Surgical strategy in aortoesophageal fistulae: endovascular stentgrafts and in situ repair of the aorta with cryopreserved homografts

OBJECTIVE: The surgical treatment of aortoesophageal fistulae (AEF) has a high morbidity and mortality rate. We report our experience with the sequential use of endovascular thoracic stentgrafts and cryopreserved aortic homografts for in situ repair of the descending thoracic aorta. METHODS: In a 7-year period, 6 patients with AEF were treated at our center. After primary endovascular repair in all cases, 4 patients subsequently underwent in situ repair of the descending thoracic aorta with cryopreserved homografts. Long-term antibiotic therapy was given in all cases. Recent clinical status and radiologic findings on follow-up studies of each patient were analyzed. The mean follow-up time was 35 months (range, 2-76). RESULTS: Endovascular stentgraft repair was technically successful in all cases. Two patients were not candidates for open surgical repair because of their medical condition; they both died within 8 weeks after discharge from the hospital, 1 from recurrent septic episodes, and the other from upper gastrointestinal bleeding. One of 4 patients who had undergone open surgical repair died 1 year later from upper gastrointestinal bleeding that occurred presumably due to an infectious degeneration of the homograft after secondary infection with a methacillin-resistant Staphyloccocus aureus. In 1 case persistent paraplegia and in another case persistent renal failure occurred. CONCLUSION: The use of cryopreserved homografts is a valuable alternative to in situ repair with prosthetic vascular grafts or extra-anatomic reconstructions in the surgical treatment of AEF. Endovascular stentgraft placement plays a role as a bridging procedure in emergency situations.     

Effective point of measurement for parallel plate and cylindrical ion chambers in megavoltage electron beams

The presence of an air filled ionization chamber in a surrounding medium introduces several fluence perturbations in high energy photon and electron beams which have to be accounted for. One of these perturbations, the displacement effect, may be corrected in two different ways: by a correction factor p_dis or by the application of the concept of the effective point of measurement (EPOM). The latter means, that the volume averaged ionization within the chamber is not reported to the chambers reference point but to a point within the air filled cavity. Within this study the EPOM was determined for four different parallel plate and two cylindrical chambers in megavoltage electron beams using Monte Carlo simulations. The positioning of the chambers with this EPOM at the depth of measurement results in a largely depth independent residual perturbation correction, which is determined within this study for the first time. For the parallel plate chambers the EPOM is independent of the energy of the primary electrons. Whereas for the Advanced Markus chamber the position of the EPOM coincides with the chambers reference point, it is shifted for the other parallel plate chambers several tenths of millimeters downstream the beam direction into the air filled cavity. For the cylindrical chambers there is an increasing shift of the EPOM with increasing electron energy. This shift is in upstream direction, i.e. away from the chambers reference point toward the focus. For the highest electron energy the position of the calculated EPOM is in fairly good agreement with the recommendation given in common dosimetry protocols, for the smallest energy, the calculated EPOM positions deviate about 30% from this recommendation.     

Pertussis--an illness with typical clinical symptoms?]

There has been a noticeable increase in the incidence of pertussis in West Germany over the last decade. Since the availability of adequate bacteriological diagnosis a much broader clinical spectrum can be attributed to infections with B. pertussis. Three patients with an unusual clinical presentation of pertussis are presented. A three month old infant presented with severe apneic spells without cough as the sole clinical symptoms of the infection. B. pertussis was isolated in the nasopharyngeal swab. A nine month old premature infant with bronchopulmonary dysplasia after long time intubation and artificial ventilation presented with apneic spells, pulmonary and cardiac decompensation and required ventilatory support. The diagnosis was suggested by a massive leucocytosis with lymphocytosis. The diagnosis on the patient was established by serologic methods. Adult contacts of this patient developed longstanding cough and clinical signs of pertussis. The diagnosis of pertussis in these persons was established by nasopharyngeal culture. The third patient with trisomy 21 and a corrected AV canal suffered from nonspecific cough and gradually developed signs of congestive heart failure with pneumonia. B. pertussis was isolated from the nasopharynx. This patient showed neither the typical paroxysmal coughing spells nor disclosed the typical lymphocytosis in his white blood count. Microbiological investigations of patients with symptoms of respiratory tract infections should include the isolation of B. pertussis. Thus, additional cases of pertussis not suspected on the basis of their initial clinical presentation will be detected.     

Immunogenicity and safety of a monovalent,multicomponent acellular pertussis vaccine in 15 month–6-year-old German children

Immunization against pertussis has been re-recommended for healthy children in Germany in 1991. In addition the former restriction of immunizing only in the first 2 years of life was abolished. In children born before 1991 immunization rates against pertussis were 15% or less. With the new recommendations physicians are now faced with an increasing demand of parents for catch-up vaccinations in these children. Since they were immunized against diphtheria and tetanus previously monovalent pertussis vaccines are needed for this indication. Therefore a monovalent, multicomponent acellular pertussis vaccine was studied in 249 German children 15 months to 6 years of age. Three doses were administered at 6–10 week intervals. Reactogenicity and antibody responses against the vaccine antigens pertussis toxin (PT), filamentous haemagglutinin (FHA), 69-kd antigen (pertactin) and fimbriae-2 (agglutinogen) were investigated. Local and systemic reactions were minimal in frequency and severity. Antibody responses against all vaccine antigens were pronounced with 93%–100% of vaccinees demonstrating at least four fold titre rises above pre-immunization after the third dose. These findings indicate that this monovalent, multicomponent acellular pertussis vaccine with excellent immunogenicity and low reactogenicity is an appropriate candidate for closing immunization gaps in older children in countries with previously low vaccination rates against pertussis. Based on the results of this study the monovalent acellular pertussis vaccine was licensed in Germany in January 1994.     

Comparison of immunogenicity and reactogenicity of a measles, mumps and rubella (MMR) vaccine in German children vaccinated at 9-11, 12-14 or 15-17 months of age

Children aged 9-11, 12-14 or 15-17 months, respectively were vaccinated with a measles, mumps and rubella (MMR) vaccine and serum antibody responses and reactogenicity were compared. The data of 118 children could be analysed (group 1=9-11 months, n=46; group 2=12-14 months, n=29, group 3, 15-17 months, n=43). The only significant difference observed was for seroconversion against measles virus between group 1 and group 3 (84.8% vs 100%, p=0.012). No serious adverse events were reported. Local side reactions were mild, infrequent and independent of age. Immunisation against MMR is safe and effective even when administered before the currently recommended age of 12 months.     

Chronic hemorrhagic pancreatitis in gallbladder polyposis as an initial symptom of metachromatic leukodystrophy

A 4 1/2 year old boy without previous neurologic disorders developed chronic hemorrhagic pancreatitis and was shown to have polyposis of the gallbladder. Neurologic symptoms emerged at the age of 5 years. The sonographic pattern of an echogenic gallbladder was suspect of metachromatic leukodystrophy. The definitive diagnosis was made by the findings of very low arylsulfatase A activity in the white blood cells and deposits of sulfatides in the stroma of the polyps of the gallbladder.     

An unusual case of invagination

Intussusception is an usual pediatric problem in the first two years of life. Nevertheless, it may occur in older children as well, but then often with an uncharacteristic history and atypical x-ray findings. Even symptoms lasting over weeks or months do not exclude intussusception. Ultrasonography is a useful diagnostic approach. In difficult cases endoscopy is indicated.