. Both patients died due to respiratory insufficiency before a tensile stent could be implanted in the bronchial light.
Six of the patients belonged to ciruyia 1 and 2 to group 2. The mean age and the weight of them in the last review was 19 months range, and 9 kg range, 6.
Surgical treatment of the hypoplasic left heart syndrome has been a reason for worry among surgical teams due to its elevated mortality. The work done in the previous years has improved short and long-term survival. This fact is related in part with the introduction of a modification in norwoood classical Norwood technique, consisting in the substitution of the fistula for a tube connecting the right ventricle with the pulmonary artery. This procedure improves the growth of the pulmonary arteries with a more uniform distribution.
The hypoplasic left heart syndrome is a cardiopathy with many anatomical variants that are frequently associated with other malformations or genetical alterations; its proper evaluation and presurgical diagnosis allows us to establish a prognosis, which is independent of the surgical technique and the postsurgical care. In contrast, in the multivariate analysis, only low birth weight and extracardiac malformations were considered as ccirugia factors for mortality.
Among the variables related to the surgical procedure, only the duration of ECC was an independent risk factor. For this motive, and coinciding with the findings of previous studies, they have not been considered as prognostic factors for early mortality.
We did not find significant differences between norwod mortality in the PICU and the surgical technique employed groups 1 and 2 Table 7probably due to the low number of patients currently included in group 2. Other authors, nonetheless, have found a difference 4,12 and promote the use of the tube from the left ventricle to the pulmonary artery because of the good results so far obtained. Cifugia our series of cases, of the 20 children that died in the first group, 8 did so in the operating room because it was impossible to take them off ECC Table 7.
Because of this, some authors support the systematic use of ventricular assist devices in the operating room and during the patients stay in the PICU, arguing that it improves cardiac output and therefore the survival, of these patients.
Experience With the Norwood Operation for Hypoplastic Left Heart Syndrome
In a similar manner to other authors, 12 we have also proven that time on ECC is a risk factor for early mortality in the PICU, in the sense that the longer the time on ECC, the most likely the patient will die. On the contrary, time of anoxia and cardiac arrest were not significant Table 3. Primary sternum closure was also a risk factor in the sense that the children that underwent such a procedure in the operating room had a higher mortality, both intrasurgically Table 6 as postsurgically in the PICU Table 3.
Based on this finding, we propose the systematical deferred closure of the sternum in all of the children intervened for this cardiopathy, avoiding in this manner cardiac compression and low output that is the result of closing the thorax. All of our patients underwent hyperfiltration during their time on ECC, without any complications, and without the necessity of suspending it owing to hemodynamic instability.
Its use has demonstrated in other studies an improvement in hemodynamics, reflected as a reduction in the heart rate and an incremented in the systolic and diastolic pressure. In relation to the surgical technique, up until some years ago some authors 16 reconstructed the aortic arch without a homograft; in this way, it was thought, long term growth of the new aorta was benefited without any residual stenosis.
Two of the patients who did not undergo the homograft had respiratory insufficiency after being weaned from mechanical ventilation, with an extrinsic compression of the pulmonary artery and left main bronchus by the neoaorta, demonstrated through an airway study.
This experience has made us consider the possibility of using a homograft in a systematic manner, as is being done by other authors with good results, 12 to elevate the position of the aortic arch and reducing the possibility of compressing adjacent structures. This mortality can be considered high if we compare it with that obtained by other authors.
Its determination in adults with respiratory distress syndrome of different causes has demonstrated to be a risk factor for death. Its evaluation makes us indirectly estimate the adequacy of the systemic flow.
Their determination has the advantage that it can be carried out easily with the common monitorization of PICU. The study of these variables is undergoing with the objective of carrying out a new analysis when the size of the sample is higher.
Medical treatment was based on a strategy of pharmacological reduction of the pulmonary and systemic vascular resistance.
Síndrome del corazón izquierdo hipoplástico | American Heart Association
This way we minimized the fluctuations in the systemic and pulmonary resistance and maintained a stable circulatory and respiratory state. Due to the advancements in medical and surgical treatments, survival of these children in the past years has increased, but they must be intervened 3 times throughout their life, with the risk inherent to this. The future, though still a ways off, will probably be the undertaking of a single procedure in the catheterism lab.
We have not demonstrated an increase in survival of children in the PICU who underwent surgery re the Sano-modified of the classic Norwood technique.
The reduction in time of ECC and the fact of choosing a systematically differed closing of the sternum in the PICU have contributed to a better postsurgical evolution and, therefore, could increase survival. Received November 17, Accepted for publication March firugia, Calls from Spain 88 87 40 9 to 18 hours.
Images subject to Copyright. Previous Article Vol July Next article. Abstract Introduction and objectives. To describe our experience and to identify risk factors for in-hospital mortality.
Criugia October and June42 children underwent the Norwood procedure. In the first 30 patients, pulmonary circulation was established using a modified Blalock-Taussig shunt Group 1while a right ventricle to pulmonary artery conduit was used in the remaining 12 Group 2. Preoperative anatomic features and procedural factors were analyzed with respect to their impact on mortality.
The association between each individual variable and mortality was investigated. Venous pCO 2the mean dead space fraction, and tissue oxygen extraction all tended to be higher among infants who died, but the difference was not statistically significant. Use of a right ventricle to pulmonary artery conduit did not improve postoperative survival.