Chemical bonding in phase-change chalcogenides.

Almost all phase-change memory materials (PCM) contain chalcogen atoms, and their chemical bonds have been denoted both as 'electron-deficient' [sometimes referred to as 'metavalent'] and 'electron-rich' ['hypervalent', multicentre]. The latter involve lone-pair electrons. We have performed calculations that can discriminate unambiguously between these two classes of bond and have shown that PCM have electron-rich, 3c-4e ('hypervalent') bonds. Plots of charge transferred between (ET) and shared with (ES) neighbouring atoms cannot on their own distinguish between 'metavalent' and 'hypervalent' bonds, both of which involve single-electron bonds. PCM do not exhibit 'metavalent' bonding and are not electron-deficient; the bonding is electron-rich of the 'hypervalent' or multicentre type.

Benchmarking outcomes for distal pancreatectomy: critical evaluation of four multicenter studies.

BACKGROUND: Benchmarking is a validated tool for outcome assessment and international comparison of best achievable surgical outcomes. The methodology is increasingly applied in pancreatic surgery and the aim of the review was to critically compare available benchmark studies evaluating distal pancreatectomy (DP). METHODS: A literature search of English articles reporting on benchmarking DP was conducted of the electronic databases MEDLINE and Web of Science (until April 2023). Studies on open (ODP), laparoscopic (LDP), and robotic DP (RDP) were included. RESULTS: Four retrospective multicenter studies were included. Studies reported on outcomes of minimally invasive DP only (n = 2), ODP and LDP (n = 1), and RDP only (n = 1). Either the Achievable Benchmark of Care™ method or the 75th percentile from the median was selected to define benchmark cutoffs. Robust and reproducible benchmark values were provided by the four studies for intra- and postoperative short-term outcomes. CONCLUSION: Benchmarking DP is a valuable tool for obtaining internationally accepted reference outcomes for open and minimally invasive DP approaches with only minor variances in four international cohorts. Benchmark cutoffs allow for outcome comparisons between institutions, surgeons, and to monitor the introduction of novel minimally invasive DP techniques.

Surgical therapy of celiac axis and superior mesenteric artery syndrome.

INTRODUCTION: Compression syndromes of the celiac artery (CAS) or superior mesenteric artery (SMAS) are rare conditions that are difficult to diagnose; optimal treatment remains complex, and symptoms often persist after surgery. We aim to review the literature on surgical treatment and postoperative outcome in CAS and SMAS syndrome. METHODS: A systematic literature review of medical literature databases on the surgical treatment of CAS and SMAS syndrome was performed from 2000 to 2022. Articles were included according to PROSPERO guidelines. The primary endpoint was the failure-to-treat rate, defined as persistence of symptoms at first follow-up. RESULTS: Twenty-three studies on CAS (n = 548) and 11 on SMAS (n = 168) undergoing surgery were included. Failure-to-treat rate was 28% for CAS and 21% for SMAS. Intraoperative blood loss was 95 ml (0-217) and 31 ml (21-50), respectively, and conversion rate was 4% in CAS patients and 0% for SMAS. Major postoperative morbidity was 2% for each group, and mortality was described in 0% of CAS and 0.4% of SMAS patients. Median length of stay was 3 days (1-12) for CAS and 5 days (1-10) for SMAS patients. Consequently, 47% of CAS and 5% of SMAS patients underwent subsequent interventions for persisting symptoms. CONCLUSION: Failure of surgical treatment was observed in up to every forth patient with a high rate of subsequent interventions. A thorough preoperative work-up with a careful patient selection is of paramount importance. Nevertheless, the surgical procedure was associated with a beneficial risk profile and can be performed minimally invasive.

Learning Curves in Open, Laparoscopic, and Robotic Pancreatic Surgery: A Systematic Review and Proposal of a Standardization.

Objective: To depict and analyze learning curves for open, laparoscopic, and robotic pancreatoduodenectomy (PD) and distal pancreatectomy (DP). Background: Formal training is recommended for safe introduction of pancreatic surgery but definitions of learning curves vary and have not been standardized. Methods: A systematic search on PubMed, Web of Science, and CENTRAL databases identified studies on learning curves in pancreatic surgery. Primary outcome was the number needed to reach the learning curve as defined by the included studies. Secondary outcomes included endpoints defining learning curves, methods of analysis (statistical/arbitrary), and classification of learning phases. Results: Out of 1115 articles, 66 studies with 14,206 patients were included. Thirty-five studies (53%) based the learning curve analysis on statistical calculations. Most often used parameters to define learning curves were operative time (n = 51), blood loss (n = 17), and complications (n = 10). The number of procedures to surpass a first phase of learning curve was 30 (20-50) for open PD, 39 (11-60) for laparoscopic PD, 25 (8-100) for robotic PD (P = 0.521), 16 (3-17) for laparoscopic DP, and 15 (5-37) for robotic DP (P = 0.914). In a three-phase model, intraoperative parameters improved earlier (first to second phase: operating time -15%, blood loss -29%) whereas postoperative parameters improved later (second to third phase: complications -46%, postoperative pancreatic fistula -48%). Studies with higher sample sizes showed higher numbers of procedures needed to overcome the learning curve (rho = 0.64, P < 0.001). Conclusions: This study summarizes learning curves for open-, laparoscopic-, and robotic pancreatic surgery with different definitions, analysis methods, and confounding factors. A standardized reporting of learning curves and definition of phases (competency, proficiency, mastery) is desirable and proposed.

Fit-for-Discharge Criteria after Esophagectomy: An International Expert Delphi Consensus.

There are no internationally recognized criteria available to determine preparedness for hospital discharge after esophagectomy. This study aims to achieve international consensus using Delphi methodology. The expert panel consisted of 40 esophageal surgeons spanning 16 countries and 4 continents. During a 3-round, web-based Delphi process, experts voted for discharge criteria using 5-point Likert scales. Data were analyzed using descriptive statistics. Consensus was reached if agreement was ≥75% in round 3. Consensus was achieved for the following basic criteria: nutritional requirements are met by oral intake of at least liquids with optional supplementary nutrition via jejunal feeding tube. The patient should have passed flatus and does not require oxygen during mobilization or at rest. Central venous catheters should be removed. Adequate analgesia at rest and during mobilization is achieved using both oral opioid and non-opioid analgesics. All vital signs should be normal unless abnormal preoperatively. Inflammatory parameters should be trending down and close to normal (leucocyte count ≤12G/l and C-reactive protein ≤80 mg/dl). This multinational Delphi survey represents the first expert-led process for consensus criteria to determine 'fit-for-discharge' status after esophagectomy. Results of this Delphi survey may be applied to clinical outcomes research as an objective measure of short-term recovery. Furthermore, standardized endpoints identified through this process may be used in clinical practice to guide decisions regarding patient discharge and may help to reduce the risk of premature discharge or prolonged admission.

No radiographic wrist damage after treatment to target in recent-onset juvenile idiopathic arthritis.

BACKGROUND: To evaluate radiographic progression of patients with new-onset juvenile idiopathic arthritis (JIA) in response to an early, tightly-controlled, treatment-to-target. METHODS: Patients with JIA participating in the BeSt-for-Kids-study, randomized to 3 treatment strategy arms, were eligible if at least 1 conventional wrist-radiograph was available. Bone damage as reflected by carpal length was assessed using the Poznanski-score. The BoneXpert-method was used to determine the Bone Age (BA, > 5 years) and bone mineral density (BMD) of the wrist. These scores were evaluated over time and compared between the treatment arms and mean JADAS10-score using linear mixed models corrected for age and symptom duration. RESULTS: In 60 patients, 252 radiographs were analysed. Baseline age and symptom duration were different between the arms. No difference in comparison to the healthy reference population was found at baseline for the Poznanski-score (IQR varying from - 0,82; 0.68), nor for BA (varying from - 0.88 to 0.74). Baseline BMD was statistically significantly lower in arm 3 (initial treatment with etanercept and methotrexate) (- 1.48; - 0.68) compared to arm 1 (- 0.84; - 0.04) and arm 2 (- 0.93; 0.15). After treatment to target inactive disease, the Poznanski-scores and the BA remained clinically unchanged, while the BMD in arm 3 improved (p < 0.05 vs arm 1). CONCLUSIONS: Recent-onset JIA patients, treated-to-target aimed at inactive disease, showed no signs of radiographic wrist damage (Poznanski-score, BA or BMD) either at baseline or at follow-up, irrespective of treatment arm. A lower BMD at baseline in arm 3, initially treated with methotrexate and etanercept, improved significantly after treatment. TRIAL REGISTRATION: NTR, NL1504 (NTR1574). Registered 01-06-2009.

Preemptive endoluminal vacuum therapy to reduce anastomotic leakage after esophagectomy: a game-changing approach?

Endoluminal vacuum therapy (EVT) is an accepted treatment for anastomotic leakage (AL) after esophagectomy. A novel concept is to use this technology in a preemptive setting, with the aim to reduce the AL rate and postoperative morbidity. Preemptive EVT (pEVT) was performed intraoperatively in 19 consecutive patients undergoing minimally invasive esophagectomy, immediately after completion of esophagogastrostomy. Twelve patients (63%) were high-risk cases with severe comorbidity. The EVT device was removed routinely three to six (median 5) days after esophagectomy. The endpoints of this study were AL rate and postoperative morbidity. There were 20 anastomoses at risk in 19 patients. One patient (5.3%) experienced major morbidity (Clavien-Dindo grade IIIb) unrelated to anastomotic healing. He underwent open reanastomosis at postoperative day 12 with pEVT for redundancy of the gastric tube and failure of transition to oral diet. Mortality after 30 days was 0% and anastomotic healing was uneventful in 19/20 anastomoses (95%). One minor contained AL healed after a second course of EVT. Except early proximal dislodgement in one patient, there were no adverse events attributable to pEVT. The median comprehensive complication index 30 days after surgery was 20.9 (IQR 0-26.2). PEVT appears to be a safe procedure that may have the potential to improve surgical outcome in patients undergoing esophagectomy.

Feasibility and effectiveness of laparoscopic transgastric stapler-assisted circumferential esophageal mucosectomy and simultaneous fundoplication in a pig model.

Laparoscopic transgastric stapler-assisted mucosectomy (SAM) has been described for minimally invasive circumferential en bloc resection of Barrett's esophagus (BE). Conceivably long-term disease control might be achieved by adding antireflux surgery after resection of BE by SAM. The aim of this study was to assess the feasibility of combined SAM and fundoplication in one laparoscopic procedure in six pigs. Furthermore, the competence of the gastroesophageal junction (GEJ) was assessed at baseline, after SAM, and after subsequent laparoscopic fundoplication. At each measuring point reflux measurements were repeated 6 times in each pig. Blue-colored water was infused into the stomach to provoke reflux. Intragastric yield pressure and volume were recorded until drainage of blue solution (DBS) was noted. Time to reflux was measured by DBS and by multichannel intraluminal impedance (MII). In all animals SAM followed by laparoscopic fundoplication was feasible in a single session. A weakening of the GEJ was found after SAM, indicated by decreased yield pressure (11.5 mmHg vs. 8.5 mmHg; P < 0.001), time to DBS (90 seconds vs. 60 seconds; P = 0.008) and MII (80 seconds vs. 33 seconds; P < 0.001). After additional Nissen fundoplication the GEJ competence was restored, with measurements returning to baseline values (time to DBS 99 seconds; P = 0.15; MII 76 seconds; P = 0.84). The yield pressure increased from 11.5 mmHg at baseline to 19.7 mmHg after SAM and fundoplication (P < 0.001). Laparoscopic fundoplication and SAM may be combined in a single laparoscopic session. Although the GEJ was weakened after SAM, Nissen fundoplication restored the GEJ as an effective reflux barrier in this experiment. For clinical validation, the results need to be confirmed in a prospective human trial.

LapTrain: multi-modality training curriculum for laparoscopic cholecystectomy-results of a randomized controlled trial.

BACKGROUND: Multiple training modalities for laparoscopy have different advantages, but little research has been conducted on the benefit of a training program that includes multiple different training methods compared to one method only. This study aimed to evaluate benefits of a combined multi-modality training program for surgical residents. METHODS: Laparoscopic cholecystectomy (LC) was performed on a porcine liver as the pre-test. Randomization was stratified for experience to the multi-modality Training group (12 h of training on Virtual Reality (VR) and box trainer) or Control group (no training). The post-test consisted of a VR LC and porcine LC. Performance was rated with the Global Operative Assessment of Laparoscopic Skills (GOALS) score by blinded experts. RESULTS: Training (n = 33) and Control (n = 31) were similar in the pre-test (GOALS: 13.7 ± 3.4 vs. 14.7 ± 2.6; p = 0.198; operation time 57.0 ± 18.1 vs. 63.4 ± 17.5 min; p = 0.191). In the post-test porcine LC, Training had improved GOALS scores (+ 2.84 ± 2.85 points, p < 0.001), while Control did not (+ 0.55 ± 2.34 points, p = 0.154). Operation time in the post-test was shorter for Training vs. Control (40.0 ± 17.0 vs. 55.0 ± 22.2 min; p = 0.012). Junior residents improved GOALS scores to the level of senior residents (pre-test: 13.7 ± 2.7 vs. 18.3 ± 2.9; p = 0.010; post-test: 15.5 ± 3.4 vs. 18.8 ± 3.8; p = 0.120) but senior residents remained faster (50.1 ± 20.6 vs. 25.0 ± 1.9 min; p < 0.001). No differences were found between groups on the post-test VR trainer. CONCLUSIONS: Structured multi-modality training is beneficial for novices to improve basics and overcome the initial learning curve in laparoscopy as well as to decrease operation time for LCs in different stages of experience. Future studies should evaluate multi-modality training in comparison with single modalities. TRIAL REGISTRATION: German Clinical Trials Register DRKS00011040.

Surgery is essential in squamous cell cancer of the rectum.

PURPOSE: Squamous cell cancer (SCC) is a rare histological subtype of rectal cancer. It is unclear whether SCC should be treated by multimodal therapy, including surgery, or by chemoradiation alone. The objective of the study was to define an optimal treatment strategy. METHODS: Patients with rectal cancer and SCC histology were identified in the Surveillance Epidemiology and End Results Database between 1990 and 2013. According to treatment, three groups were defined: radiotherapy and surgery (RT/SX), radiotherapy (RT), and surgery (SX). Overall survival (OS) and disease-specific survival (DSS) for localized, regional, and distant disease were assessed using a multivariable Cox regression model. RESULTS: Out of 856,435 colorectal cancer patients, 1747 with SCC of the rectum were eligible. Four hundred and fifty-five were treated with RT/SX, 994 with RT, and 298 with SX. Adjusted hazard ratios (HR) did not differ for OS and DSS in localized disease. In regional disease, OS and DSS were improved for RT/SX compared to RT (HR 0.751, 95% CI 0.566-0.997, P = 0.048 and HR 0.679, 95% CI 0.478-0.966, P = 0.031). In distant disease, OS and DSS were not different. CONCLUSIONS: Multimodal therapy including surgery improved OS and DSS compared to receiving a treatment without surgery for regional disease in rectal SCC. No difference was observed in localized and distant disease. The findings contradict with recent reports favoring definitive chemoradiation.

Meta-analysis of hybrid natural-orifice transluminal endoscopic surgery versus laparoscopic surgery.

BACKGROUND: Hybrid natural-orifice transluminal endoscopic surgery (NOTES), combining access through a natural orifice with small-sized abdominal trocars, aims to reduce pain and enhance recovery. The objective of this systematic review and meta-analysis was to compare pain and morbidity in hybrid NOTES and standard laparoscopy. METHODS: A systematic literature search was performed to identify RCTs and non-RCTs comparing hybrid NOTES and standard laparoscopy. The main outcome was pain on postoperative day (POD) 1. Secondary outcomes were pain during the further postsurgical course, rescue analgesia, complications, and satisfaction with the cosmetic result. The results of meta-analysis in a random-effects model were presented as odds ratio (ORs) or standard mean differences (MDs) with 95 per cent confidence intervals. RESULTS: Six RCTs and 21 non-randomized trials including 2186 patients were identified. In hybrid NOTES the score on the numerical pain scale was lower on POD 1 (-0·75, 95 per cent c.i. -1·09 to -0·42; P = 0·001) and on POD 2-4 (-0·58, -0·91 to -0·26; P < 0·001) than that for standard laparoscopy. The need for rescue analgesia was reduced in hybrid NOTES (OR 0·36, 0·24 to 0·54; P < 0·001). The reduction in complications found for hybrid NOTES compared with standard laparoscopy (OR 0·52, 0·38 to 0·71; P < 0·001) was not significant when only RCTs were considered (OR 0·83, 0·43 to 1·60; P = 0·570). The score for cosmetic satisfaction was higher after NOTES (MD 1·14, 0·57 to 1·71; P < 0·001). CONCLUSION: Hybrid NOTES reduces postoperative pain and is associated with greater cosmetic satisfaction in selected patients.

[The way from cost approval to bariatric surgery : Analysis of resource utilization in a maximum care hospital]. / Vom Antrag auf Kostengutsprache bis zur bariatrischen Operation : Personelle Ressourcenanalyse an einem Zentrum der Maximalversorgung.

BACKGROUND: Morbid obesity is a medical and economic challenge. Patients who have the indications for bariatric surgery face a long way from the first visit until surgery and a high utilization of resources is required. OBJECTIVES: The present study aimed to evaluate labor costs and labor time required to supervise obese patients from their first visit until preparation of a bariatric report to ask for cost acceptance of bariatric surgery from their health insurance. In addition, the reasons for not receiving bariatric surgery after receiving cost acceptance from the health insurance were evaluated. MATERIAL AND METHODS: Patients who had indications for bariatric surgery according to the S3 guidelines between 2012 and 2013, were evaluated regarding labor costs and labor time of the process from the first visit until receiving cost acceptance from their health insurance. Furthermore, body mass index (BMI), age, sex, Edmonton Obesity Staging System (EOSS) stage and comorbidities were evaluated. Patients who had not received surgery up to December 2015 were contacted via telephone to ask for the reasons. RESULTS: In the present study 176 patients were evaluated (110 females, 62.5%). Until preparation of a bariatric report the patients required an average of 2.7 combined visits in the department of surgery with the department of nutrition, 1.7 visits in the department of psychosomatic medicine, 1.5 separate visits in the department of nutrition and 1.4 visits in the department of internal medicine. Average labor costs from the first visit until the bariatric survey were 404.90 ± 117.00 euros and 130 out of 176 bariatric reports were accepted by the health insurance (73.8%). For another 40 patients a second bariatric survey was made and 20 of these (50%) were accepted, which results in a total acceptance rate of 85.2% (150 out of 176). After a mean follow-up of 2.8 ± 1.1 years only 93 out of 176 patients had received bariatric surgery (53.8%). Of these 16 had received acceptance of surgery by their health insurance only after a second bariatric survey. CONCLUSION: A large amount of labor and financial resources are required for treatment of obese patients from first presentation up to bariatric surgery. The cost-benefit calculation of an obesity center needs to include that approximately one half of the patients do not receive surgery within more than 2.5 years.

A comparison of three treatment strategies in recent onset non-systemic Juvenile Idiopathic Arthritis: initial 3-months results of the BeSt for Kids-study.

BACKGROUND: Combination therapy with prednisone or etanercept may induce earlier and/or more improvement in disease activity in Disease Modifying Anti Rheumatic Drug (DMARD) naïve non-systemic Juvenile Idiopathic Arthritis (JIA) patients. Here we present three months clinical outcome of initial treatments of the BeSt-for-Kids study. METHODS: Included patients were randomized to either: 1. initial DMARD-monotherapy (sulfasalazine (SSZ) or methotrexate (MTX)), 2. Initial MTX / prednisolone-bridging, 3. Initial combination MTX/etanercept. Percentage inactive disease, adjusted (a) ACR Pedi30, 50 and 70 and JADAS after 6 and 12 weeks of treatment (intention to treat analysis) and side effects are reported. RESULTS: 94 patients (67% girls, 32 (arm 1), 32 (arm 2) and 30 (arm 3) with median (InterQuartileRange) age of 9.1 (4.7-12.9) years were included. 38% were ANA positive, 10 had oligo-articular disease, 68 polyarticular JIA and 16 psoriatic arthritis. Baseline median (IQR) ACRpedi-scores: VAS physician 49 (40-58) mm, VAS patient 54 (37-70) mm, ESR 6.5 (2-14.8)mm/hr, active joint count 8 (5-12), limited joint count 3 (1-5), CHAQ score 0.88 (0.63-1.5). In arm 1, 17 started with MTX, 15 with SSZ. After 3 months, aACR Pedi 50 was reached by 10/32 (31%), 12/32(38%) and 16/30 (53%) (p = 0.19) and aACR Pedi 70 was reached by 8/32 (25%), 6/32(19%) and 14/30(47%) in arms 1-3 (p = 0.04). Toxicity was similar. Few serious adverse events were reported. CONCLUSION: After 3 months of treatment in a randomized trial, patients with recent-onset JIA achieved significantly more clinical improvement (aACRPedi70) on initial combination therapy with MTX / etanercept than on initial MTX or SSZ monotherapy. TRIAL REGISTRATION: NTR1574 . Registered 3 December 2008.

Overlap between linear scleroderma, progressive facial hemiatrophy and immune-inflammatory encephalitis in a paediatric cohort.

Linear scleroderma en coup the sabre (LSCS), progressive facial hemiatrophy (PFH) and autoimmune encephalitis are distinct clinical entities, although patients with overlapping features have been reported. We performed a multicenter retrospective review of a series of children with LSCS and/or PFH to explore the relation between these entities. The files of 16 children were reviewed, 11 presented with LSCS, 5 with PFH, with time overlapping cutaneous features were seen. Extracutaneous signs were found in both groups. ANA were present in more than 50 % of patients. Almost half of our patients presented with CNS manifestations comprising unilateral headache, migraine and epilepsy with or without abnormalities on MRI. Brain biopsy in one patient was consistent with Rasmussen encephalitis. In two other children, associated autoimmune manifestations were present. CONCLUSION: Our patient cohort brings more arguments to consider LSCS and PFH as a single disease entity with LSCS and superficial skin involvement at one end of the spectrum and PFH with involvement of subcutaneous deep tissue at the other end. In both entities, encephalitis can be observed. Our findings of circulating ANA, intradermal lymphocytes and IgG, intrathecal IgG production and clinical improvement with immunosuppressive therapy endorse the concept of a possible common immune-inflammatory pathogenesis. WHAT IS KNOWN: • LSCS, PFH and immune-inflammatory encephalitis are distinct clinical entities, but patients with overlapping features have been reported. WHAT IS NEW: • We present a unique paediatric cohort with LSCS, PFH and/or encephalitis. • We endorse the concept of a common immune-inflammatory disease process.

Axillary and rectal temperature measurements poorly agree in newborn infants.

AIM: Evaluation of the agreement between axillary temperature measurements and rectal temperature measurements in neonates. METHODS: Rectal and axillary body temperatures were simultaneously measured for 3 min in 33 neonates (gestational age 25-42 weeks, weight 840-4,005 g). Two investigators performed paired measurements, one in each neonate. A single type of thermometer was used in this study: one thermometer for each rectal and another thermometer for each axillary measurement. The Bland-Altman method was used (95% 'limits of agreement': mean +/- 2 SD) to determine the level of agreement between axillary and rectal measurements. RESULTS: The axillary temperature was significantly lower than the rectal temperature (mean +/- SD 0.27 +/- 0.20 degrees C, p < 0.05). The '95% limits of agreement' ranged from -0.13 to +0.67 degrees C. Increasing postnatal age (days) showed a significant increase in temperature difference (rectal minus axillary; r = 0.54; p < 0.05). CONCLUSIONS: The mean difference between axillary and rectal temperature shows a wide variation. Axillary temperature measurements cannot be used interchangeably with rectal measurements in neonates.