Biomedical subjects
Publications and source records attributed to H Maurer.
The anatomy of the intervertebral foramina L1-S1 was studied by the dissection of 106 foramina levels in 13 human anatomic spine specimens. Twenty foramina were examined in each level from L1 to L5 and 26 foramina from L5 to S1. It appears a safe working canal diameter is 8 mm for L1-L4 and 7 mm for L4-S1.
Meningitis associated with spinal anaesthesia is a rare but well-known complication. We report on a case of fatal bacterial meningitis following spinal anaesthesia in a former preterm infant. The aetiology of this meningitis could not be established. Former preterm infants represent a high-risk population because of their susceptibility to group B streptococcal meningitis at this age as documented in a second case. Therefore we discuss whether meningitis was consequential or coincidental with spinal anaesthesia and could have been prevented by more comprehensive preoperative laboratory screening or prophylactic antibiotics.
Multiple contusions and lacerations of the anterior two-thirds of the forehead were treated by resection of the damaged skin and immediate reconstruction of the forehead with bilateral temporal artery fasciocutaneous advancement flaps.
We evaluated the usefulness and reliability of intraventricular virtual neuroendoscopy based on a comparative anatomical study. Virtual intraventricular endoscopic images were calculated from 3D magnetic resonance images in five anatomic specimens. Contiguous 1.2 mm slices of the specimen heads were acquired at a 1.5 T MR scanner using a 3D-gradient echo sequence. The images were then transferred to an independent 3D-workstation (Sun Spark 20). After scanning the specimen heads, real endoscopy within the cerebral ventricles of these brains was performed with a standard rod lens system. Comparison between real and virtual endoscopic views of the intraventricular topography was based on the same anatomical reference and landmarks. Acquisition of MR data and virtual image post-processing have been possible in all specimens. The virtual endoscopic images of the ventricles were comparable to the intraventricular views obtained by a standard rod lens system. Virtual intraventricular neuroendoscopy can be employed for planning and simulating neuroendoscopic procedures. It enables the neurosurgeon to simulate the endoscopic procedure within the cerebral ventricles on the basis of the patient's individual anatomy prior to surgery.
AIM: To evaluate the use of intraosseous lines for rapid vascular access in primary resuscitation of preterm and full term neonates. METHODS: Thirty intraosseous lines were placed in 27 newborns, in whom conventional venous access had failed. RESULTS: All the neonates survived the resuscitation procedure, with no long term side effects. CONCLUSION: Intraosseous infusion is quick, safe, and effective in compromised neonates.
This study reports an anatomical investigation of the angular branch of the thoracodorsal artery, which can be used in reconstructive surgery to serve as a pedicle for gaining osseous material from the scapula. The study was performed on 135 samples and topography and morphometry of the vessel were investigated. It was found that this artery has five main types of origin. It courses in the fascial gliding layer between the serratus muscle, and the teres major and subscapular muscle to the inferior angle of the scapula. There it provides the bone with blood through periostal branches as part of the arterial rete on the costal and dorsal side of the scapula. The mean length of the angular branch and the thoracodorsal artery together was 148 mm, and when also adding the subscapular artery the overall length became 167 mm. It was found that the length of a pedicle consisting of the angular branch and the thoracodorsal artery is determined by the difference in origin of the vessels with minor influences of the body size. The internal diameters of unfilled fixated vessels measured 3.06 mm for the subscapular, 1.77 mm for the circumflex scapular, 1.30 mm for the thoracodorsal and 0. 64 mm for the angular branch. The exact knowledge of the microanatomy in this area is necessary to be able to use the osseous free flap more selectively and have less traumatization in the donor area.
PURPOSE: To prospectively study the value of adjuvant chemotherapy in pediatric patients with surgically resected nonrhabdomyosarcomatous soft tissue sarcomas (NRSTS). PATIENTS AND METHODS: From June 1986 to May 1992, after complete surgical resection (+/-radiotherapy) of their NRSTS, 81 eligible patients either received adjuvant chemotherapy comprising vincristine, dactinomycin, cyclophosphamide, and doxorubicin or were observed. Only 30 patients accepted randomization, and 15 were assigned to each regimen. Of the remaining 51 patients, 19 elected adjuvant chemotherapy and 32 elected observation. RESULTS: Patients were predominantly male, and 69% of all patients were white. The median age at diagnosis was 12.3 years (range, 9.2 to 20.7 years). For the 81 eligible patients, the 5-year overall survival estimate was 84.5% +/- 4.4% and event-free survival was 72.2% +/- 5.4%. Among randomized patients, the 5-year estimated overall survival rate was 93.3% +/- 7%, and the event-free survival rate was 86.7% +/- 9.5% for the observation group, compared with 69.2% +/- 13% and 40.7% +/- 14%, respectively, for those who received chemotherapy. The significantly worse outcome of patients who received adjuvant chemotherapy disappeared when survival was stratified by tumor grade. Among all patients, a grade 3 lesion conferred a significant disadvantage with respect to event-free survival (P =.0001). CONCLUSION: The administration of adjuvant chemotherapy according to the schedule and dosages used in our trial did not improve the outcome of children with resected NRSTS. In this study, tumor grade was the most important predictor of clinical outcome in patients with resected NRSTS, and this factor should be incorporated into the stratification of patients in future trials.
BACKGROUND: Although previous research has delineated medical, cognitive, and neuropsychologic late effects of central nervous system (CNS) prophylaxis for childhood acute lymphoblastic leukemia (ALL), it has been difficult to draw conclusions about the long term psychosocial sequelae of these treatments due to methodologic problems that led to inconclusive results in past studies. In the current study, the authors examined the long term psychosocial functioning of childhood ALL survivors who had been treated on a Phase III clinical protocol (Cancer and Leukemia Group B [CALGB] 7611) between 1976 and 1979, in which they were randomized to receive either 2400 centigray of cranial radiation (CRT) with intrathecal methotrexate (IT-MTX) or intermediate dose systemic methotrexate (IV-MTX) with IT-MTX. METHODS: One hundred ten survivors of childhood ALL (mean age, 20.8 years) treated on CALGB 7611 who were age 14 years or older and disease free for at least 1 year were studied a mean of 14.7 years after their entry on CALGB 7611. In a telephone interview, a psychosocial assessment battery was administered to the patients, consisting of measures that assessed psychologic, sexual, social, and vocational functioning as well as any delayed physical effects. RESULTS: Survivors who had received CRT + IT-MTX had significantly poorer academic achievement (P = 0.0001), poorer self-images with regard to their bodies (P = 0.001), and greater psychologic distress (P = 0.005). CONCLUSIONS: Cranial radiation used to treat children with ALL has significant long term sequelae in terms of poorer academic achievement and psychosocial functioning. These data add weight to the conclusion that CRT prophylaxis should only be used to treat children who are at high risk of CNS relapse.
From the interosseous membrane of the forearm a tract extends to the dorsal capsule of the distal radioulnar joint. The structure and function of this tract have been investigated. The tract originates from the radius 22 mm proximal to the distal dorsal corner of the sigmoid notch. Central fibres are attached there with fibrous cartilage and superficial bundles mix with the periosteum. The tract is 8 mm wide, 31 mm long and 1 mm thick. Distally it inserts at the capsule of the distal radioulnar joint between the tendon sheaths of extensor digiti minimi and extensor carpi ulnaris. Deep fibres insert directly at the triangular fibrocartilage. The tract of the interosseous membrane is taut in pronation and loose in supination. It strengthens the dorsal capsule of the distal radioulnar joint. During pronation the tract protects the ulnar head in a sling. Its attachment at the triangular fibrocartilage influences the distal radioulnar joint. Its insertion at the triangular fibrocartilage and the support of the weakest part of the dorsal capsule are of interest.
BACKGROUND: The Intergroup Rhabdomyosarcoma Study Group (IRSG) studies began in 1972 and initially used a clinicopathologic system to place patients into prognostic groups. Because of interest in the development of a pretreatment staging system for assessing the posttreatment outcomes of patients with this disease, potential staging elements were retrospectively evaluated in a subset of 505 patients who participated in IRS-II, an IRSG clinical trial. METHODS: Using the IRS-II data, a TNM pretreatment staging system was developed and used to stage prospectively the patients who were entering IRS-III, a subsequent treatment protocol of the IRSG. Failure free survival and overall survival were compared by pretreatment stage in IRS-III as a means of evaluating this TNM staging. RESULTS: The TNM staging system described the tumor (T) in terms of lesion size (< 5 cm or > or = 5 cm) instead of invasiveness, because these two features were not independent of each other. The clinical status of regional lymph nodes (N) was included in the staging system, as was the presence or absence of metastatic disease (M). The latter feature was extremely important, as expected. The anatomic site of the primary tumor also proved to be an important staging element. Classification of patients by tumor size, clinical status of regional lymph nodes, presence or absence of metastatic disease, and location of the primary tumor (at a favorable or unfavorable anatomic site) created four prognostically distinct staging categories that were relatively equal in size. In a prospective evaluation of this staging system with IRS-III patients, the pretreatment staging lost some prognostic impact. The survival of patients with smaller lesions at unfavorable anatomic sites without clinically involved lymph nodes (Stage II) was similar to that of patients with primary tumors at favorable anatomic sites (Stage I). CONCLUSIONS: A pretreatment TNM staging system for childhood rhabdomyosarcoma, developed with data from IRS-II, was not as predictive of patient outcome when applied prospectively to patients treated in the IRS-III trial. These findings could be due to differences in the management strategy used for IRS-III or the statistical variability in the model-fitting process used to develop the staging system. This demonstrates the need for continual reevaluation of staging systems as patient evaluation and treatment innovations are developed.
In vitro and animal studies suggest that high concentrations of recombinant human erythropoietin (rHuEPO) might divert multipotent progenitors into erythroid maturation at the expense of granulocyte production. We determined whether changes of number and lineage commitment of peripheral blood progenitor cells occur in premature infants during therapy with rHuEPO. Thirty preterm infants were randomly assigned either to receive 300 IU of eopoetin alpha s.c. per kilogram body weight three times a week for four weeks or to a control group. At study entry and after two weeks of treatment the numbers of circulating BFU-E, granulocyte-macrophage colony-forming units (CFU-GM) and granulocyte-erythrocyte-macrophage-megakaryocyte CFU (CFU-GEMM) were analyzed by semisolid culture technique, CD34+ cells and early myeloid CD34+CD45RA- progenitors by flow cytometry. As compared with the control group, rHuEPO treatment did not exert any significant modulatory effect on numbers of CFU-GM, nor was there a significant change in numbers of BFU-E, CFU-GEMM, total-CFU, percentage of CD34+ or CD34+CD45RA- cells. Mean neutrophil count was not significantly reduced at any period during the study. Compared with the control group, the infants receiving rHuEPO had higher hematocrit values (p = 0.003) and absolute reticulocyte counts (p < 0.001). The median cumulative volume of blood transfused per kilogram per day was 0.86 ml (first quartile 0.5 ml; third quartile 1.1 ml) in the control group and 0 ml (first quartile 0 ml; third quartile 0.47 ml) in the rHuEPO group (p = 0.038). We conclude using a relatively high dose of rHuEPO in premature infants, no significant in vivo effect on circulating peripheral blood progenitor or neutrophil count could be detected.
The history of minimally invasive lumbar spine surgery began in 1963 with the introduction of chemonucleolysis. Like this technique, the later development of mechanical nucleotomy and lasernucleotomy aimed primarily at reduction of the disc pressure. Miniature optical systems offered the opportunity for more specific decompression by discoscopy or, more recently, by transforaminal epiduroscopy. Initially, nucleotomy was the only feasible minimally invasive procedure. In recent years, however, minimally invasive spinal fusion became possible due to the development of new devices (Cages) and advanced transperitoneal (laparoscopic) and retroperitoneal approaches.
PURPOSE: A retrospective analysis was performed on children with nonmetastatic rhabdomyosarcomas (RMS) involving a parameningeal site treated by one of the four major cooperative groups: Intergroup Rhabdomyosarcoma Study (IRS), International Society of Pediatric Oncology (SIOP), German Cooperative Group (CWS), and Italian Cooperative Group (ICS) to analyse survival and prognostic factors. METHODS AND MATERIALS: Between 1979 and 1989, 230 children (median age 6 years) were treated in the IRS III, SIOP 84, CWS 81, and ICS 79 studies. All patients received chemotherapy, and 203 were irradiated. Radiotherapy doses were similar in the four studies, although treatment volumes were not similar. The SIOP patients had smaller volumes treated. In addition, the SIOP patients with a low risk of meningeal involvement and children under 5 years of age were not irradiated if they had a complete response (CR) to chemotherapy. Time to initiation of irradiation was earlier in the IRS and Italian studies. RESULTS: Median follow-up was 62 months (range 22-140). The 5-year survival and 5-year event-free survival were better for the IRS study (74% and 71%) than for the other study groups (55% and 36% for SIOP, 47% and 47% for CWS, and 39% and 39% for ICS). The low-risk (LR) patients in the IRS study had improved survival. However, patients with high risk of meningeal involvement had similar survival in all four studies. The most significant prognostic factor was the size of tumor (> 5 cm). CONCLUSION: The improved results from the IRS group, especially among the LR patients, could be related to the IRS treatment employed, particularly the systematic use of radiation, to the inclusion of patients with smaller tumors, and to the routine use of quality control of radiation.
The present study was based on the hypothesis that stress may contribute to increased intraocular pressure (IOP) in open-angle glaucoma patients. It is investigated whether IOP reactivity to a mental stressor test (MST) can be influenced by relaxation training. Twenty three patients with open-angle glaucoma were randomly assigned either to a training group (TG) or to a waiting-list control group (CG). Prior to as well as after the completion of the training all patients were exposed to the MST. IOP and heart rate as well as self-ratings of psychological strain were assessed three times: (1) at baseline, (2) after exposition to the stressor, and (3) after a 10-min relaxation phase. Results provide evidence that the MST is a valid procedure to induce psychophysiological activation and that elevated IOP levels in open-angle glaucoma patients might be provoked by stressing situations. However, participation in the relaxation training did not influence IOP stress reactivity.
In order to find a direct approach to the antero-inferior third of the glenoid rim, an anatomic study was performed on a total of 89 shoulders (48 cadavers). To obtain defined reference points for the anterior inferior third of the glenoid cavity, it was compared with the hour markings on a clock face. The 4:30 position on the right shoulder and the 7:30 position on the left shoulder were defined as the relevant reference points. The average distance between the palpable end of the coracoid process and the 4:30 and 7:30 positions was 19 mm. The average distance to the point of intersection of the musculocutaneous nerve with the medial margin of the conjoined tendon was more than 5 cm, and was never less than 2 cm. The average distance of the axillary nerve from the 4:30 position was 2.5 cm in the horizontal plane, with a minimum of 1.5 cm. Radially, the average distance of the axillary nerve was 1.7 cm, with a minimum of 1.3 cm. The anatomic study was followed by a clinical study of 264 patients. An antero-inferior portal located maximum 2 cm distal from the palpable coracoid tip was selected for the introduction of a trocar sheath and blunt trocar, passing through the subscapularis muscle to access the antero-inferior area of the glenoid rim. As additional protection for the musculocutaneous nerve, the direction of the trocar was adjusted during introduction. Reattachment of the labrum-capsule complex was performed extra-articularly. In all cases, at least one implant was located inferior to the 4:30 or 7:30 position. No neurovascular complications arose out of the choice of portal. Out of the 264 patients, the first 100 shoulders (98 patients) were followed-up after an average time of 35 months (18 to 62 months). The recurrence rate was 9%. Excluding the first 30 shoulders (30 patients) from the development phase of the technique, the recurrence rate is only 5.7%. The rate of return to overhead sports activities was 62% and to collision sports activities 70%.
Using a new application of the endoluminal approach, we were able to demonstrate the sonographic anatomy of the eustachian tube in vitro and in vivo and correlate it with the plastic-embedded specimen. Five adult normocephalic cadavers, two patients, and one specimen especially prepared for embedding in plastic were examined. A specifically developed device was used to insert the ultrasound transducer employing an endo-oral approach. The investigation was performed using an intravascular ultrasound unit. In all cases the tube could be visualized in its entirety and relevant anatomic structures identified and compared with the specimen at the corresponding levels. The deeper layers, including the paratubal structures and the mucosa, could be distinguished for the first time by means of endoluminal ultrasonography. Now that endoluminal ultrasonography has revealed this anatomic information, further studies will be able to gauge the clinical efficacy of our method in cases of ventilatory, drainage, and clearance problems. The images showed no difference between the structures in vitro and in vivo, and the vivo examination was even easier than the in vitro one owing to better tissue turgor.
Radiation nephropathy is a well-known late manifestation of renal irradiation in human beings and experimental animals. Its pathogenesis is unclear, but vascular injury may play a role. Endothelial cells have been demonstrated to manifest a variety of abnormalities within hours of exposure to radiation. In the present experiments mice were exposed to lethal doses of whole-body radiation, and the distribution of 111In-labeled platelets was evaluated during the first week after irradiation. The purpose was to determine if early abnormalities of endothelial cells would be manifested by altered sequestration of platelets in kidneys and other organs. It was found that the indium accumulated in the kidneys of irradiated mice to a greater extent than in nonirradiated mice, supporting the possibility of early vascular injury. In control experiments, administration of 111In-oxine was also followed by excessive accumulation of radioactivity in kidneys of irradiated mice, but the pattern of accumulation differed from that seen after injection of radiolabeled platelets. Renal hyperemia was not demonstrable with 51Cr-labeled red cells, renal vascular permeability was not detected with 125I-labeled albumin, and the pattern of renal uptake of plasma proteins labeled with 59Fe or 111In did not coincide with that seen from 111In administered as labeled platelets or oxine. Renal uptake of 111In-oxine was not associated with alterations in urinary or fecal excretion or an increase in total-body retention of the radioisotope. The findings are consistent with the notion that renal vascular injury at the time of irradiation results in accumulation of platelets or platelet constituents during the first week after total-body irradiation of mice.
PURPOSE: The Intergroup Rhabdomyosarcoma Study (IRS) initiated an escalating-dose cyclophosphamide (Cyc) pilot without hematopoietic growth factor (HGF) support in combination with vincristine (Vcr) and actinomycin-D (Amd), known as VAC, to establish a Cyc dose with myelotoxicity comparable to an ifosfamide (Ifos), Vcr, and Amd combination regimen (VAI). A Cyc dose equivalent to Ifos was to be determined when comparable myelotoxicity was achieved. PATIENTS AND METHODS: Patients with either rhabdomyosarcoma or undifferentiated soft-tissue sarcoma and gross residual (clinical group III) disease were eligible for the VAC pilot. Feasibility and toxicity were evaluated in the VAC pilot at each Cyc level before escalating the dose. Starting at CYC 1.2 g/m2 dose escalation was planned at increments of 20-25% in cohorts of 8-10 patients until myelotoxicity at a severe or worse grade was seen in > 90% of the patients. RESULTS: One hundred nineteen eligible patients were evaluated for toxicity and response at four Cyc levels: 1.2, 1.5, 1.8, and 2.2 g/m2. Eight of 87 (9%) evaluable at 2.2 g/m2 had a toxic death. Six of these were attributable to myelotoxicity. Patients age 1-3 years were most vulnerable. The overall complete response (CR) rate of 68% was poorly predicted by the weeks 8 and 20 CR rates of 20 and 40%, respectively. During the first year and overall, myelotoxicity at 2.2 g/m2'1 with VAC was comparable to Ifos 1.8 g/m2'5. Cyc was relatively more myelotoxic than Ifos in the second year of the VAC pilot. Based on actual amount of drug given, a standardized Ifos dose of 9.0 g/m2 was equivalent to 2.1 g/m2 of Cyc, giving an Ifos/Cyc ratio of 4.3. CONCLUSION: Myelotoxicity using 2.2 g Cyc/m2 in a single intravenous infusion was dose limiting in this VAC pilot without HGF. In the first year and overall, myelotoxicity is comparable to that with VAI using Ifos at 9.0 g/m2. An ongoing IRS-IV randomized trial of VAC and VAI should provide a comparison of the efficacy of Ifos and Cyc in children and adolescents with embryonal or alveolar rhabdomyosarcoma and undifferentiated soft-tissue sarcomas.