Impact of Visceral Obesity on Short-term Outcome After Laparoscopic Surgery for Colorectal Cancer: A Single Japanese Center Study

Obesity: A risk factor for postoperative complications in laparoscopic surgery for colorectal cancer

BACKGROUND

The prevalence of obesity in the Eastern Mediterranean is increasing significantly up to 20.8% in 2016. Therefore, a higher percentage of colorectal cancer (CRC) patients are expected to be obese. Laparoscopic colorectal cancer surgery (LCRCS) is regarded as a safe and feasible procedure as laparoscopic approach is becoming the gold standard in CRC surgery, especially in the early stages of disease. However, LCRCS is correlated with a higher risk of short-term post-operative complications in obese patients (body mass index [BMI] ≥30 Kg/m 2 ) than in patients with BMI <30 Kg/m 2 . This study aims to evaluate the impact of obesity on short-term post-operative complications in patients undergoing LCRCS.

MATERIALS AND METHODS

A retrospective study was conducted. Clinical data of case and control patients were extracted from medical records. These patients underwent LCRCS between January 2018 and June 2021 at Hôtel-Dieu de France Hospital, Beirut-Lebanon. Patients were divided into two groups: obese and non-obese. BMI ≥30 Kg/m 2 was used to define obese patients. Post-operative complications in the 30 days following surgery were the primary outcome. The severity of post-operative complications was evaluated using the Clavien-Dindo score. Chi-square test was used to evaluate the statistical correlation between collected variables.

RESULTS

We identified 107 patients who underwent LCRCS during this study period at our institution. Among the patients, 23 were obese (21.49%). At 30 days post-operative, 26 patients were reported to having at least one complication. Non-significant differences were found between the two groups regarding the early post-operative complications rate (obese 26.1% and non-obese 23.8% with P = 0.821). Obesity was not demonstrated as a stratification risk by severity of the early post-operative complications ( P = 0.92).

CONCLUSION

Obesity, which was defined as BMI ≥30 Kg/m 2 , was not a risk factor for early post-operative complications as well as a stratification risk by severity of post-operative complications in LCRCS.

Laparoscopic colectomy in the obese, morbidly obese, and super morbidly obese: when does weight matter?

PURPOSE

Previous studies have demonstrated that obese patients (BMI >30) undergoing laparoscopic colectomy have longer operative times and increased complications when compared to non-obese cohorts. However, there is little data that specifically evaluates the outcomes of obese patients based on the degree of their obesity. The aim of this study was to evaluate the impact of increasing severity of obesity on patients undergoing laparoscopic colectomy.

METHODS

A retrospective review was performed of all patients undergoing laparoscopic colectomy between 1996 and 2013. Patients were classified according to their BMI as obese (BMI 30.0-39.9), morbidly obese (BMI 40.0-49.9), and super obese (BMI >50). Main outcome measures included conversion rate, operative time, estimated blood loss, post-operative complications, and length of stay.

RESULTS

There were 923 patients who met inclusion criteria. Overall, 604 (65.4%), 257 (27.9%), and 62 (6.7%) were classified as obese (O), morbidly obese (MO), and super obese (SO), respectively. Clinicopathologic characteristics were similar among the three groups. The SO group had significantly higher conversion rates (17.7 vs. 7 vs. 4.8%; P = 0.031), longer average hospital stays (7.1 days vs. 4.9 vs. 3.4; P = 0.001), higher morbidity (40.3 vs. 16.3 vs. 12.4%; P = 0.001), and longer operative times (206 min vs. 184 vs. 163; P = 0.04) compared to the MO and O groups, respectively. The anastomotic leak rate in the SO (4.8%; P = 0.027) and MO males (4.1%; P = 0.033) was significantly higher than MO females (2.2%) and all obese patients (1.8%).

CONCLUSION

Increasing severity of obesity is associated with worse perioperative outcomes following laparoscopic colectomy.

CT-based assessment of visceral adiposity and outcomes for esophageal adenocarcinoma

Background

Various methods of quantifying and correlating obesity to outcomes for patients with esophageal adenocarcinoma (EA) have been evaluated. Published data suggest that quantification of adiposity may be more accurate than body mass index (BMI) as a prognostic factor. We report our analysis of adiposity as a prognostic factor in a series of patients with EA.

Methods

This single institution retrospective review included patients with EA who underwent esophagectomy from 1994-2008. Patients with BMI <20 were excluded. Using the preoperative CT scan, the visceral (VFA), subcutaneous (SFA), and total abdominal fat (TFA) areas were calculated. Each was contoured on a Siemens Leonardo workstation at the level of the iliac crest (L4/5). The Hounsfield threshold was -30 to -130. Outcomes were analyzed using Kaplan-Meier method and log-rank analysis. Multivariate analysis (MVA) was performed using the Cox proportion hazard regression model.

Results

We identified 126 patients for the analysis. There were no statistically significant differences in overall survival or disease-free survival between groups above and below the medians for TFA, SFA, or VFA/SFA ratio. However, an increase in VFA was significantly associated with worsened OS and DFS when we further classified patients into quartiles. Patients with VFA ≥182 cm² had larger tumor size (P=0.016), fewer involved lymph nodes (P=0.047), longer operating times (P=0.032), and were more likely to be males (P=0.042).

Conclusions

Published data have demonstrated an association between treatment outcomes and degree of adiposity; our study found a correlation between VFA and OS and DFS in patients with EA. Median TFA, SFA, and VFA/SFA were not prognostic on MVA. While VFA >182 cm² was associated with larger tumors, there were also fewer lymph nodes harvested in this group.

BMI as a Predictor for Perioperative Outcome of Laparoscopic Colorectal Surgery: a Pooled Analysis of Comparative Studies

BACKGROUND

There has been a long-lasting controversy about whether higher BMI is associated with worse perioperative outcomes of laparoscopic colorectal surgery. Recently, a number of newly published investigations have made it possible to draw a quantitative conclusion.

OBJECTIVE

We conducted this comprehensive meta-analysis to clarify the exact effect that BMI imposes on perioperative outcome of laparoscopic colorectal surgery.

DATA SOURCES

We systematically searched MEDLINE, Embase, and Cochrane Library databases to identify all relevant studies.

STUDY SELECTION

Comparative studies in English that investigated perioperative outcome of laparoscopic colorectal surgery for patients with different BMIs were included. Quality of studies was evaluated by using the Newcastle-Ottawa Scale.

INTERVENTION

The risk factor of interest was BMI.

MAIN OUTCOME MEASURES

Effective sizes were pooled under a random-effects model to evaluate preoperative, intraoperative, and postoperative outcomes.

RESULTS

A total of 43 studies were included. We found that higher BMI was associated with significantly longer operative time (p < 0.001), greater blood loss (p = 0.01), and higher incidence of conversion to open surgery (p < 0.001). Moreover, BMI was a risk factor for overall complication rates (p < 0.001), especially for ileus (p = 0.02) and events of the urinary system (p = 0.03). Significant association was identified between higher BMI and risk of surgical site infection (p < 0.001) and anastomotic leakage (p = 0.02). Higher BMI might also led to a reduced number of harvest lymph nodes for patients with colorectal cancer (p = 0.02). The heterogeneity test identified no significant cross-study heterogeneity, and the results of cumulative meta-analysis, sensitivity analysis, and the publication bias test verified the reliability of our study.

LIMITATIONS

Most studies included were retrospectively designed.

CONCLUSIONS

Body mass index is a practical and valuable measurement for the prediction of the perioperative outcome of laparoscopic colorectal surgery. Higher BMI is associated with worse perioperative outcome. More accurate conclusions, with more precise cutoff values, can be achieved by future well-designed prospective investigations.

Laparoscopic colorectal cancer resections in the obese: a systematic review

BACKGROUND

Laparoscopic colorectal cancer operations in obese patients pose technical challenges that may negatively impact oncologic adequacy. A meta-analysis was performed to assess the oncologic outcomes of laparoscopic colorectal cancer resections in obese compared to non-obese patients. Short- and long-term outcomes were assessed secondarily.

METHODS

A systematic literature search was conducted from inception until October 01, 2014. Studies that compared outcomes of laparoscopic colorectal malignant neoplasms in obese and non-obese patients were selected for meta-analysis. Studies that defined obesity as body mass index (BMI) ≥ 30 kg/m² were included. Oncologic, operative, and postoperative outcomes were evaluated. Pooled odds ratios (OR) and weighted mean differences (WMD) with 95 % confidence intervals (CI) were calculated using fixed-effects models. For oncologic and survival outcomes, a subgroup analysis was conducted for rectal cancer and a secondary analysis was conducted for Asian studies that used a BMI cutoff of 25 kg/m².

RESULTS

Thirteen observational studies with a total of 4550 patients were included in the meta-analysis. Lymph node retrieval, distal, and circumferential margins, and 5-year disease-free and overall survival were similar in the obese and non-obese groups. Conversion rate (OR 2.11, 95 % CI 1.58-2.81), postoperative morbidity (OR 1.54, 95 % CI 1.21-1.97), wound infection (OR 2.43, 95 % CI 1.46-4.03), and anastomotic leak (OR 1.65, 95 % CI 1.01-2.71) were all significantly increased in the obese group.

CONCLUSIONS

Laparoscopic colorectal cancer operations in obese patients pose an increased technical challenge as demonstrated by higher conversion rates and higher risk of postoperative complications compared to non-obese patients. Despite these challenges, oncologic adequacy of laparoscopic colorectal cancer resections is comparable in both groups.

The influence of obesity and body mass index on the outcome of laparoscopic colorectal surgery: a systematic literature review

AIM

The relationship between obesity, body mass index (BMI) and laparoscopic colorectal resection is unclear. Our object was to assess systematically the available evidence to establish the influence of obesity and BMI on the outcome of laparoscopic colorectal resection.

METHOD

A search of PubMed/Medline databases was performed in May 2015 to identify all studies investigating the impact of BMI and obesity on elective laparoscopic colorectal resection performed for benign or malignant bowel disease. Clinical end-points examined included operation time, conversion rate to open surgery, postoperative complications including anastomotic leakage, length of hospital stay, readmission rate, reoperation rate and mortality. For patients who underwent an operation for cancer, the harvested number of lymph nodes and long-term oncological data were also examined.

RESULTS

Forty-five studies were analysed, the majority of which were level IV with only four level III (Oxford Centre for Evidence-based Medicine 2011) case-controlled studies. Thirty comparative studies containing 23 649 patients including 17 895 non-obese and 5754 obese showed no significant differences between the two groups with respect to intra-operative blood loss, overall postoperative morbidity, anastomotic leakage, reoperation rate, mortality and the number of retrieved lymph nodes in patients operated on for malignancy. Most studies, including 15 non-comparative studies, reported a longer operation time in patients who underwent a laparoscopic procedure with the BMI being an independent predictor in multivariate analyses for the operation time.

CONCLUSION

Laparoscopic colorectal resection is safe and technically and oncologically feasible in obese patients. These results, however, may vary outside of high volume centres of expertise.

Visceral obesity, muscle mass and outcome in rectal cancer surgery after neo-adjuvant chemo-radiation

BACKGROUND

Preoperative chemoradiation has become a routine modality in the treatment of rectal carcinoma that may impair a patients general condition. In these patients, it is important to identify factors that influence postoperative recovery. Visceral obesity(VO) as a metabolic risk factor was studied in rectal cancer patients receiving preoperative chemoradiation.

AIM

The impact of VO on post-operative outcome in rectal carcinoma surgery after preoperative chemoradiation was studied. In addition, the effect of chemoradiation on body composition was studied.

METHOD

The visceral fat area(VFA), total fat area(TFA) and skeletal muscle area(SMA) were measured on cross-sectional CT-slides in 74 patients who underwent rectal cancer surgery after chemoradiation. CT-scans taken before and after chemoradiation were analysed. Associations between VFA, per- and postoperative complications were studied. A VFA of 100 cm(2) and 130 cm(2) was used to differentiate between non-VO and VO.

RESULTS

Using a VO cut-off point of a VFA of 100 cm(2), the VO patients had more per-operative blood loss(471 mL vs 271 mL p = 0.020), a higher complication rate(10% vs 49% p = 0.001), more ileus(2% vs 28% p = 0.027) and a longer length of stay(9.7days vs 13days p = 0.027). When a VFA of 130 cm(2) was used, VO patients showed more complications(17% vs 55%, p = 0.001) and ileus(10% vs 32% p = 0.017). During chemoradiation the SMA increased(Mean difference: 2.2 cm(2) p = 0.024), while the VFA showed no change.

CONCLUSION

It appears that VO is associated with co-morbidity and poor outcome in rectal cancer patients. Using different cutoff values for VO different associations with outcome were found. SMA increased during chemoradiation, a phenomenon that remains to be explained.

Visceral obesity determined by CT scan and outcomes after colorectal surgery; a systematic review and meta-analysis

BACKGROUND

Visceral obesity may affect outcome after colorectal surgery. The visceral fat area as determined by CT scanning is considered the standard in the detection of visceral obesity.

METHOD

A systematic review was performed of trials investigating the effect of visceral obesity on outcomes of patients with colorectal cancer with no radiotherapy or chemotherapy and measured by CT scanning. The main endpoints were primary hospital stay, morbidity, operative time and blood loss. Quality assessment and data extraction were performed independently by two observers.

RESULTS

Seven studies were eligible for analysis, including 1230 patients. Primary hospital stay (weighted mean difference 1.16 days, 95% CI 0.0.05 to 2.28 days, p = 0.04), morbidity rates (RR 0.15, 95% CI 0.10 to 0.21, p < 0.00001) and operative time (weighted mean difference 20.47 min, 95% CI 12.76 to 28.17 min, p < 0.00001) were significantly higher for visceral obese patients. No difference was found in blood loss.

CONCLUSION

Visceral obesity leads to a longer hospital stay, higher morbidity and longer operative time after elective colon surgery. These findings show that the preoperative CT scan for detecting disseminated disease can be used to assess visceral obesity and helps in risk profiling patients undergoing elective colon surgery.

Factors associated with conversion from laparoscopic to open colectomy using the National Surgical Quality Improvement Program (NSQIP) database

AIM

Conversion rates from laparoscopic to open colectomy and associated factors are traditionally reported in clinical trials or reviews of outcomes from experienced institutions. Indications and selection criteria for laparoscopic colectomy may be more narrowly defined in these circumstances. With the increased adoption of laparoscopy, conversion rates using national data need to be closely examined. The purpose of this study was to use data from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) to identify factors associated with conversion of laparoscopic to open colectomy at a national scale in the United States.

METHOD

The ACS-NSQIP Participant Use Data Files for 2006-2011 were used to identify patients who had undergone laparoscopic colectomy. Converted cases were identified using open colectomy as the primary procedure and laparoscopic colectomy as 'other procedure'. Preoperative variables were identified and statistics were calculated using sas version 9.3. Logistic regression was used to model the multivariate relationship between patient variables and conversion status.

RESULTS

Laparoscopy was successfully performed in 41 585 patients, of whom 2508 (5.8%) required conversion to an open procedure. On univariate analysis the following factors were significant: age, body mass index (BMI), American Society of Anesthesiologists (ASA) class, presence of diabetes, smoking, chronic obstructive pulmonary disease, ascites, stroke, weight loss and chemotherapy (P < 0.05). The following factors remained significant on multivariate analysis: age, BMI, ASA class, smoking, ascites and weight loss.

CONCLUSION

Multiple significant factors for conversion from laparoscopic to open colectomy were identified. A novel finding was the increased risk of conversion for underweight patients. As laparoscopic colectomy is become increasingly utilized, factors predictive of conversion to open procedures should be sought via large national cohorts.

Sagittal abdominal diameter is a better predictor than body mass index for duration of laparoscopic left colectomy

BACKGROUND

Visceral obesity (VO) increases technical difficulty in laparoscopic surgery. The body mass index (BMI) does not always correlate to intra-abdominal fat distribution. Our hypothesis was that simple anthropometric measures that reflect VO, could predict technical difficulty in laparoscopic colorectal surgery, as reflected by the operative time, more accurately than the BMI.

METHODS

Charts of all consecutive patients who underwent laparoscopic left colon resection in our institution between 2007 and 2010 were reviewed retrospectively. On a preoperative CT scan, anthropometric measures were taken on an axial plane at the L4-L5 level. Demographic, operative and anthropometric CT measures were correlated with the operative time. Logistic regression analysis was performed to assess the value of anthropometric CT measures or BMI to predict the duration of the colectomy.

RESULTS

121 patients with elective left colon resection for benign (56%) or malignant disease (44%) were included. There were 74 sigmoid resections (61%), 21 left hemicolectomies (17%) and 26 low anterior resections (22%). A longer sagittal abdominal diameter (≥24.8 cm) was significantly associated with longer corrected operative time (248 vs. 228 min, p = 0.043). In multivariate analysis, greater sagittal abdominal diameter, sagittal internal diameter and abdominal perimeter were significantly associated with longer operative time. No significant association was found for the BMI neither in univariate nor in multivariate analysis.

CONCLUSIONS

This study suggests that simple linear measures taken on a CT scan, such as sagittal abdominal diameter, sagittal internal diameter and abdominal perimeter, may predict longer operative time in laparoscopic left colonic resections more accurately than BMI.

The impact of body mass index on perioperative outcomes in robot-assisted laparoscopic partial nephrectomy

BACKGROUND AND PURPOSE

Obese patients undergoing surgical procedures are at increased risk for perioperative morbidity. The purpose of this study is to determine whether there is an association with body mass index (BMI), clinicopathologic features, and perioperative outcomes and complications in patients undergoing robot-assisted laparoscopic partial nephrectomy (RPN).

PATIENTS AND METHODS

Medical records of 283 patients who underwent RPN between 2007 and 2012 were reviewed from an Institutional Review Board approved database. We analyzed the association of perioperative outcomes and complications of the surgery with BMI and clinicopathologic features using analysis of variance, Kruskal-Wallis test, t test and chi-square-test. Eventually, independent factors associated with perioperative outcomes and complications were studied using univariate and multivariate regression analysis.

RESULTS

Perioperative outcomes including estimated blood loss (EBL), length of hospital stay (LOS) and operative time (OT) were significantly associated with BMI (P=0.002, P=0.009 and P=0.002, respectively). Warm ischemia time (WIT), perioperative complications, and change in glomerular filtration rate (GFR) before and after surgery were not associated with BMI (P=0.459, P=0.86 and P=0.773). In multivariate analysis, BMI, tumor size≥4 cm, and collecting system invasion were independently associated with EBL and OT. Increased LOS was independently associated with BMI and tumor size ≥4 cm.

CONCLUSIONS

Increasing BMI was not associated with a significant increase in perioperative complications, WIT, or change in GFR in patients undergoing RPN at a high-volume tertiary medical center. Collecting system invasion or tumor size ≥4 cm and BMI were independently associated with higher EBL, LOS, and OT, however.

Republished: obesity and colorectal cancer

Excess body weight, as defined by the body mass index (BMI), has been associated with several diseases and includes subjects who are overweight (BMI≥25-29.9 kg/m(2)) or obese (BMI≥30 kg/m(2)). Overweight and obesity constitute the fifth leading risk for overall mortality, accounting for at least 2.8 million adult deaths each year. In addition around 11% of colorectal cancer (CRC) cases have been attributed to overweight and obesity in Europe. Epidemiological data suggest that obesity is associated with a 30-70% increased risk of colon cancer in men, whereas the association is less consistent in women. Similar trends exist for colorectal adenoma, although the risk appears lower. Visceral fat, or abdominal obesity, seems to be of greater concern than subcutaneous fat obesity, and any 1 kg/m(2) increase in BMI confers additional risk (HR 1.03). Obesity might be associated with worse cancer outcomes, such as recurrence of the primary cancer or mortality. Several factors, including reduced sensitivity to antiangiogenic-therapeutic regimens, might explain these differences. Except for wound infection, obesity has no significant impact on surgical procedures. The underlying mechanisms linking obesity to CRC are still a matter of debate, but metabolic syndrome, insulin resistance and modifications in levels of adipocytokines seem to be of great importance. Other biological factors such as the gut microbita or bile acids are emerging. Many questions still remain unanswered: should preventive strategies specifically target obese patients? Is the risk of cancer great enough to propose prophylactic bariatric surgery in certain patients with obesity?

Obesity was associated with a decreased postoperative recurrence of rectal cancer in a Japanese population

PURPOSE

Obesity contributes to the technical difficulty of rectal surgery and is considered to be a risk factor for postoperative complications. The impact of obesity on the long-term outcomes of rectal cancer surgery remains unclear.

METHODS

A total of 263 consecutive rectal cancer patients who underwent surgery were categorized into two groups according to the body mass index (BMI) based on the Asian BMI classification: non-obese (BMI <25 kg/m(2)) and obese (BMI ≥25 kg/m(2)). The postoperative survival and recurrence rates and oncological surgical quality indicators were compared between groups using the univariate and multivariate analyses. The differences in recurrence patterns were assessed by a competing risk regression analysis.

RESULTS

64 (24%) patients were included in the obese group. The number of retrieved lymph nodes was significantly greater in the non-obese group than in the obese group (22.4 vs. 16.0, P < 0.01). The 5-year disease-free survival (DFS) rates were 86.5 and 68.8% in the obese and non-obese groups, respectively (P = 0.01). The multivariate analysis demonstrated that obesity significantly decreased the postoperative recurrence rate (P = 0.04). Moreover, the BMI was significantly associated with distant metastasis (P = 0.04).

CONCLUSIONS

Obese rectal cancer patients have high DFS rates and a decreased incidence of distant metastases compared to non-obese patients. The BMI may be a key factor for predicting the postoperative prognosis and determination of an appropriate strategy for the treatment of rectal cancer patients.

The influence of obesity on short- and long-term outcomes after laparoscopic surgery for colon cancer: a case-matched study of 152 patients

BACKGROUND

Despite the increasing prevalence of obesity and colonic diseases, the impact of obesity on short-term and oncologic outcomes of laparoscopic colorectal surgery still remains unclear.

STUDY DESIGN

Seventy-six consecutive obese patients with body mass index (BMI) ≥30 kg/m(2) who underwent laparoscopic colectomy were matched with 76 nonobese patients with BMI <30 kg/m(2). Perioperative parameters and oncologic outcomes were analyzed in the two groups.

RESULTS

Obesity was associated with greater operative time (obese vs nonobese, 182 ± 59 vs 157 ± 55 min, P = .0084) and multivariate analysis identified BMI (hazard ratio 2.11, 95% confidence interval 0.64-3.56, P = .0049) as an independent predicting factor for operative time together with cancer location (hazard ratio 28.6, 95% confidence interval 14.62-42.51, P < .0001). Obesity had no adverse influence on overall morbidity (25 vs 21%, P = .563), however, or postoperative duration of stay (median 6.0 vs 5.5 days, P = .22). Furthermore, the rate of conversion to open procedure was similar between the two groups (9 vs 9%, P > .99). Regarding oncologic outcomes, there was no statistical difference in overall and disease-free survival between the two groups (5-year overall survival rate 86 vs 89%, P = .72, 5-year disease survival rate 70 vs 77%, P = .70).

CONCLUSION

Laparoscopic colonic resection, when performed for selected patients, appears to be a safe and reasonable option in obese patients with colon cancer resulting in similar short-term and oncologic outcomes as nonobese patients.

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.

Pathophysiology of human visceral obesity: an update

Excess intra-abdominal adipose tissue accumulation, often termed visceral obesity, is part of a phenotype including dysfunctional subcutaneous adipose tissue expansion and ectopic triglyceride storage closely related to clustering cardiometabolic risk factors. Hypertriglyceridemia; increased free fatty acid availability; adipose tissue release of proinflammatory cytokines; liver insulin resistance and inflammation; increased liver VLDL synthesis and secretion; reduced clearance of triglyceride-rich lipoproteins; presence of small, dense LDL particles; and reduced HDL cholesterol levels are among the many metabolic alterations closely related to this condition. Age, gender, genetics, and ethnicity are broad etiological factors contributing to variation in visceral adipose tissue accumulation. Specific mechanisms responsible for proportionally increased visceral fat storage when facing positive energy balance and weight gain may involve sex hormones, local cortisol production in abdominal adipose tissues, endocannabinoids, growth hormone, and dietary fructose. Physiological characteristics of abdominal adipose tissues such as adipocyte size and number, lipolytic responsiveness, lipid storage capacity, and inflammatory cytokine production are significant correlates and even possible determinants of the increased cardiometabolic risk associated with visceral obesity. Thiazolidinediones, estrogen replacement in postmenopausal women, and testosterone replacement in androgen-deficient men have been shown to favorably modulate body fat distribution and cardiometabolic risk to various degrees. However, some of these therapies must now be considered in the context of their serious side effects. Lifestyle interventions leading to weight loss generally induce preferential mobilization of visceral fat. In clinical practice, measuring waist circumference in addition to the body mass index could be helpful for the identification and management of a subgroup of overweight or obese patients at high cardiometabolic risk.

A nationwide analysis of laparoscopy in high-risk colorectal surgery patients

BACKGROUND

Due to safety concerns, the use of laparoscopy in high-risk colorectal surgery patients has been limited. Small reports have demonstrated the benefit of laparoscopy in this population; however, large comparative studies are lacking.

STUDY DESIGN

A retrospective review of the Nationwide Inpatient Sample 2009 was conducted. Patients undergoing elective colorectal resections for benign and malignant pathology were included in the high-risk group if they had at least two of the following criteria: age > 70, obesity, smoking, anemia, congestive heart failure, valvular disease, diabetes mellitus, chronic pulmonary, kidney and liver disease. Using multivariate logistic regression, the outcomes of laparoscopic surgery were compared to open and converted surgery.

RESULTS

Of 145,600 colorectal surgery cases, 32.79% were high-risk. High-risk patients had higher mortality, hospital charges, and longer hospital stay compared to low-risk patients. The use of laparoscopy was lower in the high-risk group with higher conversion rates. In high-risk patients, compared to open surgery, laparoscopy was associated with lower mortality (OR = 0.60), shorter hospital stay, lower charges, decreased respiratory failure (OR = 0.53), urinary tract infection (OR = 0.64), anastomotic leak (OR = 0.69) and wound complications (OR = 0.46). Conversion to open surgery was not associated with higher mortality.

CONCLUSIONS

Laparoscopy in high-risk colorectal patients is safe and may demonstrate advantages compared to open surgery.

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.

Which fast track elements predict early recovery after colon cancer surgery?

AIM

It is questioned whether all separate fast track elements are essential for enhanced postoperative recovery. We aimed to determine which baseline characteristics and which fast track elements are independent predictors of faster postoperative recovery in patients undergoing resection for colon cancer.

METHOD

Data from the LAFA trial database were used. In this trial, fast track care was compared with standard perioperative care in 400 patients undergoing laparoscopic or open surgery for colonic cancer. During admission 19 fast track elements per patient were prospectively evaluated and scored whether or not they were successfully applied. To identify predictive factors six baseline characteristics and those fast track items that were successfully achieved were entered in a univariate and multivariate linear regression analysis with total postoperative hospital stay (THS) as the primary outcome.

RESULTS

In 400 patients, two baseline characteristics and two fast track elements were found to be significant independent predictors of THS: female sex [B = 0.85; 95% CI 0.75-0.96; reduction of 15% (CI 14-25%) in THS], laparoscopic resection [B = 0.85; 95% CI 0.75-0.96; reduction of 15% (CI 14-25%) in THS], 'normal diet at postoperative days 1, 2 and 3' [B = 0.70; 95% CI 0.61-0.81; reduction of 30% (CI 19-39%) in THS] and 'enforced mobilization at postoperative days 1, 2 and 3' [B = 0.68; 95% CI 0.59-0.80; reduction of 32% (CI 20-41%) in THS].

CONCLUSION

Evaluating only those fast track elements that were successfully achieved, enforced advancement of oral intake, early mobilization, laparoscopic surgery and female sex were independent determinants of early recovery.

Association between visceral adiposity and colorectal polyps on CT colonography

OBJECTIVE

The purpose of this article is to determine whether there is an association between visceral adiposity measured on CT colonography (CTC) and colorectal polyps.

MATERIALS AND METHODS

Patients who underwent CTC and same-day optical colonoscopy (n = 1186) were analyzed. Visceral adipose tissue volumes and volume percentages relative to total internal body volume were measured on slices in the L2-L3 regions on supine CTC scans with validated fully automated software. Student t test, odds ratio, logistic regression, and receiver operating characteristic analyses were performed.

RESULTS

For subjects with (n = 345) and without (n = 841) adenomatous polyps, the mean (± SD) volume percentages were 31.2% ± 10.8% and 28.2% ± 11.3%, respectively (p < 0.0001). For subjects with (n = 244) and without (n = 942) hyperplastic polyps, the volume percentages were 31.8% ± 10.7% and 28.3% ± 11.2%, respectively (p < 0.0001). Comparing the lowest and highest quintiles of volume percentage, the odds ratios for having at least one adenomatous polyp or hyperplastic polyp versus no polyp were 2.06 (95% CI, 1.36-3.13) and 1.71 (95% CI, 1.08-2.71), and the prevalence of having adenomatous polyps or hyperplastic polyps increased by 14% and 8%, respectively.

CONCLUSION

Subjects with higher visceral adiposity measurements on CTC have a greater risk for the presence of colonic polyps.

The impact of obesity on perioperative outcomes after laparoscopic colorectal resection

OBJECTIVE

It is commonly perceived that surgery in obese patients is associated with worse outcomes than in nonobese patients. Because of the increasing prevalence of obesity and colonic diseases in the world population, the impact of obesity on outcomes of laparoscopic colectomy remains an important subject. The aim of this review was to evaluate the feasibility and safety of laparoscopic colectomy for colorectal diseases in obese patients compared with nonobese patients.

METHODS

We conducted a comprehensive review for the years 1983-2010 to retrieve all relevant articles.

RESULTS

A total of 33 studies were found to be eligible and included 3 matched case control studies and 1 review article. Obesity, often accompanied by preexisting comorbidities, was associated with longer operative times and higher rates of conversion to open procedures mainly because of the problem of exposure and difficulties in dissection. Although some studies showed obesity was associated with increased postoperative morbidity including cardiopulmonary and systemic complications, or ileus leading to longer hospital stay, there was no evidence about the negative impact of obesity on intraoperative blood loss, perioperative mortality, and reoperation rate. Whether obesity is a risk factor for wound infection after laparoscopic colectomy remains unclear. Though sometimes in obese patients, additional number of ports were necessary to successfully complete the procedure laparoscopically, obesity did not influence the number of dissected lymph nodes in cancer surgery. Lastly, the postoperative recovery of gastrointestinal function was similar between obese and nonobese patients.

CONCLUSIONS

Laparoscopic colorectal surgery appears to be a safe and reasonable option in obese patients offering the benefits of a minimally invasive approach, with no evidence for compromise in treatment of disease.

Body mass index and death rate of colorectal cancer among a national cohort of U.S. adults

Substantial evidence suggests that increasing adiposity is associated with an increased death rate of colorectal cancer, but no studies were conducted among national representative populations in the United States. The current study examined the death rate across BMI levels in 7,016 adults who participated in the National Health and Nutrition Examination Survey in 1971-1975. BMI categories were defined as normal (18.5-24.9 kg/m(2)), overweight (25-29.9), and obese (≥30). A total of 519 cancer deaths were identified during a 17-yr follow-up with 118,998 person-years. No significantly increased death rates of total cancers, lung, breast, and prostate cancer were observed among participants with an increased BMI. However, colorectal cancer death rates were 0.39, 0.68, and 0.96/1,000 person-years, respectively, for normal weight, overweight, and obese (P value for log-rank trend test < 0.001), and the corresponding adjusted hazard ratios [95% confidence intervals (CI)] were 1.00 (reference), 1.25 (95% CI = 0.72-2.19), and 2.04 (1.08-3.83), respectively. No gender difference of the association was identified. The authors conclude that a significantly increased death rate of colorectal cancer was associated with excess body weight. The current study is an addition to the expanding body of literature indicating an increased risk of colorectal cancer development among the obese.

Outcome of laparoscopic colorectal surgery in obese and nonobese patients: a meta-analysis

BACKGROUND

Obese patients are generally believed to be at increased risk for surgery compared with those who are not obese. A meta-analysis was performed to assess the outcomes of laparoscopic colorectal surgery in obese and nonobese patients.

METHODS

A systematic literature search from inception to June 2011 was performed. Pooled odds ratios (OR) and weighted mean differences (WMD) with 95% confidence intervals (95% CI) were calculated using the fixed effects model or random effects model.

RESULTS

Eight observational studies identified and matched the selection criteria. Conversion rates (OR: 2.31, 95% CI: 1.74-3.08), operating time (WMD: 15.33, 95% CI: 1.81-28.85), and postoperative morbidity (OR: 2.11; 95% CI: 1.3-3.42) were all significantly increased in the obese group. Length of hospital stay and mortality were similar in both groups. For patients with cancer, there was no difference between groups for the number of harvested nodes and length of specimen.

CONCLUSIONS

Obesity is associated with increased conversion rate, operating time, and postoperative morbidity of laparoscopic colorectal surgery but does not affect surgical safety or oncological security.

Visceral obesity is associated with outcomes of total mesorectal excision for rectal adenocarcinoma

BACKGROUND AND OBJECTIVES

General obesity, measured by the body mass index (BMI), increases the technical difficulty of total mesorectal excision (TME) but does not affect oncologic outcomes. The purpose of this study is to compare visceral and general obesity as predictors of outcomes of TME for rectal adenocarcinoma.

METHODS

Adult patients undergoing TME for rectal adenocarcinoma were retrospectively identified. Preoperative computed tomography scans were used to measure abdominal circumference (AC), visceral (VFA), and subcutaneous fat area (SFA). BMI, AC, VFA, SFA, total fat area (TFA, sum of VFA and SFA), and VFA/SFA ratio were examined for association with operative, postoperative, oncologic, and survival outcomes in a univariate analysis model.

RESULTS

Between 1999 and 2009, 113 patients met inclusion criteria. Increasing VFA and VFA/SFA ratio were associated with reduced lymph node retrieval (P = 0.03 and P = 0.009, respectively). The association between increasing VFA/SFA ratio with delayed resumption of oral intake (P = 0.05) and prolonged overall survival (P = 0.003) were also significant. Increasing BMI was associated with improved overall (P = 0.02) but not disease-free survival (P = 0.14).

CONCLUSION

Visceral obesity, measured by VFA/SFA ratio, is a better predictor of postoperative, oncologic, and survival outcomes after TME for rectal adenocarcinoma than general obesity measured by the BMI.

Obese patients benefit from minimally invasive colorectal cancer surgery

BACKGROUND

Minimally invasive surgery (MIS) for colorectal cancer offers improved short-term outcomes compared with open surgery. However, there is concern that MIS is more difficult in obese patients and may be associated with worse oncologic outcomes while failing to preserve short-term benefits. We hypothesized that obese patients undergoing surgery for colorectal cancer (CRC) would benefit from MIS.

METHODS

Retrospective database review.

RESULTS

Database review identified 155 obese patients undergoing resections for CRC from 2002-2009. Open cases accounted for 73% (N = 113) and MIS for 27% (N = 42). Conversion from MIS to open surgery occurred in 26% of cases. Obese patients had a nonsignificantly decreased rate of wound infection after MIS (21%) versus open surgery (28%, P < 0.645), while the incidence of other complications did not differ by surgical approach. The MIS cohort demonstrated faster return of bowel function and returned home a median of 2 days faster group than in the open surgery group (P < 0.003). From an oncologic standpoint, MIS was at least equivalent to open surgery as median number of lymph nodes extracted (20 versus 15, P < 0.073) and proportion of margin negative resections (97% versus 98%, P < 0.654) did not significantly differ between the two groups.

CONCLUSIONS

Minimally invasive surgery for CRC is safe and effective in obese patients since bowel function recovers rapidly, and hospital stay is significantly reduced while the quality of oncologic care is maintained.

Obesity increases wound complications in rectal cancer surgery

BACKGROUND

Obesity increases the risk of wound infections following surgery for colon cancer. Considerably less data is available, however, regarding the impact of obesity on infections and wound complications after resection for rectal cancer. Additionally, the impact of minimally invasive surgery (MIS) on complications in rectal surgery remains unclear. We hypothesized that obesity is associated with prolonged operative time and more infectious complications in obese patients undergoing both MIS and open surgery for rectal cancer.

MATERIALS AND METHODS

Review of retrospective surgical database.

RESULTS

One hundred fifty patients underwent surgery for rectal cancer from 2002 to 2009. Open cases accounted for 72% (n = 108) and MIS for 28% (n = 42) of cases. BMI did not correlate with increased operative time in open rectal surgery, but in MIS patients, operative time increased from a median of 254 min in the lowest quartile of BMI to 333 min in the highest quartile (P < 0.004). Superficial wound infections in open rectal surgery increased from 17% to 52% with increasing BMI (P < 0.005). The increased rate of wound complications persisted in the MIS group. Rate of superficial wound infections and subsequent open packing in the MIS group increased from 0% in the lowest BMI quartile to 33% in the highest quartile (P < 0.029 and P < 0.007, respectively).

CONCLUSIONS

Elevated BMI is associated with increased wound complications in both minimally invasive and open rectal surgery. This trend may be related to prolonged operative time in obese patients, particularly in MIS. Our observations suggest that more aggressive techniques to prevent infection are warranted in obese patients undergoing rectal surgery.