Aggressive Surgery in Retroperitoneal Soft Tissue Sarcoma Carried Out at High-Volume Centers is Safe and is Associated With Improved Local Control

Background

We sought to assess morbidity and mortality in primary retroperitoneal soft tissue sarcomas (RSTS) treated by a frontline aggressive surgical approach.

Methods

A total of 249 consecutive patients with primary RSTS were treated by a frontline aggressive surgical approach at two major European institutions. Multivariable models were used for exploring the relationship between postsurgical morbidity and the number of organs resected, with adjustment for clinical variables. The impact of morbidity on local and distant recurrence-free survival was explored by multivariable models, adjusting for the main known prognostic factors.

Results

Median follow-up was 37 months (interquartile [IQ] range, 16–61 months). Median tumor size was 17 cm (IQ range, 11–26 cm). The median number of organs resected en bloc with the tumor was 2 (IQ range, 1–3). Complete macroscopic resection was achieved in 232 cases (93%). At 5 years, overall survival was 65.4% (95% confidence interval [95% CI], 56.8–72.7); local and distant recurrence crude cumulative incidences were 22.3% (95% CI, 16.5–30.2) and 24.2% (95% CI, 18.4–31.9), respectively. Postsurgical morbidity requiring at least one invasive therapeutic procedure was observed in 45 patients (18%; 95% CI, 14–23). Surgical reintervention was necessary in 30 patients (12%; 95% CI, 8–17). Eight patients died of postoperative complications (3%; 95% CI, 1–6). No statistically significant association between postsurgical morbidity and any clinical variable was detected. For number of resected organs, we documented an increased risk of morbidity for more than three organs (P = 0.007). Postsurgical morbidity did not affect oncologic outcome.

Conclusions

Frontline aggressive surgical approach to primary RSTS is safe when carried out at high-volume centers. It could be systematically considered in primary RSTS.     

工业锅炉燃烧过程的稳态优化模型

建立了一个以能源成本最低为目标、采用神经网络模拟约束条件的工业锅炉燃烧过程稳态优化模型.介绍了该模型的罚函数法求解算法,并给出了一个应用实例.理论计算和实际使用表明,该模型有相当的精度,可以显著提高系统的能源利用率.     

Optimal control analysis of a mathematical model for unemployment

Unemployment is continuously increasing worldwide because of enormous increase in population. This paper attempts to propose an optimal control policy for a deterministic unemployment model. The model considers three states, namely, unemployment, employment, and newly created vacancies. Factors like retirement and death of employed persons, termination from job, and so forth are also included in the model. The optimal control analysis for proposed unemployment model is performed using Pontryagin's maximum principle. The conditions for optimal control of the unemployment problem with effective use of implemented policies to provide employment to unemployed persons and to create new vacancies are derived and analyzed. Copyright © 2015 John Wiley & Sons, Ltd.     

Toward a Better Liver Graft Allocation That Accounts for Candidates With and Without Hepatocellular Carcinoma

In some countries where the Model for End‐Stage Liver Disease (MELD) score is used for graft allocation, selected patients with hepatocellular carcinoma (HCC) receive a fixed number of exception points at listing, and increasing priority on the list by accruing additional exception points at regular time intervals. This system originally aimed at balancing the risks of HCC patients of developing contraindications and of non‐HCC patients of dying before transplantation, is not ideal because it appears to offer an advantage to HCC patients, regardless of tumor characteristics and response to loco‐regional treatment. Scores modulated by HCC characteristics have been proposed. They are based on a more refined estimate of the risk of pretransplant drop‐out or of the posttransplant transplant benefit expressed as the life‐years gained for each graft. This review describes the newly proposed systems, and discusses their advantages and drawbacks. We believe that the current exception points allocation should be revised and that drop‐out‐equivalent or transplant benefit‐equivalent models should be studied further. As with all policy changes, these should be done under close monitoring that allows subsequent revisions.     

Impact of Teaching Facility Status and High-Volume Centers on Outcomes for Lung Cancer Resection: An Examination of 13,469 Surgical Patients

Background  Studies suggest that institutional case volume and teaching status significantly affect patient survival. We sought to compare outcomes of surgical resection for lung cancer at teaching facilities (TF) and at high-volume centers (HVC). Methods  Patients undergoing lung cancer resection with curative intent were examined using a linked dataset from 1998 to 2002 between the Florida Cancer Data System and the Florida Agency for Health Care Administration. Results  A total of 13,469 patients were analyzed and outcomes adjusted for comorbidities. Median survival time (MST) was superior for patients treated at TF versus nonteaching facilities (NTF) (47.1 versus 40.5 months, P < 0.001). Mortality rates at NTF were higher at 30 days (2.6% versus 1.1%, P < 0.001), 90 days (6.8% versus 3.8%, P < 0.001), and at 5 years (63.9% versus 59.2%, P = 0.005). Similarly, MST was superior in the cohort treated at HVC versus low-volume center (LVC) (45.1 versus 39.8 months, P < 0.001). Mortality was observed to be higher in LVC than HVC at 30 days (2.7% versus 1.6%, P < 0.001), 90 days (7.5% versus 4.0%, P < 0.001), and at 5 years (63.5% versus 59.3%, P = 0.002). Significant preoperative, independent predictors of survival include age, sex, smoking status, and the existence of certain comorbidities. Treatment at a TF or HVC were independent predictors of better outcome. Race, use of chemotherapy or radiation did not affect outcomes. Conclusion  Surgical treatment for lung cancer at TF or HVC results in significantly better short- and long-term patient outcomes.     

手外科血管危象预防护理质量评价指标的构建及应用

目的 构建手外科血管危象预防护理质量评价指标,并评价应用效果。方法 以三维质量结构模式为理论框架,通过文献分析、半结构访谈及专家函询构建手外科血管危象预防护理质量评价指标。将200例单指断指再植或皮瓣移植患者按照入院时间分为对照组和观察组各100例,对照组给予常规护理,观察组根据构建的手外科血管危象预防护理质量评价指标进行护理。结果 构建的手外科血管危象预防护理质量评价指标体系包含结构质量、过程质量、结果质量3项一级指标,10项二级指标及47项三级指标。质量评价指标应用后,观察组血管危象及时发现率、断指再植或移植皮瓣成活率及患者满意度评分显著高于对照组,患者血管危象发生率显著低于对照组(均P<0.05)。结论 构建并应用手外科血管危象预防护理质量指标有利于及时发现血管危象,降低血管危象发生率,提高再植手指或移植皮瓣成活率及患者满意度。     

Staging of Bilateral Lung Transplantation for High‐Risk Patients With Interstitial Lung Disease: One Lung at a Time

The choice of a single or bilateral lung transplant for interstitial lung disease (ILD) is controversial, as surgical risk, long‐term survival and organ allocation are competing factors. In an effort to balance risk and benefit, our center adopted a staged bilateral lung transplant approach for higher surgical risk ILD patients where the patient has a single lung transplant followed by a second single transplant at a later date. We sought to understand the surgical risk, organ allocation and early outcomes of these staged bilateral recipients as a group and in comparison to matched single and bilateral recipients. Our analysis demonstrates that staged bilateral lung transplant recipients (n = 12) have a higher lung allocation score (LAS), lower pulmonary function tests and a lower glomerular filtration rate prior to the first transplant compared to the second (p < 0.01). There was a shorter length of hospital stay for the second transplant (p = 0.02). The staged bilateral compared to the single and bilateral case‐matched controls had comparable short‐term survival (p = 0.20) and pulmonary function tests at 1 year. There was a higher incidence of renal injury in the conventional bilateral group compared to the single and staged bilateral groups. The staged bilateral procedure is a viable option in select ILD patients.     

Optimal open-loop control of the mould filling process for injection moulding machines

Product quality of injection-moulded' plastics greatly depends upon the injection flow rate of molten polymer during filling. In this paper, an optimal control of the filling process is shown to improve the properties of the moulded parts. Our goal is to provide an efficient basis for designing a supervisory computer-controlled injection moulding system. A dynamic model of the filling process is developed. It takes into account the effect of molten polymer on the dynamics of the injection ram. Based upon this model, an optimal control input, which is a control current actuating the injection ram-screw assembly, is derived from the minimization of a quadratic performance index which serves to keep the front velocity of molten polymer flow into the cavity at a desired value. The optimal input thus obtained has been implemented via a microcomputer for on-line control of the injection process. The experimental results show that surface blemish and residual stress of the moulded parts can be reduced via this optimal control.     

Investigation of Risks for Cerebral Embolism Associated With the Hemodynamics of Cardiopulmonary Bypass Cannula: A Numerical Model

Cerebral emboli originating in the ascending aorta are a major cause of noncardiac complications following cardiac surgery. The hemodynamics of the aortic cannula has been proven to play a significant role in emboli generation and distribution. The aim of the current study was to perform a thorough numerical investigation in order to examine the effect of the design and orientation of the cannula used during cardiopulmonary bypass on the risk to develop cerebral embolism. Hemodynamic analyses compared numerical models of 27 cases consisting of six different cannula orientations, four aortic anatomies, and three cannula designs. The cannula designs included a straight‐tip (ST) cannula, a moderately curved tip cannula (TIP₁), and a sharp‐angle curved cannula (TIP₂). Outcome measures included hemodynamic parameters such as emanating jet velocity, jet velocity drop, maximal shear stress, aortic wall reaction, emboli pathlines and distribution between upper and lower vessels, and stagnation regions. Based on these parameters, the risks for hemolysis, atheroembolism, and cerebral embolism were evaluated and compared. On one hand, the jet emerging from the ST cannula generated large wall‐shear stress at the aortic wall; this may have triggered the erosion and distribution of embolic atheromatous debris from the aortic arch. On the other hand, it diverted more emboli from the clamp region to the descending aorta and thus reduced the risk for cerebral embolism. The TIP₁ cannula demonstrated less shear stress on the aortic wall and diverted more emboli from the clamp region toward the upper vessels. The TIP₂ cannula exhibited a stronger emanating jet, higher shear stress inside the cannula, and highly disturbed flow, which was more stagnant near the clamp region. Current findings support the significant impact of the cannula design and orientation on emboli generation and distribution. Specifically, the straight tip cannula demonstrated a reduced risk of cerebral embolism, which may be pivotal in the clinical setting.     

Demographics and outcomes at American Society for Metabolic and Bariatric Surgery Centers of Excellence

Introduction

Surgery is currently an effective long-term therapy for morbid obesity and its complications. A variety of surgical procedures can now offer durable and safe weight control as well as previously unrealized full remission of costly comorbidities. This is a preliminary investigation of patient characteristics and outcomes at Bariatric Surgery Centers of Excellence^® (BSCOE^®) hospitals.

Methods and procedures

Data were analyzed from 235 American Society for Metabolic and Bariatric Surgery (ASMBS) BSCOE^® hospitals receiving Full Approval status from August 2005 to May 2007. Metrics for the 66,339 bariatric surgeries performed at these hospitals included type, volume and distribution of various bariatric surgical procedures performed at each hospital, patient demographics, payer information, and adverse outcomes.

Results

Data from these analyses demonstrate significant differences in terms of surgical procedure selection (laparoscopic gastric bypass 61%), patient demographics (females 83%, White 60%, mean age 43 years) and type of payer (private insurance 78%), and adverse outcomes (readmission 5%, re-operation 2%, mortality 0.36%).

Conclusions

The collective performance of ASMBS BSCOE hospitals in bariatric outcomes of readmissions, re-operations, and mortality are equivalent to, or more favorable, than currently reported outcomes. However, risk assessment and risk adjustment of the patients and each of the bariatric procedures will be necessary to appropriately evaluate these rates.     

Physician Knowledge of Breast Cancer Recurrence and Contralateral Breast Cancer Risk is Associated with Increased Recommendations for Contralateral Prophylactic Mastectomy: a Survey of Physicians at NAPBC-Accredited Centers

Annals of Surgical Oncology - Physician recommendation for contralateral prophylactic mastectomy (CPM) has been shown to influence whether a patient chooses CPM. Few studies have explored physician...     

Optimal design of trajectory parameters and position tracking with balance for riderless bicycle

Riderless bicycles are typically nonholonomic, underactuated, and nonminimum‐phase systems. The instability and complex dynamic coupling make the trajectory generation and tracking of the bicycles more challenging. In this paper, we consider both the trajectory generation and position tracking of a riderless bicycle. To achieve smooth motion performances, the desired planar trajectory of the contact point of the bicycle's rear wheel is constructed using a parameterized polynomial curve that can connect two given endpoints with associated tangent angles. The optimal parameters of the polynomial curve are obtained by minimizing the maximum of the roll angle's quasistatic trajectory of the bicycle, and this problem is solved by the particle swarm optimization algorithm. Then, position tracking of the desired planar trajectory with balance is converted into an optimization problem subject to the dynamic constraints. The cost function is designed as the combination of the position errors and the roll acceleration of the bicycle, in order to achieve an accurate tracking performance and to prevent the bicycle from falling down. This optimization problem is solved by the Gauss pseudospectral method. Simulation results are presented to demonstrate the effectiveness of the proposed method. Copyright © 2014 John Wiley & Sons, Ltd.     

Geographic Coverage and Verification of Trauma Centers in a Rural State: Highlighting the Utility of Location Allocation for Trauma System Planning

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