Perforation in the peritoneal cavity during transanal endoscopic microsurgery for rectal tumors: a real surgical complication with a challenging prognosis?

BACKGROUND: Perforation in the peritoneal cavity during transanal endoscopic microsurgery represents a major challenge. It is usually treated by primary suture, though some authors propose laparoscopic repair with or without ostomy. It is unclear whether perforation increases the risk of tumor dissemination. AIM: The purpose of the study is to assess the safety of primary suture of peritoneal perforation and the long-term risk of dissemination, also, to determine risk factors for perforation and to propose a predictive model for lesions with risk of perforation. METHOD: This is an observational study with prospective data collection at Parc Taulí University Hospital, Sabadell, of patients undergoing transanal surgery with perforation into the peritoneal cavity from June 2004 to September 2017. The main variable is postoperative morbidity and mortality. The long-term follow-up of local recurrence and peritoneal tumor dissemination is described, and a quantitative predictive model for peritoneal cavity perforation is proposed. RESULTS: Forty-five patients out of 686 (6.6%) presented perforation into the peritoneal cavity. Ten patients (22.2%) in the perforation group had morbidity, a rate similar to the non-perforated group. There was no peritoneal dissemination in patients with adenoma or with carcinoma treated with curative intent. In the quantitative predictive model, risk factors for perforation were proximal edge of tumor > 14 cm from anal verge (6 points), size ≥ 6 cm (2), age ≥ 85 years (4), anterior quadrant (3) , and sex (2). Total scores of ≥ 6 points predicted perforation. CONCLUSIONS: Primary suture after peritoneal cavity perforation during transanal surgery is safe and does not increase the risk of recurrence or peritoneal dissemination. Our predictive model provides guidance regarding the risk of perforation and the need to suture the defect after transanal surgery resection.

Morbidity after transanal endoscopic microsurgery: risk factors for postoperative complications and the design of a 1-day surgery program.

BACKGROUND: Transanal endoscopic microsurgery (TEM) is a minimally invasive procedure with low morbidity. The definition of risk factors for postoperative complications would help to identify the patients likely to require more care and surveillance in an ambulatory or 1-day surgery (A-OdS) program. The main endpoints are overall 30-day morbidity and relevant morbidity. The secondary objectives are to detect risk factors for complications, rehospitalization, and the time of occurrence of the postoperative complications, and to describe the adverse effects following hospitalization that the A-OdS program would avoid. METHODS: This is an observational study of consecutive patients undergoing TEM between June 2004 and December 2016. Overall and relevant morbidity based on the Clavien-Dindo (Cl-D) classification were recorded, as were demographic, preoperative, surgical, and pathology variables. Univariate and multivariate analyses of the risk factors were carried out. RESULTS: Six hundred and ninety patients underwent surgery, of whom 639 were included in the study. Overall morbidity rate was 151/639 patients (23.6%); the clinically relevant morbidity rate was 36/639 (Cl-D > II) (5.6%) and mortality 2/639 (0.3%). The most frequent complication was rectal bleeding, recorded in 16.9% (108/639 patients) and grade I in 86/108 patients (78. 9%). The period with the greatest risk of complications was the first 2 days. The rehospitalization rate after 48 h was 7%. The risk factors for complications were as follows: tumor size > 6 cm (OR 3.2, 95% CI 1.3-7.8), anti-platelet medication (OR 2.3, 95% CI 1.1-5.1), and surgeon's experience < 150 procedures (OR 2.0, 95% CI 1-4.1). CONCLUSIONS: TEM is a safe procedure. The low rates of morbidity, re-hospitalization, and postoperative complications in the first 2 days after surgery make the procedure suitable for A-OdS.

Endorectal ultrasound in the identification of rectal tumors for transanal endoscopic surgery: factors influencing its accuracy.

Endorectal ultrasound (ERUS) is considered the technique of choice for selecting patients for transanal endoscopic surgery (TEM). The aim of this study was to evaluate the accuracy of ERUS in patients with rectal tumors who later underwent TEM, and to analyze the factors that influence this accuracy. Observational study including prospective data collection of patients with rectal tumors undergoing TEM with curative intent between June 2004 and May 2016. Preoperative staging by EUS (uT) was correlated with the pathology results after TEM (pT). The accuracy of the EUS was evaluated and a series of variables (tumor morphology, height, lesion size, quadrant, definitive pathology, the surgeon assessing the ERUS, and waiting time from the date of the ERUS until surgery) were analyzed as possible predictors of diagnostic accuracy. Six hundred and fifty-one patients underwent TEM, of whom 495 met the inclusion criteria. The overall accuracy of EUS was 78%, sensitivity 83.78%, specificity 20%, PPV 91.3%, and NPV 11%. Forty patients (8.08%) were understaged and 50 (10.9%) were overstaged. In the multivariate analysis, the surgeon's experience emerged as the most important predictor of accuracy (p < 0.001; OR 2.75, 95% CI 1.681-4.512). The EUS was less accurate with larger lesions (p = 0.004; OR 0.219, 95% CI 0.137-0.349) and when the definitive diagnosis was adenocarcinoma (p < 0.001; OR 0.84, 95% CI 0.746-0.946). ERUS accuracy rates are variable and there is a possibility of understaging and overstaging that must be taken into consideration. This accuracy is dependent on the operator's experience as well on lesion size; in addition, it is lower for lesions shown to be cancers in the final pathology report.

American vs. European Trauma Centers: A Comparison of Preventable Deaths. / Comparación de la mortalidad evitable de un trauma center americano vs. un centro de referencia europeo.

INTRODUCTION: The aim is comparing the quality of care at a typical American trauma center (USC) vs. an equivalent European referral center in Spain (SRC), through the analysis of preventable and potentially preventable deaths. METHODS: Comparative study that evaluated trauma patients older than 16 years old who died during their hospitalization. We cross-referenced these deaths and extracted all deaths that were classified as potentially preventable or preventable. All errors identified were then classified using the JC taxonomy. RESULTS: The rate of preventable and potentially preventable mortality was 7.7% and 13.8% in the USC and SRC respectively. According to the JC taxonomy, the main error type was clinical in both centers, due to errors in intervention (treatment). Errors occurred mostly in the emergency department and were caused by physicians. In the USC, 73% of errors were therapeutic as compared to 59% in the SRC (P=.06). The SRC had a 41% of diagnosis errors vs just 18% in the USC (P = .001). In both centers, the main cause of error was human. At the USC, the most frequent human cause was 'knowledge-based' (44%). In contrast, at the SRC center the most common errors were 'rule-based' (58%) (P<.001). CONCLUSIONS: The use of a common language of errors among centers is key in establishing benchmarking standards. Comparing the quality of care of an American trauma center and a Spanish referral center, we have detected remarkably similar avoidable errors. More diagnostic and 'ruled-based' errors have been found in the Spanish center.

[Results of conservative treatment in patients with occult pneumothorax]. / Resultados del tratamiento conservador en pacientes con neumotórax oculto.

INTRODUCTION: An occult pneumothorax is found in 2-15% trauma patients. Observation (without tube thoracostomy) in these patients presents still some controversies in the clinical practice. The objective of the study is to evaluate the efficacy and the adverse effects when observation is performed. METHODS: A retrospective observational study was undertaken in our center (university hospital level II). Data was obtained from a database with prospective registration. A total of 1087 trauma patients admitted in the intensive care unit from 2006 to 2013 were included. RESULTS: In this period, 126 patients with occult pneumothorax were identified, 73 patients (58%) underwent immediate tube thoracostomy and 53 patients (42%) were observed. Nine patients (12%) failed observation and required tube thoracostomy for pneumothorax progression or hemothorax. No patient developed a tension pneumothorax or experienced another adverse event related to the absence of tube thoracostomy. Of the observed patients 16 were under positive pressure ventilation, in this group 3 patients (19%) failed observation. There were no differences in mortality, hospital length of stay or intensive care length of stay between the observed and non-observed group. CONCLUSION: Observation is a safe treatment in occult pneumothorax, even in pressure positive ventilated patients.

Source of bleeding in trauma patients with pelvic fracture and haemodynamic instability.

INTRODUCTION: The main cause of mortality in trauma patients with pelvic fractures is hypovolemic shock. We analyzed the association between the source of bleeding, mechanism of action and type of fracture. METHODS: Prospective descriptive study involving trauma patients older than 16 years old, admitted to the intensive care unit or dead before admission, with pelvic fractures and hemodynamic instability. Hemodynamic instability was defined as SBP <90 and/or HR> 100 beats/min. Pelvic fracture was defined by the Tile classification. RESULTS: A total of 157 of 1088 trauma patients had pelvic fracture. We included 63 patients, all hemodynamically unstable. A total of 85% of pelvic fractures after falls from great heights bled from the fracture itself, compared to only 44% of victims of impact (hit). A total of 65% of patients with stable pelvic fracture bled from associated lesions; 70% of patients with unstable fracture bled from the fracture itself. There is an interaction between the mechanism of action and type of fracture. The probability of pelvic bleeding is higher in the precipitated patient (> 80%) regardless of the type of fracture. Bleeding from associated injuries is greater in impact victims, doubling when the fracture is stable (91%). CONCLUSIONS: Mechanism of action is a key to determine the source of bleeding in patients with pelvic fracture. After falls patients bleed from the fracture itself, while patients with an impact (hit) can bleed both from the fracture and associated injuries, depending on the type of fracture.

Transanal endoscopic surgery with total wall excision is required with rectal adenomas due to the high frequency of adenocarcinoma.

BACKGROUND: Colorectal adenomatous polyps are considered premalignant lesions, although a high percentage are already malignant at the time of their removal. Full-thickness excision in patients with adenoma detected in preoperative biopsy enables much more accurate pathology examination and has shown that local surgery is appropriate for T1 adenocarcinoma. OBJECTIVE: To determine whether full-thickness excision during transanal endoscopic surgery is the treatment of choice for rectal adenoma, and to identify possible predictors of invasive adenocarcinoma associated with this type of lesion. DESIGN: Prospective, observational study. SETTING: The study was conducted at a university teaching hospital. PATIENTS: All patients scheduled for transanal endoscopic surgery after detection of adenoma in a preoperative biopsy between June 2004 and February 2013 entered the study. MAIN OUTCOME MEASURES: The principal variable was the presence of invasive adenocarcinoma in the pathology study. Other study variables were the epidemiological variables sex and age; the clinical variables tumor size, number of quadrants affected, distance from the anal verge, and tumor location; and the morphological variables tumor aspect, degree of dysplasia, preoperative biopsy (tubulo-villous), endorectal ultrasound, and pelvic MRI stage. Variables found to be related to the risk of malignancy in rectal adenomas were evaluated using univariate and multivariate analysis. RESULTS: Of 471 patients who underwent surgery, 277 had a preoperative diagnosis of adenoma. Final pathology studies showed 52 (18.8%) invasive adenocarcinomas, among which 27 were pT1 (52%), 16 pT2 (30.7%), and 9 pT3 (17.3%). Factors predictive of invasive adenocarcinoma were sessile morphology (OR 3.2, 95%CI 1.4-7.1), high-grade dysplasia (OR 2.3, 95%CI 1.2-4.8), and endorectal ultrasound stage uT2-T3 (OR 3.8, 95%CI 1.6-9). LIMITATIONS: The limitations are derived from the observational design. CONCLUSIONS: In this sample, half of the adenocarcinomas from adenomas were T1 adenocarcinomas. Because a high proportion of rectal adenomas are, in fact, invasive adenocarcinomas, full-thickness excision is appropriate.

Impact of ATLS training on preventable and potentially preventable deaths.

BACKGROUND: Multiple trauma continues to have a high incidence worldwide. Trauma is the leading cause of death among people between the ages of 10 and 40. The Advanced Trauma Life Support (ATLS) is the most widely accepted method for the initial control and treatment of multiple trauma patients. It is based on the following hypothesis: The application of the ATLS program may reduce preventable or potentially preventable deaths in trauma patients. MATERIALS AND METHODS: The present article reports a retrospective study based on the records of prospectively evaluated trauma patients between January 2007 and December 2012. Trauma patients over the age of 18 admitted to the critical care unit or patients who died before hospital admission were included. A multidisciplinary committee looked for errors in the management of each patient and classified deaths into preventable, potentially preventable, or nonpreventable. We recorded the number of specialists at our center who had received training in the ATLS program. RESULTS: A total of 898 trauma patients were registered. The mean injury severity score was 21 (SD 15), and the mortality rate was 10.7 % (96 cases). There were 14 cases (14.6 %) of preventable or potentially preventable death. The main errors were delay in initiating suitable treatment and performing a computed tomography scan in cases of hemodynamic instability, followed by initiation of incorrect treatment or omission of an essential procedure. As the number of ATLS-trained professionals increases, the rates of potentially preventable or preventable death fall. CONCLUSIONS: Well-founded protocols such as the ATLS can help provide the preparation health professionals need. In our hospital environment, ATLS training has helped to reduce preventable or potentially preventable mortality among trauma patients.

Psychopathological profile before and after bariatric surgery.

Presurgical psychopathological assessment usually focuses on detecting severe mental disorders. However, mild intensity psychopathology and eating behaviour pattern may also influence postsurgical outcomes. The aim was to identify psychopathology and eating behaviour pattern in candidates prepared for bariatric surgery compared to a normative population before and after surgery. A cohort of 32 patients seeking bariatric surgery in a university hospital between March 2016 and March 2017 were evaluated with Personality Assessment Inventory (PAI), 36-item EDE-Q and BES before and after surgery. Thirty-two patients before and 26 one year after surgery were included. The PAI presurgical psychometric profile suggested a mild mixed adjustment disorder focused on somatic complaints. After surgery, patients improved in somatic complaints (p < 0.001), and depression (p = 0.04). Related eating disorders were more common than those of the normative group and improved significantly after surgery in scores for compulsive intake (BES p < 0.001) and overall key behaviours of eating disorders and related cognitive symptoms (EDE-Q/G p < 0.001). In our cohort ready for bariatric surgery a mild psychopathological profile is still present and becomes closer to that of the normative group after surgery. Further studies are needed to evaluate the effects of mild psychopathology on outcomes after bariatric surgery.

[Adverse events in general surgery. A prospective analysis of 13,950 consecutive patients]. / Efectos adversos en cirugía general. Análisis prospectivo de 13.950 pacientes consecutivos.

INTRODUCTION: Adverse event (AE) rates in General Surgery vary, according to different authors and recording methods, between 2% and 30%. Six years ago we designed a prospective AE recording system to change patient safety culture in our Department. We present the results of this work after a 6 year follow-up. MATERIAL AND METHOD: The AE, sequelae and health care errors in a University Hospital surgery department were recorded. An analysis of each incident recorded was performed by a reviewer. The data was entered into data base for rapid access and consultation. The results were routinely presented in Departmental morbidity-mortality sessions. RESULTS: A total of 13,950 patients had suffered 11,254 AE, which affected 5142 of them (36.9% of admissions). A total of 920 patients were subjected to at least one health care error (6.6% of admissions). This meant that 6.6% of our patients suffered an avoidable AE. The overall mortality at 5 years in our department was 2.72% (380 deaths). An adverse event was implicated in the death of the patient in 180 cases (1.29% of admissions). In 49 cases (0.35% of admissions), mortality could be attributed to an avoidable AE. After 6 years there tends to be an increasingly lower incidence of errors. CONCLUSIONS: The exhaustive and prospective recording of AE leads to changes in patient safety culture in a Surgery Department and helps decrease the incidence of health care errors.

Preoperative Diagnostic Uncertainty in T2-T3 Rectal Adenomas and T1-T2 Adenocarcinomas and a Therapeutic Dilemma: Transanal Endoscopic Surgery, or Total Mesorectal Excision?

BACKGROUND: Endorectal ultrasound and rectal magnetic resonance are sometimes unable to differentiate between stages T2 and T3 in rectal adenomas that are possible adenocarcinomas, or between stages T1 and T2 in rectal adenocarcinomas. These cases of diagnostic uncertainty raise a therapeutic dilemma: transanal endoscopic surgery (TES) or total mesorectal excision (TME)? METHODS: An observational study of a cohort of 803 patients who underwent TES from 2004 to 2021. Patients operated on for adenoma (group I) and low-grade T1 adenocarcinoma (group II) were included. The variables related to uncertain diagnosis, and to the definitive pathological diagnosis of adenocarcinoma stage higher than T1, were analyzed. RESULTS: A total of 638 patients were included. Group I comprised 529 patients, 113 (21.4%) with uncertain diagnosis. Seventeen (15%) eventually had a pathological diagnosis of adenocarcinoma higher than T1. However, the variable diagnostic uncertainty was a risk factor for adenocarcinoma above T1 (OR 2.3, 95% CI 1.1-4.7). Group II included 109 patients, eight with uncertain diagnosis (7.3%). Two patients presented a definitive pathological diagnosis of adenocarcinoma above T1. CONCLUSIONS: On the strength of these data, we recommend TES as the initial indication in cases of diagnostic uncertainty. Multicenter studies with larger samples for both groups should now be performed to further assess this strategy of initiating treatment with TES.

Correction to: Esogastro-Pleuro-Bronchial Fistula: An Unusual Complication After Sleeve Gastrectomy.

Due to a Production error Figs. 1 and 2 were omitted from the original article.

Longitudinal changes in telomere length in a cohort of obese patients submitted to bariatric surgery: a 2-year follow-up.

BACKGROUND: Telomere length (TL) is one biomarker of cell aging used to explore the effects of the environment on age-related pathologies. Obesity and high body mass index have been identified as a risk factors for shortened TL. OBJECTIVE: To evaluate TL in different subtypes of obese patients, and to examine changes in TL in relation to weight loss after bariatric surgery. SETTING: University Hospital in Spain. METHODS: A cohort of 94 patients submitted to bariatric surgery were followed-up during 24 months (t24m: lost to follow-up = 0%). All patients were evaluated before surgery (t0) and during the postoperative period (t6m, t12m, and t24m) for body mass index and metabolic variables. We assessed TL at each timepoint using quantitative polymerase chain reactions and the telomere sequence to single-copy gene sequence ratio method. RESULTS: Patients with class III obesity showed significantly shorter TL at baseline than those patients with class II obesity (P = .027). No differences in TL were found between patients with or without type 2 diabetes or metabolic syndrome. Longitudinal analysis did not show an effect of time, type of surgery, age, or sex on TL. However, a generalized estimating equation model showed that TL was shorter amongst class III obesity patients across the time course (P = .008). Comparison between patients with obesity class II and class III showed differences in TL at t6m (adjusted P = .024), whereby class II patients had longer TL. However, no difference was observed at the other evaluated times. CONCLUSION: Obesity severity may have negative effects on TL independently of type 2 diabetes or metabolic syndrome. Although TL is significantly longer in class II obesity patients relative to class III 6 months after bariatric surgery. This difference is not apparent after 24 months.

Burnout in General Surgery Residents. Survey From the Spanish Association of Surgeons. / Desgaste profesional o burnout en los residentes de Cirugía General. Encuesta de la Asociación Española de Cirujanos.

INTRODUCTION: Physicians, especially surgeons, are significatively affected by burnout. Duty-hour violation, as well as discrimination, abuse and sexual harassment may contribute to burnout. A study about this topic has been published in residents from United States, demonstrating a high incidence of burnout. Our objective is to know which is the situation in Spain and to compare it with United States. METHODS: Cross-sectional observational study carried out in January-February 2020, based on the responses to a validated survey administered to General Surgery residents in Spain. RESULTS: There are 931 General Surgery Residents. 739 have entered in the survey and 452 (61.2%) eventually responded to it. In any occasion during the training period, 55.1% reported discrimination based on their gender, 8.8% reported racial discrimination, 73.9% reported verbal/psychological abuse, 7.1% reported physical abuse and 16.4% reported sexual harassment. Attending surgeons are the most frequent source of sexual harassment and physical and verbal abuse, whereas patients are the most frequent cause of gender discrimination. Burnout symptoms were reported by 47.6% of residents and 4.6% reported suicidal thoughts. 98% of residents reported duty-hour violations and 47% of them do not have the day off after to be on call. Both of these issues are burnout predictive factors. CONCLUSIONS: Mistreatment (discrimination, abuse and harassment) occurs among General Surgery residents during their training period in our country. Every kind of mistreatment is more frequent in Spain than in the United States, with the exception of racial discrimination. It is associated with exceeding weekly duty-hour. It is necessary to know these problems and to avoid them in order to improve work environment of General Surgery training period.

An evaluation of morbidity and mortality in oncologic gastric surgery with the application of POSSUM, P-POSSUM, and O-POSSUM.

OBJECTIVE: Evaluation of surgical results observed in oncologic gastric surgery with reference to estimation of risks through POSSUM (Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity), P-POSSUM (Portsmouth POSSUM), and O-POSSUM (regression model based on the POSSUM and P-POSSUM, especially designed for gastric and esophagus surgery). METHODS: A prospective follow-up of a cohort of 106 consecutive patients, gastrectomized because of gastric cancer. The variables studied were: age, sex, technical surgery, American Society of Anesthesiologists (ASA) score, the Charlson comorbidity index, morbidity, and mortality. RESULTS: From January 2004 to April 2008, 131 patients were operated on for gastric neoplasia. Of these, 28 patients were excluded: 5 because of nonstandard gastrectomy, 17 because of staging laparoscopy or unresectable cancer after laparotomy, and 3 because of palliative gastroenteroanastomosis; 106 patients were included. We performed 38 total gastrectomies, 65 distal gastrectomies, 2 esophagogastrectomies, and 1 proximal gastrectomy. The mean age was 68 years (standard deviation (SD) = 12.1; range, 34-85 years). Associated comorbidity (Charlson) was 5.4 (SD = 2.7; range, 2-16); ASA 1 at 1.9%; ASA 2 at 36.8%; ASA 3 at 43.4%; and ASA 4 at 17.9%. Expected morbidity, according to POSSUM was 46.7%; observed morbidity was 50.5%. Morbidity ratio observed/expected was 1.08. Expected mortality, according to POSSUM = 13%, according to P-POSSUM = 4.9%, and according to O-POSSUM = 12.1%. Observed mortality was 7.8%. Mortality ratio observed/expected according to POSSUM, P-POSSUM, O-POSSUM was 0.6, 1.6, and 0.6, respectively. Morbidity results were within the confidence interval of the POSSUM estimation. Our results show lower mortality than the POSSUM and the O-POSSUM estimation (P < 0.001) and higher mortality regarding P-POSSUM estimation (P < 0.001). CONCLUSIONS: The control systems of risk allow us continuous evaluation of our results and objective comparison to other teams. Compared with the POSSUM scoring systems, our series showed quality improvement (morbidity and mortality) over time.

Analysis of quality of life after major trauma: a spanish follow-up cohort study.

PURPOSE: Study objectives are to determine whether quality of life is recovered completely after major injury and to identify determinants associated with a worse quality of life. METHODS: Prospective 12-month follow-up of injured patients admitted to the intensive care unit in a Spanish level 1 trauma centre. The main outcome (quality of life) was measured using the EQ-5D-5L. The relationships between sociodemographic factors, injury severity and location, and quality of life scores were evaluated. Mean comparison analysis (95% confidence interval) was performed with the student "t" test for quantitative variables and with chi-squared for proportion comparison (qualitative variables). A multivariate logistic regression (odds ratio and 95% confidence interval) was performed to identify determinants of each dimension, and a multivariate linear regression (regression coefficient and 95% confidence interval) to identify the determinants of EQus and EQvas. RESULTS: Over a 2-year period, 304 patients who met the inclusion criteria were identified, and 200 patients (65.8%) were finally included. Most of patients suffered blunt trauma (91.5%), 72.5% were men, mean age was 47.8, mean ISS was 15.2. The overall health index (EQvas) improved slightly, but its mean value at 12 months was below the Spanish population norm (P < 0.001). In the multivariate analysis, age ≥ 55, female gender and unskilled employment were risk factors for a lower EQvas. Also in the multivariate analysis, having a severe extremity injury was associated with a lower score on the mobility dimension (OR 6.56 95% CI 2.00, 21.55) while age ≥ 55 years was associated with a lower score on the usual activities dimension (OR 3.52 95% CI 1.17, 10.57). Female gender was the most important factor associated with suffering pain (OR 4.54, 95% CI 2.01, 10.27) and depression/anxiety (OR 4.04, 95% CI 1.88, 8.65). In the univariate and multivariate analyses, female gender, age ≥ 55 years, ISS ≥ 25 and severe extremity injury were associated with a lower EQ utility score (EQus). CONCLUSIONS: The quality of life score improves during the first year after major trauma. However, it does not return to the reference levels for the normal population. Female gender and age ≥ 55 years are statistically significant determinants of poorer EQvas and EQus.

Human Subcutaneous Tissue Response to Glucose Sensors: Macrophages Accumulation Impact on Sensor Accuracy.

BACKGROUND: Subcutaneous (s.c.) glucose sensors have become a key component in type 1 diabetes management. However, their usability is limited by the impact of foreign body response (FBR) on their duration, reliability, and accuracy. Our study gives the first description of human acute and subacute s.c. response to glucose sensors, showing the changes observed in the sensor surface, the inflammatory cells involved in the FBR and their relationship with sensor performance. METHODS: Twelve obese patients (seven type 2 diabetes) underwent two abdominal biopsies comprising the surrounding area where they had worn two glucose sensors: the first one inserted 7 days before and the second one 24 h before biopsy procedure. Samples were processed and studied to describe tissue changes by two independent pathologists (blind regarding sensor duration). Macrophages quantification was studied by immunohistochemistry methods in the area surrounding the sensor (CD68, CD163). Sensor surface changes were studied by scanning electron microscopy. Seven-day continuous glucose monitoring records were considered inaccurate when mean absolute relative difference was higher than 10%. RESULTS: Pathologists were able to correctly classify all the biopsies regarding sensor duration. Acute response (24 h) was characterized by the presence of neutrophils while macrophages were the main cell involved in subacute inflammation. The number of macrophages around the insertion hole was higher for less accurate sensors compared with those performing more accurately (32.6 ± 14 vs. 10.6 ± 1 cells/0.01 mm2; P < 0.05). CONCLUSION: The accumulation of macrophages at the sensor-tissue interface is related with decrease in accuracy of the glucose measure.

Impact of Bariatric Surgery on Heme Oxygenase-1, Inflammation, and Insulin Resistance in Morbid Obesity with Obstructive Sleep Apnea.

INTRODUCTION: Morbid obesity and obstructive sleep apnea (OSA) interact at an inflammatory level. Bariatric surgery reduces inflammatory responses associated with obesity. Heme oxygenase-1 (HO-1) is an enzyme with anti-inflammatory properties, which might be increased in morbid obesity or OSA. We studied morbidly obese patients with OSA to determine: (a) HO-1 plasma concentrations according to OSA severity and their relationship with insulin resistance and inflammation and (b) the impact of bariatric surgery on HO-1 and parameters of insulin resistance and inflammation. MATERIAL AND METHODS: We analyzed the homeostasis model insulin resistance index (HOMA) and plasma concentrations of HO-1, tumor necrosis factor alpha, interleukin-6, interleukin-1-beta, C reactive protein (CRP), and adiponectin according to polysomnography findings in 66 morbidly obese patients before bariatric surgery and 12 months after surgery. RESULTS: Before surgery, HO-1 plasma concentrations were similar in three groups of patients with mild, moderate, and severe OSA, and correlated with HOMA (r = 0.27, p = 0.02). Twelve months after surgery, low-grade inflammation and insulin resistance had decreased in all the groups, but HO-1 plasma concentration had decreased only in the severe OSA group (p = 0.02). In this group, the reduction in HO-1 correlated with a reduction in CRP concentrations (r = 0.43, p = 0.04) and with improved HOMA score (r = 0.37, p = 0.03). CONCLUSIONS: Bariatric surgery decreases HO-1 concentrations in morbid obesity with severe OSA, and this decrease is associated with decreases in insulin resistance and in inflammation.