Felix Stang

Improvement of cutaneous microcirculation by cold atmospheric plasma (CAP): Results of a controlled, prospective cohort study.

BACKGROUND Cold atmospheric plasma (CAP) has proven its benefits in the reduction of various bacteria and fungi in both in vitro and in vivo studies. Moreover, CAP generated by dielectric barrier discharge (DBD) promoted wound healing in vivo. Charged particles, chemically reactive species (such as O3, OH, H2O2, O, NxOy), ultraviolet radiation (UV-A and UV-B), strong oscillating electric fields as well as weak electric currents are produced by DBD operated in air. However, wound healing is a complex process, depending on nutrient and oxygen supply via cutaneous blood circulation. Therefore, this study examined the effects of CAP on cutaneous microcirculation in a prospective cohort setting. HYPOTHESIS Cold atmospheric plasma application enhances cutaneous microcirculation. METHODS Microcirculatory data of 20 healthy subjects (11 males, 9 females; mean age 35.2 ± 13.8 years; BMI 24.3 ± 3.1 kg/m(2)) were recorded continuously at a defined skin area at the radial forearm. Under standardized conditions, microcirculatory measurements were performed using a combined laser Doppler and photospectrometry system. After baseline measurement, CAP was applied by a DBD plasma device for 90 s to the same defined skin area of 22.5 cm(2). Immediately after the application cutaneous microcirculation was assessed for 30 min at the same site. RESULTS After CAP application, tissue oxygen saturation immediately increased by 24% (63.8 ± 13.8% from 51.4 ± 13.2% at baseline, p<0.001) and stayed significantly elevated for 8 min. Cutaneous blood flow increased by 73% (41.0 ± 31.2 AU from 23.7 ± 20.8 AU at baseline, p<0.001) and remained upregulated for 11 min. Furthermore, cutaneous blood flow showed two peaks at 14 (29.8 ± 25.0 AU, p=0.049) and 19 min (29.8 ± 22.6 AU, p=0.048) after treatment. Postcapillary venous filling pressure continuously increased, but showed no significant change vs. baseline in the non-specific BMI group. Subgroup analysis revealed that tissue oxygen saturation, postcapillary venous filling pressure and blood flow increased more in case of a lower BMI. CONCLUSION CAP increases cutaneous tissue oxygen saturation and capillary blood flow at the radial forearm of healthy volunteers. These results support recently published data on wound healing after CAP treatment. However, further studies are needed to determine if this treatment can improve the reduced microcirculation in diabetic foot ulcers. Moreover, repetitive application protocols have to be compared with a single session treatment approach.

Prospective clinical study on digital nerve repair with collagen nerve conduits and review of literature.

Little data are available concerning conduit repair of digital nerve lesions. We are presenting a prospective two-center cohort study on digital nerve reconstruction with collagen nerve conduits. The data are put into the context of a comprehensive review of existing literature. Over a period of 3 years, all consecutive digital nerve lesions that could not be repaired by tensionless coaptation with a gap length of less than 26 mm were reconstructed with nerve conduits made from bovine collagen I. Sensibility was assessed 1 week, 3, 6, and 12 months postoperatively by static and moving 2-point-discrimination (2PD) and monofilament testing. Forty-nine digital nerve lesions in 40 patients met the inclusion criteria. The mean nerve gap was 12.3 ± 2.3 mm (span 5-25 mm). Forty nerve reconstructions could be included in the 12-month follow-up. Three cases, assessed 12 months postoperatively, showed excellent sensibility (static 2PD <6 mm). Seventeen achieved good (2PD 6-10 mm), 5 fair (2PD 11-15 mm), 6 poor (2PD >15 mm, but protective sensibility), and 9 achieved no sensibility. Monofilament test results were significantly better if gap length was shorter than 12 mm. Our results confirm tubulization as one possible technique in nerve reconstruction for gap lengths of 5 to 25 mm.

Management of difficult intra-articular fractures or fracture dislocations of the proximal interphalangeal joint

Intra-articular fractures or fracture dislocations of the proximal interphalangeal joint are difficult clinically because the bone and soft tissue structures are small and intricate. Suboptimal treatment of intra-articular fractures typically leads to functional impairment of the hand. This article reviews the current methods of treatment, together with the senior author’s experience in treating difficult proximal interphalangeal joint fractures and dislocations. Besides conservative treatments, surgical treatments include open or closed reduction with traditional Osteosynthesis, such as K-wires, screws or plates. Among recent developments are the percutaneous application of thin cannulated compression screws and novel dynamic external fixators. After a preferred minimally invasive treatment with stable reconstruction of the articular surface, sufficient aftercare is necessary to improve surgical outcomes.

Repetitive shock wave therapy improves muscular microcirculation

BACKGROUND Extracorporeal shock wave therapy (ESWT) is mainly applied in tendon as well as bone problems based on stem-cell activation and healing acceleration. The effect of ESWT on muscle tissue is much less understood to date. However, from a clinical perspective, muscle injuries are of distinct interest especially in elite athletes such as soccer players. MATERIAL AND METHODS A total of 26 rats were randomized into two groups. Group A received a single application of high-energetic focused ESWT (0.3 mJ/mm(2), 4 Hz, 1000 impulses, 10 J), whereas group B underwent the same procedure every 10 min for three sessions (3 × 0.3 mJ/mm(2), 4 Hz, 3 × 1000 impulses, totaling 30 J). Blood flow at a depth of 8 mm was measured continuously and noninvasively by a combined Laser-Doppler-Imaging and photospectrometric technique (Oxygen-to-see, O2C, LEA Medizintechnik, Germany). RESULTS One minute after the application of high-energy ESWT blood flow in group A increased by 16.5% (P = 0.007). Thereafter, it decreased from minute 2 after application and remained significantly unchanged to baseline value until the end of the measuring period at 50 min (P = 0.550). Group B showed a similar significant increase in blood flow of 16.4% (P = 0.049) and a decrease afterward, too. After the second focused ESWT blood flow was boosted to 26.6% (P = 0.004), remaining significantly elevated until the third application was initiated. Muscular blood flow was increased to 29.8% after the third focused ESWT (P < 0.001), remaining significantly increased for another 10 min. CONCLUSIONS Focused ESWT enhances blood flow in the muscle of rats. Moreover, repetitive ESWT extended this beneficial effect.

Is Nerve Regeneration after Reconstruction with Collagen Nerve Conduits Terminated after 12 months? The Long-Term Follow-Up of Two Prospective Clinical Studies

BACKGROUND Long-term follow-up data of digital nerve reconstructions with nerve conduits are limited. Furthermore, it is not known whether nerve regeneration after tubulization is terminated after 12 months, or whether improvement can be expected after this period of time. Therefore, we present the long-term follow-up of two prospective clinical trials. PATIENTS AND METHODS We invited 45 patients who were enrolled in two prospective clinical trials for long-term follow-up. All patients underwent digital nerve reconstruction with conduits made from bovine collagen I due to a gap length of < 26 mm. Sensibility was assessed using static and moving two-point discrimination and monofilament testing. Follow-up data of 1 week, 3, 6, and 12 months, and the current examination were available. Improvement of sensibility was investigated by comparison of the American Society for Surgery of the Hand classification score at 12-month follow-up with the score raised at current examination. RESULTS We examined 20 reconstructed nerves in 16 patients with a mean follow-up of 58.1 months (range, 29.3-93.3 months). We found an improved sensibility at current follow-up compared with the 12-month follow-up in 13 cases. Three cases had the same values whereas four cases had worsened sensibility. Improvement of sensibility was associated with a significantly shorter nerve gap length with significantly better results if the gap length was < 10 mm. CONCLUSION Our results provide evidence that the long-term recovery of sensibility after digital nerve tubulization depends on the nerve gap length with better results in those < 10 mm. Nerve regeneration after tubulization seems not to be terminated after 12 months.

Removal of collagen nerve conduits (NeuraGen) after unsuccessful implantation: focus on histological findings.

Nerve conduits are nonneural, hollow tubular structures designed to bridge the gap of a sectioned nerve, to protect the nerve from scar formation, and to guide the regenerating fibers into the distal nerve stump. In the 8-year experience of our department, four patients aged 14 to 50 years had an unsuccessful implantation of a nerve conduit (NeuraGen, Integra, Plainsboro, NJ). In these four patients, the collagen tubes were replaced by an autogenous nerve graft. The histological specimens showed characteristic histological findings of a scar neuroma without any signs of foreign body reaction in three cases and with minimal foreign body reaction in one case. The collagen nerve tube was completely resorbed in all cases after a time period of 6 to 17 months and could not be detected marco- or microscopically.To our knowledge, this is the first report in the English and German literature describing the histological characteristics of explanted collagen nerve tubes in humans.

Mammary gland-derived nestin-positive cell populations can be isolated from human male and female donors

IntroductionNestin-expressing cells isolated from different human tissues reveal self-renewal capacity and a multilineage differentiation potential. In particular, adult stem/progenitor cell populations from exocrine glands such as the pancreas, salivary gland and sweat gland are characterized by prominent nestin expression. Interestingly, human mammary gland histological examinations also demonstrated the existence of nestin-positive cells in the ductal compartments. Within the scope of our previous work we wonder whether an isolation of nestin-positive cell populations from human mammary gland biopsies is possible and what characteristics they have in vitro. Cell populations from both sexes were propagated and subjected to a comparison with other gland-derived cell populations.MethodsHuman mammary tissue biopsies were mechanically and enzymatically treated, and the isolated acini structures were observed with time-lapse microscopy to track adherently outgrowing cells. The proliferation potential of the cell population was assessed by performing growth curves. On the gene and protein levels we investigated the expression of stem cell markers as well as markers indicating multilineage differentiation.ResultsWe succeeded in establishing proliferating cell populations from breast tissue biopsies of both sexes. Our results display several similarities to the glandular stem cell populations from other exocrine glands. Beside their proliferation capacity during in vitro culture, the obtained cell populations are characterized by their prominent nestin expression. The cells share surface proteins commonly expressed on adult stem cells. We demonstrated the expression of stem cell-related genes like Oct4, Sox2, KLF4 and Nanog, and confirmed multipotent differentiation capacity by detecting transcripts expressed in endodermal, mesodermal and ectodermal cell types.ConclusionWith this study we present an efficient procedure for isolation and propagation of nestin-positive stem cells obtained from male and female breast tissue, which is frequently available. The established multipotent cell populations could be easily expanded in vitro and thus hold promise for cell-based therapies and personalized medicine.

Increased mortality in hypernatremic burned patients

Introduction: In-hospital hypernatremia develops usually iatrogenically from inadequate or inappropriate fluid prescription. In severely burned patient an extensive initial fluid resuscitation is necessary for burn shock survival. After recovering of cellular integrity the circulating volume has to be normalized. Hereby extensive water and electrolyte shifts can provoke hypernatremia. Purpose: Is a hypernatremic state associated with increased mortality? Method: Retrospective study for the incidence of hypernatremia and survival in 40 patients with a totally burned surface area (TBSA) >10%. Age, sex, TBSA, ABSI-Score and fluid resuscitation within the first 24 hours were analyzed. Patients were separated in two groups without (Group A) or with (Group B) hypernatremia. Results: Hypernatremia occurred on day 5±1.4. No significant difference for age, sex, TBSA, ABSI-Score and fluid resuscitation within the first 24 hours were calculated. In Group A all patients survived, while 3 of the hypernatremic patient in Group B died during ICU-stay (Odds-ratio = 1.25; 95% CI 0.971–1.61; p=0.046). Conclusion: Burned patients with an in-hospital acquired hypernatremia have an increased mortality risk. In case of a hypernatremic state early intervention is obligatory. There is a need of a fluid removal strategy in severely burned patient to avoid water imbalance.

The Use of Bone Graft Substitute in Hand Surgery: A Prospective Observational Study

AbstractBone defects are a very common problem in hand surgery, occurring in bone tumor surgery, in complicated fractures, and in wrist surgery. Bone substitutes may be used instead of autologous bone graft to avoid donor site morbidity. In this article, we will review our experience with the use of Cerament bone void filler (Bonesupport, Lund, Sweden) in elective and trauma hand surgery. A prospective clinical study was conducted with 16 patients treated with this bone graft substitute in our department over a period of 3.5 years. Twelve patients (2 female, 10 male; with an average age of 42.42 years) with monostoic enchondroma of the phalanges were treated and 4 patients (1 female, 3 male; with an average age of 55.25 years) with complicated metacarpal fractures with bone defect. Data such as postoperative course with rating of pain, postoperative complications, functional outcome assessment at 1, 2, 3, 6 months, time to complete remodeling were registered. Postoperative redness and swelling after bone graft substitute use was noticed in 7 patients with enchondroma surgery due to the thin soft-tissue envelope of the fingers. Excellent total active motion of the involved digit was noticed in 10 of 12 enchondroma patients and in all 4 fracture patients at 2-month follow-up. In summary, satisfying results are described, making the use of injectable bone graft substitute in the surgical treatment of enchondromas, as well as in trauma hand surgery a good choice.

Handinfektionen: Evaluation eines zweizeitigen Therapieregimes

INTRODUCTION Infections of the hand are common diseases in hand surgery departments. The correct diagnosis and subsequent treatment is difficult and is often underestimated. In literature different and often conflicting treatments are recommended. The present study retrospectively analysed our two-stage surgical treatment. PATIENTS AND METHODS 60 patients (mean age: 51 years, 38 male, 22 female) were studied retrospectively on the basis of the diagnosis hand infection (ICD L03.-). In all patients, a rapid and radical surgical debridement without wound closure was performed. An antibiotic therapy was initiated. We investigated how often wound closure during a second-look operation, following a period of open wound treatment with antiseptic dressing was successful possible. Furthermore, the patients were followed up in our outpatient clinic. RESULTS A successful secondary wound closure was possible after on average 38.7 h and in 92% of the patients. 8% of patients required further surgical treatment. These patients presented with either an existing disease or a delayed presentation with initial antibiotic treatment. Antibiotic therapy was performed on an average for 8.7 days. Altogether for 85% of the 58 patients examined in our outpatient clinic the therapy could be terminated after 3 weeks with a full recovery of function of the injured hand and with full force measurements. The inability to work was on average 16 days. DISCUSSION The two-stage surgical treatment, with radical debridement and open wound dressing in our collective is an adequate treatment for infections of the hand. It is a safe procedure, that allows for combination with an antibiotic therapy by which a rapid restoration of function of the injured hand is possible.