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Biomedical subjects

N A Papadopulos

Publications and source records attributed to N A Papadopulos.

16 recordsLinked to original sources
PubMed2007

Comparison of experimental microvascular end-to-end anastomosis via VCS-Clips versus conventional suture technique in an animal model.

In this experimental study on 96 CD rats, microvascular end-to-end anastomoses created via suture or alternatively by means of a VCS-Clip-Application-System, were compared. The aorta abdominalis of the animals, with a diameter of 1.5 +/- 0.2 mm, was experimentally dissected, and the free ends of the vessel then anastomosed. The results were evaluated using sonography, microangiography, histologic examination, and vascular imprints. Postoperative examination was carried out after 1, 3, 7, 14, or 30 days. Major advantages of the VCS-Clip technique over suturing were that it was easy to learn, significantly faster to perform (execution of anastomosis 10.9 +/- 2.6 min versus 19.4 +/- 5.0 min), and produced significantly more favorable histologic results in terms of less inflammatory response, foreign body reaction, necrosis of the tunica media, hyperplasia of the intima, and thrombosis of the vessel lumen. The main disadvantage of the clip technique was a significantly higher rate of stenoses (15.8 +/- 6.0 versus 4.1 +/- 6.6 percent).

Anastomosis, Surgical↗
PubMed2006

Three-dimensional recording of the human face with a 3D laser scanner.

Three-dimensional recording of the surface of the human body or of certain anatomical areas has gained an ever increasing importance in recent years. When recording living surfaces, such as the human face, not only has a varying degree of surface complexity to be accounted for, but also a variety of other factors, such as motion artefacts. It is of importance to establish standards for the recording procedure, which will optimise results and allow for better comparison and validation. In the study presented here, the faces of five male test persons were scanned in different experimental settings using non-contact 3D digitisers, type Minolta Vivid 910). Among others, the influence of the number of scanners used, the angle of recording, the head position of the test person, the impact of the examiner and of examination time on accuracy and precision of the virtual face models generated from the scanner data with specialised software were investigated. Computed data derived from the virtual models were compared to corresponding reference measurements carried out manually between defined landmarks on the test persons' faces. We describe experimental conditions that were of benefit in optimising the quality of scanner recording and the reliability of three-dimensional surface imaging. However, almost 50% of distances between landmarks derived from the virtual models deviated more than 2mm from the reference of manual measurements on the volunteers' faces.

Adult↗
PubMed2006

[Transsexuals' life satisfaction after gender transformation operations].

BACKGROUND: More and more frequently, the registration of life satisfaction is being used to evaluate different medical treatments. So far, there have been only few such surveys on transsexuals (TS). Therefore, the aim of this study was to evaluate the general and the health-related life satisfaction of transsexuals after gender transformation operations. PATIENTS AND METHODS: Forty patients took part in this German cross-sectional study. The Questions on Life Satisfaction Module (FLZ) and free questions on different aspects of the new gender identity were used as measuring instruments. RESULTS: Of the TS studied, 85-95% were "very satisfied" or "satisfied" with the results of their gender transformation operation in respect to gender identity. The TS were significantly less satisfied (P>0.001) in overall "general life satisfaction" than the general population. In overall FLZ scores for "health-related life satisfaction", no differences were seen. CONCLUSION: These data indicate a discrepancy between subjective satisfaction with new gender identity and current life situation, and they identify problems with life satisfaction.

Adult↗
PubMed2006

[Quality of life and patient satisfaction after breast reconstruction].

BACKGROUND: Nowadays, the array of methods for reconstruction of the female breast following mastectomy is vast. In this study, we investigate and compare quality of life after breast reconstruction and satisfaction with the results of two commonly used techniques (autologous tissue vs. expander/implant). METHODS: Ninety-one consecutive patients who underwent breast reconstruction at a German clinic between 1996 and 2001 were included in the study. Patient satisfaction and quality of life were assessed retrospectively using self-evaluation questionnaires. RESULTS: Patients were generally more satisfied with the outcome of the operation when autologous tissue was used. This was significant in the following areas: breast size, form, definition of the lower breast fold, softness of the breast, and symmetry of the breasts. In both groups the quality of life following breast reconstruction at least 2 years after the operation was equal to that of healthy women of the same age group. CONCLUSION: Although patients were more satisfied with the results of autologous breast reconstruction, procedure choice did not affect quality of life.

Adult↗
PubMed2006

[Soft tissue defects as a complication in knee arthroplasty. Surgical strategies for soft tissue reconstruction].

Soft tissue defects after knee arthroplasty are a severe problem, which can even result in a loss of the prosthesis or the limb. Well-planned strategies are necessary for sufficient soft tissue reconstruction, resulting in optimal functional and aesthetic results. This report provides information on the classification of the tissue defects and the appropriate options for surgical reconstruction. Besides the basic therapy principles of immobilisation, débridement, planned lavages and antibiotic therapy, defect-dependent surgical techniques of reconstructive surgery are implemented. These include skin transplantation, local fasciocutaneous flaps, local pedicled muscle flaps and free flaps. For best results, interdisciplinary treatment by orthopaedic surgeons, plastic surgeons, microbiologists and physiotherapists is mandatory.

Arthroplasty, Replacement, Knee↗
PubMed2006

Accuracy and precision of the three-dimensional assessment of the facial surface using a 3-D laser scanner.

Three-dimensional (3-D) recording of the surface of the human body or anatomical areas has gained importance in many medical specialties. Thus, it is important to determine scanner precision and accuracy in defined medical applications and to establish standards for the recording procedure. Here we evaluated the precision and accuracy of 3-D assessment of the facial area with the Minolta Vivid 910 3D Laser Scanner. We also investigated the influence of factors related to the recording procedure and the processing of scanner data on final results. These factors include lighting, alignment of scanner and object, the examiner, and the software used to convert measurements into virtual images. To assess scanner accuracy, we compared scanner data to those obtained by manual measurements on a dummy. Less than 7% of all results with the scanner method were outside a range of error of 2 mm when compared to corresponding reference measurements. Accuracy, thus, proved to be good enough to satisfy requirements for numerous clinical applications. Moreover, the experiments completed with the dummy yielded valuable information for optimizing recording parameters for best results. Thus, under defined conditions, precision and accuracy of surface models of the human face recorded with the Minolta Vivid 910 3D Scanner presumably can also be enhanced. Future studies will involve verification of our findings using test persons. The current findings indicate that the Minolta Vivid 910 3D Scanner might be used with benefit in medicine when recording the 3-D surface structures of the face.

Algorithms↗
PubMed2005

Foetal surgery and cleft lip and palate: current status and new perspectives.

Now-a-days, high-resolution ultrasound allows an accurate and relatively early diagnosis of congenital malformations. In a limited number of such conditions foetal surgery may be lifesaving. However, premature labour has been the major drawback for open foetal surgery. Recently, improvement of video-endoscopic technology has boosted the development of operative techniques for feto-endoscopic surgery, which has been demonstrated to be less invasive than the open approach. Main clinical application of fetoscopic procedures today is the treatment of feto-foetal transfusion syndrome. Although still in development, feto-endoscopic surgery seems to offer new hope for surgical foetal therapy not only in cases of life threatening conditions. Experimental intrauterine correction of cleft lip and palate (CLP) has been lately performed using the feto-endoscopic approach. This procedure offers two major advantages: first, scarless foetal wound healing and bone healing without callus formation, which would also allow a better/normal maxillary growth, and second, significant decrease of foetal and maternal morbidity. Herein, we report the current status of experimental and clinical foetal surgery and propose possible directions for continuing research to make intrauterine procedures safer. Furthermore, we discuss current knowledge and new perspectives of experimental foetal cleft lip and palate repair, which in the future may lead to such excellent results in the operative treatment of clefts, that less or no secondary corrections and therapies, such as orthodontic, dental, logopedic, etc. would be needed. Only if these conditions can be fulfilled, will we be able to improve substantially our therapy for the human foetus with a cleft lip and palate. In spite of all efforts, however, it must be considered that it may not ever be possible to find the optimal treatment method for this or other craniofacial malformations.

Animals↗
PubMed2005

Computer aided surgical reconstruction after complex facial burn injuries -- opportunities and limitations.

In severe facial burn injuries with extensive destruction of anatomical structures, cosmetic and functional outcome of treatment are frequently not satisfactory. Although operative therapy is being continuously refined, the variety and proximity of structures in the facial region is considered a major challenge in reconstructive surgery. We present the case of a 16-year-old patient with a severe facial burn injury. In planning the reconstructive procedures, we used a multimodal approach employing data from computerized tomography imaging, as well as from surface laser scanning, which provided three-dimensional visualization of facial soft tissues. Amount and pattern of structural loss could thus be determined more precisely and studied more vividly than by inspection of two-dimensional imaging alone. Anatomical features to be reconstructed could be projected onto the skin area of the prelaminated vertical rectus abdominis muscle (VRAM) flap that has been chosen to cover the defect. Prior to surgery, correction of the defects was simulated and the results of the virtual procedure superimposed on a three-dimensional head model of the patient. Tissue elasticity and thickness of the flap, however, could not be ascertained in advance, indicating the limitations of the method.

Adolescent↗
PubMed2004

[Fetal wound healing: current status and new perspectives].

The characteristic of fetal wound healing is scarless wound repair in early gestation. During the last two decades, intensive research efforts have focused on unraveling the molecular regulations underlying the phenomenon of scarless wound healing. Better understanding of synthesis and degradation will enable us to develop important therapeutic options for the prevention and reduction of scarring. The aim of this article is to present an overview, discuss the most important research works of the last two decades on the field of fetal wound healing, and report current therapeutic developments for the modulation of adult wound repair. Recent experimental results using these new therapeutic approaches are very promising and present great possibilities and chances for future surgery.

Animals↗
PubMed2002

[Experimental endoscopic intrauterine surgery for craniofacial malformations such as the cleft lip and palate].

INDICATION FOR FETAL SURGERY: The widespread use of high-resolution ultrasound in prenatal diagnosis allows nowadays an accurate and early diagnosis of congenital malformations. Some of these can be corrected surgically. In certain cases intrauterine surgery could present functional and aesthetic advantages or be even lifesaving. Due to the extreme sensitiveness of the fetal patient and the fetal membranes, only some defined anomalies currently meet the criteria for intrauterine surgery. However, the list can change in the future since prenatal diagnosis, technical advances, and knowledge of pathophysiology improve constantly. ENDOSCOPIC INTRAUTERINE SURGERY: Additionally, the recent development of endoscopic intrauterine surgery represents a new and more careful possibility for intrauterine surgery. Endoscopic procedures could avoid the disadvantages of open intrauterine surgery and thus make fetal operations safer, in life-threatening as well as in non-life-threatening malformations such as cleft lip and palate (CLP). The main advantages of these procedures are (1) scarless wound healing and bone healing without callus formation that leave to expect normal growth of the midface and (2) lower fetal and maternal morbidity. DISCUSSION: Based on the results achieved until now, it can be stated that at present the intrauterine operation of CLP on humans cannot be recommended. The high morbidity and mortality risk for mother and fetus cannot be counterbalanced by the unsatisfactory results of a prenatal operation. CONCLUSION: In this study first results of an experimental investigation with the new endoscopic techniques are presented, whereby the possibilities for optimization and quality improvement of the intrauterine surgical procedures are analyzed in detail.

Animals↗
PubMed2001

Usefulness of free sensate osteofasciocutaneous forearm and fibula flaps for neophallus construction.

Female-to-male transsexuals have been treated by the authors since the 1970's, using different operative methods. Since 1981, these patients have received neophallus construction with free sensate osteofasciocutaneous forearm flaps and, since 1993, with free sensate osteofasciocutaneous fibula flaps. In order to evaluate the usefulness of these flaps, the authors performed, in 24 patients (12 with forearm and 12 with fibula flaps), the following examinations: clinical and radiologic evaluations of the neophallus and its donor site, as well as patient questionnaires. In all patients, subjective findings and clinical examinations showed no significant variations in neophallus size and form. Patients with fibula flaps had better sexual intercourse, although their neophallus sensibility was minor, when compared to the forearm flap patients. Donor-site morbidity was moderate in both groups. On radiologic examination, robust, calcified bone structure, and no fracture of the neophallus bone and its donor site, as well as no instability of the ankle joint (in the fibula flap patients) were found. These findings further support the use of these free sensate osteofasciocutaneous flaps for neophallus construction. In the authors' opinion, it is the patient who must decide which method should be used for neophallus construction.

Female↗
PubMed1999

The midgestational rabbit as a model for the creation of membrane defects after needle fetoscopy.

OBJECTIVES: The aim of the study was to determine whether the pregnant rabbit at mid gestation could be used as a suitable in vivo model for the study of membrane defects after invasive procedures. STUDY DESIGN: Pregnant rabbits at gestational ages of 22 and 18 days (term is 32 days' gestation) underwent needle insertion with different instrument diameters (1.1 mm, 1.35 mm, 2.0 mm, and 2.7 mm). Two different insertion techniques were evaluated, blind amniotic puncture and puncture through surgically exposed amnion. Membrane integrity, presence of amniotic fluid, and fetal lung/body weight ratio were evaluated at 31 days' gestation. RESULTS: Among rabbits operated on at 22 days' gestation the amniotic integrity restoration at 31 days' gestation ranged from 46% to 76% in the different diameter and access technique groups, as compared with 98% in untreated sacs (P <.05 for all groups). Fetuses from sacs with persisting membrane defects had oligohydramnios and significantly lower fetal lung/body weight ratios. Survival rates among fetuses operated on at 18 days' gestation were so poor that appropriate statistical analysis was not possible in this group. CONCLUSIONS: The rabbit at mid gestation can be used as a model to reproduce permanent membrane defects after fetoscopy, reproducing oligohydramnios and pulmonary hypoplasia. This may provide a suitable in vivo model for the study of iatrogenic membrane defects.

Amnion↗
PubMed1999

Closure techniques for fetoscopic access sites in the rabbit at mid-gestation.

Operative fetoscopy may be limited by its relatively high associated risk of preterm prelabour rupture of membranes. The objective of this study was to study closure techniques of the access site for fetoscopy in the mid-gestational rabbit. A total of 32 does (288 amniotic sacs) at 22 days gestational age (GA; term = 32 days) underwent 14 gauge needle fetoscopy, by puncture through surgically exposed amnion. Entry site was randomly allocated to four closure technique groups: myometrial suture (n = 14), fibrin sealant (n = 15), autologous maternal blood plug (n = 13), collagen plug (n = 14); 16 sacs were left unclosed (positive controls), and the unmanipulated 216 sacs were negative controls. Membrane integrity, presence of amniotic fluid and fetal lung to body weight ratio (FLBWR) were evaluated at 31 days GA. Following fetoscopy without an attempt to close the membranes, amniotic integrity was restored in 41% of cases (amniotic integrity in controls 94%; P = 0.00001). When the access site was surgically closed, the amnion resealed in 20-44% of cases, but none of the tested techniques was significantly better than the others or than positive controls. Permanent amniotic disruption was associated with a significantly lower FLBWR in all groups. In conclusion, the rate of fetoscopy-induced permanent membrane defects in this model did not improve by using any of the closure techniques tested here.

Animals↗
PubMed1998

Fetal membrane closure techniques after hysteroamniotomy in the midgestational rabbit model.

OBJECTIVE: We studied closure techniques for amniotic access in midgestational rabbits. STUDY DESIGN: Twenty-eight rabbits with a total of 313 amniotic sacs were used for this study. In each animal a 1 cm hysteroamniotomy was made in two amniotic sacs at 22 days' gestation (term = 32). For 12 amniotic sacs (group 1) only the myometrium was closed by microsurgical suturing. In group 2 (n = 12), sutures included myometrium and membranes. In group 3 (n = 8), a collagen plug was placed, and in group 4 (n = 12) fibrin glue was used. Twelve sacs were left unclosed (positive controls) and the unmanipulated 257 sacs were negative controls. Eight days later (gestational age 30 days) amniotic sacs were evaluated for the presence of amniotic fluid, membrane integrity, and fetal weight and survival. Statistics were done with two-tailed Fisher's exact test and one-way analysis of variance. RESULTS: Membrane integrity (p = 0.0036) and amniotic fluid (p = 0.047) were best restored after myometrial closure. Fetal weight and survival rate were not affected by different closure techniques. CONCLUSION: In this model primary closure of the myometrium only yielded best results.

Amnion↗
PubMedDate not supplied

Fetoscopy in the pregnant rabbit at midgestation.

OBJECTIVE: To develop a small animal model for fetoscopy. METHODS: In 12 time-dated pregnant rabbits at 22 days' gestational age (term 32 days) one amniotic sac in each uterine horn (n = 24) was used for a fetoscopic procedure. After laparotomy, a 2- to 3-mm microsurgical myometrial incision was made to expose the chorionic and amniotic membrane. Under microscopic control, a 2-mm needle was inserted into the amniotic sac. Through this a 1.2-mm endoscope was passed to carry out fetoscopy during maximally 10 min, using 5-10 ml saline amnioinfusion. Mean outcome measurements were ability to visualize the placenta, umbilical cord and the different fetal elements during fetoscopy, as well as fetal survival and weight at second-look operation at 30 days. The untreated amniotic sacs served as negative controls. RESULTS: In all cases, fetoscopy could be carried out successfully, and all fetuses survived till delivery without significant influence on fetal birth weight. CONCLUSION: The midgestational rabbit can be used to perform fetoscopy.

Amnion↗