[Gender affirmation female to male-metaidoioplasty]. / Geschlechtsangleichung von Frau zu Mann ­ Klitorispenoid.

BACKGROUND: Description of an improved technique of metaidoioplasty (clitoris penoid) and presentation of the follow-up of our own patients in comparison to results in the literature. PATIENTS AND METHODS: To reduce the complication rate of urethral strictures and urethrocutaneous fistula, the technique of metaidoioplasty was modified: After elongation of clitoris by incision of chorda the urethra-including the clitoral hood-was reconstructed by distally, broadly based flap of labia minora. In a retrospective follow-up study over 4 years, 75 patients completed questionnaires to assess complications and satisfaction/quality of life and urinary symptoms (ICIQ-FLUTS questionnaire). The same questionnaires were completed by 25 patients pre- and 3 months postoperatively. RESULTS: In the retrospective study, urethral strictures were detected in 1.4% of patients and urethrocutaneous fistulas in 9.4% of patients, which could be repaired in all cases. Furthermore, 39.5% of patients did not decide for phalloplasty and were satisfied with the appearance of the clitoris penoid in 85% and with their function in 88%. A small proportion of the patients developed urinary symptoms, which were mainly of minor severity and significantly dependent on age. In the prospective study, postoperative-versus preoperative-symptoms of urinary incontinence, nocturia, and obstructive micturition were slightly elevated, but mainly of minor severity. CONCLUSIONS: The improved technique of metaidoioplasty using distally broadly based labia-minora flaps resulted in high satisfaction with low urethral complication rates.

Microsurgical lymphatic vascular grafting and secondary liposuction: Results of combination treatment in secondary lymphedema.

Surgical treatment of lymphedema with liposuction typically requires subsequent compression therapy. Here we describe an approach where secondary arm lymphedemas are initially treated by autologous lymphatic grafting to bypass the axilla and restore lymphatic flow. In the presence of excess adipose tissue, liposuction is then performed in a second procedure. To assess outcomes, the authors evaluated 28 consecutive adult patients who had undergone secondary liposuction following lymphatic grafting. Arm volumes were measured prior to lymphatic grafting and after the secondary liposuction. The necessity for additional treatment by compression garment and manual lymphatic drainage was assessed prior to lymphatic grafting and after the secondary liposuction following the direct postoperative regimen. The mean arm volumes were reduced significantly (p<0.001) from a mean of 3417± 171 (SEM) cm3 prior to lymphatic grafting to 3020±125 cm3 after reconstruction of the lymphatic vascular system and finally to 2516±104 cm3 after the secondary liposuction (SLS). All 28 adult patients underwent continuous compression and manual lymph-drainage (MLD) prior to the reconstructive surgery. All 28 patients were evaluated regarding necessity of any additional therapy more than 6 months after SLS with a median follow up period of 37 months (range, 7-160 months). 18 of 28 patients did not require any supportive therapy beyond 6 months after SLS to maintain the results. Three patients continued to utilize manual lymphatic drainage, 4 used a combination of MLD and compression therapy and 3 used elastic compression therapy (one patient only while at work). These results indicate that microsurgical restoration of lymphatic outflow followed by SLS eliminates the need for additional treatment in more than two thirds of patients.

Chylothorax and chylous ascites. Clinical utility of planar scintigraphy and tomographic imaging with SPECT/CT.

UNLABELLED: The aim was to analyze conventional planar scintigraphy and SPECT/CT in patients clinically suspicious for chylothorax or chylous ascites. Lymphoscintigraphy was performed for two reasons: first, to help diagnose chylothorax or -abdomen, by demonstrating diffuse uptake in fluid accumulations, and then secondly, to detect the site of leakage to test the prediction that additional use of SPECT/CT-technique improves upon the diagnostic value of planar lymphoscintigraphy in the baseline detection of thoraco-abdominal lymphatic disorders. PATIENTS, MATERIAL, METHODS: From 7/2008-7/2014 a total of 24 consecutive patients (8 woman, 16 men; age, range 31-79 years) presenting with clinical symptoms suspicious for chylothorax and/or chylous ascites were examined by planar lymphoscintigraphy (n = 26) and additional tomographic SPECT/CT- (n = 22) or SPECT-technique (n = 2). RESULTS: Chylothorax could be scintigraphically confirmed in n = 9, chylous ascites in n = 5 scintigraphies, and excluded in n = 10 patients. In all planar scintigraphy findings of pathological lymph drainage regions (n = 14), SPECT/CT delivered additional relevant information, notably the anatomic localization of the lymphatic leakage. For the baseline detection of thoraco-abdominal lymphatic transport disorders, lymphoscintigraphy showed sensitivity of 88%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 80%. CONCLUSIONS: Our findings show that due to the particular advantages presented by tomographic separation of overlapping sources, SPECT/CT specifies better the anatomical sites, improving the localization of lymphatic leakage in aid of planning surgical re-interventions.

[Free Gracilis Flap for Anatomic Reconstruction after Limb-sparing Sarcoma Resection]. / Freie M. gracilis-Lappenplastik zur anatomischen Rekonstruktion nach gliedmaßen-erhaltender Weichteil-Sarkom Resektion.

INTRODUCTION: Limb-sparing surgery is considered as first choice in most patients with soft tissue sarcomas of the extremities. 5-year survival rates after limb soft tissue sarcoma resection have been promising in many specalised interdisciplinary centres. Quality of life as well as extremity function have thus become an integral aspect of the surgical management of soft tissue sarcomas of the extremities. OBJECTIVE: We herein report on our experience in the anatomic reconstruction of the extremities following limb-sparing soft tissue sarcoma resection using microvascular gracilis muscle flap and skin grafts. PATIENTS AND METHODS: Between 2012 and 2014 an anatomic reconstruction of the hand and foot using gracilis muscle flaps following limb-sparing sarcoma resection (leiomyosarcoma N=2, myxofibrosarcoma N=2, clear cell sarcoma N=1, myxoinflammatory fibroblastic sarcoma N=1, granular cell tumour N=1, pleomorphic sarcoma N=1) was performed in N=8 patients (4 females, 4 males), average age: 44 years (23-76 years), average follow-up time 444 days (98-820). RESULTS: In all patients successful defect coverage with unimpaired wound healing was achieved (adjunctive radiotherapy n=4). The tendon of the harvested gracilis muscle was used for anatomic reconstruction of consequently resected essential anatomic structures (extensor retinaculum n=1, flexor/extensor tendons n=4, extensor expansion n=2, tendon reinsertion n=1, proximal interphalangeal joint collateral ligament n=4, dorsal metatarsal ligament n=1). During follow-up neither local recurrence nor metastasis was observed. CONCLUSION: Reconstruction of multidirectional stability as well as restoring biomechanics and kinetics of the hand and foot should be considered during defect coverage and dead space obliteration management after sarcoma resection of the extremities. For reasons of sound options in anatomic extremity reconstruction with minimal donor site morbidity, the gracilis muscle flap excels in the field of limb-sparing sarcoma resection.

Protective effects of activated protein C (APC) on free groin flaps after secondary venous stasis in the rat model.

BACKGROUND: The goal of this study was to determine whether the focused delivery of APC by rinsing of free adipocutaneous groin flaps shows protective effects on flap survival following a fatal secondary venous stasis in a rat model. METHODS: 36 Sprague Dawley rats were randomized to three groups and free microvascular groin flaps were transplanted to the neck in each animal. 20 hours postoperatively the flap pedicle was re-explored and the distal stump of the flap artery was catheterised. Animals in group I (n = 12) remained untreated, whereas animals of group II were treated with 1 ml of Ringer's solution. Those in group III received 1 ml of APC (2 mg/kg). Afterwards the flap vein was clamped for 35 minutes. The skin of the flaps and the native contralateral groin was examined by intravital video microscopy using FITC-Dextran and CFDA-SE-labelled thrombocytes. RESULTS: APC-pretreatment significantly increased the functional capillary density (FCD) of the flaps. Flap viability was 8% in group I (n = 1/12), 9% in group II (n = 1/11) and 60% in group III (n = 6/10), respectively. No partial flap loss was detected. CONCLUSIONS: The focused delivery of APC resulted in significantly improved flap salvage.

Examination of the protective effects of heparin and recombinant tissue plasminogen activator (rtPA) in compromised adipocutaneous free flaps in the rat model using intravital video microscopy.

BACKGROUND: The purpose of this study was to determine whether the focused delivery of heparin or recombinant tissue plasminogen activator (rtPA) by rinsing accords protective effects which increases the survival of free groin flaps following fatal secondary venous stasis. METHODS: Free microvascular groin flaps (n = 40) were transplanted to the necks of adult Sprague-Dawley rats 20 hours before the experiment. The study groups (each n = 10 animals) were: No adjunctive treatment (Group I), Ringer's solution (Group II), heparin solution (100 IU/kg, group III) and rtPA (2 mg/kg, group IV), respectively. The flap vein was then clamped for 35 minutes. Intravital video microscopy was applied and flap viability was assessed 14 days later. RESULTS: Mean flap necrosis was 90% in group I and II, whereas the rate of flap survival was 80% in group III and 60% in group IV, respectively. CONCLUSIONS: Even though clinical and microvascular flap perfusion parameters in both the rtPA-group and heparin group were initially similar, it has been demonstrated here in our investigations that the flaps treated with heparin showed a higher viability rate. Therefore, we can conclude that the focused delivery of heparin and rtPA resulted in a significantly improved flap salvage.

Magnetic resonance imaging versus lymphoscintigraphy for the assessment of focal lymphatic transport disorders of the lower limb: first experiences.

PURPOSE: To compare the diagnostic accuracy of magnetic resonance imaging (MR-lymphangiography) and lymphoscintigraphy for assessment of focal lesions of the peripheral lymphatic system. Patients with focal lymphatic transport disorders might benefit from surgi-cal interventions. PATIENTS, METHODS: We examined by lymphoscintigraphy and MR-lymphangiography a total of 85 lower limbs in 46 consecutive patients (33 women; mean age 41 years; range 9-79 years) presenting with uni- or bilateral lymphedema. MR-lymphangiographies were obtained at isotropic sub-millimeter resolution with a 3.0 Tesla magnet after injection of gadolinium contrast medium. MR-lymphangiography was reviewed by radiologists, whereas lymphoscintigraphy was reviewed by nuclear medicine physicians. The images were examined for localization and distribution of any focal lesions of the lymphatic vessel system. Diagnostic accuracy of the MR-approach was calculated relative to the lymphoscintigraphy gold standard. RESULTS: There was substantial correlation of results by the two modalities (κ = 0.62). MR-lymphangiography had sensitivity of 68%, specificity of 91%, positive predictive value of 82%, and negative predictive value of 83%. CONCLUSIONS: Imaging findings of both lymphoscintigraphy and MR-lymphangiography showed good diagnostic accuracy. MR-lymphangiography proved more information about anatomic location of focal lesions of the lymphatic vessels, but use of MR-lymphangiography is currently constrained due to the requirement for off-label subcutaneous injection of gadolinium chelates. Consequently, and due to its superior sensitivity lymphoscintigraphy remains the most common imaging method to assess functional lymphatic disorders of the lower limb.

Simvastatin reduces leucocyte- and platelet-endothelial cell interaction in murine antigen-induced arthritis in vivo.

OBJECTIVES: The use of statins in the prevention and treatment of cardiovascular diseases is well established. Their use as anti-inflammatory and immunomodulatory agents in the treatment of rheumatoid arthritis (RA) has also been investigated, with several clinical and experimental studies indicating an anti-inflammatory effect of statins for RA, but other studies showing no effect or even the opposite. The current study was designed to examine the effect of simvastatin in an in vivo murine model of arthritis using intravital microscopy. METHOD: We assigned four groups (n = 7, female C57Bl6 mice), two with and two without antigen-induced arthritis (AiA), from which one of the non-AiA groups and one of the AiA groups were treated with simvastatin 40 mg/kg i.p. daily for 14 consecutive days after induction of arthritis. Platelet- and leucocyte-endothelial cell interaction was assessed by measurement of rolling and adherent fluorescence-labelled platelets and leucocytes, functional capillary density (FCD) was evaluated, and knee joint diameter was determined as a clinical parameter. RESULTS: In arthritic mice treated with simvastatin, a significant reduction in platelet- and leucocyte-endothelial cell interaction was observed in comparison to arthritic mice treated with vehicle. In addition, a significant reduction in FCD was seen in arthritic mice treated with simvastatin, along with a reduction in knee joint swelling of the AiA mice. CONCLUSIONS: Treatment of AiA mice with simvastatin showed significant reductions in platelet- and leucocyte-endothelial cell interactions, in FCD, and in the swelling of the knee joint. These results support the hypothesis of the anti-inflammatory effects of statins in the treatment of RA.

Protective effects of antithrombin on free groin flaps after secondary venous stasis in the rat model.

BACKGROUND: The anticoagulant activity of heparin is well established and led to its widespread clinical use for the prophylaxis and treatment of venous thrombosis in microsurgery. Heparin accelerates antithrombin (AT)-mediated inhibition of clotting and fibrinolytic proteinases. AIM: The aim of the study is to determine whether the focussed delivery of AT by rinsing of free adipocutaneous groin flaps shows protective effects on flap survival, following a fatal secondary venous stasis in the rat model. Further, intravital video microscopy (IVM) is used to detect substance-specific alterations in microvascular perfusion with special focus on regional differences between central and peripheral flap regions. METHODS: Free microvascular groin flaps (n = 22) were transplanted to the neck in adult Sprague-Dawley rats. The flap pedicle was re-explored and the distal stump of the flap artery was catheterised 20 h later. Animals in group I (n = 11) were treated with 1 ml of Ringer's solution administered over 10 min via intraarterial infusion. Those in group II (n = 11) received 1 ml of AT (50 IU/kg). Afterwards, the flap vein was clamped for 35 min. The skin of the flaps and the native contralateral groin was examined by IVM using the plasma-marker fluorescein isothiocyanate (FITC)-dextran and carboxyfluorescein diacetate succinimidyl ester (CFDA-SE)-labelled thrombocytes. After 14 days, the viability of the flaps was evaluated. RESULTS: The treatment with AT significantly increased the functional capillary density (FCD) of the flaps. After 14 days, flap necrosis occurred in nine animals of group I and three animals of group II, respectively. No partial flap loss was detected. CONCLUSIONS: The focussed delivery of AT resulted in significantly improved flap salvage. The results may reinforce the clinical custom of AT substitution in the setting of major surgical procedures such as elaborate microsurgical reconstructions, at least in cases with diminished AT levels.

[Optimising care structures for severe hand trauma and replantation and chances of launching a national network]. / Über Versorgungsstrukturen und Möglichkeiten der Optimierung durch Vernetzung bei schweren Handverletzungen und Replantationen.

Severe hand traumata have a significant impact on our health system and on insurance companies, respectively. It is estimated that 33% of all occupational injuries and 9% of all invalidity pensions are due to severe hand trauma. Unfortunately, these high numbers are not only due to the severity of the trauma but to organisational deficiencies. Usually, the patient is treated at the general surgical emergency in the first place and only then forwarded to a microsurgeon. This redirection increases the time that is required for the patient to finally arrive at an expert for hand surgery. On the one hand, this problem can be explained by the population's lack of awareness for distinguished experts for hand and microsurgery, on the other hand, the emergency network, or emergency doctors in particular are not well informed about where to take a patient with a severe hand trauma - clearly a problem of communication between the hospitals and the ambulance. It is possible to tackle this problem, but put participating hand trauma centres have to work hand in hand as a network and thus exploit synergy effects. The French system "FESUM" is a good example for such a network and even comprises centres in Belgium and Switzerland. To improve the treatment of severe hand trauma, a similar alliance was initiated in Germany just recently. The pilot project "Hand Trauma Alliance" (www.handverletzung.com) was started in April 2013 and currently comprises two hospitals within the region of upper Bavaria. The network provides hand trauma replantation service on a 24/7 basis and aims at shortening the way from the accident site to the fully qualified hand surgeon, to improve the therapy of severe hand injuries and to optimise acute patient care in general. In order to further increase the alliance's impact it is intended to extend the project's scope from regional to national coverage - nevertheless, such an endeavour can only be done in collaboration with the German Society for Hand Surgery (DGH). This article comprises 2 parts. First, the state-of-the-art of acute severe hand trauma care is summarised and explained. Subsequently, the above-mentioned pilot project is described in every detail, including positive effects but also barriers that still have to be overcome.

[The clinical yield of SPECT/CT for the assessment of lymphatic transport disorders. First experiences]. / SPECT/CT zur Untersuchung von Lymphtransportstörungen. Erste Erfahrungen zum klinischen Nutzen.

UNLABELLED: The aim of this study was to determine whether the additional use of SPECT/CT-technique improves the diagnostic value of planar lymphoscintigraphy in patients presenting with lymphatic transport disorders. PATIENTS, METHODS: For a defined period of two years 36 consecutive patients (27 women, 9 men; age 27-87 years) were included in our study. In addition to planar scintigraphy further acquisition of the affected extremities or of the trunk was performed using SPECT/CT-technique. In total, 48 anatomic lymph drainage areas were prospectively analysed by planar scintigraphy and tomographic SPECT/CT. RESULTS: In 28/48 cases (58%) the SPECT/CT-imaging provided relevant additional information before treatment compared to planar technique; among them 27 regarding the exact anatomic localization of lymphatic transport disorders and 8 cases in which the dimension of the lymphatic transport disorders were estimated to a greater extent than in single use of planar lymphoscintigraphy. In 3 cases SPECT/CT provides differential diagnosis of lymph nodes versus lymphoceles. In none of the cases lymph vessels or lymph vessel grafts could be demonstrated by the morphological CT-component. CONCLUSIONS: Additionally to planar lymphoscintigraphy, SPECT/CT specifies anatomical correlation of lymphatic transport disorders and thus the assessment of the extension of the pathology. Furthermore, SPECT/CT dissipates overlapping of anatomic structures by tomographic acquisition and enables differential diagnosis of lymph nodes versus lymphoceles.

[MR lymphangiography for assessment of focal dermal backflow for presurgical work-up in patients with peripheral lymphoedema]. / Die MR-Lymphangiografie in der präoperativen Diagnostik des fokalen "dermal backflow" bei peripheren Lymphödemen.

BACKGROUND: MR lymphangiography might provide valuable morphological information in the diagnosis of peripheral lymphedema in addition to lymphoscintigraphy. Even patients with focal dermal backflow can benefit from surgical intervention. The purpose of this study was to assess the feasibility of MR-Lymphangiography for assessment of focal dermal backflow for pre-surgical work-up. PATIENTS/MATERIALS & METHODS: 50 patients with peripheral lymphedema were included in this study. Patients showing focal dermal backflow in MR-Lymphangiography were reviewed and analyzed separately. The MR findings were correlated to lymphoscintigraphy. Concordance of the 2 modalities regarding existence and distribution of dermal backflow were examined. Furthermore the feeding vessels of the dermal backflow were assessed and visualized. RESULTS: Dermal backflow was diagnosed with MR lymphangiography in 13 patients. Dermal backflow was confirmed by lymphoscintigraphy in 12 patients (92.3%). The feeding vessels of the dermal backflow configuration could be visualized in 9 patients (69.2%) and could be visualized with 3-dimensional reconstructions. The latter is not possible with lymphoscintigraphy. CONCLUSION: MR lymphangiography provides important supplementary diagnostic information in patients with peripheral lymphedema additional to lymphoscintigraphy. Particularly in patients with focal dermal backflow and intended surgery, MR lymphangiography holds high potential for pre-surgical work-up.

[Update on special surgical approaches in the therapy for lymphedemas]. / Die Vielfalt in der chirurgischen Therapie beim Lymphödem - was ist aktuell?

Despite recent medical progress primary and secondary lymphedemas still represent a therapeutic challenge and they often lead to a significant reduction in quality of life. Lymphedemas usually develop in the extremities, the male external genitals as well as the female breast as a consequence to the axial alignment of the lymphatic collectors. Early stages are characterized by an excess of lymph fluid increasing the volume of the affected part of the body whereas later stages represent an increasing amount of solid tissue. Thus therapeutic efforts can focus on the reduction of the surplus of liquid and/or solid components. Generally there are conservative and operative strategies. Conservative measures mainly focus on the improvement of fluid mobilization and drainage and comprise compression garments, manual lymphatic drainage, and apparative intermittent compression. Operative approaches comprise procedures for surgical tissue reduction (symptomatic/ablative approaches) and/or procedures with the intention of enhancing lymphatic transport (causal approaches). Surgical tissue reduction can be performed by open resection and/or liposuction. Traditional surgical causal techniques such as transposition of local flaps aim at leading lymph away from the congested region of the body. Modern microsurgical causal approaches contain methods of reconstruction of interrupted lymphatic pathways as well as techniques for the conduction of lymph into local veins. In this review we depict and discuss the features of the multiform spectrum of the surgical therapy of lymphedemas on the basis of literature as well as our own clinical and experimental experience.

Experimental study on the microsurgical or spontaneous formation of lympho-lymphonodular anastomoses in the rat model.

BACKGROUND: The restoration of the lymphatic function in chronic lymphoedemas can be achieved by microsurgical lymphatic vessel transplantation. Usually, end-to-end anastomoses are performed between the lymphatic vessels. Sometimes, the lack of appropriate lymphatic recipient vessels impels the idea of connecting the grafts to local lymph nodes. This study focusses on the microsurgical completion of durable lympho-lymphonodular anastomoses and further the detection of a spontaneous formation. METHODS: In 36 Sprague-Dawley rats the retroperitoneal lymphatic structures were prepared after staining with patent blue V dye. In group A (n = 12), the left lumbar trunk was cut cranially and its distal part was turned over to the right lumbar lymph node where a microsurgical lympho-lymphonodular anastomosis was performed. In group B (n = 12), treatment was similar but without anastomosing. In group C (n = 12), the left lumbar trunk was transected and the capsule of the contralateral lumbar lymph node was incised. Finally, the lumbar region was re-exposed and the lymphatic drainage was examined using patent blue in four animals of each group after 8, 12 and 16 weeks, respectively, to examine the development of possible spontaneous formations of lymphatic connections. RESULTS: In 12/12 animals of group A, patent transposed lymph vessels and anastomoses with blue staining of the right lumbar lymph node were observed. Only 1/12 animals of group B and 2/12 animals of group C showed a blue staining of the right lumbar lymph node. CONCLUSIONS: The microsurgical fabrication of lympho-lymphonodular anastomoses leads to a safe and durable lymphatic connection. The known plasticity of lymphatic vessels with the potential of spontaneous anastomosing seems to be higher between lymphatic vessels than between lymphatic vessels and a lymph node.

[Treatment of Dupuytren's contracture by means of injectable collagenase: first clinical experiences]. / Die Behandlung der Dupuytrenschen Kontraktur mittels Kollagenase- Erste klinische Erfahrungen.

Recently a minimal invasive therapeutic option by means of enzymatic lysis of Dupuytren's cord was introduced in Europe under the name Xiapex® (Pfizer, Germany).Here we present our first experiences in clinical application with special remarks on complications.In this study 16 injections on 12 Dupuytren's cords in 8 patients were conducted. The average age of the patients was 62.5 (48-74) years. Constitution and application were carried out according to the manufacturer's guidelines. If both the metacarpophalangeal (MP)- and the proximal interphalangeal (PIP) joint were affected, injections were carried out on different points in time. 5 injections were done for contracture of the MPjoint, 4 injections for the PIPjoint, and 3 injections of both, the MP- and PIPjoint. Before the treatment and after 2 weeks the contracture of the treated joint was measured with use of a goniometer for small joints. Side effects and complications were documented as well as whether patients needed - and if yes, for how many days - a pain medication.Total flexion contracture of treated joints could be significantly reduced from 103°±12° to 37°±9°. In MPjoints the flexion contracture was reduced from 47°±8° to 14°±5° and in PIPjoints from 69°±10° to 37°±11° (p<0.05). 5 treated cords showed no signs of complication, recorded local adverse effects were edema (n=5), erythema (n=4) and tearing of skin (n=2). 6 patients needed pain medication for a maximum of 4 days.Treatment with collagenase appears to be an effective and safe therapeutic option for selective cases. Though the procedure ostensibly seems easy, one must emphasize the need for the appropriate application performed only by professionals with a high level of experience both in anatomical knowledge as well as hand surgical know-how to cope potential complications. The value of the new method in relation to the standard partial aponeurectomy and percutaneous needle fasciotomy needs to be ascertained by further research in order to establish a clear indication for each method of treatment.

Epidermal growth factor (EGF) transfection of human bone marrow stromal cells in bone tissue engineering.

A novel therapeutic approach for the treatment of bone defects is gene therapy assisted bone tissue engineering using bone marrow stromal cells (hBMSC). The aim of this study was to investigate the influence of human epidermal growth factor (hEGF) on proliferation and alkaline phosphatase (AP) activity of primary hBMSC in vitro. hBMSC cultures were achieved by explantation culture of bone chips. Following exposure to 0-10 ng recombinant hEGF (rhEGF)/ml cell numbers were determined by automated cell counting and cell bound AP activity was measured spectrophotometrically. hBMSC were transfected with hEGF plasmids and the proliferative effect was studied by cocultivation of transfected and untreated cells using porous cell culture inserts. The persistence of hEGF expression even after cell transfer was studied by the generation of possibly osteogenic constructs introducing transfected hBMSC in fibrin glue and bovine cancellous bone. The maximum increase in proliferation (156 +/- 7%) and AP activity (220 +/- 34%) was detected after exposition to 10 ng rhEGF/ml. In the separation chamber assay transfected cells produced hEGF concentrations up to 3.6 ng/ml, which induced a mean proliferation increase of 93% which could be significantly inhibited by a neutralizing hEGF antibody. Further, EGFsecretion of transfected hBMSC in 3D-culture was verified. Recombinant and transgenic hEGF stimulate proliferation of primary hBMSC in vitro. Lipotransfection of hBMSC with hEGF plasmids allows the transient and site directed delivery of biologically active transgenic hEGF. The introduction of mitogenic, angiogenic and chemoattractive factors in gene therapy assisted bone tissue engineering is discussed by the example of EGF.