Noninvasive grading of untreated gliomas: a comparative study of MR imaging and 3-(iodine 123)-L-alpha-methyltyrosine SPECT

PURPOSE: To compare the accuracy of magnetic resonance (MR) imaging scores with that of 3-(iodine 123)-L-alpha-methyltyrosine ((123)I-IMT) single photon emission computed tomography (SPECT) in the noninvasive grading of untreated gliomas. MATERIALS AND METHODS: The study comprised 15 patients with low-grade gliomas (grades I-II, according to World Health Organization criteria) and 33 patients with high-grade gliomas (grades III-IV). The lesions were evaluated by using an MR imaging score based on nine criteria. The (123)I-IMT uptake was quantified as the ratio between the amino acid uptake in the tumor and that in the contralateral hemisphere. To test for potentially significant differences in diagnostic performance between contrast material-enhanced MR imaging and (123)I-IMT SPECT, binormal receiver operating characteristic curves were fitted to the data and compared by using the area test. RESULTS: The accuracy of MR imaging in the noninvasive grading of untreated gliomas was higher than that of (123)I-IMT SPECT (88% vs 79%). However, the difference in diagnostic performance was not significant on the basis of findings at receiver operating characteristic analysis (P >.2). Neither MR imaging nor (123)I-IMT SPECT allowed differentiation between high-grade gliomas (grades III and IV). CONCLUSION: Although (123)I-IMT uptake is significantly higher in high-grade gliomas than in low-grade gliomas, the performance of (123)I-IMT SPECT adds little to the accuracy of determining tumor grade when MR imaging is performed.     

A non-randomized controlled clinical trial on autologous chondrocyte implantation (ACI) in cartilage defects of the medial femoral condyle with or without high tibial osteotomy in patients with varus deformity of less than 5°

Purpose

High tibial osteotomy (HTO) is a recommended concomitant surgery when treating cartilage lesions of the medial femoral condyle (MFC). Varus deformities of 5° and more were considered an indication for HTO in patients with cartilage defects. This study compares clinical outcome in patients with ACI and concomitant varus deformity of <5° with or without additional HTO.

Methods

43 patients with isolated cartilage defect of the MFC and varus deformity between 1° and 5° (mean age 39.14 ± 8.35 years; mean varus deformity 2.84 ± 1.19°) were included (follow-up 71.88 ± 23.99 months). Group A (n = 19) was treated with ACI and additional HTO; group B (n = 24) received ACI only. Survival rate in terms of absence of the need of reintervention was defined as main outcome parameter. In the subgroup without reintervention, functional outcome (KOOS and WOMAC) was evaluated.

Results

Overall rate of reintervention was 12 (27.9 %). Survival was significantly higher in group A (group A 89.5 %, group B 58.33 %; p = 0.023). Although a trend for better clinical outcome was observed for group A in the subgroup without reintervention, this observation lacked statistical significance (KOOS_symptoms group A 73.23, group B 59.64; p = 0.274).

Conclusion

While there is general consensus for treating varus deformities of >5° in patients with cartilage lesions of the medial femoral condyle, HTO also leads to a reduced rate of reinterventions and longer survival rates in patients with varus deformities of <5°.     

Measurement of skeletal muscle motion in vivo with phase-contrast MR imaging

The ability to measure skeletal muscle motion with phase-contrast magnetic resonance (MR) imaging was tested with a motion phantom that simulated muscle activity. Quantitative analytic data on unidimensional, bidirectional skeletal muscle motion measured in vivo was obtained in four healthy volunteers. MR images of the subjectss' forearms were obtained during flexion and extension of the fingers and of the anterior and posterior muscle compartments of the lower leg with various resistances to ankle dorsiflexion and plantar flexion. It was necessary to correct the data for the effects of eddy currents. In vitro evaluation of the technique was done by studying through-plane sinusoidal motion of solid objects. The largest error was underestimation of the peak excursion of 11.5 mm by 0.09 mm (the root mean square error for the cycle was 0.04 mm) In vivo experiments demonstrated the contraction of muscles in relation to each other. Data acquisition and analysis techniques must be refined, but measuring skeletal muscle motion with phase-contrast MR imaging should enhance the understanding of bioengineering fundamentals and muscular changes in disease and adaptation.     

Radical Resection of Giant Congenital Melanocytic Nevus and Reconstruction With Meek-Graft Covered Integra Dermal Template

BACKGROUND: Giant congenital melanocytic nevi represent a surgical challenge, particularly in cases in which the size of the nevus exceeds certain extend and malignant transformations have to be considered. OBJECTIVE: To discuss through case report considerable surgical options when extensive giant congenital melanocytic nevi with malignant transformation are encountered. METHODS: We present an unusual case of a giant congenital melanocytic nevi of the entire back of a 44-year-old patient. To achieve radical resection with direct appropriate wound closure and acceptable outcome, the integument of the entire back was excised and covered with Integra, followed by split-thickness skin grafting after stable integration of the matrix. RESULTS: The approach resulted in a complete excision of the tumor and acceptable cosmetic and excellent biomechanical outcome. CONCLUSION: The introduced practice demonstrates a useful alternative to established methods, particularly if tumor excision in large areas and subsequent wound closure might be achieved in one procedure.     

The ryanodine contracture test may help diagnose susceptiblity to malignant hyperthermia

PURPOSE: The ryanodine contracture test (RCT) using the plant alkaloid ryanodine as the triggering agent has been proposed to reduce equivocal results of the in vitro caffeine-halothane-contracture test (IVCT), which is the accepted and standardized procedure to diagnose malignant hyperthermia (MH). However, the response of skeletal muscle of non-MH affected patients (controls) to ryanodine has not yet been characterized. METHODS: Skeletal muscle biopsies were studied in 33 controls and in six patients with a history of fulminant MH. Following the IVCT, the RCT was performed in all specimens using ryanodine 1 micro M. Onset time of contracture and time to reach a contracture level of 10 mN above lowest resting tension and above predrug tension were calculated. RESULTS: With the standard IVCT, all controls were labelled MH non-susceptible; all clinically diagnosed MH patients were labelled MH susceptible. With ryanodine, control muscle differed from MH susceptible muscle regarding onset time of contracture (26 vs 3.8 min, P < 0.05) and time to reach a contracture of 10 mN (49 vs 12.5 min, P < 0.05; all median). Tissue viability and patient's age significantly influenced contracture times. CONCLUSIONS: Despite the highly specific binding of ryanodine at the myocytic sarcoplasmic reticulum, the wide range of contracture times of the controls points toward heterogeneity of ryanodine receptors within physiologic limits. This may also be caused in part by tissue viability and the patients' age. The ryanodine contracture test performed in addition to the IVCT may add clarity into diagnosing a patient as MH-susceptible or not.     

The role of ultrasonography in the assessment of renal function in the elderly

BACKGROUND: Ageing is associated with a progressive loss of renal mass and kidney length and a decline in glomerular filtration rate (GFR). This study evaluated a possible correlation between renal function and kidney size measured by ultrasonography (US), and whether the latter helps estimate GFR in the elderly. METHODS: Twenty-five medically stable elderly patients (mean age 85 +/- 5 yrs) were examined in a geriatric ward at a university hospital. Blood samples were taken to determine serum creatinine (Cr) levels. On the same day, 51chromium ethylenediamine tetraacetic acid (51Cr-EDTA) clearance was performed as the gold standard of GFR. US measured kidney length, transverse and anteroposterior dimensions. RESULTS: Serum Cr (r=-0.67; p=0.0002), Cockcroft-Gault formula (r=0.82; p<0.0001), absolute length (r=0.51; p=0.008) and volume kidney (r=0.46; p=0.02) correlated significantly with GFR. After receiver operating curve (ROC) analysis, length was less specific than sensitive in detecting renal impairment. Adding length to the Cockcroft-Gault formula did not improve GFR estimation (p=0.44). In contrast, adding length to serum Cr levels improved GFR estimation (p=0.015). CONCLUSION: In the elderly, kidney length and volume significantly correlated with GFR. However, length has a low specificity in predicting renal impairment. Therefore, in clinical practice, serum Cr levels and calculated Cr clearance are more useful in predicting renal impairment. However, normal kidney length can help to exclude renal impairment in the elderly at risk of GFR underestimation by a calculated Cr clearance.     

Outcome in a post-cardiac surgery population with acute renal failure requiring dialysis: does age make a difference?

BACKGROUND: Acute renal failure (ARF), requiring dialysis (ARF-d), develops in 1-5% of patients undergoing cardiac surgery and is associated with higher in-hospital mortality. Age is one of the known risk factors for the development of ARF. As the ageing population is increasing, the nephrologist will be faced with a large population of elderly patients requiring dialysis following cardiac surgery. The aim of our study was to evaluate the influence of age on and the risk factors for in-hospital mortality. METHODS: Eighty-two patients with ARF following cardiac surgery and requiring dialysis between January 1997 and October 2001 were included. Two groups of patients were studied: the younger population (<70 years, 42 patients, mean age 59+/-10) and an elderly population (>/=70 years, 40 patients, mean age 76+/-4). Severity of disease was evaluated using the SAPS (Simplified Acute Physiology Score), the Liano score and the SHARF (Stuivenberg Hospital Acute Renal Failure) score. RESULTS: Overall mortality in the population with ARF-d was 56.1%. No difference in mortality rate was found between the younger (61.9%) and elderly patient group (50.0%). The two groups were very similar in baseline and procedural characteristics with exception of body weight (P=0.02) and preoperative glomerular filtration rate (P=0.0001). No significant difference was found in the scoring systems between the old and the young (SAPS P=0.52; Liano P=0.96; SHARF T0 P=0.06; SHARF T48 P=0.15). Mortality in the elderly was significantly correlated with hypotension before starting renal replacement therapy (RRT) (P=0.002), mechanical ventilation (P=0.002), presence of multiorgan failure (MOF) (P=0.0001) and higher scores in the severity models (SAPS: P=0.01; Liano: P<0.0001 and SHARF: P<0.0001). CONCLUSION: The outcome in the elderly requiring dialysis due to ARF post-cardiac surgery is comparable with the outcome in a younger population. No significant difference was found in severity of disease between the elderly and the younger. Variables predicting mortality in the elderly are the presence of MOF, mechanical ventilation and hypotension 24 h before starting RRT. These findings indicate that at the time the nephrologist is called for an elderly patient requiring dialysis due to ARF following cardiac surgery, age per se is not a reason to withhold RRT.     

Echocardiographic monitoring during induction of general anesthesia with a miniaturized esophageal probe

Standard transesophageal echocardiography (TEE) does not allow cardiac monitoring during the induction of anesthesia because standard probes would limit the oropharyngeal space and impair mask ventilation and tracheal intubation. We hypothesized that a prototype, miniaturized TEE probe could be safely introduced transnasally in awake patients and that mask ventilation and orotracheal intubation could be performed while continuously monitoring left ventricular (LV) function during the induction of anesthesia. Forty-five patients were studied prospectively. The transnasal TEE probe was introduced through one of the nares and advanced until a transverse plane image of the LV at the level of the papillary muscles was seen. Anesthesia was induced, and the patients were ventilated with a mask that had previously been threaded over the TEE probe via a central perforation. Probe insertion was successful in 12 patients under local anesthesia alone and in an additional 31 patients with a combination of local anesthesia and mild sedation. In two cases, probe placement was unsuccessful. Overall, hemodynamic variables did not change significantly during insertion. No case of significant mucosal bleeding was seen. In one patient, regurgitation of gastric contents occurred without affecting the perioperative outcome. The two-dimensional echocardiogram image quality of the LV during the induction of anesthesia was good or acceptable in 95% of patients. We conclude that transnasal TEE can effectively be used for cardiac monitoring during the induction of general anesthesia. IMPLICATIONS: This study demonstrates that it is feasible and generally safe to introduce a miniaturized transesophageal echocardiography probe transnasally in awake cardiac risk patients to monitor cardiac performance during the induction of general anesthesia.     

Is colonoscopy alone sufficient to screen for ulcerative colitis-associated colorectal carcinoma?

Patients with ulcerative colitis (UC) are at increased risk for colorectal carcinoma (CAC). Despite the fact that patients at risk are followed closely by colonoscopy to screen for dysplasia, the prevalence of CAC is still unacceptably high. The aim of this study was to evaluate the prevalence of risk factors for CAC, such as dysplasia, and to determine the relevance of colonoscopic surveillance in the group who went on to develop cancer. A series of 24 patients with UC were diagnosed with CAC. The patients' records were analyzed retrospectively for duration of UC, prevalence of preoperative dysplasia, and other cancer risk factors (CRFs) (e.g., pancolitis, primary sclerosing cholangitis, early onset of UC, and backwash ileitis). The mean age of the patients at the time of cancer diagnosis was 43 years with an average UC duration of 15 years (6 patients had had UC less than 8 years). CAC was identified preoperatively by colonoscopy in 15 of 24 patients, with an additional 7 of 15 showing flat dysplasia. Five of nine patients without preoperatively diagnosed CAC had flat dysplasia. Overall, 19 patients had additional CRFs, most of them with at least two more CRFs. Despite a regular colonoscopic follow-up for most patients with UC, flat dysplasia was missed in 12 patients preoperatively. Therefore we suggest that patient information should also always include surgical options in each case where significant cancer risk factors are found.     

Androgen and estrogen receptors in the human corpus cavernosum penis: immunohistochemical and cell culture results

Despite the central and peripheral effects of androgens on the nervous system, the local effects of androgens in the corpus cavernosum penis and their importance for erectile function is still unclear. In this study corpus cavernosum biopsies of eight adult potent patients, aged 19–63 years, undergoing penile deviation surgery (group A) and 12 patients undergoing male-to-female transsexual surgery (group B) were immunostained for nuclear androgen and estrogen-alpha receptors. Additionally, primary corpus cavernosum endothelial cell cultures were obtained from six transsexual patients and exposed to testosterone, dihydrotestosterone, estradiol and progesterone likewise for 7 days. Total cell count was performed and cell metabolic activity was measured by a tetrazolium salt-based assay. Androgen and estrogen-alpha receptors were detected in stromal as well as in endothelial cells. Of all cell nuclei, 74.9% (SD 16.4) in group A and 63.5% (SD 17.1) in group B were positively stained for androgen receptors. The respective percentage of estrogen receptors was 11% (SD 9.5) and 21.2% (SD 12.6). An age-dependent difference in receptor distribution was not observed in either group. In the cell culture system only cultures exposed to testosterone and dihydrotestosterone showed a dose-dependent increase of cell metabolic activity compared to the cultures supplemented with estradiol and progesterone. The significant and age-independent high androgen and low estrogen-alpha receptor distribution found in both groups suggests a possible peripheral effect of androgens at the level of the corpus cavernosum penis in adult humans. This is supported by the observed effect of testosterone and dihydrotestosterone on cell count and endothelial cell metabolism in our cell culture system. The role of estrogens remains unclear.