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Biomedical subjects

Raymund E Horch

Publications and source records attributed to Raymund E Horch.

At least 19 recordsLinked to original sources
PubMed2006

Laryngotracheal reconstruction using prefabricated and preconditioned composite radial forearm free flaps. A report of two cases.

OBJECTIVE: Total or subtotal laryngectomy performed as surgical treatment of locally advanced laryngeal tumors requires a permanent laryngostomy or tracheostomy, and are both associated with severe and lifelong disability. The hitherto published reconstructive methods for the rehabilitation of patients after subtotal anterior laryngotracheal resection of extended laryngotracheal malignancies have not been thoroughly convincing. METHODS: We present a successful method of extended laryngotracheal reconstruction that combines modern surgical and biomedical techniques. RESULTS: A stable three-dimensional anterior neolarynx was prefabricated, including the use of vacuum-assisted prelamination and preconditioning of a composite radial forearm free flap, which was then transferred to the neck and vascularized by microvascular anastomosis to the cervical vessels. This reconstructive procedure permitted the restoration of a stable laryngotracheal conduit in two cases, with the subsequent successful closure of the tracheo-laryngostomy. CONCLUSION: In the reported cases the pre- or post-operative irradiation did not compromise the success of reconstruction. Not only did our technique facilitate the rehabilitation of patients suffering from drawbacks of the laryngo-tracheofissure, but it also assisted in avoiding total laryngectomy in cases of advanced anterior laryngeal cancer by extending the indications for subtotal anterior laryngeal resections followed by reconstructive surgery.

Cartilage↗
PubMed2006

Amnion cells engineering: a new perspective in fetal membrane healing after intrauterine surgery?

In this study we aimed to set up an in vitro culture of the rabbit amnion in order to support in vivo fetal membrane healing capacity following fetoscopy. Fetal membranes were collected from a mid-gestational rabbit, and cultured on collagen support material for 14 days. 34 rabbits at 22-23 days gestational age (GA) underwent fetoscopy. The entry site was randomly allocated to 4 closure technique study groups: group I, human amnion membrane (n = 23); group II, collagen foil (n = 16); group III, collagen plug (n = 19), and group IV, collagen plug with cultured amnion cells (n = 19). In all groups membrane access sites were additionally sealed with fibrin sealant, and the myometrium was closed with sutures. Fetal survival, amnion membrane integrity, and the presence of amniotic fluid were evaluated at 30 days GA. Cultures showed good survival in the collagen support material. Increased cellularity, survival and proliferations were observed. The amnion at the access site resealed in 58-64% of cases in groups II-IV, but none of the tested techniques was significantly better than the other. Histological examination indirectly revealed the anatomic repair of the membranes, since no entrapment of the membranes could be demonstrated in the myometrial wound.

Amnion↗
PubMed2006

Engineering of vascularized transplantable bone tissues: induction of axial vascularization in an osteoconductive matrix using an arteriovenous loop.

INTRODUCTION: Vascularization remains an obstacle to engineering of larger volume bone tissues. Our aim was to induce axial vascularization in a processed bovine cancellous bone (PBCB) matrix using an arteriovenous (AV) loop (artery, vein graft, and vein). METHODS: Custom-made PBCB discs (9 x 5 mm) were implanted into rats. In group A (n = 19), the matrices were inserted into microsurgically constructed AV loops between the femoral vessels using a vein graft from the contralateral side. In group B (n = 19), there was no vascular carrier. The matrices were encased in isolation chambers. After 2, 4, and 8 weeks, the animals were perfused with India ink via the abdominal aorta. Matrices were explanted and subjected to histological and morphometric analysis. Results were compared with intravital dynamic micro & magnetic resonance imaging and scanning electron microscopy images of vascular corrosion replicas. RESULTS: In group A, significant vascularization of the matrix had occurred by the 8th week. At this time, vascular remodeling with organization into vessels of different sizes was evident. Blood vessels originated from all 3 zones of the AV loop. Group A was significantly superior to group B in terms of vascular density and vascularization kinetics. DISCUSSION: This study demonstrates for the first time successful vascularization of solid porous matrices by means of an AV loop. Injection of osteogenic cells into axially prevascularized matrices may eventually create functional bioartificial bone tissues for reconstruction of large defects.

Animals↗
PubMed2006

Radial collateral ligament repair of the thumb metacarpophalangeal joint using the abductor pollicis brevis tendon.

BACKGROUND: Injuries to the radial collateral ligament of the thumb metacarpophalangeal joint are less common than injuries to the ulnar side. Therefore, published data on this subject are scarce. An innovative method of radial collateral ligament repair is hereby presented, placing emphasis on the long-term results. This technically simple method was developed to allow for a biological joint stabilization based on functional and anatomical considerations. The key concept is to reestablish joint stability by spanning the tendinous portion of the insertion of the abductor pollicis brevis over the radial side of the metacarpophalangeal joint. METHODS: Nine patients with rupture of the radial collateral ligament were treated by means of the abductor pollicis brevis-plasty. All patients suffered from subacute or chronic radial ligament insufficiency. To determine the subjective results of the repair, a score was developed grading the patient's ranking of the results achieved by the abductor pollicis brevis-plasty. All patients graded the results on a scale from 1 (excellent) to 6 (unacceptable). RESULTS: Patients were operated on 37.1 +/- 14.6 days after trauma. Long-term examination was performed after 39 +/- 14.5 months. The patients showed a high satisfaction score of 1.7 +/- 0.5, with good mobility of the metacarpophalangeal I joint (range of motion, 52.2 +/- 6.7 degrees). CONCLUSION: Favorable results suggest that the abductor pollicis brevis-plasty is a suitable, safe, and technically feasible procedure for the operative treatment of chronic instability of the thumb metacarpophalangeal joint after radial hyperadduction trauma and complete rupture or deinsertion of the radial collateral ligament.

Adolescent↗
PubMed2006

Increased metabolic activity of fibroblasts derived from cords compared with nodule fibroblasts sampling from patients with Dupuytren's contracture.

BACKGROUND: The pathogenesis of Dupuytren's contracture is characterized by progress in several stages. The disease process includes two structurally distinct fibrotic elements, the so-called nodule and the cord. Several hypotheses have been proposed regarding the cause. Until now, there has been ongoing discussion regarding whether cords or nodules are the primary source of the disease. METHODS: Tissues from 24 patients with Dupuytren's disease were obtained during hand surgery, providing samples from nodules and cords for cell culture. Tissue from the flexor retinaculum excised from healthy patients during surgical procedures on the hand served as control. By using the explant culture technique, fibroblasts were isolated and grown in standard medium. Besides morphological analysis, XTT proliferation tests were performed at various time periods to measure the metabolic activity of the cultivated fibroblasts. RESULTS: Statistical analysis revealed significant differences of nodule- and cord-derived fibroblasts after 1 hour (p = 0.0150), 8 hours (p < 0.0001), and 16 hours (p < 0.0001). CONCLUSIONS: The authors suggest that distinct proliferative properties of Dupuytren-derived fibroblasts are dependent on the cells' origin. Conclusions about the cause or pathogenesis cannot yet be drawn. Further investigation concerning their apparently different fibroproliferative properties is necessary.

Cells, Cultured↗
PubMed2005

Unusual explosive growth of a squamous cell carcinoma of the scalp after electrical burn injury and subsequent coverage by sequential free flap vascular connection--a case report.

BACKGROUND: Squamous cell carcinomos may arise from chronic ulcerating wounds in scars, most commonly postburn scars. Tumour growth usually takes place over months to years. Localization on the scalp is a relatively rare condition. CASE PRESENTATION: This report presents the case of a 63-year-old man with chronic ulceration of a postburn scar of the scalp due to an electrical burn 58 years ago. Sudden tumour growth started within weeks and on presentation already had extended through the skull into frontal cortex. After radical tumour resection, defect was covered with a free radial forearm flap. Local recurrence occurred 6 weeks later. Subsequent wide excision including discard of the flap and preservation of the radial vessels was followed by transfer of a free latissimus dorsi muscle flap, using the radial vessels of the first flap as recipient vessels. The patient received radiotherapy post-operatively. There were no problems with flap survivals or wound healing. Due to rapidly growing recurrence the patient died 2 months later. CONCLUSION: Explosive SCC tumour growth might occur in post-burn scars after more than 50 years. As a treatment option the use of sequential free flap connections might serve in repeated extensive tumour resections, especially in the scalp region, where suitable donor vessels are often located in distance to the defect.

Burns, Electric↗
PubMed2005

Treatment of second degree facial burns with allografts--preliminary results.

Facial burns are very common and have significant clinical impact. However, the treatment regimen for superficial to deep facial burns is not well defined. The purpose of this study was to investigate the effects of cadaver skin grafting in deep partial thickness facial burns in comparison to standard care. In a prospective open study design severely injured patients with superficial and deep partial thickness burns were randomized into the group receiving open treatment with silversulfadiazine (standard n=5) or into the group receiving early superficial debridement followed by coverage with glycerolized cadaver skin (n=5). The outcome measures were time and quality of wound healing, and incidence of hypertrophic scarring at 3 and 6 months post burn. There were no significant differences in demographics between groups. In the group treated with the allogenic material time to reepithelialization was 10.5 days, while it was 12.4 days in the silversulfadiazine group (p<0.05). Scar quality was found to be significantly improved in the allogenic treatment group. Three and 6 months postburn there were no patients with significant hypertrophic scarring in the allogenic group while there were two patients who developed hypertrophic scars in the silversulfadiazine group (p<0.05). In this study, we demonstrated that glyzerolized cadaver allograft skin represents a superior biological dressing for shallow and deep partial thickness facial burns. This is in concordance with other reports on scalds. It would be worthwhile to perform more clinical studies with a larger number of patients to further evaluate the effect and function of allogenic skin for facial burns.

Adult↗
PubMed2005

Vacuum application increases therapeutic safety and allows intensified local radiation treatment of malignant soft-tissue tumors.

PURPOSE: In order to simplify and improve outcome of radiation therapy and final defect coverage in patients suffering from invasive soft-tissue tumors, brachytherapy and application of V.A.C.uum-assisted closure (V.A.C.) were combined with delaying flap incision. PATIENTS AND METHODS: Two patients were excised as radically as possible and brachytherapy tubes were implanted directly on the tumor bed. At the same time, flaps for later defect coverage were preconditioned by circumcision. Brachytherapy and external- beam irradiation were performed directly on the vacuum sponge followed by subsequent defect coverage with the preconditioned flaps. RESULTS: Excision significantly reduced tumor masses in both patients; in one case sensible and motor function of the involved extremity was clearly improved. V.A.C. coverage allowed repeated brachytherapy and external-beam applications following exact placing of plastic tubes and FLABs on the tumor bed. Sequential irradiation had no effect on neighboring flap tissues, which healed without impairment following transposition. CONCLUSION: Combination of V.A.C. and brachytherapy can effectively replace circumstantial and laborious IORT (intraoperative radiotherapy) procedures. Exact placement of tubes on the tumor bed without subsequent tissue coverage is conserving preconditioned flap tissues, which are transposed for final defect coverage at the end of radiotherapy. However, by circumventing radiation exposure of these tissues, a possible later irradiation sequence can be performed without endangering defect-covering flaps.

Adult↗
PubMed2005

Delayed reverse sural flap for staged reconstruction of the foot and lower leg.

BACKGROUND: Soft-tissue defects of the foot and lower leg caused by traumatic injury, tumor ablation, or infection associated with osteomyelitis often require coverage by flaps. One excellent option for reconstruction of these defects is the distally based neurofasciocutaneous sural flap. It allows rapid and reliable coverage of defects from the distal third of the lower leg to the forefoot without significant functional donor-site morbidity. However, the maximal size of the flap is limited by the delicate perfusion of the arterial network associated with the superficial sensory nerve. Delay procedures may increase the reliability of large sural flaps. METHODS: The authors successfully used delayed sural flaps based on a two-step procedure for the treatment of 11 patients (three women and eight men, age 50.1 +/- 20.0 years) with osteomyelitis (n = 3), melanoma (n = 3), sarcoma (n = 1), squamous cell carcinoma (n = 1), posttraumatic defects (n = 2), and recurrent gouty ulcer (n = 1). The delay period ranged from 7 to 15 days (9.7 +/- 3.1), the length of the flap was from 9 to 19 (14.8 +/- 3.0) cm, and the width of the flap from 7 to 12 (9.2 +/- 1.3) cm. Temporary wound coverage was achieved by vacuum-assisted closure during the delay period. RESULTS: All defects were covered successfully without major complications. CONCLUSIONS: The delay procedure positively affects the viability of large sural neurofasciocutaneous flaps. The authors recommend this modification for patients with large defects at the distal third of the lower leg or foot, requiring a two-step surgical approach due to the underlying disease.

Adult↗
PubMed2004

A case of familial tumoral calcinosis in a neonate and review of the literature.

BACKGROUND: Tumoral calcinosis occurs in two distinct clinical forms. The sporadic form is secondary to chronic renal failure, hyperparathyroidism, milky-alkali syndrome, hypervitaminosis D and other systemic disorders. The familial form is extremely rare (around 100 cases worldwide) and affects patients in the first or second decade of life. It is believed to be transmitted in a dominant autosomal manner with variable clinical expressivity and is manifested as hyperphosphatemia, elevated serum 1,25-dihydroxyvitamin D with juxta-articular tumorous calcifications. Moreover, the theory of a unique dental malformation serving as a screening marker for clinically non-apparent affected individuals is revisited and reconfirmed. CASE REPORT: We present a case of a Caucasian male newborn, as well as a review of the literature with differential diagnostic considerations and their therapeutical implications.

Calcinosis↗
PubMed2004

The versatility of the free osteocutaneous fibula flap in the reconstruction of extremities after sarcoma resection.

BACKGROUND: An understanding of the biology of bone and soft-tissue sarcomas, knowledge of adjuvant therapies and refinement in techniques of reconstructive surgery have allowed limb-sparing and limb salvage surgery to become a reality in the management of malignant tumors of the extremities. Functional limb salvage following radical resection has become a possibility in many resectable tumors by the use of alloplastic prostheses, homograft or autogenous bone for skeletal reconstitution combined with vascularized soft tissue coverage. Although the free fibula flap has been well described for reconstructions of the mandible and oral cavity, it has not been widely presented as an ideal tool to preserve extremities and to circumvent amputation. PATIENTS AND METHODS: We describe the complex surgical reconstruction in four patients with primary sarcomas of the extremities. The sarcomas (Ewing's sarcoma, osteosarcoma and epitheloid sarcoma) were resected radically and the massive bone and soft tissue defect was replaced by vascularized free fibula transfer. RESULTS: We present our experience with versatility of this osteocutaneous flap to allow reconstruction and salvage of extremitity sarcomas. There were no operative or postoperative complication and all the four patients had good limb function. The flap was found to be versatile as it could be used for either upper limb or lower limb and for large defects. The results were better in upper limb than in lower limb. CONCLUSIONS: Free fibular graft was found to be effective for salvaging limb function where a massive bone defect resulted from wide tumor resection in the extremities.

Journal Article↗
PubMed2004

Correlation between serum creatinine kinase levels and extent of muscle damage in electrical burns.

The relationship between clinical course and changes of laboratory findings in patients with high-voltage electrical burns with regard to creatinine kinase activity was analyzed in order to determine the value of this prognostic parameter with regard to patients survival and risk of limb amputation. In a retrospective study 42 patients with electrical burns were reviewed. CK serum levels were determined every day during the first 10 days following submission. Analysis of data revealed a relation between strongly elevated CK levels and patients risk of limb amputation and mortality. Although further research is necessary, there is strong evidence that the amount of burned body surface area does not directly correlate with the true extent of tissue damage caused by high tension injuries. Our data suggest that the degree of muscle tissue violation corresponds with the initial excess of creatinine kinase levels in blood serum. This may be an additional factor to support the decision for early surgical decompression of electrically burned extremities and aggressive surgical management of the high-voltage burn victim. Furthermore, it may provide a prognostic parameter for the clinical outcome of these patients.

Adolescent↗
PubMed2004

Accelerated wound healing by in vivo application of keratinocytes overexpressing KGF.

Epidermal regeneration is a complex process, strongly influenced by growth factors, including keratinocyte growth factor (KGF). The objective of this study was to establish immortalized HaCaT keratinocytes and KMST-6-fibroblasts stably expressing KGF. Transfection efficiency, genomic integration, and functionality of the transgene were determined by ELISA and PCR, and KGF-expressing clones were selected using an air-liquid interface test system. HaCaT cells displayed stronger transgene expression compared to transfected fibroblasts, and the most effective HaCaT clone was incubated on a membrane carrier to form a "membrane cell graft." Twenty-one superficial second-degree burn wounds were created in each of three pigs, and wound healing capacity of the generated "polypeptide cell delivery system" after grafting was examined. Untransfected HaCaT keratinocytes and membrane-covered and untreated burn wounds served as controls. Histological and macroscopical follow-up revealed that grafting of transfected HaCaT cells resulted in complete reepithelialization within 5 days, while wounds covered with untransfected cells needed 2 days longer. At untreated sites, a thin epithelium was detectable after 10 days. The results indicate that wound healing processes can be stimulated distinctly by growth factors secreted from HaCaT cells, with a prominent role for transgenic KGF.

Animals↗