[Macular pucker surgery with and without delamination of the internal limiting membrane-a prospective randomized study]

BACKGROUND

There is evidence that additional internal limiting membrane (ILM) removal reduces the recurrence rate after pucker surgery with a similar functional outcome. On the other hand, morphological changes of the inner retinal layers after ILM peeling have been described. The aim of this study was to compare the long-term data after vitrectomy with and without ILM delamination in order to uncover possible differences in morphological and functional results.

METHODS

In a prospective study of 32 patients with idiopathic epiretinal membrane, 16 patients were randomized into each of 2 groups. Both groups underwent pars plana vitrectomy (ppV) with peeling of the epiretinal membrane. In group 1 no forced additional peeling of the ILM was performed and in group 2 the ILM or ILM residues were additionally removed after staining. The investigated parameters were visual acuity, central retinal thickness (CRT) in optical coherence tomography (OCT), metamorphopsia and surgical complications. The time points of the examinations were directly preoperative, after 1, 3 and 6 months and partly 8.4 years postoperatively.

RESULTS

In group 1 (n = 15) the preoperative mean visual acuity improved from 0.54 logMAR to 0.38 logMAR after 6 months postoperatively (n = 13). Of this group 6 patients could be examined in the long-term course and the visual acuity improved further to 0.32 logMAR after 8 years. The CRT decreased from 473 µm preoperatively to 235 µm in the long-term interval. In group 2 (n = 15) the mean visual acuity preoperatively was 0.47 logMAR and improved 6 months postoperatively (n = 13) to 0.38 logMAR and in the long-term examination (n = 5) to 0.1 logMAR. The CRT in this group decreased from 417 µm preoperatively to 278 µm in the long-term interval. In group 1 one recurrence occurred in the follow-up period, in group 2 none.

CONCLUSION

The study showed that there was no significant difference in visual acuity and CRT between the two groups neither after 6 months nor after 8 years of follow-up. The observed recurrence in the group without ILM delamination underlines the assumption that additional ILM peeling could reduce the recurrence rate.

Prefabrication and free transfer of a tissue engineered composite flap - An experimental model in the rat

BACKGROUND

The technique of flap-prefabrication has been successfully established in tissue engineering: missing intrinsic vascularisation of engineered tissue can be generated in vivo by microsurgical vesselloop construction. It is possible to move engineered tissue into a defect with microsurgery. In the literature, the combination of engineered tissue covered with skin is not widely reported.

OBJECTIVE

Aim of this study was to establish a model to investigate scaffold prefabrication with full thickness skin graft coverage with subsequent free tissue transfer.

METHODS

8 Wistar rats were operated in 2 separate steps: 1) after creating an arteriovenous loop with the femoral vessels, a porous scaffold was placed on the loop and covered with an inguinally based skin flap. A control was implanted without loop into the contralateral groin. 2) 6 weeks later the prefabricated composite flaps were microsurgically transferred to the cervical region. Skin-island monitoring was performed with Laser Doppler-scanner after the transfer.

RESULTS

Continuous loss of the skin islands was observed within 72 hours. Complications included wound-dehiscence, thrombosis and death from anaesthesia; in spite of consistent loop viability.

CONCLUSION

Evaluation showed that modifications are necessary to maintain the skin-island cove.

Total reconstruction of the auricle: our experiences on indications and recent techniques

INTRODUCTION

Auricular reconstruction is a great challenge in facial plastic surgery. With the advances in surgical techniques and biotechnology, different options are available for consideration. The aim of this paper is to review the knowledge about the various techniques for total auricular reconstruction based on the literature and our experience.

METHODS

Approximately 179 articles published from 1980 to 2013 were identified, and 59 articles were included. We have focused on the current status of total auricular reconstruction based on our personal experience and on papers of particular interest, published within the period of review. We have also included a prospective view on the tissue engineering of cartilage.

RESULTS

Most surgeons still practice total auricular reconstruction by employing techniques developed by Brent, Nagata, and Firmin with autologous rib cartilage. Within the last years, alloplastic frameworks for reconstruction have become well established. Choosing the reconstruction techniques depends mainly on the surgeon's preference and experience. Prosthetic reconstruction is still reserved for special conditions, even though the material is constantly improving. Tissue engineering has a growing potential for clinical applicability.

CONCLUSION

Auricular reconstruction still receives attention of plastic/maxillofacial surgeons and otolaryngologists. Even though clinical applicability lags behind initial expectations, the development of tissue-engineered constructs continues its potential development.

[Complications in 312 cases of nasal and auricular reconstruction via autologous rib cartilage]

BACKGROUND

We present the results and complications with autologous rib cartilage in comparison to other materials in nasal and auricular reconstruction using a large patient collective from our clinic.

MATERIAL AND METHODS

The retrospective study included all cases of auricular and nasal reconstruction via rib cartilage between 2001 and 2009. The outcome was analysed by subjective and objective parameters.

RESULTS

51/321 patients underwent plastic reconstructive surgery of the nose, 270/321 received a partial or complete auricle reconstruction with autologous rib cartilage. The complication rate e.g. of hematomas, lesions of the pleura, postoperative pain and keloids at the donation site was small. Concerning the aesthetic results of the nose and auricles 273 of 321 (85%) were satisfied after the first operation. Only 3/51 nasal reconstructions underwent a second operation. In case of complete auricular reconstructions, all patients underwent at least 2 operations for the three-dimensional look.

CONCLUSIONS

The use of autologous rip cartilage is still a good option in the auricular and nasal reconstruction. Depending on the expertise of the surgeon the postoperative aesthetic results are good with a low complication rate. However concerning the bigger effort in several aspects for the surgeon as the patient it should be reserved to specific indication criterias.

[Management and prognosis of patients with squamous cell carcinomas of the nasal cavity and the paranasal sinuses]

Squamous cell carcinomas (SCC) of the nasal cavity and the paranasal sinuses are a very rare and poorly understood tumor entity. To date, no consistent management strategy exists. The purpose of our study was to demonstrate our therapeutic strategy and to correlate clinicopathological features with clinical follow-up data.45 patients with primarily resected SCC of the nasal cavity (n=35) and the paranasal sinuses (n=10) between 1994 and 2010 were reviewed retrospectively (mean follow-up period 2.6 years; range 0.3 to 14.9 years).Tumors of the nasal cavity were diagnosed at an early stage (97% T1 and T2) whereas tumors of the parasinuses were found at an advanced stage (90% T3 and T4). Lymph node metastases were only found 2 patients. 13 patients (29%) had a local tumor progress, 2 patients showed lymph node metastases and 4 patients had distant metastases in follow up. The prognosis of tumors of the nasal cavitiy or the paranasal sinuses was bad (31% 5-year overall survival) especially by patients with a relapse.Reconstructive surgery was performed after 12 months, when early local relapse could be excluded. There was no positive correlation between clinicopathological features and survival data.The prognosis of tumors of the nasal cavity and paranasal sinuses depends mainly on the control of local tumor growth. Modern strategies of surgical treatment in combination with radiotherapy need to be implemented in an effort to achieve continuous tumor-free survival.

[Grisel's syndrome after otoplasty]

Grisel's syndrome is known as a very rare complication of ENT surgery. It is described as non-traumatic atlantoaxial rotatory subluxation, often seen after tonsillectomy or adenoidectomy in children. Therapy is staged according to the Fielding classification. We report the case of a 9-year-old female patient with Grisel's syndrome after otoplasty. The diagnosis was confirmed by CT scan. Manual reposition was performed under general anaesthesia, followed by temporary immobilization with a Minerva orthesis.

[Microsurgical thumb replantation following traumatic amputation: preliminary results in Hanoi, Vietnam]

INTRODUCTION

Replantation using microsurgical techniques is a fairly new procedure in Vietnam. We reviewed and evaluated our 7-year results of thumb replantation in Vietnamese patients following traumatic thumb amputation.

MATERIAL AND METHODS

Traumatic thumb amputations between September 1999 and July 2006 were reexamined and evaluated. Postoperative functional results were evaluated based on four main criteria: 1) the patient's subjective attitude regarding the replanted thumb, 2) the degree of mobility of the replanted thumb compared with its counterpart, 3) the level of sensitivity of the replanted thumb, and 4) the objective ability to perform daily tasks.

RESULTS

A total of 26 patients were documented. The duration of follow-up averaged 22 months (range 6-72 months). The success rate of replantation was 81%. A rating of either "good" or "very good" was obtained for 81% of the replanted thumbs.

DISCUSSION

Vascular thrombosis was the cause of all failures. Proper debridement, standardized microvascular techniques, timely detection of thrombosis formation, and reoperation using vein grafts play a decisive role in the final success.

[Loss of olfaction with aging: a frequent disorder receiving little attention]

Loss of olfaction in old age is a frequent problem, which occurs at the same frequency as diabetes or severe sensorineural hearing loss. Problems caused by loss of the sense of smell may include weight loss due to loss of appetite, intake of rotten foods, social isolation and depression. Until now the loss of olfactory function has received relatively little attention compared to diabetes or hearing loss. In this article we review the loss of the sense of smell with age. Possible therapies are discussed to improve the quality of life in older people.

Management of facial necrotizing fasciitis

Necrotizing fasciitis is a progressive, life-threatening, bacterial infection of the skin, the subcutaneous tissue and the underlying fascia, in most cases caused by ss-hemolytic group A streptococcus. Only early diagnosis and aggressive therapy including broad spectrum antibiotics and surgical intervention can avoid systemic toxicity with a high mortality rate. This uncommon disease generally occurs in the lower extremities and trunk, and only rarely affects the head and neck region. When located in the face necrotizing fasciitis is associated with severe cosmetic and functional restrictions due to the invasive infection and often to the necessary surgical treatment. Generally surgical intervention cannot be performed in the face as aggressively as in the extremities and trunk, since a lot of vital structures are found in a relatively small area. In the following article, we present the successful diagnostic and therapeutic management of an isolated facial necrotizing fasciitis as a consequence of a nasal bone fracture with a minor dermal cut.

Case reports: thumb reconstruction using amputated fingers

Reconstruction of an irreparably amputated thumb in multiple digit amputations using amputated fingers can considerably improve hand function and allows creation of a newly transplanted thumb with acceptable cosmetic and functional attributes. However, the surgery is challenging and rarely reported. We report six cases using this procedure in patients with crushed thumbs unsuitable for replantation. In four of the patients, the remnant of the index finger was replanted on the thumb stump and in another two patients, an amputated middle finger and ring finger were used. The patients had a minimum followup of 12 months (mean, 18 months; range, 12-45 months). All newly transplanted thumbs survived resulting in the patients having satisfactory postoperative hand function and appearance.

Therapy of auricular keloids: review of different treatment modalities and proposal for a therapeutic algorithm

Keloids are abnormal wound reactions of connective tissue. Auricular keloids can develop as a result of, e.g., otoplasty, ear piercing, or skin trauma. A wide variety of therapeutic options exists, including surgery as primary treatment. Furthermore, there are medical, physical, radiotherapeutic and experimental options. The present paper focuses on the different techniques including the therapeutic outcome and quality rating for each chosen pathway. In addition to the experience of the university hospitals, a thorough review of the literature was performed in order to update and compare today's therapeutic options. Surgical techniques are customized to the lesion's specific localization and extent. They may include revision of otoplasty. With medical treatment, established modalities such as steroid injection have to be distinguished from experimental methods like interferon, 5-FU, verapamil, imiquimod, or mitomycin C. Radiation is generally accepted to be effective, especially applied accompanying surgery, but needs to be restricted due to possible side effects. Physical therapy, e.g., pressure in a variety of application modalities, has gained a profound position in the therapy of auricular keloids. The success rates of the different treatment modalities vary markedly, and the number of patients per study is considerably low. Resuming the results, a periodic follow-up and good patients' compliance are mandatory to early realize and treat auricular keloids. However, studies are needed to evaluate accepted and experimental therapies including larger number of patients.

[Does nicotine add to the carcinogenic strain of tobacco smoke?]

BACKGROUND

It is accepted that nicotine in tobacco smoke causes addiction via nicotinic acetylcholine receptors in the central nervous system. For a long time, the tumorigenic potential of smoking was attributed to compounds other than nicotine. However, more recently data have accumulated which suggest that nicotine may add to the cancer risk by stimulating cellular growth via non-neuronal acetylcholine receptors, by suppressing apoptosis, and by inducing angiogenesis not only in atheromatous plaques but also in tumors. In the present study the possible direct genotoxic effects of nicotine on DNA were investigated in human target cells of carcinogenesis in the upper aerodigestive tract.

PATIENTS AND METHODS

Human nasal mucosa, lymphatic tissue of the palatine tonsils, supraglottic epithelium of the larynx, and peripheral lymphocytes were exposed to rising concentrations of nicotine. DNA damage was investigated by alkaline single-cell microgel electrophoresis (Comet) assay. Cytotoxicity was assessed by trypan blue exclusion.

RESULTS

Nicotine induced dose-dependent DNA damage in all cell types at low cytotoxic concentrations that allowed viabilities well above 80%. The lowest nicotine concentrations eliciting a significant increase in DNA migration were 1 mM for tonsillar cells and 0.25 mM for all other cell types.

CONCLUSION

Nicotine induces genotoxic effects in human target cells of carcinogenesis in the upper aerodigestive tract at relevant concentrations. Thus, nicotine may contribute directly to tumor initiation resulting from smoking.

Alleinige Kondylusresektion versus alloplastische Rekonstruktion

After condylar resection a decision on whether to proceed immediately to reconstruction has to be decided. In this paper, two patients who had undergone hemimandibulectomy including exarticulation, in one because of an expanded keratocystic odontogenic tumour and in the other because of oral squamous cell carcinoma, are presented. In one patient a metallic condylar reconstruction plate combined with an iliac crest graft was implanted for primary mandibular reconstruction, whereas in the other the part of the mandible that had been removed and the condylar head were not replaced. One patient was followed up for 5 years and the other for 6 years. Functional (max. incisal distance, protrusive and lateral excursions, occlusion and joint noises) and cosmetic results (scarring, facial nerve function), and also quality of life with and without primary mandibular replacement by a metallic condylar reconstruction plate are compared.

[Optimized auricular reconstruction with autologous cartilage. Experience from 120 cases]

INTRODUCTION

Auricular reconstruction with autologous cartilage has become well established in the last decade. By optimizing the technique, both the results and reliability have improved.

OPERATION AND RESULTS

Based on our experience with 120 cases, we developed a concept that allows total ear reconstruction in two surgical steps. In the first operation, autologous rib cartilage is harvested and a natural framework created following the template of the opposite ear. The ear remnant is transposed and the framework placed in a subcutaneous pocket on the mastoid plane. After a healing period of around 6 weeks, the second operation reconstructs the auricular projection and the postauricular fold. The surgical procedure has to be adapted to difficult soft tissue situations. Most important is the specific analysis of local tissue and its resulting limitations. Deep scaring and skin grafting from previous operations need coverage of the framework with a subgaleal fascia flap.

CONCLUSION

This optimized and adapted surgical procedure allows auricular reconstruction with autologous rib cartilage from the age of around 8 years into old age with good, reproducible results.

[Effects of nicotine with special consideration given to tumorigenesis in the head and neck region]

BACKGROUND

Tumorigenesis is based on initiation, promotion, and progression, whereas tobacco smoke is a decisive predisposing factor for squamous cell carcinomas of the upper aerodigestive tract. A variety of tobacco smoke compounds is known to potentially initiate tumors, but the alkaloid nicotine is generally considered to induce addiction only. However, there is growing evidence that nicotine may also contribute to early stages of tumorigenesis. In the present study, a possible direct genotoxic potential of nicotine is investigated.

MATERIAL AND METHODS

Lymphatic tissue of the tonsilla palatina of eight donors was harvested during surgery and incubated with nicotine. DNA damage was measured with the comet assay.

RESULTS

Genotoxic effects of nicotine could be demonstrated.

DISCUSSION

The results suggest a direct contribution of nicotine to tumor initiation and carcinogenesis.

Zentrales Riesenzellgranulom des Unterkiefers

The synopsis of radiographic examination (uni- or multilocular radiolucency), histologic findings (giant cells throughout a benign fibroblastic matrix), blood chemistry analysis (normal serum parathyroid hormone) and clinical features provides the definitive diagnosis of giant cell granuloma, allowing the clearly defined surgical management of this lesion. The case history of a 48-year-old female patient who presented with a giant cell granuloma in the right mandible is used to illustrate this controversially discussed intra-osseous lesion. The potential therapeutic change from radical operative treatment, including functional maintenance, to conservative procedures is emphasized.

[Correction of ear malformations with autologous rib cartilage]

INTRODUCTION

Ear malformations are mainly isolated deformations but exist also in combination with various syndromes. A visible malformation in cases of microtia is a problem for the entire family. Auricular reconstruction with autologous cartilage has been well established in the last decade. Optimization of the technique has led to improved and reliable results.

OPERATION AND RESULTS

Based on the experience of 120 cases we developed a concept that allows total ear reconstruction in two operative steps. In the first operation autologous rib cartilage is harvested and a natural framework is created following the template from the opposite ear. The ear remnant is transposed and the framework placed in a subcutaneous pocket on the mastoid plane. After a healing period of around 6 weeks the second operation reconstructs the auricular projection and the retroauricular fold.

CONCLUSION

Based on an individualized surgical treatment, auricular reconstruction with autologous rib cartilage are possible from the age of around 8 to the advanced period of life with reproducibly good results.

Zahnverletzungen bei Miniplattenosteosynthese

BACKGROUND

In spite of a monocortical design, miniplate osteosynthesis can injure dental roots directly as well as damage dental substance indirectly by interrupting the apical blood stream.

PURPOSE

The present retrospective study classifies different types of dental root trauma caused by monocortical screws, suggests therapeutic options based on diagnosis, and documents survival probability and prognosis after tooth trauma.

PATIENTS AND METHODS

During a period of 11 years, 380 patients with permanent dentition underwent miniplate osteosynthesis for the treatment of mandibular fractures, 29 of whom sustained dental root trauma caused by drilling failure. These patients were clinically and radiographically examined for a follow-up time of not less than 38 months.

RESULTS

The 29 patients could be classified into four different types of dental root trauma: 13 pulp injuries above the apical third of the root (type Ia), 6 pulp injuries in the apical third of the root or extradental lesions interrupting the apical blood stream (type Ib), 4 lesions to the central radicular dentin without pulp injury (type II), and 6 lesions to the peripheral radicular dentin and root cementum (type III). Of 13 type Ia injuries, 5 developed apical periodontitis and dilatation of the periodontal space. Therefore one root canal treatment and three apicoectomies were performed. One tooth had to be extracted. Three further type Ia injuries and two type Ib injuries showed root resorptions inducing two root canal treatments. One of six type Ib injuries required root canal treatment because of apical periodontitis. One of four type II injuries caused root resorption not requiring therapy. No relevant, pathological finding could be identified after type III injury.

CONCLUSIONS

The type of dental root trauma caused by miniplate osteosynthesis determines therapy, complication rate, and survival of the injured tooth.

Navigation-Assisted Construction of an External Ear Canal Using an Autogenous Foreskin Graft

Classic microtia is combined with external ear canal atresia and middle ear malformation. In order to evaluate whether an operation to improve hearing ability and the use of computer-assisted surgery are indicated, preoperative high-resolution navigation CT is mandatory. We combined atresia surgery and tympanoplasty with auricular reconstruction in the case of an 8-year-old boy with bilateral microtia, aural atresia and malformation of the middle ear. After creating an auricle framework with rib cartilage and transplanting it under the skin of the mastoid plane, we shifted it forward in the second step, and the new auditory canal was drilled under computer-assisted navigation and facial nerve monitoring. In the same operation, tympanoplasty was accomplished, and a silastic cylinder, wrapped into pieces of rib cartilage, was inserted into the constructed canal and removed 2 months later. For lining the new auditory canal, we used the patient's prepuce, harvested by elective circumcision.

Prefabrication of large fasciocutaneous flaps using an isolated arterialised vein as implanted vascular pedicle

Flap prefabrication represents a new trend in microsurgical tissue transfer. Based on the concept of neovascularisation, in Chinchilla Bastard rabbits (n=40), an isolated venous pedicle dissected from the femoral and saphena magna vein was arterialised by end-to-end anastomosis to the femoral artery at the inguinal ligament. This arterialised venous loop was implanted beneath a random-pattern vascularised abdominal fasciocutaneous flap as large as 8 x 15 cm(2) to investigate the development of neovascularisation at various evaluating times of 4, 8, 12, 16 and 20 days. To prevent neoangiogenesis from occurring between the underlying vascular bed and abdominal flap, a silicone sheet with the corresponding dimension of 8 cm x 15 cm x 0.25 mm was placed and fixed on the abdominal wall. The flap viability and the neovascularisation process in the prefabricated abdominal skin flaps were evaluated by macroscopic observation, blood analysis, selective microangiography and histology. The experimental results showed that newly formed vessels originating from the implanted isolated venous pedicle were evident on the angiograms 4 days after pedicle implantation. In the 8- and 12-day groups, newly formed vessels became larger and some were connected to the originally available vasculature in the abdominal fasciocutaneous flaps. In the 20-day group, entire flaps were perfused by the blood flow supplied from the newly implanted venous pedicles through newly formed vessels and their vascular connections. This study indicated that large flap prefabrication can be created by implantation of an isolated arterialised venous pedicle into a random-pattern vascularised fasciocutaneous flap. Twenty days appears to be the minimal length of time required after arterialised venous pedicle implantation for the maturation of neovascularisation in the prefabricated flap.

Toxicological assessment of noxious inhalants

In the past centuries mankind has been exposed to various forms of air pollution not only at his occupational but also in his social environment. He mainly gets exposed with these pollutants through the respiratory organs and partially absorbs them into the body. Many of these airborne substances can be harmful for humans and some of them may account for tumorigenic effects.The following essay describes the main features of toxicological assessment of inhalative environmental and workplace xenobiotics. The essay also explains relevant characteristics and limit values of noxious compounds and gases and depicts modern testing methods. To this end, emphasis is given on methods characterizing the different stages of tumorigenic processes. Various test systems have been developed which can be used in vivo, ex vivo or in vitro. They are to a great part based on the evidence of changes in DNA or particular genes of cells. Among others they have highlighted the impact of interindividual variability on enzymatic activation of xenobiotics and on susceptibility of the host to tumor diseases.Unfortunately, for many inhalative environmental noxious agents no sufficient risk profiles have been developed. The completion of these profiles should be the goal of toxicological assessment in order to allow reasonable socioeconomic or individual-based risk reduction.

[Experimental investigation of neovascularisation in large prefabricated flaps after arteriovenous pedicle implantation]

The principle of prefabricated flaps is based on the transformation of a formerly random-pattern vascularized flap, through implantation of a vascular pedicle, into a newly neovascularized axial flap, which can be transferred after a period of neovascularisation from the prepared donor site to the recipient site by using microvascular techniques. In 30 Chinchilla Bastard rabbits weighing from 3700 to 4200 g, a skeletonized arteriovenous pedicle with distal ligation harvested from the femoral and saphena magna artery and vein was implanted beneath an 8 x 15 cm abdominal skin flap to investigate the neovascularisation process in the flap over the course of time. In order to prevent neovascularisation occurring from the underlying vascular bed into the flap, a silicon sheet measuring 8 x 15 cm x 0.25 mm was placed and fixed on the abdominal wall. Flap vitality and neovascularisation process in prefabricated flaps were evaluated by macroscopic observation, blood analysis, selective microangiography, histology and scintigraphy at the various time intervals of 4, 8, 12, 16 and 20 days. The study results showed that newly formed vessels sprouting from the implanted pedicle were seen four days after pedicle implantation. With the retention time of pedicle in the flaps, they continued to grow, became meander and more dense. Respective connections between newly formed vessels and the originally available vasculature of the abdominal flap were markedly observed in the 12- and 16-day groups. Twenty days after prefabrication, the abdominal flap was completely perfused by the blood flow supplied from the newly implanted arteriovenous pedicle through newly formed vessels arising from the implanted pedicle and their rich vascular communications. The neovascularisation in the prefabricated flap consisted of the implanted pedicle, newly formed vessels, the originally available vasculature and their vascular connections. In comparison to the control group (the quantification was determined of 100 %), the vessel quantity in the prefabricated flap of the 20-day group had increased to 98.7 %. As a pre-clinical test, prefabricated flaps through arteriovenous pedicle implantation with special advantages can be a new useful method in plastic and reconstructive surgery.

Gez�chtetes Knorpelgewebe in einem pr�fabrizierten, mikrovaskul�ren Lappen

INTRODUCTION

In reconstructive surgery, the integration of tissue-engineered cartilage in a prefabricated free flap may make it possible to generate flaps combining a variety of tissue components to meet the special requirements of a particular defect. The aim of the present study was to establish the technique of prefabricating a microvascular free flap by implanting a vessel loop under a skin flap in a rabbit model. The second aim was to gather experience with prelaminating the flap with autologous tissue-engineered cartilage in terms of matrix development, inflammatory reaction and host-tissue interaction.

METHODS

The microvascular flap was created by implanting a vessel loop under a random pattern abdominal skin flap. The tissue-engineered cartilage constructs were made by isolating chondrocytes from auricular biopsies. Following a period of amplification, the cells were seeded onto a non-woven scaffold made of a hyaluronic acid derivative and cultivated for 2-3 weeks. One cell-biomaterial construct was placed beneath the prefabricated flap, and the others were placed subcutaneously under the abdominal skin and intermuscularly at the lower extremity. In addition, a biomaterial sample without cells was placed subcutaneously as a control. All implanted specimens were left in position for 6 or 12 weeks. After explantation, the specimens were examined by histological and immunohistological methods. The prefabricated flap was analyzed by angiography.

RESULTS

The prefabricated flaps showed a well-developed network of blood vessels formed by neovascularization between the implanted vessel loop and the original random-pattern blood supply. The tissue-engineered constructs remained stable in size and showed signs of tissue similar to hyaline cartilage, as evidenced by the expression of cartilage-specific collagen type II and proteoglycans. No hints of inflammatory reactions were observed.

CONCLUSION

These results show the potential of prefabricated flaps as custom-made flaps for reconstructive surgery in difficult circumstances, more or less independent of anatomical prerequisites. Cartilage tissue engineering provides a 3-dimensional structure with minimal donor-site morbidity.

Clinical aspects and strategy for biomaterial engineering of an auricle based on three-dimensional stereolithography

At the present time, the partial and/or complete reconstruction of an auricle from autologous rib cartilage is one of most widely published techniques. In the field of tissue engineering, different techniques have been described to generate cartilage tissue using isolated chondrocytes. The basis of these tissue-engineering techniques is bioresorbable or non-bioresorbable biomaterials, which serve as a three-dimensional cell carrier. Tissue engineering of an auricle requires preformed bioresorbable biomaterials designed to fit the form of a patient's auricular defect. Three-dimensional imaging acquired from computed tomography scans or laser surface scanning has become an important tool in modern medicine. This study represents the preoperative procedures for the reconstruction of an auricle through tissue engineering in accordance with the clinical aspects. Hyaff 11, a hyaluronic acid derivative, was used as a three-dimensional cell carrier for isolated human nasoseptal chondrocytes. The chondrocytes were amplified in a conventional monolayer culture before the cells were seeded on a hyaluronic non-woven mesh and cultured in vitro for 4 weeks. The chondrogenic potential of human nasal chondrocytes in Hyaff 11 was investigated by confocal laser scanning microscopy, histology (toluidine blue) and immunohistochemistry (collagen type II). Computer-aided design (CAD) and manufacture of an auricle model with stereolithographical methods were used for the prefabrication of a bioresorbable three-dimensional cell carrier designed in the form of a patient's auricular defect. The cell carrier used was Hyaff 11, a fully benzyl-esterified hyaluronic acid derivative. Confocal laser scanning microscopy has shown good cell attachment, a homogenous distribution of amplified chondrocytes and a viability of more than 90%. After 4 weeks in vitro culture the human nasoseptal chondrocytes synthesized new cartilage with the expression of cartilage-specific collagen type II. In order to shape a patient's designed scaffold the auricle model was fitted exactly and symetrically to the contralateral side. Subsequently, the mirror image patient-specific model was used to prepare an identical scaffold model made of a fully benzyl-esterified hyaluronic acid derivative. The bioresorbable scaffold that was produced gave a satisfactory representation of auricle structure. Bioresorbable preformed biomaterials in the form of a patient's auricle defect represent an important prerequisite for the tissue engineering of autologous auricle grafts. Hyaff 11 seems to be a promising material for tissue engineering of cartilage transplants, and the application of this approach will improve conventional reconstructive surgery in the future.

[Malformations of the auricle and their correction]

Owing to the stigma attached to auricular malformations, many patients request surgical correction. According to Weerda, such malformations can be classified into three grades of severity. Since the higher-grade malformations are often associated with malformation of the auditory canal and middle ear, and thus with hardness of hearing, early ENT evaluation of hearing problems is mandatory. Surgical correction of the auricle should not be attempted before the age of 5 years, and partial or total reconstruction in the case of anotia, is not considered before the age of 8. In such cases, autologous rib cartilage is needed to ensure construction of a natural-looking auricle. Standardized surgical procedures are available to correct the whole range of auricular malformations with good cosmetic results and a high level of patient satisfaction.

[Mesenchymal stem cells--a new pathway for tissue engineering in reconstructive surgery]

INTRODUCTION

Mesenchymal stem cells (MSC) have the capacity to differentiate into chondrocytes with the synthesis of cartilage. This report presents the use of human adult bone marrow derived mesenchymal stem cells for tissue engineering of autologous cartilage grafts.

METHODS

Human bone marrow aspirates were obtained from the iliac crest and fractionated on a Percoll gradient. The isolated hMSC were plated at 20 x 10 (6) cells per 100 mm (2) culture dish. After 21 days in culture at 37 degrees C with 5 % CO 2, the adherent multiplied MSC were trypsinized, counted, and tested for viability by trypan blue assay. The hMSCs were loaded into a sterile 15 ml polypropylene tube (0.5 Mio cells/ml) and centrifuged on the bottom of the tube at 500 g for 5 minutes. The MSC were cultivated for 3 weeks in vitro in a specific chondrogenetic medium composed of Dulbecco's Modified Eagles Medium-High Glucose supplemented with 10 ng/ml transforming growth factor-beta 1, 1 % ITS-Premix medium, 80 micro M ascorbic acid, and 100 nM dexamethasone.

RESULTS

Histological and immunohistochemical studies performed after 3 weeks in three dimensional culture demonstrated the expression of cartilage specific collagen type II and X as well as proteoglycans.

CONCLUSION

Human adult mesenchymal stem cells derived from bone marrow aspirates have the ability to differentiate into chondrocytes under specific culture conditions by growth factors. The use of adult mesenchymal stem cells may be a promising tool for tissue engineering of autologous cartilage grafts in reconstructive surgery in the future.

[Dilated pneumosinus of the frontal sinus]

Pneumosinus dilatans is a rare disorder of the frontal sinus most commonly found in 20- to 40-year-old males. The deformity is caused by an abnormal enlargement of the frontal sinus by hyperpneumatization. A valve mechanism raising the pressure inside the sinus is regarded to be responsible for this condition. The diagnostic and surgical approach is presented in a 25-year-old male. A preoperative computed tomography (CT) scan in three planes illustrates the anatomical conditions and possible etiologic mechanisms. The surgical procedure is supposed to correct the esthetic deformity and the cause of the disorder. A bicoronal incision allows the best exposition of the frontal sinus. The osteoplastic correction is stabilized by titanium micro-osteosynthesis plates, which do not have to be removed. Functional endoscopic sinus surgery should be performed concomitantly in order to remove the cause of pneumosinus dilatans.

[Local reconstruction of partial auricular defects]

INTRODUCTION

Partial auricular defects are often caused by resection of skin tumors. These patients are mainly older and often in reduced general condition. Therefore very expenditure surgical approaches seem to be dangerous.

SURGICAL APPROACH

In most cases the resection of the tumor is possible in local anaesthesia. The reconstruction should be started after maintenance of the final histology. Next to the defect, the localisation leads to the right way of surgical treatment. Localized defects of the helical rim or auricular dorsum, concha and lobulus can be corrected with easy-to-perform local tissue transfers and flaps. Complex auricular defects with additional surgical steps like a neck dissection need general anaesthesia. As result of the preselected patients surgical single step reconstruction-procedure are preferable. In these patients, because of the size of the defect, previous operations or radiation larger local flaps from the neck region or the scalp are necessary.

RESULTS AND CONCLUSION

With limited surgical expenditure most patients can obtain an aesthetically satisfying result. This avoids stigmatisation in an area that is hard to hide, which is important to elderly patients as well.

[Microtia: technique for external ear reconstruction with autologous rib cartilage]

Various methods for treatment of classic microtia are known. Beside a prosthesis, the most common way of auricle reconstruction is the use of autogenous rib cartilage; a process that requires two to three operations. In the first operation, rib cartilage is harvested from the 6th to the 9th rib. The base of the framework is the 6th and 7th rib cartilage which is taken under preservation of the synchondrosis. To mimic a 3-dimensional structure, the triangular fossa and scapha are carved into the groundplate and the 8th rib is fixed as a helical rim. After optimising the framework, it is placed in a subcutaneous pocket on the mastoid plane. In a second operation, approximately three months later, the auriculocephalic angle is reconstructed with a cartilage wedge, which is covered by a temporalis fascia flap and split skin-graft from the hairbearing skull. Commonly, a third operation is needed for minor refinements. Currently, autogenous rib cartilage is the ideal material available for ear reconstruction resulting in an excellent cosmetical outcome, although harvesting of the cartilage causes a specific donor-site morbidity. Operations improving the hearing ability by building up the external hearing channel and middle ear are mainly done in cases of bilateral microtia. Ear reconstruction with autogenous rib cartilage produces a replicable aesthetic result. The patients should be at least eight years old.

[Color comparison of donor sites of free flaps and the face]

Microsurgical reconstructions of the face using free flaps from the body and the extremities often lead to imperfect aesthetic results. In order to find the optimal free-flap donor site with respect to its colour we compared the colour of the face and of typical free-flap donor sites. In a study of 19 healthy, untanned subjects with skin type II-III (Fitzpatrick 1988), we measured the colour of four facial areas and of ten common free-flap donor sites and compared them statistically. Measurements were carried out with a Minolta CR-300 chromameter and the CIELAB colour system. We found that the face itself can be divided into two statistically significant different colour regions. The forehead-, cheek- and mandible areas have a distinctly different colour than the nose. The donor sites showing the best colour match with the forehead-, cheek- and mandible area were pectoralis, lateral upper arm, radialis, fibula, and latissimus. The nose area is clearly darker and less colourful. For this reason the colour match of all the free-flap donor sites in our investigation is poorer. Here the best suited donor site area is still the dorsalis pedis area.

[Highly malignant T-cell non-Hodgkin lymphoma (nasal type) of the hard palate]

The monomorphic clinical aspect of destructive mid-face lesions is characterised by inflammation, induration and granulomatous transformation. This feature can be caused by various infections, toxical noxa, Wegener's Granulomatosis and different neoplasms. The case of a 19 year old patient with EBV associated nasal type T-cell lymphoma located at the hard palate is presented. The diagnostic approach and difficulties in diagnosing this entity assessing by using multiple biopsies, serological and molecularbiological detection of EBV association and immunohistochemistry for atypic T-cells are elucidated. In the presented case the treatment with chemotherapy and irradiation following a well-defined therapy concept leaded to a three year recurrence-free survival so far. The comparison of the key-histological findings and the major differential diagnoses is mandatory to establish the final diagnosis of lymphoma. This is the basement for treating this disease with combined chemotherapy and irradiation for optimizing survival.

[Subcutaneous preservation of an amputated auricle. Morphological changes]

BACKGROUND

Microsurgical replantation of an avulsed auricle remains a challenge in reconstructive surgery. Secondary reconstruction of a traumatic lost auricle is usually performed using a costal cartilage framework according to well documented techniques or with a prosthesis. In order to minimize donor-site morbidity, various efforts can be undertaken to preserve the amputated auricle by implanting the de-epithelialized cartilage framework in a subcutaneous pocket on the surface of the mastoid. Where preservation is successful, this original cartilage could be used for reconstructive treatment.

PATIENT AND RESULTS

This study describes the histologic and immunohistologic changes in a complete traumatic avulsion of the auricle with subsequent cartilage conservation for eight months within a skin pocket. Trauma, preparation and preservation were accompanied by morphologic changes that included generation of local ossification centers and infiltration of fibrous tissue. We compared the macroscopic and microscopic morphology of the amputated part to native elastic cartilage following maximal denutrition and temporary heterotopic implantation in conjunction with atypical tension and pressure properties of the retroauricular pocket.

CONCLUSION

In this case, the limited success of cartilage conservation in the subcutaneous pocket required conventional auricle reconstruction with autologous costal cartilage.

[Autologous rib cartilage harvesting: operative procedure and postoperative pain reduction]

INTRODUCTION

In reconstructive surgery there is a growing demand for cartilage grafts. For small amounts of autologous tissue, cartilage from the nasal septum or ear concha is a sufficient and reliable tissue, but in cases of extensive defects or higher mechanical load autologous rib cartilage is a commonly used transplant. Nevertheless, a serious donor-site morbidity, especially postoperative pain, has to be taken into consideration. We present a modified technique for harvesting rib cartilage with a consecutive local pain therapy.

TECHNIQUE

In contrast to the commonly used incision through all layers of tissue the described technique follows the anatomical structures of skin tension-lines, the fascial and muscle fibers and tissue sliding-planes. Starting with a transversal skin incisions 1.5 cm above the costal arch, longitudinal splitting of the rectus abdominis fascia and muscle, the rib cartilage of the ribs 6 to 8 can be exposed. Grafts in the size of at least 3 to 8 cm can be harvested under preservation of the perichondrium. This technique causes a high degree of stability and good function of the abdominal wall. POSTOPERATIVE PAIN THERAPY: After harvesting rib cartilage most patients complain about extensive postoperative pain. For adequate treatment the local application of a long-lasting anesthetic substance close to the intercostal nerves is helpful. The introduction of a peridural catheter opens the feasibility of continuously applying a local anesthetic for 3 to 4 days directly into the donor-site. This procedure reduces the need for general anesthetics dramatically and prevents further complications.

DISCUSSION

This modified technique for harvesting rib cartilage diminishes the donor-site morbidity by reducing the risk of pneumothorax, hernias and functional deficits. Moreover, the local pain therapy assures postoperative wellness and mobility.

[Free microvascular rectus abdominis muscle flap for soft tissue reconstruction of the lower leg and foot: results and donor site defect]

The free rectus abdominis muscle flap is now a routine procedure for the reconstruction of soft tissue defects in the lower extremity. We present the follow-up of 21 out of 27 patients operated in our clinic between 1986 and 1994. The recipient leg always showed a stable soft-tissue coverage. Clinical or radiological signs of osteitis were not found. In many of the cases, where the transplantion was to the ankle region, the muscle bulk led to an alteration of the shape of the leg, without impairment of function. When harvested through a low transverse abdominal incision, the aesthetic results in the donor site are convincing. The functional donor site defect is negligible as long as only a segment of the muscle is used. Abdominal muscle tests showed good results when only a segment of the muscle was used. The patients reported no impairment in daily life. Abdominal wall weakness was present only when the entire muscle was harvested. There was one hernia after postoperative wound infection and secondary wound healing. In all other cases, the abdominal wall was stable. In the segmental use of the free rectus abdominis muscle flap, the good results obtained in our examination correlate to the high degree of patient satisfaction.

[Results of surgical management of lunate malacia. A retrospective clinical study]

We investigated the results of 53 patients in a retrospective study after surgical treatment for Kienböck's disease. Surgery included shortening of the radius (35 cases), cancellous bone graft (four cases), pisiform transposition (two cases), Swanson prostheses (two cases), tendon interposition arthroplasty (one case), STT-arthrodesis (six cases), denervation of the wrist (one case), and wrist arthrodesis (two cases). The average follow-up was 43 months (minimum 12, maximum 84 months). Criteria for rating the results were subjective satisfaction and pain profile. Objective criteria were X-ray findings and range of motion of the hand and wrist. We paid particular attention to the economic consequences for the patients. Based on our own results and the results in the literature, we recommend bone-grafting in the early Decoulx stages I and II. In stages II and III, we recommend in cases of ulna-minus variance the shortening of the radius in combination with a bone grafting; in case of an ulna-zero variance, we have the possibility of a radius wedge osteotomy or a pisiform transposition. Stage III, especially IIIb according to Lichtman, is suitable for STT-arthrodesis. In stage IV, we recommend total wrist arthrodesis, the denervation of the wrist can be combined with all the other methods or as a salvage procedure prior to wrist arthrodesis.