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Biomedical subjects

O Frerichs

Publications and source records attributed to O Frerichs.

At least 19 recordsLinked to original sources
PubMed2006

[Surgical treatment of groin soft tissue defects].

BACKGROUND: Treatment of groin defects remains challenging due to their location and origin. Such defects commonly result from resection of tumours but can also occur after surgical or medical therapy. MATERIAL AND METHODS: From 2003 to 2005, 11 patients were treated with groin defects following radiation therapy and resection of lymph node metastasis, primary carcinoma, and sarcoma. Seven patients received wound closure with rectus femoris muscle flaps, and three had vertical rectus abdominis muscle flaps. One patient was amputated at the hip, and the defect was covered with dorsally pedicled muscle and skin flaps. RESULTS: All flaps healed primarily. There were no secondary infections or lymphorrhea. CONCLUSION: The flaps described here are well vascularised standard flaps which are easily harvested with no major donor site morbidity. They provide sufficient coverage for the groin, reduce long-term conservative treatment, hospitalisation, and problems such as scar contracture.

Carcinoma, Squamous Cell↗
PubMed2006

[Distally pedicled peroneus brevis muscle flap for defect coverage on the lower leg].

BACKGROUND: Defects of the lower leg with exposed tendons or bone require either a local or free flap coverage. The distally pedicled peroneus brevis muscle flap has been proven to be a sufficient local flap alternative. MATERIAL AND METHOD: Using this technique the muscle is perfused by the non dominant distal perforators. This allows the muscle to be transposed to more distal lesions. The muscle is then covered with meshed split skin graft. Between 2000 and 2004 12 patients with defects of the lower leg in the distal lower third have been treated by using this muscle flap. The defects were located over the tibial bone, the extensor tendons, the achilles tendon and the lateral malleolar region. RESULTS: All muscles healed primarily, 4 patients had minor wound healing complications of the skin graft, which in all cases healed conservatively. The muscle and skin graft remained stable. Donor site morbidity is restricted to the scar in the lateral lower leg. Pronation of the foot is not impaired. CONCLUSION: These cases show that the distally based peroneus brevis muscle has a wide range of coverage and even allows a closure down to the calcaneal tuberosity. Additionally, a local flap management with a safe muscle transposition is an economic procedure with short operation time and decreased hospital stay. If the muscle does not cover the wound sufficiently, free flap surgery can still be performed.

Adult↗
PubMed2006

[Value of V.A.C.-therapy in the treatment of sternal infections].

Osteomyelitis of the sternum is a dreaded complication after sternotomy and is related to high mortality. Control of infection by radical debridement is the key to successful treatment. Instability of the thoracic cage can lead to a high complication rate. 16 Patients with an infected and unstable sternum underwent radical debridement with resection of the sternum and adjacent ribs. 6 Patients (group A) received an immediate defect coverage with a pedicled muscle flap. 10 Patients (group B) were treated with a vacuum-assisted closure (V.A.C.)-therapy until stabilization of their general condition and underwent defect coverage in a second operation. Healing of the flaps was uneventful in all cases despite minor problems. 5 patients of group A had severe complications with pulmonary or cardiac failure and thoracic instability which lead to prolonged periods of mechanical ventilation. 2 patients of this group died due to multi organ failure. All patients of group B survived and there were no major complications. All of the patients were free of recurrence from their osteomyelitis during follow-up. V.A.C.-therapy after radical resection of sternum osteomyelitis proved to be an effective measure to bridge time while optimizing the status of the patient and it's wound. With this approach we believe to have lowered the rate of major complications in this multi-morbid patient group by reducing the burden of one large operation and by improving thoracic stability.

Aged↗
PubMed2006

[Malignant eccrine poroma].

INTRODUCTION: Malignant eccrine poroma is a very rare tumour of the sweat glands with high malignancy and presenting with a polymorph clinical and histological picture. CASE REPORT: We describe the case of a 99-year-old patient with a malignant poroma on the buttock. Despite the large size of the tumour, no metastasis was found with standard examination techniques. Radical excision and defect closure with a Limberg flap was performed. RESULT: The healing course was uneventful and without complications. CONCLUSION: The malignant poroma is a tumour of high malignancy which can easily be misdiagnosed because of its different forms of presentation. Radical surgical therapy is the only known effective treatment.

Acrospiroma↗
PubMed2006

[Patients' satisfaction and social reintegration after breast reconstruction with the DIEP/TRAM flap].

The aim of the study was to evaluate social reintegration and patients' perception after breast reconstruction with the free TRAM/DIEP flap. Between 2004 and 2006, 100 patients with an average age of 48 years with breast cancer, capsular contracture and lymphangioma underwent single or second stage autologous tissue transfer. In 7 patients reconstruction was performed on both sides (altogether 107 flaps). The patients were seen for postoperative evaluation and were asked for their personal acceptance after reconstruction. Postoperatively, no instability of the abdominal wall was seen. 3 patients had a total flap loss, in 2 patients a partial loss was evident, 1 had a hematoma, 2 showed successfully treated thrombosis of the flap vein, and 2 patients suffered from wound healing problems at the flap and 4 patients at the abdomen. Aesthetic results concerning natural feeling and breast symmetry were graded as excellent and patients' satisfaction was high.

Adult↗
PubMed2004

[Autologous tissue transplantation (TRAM/DIEP) as an option of therapy in capsular contracture].

Free microvascular abdominal tissue transfer (TRAM/DIEP) has become standard in breast reconstruction after mastectomy. A new indication for abdominal tissue transfer is severe capsular contracture after augmentation by implants. Capsular contracture following aesthetic or reconstructive augmentation mammaplasty occurs in only a small percentage of cases, but warrants adequate therapy. Between 1999 and 2003, six patients with an average age of 35 years with symptomatic capsular contracture after augmentation mammaplasty underwent autologous tissue transfer with the free TRAM/DIEP flap. The flap was harvested either with a perforator of the deep epigastric artery (DIEP) or as muscle sparing flap (TRAM) and was anastomosed to vessels of the subscapular system. Operation time was reduced by operating with two teams. Besides minor dog-ear deformities at the donor sites, no complications were noted. Postoperatively, neither, instability of the abdominal wall nor flap loss was seen. In some cases, a secondary mastopexy was necessary. Aesthetic results concerning natural feeling and breast symmetry were graded as excellent. In our experience, the free microvascular transfer of abdominal tissue (TRAM/DIEP flap) offers a treatment option for patients seeking alternatives other than repeated capsulectomies and implant changes for severe capsular contracture.

Adult↗
PubMed2002

[The influence on nerve regeneration by the beta2-receptor agonist clenbuterol].

PURPOSE: Clenbuterol has shown a neuroprotective action in the central nervous system by induction of growth factors after cellular damage. Additionally, the atrophy of sceletal muscle is attenuated by the application of Clenbuterol after denervation. This experiment was performed to show the influence of Clenbuterol on regeneration of peripheral nerves. MEHOD AND MATERIAL: In a rat model, the sciatic nerve was transected and microsurgically coaptated. Eight animals in each group received a daily oral dosage of 100 microg/kg bodyweight during four, respectively six weeks. Two control groups received only drinking water under the otherwise same protocol. The assessment was done histologically, morphometrically and clinically. The weight ratio of the soleus and extensor digitorum muscles of the operated to the contralateral side was measured. RESULTS: The groups treated with Clenbuterol showed histologically and morphometrically a significantly increased axon count and a better g-ratio. The muscle weight ratio was significantly higher in the Clenbuterol group after six weeks and more animals in this group were able to spread their toes. CONCLUSION: The oral application of Clenbuterol in a rodent model shows a positive influence on nerve regeneration.

Adrenergic beta-Agonists↗
PubMed2002

Healing of Achilles tendon, an experimental study: part 2--Histological, immunohistological and ultrasonographic analysis.

In 105 rabbits the course of healing was examined at one, two, four, eight and 12 weeks (21 rabbits per group) after an experimental Achilles tendon rupture. The following treatment modalities were compared: A) primary functional treatment; B) operative functional treatment (resorbable suture); and C) operative functional treatment with fibrin glue. For the functional (after)-treatment a special orthosis was applied. A 7.5 MHz Ultrasound probe was used for ultrasonographic evaluation. The histological specimens were stained in Masson-Goldner and Azan technique. Collagen Type III was depicted immunhistologically. A semiquantitative fibrocyte count was performed. The histological results showed a smooth healing in the primary functional treatment group (A), reaching parallel orientation of collagen fibers at 12 weeks. In the suture group (B), a secondary gapping of the tendon stumps was detectable after one week as in all other groups. In the fibrin group (C), the fibrin was resorbed after four weeks without essential influence to the course of healing. At 12 weeks the histological evaluation in all groups showed approximately normal tendon pattern. Immunohistochemically, all groups showed cell-associated positive reactions for type-III collagen after one week with a maximum after two weeks. The semiquantitative fibrocyte count in the primary functional group showed a maximal number after one week. In the fibrin glue and suture groups the maximal number could be found after two weeks. Sonographically an increase in tendon thickness was detectable up to the fourth week in all groups. The secondary gapping of the tendon stumps in the suture group could also be detected sonographically. The echogenicity of the tendon during the course of healing showed increasing homogeneity and parallelism in all groups. At 12 weeks the echogenicity was comparable in all groups. The experiment suggests the equivalence of primary functional treatment to a combination of operative and functional therapy in Achilles tendon rupture.

Achilles Tendon↗
PubMed2001

Regeneration of peripheral nerves after clenbuterol treatment in a rat model.

Clenbuterol is known to act as a neuroprotective substance in the central nervous system, and also reduces muscle atrophy after denervation. The aim of this study was to evaluate its influence on peripheral nerve regeneration. The rat sciatic nerve model was used in four groups (n = 8 per group). After complete nerve transection and microsurgical coaptation, two groups received a daily oral dose of 100 microg/kg clenbuterol and two served as controls. Regeneration was assessed clinically, histologically, and morphometrically after 4 and 6 weeks. The weight ratios of calf muscles were calculated. Histological examination showed significantly increased axon counts in the clenbuterol group and a better degree of myelination. Muscle weight ratios of the clenbuterol group were significantly increased after 6 weeks, and the animals showed improved function of the hindlimb. Thus, therapy with 100 microg/kg clenbuterol daily after coaptation of a sciatic nerve showed a positive influence on clinical, histological, and morphometrical parameters in the rat model. The underlying mechanism remains unclear.

Animals↗
PubMed2001

[Heterotopic replantation after bilateral lower leg amputation].

INTRODUCTION: Replantation is an established procedure in reconstructive surgery. In a bilateral lower leg amputation attempts should be made to rescue at least one extremity, if the patients' vital conditions are stable. PATIENT AND METHOD: We report on a patient who has suffered a bilateral lower leg amputation. Due to the complex injuries the left leg was heterotopically (cross-over) replanted to the right leg. At the left leg an above knee stump was created. In a second operation a soft tissue defect at the replanted extremity was covered by a free microvascular latissimus dorsi muscle flap. In addition, the tibial nerve was reconstructed. Thirteen months later the patient is able to walk with a prosthesis for his left leg and complete weight bearing of the replanted extremity. DISCUSSION: Indication for replantation depends on accompanying injuries and vital functions of the patient. Compared to a simple amputation a lower leg replantation prolongs hospital stay, delays mobilisation of the patient, and increases the necessary secondary procedures. However, after replantation functional outcome is mostly better than with prosthetic fitting, especially if reconstruction of sensation in the weight-bearing area is successful. Thus, in a bilateral amputation movement and stability, as well as quality of life, are improved by a replanted extremity.

Amputation Stumps↗
PubMed2001

[Therapy of chest wall osteomyelitis].

INTRODUCTION: Chronic osteomyelitis of the chest wall requires radical debridement and defect coverage with well-perfused tissue. The implantation of synthetic material is still under discussion because of the risk of infection. METHODS: A retrospective study was conducted on the complications and functional and aesthetic results of 26 patients with chest wall osteomyelitis after radiation or sternotomy treated by radical debridement and neurovascular pedicled latissimus dorsi muscle. RESULTS: The functional results were excellent with a low complication rate. The muscle showed electric activity synchronous with inspiration and clinically a stabilization of the thoracic defect. DISCUSSION: Maintained muscular activity may play an essential role for stabilizing thoracic defects of up to four ribs or the sternum; implantation of synthetic material is not necessary.

Adult↗
PubMed2001

Healing of the Achilles tendon: an experimental study.

Biomechanical properties of healing ruptures in the Achilles tendon of rabbits were examined after two, four, eight and 12 weeks. Treatment modalities were (n7): a) suture, b) fibrin-glue, c) non-surgical treatment. All animals received a functional aftertreatment consisting of a special orthotic support and free ambulation. For biomechanical testing a fixation-technique was applied that guaranteed intratendinous rupture. After two weeks, the tendons treated with fibrin glue showed better results (stiffness, maximum force to rupture, tensile stress to rupture) compared with the non-surgically treated group. The results for sutured tendons were in between those for the other groups. After four weeks, the results for sutured and for glued tendons were nearly equal and slightly better than the tendons in the non-surgical group. Late results revealed comparable biomechanical properties among all treatment groups and control tendons, suggesting our conclusion that non-surgical treatment is equal to repair using sutures or using fibrin glue as measured by stiffness and tensile stress.

Achilles Tendon↗
PubMed1999

[Functional treatment of acute Achilles tendon rupture. A histological, immunohistological and ultrasonographic analysis of the animal model].

In 105 rabbits the course of healing was examined at 1, 2, 4, 8 and 12 weeks (21 rabbits per group) after an experimental Achilles tendon rupture. The following treatment modalities were compared: a. operative functional treatment (resorbable suture, Kleinert technique) b. operative functional treatment with fibrin glue c. primary functional treatment. For the functional (after)-treatment a special orthosis was applied. A 7.5 MHz Ultrasound probe was used for the ultrasonographic evaluation. The histological specimens were stained after Masson-Goldner with Azan. Collagen Type III was depicted immunohistologically with polyclonal antibodies. A semiquantitative fibrocytes count was performed. The histological results showed a smooth healing in the prim. functional treatment group reaching parallel orientation of collagen fibers at 12 weeks. In the fibrin glue-group the fibrin was resorbed after 4 weeks without essential influence to the course of healing. In the suture-group a secondary gapping of the tendon stumps was detectable. At 12 weeks the histological evaluation in all groups showed approximately normal tendon pattern. Immunohistochemically all groups showed cell-associated positive reactions for type III-collagen after 1 week with a maximum after 2 weeks. The semiquantitative fibrocyte count in the primary funct. group showed a maximal number after 1 week, in the fibrin glue- and suture-groups the maximal number could be found after 2 weeks. Sonographically an increase in tendon thickness was detectable up to the 4th weeks in all groups. The secondary gapping of the tendon stumps in the suture group could be detected sonographically. The echogenicity of the tendon during the course of healing showed increasing homogeneity and parallelism in all groups. At 12 weeks the echogenicity was comparable in all groups. The experiment could prove the equivalence of the primary functional treatment to operative therapy in Achilles tendon rupture.

Achilles Tendon↗
PubMed1999

[Effect of pre-degeneration of peripheral nerves on plasticity of cultivated Schwann cells and their cell number in vitro].

Predegeneration of peripheral nerve grafts is known to improve axonal regeneration in the sciatic nerve of the rat. Predegeneration involves sectioning the donor nerve in situ for a period of time prior to harvesting in order to allow Wallerian degeneration to take place. It is suggested that proliferating Schwann cells are responsible for this regeneration-promoting effect due to an increased production and accumulation of trophic factors. The aim of this study was to evaluate whether the proliferation of Schwann cells is increased after various predegeneration periods and whether predegeneration does affect the production of trophic factors. The rat's sciatic nerve was transsected distal to the spinal ganglion. Predegeneration was allowed to take place for one, two, three and four days and one, two and three weeks, respectively. The nerve was resected and prepared for Schwann cell cultivation. Cells cultivated from the contralateral untreated nerve served as control. S100 immunostaining, nerve-growth factor (NGF), and N-cadherin were used to characterize Schwann cells. Viability was assessed by fluoresceine fluorescence staining. Proliferation index was determined by BrdU DNA incorporation. Cultivation of cells harvested from predegenerated nerves indicated an increased proliferation of Schwann cells compared to the control. Proliferation effects depended on the period of predegeneration. A higher cell yield was obtained as early as 24 hours and up to three weeks after predegeneration. Optimal proliferation was seen after one week of predegeneration. The rapid expansion of Schwann cell populations oppressed the development of contaminating fibroblasts. NGF and N-cadherin were expressed by all S100-positive cells. Predegeneration did not affect viability. The determined high mitotic activity of predegenerated Schwann cells in combination with an early onset of proliferation may explain the regenerating-promoting effect of predegenerated nerve grafts. The expression of both NGF and N-cadherin in the predegenerated cultures indicates a high level of plasticity with dedifferentiation capacity, which in turn promotes neural regeneration. Predegeneration allows a proliferation of Schwann cells without concomitant pharmacological treatment. Thus, predegeneration of peripheral nerves is considered to be a highly efficacious method if a high yield of activated Schwann cells is desired within a short period of time. This may become relevant in the future of repair of peripheral nerve lesions, when autologous Schwann cells with their capacity to provide neurotrophines and cell adhesion molecules are used as cellular prostheses to bridge nerve gaps.

Animals↗
PubMed1999

Successful implantation of Schwann cells in acellular muscles.

Acellular muscle grafts can support axonal regeneration over short gaps. Due to the lack of viable Schwann cells in the grafts, failure of regeneration is evident with increasing gap lengths. To create a biological nerve conduit, Schwann cells were implanted into acellular muscle. The grafts were then incubated in vitro and assessed histologically and morphometrically. For cultivation of the Schwann cells, rat sciatic nerves were allowed to predegenerate to obtain a high cell yield. Rat gracilis muscles were harvested and made acellular by a liquid nitrogen treatment. After Schwann cell implantation, the muscles were incubated in vitro for 2, 5, and 7 days. S100-immunostaining, NGF, and N-cadherin, characterized the Schwann cells within the muscle. Viability was assessed by fluoresceine-fluorescence staining. Proliferation was determined by BrdU-DNA incorporation. Cell implantation did not to affect Schwann cell viability. Cells were seen throughout the entire length of the muscle basal lamina. They aligned and formed a cell column. Immunostained for S-100, implanted cells showed 100 percent staining. N-cadherin and NGF were expressed by all of the S-100 positive cells. Predegeneration is considered to be a highly efficacious method, if a high yield of activated Schwann cells is required. The successful implantation of the cells into an acellular muscle provides the possibility of a biologic conduit, offering the advantage of large basal lamina tubes serving as a pathway for regenerating axons. It also provides the beneficial effects of viable Schwann cells that produce neurotrophic and neurotropic factors to support axonal regeneration. Functional outcomes require evaluation in further in vivo studies.

Animals↗
PubMed1998

[Artifactual illness in plastic surgery].

The therapy of factitious disorders is a challenge for the treating surgeon. Only a clear understanding of the underlying causes and a good doctor-patient relationship make a successful outcome possible. Discussion about a confrontation of the patient with the diagnosis and the best made of treatment is still in progress. Early diagnosis and the cooperation between surgeons and psychiatrists are the most important parts of dealing with factitious disorders. This article gives an overview of symptoms and therapies. Six case reports demonstrate possibilities of the disorder's appearance.

Adult↗
PubMed1995

[Functional treatment of acute rupture of the Achilles tendon. An experimental biomechanical study].

In 84 adult rabbits the biomechanical properties of healing Achilles tendon rupture were examined 2, 4, 8 and 12 weeks (21 each group) after the injury. For the first time a mop-end-tear was performed. The following treatment modalities were applied (7 rabbits in each subgroup): (a) operative functional treatment (resorbable suture; Kleinert techniques); (b) operative functional treatment (fibrin glue); (c) primary functional treatment (conservative). The functional after treatment in all groups was performed with a specially developed orthesis, which was taped to the limb. For biomechanical testing a newly developed fixation technique (cryo-clamp) was applied, which guaranteed secure intratendineal rupture. After 2 weeks the fibrin glue-treated tendon ruptures showed the best results with regard to stiffness, tensile stress and max. rupture force. These results and a higher tensile stress of the sutured tendons were significantly different from those in the conservatively treated groups. After 4 weeks the stiffness in the fibrin group and the energy and rupture force in the suture group were significantly higher than in the group treated conservatively. The 8-week results revealed comparable biomechanical properties. The only significant difference was a higher energy in the fibrin glue group than in the conservative treatment group. The experiment revealed no significant biomechanical differences after 3 months. Compared with the results recorded for plaster immobilization in the literature, the functional treatment resulted in a significantly faster course of healing.

Achilles Tendon↗