Numerical and experimental analysis of labyrinth seals with rhomboidal cells

The labyrinth seals are devices commonly used in turbomachinery to reduce hot gas leakages through engine clearances, which adversely affect the gas turbine performance. For this reason, in the last decades, many in-depth analyses and optimization studies were carried out on this topic using experimental, analytical and numerical approaches. In this work, an innovative rhomboidal pattern is presented, obtained through Computational Fluid Dynamics (CFD) simulations, which is more dissipative than commonly used honeycomb cells. The experiments, performed using a Test Article that reproduces a stage and the next stator of a real low-pressure turbine suitably scaled, allowed to validate the numerical results in a situation that closely approximates the real one of use. The results obtained show that the leakages flow fraction of the total mass flow rate that bypasses the blade, which is 29.4% using a honeycomb pattern, is reduced to 27% with rhomboidal cells. The experimental results also made it possible to verify that the new pattern also behaves well from a thermal point of view, giving rise to temperature differences with respect to the honeycomb of less than 1%

Ecodialysis: first strategies to limit damages and reduce costs

In the medical field, the attention to the environmental impact of industrial processes and products is still limited. In recent years there has been an increased sensitivity towards the environment; meanwhile, the economic burden of hazardous waste disposal is becoming evident. Dialysis is a "big producer" of waste and it has been estimated that disposal costs can be up to 10-40% of the cost of disposables. So there are several reasons of interest on "ecodialysis": the high amount of waste defined as "potentially hazardous", which requires a very expensive management and the recyclability potential of the non-contaminated waste, that has not yet been fully explored in dialysis. This primary study has been performed in collaboration with the Politecnico di Torino. Its aim has been to define a schedule of activities by a few brainstorming sessions. This schedule is to be readily performed or it should be developed in detail to optimize, by reducing and recycling, the waste production during the dialysis session. The discussion identified seven basic points for the eco-sustainability of haemodialysis to: [1] reduce packaging; [2] facilitate separation of materials, and [3] their discharge; [4] differentiate materials; [5] clearly highlight the potentially hazardous materials; [6] improve the recyclability of plastic products; [7] propose a path of recovery and reuse. Although a full optimization requires a close cooperation with the manufacturers and is achievable only in the long term, the reduction of one pound of potentially contaminated materials could presently lead, on a national scale, to a saving of several million euros, which can be better employed in investments to improve our treatments

Elderly and very elderly advanced ovarian cancer patients: Does the age influence the surgical management?

Background: To examine the surgical treatment and clinical outcome of elderly and very elderly advanced epithelial ovarian cancer patients. Methods: We retrospectively analyzed FIGO stage IIIC-IV ovarian cancer patients, divided in elderly (Group A, >65 and <75 years) and very elderly patients (Group B, ≥75 years) treated by primary debulking surgery (PDS) or by interval debulking surgery (IDS) at the Catholic University at Rome and Campobasso, Italy. Results: 164 patients were included: 123 (Group A) and 41 (Group B). Complete cytoreduction was achieved in 60 patients (60.6%) in Group A and in 20 patients (62.5%) in Group B (p = 0.75). In the remaining cases, optimal cytoreduction was performed (39 cases (39.4%) in Group A and 12 (37.5%) in Group B; p = 0.75). In Group A complete/optimal debulking was achieved in 53 patients (53.5%) at PDS and in 46 patients (46.5%) at IDS (p = 0.55). In the Group B a higher rate of patients was debulked at IDS with respect to PDS (10 (31.3%) vs. 22 patients (68.7%); p = 0.02). In Group A patients debulked at PDS showed better DFS (p = 0.007) and OS (p = 0.003) with respect to patients submitted to successful IDS, whereas in group B we did not observed any survival difference according to time of cytoreduction. Conclusions: Our data suggest that elderly and very elderly patients may tolerate radical and ultra-radical surgery. These patients should be managed in a gynecologic oncology unit, with prudent but complete approach. © 2012 Elsevier Ltd. All rights reserved

Positron Emission Tomography-Laparoscopy Based Method in the Prediction of Complete Cytoreduction in Platinum-Sensitive Recurrent Ovarian Cancer

BACKGROUND: This study was designed to evaluate the positron emission tomography-laparoscopy-based method in the prediction of complete/optimal cytoreduction in platinum sensitive recurrent epithelial ovarian cancer patients. METHODS: We analysed 223 consecutive recurrent epithelial ovarian cancer patients. Inclusion criteria were absence of extra-abdominal disease and Eastern Cooperative Oncology Group Performance Status ≤2. Complete and optimal secondary cytoreduction are defined as macroscopic absence or less than 1 cm of residual tumor at the end of surgery. RESULTS: Laparoscopy was feasible in 210 of 223 patients (94.2 %). Laparoscopy stated 127 (60.5 %) possible cytoreductions and 83 (39.5 %) systemic chemotherapies. In the same population, AGO score evaluation avowed 150 possible cytoreduction (71.5 %) and 60 unresectable women (28.5 %). Overall, 115 of 210 patients (54.7 %) underwent successful secondary cytoreduction: complete and optimal cytoreduction was obtained in 103 (89.5 %) and 12 (10.5 %) patients, respectively. Laparoscopy obtained a positive predictive value of 91.3 %. Laparoscopy recovered to secondary cytoreduction 13 of 60 patients (21.7 %) deemed as not resectable according to AGO score. Forty-eight of 150 AGO score positive patients (32 %) were judged nonresectable by laparoscopy. CONCLUSIONS: This study confirmed that laparoscopy could be effective for the selection of platinum-sensitive recurrent epithelial ovarian cancer patients suitable for complete cytoreduction

Tumor Size, an Additional Risk Factor of Local Recurrence in Low-Risk Endometrial Cancer: A Large Multicentric Retrospective Study

Objective: The identification of patients with endometrial cancer (EC) at higher risk for relapse is critical to individualize and better tailor postoperative treatment. No evidence is available regarding the possible association between tumor size (TS) and the risk of local recurrence. The purpose of this study was to analyze the correlation between TS and risk/type of recurrence in EC patients, stratified according to the new European Society of Medical Oncology-European Society of Gynecological Oncology-European Society for Radiotherapy and Oncology classification. Methods: Data of patients with histologically proven EC who received primary surgical treatment between November 1999 and June 2015 were retrospectively retrieved from 5 institutions. Optimal TS cutoff was calculated using a receiver operating characteristic curve. Site of recurrence as a function of TS and groups of risk were analyzed. Local recurrence-free survival, recurrence-free survival, and overall survival were calculated using the Kaplan-Meier method. Results: Data of 1166 patients were analyzed. Among them, 514 (44.1%) had low-risk EC, 174 (14.9%) had intermediate risk EC, 173 (14.8%) had high-intermediate risk EC, and 305 (26.2%) had high-risk EC. A total of 134 (11.5%) women had recurrence: 47 (4%) of them had local relapse, 30 (2.6%) had locoregional relapse, and 57 (4.9%) had distant relapse. Tumor size 25 mm or greater emerged as the threshold for the prediction of a higher rate of local recurrence (P &lt; 0.0001, hazard ratio = 18.2, P = 0.005) and a lower local recurrence-free survival and recurrence-free survival (P &lt; 0.0001) only in patients with low-risk EC. There was no statistically significant correlation between TS and recurrence in the other risk groups. Conclusions: In this very large series, tumor size emerges as an independent prognostic factor of local recurrence in women with low-risk EC and could be a valuable additional criterion to personalize the treatment approach to these patients

Minilaparoscopic Versus Single-Port Total Hysterectomy: A Randomized Trial

Study Objective: To compare perioperative outcomes and postoperative pain of minilaparoscopic (M-LPS) and laparoendoscopic single-site total hysterectomy (LESS). Design: Prospectively randomized study (Canadian Task Force classification II-2). Setting: Department of Obstetrics and Gynecology, Division of Gynecologic Oncology, Catholic University of the Sacred Heart, Rome. Patients: A total of 86 patients underwent total hysterectomy. Seventy-one met the inclusion criteria and were included in this study. Three of them refused randomization, 34 were randomly assigned to undergo to single-port hysterectomy and 34 to undergo to minilaparoscopy. Interventions: The operative technique is the same in the 2 groups with the exception of videolaparoscopy, port type, and some specific instruments. All surgical procedures were performed with an intrauterine manipulator. Single-port hysterectomy was performed through a multichannel single trocar inserted in the umbilicus. Minilaparoscopic hysterectomy was performed through one optical transumbilical 5-mm trocar and three 3-mm suprapubic ancillary ports. Measurements and Main Results: Sixty-eight patients met the inclusion criteria and were enrolled in the study. The baseline characteristics of the 2 groups were comparable. Median operative time was longer in LESS with respect to M-LPS (120 minutes vs 90 minutes; p = .038). There were no differences between the 2 groups for median estimated blood loss, ileus, and postoperative stay. Additional 5-mm port insertion was needed in 1 case (2.9%) in the M-LPS group and in 2 cases (5.9%) in the LESS group, respectively (p = .311). No patient had development of intraoperative or early postoperative complications. Patients in the M-LPS group experienced a minor pain at each evaluation, compared with patients who underwent LESS. The rescue analgesic requirement was similar in the 2 groups. Conclusions: Laparoscopic hysterectomy can be safely performed by M-LPS and LESS. M-LPS is associated with significantly lower operative time and less postoperative pain than LESS. Advantages of M-LPS hysterectomy than LESS have no noteworthy impact on the patients' early postoperative management. The decision on the best access to the hysterectomy might take into account the surgeon's skill and feeling with the different possible approaches. © 2013 AAGL

The role of sentinel node in early ovarian cancer: A systematic review

INTRODUCTION: Early ovarian cancer (EOC) is defined as ovarian cancer macroscopically limited to the ovaries at the time of initial diagnosis. Approximately only 25% of patients with ovarian cancer are affected by EOC. This condition requires complete surgical staging, including systematic lymphadenectomy up to the level of the renal vessels, with the consequent risk of complications and morbidity. With the aim to reduce the procedure-related morbidity, sentinel lymph node mapping (SLNm) has been introduced as an experimental procedure in EOC staging. The aim of the present study is to systematically review the available series on this interesting issue. EVIDENCE ACQUISITION: Studies were identified by searching electronic databases. The search was systematically applied to PubMed, ClinicalTrials.gov, Scopus and Web of Science looking for records describing the use of sentinel lymph node technique in EOC from January 1st, 1989 to January 1st, 2019. A total of 10 studies were identified for inclusion. Of the 121 patients involved in these studies, only 43 had a histologically-confirmed diagnosis of EOC and were included in the present analysis. EVIDENCE SYNTHESIS: SLN (paraaortic and/or pelvic) overall detection rate (DR) was of 97.6%. The overall sensitivity (SS) and negative predictive value (NPV) of the included cases were 66.7% and 96.6%, respectively. We calculated also NPV, SS and DR based on the anatomical lymph node district, with a value of 100% both in the lumbo-aortic and in the pelvic district and a DR of 83.3% and 43% respectively. CONCLUSIONS: This review shows that evidence on SLNm in EOC is still scant. Based on the limited data available, SLNm may provide potentially useful information on nodal status in patients affected by this disease

Pre-hysterectomy cone biopsy is able to predict response in locally advanced cervical cancer patients submitted to neo-adjuvant chemoradiation

Background: To evaluate the feasibility and the predictive value of cone biopsy before performing radical hysterectomy in locally advanced cervical cancer patients showing complete clinical response to neo-adjuvant chemoradiation. Methods: Between March 2010 to March 2012 74 consecutive FIGO stage IIA2-IIB patients were submitted to neo-adjuvant chemoradiation. All complete clinical responder patients were enrolled in this pilot trial. Results: Fifty-seven out of 74 patients (77%) showed complete clinical response and were enrolled in the study. Forty-two out of 57 patients (74%) underwent successful pre-completion surgery cone biopsy with a median cone's tissue diameter of 24 mm (range 18-35). In 33 out of 42 patients (58%) a complete pathological response was found. In the remaining 5 (9%) and 4 (7%) a microscopic partial and partial response was found, respectively. All 33 cases (58%) with negative cone showed complete pathological response in the radical hysterectomy specimens. Patients with microscopic residual tumor foci in the cone showed negative residual cervical and paracervical tissue at definitive diagnosis, whereas in patients with partial response macroscopic residual disease in the surgical specimens was found. The negative predictive value of cone biopsy, MRI and PET/CT in the prediction of pathological status of the cervical and paracervical tissue was 100%, 79% and 79%, respectively (Table 2). Conclusions: In this study we observed that, in locally advanced cervical patients showing complete clinical response to neo-adjuvant chemoradiation, the cone biopsy feasibility was almost 75%, and that there is a complete pathological correspondence between cone and definitive pathology. (C) 2013 Elsevier Ltd. All rights reserved