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PubMed2006

Our algorithm for nasal reconstruction.

Nasal reconstruction is always challenging for plastic surgeons. Its midfacial localisation and the relationship between convexities and concavities of nasal subunits make impossible to hide any sort of deformity without a proper reconstruction. Nasal tissue defects can be caused by tumor removal, trauma or by any other insult to the nasal pyramid, like cocaine abuse, developing an irreversible sequela. Due to the special characteristics of the nasal pyramid surface, the removal of the lesion or the debridement must be performed according to nasal subunits as introduced by Burget. Afterwards, the reconstructive technique or a combination of them must be selected according to the size and the localisation of the defect created, and tissue availability to fulfil the procedure. An anatomical reconstruction must be completed as far as possible, trying to restore the nasal lining, the osteocartilaginous framework and the skin cover. In our department, 35 patients were operated on between 2000 and 2002: three bilobed flaps, five nasolabial flaps, two V-Y advancement flaps from the sidewall, three dorsonasal flaps modified by Ohsumi, 19 paramedian forehead flaps, three cheek advancement flaps, three costocondral grafts, two full-thickness skin grafts and two auricular helix free flaps for alar reconstruction. All flaps but one free flap survived with no postoperative complications. After 12-24 months of follow-up, all reconstructions remained stable from cosmetic and functional point of view. Our aim is to present our choice for nasal reconstruction according to the size and localization of the defect, and donor tissue availability.

Adult↗

PubMed2006

The influence of radiotherapy on capsule formation and aesthetic outcome after immediate breast reconstruction using biodimensional anatomical expander implants.

BACKGROUND: Capsular contracture occurs more frequently when immediate breast reconstruction (IBR) is associated with radiotherapy (RT) in a post-mastectomy field. The aim of this study was to investigate the impact of RT on surgical outcome after IBR using a single implant type. METHODS: One hundred and thirty-six breast reconstructions were studied in 114 patients: 62 reconstructions were performed using submuscular implants alone and 74 had an implant-assisted latissimus dorsi myocutaneous flap using a McGhan 150 biodimensional permanent expander implant. Data were prospectively collected on capsule contracture, geometric measurements, photographic assessments and pain scores. The median follow-up was 4 (range, 2-5) years. RESULTS: The mean age of the 114 patients studied was 45 (range, 20-77) years. Forty-four reconstructed breasts received RT. Capsule formation was detected in 13/92 (14.1%) reconstructed breasts with no RT and in 17/44 (38.6%) reconstructed breasts with RT. On univariate analysis, RT was the only variable related to capsule formation (p<0.001). Significant differences in geometric measurements of symmetry were identified in patients with capsules compared with those without capsules. Photographic assessments were worse in the capsule group: mean photo score 8 (95% CI 8, 8.5) compared with the no capsule group 6.5 (95% CI 5, 7.5), p<0.001. Persistent pain two years or more after surgery was present in 8/30 patients with capsules and 1/106 with no capsule group, p<0.01. Capsule formation is three times more likely to occur after IBR in association with an RT field. However, as more than 60% of patients do not get capsules despite RT at four years, implant-assisted tissue expansion techniques using a biodimensional device is a viable breast reconstructive option in selected cases.

Adult↗

PubMed2006

One-stage breast reconstruction using McGhan Style 150 biodimensional expanders: a review of 107 implants with six years experience.

Permanent expanders have revolutionised breast reconstructive surgery, allowing one-stage procedures and the development of increasingly sophisticated implants (textured, anatomically shaped) has played an important role in enhancing the aesthetic outcomes. It is important to evaluate the tolerability of the implant. The aim of this present study was to evaluate the survival curves for McGhan Style 150 permanent expanders, in a consecutive series of breast reconstructions. Complications rates were also examined. Between April 1997 and May 2003, 107 McGhan Style 150 expanders (either full height or short height depending on patients' requirements) were used in 97 consecutive patients for a variety of breast reconstructive procedures. Overall, 46 devices were used for immediate reconstruction, 15 for delayed reconstruction and 46 for implant exchange, respectively. The mean age at implantation was 48 years (min: 26; max: 71). The mean follow-up was 60 months (min: 12; max: 72). Explantation was considered the most objective outcome variable, therefore this parameter was carefully monitored and then analysed using the Kaplan-Meier method of survival analysis. Different curves were compared using the log-rank test. Long term complications were also recorded. Among complications the most frequent finding was Baker 3-4 capsular contracture, occurring in 26% of immediate reconstructions at six years. Explantations increased in an almost linear fashion, with an overall rate of 25%, with a statistically significant difference among immediate reconstruction group and the implant exchange group. The rate of explantations was high, if compared with other series, because the sample included patients undergoing strong adjuvant therapies, particularly in the immediate group (locally advanced disease). The overall rate of explantations and of capsular contracture was found to be significantly lower in the delayed and substitution groups, than the immediate group (p<0.05). In our hands, the McGhan Style 150 anatomically shaped permanent expanders were associated with acceptable results, especially when used as 'permanent prostheses' for second stage procedures.

Adult↗

PubMed2006

Complications analysis of 266 immediate breast reconstructions.

The purpose of this study was to describe the complications of immediate breast reconstruction, to compare their rates with respect to the surgical procedure and to patient's characteristics, in order to improve surgical indications and patient information. We carried out a retrospective study of 266 immediate breast reconstructions (249 women) over a 12-year period (latissimus dorsi myocutaneous flap with implant 61%, autologous latissimus dorsi myocutaneous flap 15%, subpectoral implant 24%). Mean age was 48 and the median follow-up was seven years (2-14). The overall complication rate was 49% (128), and there were 10 reconstruction failures. The most frequent complications were dorsal seroma 26% (70), capsular contracture 10% (27), skin necrosis 8.3% (22), and haematoma 5.6% (15). The complication rate for immediate breast reconstruction with implant alone (39%) was lower than that associated with latissimus dorsi with or without implant (51%), but the difference was not significant (Chi-square: p=0.07). The risk factors for complications were smoking (skin necrosis, Fisher: p=0.02), obesity (infection, Fisher: p=0.004), and radiotherapy (capsular contracture, Chi-square: p=2.6 x 10(-5)). Smoking was found as the only risk factor of reconstruction failure (Fisher: p=0.015). Capsular contractures were more frequent when implants were used alone (25%) as well as when used along with a flap (6.8%) (Chi-square: p=2 x 10(-5)). Infections were also higher in the non-flap group than in the flap group (Fisher: p=0.02). In our opinion, latissimus dorsi myocutaneous flap with or without an implant is a good compromise between complication risk and necessity of good cosmetic result requirement. These results have led us to delay or contraindicate reconstruction in the case of obesity or heavy smoking. In the case of probable post-operative radiotherapy, we prefer to delay the breast reconstruction.

Adult↗

PubMed2006

Surgeons and scars: differences between patients and surgeons in the perceived requirement for reconstructive surgery following burn injury.

BACKGROUND: Reconstruction of the burn patient presents a challenge to the burns surgeon. The variety of issues and the timing of surgery can be a daunting task. A group of 11 patients who were injured 1 year previously at the time of the Bali bomb blast were reviewed. METHODS: A customised assessment form was developed in order to quantify the patient's perceived need for reconstruction. Each patient was asked to prioritise, in order of preference any injured area they might consider for further surgery. These patients were then assessed independently by a consultant plastic and reconstructive surgeon and a senior trainee, using an identical form. The surgeons were asked to prioritise, in order of preference any area they might consider for further surgery and to indicate from a list the procedure they would employ. This list ranged from simple excision to free flap encompassing the entire reconstructive ladder. RESULTS: The patients all showed a strong reluctance to undergo further reconstruction. However there was a strong correlation between the surgeons, concurring on issues of function but there were discrepancies regarding "aesthetic" reconstruction. CONCLUSIONS: This study highlights the absolute need for secondary burns reconstruction to be a patient driven service.

Adult↗

PubMed2006

The classification and treatment algorithm for post-burn cervical contractures reconstructed with free flaps.

Neck contractures after burn produce restrictions in motion and unacceptable aesthetic outcomes. Proper planning and tissue selection is essential to minimize donor site morbidity while optimizing outcomes. A classification system and treatment algorithm aids in achieving this goal. Between December 1999 and January 2003, 40 burn patients underwent release and reconstruction with free perforator flaps. Neck extensibility and zone of injury were evaluated. Choice of reconstruction was based on available tissue, restriction degree and zones involved. Cervical territories were classified according to movement restrictions and amount of improvement. Reconstructive territories were classified as central above (CA), central below (CB), central above and below (CAB) and lateral (L). Single, split, double and preexpanded free flaps were used for the reconstructions. Maximal gain in motion was noted at 4 weeks and maintained for the average 11 months follow-up. Types of reconstructive territories showed significant effects on range of motion while etiology and time between injury and reconstruction showed no impact on the functional outcome. Classification of neck territories aids in improving outcomes while minimizing donor morbidity. The central above territory, when reconstructed with free flaps, yielded the most rewarding improvement. A classification and treatment algorithm aids in achieving significant improvements in range of neck motion while taking into consideration the donor sites.

Adolescent↗

PubMed2004

Benefits of an anatomical reconstruction of the humeral head during shoulder arthroplasty: a finite element analysis.

OBJECTIVE: To study the influence of the shape of the prosthetic humeral head on shoulder biomechanics and then to evaluate the benefits of an anatomical reconstruction of the humeral head after shoulder arthroplasty. DESIGN: A 3D numerical model of a healthy shoulder was reconstructed. The model included the proximal humerus, the scapula and, for stability purposes, the subscapularis, infraspinatus and supraspinatus rotator cuff muscles. BACKGROUND: Shoulder prostheses used nowadays, called third generation, allow for a better adaptation of the implant to the anatomy of the proximal humerus than previously used implants. However, no biomechanical study has shown the benefits of this anatomical reconstruction of the humeral head. METHODS: The model was used to compare the biomechanics of a shoulder without implant with the biomechanics of the same shoulder after humeral hemiarthroplasty. Two humeral components were tested: a second-generation prosthesis and an implant with an anatomically reconstructed humeral head. RESULTS: The anatomical reconstruction of the humeral head restored the physiological motions and limited eccentric loading of the glenoid. Conversely, the second-generation implant produced contact forces in the superior extremity of the glenoid surface leading to bone stresses up to 8 times higher than for the intact shoulder. CONCLUSIONS: This analysis provided insights into the mechanical effects of different reconstructions of the humeral head and highlighted the advantages of anatomical reconstructions of the humeral head during shoulder arthroplasty.

Arthroplasty, Replacement↗

PubMed2004

Fast accurate stereoradiographic 3D-reconstruction of the spine using a combined geometric and statistic model.

OBJECTIVE: To describe and evaluate a fast accurate stereoradiographic 3D-reconstruction method of the spine. BACKGROUND: Stereoradiographic methods based on anatomical landmarks identification are the only ones providing information on 3D-deformities of the spine in a standing position, but require 2-4 h for the whole spine, making the method inadequate for clinical routine. METHODS: The proposed semi-automated method is based on (1) vertebral body volume reconstruction, (2) definition of a local referential associated to this volume, (3) reliable a priori knowledge of the vertebral shape using eight morphologic descriptors of the vertebral body to estimate, from a multiple linear regression, 21 3D-point coordinates per vertebra, (4) kriging of a 2000 points model with regard to the 21 points. The method was evaluated for vertebral orientation and shape accuracy. RESULTS: 3D models of the whole spine are obtained within 15 min. Manual vs. semi-automated reconstruction comparison yield similar accuracy regarding the CT-scan references. For vertebrae orientation, results were slightly different from the manual reconstruction method (however an absolute reference is lacking). CONCLUSION: The stereoradiographic 3D-reconstruction method allows for a significant reduction of the whole reconstruction time, with regard to previously described methods. Moreover, the accuracy was evaluated and was found to be comparable to the accuracy of previous methods. The results of this study show that stereoradiography could now be employed in routine clinical environment. RELEVANCE: 3D spine reconstruction from biplanar radiographs in standing position can be obtained using a fast and accurate method.

Algorithms↗

PubMed2005

Fast 3D-EM reconstruction using Planograms for stationary planar positron emission mammography camera.

At the University of Pisa we are building a PEM prototype, the YAP-PEM camera, consisting of two opposite 6 x 6 x 3 cm3 detector heads of 30 x 30 YAP:Ce finger crystals, 2 x 2 x 30 mm3 each. The camera will be equipped with breast compressors. The acquisition will be stationary. Compared with a whole body PET scanner, a planar Positron Emission Mammography (PEM) camera allows a better, easier and more flexible positioning around the breast in the vicinity of the tumor: this increases the sensitivity and solid angle coverage, and reduces cost. To avoid software rejection of data during the reconstruction, resulting in a reduced sensitivity, we adopted a 3D-EM reconstruction which uses all of the collected Lines Of Response (LORs). This skips the PSF distortion given by data rebinning procedures and/or Fourier methods. The traditional 3D-EM reconstruction requires several times the computation of the LOR-voxel correlation matrix, or probability matrix {p(ij)}; therefore is highly time-consuming. We use the sparse and symmetry properties of the matrix {p(ij)} to perform fast 3D-EM reconstruction. Geometrically, a 3D grid of cubic voxels (FOV) is crossed by several divergent 3D line sets (LORs). The symmetries occur when tracing different LORs produces the same p(ij) value. Parallel LORs of different sets cross the FOV in the same way, and the repetition of p(ij) values depends on the ratio between the tube and voxel sizes. By optimizing this ratio, the occurrence of symmetries is increased. We identify a nucleus of symmetry of LORs: for each set of symmetrical LORs we choose just one LOR to be put in the nucleus, while the others lie outside. All of the possible p(ij) values are obtainable by tracking only the LORs of this nucleus. The coordinates of the voxels of all of the other LORs are given by means of simple translation rules. Before making the reconstruction, we trace the LORs of the nucleus to find the intersecting voxels, whose p(ij) values are computed and stored with their voxel coordinates on a hard disk. Only the non-zero p(ij) are considered and their computation is performed just once. During the reconstruction, the stored values are loaded and are available in the random access memory for all of the operations of normalization, backprojection and projection: these are now performed rapidly, because the application of the translation rules is much faster than the probability computations. We tested the algorithm on Monte Carlo data fully simulating the typical YAP-PEM clinical condition. The adopted algorithm gives an excellent positioning capability for hot spots in the camera FOV. To use all of the possible skew LORs in the FOV avoids the software rejection of collected data. Reconstructed images indicate that a 5mm diameter tumor of 37 kBq/cm3, in an active breast with a 10:1 Tissue to Background ratio (T/B), with a 10 min acquisition, for a head distance of 5 cm, can be detected by the YAP-PEM with a SNR of 8.7+/-1.0. The obtained SNR values depend linearly on the tumor volume. The algorithm allows one to discriminate between two hot sources of 5.0 mm diameter if they do not lie on the same axis. The YAP-PEM is now in the assembly stage.

Algorithms↗

PubMed2006

Free flap reconstruction in the treatment of tumors involving the hard palate.

AIM: To report our experience in free flap reconstruction of the hard palate after malignant tumor resection, in terms of reconstruction method, immediate post-operative course and subjective functional results. PATIENTS AND METHODS: Files from 1988 to 1999 were reviewed for patients having undergone microvascular reconstruction of the hard palate. The immediate post-operative course (during the first month) was reviewed to determine the occurrence of complications. The surgeon's evaluation 1 year post-operatively was used to determine the intelligibility of speech, type of diet and the quality of nasal permeability. RESULTS: Thirty eight patients (28 men and 10 women) with malignant tumors involving the hard palate had undergone surgical reconstruction using microvascular free flap techniques: free radial forearm flap (13 cases), scapular flap (24 cases) or fibular flap (five cases). Two different flaps were employed in two cases (scapula plus fibula). A second flap was used with success in two cases of failure of the first flap, for a total of 42 free flaps for 38 patients. Complications occurred in seven cases, with two cases of flap necrosis. At 1 year, 33 patients achieved a normal diet and 35 normal or easily intelligible speech. CONCLUSIONS: Microsurgical reconstruction using free tissue transfer allows reconstruction of large defects of the hard palate, with low morbidity and an excellent functional outcome. We propose criteria for free flap reconstruction and choice of flap.

Adult↗

PubMed2006

Long-term evaluation of biliary reconstruction after partial resection of segments IV and V in iatrogenic injuries.

Roux-en-Y hepatojejunostomy is the procedure of choice for biliary reconstruction after complex iatrogenic injury that is usually associated with vascular injuries and concomitant ischemia of the ducts. To avoid the ischemic component, our group routinely performs a high repair to assure an anastomosis in noninflamed, nonscarred, and nonischemic ducts. If the duct bifurcation is preserved, the Hepp-Couinaud approach for reconstruction is an excellent choice. Partial liver resection of segments IV and V allows adequate exposure of the bile duct at its bifurcation with an anterior approach of the ducts (therefore not jeopardizing the circulation), allowing a high quality anastomosis. Long-term results of bile duct reconstruction using this approach are described. Two hundred eighty-five bile duct reconstructions were done between 1989 and 2004 in a tertiary care university hospital. The first partial-segment IV resection was done in 1994; 94 cases have been reconstructed since then using this approach. All of them had a complex injury (Strasberg E1-E5), and although in many cases the bifurcation was preserved (E1-E3), a high bilioenteric anastomosis was done to facilitate the reconstruction. In 70 cases, the bifurcation was identified, and in the 24 in which the confluence was not preserved, the right and left ducts were found except in one case. In three patients, the right duct was found unsuitable for anastomosis, and a liver resection was done. In the remaining 21, an anastomosis was done using a stent (transhepatic, transanastomotic) through the right duct. According to Lillemoe's criteria, 86 cases had good results (91%). In four of the eight remaining patients, there was the need to operate again due to the presence of an obstruction and/or cholangitis. In the rest, radiological instrumentation was done. Four of these cases have developed secondary biliary cirrhosis, two of which have died while waiting for a liver transplant, four and six years after reconstruction. Partial segments IV and V resection allows adequate exposure of the confluence and the isolated left or right hepatic ducts. Anterior exposure of the ducts allows an anastomosis in well-preserved, nonischemic, nonscarred, or noninflamed ducts. Parenchyma removal also allows the free placement of the jejunal limb, without external compression and tension, obtaining a high quality anastomosis with excellent long-term results.

Adolescent↗

PubMed2006

Analysis of mechanical stress in reconstruction plates for bridging mandibular angle defects.

INTRODUCTION: The objective of the present study was to evaluate the mechanical stress in reconstruction plates and the screw-plate-bone interface used in bridging a mandibular angle defect by means of the finite element method (FEM). The influence of plate geometry as well as the configuration and the diameter of the screws on the mechanical stress distribution was to be determined at the same time and was used as the basis for developing suggestions to optimize the design of the reconstruction plates. MATERIAL: Based on the geometrical data of a human mandible, an angle defect bridged by a titanium reconstruction plate was generated and exposed to chewing force. First a reconstruction plate was tightly fixed with M2.7 titanium screws. Then, plate design, screw configuration and screw diameter were varied. The mechanical stress was calculated according to von Mises stress hypothesis. RESULTS: In the standard reconstruction plate, the result of the finite element analysis revealed stress resulting from the simulated functional loadings which far exceeded the strengths of the components. Possible clinical consequences could be a fatigue fracture of the plate itself, gradual loosening of the osteosynthesis screws and loss of bone. The stress can be reduced to less than half by increasing the diameter of the screw threads 1.5 fold. CONCLUSION: Maximizing the interface between bone and reconstruction plate had a favourable effect. As a consequence of the large interface and a triangular or square configuration of the screws, the stresses could be substantially reduced, the plate could be made thinner and thus better adapted to the mandible. As a preliminary result, the newly designed reconstruction plate could be thinned in areas subject to less mechanical stress.

Bite Force↗

PubMed2005

Comparison of distal radioulnar joint reconstructions using an active joint motion simulator.

PURPOSE: Distal radioulnar joint (DRUJ) instability can result in pain and functional disability. Numerous DRUJ reconstructive options have been described with minimal biomechanical analysis. The purpose of this study was to evaluate the ability of 4 well-described DRUJ reconstructions to restore joint kinematics using a dynamic, motion-controlled simulator. METHODS: Eleven cadaveric upper extremities had computer-controlled simulated active forearm rotation. Joint kinematics were quantified by using an electromagnetic tracking system. We compared the passive and simulated active kinematics of the intact, unstable, and reconstructed DRUJ (capsular repair, 2 described radioulnar ligament reconstructions, and a radioulnar tethering procedure). RESULTS: All reconstructions improved significantly the kinematics of the unstable DRUJ. The capsule repair restored simulated active joint kinematics closest to the intact DRUJ. CONCLUSIONS: All 4 reconstructions improved DRUJ stability significantly. The capsule repair most closely matched intact DRUJ kinematics and the radioulnar ligament reconstructions were found to be superior to a radioulnar tethering procedure.

Adult↗

PubMed2005

Reconstructive procedure for unstable radial-sided triangular fibrocartilage complex avulsions.

PURPOSE: Radial-sided avulsions of the triangular fibrocartilage complex (TFCC) (Palmer 1D) with distal radioulnar joint (DRUJ) instability remain a challenging pathology to treat. We tested an intra-articular reconstruction that addresses unstable radial-sided TFCC avulsions. METHODS: Ten preserved, dissected, cadaveric forearm specimens with intact TFCC and without ulnar-positive variance had biomechanical testing using a hydraulic testing device. The measurement of total displacement of the ulna relative to the radius was performed with an applied load ranging from 20 N in a volar direction to 20 N in a dorsal direction. Specimens were tested sequentially with intact TFCC, with surgically induced Palmer 1D lesions, and after reconstruction of the TFCC. All tests were performed at neutral, maximal pronation, and maximal supination. RESULTS: The mean total displacements of the DRUJ of the specimens at neutral rotation were as follows: 4.1 +/- 0.4 mm for the intact specimens compared with 11.8 +/- 0.8 mm after creation of the tear and 3.9 +/- 0.7 mm for the reconstructed specimens. In maximal pronation the mean total displacements were as follows: 2.4 +/- 0.3 mm intact versus 4.9 +/- 0.7 mm for torn and 2.1 +/- 0.3 mm after reconstruction. In maximal supination the mean total displacements were as follows: 1.4 +/- 0.2 mm intact versus 5.7 +/- 1.3 mm for torn and 1.0 +/- 0.1 mm after reconstruction. All specimens obtained the preoperative pronation and supination motion after the reconstruction. CONCLUSIONS: Current procedures are unable to restore DRUJ stability without a significant limitation of pronation and supination. This intra-articular reconstruction of radial-sided TFCC avulsions succeeded in restoring baseline stability to the DRUJ without interfering with pronation/supination.

Biomechanical Phenomena↗

PubMed2004

Mandibular reconstruction using the titanium functionally dynamic bridging plate system: A retrospective study of 34 cases.

PURPOSE: We sought to examine the use of the Titanium Functionally Dynamic Bridging Plate System (Howmedica Leibinger, Freiburg, Germany) for mandibular reconstruction after oncologic resection in 34 patients. PATIENTS AND METHODS: A retrospective study of 34 patients who had mandibular reconstruction using the titanium dynamic bridging plate system for mandibular reconstruction after oncologic resection were evaluated. The indications and postoperative outcomes were studied. Our evaluation focuses on the tolerance and aesthetic and functional results of this system. RESULTS: The follow-up ranged from 1 to 4 years. At the end of the study, 18 of the 34 patients (53%) still had the plate in place. One plate fracture and 1 plate exposure requiring surgical management were found. Surgical results were satisfying, particularly when looking at healing delay or long-term tolerance. Aesthetic (79% rated the results as good or acceptable) and functional results of this reconstruction material were satisfying. CONCLUSION: This reconstruction system provides a solution for a safe and rapid mandibular reconstruction for patients with a poor prognosis or poor general condition. This method also preserves the possibility of secondary reconstruction.

Adult↗

PubMed2006

Reconstruction of perioral defects following resection for oral squamous cell carcinoma.

PURPOSE: The aim of this study was to review and describe techniques for the reconstruction of large, complex perioral defects after resection of oral squamous cell carcinoma with emphasis on cosmetic and functional outcome. PATIENTS AND METHODS: A review of techniques and selected case presentations using different flap designs for the reconstruction of large perioral defects following resection of squamous cell carcinoma was performed. The Bernard and Karapandzic flaps were used for large lower lip defects. A Zisser flap technique was used to reconstruct a large commissure defect. RESULTS: All reconstructed patients had acceptable functional results and healed without complication. The large lower lip defects were easily closed with the Bernard and Karapandzic flaps. The commissure defect was reconstructed using the Zisser technique. While cosmesis was acceptable in all cases, the commissure was the most difficult region to reconstruct with a favorable appearance. There were no flap failures. The Karapandzic flap led to greater rounding of the commissure area and the composite resection resulted in a lack of lower lip support that was improved with prosthesis. Function was noted to be excellent in the Bernard and Karapandzic flaps, with the patients able to purse lips and blow up balloon-type devices. CONCLUSION: The Bernard, Karapandzic, and Zisser flaps provide a predictable method to reconstruct large perioral defects following resection for oral cancer. Subsequent fabrication of a prosthesis can aid in lip support for the resected area.

Aged, 80 and over↗

PubMed2006

Implementation and performance evaluation of reconstruction algorithms on graphics processors.

The high-throughput needs in electron tomography and in single particle analysis have driven the parallel implementation of several reconstruction algorithms and software packages on computing clusters. Here, we report on the implementation of popular reconstruction algorithms as weighted backprojection, simultaneous iterative reconstruction technique (SIRT) and simultaneous algebraic reconstruction technique (SART) on common graphics processors (GPUs). The speed gain achieved on the GPUs is in the order of sixty (60x) to eighty (80x) times, compared to the performance of a single central processing unit (CPU), which is comparable to the acceleration achieved on a medium-range computing cluster. This acceleration of the reconstruction is caused by the highly specialized architecture of the GPU. Further, we show that the quality of the reconstruction on the GPU is comparable to the CPU. We present detailed flow-chart diagrams of the implementation. The reconstruction software does not require special hardware apart from the commercially available graphics cards and could be easily integrated in software packages like SPIDER, XMIPP, TOM-Package and others.

Algorithms↗

PubMed2005

Long-segment, supercharged, pedicled jejunal flap for total esophageal reconstruction.

OBJECTIVE: Many patients with cancer have limited esophageal reconstruction options when the stomach is unavailable as a replacement conduit or when long-segment discontinuity exists. Jejunum has been used as an alternative conduit, both as a pedicled or free flap interposition; however, reports of this are usually limited to short-segment repairs. Microvascular augmentation of a pedicled jejunal flap allows creation of a longer conduit, making it possible to replace the entire esophagus with jejunum. Few reports describe this technique in patients with cancer. We report our initial experience with "supercharged" pedicled jejunum as an alternative conduit for total esophageal reconstruction. METHODS: Review of a prospectively collected departmental database was performed to identify those patients who underwent total esophageal reconstruction with supercharged pedicled jejunum. Data regarding their perioperative course and postoperative function were gathered from the prospectively collected clinical data, review of hospital records, and patient interviews. RESULTS: Total esophageal reconstruction with supercharged pedicled jejunum was attempted in 26 patients (age range, 37-74 years) between March 2000 and April 2004. Twenty-four of 26 patients were ultimately discharged with an intact supercharged pedicled jejunum flap, for an overall success rate of 92.3%. One patient experienced intraoperative flap loss caused by technical difficulties harvesting the flap and never had the flap interposed. One other flap loss occurred in the early postoperative period in a patient who had multisystem organ failure after a prolonged reconstruction. Cervical anastomotic leaks occurred in 19.2% (5/26) of the patients. Two midconduit leaks occurred that were suspicious for iatrogenic perforation from nasogastric tube placement; one required reoperation. One additional early reoperation was performed for cecal ischemia. There were no mortalities. Functional results were available in 95.4% (21/22) of the patients receiving supercharged pedicled jejunum who survived at least 6 months after reconstruction. At the time of follow-up, 95% (20/21) of the patients were tolerating regular diet, and 76.2% (16/21) did not require any supplemental alimentation. Ninety-five percent (20/21) of the patients were free from reflux symptoms, and 80.9% (17/21) had no dumping symptoms. Only 1 patient required dilation of a midconduit stricture. One patient required late reoperation for conduit redundancy. CONCLUSIONS: Supercharged pedicled jejunum is a suitable alternative conduit for total esophageal replacement in patients with cancer with otherwise limited reconstructive options. Functional outcomes are excellent, despite the severity of disease and technical challenges in this patient population.

Adult↗