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A new analytical model of enhanced distributed channel access (EDCA) which builds on an existing comprehensive model is presented. The model implements virtual collisions and combines the advantages of both accurate backoff countdown and accurate arbitration inter-frame space (AIFS) differentiation. The correctness of the model is evaluated by comparison with ns-2 simulations and two previous models. The comparison gives very good results. [ABSTRACT FROM AUTHOR]

We present a novel model of IEEE 802.11 EDCA with support for analysing networks with misbehaving nodes. In particular, we consider backoff misbehaviour. Firstly, we verify the model by extensive simulation analysis and by comparing it to three other IEEE 802.11 models. The results show that our model behaves satisfactorily and outperforms other widely acknowledged models. Secondly, a comparison with simulation results in several scenarios with misbehaving nodes proves that our model performs correctly for these scenarios. The proposed model can, therefore, be considered as an original contribution to the area of EDCA models and backoff misbehaviour.

Wireless Local Area Networks (WLANs) have revolutionized modern communication by providing a user-friendly and cost-efficient solution for Internet access and network resources. However, the increasing popularity of WLANs has also led to a rise in security threats, including jamming, flooding attacks, unfair radio channel access, user disconnection from access points, and injection attacks, among others. In this paper, we propose a machine learning algorithm to detect Layer 2 threats in WLANs through network traffic analysis. Our approach uses a deep neural network to identify malicious activity patterns. We detail the dataset used, including data preparation steps, such as preprocessing and division. We demonstrate the effectiveness of our solution through series of experiments and show that it outperforms other methods in terms of precision. The proposed algorithm can be successfully applied in Wireless Intrusion Detection Systems (WIDS) to enhance the security of WLANs and protect against potential attacks.

This paper presents an analysis of the IEEE 802.11ax networks' coexistence with legacy stations, namely IEEE 802.11ac, IEEE 802.11n, and IEEE 802.11a. The IEEE 802.11ax standard introduces several new features that can enhance network performance and capacity. The legacy devices that do not support these features will continue to coexist with newer devices, creating a mixed network environment. This usually leads to a deterioration in the overall performance of such networks; therefore, in the paper, we want to show how we can reduce the negative impact of legacy devices. In this study, we investigate the performance of mixed networks by applying various parameters to both the MAC and PHY layers. We focus on evaluating the impact of the BSS coloring mechanism introduced to the IEEE 802.11ax standard on network performance. We also examine the impact of A-MPDU and A-MSDU aggregations on network efficiency. Through simulations, we analyze the typical performance metrics such as throughput, mean packet delay, and packet loss of mixed networks with different topologies and configurations. Our findings indicate that implementing the BSS coloring mechanism in dense networks can increase throughput by up to 43%. We also show that the presence of legacy devices in the network disrupts the functioning of this mechanism. To address this, we recommend using an aggregation technique, which can improve throughput by up to 79%. The presented research revealed that it is possible to optimize the performance of mixed IEEE 802.11ax networks.

Background: The incidence of the highly morbid and potentially lethal gangrenous cholecystitis was reportedly increased during the COVID-19 pandemic. The aim of the ChoCO-W study was to compare the clinical findings and outcomes of acute cholecystitis in patients who had COVID-19 disease with those who did not., Methods: Data were prospectively collected over 6 months (October 1, 2020, to April 30, 2021) with 1-month follow-up. In October 2020, Delta variant of SARS CoV-2 was isolated for the first time. Demographic and clinical data were analyzed and reported according to the STROBE guidelines. Baseline characteristics and clinical outcomes of patients who had COVID-19 were compared with those who did not., Results: A total of 2893 patients, from 42 countries, 218 centers, involved, with a median age of 61.3 (SD: 17.39) years were prospectively enrolled in this study; 1481 (51%) patients were males. One hundred and eighty (6.9%) patients were COVID-19 positive, while 2412 (93.1%) were negative. Concomitant preexisting diseases including cardiovascular diseases (p < 0.0001), diabetes (p < 0.0001), and severe chronic obstructive airway disease (p = 0.005) were significantly more frequent in the COVID-19 group. Markers of sepsis severity including ARDS (p < 0.0001), PIPAS score (p < 0.0001), WSES sepsis score (p < 0.0001), qSOFA (p < 0.0001), and Tokyo classification of severity of acute cholecystitis (p < 0.0001) were significantly higher in the COVID-19 group. The COVID-19 group had significantly higher postoperative complications (32.2% compared with 11.7%, p < 0.0001), longer mean hospital stay (13.21 compared with 6.51 days, p < 0.0001), and mortality rate (13.4% compared with 1.7%, p < 0.0001). The incidence of gangrenous cholecystitis was doubled in the COVID-19 group (40.7% compared with 22.3%). The mean wall thickness of the gallbladder was significantly higher in the COVID-19 group [6.32 (SD: 2.44) mm compared with 5.4 (SD: 3.45) mm; p < 0.0001]., Conclusions: The incidence of gangrenous cholecystitis is higher in COVID patients compared with non-COVID patients admitted to the emergency department with acute cholecystitis. Gangrenous cholecystitis in COVID patients is associated with high-grade Clavien-Dindo postoperative complications, longer hospital stay and higher mortality rate. The open cholecystectomy rate is higher in COVID compared with non -COVID patients. It is recommended to delay the surgical treatment in COVID patients, when it is possible, to decrease morbidity and mortality rates. COVID-19 infection and gangrenous cholecystistis are not absolute contraindications to perform laparoscopic cholecystectomy, in a case by case evaluation, in expert hands., (© 2022. The Author(s).)

Background: Laparoscopic adrenalectomy (LA) has become the "gold standard" for treating most adrenal tumors in the past decade. However, it is still considered a relatively complicated procedure requiring experience from surgeon. The aim of the study was to evaluate the safety of laparoscopic adrenalectomy performed by residents who are undergoing training in general surgery., Methods: A prospectively collected database containing all 300 transperitoneal laparoscopic adrenalectomies performed in II Department of General Surgery JU MC, Krakow between January 2013 and March 2018 was retrospectively reviewed. Patients were divided into two groups; patients operated on by residents (group 1, 54 operations) and by attending general surgeons (group 2, 246 operations). We compared the course of the operation and patient hospitalization in these two groups. If the operation was completed by a different person than the one who started the procedure, we refer to this as "operator conversion"., Results: We found no differences in demographic factors or comorbidities between the two groups. The mean operative time was similar in the residents' and the specialists' groups (p = 0.5761). Median blood loss did not differ between the groups (p = 0.4325). The overall ratio of intraoperative adverse events was similar in both groups (p = 0.8643). The difference in the ratio of perioperative complications between the groups was not statistically significant (p = 0.6442). The average mean hospital stay after surgery was 2 days for both groups. We identified 25 cases (8.33%) of operator conversion; the difference in operator conversions between two groups was not statistically significant (p = 0.1741)., Conclusions: Laparoscopic transperitoneal adrenalectomy performed by a supervised resident is a safe procedure. The course of the operation and patient hospitalization did not differ importantly when comparing procedures performed by residents and attending surgeons. Liberal use of operator conversions from resident to attending surgeon and from a surgeon to a senior surgeon provides reasonable safety and prevents complications. In high-volume centers performing minimally invasive techniques, closed supervision allows residents to safely perform LA.

Introduction: The primary treatment of Conn's syndrome (CS) is laparoscopic adrenalectomy and aims to normalize arterial blood pressure and biochemical parameters., Aim: To analyse short- and long-term results of laparoscopic adrenalectomy for Conn's syndrome (CS)., Material and Methods: The analysis included 44 consecutive patients, who underwent laparoscopic adrenalectomy between 2004 and 2015 for CS. We analysed short- and long-terms results of operations. All patients were followed up 6 and 24 months after surgery to determine changes in the biochemical parameters, and clinical regression of arterial hypertension. We also evaluated the aldosteronoma resolution score (ARS) in predicting the resolution of hypertension., Results: No conversions were needed. Complications occurred in 5 (11.4%) patients. Preoperative hypokalaemia and hypernatraemia were present in 83.4% and 15.8% of patients, respectively. After surgery, both hypokalaemia and hypernatraemia resolved in all patients. At the follow-up 6 months after the surgery, only 11.3% of patients had complete remission (CR) of hypertension. In 43.2% of cases we observed partial remission (PR). After 24 months CR was found in 13.6% of patients, 45.5% patients fulfilled criteria for PR, and 29.5% of patients changed the group of remission comparison to the first follow-up visit. Only 50% of patients with an ARS of 4 or 5 points achieved CR 6 months after surgery., Conclusions: Laparoscopic adrenalectomy is a safe method of treatment for CS. Although it effectively eliminates electrolyte imbalance, it does not allow for the CR of hypertension in the majority of patients, especially in the elderly group. We did not find ARS to be an effective tool in predicting postoperative resolution of hypertension.

Introduction: Even though laparoscopic adrenalectomy is currently a standard, there are important variations between different centres in short-term treatment results such as length of hospital stay (LOS) or morbidity., Aim: To determine the factors affecting LOS in patients after laparoscopic transperitoneal lateral adrenalectomy (LTA)., Material and Methods: The study enrolled 453 patients (173 men and 280 women, mean age 57 years) who underwent LTA between 2009 and 2017. Discharge from hospital after more than median hospital stay was considered as prolonged LOS. We evaluated factors that potentially may influence LOS (primary length of stay after surgery, excluding readmissions). Logistic regression models were used in univariate and corrected multivariate analyses, in order to identify the factors related to prolonged LOS., Results: The median LOS after LTA in the studied group was 2 days. One hundred seventy-five (38.5%) patients required prolonged hospitalization. Univariate logistic regression showed that the following factors were related to prolonged LOS: presence of any comorbidity, cardiovascular disease, intraoperative complications, postoperative complications, day of the week of operation (surgery on Thursday or Friday), intraoperative blood loss, need for transfusion, hormonal activity, postoperative drainage, ASA (III-IV) and histological type - pheochromocytoma. Multivariate logistic regression showed that only complications (OR = 3.86; 95% CI: 1.84-8.04), day of the week of operation (Thursday or Friday) (OR = 4.85; 95% CI: 3.04-7.73), need for drainage (OR = 3.63; 95% CI: 1.55-8.52), and histological type - pheochromocytoma (OR = 2.48; 95% CI: 1.35-4.54) prolonged LOS., Conclusions: Prolonged length of hospital stay following laparoscopic transperitoneal lateral adrenalectomy is strongly associated with the presence of postoperative complications, day of the week of operation (Thursday or Friday), need for drainage, and histological type - pheochromocytoma.

Purpose: Laparoscopic sleeve gastrectomy (LSG) has become an attractive bariatric procedure with promising treatment effects yet amount of data regarding institutional learning process is limited., Materials and Methods: Retrospective study included patients submitted to LSG at academic teaching hospital. Patients were divided into groups every 100 consecutive patients. LSG introduction was structured along with Enhanced Recovery after Surgery (ERAS) treatment protocol. Primary endpoint was determining the LSG learning curve's stabilization point, using operative time, intraoperative difficulties, intraoperative adverse events (IAE), and number of stapler firings. Secondary endpoints: influence on perioperative complications and reoperations. Five hundred patients were included (330 females, median age of 40 (33-49) years)., Results: Operative time in G1-G2 differed significantly from G3-G5. Stabilization point was the 200th procedure using operative time. Intraoperative difficulties of G1 differed significantly from G2-G5, with stabilization after the 100th procedure. IAE and number of stapler firings could not be used as predictor. Based on perioperative morbidity, the learning curve was stabilized at the 100th procedure. The morbidity rates in the groups were G1, 13%; G2, 4%; G3, 5%; G4, 5%; and G5, 2%. The reoperation rate in G1 was 3%; G2, 2%; G3, 2%; G4, 1%; and G5, 0%., Conclusion: The institutional learning process stabilization point for LSG in a newly established bariatric center is between the 100th and 200th operation. Initially, the morbidity rate is high, which should concern surgeons who are willing to perform bariatric surgery.

Carcinogenesis is a multistep process in which inflammation plays an important role. Tumour necrosis factor a (TNF-α) is a cytokine that plays a major role in inflammation. Activity of the TNF cytokine family could influence progression of colorectal cancer (CRC). The aim of the study was to establish an association between TNF-α promoter variability and stage/grade in individuals with sporadic CRC. The study included 152 CRC patients and 107 healthy volunteers. Four single nucleotide polymorphisms (rs361525, rs1800629, rs1799724, and rs1799964) located at the promoter of TNFA gene were genotyped using commercially available TaqMan allelic discrimination assays by real-time PCR. CRC stage was described on the basis of preoperative imaging studies and postoperative histopathological report. The grade was described on the basis postoperative pathological examination of the specimen. In the case of rs361525, there was a statistically significant association with M-score (p = 0.0209). Rs361525 has significant association with tumour grade (p = 0.0260). We failed to demonstrate significant association between the other 3 SNPs and cancer grade. Rs361525 potentially could be under consideration when the survival rate and prognosis is assessed.

Background: Identification of patients in whom adrenalectomy may be more difficult, can help in decision making in borderline and doubtful cases. The aim of the study was to determine patients criteria influencing difficulty of laparoscopic lateral transperitoneal adrenalectomy (LTA)., Material and Methods: The study enrolled 275 patients who underwent LTA. We analyzed the impact of gender, age, history of previous abdominal surgery, body mass index, risk of anesthesia measured as ASA scale, size, localization (left/right), and histological type of the tumor on parameters reflecting the level of difficulty of the procedure: operative time, intraoperative blood loss, conversion rate and intraoperative complications rate., Results: Multivariate logistic regression showed that following factors were associated with longer operative time: gender, tumor size and malignant lesions. In another model it was shown that age, size of the tumor and malignancy were associated with more excessive blood loss. Moreover, it was shown, that tumor size predictive factor for conversion. Univariate analysis showed a relation with malignancy, but multivariate analysis revealed no significance., Conclusions: Patient age, gender, size and histological type of the tumor are criteria influencing parameters reflecting the level of difficulty. This criteria could be considered as predictors of the difficulty of LTA. Surgery in case of patients with combination of this risk factors should be handled by surgeon with sufficient experience to minimalize the risk of adverse events., (Copyright © 2017 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.)

Objectives: To evaluate the impact of obesity and morbid obesity on short-term outcomes after laparoscopic adrenalectomy., Methods: The study included 520 consecutive patients undergoing laparoscopic adrenalectomy for adrenal tumor. The entire study group was divided depending on the body mass index: group 1 (normal weight), <25 kg/m 2 ; group 2 (overweight), 25-30 kg/m 2 ; and group 3 (obese) 30-40 kg/m 2 . Additionally, group 4 (morbidly obese) was distinguished. Study end-points were: operative time, intraoperative blood loss, total length of hospital stay, morbidity rate and 30-day readmission rate., Results: The mean operative times were 88.8, 94.7, 93.5, and 99.9 min in groups 1, 2, 3 and 4, respectively (P = 0.1444). Complications were comparable between groups (12.8% vs 8.8% vs 8.2% vs 11.5%, P = 0.5295). The mean intraoperative blood loss was 66.8 versus 78.3 versus 60.7 versus 92.4, P = 0.1399. There were no differences in conversion rate between groups., Conclusions: Obesity has no influence on short-term outcomes of laparoscopic transperitoneal adrenalectomy. This procedure is feasible regardless of the body mass index. Therefore, it can be offered to all patient groups including those morbidly obese individuals in whose case preoperative weight loss seems unnecessary., (© 2016 The Japanese Urological Association.)

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.

Background: Laparoscopic adrenalectomy is the gold standard for treatment of benign adrenal lesions. Tumor size is a factor that might influence decision-making concerning the use of laparoscopic approach. The aim of this study was to analyze the results of adrenalectomy for tumors ≥6 cm in diameter., Methods: Two groups of patients were analyzed: first group comprised 441 patients with tumors <6 cm in diameter and second group consisted of 89 patients with tumors ≥6 cm. Both groups were compared with regard to the duration of surgery, intraoperative blood loss, conversion and complications rate., Results: Median duration of surgery in groups 1 and 2 amounted to 86.6 and 111.9 min (p < 0.0001), respectively. Median intraoperative blood loss in groups 1 and 2 was 56.5 and 172.8 ml (p < 0.0001), respectively. There was a linear relationship between tumor size and the duration of surgery, and between tumor size and intraoperative blood loss (p < 0.0001). There were 2 (0.5%) and 6 (6.7%) conversions in groups 1 and 2, respectively. There were 41 (9.3%) and 14 (15.7%) complications in groups 1 and 2 (p = 0.0692), respectively., Conclusions: Laparoscopic adrenalectomy of tumors ≥6 cm is more difficult, but it can be regarded safe and beneficial for patients., (© 2016 S. Karger AG, Basel.)

Background: There is strong evidence for the use of Enhanced Recovery After Surgery (ERAS) protocol with colorectal surgery. However, in most studies on ERAS, patients with stage IV colorectal cancer (CRC) are commonly excluded. It is not certain if the ERAS protocol combined with laparoscopy improves outcomes in this group of patients as well. The aim of the study is to assess the feasibility of the ERAS protocol implementation in patients operated laparoscopically due to stage IV CRC., Methods: A prospective analysis of patients undergoing laparoscopic colorectal surgery was performed. Group 1 included patients with stages I-III, and group 2 included patients with stage IV CRC. Demographic, surgical factors, length of stay (LOS), complications, readmissions, ERAS implementation and early postoperative recovery were compared between the groups., Results: Group 1 included 168 patients, and group 2 included 20 patients. There was no difference in the age, sex, BMI, ASA, cancer localisation or surgical parameters. No statistically significant difference was noted in complications (26.8 vs 20 %, p = 0.51344), LOS (4.7 vs 5.7 days, p = 0.28228) or readmissions (6 vs 10 %, p = 0.48392). The ERAS protocol compliance was 86.3 and 83.0 %, respectively (p = 0.17158)., Conclusions: Implementation of the ERAS protocol and laparoscopic surgery among patients with stage IV CRC is feasible and provides similar short-term clinical outcomes and recovery as with patients with stages I-III.

Enhanced Recovery After Surgery protocol in colorectal surgery allows shortening length of hospital stay and reducing complication rate. Despite the clear guidelines and conclusive evidence their full implementation and putting them into daily practice meets certain difficulties, especially in the early stage. The aim of the study was to analyse the course of implementation of the ERAS protocol into daily practice on the basis of adherence to the protocol. Group included 92 patients (43F/49M) with colorectal cancer submitted to laparoscopic resection during the years 2013-2014. Perioperative care in all of them based on ERAS protocol consisting of 16 items. Its principles and discharge criteria were based on the guidelines of the ERAS Society guidelines. The entire analysed group of patients was divided into 3 subgroups (30 patients) depending on the time from ERAS protocol implementation. We analysed the compliance with the protocol and its influence on length of hospital stay, postoperative complications and readmission rate in different subgroups. The average compliance with the protocol differed significantly between groups and was 65% in group 1, 83.9% in group 2 and 89.6% in group 3. The compliance with subsequent protocol elements was different. The length of stay and complication rate was statistically different in analysed subgroups. The whole group demonstrated an inverse correlation between compliance and length of stay. This analysis leads to the conclusion that the introduction of the ERAS protocol is a gradual process, and its compliance at the level of 80% or more requires at least 30 patients and the period of about 6 months. The initial derogation from the assumed proceedings is inevitable and should not discourage further action. Particular emphasis in the initial stage should be put on continuous training of personnel of all specialties and continuous evaluation of the results., (Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.)

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.

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.

Introduction and Purpose: Morbid obesity together with obesity-related diseases has a negative impact on the quality of life. The aim of the study was to assess the quality of life amongst patients with morbid obesity as well as the impact of bariatric treatment on body weight and obesity-related diseases in addition to conducting an analysis of changes in the quality of life after surgical treatments, in the context of the surgical procedure type and degree of body weight loss., Material and Methods: Sixty-five patients were treated for morbid obesity. The sample group consisted of 34 patients treated with laparoscopic sleeve gastrectomy (LSG) and 31 persons qualified for laparoscopic Roux-en-Y gastric bypass (LRYGB). The average body weight before the procedure was 146.2 kg. In the sample group, 89 % of persons qualified for the surgical treatments were diagnosed with hypertension and 52 % persons that were operated on were diagnosed with diabetes type 2 before the surgical procedure. Before commencement of the surgical treatment, the quality of life was assessed, which in both groups qualified for given types of bariatric procedures was considerably low., Results and Conclusions: Percentage excessive weight loss (%EWL) was 58.8 %. No significant differences in body weight loss were noted between the two types of procedures. Improvement was observed in the treatment of obesity-related diseases. Also, the quality of life was enhanced significantly. No differences were noted in terms of the quality of life improvement between particular types of surgical procedures. No significant differences were observed during the analysis of body weight loss impact on the quality of life improvement.

Background: Laparoscopic adrenalectomy is still controversial in cases where malignancy is suspected. However, many proponents of this technique argue that in the hands of an experienced surgeon, laparoscopy can be safely performed. The aim of this study is to present our own experience with the application of laparoscopic surgery for the treatment of malignant and potentially malignant adrenal tumours., Methods: Our analysis included 52 patients who underwent laparoscopic adrenalectomy in 2003-2014 due to a malignant or potentially malignant adrenal tumour. Inclusion criteria were primary adrenal malignancy, adrenal metastasis or pheochromocytoma with a PASS score greater than 6. We analyzed the conversion rate, intra- and postoperative complications, intraoperative blood loss and R0 resection rate. Survival was estimated using the Kaplan-Meier method., Results: Conversion was necessary in 5 (9.7%) cases. Complications occurred in a total of 6 patients (11.5%). R0 resection was achieved in 41 (78.8%) patients and R1 resection in 9 (17.3%) patients. In 2 (3.9%) cases R2 resection was performed. The mean follow-up time was 32.9 months. Survival depended on the type of tumour and was comparable with survival after open adrenalectomy presented in other studies., Conclusions: We consider that laparoscopic surgery for adrenal malignancy can be an equal alternative to open surgery and in the hand of an experienced surgeon it guarantees the possibility of noninferiority. Additionally, starting a procedure with laparoscopy allows for minimally invasive evaluation of peritoneal cavity. The key element in surgery for any malignancy is not the surgical access itself but the proper technique.

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.

Introduction: Although laparoscopic adrenalectomy is considered relatively safe, the results of treatment vary depending on the profile of the hospital. We would like to present our experience with laparoscopic surgery of the adrenals., Methods: We conducted a retrospective cohort study of consecutive patients operated for adrenal tumours in the years 2003-2014. The study group included 175 (35%) men and 325 (65%) women. The entire group was divided into 4 cohorts of 125 consecutively operated patients. Primary outcomes were operative measures (operative time, its correlation with tumour size, blood loss, conversion rate, use of peritoneal drainage). Secondary outcomes were the intra- and postoperative complications (using the Clavien-Dindo classification), histological type of the tumours and length of hospital stay., Results: There were no differences between groups in terms of the size and location of the tumour. The mean operative time in each group was 85.7; 83.7; 89.6; 104.6 min (p < 0.001). The operative time correlated to the size of the tumour. There were no differences in the conversion rates as well as in the blood loss. However, it was observed that the complication rate was declining in subsequent subgroups (14.4%, 11.2%, 8% and 5.6%, respectively, p = 0.013). Length of hospital stay was 4.9 days, 3.9 days, 2.9 days, 2.4 days, respectively (p < 0.001)., Conclusion: The results of laparoscopic adrenalectomy depend not only on the experience of the single surgeon, but on the whole team involved in perioperative care. In high volume centers with extensive experience in surgery of adrenals, this technique may provide an alternative to open surgery, also in selected cases of malignant tumours., (Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.)

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.

Introduction: The last two decades have observed development of surgical treatment of benign conditions of the gastroesophageal junction (GEJ), including anti-reflux surgery, due to the growing popularity of the laparoscopic approach. Migration of the fundoplication band and recurrent hiatal hernia are a result of the lack of correct diagnosis and appropriate management of the so-called short esophagus. According to various authors, short esophagus is present in up to 60% of patients qualified for anti-reflux surgery. However, some researchers question the existence of this condition., Aim: To analyze the prevalence of short esophagus in patients subjected to laparoscopic Nissen fundoplication., Material and Methods: The study included 202 patients who were subjected to laparoscopic Nissen fundoplication., Results: As many as 96% of the patients qualified for the surgical treatment showed supradiaphragmatic location of the high pressure zone. The extent of GEJ protrusion ranged from 0 cm to 3 cm (mean: 2 cm). The extent of dissection within the mediastinum was determined by the level of GEJ protrusion, and ranged from 5 cm to 12 cm (mean: 6 cm). Upon complete mobilization of the esophagus within the mediastinum, no cases of significantly shortened esophagus, precluding downward retraction of at least a 2.5-cm segment below the diaphragmatic crura, were documented. Therefore, none of the patients required Collis gastroplasty., Conclusions: The presence of "true" short esophagus is a sporadic finding among patients qualified for anti-reflux surgery. Mediastinal dissection of the esophagus and its mobilization at an appropriate, individually defined level seems a sufficient treatment in the vast majority of these patients.

Tumor size smaller than 4 cm as an indication for surgical treatment of incidentaloma is still a subject of discussion. Our aim was the estimation of the incidence of malignancy and analysis of treatment outcomes in patients with incidentaloma smaller than 4 cm in comparison to bigger lesions. 132 patients who underwent laparoscopic adrenalectomy for nonsecreting tumors were divided into two groups: group 1 (55 pts., size < = 40 mm) and group 2 (77 pts., size > 40 mm). Operation parameters and histopathological results were analyzed. No differences in group characteristics, mean operation time, and estimated blood loss were noted. Complications in groups 1 and 2 occurred in 3.6% and 5.2% of patients, respectively (P = 0.67). Malignancy in groups 1 and 2 was present in 1 and 6 patients, respectively (P = 0.13). Potentially malignant lesions were identified in 4 patients in group 1 and 4 patients in group 2 (P = 0.39). The results do not allow for straightforward recommendations for surgical treatment of smaller adrenal tumors. The safety of laparoscopy and minimal, but impossible to omit, risk of malignancy support decisions for surgery. On the other hand, the risk of malignancy in smaller adrenal tumors is lower than surgical complications, which provides an important argument against surgery.

To seek for novel rare and/or sporadic mutations within genomic neighborhood of common -344 C>T (rs2427827) FCER1A proximal promoter polymorphism, which by its prevalence could have masked the presence of less frequent genetic variants in our previous single-stranded conformational polymorphism (SSCP) mutational search study, SSCP screening was repeated using primers fixing -344 C>T variant. The genomic region surrounding -344 C>T polymorphism was confirmed to be fairly conservative and only a single sporadic mutation (present in 1 out of 196 chromosomes), a 6-bp deletion -262 to 257 del CTAGAC, was found. From the methodological point of view, we demonstrated a successful detection of a short-length polymorphism using SSCP screening in a population, in which the same genomic region contained frequent single-nucleotide polymorphic variant. In conjunction with subsequent cloning of aberrantly migrating PCR products and SSCP-driven indirect sequencing of the clones, this method offers a superior (to direct sequencing of PCR products) detection of rare mutations. The cost-effective method applied by us enables a reliable characterization of infrequent (thus present only in heterozygotic form) short-length variance of the sequence which are difficult to interpret by direct sequencing.