Aktuelle Konzepte der Intensivtherapie des raumfordernden Mediainfarkts

The aim of this paper is to review new developments in the intensive care of patients with space-occupying middle cerebral artery infarctions. Elevated blood pressure should not be treated; however, there is no scientific basis to induce arterial hypertension in these patients. It is not recommended generally to nurse the patients in a position with the head elevated. If therapy is targeted for an optimum cerebral perfusion pressure, the patients should be nursed in a flat position. Decompressive surgery is associated with a marked reduction in an otherwise high mortality. The functional outcome after surgery is similar to the outcome of the survivors after conventional treatment alone. Treatment options for an acutely raised intracranial pressure are mannitol or hypertonic saline solutions, although the long-term effects have not been ascertained yet. There is not enough evidence supporting a prophylactic standard therapy with hypertonic solutions. Patients who require artificial ventilation can be safely ventilated using PEEP or an inverse inspiration/expiration ratio, if the blood pressure is monitored and a possible drop of the arterial blood pressure is treated. Corticoids and hemodilution are obsolete therapies in these patients.

Combined microneurosurgical and endovascular "trapping-evacuation" technique for clipping proximal paraclinoidal aneurysms

A method is described in which a combined endovascular and microneurosurgical approach is used for clipping aneurysms of the proximal paraclinoidal segment of the internal carotid artery. By temporary occlusion of the cervical carotid artery and continuously retrograde sucking of blood from the distal vessel via a double lumen ballon catheter, clip application to large and critically located aneurysms is facilitated applying decompression to the trapped arterial segment under intraoperative somatosensory-evoked potential (SEP) monitoring.

[A prospective comparison of video colonoscopy and CT colonography in asymptomatic patients screened for colorectal cancer]

BACKGROUND AND OBJECTIVE

It was the aim of this study to compare the sensitivity and specificity of low-dose CT colonography (CTC) with that of optical colonoscopy (OC) in asymptomatic patients undergoing these tests in a screening program for colonic cancer.

PATIENTS AND METHODS

58 patients (mean age 62.6 years) were included. They underwent low dose CTC and, immediately afterwards, colonoscopy. The colonoscopists were unaware of the CTC findings. A "second look" was performed if a lesion seen in CTC had been missed in the first colonoscopy.

RESULTS

A total of 150 lesions were detected and histologically confirmed. 136 were found to be polypoid lesions, classified as either hyperplastic polyps (n = 66) or polyps with intraepithelial neoplasia (n = 70). In the per-patient analysis only 22.4 % of patients had no polypoid lesion, 27.6 % had at least one hyperplastic and 50.0 % had at least one adenomatous lesion. Sensitivity for adenomas of all size categories was calculated 55.7 % for CTC and 92.9 % for OC. This marked difference (both for the detection of individual lesions and the per-patient analyses) does not reach significance in the two-sided McNemar test.

CONCLUSIONS

There was a high prevalence of lesions with intraepithelial neoplasia in this screening group. OC had a higher sensitivity than CTC in the detection of lesions smaller than 10 mm.

[Embolisation of aneurysmal bone cysts as a minimally invasive treatment option - presentation of two cases]

AIM

The aim of this study was to evaluate embolisation as a therapy option for aneurysmal bone cysts of the trunk.

METHOD

Case reports about two males with intermittent pseudo-radicular lumboischialgia and coxalgia are discussed.

RESULTS

The diagnostic work-up and biopsies verified an aneurysmal bone cyst in both males. In one patient the tumour-like lesion was localised in the fifth lumbar vertebral body, in the other in the left ischium and pubis. Arterial embolisation was performed in both cases. Follow-up at 6 and 24 months after embolisation showed a significant increase of sclerosis and a reduced volume of the cysts.

CONCLUSION

In accord with literature data, arterial embolisation seems to be a sufficient and minimally invasive therapy option in aneurysmal bone cysts of the spine and the pubis.

Changing caveolin-1 and oxytocin receptor distribution in the ageing human prostate

Several observations suggest that caveolin-1 has an important role in control of cell proliferation and cancerogenesis. For instance, oxytocin provokes a proliferative response in the prostate tissue when the oxytocin receptor is localized mainly in caveolin-1-enriched domains and an anti-proliferative effect when the same receptor is not localized in caveolae. Moreover, oxytocin concentrations are elevated in prostate tissue of patients with benign prostatic hyperplasia (BPH). In this study the expression pattern of the molecules caveolin-1, oxytocin receptor, androgen receptor and p21 (cell cycle arrest indicator) was investigated in the prostate tissue of BPH patients and of young controls. We found that both caveolin-1 and oxytocin receptor expression is drastically increased with age in both smooth muscle and epithelium of the prostate. We also found a significantly increased co-localization of the oxytocin receptor with caveolin-1 in both the muscle and the epithelium, especially in BPH patients. Androgen receptor and p21 staining was found throughout the prostate but did not change significantly with age or in BPH patients. We conclude that oxytocin may have a proliferative effect on the prostate tissue through the caveolae-associated receptors and thus contribute to BPH. This process seems to be androgen receptor independent.

Dynamics in the ultrastructure of asymmetric axospinous synapses in the frontal cortex of hibernating European ground squirrels (Spermophilus citellus)

Recent theories on the function of arousals from torpor in hibernating mammals focus on the repair of the central nervous system from damage accumulating during prolonged hypothermia. In this framework, we investigated the synaptic ultrastructure in Layer 2 of the frontal cortex from hibernating European ground squirrels (Spermophilus citellus) sacrificed at four different phases in the torpor-arousal cycle. Using electron microscopy, we quantified synapse number and morphometric data on asymmetric axospinous synapses. Length, width, and surface area of postsynaptic densities (PSDs), and the synaptic apposition length of the analyzed synapse were measured. Five groups of animals were compared during entrance into torpor (Torpor Early, TE, n = 6), late torpor (Torpor Late, TL, n = 5), beginning of euthermic arousal episodes (Arousal Early, AE, n = 5), late in the euthermic arousal episode (Arousal Late, AL, n = 5), and during continuous euthermy in spring (EU, n = 6). The results showed that during torpor and at the beginning of arousals the PSD length and synaptic apposition length are significantly increased compared to synapses during late arousal and in spring conditions. In contrast, the width and surface area of the PSDs are decreased in torpor. At the beginning of an arousal the width of the PSD increases and gains maximum value in late arousals (AL), returning to spring (EU) values. No differences were found in total number of synapses during the torpor-arousal cycle. The results indicate reversible changes in ultrastructure of (asymmetric axospinous) synapses in the frontal cortex, which may be critical for the maintenance of cortical neuronal networks and for protection against potential deleterious effects of prolonged hypothermic phases of hibernation.

DNA Fragmentation in Acute and Chronic Rejection After Renal Transplantation

Acute and chronic rejections are important denominators for the long-term function of renal grafts. One important indicator of cell damage is enzymatic DNA fragmentation. To investigate possible mechanisms, the rate of DNA fragmentation (TUNEL staining), the expression of tissue transglutaminase II (a marker of advanced DNA damage), and 8-hydroxy-2'-deoxyguanosine (8-OhdG), an indicator of oxidative injury of nucleic acids, were studied by immunohistochemistry. Semithin sections of renal biopsies revealed 23 patients to show acute interstitial rejections (Banff 97 IA, IB); eight patients, acute vascular rejection (Banff 97 IIA, IIB); and 20 patients, chronic allograft nephropathy (Banff 97 I to III). Correlations were calculated between apoptotic cells and serum creatinine at the time of biopsy and after 6 months. In acute rejection, the proximal tubular cells were apoptotic, particularly in regions with mononuclear infiltrates. In consecutive sections, these apoptotic tubular cells also showed damage by reactive oxygen species (positive 8-OhdG staining). Patients with acute interstitial rejection revealed the highest number of tubular DNA fragmentation (14.9 +/- 10.3) versus chronic allograft nephropathy (9.2 +/- 5.6) as TUNEL-positive cells per 80,000 micro m(2) (P < .05). Patients with acute vascular rejection showed a low degree of tubular apoptosis (6.8 +/- 5.1). There was no significant difference in glomerular DNA fragmentation between acute interstitial and chronic rejections: acute interstitial rejection = 7.1 +/- 5.9 versus chronic allograft nephropathy=6.1 +/- 3.9 TUNEL-positive cells per 80,000 micro m(2). There was a significant negative correlation between the degree of tubular (P < .01) and glomerular (P < .05) apoptosis and the serum creatinine at the time of biopsy as well as after 6 months in all patients irrespective of the Banff class. However, there was heterogeneity in the correlation between renal function and the degree of apoptosis in the glomerular and tubular compartments in the various Banff classes. A positive correlation (P < .01) was observed between the degree of tubular apoptosis and serum creatinine at 6 months after biopsy among patients with acute vascular rejection (Banff 97 IIA, IIB). The present data revealed a high degree of tubular DNA fragmentation associated with oxidative stress in acute interstitial rejection. Nevertheless, apoptosis did not generally negatively influence future renal function and may be important to clear proliferating cells. Apoptosis may also play a different pathophysiological role depending on the type of rejection.

DNA Fragmentation in Chronic Glomerulonephritis: An Immunohistological Analysis

BACKGROUND

Experimental data suggest that apoptosis plays an important pathophysiological role in glomerulonephritis by restoring tissue structure after proliferation of intrinsic renal cells and infiltration of leukocytes. Relatively little is known of apoptosis in human glomerulonephritis, particularly in predicting renal function during follow-up.

METHODS

In order to colocalize different markers for cell damage in renal tissue from patients with different forms of glomerulonephritis (GN), a series of semithin sections from 34 kidney biopsies were studied retrospectively. Normal kidney from a nephrectomy specimen with a small renal adenocarcinoma served as a control. DNA fragmentation, expression of tissue transglutaminase II, BAX and BCL-2 were visualized immunohistochemically. In some renal biopsies, immunohistochemical staining for activated caspase 3 was performed. Proinflammatory markers (C-reactive protein, leukocytes), serum creatinine, creatinine clearance, total proteinuria, albuminuria, alpha(1)-microglobulin and IgG excretion were determined at the time of biopsy. Serum creatinine and total proteinuria were assessed 6 and 12 months after renal biopsy.

RESULTS

Nuclei with different degrees of DNA fragmentation were mainly found in epithelial cells of tubules, but also in glomerular cells, regardless of the form of GN studied. Transglutaminase II expression was found only in cells with a strong staining for DNA fragmentation. DNA fragmentation localized to glomerular cells was more pronounced in proliferative than in non-proliferative forms of GN, being most abundant in patients with rapid progressive GN. Staining for activated caspase 3 in selected biopsies confirmed the presence of apoptosis. BAX and BCL-2 staining was detected within the same cells, but exhibited a different intracellular distribution. In proliferative GN, the extent of DNA damage in tubular epithelial cells significantly corresponds with the concentration of serum creatinine (p < 0.04) and with urinary excretion of alpha(1)-microglobulin (p < 0.01) at the time of biopsy. A significant correlation (p < 0.01) was seen between glomerular DNA fragmentation and follow-up total proteinuria 12 months after biopsy for proliferative forms of GN. The damaged glomerular area (e.g. mesangial sclerosis) significantly correlated with DNA fragmentation in proliferative, but not in nonproliferative GN at the time of biopsy. Furthermore, glomerular damaged showed a significant correlation with tubular DNA damage in proliferative GN.

CONCLUSION

In glomerular cells, apoptosis may be important for the clearance of proliferating cells whereas in tubules, cell damage showed dependence on the degree of tubular injury mediated by inflammation and/or proteinuria. Although the degree of apoptosis in tubular cells correlates with serum creatinine in proliferative GN at the time of biopsy, it is of limited use to predict future renal function.

3D ultrasound navigation in syrinx surgery - a feasibility study

BACKGROUND

The prototype of a 3D ultrasound navigation system, with a trackable 4- to 8-MHz phased-array ultrasound probe was used in syrinx-surgery. The aim of this study was to evaluate the advantages offered by 3D ultrasound and navigation in syringomyelial surgery.

METHODS AND MATERIALS

After laminectomy, with a free-handed tilt of the ultrasound probe, the 3D volume of the target area is acquired within 15 seconds. The data are visualized after reconstruction in an axial, coronal, and sagittal view, offering the possibility of ultrasound-based guided surgery.

RESULTS

Based on the intraoperative volume information, it was possible to navigate with the 3D ultrasound images in all cases. The orientation and image quality with respect to resolution, spatial information, and the identification of anatomical structures facilitated the surgery in all seven cases. The navigation tool, with a length of 12 cm and a tip diameter of 1 mm, was simple to place into the surgical site. The availability of an up-to-date 3D-image resulted in less interruption of the surgical procedure, with no need to repeatedly fill the cavity with sterile saline for new ultrasound acquisitions. New ultrasound images were only required if shift occurred. The coronal and "trajectory-plane" views, offer additional information about the syrinx cavity. The target borders are easier to determine and orientation in separated cavities was possible. Particularly in syringomyelial surgery it was helpful to determine the surface point of the syrinx to place the myelotomy or insert a catheter.

CONCLUSION

3D ultrasound offers the advantages of visualizing the third dimension of the target. For orientation and border determination navigation within the 3D ultrasound volume is very helpful and can take place with the ultrasound probe out of the way. Any disruption in the surgical procedure is minimized by not having to repeatedly fill the cavity with a sterile saline solution, there are fewer difficulties with image orientation because of new image adjustments.

[Spontaneous intracerebral hemorrhages]

Spontaneous intracerebral hemorrhage (ICH) accounts for 8-15% of all cases of stroke and among patients receiving oral anticoagulants this number increases up to 40%. Mortality and morbidity are considerably higher in patients with ICH compared to patients with ischemic stroke. Large randomized controlled trials provide only little evidence for therapeutic strategies in patients with spontaneous ICH. In this review we summarize the available data and give recommendations on the management of spontaneous ICH.

Hemicraniectomy with dural augmentation in medically uncontrollable hemispheric infarction

Surgical decompression to alleviate raised intracranial pressure has been reported repeatedly in the past decades in small series of patients. Only recently have there been indications from larger trials that surgical decompression may be beneficial in treating space-occupying hemispheric infarction. However, surgical requirements for the procedure to be effective have not yet been defined. Based on theoretical criteria, the authors operated on 43 patients with medically uncontrollable hemispheric infarctions. The craniectomies were planned to be as large as possible and performed in combination with a subtemporal decompression. Postoperative computerized tomography scans were evaluated for these criteria. The mean survival rate for the group of 43 patients was 72.1% and no surviving patient ended up in a vegetative state. The mean area of craniectomy was found to be 84.3 +/- 16.5 cm2 and the mean distance of the inferior craniectomy margin to the middle fossa was 1.8 +/- 1.3 cm. Comparison of survivors and nonsurvivors failed to show a significant difference in the size of craniectomy or the distance to the floor of the middle fossa. Compared with the reported 80% fatality rate for medically treated stroke patients, in this subgroup the outcome (72.1% survival rate) is remarkably good. The authors conclude that decompressive craniectomy is an effective treatment, able to reduce mortality, and to improve neurological outcome in patients with space-occupying cerebral infarction if the size of craniectomy is large enough. Nevertheless, there is a need for further investigation to identify patients who will benefit from surgery and predictors to optimize the timing of surgical intervention.