Henning Ryssel

Stroke magnetic resonance imaging within 6 hours after onset of hyperacute cerebral ischemia.

We studied the diagnostic and prognostic value of diffusion‐ and perfusion‐weighted magnetic resonancce imaging (DWI and PWI) for the initial evaluation and follow‐up monitoring of patients with stroke that had ensued less than 6 hours previously. Further, we examined the role of vessel patency or occlusion and subsequent recanalization or persistent occlusion for further clinical and morphological stroke progression so as to define categories of patients and facilitate treatment decisions. Fifty‐one patients underwent stroke magnetic resonance imaging (DWI, PWI, magnetic resonance angiography, and T2‐weighted imaging) within 3.3 ± 1.29 hours, and, of those, 41 underwent follow‐up magnetic resonance imaging on day 2 and 28 on day 5. In addition, we assessed clinical scores (on the National Institutes of Health Stroke Scale, Scandinavian Stroke Scale, Barthel Index, and Modified Rankin Scale) on days 1, 2, 5, 30, and 90 and performed volumetric analysis of lesion volumes. In all, 25 patients had a proximal, 18 a distal, and 8 no vessel occlusion. Furthermore, 15 of 43 patients exhibited recanalization on day 2. Vessel occlusion was associated with a PWI‐DWI mismatch on the initial magnetic resonance imaging, vessel patency with a PWI‐DWI match (p < 0.0001). Outcome scores and lesion volumes differed significantly between patients experiencing recanalization and those who did not (all p < 0.0001). Acute DWI and PWI lesion volumes correlated poorly with acute clinical scores and only modestly with outcome scores. We have concluded on the basis of this study that early recanalization saves tissue at risk of ischemic infarction and results in significantly smaller infarcts and a significantly better clinical outcome. Patients with proximal vessel occlusions have a larger amount of tissue at risk, a lower recanalization rate, and a worse outcome. Urgent recanalization seems to be of utmost importance for these patients. Ann Neurol 2001;49:460–469

Monitoring Intravenous Recombinant Tissue Plasminogen Activator Thrombolysis for Acute Ischemic Stroke With Diffusion and Perfusion MRI

BACKGROUND AND PURPOSE Intravenous recombinant tissue plasminogen activator (rtPA) administration is an effective therapy for ischemic stroke when initiated within 3 hours and possibly up to 6 hours after symptom onset. To improve patient selection, a fast diagnostic tool that allows reliable diagnosis of hemorrhage and ischemia, vessel status, and tissue at risk at an early stage may be useful. We studied the feasibility of stroke MRI for the initial evaluation and follow-up monitoring of patients undergoing intravenous thrombolysis. METHODS Stroke MRI (diffusion- and perfusion-weighted imaging [DWI and PWI, respectively], magnetic resonance angiography, and T2-weighted imaging) was performed before, during, or after thrombolysis and on days 2 and 5. We assessed clinical scores (National Institutes of Health Stroke Scale [NIHSS], Scandinavian Stroke Scale [SSS], Barthel Index, and Rankin scale) at days 1, 2, 5, 30, and 90. Furthermore, we performed volumetric analysis of infarct volumes on days 1, 2, and 5 as shown in PWI, DWI, and T2-weighted imaging. RESULTS Twenty-four patients received rtPA within a mean time interval after symptom onset of 3.27 hours and stroke MRI of 3.43 hours. Vessel occlusion was present in 20 of 24 patients; 11 vessels recanalized (group 1), and 9 did not (group 2). The baseline PWI lesion volume was significantly larger (P=0.008) than outcome lesion size in group 1, whereas baseline DWI lesion volume was significantly smaller (P=0.008) than final infarct size in group 2. Intergroup outcome differed significantly for all scores at days 30 and 90 (all P<0.01). Intragroup differences were significant in group 1 for change in SSS and NIHSS between day 1 and day 30 (P=0.003) and for SSS only between day 1 and day 90 (P=0.004). CONCLUSIONS Stroke MRI provides comprehensive prognostically relevant information regarding the brain in hyperacute stroke. Stroke MRI may be used as a single imaging tool in acute stroke to identify and monitor candidates for thrombolysis. It is proposed that stroke MRI is safe, reliable, and cost effective; however, our data do not prove this assumption. Early recanalization achieved by thrombolysis can save tissue at risk if present and may result in significantly smaller infarcts and a significantly better outcome.

Comparison of CT with diffusion-weighted MRI in patients with hyperacute stroke

Dear colleagues, We appreciate your comments on our article of August 2001 [1]. Like others, we examined a limited cohort of patients [2, 3]. In contrast to Gonzáles et al. we never used the term ‘‘sensitivity’’. The aim of our study was to compare CT and DWI under similar clinical conditions. We not only looked for the detection rate but also compared the findings of the initial examinations with follow up. (1) DWI is associated with a much better kappa value when lesion extent is judged, and (2) in 48% of our cases the lesion size observed on DWI was the same as that on follow-up scans (CT 26% only). In small cohorts it may be problematic to calculate values of sensitivity, specificity, or predictive values. During the past 4 years we observed some patients with cerebral ischemia without DWI lesions during the first hours after symptom onset. In brainstem infarction we observed hyperintensities at very low signal-to-noise ratios that were not diagnostic. The great variability of cerebral ischemia which initially may cause oligemia/penumbra without infarction may explain the findings reported by Parizel and colleagues; it all depends on the timing of stroke MR during infarct evolution. The parameters of image documentation may also result in misinterpretation if contrast is diminished due to inappropriate window setting. To evaluate the real sensitivity and accuracy of CT and DWI under the same clinical conditions we randomized our hyperacute stroke patients for the order of imaging modalities from January 2000 onwards. The results of blind readings of the images of more than 50 patients have been submitted and will be published in 2002. The hyperintense vessel sign on FLAIR images discussed by Parizel et al. may also be observed on proton-density-weighted images. These images can be acquired within 50 s with a multi-echo sequence. The little additional information of FLAIR images compared with DWI and T2-weighted images can be compensated for with ADC maps. Therefore, we eliminated FLAIR images from the Heidelberg stroke MRI protocol. The vessel status in hyperacute stroke was sufficiently assessed with MR angiography as reported previously [4, 5].

The antimicrobial effect of acetic acid—An alternative to common local antiseptics?

Acetic acid has been commonly used in medicine for more than 6000 years for the disinfection of wounds and especially as an antiseptic agent in the treatment and prophylaxis of the plague. The main goal of this study was to prove the suitability of acetic acid, in low concentration of 3%, as a local antiseptic agent, especially for use in salvage procedures in problematic infections caused by organisms such as Proteus vulgaris, Acinetobacter baumannii or Pseudomonas aeruginosa. This study was designed to compare the in vitro antimicrobial effect of acetic acid with those of common local antiseptics such as povidone-iodine 11% (Betaisodona), polyhexanide 0.04% (Lavasept), mafenide 5% and chlohexidine gluconate 1.5% cetrimide 15% (Hibicet). Former studies suggest the bactericidal effect of acetic acid, but these data are very heterogeneous; therefore, a standardised in vitro study was conducted. To cover the typical bacterial spectrum of a burn unit, the following Gram-negative and Gram-positive bacterial strains were tested: Escherichia coli, P. vulgaris, P. aeruginosa, A. baumannii, Enterococcus faecalis, Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus (MRSA) and beta-haemolytic Streptococcus group A and B. The tests showed excellent bactericidal effect of acetic acid, particularly with problematic Gram-negative bacteria such as P. vulgaris, P. aeruginosa and A. baumannii. The microbiological spectrum of acetic acid is wide, even when tested at a low concentration of 3%. In comparison to our currently used antiseptic solutions, it showed similar - in some bacteria, even better - bactericidal properties. An evaluation of the clinical value of topical application of acetic acid is currently underway. It can be concluded that acetic acid in a concentration of 3% has excellent bactericidal effect and, therefore, seems to be suitable as a local antiseptic agent, but further clinical studies are necessary.

Dermal substitution with Matriderm® in burns on the dorsum of the hand

BACKGROUND Dermal substitutes are used increasingly in deep partial and full-thickness burn wounds in order to enhance elasticity and pliability. In particular, the dorsum of the hand is an area requiring extraordinary mobility for full range of motion. The aim of this comparative study was to evaluate intra-individual outcomes among patients with full-thickness burns of the dorsum of both hands. One hand was treated with split-thickness skin grafts (STSG) alone, and the other with the dermal substitute Matriderm(®) and split-thickness skin grafts. MATERIAL AND METHODS In this study 36 burn wounds of the complete dorsum of both hands in 18 patients with severe burns (age 45.1±17.4 years, 43.8±11.8% TBSA) were treated with the simultaneous application of Matriderm(®), a bovine based collagen I, III, V and elastin-hydrolysate based dermal substitute, and split-thickness skin grafting (STSG) in the form of sheets on one hand, and STSG in the form of sheets alone on the other hand. The study was designed as a prospective comparative study. Using both objective and subjective assessments, data were collected at one week and 6 months after surgery. The following parameters were included: After one week all wounds were assessed for autograft survival. Skin quality was measured 6 months postoperatively using the Vancouver Burn Skin Score (VBSS). Range of motion was measured by Finger-Tip-Palmar-Crease-Distance (FPD) and Finger-Nail-Table-Distance (FNTD). RESULTS Autograft survival was not altered by simultaneous application of the dermal matrix (p>0.05). The VBSS demonstrated a significant increase in skin quality in the group with dermal substitutes (p=0.02) compared to the control group with non-substituted wounds. Range of motion was significantly improved in the group treated with the dermal substitute (p=0.04). CONCLUSION From our results it can be concluded that simultaneous use of Matriderm(®) and STSG is safe and feasible, leading to significantly better results in respect to skin quality of the dorsum of the hand and range of motion of the fingers. Skin elasticity was significantly improved by the collagen/elastin dermal substitute in combination with sheet-autografts.

Single-stage Matriderm® and skin grafting as an alternative reconstruction in high-voltage injuries

This article presents a retrospective analysis of a series of nine patients requiring reconstruction of exposed bone, tendons or joint capsules as a result of acute high‐voltage injuries in a single burn centre. As an alternative to free tissue transfer, the dermal substitute Matriderm® was used in a one‐stage procedure in combination with split‐thickness skin grafts (STSG) for reconstruction. Nine patients, in the period between 2005 and 2009 with extensive high‐voltage injuries to one or more extremities which required coverage of exposed functional structures as bone, tendons or joint capsule, were included. A total of 11 skin graftings and 2 local flaps were performed. Data including regrafting rate, complications, hospital stays, length of rehabilitation and time until return to work were collected. Eleven STSG in combination with Matriderm® were performed on nine patients (success rate 89%). One patient died. One patient needed a free‐flap coverage as a secondary procedure. The median follow‐up was 30 months (range 6–48 months). The clinical results of these nine treated patients concerning skin‐quality and coverage of exposed tendons or joint capsule were very good. In high‐voltage injuries free‐flap failure occurs between 10% and 30% if performed within the first 4–6 weeks after trauma. The use of single‐stage Matriderm® and skin grafting for immediate coverage described in this article is a reliable alternative to selected cases within this period.

Suprathel―Acetic Acid Matrix Versus Acticoat and Aquacel as an Antiseptic Dressing: An In Vitro Study

Background:The treatment of burn wounds is still a challenge regarding the management of antiseptic wound conditioning. Especially, in the United States, silver-containing dressings, such as Acticoat and Aquacel are frequently used. Because silver-containing dressings have well-known drawbacks such as an antimicrobial lack against Pseudomonas aeruginosa, we sought to develop an alternative dressing method. In previous studies, we could demonstrate the excellent antiseptic properties of acetic acid against common burn unit germs, and in another study, the feasibility and suitability of a Suprathel–acetic acid matrix as an antiseptic dressing. Materials and Methods:This study was designed to test the in vitro antimicrobial effect of a Suprathel–acetic acid matrix versus Acticoat and Aquacel. To cover the typical bacterial spectrum of a burn unit, the following Gram-negative and Gram-positive bacteria strains were tested: Escherichia coli, extended-spectrum beta-lactamase–positive Klebsiella pneumoniae, P. aeruginosa, Acinetobacter baumannii, Enterococcus faecalis, and methicillin-resistant Staphylococcus aureus. Results:The tests showed an excellent bactericidal effect of the Suprathel–acetic acid matrix particularly with problematic Gram-negative bacteria such as Proteus vulgaris, P. aeruginosa, and Acinetobacter baumannii. The efficiency was superior to that of Acicoat and Aquacel. Conclusions:Our results support the notion, that the Suprathel–acetic acid matrix has an excellent bactericidal effect and therefore seems to be suitable as a local antiseptic agent in the treatment of burn wounds.

Arteriovenous loops in microsurgical free tissue transfer in reconstruction of central sternal defects

OBJECTIVE In some patients with chest wall defects, free tissue transfer is indicated. Complications arise if multiple operations have left the trunk devoid of recipient vessels. In such patients, an arteriovenous loop between the cephalic vein and the thoracoacromial artery can be used. METHODS A review of all our patients who underwent chest wall reconstruction with a cephalic vein-thoracoacromial artery loop between 2000 and 2009 was performed (n = 29, 19 women and 10 men). The mean age was 64.9 years. Underlying causes were sternal osteomyelitis (n = 20), tumor (n = 4), and osteoradionecrosis (n = 5). All patients were in American Society of Anesthesiologists classes III and IV. Flap selection, intraoperative and postoperative complications, operative time, time of ventilatory support, mean hospital stay, and midterm survival were recorded. RESULTS Twenty-five patients received a tensor fascia lata flap, 2 a vertical rectus myocutaneuos flap, and 2 a deep inferior epigastric perforator flap. Mean duration of surgery was 6.8 hours (4.7-10.5 hours). Two transplanted tissue flaps died and/or had to be removed and 4 were revised successfully. Seven patients had wound complications such as infection or prolonged wound healing. Mean time for ventilator support was 93.6 hours (4-463 hours). The median intensive care unit time was 11 days and the overall hospital stay 27.4 days (11-102 days). One-year survival in the whole group was 69.8%. CONCLUSIONS The concept of arteriovenous loops allows creation of neovessels at the recipient site and has proven to be a superb tool to facilitate free tissue transfer or to provide an exit strategy in situations with unexpected vascular problems at the recipient site.

Pathophysiologie der chronischen Wunde

ZusammenfassungChronische Wunden und ihre Therapie sind nicht nur ein wichtiges medizinisches, sondern vor allem auch ein großes gesellschaftliches Problem, denn sie führen zu einer sozialen Isolierung der Patienten, zu lang andauernder Arbeitsunfähigkeit und sie beeinträchtigen die Lebensqualität der Betroffenen nachhaltig. Um suffiziente Therapiemöglichkeiten zu entwickeln, ist das Verständnis der Wundheilungsvorgänge sowie der Faktoren, die die physiologische Wundheilung stören, eine wichtige Grundvoraussetzung. Diese Arbeit soll einen Überblick über die wichtigsten intrinsischen und extrinsischen Faktoren geben, die eine physiologische Wundheilung stören können und so zur Entwicklung einer chronischen Wunde führen. Ansatzpunkte, die sich hieraus für eine molekulare Beeinflussung der Wundheilung ergeben, werden dargestellt.AbstractChronic, nonhealing wounds and their therapy are not only a medical problem but a severe economic one as well. Such wounds have a great effect on quality of life. Basic research has enhanced our understanding of the stimulation and inhibition of wound healing and provides the basis for introducing new and innovative treatment methods. This paper reviews the most relevant in- and extrinsic factors that disturb physiologic wound healing to result in chronic nonhealing wounds. In addition, molecular intervention modalities targeting various aspects of wound repair are demonstrated.Chronic, nonhealing wounds and their therapy are not only a medical problem but a severe economic one as well. Such wounds have a great effect on quality of life. Basic research has enhanced our understanding of the stimulation and inhibition of wound healing and provides the basis for introducing new and innovative treatment methods. This paper reviews the most relevant in- and extrinsic factors that disturb physiologic wound healing to result in chronic nonhealing wounds. In addition, molecular intervention modalities targeting various aspects of wound repair are demonstrated.

Antiseptic therapy with a polylacticacid-acetic acid matrix in burns

Bacterial colonization and infection are still the major causes of delayed healing and graft rejection following burns and they are furthermore the basis for second and third hit sepsis. Topical treatment is necessary to reduce the incidence of burn wound infection. Silver sulphadiazine (SD‐Ag) is a frequently used microbicidal agent. However, this treatment causes adverse reactions and side‐effects. Additionally, in recent years multiresistant bacteria, which have not been treated sufficiently, are on the rise. On the basis of experimental data and clinical application of a polylacticacid–acetic acid matrix, we performed this study to establish the effectiveness of the antiseptic therapy with the topical application of a polylacticacid–acetic acid matrix to provide an alternative method for burn treatment, using SD‐Ag as a reference. Twenty patients with IIb° or III° burns from the Plastic Surgery and Burns Unit were treated within a matched pair comparative setting. One burned area was treated with SD‐Ag, the other corresponding area with the polylacticacid–acetic acid matrix. All patients underwent a necrectomy 4–5 days after the trauma. The excised burned skin was sent to our microbiological laboratory to determine the different bacteria per gram in this tissue. Despite the number of 20 patients, statistical significance was not achieved, there were tendencies to a better antiseptic effectiveness of the polylacticacid–acetic acid matrix. These results suggest that the polylacticacid–acetic acid matrix should be studied in greater depth and could be used as a valid alternative for the topical treatment of burns, as it is equivalent or even more effective than SD‐Ag.