Preoperative Identification Of High-risk Patients Research Articles

Development of postoperative delirium prediction models in patients undergoing cardiovascular surgery using machine learning algorithms

Associations between delirium and postoperative adverse events in cardiovascular surgery have been reported and the preoperative identification of high-risk patients of delirium is needed to implement focused interventions. We aimed to develop and validate machine learning models to predict post-cardiovascular surgery delirium. Patients aged ≥ 40 years who underwent cardiovascular surgery at a single hospital were prospectively enrolled. Preoperative and intraoperative factors were assessed. Each patient was evaluated for postoperative delirium 7 days after surgery. We developed machine learning models using the Bernoulli naive Bayes, Support vector machine, Random forest, Extra-trees, and XGBoost algorithms. Stratified fivefold cross-validation was performed for each developed model. Of the 87 patients, 24 (27.6%) developed postoperative delirium. Age, use of psychotropic drugs, cognitive function (Mini-Cog < 4), index of activities of daily living (Barthel Index < 100), history of stroke or cerebral hemorrhage, and eGFR (estimated glomerular filtration rate) < 60 were selected to develop delirium prediction models. The Extra-trees model had the best area under the receiver operating characteristic curve (0.76 [standard deviation 0.11]; sensitivity: 0.63; specificity: 0.78). XGBoost showed the highest sensitivity (AUROC, 0.75 [0.07]; sensitivity: 0.67; specificity: 0.79). Machine learning algorithms could predict post-cardiovascular delirium using preoperative data.Trial registration: UMIN-CTR (ID; UMIN000049390).

Preoperative risk assessment for postoperative pancreatic fistula (POPF): Image-based calculation of duct-to-parenchyma (D/P) ratio and an Alignment of Duct and Mucosa (ADAM) anastomosis may lead to a low POPF rate-results from 386 patients.

Postoperative pancreatic fistula (POPF) is the most critical complication after pancreatoduodenectomy (PD). Preoperative identification of high-risk patients and optimal pancreatic reconstruction technique can be a way to reduce postoperative complications. A series of 386 patients underwent PD over a 10-year period (2009-2019). On routinely performed preoperative computed tomography (CT) images, the ventro-dorsal diameters of duct (D) and parenchyma (P) were measured in the cutting plane at the superior mesenteric vein. Then, the ratio of both values was calculated (D/P ratio) Double-layer pancreatojejunostomy with alignment of duct and mucosa (ADAM) by two monofilament threads (MFT) was performed in 359 patients and pancreatogastrostomy (PG) in 27 patients. The incidence of POPF was diagnosed according to the International Study Group for Pancreatic Fistula criteria. The overall rate of POPF was 21% (n = 80), and the rate of clinically relevant type B/C fistulas 6.5% (n = 25). A D/P ratio of <0.2 was significantly associated with type B/C fistula (11%, p < 0.01). In low-risk patients (D/P ratio >0.2), type B/C fistula occurred only in 2%, and in high-risk patients (D/P ratio <0.2) in 9%. ADAM anastomosis was performed safely by two different surgeons. A PG anastomosis had double-digit POPF rates in all groups. Preoperative CT imaging with D/P measurement may predict the risk of POPF development. A cut off D/P ratio of <0.2 was significantly associated with clinical relevant POPF. ADAM anastomosis may be an option for pancreatojejunostomy. However, preoperative knowledge of the D/P ratio could guide decision-making for primary pancreatectomy when pancreatic reconstruction is critical.

Mesenteric occlusive disease of the inferior mesenteric artery is associated with anastomotic leak after left-sided colon and rectal cancer surgery: a retrospective cohort study

PurposeAnastomotic leak (AL) is a serious complication following colorectal surgery. Atherosclerosis causes inadequate anastomotic perfusion and is suggested to be a risk factor for AL. The aim of this study was to investigate the association of mesenteric occlusive disease on preoperative computed tomography (CT) scan with AL after left-sided colon or rectal cancer surgery.MethodsThis was a retrospective, multicenter cohort study including 1273 patients that underwent left-sided or rectal cancer resection between 2009 and 2018 from three hospitals in the Netherlands. AL patients were 1:1 matched with non-leak patients and preoperative contrast-enhanced CT-scans were retrospectively analyzed for mesenteric atherosclerotic lesions. The main outcome measure was the presence of mesenteric occlusive disease on the preoperative CT-scan.ResultsAnastomotic leak developed in 6% of 1273 patients (N = 76). Low anterior resection and stage I–III disease were statistically significant associated with AL (p = 0.01, p = 0.04). No other statistically significant differences in patient characteristics between AL and non-leak patients were found. A clinically significant stenosis (≥ 70–100%) of the inferior mesenteric artery was statistically significant more frequent present in AL patients, compared to non-leak patients (p < 0.01). No statistically significant differences in the presence of mesenteric occlusive disease of the celiac artery and superior mesenteric artery between AL patients and non-leak patients were found.ConclusionMesenteric occlusive disease of the IMA on preoperative CT-scan is associated with AL after left-sided colon or rectal resection for cancer. Preoperative identification of high-risk patients with a preoperative CT-scan of the mesenteric vasculature might be useful to reduce the risk of AL.

Influence of diabetes on short-term outcome after major hepatectomy: an underestimated risk?

BackgroundPatient-related risk factors such as diabetes mellitus and obesity are increasing in western countries. At the same time the indications for liver resection in both benign and malignant diseases have been significantly extended in recent years. Major liver resection is performed more frequently in a patient population of old age, comorbidity and high rates of neoadjuvant chemotherapy. The aim of this study was to evaluate whether diabetes mellitus, obesity and overweight are risk factors for the short-term post-operative outcome after major liver resection.MethodsFour hundred seventeen major liver resections (≥ 3 segments) were selected from a prospective database. Exclusion criteria were prior liver resection in patient’s history and synchronous major intra-abdominal procedures. Overweight was defined as BMI ≥ 25 kg/m2 and < 30 kg/m2 and obesity as BMI ≥ 30 kg/m2. Primary end point was 90-day mortality and logistic regression was used for multivariate analysis. Secondary end points included morbidity, complications according to Clavien–Dindo classification, unplanned readmission, bile leakage, and liver failure. Morbidity was defined as occurrence of a post-operative complication during hospital stay or within 90 days postoperatively.ResultsFifty-nine patients had diabetes mellitus (14.1%), 48 were obese (11.6%) and 147 were overweight (35.5%). There were no statistically significant differences in mortality rates between the groups. In the multivariate analysis, diabetes was an independent predictor of morbidity (OR = 2.44, p = 0.02), Clavien–Dindo grade IV complications (OR = 3.6, p = 0.004), unplanned readmission (OR = 2.44, p = 0.04) and bile leakage (OR = 2.06, p = 0.046). Obese and overweight patients did not have an impaired post-operative outcome compared patients with normal weight.ConclusionsDiabetes has direct influence on the short-term postoperative outcome with an increased risk of morbidity but not mortality. Preoperative identification of high-risk patients will potentially decrease complication rates and allow for individual patient counseling as part of a shared decision-making process. For obese and overweight patients, major liver resection is a safe procedure.

Association Among Preoperative Cognitive Performance, Regional Cerebral Oxygen Saturation, and Postoperative Delirium in Older Portuguese Patients.

Postoperative delirium is common among older patients and preoperative identification of high-risk patients is widely recommended. The aim of this study was to assess whether preoperative cognitive performance using brief screening tools or regional cerebral oxygen saturation (Scto2) was associated with the development of postoperative delirium in older Portuguese patients undergoing elective surgery. Prospective observational cohort study where preoperative cognitive screening tools (Mini-Cog, Mini-Mental State Examination, verbal fluency) and Scto2 (INVOS 5100C; Medtronic, Ireland) were assessed in 238 patients ≥65 years old undergoing elective surgery between July 2017 and May 2019 at a tertiary academic center in Portugal. The primary outcome was postoperative delirium detected by the 3D-Confusion Assessment Method. Data were analyzed by univariate analysis and multivariable logistic regression. Delirium was identified in 53 patients (22%); 162 patients (68%) had completed only 4 years of education. On multivariable analysis, probable cognitive impairment tested by the Mini-Cog (odds ratio [OR] = 1.57; 95% confidence interval [CI], 0.70-3.53; corrected P value >.999), by the Mini-Mental State Examination (OR = 2.75; 95% CI, 1.23-6.13; corrected P value = .052), and by the animal verbal fluency test (OR = 1.24; 95% CI, 0.49-3.16; corrected P value >.999) were not significantly associated with the development of postoperative delirium. In contrast, lower preoperative Scto2 (OR = 1.08; 95% CI, 1.02-1.14; corrected P value = .024 for each point decrease in Scto2) was associated with postoperative delirium. We did not find enough evidence to suggest that poor preoperative cognitive performance was significantly associated with the development of postoperative delirium in an older Portuguese surgical population with an overall low level of formal education, but rather that preoperative Scto2 may be helpful in identifying patients at risk for delirium.

207. Postmenopausal women presenting for spinal fusion surgery have abnormal microarchitecture despite normal DXA

BACKGROUND CONTEXT More than 400,000 spinal fusion surgeries are performed annually in the US, with related health care costs exceeding $287 billion. As spinal fusion involves extensive instrumentation of the vertebrae, patients with skeletal abnormalities may be at increased risk for complications. However, preoperative identification of high-risk patients remains a challenge. Due to skeletal effects of aging and estrogen deficiency, postmenopausal (PM) women may be at particular risk. Dual energy x-ray absorptiometry (DXA) measurements of areal BMD are subject to artifact in patients with spinal pathology, and may be limited as screening tests. PURPOSE This prospective study investigated skeletal health in postmenopausal women having lumbar spine fusion and matched controls using DXA and high resolution peripheral QCT (HRpQCT) measurements of volumetric BMD (vBMD) and microarchitecture. We aimed to determine if HRpQCT would reveal additional abnormalities in vBMD and microarchitecture in fusion patients compared to DXA. STUDY DESIGN/SETTING Prospective, single center study. PATIENT SAMPLE A total of 60 patients were included in this study. PM women undergoing lumbar fusion were prospectively enrolled and compared to PM controls. OUTCOME MEASURES HRpQCT measurements of cortical and trabecular vBMD and microarchitecture, DXA, age and BMI. METHODS PM women undergoing lumbar fusion (n=20) were matched 1:2 by age with PM controls (n=40) who had no history of spine surgery or secondary osteoporosis. Subjects had assessments by standard DXA and high resolution peripheral QCT (HRpQCT) to measure cortical (Ct) and trabecular (Tb) vBMD and microarchitecture of the distal radius and tibia. RESULTS Mean age of subjects was 66+/-6 years, BMI (28+/-6 kg/m2) without any significant differences between groups. By DXA, T-scores in fusion patients were normal at the lumbar spine (mean 0.0) and osteopenic at the total hip (-1.2), femoral neck (-1.5) and 1/3 radius (-1.5). T- Scores did not differ significantly from controls at any site. In contrast, HRpQCT revealed low vBMD (total, Ct, Tb) in fusion patients compared to controls at both radius and tibia, with total vBMD 21-30% lower, Ct density ∼7% and Tb density ∼25% lower. Fusion patients had microarchitectural abnormalities, significantly fewer, thinner and more widely spaced trabeculae. Specifically, Tb number was 9% lower, Tb thickness 6% lower, and Tb separation 23% greater at the radius with similar differences at the tibia. CONCLUSIONS In summary, PM women presenting for spine fusion surgery had low volumetric BMD and abnormal trabecular microarchitecture, despite DXA values that were normal or slightly low. Our results suggest that additional techniques may be necessary for detection of bone quality deficits in patients presenting for spinal fusion. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Independent Risk Factors for Impaired Early Outcome after Isolated Ankle Fracture - A Multivariate Analysis and Prognostic Models.

Ankle fractures are common operative indications in orthopedic surgery. Their incidence is increasing. To identify independent risk factors and to develop prognostic models for the prediction of prolonged length of hospital stay (LOS) and the onset of postoperative complications. This is a single-center, retrospective, observational study analyzing data of 154 consecutive, isolated, surgically treated ankle fractures. Multivariate binary logistic regression analysis was applied to identify significant independent risk factors. The validity and clinical applicability of the developed prognostic models was assessed with ROC-curve analysis (ROC: Receiver Operating Characteristic). Internal validation of prognostic models was performed with randomized backwards bootstrapping. The median LOS was 7 days. 50 patients (33%) had a longer LOS. 13% of operated patients had a postoperative complication (n = 20). Independent preoperative risk factors for prolonged length of stay were leukocytosis (p = 0.020; OR: 1.211), an increased CRP-level (p = 0.005; OR: 1.901), as well as a bi- (p = 0.002; OR: 15.197) or trimalleolar (p = 0.001; OR: 10.678) fracture type. Immediate operative therapy was an independent beneficial factor (p < 0.001; OR: 0.070). The onset of complications was associated significantly with diabetes mellitus (p = 0.004; OR: 9.903) and an elevated ASA score (p = 0,004; OR: 3.574). The developed prognostic models for the prediction of prolonged LOS (AUROC: 0.736) and postoperative complications (AUROC: 0.724) had a good clinical validity and were internally validated. The current data pronounce the importance of preoperative laboratory works. Furthermore, co-morbidities play a major role in the prognosis of outcome. The developed prognostic models are able to reliably predict the outcome and enable the preoperative identification of high-risk patients.

Asparaginase-like protein 1 expression in curettage independently predicts lymph node metastasis in endometrial carcinoma: a multicentre study.

Correct preoperative identification of high-risk patients is important to optimise surgical treatment and improve survival. We wanted to explore if asparaginase-like protein 1 (ASRGL1) expression in curettage could predict lymph node metastases and poor outcome, potentially improving preoperative risk stratification. Multicentre study. Ten hospitals in Norway, Sweden and Belgium. Women diagnosed with endometrial carcinoma. ASRGL1 expression in curettage specimens from 1144 women was determined by immunohistochemistry. ASRGL1 status related to disease-specific survival, lymph node status, preoperative imaging parameters and clinicopathological data. ASRGL1 expression had independent prognostic value in multivariate survival analyses, both in the whole patient population (hazard ratio (HR) 1.63, 95% CI 1.11-2.37, P=0.012) and in the low-risk curettage histology subgroup (HR 2.54, 95% CI 1.44-4.47, P=0.001). Lymph node metastases were more frequent in women with low expression of ASRGL1 compared with women with high ASRGL1 levels (23% versus 10%, P<0.001), and low ASRGL1 level was found to independently predict lymph node metastases (odds ratio 2.07, 95% CI 1.27-3.38, P=0.003). Low expression of ASRGL1 in curettage independently predicts lymph node metastases and poor disease-specific survival. Low ASRGL1 expression in curettage predicts lymph node metastasis and poor survival in endometrial carcinoma.

Frailty, Aging, and Cardiovascular Surgery.

Older adults make up an ever-increasing number of patients presenting for surgery, and a significant percentage of these patients will be frail. Frailty is a geriatric syndrome that has been conceptualized as decreased reserve when confronted with stressors, although the precise definition of frailty has not been easy to standardize. The 2 most popular approaches to define frailty are the phenotypic approach and the deficit accumulation approach, although at least 20 tools have been developed, which has made comparison across studies difficult. In epidemiologic studies, baseline frailty has been associated with poor outcomes in both community cohorts and hospitalized patients. Specifically in cardiac surgery (including transcatheter aortic valve implantation procedures), frailty has been strongly associated with postoperative mortality and morbidity, and thus frailty likely improves the identification of high-risk patients beyond known risk scores. For perioperative physicians then, the question arises of how to incorporate this information into perioperative care. To date, 2 thrusts of research and clinical practice have emerged: (1) preoperative identification of high-risk patients to guide both patient expectations and surgical decision-making; and (2) perioperative optimization strategies for frail patients. However, despite the strong association of frailty and poor outcomes, there is a lack of well-designed trials that have examined perioperative interventions with a specific focus on frail patients undergoing cardiac surgery. Thus, in many cases, principles of geriatric care may need to be applied. Further research is needed to standardize and implement the feasible definitions of frailty and examine perioperative interventions for frail patients undergoing cardiac surgery.

The Association Between Preoperative Frailty and Postoperative Delirium After Cardiac Surgery.

Delirium is common after cardiac surgery, and preoperative identification of high-risk patients could guide prevention strategies. We prospectively measured frailty in 55 patients before cardiac surgery and assessed postoperative delirium using a validated chart review. The prevalence of frailty was 30.9%. Frail patients had a higher incidence of delirium (47.1%) compared with nonfrail patients (2.6%; P < 0.001). In multivariable models, the relative risk of delirium was ≥2.1-fold greater in frail compared with nonfrail patients (relative risk, 18.3; 95% confidence interval, 2.1-161.8; P = 0.009). Frailty may identify patients who would benefit from delirium-prevention strategies because of increased baseline risk for delirium.

Hypoalbuminemia More Than Morbid Obesity is an Independent Predictor of Complications After Total Hip Arthroplasty

Health care reform is directing clinical practice towards improving outcomes and minimizing complications. Preoperative identification of high-risk patients and modifiable risk factors present opportunity for clinical research. A total of 49,475 total hip arthroplasty patients were identified from National Surgical Quality Improvement Program between 2006 and 2013. We compared morbidly obese patients (BMI≥40kg/m2) and non-morbidly obese patients (BMI 18.5–40kg/m2). We also compared patients with hypoalbuminemia (serum albumin <3.5g/dL) against those with normal albumin. Our study demonstrates that hypoalbuminemia is a significant risk factor for mortality and major morbidity among total hip arthroplasty patients, while morbid obesity was only associated with an increased risk of superficial surgical site infection. Impressively, hypoalbuminemia patients carried a 5.94-fold risk of 30-day mortality.

Metabolic Tumor Volume on 18F-FDG PET/CT Improves Preoperative Identification of High-Risk Endometrial Carcinoma Patients.

Our objective was to prospectively explore the diagnostic value of (18)F-FDG PET/CT for preoperative staging in endometrial carcinomas and to investigate whether (18)F-FDG PET-specific quantitative tumor parameters reflect clinical and histologic characteristics. Preoperative (18)F-FDG PET/CT was prospectively performed on 129 consecutive endometrial carcinoma patients. Two physicians who did not know the clinical findings or staging results independently reviewed the images, assessing primary tumor, cervical stroma involvement and metastatic spread, and determining maximum and mean standardized uptake value (SUVmax and SUVmean, respectively) for tumor, metabolic tumor volume (MTV), and total lesion glycolysis (TLG). All parameters were analyzed in relation to histomorphologic and clinical tumor characteristics. Receiver-operating-characteristic curves for identification of deep myometrial invasion and lymph node metastases were generated, and MTV cutoffs for predicting deep myometrial invasion and lymph node metastases were calculated. The sensitivity, specificity, and accuracy of (18)F-FDG PET/CT for the detection of lymph node metastases were 77%-85%, 91%-96%, and 89%-93%, respectively. SUVmax, SUVmean, MTV, and TLG were significantly related to deep myometrial invasion, presence of lymph node metastases, and high histologic grade (P < 0.015 for all) and independently predicted deep myometrial invasion (P < 0.015) and lymph node metastases (P < 0.025) after adjustment for preoperative histologic risk (based on subtype and grade) in endometrial biopsies. Optimal cutoffs for MTV in predicting deep myometrial invasion (20 mL) and the presence of lymph node metastases (30 mL) yielded odds ratios of 7.8 (P < 0.001) and 16.5 (P = 0.001), respectively. (18)F-FDG PET/CT represents a clinically valuable tool for preoperatively evaluating the presence of lymph node metastases in endometrial carcinoma patients. Applying MTV cutoffs for the prediction of deep myometrial invasion and lymph node metastases may increase diagnostic accuracy and aid preoperative identification of high-risk patients, enabling restriction of lymphadenectomy for patients with a low risk of aggressive disease.

Tumour apparent diffusion coefficient is associated with depth of myometrial invasion and is negatively correlated to tumour volume in endometrial carcinomas

To explore possible correlations between tumour apparent diffusion coefficient (ADC), morphological tumour volume, and clinical and histological characteristics in endometrial carcinomas and to evaluate interobserver agreement for preoperative staging by MRI and for ADC measurements. Preoperative conventional MRI including diffusion-weighted imaging (DWI) was performed in 105 endometrial carcinoma patients. Three radiologists independently reviewed the images for the presence of deep myometrial invasion, cervical stromal invasion, and lymph node metastases, and measured tumour ADC in regions of interest (ROIs). ADC values were analysed in relation to histomorphological characteristics and tumour volume. Kappa coefficients (κ) and intraclass correlation coefficients (ICC) for interobserver agreement for MRI staging results and ADC measurements, respectively, were calculated, and receiver operating characteristic (ROC) curves for identification of deep of myometrial invasion were generated. Mean tumour ADC was significantly lower in tumours with deep myometrial invasion (ADC = 0.75 × 10(-3) mm(2)/s) compared to tumours with superficial or no myometrial invasion (ADC = 0.85 × 10(-3) mm(2)/s; p < 0.001). ADC was negatively correlated to tumour size (p = 0.007). The interobserver agreement was fair (κ = 0.32) for depth of myometrial invasion, good for cervical stromal invasion (κ = 0.66), and moderate for lymph node metastases (κ = 0.54), and the interobserver variability for ADC value measurements was low (ICC = 0.60). Tumour ADC measurements may in the future provide an adjunct tool, aiding in the preoperative identification of high-risk patients with deep myometrial infiltration.

Preoperative Pancreatic Resection (PREPARE) score: a prospective multicenter-based morbidity risk score.

Development of a simple preoperative risk score to predict morbidity related to pancreatic surgery. Pancreatic surgery is standardized with little technical diversity among institutions and unchanging morbidity and mortality rates in recent years. Preoperative identification of high-risk patients is potentially one of the rare avenues for improving the clinical course of patients undergoing pancreatic surgery. Using a prospectively collected multicenter database of patients undergoing pancreatic surgery (n=703), surgical complications were classified according to the Clavien-Dindo classification. A new scoring system for preoperative identification of high-risk patients that included only objective preoperatively assessable variables was developed using a multivariate regression model. Subsequently, this scoring system was prospectively validated from 2011 to 2013 (n=429) in a multicenter setting. Eight independent preoperatively assessable variables were identified and included in the scoring system: systolic blood pressure, heart rate, hemoglobin level, albumin level, ASA (American Society of Anesthesiologists) score, surgical procedure, elective surgery or not, and disease of pancreatic origin or not. On the basis of 3 subgroups (low risk, intermediate risk, high risk), the proposed scoring system reached an accuracy of 75% for correctly predicting occurrence or nonoccurrence of major surgical complications in 80% of all analyzed patients within the validation cohort (c-statistic index=0.709, P<0.001, 95% confidence interval=0.657-0.760). We present an easily applied scoring system with convincing accuracy for identifying low-risk and high-risk patients. In contrast to other systems, the score is exclusively based on objective preoperatively assessable characteristics and can be rapidly and easily calculated.

"Molecular profiling and ways towards personalized medicine in advanced differentiated thyroid cancer".

The increasing incidence of thyroid nodules and cancer is associated with a higher demand for the diagnosis of thyroid nod-ules, and the treatment of this aggressive disease. Molecular biology in the last decades has given important contributions in the understanding of the pathogenesis of thyroid cancer, and it is successfully used for the diagnosis of thyroid nodules. An important diagnostic impact can be achieved by testing fine needle aspiration samples, from thyroid nodules, for a panel of mutations that typically includes BRAF, RAS, RET/PTC, and PAX8/PPARg. The use of these and other emerging molecular markers is expected to improve significantly the accuracy of cancer diagnosis in thyroid nodules, overall in those with undeterminate cytology (Thyr 3). With this aim many researches evaluated (by new promising techniques) proteomics, and metabolomics of fine needle aspiration. Mortality rates from thyroid cancer mainly depend on its aggressiveness. Geno- and pheno-typing of aggressive thyroid cancer has advanced our understanding of treatment failures and of potential future therapies. Unraveling molecular signaling pathways of thyroid cancer including its aggressive forms will hopefully pave the road to reduce mortality but also morbidity from this cancer. Reliable pre-operative identification of high-risk patients may productively guide the initial surgical management since re-operative neck surgery is associated with increased morbidity. Pre-operative knowledge of mutations typically associated with thyroid cancer could alter the initial surgical treatment for at least 20% of patients and can potentially prevent the increased morbidity associated with reoperative neck exploration. Despite the generally good prognosis of differentiated thyroid carcinoma (DTC), about 5% of patients will develop metastases which fail to respond to radioactive iodine (RaI), and other traditional therapies, exhibiting a more aggressive behavior. The advent of low-cost individual genomic analysis provides hope that we are entering a new era of personalized, patient-specific care. The recent advances in the pathogenesis of these diseases have revealed key targets (BRAF, RAS, RET, VEGFR, EGFR, etc.) that are now being evaluated in the clinical setting. The lack of effective therapies for DTC, resistant to radioiodine and traditional therapies, is now being overcome by the development of targeted novel compounds that have been demonstrated to induce clinical responses and stabilization of the disease. Interestingly, the most promising responses have been reported in patients treated with antiangiogenic inhibitors such as vandetanib and XL184 in medullary thyroid cancer, and sorafenib in papillary and follicular DTC. However, the increasing complexity of the diagnostic and therapeutic tools for thyroid cancer needs, more and more, effort to personalize the diagnosis and the treatment, to reach the maximum success, avoiding unnecessary and potentially harmful treatments. The aim of this Mini-Thematic Issue was to present and to discuss the most recent advancements to personalize the diagnosis and the treatment of thyroid nodules and cancer.

Rectal cancer staging: focus on the prognostic significance of the findings described by high-resolution magnetic resonance imaging.

High-resolution (HR) magnetic resonance imaging (MRI) has become an indispensable tool for multidisciplinary teams (MDTs) addressing rectal cancer. It provides anatomic information for surgical planning and allows patients to be stratified into different groups according to the risk of local and distant recurrence. One of the objectives of the MDT is the preoperative identification of high-risk patients who will benefit from neoadjuvant treatment. For this reason, the correct evaluation of the circumferential resection margin (CRM), the depth of tumor spread beyond the muscularis propria, extramural vascular invasion and nodal status is of the utmost importance. Low rectal tumors represent a special challenge for the MDT, because decisions seek a balance between oncologic safety, in the pursuit of free resection margins, and the patient’s quality of life, in order to preserve sphincter function. At present, the exchange of information between the different specialties involved in dealing with patients with rectal cancer can rank the contribution of colleagues, auditing their work and incorporating knowledge that will lead to a better understanding of the pathology. Thus, beyond the anatomic description of the images, the radiologist’s role in the MDT makes it necessary to know the prognostic value of the findings that we describe, in terms of recurrence and survival, because these findings affect decision making and, therefore, the patients’ life. In this review, the usefulness of HR MRI in the initial staging of rectal cancer and in the evaluation of neoadjuvant treatment, with a focus on the prognostic value of the findings, is described as well as the contribution of HR MRI in assessing patients with suspected or confirmed recurrence of rectal cancer.

Systematic Review of Obesity Surgery Mortality Risk Score—Preoperative Risk Stratification in Bariatric Surgery

Bariatric surgery is the best long term treatment for morbid obesity. However, it carries risks of considerable morbidity and potential mortality. There is no published review on pre-operative identification of high-risk patients in bariatric surgery. This systematic review analyses obesity surgery mortality risk score (OS-MRS) as a tool for pre-operative prediction of mortality risk in bariatric surgery. Medline and Embase was systematically searched using the medical subjects headings (MeSH) terms 'bariatric surgery' and 'mortality' with further free text search and cross references. Studies that described OS-MRS to predict mortality risk after bariatric surgery were included in this review. Six studies evaluated 9,382 patients to assess the validity of OS-MRS to predict the mortality risk after bariatric surgery. Patient's age ranged from 19 to 67 years, and the body mass index ranged from 30 to 84. There were 83 deaths among the 9,382 patients (0.88 %) with individual studies reporting a mortality range from 0 % to 1.49 %. There were 13 deaths among 4,912 (0.26 %) class A patients, 55 deaths among 4,124 (1.33 %) class B patients and 15 deaths among 346 (4.34 %) class C patients. Mortality in classes A, B and C was significantly different from each of the other two classes (P < 0.05, χ(2)). This systematic review confirms that OS-MRS stratifies the mortality risk in the three-risk classification subgroups of patients. The OS-MRS can be used for pre-operative identification of high-risk patients undergoing primary Roux-en-Y gastric bypass surgery.

Antiplatelet Drugs: Mechanisms and Risks of Bleeding Following Cardiac Operations

Preoperative antiplatelet drug use is common in patients undergoing coronary artery bypass grafting (CABG). The impact of these drugs on bleeding and blood transfusion varies. We hypothesize that review of available evidence regarding drug-related bleeding risk, underlying mechanisms of platelet dysfunction, and variations in patient response to antiplatelet drugs will aid surgeons as they assess preoperative risk and attempt to limit perioperative bleeding. The purpose of this review is to (1) examine the role that antiplatelet drugs play in excessive postoperative blood transfusion, (2) identify possible mechanisms to explain patient response to antiplatelet drugs, and (3) formulate a strategy to limit excessive blood product usage in these patients. We reviewed available published evidence regarding bleeding risk in patients taking preoperative antiplatelet drugs. In addition, we summarized our previous research into mechanisms of antiplatelet drug-related platelet dysfunction. Aspirin users have a slight but significant increase in blood product usage after CABG (0.5 U of nonautologous blood per treated patient). Platelet adenosine diphosphate (ADP) receptor inhibitors are more potent antiplatelet drugs than aspirin but have a half-life similar to aspirin, around 5 to 10 days. The American Heart Association/American College of Cardiology and the Society of Thoracic Surgeons guidelines recommend discontinuation, if possible, of ADP inhibitors 5 to 7 days before operation because of excessive bleeding risk, whereas aspirin should be continued during the entire perioperative period in most patients. Individual variability in response to aspirin and other antiplatelet drugs is common with both hyper- and hyporesponsiveness seen in 5 to 25% of patients. Use of preoperative antiplatelet drugs is a risk factor for increased perioperative bleeding and blood transfusion. Point-of-care tests can identify patients at high risk for perioperative bleeding and blood transfusion, although these tests have limitations. Available evidence suggests that multiple blood conservation techniques benefit high-risk patients taking antiplatelet drugs before operation. Guidelines for patients who take aspirin and/or thienopyridines before cardiac procedures include some or all of the following: (1) preoperative identification of high-risk patients using point-of-care testing; (2) withdrawal of aspirin or other antiplatelet drugs for a few days and delay of operation in patients at high risk for bleeding if clinical circumstances permit; (3) selective perioperative use of evidence-based blood conservation interventions (e.g., short-course erythropoietin, off-pump procedures, and use of intraoperative blood conservation techniques), especially in high-risk patients; and (4) platelet transfusions if clinical bleeding occurs.

Outpatient Electrical Cardioversion of Atrial Fibrillation: 8 Years’ Experience. Analysis of Shock‐Related Arrhythmias

Outpatient electrical cardioversion (EC) of atrial fibrillation is currently the standard of care. Shock-related arrhythmias may be particularly deleterious in this setting. Preoperative identification of high-risk patients may be very useful. A retrospective analysis was made of 543 consecutive elective EC procedures in 457 outpatients over an 8-year period in a university cardiological institute. The protocol included adequate anticoagulation, intravenous anesthesia, direct current shock, and a direct observation after a shock to detect procedure-related complications. No patients were excluded due to severity of pathology or comorbidities. Clinical characteristics, energy delivered, medications, arrhythmic phenomena, and predictors of success and complications were analyzed. Of 543 ECs performed, 88.2% restored sinus rhythm, which persisted at discharge in 83.2%. No anesthesia-related complications were detected. No thromboembolic complications were detected. Use of a biphasic cardioverter was the only predictor of success (P = 0.0001). The bradyarrhythmic complication rate was 1.5%. No ventricular arrhythmic events were detected. Atrial flutter was present in five of eight patients who developed complications versus 44 of 535 patients who had no complications (P < 0.0005), and prosthetic heart valves in four of eight complicated versus 40 of 535 uncomplicated cases (P = 0.0044). The combination of atrial flutter and prosthetic heart valve was found in four of eight complicated versus 11 of 535 uncomplicated cases (P < 0.0005). Shock-related arrhythmias are essentially bradyarrhythmias. Atrial flutter and previous cardiac surgery identify a subgroup of patients at high risk of postshock bradyarrhythmic complications.