Pathophysiology of Demineralization, Part I: Attrition, Erosion, Abfraction, and Noncarious Cervical Lesions.

PURPOSE OF THE REVIEW: Compare pathophysiology for infectious and noninfectious demineralization disease relative to mineral maintenance, physiologic fluoride levels, and mechanical degradation. RECENT FINDINGS: Environmental acidity, biomechanics, and intercrystalline percolation of endemic fluoride regulate resistance to demineralization relative to osteopenia, noncarious cervical lesions, and dental caries. Demineralization is the most prevalent chronic disease in the world: osteoporosis (OP) >10%, dental caries ~100%. OP is severely debilitating while caries is potentially fatal. Mineralized tissues have a common physiology: cell-mediated apposition, protein matrix, fluid logistics (blood, saliva), intercrystalline ion percolation, cyclic demineralization/remineralization, and acid-based degradation (microbes, clastic cells). Etiology of demineralization involves fluid percolation, metabolism, homeostasis, biomechanics, mechanical wear (attrition or abrasion), and biofilm-related infections. Bone mineral density measurement assesses skeletal mass. Attrition, abrasion, erosion, and abfraction are diagnosed visually, but invisible subsurface caries <400µm cannot be detected. Controlling demineralization at all levels is an important horizon for cost-effective wellness worldwide.

Pathophysiology of Demineralization, Part II: Enamel White Spots, Cavitated Caries, and Bone Infection.

PURPOSE OF REVIEW: Compare noninfectious (part I) to infectious (part II) demineralization of bones and teeth. Evaluate similarities and differences in the expression of hard tissue degradation for the two most common chronic demineralization diseases: osteoporosis and dental caries. RECENT FINDINGS: The physiology of demineralization is similar for the sterile skeleton compared to the septic dentition. Superimposing the pathologic variable of infection reveals a unique pathophysiology for dental caries. Mineralized tissues are compromised by microdamage, demineralization, and infection. Osseous tissues remodel (turnover) to maintain structural integrity, but the heavily loaded dentition does not turnover so it is ultimately at risk of collapse. A carious tooth is a potential vector for periapical infection that may be life-threatening. Insipient caries is initiated as a subsurface decalcification in enamel that is not detectable until a depth of ~400µm when it becomes visible as a white spot. Reliable detection and remineralization of invisible caries would advance cost-effective wellness worldwide.

The Effect of Postoperative Complications After Minimally Invasive Esophagectomy on Long-term Survival: An International Multicenter Cohort Study.

BACKGROUND: Esophagectomy is a technically challenging procedure, associated with significant morbidity. The introduction of minimally invasive esophagectomy (MIE) has reduced postoperative morbidity. OBJECTIVE: Although the short-term effect on complications is increasingly being recognized, the impact on long-term survival remains unclear. This study aims to investigate the association between postoperative complications following MIE and long-term survival. METHODS: Data were collected from the EsoBenchmark Collaborative composed by 13 high-volume, expert centers routinely performing MIE. Patients operated between June 1, 2011 and May 31, 2016 were included. Complications were graded using the Clavien-Dindo (CD) classification. To correct for short-term effects of postoperative complications on mortality, patients who died within 90 days postoperative were excluded. Primary endpoint was 5-year overall survival. RESULTS: A total of 915 patients were included with a mean follow-up time of 30.8 months (standard deviation 17.9). Complications occurred in 542 patients (59.2%) of which 50.2% had a CD grade ≥III complication [ie, (re)intervention, organ dysfunction, or death]. The incidence of anastomotic leakage (AL) was 135 of 915 patients (14.8%) of which 84 patients were classified as a CD grade ≥III. Multivariable analysis showed a significantly deteriorated long-term survival in all patients with AL [hazard ratio (HR) 1.68, 95% confidence interval (CI) 1.25-2.24]. This inverse relation was most distinct when AL was scored as a CD grade ≥III (HR 1.83, 95% CI 1.30-2.58). For all other complications, no significant association with long-term survival was found. CONCLUSION: The occurrence and severity of AL, but not overall complications, after MIE negatively affect long-term survival of esophageal cancer patients.

Role of intravoxel incoherent motion parameters in gastroesophageal cancer: relationship with 18F-FDG-positron emission tomography, computed tomography perfusion and magnetic resonance perfusion imaging parameters.

BACKGROUND: Identification of pretherapeutic predictive markers in gastro-esophageal cancer is essential for individual-oriented treatment. This study evaluated the relationship of multimodality parameters derived from intravoxel incoherent motion method (IVIM), 18F-FDG-positron emission tomography (PET), computed tomography (CT) perfusion and dynamic contrast enhanced magnetic resonance imaging (MRI) in patients with gastro-esophageal cancer and investigated their histopathological correlation. METHODS: Thirty-one consecutive patients (28 males; median age 63.9 years; range 37-84 years) with gastro-esophageal adenocarcinoma (N.=22) and esophageal squamous cell carcinoma (N.=9) were analyzed. IVIM parameters: pseudodiffusion (D*), perfusion fraction (fp), true diffusion (D) and the threshold b-value (bval); PET-parameters: SUVmax, metabolic tumor volume (MTV) and total lesion glycolysis (TLG); CT perfusion parameters: blood flow (BF), blood volume (BV) and mean transit time (MTT); and MR perfusion parameters: time to enhance, positive enhancement integral, time-to-peak (TTP), maximum-slope-of-increase, and maximum-slope-of-decrease were determined, and correlated to each other and to histopathology. RESULTS: IVIM and PET parameters showed significant negative correlations: MTV and bval (rs =-0.643, P=0.002), TLG and bval (rs=-0.699, P<0.01) and TLG and fp (rs=-0.577, P=0.006). Positive correlation was found for TLG and D (rs=0.705, P=0.000). Negative correlation was found for bval and staging (rs=0.590, P=0.005). Positive correlation was found for positive enhancement interval and BV (rs=0.547, P=0.007), BF and regression index (rs=0.753, P=0.005) and for time-to-peak and staging (rs=0.557, P=0.005). CONCLUSIONS: IVIM parameters (bval, fp, D) provide quantitative information and correlate with PET parameters (MTV, TLG) and staging. IVIM might be a useful tool for additional characterization of gastro-esophageal cancer.

Technique of open and minimally invasive intrathoracic reconstruction following esophagectomy-an expert consensus based on a modified Delphi process.

BACKGROUND: In recent years, minimally invasive Ivor Lewis (IL) esophagectomy with high intrathoracic anastomosis has emerged as surgical standard of care for esophageal cancer in expert centers. Alongside this process, many divergent technical aspects of this procedure have been devised in different centers. This study aims at achieving international consensus on the surgical steps of IL reconstruction using Delphi methodology. METHODS: The expert panel consisted of specialized esophageal surgeons from 8 European countries. During a two-round Delphi process, a detailed analysis and consensus on key steps of intrathoracic gastric tube reconstruction (IL esophagectomy) was performed. RESULTS: Response rates in Delphi rounds 1 and 2 were 100% (22 of 22 experts) and 83.3% (20 of 24 experts), respectively. Three essential technical areas of intrathoracic gastric tube reconstruction were identified: first, vascularization of the gastric conduit, second, gastric mobilization, tube formation and pull-up, and third, anastomotic technique. In addition, 3 main techniques for minimally invasive intrathoracic anastomosis are currently practiced: (i) end-to-side circular stapled, (ii) end-to-side double stapling, and (iii) side-to-side linear stapled technique. The step-by-step procedural analysis unveiled common approaches but also different expert practice. CONCLUSION: This precise technical description may serve as a clinical guideline for intrathoracic reconstruction after esophagectomy. In addition, the results may aid to harmonize the technical evolution of this complex surgical procedure and thereby facilitate surgical training.

Incidence and Grading of Complications After Gastrectomy for Cancer Using the GASTRODATA Registry: A European Retrospective Observational Study.

OBJECTIVE: Utilizing a standardized dataset based on a newly developed list of 27 univocally defined complications, this study analyzed data to assess the incidence and grading of complications and evaluate outcomes associated with gastrectomy for cancer in Europe. SUMMARY BACKGROUND DATA: The absence of a standardized system for recording gastrectomy-associated complications makes it difficult to compare results from different hospitals and countries. METHODS: Using a secure online platform (www.gastrodata.org), referral centers for gastric cancer in 11 European countries belonging to the Gastrectomy Complications Consensus Group recorded clinical, oncological, and surgical data, and outcome measures at hospital discharge and at 30 and 90 days postoperatively. This retrospective observational study included all consecutive resections over a 2-year period. RESULTS: A total of 1349 gastrectomies performed between January 2017 and December 2018 were entered into the database. Neoadjuvant chemotherapy was administered to 577 patients (42.8%). Total (46.1%) and subtotal (46.4%) gastrectomy were the predominant resections. D2 or D2+ lymphadenectomy was performed in almost 80% of operations. The overall complications' incidence was 29.8%; 402 patients developed 625 complications, with the most frequent being nonsurgical infections (23%), anastomotic leak (9.8%), other postoperative abnormal fluid from drainage and/or abdominal collections (9.3%), pleural effusion (8.3%), postoperative bleeding (5.6%), and other major complications requiring invasive treatment (5.6%). The median Clavien-Dindo score and Comprehensive Complications Index were IIIa and 26.2, respectively. In-hospital, 30-day, and 90-day mortality were 3.2%, 3.6%, and 4.5%, respectively. CONCLUSIONS: The use of a standardized platform to collect European data on perioperative complications revealed that gastrectomy for gastric cancer is still associated with heavy morbidity and mortality. Actions are needed to limit the incidence of, and to effectively treat, the most frequent and most lethal complications.

Three-dimensional condylar changes from Herbst appliance and multibracket treatment: A comparison with matched Class II elastics.

INTRODUCTION: The purpose of this study was to quantify and qualify the 3-dimensional (3D) condylar changes using mandibular 3D regional superimposition techniques in adolescent patients with Class II Division 1 malocclusions treated with either a 2-phase or single-phase approach. METHODS: Twenty patients with Herbst appliances who met the inclusion criteria and had cone-beam computed tomography (CBCT) images taken before, 8 weeks after Herbst removal, and after the completion of multibracket appliance treatment constituted the Herbst group. They were compared with 11 subjects with Class II malocclusion who were treated with elastics and multibracket appliances and who had CBCT images taken before and after treatment. Three-dimensional models generated from the CBCT images were registered on the mandible using 3D voxel-based superimposition techniques and analyzed using semitransparent overlays and point-to-point measurements. RESULTS: The magnitude of lateral condylar growth during the orthodontic phase (T2-T3) was greater than that during the orthopedic phase (T1-T2) for all condylar fiducials with the exception of the superior condyle (P <0.05). Conversely, posterior condylar growth was greater during the orthopedic phase than the subsequent orthodontic phase for all condylar fiducials (P <0.05). The magnitude of vertical condylar development was similar during both the orthopedic (T1-T2) and orthodontic phases (T2-T3) across all condylar fiducials (P <0.05). Posterior condylar growth during the orthodontic phase (T2-T3) of the 2-phase approach decreased for all condylar fiducials with the exception of the posterior condylar fiducial (P <0.05) when compared with the single-phase approach. CONCLUSIONS: Two-phase treatment using a Herbst appliance accelerates condylar growth when compared with a single-phase regime with Class II elastics. Whereas the posterior condylar growth manifested primarily during the orthopedic phase, the vertical condylar gains occurred in equal magnitude throughout both phases of the 2-phase treatment regime.

Anastomotic Techniques and Associated Morbidity in Total Minimally Invasive Transthoracic Esophagectomy: Results From the EsoBenchmark Database.

OBJECTIVE: The aim of this study was to describe anastomotic techniques used for total minimally invasive transthoracic esophagectomy (ttMIE) and to analyze the associated morbidity. BACKGROUND: ttMIE faces increasing application in surgical treatment of esophageal cancer. For esophagogastric reconstruction, different anastomotic techniques are currently used, but their effect on postoperative anastomotic leakage and morbidity has not been investigated. PATIENTS AND METHODS: Patients were selected from a basic dataset, collected during a 5-year period from 13 international surgical high-volume centers. Endpoints were anastomotic leakage rate and postoperative morbidity in correlation to anastomotic techniques, measured by the Clavien-Dindo classification and the Comprehensive Complication Index (CCI). RESULTS: Five anastomotic techniques were identified in 966 patients after ttMIE: intrathoracic end-to-side circular-stapled technique in 427 patients (double-stapling n = 90, purse-string n = 337), intrathoracic (n = 109) or cervical (n = 255) side-to-side linear-stapled, and cervical end-to-side hand-sewn (n = 175). Leakage rates were similar in intrathoracic and cervical anastomoses (15.9% vs 17.2%, P = 0.601), but overall complications (56.7%% vs 63.7%, P = 0.029) and median 90-day CCI {21 [interquartile range (IQR) 0-36] vs 29 [IQR 0-40], P = 0.019} favored intrathoracic reconstructions. Leakage rates after intrathoracic end-to-side double-stapling (23.3%) and cervical end-to-side hand-sewn (25.1%) techniques were significantly higher compared with intrathoracic side-to-side linear (15.6%), end-to-side purse-string (13.9%), and cervical side-to-side linear-stapled esophagogastrostomies (11.8%) (P < 0.001). Multivariable analysis confirmed anastomotic technique as independent predictor of leakage after ttMIE. CONCLUSION: Results of this analysis present the current status of the technical evolution of ttMIE with anastomotic leakage as predominant surgical complication. However, technique-related morbidity requires cautious interpretation considering the long learning curve of this complex surgical procedure.

Distribution of lymph node metastases in esophageal carcinoma [TIGER study]: study protocol of a multinational observational study.

BACKGROUND: An important parameter for survival in patients with esophageal carcinoma is lymph node status. The distribution of lymph node metastases depends on tumor characteristics such as tumor location, histology, invasion depth, and on neoadjuvant treatment. The exact distribution is unknown. Neoadjuvant treatment and surgical strategy depends on the distribution pattern of nodal metastases but consensus on the extent of lymphadenectomy has not been reached. The aim of this study is to determine the distribution of lymph node metastases in patients with resectable esophageal or gastro-esophageal junction carcinoma in whom a transthoracic esophagectomy with a 2- or 3-field lymphadenectomy is performed. This can be the foundation for a uniform worldwide staging system and establishment of the optimal surgical strategy for esophageal cancer patients. METHODS: The TIGER study is an international observational cohort study with 50 participating centers. Patients with a resectable esophageal or gastro-esophageal junction carcinoma in whom a transthoracic esophagectomy with a 2- or 3-field lymphadenectomy is performed in participating centers will be included. All lymph node stations will be excised and separately individually analyzed by pathological examination. The aim is to include 5000 patients. The primary endpoint is the distribution of lymph node metastases in esophageal and esophago-gastric junction carcinoma specimens following transthoracic esophagectomy with at least 2-field lymphadenectomy in relation to tumor histology, tumor location, invasion depth, number of lymph nodes and lymph node metastases, pre-operative diagnostics, neo-adjuvant therapy and (disease free) survival. DISCUSSION: The TIGER study will provide a roadmap of the location of lymph node metastases in relation to tumor histology, tumor location, invasion depth, number of lymph nodes and lymph node metastases, pre-operative diagnostics, neo-adjuvant therapy and survival. Patient-tailored treatment can be developed based on these results, such as the optimal radiation field and extent of lymphadenectomy based on the primary tumor characteristics. TRIAL REGISTRATION: NCT03222895 , date of registration: July 19th, 2017.

International consensus on a complications list after gastrectomy for cancer.

BACKGROUND: Perioperative complications can affect outcomes after gastrectomy for cancer, with high mortality and morbidity rates ranging between 10 and 40%. The absence of a standardized system for recording complications generates wide variation in evaluating their impacts on outcomes and hinders proposals of quality-improvement projects. The aim of this study was to provide a list of defined gastrectomy complications approved through international consensus. METHODS: The Gastrectomy Complications Consensus Group consists of 34 European gastric cancer experts who are members of the International Gastric Cancer Association. A group meeting established the work plan for study implementation through Delphi surveys. A consensus was reached regarding a set of standardized methods to define gastrectomy complications. RESULTS: A standardized list of 27 defined complications (grouped into 3 intraoperative, 14 postoperative general, and 10 postoperative surgical complications) was created to provide a simple but accurate template for recording individual gastrectomy complications. A consensus was reached for both the list of complications that should be considered major adverse events after gastrectomy for cancer and their specific definitions. The study group also agreed that an assessment of each surgical case should be completed at patient discharge and 90 days postoperatively using a Complication Recording Sheet. CONCLUSION: The list of defined complications (soon to be validated in an international multicenter study) and the ongoing development of an electronic datasheet app to record them provide the basic infrastructure to reach the ultimate goals of standardized international data collection, establishment of benchmark results, and fostering of quality-improvement projects.

18FDG-PET-CT identifies histopathological non-responders after neoadjuvant chemotherapy in locally advanced gastric and cardia cancer: cohort study.

BACKGROUND: Pathologic response to neoadjuvant chemotherapy (neoCTX) is a prognostic factor in many cancer types, and early prediction would help to modify treatment. In patients with gastric and esophagogastric junction (AEG) cancer, the accuracy of FDG PET-CT to predict early pathologic response after neoadjuvant chemotherapy (neoCTX) is currently not known. METHODS: From a consecutive cohort of 72 patients, 44 patients with resectable, locally-advanced gastric cancer or AEG Siewert type II and III received neoCTX after primary staging with endoscopic ultrasound, PET-CT and laparoscopy. Overall, 14 patients did not show FDG uptake, and the remaining 30 were restaged by PET-CT 14 days after the first cycle of neoCTX. Metabolic response was defined as decrease of tumor standardized uptake value (SUV) by ≥35%. Major pathologic regression was defined as less than 10% residual tumor cells. RESULTS: Metabolic response after neoCTX was detected in 20/30 (66.7%), and non-response in 10/30 (33.3%) patients. Among metabolic responders, n = 10 (50%) showed major and n = 10 (50%) minor pathologic regression. In non-responders, n = 9 (90%) had minor and 1 (10%) a major pathologic regression. This resulted in a sensitivity of 90.9%, specificity 47.3%, positive predictive value 50%, negative predictive value 90% and accuracy of 63.3%. CONCLUSION: Response PET-CT after the first cycle of neoCTX does not accurately predict overall pathologic response. However, PET-CT reliably detects non-responders, and identifies patients who should either immediately proceed to resection or receive a modified multimodality therapy. TRIAL REGISTRATION: The trial was registered and approved by local ethics committee PB_2016-00769.

Stent-over-sponge (SOS): a novel technique complementing endosponge therapy for foregut leaks and perforations.

BACKGROUND AND STUDY AIMS: Endoluminal vacuum therapy (EVT) has evolved as a promising option for endoscopic treatment of foregut wall injuries in addition to the classic closure techniques using clips or stents. To improve vacuum force and maintain esophageal passage, we combined endosponge treatment with a partially covered self-expandable metal stent (stent-over-sponge; SOS). PATIENTS AND METHODS: Twelve patients with infected upper gastrointestinal wall defects were treated with the SOS technique. RESULTS: Indications for SOS were anastomotic leakage after surgery (n = 11) and chronic foregut fistula (n = 1). SOS treatment was used as a first-line treatment in seven patients with a success rate of 71.4 % (5/7) and as a second-line treatment after failed previous EVT treatment in five patients (success rate 80 %; 4/5). Overall, SOS treatment was successful in 75 % of patients (9/12). No severe adverse events occurred. CONCLUSION : SOS is an effective method to treat severely infected foregut wall defects in patients where EVT has failed, and also as a first-line treatment. Comparative prospective studies are needed to confirm our preliminary results.

WITHDRAWN: Evaluation of multifunctional imaging parameters in gastro-oesophageal cancer using F-18-FDG-PET/CT with integrated perfusion CT.

Ahead of Print article withdrawn by publisher.

Endemic Molar Incisor Hypomineralization: a Pandemic Problem That Requires Monitoring by the Entire Health Care Community.

PURPOSE OF REVIEW: This review brings a major, previously under-recognized dental and general health problem to the attention of the medical and scientific community. The goals are to help clinicians make early diagnoses, thereby improving treatment outcomes, and to stimulate increasing research efforts to understand the etiology and ultimately prevention. RECENT FINDINGS: There are two recent systematic reviews of molar incisor hypomineralization (MIH). One reveals the global burden of the condition; mean global prevalence is 13% with 878 million people affected, with 4.8 million cases per year requiring treatment. The review into etiology found a lack of definitive knowledge, but that it is likely to be multifactorial, with childhood illness including fever possibly implicated. The review presents details of MIH sufficient to enable clinicians to recognize it and understand its impact on affected children, its management, and the importance of early intervention. Much further research is needed.

Three-dimensional treatment outcomes in Class II patients with different vertical facial patterns treated with the Herbst appliance.

INTRODUCTION: The aims of this study were to evaluate, using 3-dimensional superimposition techniques, the skeletal changes in Class II subjects with different vertical facial patterns treated with the Herbst appliance and to compare these skeletal changes to those of Class II controls treated with elastics. METHODS: Sixteen Herbst patients who met the inclusion criteria were divided into 2 equal groups based on vertical facial pattern as determined by the Frankfort mandibular plane angle (brachyfacial, ≤22°; mesofacial, 23°-29°) and had cone-beam computed tomographs taken before treatment, 8 weeks after Herbst appliance removal, and after subsequent fixed appliance treatment. Eleven Class II control patients treated with fixed appliances and elastics had cone-beam computed tomographs taken before and after treatment. Three-dimensional models were generated from the cone-beam computed tomography images, registered on the anterior cranial bases, and analyzed using color maps and point-to-point measurements. RESULTS: There were minimal differences in treatment response between the 2 Herbst groups across all skeletal parameters measured. The Herbst subjects showed a greater inferior displacement of anterior nasal spine compared with the Class II controls (Herbst brachyfacial, -1.44 mm; Herbst mesofacial, -1.95 mm) with other maxillary changes being clinically insignificant. The Herbst subjects showed greater inferior displacement of B-point compared with the Class II controls (Herbst brachyfacial, -2.59 mm; Herbst mesofacial, -2.75 mm). There were no statistically significant differences in mean linear mandibular measurements. All groups showed a trend toward posterior displacement of the condyles and glenoid fossae from the start to the end of treatment, with no significant differences across the 3 groups. There were minimal differences in the changes in gonial angle and Frankfort mandibular plane angle across all groups. CONCLUSION: Approximately 2 years after Herbst treatment, the Herbst subjects with different vertical facial patterns showed similar patterns of skeletal change compared with the Class II controls treated with elastics.

A cephalometric study of the skeletal and dento-alveolar effects of the modified Louisiana State University activator in Class II malocclusion.

Objectives: To analyse the skeletal and dento-alveolar effects of the modified Louisiana State University activator (MLSUA) in Class II treatment. Materials and methods: A test group of 46 participants (25 females, 21 males) with Class II malocclusion treated with MLSUA followed by fixed appliances was compared with a matched Class II control group. Lateral cephalograms were taken at T1 (initial records), T2 (completion of MLSUA treatment), and T3 (before deband). The participants were also divided into two groups: pre-pubertal and pubertal according to skeletal maturity and three groups of different vertical facial patterns at the start of the treatment: brachyfacial, mesofacial, and dolichofacial. Statistical comparisons were performed with t-tests and analysis of variance (ANOVA). Results: Statistically significant supplementary mandibular growth (Co-Gn) in the test group (2.6 mm) was associated with improvement of overjet (OJ), overbite (OB), and molar relationship. Short-term mandibular growth was greater in pubertal than pre-pubertal groups (2.4 mm, P < 0.05). Mandibular incisors retroclined by 2.1 degrees after MLSUA treatment. The brachyfacial group showed greater reduction in the ANB angle and forward movement of pogonion. Mandibular, palatal, and occlusal plane angles showed insignificant change regardless of the facial type. Conclusions: MLSUA treatment corrected the Class II malocclusion by accelerating mandibular growth in the short-term with minimal dento-alveolar compensation, and the correction was maintained before deband. The treatment may be more effective if started at puberty. The mandibular, palatal, and occlusal planes remained stable throughout the treatment. Brachyfacial patients showed more favourable horizontal growth.

Defining Benchmarks for Transthoracic Esophagectomy: A Multicenter Analysis of Total Minimally Invasive Esophagectomy in Low Risk Patients.

OBJECTIVE: To define "best possible" outcomes in total minimally invasive transthoracic esophagectomy (ttMIE). BACKGROUND: TtMIE, performed by experts in patients with low comorbidity, may serve as a benchmark procedure for esophagectomy. PATIENTS AND METHODS: From a cohort of 1057 ttMIE, performed over a 5-year period in 13 high-volume centers for esophageal surgery, we selected a study group of 334 patients (31.6%) that fulfilled criteria of low comorbidity (American Society of Anesthesiologists score ≤2, WHO/ECOG score ≤1, age ≤65 years, body mass index 19-29 kg/m). Endpoints included postoperative morbidity measured by the Clavien-Dindo classification and the comprehensive complication index. Benchmark values were defined as the 75th percentile of the median outcome parameters of the participating centers to represent best achievable results. RESULTS: Benchmark patients were predominantly male (82.9%) with a median age of 58 years (53-62). High intrathoracic (Ivor Lewis) and cervical esophagogastrostomy (McKeown) were performed in 188 (56.3%) and 146 (43.7%) patients, respectively. Median (IQR) ICU and hospital stay was 0 (0-2) and 12 (9-18) days, respectively. 56.0% of patients developed at least 1 complication, and 26.9% experienced major morbidity (≥grade III), mostly related to pulmonary complications (25.7%), anastomotic leakage (15.9%), and cardiac events (13.5%). Benchmark values at 30 days after hospital discharge were ≤55.7% and ≤30.8% for overall and major complications, ≤18.0% for readmission, ≤3.1% for positive resection margins, and ≥23 for lymph node yield. Benchmarks at 30 and 90 days were ≤1.0% and ≤4.6% for mortality, and ≤40.8 and ≤42.8 for the comprehensive complication index, respectively. CONCLUSION: This outcome analysis of patients with low comorbidity undergoing ttMIE may serve as a reference to evaluate surgical performance in major esophageal resection.

Quantitative analysis of enamel on debonded orthodontic brackets.

INTRODUCTION: Iatrogenic damage to the tooth surface in the form of enamel tearouts can occur during removal of fixed orthodontic appliances. The aim of this study was to assess debonded metal and ceramic brackets attached with a variety of bonding materials to determine how frequently this type of damage occurs. METHODS: Eighty-one patients close to finishing fixed orthodontic treatment were recruited. They had metal brackets bonded with composite resin and a 2-step etch-and-bond technique or ceramic brackets bonded with composite resin and a 2-step etch-and- bond technique, and composite resin with a self-etching primer or resin-modified glass ionomer cement. Debonded brackets were examined by backscattered scanning electron microscopy with energy dispersive x-ray spectroscopy to determine the presence and area of enamel on the base pad. RESULTS: Of the 486 brackets collected, 26.1% exhibited enamel on the bonding material on the bracket base pad. The incidences of enamel tearouts for each group were metal brackets, 13.3%; ceramic brackets, 30.2%; composite resin with self-etching primer, 38.2%; and resin-modified glass ionomer cement, 21.2%. The percentage of the bracket base pad covered in enamel was highly variable, ranging from 0% to 46.1%. CONCLUSIONS: Enamel damage regularly occurred during the debonding process with the degree of damage being highly variable. Damage occurred more frequently when ceramic brackets were used (31.9%) compared with metal brackets (13.3%). Removal of ceramic brackets bonded with resin-modified glass ionomer cement resulted in less damage compared with the resin bonding systems.

Protocol requirements and diagnostic value of PET/MR imaging for liver metastasis detection.

PURPOSE: To compare the accuracy of PET/MR imaging with that of FDG PET/CT and to determine the MR sequences necessary for the detection of liver metastasis using a trimodality PET/CT/MR set-up. METHODS: Included in this single-centre IRB-approved study were 55 patients (22 women, age 61 ± 11 years) with suspected liver metastases from gastrointestinal cancer. Imaging using a trimodality PET/CT/MR set-up (time-of-flight PET/CT and 3-T whole-body MR imager) comprised PET, low-dose CT, contrast-enhanced (CE) CT of the abdomen, and MR with T1-W/T2-W, diffusion-weighted (DWI), and dynamic CE imaging. Two readers evaluated the following image sets for liver metastasis: PET/CT (set A), PET/CECT (B), PET/MR including T1-W/T2-W (C), T1-W/T2-W with either DWI (D) or CE imaging (E), and a combination (F). The accuracy of each image set was determined by receiver-operating characteristic analysis using image set B as the standard of reference. RESULTS: Of 120 liver lesions in 21/55 patients (38%), 79 (66%) were considered malignant, and 63/79 (80%) showed abnormal FDG uptake. Accuracies were 0.937 (95% CI 89.5 - 97.9%) for image set A, 1.00 (95% CI 99.9 - 100.0%) for set C, 0.998 (95% CI 99.4 - 100.0%) for set D, 0.997 (95% CI 99.3 - 100.0%) for set E, and 0.995 (95% CI 99.0 - 100.0%) for set F. Differences were significant for image sets D - F (P < 0.05) when including lesions without abnormal FDG uptake. As shown by follow-up imaging after 50 - 177 days, the use of image sets D and both sets E and F led to the detection of metastases in one and three patients, respectively, and further metastases in the contralateral lobe in two patients negative on PET/CECT (P = 0.06). CONCLUSION: PET/MR imaging with T1-W/T2-W sequences results in similar diagnostic accuracy for the detection of liver metastases to PET/CECT. To significantly improve the characterization of liver lesions, we recommend the use of dynamic CE imaging sequences. PET/MR imaging has a diagnostic impact on clinical decision making.

International External Validation of Risk Prediction Model of 90-Day Mortality after Gastrectomy for Cancer Using Machine Learning.

BACKGROUND: Radical gastrectomy remains the main treatment for gastric cancer, despite its high mortality. A clinical predictive model of 90-day mortality (90DM) risk after gastric cancer surgery based on the Spanish EURECCA registry database was developed using a matching learning algorithm. We performed an external validation of this model based on data from an international multicenter cohort of patients. METHODS: A cohort of patients from the European GASTRODATA database was selected. Demographic, clinical, and treatment variables in the original and validation cohorts were compared. The performance of the model was evaluated using the area under the curve (AUC) for a random forest model. RESULTS: The validation cohort included 2546 patients from 24 European hospitals. The advanced clinical T- and N-category, neoadjuvant therapy, open procedures, total gastrectomy rates, and mean volume of the centers were significantly higher in the validation cohort. The 90DM rate was also higher in the validation cohort (5.6%) vs. the original cohort (3.7%). The AUC in the validation model was 0.716. CONCLUSION: The externally validated model for predicting the 90DM risk in gastric cancer patients undergoing gastrectomy with curative intent continues to be as useful as the original model in clinical practice.