Prediction of pancreatic anastomotic failure after pancreatoduodenectomy: the use of preoperative, quantitative computed tomography to measure remnant pancreatic volume and body composition.

OBJECTIVE: To determine whether remnant pancreatic volume (RPV), subcutaneous/visceral adipose tissue(SAT/VAT) area, and skeletal muscle (SM) area calculated from preoperative computed tomography (CT) can predict the occurrence of pancreatic anastomotic failure (PAF) after pancreatoduodenectomy (PD). BACKGROUND: Increased body mass index, small main pancreatic duct, and soft pancreatic texture are well-established predictors of PAF after PD. The impact on PAF of anthropomorphic measurements, such as RPV and body composition, is unknown. METHODS: In 173 patients undergoing PD from 2004 to 2009, cross sections of SAT/VAT/SM area were quantitated volumetrically, respectively, from preoperative CT. RPV was calculated from the CT as the sum of pancreatic tissue area to the left of the presumed pancreatic transection site. The predictive ability for multiple models using combinations of body mass index, RPV, SAT/VAT area, SM area, main pancreatic duct size, and pancreatic gland texture was described using a concordance index (c-index). RESULTS: Clinically relevant PAF occurred in 22 patients (13%). Multivariate logistic regression analysis identified RPV (P = 0.0012), VAT area (P = 0.0003), and SM area (P = 0.0006) as independent predictors of PAF. Using previously identified risk factors, the best 2-predictor model (body mass index and pancreatic duct size) resulted in a c-index of 0.748. Using anthropomorphic factors, however, the 2-predictor model using VAT and SM areas revealed a superior c-index of 0.959. CONCLUSIONS: Our 2-predictor model using VAT area and SM area based on volumetric quantification using preoperative CT may offer clinical benefit as an objective prognostic measure to predict clinically relevant PAF after PD.

Distribution of body fat and its influence on esophageal inflammation and dysplasia in patients with Barrett's esophagus.

BACKGROUND & AIMS: Increased waist circumference and visceral fat are associated with increased risk of Barrett's esophagus (BE) and esophageal adenocarcinoma. This association might be mediated by mechanical and endocrine mechanisms. We investigated the distribution of fat in subjects with BE and its association with esophageal inflammation and dysplasia. METHODS: We collected data from 50 BE cases and 50 controls (matched for age and sex, identified from a radiology trauma database) seen at the Mayo Clinic in 2009. Abdominal (subcutaneous and visceral) and gastroesophageal junction (GEJ) fat area was measured using computed tomography with standard techniques. Esophageal inflammation (based on a histologic score) and dysplasia grade were assessed from esophageal biopsies of BE cases by a gastrointestinal pathologist. Conditional logistic regression was used to assess the association of body fat depot area with BE status, esophageal inflammation, and dysplasia. RESULTS: All BE subjects had controlled reflux symptoms without esophagitis, based on endoscopy. The GEJ fat area (odds ratio [OR], 6.0; 95% confidence interval [CI], 1.3-27.7; P = .02), visceral fat area (OR, 4.9; 95% CI, 1.0-22.8; P = .04), and abdominal circumference (OR, 9.1; 95% CI, 1.4-57.2; P = 0.02) were associated with BE, independent of body mass index (BMI). The subcutaneous fat area was not associated with BE. Visceral and GEJ fat were significantly greater in BE subjects with esophageal inflammation (compared with those without, P = .02) and high-grade dysplasia (compared with those without, P = .01), independent of BMI. CONCLUSIONS: GEJ and visceral fat are associated with BE, and with increased esophageal inflammation and high-grade dysplasia in BE subjects, independent of BMI. Visceral fat therefore might promote esophageal metaplasia and dysplasia.

Stenting and the rate of pancreatic fistula following pancreaticoduodenectomy.

OBJECTIVE: To evaluate the efficacy of transanastomotic pancreatic duct internal stenting in the reduction of postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy. DESIGN: Retrospective study. SETTING: Mayo Clinic. PATIENTS: Between January 1, 1999, and September 30, 2010, 553 patients underwent pancreaticoduodenectomy by a single surgeon. MAIN OUTCOME MEASURES: Rates of POPF, morbidity, and mortality between stent and no-stent groups. RESULTS: The clinically relevant POPF (International Study Group on Pancreatic Fistula definition grade B or C) rates in the stent and no-stent groups were similar (9.6% [43 of 449 patients] and 12.5% [13 of 104 patients], respectively; P = .38). Postoperative outcomes and morbidity were also similar between the 2 groups. Mortality was 0.7% (3 of 449 patients) for the stent group and 1.0% (1 of 104 patients) for the no-stent group. Four patients (0.9%) required endoscopic retrieval of the anastomotic stent. In subset analysis, the clinically relevant POPF rates in patients with a small pancreatic duct (≤3 mm; n = 167) were similar in the stent and no-stent groups (17.7% [23 of 130 patients] and 24.3% [9 of 37 patients], respectively; P = .38). In patients with a soft pancreatic gland (n = 64), rates of clinically relevant pancreatic fistulae were also similar in the stent and no-stent groups (31.7% [13 of 41 patients] and 17.4% [4 of 23 patients], respectively; P = .20). CONCLUSIONS: Internal transanastomotic pancreatic duct stenting does not decrease the frequency or severity of POPF. The effect of stenting on long-term anastomotic patency warrants further investigation.

Dual-phase computed tomography for assessment of pancreatic fibrosis and anastomotic failure risk following pancreatoduodenectomy.

INTRODUCTION: Delayed or decreased computed tomography (CT) enhancement characteristics in pancreatic fibrosis have been described. METHODS: A review of 157 consecutive patients with preoperative dual-phase CT between 2004 and 2009 was performed. Pancreatic CT attenuation upstream from the tumor was measured in the pancreatic and hepatic imaging phases. The ratio of the mean CT attenuation value [hepatic to pancreatic phase; late/early (L/E) ratio] and histological grade of pancreatic fibrosis was correlated with the development of a clinically relevant pancreatic anastomotic failure (PAF) and other clinical parameters. RESULTS: A clinically relevant PAF was observed in 21 patients (13.4%) with morbidity and mortality of 39.5% and 0%, respectively. The PAF group showed maximum enhancement in the pancreatic and washout in the hepatic CT phase, while the no PAF group showed a delayed enhancement pattern. Degree of pancreatic fibrosis and L/E ratio were significantly lower for the PAF group than the no PAF group (0.86 ± 0.14 vs. 1.09 ± 0.24; P < 0.0001 and 21.0 ± 17.9 vs. 40.4 ± 29.8; P < 0.0001); fewer PAF patients showed an atrophic histological pattern (14% vs. 39%; P = 0.046). The L/E ratio was positively correlated with pancreatic fibrosis. Pancreatic fibrosis and L/E ratio increased with larger duct size (P < 0.001), the presence of diabetes (P < 0.05), and the surgeon's assessment of pancreas firmness (P < 0.001). In multivariate analyses, L/E ratio and body mass index were significant predictors for the development of a clinically relevant PAF; a 0.1-U increase of L/E ratio decreased the odds of a PAF by 54%. CONCLUSION: Pancreatic CT enhancement pattern can accurately assess pancreatic fibrosis and is a powerful tool to predict the risk of developing a clinically relevant PAF following PD.

Tumor invasion of lymph node capsules in patients with Dukes C colorectal adenocarcinoma.

PURPOSE: The objective of this study was to investigate the correlation between the microscopic findings of positive lymph nodes, especially focusing on capsular invasion, and the outcome after curative surgical resection of colorectal cancer. METHODS: We analyzed 480 positive lymph nodes from 155 consecutive patients with Stage III colorectal cancer to determine the frequency and significance of lymph node capsular invasion. Recurrence-free and cancer-specific survival rates were assessed in the patients with and without lymph node capsular invasion. RESULTS: Between April 1995 and December 2000, 406 consecutive patients with primary colorectal cancer underwent curative resection. Regional lymph node metastases were present in 155 cases (38.2 percent). During the median follow-up period of 4.8 years, 41 patients (26.5 percent) developed recurrent disease and 28 patients died of cancer. Lymph node capsular invasion was detected in one or more lymph nodes from 75 cases (48.3 percent). The five-year recurrence-free rate was 56.1 percent in this group, whereas in the 80 patients without lymph node capsular invasion the rate was 88 percent (P<0.01). Features that were associated with recurrent disease were greater number of positive lymph nodes, venous invasion in primary tumor, infiltrative growth pattern of intranodal tumor, and presence of lymph node capsular invasion. Multivariate analysis identified lymph node capsular invasion as the only significant prognostic factor for recurrence. In multivariate analysis with regard to survival, lymph node capsular invasion, venous invasion, and number of positive nodes remained as significant prognostic factors. CONCLUSIONS: Lymph node capsular invasion, determined by routine hematoxylin-eosin staining, is a potent prognostic factor in Stage III colorectal cancer.

Lipopolysaccharide induces CD25-positive, IL-10-producing lymphocytes without secretion of proinflammatory cytokines in the human colon: low MD-2 mRNA expression in colonic macrophages.

Despite the huge number of colonized Gram-negative bacteria in the colon, the normal colon maintains its homeostasis without any excessive immune response. To investigate the potential mechanisms involved, human colonic lamina propria mononuclear cells (LPMCs) obtained from uninflamed mucosa were cultured with lipopolysaccharide (LPS) prepared from Bacteroides vulgatus (BV-LPS) or Bacteroides fragilis (BF-LPS), as representatives of indigenous flora, or pathogenic Salmonella minnesota (SM-LPS). Colonic LPMCs failed to produce inflammatory cytokines in response to any type of LPS. Colonic macrophages barely expressed mRNA for MD-2, an essential association molecule for LPS signaling via Toll-like receptor 4. Further, BV-LPS induced CD25 and Foxp3 expression in lymphocytes and CD4(+)CD25(+) cells expressed IL-10 mRNA. Thus, the low expression of functioning LPS receptor molecules and induction of IL-10-producing CD4(+)CD25(+) lymphocytes by indigenous LPS may play a central role in the maintenance of colonic immunological homeostasis.