Waist circumference predicts increased complications in rectal cancer surgery

Phase angle is a predictor for postoperative complications in colorectal cancer

Aim

The aim of this study was to develop a validated nomogram to predict the risk of postoperative complications in colorectal cancer (CRC) patients by analyzing the factors that contribute to these complications.

Methods

We retrospectively collected clinical information on patients who underwent CRC surgery at a single clinical center from January 2021 to December 2021. Univariate and multivariate logistic regression analysis to identify independent risk factors for postoperative complications and to develop a predictive model. A receiver operating characteristic (ROC) curve was used to calculate the area under the curve (AUC) to assess the predicted probability. Calibration curve was drawn to compare the predicted probability of the nomogram with the actual probability, and decision curve analysis (DCA) was employed to evaluate the clinical utility of the nomogram.

Results

A total of 190 CRC patients were included in this study. We retrospectively collected baseline information, clinical information, surgical information, and nutrition-related indicators for all patients. Through multivariate logistic regression analysis, preoperative albumin (p = 0.041, OR = 0.906, 95% CI = 0.824-0.996), surgical time (p = 0.009, OR = 1.006, 95% CI = 1.001-1.010), waistline (p = 0.049, OR = 1.011, 95% CI = 1.002-1.020) and phase angle (PA) (p = 0.022, OR = 0.615, 95% CI = 0.405-0.933) were identified as independent risk factors for postoperative complications in CRC, and a nomogram prediction model was established using the above four variables. The AUC of 0.706 for the ROC plot and the high agreement between predicted and actual probabilities in the calibration curves suggested that the prediction model has good predictive power. The DCA also confirmed the good clinical performance of the nomogram.

Conclusion

This study developed a nomogram to predict the risk of postoperative complications in CRC patients, providing surgeons with a reliable reference to personalized patient management in the perioperative period and preoperative nutritional interventions.

Predicting Waist Circumference From a Single Computed Tomography Image Using a Mobile App (Measure It): Development and Evaluation Study

Background

Despite the existing evidence that waist circumference (WC) provides independent and additive information to BMI when predicting morbidity and mortality, this measurement is not routinely obtained in clinical practice. Using computed tomography (CT) scan images, mobile health (mHealth) has the potential to make this abdominal obesity parameter easily available even in retrospective studies.

Objective

This study aimed to develop a mobile app as a tool for facilitating the measurement of WC based on a cross-sectional CT image.

Methods

The development process included three stages: determination of the principles of WC measurement from CT images, app prototype design, and validation. We performed a preliminary validity study in which we compared WC measurements obtained both by the conventional method using a tape measurement in a standing position and by the mobile app using the last abdominal CT slice not showing the iliac bone. Pearson correlation, student t tests, and Q-Q and Bland-Altman plots were used for statistical analysis. Moreover, to perform a diagnostic test evaluation, we also analyzed the accuracy of the app in detecting abdominal obesity.

Results

We developed a prototype of the app Measure It, which is capable of estimating WC from a single cross-sectional CT image. We used an estimation based on an ellipse formula adjusted to the gender of the patient. The validity study included 20 patients (10 men and 10 women). There was a good correlation between both measurements (Pearson R=0.906). The student t test showed no significant differences between the two measurements (P=.98). Both the Q-Q dispersion plot and Bland-Altman analysis graphs showed good overlap with some dispersion of extreme values. The diagnostic test evaluation showed an accuracy of 83% when using the mobile app to detect abdominal obesity.

Conclusions

This app is a simple and accessible mHealth tool to routinely measure WC as a valuable obesity indicator in clinical and research practice. A usability and validity evaluation among medical teams will be the next step before its use in clinical trials and multicentric studies.

A meta-analysis of the effect of different body mass index on surgical wound infection after colorectal surgery

We conducted a meta-analysis to assess the effect of different body mass index on surgical wound infection after colorectal surgery. A systematic literature search up to November 2022 was performed and 2349 related studies were evaluated. The chosen studies comprised 15 595 colorectal surgery subjects participated in the selected studies' baseline trials; 4390 of them were obese according to the selected body mass index cut-off used to measure obesity in the selected studies, while 11 205 were nonobese. Odds ratio (OR) with 95% confidence intervals (CIs) were calculated to assess the effect of different body mass index on wound infection after colorectal surgery by the dichotomous methods with a random or fixed effect model. The body mass index ≥30 kg/m2 resulted in significantly higher surgical wound infection after colorectal surgery (OR, 1.76; 95% CI, 1.46-2.11, P < .001) compared with the body mass index <30 kg/m2 . The body mass index ≥25 kg/m2 resulted in significantly higher surgical wound infection after colorectal surgery (OR, 1.64; 95% CI, 1.40-1.92, P < .001) compared with the body mass index <25 kg/m2 . The subjects with higher body mass index had a significantly higher surgical wound infection after colorectal surgery compared with the subjects with normal body mass index.

BMI: does it predict the need for component separation?

PURPOSE

Patient optimization and selecting the proper technique to repair large incisional hernias is a multifaceted challenge. Body mass index (BMI) is a modifiable variable that may infer higher intra-abdominal pressures and, thus, predict the need for component separation (CS) at the time of surgery, but no data exist to support this. This paper assesses if the ratio of anterior-posterior (AP): transverse (TRSV) abdominal diameter, from pre-operative CT imaging, indicates a larger proportion of intra-abdominal fat and correlates with a hernia defect requiring a component separation for successful tension-free closure.

METHODS

Ninety patients were identified who underwent either an open hernia repair with mesh by primary closure (N = 53) or who required a component separation at the time of surgery (N = 37). Pre-operative CT images were used to measure hernia defect width, AP abdominal diameter, and TRSV abdominal diameter. Quantitative data, nominal data, and logistic regression was used to determine predictors associated with surgical group categorization.

RESULTS

The average hernia defect widths for primary closure and CS were 7.7 ± 3.6 cm (mean ± SD) and 9.8 ± 4.5, respectively (p = 0.015). The average BMI for primary closure was 33.9 ± 7.2 and 33.8 ± 4.9 for those requiring CS (p = 0.924). The AP:TRSV diameter ratios for primary closure and CS were 0.41 ± 0.08 and 0.49 ± 0.10, respectively (p < 0.001). In a multivariate analysis including both defect width and AP:TRSV diameter ratio, only AP:TRSV diameter ratio predicted the need for a CS (p = 0.001) while BMI did not (p = 0.92).

CONCLUSION

Intraabdominal fat distribution measured by AP:TRSV abdominal diameter ratio correlates with successful tension-free fascial closure during incisional hernia repair, while BMI does not.

Preoperative Muscle-Adipose Index: A New Prognostic Factor for Gastric Cancer

BACKGROUND

Studies have shown that traditional nutrition indicators and body composition indicators are closely related to prognosis after radical gastric cancer (GC) surgery. However, the effect of the combined muscle and adipose composite on the prognosis of GC has not been reported.

METHODS

The clinicopathological data of 514 patients with GC were retrospectively analyzed. The skeletal muscle adipose tissue were measured by preoperative CT images to obtain the muscle index and adipose index. X-tile software was used to determine the diagnostic threshold of muscle-adipose imbalance.

RESULTS

The 5-year OS and RFS of the muscle-adipose imbalanced group were significantly worse than those of the balanced group. Multivariate analysis showed that muscle-adipose imbalance and the CONUT score were independent prognostic factors of OS and RFS (p < 0.05). The nuclear density curve showed that the recurrence risk of the muscle-adipose imbalanced group was higher than that of the balanced group, whereas the nuclear density curve of the CONUT score was confounded. Incorporating the muscle-adipose index into cTNM has the same prognostic performance as the pTNM staging system. Chemotherapy-benefit analysis showed that stage II/III patients in the muscle-adipose balanced group could benefit from adjuvant chemotherapy.

CONCLUSIONS

The preoperative muscle-adipose index discovered for the first time is a new independent prognostic factor that affects the prognosis with GC. In addition, the preoperative muscle-adipose index is better than traditional nutrition and body composition indicators in terms of the prognostic evaluation of GC patients and the predictive value of recurrence risk.

Association of Obesity With Septic Complications After Major Abdominal Surgery: A Secondary Analysis of the RELIEF Randomized Clinical Trial

IMPORTANCE

Body mass index (BMI) has been the most common obesity measure to assess perioperative risk; however, cardiometabolic risk is associated with the burden of visceral fat. Definitive evidence on the association of visceral fat measures, such as waist circumference and waist-to-hip ratio (WHR), with postoperative complications is lacking.

OBJECTIVE

To compare the value of waist circumference with the value WHR and BMI in predicting adverse outcomes, including major septic complications and persistent disability, following major abdominal surgery.

DESIGN, SETTING, AND PARTICIPANTS

This planned secondary analysis of the Restrictive vs Liberal Fluid Therapy for Major Abdominal Surgery (RELIEF) randomized clinical trial took place at 47 centers in 7 countries between October 2013 and September 2016, with 90-day follow-up. A total of 2954 adult RELIEF participants were coenrolled in this secondary analysis. Data analysis took place from December 2018 to September 2019.

EXPOSURES

Waist circumference, WHR, and BMI measurements.

MAIN OUTCOMES AND MEASURES

The primary outcomes were 30-day major septic complications and 90-day persistent disability or death.

RESULTS

Of 2954 eligible participants, 2755 were included (mean [SD] age, 65.9 [12.9] years; 1426 [51.8%] men) in the final analysis. A total of 564 participants (20.6%) experienced at least 1 major septic complication within 30 days after surgery (sepsis, 265 [9.7%]; surgical site infection, 409 [14.9%]; anastomotic leak, 78 [2.8%]; pneumonia, 104 [3.8%]). Waist circumference had a statistically significantly larger odds ratio (OR) and discrimination indices as well as a smaller prediction error than WHR or BMI for 30-day major septic complications or death (waist circumference: OR, 1.44; 95% CI, 1.28-1.62; P < .001; area under the receiver operating characteristic curve, 0.641; net reclassification index, 0.266; integrated discrimination improvement [score × 104], 152.98; Brier score, 0.162; WHR: OR, 1.15; 95% CI, 1.03-1.28; P = .01; area under the receiver operating characteristic curve, 0.621; net classification index, 0.199; integrated discrimination improvement [score × 104], 28.47; Brier score, 0.164; BMI: OR, 1.33; 95% CI, 1.17-1.50; P < .001; area under the receiver operating characteristic curve, 0.629; net reclassification index, 0.205; integrated discrimination improvement [score × 104], 85.61; Brier score, 0.163) but not for any other outcomes.

CONCLUSIONS AND RELEVANCE

In this secondary analysis of the RELIEF randomized clinical trial, waist circumference was observed to be superior to other adiposity indices in predicting 30-day major septic complications alone or in conjunction with death following elective major abdominal surgery. Findings suggest that waist circumference is a useful adiposity measure that should be incorporated in preoperative risk assessment for such complications.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01424150.

Exploring the role of obesity and overweight in predicting postoperative outcome of abdominal surgery in a sub-Saharan African setting: a prospective cohort study

OBJECTIVE

Current literature on the role of excess weight in predicting surgical outcome is controversial. In sub-Saharan Africa, there is extreme paucity of data regarding this issue in spite of the increasing rates of obesity and overweight in the region. This prospective cohort study, carried out over a period of 4 months at Limbe Regional Hospital in the Southwest region of Cameroon, assessed 30-day postoperative outcome of abdominal surgery among consecutive adults with body mass index (BMI) ≥ 25 kg/m2. Adverse postoperative events were reported as per Clavien-Dindo classification.

RESULTS

A total of 103 patients were enrolled. Of these, 68.9% were female. The mean age was 38.2 ± 13.7 years. Sixty-four (62.1%) of the patients were overweight and the mean BMI was 29.2 ±4.3 kg/m2. The physical status scores of the patients were either I or II. Appendectomy, myomectomy and hernia repair were the most performed procedures. The overall complication rate was 13/103 (12.6%), with 61.5% being Clavien-Dindo grades II or higher. From the lowest to the highest BMI category, there was a significant increase in the proportion of patients with complications; 25-29.9 kg/m2: 6.25%, 30-34.9 kg/m2: 18.75%, 35-39.9 kg/m2: 25.0%, and ≥ 40 kg/m2: 66.70%; p = 0.0086.

A case-control study of the association between metabolic syndrome and colorectal cancer: a comparison of International Diabetes Federation, National Cholesterol Education Program Adults Treatment Panel III, and World Health Organization definitions

Background

Metabolic syndrome was linked with various chronic diseases, including cancer. The study on the effect of metabolic syndrome on colorectal cancer (CRC) was not conducted in Malaysia. Therefore, this study aims to determine the association between metabolic syndromes and its components with CRC, based on the three established definitions.

Methods

A multi-centred matched case control study was conducted in five local hospitals. A total of 140 histologically confirmed CRC cases were matched with 280 cancer free controls. Mean value and prevalence of the components of metabolic syndrome between cases and controls were measured based on the three definitions. A multiple variable analysis using Cox regression was conducted to measure the strength of the association between the definitions of MetS, components of MetS and risk of CRC.

Results

Multiple variable analyses showed that metabolic syndrome significantly and independently increased the risk of CRC, with an odds ratio ranging from 1.79 to 2.61. This study identified that the definition of metabolic syndrome by the International Diabetes Federation is the most sensitive in predicting the risk of CRC, compared to metabolic syndrome as defined by the World Health Organization and National Cholesterol Education Program Adults Treatment Panel III. Abdominal obesity, low HDL-cholesterol, and hypertension were identified as the three core risk factors, which promote inflammatory signals that contribute to metabolic syndrome and an increased risk of CRC.

Conclusions

These data hypothesized that simple measurement of abdominal obesity, abnormal BP and HDL-cholesterol especially using International Diabetes Federation (IDF) definition of MetS for South Asians for to detect individuals at CRC risk may have higher clinical utility than applying other universal complex MetS definitions.

Prospective Validation of the Iowa Rectal Surgery Risk Calculator

BACKGROUND

The Iowa Rectal Surgery Risk Calculator estimates risk for proctectomy procedures. The Iowa Calculator performed well on NSQIP 2010-2011 training and 2005-2009 validation datasets, but was not prospectively validated and did not include low anterior resections. This study sought to demonstrate validity on new independent data, to update the calculator to include low anterior resection, and to compare performance to other risk assessment tools.

METHODS

Non-emergent ACS-NSQIP proctectomy and low anterior resection data from 2010 to 2015 (n = 65,683) were included. The Iowa Calculator generated risk estimates for 30-day morbidity using 2012-2015 data. An Updated Calculator used 2010-2011 training data to include low anterior resection, with validation on 2012-2015 data. NSQIP data provided NSQIP Morbidity Model predictions and a custom web-script collected ACS-NSQIP Online Surgical Risk Calculator predictions for all patients.

RESULTS

Proctectomy morbidity (not including low anterior resection) decreased from 40.4% in 2010-2011 to 37.0% in 2012-2015. Low anterior resection had lower morbidity (22.4% in 2012-15). The Iowa Calculator demonstrated good discrimination and calibration using 2012-2015 data (C-statistic 0.676, deviance + 9.2%). After including low anterior resection, the Updated Iowa Calculator performed well during training (c-statistic 0.696, deviance 0%) and validation (C-statistic 0.706, deviance + 7.9%). The Updated Iowa Calculator had significantly better discrimination and calibration than morbidity predictions from the ACS Online Calculator (C-statistic 0.693, P < 0.001, deviance - 28.1%) and NSQIP General/Vascular Surgery Model (C-statistic 0.703, P < 0.05, deviance - 40.8%).

CONCLUSION

When applied to new independent data, the Iowa Calculator supplies accurate risk estimates. The Updated Iowa Calculator includes low anterior resection, and both are prospectively validated. Risk estimation by the Iowa Calculators was superior to ACS-provided risk tools.

The Impact of Body Mass Index and Waist Circumference on Health-related Quality of Life Among Colorectal Cancer Survivors: Results from the PROFILES Registry

BACKGROUND

We aimed to assess the association of waist circumference (WC) and body mass index (BMI) with health-related quality of life (HRQL) among colorectal cancer (CRC) survivors.

METHODS

CRC survivors diagnosed between 2000 and 2009 completed questionnaires in August 2013 (with self-reported weight, height, and self-assessed WC) and January 2014 (with HRQL using the EORTC-QLQ-C30). Clinical characteristics were retrieved from the Netherlands Cancer Registry. In multivariable linear regression analyses associations of BMI only, WC only and both BMI and WC with HRQL outcomes were assessed.

RESULTS

1,111 CRC survivors were included of whom 34% had a normal weight (18.5 ≤ BMI < 25 kg/m²), 49% had overweight (25 ≤ BMI < 30 kg/m²), 17% had obesity (BMI ≥ 30 kg/m²), and 44% had an increased WC (i.e., >102 and >88 cm for men and women, respectively). Both BMI and WC were separately associated with worse global health status, functioning, and more symptoms of fatigue. Increased WC was associated with lower physical, role and emotional functioning, regardless of BMI, with average differences ranging between 3 and 5 points.

CONCLUSION

Future research on HRQL among CRC survivors should consider both BMI and WC. Furthermore, weight reduction trials should not only focus on general weight loss but also on the loss of abdominal fat.

Association Between Obesity and Wound Infection Following Colorectal Surgery: Systematic Review and Meta-Analysis

BACKGROUND

The aim of this meta-analysis is to comprehensively review and quantify the excess risk of surgical site infections (SSI) in obese patients following colorectal surgery.

METHODS

A systematic electronic search of the MEDLINE and EMBASE databases identified studies that investigated the association of obesity, defined by body mass index (BMI) with SSI among colorectal surgery patients.

RESULTS

Twelve studies were included in the final analysis. Patients with BMI ≥30 kg/m² were at 1.5 times (pooled OR 1.51, 95% CI: 1.39, 1.63, p < 0.001) higher odds of developing SSI after colorectal surgery when compared to BMI <30 kg/m². Subgroup analysis of the eight studies that investigated only elective procedures showed that the odds of developing SSI when BMI ≥30 kg/m² is 1.6 times that of those with BMI <30 kg/m² (pooled OR 1.60; 95% CI 1.34, 1.86; p < 0.001). The odds of having SSI when BMI is 25-29.9 kg/m² are 1.2 times than those with BMI <25 kg/m² (pooled OR 1.17; 95% CI 1.07, 1.28; p < 0.001).

CONCLUSION

Overweight and obese patients carry at least 20% and 50% higher odds of developing SSI after colorectal surgery compared to normal weight patients, respectively.

Association of waist circumference with outcomes in an acute general surgical unit

BACKGROUND

Obesity prevalence is increasing in Australia, particularly in non-metropolitan areas. The effect of obesity on acute surgical outcomes is not known. We aimed to record waist circumference (WC) (surrogate for obesity) amongst acute surgical unit (ASU) patients in a New South Wales regional hospital, and compare outcome measures (length of stay (LOS), unplanned return to theatre, readmission rates, intensive care unit (ICU) admission and mortality).

METHODS

Retrospective cohort study of 4 months of consecutive ASU admissions, excluding age <16, pregnancy, out-of-area transfer and incomplete data. Patients were classified according to World Health Organization WC definitions as high-risk or non-high-risk (increased-risk and no-risk).

RESULTS

Of 695 admissions, 512 met the inclusion criteria (47.1% female, average age 52.8 years (SD 22.3)), with 85.1% (P < 0.001) of females and 69.4% (P = 0.166) of males having an increased- or high-risk WC. This compares to rates amongst inner regional populations of 71.0% (female) and 66.4% (male). LOS was longer for high-risk patients (5.0 days versus 3.7 days, P = 0.002). However, the mean age of high-risk patients was greater (56.6 years versus 46.9 years, P = 0.001) and LOS was longer for those aged ≥60 (P < 0.001). After controlling for age, high-risk WC was not associated with any outcome measure, except amongst ICU admissions, where high-risk patients stayed longer (15.5 days versus 6.8 days, P < 0.001).

CONCLUSION

Increased- and high-risk WC was overrepresented amongst female ASU patients. High-risk WC was associated with a significantly greater LOS in patients admitted to ICU. High-risk WC was not associated with other outcomes independent of age. WC is useful for quantifying obesity in the inpatient setting.

The Effect of Obesity and Increased Waist Circumference on the Outcome of Laparoscopic Nephrectomy

Introduction. The prevalence of obesity is increasing worldwide. Obesity can be determined by body mass index (BMI); however waist circumference (WC) is a better measure of central obesity. This study evaluates the outcome of laparoscopic nephrectomy on patients with an abnormal WC. Methods. A WC of >88 cm for women and >102 cm for men was defined as obese. Data collected included age, gender, American Society of Anaesthesiologists (ASA) score, renal function, anaesthetic duration, surgery duration, blood loss, complications, and duration of hospital stay. Results. 144 patients were assessed; 73 (50.7%) of the patients had abnormal WC for their gender. There was no difference between the groups for conversion to open surgery, number of ports used, blood loss, and complications. Abnormal WC was associated with a longer median anaesthetic duration, 233 min, IQR (215-265) versus 204 min, IQR (190-210), p = 0.0022, and operative duration, 178 min, IQR (160-190) versus 137 min, IQR (128-162), p < 0.0001. Patients with an abnormal WC also had a longer inpatient stay, p = 0.0436. Conclusion. Laparoscopic nephrectomy is safe in obese patients. However, obese patients should be informed that their obesity prolongs the anaesthetic duration and duration of the surgery and is associated with a prolonged recovery.

Risk factors for surgical site infection following colorectal resection: a multi-institutional study

INTRODUCTION

Surgical site infection (SSI) is an infection occurring in an incisional wound within 30 days of surgery and significantly affects patients undergoing colorectal surgery. This study examined a multi-institutional dataset to determine risk factors for SSI following colorectal resection.

METHODS

Data on 386 patients who underwent colorectal resection in three institutions were accrued. Patients were identified using a prospective SSI database and hospital records. Data are presented as median (interquartile range), and logistic regression analysis was used to identify risk factors.

RESULTS

Patients (21.5%) developed a postoperative SSI. The median time to the development of SSI was 7 days (5-10). Of all infections, 67.5% were superficial, 22.9% were deep and 9.6% were organ space. In univariate analysis, an ASA grade of II (RR 0.6, CI 0.3-0.9, P = 0.019), having an elective procedure (RR 0.4, CI 0.2-0.6, P < 0.001), using a laparoscopic approach (RR 0.5, CI 0.3-0.9, P = 0.019), having a daytime procedure (RR 0.3, CI 0.1-0.7, P = 0.006) and having a clean/contaminated wound (RR 0.4, CI 0.2-0.7, P = 0.001) were associated with reduced risk of SSI. In multivariate analysis, an ASA grade of IV (RR 3.9, CI 1.1-13.7, P = 0.034), a procedure duration over 3 h (RR 4.3, CI 2.3-8.2, P < 0.001) and undergoing a panproctocolectomy (RR 6.5, CI 1.0-40.9, P = 0.044) were independent risk factors for SSI. Those who developed an SSI had a longer duration of inpatient stay (22 days [16-31] vs 15 days [10-26], P < 0.001).

CONCLUSIONS

Patients who develop an SSI have a longer duration of inpatient stay. Independent risk factors for SSI following colorectal resection include being ASA grade IV, having a procedure duration over 3 h, and undergoing a panproctocolectomy.

Influence of BMI on short-term surgical outcome after colorectal cancer surgery: a study based on the Swedish national quality registry

PURPOSE

It is well known that an increased body mass index (BMI) is associated with cancer development. Results from studies on colorectal cancer (CRC) treatment outcome and BMI are however conflicting. Our hypothesis was that a high as well as a low BMI will have negative effects on short-term outcome after CRC surgery.

METHODS

Data from the Swedish Colorectal Cancer Registry from 2007 to 2012 was analyzed. A total of 24,587 patients operated on for CRC were included in the study and divided into one of five categories for BMI. Operative bleeding, operating time, surgical complications, and 30-day mortality were compared between groups.

RESULTS

Operative bleeding as well as operating time was significantly increased when comparing normal-weight patients to overweight (p < 0.001). 15.1% of normal-weight patients suffered from postoperative surgical complications. This was significantly increased with each BMI step but did not affect the 30-day mortality. However, underweight patients, on the other hand, had fewer complications (13.3%) but an increased 30-day mortality.

CONCLUSION

Longer operating times and increased perioperative bleeding may be explanatory factors behind increased postoperative complication rates for CRC patients with higher BMI. In underweight patients, advanced disease may be a reason for a higher 30-day mortality. To improve outcome, specific precautions are suggested when operating on under- as well as overweight CRC patients. We also suggest that the registry introduces a better marker than BMI for central visceral fat-the link between obesity and cancer development. Further studies are needed to analyze the findings in detail and to study long-term effects.

Association of abdominal obesity in children with perioperative respiratory adverse events

BACKGROUND/PURPOSE

Waist circumference (WC), a measure of abdominal obesity, is associated with several chronic disorders. Less is known about the association between WC and acute perioperative adverse events. The purpose of the present investigation was to test the hypothesis that abdominal obesity increases the occurrence of perioperative adverse events in children undergoing elective, noncardiac surgeries.

DESIGN

Prospective observational study.

METHODS

We studied the association between WC and perioperative adverse events in children aged 6 to 18 years who underwent elective noncardiac surgeries at our institution. Patients were considered to have abdominal obesity if WC was 90th percentile or greater for age and gender. Subsequently, univariate factors associated with abdominal obesity were explored and then odds ratios for the occurrence of perioperative respiratory adverse events were calculated from logistic regression after controlling for clinically pertinent covariates.

RESULTS

Among 1,102 patients, the prevalence of abdominal obesity was 23.1%. WC was positively correlated with age and measured anthropometric parameters. Composite perioperative adverse events were more frequent in children with abdominal obesity. After adjusting for several clinically relevant risk factors, abdominal obesity independently predicted increased relative odds of respiratory adverse events (OR = 2.35, 95% CI = 1.6 to 3.5, P < .001). Abdominal obesity was also associated with prolonged postanesthesia care unit (PACU) length of stay.

CONCLUSION

WC, a measure of abdominal obesity, is an independent predictor of perioperative respiratory adverse events in children undergoing elective noncardiac surgery. Furthermore, abdominal obesity was associated with prolonged PACU length of stay.

Impact of obesity on complications after resection for rectal cancer

AIM

The prevalence of obesity in Australia is high and increasing, with associated serious negative effects on health. The technical complexity of rectal cancer surgery is exacerbated in obese patients, which may compromise outcomes. The aim of this study was to examine the association between obesity and complications after resection of rectal cancer.

METHOD

Data were drawn from a comprehensive prospective registry of rectal cancer resections performed from 2007 to 2011 by members of the colorectal surgical unit in a tertiary referral hospital and in a single private hospital with which they were affiliated.

RESULTS

Of 255 patients who had a resection for rectal cancer during the study period, 95 (37%) were classified as obese on the basis of a body mass index (BMI) ≥ 30 kg/m(2) . Among 24 postoperative complications the only significant differences for obese patients were higher rates of wound complications (16% vs 8%, P = 0.038), small bowel obstruction (4% vs 0%, P = 0.019) and prolonged ileus (18% vs 8%, P = 0.011). The total number of complications did not differ significantly between obese and nonobese patients, and there was no difference between obese and nonobese patients in the rates of reoperation and postoperative death.

CONCLUSION

This study did not support an association between obesity and early postoperative complications after resection of rectal cancer.

Effect of BMI on outcomes in proctectomy

BACKGROUND

The unique surgical challenges of proctectomy may be amplified in obese patients. We examined surgical outcomes of a large, diverse sample of obese patients undergoing proctectomy.

OBJECTIVE

The purpose of this work was to determine whether increased BMI is associated with increased complications in proctectomy.

DESIGN

This was a retrospective review.

SETTINGS

The study uses the American College of Surgeons National Surgical Quality Improvement Program database (2010 and 2011).

PATIENTS

Patients included were those undergoing nonemergent proctectomy, excluding rectal prolapse cases. Patients were grouped by BMI using the World Health Organization classifications of underweight (BMI <18.5); normal (18.5-24.9); overweight (25.0-29.9); and class I (30.0-34.9), class II (35.0-39.9), and class III (≥40.0) obesity.

MAIN OUTCOME MEASURES

We analyzed the effect of preoperative and intraoperative factors on 30-day outcomes. Continuous variables were compared with Wilcoxon rank-sum tests and proportions with the Fisher exact or χ tests. Logistic regression controlled for the effects of multiple risk factors.

RESULTS

Among 5570 patients, class I, II, and III obesity were significantly associated with higher rates of overall complications (44.0%, 50.8%, and 46.6% vs 38.1% for normal-weight patients; p < 0.05). Superficial wound infection was significantly higher in classes I, II, and III (11.6%, 17.8%, and 13.0% vs 8.0% for normal-weight patients; p < 0.05). Operative times for patients in all obesity classes were significantly longer than for normal-weight patients. On multivariate analysis, an obese BMI independently predicted complications; ORs (95% CIs) were 1.36 (1.14-1.62) for class I obesity, 1.99 (1.54-2.54) for class II, and 1.42 (1.02-1.96) for class III.

LIMITATIONS

This study was a retrospective design with limited follow-up.

CONCLUSIONS

Class I, II, and III obese patients were at significantly increased risk for morbidity compared with normal BMI patients. Class II obese patients had the highest rate of complications, a finding that deserves further investigation.

Development of an improved risk calculator for complications in proctectomy

BACKGROUND

Rectal surgery is associated with high complication rates, but tools to prospectively define surgical risk are lacking. Improved preoperative risk assessment could better inform patients and refine decision making by surgeons. Our objective was to develop a validated model for proctectomy risk prediction.

METHODS

We reviewed non-emergent ACS-NSQIP proctectomy data from 2005 to 2011 (n = 13,385). Logistic regression identified variables available prior to surgery showing independent association with 30-day morbidity in 2010-2011 (n = 5,570). The resulting risk model's discrimination and calibration were tested against the NSQIP-supplied morbidity model, and performance was validated against independent 2005-2009 data.

RESULTS

Overall morbidity for proctectomy in 2010-2011 was 40.2%; significantly higher than the 23.0 % rate predicted by the NSQIP-provided general and vascular surgery risk model. Frequent complications included bleeding (16.3%), superficial infection (9.2%), and sepsis (7.4%). Our novel model incorporating 17 preoperative variables provided better discrimination and calibration (p < 0.05) than the NSQIP model and was validated against the 2005-2009 data. A web-based calculator makes this new model available for prospective risk assessment.

CONCLUSIONS

We conclude that the NSQIP-supplied risk model underestimates proctectomy morbidity and that this new, validated risk model and risk prediction tool ( http://myweb.uiowa.edu/sksherman ) may allow clinicians to counsel patients with accurate risk estimates using data available in the preoperative setting.

The relationship between visceral obesity and colorectal cancer

SUMMARY The prevalence of obesity continues to rise globally and physicians and healthcare systems have to prepare for rising rates of obesity-associated disease. Aside from cardiovascular disease and diabetes, recent evidence suggests a strong association between obesity and the development of cancer, including colorectal cancer. Using BMI as a marker for obesity, excess body fat is associated with an increased risk of colorectal cancer; however, this relationship appears to be stronger among males and more consistent for colon rather than rectal cancer. Epidemiologic literature evaluating the risk of obesity on colorectal cancer survival using BMI is less consistent. Recent evidence suggests that visceral fat plays a greater role in the development of disease. Current research on the effect of visceral obesity on colorectal cancer outcomes is in its infancy, but may drive a new wave of practice for this ever-growing population of colorectal cancer patients.

Laparoscopic surgery compared with open surgery decreases surgical site infection in obese patients: a systematic review and meta-analysis

OBJECTIVE

To compare surgical site infections rate in obese patients after laparoscopic surgery with open general abdominal surgery.

BACKGROUND

In mixed surgical populations, surgical site infections are fewer in laparoscopic surgery than in open surgery. It is not clear if this is also the case for obese patients, who have a higher risk of surgical site infections than nonobese patients.

METHODS

MEDLINE, Embase, and The Cochrane library (CENTRAL) were searched systematically for studies on laparoscopic surgery compared with open abdominal surgery. Randomized controlled trials (RCTs) and observational studies reporting surgical site infection in groups of obese patients (body mass index ≥ 30) were included. Separate meta-analyses with a fixed effects model for RCTs and a random effects model for observational studies were performed. Methodological quality of the included studies was assessed according to the Cochrane method and the Newcastle-Ottawa Scale.

RESULTS

Eight RCTs and 36 observational studies on bariatric and nonbariatric surgery were identified. Meta-analyses of RCTs and observational studies showed a significantly lower surgical site infection rate after laparoscopic surgery (OR = 0.19; 95% CI [0.08-0.45]; P = 0.0002 and OR = 0.33; 95% CI [0.26-0.42]; P = 0.00001). Sensitivity analyses to assess the impact of selection and detection bias confirmed the significant estimates with acceptable heterogeneity. No publication bias was present for the observational studies.

CONCLUSIONS

Laparoscopic surgery in obese patients reduces surgical site infection rate by 70%-80% compared with open surgery across general abdominal surgical procedures. Future efforts should be focused on further development of laparoscopic surgery for the growing obese population.

Visceral obesity and colorectal cancer: are we missing the boat with BMI?

INTRODUCTION

Compared to subcutaneous fat, visceral fat is more metabolically active, leading to chronic inflammation and tumorigenesis. The aim of this study is to describe the effect of visceral obesity on colorectal cancer outcomes using computed tomography (CT) imaging to measure visceral fat.

MATERIALS AND METHODS

We conducted a retrospective chart review of patients who underwent surgical resection for colorectal cancer. Visceral fat volume was measured by preoperative CT scans. Final analysis was performed by stratifying patients based on oncologic stage.

RESULTS

Two hundred nineteen patients met the inclusion criteria, 111 viscerally obese and 108 nonobese. Body mass index (BMI) weakly correlated with visceral fat volume measurements (R (2) = 0.304). Whereas obese patients had no difference in survival when categorizing obesity by BMI, categorizing based on visceral fat volume resulted in significant differences in stage II and stage III patients. In stage II cancer, viscerally obese patients had a nearly threefold decrease in disease-free survival (hazard ratio (HR) = 2.72; 95 % confidence interval (CI) = 1.21, 6.10). In stage III cancer, viscerally obese patients had a longer time to recurrence (HR = 0.39; 95 % CI = 0.16, 0.99).

CONCLUSION

This study shows that viscerally obese patients with stage II colorectal cancer are at higher risk for poor outcomes and should be increasingly considered for adjuvant chemotherapy.

Preoperative body size and composition, habitual diet, and post-operative complications in elective colorectal cancer patients in Norway

BACKGROUND

Both malnutrition and obesity are related to worsened post-operative outcomes after colorectal surgery. Obese cancer patients may be malnourished as a result of short-term weight loss. The present study aimed to evaluate preoperative nutritional status, body composition and dietary intake related to post-operative complications (POC) and post-operative hospital days (POHD) in elective colorectal cancer (CRC) patients.

METHODS

Anthropometry, body composition measured by bioelectric spectroscopy and dietary habits assessed by a validated food-frequency questionnaire were examined in 100 newly-diagnosed CRC patients. Data from 30-day POC and POHD were collected from medical records. Nonparametric and chi-squared tests and logistic regression were used to analyse associations between body and dietary variables and post-operative outcome.

RESULTS

Twenty-nine patients had at least one POC. The median POHD was six. Body size and composition measures and short-term weight loss were no different between patients with and without POC, or between patients with POHD <7 and ≥7. Dietary variables were otherwise no different between patients with and without POC, although the median intake of marine n-3 polyunsaturated fatty acids (PUFA, the sum of eicosapentaenoic and docosahexaenoic acids) was significantly lower in patients with versus without POC (0.7 versus 1.2 g day(-1) , P = 0.04).

CONCLUSIONS

We found that preoperative body size, body composition and short-term weight loss were not related to 30-day post-operative outcomes in CRC patients. A high content of marine n-3 PUFA in preoperative habitual diets may protect against POC after CRC surgery.

The influence of iron status and genetic polymorphisms in the HFE gene on the risk for postoperative complications after bariatric surgery: a prospective cohort study in 1,064 patients

BACKGROUND

Gastric bypass surgery is a highly effective therapy for long-term weight loss in severely obese patients, but carries significant perioperative risks including infection, wound dehiscence, and leaks from staple breakdown. Iron status can affect immune function and wound healing, thus may influence peri-operative complications. Common mutations in the HFE gene, the gene responsible for the iron overload disorder hereditary hemochromatosis, may impact iron status.

METHODS

We analyzed 1064 extremely obese Caucasian individuals who underwent open and laparoscopic Roux-n-Y gastric bypass surgery at the Geisinger Clinic. Serum iron, ferritin, transferrin, and iron binding capacity were measured pre-operatively. All patients had intra-operative liver biopsies and were genotyped for the C282Y and H63D mutations in the HFE gene. Associations between surgical complications and serum iron measures, HFE gene status, and liver iron histology were determined.

RESULTS

We found that increased serum iron and transferrin saturation were present in patients with any post-operative complication, and that increased serum ferritin was also increased in patients with major complications. Increased serum transferrin saturation was also associated with wound complications in open RYGB, and transferrin saturation and ferritin with prolonged lengths of stay. The presence of 2 or more HFE mutations was associated with overall complications as well as wound complications in open RYGB. No differences were found in complication rates between those with stainable liver iron and those without.

CONCLUSION

Serum iron status and HFE genotype may be associated with complications following RYGB surgery in the extremely obese.