Visceral Fat and Anastomotic Leakage After Colon Cancer Resection

Association of computed tomography-derived body composition and complications after colorectal cancer surgery: A systematic review and meta-analysis

The prediction of the risk of developing complications after colorectal surgery for colorectal carcinoma remains imprecise. Body composition measurements on a computed tomography (CT) scan can potentially contribute to a better preoperative risk assessment. The aim of this systematic review is to evaluate the evidence for the use of body composition measurements on CT scans to predict short-term complications after colorectal cancer surgery. A literature search (in PubMed, Embase and Web of Science) was performed up to 1 August 2022. Two researchers independently screened the articles, extracted data and assessed the quality of the studies using the Quality in Prognosis Studies tool. The primary outcome measure was the occurrence of complications within 30 days after surgery. Meta-analysis was conducted using a random-effects model to synthesize a pooled odds ratio (OR). The study protocol was registered in PROSPERO (CRD42021281010). Forty-five articles with a total of 16 537 patients were included. In total, 26 body composition measures were investigated: 8 muscle-related measures, 11 adipose tissue measures, 4 combined muscle and adipose tissue measures, and 3 other measures. These were investigated as potential predictors for more than 50 differently defined postoperative complications. Meta-analysis was only possible for two measurements and showed that higher amounts of visceral fat increase the risk of developing overall complications (OR: 2.52 [1.58-4.00], P < 0.0001) and anastomotic leakage (OR: 1.76 [1.17-2.65], P = 0.006). A wide variety of body composition measurements on preoperative CT scans have been investigated as a predictive factor for postoperative complications. Visceral fat appeared to be associated with overall complications and anastomotic leakage; however, the association is weak, and its clinical relevance or applicability is questionable. The current evidence is limited by methodological heterogeneity and the risk of bias. To improve comparability of results across studies and improve decision-making, future studies should use standardized methods for measuring body composition on CT scans, outcome definitions and statistical analyses.

Impact of body fat location and volume on incisional hernia development and its outcomes following repair

BACKGROUND

Obesity is known to increase the likelihood of developing abdominal wall hernias, body mass index (BMI) alone does not provide detailed information about the amount and location of body fat. The aim of this study was to investigate the link between various adipose tissue parameters and the incidence of incisional hernias (IHs), as well as the outcomes of hernia repair.

METHODS

We conducted a comprehensive review of the existing literature to examine the relationship between various body fat parameters and the occurrence of IHs after abdominal surgeries, as well as the outcomes of hernia repair.

RESULTS

Thirteen studies were included for analysis. Eight trials evaluated the IH development after abdominal surgeries via specific fat parameters, and five studies evaluated the postoperative outcomes after IH repair. The findings of this study suggest that an increase in visceral fat volume (VFA or VFV) and subcutaneous fat (SFA or SFV) are linked to a higher incidence of IHs after abdominal surgeries. Higher levels of VFV or VFA were associated with more challenging fascia closure and greater postoperative recurrence rates following repair. Whereas BMI did not demonstrate a significant association.

CONCLUSION

Measuring visceral and subcutaneous fat composition preoperatively can be a useful tool for assessing the risk of IH, and is more reliable than BMI. Elevated levels of these fat parameters have been linked to increased recurrence of IH following hernia repair, as well as the use of complex surgical techniques during repair.

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.

Predictive modeling based on tumor spectral CT parameters and clinical features for postoperative complications in patients undergoing colon resection for cancer

BACKGROUND

Colon cancer is a particularly prevalent malignancy that produces postoperative complications (POCs). However, limited imaging modality exists on the accurate diagnosis of POCs. The purpose of this study was therefore to construct a model combining tumor spectral CT parameters and clinical features to predict POCs before surgery in colon cancer.

METHODS

This retrospective study included 85 patients who had preoperative abdominal spectral CT scans and underwent radical colon cancer resection at our institution. The patients were divided into two groups based on the absence (no complication/grade I) or presence (grades II-V) of POCs according to the Clavien-Dindo grading system. The visceral fat areas (VFA) of patients were semi-automatically outlined and calculated on L3-level CT images using ImageJ software. Clinical features and tumor spectral CT parameters were statistically compared between the two groups. A combined model of spectral CT parameters and clinical features was established by stepwise regression to predict POCs in colon cancer. The diagnostic performance of the model was evaluated using the receiver operating characteristic (ROC) curve, including area under the curve (AUC), sensitivity, and specificity.

RESULTS

Twenty-seven patients with POCs and 58 patients without POCs were included in this study. MonoE40keV-VP and VFA were independent predictors of POCs. The combined model based on predictors yielded an AUC of 0.84 (95% CI: 0.74-0.91), with a sensitivity of 77.8% and specificity of 87.9%.

CONCLUSIONS

The model combining MonoE40keV-VP and VFA can predict POCs before surgery in colon cancer and provide a basis for individualized management plans.

CRITICAL RELEVANCE STATEMENT

The model combining MonoE40keV-VP and visceral fat area can predict postoperative complications before surgery in colon cancer and provide a basis for individualized management plans.

KEY POINTS

• Visceral fat area and MonoE40keV-VP were independent predictors of postoperative complications in colon cancer. • The combined model yielded a high AUC, sensitivity, and specificity in predicting postoperative complications. • The combined model was superior to the single visceral fat area or MonoE40keV-VP in predicting postoperative complications.

Visceral obesity and anastomotic leakage rates in colorectal cancer: a systematic review and meta-analysis

Background

Numberous studies have heatedly discussed whether obesity is a risk factor for anastomotic leakage (AL) because of the increasing number of colorectal cancer (CRC) cases and high incidence of CRC in patients with obesity.

Objective

We aimed to explore the relationship between visceral obesity(VO) and AL after CRC surgery. The databases of Pubmed, Embase, and the Cochrane Library were searched for relevant data and articles published until November 1, 2022. We identified the difference in the incidence of AL after CRC surgery between patients with and without VO. The quality of included studies was evaluated using the Newcastle- Ottawa Scale, and odds ratio (OR) and 95% CI were used to assess the association between VO and AL.

Results

This meta-analysis included 7 studies with 2,136 patients. The OR of patients with VO versus those without VO was 2.15 (95%CIs = 1.46-3.15, test for heterogeneity: P = 0.29, I2 = 18%) based on the fixed-effect model in seven studies. Notably, the difference between the two groups was statistically significant (Z = 3.91 P < 0.0001). Patients with VO in the colon cancer group exhibited a higher incidence of AL (OR = 2.88, 95% CIs = 1.38-5.99, test for heterogeneity: P = 0.27, I2 = 20%) than those in the rectal cancer group (OR = 2.74, 95% CIs = 1.13-6.65, test for heterogeneity: P = 0.20, I2 = 38%). In the studies in the relevant literature, heterogeneity was low. Regarding patients with VO, four Asian studies reported increased morbidity due to AL (OR = 2.79, 95% CIs = 1.35-5.78, test for heterogeneity: P = 0.35, I2 = 9%) compared with three non-Asian studies.

Conclusions

Our findings confirmed the significant relationship between VO and AL. Thus, VO could be considered a reliable risk factor of surgery for colon cancer.

Anastomotic leak risk factors following colon cancer resection: a systematic review and meta-analysis

BACKGROUND

Despite improved surgical techniques, anastomotic leakage is still a serious complication that can occur after colon cancer resection, resulting in increased morbidity and mortality. The aim of this study was to evaluate the risk factors for anastomotic leakage after colon cancer surgery, provide a theoretical basis for reducing its occurrence, and guide the practice of clinicians.

METHODS

A systematic review of PubMed, Ovid, Web of Science and Cochrane Central Register of Controlled Trials databases was conducted by using a combination of subject terms and free words for online searches. The databases were searched from their inception to 31 March 2022, and all cross-sectional, cohort or case‒control studies examining the risk factors for the development of anastomotic fistula after surgery for colon cancer were identified.

RESULT

A total of 2133 articles were searched for this study, and 16 publications were ultimately included, all of which were cohort studies. A total of 115,462 subjects were included, and a total of 3959 cases of anastomotic leakage occurred postoperatively, with an incidence of 3.4%. The odds ratio (OR) and 95% confidence interval (CI) were used for evaluation. Male sex (OR = 1.37, 95% CI: 1.29-1.46, P < 0.00001), BMI (OR = 1.04, 95% CI: 1.00-1.08, P = 0.03), diabetes (OR = 2.80, 95% CI: 1.81-4.33, P < 0.00001), combined lung disease (OR = 1.28, 95% CI: 1.15-1.42, P < 0.00001), anaesthesia ASA score (OR = 1.35, 95% CI: 1.24-1.46, P < 0.00001), ASA class ≥ III (OR = 1.34, 95% CI: 1.22-1.47, P < 0.00001), emergency surgery (OR = 1.31, 95% CI: 1.11-1.55, P = 0.001), open surgery (OR = 1.94, 95% CI: 1.69-2.24, P < 0.00001) and type of surgical resection (OR = 1.34, 95% CI: 1.12-1.61, P = 0.002) are risk factors for anastomotic leakage after colon cancer surgery. There is still a lack of strong evidence on whether age (OR = 1.00, 95% CI: 0.99-1.01, P = 0.36) and cardiovascular disease (OR = 1.18, 95% CI: 0.94-1.47, P = 0.16) are factors influencing the occurrence of anastomotic leakage after colon cancer surgery.

CONCLUSIONS

Male sex, BMI, obesity, coexisting pulmonary disease, anaesthesia ASA score, emergency surgery, open surgery and type of resection were risk factors for anastomotic leakage after colon cancer surgery. The effect of age and cardiovascular disease on postoperative anastomotic leakage in patients with colon cancer needs further study.

Sarcobesity, but not visceral fat, is an independent risk factor for complications after radical resection of colorectal cancer

Background

The influence of body composition on the outcome of colorectal cancer surgery is controversial. The aim of this study was to evaluate the effects of visceral obesity and sarcobesity on the incidence of total and surgical complications after radical resection of colorectal cancer.

Methods

We collected a total of 426 patients who underwent elective radical resection of colorectal cancer at Beijing Friendship Hospital, Capital Medical University from January 2017 to May 2018. According to the inclusion and exclusion criteria, 387 patients were finally included. A CT scan at the level of the L3-L4 intervertebral disk was selected to measure the values of visceral fat area and skeletal muscle area. Multivariate analysis was used to explore the independent risk/protective factors affecting postoperative complications.

Results

128 (33.1%) patients developed complications, and 44 (11.4%) patients developed major complications. Among them, 111 patients developed surgical complications and 21 developed medical complications. Visceral fat area (Z = -3.271, p = 0.001), total fat area (Z = -2.613, p = 0.009), visceral fat area to subcutaneous fat area ratio (V/S, Z = -2.633, p = 0.008), and sarcobesity index (Z = -2.282, p = 0.023) were significantly associated with total complications. Visceral fat area (Z = -2.119, p = 0.034) and V/S (Z = -2.010, p = 0.044) were significantly associated with total surgical complications. Sarcobesity index, smoking, stoma, blood loss, surgery time, and American Society of Anesthesiology (ASA) score were selected as risk factors for total postoperative complications according to LASSO regression. Multivariate logistic regression analysis suggested that sarcobesity index was an independent risk factor for postoperative total complications and surgical complications. Subgroup analysis suggested that albumin level was an independent protective factor for postoperative total complications in male patients. Smoking, operative time, and sarcobesity index were independent risk factors, and cholesterol was an independent protective factor for total postoperative complications in female patients.

Conclusion

Increased sarcobesity index is an independent risk factor for postoperative complications in patients with colorectal cancer, while visceral fat area is not. For female patients, smoking, operation time, and obesity index are independent risk factors for postoperative complications, while cholesterol is an independent protective factor. For male patients, serum albumin is an independent protective factor for postoperative complications.

Predictive Factors for Anastomotic Leakage Following Colorectal Cancer Surgery: Where Are We and Where Are We Going?

Anastomotic leakage (AL) remains one of the most severe complications following colorectal cancer (CRC) surgery. Indeed, leaks that may occur after any type of intestinal anastomosis are commonly associated with a higher reoperation rate and an increased risk of postoperative morbidity and mortality. At first, our review aims to identify specific preoperative, intraoperative and perioperative factors that eventually lead to the development of anastomotic dehiscence based on the current literature. We will also investigate the role of several biomarkers in predicting the presence of ALs following colorectal surgery. Despite significant improvements in perioperative care, advances in surgical techniques, and a high index of suspicion of this complication, the incidence of AL remained stable during the last decades. Thus, gaining a better knowledge of the risk factors that influence the AL rates may help identify high-risk surgical patients requiring more intensive perioperative surveillance. Furthermore, prompt diagnosis of this severe complication may help improve patient survival. To date, several studies have identified predictive biomarkers of ALs, which are most commonly associated with the inflammatory response to colorectal surgery. Interestingly, early diagnosis and evaluation of the severity of this complication may offer a significant opportunity to guide clinical judgement and decision-making.

Impacts of trans-anal tube placement in patients with sigmoid colon cancer: Risk verification analysis using inverse probability weighting analysis

Purpose

Anastomotic leakage (AL) is a serious postoperative complication that affects short- and long-term outcomes. The use of a trans-anal drainage tube (TDT) is reported to prevent AL in rectal cancer patients, but its value in sigmoid colon cancer patients is unknown.

Methods

Admitted to the study were 379 patients who underwent surgery for sigmoid colon cancer between 2016 and 2020. Patients were divided into two groups according to the placement (n = 197) or nonplacement of a TDT (n = 182). To determine the factors affecting the association between TDT placement and AL, we estimated average treatment effects by stratifying each factor using the inverse probability of treatment weighting method. The association between prognosis and AL was evaluated in each identified factor.

Results

Factors associated with postsurgical insertion of a TDT were advanced age, male sex, high body mass index (BMI), poor performance status, and presence of comorbidities. TDT placement was associated with a significantly lower AL in male patients (odds ratio [OR], 0.22; 95% confidence interval [CI], 0.07-0.73; P = .013) and for BMI ≥ 25 kg/m2 (OR, 0.13; 95% CI, 0.02-0.65; P = .013). In addition, there was a significant association of AL with poor prognosis in patients with BMI ≥ 25 kg/m2 (P = .043), age > 75 y (P = .021), and pathological node-positive disease (P = .015).

Conclusion

Sigmoid colon cancer patients with BMI ≥ 25 kg/m2 are the most appropriate candidates for postoperative TDT insertion, in terms of reduced incidence of AL and improved prognosis.

Exposure to oestrogen and risk of anastomotic leakage after colorectal cancer surgery - A clue to the different leak rates in men and women

BACKGROUND

Colorectal anastomotic leakage is consistently more common in men, regardless of tumour location. This fact is largely unexplained but might be a consequence of biological differences including hormonal exposure and not only related to anatomy.

METHODS

This was a retrospective, nationwide registry-based observational study of post-menopausal women operated for colorectal cancer with an anastomosis between 2007 and 2016. Hormonal exposure before surgery, as defined by prescribed drugs affecting oestrogen levels, was related to postoperative anastomotic leakage, using mixed-effects logistic regression models with adjustment for confounding. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were derived. In addition, separate estimates according to tumour location were computed, and a sensitivity analysis excluding topical oestrogen hormone exposure was conducted.

RESULTS

Some 16,535 post-menopausal women were included, of which 16.2% were exposed to drugs increasing oestrogen levels before surgery. In this exposed group compared to the unexposed, leak rates were 3.1 and 3.8%, respectively. After adjustment, a reduction of anastomotic leakage in the exposed group was detected (OR: 0.77; 95% CI: 0.59-0.99). This finding was largely attributed to the rectal cancer subgroup (OR: 0.55; 95% CI: 0.36-0.85), while the exclusion of topical oestrogen drugs further reduced the estimates of the main analysis (OR: 0.63; 95% CI: 0.38-1.02).

CONCLUSIONS

Anastomotic leakage rates are lower in women exposed to hormone replacement therapy before surgery for colorectal cancer, which might explain some of the difference in leak rates between men and women, especially regarding rectal cancer.

Impact of atherosclerosis on the postoperative complications of colorectal surgery in older patients with colorectal cancer

BACKGROUND

Atherosclerosis is associated with various comorbidities; nonetheless, its effect on the postoperative complications of colorectal surgery in older patients with colorectal cancer (CRC) remains unclear. This study aimed to evaluate the impact of atherosclerosis on the postoperative complications of colorectal surgery in older adults with CRC.

METHODS

Patients aged ≥ 65 years who underwent surgery for CRC between April 2017 and October 2020 were enrolled. To evaluate atherosclerosis, we prospectively calculated the cardio-ankle vascular index (CAVI) measured by the blood pressure/pulse wave test and abdominal aortic calcification (AAC) score from computed tomography. Risk factors for Clavien-Dindo grade ≥ III postoperative complications were evaluated by univariate and logistic regression analyses.

RESULTS

Overall, 124 patients were included. The mean CAVI value and AAC score were 9.5 ± 1.8 and 7.0 ± 8.0, respectively. Clavien-Dindo grade ≥ III postoperative complications were observed in 14 patients (11.3%). CAVI (odds ratio, 1.522 [95% confidence interval, 1.073-2.160], p = 0.019), AAC score (1.083 [1.009-1.163], p = 0.026); and operative time (1.007 [1.003-1.012], p = 0.001) were identified as risk factors for postoperative complications. Based on the optimal cut-off values of CAVI and AAC score, the probability of postoperative complications was 27.8% in patients with abnormal values for both parameters, which was 17.4 times higher than the 1.6% probability of postoperative complications in patients with normal values.

CONCLUSIONS

Atherosclerosis, particularly that assessed using CAVI and AAC score, could be a significant predictor of postoperative complications of colorectal surgery in older adults with CRC.

Comprehensive abdominal composition evaluation of rectal cancer patients with anastomotic leakage compared with body mass index-matched controls

BACKGROUND

Anastomotic leakage (AL) is a fatal complication in patients with rectal cancer after undergoing anterior resection. However, the role of abdominal composition in the development of AL has not been studied.

AIM

To investigate the relationship between abdominal composition and AL in rectal cancer patients after undergoing anterior resection.

METHODS

A retrospective case-matched cohort study was conducted. Complete data for 78 patients with AL were acquired and this cohort was defined as the AL group. The controls were matched for the same sex and body mass index (± 1 kg/m2). Parameters related to abdominal composition including visceral fat area (VFA), subcutaneous fat area (SFA), subcutaneous fat thickness (SFT), skeletal muscle area (SMA), skeletal muscle index (SMI), abdominal circumference (AC), anterior to posterior diameter of abdominal cavity (APD), and transverse diameter of abdominal cavity (TD) were evaluated based on computed tomography (CT) images using the following Hounsfield Unit (HU) thresholds: SFA: -190 to -30, SMA: -29 to 150, and VFA: -150 to -20. The significance of abdominal composition-related parameters was quantified using feature importance analysis; an artificial intelligence method was used to evaluate the contribution of each included variable.

RESULTS

Two thousand two hundred and thirty-eight rectal cancer patients who underwent anterior resection from 2010 to 2020 in a large academic hospital were investigated. Finally, 156 cases were enrolled in the study. Patients in the AL group showed longer operative time (225.03 ± 55.29 vs 207.17 ± 40.80, P = 0.023), lower levels of preoperative hemoglobin (123.32 ± 21.17 vs 132.60 ±1 6.31, P = 0.003) and albumin (38.34 ± 4.01 vs 40.52 ± 3.97, P = 0.001), larger tumor size (4.07 ± 1.36 vs 2.76 ± 1.28, P < 0.001), and later cancer stage (P < 0.001) compared to the controls. Patients who developed AL exhibited a larger VFA (125.68 ± 73.59 vs 97.03 ± 57.66, P = 0.008) and a smaller APD (77.30 ± 23.23 vs 92.09 ± 26.40, P < 0.001) and TD (22.90 ± 2.23 vs 24.21 ± 2.90, P = 0.002) compared to their matched controls. Feature importance analysis revealed that TD, APD, and VFA were the three most important abdominal composition-related features.

CONCLUSION

AL patients have a higher visceral fat content and a narrower abdominal structure compared to matched controls.

The impact of multiple firings on the risk of anastomotic leakage after minimally invasive restorative rectal cancer resection and the impact of anastomotic leakage on long-term survival: a population-based study

PURPOSE

The aim of this study was to evaluate the anastomotic leakage (AL) rate and predictors for AL following minimally invasive restorative rectal resection (RRR) among rectal cancer patients managed according to up-to-date standardized treatment. Furthermore, we explored the impact of symptomatic AL on long-term survival.

METHODS

The study cohort was rectal cancer patients undergoing minimally invasive RRR in Central Denmark Region between 2013 and 2017. Data was retrieved from a prospective clinical quality database and supplemented with data from medical records. The AL rate was calculated as the proportion of patients who developed symptomatic AL within 30 days. Predictors for AL were identified through logistic regression. The impact of AL on long-term survival was analyzed using Kaplan-Meier methods and Cox regression.

RESULTS

AL occurred in 15.1% of 604 patients. The AL rate for males was 20.1% (95% CI 16.3-24.3) and 5.0% (95% CI 2.4-9.0) for females. Odds ratio (OR) of AL in females vs. males was 0.25 (95% CI 0.12-0.51). The use of at least three firings when transecting the rectum was associated with OR of 2.71 (95% CI 1.17-6.26) for AL. The 5-year survival for patients with vs. those without AL was 76.1% (95%CI 65.1-84.0) and 83.6% (95%CI 79.8-86.7), corresponding to adjusted hazard ratio of 1.43 (95%CI 0.84-2.41).

CONCLUSION

Symptomatic AL is still a challenge in a standardized setting using minimally invasive surgery in rectal cancer patients undergoing RRR, especially in men. Multiple firings should be avoided in transection of the rectum with an endoscopic stapler. AL had a statistical non-significant negative impact on survival.

Identifying Key Genes and Functionally Enriched Pathways of Diverse Adipose Tissue Types in Cattle

Background: Fat is a tissue that not just stores energy and plays a protective role; it is also a vital endocrine organ that generates and integrates signals to influence metabolism. Meanwhile, the excessive accumulation of lipids in adipose tissue can lead to metabolic disturbance and diseases. To date, the complicated molecular mechanisms of bovine adipose tissue are still unknown. This study aimed to identify key genes and functionally enriched pathways in various adipose tissue types.

Results: The RNAseq data of 264 samples were downloaded from Gene Expression Omnibus (GEO) and analyzed by weighted gene co-expression network analysis (WGCNA). We identified 19 modules that significantly associated with at least one adipose tissue type. The brown module from GSE39618 was most closely associated with intramuscular fat tissue, which contained 550 genes. These genes were significantly enriched in pathways that related to inflammation and disease, such as TNF signaling pathway, IL-17 signaling pathway, and NF-kappa B signaling pathway. The pink module (GSE39618) that contained 58 genes was most closely associated with omental fat tissue. The turquoise (GSE39618), blue (GSE116775), and yellow (GSE65125) module were most closely associated with subcutaneous fat tissue. Genes in these modules were significantly enriched in pathways related to fat metabolism, such as the PPAR signaling pathway, fatty acid metabolism and PI3K-Akt signaling pathway. At last, key genes for intramuscular fat (PTGS2 and IL6), omental fat (ARHGEF5 and WT1), and subcutaneous fat (KIT, QR6Q1, PKD2L1, etc.) were obtained and verified. In addition, it was found that IL10 and VCAM1 might be potential genes to distinguish adipose and muscle.

Conclusion: The study applied WGCNA to generate a landscape of adipose tissue and provide a basis for identifying potential pathways and hub genes of different adipose tissue types.

Risk Factors and Preventive Measures for Anastomotic Leak in Colorectal Cancer

Anastomotic leak (AL) represents one of the most detrimental complications after colorectal surgery. The patient-related factors and surgery-related factors leading to AL have been identified in previous studies. Through early identification and timely adjustment of risk factors, preventive measures can be taken to reduce potential AL. However, there are still many problems associated with AL. The debate about preventive measures such as preoperative mechanical bowel preparation (MBP), intraoperative drainage, and surgical scope also continues. Recently, the gut microbiota has received more attention due to its important role in various diseases. Although the underlying mechanisms of gut microbiota on AL have not been validated completely, new strategies that manipulate intrinsic mechanisms are expected to prevent and treat AL. Moreover, laboratory examinations for AL prediction and methods for blood perfusion assessment are likely to be promoted in clinical practice. This review outlines possible risk factors for AL and suggests some preventive measures in terms of patient, surgery, and gut microbiota.

Metabolic syndrome; associations with adverse outcome after colorectal surgery. A systematic review and meta-analysis

Background

Increasing evidence shows that patients with Metabolic Syndrome (MetS) are at risk for adverse outcome after abdominal surgery. The aim of this study was to investigate the impact of MetS and preoperative hyperglycemia, as an individual component of MetS, on adverse outcome after colorectal surgery.

Methods

A literature review was systematically performed according to the PRISMA guidelines. Inclusion criteria were observational studies that evaluated the relationship between MetS or preoperative hyperglycemia and outcomes after colorectal surgery (i.e. any complication, severe complication defined as Clavien-Dindo grade ≥ III, anastomotic leakage, surgical site infection, mortality and length of stay).

Results

Six studies (246.383 patients) evaluated MetS and eight studies (9.534 patients) reported on hyperglycemia. Incidence rates of MetS varied widely from 7% to 68% across studies. Meta-analysis showed that patients with MetS are more likely to develop severe complications than those without MetS (RR 1.62, 95% CI 1.01–2.59). Moreover, a non-significant trend toward increased risks for any complication (RR 1.35, 95% CI 0.91–2.00), anastomotic leakage (RR 1.67, 95% CI 0.47–5.93) and mortality (RR 1.19, 95% CI 1.00–1.43) was found. Furthermore, preoperative hyperglycemia was associated with an increased risk of surgical site infection (RR 1.35, 95% CI 1.01–1.81).

Conclusion

MetS seem to have a negative impact on adverse outcome after colorectal surgery. As a result of few studies meeting inclusion criteria and substantial heterogeneity, evidence is not conclusive. Future prospective observational studies should improve the amount and quality in order to verify current results.

•

The prevalence of metabolic syndrome (MetS) in colorectal surgery patients is 7–68%.

•

MetS increases the risk of severe complications after colorectal surgery.

•

Preoperative hyperglycemia, as an individual component of MetS, is associated with surgical site infection.

•

Identification of MetS could be valuable in preoperative risk stratification.

Body composition in relation to postoperative anastomotic leakage and overall survival in patients with esophageal cancer

BACKGROUND

Body composition was reported to be related to the prognosis of patients with cancer. This study aimed to investigate the influence of preoperative body composition on anastomotic leakage and overall survival in patients with esophageal cancer.

METHODS

In this retrospective study, 93 patients with esophageal cancers were evaluated. Skeletal muscle area, intermuscular adipose tissue, visceral adipose tissue (VAT), and subcutaneous adipose tissue were measured on computed tomography images at the level of the third lumbar vertebra. Subsequently, each body composition index was also calculated by dividing the body composition by the square of the height. The cut-off values of body compositions were defined using X-tile software (version 3.6.1; Yale University, New Haven, CTA). Univariate and multivariate analyses were performed to evaluate the risk factors of anastomotic leakage. Kaplan-Meier method and Cox regression analysis were used to evaluate the risk factors of overall survival.

RESULTS

VAT and visceral fat index (VFI) were higher in patients with anastomotic fistula than in those without anastomotic fistula, but none of them were independent risk factors. Patients with higher body mass index (BMI), higher VFI, and higher subcutaneous fat index (SFI) had better overall survival. By multivariate analysis, SFI >27.6 cm²/m² was still significantly associated with overall survival.

CONCLUSION

Patients with higher VAT and VFI were prone to have an anastomotic leakage. Lower BMI, VFI, and SFI were associated with a reduction in overall survival.

Visceral obesity is a predictor of surgical site occurrence and hernia recurrence after open abdominal wall reconstruction

PURPOSE

High body mass index (BMI) increases the risk of postoperative complications and hernia recurrence after abdominal wall reconstruction (AWR). However, BMI does not provide specific information on the mass and distribution of adipose tissue. We hypothesized that visceral fat volume (VFV) was a better predictor than BMI for recurrence after AWR.

METHODS

We included all patients undergoing AWR at our institution from November 2010 to December 2016. Data were collected from a prospective database and all patients were summoned for follow-up. VFV was calculated from preoperative CT. The primary and secondary outcomes were hernia recurrence and 30-day postoperative surgical site occurrences (SSO), respectively.

RESULTS

We included a total of 154 patients. At follow-up, 42 (27.3%) patients had developed recurrence. The recurrence rate was significantly higher in patients with a VFV higher than the mean compared to a VFV lower than the mean, P = 0.004. After multivariable Cox-regression, VFV remained significantly predictive of recurrence (HR 1.09 per 0.5 L increase of VFV, P = 0.018). In contrary, BMI was not associated with hernia recurrence. There was no significant difference in the rate of SSO between patients with a VFV above and below the mean. A multivariable logistic regression model showed that VFV was significantly associated with development of SSO (OR 1.12 per 0.5 L increase, P = 0.009).

CONCLUSION

VFV was significantly associated with recurrence and SSOs after AWR. This study suggests VFV as a risk assessment tool for patients undergoing AWR.