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At least 73 records · Page 4Linked to original sources

PubMed1995

Average-intensity reconstruction and Wiener reconstruction of bioelectric current distribution based on its estimated covariance matrix.

This paper proposes two methods for reconstructing current distributions from biomagnetic measurements. Both of these methods are based on estimating the source-current covariance matrix from the measured-data covariance matrix. One method is the reconstruction of average current intensity distributions. This method first estimates the source-current covariance matrix and, using its diagonal terms, it reconstructs current intensity distributions averaged over a certain time. Although the method does not reconstruct the orientation of each current element at each time instant, it can retrieve information regarding the current time-averaged intensity at each voxel location using extremely low SNR data. The second method is Wiener reconstruction using the estimated source-current covariance matrix. Unlike the first method, this Wiener reconstruction can provide a current distribution with its orientation at each time instant. Computer simulation shows that the Wiener method is less affected by the choice of the regularization parameter, resulting in a method that is more effective than the conventional minimum-norm method when the SNR of the measurement is low.

Computer Simulation↗

PubMed1992

Pediatric airway reconstruction at Great Ormond Street: a ten-year review. II. Revisional airway reconstruction.

One hundred eight consecutive patients with pediatric laryngotracheal stenosis requiring airway reconstruction over a 10-year period were reviewed. Thirty-two patients required revisional airway reconstruction in an attempt to achieve decannulation. Patients underwent from one to four revisional airway reconstructions, most often laryngotracheal reconstruction with costal cartilage grafting. In the Cotton grading scheme of preoperative stenosis, those patients requiring revisional airway surgery tended to come from the more severely affected categories. Twenty-two patients of 32 (69%) achieved decannulation with revisional airway reconstruction. Thus, revisional airway reconstruction is indicated if the first attempt fails.

Child↗

PubMed2003

Canal wall down tympanoplasty with canal reconstruction for middle-ear cholesteatoma: post-operative hearing, cholesteatoma recurrence, and status of re-aeration of reconstructed middle-ear cavity.

The post-operative outcome of hearing, the reconstructed external auditory canal, and the state of the reconstructed middle-ear cavity after canal wall down tympanoplasty with canal and attico-antrum reconstruction was studied in 103 ears with middle-ear cholesteatoma. The reconstructed mastoid cavity was re-aerated in 36.5 per cent of the cases, which was significantly lower than for the epitympanum (63.5 per cent) and tympanic cavity (82.4 per cent). Tympanoplasty was successful in terms of hearing results in 68.9 per cent of all subjects and in 75.4 per cent of the ears having a re-aerated tympanic cavity, which was significantly better than the 38.5 per cent for ears in which the tympanic cavity was not re-aerated. The findings of recurrent cholesteatoma, tympanic atelectasis, and tympanic effusion were observed with significantly (p<0.03) high incidence in ears with no re-aerated space in their reconstructed mastoid cavities. It was revealed that the post-operative outcome of this surgical technique was significantly related to the state of re-aeration of the reconstructed middle-ear cavity.

Adolescent↗

PubMed2006

Morbidity and cost differences between free flap reconstruction and pedicled flap reconstruction in oral and oropharyngeal cancer: Matched control study.

BACKGROUND: To compare morbidity and cost in patients who underwent primary reconstruction with free tissue transfer with those with pectoralis major myocutaneous flap (PMMF) reconstructions after ablation of oral and oropharyngeal squamous cell carcinoma. METHODS: Over a 6-year period, 36 patients had PMMF reconstructions and 127 patients had a variety of free flap (FRF) reconstructions after oral and oropharyngeal cancer ablation. Correction for confounding patient and disease variables was performed by matching all PMMF patients to a randomly selected cohort of FRF patients for age, sex, International Union Against Cancer-American Joint Committee on Cancer T category, tumour subsite, and radiotherapy status. This resulted in two groups of 32 patients each, with the flap reconstruction being the only variable. The following outcome variables were analyzed: operative time; blood loss; admission length, including intensive care unit and coronary care unit stay; complications; secondary interventions; readmissions; and feeding status. Cumulative costs of nursing care, hospital supplies and charges, surgeon's fees, and anesthesiologist's fees were calculated. Statistical analysis applied the paired Student's t-test and the chi-square test. RESULTS: Of all morbidity parameters, only operative time was significantly longer for FRF (p < .0001). Analysis of other outcome variables and costs showed no statistically significant differences (p > .05). CONCLUSION: There is no evidence that morbidity and cost differ between the pedicled flap and free tissue transfer reconstruction strategies, other than lengthier operating room time for FRF.

Adult↗

PubMed1998

[Breast reconstruction with the free microvascular abdominal flap. Accessory reconstruction or gold standard?].

Long time results of breast reconstruction after ablative surgery with skin expander and prothesis is perceived as unsatisfactory by most patients. Breast reconstruction with autologous tissue however is connected with a high technical expenditure and especially in the case of the free TRAM-flap connected with the risk of total loss of the transplanted tissue. In view of the total effort in secondary interventions, and reduction of the collateral side, the autologous reconstruction proves to need less time, resources and hospital admissions already after a 2 year period. Minor revisions mark the long time course of breast reconstruction with expander and prothesis. Judging by the patients themselves they prefer the reconstruction with autologous tissue and in this subgroup microsurgical reconstruction yields the better results to the patient. Review shows that the microsurgical procedure allows the transfer of larger volumes and better positioning of the breast including a physiologic breast ptosis. TRAM-flap donorsites seem to yield equal results in dynamic as well as static exercise regardless of the microsurgical or pedicled technique. The review of our own 48 patients with 50 TRAM-flaps coincide with the review of the current literature.

Breast Neoplasms↗

PubMed2000

[Functional results in the reconstruction of the ossicular chain in partial or total atrophy of the incus. Comparison between reconstruction using a moulded incus and hydroxyapatite PORP].

Ossicular chain defects modifying sound transmission through the middle ear can be treated with (re)implantation of remodeled autologous o homologous ossicles. In recent years, thanks to improved biocompatibility of the materials on the market, prostheses have been increasingly used in the partial or total ossicular chain reconstruction. The present study evaluates auditory ossicle reconstruction as a result of partial or total atrophy of the incus, comparing the use of the remodeled autologous incus with the use of partial hydroxyapatite prostheses (PORP). The study involved 79 patients of which 59 (74.7%) underwent ossicular chain reconstruction using a remodeled, inverted autologous incus while in the remaining 20 cases (25.3%) a hydroxyapatite prosthesis (PORP) was used. The effectiveness of the ossicular chain was evaluated by comparing pre- and postoperative audiometry and evaluating the average thresholds at frequencies of 0.5, 1, 2 and 3 KHz. The average preoperative audiometric gap (understood as the relationship between the air-bone gap) was 23 dB (Standard Deviation 11.2) while postoperatively it was 11 dB (SD 8.5) (p < 0.0001). Therefore the improvement in the air-bone gap was 12 dB (SD 11) for the overall population: 13 dB (SD 10) in those cases where reconstruction was performed using a remodeled incus and 8 dB (SD 11) when PORP was used. The postoperative cumulative gap between the air and bone pathways fell between 0 and 20 dB in 84% of the total population: 89% of those reconstructed with a remodeled incus and 73% of those using PORP. The middle ear ossicular chain reconstruction was performed using remodeled, inverted autologous incus in those cases where ossicular damage did not compromise its use while prostheses made of a biocompatible material (hydroxyapatite PORP) were reserved for those cases where the incus was absent or severely worn. The results obtained are satisfactory, remained stable in time and reflect the average values reported in the Literature.

Adolescent↗

PubMed2006

[Analyzing the methods to smooth field reconstructed by algebraic reconstruction technique with spectroscopy].

The effects of filters and filtering methods on the field reconstructed by algebraic reconstruction technique (ART) is discussed with spectroscopy. The field to be constructed was simulated with numerical simulation technique. The effects of many kinds of filters and filtering methods on the field reconstructed by ART were analyzed with spectroscopy. The filters used included quarter, fifth, eighth averaging filter, fifth center filter, and third row, column filter. The filtering methods included filter being inserted in the iterating process or set at its end. The averaging filter mentioned above meant that the value was acquired from the average of the four data, named quarter averaging filter, and so on. The fifth center filter meant that the value was acquired from the center, the third one in ascendant or descendant sequence of the five data. As a result, the authors found that a larger difference existed in the effects of different filters and filtering methods on the reconstructed field. First, the field reconstructed by ART contained much big noise and needed to be smoothed. Secondly, the reconstructive accuracy declined much when an averaging filter, such as quarter, fifth or eighth filter, was only set at the end of iterating process. Thirdly, the accuracy could be improved a little with a quarter or eighth averaging filter inserted in the iterating process and activated according to iterating times. Forthly, a better accuracy could be obtained with a fifth center filter inserted in the iterating process than with a fifth averaging one inserted. Fifthly, the best result in this work was obtained with a fifth averaging filter and a fifth center one inserted in the iterating process and activated alternately according to iterating times.

English Abstract↗

PubMed1996

Bladder neck reconstruction: long-term followup of reconstruction with omentum and silicone sheath.

PURPOSE: In 1986 we reported the placement of a silicone sheath sandwiched between layers of omentum around a newly reconstructed bladder neck. We now present long-term followup of 94 cases of silicone sheath bladder neck reconstruction. MATERIALS AND METHODS: A total of 94 silicone sheaths was placed in 84 patients between August 1983 and October 1992. We retrospectively reviewed our results and divided the reconstructions into 3 groups according to modifications in surgical technique. We report the results of each modification and current recommendations for use. RESULTS: Each sequential modification of silicone sheath bladder neck reconstruction significantly reduced the risk of erosion from 100%, 32% and 7%, respectively (p < 0.05). Erosion was independent of patient age, sex, pathological condition or whether bladder neck reconstruction was a repeat procedure. Patients who had silicone sheath erosion did not have different continence or loss of urethral continuity than those with no erosion. In 13 patients (16%) artificial sphincter placement was clearly facilitated by the silicone sheath. CONCLUSIONS: Modifications in the surgical technique of silicone sheath placement around a reconstructed bladder neck have resulted in a decrease in the erosion rate to 7%. The primary benefit of silicone sheath placement is ease of subsequent sphincter placement. Currently we reserve silicone sheath placement for a small subset of patients who are most likely to benefit from subsequent artificial sphincter placement.

Adolescent↗

PubMed2003

Reconstruction of segmental mandibular defects by distraction osteogenesis for mandibular reconstruction.

BACKGROUND: Distraction osteogenesis is an established technique for the lengthening of long bones and correction of selected craniofacial deformities. Regenerate osteoid bone matrix formed during the distraction phase is malleable and can recreate the three-dimensional form of native bones. Animal experiments and early clinical experience have confirmed that distraction osteogenesis can be used for the reconstruction of segmental bony defects. Herein we discuss the principles of distraction osteogenesis in reference to reconstruction of segmental bony defects and report its clinical application of the mandible continuity defects. PATIENTS AND METHODS: Four patients (age, 7-83 years) with critical segmental mandibular defects (range, 3.5 cm-6.5 cm), resulting from ablative oncologic head and neck surgery underwent primary mandibular reconstruction by transport distraction osteogenesis. Two defects were at the angle and body region, one at the body, and the other at the parasymphysis and body region. Synthes Titanium Multi-vector and Leibinger Multi-guide distractors in bifocal (n = 2) and trifocal (n = 2) architecture were used after the stabilization of the segmental continuity defect using a defect-bridging mandibular reconstruction plate. Osteodistraction was carried out at a rate of 1 mm per day, with once or twice a day rhythm, after a 1-week latency period. The consolidation period was equal to the period of distraction. RESULTS: All patients tolerated the distraction procedure. Satisfactory bone formation was observed in two patients, and partial bone formation was seen in one patient. Treatment failure was encountered in one patient who had a second oral cavity primary tumor observed during the consolidation period, requiring interruption of the treatment sequence. CONCLUSIONS: Mandibular reconstruction with distraction osteogenesis is a potentially useful technique in selected patients with segmental mandibular continuity defects after ablative head and neck cancer surgery.

Aged↗

PubMed2004

Comparison of miniplates and reconstruction plates in mandibular reconstruction.

BACKGROUND: The aim of this study is to compare complication rates of miniplates versus reconstruction plates in the fixation of vascularized grafts into segmental mandibular defects. METHODS: Retrospective analysis of 143 consecutive successful microvascular composite flaps performed between 1993 and 2001 was performed. Data were gathered from a computerized database, case notes and pathology reports. Complications were classified as dehiscence, infection, plate or bone removal. RESULTS: In the series, 49% of patients received miniplates, and 51% received plates. No significant differences in complication rates were found between those grafts fixed with miniplates (27%) and those with reconstruction plates (30%). Plate choice was primarily determined by consultant preference. No significant differences were found in patient, defect, treatment, or follow-up characteristics between the plate groups. Twenty-nine percent of patients had at least one late complication at the reconstructed site, and this was higher (39%) in those who had postoperative radiotherapy. CONCLUSIONS: No evidence was found in this study that the increased rigidity offered by reconstruction plates influences the rate of plate or bone removal, infection, or plate exposure. Thus, the decision to use reconstruction or miniplates is not dependent on the rate of plate complications.

Adult↗

PubMed2006

Efficacy of small reconstruction plates in vascularized bone graft mandibular reconstruction.

BACKGROUND: Utilization of vascularized bone grafts rigidly fixated with titanium reconstruction plates is the method of choice for reconstruction of segmental mandibular defects. We hypothesized that the use of the newer 2.0-mm locking reconstruction plate (LRP) is not associated with higher rates of complications when compared with larger, previously used plating systems. METHODS: A retrospective case series of 184 patients undergoing 185 vascularized bone graft reconstruction procedures of the mandible was conducted. RESULTS: There were 37 plate complications. There was no significant difference in complication rates for the 2 most used plate types (14.5% with the 2.0-mm LRP and 22.2% with the 2.4-mm LRP). CONCLUSIONS: Use of the smaller 2.0-mm LRP was not associated with an increase in the complications of plate fracture, exposure, infection, or nonunion. Because of its lower profile and ease of application, the 2.0-mm LRP is our plate of choice for mandibular reconstruction.

Adult↗

PubMed1994

Digital amputations and their reconstruction: reconstructive surgery of the fingers.

Reconstructive surgery of the fingers has been greatly modified and improved by the introduction of microsurgery. Fifty-three cases, in the past five years, of hand mutilation due to an amputation and the reconstructive techniques used have been reviewed. In the majority of the secondary reconstructions, three fundamental methods have been combined: (1) medialisation of the digits, (2) prolongation of the digits from "nearby" transpositions (remainders of proximal fingers), and (3) transfers from foot to hand. Beginning with this analysis, a classification of the procedures according to the defect to be reconstructed can be developed. Finally, the results in relation to the procedures applied have been analysed and technical observations that derive from these are pointed out, both for the donor foot as well as for the reconstructed hand.

Amputation, Traumatic↗

PubMed1990

A new method for three-dimensional reconstruction from serial sections by computer graphics using "meta-balls": reconstruction of "hepatoskeletal system" formed by Ito cells in the cod liver.

A new method is described for three-dimensional reconstruction from serial ultrathin sections, using "meta-balls" as a primitive of object modeling in computer graphics (CG). We take advantage of the meta-ball's blobbiness characteristic and its rendering system for reconstructing images. The two-dimensional outline data from serial sections are converted into three-dimensional meta-ball data with a graphic editor, "Metack," by which we can check the correctness of the data conversion. Then the converted data are visualized on a color display with a CG rendering software, "Tracy". This reconstruction method is applied in studying the spatial distribution of Ito cells (fat storing cells) in the cod liver in relation to the blood capillary. By observing the reconstructed images, we can easily understand the three-dimensional relationship between the Ito cells and the blood capillary. The Ito cells surround the blood capillary and extend their cytoplasmic processes into the inter-parenchymal space to make a well-developed network system. These findings would support a concept of "hepatoskeletal system" formed by Ito cells in the cod liver. Therefore, we think that the meta-ball reconstruction method is useful in morphological study.

Animals↗

PubMed2004

[From the French Society of Plastic and Reconstructive Surgery to the French Society of Plastic Reconstructive and Aesthetic Surgery].

(The) 3rd December 1952, 11 surgeons and other specialists found the French Society of Plastic and Reconstructive Surgery (SFCPR) which was officially published on (the) 28 September 1953. The first congress was during October 1953 and the first president as Maurice Aubry. The first secretary was Daniel Morel Fatio. The symposiums were after about three of four times each year and the thematic subjects were initially according the reconstructive surgery. The review "Annales de chirurgie plastique" was free in 1956. The members of the Society were about 30 initially, but their plastic surgery in the big hospitals at Paris and other big towns in France. The "specialty" of plastic surgery was created in 1971. On "syndicate", one French board of plastic reconstructive and aesthetic surgery, the increasing of departments of plastic surgery were the front of increasing of the plastic surgery in French and of the number of the French Society of Plastic Reconstructive surgery (580 in 2003). The French Society organized the International Congress of Plastic Surgery in 1975. The society SFCPR became the French Society of plastic reconstruction and Aesthetic Surgery (SFCPRE) in 1983 and the "logo" (front view) was in the 1994 SOF.CPRE.

Congresses as Topic↗

PubMed2004

A comparative study of envelope mastectomy and immediate reconstruction (EMIR) with standard latissimus dorsi immediate breast reconstruction.

BACKGROUND: Latissimus dorsi breast reconstruction has problems with scars at the donor site and on the reconstructed breast. We report the feasibility and aesthetic results of Envelope Mastectomy and Immediate Reconstruction (EMIR), which utilises a single lateral mammary fold incision. PATIENTS AND METHODS: Between 2001 and 2002, 20 EMIRs were performed in 19 patients, one as a staged bilateral procedure. Twenty consecutive patients, matched for body habitus, who had undergone standard latissimus dorsi breast reconstruction by the same surgeon from 1996 to 2000 were used as controls. Patient satisfaction was assessed using a validated Body Image Scale. Standard post-operative photographs were scored by three independent observers. RESULTS: Length of stay and complication rates were equivalent between both groups. Cosmetic self-assessment scores on the Body Image Scale and scores by the independent observers were satisfactory for both groups but no statistically significant difference was observed between groups. CONCLUSIONS: EMIR is a technically feasible and cosmetically acceptable method of immediate breast reconstruction.

Breast Neoplasms↗

PubMed2001

Anterior cruciate ligament reconstruction in patients with or without accompanying injuries: A re-examination of subjects 5 to 9 years after reconstruction.

PURPOSE: The purpose of this study was to compare the clinical and radiologic results of an anterior cruciate ligament (ACL) reconstruction in patients with an isolated ACL tear and patients with an ACL tear and accompanying injuries. TYPE OF STUDY: A retrospective investigation. METHODS: Seventy-two patients who did not have previous knee surgery or surgery of the contralateral knee were re-examined 5 to 9 years after the primary ACL reconstruction. The clinical assessment was made using the International Knee Documentation Committee (IKDC) evaluation system, and the Lysholm and the Marshall knee scores. Also, radiographic evaluation and isokinetic strength testing were performed. There were 34 patients (25 men and 9 women) with an isolated ACL tear (group A), and 38 patients (23 men and 15 women) with an ACL tear and accompanying injuries (group B). The mean age was 29 years (SD 9; range, 15 to 49 years) in group A, and 34 years (SD 12; range, 15 to 61 years) in group B. Bone-patellar tendon-bone autograft with mini-arthrotomy technique and screw fixation was used in all patients. Postoperative rehabilitation was also similar in both groups. In group B, 10 medial and 12 lateral (partial or subtotal) arthroscopic meniscectomies were performed at the same time as the ACL reconstruction. Also, 18 of the 19 medial collateral ligament ruptures, the 2 lateral collateral ligament ruptures, and the 1 posterior cruciate ligament rupture were treated surgically at this operation. RESULTS: Subjectively (overall assessment, pain, swelling, and giving way of the knee) and objectively (range of motion, stability, crepitation, isokinetic strength testing, and radiological changes of the knee), the groups did not have any significant differences in the 5- to 9-year results. Also, the final evaluation results using the IKDC and the Lysholm and the Marshall knee scores were similar in both groups. However, there were significantly more subsequent knee surgeries in the injured knee in group B than in group A. CONCLUSIONS: Our results show no large differences between patients with an isolated ACL tear and those with an ACL tear with accompanying injuries 5 to 9 years after an ACL reconstruction with a bone-patellar tendon-bone autograft. Tibiofemoral osteoarthritis was quite rare, and this may be partly attributable to the fact that the ACL reconstructions were successful, so that all the knees were stable at the re-examination. However, the future will show the final outcome for the patients.

Adolescent↗

PubMed1994

Oral and maxillofacial reconstruction using the free rectus abdominis myocutaneous flap. Various modifications for reconstruction sites.

The rectus abdominis myocutaneous flap consists of the skin paddle, anterior rectus sheath, rectus muscle and deep inferior epigastric artery and veins. Of these four components, the skin paddle, rectus sheath and rectus muscle could all be adjusted appropriately for reconstruction sites. Only one or two large perforators in the paraumbilical region could easily supply the large abdominal wall. The bulkiness of the rectus abdominis flap is reduced by removal of subcutaneous fat and rectus muscle. These possibilities can provide many modification of the flap for various reconstruction sites. 16 cases were reconstructed primarily and secondarily using this flap after oral and maxillofacial tumour ablation. The results of these cases indicated a very favourable and reliable vascularity. The rectus abdominis myocutaneous flap was considered to be one of the most suitable flaps for oral and maxillofacial reconstruction. Various modifications for different reconstruction sites are mainly discussed.

Adipose Tissue↗

PubMed1988

Titanium-coated hollow screw and reconstruction plate system (THORP) in mandibular reconstruction.

Clinical results are presented which have been obtained from mandibular reconstruction with the Titanium-coated Hollow Screw and Reconstruction-Plate system (THORP) in 7 selected patients. In 3 of the patients primary bone grafting was performed with simultaneous implantation of titanium fixtures for dental reconstruction. The reconstruction-plates have shown excellent functional stability with no failures, such as loosening of screws, within an observation period up to 2 1/2 years. The system was submitted to immediate full functional loading despite the limited number of 2-3 fixation screws for each end of the plate. Among several technical advantages of the system are the possibility of lingual plate application and reconstruction with a three-dimensionally free, adjustable condylar prosthesis.

Adult↗