Search

In this work, melt-spun ribbons of AlSi10Mg added with modifiers (Er, Sr, or nano-TiB2) were produced to investigate the combined effect of modification and rapid solidification on eutectic Si. The resulting eutectic microstructures are more isotropic in comparison to that of the base alloy affecting the mechanical properties of the alloys. The modification of Si morphology and supersaturation caused by the modifiers were investigated by microscopy, X-ray diffraction, and differential scanning calorimetry. Compared to melt-spun AlSi10Mg, the eutectic Si network is finer and less continuous when Er or Sr is added, and disrupted with rounded crystals dispersed in the matrix when adding nano-TiB2. The level of supersaturation decreases in the order Er–nano-TiB2–Sr. A transition from columnar Al grains at the wheel side to finer equiaxed grains at the air side was found in the unmodified ribbon and in the one containing nano-TiB2 by means of electron backscattered diffraction. The Er- and Sr-modified ribbons display equiaxed Al grains of constant size throughout their thickness. The average hardness obtained by nano-indentation tests was lower than that of AlSi10Mg. The less continuous Si network causes the hardness drop but provides more isotropic mechanical properties.

Tin-bronze alloys with a tin content of at least 10 wt% have excellent mechanical properties, wear resistance, and corrosion resistance. Among these alloys, Cu-10Sn was investigated in this study for production with the laser powder bed fusion process with a 500W Yb:YAG laser. In particular, a design of experiment (DoE) was developed in order to identify the optimal process parameters to obtain full density, low surface roughness, and high dimensional accuracy. Samples were characterized with Archimedes’ method and optical microscopy to determine their final density. It was shown that the first method is fast but not as reliable as the second one. A first mechanical characterization was performed through microhardness tests. Finally, a set of process parameters was identified to produce fully dense samples with low surface roughness and high accuracy. The results showed that the volumetric energy density could represent an approach that is too simplified, therefore limiting the direct correlation with the physical aspects of the process.

Metal parts produced by Additive Manufacturing, and in particular Laser Powder Bed Fusion (LPBF), suffer from residual stresses due to high thermal gradients causing cyclic expansion and contraction of the alloy. This work deals with the determination of residual stress in rapidly solidified AlSi10Mg samples using two non-destructive techniques: Raman spectroscopy, rapid, unconventional but applicable to Al Si alloys, and XRD (ω-method), used as benchmark, being a classical method for determining residual stresses. Al stress level was studied by XRD both on the surface of LPBF samples and in the interior, after in-depth sectioning. Raman was employed to assess the stress on Si. The effect of particle size and stress on the Raman was separated determining the size distribution of Si particles, making Raman suitable to study residual stresses in alloys containing free Si. Al and Si stresses were evaluated also by means of the Williamson-Hall method: stresses are of tensile type with agreement among all methods. Considering the alloy as a composite, stress on Si was estimated using the Eshelby's model, showing that larger eutectic particles undergo lower stress with respect to nanometric precipitates.

IntroductionThe ERAS protocol (Enhanced Recovery After Surgery) is a multimodal pathway aimed to reduce surgical stress and to allow a rapid postoperative recovery. Application of the ERAS protocol to colorectal cancer surgery has been limited to a minority of hospitals in Italy. To promote the systematic adoption of ERAS in the entire regional hospital network in Piemonte an Audit and Feedback approach (A&F) has been adopted together with a cluster randomised trial to estimate the true impact of the protocol on a large, unselected population.MethodsA multicentre stepped wedge cluster randomised trial is designed for comparison between standard perioperative management and the management according to the ERAS protocol. The primary outcome is the length of hospital stay (LOS). Secondary outcomes are: incidence of postoperative complications, time to patients’ recovery, control of pain and patients’ satisfaction. With an A&F approach the adherence to the ERAS items is monitored through a dedicated area in the study web site. The study includes 28 surgical centres, stratified by activity volume and randomly divided into four groups. Each group is randomly assigned to a different activation period of the ERAS protocol. There are four activation periods, one every 3 months. However, the planned calendar and the total duration of the study have been extended by 6 months due to the COVID-19 pandemic.The expected sample size of about 2200 patients has a high statistical power (98%) to detect a reduction of LOS of 1 day and to estimate clinically meaningful changes in the other endpoints.Ethics and disseminationThe study protocol has been approved by the Ethical Committee of the coordinating centre and by all participating centres. Study results will be timely circulated within the hospital network and published in peer-reviewed journals.Trial registration numberNCT04037787.

Banded and discontinuous eutectic microstructures were found in melt quenched ribbons and laser melted single tracks of an Al-3%wt Er alloy, respectively. The bands occurring in ribbons are made of alternate primary α-Al phase and eutectic. Their formation is well described by the Han-Trivedi model for banding in alloy solidification. Microstructure fluctuations between fibrous and discontinuous eutectic are seen in laser melted single tracks on the same length scale of bands due to change in local temperature gradient. Overall, various transitions in phase morphology are found in thin zones of material constituting a valuable guideline for interpretation of the solidification mechanism. Nano-indentation tests show that the fine microstructures induce substantial hardening.

In Selective Laser Melting (SLM) layers of atomized powder are spread sequentially on a building platform and melted locally by a laser beam. The melt pool is quenched by the underlying material. SLM of AlSi10Mg alloys results in the development of microstructures consisting of supersaturated primary Al-rich phase surrounded by varied amounts of Al-Si eutectic. The origin of such microstructure is not fully understood. For insight into this issue, this work compares the results of processing AlS10Mgi alloys by SLM and by single-step rapid solidification techniques: Melt Spinning (MS) and Copper Mould Casting (CMC) achieving a range of cooling rates and microstructures which are analysed by means of microscopy, XRD and DSC. The results obtained in these experiments together with the literature available on rapidly solidified Al-Si alloys suggest a correlation among microstructures of the products made with the three techniques. Data on lattice parameter and enthalpy of Si precipitation from primary Al concur in indicating that Si supersaturation scales in the order SLM > CMC > MS. The type and size of microstructural features, i.e. cells, columns, fibrous and lamellar eutectic, reveal the role of solidification conditions (undercooling, recalescence) and precipitation in the solid state for all techniques. Dendrite growth modelling validates the solidification results.

Objectives Veno-occlusive disease after liver transplant has been sporadically reported, and significant uncertainty exists concerning the best treatment and the long-term outcomes. Here, we reviewed our experience to evaluate clinical presentation, treatment, and the long-term outcomes of these patients. Materials and methods Between 2000 and 2015, 2165 patients underwent liver transplant at our center. The incidence of veno-occlusive disease was 0.3% (7/2165). Results Timing of veno-occlusive disease onset (median 4.7 mo; interquartile range, 2.5-11.1 mo) varied widely as did clinical presentation, which was characterized by a variable association of liver failure and portal hypertension and different disease pro-gression rates. In all cases, diagnosis of veno-occlusive disease was confirmed by liver biopsy. Six patients (85.7%) presented with veno-occlusive disease after a previous episode of acute cellular rejection. Three patients died due to veno-occlusive disease (n = 2) or due to hepatocellular carcinoma recurrence (n = 1). Two patients were treated by increasing immunosuppression and with interventional procedures (pleurodesis and transjugular intrahepatic portosystemic shunt, respectively), and 2 had successful retransplants. 5-year patient and graft survival rates were 57.1% and 28.6%, respectively. Conclusions A tailored approach based on clinical features and including retransplant can achieve acceptable long-term survival in patients with veno-occlusive disease after liver transplant.

Constipation, obstructed defecation, and fecal incontinence are frequent complaints in multiple sclerosis. The literature on the pathophysiological mechanisms underlying these disorders is scant. Using anorectal manometry, we compared the anorectal function in patients with and without multiple sclerosis. 136 patients referred from our Center for Multiple Sclerosis to the Coloproctology Outpatient Clinic, between January 2005 and December 2011, were enrolled. The patients were divided into four groups: multiple sclerosis patients with constipation (group A); multiple sclerosis patients with fecal incontinence (group B); non-multiple sclerosis patients with constipation (group C); non-multiple sclerosis patients with fecal incontinence (group D). Anorectal manometry was performed to measure: resting anal pressure; maximum squeeze pressure; rectoanal inhibitory reflex; filling pressure and urge pressure. The difference between resting anal pressure before and after maximum squeeze maneuvers was defined as the change in resting anal pressure calculated for each patient. Results Group A patients were noted to have greater sphincter hypotonia at rest and during contraction compared with those in group C (p=0.02); the rectal sensitivity threshold was lower in group B than in group D patients (p=0.02). No voluntary postcontraction sphincter relaxation was observed in either group A or group B patients (p=0.891 and p=0.939, respectively). Conclusions The decrease in the difference in resting anal pressure before and after maximum squeeze maneuvers suggests post-contraction sphincter spasticity, indicating impaired pelvic floor coordination in multiple sclerosis patients. A knowledge of manometric alterations in such patients may be clinically relevant in the selection of patients for appropriate treatments and for planning targeted rehabilitation therapy.

The material palette available for Laser Powder Bed Fusion (LPBF) process is still limited. The mixing of different powders, here AlSi10Mg + Cu, and alloy synthesis by Single Scan Tracks (SSTs) and Melt Spinning (MS) were performed in this work for fast testing the new composition and reducing the building time and amount of powder employed. Then LPBF massive samples were manufactured to verify the outcome of the procedure. In all three cases an AlSi10Mg + Cu alloy was obtained, some residual inhomogeneity in Cu distribution being found in the SST sample. Microstructural features of the LPBF sample are intermediate with respect to SST and MS ones in terms of cell size of primary Al, while the eutectic morphology of Si is close to that of the ribbons. Nanoindentation tests showed an increase in hardness of the Cu-added samples with respect to that of the base AlSi10Mg alloy. XRD results indicated the occurrence of supersaturation of both Si and Cu in the as quenched samples and DSC analyses provided information on temperature and enthalpy of exothermal signals due to precipitation.

We present the case of a 29-years-old male patient, affected by a voluminous post-traumatic mesenteric cyst, a rare abdominal disease; our patient represents a rarely affected age group.Treatment was based on interventional radiology with an US-guided drainage and sclerosis by ethyl alcohol of the lesion.The intervention performed on this patient represents the application of a standardized radiological technique to a new contest, mesenteric cysts, whose gold-standard treatment is represented in literature by surgery.In our case we obtained an optimal result, with complete regression of the treated cyst: it proved to be an effective, feasible, safe and minimally invasive procedure.

Introduction : Inguinal hernia surgery is one of the most common surgical procedures performed worldwide. Some studies demonstrated clear advantages of laparoscopic approach in terms of chronic pain, recurrence rate and daily life activities Aim of this study was to compare short and long-terms outcome of tacks and fibrin glue used during laparoscopic transabdominal hernioplasty (TAPP). Methods : This is a retrospective study conducted by our division of General Surgery. From May 2008 to May 2013 we performed 116 hernioplasty with TAPP technique. We compared two groups of patients: a group of 59 patients treated with fibrin glue and a group of 57 patients treated with conventional tacks and the two subgroups of patients over 65 years old. We evaluated: perioperative outcomes, early and late complications. Results : There were no significative difference about length of postoperative stay, time to return to work, recurrence rate and complications. Discussion : This study demonstrates that fibrin glue are same tolerated than tacks by patients and that the glues lead to the same good results during initial follow-up and in long term data also in the elderly. Meticulous preparation of the groin with preservation of spermatic sheet is in our opinion necessary to provide effective pain reduction and a good result in every TAPP procedure.

Definition of the main process parameters, laser power (P), scanning speed (v), hatching distance (hd) and scanning strategy useful for producing dense samples, is fundamental to develop novel alloy compositions for Laser Powder Bed Fusion (LPBF). The present work has two aims: on one side, to verify the processability of a new AlSi10Mg + 4Cu alloy of mixed powders by LBPF; on the other side, on the basis of the experimental analysis, to define a method for processing new alloys. Producing Single Scan Tracks (SSTs), samples with unidirectional scanning strategy and samples with 67° rotated scanning strategy, the proper P-v-hd combinations were identified reaching a final porosity lower than 1.5%. A scenario of hardness and build-up rate vs. energy density is given, to adopt the main process parameters suitable to maximize mechanical properties or productivity. According to the novel method, P-v-hd combinations can be defined through the production and characterization of SSTs and samples with 67° rotated scanning strategy. Through two production steps dense samples can be then obtained, allowing the development of new compositions saving time and reducing costs related to the powder usage. Keywords: Laser Powder Bed Fusion (LPBF), Single scan tracks (SSTs), Hatching distance (hd), Overlap, Process parameters, Hardness, Build-up rate

Venous ulceration is a complex and serious problem that affects 1-2% of the global elderly population (>65 years), and its incidence is constantly increasing. The population group with higher risk of development of venous ulceration is the elderly. These lesions have a significant negative impact on patients' quality of life. Our aim was to analyze the state of the art, starting with the medical literature review. The evidence supports that managing chronic wounds with a multidisciplinary wound care team significantly increases wound healing and reduces the severity of wound-associated pain and the required daily wound treatments compared with persons who are not managed by such a team.

Background Surgical informed consent forms can be complicated for patients to read and understand. We created a consent form with key information presented in bulleted texts and diagrams combined in a graphical format to facilitate the understanding of information during the verbal consent discussion. Methods This prospective, randomized study involved 70 adult patients awaiting cholecystectomy for gallstones. Consent was obtained after standard verbal explanation using either a graphically formatted (study group, n=33) or a standard text document (control group, n=37). Comprehension was evaluated with a 9-item multiple-choice questionnaire administered before surgery and factors affecting comprehension were analyzed. Results Comparison of questionnaire scores showed no effect of age, sex, time between consent and surgery, or document format on understanding of informed consent. Educational level was the only predictor of comprehension. Conclusions Simplified surgical consent documents meet the goals of health literacy and informed consent. Educational level appears to be a strong predictor of understanding.

Laparoscopic cholecystectomy (LC) is currently the gold standard treatment for symptomatic cholelithiasis. LC is actually condidered a medium complexity surgical operation. LC could be technically hard, especially if patient underwent previous surgical operation. These difficulties increase in outcome of previous operation in right upper quadrant (RUQ): in this case laparoscopic access is defined as an “hard access”. We present two cases in which an unconventional access was performed: laparoscopic cholecistectomy is a safe and feasible procedure, although a careful assessment preoperative is indispensable. In particular, caution is required in both the triangulation of the trocar, which in pneumoperitoneum induction.

Introduction Incidence of neuroendocrine tumor (NET) is increased in the last thirty years from 1.1 to 5.2 cases per 100,000 people in the United States. They can originate from the pancreatic gland and for the majority of cases are not functioning (80%). A small percentage of functioning may produce adrenocorticotropic hormone (ACTH) and lead to ectopic ACTH Syndrome (EAS), responsible of Cushing-Syndrome. Results We present a case of a 30 year-old woman suffering from EAS due to a neoformation of the pancreatic tail of the maximum diameter of 4 cm. The lesion was resectable at preoperatory imaging. The patient was subjected to distal splenopancreasectomy. Histological examination showed a well-differentiated neuroendocrine carcinoma pT3N0. The postoperative course was regular. At two years of follow-up patient is almost completely asymptomatic for Cushing's but she has developed multiple liver metastases, for which she began chemotherapy. Discussion p-NET responsible for EAS is usually malignant and the radical treatment of excision of the lesion is not possible because they occur at the time of diagnosis with liver metastases or unresectable. Our patient had a mass at the time of diagnosis resectable but despite radical surgery, she has developed multiple liver metastases at two years and she was undergoing chemotherapy. Conclusions In agreement with previous literature we confirm the aggressive nature of pancreatic tumors secreting ACTH, despite radical surgery. Conversely, surgical treatment is effective on the resolution of clinical symptoms.

An intact hepatic artery is the gateway to successful hepato-biliary surgery. Introduction of laproscopic cholecystectomy (LC) has stimulated a renewed interest in the anatomy of hepatic artery. In this case report we have highlighted importance of variations of right hepatic artery in terms of origin and course We present a rare asymptomatic case of liver atrophy due to an intraoperative lesion of right hepatic artery. We also performed a literature review about surgical vascular lesions and tried to confirm the right concept behind “non trivial procedure” of the LC.

Introduction : Endorectal ultrasound (ERU) is used for locoregional staging of rectal cancer. Our work compares the data in the literature regarding diagnostic accuracy of the technique and results of routine use of the technique in two centers in Piedmont. Material and methods : 77 reports ultrasound with the final diagnosis of rectal cancer from the period 2008–2012 were examined. The echographies were performed by two experienced operators, using two ultrasound device with the same technical characteristics. Results : Sensitivity levels are high, with the exception of stage T3. Specificity is always high. The relationships of verisimilitude, both negative and positive, showing that the accuracy of the test is still high. The risk of overstaging is higher for pT1, while most important the risk of understaging concerns the stage T3 (23.5%); on the contrary the ERU is able to exclude infiltration of perirectal organs with a good accuracy (NPV of 99.3%). Conclusion : Although our study was a retrospective study, likewise some literature's reports, the interpretation of our analysis results shows a significant risk of downstaging T3 and N+ tumors. ERU represents in our experience a very important radiological staging methods to evaluate T1 and T2 rectal cancer.

Background Gallbladder carcinoma is a rare high malignancy neoplasm. The incidence of intra or post-operative incidental gallbladder carcinoma diagnosis is estimated between 0,2 and 2,8%. Primary aim of our study is to evaluate incidental gallbladder carcinoma's incidence in our experience. Methods We retrospectively reviewed our Surgery Division's experience about the totality of laparoscopic cholecystectomies with post-operative histological evidence of incidental gallbladder cancer. We evaluated patients' characteristics, surgical related variables, histological response, surgivcal radicalization characteristics and surgical outcome. Results In the considered sample we observed 7 accidental gallbladder adenocarcinomas in post-operative histological examination. Pathological results were:1 pT1b N0 (G1), 2 pT2 N0 (G2), 2 pT2 N1 (G3b), 2 pT3 N1 (G3b) (Table 1). In 5 cases we performed neoplasm radicalization surgery with standard procedure revision. Two patients died before radicalization. Median global survival was 34 months. Conclusion With the increase of laparoscopic cholecystectomies both elective and urgent performed in our centre we observed also an increase of incidentally diagnosed gallbladder neoplasms. Early diagnosis, meticulous peri-operative study and accurate surgical strategy are essential factors to obtain good results in incidental gallbladder cancer.

Background Laparoscopic appendectomy for acute appendicitis is one of the most common surgical procedures performed in the world. We aimed to compare laparoscopic and open appendectomy in the elderly in our experience. Methods We performed a retrospective review of elderly patients who underwent appendectomy for acute appendicitis from 1st of January 2006 to the 31st of July 2012. We analyzed 39 appendectomies in elderly patients: 20 procedures were performed using open technique (Group O) and 19 using laparoscopic technique (Group L). Results In the analysis of intraoperative variables there was no statistically significant difference. In this study there was no statistically significant difference also in peri-operative variables. Conclusion Laparoscopic appendectomy is a safe and feasible technique in acute appendicitis also in the elderly.

Corrigendum to “Percutaneous drainage and sclerosis of mesenteric cysts: Literature overview and report of an innovative approach” [Int. J. Surg. 12 (2014) S90eS93] Giada Pozzi a, , Alessia Ferrarese , Marco Busso , Alessandro Borello , Silvia Catalano , Alessandra Surace , Silvia Marola , Valentina Gentile , Valter Martino , Mario Solej , Mario Nano a a University of Turin, Department of Oncology, University Section of General Surgery, Teaching Hospital “San Luigi Gonzaga”, Italy b University of Turin, Department of Oncology, University Section of Radiology, Teaching Hospital “San Luigi Gonzaga”, Italy

Background We aimed to analyze outcomes of early and delayed laparoscopic cholecystectomy in the elderly in our General Surgery Division. Methods We analyzed 114 LC performed from the 1st of January 2008 to the 31st of December 2012 in our General Surgery division: 67 LC were performed for gallbladder stones and 47 for acute cholecystitis. Results and discussion Comparison between Ordinary and Emergency groups showed that drain placement and post-operative hospital stay were significatively different. There were no significative differences between Early Laparoscopic Emergency Cholecystectomy (E-ELC) and Delayed Laparoscopic Emergency Cholecystectomy (D-ELC). There weren't any differences about Team's evaluation. Conclusion We consider LC a safe and effective treatment for cholelitiasis and acute cholecystitis in Ordinary and Emergency setting, also in the elderly. We also demonstrate that, in our experience, LC for AC is feasible as well.

Hartmann's procedure (HP) is the most performed technique for acute diverticulitis. Laparoscopic lavage and drainage (LLD) is an option evaluated as definitive treatment for diverticulitis Hinchey grade II–III. Aim of the study is to analyze and compare LLD vs HP outcomes.From January 1st 2009 and December 31st 2012 we prospectively enrolled 30 patients with diagnosis of acute diverticulitis Hinchey grade II–III. Fourteen patients underwent to LLD (LLD group, LLDG) and 16 patients to HP (Hartmann group, HG). We evaluated: demographic variables, comorbidities, admission clinical status, radiological imaging, intraoperative outcomes (operative time), postoperative outcomes (admission to ICU, timing of drainage removal, restore of bowel functions, timing of oral solid intake), mortality rate (perioperative and after 12 months) and morbidity rate (surgical, infectious, cardiovascular, renal and systemic complications). Exclusion criteria were: other diseases, colon cancer's suspect or diagnosis, conversion to HP.Patients' mean age was 64.8 years in HG and 62.6 in LLDG. M:F ratio was 6:10 in HG, 8:6 in LLDG. Data showed improved outcomes in LLDG for: total operative time (p