Systemic Tranexamic Acid for Reduced Postoperative Blood Loss and Less Bleeding Complications in Fleur-de-lis Abdominoplasty and Apronectomy.

BACKGROUND: Strategies minimizing surgical bleeding, including the antifibrinolytic agent tranexamic acid, play a crucial role in clinical practice to optimize overall surgical outcomes. Despite its proven efficacy in various clinical fields, there is a limited understanding regarding the use of tranexamic acid in plastic and aesthetic procedures. This study is the first investigating the effects of systemically administered tranexamic acid on postoperative blood loss and bleeding complications in fleur-de-lis abdominoplasties and apronectomies. METHODS: Patients who received 1 g tranexamic acid (n = 44) during fleur-de-lis abdominoplasty or apronectomy were retrospectively compared with those who did not (n = 44). In this context, the outcome parameters 24-h and total drain fluid production, drain time, hospital stay, absolute and relative drop in hemoglobin and hematocrit level as well as bleeding complications such as blood transfusion, hematoma puncture and evacuation were evaluated. RESULTS: Tranexamic acid significantly decreased both drainage volume in 24 h (40.5%, p = 0.0046) and total drain fluid production (42.5%, p = 0.0017). Moreover, a shorter drainage time (19.4%, p = 0.0028) and hospital stay (21.4%, p = 0.0009) were observed. The administration of tranexamic acid was also associated with a reduced postoperative decline in hemoglobin and hematocrit levels. Notably, no bleeding complications were observed in patients who received tranexamic acid, while 6 events occurred in patients without (p = 0.0262). CONCLUSION: Systemic administration of tranexamic acid effectively reduced postoperative blood loss and bleeding complications in fleur-de-lis abdominoplasties and apronectomies. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A Single-Center 10-Year Experience of 180 Transmasculine Patients Undergoing Gender-Affirming Mastectomy While Continuing Masculinizing Hormone Replacement Therapy.

BACKGROUND: Gender-affirming mastectomy is a fundamental step in the transition process of transmasculine patients following the initiation of hormone replacement therapy. Its perioperative management, however, remains underreported and controversial. In this study, a large series of mastectomies in transmen maintaining hormonal therapy is presented. METHODS: Over a 10-year study period, a consecutive series of 180 transmasculine patients undergoing chest masculinizing surgery was evaluated. Demographical and surgical data were collected and analyzed for potential factors influencing outcome. RESULTS: The overall rate of complications was 15.5%. Patients who underwent periareolar incision mastectomy were significantly more likely to develop any type of complication than patients with a sub-mammary incision (28.6% vs. 13.2%, p = 0.045). Hematoma was the most common reason for surgical revision. It occurred significantly more often among the periareolar group (21.4% vs. 7.9%, p = 0.041). Duration and type of hormonal therapy did not differ between patients with or without complications. In a multivariate regression analysis, smoking and type of incision were identified as significant predictors of the all-cause complication rate, whereas the influence of BMI and resection weight diminished after adjusting for confounding factors. CONCLUSION: There is scarcity of information concerning the influence of perioperative hormonal therapy in patients undergoing chest wall masculinization. The observed complication rates-with special regard to hematoma-were comparable to current reports; yet further research is needed to profoundly evaluate this topic and provide evidence-based recommendations for the perioperative management of HRT of transmasculine patients. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 .

Radial Forearm Free Flap Phalloplasty in Female-to-Male Transsexuals - A Comparison Between Gottlieb and Levine's and Chang and Hwang's Technique.

BACKGROUND: Phalloplasty is a crucial part of female-to-male genital gender-affirming surgery, however, up to date, there is still no standardized phalloplasty technique. AIM: To evaluate the outcome of a single-center series of phalloplasties using the free radial forearm flap variations by Chang and Hwang vs by Gottlieb and Levine on a similar number of transgender patients. METHODS: Between 2018 and 2020, 45 female to male transgender patients underwent phalloplasty using a neuro-microvascular free radial forearm flap in our department. Twenty patients underwent phalloplasty by the use of the Chang and Hwang design, whereas 25 patients were subjects to a phalloplasty according to Gottlieb and Levine technique. Patients' demographics, procedural characteristics, postoperative complications, and outcome of both groups were retrospectively evaluated and compared with each other. RESULTS: Patients' demographics were similar in both groups. We did not observe relevant differences concerning postoperative complications comparing the two groups, except for the statistically significant lower rate of partial flap necrosis in the Gottlieb and Levine group. No statistically significant risk factors for an increase in complication rate could be identified. Urethral fistulas were the leading cause of revision. CLINICAL IMPLICATION: Optimizing a phalloplasty surgical technique and contributing to establish the gold standard in phalloplasty. STRENGTHS & LIMITATION: This retrospective study presents the first comparison between the free radial forearm flap phalloplasty by Chang and Hwang and by Gottlieb and Levine performed at the same department on a similar number of transgender patients published so far. CONCLUSION: The Chang and Hwang design is associated with a lower rate of urologic complications (fistulas, stenosis) while the Gottlieb and Levine design has a statistically significant lower incidence of partial flap necrosis. Future prospective trials are needed to establish the gold standard in phalloplasty. Spennato S, Ederer IA., Borisov K et al. Radial Forearm Free Flap Phalloplasty in Female-to-Male Transsexuals - A Comparison Between Gottlieb and Levine's and Chang and Hwang's Technique. J Sex Med 2022;19:661-668.

Air Flow Cooling Improves Anterolateral Thigh Perforator Mapping Using the FLIR ONE Thermal Camera.

BACKGROUND: Due to the variable vascular anatomy preoperative perforator mapping facilitates anterolateral thigh (ALT) free flap harvesting. Dynamic infrared perforator imaging can assist preoperative planning by displaying hot spots that represent angiosomes. This study aims to compare previously described precooling methods to develop a standardized simplified protocol for ALT perforator planning. METHODS: Fifty thighs were examined with a FLIR ONE thermal camera. Four different cold challenges, including alcoholic disinfection, wet laparotomy sponge cooling, fan cooling, and cold pack application, were compared. Hot spot locations within a 250 mm × 80 mm area were compared double-blinded to perforator locations determined by Doppler ultrasonography considered as gold standard. RESULTS: The matching rate of thermographic hot spots and sonographically identified perforators was 34.9 ± 22.2%. An increased matching rate of 62.2 ± 42.2% was noted taking only favored perforators (septocutaneous course, diameter >1 mm, distance <3 cm to the center, and visible concomitant veins) into account. Precooling with a fan followed by alcoholic disinfection provided clearest thermograms and fastest results. CONCLUSION: Thermographic imaging is a reliable method for perforator imaging. Its supplemental use to ultrasound may reduce examination time and yield additional information. Precooling by air flow or alcoholic disinfection can be easily implemented and provide the best thermograms. The matching rate of thermographic hot spots and perforators increases when taking only clinically relevant perforators into account. Thermal perforator mapping therefore reduces distraction by negligible perforators.

A Training Model for Local Flaps Using Fresh Human Skin Excised During Body Contouring Procedures.

BACKGROUND: The safe execution of local flaps tends to be challenging for surgical residents. Thus, the purpose of the study was to evaluate a training model of local flaps based on fresh human skin excised from body contouring procedures. MATERIALS AND METHODS: A questionnaire and surgical skills evaluation-analyzing the theoretical and procedural knowledge about local flaps-were held both before and after the surgical skills training. All surgical procedures were executed on a simulation model based on fresh human skin. Skills evaluation was done according to a modified version of the Objective Structured Assessment of Technical Skills Score. Results before and after the training were compared using SPSS, version 21. RESULTS: In pretraining evaluation, residents showed great difficulty regarding the accuracy of flap design and sufficiency of wound coverage indicating the need for surgical training outside the operating theater. After training, the procedural skills significantly improved as depicted by the modified Objective Structured Assessment of Technical Skills score with a mean cumulative pretraining score of 26.81 ± 5.41 and posttraining score of 43.59 ± 5.72 (P = 0.008). Also, theoretical knowledge significantly improved in the posttraining evaluation with exception to the indication of a Z-plasty (P = 0.257). The training model itself was generally regarded as highly useful and thus recommendable to others. CONCLUSIONS: Surgical handling and the understanding of tissue rotation clearly improved by the presented model which mimics very realistic conditions. The simulation model based on fresh human skin shows cost-effectiveness and allows a broad range for flap procedures wherefore its use should be further promoted.

The role of near-infrared fluorescence imaging with indocyanine green dye in pedicle division with the paramedian forehead flap.

The paramedian forehead flap is considered the gold standard for nasal reconstruction following oncologic surgery. During the 21-day delay in two-stage surgery protocols, many patients report considerably reduced quality of life because of the pedicle. This prospective case series study examined the usefulness of near-infrared (NIR) fluorescence with indocyanine green (ICG) for flap perfusion assessment and identified variables associated with time to flap perfusion. Ten patients (mean age 75.3 ± 11.6 years) with diagnosis of basal cell carcinoma (n = 9) or squamous cell carcinoma (n = 1) underwent intravenous indocyanine injection and NIR fluorescence imaging for assessment of flap vascularisation 2 to 3 weeks after stage 1 surgery. NIR fluorescence imaging showed 90% to 100% perfusion areas in all patients after 14 to 21 days. Early pedicle division occurred in two patients on postoperative days 14 and 16. One minor complication (wound healing disorder) was seen following flap takedown after 14 days. There were no associations between time to flap perfusion and defect size or flap area. NIR fluorescence imaging with ICG dye is a useful method for non-invasive perfusion assessment when used in conjunction with clinical assessment criteria. However, a decision for early pedicle division may raise risk of complications in specific patient groups and must therefore be made with great care.

A quantitative study of hydration level of the skin surface and erythema on conventional and microclimate management capable mattresses and hospital beds.

BACKGROUND: In addition to pressure itself, microclimate factors are gaining more attention in the understanding of the development of pressure ulcers. While there are already various products to reduce pressure on sore-prone areas to prevent pressure ulcers, there are only a few mattresses/hospital beds that actively influence skin microclimate. In this study, we investigated if microclimate management capable mattresses/hospital beds can influence skin hydration and skin redness/erythema. METHODS: We included 25 healthy subjects in our study. Measurements were made using Courage & Khazaka Multi Probe Adapter MPA with Corneometer CM825 and Mexameter MX18 to determine skin hydration of the stratum corneum and skin redness/erythema before and after the subjects were lying in conventional (Viskolastic® Plus, Wulff Med Tec GmbH, Fedderingen, Germany and Duo™ 2 mattress, Hill-Rom GmbH Essen, Germany) or microclimate management capable mattresses/hospital beds (ClinActiv + MCM™ and PEARLS AFT, Hill-Rom GmbH Essen, Germany). RESULTS: While there was no difference in skin redness/erythema on the different mattresses/hospital beds, skin hydration of the stratum corneum decreased significantly in an air fluidized bed compared to baseline values and values measured on standard mattress/Viskolastic® Plus. CONCLUSION: Air-fluidized therapy reduces skin hydration and therefore could contribute to prevent moisture associated ulcers. Changes in skin hydration as one important factor of skin microclimate can be detected after a short time of incubation and even before an erythema appears.

Bilateral reduction mammaplasty with pulsed electron avalanche knife PlasmaBlade™ and conventional electrosurgical surgery: A retrospective, randomised controlled clinical trial.

Wound-healing disorders are common complications in bilateral reduction mammaplasty. Traditional electrosurgical devices generate large amounts of thermal energy, often causing extensive thermal-related collateral tissue damage. This study aimed to retrospectively analyse the operative performance of a novel low-thermal plasma dissection device (pulsed electron avalanche knife-PEAK PlasmaBlade™) compared with traditional electrosurgery. Twenty patients with breast hypertrophy were randomly treated with PEAK PlasmaBlade™ on one breast and conventional electrosurgery on the other. Primary outcome measures were resection weight, drain duration, total drainage volume, and drain output on the first postoperative day. Breasts treated with PEAK PlasmaBlade™ had significantly higher resection weights (728.0 ± 460.1 g vs 661.6 ± 463.4 g; P = .038), significantly lower drain output on the first postoperative day (15.9 ± 15.2 mL vs 27.6 ± 23.5 mL; P = .023), and significantly lower drain durations (2.8 ± 1.0 days vs 3.3 ± 1.0 days; P = .030). Mean total drainage volume was lower where breast reduction was performed with PEAK PlasmaBlade™, but this difference was not significant. No major complications occurred, but wound-healing disorders were documented in almost one-third of the patients (35.0%, n = 7). The PEAK PlasmaBlade™ seems to be superior to conventional electrosurgery for bilateral reduction mammaplasty in terms of tissue damage and wound healing.

Effect of low-thermal dissection device versus conventional electrocautery in mastectomy for female-to-male transgender patients.

Subcutaneous mastectomy, the first step in sexual reassignment surgery of female-to-male transsexuals, is associated with high rates of complication and revision surgery. Also, conventional electrosurgery and the associated thermal tissue damage may compromise outcome. This retrospective randomised clinical study evaluated the effect of low-thermal plasma dissection device (PEAK PlasmaBlade, Medtronic, Minneapolis, Minnesota) in comparison with conventional electrosurgery. A total of 17 female-to-male transsexuals undergoing mastectomy were randomised to PEAK PlasmaBlade on one breast side and to monopolar electrosurgery on the other side of the same patient. Wounds of 17 patients were examined histologically for acute thermal injury. Significantly less total volume of drain output (58.8 ± 37.4 mL vs 98.5 ± 76.4 mL; P = .012) was found on the PEAK PlasmaBlade side compared with the electrosurgery side. Duration of drain was significantly shorter on the PEAK PlasmaBlade side (2.5 ± 0.7 days vs 3.2 ± 0.6 days; P = .010). Furthermore, the PEAK PlasmaBlade side showed fewer thermal damages (41.2% vs 82.4%; P = .039) and thermal injury depth from PEAK PlasmaBlade side was less (3170 vs 4060 µm). PEAK PlasmaBlade appears to be superior to monopolar electrosurgery for mastectomy in female-to-male transsexuals, because it demonstrated less thermal tissue damage, less total volume of drain output, and shorter duration of drain, resulting in faster wound healing.

Comparison of spontaneous sensory recovery of noninnervated anteromedial thigh flap, latissimus dorsi flap, and gracilis muscle flap in lower extremity reconstruction: A prospective comparative study.

BACKGROUND: We evaluated the time course and differences in the sensory recovery of three commonly used free flaps for lower extremity reconstruction. Furthermore, the sensory recovery of skin-grafted muscle and skin paddle in latissimus dorsi flaps (LDMF) were differentiated. METHODS: In a prospective study, 26 patients who had undergone free flap lower extremity reconstruction were enrolled. Among them, 9 received LDMF, 9 received gracilis muscle flaps (GMF), and 8 received anterior lateral thigh flaps (ALTF). The sensory recovery was investigated by using the Semmes-Weinstein test (SWT) at 6 and 12 months after the surgery. RESULTS: All flaps recorded spontaneous sensory recovery. The GMF showed the smallest anesthetic area after 12 months as compared with the ALTF and LDMF (1 ± 3% vs. 18 ± 39% (p < .05) vs. 35 ± 35% (p < .05), respectively). Qualitatively, ALTF exhibited the best sensory recovery with the lowest SWT values (ALTF 4.57 ± 1.12 vs. GMF 5.01 ± 0.81 8 [p < .05], vs. LDMF 5.84 ± 0.52 [p < .05]). The sensory recovery of skin-grafted muscle was superior to that of the skin paddle in the LDMF (anesthetic area 29 ± 36% vs. 54 ± 33% [p < .05], SWT 5.85 ± 0.60 vs. 6.30 ± 0.18 [p < .05], respectively). CONCLUSION: All flaps displayed spontaneous sensory recovery potential over the investigation period, which appeared to be influenced by the flap type and size. The LDMF skin paddle showed lower potential for sensory recovery as compared with the skin-grafted muscle area of the same flap. The GMF demonstrated a near-complete sensory recovery after 12 months.

Elastic Wrapping of Lower Extremity Free Flaps during Dangling Improves Microcirculation and Reduces Pain as well as Edema.

BACKGROUND: Free tissue transfer has become a common and safe reconstructive procedure. However, total or partial flap losses remain a looming threat, especially for lower extremity free flaps due to the gravitational challenge associated with dependency. Thus, the majority of microsurgical centers apply some kind of structured flap training. However, due to the lack of evidence, these differ greatly, for example, in the application of an elastic wrapping during dangling. Therefore, the aim of this study was to assess the impact of an elastic wrapping on free flap microcirculation, edema, and pain during dangling. METHODS: Standardized dangling was performed from postoperative day (POD) 6 to 9 in 30 patients with microvascular reconstruction of the lower extremity. The first dangling per day was performed without elastic wrapping, followed by another session with 30 mm Hg of elastic wrapping. Tissue oxygen saturation (StO2), regional hemoglobin content (rHb), and blood flow (BF) were continuously measured in the free flap; the circumference of the flap as well as pain was assessed. RESULTS: During wrapped dangling, BF as well as StO2 was significantly increased, while rHb was significantly lower on all PODs. Wrapped dangling was rated significantly more comfortable and the girth of the free flaps was significantly less after wrapped dependency when compared with unwrapped dangling. CONCLUSION: Dangling with an elastic wrapping with 30 mm Hg pressure improved flap microcirculation and reduced pain and edema formation.

Quantitative Analysis of Heel Skin Microcirculation Using Laser Doppler Flowmetry and Tissue Spectrophotometry.

OBJECTIVE: To examine perfusion changes in the heel skin of individuals with and without diabetes mellitus to understand how skin is pathologically affected by diabetes mellitus. METHODS: This case-control study was conducted at an academic hospital in Tuebingen, Germany. A total of 30 subjects were enrolled in the study: 15 with known type 2 diabetes mellitus and 15 without. Each subject was asked to lie in a supine position on a hard lateral transfer mat for 10 minutes. MAIN OUTCOME MEASURES: Heel perfusion was quantitatively assessed directly after relief of pressure and after 3 and 6 minutes after relief of pressure using laser Doppler flowmetry and tissue spectrophotometry. MAIN RESULTS: Directly after relief of pressure, blood flow increased in the superficial skin layers (2 mm below the surface of the skin) in both groups. However, in deep skin layers (8 mm below the surface of the skin), blood flow increased in patients with diabetes mellitus and decreased in healthy patients. Oxygen saturation (SO2) was higher in healthy subjects directly after pressure relief. CONCLUSIONS: The increase in blood flow in superficial skin layers indicates reactive hyperemia after exposure in both groups. The prolonged hyperemia in deep skin layers in patients with diabetes indicates increased tissue vulnerability. Despite the increase in blood flow in deep skin layers, the SO2 and thus supply of tissue in patients with diabetes were reduced.

A quantitative study of transepidermal water loss (TEWL) on conventional and microclimate management capable mattresses and hospital beds.

BACKGROUND: Transepidermal water loss (TEWL) is regarded as one of the most important parameters characterizing skin barrier integrity and has found to be higher in impaired skin barrier function. Reduced or low TEWL instead indicates skin barrier integrity or improvement. We evaluated if different mattresses/hospital beds can influence this skin barrier function by measuring TEWL before and after subjects lying in conventional and microclimate management capable mattresses/hospital beds. METHODS: We included 25 healthy subjects in our study. Measurements were made using Courage & Khazaka Multi Probe Adapter MPA with Tewameter TM300 to determine TEWL before and after the subjects were lying in conventional (Viskolastic® Plus, Wulff Med Tec GmbH, Fedderingen, Germany and Duo™ 2 mattress, Hill-Rom GmbH Essen, Germany) or microclimate management capable mattresses/hospital beds (ClinActiv + MCM™ and PEARLS AFT, Hill-Rom GmbH Essen, Germany). RESULTS: While there was no statistically significant difference in standard mattresses/hospital beds (22.19 ±â€¯12.99 and 19.80 ±â€¯11.48 g/hm2), the decrease of TEWL was statistically significant in both microclimate management capable mattresses/hospital beds we investigated (16.89 ±â€¯8.586 g/hm2 and 17.41 ±â€¯7.203 g/hm2) compared to baseline values (35.85 ±â€¯24.51 g/hm2). CONCLUSION: As higher TEWL announces impaired skin barrier function these findings indicate that the choice of the mattress/hospital bed is important for skin barrier function and microclimate management systems improve skin barrier function of the skin.

[Preservation of the outer ear in a complex burn injury]. / Erhalt des äußeren Ohres bei einer komplexen Verbrennung.

Saving the outer ear in burn injuries is a challenging task for the treating surgeon that should not be underestimated. Burns which are initially evaluated as superficial, particularly in this region, often have a tendency to undergo progressive tissue destruction whereby conservative treatment is often no longer sufficient to preserve the skin of the auricle with the underlying cartilage. Various possibilities for saving the ear and for ear reconstruction are described, but in the case of severely burned patients it is often necessary to carry out a quick and relatively simple treatment. In the complicated case of a severely burned patient involving the external ear, a good cosmetic result could be finally obtained with preservation of form and function by means of an economical cartilage resection with subsequent adaptation.

Quantification of the vasodilatory effect of axillary plexus block. A prospective controlled study.

BACKGROUND: Axillary plexus block is a common method for regional anesthesia, especially in hand and wrist surgery. Local anesthetics (e.g., mepivacaine) are injected around the peripheral nerves in the axilla. A vasodilatory effect due to sympathicolysis has been described, but not quantified. MATERIALS AND METHODS: In a prospective controlled study between October 2012 and July 2013, we analyzed 20 patients with saddle joint arthritis undergoing trapeziectomy under axillary plexus block. Patients received a mixture of mepivacaine 1% and ropivacaine 0.75% in a 3:1 ratio. The measurements were carried out on the plexus side and the contralateral hand, which acted as the control. Laser-Doppler spectrophotometry (oxygen to see [O2C] device) was used to measure various perfusion factors before and after the plexus block, after surgery and in 2-h intervals until 6 h postoperatively. RESULTS: Compared with the contralateral side, the plexus block produced an enhancement of tissue oxygen saturation of 117.35 ± 34.99% (cf. control SO2: 92.92 ± 22.30%, P < 0.010) of the baseline value. Furthermore, blood filling of microvessels (rHb: 131.36 ± 48.64% versus 109.12 ± 33.25%, P < 0.0062), peripheral blood flow (219.85 ± 165.59% versus 129.55 ± 77.12%, P < 0.018), and velocity (163.86 ± 58.18% versus 117.16 ± 45.05%, P < 0.006) showed an increase of values. CONCLUSIONS: Axillary plexus block produces an improvement of peripheral tissue oxygen saturation of the upper extremity over the first 4 h after the inception of anesthesia.

Skin Perfusion Changes within 12 h after Axillary Plexus Block.

BACKGROUND/PURPOSE: An improvement of the blood flow would be beneficial in microvascular upper-extremity reconstruction and in digit replantation. In the present work, skin perfusion changes and their duration due to axillary plexus block were quantified. METHODS: The peripheral blood flow of the upper extremities in 20 patients undergoing trapeziectomy under axillary plexus block was analyzed. RESULTS: Laser Doppler spectrophotometry was used to measure perfusion factors over a 12-h period, with the contralateral hand acting as the control. Axillary plexus block produced a significant increase of peripheral oxygen saturation (117 ± 35% vs. control 93 ± 22%, p = 0.019), peripheral blood flow (220 ± 166% vs. 130 ± 77%, p = 0.037), and velocity (164 ± 58% vs. 117 ± 45%, p = 0.011). CONCLUSION: Axillary plexus block produces an improvement of peripheral tissue oxygen saturation of the upper extremities over the first 6 h after the inception of anesthesia. This suggests a potential benefit especially for critically perfused tissues.

A Quantitative Analysis of Microcirculation in Skin Defects Covered with Topical Wound Dressings or a Newly Developed Collagen Matrix.

OBJECTIVE: Innovative skin substitutes and temporary wound dressings are frequently used in the treatment of superficial and partial-thickness wounds. The aim of this study was to compare 2 commonly used temporary skin dressings with a newly developed collagen matrix to determine changes in microcirculation as measured by blood flow, hemoglobin oxygenation, and relative hemoglobin values during healing of partial-thickness skin defects. METHODS: This animal study involved 28 adult male Lewis rats. On the back of each rat, 2 standardized partial-thickness skin defects were generated through a skin dermatome (n = 56). Then, wounds were treated with polylactide-based copolymer skin substitute (Suprathel, PolyMedics, Denkendorf, Germany; n = 14), biosynthetic skin dressing (Biobrane, Smith & Nephew, Hamburg, Germany; n = 14), or Collagen Cell Carrier (CCC; Naturin Viscofan, Weinheim, Germany; n = 14). The remaining control wounds were left untreated (n = 14). MAIN OUTCOME MEASURES: Perfusion dynamics were assessed every 10 days for 80 days with the O2C device (LEA Medizintechnik, Gießen, Germany) to determine blood flow, hemoglobin oxygenation, and relative amount of hemoglobin. MAIN RESULTS: Blood flow was increased in all wounds for at least 30 days after wound generation. The relative amounts of hemoglobin were increased in superficial layers (2 mm) for 10 to 20 days. Hemoglobin oxygenation in the superficial layers decreased in the polylactide-based copolymer skin substitute and biosynthetic skin dressing-treated groups and initially increased in the untreated wounds and CCC groups on day 10; these values also decreased. CONCLUSIONS: The presented results demonstrate the complex changes in microcirculation in the course of healing partial-thickness wounds with different wound dressings and contribute to a better understanding of these wounds. However, based on the results of the study, a clear recommendation for a specific substitute is not yet possible.

Determining the appropriate number and duration of leech therapy in congested tissues using tissue spectrophotometry and laser Doppler flowmetry.

A universal protocol determining the number of leeches and their application time does not exist. The aim of this study, therefore, is to quantify perfusion dynamics in venous congested tissues after leech application to get more detailed information about changes due to leech-induced skin microcirculation and to evaluate the usability of the Oxygen to See (O2C) device in terms of determining the appropriate number of leeches and the duration of therapy. Twelve patients with the need for leech therapy participated in the study. Perfusion dynamics of the congested tissue was assessed using the O2C device, which determines blood flow (BF), the relative amount of hemoglobin (rHB), and the oxygen saturation (SO2). Measurements were carried out before leech application and on various intervals like 10 minutes, one hour, and three hours after leech application. The leech application effectuated after 10 minutes a nonsignificant perfusion improvement, which further increased after one hour with a significant reduction of the relative amount of hemoglobin and a significant increase of blood flow and oxygen saturation (BF= +56.7%; rHB= -25.5%; SO2= +53.7%). After three hours, the values returned to the levels before leech administration. In two cases, in which further administration of leeches within the measurement period was necessary, no substantial perfusion changes were obtained. The results of this study forms a more precise pattern of microcirculatory changes of leech therapy in congested tissues. According to our measurements a venous drainage improvement can be expected in congested tissue one hour after leech administration. The O2C seems to be a useful method to determine the appropriate number and duration of leech therapy.

Utilization of laser Doppler flowmetry and tissue spectrophotometry for burn depth assessment using a miniature swine model.

Currently, the diagnosis of burn depth is primarily based on a visual assessment and can be dependent on the surgeons' experience. The goal of this study was to determine the ability of laser Doppler flowmeter combined with a tissue spectrophotometer to discriminate burn depth in a miniature swine burn model. Burn injuries of varying depth, including superficial-partial, deep-partial, and full thickness, were created in seven Göttingen minipigs using an aluminium bar (100 °C), which was applied to the abdominal skin for periods of 1, 3, 6, 12, 30, and 60 seconds with gravity alone. The depth of injury was evaluated histologically using hematoxylin and eosin staining. All burns were assessed 3 hours after injury using a device that combines a laser light and a white light to determine blood flow, hemoglobin oxygenation, and relative amount of hemoglobin. The blood flow (41 vs. 124 arbitrary units [AU]) and relative amount of hemoglobin (32 vs. 52 AU) were significantly lower in full thickness compared with superficial-partial thickness burns. However, no significant differences in hemoglobin oxygenation were observed between these depths of burns (61 vs. 60%). These results show the ability of laser Doppler flowmeter and tissue spectrophotometer in combination to discriminate between various depths of injury in the minipig model, suggesting that this device may offer a valuable tool for burn depth assessment influencing burn management.

Post-operative monitoring of free muscle transfers by Laser Doppler Imaging: A prospective study.

PURPOSE: Despite different existing methods, monitoring of free muscle transfer is still challenging. In the current study we evaluated our clinical setting regarding monitoring of such tissues, using a recent microcirculation-imaging camera (EasyLDI) as an additional tool for detection of perfusion incompetency. PATIENTS AND METHODS: This study was performed on seven patients with soft tissue defect, who underwent reconstruction with free gracilis muscle. Beside standard monitoring protocol (clinical assessment, temperature strips, and surface Doppler), hourly EasyLDI monitoring was performed for 48 hours. Thereby a baseline value (raised flap but connected to its vascular bundle) and an ischaemia perfusion value (completely resected flap) were measured at the same point. RESULTS: The mean age of the patients, mean baseline value, ischaemia value perfusion were 48.00 ± 13.42 years, 49.31 ± 17.33 arbitrary perfusion units (APU), 9.87 ± 4.22 APU, respectively. The LDI measured values in six free muscle transfers were compatible with hourly standard monitoring protocol, and normalized LDI values significantly increased during time (P < 0.001, r = 0.412). One of the flaps required a return to theatre 17 hours after the operation, where an unsalvageable flap loss was detected. All normalized LDI values of this flap were under the ischaemia perfusion level and the trend was significantly descending during time (P < 0.001, r = -0.870). CONCLUSION: Due to the capability of early detection of perfusion incompetency, LDI may be recommended as an additional post-operative monitoring device for free muscle flaps, for early detection of suspected failing flaps and for validation of other methods.