Analysis of surgical management of calvarial tumours and first results of a newly designed robotic trepanation system.

This study was performed to evaluate the surgical strategy in patients with calvarial tumours, in order to design and modify a robot-assisted trepanation system. A total of 75 patients underwent craniectomy for the treatment of calvarial tumours during the 10-year period from 1993 to 2002. The patients' complaints, the size, location and histology of the tumour, and the various cranioplasty techniques used were analysed retrospectively. In a second procedure several craniectomies at typical locations according to the study's results were performed in a laboratory setting using a hexapod robotic tool, constructed at the Helmholtz-Institute, RWTH Aachen University, and plastic model heads. The workflow was documented and the reproducibility and the accuracy of the procedure were registered. A total of 83 surgical procedures were performed on 75 patients. The majority (87 %) of lesions treated surgically were located in the frontal, temporal and anterior parts of the parietal region. Histological examination revealed benign lesions in 66 % of the patients and dural involvement in 46 %. According to these results craniectomies were performed using the robotic system. Mean positioning accuracy of the robotic system while milling was 0.24 mm, with a standard deviation of 0.04 mm, and maximum error under 1 mm. Craniectomies leaving a 1-mm layer of the tabula interna intact to ensure a healthy dura were performed in several regions successfully. The majority of calvarial tumours, requiring surgical treatment in our patients, were located in cosmetically relevant areas in which drilling can be carried out with the robotic trepanation system. Consequently, the surgical approach had to be planned carefully in order to achieve a good cosmetic outcome.     

Angioid streaks associated with abetalipoproteinemia

Angioid streaks were observed in a 31-year-old man with abetalipoproteinemia. Angioid streaks have now been described in hereditary spherocytosis, beta thalassemia, alpha thalassemia, sickle cell anemia, and acanthocytosis secondary to abetalipoproteinemia and hypobetalipoproteinemia. The nature of the association of angioid streaks and structural defects of hemoglobin and the red blood cell is not understood.     

Haematogenous brain abscess complicating a case of Austrian syndrome

Austrian syndrome includes pneumococcal endocarditis, meningitis and rupture of the aortic valve. This study reports a case with a haematogenous brain abscess. Physicians should be aware of the risk factors and dramatic evolution of this rare disease, to avoid delays in diagnosis, and to prevent embolic complications and rupture of the aortic valve.     

Multidetector CT with double arterial phase and high–iodine–concentration contrast agent in the detection of hepatocellular carcinoma

PURPOSE: The purpose of this study was to determine whether the double arterial phase with multidetector computed tomography MDCT and high-iodine-concentration contrast material (CM) improves identification of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Fifty patients with 111 HCC foci (61 confirmed histologically, 46 confirmed by percutaneous interventional procedures, four confirmed by CT follow-up of at least 6 months) underwent MDCT with a double arterial phase and a portal venous phase after administration of contrast material with a high iodine concentration (400 mgI/ml, 2 ml/kg, 5 ml/s). Two radiologists independently evaluated the images in three distinct reading sessions (early arterial phase (EAP), late arterial phase (LAP) and double arterial phase) to determine presence, number and degree of suspicion of HCC. The sensitivity and the positive predictive value (PPV) were calculated for every reading session. The following statistical evaluations were used: k statistic and McNemar's test. RESULTS: Mean sensitivity and PPV in the detection of HCC were, respectively, 83.8% and 93.5% for EAP, 90.5% and 94.8% for LAP, and 94.1% and 95.1% for the double arterial phase. Sensitivity of the double arterial phase was statistically higher when compared with EAP alone but showed no statistically significant difference when compared with LAP. The k values ndicated moderate-to-excellent interobserver agreement in all reading sessions. CONCLUSIONS: Sensitivity and PPV increase progressively when passing from EAP to LAP to double-arterial-phase images obtained with contrast material with a high iodine concentration. However, the difference in sensitivity between LAP and the double arterial phase was not statistically significant.     

Analysis and technical refinements of endoscopic treatment of vesico-ureteral reflux in children with a 40-month follow up

We report our experience with the endoscopic treatment of vesicoureteral reflux by submucosal injection of Teflon in children. During a period of 40 months, 450 children and a total of 678 ureters were treated; 606 ureters were available with a follow-up of more than 3 months and examined by cystography. The overall success rate was 84.2% after one injection and 94.3% after two injections; 96.2% of the primary refluxes disappeared after two injections. We believe that in duplicated ureters and grade IV and V refluxes only one injection should be tried. If this fails we undertake surgical reimplantation. The success rate in neurogenic bladders and failures of previous surgical reimplantations allows surgery to be avoid in these difficult cases. We found seven non-pathological Teflon granuloma calcifications that had no influence on the results. Offprint requests to: P. Sauvage