Microstructural, Electrical, and Tribomechanical Properties of Mo-W-C Nanocomposite Films.

This study investigates the phase composition, microstructure, and their influence on the properties of Mo-W-C nanocomposite films deposited by dual-source magnetron sputtering. The synthesised films consist of metal carbide nanograins embedded in an amorphous carbon matrix. It has been found that nanograins are composed of the hexagonal ß-(Mo2 + W2)C phase at a low carbon source power. An increase in the power results in the change in the structure of the carbide nanoparticles from a single-phase to a mixture of the ß-(Mo2 + W2)C and NaCl-type α-(Mo + W)C(0.65≤k≤1) solid-solution phases. The analysis of electrical properties demonstrates that the nanograin structure of the films favours the occurrence of hopping conductivity. The double-phase structure leads to a twofold increase in the relaxation time compared to the single-phase one. Films with both types of nanograin structures exhibit tunnelling conductance without the need for thermal activation. The average distance between the potential wells produced by the carbide nanograins in nanocomposite films is approximately 3.4 ± 0.2 nm. A study of tribomechanical properties showed that Mo-W-C films composed of a mixture of the ß-(Mo2 + W2)C and α-(Mo + W)C(0.65≤k≤1) phases have the highest hardness (19-22 GPa) and the lowest friction coefficient (0.15-0.24) and wear volume (0.00302-0.00381 mm2). Such a combination of electrical and tribomechanical properties demonstrates the suitability of Mo-W-C nanocomposite films for various micromechanical devices and power electronics.

Effect of 160 MeV Xenon Ion Irradiation on the Tribological Properties and Crystal Structure of 100Cr6 Bearing Steel.

This is the first study ever to show the impact of high-energy 160 MeV xenon ion irradiation on the properties of 100Cr6 bearing steel. The projected range (Rp) of xenon ions is 8.2 µm. Fluence-dependent variations in the coefficient of friction and wear of the 100Cr6 steel material have been observed. These changes correlate with shifts in the crystal lattice constant and variations in the oxygen, carbon, and iron content in the wear track. Fluence-dependent changes in these parameters have been observed for the first time. Irradiation reduces stresses in the crystal lattice, leading to crystallite size increase. The modifications in the properties of 100Cr6 steel result from radiation-induced defects caused by electronic ion stopping. The degree of these modifications depends on the applied irradiation fluence. Furthermore, the use of a higher irradiation fluence value appears to mitigate the effects produced by a lower fluence.

Thyroidectomy: is it safe to be performed by general surgery residents? - single centre experience.

BACKGROUND: Thyroidectomy carries a risk of two crucial complications - recurrent nerve palsy and hypocalcaemia. The aim of the study was to assess the safety of thyroidectomy performed by general surgery residents. METHODS: Data of 515 patients, who underwent total thyroidectomy between the years 2015 and 2019, were prospectively collected. Inclusion criteria were as follows: age >18 years old, patients who underwent total thyroidectomy, no change of operator during the surgery. The study group was divided into two groups: operated by general surgery specialists (385 patients-group 1) and operated by residents with the supervision of experienced general surgery specialists as assistants (130 patients-group 2). RESULTS: Demographic factors did not differ statistically between groups. Median operative time was 65 min (55-85 IQR) and 90 min (75-110 IQR) in groups 1 and 2, respectively (p < 0.001). Complications occurred in 97 (18.7%) patients in group 1 and 25 (19.3%) patients in group 2 (p = 0.893). Recurrent nerve palsy diagnosed with laryngoscopy was the most common complication - 10.2% and 9.2% of patients, respectively (p = 0.754). Permanent vocal paresis occurred in 2.3% and 3.2%, respectively (p = 0.786). Postoperative symptomatic hypocalcaemia occurred in 7% of patients in group 1 and 10% of patients in group 2 (p = 0.271). Logistic regression did not show that resident as the operator with or without intraoperative neuromonitoring is a risk factor for any complications. CONCLUSION: The results of the present study show that thyroidectomy performed by a general surgery resident under supervision can be as safe as the one performed by a specialist.

IMUMETER-A Convolution Neural Network-Based Sensor for Measurement of Aircraft Ground Performance.

The paper presents the development of the IMUMETER sensor, designed to study the dynamics of aircraft movement, in particular, to measure the ground performance of the aircraft. A motivation of this study was to develop a sensor capable of airplane motion measurement, especially for airfield performance, takeoff and landing. The IMUMETER sensor was designed on the basis of the method of artificial neural networks. The use of a neural network is justified by the fact that the automation of the measurement of the airplane's ground distance during landing based on acceleration data is possible thanks to the recognition of the touchdown and stopping points, using artificial intelligence. The hardware is based on a single-board computer that works with the inertial navigation platform and a satellite navigation sensor. In the development of the IMUMETER device, original software solutions were developed and tested. The paper describes the development of the Convolution Neural Network, including the learning process based on the measurement results during flight tests of the PZL 104 Wilga 35A aircraft. The ground distance of the test airplane during landing on a grass runway was calculated using the developed neural network model. Additionally included are exemplary measurements of the landing distance of the test airplane during landing on a grass runway. The results obtained in this study can be useful in the development of artificial intelligence-based sensors, especially those for the measurement and analysis of aircraft flight dynamics.

Formation of Si-Rich Interfaces by Radiation-Induced Diffusion and Microsegregation in CrN/ZrN Nanolayer Coating.

A combination of coating deposition and consequent ion implantation could be beneficial in wear-resistant antifriction surface design and modification. In the present paper, the effects of low-energy 60 keV Si-ion implantation on multinanolayered CrN/ZrN grown on a stainless-steel substrate have been investigated. Complementary experimental (X-ray diffraction, high-resolution transmission electron microscopy, energy-dispersive spectroscopy, secondary ion mass spectrometry) and theoretical (first-principles) methods have been employed to investigate the structure, phase, and composition under a 1 × 10-17 cm-2 irradiation dose. This study has revealed a moderate radiation-tolerance of the CrN/ZrN system, with a 26 nm bilayer period, where the effective ion range after irradiation was below 110 nm. Within the ion range, a decrease in composition homogeneity and structure crystallinity has been found. Si negative ions have been distributed asymmetrically with peak concentrations (10 and 6%) occupying the interfaces between the CrN and ZrN layers. First-principles investigations of the CrN/ZrN(001) heterostructures were carried out to validate the experimental results, which showed that the alignment of Si-rich interfaces closer to chromium layers is a consequence of the lower substitution energy of CrN rather than ZrN. Thus, strong Si-Cr bindings and difference in displacement energies of ZrN and CrN have been attributed as the main factors in Si-rich interface formation. The pin-on-ball tribological test results have exposed the enhancement in wear resistance and the friction coefficient of nanoscale coating via amorphous Si particles descending from interfacial areas and acting as a third-body.

Application of GNSS/INS and an Optical Sensor for Determining Airplane Takeoff and Landing Performance on a Grassy Airfield.

The performance of a PZL 104 Wilga 35A airplane was determined and analyzed in this work. Takeoff and landing distances were determined by means of two different methods: one which utilized a Global Navigation Satellite System/Inertial Navigation System (GNSS/INS) sensor and another in which airplane ground speed was measured with the use of an optical non-contact sensor. Based on the airfield measurements, takeoff and landing distances as well as rolling resistance coefficients were determined for the used airplane on a grassy runway at the Radawiec airfield, located near Lublin, southeast Poland. The study was part of the "GARFIELD" project that is expected to deliver an online information system on grassy airfield conditions. It was concluded that both sensors were suitable for the aimed research. The results obtained in this study showed the effects of high grass upon the takeoff and landing performances of the test airplane. Also, the two methods were compared against each other, and the final results were compared to calculations of ground distances by means of the chosen analytical models.

Application of the TDR Soil Moisture Sensor for Terramechanical Research.

This paper presents examples of the application of the TDR (Time-Domain Reflectometry) sensor in terramechanical research. Examples include the determination of soil moisture content during off-road vehicle mobility tests, the determination of snow density before and after the wheeling of a snow grooming machine and an airplane, as well as the monitoring of turf moisture on a grassy airfield for the analysis and prediction of safe and efficient flight operations (takeoff and landing). A handheld TDR meter was used in these experiments. Soil moisture data were correlated with the vehicle mobility index and a simple model for this correlation was derived. Using grassy airfield research, soil moisture data were related to meteorological impacts (precipitation, sunlight, etc.). Generally, it was concluded that the TDR meter, in its handheld version, was a useful tool in the performed research, but a field sensor that operates autonomically would be an optimal solution for the subject applications.

Is ITP really a desirable indication for teaching laparoscopic splenectomy? Cohort study.

Background: We aimed to evaluate the outcomes of laparoscopic splenectomy (LS) in patients with immune thrombocytopenic purpura (ITP) compared with operated for other indications. Methods: Retrospective cohort study of patients who underwent LS in 1998-2017. Group 1 consisted of 256 patients operated for ITP, and Group 2 of 231 operated for other indications. Primary outcome was procedure difficulty. Secondary was perioperative course (30 days of surgery). Results: Patients in Group 1 were younger (p < .001) with lower ASA (p < .001). The spleen was larger in Group 2 (p < .001). Operative time was longer in Group 2 [110 (80-150) vs. 90 (65-115) min; p < .001)]. Intraoperative blood loss was greater in Group 2 (p < .001). Conversions were higher in Group 2 (4.76 vs. 6.93%, p = .037), as were intraoperative complications (7.79 vs. 3.91%, p = .048). Morbidity, reoperations and mortality did not differ between groups (respectively, p = .899, .697, and .999). Median length of stay was similar (p = .211). Among the first 10 LSs performed by trainees, 63.66% were done for ITP. Later (after 11+ procedures) this dropped to 48.12% (p = .002). Conclusions: ITP may be a preferred indication for surgeons training for LS. Patients' characteristics and intraoperative factors allow an expectation for a relatively easy and hassle-free operation in those patients.

Determining Wheel Forces and Moments on Aircraft Landing Gear with a Dynamometer Sensor.

This paper describes airfield measurement of forces and moments that act on a landing gear wheel. For the measurement, a wheel force sensor was used. The sensor was designed and built based on strain gage technology and was embedded in the left landing gear wheel of a test aircraft. The sensor is capable of measuring simultaneously three perpendicular forces and three moments and sends data to a handheld device wirelessly. For the airfield tests, the sensor was installed on a PZL 104 Wilga 35A multipurpose aircraft. The aircraft was towed at a "marching man" speed and the measurements were performed at three driving modes: Free rolling, braking, and turning. The paper contains results obtained in the field measurements performed on a grassy runway of the Rzeszów Jasionka Aerodrome, Poland. Rolling resistance of aircraft tire, braking friction, as well as aligning moment were analyzed and discussed with respect to surface conditions.

Quest for the optimal technique of laparoscopic splenectomy - vessels first or hilar transection?

INTRODUCTION: Throughout our 20 years of experience, we have used several different techniques for laparoscopic splenectomy (LS). However, two methods have been used most frequently: "vessels first" and "hilar transection". AIM: To evaluate the outcomes of LS performed with these two different approaches. MATERIAL AND METHODS: It was an observational study based on retrospective analysis of consecutive patients undergoing LS in a tertiary referral surgical center in the period 1998-2017. We excluded patients with splenic trauma, initially submitted to open surgery, stapled transection of splenic hilum, partial resections of the spleen and other spleen-preserving procedures. Patients were divided into two groups: group 1 ("vessels first") with 188 patients, and group 2 ("hilar transection") with 287 patients. RESULTS: Mean operative time was shorter (p < 0.001) and blood loss was lower (p < 0.001) in group 2. The need for blood transfusions and the conversion rate were higher in group 1 (p = 0.044 and p = 0.003 respectively). There was no difference in intraoperative adverse events (p = 0.179). Overall postoperative morbidity did not differ between groups (p = 0.081) and we noted mortality of 0.21% (1 patient of group 2). The morbidity rate associated with accidental injury of the pancreatic parenchyma was significantly higher in group 1 (p = 0.028). Median length of hospital stay was 4 days (range: 1-99) and did not differ between groups (p = 0.175). CONCLUSIONS: The "vessels first" technique is associated with longer operative time, higher blood loss and increased risk of conversion. "Hilar transection" is associated with lower incidence of local complications related most likely to accidental injury of the pancreatic tail. In the case of a large caliber of splenic vessels the "vessels first" approach remains the technique of choice.

20 years' experience with laparoscopic splenectomy. Single center outcomes of a cohort study of 500 cases.

BACKGROUND: Laparoscopic splenectomy (LS) has become the gold standard in elective spleen surgery. Although it is considered relatively safe, treatment results vary depending on a hospital's profile and the experience of the surgeon and center. We would like to present experience of a high-volume referral center with minimally invasive operations of the spleen. MATERIAL AND METHODS: The retrospective cohort study included consecutive patients undergoing laparoscopic splenectomy in tertiary referral surgical center in 1998-2017. The entire study population (500 patients) was grouped into 5 cohorts of 100 consecutively operated patients. The primary endpoints were short-term outcomes of LS and secondary - analysis of indications and operative technique. The study group consisted of 316 women and 184 men, 46 (28-59) years old on average. RESULTS: The most common indications for splenectomy were ITP (53%), lymphoma (21%) and spherocytosis (7%). Ratio of ITP versus other indications decreased significantly over time in favor of more difficult cases (<0.001). Average operative time of 100 (75-132.5) min and blood loss of 50 (20-150) ml were changing during study. Forty two patients required a blood transfusion with no difference among groups (p = 0.765). The use of postoperative drainage diminished from 100% to 7% (p < 0.001). The overall conversion rate (3%) and intraoperative complications (5%) did not differ among groups (p = 0.863 and 0.888). Perioperative morbidity was 8.6% and decreased significantly over time (OR: 0.78, 95%CI: 0.62-0.98). We noted mortality of 0.4% (1 patient in 1st and 1 in 5th group). Median LOS was 4 (1-16) days. A significant change in the operative technique from vessels first to hilar transection was noted. CONCLUSION: Laparoscopic splenectomy seems to be a safe method associated with a low risk of perioperative complications and mortality. A careful reproducible operative technique, along with a well-trained team and standardized modern postoperative care is critical to improving outcomes.

Impact of bariatric surgery on non-alcoholic fatty liver disease.

Introduction; p to 300 million people have the body mass index (BMI) greater than 30 kg/m2. Obesity is the cause of many serious diseases, such as type 2 diabetes, hypertension, and non-alcoholic fatty liver disease (NAFLD). Bariatric surgery is the only effective method of achieving weight loss in patients with morbid obesity. OBJECTIVES: The aim of the study was to assess the impact of bariatric surgery on non-alcoholic fatty liver disease in patients operated on due to morbid obesity. MATERIAL AND METHODS: We included 20 patients who were qualified for bariatric procedures based on BMI > 40 kg/ m2 or BMI > 35kg/m2 with the presence of comorbidities. The average body weight in the group was 143.85kg, with an average BMI of 49.16kg/m2. Before the procedure, we evaluated the severity of non-alcoholic fatty liver disease in each patient using the Sheriff-Saadeh ultrasound scale. We also evaluated the levels of liver enzymes. Follow-up evaluation was performed twelve months after surgery. RESULTS: Twelve months after surgery, the average weight was 102.34 kg. The mean %WL was 33.01%, %EWL was 58.8%, and %EBMIL was 61.37%. All patients showed remission of fatty liver disease. Liver damage, evaluated with ultrasound imaging, decreased from an average of 1.85 on the Sheriff-Saadeh scale, before surgery, to 0.15 twelve months after surgery (p < 0.001). As regards liver enzymes, the level of alanine aminotransferase decreased from 64.5 (U/l) to 27.95 (U/l) (p < 0.001), and the level of aspartate aminotransferase decreased from 54.4 (U/l) to 27.2 (U/l). CONCLUSIONS: Bariatric procedures not only lead to a significant and lasting weight loss, but they also contribute to the reduction of fatty liver disease and improve liver function.

Laparoscopic Gastrectomy with Enhanced Recovery After Surgery Protocol: Single-Center Experience.

BACKGROUND Surgery remains the mainstay of gastric cancer treatment. It is, however, associated with a relatively high risk of perioperative complications. The use of laparoscopy and the Enhanced Recovery After Surgery (ERAS) protocol allows clinicians to limit surgically induced trauma, thus improving recovery and reducing the number of complications. The aim of the study is to present clinical outcomes of patients with gastric cancer undergoing laparoscopic gastrectomy combined with the ERAS protocol. MATERIAL AND METHODS Fifty-three (21 female/32 male) patients who underwent elective laparoscopic total gastrectomy due to cancer were prospectively analyzed. Demographic and surgical parameters were assessed, as well as the compliance with ERAS protocol elements, length of hospital stay, number of complications, and readmissions. RESULTS Mean operative time was 296.4±98.9 min, and mean blood loss was 293.3±213.8 mL. In 3 (5.7%) cases, conversion was required. Median length of hospital stay was 5 days. Compliance with ERAS protocol was 79.6±14.5%. Thirty (56.6%) patients tolerated an early oral diet well within 24 h postoperatively; in 48 (90.6%) patients, mobilization in the first 24 hours was successful. In 17 (32.1%) patients, postoperative complications occurred, with 7 of them (13.2%) being serious (Clavien-Dindo 3-5). The 30-day readmission rate was 9.4%. CONCLUSIONS The combination of laparoscopy and the ERAS protocol in patients with gastric cancer is feasible and allows achieving good clinical outcomes.

Gastrointestinal obstruction in patients previously treated for malignancies.

UNLABELLED: Bowel obstruction is a common condition in acute surgery. Among the patients, those with a history of cancer consist a particular group. Difficulties in preoperative diagnosis - whether obstruction is benign or malignant and limited treatment options in patients with reoccurrence or dissemination of the cancer are typical for this group. The aim of the study was to analyze causes of bowel obstruction in patients with history of radical treatment due to malignancy. MATERIAL AND METHODS: Patients with symptoms of bowel obstruction and history of radical treatment for malignancy who were operated in 2nd and 3rd Department of General Surgery JUCM between 2000 and 2014 were included into the study. The patients were divided into 2 groups based on type of mechanical bowel obstruction (group 1 - adhesions, group 2 - malignant process). RESULTS: 128 patients were included into the study - group 1: 67 (52.3%) and group 2: 61 (47.7%). In the second group bowel obstruction was caused by reoccurrence in 25 patients (40.98%) and dissemination in 36 (59.02%). The mean time between onset of the symptoms of bowel obstruction and the end of treatment for the cancer was 3.7 and 4.4 years, respectively in group 1 and 2 (p>0.05). Median time between onset of the symptoms and admission to Emergency Department was significantly longer in patients with malignant bowel obstruction compared to those with adhesions (11.6 ±17.8 days vs 5.1 ± 6.9 days, p=0.01). Considering type of surgery due to bowel obstruction, in first group in most patients (69.2%) bowel resection was not necessary and in the second group creation of jejuno-, ileo- or colostomy was the most common procedure. Morbidity was significantly higher in second group (45.9% vs 28.26%, p<0.05) but there was no difference in mortality (26% vs 24%, p>0.05). In both groups the most common localization of primary malignancy was colon. CONCLUSIONS: In analyzed group of patients frequency of bowel obstruction caused by adhesions and malignancy was similar. However, in patients with bowel obstruction caused by malignancy morbidity was significantly higher and duration of symptoms was longer. There was no diagnostic procedure which would allow to differentiate the cause of bowel obstruction preoperatively and the diagnosis was made during the operation.

Early results of liver resection using laparoscopic technique.

UNLABELLED: The aim of the study was to present early outcomes of liver resection using laparoscopic technique. MATERIAL AND METHODS: Retrospective analysis of patients who underwent liver resection using laparoscopic method was conducted. The analyzed group included 23 patients (11 women and 12 men). An average patient age was 61.3 years (37 - 83 years). Metastases of the colorectal cancer to the liver were the cause for qualification to the procedure of 15 patients, metastasis of breast cancer in 1 patient and primary liver malignancy in 5 patients. The other 2 patients were qualified to the liver resection to widen the surgical margins due to gall-bladder cancer diagnosed in the pathological assessment of the specimen resected during laparoscopic cholecystectomy, initially performed for other than oncology indications. RESULTS: Hemihepatectomy was performed in 11 patients (9 right and 2 left), while the other 12 patients underwent minor resection procedures (5 metastasectomies, 4 nonanatomical liver resections, 1 bisegmentectomy, 2 resections of the gall-bladder fossa). An average duration of the surgical procedure was 275 minutes 65 - 600). An average size of the resected tumors was 28 mm (7 - 55 mm). In three cases conversion to laparotomy occurred, caused by excessive bleeding from the liver parenchyma. Postoperative complications were found in 4 patients (17.4%). Median hospitalization duration was 6 days (2 - 130 days). One patient (4.3%) was rehospitalized due to subhepatic abscess and required reoperation. Histopathology assessment confirmed radical resection (R0) in all patients in our group. CONCLUSION: Laparoscopic liver resections seem to be an interesting alternative in the treatment of focal lesions in the liver.

Foxp3+ lymphocyte count in Barrett's esophagus tissue is higher than in in amed esophageal tissue.

INTRODUCTION: The number of Foxp3+ lymphocytes is increased in patients with esophageal carcinoma. Little is known about Foxp3+ cells count in Barret's esophagus, which is a precancerous state for esophageal cancer. A i m: To count the number of Foxp3+ lymphocytes in tissue samples from patients with Barrett's and compare it with samples from individuals with esophagitis and esophageal cancer. MATERIALS AND METHODS: 43 patients were enrolled to the study: 14 with esophageal carcinoma, 15 with Barrett's esophagus and 14 with non-metaplastic esophagitis. Every patient undergone gastroscopy during which a tissue sample was taken. Foxp3+ lymphocytes and CD4+ lymphocytes were detected by using immunohistochemistry. RESULTS: Mean density of Foxp3+ cells in patients with esophagitis was 7.37/10HPF (range: 1-9), 18.5/10HPF (range: 5-29) and 26.8/10HPF (range: 16-40) in patients with dysplastic and non-dysplastic BE, respectively and 47.92/10HPF in individuals with esophageal a carcinoma. These intergroup differences turned out to be statistically significant (p = 0.000; Fig. 3). Patients, either with dysplasia or without, presented with significantly higher Foxp3+ cell counts than the subjects with esophagitis (p = 0.0003 and p = 0.0006, respectively). Also the number of Foxp3+ lymphocytes in esophageal adenocarcinoma specimens turned out to be significantly higher than in esophagitis (p = 0.0001), non-dysplastic and dysplastic BE tissue (p = 0.016 and p = 0.00047, respectively). CONCLUSIONS: Barrett's metaplasia, either with dysplasia or without, is associated with an evident increase in the number of Foxp3 lymphocytes within the esophagogastric junction mucosa. Restoration of lymphocyte balance in esophageal tissue might prevent malignant transformation of Barrett's metaplasia.

Changing patterns in the surgical treatment of perforated duodenal ulcer - single centre experience.

INTRODUCTION: Although the surgical treatment of patients with perforated duodenal ulcer is the method of choice, the introduction of effective pharmacotherapy has changed the surgical strategy. Nowadays less extensive procedures are chosen more frequently. The introduction of laparoscopic procedures had a significant impact on treatment results. AIM: To present our experience in the treatment of perforated duodenal ulcer in two periods, by comparing open radical anti-ulcer procedures with laparoscopic ulcer repair. MATERIAL AND METHODS: The analysis covered patients operated on for perforated duodenal ulcer. Two groups of patients were compared. Group 1 included 245 patients operated on in the period 1980-1994 with a traditional method (pyloroplasty + vagotomy) before introduction of proton pump inhibitors (PPI). Group 2 included 106 patients treated in the period 2000-2014 with the laparoscopic technique supplemented with PPI therapy. Groups were compared in terms of patients' demographic structure, operative time, complication rate and mortality. RESULTS: The mean operative time in group 1 was shorter than in group 2 (p < 0.0001). Complications were noted in 57 (23.3%) patients in group 1 and 14 (13.5%) patients in group 2 (p = 0.0312). Reoperation was necessary in 13 (5.3%) cases in group 1 and in 5 cases in group 2 (p = 0.8179). The mortality rate in group 1 was significantly higher than in group 2 (10.2% vs. 2.8%, p = 0.0192). In group 1, median length of hospital stay was 9 days and differed significantly from group 2 (6 days, p < 0.0001). CONCLUSIONS: Within the last 30 years, significant changes in treatment of perforated peptic ulcer (PPU) have occurred, mainly related to abandoning routine radical anti-ulcer procedures and replacing the open technique with minimally invasive surgery. Thus it was possible to improve treatment results by reducing complication and mortality rates, and shortening the length of hospital stay. Although the laparoscopic operation is longer, it improves outcomes. In the authors' opinion, in each patient with suspected peptic ulcer perforation, laparoscopy should be the method of choice.

Laparoscopic adrenalectomy for pheochromocytoma is more difficult compared to other adrenal tumors.

INTRODUCTION: Laparoscopic adrenalectomy is the gold standard for the treatment of benign adrenal tumors. However, some authors raise the problem of differences in surgery for pheochromocytoma in comparison to other lesions. AIM: To compare laparoscopic adrenalectomy for pheochromocytoma and for other tumors. MATERIAL AND METHODS: Four hundred and thirty-seven patients with adrenal tumors were included in the retrospective analysis. Patients were divided into two groups: 1 (124 patients treated for pheochromocytoma) and 2 (313 patients with other types of tumor). The two groups were compared with respect to mean operative time, intraoperative blood loss, conversion rate, complication rate and the relationship of tumor size with operative time. RESULTS: The mean operative time in group 1 was 91 min, and in group 2 it was 82 min (p = 0.016). In both groups 1 and 2, tumor size correlated with operative time (p < 0.0001 and p = 0.0003, respectively). The mean blood loss in groups 1 and 2 was 117 ml and 54 ml, respectively (p = 0.0011). The complication rate in groups 1 and 2 was 4% and 4.2%, respectively (p = 0.9542). In groups 1 and 2, conversion was necessary in 2 (1.6%) and 5 (1.6%) cases, respectively (p = 0.9925). CONCLUSIONS: Longer operative time and higher blood loss after laparoscopic adrenalectomy for pheochromocytoma indicate its greater difficulty. However, despite these drawbacks, minimally invasive surgery still seems to be an effective and safe method.

Randomized Clinical Trial To Compare The Effects Of Preoperative Oral Carbohydrate Loading Versus Placebo On Insulin Resistance And Cortisol Level After Laparoscopic Cholecystectomy.

UNLABELLED: Postoperative insulin resistance, used as a marker of stress response, is clearly an adverse event. It may induce postoperative hyperglycemia, which according to some authors can increase the risk of postoperative complications. One of the elements of modern perioperative care is preoperative administration of oral carbohydrate loading (CHO-loading), which shortens preoperative fasting and reduces insulin resistance. The aim of the study is to establish the influence of CHO-loading on the level of insulin resistance and cortisol in patients undergoing elective laparoscopic cholecystectomy. MATERIAL AND METHODS: Patients were randomly allocated to one of 2 groups. The intervention group included 20 patients who received CHO-loading (400 ml Nutricia pre-op®) 2 hours prior surgery. The control group received a placebo (clear water). In every patient blood samples were taken 2 hours prior to surgery, immediately after surgery, and on the 1st postoperative day. Levels and changes in glucose, cortisol and insulin resistance were analyzed in both groups. RESULTS: Although there were differences in the levels of cortisol, insulin, and insulin resistance, no statistically significant differences were observed between groups in every measurement. The length of stay and postoperative complications were comparable in both groups. CONCLUSIONS: We believe that CHO-loading is not clinically justified in case of laparoscopic cholecystectomy. No effect on the levels of glucose, insulin resistance and cortisol was observed. Even though such procedure is safe, in our opinion there is no clinical benefit from CHO-loading prior to laparoscopic cholecystectomy.

The usefulness of the Mannheim Peritonitis Index score in assessing the condition of patients treated for peritonitis.

UNLABELLED: The aim of the study was to verify the Mannheim Peritonitis Index (MPI) suitability to determine the probability of death among patients in Polish population operated due to peritonitis and to assess the possibility of using the Index to determine the risk of postoperative complications, relaparotomy and need for postoperative hospitalization in intensive care unit. MATERIAL AND METHODS: Retrospective analysis covered 168 patients (M: F = 83: 85, mean age = 48.45 years, SD ± 22.2) treated for peritonitis. The MPI score was calculated for each patient. According to MPI results, patients were divided to the appropriate groups (<21, 21-29, > 29) and within analyzed. The statistical analysis used Chi-square, Mann Withney U and Kolmogorov-Smirnov test. The best cut-off point for MPI was calculated on the basis of ROC analisys. RESULTS: Mortality in the study group was 13.1%. In groups <21, 21-29 and > 29 points according to MPI mortality was 1.75%, 28.13% and 50% respectively, the difference was statistically significant (p = 0.0124). Significant differences were observed in mortality depending on the diagnosis. Based on the ROC curve the cut-off point was identified as 32 with an accuracy of 85.9% and AUC = 81%. There has been a significant correlation between the MPI count and and the occurrence of: cardio-respiratory failure, acidosis, electrolyte imbalance, surgical wound complications, the need for treatment in the intensive care unit after surgery. CONCLUSIONS: The MPI is a simple and effective predictor of death among patients operated due to peritonitis. It can also provide assistance in assessing the risk of postoperative complications and the need for treatment in the intensive care unit.