Complete mesocolic resection and extended lymphadenectomy for colon cancer: a systematic review.

AIM: Complete mesocolic excision (CME) and extended lympha-denectomy (EL) have been proposed as safe procedures for improving colon cancer survival outcomes. The aim of this study was to evaluate the evidence regarding oncological outcomes, morbidity and mortality after such techniques for colon cancer. METHOD: A systematic review of the literature was conducted to evaluate evidence regarding oncological outcomes, morbidity and mortality after CME or EL. Three major databases (PubMed, MEDLINE and the Cochrane Library) were searched. The review included original articles reporting outcomes after CME or EL from January 1950 to July 2012. RESULTS: Twenty-one, predominately retrospective, studies involving 5246 patients (mean age 68.2 years, 56.5% men) were included. Reporting of outcomes was inconsistent. Median follow up was 60 months. The operative mortality rate was 3.2% and the cumulative morbidity rate was 21.5%. The weighted mean local recurrence rate and the 5-year overall and disease-free survival rates were 4.5%, 58.1% and 77.4%, respectively. CONCLUSION: The available data for CME and EL have numerous fundamental limitations that prohibit adoption. Contemporary controlled studies are required before universal recommendation.

Omentoplasty to assist perineal defect closure following laparoscopic abdominoperineal resection.

AIM: This technical note describes laparoscopic production of a well vascularized, omental flap of adequate size to fill the pelvic floor defect in the course of laparoscopic abdominoperineal resection (LAPR). METHOD: The omentum is laparoscopically mobilized and transposed to the pelvis following full LAPR in three discrete stages. RESULTS: Laparoscopic omental mobilization, transfer and buttressing of a primary perineal repair reduces pelvic dead space and facilitates closure following LAPR with minimal additional operative time or complications and a potential reduction in perineal wound associated morbidity. CONCLUSION: Laparoscopic omental mobilization is technically feasible and provides a safe method to aid perineal wound closure.

Omental pedicle flaps following proctectomy: a systematic review.

AIM: Abdominoperineal excision (APR) for cancer carries significant morbidity of the perineal wound. An omental pedicle graft has been used to fill the pelvis and limit attendant complications after radical extirpation of the anorectum. A review of the literature was conducted to determine whether omentoplasty following APR reduces perineal wound complications. METHOD: Three major databases (PubMed, MEDLINE and the Cochrane Library) were searched. The review included original articles reporting outcomes after APR and omentoplasty from January 1950 to July 2012. RESULTS: Fourteen studies involving 891 patients (mean age 61 years, 59.8% men) were included. Median follow-up was 13.5 months. A variety of omentoplasty techniques added a median of 20 min to the operating time. The mean rate of primary wound healing was 66.8%, time to wound healing 24 days and weighted mean wound infection rate 14.4% with omentoplasty compared with 50.1%, 79 days and 18.5% in patients having no omentoplasty. CONCLUSION: Omental mobilization, transfer and buttressing of primary perineal repair following proctectomy reduces perineal wound morbidity with minimal additional operating time or flap-associated morbidity.

Simultaneous pancreas kidney transplantation in the HIV-positive patient.

HIV is no longer an absolute contraindication to solid organ transplantation. However, few reports have been published with regards to pancreas or simultaneous pancreas kidney transplantation in the HIV-positive recipient. We report, to our knowledge, the first simultaneous pancreas kidney transplantation (SPK) performed in an HIV-positive patient in the United Kingdom. We reflect on the article recently published by Miro et al in Transplantation Proceedings and highlight strategies used by our department to prevent drug interactions in these complex patients.

Alemtuzumab induction and sirolimus plus mycophenolate mofetil maintenance for CNI and steroid-free kidney transplant immunosuppression.

We performed a pilot study in which 22 kidney recipients (14 LD: 8 DCD) were given alemtuzumab induction (30 mg day 0 and 1), steroids (500 mg mp day 0 and 1, none thereafter), mycophenolate mofetil (MMF) maintenance (500 mg b.i.d) and sirolimus (concentration controlled 8-12 ng/mL). With a mean follow-up of 15.9 months, patient survival is (21/22) 96% and graft survival (19/22) 87%. Acute rejections occurred in (8) 36.3% (two humoral). Of 19 surviving grafts, 18 (95%) remain steroid and 15 (79%) CNI-free. At 1 year, mean creatinine was 1.43 mg/dL. Overall infection rates were low, but 2 patients developed severe acute respiratory distress syndrome (ARDS) at month 3 and 7, respectively, resulting in mortality in one and a graft loss in the other. No cancer or PTLD was observed. Leukopenia was common and MMF dose was reduced or eliminated in 6/22 (27%) patients. The reported higher than expected rate of acute rejection, leukopenia and possible pulmonary toxicity suggests excessive morbidity. Modifications such as an initial period of CNI use should be considered.

Ecological outcomes of adolescents in a psychoeducational residential treatment facility.

Cross-sectional follow-up data on 111 adolescents in a re-education residential facility were obtained in three domains--school, legal, and level of care--at 6, 12, 18, and 24 months postdischarge. Reports by community-based professionals on individual functioning were assessed on several criteria, the most stringent of which indicated successful outcomes for nearly 60% of the adolescents. Characteristics of the more successful students are noted, applications of the psychoeducational residential approach for program structure are considered, and implications for positive ecological outcomes are discussed.

Inverse source problem and minimum-energy sources.

We present a new linear inversion formalism for the scalar inverse source problem in three-dimensional and one-dimensional (1D) spaces, from which a number of previously unknown results on minimum-energy (ME) sources and their fields readily follow. ME sources, of specified support, are shown to obey a homogeneous Helmholtz equation in the interior of that support. As a consequence of that result, the fields produced by ME sources are shown to obey an iterated homogeneous Helmholtz equation. By solving the latter equation, we arrive at a new Green-function representation of the field produced by a ME source. It is also shown that any square-integrable (L2), compactly supported source that possesses a continuous normal derivative on the boundary of its support must possess a nonradiating (NR) component. A procedure based on our results on the inverse source problem and ME sources is described to uniquely decompose an L2 source of specified support and its field into the sum of a radiating and a NR part. The general theory that is developed is illustrated for the special cases of a homogeneous source in 1D space and a spherically symmetric source.

Higher-order (nonlinear) diffraction tomography: reconstruction algorithms and computer simulation.

The usual propagation transform of diffraction tomography is generalized into higher-order (nonlinear) propagation transforms via use of the Born series as the data-generating model in scattering experiments. Nonlinear tomographic reconstruction algorithms are developed for inversion of scattered field data modeled up to an arbitrarily large (possibly infinite) number of terms in the Born series. A computer simulation study is included to illustrate the performance of the algorithms for the case of scattering objects with cylindrical symmetry.

Estimation of object location from wideband scattering data.

We present a time domain algorithm for computation of the maximum likelihood estimate of the location of a known scattering object from wide-band scattering data acquired in a suite of scattering experiments. The algorithm consists of a three-step procedure: (1) data filtering, (2) time-domain backpropagation, and (3) coherent summation and is implemented via a number of forward and inverse Radon transforms integrated into a tomographic scheme. A computer simulation is included for illustration purposes.

Three-dimensional images generated by quadrature interferometry.

Quadrature detection techniques have been applied to images obtained from a Mach-Zehnder interferometer with differently polarized beams to yield the real and the imaginary parts of the diffracted fields simultaneously. This approach eliminates the need for phase retrieval by providing complete information on the complex amplitude of the diffracted signal. We present results in which we demonstrate our ability to reconstruct two- and three-dimensional microscopic objects from their complex diffraction patterns.

Decrease in spatial coherence of light propagating in free space.

It is shown that a highly spatially incoherent light distribution may be generated from a highly coherent one on propagation in free space. This result essentially demonstrates that there exists an inverse of a classic result of optical coherence theory, namely, the van Cittert-Zernike theorem. The analysis also indicates that the technique of phase conjugation may be used to reverse changes in the coherence properties of light, at least those which are generated on propagation in free space.

Young boys who commit serious sexual offenses: demographics, psychometrics, and phenomenology.

This study reports on a population of early adolescent male sexual offenders 9 to 14 years of age compared with a clinic control group matched for age, sex, ethnic status, and the presence of a DSM-III-R conduct disorder. The sex offenders were found to exhibit a significant history of nonsexual antisocial behavior, physical and sexual abuse, and psychiatric comorbidity. The two groups did not differ in number and category of comorbid psychiatric diagnoses, the number of nonsexual aggressive and nonaggressive symptoms of conduct disorder, symptoms of major depressive disorder or dysthymia, and symptoms of anxiety disorders. The EGTC group demonstrated significantly lower mathematic achievement. There is evidence that sexual offending behavior in this population is one aspect of a pattern of antisocial behavior. Sixty-five percent of the index group had a history of early sexual victimization.

Application of a maximum likelihood estimator in an experimental study in ultrasonic diffraction tomography.

A recently proposed approach to the inverse problem of detecting the presence and estimating the location of a known object from data collected in a set of diffraction tomographic experiments is evaluated. Experimental data are used to validate of the filtered backpropagation algorithms used, and their robustness to modeling errors and to severe limitations in the angular coverage of the tomographic data is demonstrated. A potential application to medical imaging of soft tissue is illustrated.

Application of an art algorithm in an experimental study of ultrasonic diffraction tomography.

This paper describes results obtained using a recently developed Algebraic Reconstruction Technique (ART) for diffraction tomography on experimental data obtained from an ultrasound scanner built by Norwave Development A.S. of Oslo, Norway. The test objects (phantoms) employed in the study are low contrast cylindrical rods made out of agar with dimensions comparable to the wavelength of the incident wavefield. The reconstructions obtained from the ART algorithm are compared to the ones obtained from the filtered backpropagation algorithm. It is determined that the ART algorithm out performs the filtered backpropagation algorithm for cases where data from only a small number of tomographic experiments are available.

Diffraction tomographic reconstruction from intensity data.

The problem of reconstructing the complex index of refraction of a weakly inhomogeneous scattering object from measurements of the magnitude (intensity) of the transmitted wavefields in a set of scattering experiments within the context of diffraction tomography (DT) is addressed. It is shown that high quality approximate reconstructions can be obtained from such intensity data using standard reconstruction procedures of DT. The physical basis for the success of these procedures when applied to intensity data is discussed and computer simulations are presented comparing the approximate reconstructions generated from intensity data with the optimum reconstructions generated from both the magnitude and phase of the transmitted wavefields.

Generalized projection-slice theorem for fan beam diffraction tomography.

A generalized projection-slice theorem is derived for transmission fan beam diffraction tomography within the Born or Rytov approximations. The development is based on the use of the so-called paraxial approximation which requires that the object being probed subtend a small angle relative to the source point and to the measurement plane. Within this approximation it is shown that the transmitted field measured over a plane surface located on the opposite side of the object from the insonifying point source determines the three-dimensional spatial Fourier transform of the object profile over the surface of an ellipsoid of revolution in Fourier space. In the special case where the point source is in the far field of the object the semiaxes of the ellipsoid become equal and the surface degenerates to a sphere and the result reduces to the usual projection-slice theorem of plane beam diffraction tomography.

Diffraction tomography using arbitrary transmitter and receiver surfaces.

The theory of diffraction tomography for two-dimensional objects within the Born approximation is presented for cases where the scattered field is measured over arbitrarily shaped boundaries surrounding the object. Reconstruction algorithms are presented for both plane wave (parallel beam) and cylindrical wave (fan beam) insonification. Special attention is devoted to cases where the measurement and source boundaries are either lines or circles. The theory and algorithms presented are shown to be readily extended to the case of three-dimensional objects.