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PubMed2004

Satisfaction with breast reconstruction in women with bilateral prophylactic mastectomy: a descriptive study.

Prophylactic bilateral mastectomy is an option for women who are at an increased risk of developing breast cancer. Prophylactic mastectomy is often performed with immediate reconstruction (i.e., at the same time and under the same anesthetic as the mastectomy). Satisfaction with reconstruction has been described previously for women with mastectomy for breast cancer. However, the authors know of no previous research that has reported on satisfaction with reconstruction in patients who have electively sought mastectomy for the prevention of breast cancer. Women in the province of Ontario who had undergone prophylactic bilateral mastectomy plus breast reconstruction between 1991 and 2000 were asked to rate their level of satisfaction with the cosmetic results of their mastectomy and reconstruction and their overall satisfaction with their decision to have prophylactic mastectomy. Women were also asked whether they experienced complications associated with their surgery and what types of complications they experienced. Thirty-seven women completed questionnaires for this study, and all of them had immediate breast reconstruction after prophylactic mastectomy. The majority of women (70.3 percent) reported being satisfied or extremely satisfied with the cosmetic results of their breast reconstruction. Women with self-reported postsurgical complications (16.2 percent) were significantly less satisfied with reconstruction than those who did not report complications (p = 0.009). Personal subjective risk of breast cancer before prophylactic mastectomy was negatively correlated with satisfaction with reconstruction (r = -0.38, p = 0.024) and with subjective risk estimation after prophylactic surgery (r = -0.54, p = 0.001). Women who did not worry about developing breast cancer after prophylactic mastectomy had significantly higher levels of satisfaction with breast reconstruction than those who continued to worry (p < 0.001). Women who reported an improved body image after reconstruction were significantly more likely to report higher levels of satisfaction than those who reported a diminished body image (p = 0.007). The majority of women were satisfied with the cosmetic results of breast reconstruction after prophylactic mastectomy. Women who overestimated their breast cancer risk had lower satisfaction levels. Correcting overestimation of breast cancer risk in women who have prophylactic mastectomy may improve satisfaction with reconstruction following prophylactic mastectomy.

Adult↗

PubMed2006

Multisegment and halfscan reconstruction of 16-slice computed tomography for assessment of regional and global left ventricular myocardial function.

RATIONALE AND OBJECTIVES: We sought to prospectively compare multisegment and halfscan reconstruction of 16-slice computed tomography (CT) for the assessment of regional and global left ventricular myocardial function with magnetic resonance imaging (MRI) as the reference standard. MATERIALS AND METHODS: Forty-two patients underwent CT with 16 x 0.5-mm detector collimation. Electrocardiogram-gated reconstructions were generated with multisegment reconstruction (using up to 4 segments correlated with the raw data of up to 4 heartbeats) and standard halfscan reconstruction. Steady-state free-precession cine MRI was acquired within 24 hours. RESULTS: More normal myocardial segments were identified correctly with multisegment (95%, 620/656) compared with halfscan reconstruction (88%, 582/656) of CT (P < 0.001). Also, the accuracy (92% [657/714] vs. 87% [620/714]) and rate of nondiagnostic segments (0% vs. 5% [33/714]) were significantly better when using multisegment reconstruction (P < 0.001). The image quality with multisegment reconstruction was significantly superior to that achieved with halfscan reconstruction (P < 0.001). In the assessment of global left ventricular function, multisegment and halfscan reconstruction of CT showed high correlations for all parameters with MRI, whereas Bland-Altman analysis revealed smaller limits of agreement for assessment of myocardial mass with multisegment reconstruction (P = 0.025), but no significant differences between both reconstruction techniques in the measurement of left ventricular volumes as compared with MRI. CONCLUSIONS: Multisegment reconstruction of 16-detector row CT improves image quality and assessment of regional wall motion compared with standard halfscan reconstruction.

Adult↗

PubMed2006

Institutional review of free TRAM flap breast reconstruction.

INTRODUCTION: A 10-year experience with breast reconstruction in a university hospital was recently reviewed. The purpose of this study was to determine the subtypes of breast reconstructive procedures and to evaluate the frequency and change in technique over time of free TRAM (transverse rectus abdominis muscle) flap breast reconstruction performed at one institution. Trends in the development of the procedure over this period were also reviewed. MATERIALS & METHODS: Between November 1994 and September 2004, a 10-year retrospective chart review was conducted. The indications for mastectomy and reconstruction were determined. The median age was 48 (range 31-66). The range of follow-up was 2 to 71 months, with a median of 19.5 months. The mean follow-up was 23.5 months. Outcome data were grouped into 2 consecutive 5-year periods (period 1: 1994-1998; period 2: 1999-2004) and evaluated for changes over time in techniques and outcome. Statistical analysis (Decision Analyst, Inc., STATS Statistics software, version 1.1, 1998) was performed using the difference between 2 proportions module to assess the probability of a significant difference in the data for period 1 and period 2 parameters. RESULTS: Over a 10-year period, 117 patients underwent breast reconstruction. This consisted of 12 pedicle procedures (11.3%), including 1 bipedicle flap (0.9%) and 2 bilateral pedicle procedures (1.8%). There were 3 latissimus dorsi pedicle flaps (2.8%). Sixteen patients (15.1%) received tissue expander or implant reconstructions. Of the 117 patients, 79 underwent free flap breast reconstruction. Of the 79 free-flap patients, 22 (27.8%) had bilateral procedures, for a total of 101 free flaps performed in these 79 patients. Fifty-two patients underwent immediate reconstruction (65.8%) and 25 were delayed (31.6%) reconstructions using either deep inferior epigastric artery perforator (DIEP) flaps (4 = 3.9%) or free TRAM flaps (97 = 96.0%). A muscle-sparing technique was used in 43 of the 97 free TRAM flaps (44.3%). The preferred vascular inflow was the internal mammary artery, which was used in 66 out of 101 flaps (65.3%). The rate of anastomotic revision (arterial and venous) was 4.9%. The majority of cases used a 2.5-mm venous coupler (65.3%). In 2 of the free TRAM cases, there was insufficient volume to establish the patients preexisting volume. Therefore, at the patient's request, immediate implants were used to augment the reconstruction. The average hospital stay was 8.13 days, and the average intensive care stay was 4.59 days. When assessed for trends over time, we noted a reduction in our hospital length of stay and our ICU length of stay. CONCLUSION: The experience with free tissue breast reconstruction reveals predominant use of the TRAM flap. This is justified by the reliability of this flap and the advances in achieving esthetic breast reconstruction. Additionally, we have begun performing DIEP free-flap reconstructions. Our clinical practice has evolved concurrent with standards of care, as noted by the increase in use of muscle-sparing techniques and the reduction in the use of dextran. We do not routinely use therapeutic anticoagulation in our cases. Our hospital length of stay and average intensive care length of stay have also decreased over time, consistent with a system-wide effort to increase the efficiency of healthcare delivery.

Adult↗

PubMed2004

A filtered backprojection algorithm for cone beam reconstruction using rotational filtering under helical source trajectory.

With the evolution from multi-detector-row CT to cone beam (CB) volumetric CT, maintaining reconstruction accuracy becomes more challenging. To combat the severe artifacts caused by a large cone angle in CB volumetric CT, three-dimensional reconstruction algorithms have to be utilized. In practice, filtered backprojection (FBP) reconstruction algorithms are more desirable due to their computational structure and image generation efficiency. One of the CB-FBP reconstruction algorithms is the well-known FDK algorithm that was originally derived for a circular x-ray source trajectory by heuristically extending its two-dimensional (2-D) counterpart. Later on, a general CB-FBP reconstruction algorithm was derived for noncircular, such as helical, source trajectories. It has been recognized that a filtering operation in the projection data along the tangential direction of a helical x-ray source trajectory can significantly improve the reconstruction accuracy of helical CB volumetric CT. However, the tangential filtering encounters latitudinal data truncation, resulting in degraded noise characteristics or data manipulation inefficiency. A CB-FBP reconstruction algorithm using one-dimensional rotational filtering across detector rows (namely CB-RFBP) is proposed in this paper. Although the proposed CB-RFBP reconstruction algorithm is approximate, it approaches the reconstruction accuracy that can be achieved by exact helical CB-FBP reconstruction algorithms for moderate cone angles. Unlike most exact CB-FBP reconstruction algorithms in which the redundant data are usually discarded, the proposed CB-RFBP reconstruction algorithm make use of all available projection data, resulting in significantly improved noise characteristics and dose efficiency. Moreover, the rotational filtering across detector rows not only survives the so-called long object problem, but also avoids latitudinal data truncation existing in other helical CB-FBP reconstruction algorithm in which a tangential filtering is carried out, providing better noise characteristics, dose efficiency and data manipulation efficiency.

Algorithms↗

PubMed2004

Posterior cruciate ligament reconstruction using single-bundle patella tendon graft with tibial inlay fixation: 2- to 10-year follow-up.

PURPOSE: Reconstruction of the posterior cruciate ligament (PCL) using the tibial inlay fixation has been reported as an alternative to the transtibial tunnel technique. Previous failures in PCL reconstruction and early reports raising potential biomechanical and clinical advantages have spurred interest in this technique. The purpose of this study was to evaluate the minimum 2-year results of PCL reconstruction using a single-bundle bone-patellar tendon-bone graft and tibial inlay fixation. METHODS: The authors prospectively studied 44 patients having isolated or combined PCL reconstruction using the direct tibial inlay fixation technique. The study period was from 1991 to 2001. Two-year minimum follow-up was 93% (41/44) and averaged 39.4 months. These 41 patients comprised the study group. Thirty-one patients were male and 10 patients were female; average age was 28 years. There were 35 primary and 6 revision reconstructions. Surgery was performed in the acute or subacute setting (<8 weeks) in 34% (14/41) and chronic setting in 66% (27/41). Combined reconstructions involving the posterolateral corner, anterior cruciate ligament (ACL), or medial collateral ligament (MCL) were done in 85% (35/41). In all patients, preoperative posterior drawer (PD) examination demonstrated greater than 12 mm posterior translation. All PCL reconstructions were performed with bone-patellar tendon-bone graft, which was 12 to 18 mm in width (16 autograft; 25 allograft). Wider tendon grafts were prepared from the allografts and tubularized to fit through an 11-mm tunnel. All patients were evaluated with preoperative and postoperative examination and x-rays. Final follow-up International Knee Documentation Committee (IKDC) subjective evaluation, final follow-up IKDC objective evaluation, and final follow-up Telos stress radiography were performed in all patients. RESULTS: Postoperative PD examination demonstrated the following: 0 (normal) in 9 patients, 1+ in 25 patients, 2+ in 7 patients, and none >2+, as compared to preoperative PD 3+ or greater in all patients in this report. No patient had <12 mm PD preoperatively. Mean improvement in PD was >2 grades of translation as compared to preoperative exam. Forty of forty-one demonstrated a solid endpoint on clinical PD testing. Final follow-up Telos stress radiography with 25 kg posterior load applied at 80 degrees to 90 degrees of flexion demonstrated average side-to-side difference of 4.11 mm (-2 to 10 mm). Average flexion loss was 4 degrees (0-15 degrees ). None lost extension. Preoperative IKDC objective evaluation rated all knees as severely abnormal based on instability. Final follow-up objective IKDC evaluation distribution was as follows: A, 4 knees; B, 24 knees; C, 11 knees; and D, 2 knees, as compared to all 41 D preoperatively. Average final follow-up IKDC subjective score was 75.1 (20-100). When assessing final follow-up stability with Telos stress radiography, primary cases were significantly more stable than revision cases (P <.05). There was no difference in stability when comparing allograft versus autograft, but improved IKDC scores were seen with allograft (P <.05). There was a trend for combined reconstructions to be more stable than isolated reconstructions. All patients evaluated their knee as improved or greatly improved and would repeat the procedure. CONCLUSIONS: Reconstruction of the PCL-deficient knee with severe posterior laxity is a challenging surgical problem, as combined instability patterns frequently coexist (85% in this study). When appropriate combined reconstructions or primary repair is used, PCL reconstruction with autologous or allograft bone-patellar tendon-bone graft using tibial inlay fixation was shown to be a successful technique at 2- to 10-year follow-up. Based on their initial experience with this technique and previous experience with open and arthroscopic techniques using a transtibial tunnel, the authors continue to use the tibial inlay technique as their preferred technique for isolated or combined reconstruction of the PCL.

Adolescent↗

PubMed1992

The management of breast cancer with immediate or delayed reconstruction.

In patients with stage I and stage II disease who are candidates for a mastectomy, either immediate or delayed reconstruction can be accomplished with remarkably good cosmetic results. Age is not a specific contraindication to reconstruction, but, in my experience, the majority of women over 55 years of age are not interested. Mastectomy or modified radical mastectomy should be performed in these patients using a technique that facilitates delayed reconstruction. The patient may or may not elect to have the reconstruction eventually. Immediate or delayed reconstruction is appealing to a significant number of women under 55 years of age. They should see a plastic surgeon in consultation and the advantages and disadvantages of a subpectoral silicone implant vs. a myocutaneous flap (usually a transverse rectus abdominis musculocutaneous flap) should be discussed in detail. The patient's acceptance of the cosmetic result is better if she has an opportunity preoperatively to review photographs of reconstructed breasts and to discuss the results with women who have undergone a similar procedure. The timing of the reconstruction is a matter of clinical judgment; no prospective clinical trials have been performed. Immediate reconstruction is feasible if the skin flaps will accept the slight tension produced by either a subpectoral implant or a transposed muscle flap. A subpectoral silicone implant produces a satisfactory cosmetic result in the majority of patients, particularly if both breasts are supported by a properly fitting brassiere. In long-term follow-up, infection, contracture, and displacement requiring removal and reinsertion occur in approximately 15% of patients. Reconstruction by a myocutaneous flap is a technically more difficult operation. The operating time is prolonged significantly and blood loss is increased. In my opinion, a myocutaneous flap probably is not worth the risk of a heterologous transfusion. The long-term cosmetic results, however, are considerably better in comparison to a subpectoral silicone implant. The reconstructed breast is much more mobile, making it a more realistic replacement of the original breast. In most cases, it is better to perform this type of reconstruction with a myocutaneous flap as a delayed procedure. In experienced hands, however, immediate reconstruction, with the transverse rectus abdominis musculocutaneous flap harvested while the modified radical mastectomy is being performed, is perfectly feasible. Nipple/areolar reconstruction is available. However, the cosmetic results are only fair to good, and the patient should be aware of this before undergoing the procedure. The problem of symmetry between the breasts requires a good deal of judgment.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMed2005

[Allograft for surgical reconstruction of the cruciate ligaments of the knee - part 1].

PURPOSE OF THE STUDY: The growing numbers of anterior cruciate ligament (ACL) reconstructions performed by an increasing number of surgeons have resulted in an increased number of failed reconstructed ligaments. For repeat surgery, autologous tissues are most frequently used, namely BTB graft, hamstring tendons or quadriceps tendon construct. However, these alternative methods have certain disadvantages and therefore we decided to use BTB allografts from cadaverous donors. The risk of disease transmission due to allograft implantation has been reported to be low, but a thorough serological screening of donors is the prerequisite. We used BTB allografts first in revision ACL surgery only, but because of good results we started using theme for reconstruction of both cruciate ligaments and, in some cases, also for primary reconstruction. MATERIAL: In the period from 2002 to 2004, patellar ligaments harvested from 23 cadaverous donors were used at the orthopedic ward of the Ceské Budejovice hospital to prepare 87 BTB grafts, of which 42 were implanted. In 57 % of the procedures, an allograft was used in revision surgery carried out for the failure of a ;previously reconstructed ACL in 10 % it was used in complete reconstruction of both cruciate ligaments, and in 14 % it was used for primary ACL reconstruction in indicated cases. In 19 % of the cases, allograft was used when autologous graft failed or was damaged during the primary operation. METHODS: Graft harvesting, storage, handling and implantation have been carried out in accordance with the practices included in Act no. 285/2002 Coll. Serological examination of the donors and bacteriological assays of the grafts were performed according to the current regulations. The implantation of BTB allografts in ACL reconstruction was carried out by the standard method used in reconstructive procedures. RESULTS: Out of 87 BTB allografts prepared, 16 were discarded because of positive culture findings. Two allografts could not be used because the screening was positive for CMV infection. No infectious complications, poor healing or a systemic response to the allograft implanted were recorded in any of the patients. DISCUSSION: The use of allografts is a method suitable for revision surgery in failed ACL reconstruction. It allows us to avoid further weakening of the structures associated with the knee joint. The size of allograft bony blocks permits treatment of defects in the tibial or the femoral tunnel. CONCLUSIONS: The use of a BTB allograft is a reliable and safe procedure. It has advantages not only in revision ACL reconstruction, but also in reconstruction of both cruciate ligaments. Also primary ACL reconstruction in indicated cases achieved good results.

Adult↗

PubMed2006

[Analyzing the effect of field frequencies on reconstructive accuracy of rebuilt field with spectroscopy].

The field to be reconstructed was simulated with numerical simulation technique. The effect of a three-dimensional field's characteristics, especially, its frequency components, on the reconstructive accuracy was discussed with spectroscopy. A double-peaked field model was built with Gaussian function, and its frequency components were analyzed by Fourier transform. With algebraic reconstruction technique, the model field was reconstructed. The reconstructed field was analyzed with many error indexes. As a result, the reconstructed field was similar to the model one in respect of the position, pointing and shape of the peaks, but the heights of the peaks were shorter than those of corresponding ones in the model. The border of the reconstructive field showed obvious fluctuation. It was considered that the main causation of the reconstructive result was the filtering inserted in iterating process. To confirm this idea, the convergence factor, represented with A, of Gaussian function was changed from six to thirty in order to change the frequency components of the model field, and the same numerical simulation as the one for the first model field with A=18 was carried out for these new model ones consisting of different frequency. As a result, the idea proved to be right. At the same time, it was found that the characteristics of the field at the edge of the reconstructed zone had a deeper effect on the reconstructive accuracy. When the precondition that the field edge approximated to zero could no longer existed, the reconstructive accuracy declined, and furthermore, it would make iterating process divergent. From all the above, the characteristics of the field at the edge should draw much attention when we reconstruct a field with Algebraic reconstruction technique.

English Abstract↗

PubMed1996

Lateral mandibular reconstruction using soft-tissue free flaps and plates.

OBJECTIVE: To assess the outcome of patients who are undergoing reconstruction of segmental lateral mandibular defects by using soft-tissue free flaps combined with mandibular reconstruction plates. DESIGN: Retrospective case series of 15 patients who were undergoing primary reconstruction of mandibular segments posterior to the mental foramen, resulting from treatment of head and neck cancer. All patients received either preoperative or postoperative radiation therapy. SETTING: Academic tertiary care referral center. INTERVENTIONS: Fourteen patients had mandibular continuity restored by using the titanium hollow screw reconstruction plate system, and 1 patient received a stainless steel mandibular reconstruction plate. Associated soft-tissue defects were repaired by using radial forearm (n = 11), rectus abdominis (n = 2), scapular and parascapular (n = 1), or lateral arm (n = 1) free flaps. MAIN OUTCOME MEASURES: Early and delayed complications. RESULTS: All 15 microvascular free tissue transfers were successful. Early complications were minor and occurred in 5 (33%) of 15 patients. One patient in whom the titanium hollow screw reconstruction plate system had been used experienced a fracture at 15 months after reconstruction. Three patients experienced delayed external plate exposure between 7 and 15 months after primary oromandibular reconstruction. Patients who experienced delayed external plate exposure required secondary reconstruction with a vascularized bone-containing free flap. The overall rate of delayed reconstructive failure was 40% in patients who were followed up for a minimum of 1 year. CONCLUSIONS: For patients who are undergoing free flap reconstruction of lateral mandibulectomy defects, the technique that used soft-tissue free flaps combined with mandibular reconstruction plates has been abandoned in favor of using vascularized bone-containing free flaps or a combination of free flaps to achieve optimal long-term results.

Adult↗

PubMed2003

Hepatic resection combined with portal vein or hepatic artery reconstruction for advanced carcinoma of the hilar bile duct and gallbladder.

Hepatectomy with vascular reconstruction for biliary malignancy remains controversial. This study aimed to clarify the indications for surgery. Patients with advanced hilar bile duct cancer (HBDC) (n = 26) and gallbladder cancer (GBC) involving the hepatoduodenal ligament (n = 13) who underwent hepatectomy were enrolled. They were divided into two groups on the basis of whether vascular reconstruction was performed (HBDC, 10 yes vs. 16 no; GBC, 5 yes vs. 8 no). Portal vein (PV) reconstruction was performed on the right branch in seven patients and on the left branch in two; hepatic artery (HA) reconstruction was done on the right branch in 11 patients and on the left branch in 1. Five patients with HBDC and one with GBC underwent both PV and HA reconstruction. Patency rates were 88.0% and 83.3% for PV and HA reconstructions, respectively. Vascular reconstruction-related morbidity occurred in one patient with fatal liver failure owing to a portal thrombus and in two patients with multiple liver abscesses caused by arterial obstruction. Microsurgery eliminated reconstruction-related morbidity. Mortality in vascular reconstruction cases was 13.3% (2/15), and in those without reconstruction it was 8.3% (2/24). Curability rates (R0 and R1+R2) were 50.0% and 56.0% for HBDC and 40.0% and 62.5% for GBC, respectively. The 3-year survivals of HBDC patients were, respectively, 33% and 42%, and the 5-year survivals were 18% and 25%, whereas for GBC the 1-year survivals were 20% and 60% and the 2-year survivals 0% and 25%. Two patients with vascular involvement who underwent PV with HA reconstruction survived more than 3 years. Hepatectomy with vascular reconstruction for selected HBDC patients offers low surgical risk and increased survival by curable resection, but it is not recommended for advanced GBC.

Aged↗

PubMed2003

Sentinel lymph node biopsy followed by delayed mastectomy and reconstruction.

BACKGROUND: The role of sentinel lymph node (SLN) biopsy with total mastectomy is evolving. In patients who desire mastectomy with immediate reconstruction, the final pathologic results of the SLN may create unique problems. Specifically, if the SLN is found to be positive on final pathology, the reconstructed patient would generally require a potentially difficult re-operation on the remaining axillary nodes. The purpose of this study was to review the results of patients who underwent an initial SNL biopsy followed by a planned mastectomy and reconstruction. METHODS: A chart review of patients who underwent staged SLN biopsy with subsequent definitive procedure between 1997 and 2001 was conducted. These were evaluated with regard to type of tumor, status of sentinel node, and design of subsequent operation. RESULTS: There were 40 patients who underwent an initial SLN biopsy followed by a staged mastectomy with reconstruction. Tumors included high-grade carcinoma in situ (n = 4), infiltrating ductal carcinoma (n = 28), invasive lobular carcinoma (n = 4), mucinous carcinoma (n = 1), adenoid cystic carcinoma (n = 1), and mixed ductal and lobular carcinoma (n = 2). Tissue biopsy was obtained by either open (n = 9) or needle (n = 31) technique. Twenty-five patients had a negative SLN biopsy and a delayed total mastectomy with immediate reconstruction. Positive SLNs were identified in 15 patients (37%). Eight patients had macroscopic nodal metastases and underwent a delayed modified radical mastectomy and immediate reconstruction. Seven patients had microscopic nodal metastases and 3 declined further axillary dissection. They proceeded with total mastectomy and immediate reconstruction. CONCLUSIONS: These data suggest that a substantial proportion of patients treated with SLN biopsy, simple mastectomy, and reconstruction will have positive sentinel lymph nodes. Thus, the ideal approach for patients who wish to have reconstruction should involve an initial SLN biopsy as a separate procedure. If the SLN is benign, the patient may undergo a total mastectomy with immediate reconstruction. However, a patient with a positive SLN may proceed to a modified radical mastectomy with immediate reconstruction. This treatment algorithm eliminates a potentially difficult reoperation on the axilla following reconstruction.

Breast Neoplasms↗

PubMed1999

Single-or-two-stage laryngotracheal reconstruction; comparison of outcomes.

To compare single-stage laryngotracheal reconstruction (SSLTR) and reconstruction with tracheostomy and indwelling stent (two-stage LTR), a retrospective review was made of 69 patients undergoing laryngotracheal reconstruction for subglottic stenosis at Great Ormond Street Hospital for Sick Children. Pre-operative details recorded included grade and aetiology of subglottic stenosis, history of previous laryngeal surgery, sex of patient and age at reconstruction. As a measure of outcome, the total number of procedures including all endoscopy and further reconstruction was recorded as well as de-cannulation rate, and the need for more than one reconstruction. The patients undergoing two-stage reconstruction tended to have more severe stenosis (mean grade = 2.56) compared to the SSLTR group (mean grade = 2.14) and were more likely to have had previous laryngeal surgery. Inevitably, the outcome after reconstruction in the two-stage patients is therefore less favourable, and direct comparison of the two groups is not statistically valid. However, multiple regression analysis reveals that single-stage reconstruction does confer a significant independent advantage over the two-stage procedure in terms of average number of post reconstruction procedures (p = 0.006), and a significant advantage in de-cannulation rate (p = 0.03). No difference was noted in the requirement for further reconstruction between the two groups. Although a two-stage procedure is still required in certain cases such as those with very severe stenosis or respiratory insufficiency, the single-stage reconstruction is the procedure of choice for uncomplicated paediatric subglottic stenosis.

Child↗

PubMed2001

Breast reconstructive techniques in cancer patients: which ones, when to apply, which immediate and long term risks?

Breast reconstruction is considered as part of the breast cancer treatment when a mastectomy is required. The techniques available today, allow reconstruction of the breast even in almost all the cases even in poor local conditions. In 60-70% of the cases, the reconstruction can be performed with an implant inserted behind the pectoralis muscle. Special implants called expanders, are inflatable progressively in the postoperative course thanks to a reservoir located subcutaneously. They provide a progressive distention of the teguments and a more natural shape after substitution of the expander with a definitive implant. The symmetry is usually obtained thanks to a contralateral plastic surgery, which allows at the same time histological check up of the glandular tissue of the opposite breast. The nipple areolar complex is usually reconstructed in a second stage under local anesthesia, using local flaps for the nipple and a tattoo for the colour of the areola. In 30% of the cases, especially after radiotherapy when a salvage mastectomy is required, a flap reconstruction is preferred. The autologous tissue reconstruction with the rectus myocutaneous flap gives excellent cosmetic results and the most natural shape for the breast. But it is a more demanding technique requiring a good experience. In some occasions, the reconstruction with the latissimus flap can also be autologous but usually requires the addition of prosthesis. In most cases, the reconstruction can be performed immediately. The delayed reconstruction is usually preferred when the adjuvant chemotherapy should be delivered as soon as possible after the mastectomy. Complications of the reconstruction such as local necrosis or infections, leading to implant removal or revision of the flap could be detrimental to the patient in delaying the start of the chemotherapy. It is not recommended to reconstruct the breast immediately in case of locally advanced breast cancer. Partial breast reconstruction using plastic surgery procedures can also be performed in case of quadrantectomy in order to obtain a better cosmetic result. Local glandular flaps, as well as specific incisions according to the location of the tumor in the breast allow the reshaping of the breast even in case of large resection and, therefore, provide an opportunity to increase the number of conservative treatment indications, especially in case of in-situ carcinomas.

Breast Neoplasms↗

PubMed2003

Effects of attenuation correction and reconstruction method on PET activation studies.

The outcome of Statistical Parametric Mapping (SPM) analyses of PET activation studies depends among others, on the quality of reconstructed data. In general, filtered back-projection (FBP) is used for reconstruction in PET activation studies. There is, however, increasing interest in iterative reconstruction algorithms such as ordered subset expectation maximization (OSEM) algorithms. The aim of the present study was to investigate the effects of reconstruction techniques and attenuation correction (AC) on the detection of activation foci following statistical analysis with SPM. First, a replicate study was performed to assess the effects of the reconstruction method on pixel variance. Second, a phantom study was performed to evaluate the influence of both locations of an activated area and applied reconstruction method on SPM outcome. A volumetric method was used to compute the number of false positive voxels for all reconstructions. In addition, average t values within activation foci and for false positive voxels were calculated. For the assessment of the effects of reconstruction on clinical data, a group of 11 patients was studied. For all reconstructions SPM maps were created and compared. Both the clinical and the phantom data showed that use of iterative reconstruction methods reduced false positive results, while showing similar SPM results within activated areas as FBP. Reconstruction of data without attenuation correction reduced noise for FBP only, but did not affect the quality of SPM results for OSEM. It is concluded that OSEM is a good alternative for FBP reconstructions providing SPM results with less noise.

Algorithms↗

PubMed2006

Automated detection of lung nodules in multidetector CT: influence of different reconstruction protocols on performance of a software prototype.

PURPOSE: To evaluate the accuracy of software for computer-aided detection (CAD) of lung nodules using different reconstruction slice thickness protocols in multidetector CT. MATERIALS AND METHODS: Raw image data sets for 15 patients who had undergone 16-row multidetector CT (MDCT) for known pulmonary nodules were reconstructed at a reconstruction thickness of 5.0, 2.0 and 1.0 mm with a reconstruction increment of 1.5, 1.0 and 0.5 mm, respectively. The "Nodule Enhanced Viewing" (NEV) tool of LungCare for computer-aided detection of lung nodules was applied to the reconstructed images. The reconstructed images were also blinded and then evaluated by 2 radiologists (A and B). Data from the evaluating radiologists and CAD was then compared to an independent reference standard established using the consensus of 2 independent experienced chest radiologists. The eligible nodules were grouped according to their size (diameter > 10, 5 - 10, < 5 mm) for assessment. Statistical analysis was performed using the receiver operating characteristic (ROC) curve analysis, t-test and two-rater Cohen's Kappa co-efficient. RESULTS: A total of 103 nodules were included in the reference standard by the consensus panel. The performance of CAD was marginally lower than that of readers at a 5.0-mm reconstruction thickness (AUC = 0.522, 0.517 and 0.497 for A, B and CAD, respectively). In the case of 2.0-mm reconstruction slices, the performance of CAD was better than that of the readers (AUC = 0.524, 0.524 and 0.614 for A, B and CAD, respectively). CAD was found to be significantly superior to radiologists in the case of 1.0-mm reconstruction slices (AUC = 0.537, 0.531 and 0.675 for A, B and CAD, respectively). The sensitivity at a reconstruction thickness of 1.0 mm was determined to be 66.99 %, 68.93 % and 80.58 % for A, B and CAD, respectively. The time required for detection was shortest for CAD at reconstruction slices of 1.0 mm (mean t = 4 min). The performance of radiologists was greatly enhanced when using CAD: sensitivity 91.26 % and 94.17 % for CAD+A and CAD+B, respectively (AUC = 0.889 and 0.917). CAD was most advantageous in the detection of nodules < 10 mm. CONCLUSION: At a 1.0-mm reconstruction thickness, CAD's ability to detect nodules < 10 mm is superior to that of radiologists and its relatively short evaluation time makes it a viable second reader.

Diagnosis, Computer-Assisted↗

PubMed2001

Ischemic mitral valve reconstruction and replacement: comparison of long-term survival and complications.

OBJECTIVE: This study reviews the 223 consecutive mitral valve operations for ischemic mitral insufficiency performed at New York University Medical Center between January 1976 and January 1996. The results for mitral valve reconstruction are compared with those for prosthetic mitral valve replacement. METHODS: From January 1976 to January 1996, 223 patients with ischemic mitral insufficiency underwent mitral valve reconstruction (n = 152) or prosthetic mitral valve replacement (n = 71). Coronary artery bypass grafting was performed in 89% of cases of mitral reconstruction and 80% of cases of prosthetic replacement. In the group undergoing reconstruction, 77% had valvuloplasty with a ring annuloplasty and 23% had valvuloplasty with suture annuloplasty. In the group undergoing prosthetic replacement, 82% of patients received bioprostheses and 18% received mechanical prostheses. RESULTS: Follow-up was 93% complete (median 14.6 mo, range 0-219 mo). Thirty-day mortality was 10% for mitral reconstruction and 20% for prosthetic replacement. The short-term mortality was higher among patients in New York Heart Association functional class IV than among those in classes I to III (odds ratio 5.75, confidence interval 1.25-26.5) and was reduced among patients with angina relative to those without angina (odds ratio 0.26, confidence interval 0.05-1.2). The 30-day death or complication rate was similarly elevated among patients in functional class IV (odds ratio 5.53; confidence interval 1.23-25.04). Patients with mitral valve reconstruction had lower short-term complication or death rates than did patients with prosthetic valve replacement (odds ratio 0.43, confidence interval 0.20-0.90). Eighty-two percent of patients with mitral valve reconstruction had no insufficiency or only trace insufficiency during the long-term follow-up period. Five-year complication-free survivals were 64% (confidence interval 54%-74%) for patients undergoing mitral valve reconstruction and 47% (confidence interval 33%-60%) for patients undergoing prosthetic valve replacement. Results of a series of statistical analyses suggest that outcome was linked primarily to preoperative New York Heart Association functional class. CONCLUSIONS: Initial mortalities were similar among patients undergoing prosthetic replacement and valve reconstruction. Poor outcome was primarily related to preexisting comorbidities. Patients undergoing valve reconstruction had fewer valve-related complications. Valve reconstruction resulted in excellent durability and freedom from complications. These findings suggest that mitral valve reconstruction should be considered for appropriate patients with ischemic mitral insufficiency.

Aged↗

PubMed2004

Ancestral sequence reconstruction in primate mitochondrial DNA: compositional bias and effect on functional inference.

Reconstruction of ancestral DNA and amino acid sequences is an important means of inferring information about past evolutionary events. Such reconstructions suggest changes in molecular function and evolutionary processes over the course of evolution and are used to infer adaptation and convergence. Maximum likelihood (ML) is generally thought to provide relatively accurate reconstructed sequences compared to parsimony, but both methods lead to the inference of multiple directional changes in nucleotide frequencies in primate mitochondrial DNA (mtDNA). To better understand this surprising result, as well as to better understand how parsimony and ML differ, we constructed a series of computationally simple "conditional pathway" methods that differed in the number of substitutions allowed per site along each branch, and we also evaluated the entire Bayesian posterior frequency distribution of reconstructed ancestral states. We analyzed primate mitochondrial cytochrome b (Cyt-b) and cytochrome oxidase subunit I (COI) genes and found that ML reconstructs ancestral frequencies that are often more different from tip sequences than are parsimony reconstructions. In contrast, frequency reconstructions based on the posterior ensemble more closely resemble extant nucleotide frequencies. Simulations indicate that these differences in ancestral sequence inference are probably due to deterministic bias caused by high uncertainty in the optimization-based ancestral reconstruction methods (parsimony, ML, Bayesian maximum a posteriori). In contrast, ancestral nucleotide frequencies based on an average of the Bayesian set of credible ancestral sequences are much less biased. The methods involving simpler conditional pathway calculations have slightly reduced likelihood values compared to full likelihood calculations, but they can provide fairly unbiased nucleotide reconstructions and may be useful in more complex phylogenetic analyses than considered here due to their speed and flexibility. To determine whether biased reconstructions using optimization methods might affect inferences of functional properties, ancestral primate mitochondrial tRNA sequences were inferred and helix-forming propensities for conserved pairs were evaluated in silico. For ambiguously reconstructed nucleotides at sites with high base composition variability, ancestral tRNA sequences from Bayesian analyses were more compatible with canonical base pairing than were those inferred by other methods. Thus, nucleotide bias in reconstructed sequences apparently can lead to serious bias and inaccuracies in functional predictions.

Animals↗

PubMed1994

Recurrent breast cancer following immediate reconstruction with myocutaneous flaps.

As immediate breast reconstruction with rectus abdominis and latissimus dorsi myocutaneous flaps has become a recognized technique for patients requiring mastectomy, concerns have arisen regarding the detection and treatment of locoregional recurrence of breast cancer. Because most recurrences develop in the residual native skin of the chest wall following a mastectomy, breast reconstruction procedures involving the placement of a subpectoral prosthesis are unlikely to interfere with postoperative cancer surveillance. Myocutaneous flaps, however, transpose blocs of soft tissues into the mastectomy site. This study was done to evaluate the influence of a myocutaneous flap on the subsequent diagnosis and treatment of locoregional recurrence of breast cancer. Data were obtained from 161 patients with breast cancer who had immediate reconstruction with a myocutaneous flap between 1982 and 1990. Of the 161 patients reviewed, 120 had primary mastectomy with immediate reconstruction; 41 patients had salvage mastectomy and immediate reconstruction after failed conservative surgery and radiation therapy. Modified radical mastectomy was performed on all patients. Either a rectus abdominis (n = 65) or latissimus dorsi (n = 97) myocutaneous flap breast reconstruction was performed. Recurrent tumor was observed in 17 of the 161 patients reviewed (10.6 percent). Fourteen of the 17 recurrences occurred in 120 patients having primary mastectomy and immediate reconstruction for a rate of 11.7 percent; 3 of 41 patients (7.3 percent) who had salvage mastectomy and flap reconstruction developed recurrences. Of the 17 recurrences, 6 patients were stage II, 10 were stage III, and 1 was stage IV. All 17 patients who developed a recurrence had invasive breast cancer, with infiltrating and inflammatory tumors predominating. All locoregional recurrences of breast cancer developed within the native skin and subcutaneous tissues adjacent to the mastectomy and flap reconstruction site. Recurrences were seen as rapidly as 2 weeks or as long as 3.8 years (mean 1.4) after the mastectomy and flap reconstruction. Overall mean follow-up for the entire group of 161 patients was 5.4 years. Thirteen of the 17 patients (76.5 percent) developed distant metastases either concomitantly with the locoregional recurrence or within 4.3 years (mean 1.7). From an oncologic viewpoint, the technique of myocutaneous flap breast reconstruction with rectus abdominis or latissimus dorsi flaps appears to be a safe one. An analysis of locoregional recurrence of breast cancer in patients undergoing primary mastectomy or salvage mastectomy with myocutaneous flap breast reconstruction did not show concealment by the flap of any recurrent tumor.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenocarcinoma↗