Investigation of Dry Sliding Friction, Wear and Mechanical Behavior of the Ti-6Al-7Nb Alloy after Thermal Oxidation.

The mechanical and tribological characteristics of the Ti-6Al-7Nb alloy were investigated within a wide range of temperature and time parameters of thermal oxidation. The hardness, HIT, and indentation modulus, EIT, of the alloy in question, with and without an anti-wear oxide layer, were determined. The tribological properties of sliding couples were studied under technically dry friction conditions, using a ball-on-disc tribometer. The test pieces were non-oxidized and oxidized Ti-6Al-7Nb alloy discs, and Al2O3, ZrO2, and 100Cr6 balls were used as counter specimens. After thermal oxidation, the surface of the titanium alloy was characterized by a significantly higher hardness, HIT (8-10 GPa), compared to the surface not covered with oxide layers (3.6 GPa). The study showed that the curvature of the loading segments increased with an increasing oxidation temperature, indicating a strong positive dependence of hardness on the thermal oxidation temperature. The value of the indentation modulus, EIT, was also found to increase with the increasing oxidation temperature. The intensity of the tribological processes was strictly dependent on the oxidation parameters and the couple's material (Al2O3, ZrO2, 100Cr6). It has been shown that the thermal oxidation process makes it possible to control, within a wide range, the friction-wear characteristics of the Ti-6Al-7Nb alloy.

Deposition of Biocompatible Polymers by 3D Printing (FDM) on Titanium Alloy.

Nowadays, the replacement of a hip joint is a standard surgical procedure. However, researchers have continuingly been trying to upgrade endoprostheses and make them more similar to natural joints. The use of 3D printing could be helpful in such cases, since 3D-printed elements could mimic the natural lubrication mechanism of the meniscus. In this paper, we propose a method to deposit plastics directly on titanium alloy using 3D printing (FDM). This procedure allows one to obtain endoprostheses that are more similar to natural joints, easier to manufacture and have fewer components. During the research, biocompatible polymers suitable for 3D FDM printing were used, namely polylactide (PLA) and polyamide (PA). The research included tensile and shear tests of metal-polymer bonds, friction coefficient measurements and microscopic observations. The friction coefficient measurements revealed that only PA was promising for endoprostheses (the friction coefficient for PLA was too high). The strength tests and microscopic observations showed that PLA and PA deposition by 3D FDM printing directly on Ti6Al4V titanium alloy is possible; however, the achieved bonding strength and repeatability of the process were unsatisfactory. Nevertheless, the benefits arising from application of this method mean that it is worthwhile to continue working on this issue.

A rare combination of tumor-induced osteomalacia caused by sinonasal glomangiopericytoma and coexisting parathyroid adenoma: case report and literature review.

BACKGROUND: Tumor-induced osteomalacia (TIO) is a rare, acquired disease of renal phosphate wasting and disturbed vitamin D homeostasis as a result of the action of a phosphaturic protein - FGF-23, produced by a neoplasm. Although the clinical and biochemical profile of the syndrome is characteristic, it remains underreported and unrecognized by clinicians. Hyperparathyroidism is rarely associated with oncogenic osteomalacia, but it should be considered because of potentially life-threatening hypophosphatemia caused by both conditions. CASE PRESENTATION: We report a case of a 42-year-old woman admitted to the Department of Otolaryngology of the Military Institute of Medicine in Warsaw for the endoscopic resection of hormonally active glomangiopericytoma extending into the anterior skull base. She presented with a 5-year history of musculoskeletal pain and progressive weakness of the extremities which finally led her to become bedridden. After the excision of the tumor her symptoms and laboratory results gradually improved except increasing PTH serum levels. Further examination revealed a parathyroid proliferative tumor, which was surgically removed. The patient walked without aids at follow-up 16 months after the surgery. CONCLUSIONS: This case is unusual because of tumor-induced osteomalacia and parathyroid adenoma occurring concomitantly. Further investigations of FGF-23 and PTH interplay should be conducted to elucidate the pathogenesis of hyperparathyroidism and tumorigenesis in some cases of TIO. By presenting this case, we wanted to remind clinicians of a rare and misdiagnosed paraneoplastic syndrome and highlight the importance of monitoring PTH concentrations during the follow-up of patients with TIO.

The impact of severe postoperative complications on outcomes of bariatric surgery-multicenter case-matched study.

BACKGROUND: Bariatric surgery has relatively low complication rates, especially severe postoperative complications (defined by Clavien-Dindo classification as types 3 and 4), but these rates cannot be ignored. In other than bariatric surgical disciplines, complications affect not only short-term but also long-term results. In the field of bariatric surgery, this topic has not been extensively studied. OBJECTIVES: The aim of the study was to assess the outcomes of bariatric treatment in patients with obesity and severe postoperative complications in comparison to patients with a noneventful perioperative course. SETTING: Six surgical units at Polish public hospitals. METHODS: We performed a multicenter propensity score matched analysis of 206 patients from 6 Polish surgical units and assessed the outcomes of bariatric procedures. A total of 103 patients with severe postoperative complications (70 laparoscopic sleeve gastrectomy [SG] and 33 with laparoscopic Roux en Y gastric bypass [RYGB]) were compared to 103 patients with no severe complications in terms of peri- and postoperative outcomes. RESULTS: The outcomes of bariatric treatment did not differ between compared groups. Median percentage of total weight loss 12 months after the surgery was 28.8% in the group with complications and 27.9% in patients with no severe complications (P = 0.993). Remission rates of both type 2 diabetes mellitus and arterial hypertension showed no significant difference between SG and RYGB (36% versus 42%, P = 0.927, and 41% versus 46%, P = 0.575. respectively). CONCLUSIONS: The study suggests that severe postoperative complications had no significant influence either on weight loss effects or obesity-related diseases remission.

Investigation of Micromechanical Properties and Tribological Behavior of WE43 Magnesium Alloy after Deep Cryogenic Treatment Combined with Precipitation Hardening.

This study investigated the micromechanical and tribological properties of WE43 alloy (Mg-Y-Nd-Zr) alloy subjected to cryogenic treatment and precipitation hardening. Microindentation tests were carried out in the range of load from 100 to 1000 mN. The introduction of deep cryogenic treatment (DCT) was shown to increase hardness and Young's modulus, and reduce the total indentation work. As the load set during the tests increased, a gradual decrease in the measured values was observed, indicating a significant relationship between the indent size and the value of the measured parameters. Cryogenic treatment used in conjunction with precipitation hardening (after solutioning and after aging) reduces the tribological wear of the alloy. Tests have shown an almost twofold reduction in the area of the wear trace and in the volumetric wear of the alloy, as well as a more than twofold reduction in linear wear, with relatively small fluctuations in the coefficient of friction. Abrasion was the main mechanism of wear. Areas where microcutting, adhesion and plastic deformation occurred were also observed. The results indicate the significant effectiveness of the applied heat treatment in improving the service life of the WE43 alloy containing rare earth metals.

The impact of the last ten minutes of surgery on hemorrhagic complications after laparoscopic sleeve gastrectomy. Case-control study.

INTRODUCTION: Hemorrhagic complications after laparoscopic sleeve gastrectomy (LSG) are among the most common adverse events. The last 10 min of LSG are essential in terms of hemostasis. AIM: To assess the blood pressure profile in the last 10 min of LSG in patients who experienced hemorrhagic complications after laparoscopic sleeve gastrectomy. MATERIAL AND METHODS: We performed a retrospective case-control study. The medical records of 867 patients who underwent primary LSG were analyzed. Cases were defined as patients who required surgical revision due to hemorrhagic complications within 72 h. Controls were matched (1 : 1) with cases by age, body mass index, gender, staple line reinforcement, comorbidities and surgeon's experience. Comparison of the last three intraoperative blood pressure measurements at the end of surgery was made. RESULTS: The bleeding rate was 3.0%. A total of 24 subjects (12 matched pairs) were included in the study. Cases had statistically significant increased mean arterial blood pressure (mm Hg) 5 min before the end of surgery (87.8 ±11.9 vs. 79.4 ±8.8 mm Hg, p = 0.049) and at the end of surgery (89.2 ±11.7 vs. 77.5 ±11.8 mm Hg, p = 0.011). Higher diastolic blood pressure measurements were observed 5 min before the end (72.1 ±10.7 vs. 62.8 ±8.1 mm Hg, p = 0.023) and at the end of surgery (74.2 ±10.0 vs. 60.8 ±11.2 mm Hg, p = 0.004). CONCLUSIONS: Compared with closely matched control subjects, patients with HC after LSG have increased mean arterial pressure in the last 5 min of surgery. This phenomenon has not been reported in the literature before.

Printable and Machinable Dental Restorative Composites for CAD/CAM Application-Comparison of Mechanical Properties, Fractographic, Texture and Fractal Dimension Analysis.

Thanks to the continuous development of light-curing resin composites it is now possible to print permanent single-tooth restorations. The purpose of this study was to compare resin composites for milling -Gandio Blocks (GR), Brilliant Crios (CR) and Enamic (EN) with resin composite for 3D printing-Varseo Smile Crown plus (VSC). Three-point bending was used to measure flexural strength (σf) and flexural modulus (Ef). The microhardness was measured using a Vickers method, while fractographic, microstructural, texture and fractal dimension (FD) analyses were performed using SEM, optical microscope and picture analysis methods. The values of σf ranged from 118.96 (±2.81) MPa for EN to 186.02 (±10.49) MPa for GR, and the values of Ef ranged from 4.37 (±0.8) GPa for VSC to 28.55 (±0.34) GPa for EN. HV01 ranged from 25.8 (±0.7) for VSC to 273.42 (±27.11) for EN. The filler content ranged from 19-24 vol. % for VSC to 70-80 vol. % for GR and EN. The observed fractures are typical for brittle materials. The correlation between FD of materials microstructure and Ef was observed. σf of the printed resin depends on layers orientation and is significantly lower than σf of GR and CR. Ef of the printed material is significantly lower than Ef of blocks for milling.

Impact of the COVID-19 Pandemic on the Patient's Decision about Bariatric Surgery: Results of a National Survey.

Background: the COVID-19 pandemic and the implemented restrictions have changed the functioning of healthcare systems worldwide. The purpose of the study was to evaluate the impact of the present epidemiological situation on patients' decisions about undergoing weight loss surgery. Methods: data were collected from 906 bariatric patients by the means of a national online survey, the majority of whom were women (87.9%). The survey started on 9 April 2020 and was open until 28 April 2020. The questionnaire included multiple choice and open questions, divided into three chapters: general information about the patient, life during the COVID-19 pandemic, and bariatric care during the COVID-19 pandemic. Results: despite the pandemic and the associated risk of COVID-19 infection, 443 responders (48.9%) would have decided to undergo bariatric surgery. Awareness of the negative impact of obesity on the course of COVID-19 illness had only marginable impact on patients' decision-making (76.6% vs. 75.3%; p < 0.80). Contact with COVID-19 prior to the survey had a negative impact on the willingness to undergo bariatric surgery (3.0% vs. 4.4%; p < 0.55). There was a positive correlation between the BMI and preference for bariatric surgery in the time of the pandemic (37.4 ± 9.0 vs. 34.9 ± 8.7; p < 0.001). Conclusions: the level of awareness about the advantages of operative treatment of obesity is high among bariatric patients. The majority of patients awaiting bariatric surgery at the moment of the survey were positive about undergoing bariatric surgery despite the increased risk of a serious course of COVID-19 infection. Therefore, a large proportion of patients was determined to have bariatric treatment even during the pandemic, being aware of the increased risk of worse pace of COVID-19 disease in case of obesity and related diseases.

Influence of COVID-19 Pandemic Lockdown on Patients from the Bariatric Surgery Waiting List.

Background and Objectives: Social isolation and lockdown due to the COVID-19 pandemic have influenced dietary habits and physical activity of all the population, but the obese population is the most vulnerable to weight gain. Material and Methods: A group of 189 patients (166 female and 23 male) from the bariatric surgery waiting list filled in a survey about the influence of COVID-19 pandemic lockdown on their dietary habits, physical activity, and the possibility of contact with their bariatric care center. Results: The majority of patients with weight gain declared a decrease in physical activity, compared to half of the patients without weight gain (50.5% vs. 74.5%, p < 0.05). The continuation of bariatric care and the possibility of contact with a bariatric surgeon, dietician, and psychologist had each significant influence on reducing the risk of patients' weight gain (p < 0.05). Conclusions: Maintaining physical activity and contact with bariatric care specialists are important factors in allowing to avoid weight gain in patients waiting for bariatric surgery.

Decision Regret after Laparoscopic Sleeve Gastrectomy-5 Years' Perspective.

INTRODUCTION: Patient's satisfaction after weight loss surgery is in the research spotlight. However, there are still no quantitative data regarding whether patients regret their decision to undergo laparoscopic sleeve gastrectomy (SG). OBJECTIVES: The present study aimed to evaluate whether patients regret their decision to undergo SG 5 years after surgery. The secondary objective was to identify whether weight loss and a higher quality of life (QoL) score correlate with the regret expressed by patients. SETTING: Military Hospital, Poland METHODS: A telephone survey was carried out among patients 5 years after surgery. Patient satisfaction regarding their decision to undergo SG was assessed using the Decision Regret Scale. QoL scores were determined using the 36-Item Short Form Survey (SF-36). RESULTS: One hundred and four patients who answered a full telephone survey were enrolled in the study. Change in body mass index (ΔBMI) was 12.31±6.2, excess body mass index loss (%EBMIL) was 55.45%±25.52%, and percent total weight loss (%TWL) was 25.20%±11.7%. At the 5-year postoperative telephone survey, the mean general health score was 50.96±14.0 and the mean regret score was 32.33±13.24 (range, 25-85). A statistically significant negative correlation was observed between %EBMIL and regret score (r=-0.435; p<0.001). There was a significant negative association between regret score and energy/fatigue QoL (r=-0.205; p=0.040). Only eight patients (7.69%) scored >50 on the Decision Regret Scale, which was considered to represent overall regret for their decision. CONCLUSION: Our study suggests that, in general, patients did not regret their decision to undergo SG. KEY POINTS: The majority of patients did not regret their decision to undergo SG. There was a statistically significant negative correlation between weight loss and patients' feelings of regret. Energy/fatigue QoL was the strongest correlate of whether patients regretted their decision to undergo SG.

Bariatric tourists. Foreign bariatric patients treated in Poland - a survey based study.

<b>Introduction:</b> Bariatric procedures are becoming more popular worldwide. We present a current situation of foreign patients treated by high-volume bariatric surgeons in Poland in 2016. <br><b>Material and Methods:</b> We sent an online survey to twenty high-volume bariatric surgeons. The questionnaire regarded the year 2016. We asked for number and types of bariatric procedures performed or supervised, number of foreign bariatric patients, their qualification process, country of origin, types of procedure, and post-op recommendations. <br><b>Results:</b> We received 9 surveys (45%). Five surgeons performed or supervised from 100 to 300 bariatric procedures, 2 performed or supervised over 300 procedures, 2 performed or supervised from 50 to 100 procedures. All of the respondents performed laparoscopic sleeve gastrectomy (LSG) and laparoscopic gastric bypass (LRYGB), four carried out mini gastric bypass, two - gastric banding (LAGB), one - SADI-S and duodenal switch (DS). Six surgeons operated on the total of 64 foreign patients, mainly performing LSG, LRYGB and mini gastric bypass. Most of the patients were qualified based on international criteria [body mass index (BMI) over 40 kg/m² or BMI over 35 kg/m² with comorbidities]. United Kingdom was the most popular country of origin, followed by Germany, USA, Ireland and Sweden. Qualification for surgery was based on a personal visit. After surgery, 83.3% (n = 5) of the respondents gave out discharge documents in English, recommending long-term bariatric follow-up in the country of origin. Every respondent carried out 3-month personal follow-up of every foreign patient. <br><b>Conclusions:</b> Foreign bariatric patients travelling to Poland are qualified for surgery according to known international standards. Most of the patients receive post-op discharge documents in English, with a 3-month follow-up performed by their surgeon. Further bariatric supervision in the country of origin is routinely recommended.

The Influence of Bariatric Surgery on Pregnancy and Perinatal Outcomes-A Case-Control Study.

INTRODUCTION: Obesity in pregnant women increases the incidence of pregnancy-induced comorbidities and the rate of operative deliveries. PURPOSE OF THE STUDY: As bariatric surgery is the reference method of treatment of obesity, we wanted to evaluate its influence on the course of pregnancy and perinatal outcomes. MATERIAL AND METHODS: Data was collected from 627 female patients after bariatric surgery, of whom 107 had a history of pregnancy after the surgery, and 345 non-bariatric patients who had a delivery at a tertiary perinatal center. Sixty-one cases were matched (1:1) with controls for age, pre-pregnancy BMI and presence of pre-pregnancy comorbidities. The main endpoints were gestational diabetes mellitus (GDM), pregnancy-induced hypertension (PIH), small (SGA) and large for gestational age infants (LGA) and cesarean sections (CS). RESULTS: Patients after bariatric procedures were significantly less likely to have GDM (19.67%/37.7%; p = 0.0433), PIH (11.47%/16.39%; p = 0.6072) and preterm delivery (13.11%/37.7%; p = 0.0026). The CS rate was higher (57.38%/40.98%; p = 0.0987). There was an increased risk of SGA (18.03%/13.11%; p = 0.6072) and a decreased risk of LGA (6.56%/16.39%; p = 0.146). CONCLUSIONS: Patients after bariatric surgery have a decreased risk of pregnancy-induced comorbidities, preterm deliveries and LGA infants, with an increase in rate of CS and SGA infants compared to general population matched for pre-pregnancy BMI, age and presence of pre-pregnancy comorbidities.

Outcomes of sleeve gastrectomy in patients older than 60 years: a multicenter matched case-control study.

INTRODUCTION: The prevalence of obesity is increasing according to the World Health Organization. Furthermore, global aging is increasing, especially in developed countries in Europe. Whether bariatric surgery should be performed in elderly people is still controversial. AIM: To determine the clinical outcomes of sleeve gastrectomies (SG) in older central European patients. We compared the safety and efficacy of SG in patients older than 60 years with younger patients. MATERIAL AND METHODS: Eighty-nine patients older than 60 years, who underwent SG, were included in the study. Eighty-nine younger patients (aged 18-40 years) were matched according to body mass index (BMI) and comorbidities. The analyzed data included age, sex, total body weight, BMI, length of hospital stay, 30-day complications and improvement in comorbidities. RESULTS: There was no significant difference in the complication rate between the 2 age groups (p = 0.59). An improvement in hypertension was observed in 73.1% of older patients and in 69.2% of younger patients (p = 0.67). There was improvement in diabetes mellitus in 40% of older patients and in 31.1% of younger patients (p = 0.25). The ΔBMI after 12, 24 and 36 months was significantly lower in older patients than in younger patients (p = 0.002, p = 0.001; p = 0.043, respectively). Percent excess BMI loss (%EBMIL) after 12, 24, and 60 months was significantly lower in older than in younger patients (p = 0.001, p = 0.001, p = 0.028, respectively). CONCLUSIONS: Better weight loss is achieved in younger than in older patients, while maintaining a similar effect on the risk of complications and improvement in comorbidities. Therefore, SG is safe and effective in older people.

The Influence of Deformation under Tension on Some Mechanical and Tribological Properties of High-Density Polyethylene.

Polymer materials are increasingly being used for sliding machine elements due to their numerous advantages. They are used even where they are deformed and in such a state that they interact frictionally, e.g., in machine hydraulics or lip seals. Few publications deal with the influence of deformation, which is the effect of, e.g., assembly on tribological properties of polymeric material. This deformation can reach up to ε ≈ 20% and is achieved without increasing the temperature of the polymer material. The paper presents the results of investigations in which high-density polyethylene (PE-HD) was maintained in deformation by means of a special grip (holder). The wear of the sample was significantly higher than that of the undeformed sample. This effect persisted even after partial relaxation of the stress in the sample after 24 h. Additional investigations were carried out to explain the obtained results. There were the microscopic observations of the surface after friction, measurements of microhardness, and surface free energy. Changes in the value of surface free energy and a significant decrease in microhardness with deformation under tension were observed. Deformed materials have a different surface appearance after friction and a different size and form of wear products. It was indicated that it is probable that the cohesion of the material will decrease and that the character of the wear process will change as a result of tension. Deformation under tension without heating of polymeric material (PE-HD), e.g., as a result of assembly, has been qualified as a threat to be taken into account when designing and analysing polymeric sliding elements.

Current Practice of Global Bariatric Tourism-Survey-Based Study.

PURPOSE: Our goal was to present the experience of bariatric surgeons with medical tourism on a global scale. MATERIALS AND METHODS: An online-based survey was sent to bariatric surgeons worldwide regarding surgeon's country of practice, number and types of bariatric procedures performed, number of tourists treated, their countries of origin, reasons for travel, follow-up, and complications. RESULTS: Ninety-three responders performed 18,001 procedures in 2017. Sixty-four of those 93 responders operated on foreign patients performing a total of 3740 operations for them. The majority of the responders practice in India (n = 11, 17%), Mexico (n = 10, 16%), and Turkey (n = 6, 9%). Mexico dominated the number of bariatric surgeries for tourists with 2557 procedures performed in 2017. The most frequent procedures provided were laparoscopic sleeve gastrectomy (LSG) provided by 89.1% of the respondents, laparoscopic Roux-en-Y gastric bypass (40.6% of respondents), and one anastomosis gastric bypass (37.5% of respondents). CONCLUSION: At least 2% of worldwide bariatric procedures are provided for medical tourists. Countries such as Mexico, Lebanon, and Romania dominate as providers for patients mainly from the USA, UK, and Germany. The lack of affordable bariatric healthcare and long waiting lists are some of the reasons for patients choosing bariatric tourism.

The Safety and Benefits of Laparoscopic Sleeve Gastrectomy in Elderly Patients: a Case-Control Study.

INTRODUCTION: The advancement of minimal invasive techniques pushed the age limit for patients qualified for bariatric surgery. AIM: The aim of the study was to evaluate the safety and effectiveness of laparoscopic sleeve gastrectomy (LSG) in a cohort of patients aged 60 years or more, compared with a group of matched controls below 40 years old. METHODS: The medical records of 856 patients were analyzed. Patients aged 60 years or older were identified as cases. Those below 40 years were identified as the controls. Cases were closely matched (1:1) with the controls by body mass index (BMI) (± 1 kg/m2) and presence or absence of hypertension and diabetes mellitus. RESULTS: A 34 matched pairs were included in the study. There was no significant difference in the median operation length. No conversion from laparoscopic to open surgery was needed. The hospital length of stay was significantly longer in the study group (4.5 ± 1.9 vs 3.9 ± 1.5 days, p = 0.047). The complication, 30-day reoperation, and 30-day reoperation rates were comparable in both groups. There were no 30-day readmissions nor 30-day mortality. ΔBMI after 12 months was significantly lower in the study group (13.56 ± 6.05 vs 10.3 ± 4.89, p = 0.008) as well as %EBMIL (50.71 ± 25.94 vs 64.20 ± 23.29, p = 0.015). CONCLUSIONS: The study suggests that LSG is a safe method of bariatric treatment in patients aged above 60 years. Even though weight loss may be lesser than in younger patients, it can still be considered satisfactory.

Present trends in bariatric surgery in Poland.

INTRODUCTION: As obesity has become a major health problem in Poland and bariatric procedures are the best way of treatment, an increasing trend has been observed in Polish bariatric surgery for the last decade. AIM: Our purpose was to provide an updated overview of the bariatric surgical procedures performed in Polish institutions in comparison to the situation in Europe as well as to analyze the trends in Polish bariatric surgery over the last decades. MATERIAL AND METHODS: A questionnaire about the number and type of bariatric procedures performed in 2016 was sent to all Polish surgical departments. Two hundred and sixty surgical departments returned the questionnaires. RESULTS: Twenty-seven departments reported having performed bariatric operative or endoscopic procedures in 2016. The total number of procedures reported was 1958, the most popular being the laparoscopic sleeve gastrectomy (LSG). More than 99% of procedures were performed using laparoscopic techniques. The most common operations were: LSG (64.6%, n = 1032) and laparoscopic Roux-en-Y gastric bypass (LRYGB) (18.2%; n = 291), followed by one anastomosis gastric bypass (OAGB) (8.3%; n = 132) and laparoscopic adjustable gastric banding (LAGB) (7.3%; n = 117). CONCLUSIONS: Registers of bariatric procedures provide information that helps in planning treatment and predicting possible complications. Adequate reporting of bariatric procedures is necessary to present the importance of the high incidence of obesity and the importance of its treatment. To collect reliable data, a national Polish bariatric surgery registry should be created.

Macroscopic Evaluation of Gastric Specimens After Laparoscopic Sleeve Gastrectomy-an Optimum Screening Test for Incidental Pathologies?

INTRODUCTION: Obesity is a serious lifestyle disease with various comorbidities and an augmented risk of cancer. Laparoscopic sleeve gastrectomy (LSG) has recently become the most popular bariatric procedure worldwide. While the cost-effectiveness is a major healthcare providers' concern, the point of histological exam of each resected tissue may be questioned. MATERIAL/METHODS: We prospectively included patients who underwent LSG. Before the surgery, gastroscopy and abdominal sonography were performed to exclude malignancies. The gastric specimen was cut open after the surgery and inspected macroscopically, then sent for a microscopic examination. RESULTS: In 5 cases out of 115, macroscopic evaluation of the resected specimen performed by the surgeon suggested existing pathology, confirmed by a microscopic evaluation in 3 out of 5 cases. In the remaining 2 cases, pathological analysis did not reveal abnormalities. In 110 cases, the gastric specimen was recognized to be unchanged by the surgeon, 109 out of which were confirmed by the pathologist to be normal, in 1 case a hyperplastic polyp was found. The sensitivity of macroscopic evaluation reached 75% (95% CI, 19.4-99.4%, p = 0.625), with specificity of 98.2% (95% CI, 93.6-99.8%, p < 0.0001), and negative predictive value of 99.1% (95% CI, 95-99.9%, p < 0.0001). CONCLUSIONS: During LSG, a thorough visual inspection of the peritoneal cavity along with a macroscopic surgical evaluation of specimen in patients who had preoperative endoscopy with no findings allows to achieve very good specificity and good sensitivity. Therefore, this procedure may be useful as a screening test for incidental pathologies in bariatric patients and may exclude unnecessary histological examination.

Effectiveness and Safety of Roux-en-Y Gastric Bypass in Elderly Patients-Systematic Review and Meta-analysis.

INTRODUCTION: As the population ages, there is more interest in bariatric surgery for older patients. There are controversies regarding the safety and effectiveness of surgical weight loss in this population. AIM: The aim of this study was to compare the safety and efficacy of Roux-en-Y gastric bypass in patients over the age of 60 years with younger patients. METHODS: The available literature was searched for eligible studies up to February 2018. Inclusion criteria were reports on mortality, morbidity, percentage excess weight loss (%EWL), remission of diabetes, remission of hypertension, and remission of obstructive sleep apnea. Random effects meta-analyses were performed. RESULTS: The initial search yielded 2000 references. The final meta-analysis involved nine studies and revealed significant differences in mortality (odds ratio 4.38, 95% confidence interval [1.25, 15.31], p = 0.02), morbidity (OR 1.88, CI [1.07, 3.30], p = 0.03), %EWL (mean difference - 5.86, 95% CI [- 9.15, - 2.56], p < 0.001), and remission of comorbidities. CONCLUSION: Higher mortality and morbidity were found in the group of older patients. The analysis suggested lower effectiveness of Roux-en-Y gastric bypass for weight loss and improvement in comorbidity in older patients when compared with younger patients.

Challenges associated with bariatric surgery - a multi-center report.

INTRODUCTION: Due to the constantly growing demand for surgical treatment of obesity, it is necessary to create new bariatric centers and further improve presently active ones. AIM: To identify which stages of conducting peri-operative care and organizing a modern bariatric center currently pose the greatest challenge. MATERIAL AND METHODS: An anonymous survey was designed and distributed to bariatric surgeons. Our questionnaire was divided into three parts: demographic characteristics, difficulties associated with peri-operative care for bariatric patients (assessed on a scale of 1-5) and difficulties associated with organization or running of bariatric centers in which participants are currently working (assessed on a scale of 1-5). RESULTS: Overall, 70 surgeons and surgical residents from 17 surgical centers participated in our survey. The most difficult element of the pre-operative care was compliance with the recommendation to cease smoking (3.47 ±1.28). The most difficult obstacle during the postoperative care period was implementation of the enhanced recovery after surgery (ERAS) protocol (2.27 ±1.31). Funding for the bariatric treatment was obtained exclusively from the National Health Fund by 60 (85.7%) respondents working in 15 different bariatric centers (88.2%). Among elements of bariatric infrastructure access to operating theater equipment sized for morbidly obese patients was reported to be the most difficult (3.8 ±1.68). CONCLUSIONS: Pre-operative recommendations including smoking, physical activity or weight loss, as well as introducing ERAS protocol based peri-operative care, are difficult to execute in bariatric departments. Future specialized bariatric centers should be included in the centralized register and equipped with specialized infrastructure for morbidly obese patients.