Interferometric grazing incidence test of rough steep convex aspherics: full 3D reconstruction of the object.

A grazing incidence interferometric measurement procedure is applied to test rough convex steep rotationally symmetric aspherics. The measurement of rough surfaces is possible; i.e., without the need to polish the surfaces, due to the large effective wavelength (λeff=10µm) of the test. One measurement step using diffractive beam splitters and phase-shifting techniques delivers the surface information along one meridian. The full surface description can be stitched together from several phase results combined with appropriate object rotations. This publication includes, besides the short recapitulation of the measurement principle and experimental setup, a presentation of the simulated and measured data of an aspherical object under test. The data analysis of each meridian is focused on the elimination of the misalignment aberrations caused by specimen displacements. Finally, the stitching of multiple meridian regions to a 3D surface map of the specimen is shown.

Interferometric grazing incidence test of rough steep convex spherics: experimental data analysis.

Grazing incidence interferometry has been applied to plane, cylindrical, acylindrical, and general rod-like surfaces using diffractive beam splitters. Here, in a first step towards measuring aspherics, we demonstrate that also rough convex steep rotationally symmetric spherics can be measured along one meridian in a single step using diffractive beam splitters and phase shifting techniques. The measurement of rough surfaces is possible, i.e., without the need to polish the surfaces, due to the large effective wavelength (λeff≈10µm) of the test. We include, besides the short recapitulation of the measurement principle and experimental setup, a presentation of the measured data of one small meridian region for the special case of spherical objects under test. The subsequent data analysis combined with suitable simulations focuses on elimination of the misalignment aberrations from the results caused by specimen displacements in the setup.

Phase singularity reduction in speckle interferometry by tailoring the spatial coherence of light.

Reducing the number of phase singularities in speckle interferometry by physical means increases the quality of the phase deconvolution and enhances the separability of fringe systems, especially for highly dynamic fringe systems. The reduction is achieved by tailoring the spatial coherence of the light source at the entrance of the interferometer. The reduction mechanism is non-intuitive and rests on a change of size and of position of the speckle patterns as a result of the spatially shaped coherence. After demonstrating the amount of reduction that may be achieved, the reduction mechanism is explained theoretically and via simulations, and it is vindicated in an experiment using a Michelson-Mach-Zehnder interferometer hybrid.

Absolute testing of the reference surface of a Fizeau interferometer through even/odd decompositions.

Absolute testing of spherical surfaces is a technological necessity because of increased accuracy requirements. In a Fizeau setup, the main part of the interferometer deviations thereby comes from the reference surface. We demonstrate the validity of an absolute testing procedure for the reference surface that has been proposed earlier. The procedure relies on the decomposition of the surface deviations into odd and even parts and could be used in partially coherent illumination. The odd deviations are obtained from a basic and a 180 degree-rotated position of an auxiliary sphere, and the even deviations can be measured with the help of a cat's eye position in double pass using an opaque half screen in the interferometer aperture.

Bilateral bronchial balloon dilatation and Strecker stent implantation in a ventilated child with malignant carinal stenosis.

Tracheobronchial endoluminal reconstruction and stenting has become a valuable palliative tool in adults with intrathoracic tumors compromising the airways. Tracheobronchial balloon dilatation has been recently used in children and even neonates. We report a case of severe airway obstruction requiring emergency intubation and artificial ventilation in a 5-year-old child with intrathoracic recurrence of a rhabdomyosarcoma. Endoscopic balloon dilatation through the endotracheal tube with subsequent implantation of a non self-expanding metal mesh stent was used successfully, allowing extubation and discharge of the child from ICU.

Metal airway stent implantation in children: follow-up of seven children.

Long segment malacia of the trachea or main stem bronchi in children is not always suitable for surgical correction; patients may therefore remain ventilator-dependent and/or experience severe obstructive crises. We treated 7 children (ages, 4 months to 9 years) with extreme structural central airway obstruction with stent implantations. Six were mechanically ventilated; 5 had frequent life-threatening obstructive spells requiring deep sedation or paralysis. Diagnoses were: syndrome-associated tracheobronchomalacia (n = 4), malignancy infiltrating the carina (n = 1), congenital tracheal stenosis (n = 1), and tracheobronchial compression by a malpositioned aorta (n = 1). Six tracheal and 13 bronchial stents were endoscopically placed. The prostheses included mesh titan (n = 5), the newer shape memory material nitinol (n = 13), and 1 Y-shaped carina stent. Follow-up was reported for 7 weeks to 72 months. All patients showed marked improvement of their respiratory obstruction. Six children were weaned at least temporarily from ventilation. No significant bleeding, stenosis, or perforation was observed. Seven stents were changed after up to 14 months. Three children are well and at home. In 2 children airway stabilization was successful, but they later died from causes unrelated to stent placement, and 2 children died due to generalized airway disease. Soft metal mesh airway stents can offer a therapeutic option in life-threatening inoperable obstruction of the trachea and main stem bronchi in children.

Treatment of congenital tracheoesophageal fistula by endoscopic laser coagulation: preliminary report of three cases.

Three newborns with congenital tracheoesophageal fistula were treated by endoscopic laser coagulation. After radiologic and endoscopic diagnosis, laser coagulation of the mucosal layer of the fistula followed using Nd:YAG laser light transferred through an uncovered quartz fiber of 600 microns diameter. The successful and uneventful course in two cases contrasts with the incomplete obliteration in one case caused by inadequate energy application and/or early localized instillation of contrast medium for radiologic control examination. The advantages of this method include elimination of an operative procedure, exclusion of operative complications, and the possibility of repetition in recurrent cases. Care must be taken to prevent esophageal and tracheal damage by use of this method.

Deviated trachea in hypoplasia and aplasia of the right lung: airway obstruction and its release by aortopexy.

Three cases of male infants with hypoplasia and aplasia of the right lung and dextrocardia are reported. The infants developed increasing obstructive respiratory distress in the first 4 months of life. In all three cases, there was an opaque right hemithorax with overinflation of the left lung, a posterior deviation of the trachea with pulsatile stenosis, and a posteriorly located aortic arch. Hypoplasia (two cases) or aplasia (one case) of the right pulmonary artery and an absence or a remnant of the right main bronchus were also observed. Associated malformations were esophageal atresia with an abnormal high pouch of the proximal esophagus in case 1, and hypertelorismus syndrome in case 2. Because of severe respiratory distress in all three patients, an aortopexy was performed at the ages of 5 months (one infant) and 10 months (two infants). The obstructive respiratory signs disappeared postoperatively in the following weeks. It has been observed that tracheal stenosis in aplasia or hypoplasia of the right lung may be caused by the dislocated aortic arch. An aortopexy can release the airway compression in such cases. Because of associated malformations, a careful evaluation of the airway and vessels is recommended.

Severe lower tracheal stenosis in infancy.

16 infants with severe distal tracheal stenosis (TS) seen from 1978-1988 are reviewed. Diagnosis was established by endoscopy and confirmed by radiographic methods, including magnetic resonance imaging (MRI) in three cases. Types of TS ranged from segmental stenosis to complex lesions involving the carina and bronchi. Associated vascular anomalies were found in nine patients (56%). All patients needed long-term intubation or a tracheostomy (seven cases) for stenting of the airway. Patients with congenital TS (CTS) were treated by tracheal resection (two survivors), dilatation (one survivor, two non-survivors), or observation (two non-survivors). Patients with pulmonary artery sling (PAS) were treated by division of the vascular sling (three survivors, one non-survivor), or combined vascular and tracheal surgery (one non-survivor). One patient with dilated pulmonary arteries compressing both main bronchi died in spite of oxygen therapy. Two cases of compression by an anomalous aorta were managed with dilatation (one survivor, one non-survivor). One patient with a severe stricture after a tracheal resection was successfully treated by dilatation. The overall mortality was 50%. We conclude that 1. endoscopic examination of the tracheobronchial tree and thorough evaluation of associated anomalies is mandatory in symptomatic patients; 2. if indicated surgical correction is the treatment of choice for tracheal stenosis; 3. dilatation and stenting of the stenosis are invaluable tools in the management of these infants.

[Drowning accidents in childhood]. / Ertrinkungsunfälle im Kindesalter.

This is a report on five boys aged between 1 and 5 years who, after prolonged submersion in cold water, were treated at our department. On being taken out of the water, all the patients were clinically dead. After 1- to 3-hour successful cardiopulmonary resuscitation, with a rectal temperature of about 27 degrees C, they were rewarmed at a rate of 1 degree/hour. Two patients died within a few hours after the accident. One patient survived with an apallic syndrome, 2 children survived with no sequelae. In the event of a water-related accident associated with hypothermia, we consider suitable resuscitation to have preference over rewarming measures. The most important treatment guidelines and prognostic factors are discussed.

Tracheobronchial foreign body aspiration in childhood. A report on 224 cases.

In 224 patients aged 7 months to 14 years aspirated foreign bodies (FB) were extracted from the tracheobronchial system. Eighty-one percent of the children were younger than 3 years, 50% were in the second year of life. There were twice as many boys as girls. Sixty-seven percent of the FB were nuts, of these more than half were peanuts. Fifty-six percent of aspirated FB were localized in the right bronchial system, 39% in the left and 5% subglottic or tracheal. All FB could be removed by endoscopy under general anaesthesia with muscle relaxation. The development of an extraction technique without forceps ("encasing") led to an easier way of removing crumbling FB, like nuts. Complications were rare, no postoperative tracheotomy was necessary, no cardiac arrest and no death occurred. The interval between aspiration and intervention was longer than 3 weeks in one-third of the cases; in some cases it was months or years with the consequence of chronic damage of the bronchial system or the lung. The possibilities of prevention appear to be limited; thus it is necessary to diminish the frequency of prolonged lodging of FB in the respiratory tract by considering aspiration early in the differential diagnosis of airway symptoms.

[Therapeutic problems of pediatric tracheobronchial foreign bodies]. / Therapeutische Probleme kindlicher, tracheo-bronchialer Fremdkörper.

The report is based on 251 extractions of tracheo-bronchial foreign bodies performed since 1968. Bronchoscopy for foreign bodies, particularly chronic ones, is a high risk procedure in small children and even more in infants and should be limited to a skilled bronchologist. Progress in paediatric anaesthesiology and paediatric intensive care as well as bronchological devices designed specially for children facilitate the task. Technique of extraction, monitoring and pre- and postoperative management are described in detail. A recently developed method for the extraction of crumbly material, particularly peanuts, without forceps is presented.

[Malignant hyperthermia in a child with acute lymphatic leukemia]. / Maligne Hyperthermie bei einem Kind mit akuter lymphatischer Leukämie.

A 5-year-old boy with acute lymphatic leukemia in remission developed signs of malignant hyperthermia (MH) during general anesthesia for removal of a central venous access port. The anesthetic procedure for implantation of the port 17 months before had been uneventful despite use of the same triggering agents, halothane and succinylcholine. Meanwhile, the patient had received chemotherapy (COALL-03-85). The first sign of MH was masseter spasm following succinylcholine; then tachycardia, acidosis, myoglobinuria, and CPK elevation (8953 IU) appeared. There was only moderate temperature elevation to 37.8 degree C. Rapid improvement and complete recovery occurred after dantrolene i.v. The patient's father was found to have undiagnosed muscle pain and an elevated CPK level. An in vitro contracture test with halothane and caffeine revealed susceptibility to MH and supported the patient's diagnosis and genetic predisposition. Referring to several other cases in the literature concerning MH in patients with lymphomas and leukemias, a possible correlation between the two diseases is discussed. As the MH crisis in our patient was most probably genetic in origin, a common acquired cause such as a viral infection seems less probable. We do not believe the chemotherapy our patient received between the two anesthetics was the cause since about one-half of the patients in the literature had not had chemotherapeutic pretreatment at the time of the MH crisis. We believe that a common genetic predisposition is the most likely link between the two diseases. In any case, patients with leukemias and lymphomas should be monitored very carefully for symptoms of MH.(ABSTRACT TRUNCATED AT 250 WORDS)

[Diagnosis of Pneumocystic carinii pneumonia by lavage of the bronchial system (author's transl)]. / Diagnose einer Pneumocystis carinii pneumonie durch Bronchialspülung

This report deals with a 10 year old girl suffering from an acute lymphoblastic leukemia since 1971. The child was hematologically in full remission, when she developed a pneumonia due to pneumocystis carinii. The diagnosis was established by demonstrating the agent in bronchial secretions. The material was obtained by rinsing the bronchial system. The patient was treated with pentamidine and co-trimoxazol (Bactrim) with good success.

The significance of tracheal stenosis in esophageal atresia.

The significance of tracheal stenosis in children operated upon for esophageal atresia is described. Stenosis is caused mainly by tracheal compression by the innominate artery leading to tracheal malacia. Following esophageal repair tracheal compression is increased causing life-threatening asphyctic attacks during feeding. After establishment of diagnosis urgent surgery by means of truncopexy is indicated. The incidence of this complication is about 1 in 20 according to our figures and 1 in 40 according to Filler (Filler et al. 1976).

[Life threatening late dislocation in chronic foreign body aspiration]. / Lebensgefährliche Spätdislokation bei chronischer Fremdkörperaspiration.

We report a case of a boy with a long-standing foreign body aspiration in the left main bronchus causing severe pneumonia of the left lung. During intravenous therapy with antibiotics there was a life-threatening event with acute dislocation of the foreign body into the right main bronchus, leading to acute respiratory insufficiency. We conclude that in chronic foreign body aspiration antibiotic therapy preceding bronchoscopy should only be performed in in-patients and with strict monitoring.

[Surgical treatment of pediatric laryngeal stenosis in the area of the ring cartilage]. / Die chirurgische Behandlung der kindlichen Larynxstenose im Ringknorpelbereich.

In the past 15 years, infants and children with laryngeal stenosis have also been successfully treated with laryngotracheoplasty. From 1991 to 1993 we performed a surgical treatment in 20 pediatric patients with subglottic stenosis. The anterior cricoid split procedure should always be considered in children who cannot be extubated before undergoing tracheotomy, especially because in case of failure there are no disadvantages for any further operative measurements. By modifying the technique described by Cotton and Seid (1980), we performed an endoscopically controlled anterior cricoid split in 5 children via an endolaryngeal approach. 4 of these patients were extubated within 10 days after using a nasotracheal tube for splinting the cricoid level. In 14 patients with a tracheostoma we used a modification of Réthi's division of the posterior lamina of the cricoid by the placement of a autogenous costal cartilage graft. A 6-week-period of stenting is required for sufficient healing and stability of the reconstructed airway.

[Cavathrombosis: a complication of cava long-time catheter]. / Die Cavathrombose als Komplikation des Cava-Langzeitkatheters.

The Vena-Cava-Catheter is necessary in long term parenteral nutrition. The thrombosis of Vena Cava as a complication of the long term Cava-catheter is seldom. It is impossible to show the incidence of Vena Cava thrombosis, because there must not be clinical signs. In six cases we could show the thrombosis of Vena Cava. Sepsis, changing of the catheter, distance, large catheters and hyperosmolaric solutions are responsible for thrombosis of Vena Cava.

[Tracheal compression by the innominate artery. Angiographic investigations (author's transl)]. / Trachealkompression durch den Truncus brachiocephalicus. Angiographische Beurteilung.

Angiocardiograms in 11 infants without anatomical abnormalities of the heart and the great arteries were compared with angiocardiograms in 17 patients with tracheal compression caused by the innominate artery. The direction of the left ventricular outlet, the course of the aortic arch, the innominate artery and the right common carotid artery were studied with regard to the position of the trachea and the vertebral bodies. Course and origin of the innominate artery depends on the direction of the left ventricular outflow. The influence of haemodynamic factors in the formation of the aortic arch system is discussed. The innominate artery, which is arched in early infancy, straightens due to the descending heart and the growth of the infant. Its topographic relation to the trachea changes with age. In view of these developmental changes it is unlikely, that an aberrant origin of the innominate artery accounts for the tracheal compression.