Main Duct Diameter Research Articles

Open-Y technique for the internal mammary vein in the free abdominal flap of unilateral breast reconstruction

BackgroundIn microvascular breast reconstruction, the internal mammary vein (IMV) has emerged as the most common recipient vein. The open-Y technique can increase the vessel diameter via the bifurcation site. This study aims to investigate the open-Y technique for IMV. MethodsThe characteristics and details of the operative procedure in patients who had undergone unilateral breast reconstruction with and without the open-Y approach for the free abdominal flap were compared. Differences in IMV anastomosis site (the bifurcation of the main duct or that of the perforator branch) were also compared in patients with the open-Y technique. The open-Y technique was performed on the IMV side. ResultsThe open-Y and conventional groups included 127 and 62 patients respectively. The main duct diameter of IMV was significantly smaller (median 2.5 vs. 3.0mm, P < 0.001), and the rate of right-sided anastomosis (47.2 vs. 82.3%, P < 0.001) was significantly lower in the open-Y group. When comparing the main duct and perforator groups, the branch diameter (1.8 vs. 1.0mm, P < 0.001) and the diameter after the open-Y technique (5.0 vs. 3.9mm, P < 0.001) were significantly higher, and the angle of bifurcation (45° vs. 60°, P = 0.007) was significantly lower in the main duct group. ConclusionsGiven a small venous diameter, the open-Y technique is superior, especially for left-sided breast reconstruction. Owing to the lower angle of bifurcation and large diameter, the open-Y technique at the main duct bifurcation of IMV causes less turbulence in the blood flow. Take home messageThe open-Y technique is especially effective for left-sided breast reconstruction. Considering the lower angle of bifurcation and large diameter, the open-Y technique at the main duct bifurcation of the internal mammary vein causes less turbulence in the blood flow.

Drain fluid volume combined with amylase level predicts clinically relevant postoperative pancreatic fistula after pancreaticoduodenectomy: A retrospective clinical study.

Several indicators are recognized in the development of clinically relevant postoperative pancreatic fistula (CR-POPF) after pancreaticoduodenectomy (PD). However, drain fluid volume (DFV) remains poorly studied. We aimed to discover the predictive effects of DFV and guide clinical management. We retrospectively reviewed the clinical data of patients that received PD between January 2015 and December 2019 in a high-volume center. DFV was analyzed as a potential risk factor and postoperative short-term outcomes as well as drain removal time were compared stratified by different DFV levels. Receiver operating characteristic curves and area under curves (AUC) were compared for DFV alone and DFV combined with drain fluid amylase (DFA). Subgroup analysis of DFV stratified by DFA evaluated the predictability of CR-POPF. CR-POPF occurred in 19.7% of 841 patients. Hypertension, postoperative day 3 (POD3) DFA≥300U/L, and POD3 DFV≥30mL were independent risk factors, while pancreatic main duct diameter ≥3mm was a protective factor. POD3 DFV≥30mL increased the overall occurrences of CR-POPF and major complications (P=0.017; P=0.029). POD3 DFV alone presented a low predictive value (AUC 0.602), while POD3 DFV combined with DFA had a high predictive value (AUC 0.759) for CR-POPF. Subgroup analysis showed that the combination of POD3 DFV≥30mL and DFA≥300U/L led to higher incidences of CR-POPF (P=0.003). CR-POPF is common after PD, and high DFV combined with DFA may predict its occurrence and facilitate appropriate management.

Surgical revision for pancreatojejunostomy stricture: a case series of 14 patients

BackgroundPancreatojejunostomy stricture (PJS) is a rare long-term complication of pancreaticojejunal anastomosis. This study aimed to investigate the role of surgery in the management of pancreatojejunostomy strictures.MethodsThe database of the Pancreas Center of Nanjing Medical University was retrospectively screened for patients who underwent a surgical revision for PJS between June 2012 and August 2019, and their clinical characteristics and management modalities were reviewed.ResultsFourteen consecutive cases were retrieved, the median age at index operation was 41.1 years (19–71). The average time between the two operations was 70.6 months (8–270 months). Index procedures included pancreaticoduodenectomy (PD) (7/14, 50%), pylorus-preserving PD (4/14, 28.6%), Berger procedure (2/14, 14.3%), and middle pancreatectomy (1/14, 7.1%). The diameter of the main pancreatic duct was < 4 mm in all 14 cases, and nine underwent pancreaticojejunostomy (PJ) stenting during the index operation. The most frequent complaints were abdominal pain (6/14, 42.9%), recurrent acute pancreatitis (6/14, 42.9%), pancreatic fistula (1/14, 7.1%), and abdominal distention (1/14, 7.1%). The diagnosis of PJ stricture was confirmed by computed tomography or magnetic resonance imaging in all cases. All patients had a main duct diameter > 5 mm before surgical revision. All patients underwent wedge excision with interrupted one-layer suturing with absorbable sutures and without stent placement. In this series, only one patient required reoperation. Upon follow-up, 11 of 12 patients had complete resolution of the PJ stricture.ConclusionPJS is a long-term complication of pancreatojejunostomy. Surgical revision of the anastomosis is a safe and effective treatment modality.

Pancreatico-Jejunostomy On Isolated Loop After Pancreatico-Duodenectomy: Is It Worthwhile?

BackgroundPostoperative morbidity remains a significant problem after pancreatico-duodenectomy. The management of pancreatic stump continues to be a challenge, and many technical solutions have been developed over the years. In this study, we report the results obtained with the use of an isolated loop for pancreatico-jejunostomy in patients with soft pancreas and small pancreatic duct diameter. MethodsClinical data of patients submitted to pancreatico-duodenectomy in a period of sixteen years (2005–2020) were extracted from a prospective database. Patients with soft pancreas, main duct diameter < 2 mm and reconstruction by pancreatico-jejunostomy on single loop or isolated loop were selected. Primary end-point was the incidence of clinically relevant fistulas in the two groups of patients. Secondary endpoint was the length of postoperative hospital stay. A propensity score matching analysis was used for the statistics. ResultsTwo hundred and twenty-one patients with the above characteristics were found in the database. One hundred and twelve of these received a single-loop reconstruction and 109 an isolated loop reconstruction. Incidence of clinically relevant fistulas was higher in the first group (41% vs 27%; p = 0.023). Postoperative hospital stay was significantly shorter in the second group (21 days vs 15; p < 0.001). These results were confirmed at the propensity score matching. ConclusionIn patients with soft pancreatic texture and small main duct diameter, pancreatico-jejunostomy on isolated loop is associated with a lower incidence of clinically relevant fistulas than after classic reconstruction. The duration of postoperative hospital stay was significantly reduced, with consequent reduction of cost.

Single-operator peroral pancreatoscopy in the preoperative diagnostics of suspected main duct intraductal papillary mucinous neoplasms: efficacy and novel insights on complications

BackgroundDistinguishing intraductal papillary mucinous neoplasms (IPMNs) from other pancreatic cystic lesions is essential since IPMNs carry the risk of becoming malignant. Differentiating the main pancreatic duct involving IPMNs (MD-IPMNs) through conventional imaging is deficient. Single-operator peroral pancreatoscopy (SOPP) represents a promising method offering additional information on suspected lesions in the pancreatic main duct (MD). We aimed to determine the role of SOPP in the preoperative diagnostics of suspected MD-IPMNs and identify factors contributing to SOPP-related complications.Materials and MethodsIn this primarily retrospective study, SOPPs were performed at three high-volume centers on suspected MD-IPMNs. Primary outcome was the clinical impact of SOPP to subsequent patient care. Additionally, we documented post-SOPP complications and analyzed several assumed patient- and procedure-related risk factors.ResultsOne hundred and one (101) SOPPs were performed. Subsequent clinical management was affected due to the findings in 86 (85%) cases. Surgery was planned for 29 (29%) patients. A condition other than IPMN explaining MD dilatation was found in 28 (28%) cases. In 35 (35%) cases, follow-up with MRI was continued. Post-SOPP pancreatitis occurred in 20 (20%) patients and one of them was fatal. A decrease in odds of post-SOPP pancreatitis was seen as the MD diameter increases (OR 0.714 for 1.0 mm increase in MD diameter, CI 95% 0.514–0.993, p = 0.045). Furthermore, a correlation between lower MD diameter values and higher severity post-SOPP pancreatitis was seen (TJT = 599, SE = 116.6, z = − 2.31; p = 0.020). History of pancreatitis after endoscopic retrograde cholangiopancreatography was a confirmed risk factor for post-SOPP pancreatitis. Conclusions between complications and other risk factors could not be drawn.ConclusionSOPP aids clinical decision-making in suspected MD-IPMNs. Risk for post-SOPP pancreatitis is not negligible compared to non-invasive imaging methods. The risk for pancreatitis decreases as the diameter of the MD increases.

Pancreatic cyst nodules in clinical practice: ethereal or real?

Presenter: Oswaldo Aguirre MD | Medstar Georgetown University Hospital/Georgetown University School of Medicine Background: Risk stratification in patients with pancreatic cysts continues to rely heavily on structural characteristics, as imaged both by endoscopic ultrasound and axial imaging with CT and MRI. The most recent international guidelines of the IAP use the presence of a cyst wall nodule, the nodule’s size in mm, and the presence of flow within the nodule to help risk stratify patients under investigation for pancreatic cysts. At present, the guidelines do not differentiate between nodules or solid components as seen by EUS and those imaged by CT/MRI. Further, the rate of discordance between modalities is not well known. The aim of this study was to examine the structural characteristics as seen by axial imaging in patients with endoscopically identified nodules and to determine the rate of concordance. Methods: All patients who had endoscopic ultrasound and pancreatic cyst fluid molecular testing at a single institution over a 7 year period (2012-2019) were studied. Cyst fluid molecular alterations, including DNA quantity and quality, KRAS/GNAS mutations, and tumor suppressor gene mutations were included, in addition to routine endoscopic variables. The presence of a nodule and its associated features were recorded on the endoscopic report. Clinical variables, including imaging characteristics, clinical features, and pathologic/cytologic data, were collected retrospectively using primary source data. Continuous and categorical variables were summarized and compared using standard statistical testing. Results: A total of 791 endoscopic ultrasound procedures with associated cyst fluid samples with molecular testing were available from the selected time period. Of those, 93 patients were found to have a pancreatic cyst nodule by high resolution endoscopic ultrasound. The median age of that subset was 68 (SD 14.6), and median body mass index was 26 (SD 6.4). The median cyst size was 20 mm (SD 19 mm) in maximum diameter. 60% of patients with EUS identified nodules were categorized by cyst fluid molecular testing as low risk, and 2% were predicted to have “aggressive” phenotypes. Only 42% of cysts with nodules by EUS had CEA levels >192. Importantly, only 12.8% of patients were noted to have nodules visualized by axial imaging, and just 30% of those demonstrated enhancement. Despite that rate of discordance, 75% of patients had at least one “worrisome” structural imaging feature (e.g. cyst size, solid component, cyst nodules, main duct diameter, growth rate). Conclusion: : The presence of a pancreatic nodule has a prominent place in risk stratification tools for pancreatic cysts, and both high quality endoscopic ultrasound imaging (with cyst fluid analysis) and high resolution axial imaging are central to this determination. However, in practice, there remains a significant rate of discordance between these modalities in the determination of cyst wall nodules, likely due to the inherent differences in resolution and limitations of each. Future study into other variables which modulate the prognostic importance of pancreatic cystic nodules as imaged by both EUS and CT/MRI is needed.

The Preoperative Dysplasia Grade Prediction Nomogram for Main-duct/Mixed Type Pancreatic Intraductal Papillary Mucinous Neoplasms (MD-IPMNs): The Development and Validation Based on a 7-year Single Center Database

Introduction: Surgical indications for MD-IPMN remain controversial due to the risk of pancreatic surgical procedure. Previous guidelines and predictive models were mainly focused on branch duct type IPMNs(BD-IPMNs) and have been relatively insufficient for both development and independent validation. Method: IPMN patients who had undergone resection were collected retrospectively between 2013 and 2019. Patients were separated into MD-IPMN and BD-IPMN based on preoperative imaging. 177 MD-IPMN patients were finally enrolled and divided into training subset and test subset. Logistic regression modeling was used to develop model for identifying low-risk(low-/intermediate-grade dysplasia) or high-risk(high-grade dysplasia or invasive carcinoma) disease. The test subset was used for validating model by AUC, Brier's Score and C-index. Results: We identified 203 IPMN patients underwent resection[MD:193(95.1%), BD:10(4.9%)]. 12 loss-pathology-patients were excluded. In MD-group, high-risk was present in 103 patients(53%) which is comparable to 74 low-risk patients(47%). MD-IPMN predictive nomogram was developed on the training set(70%, 124 patients) and validated on the test set(30%, 53 patients). The significant risk factor associated with high-risk disease including the presence of enhancing nodule(P=0.036), mural nodule(P=0.03), main-duct diameter(P=0.004) and the abnormal of CA19-9 value(P=0.028). Other potential risk factors including age, time since detection and cyst size. Brier's Score were 0.092 and 0.152, C-indexes were 0.94 and 0.85 on training and independent validation sets, respectively; AUCs were 0.916 and 0.856, respectively. Conclusions: We present an independently validated nomogram for the prediction of MD-IPMNs malignant risk which thereby improve the identification of high-risk precursor and help avoid unnecessary damage by redundant surgical procedure.

Risk prediction for malignant intraductal papillary mucinous neoplasm of the pancreas: logistic regression versus machine learning

Most models for predicting malignant pancreatic intraductal papillary mucinous neoplasms were developed based on logistic regression (LR) analysis. Our study aimed to develop risk prediction models using machine learning (ML) and LR techniques and compare their performances. This was a multinational, multi-institutional, retrospective study. Clinical variables including age, sex, main duct diameter, cyst size, mural nodule, and tumour location were factors considered for model development (MD). After the division into a MD set and a test set (2:1), the best ML and LR models were developed by training with the MD set using a tenfold cross validation. The test area under the receiver operating curves (AUCs) of the two models were calculated using an independent test set. A total of 3,708 patients were included. The stacked ensemble algorithm in the ML model and variable combinations containing all variables in the LR model were the most chosen during 200 repetitions. After 200 repetitions, the mean AUCs of the ML and LR models were comparable (0.725 vs. 0.725). The performances of the ML and LR models were comparable. The LR model was more practical than ML counterpart, because of its convenience in clinical use and simple interpretability.

Invasive Intraductal Papillary Mucinous Neoplasms: CT Features of Colloid Carcinoma Versus Tubular Adenocarcinoma of the Pancreas.

OBJECTIVE. The purpose of this study is to compare the CT features of colloid carcinoma and tubular adenocarcinoma of the pancreas arising in association with intraductal papillary mucinous neoplasms (IPMNs). MATERIALS AND METHODS. The preoperative CT images of 85 patients with histopathologically proven IPMNs and associated invasive adenocarcinoma located next to each other were retrospectively reviewed. Twenty-nine patients (34.1%; 19 men and 10 women; mean [± SD] age, 68.0 ± 9.5 years) had invasive colloid carcinoma, and 56 patients (65.9%; 31 men and 25 women; mean age, 70.8 ± 10.6 years) had invasive tubular adenocarcinoma. We compared the following CT features between the two groups: IPMN type, main pancreatic duct (MPD) and common bile duct diameters, diameter and characteristics of the largest cystic lesion for branch duct and mixed-type IPMNs, presence of an extracystic or extraductal solid mass next to the cystic lesion or MPD, morphologic features of the upstream MPD in relation to the cystic lesion or solid mass, and presence of a fistula to the adjacent organs. RESULTS. An MPD size of 9.5 mm or greater, a largest cystic lesion diameter of 28 mm or greater, location in the head or neck, septation, calcification, presence of a mural nodule(s) within a cystic lesion or MPD, and presence of a fistula were all more commonly associated with colloid carcinoma. In contrast, presence of an extracystic or extraductal solid mass and an abrupt change in the caliber of the dilated MPD were associated with tubular adenocarcinoma. The best CT feature for differentiating between the two groups was the morphologic features of the upstream MPD in relation to the cystic lesion or solid mass (sensitivity, 81.3%; specificity, 92.3%). CONCLUSION. Preoperative CT is helpful in differentiating two types of invasive carcinoma arising in association with IPMNs. These findings are clinically important because prognosis is better for colloid carcinoma than for tubular adenocarcinoma.

Validation of a nomogram to predict the risk of cancer in patients with intraductal papillary mucinous neoplasm and main duct dilatation of 10 mm or less

Intraductal papillary mucinous neoplasm (IPMN) is premalignant pancreatic lesion. International guidelines offer limited predictors of individual risk. A nomogram to predict individual IPMN malignancy risk was released, with good diagnostic performance based on a large cohort of Asian patients with IPMN. The present study validated a nomogram to predict malignancy risk and invasiveness of IPMN using both Eastern and Western cohorts. Clinicopathological and radiological data from patients who underwent pancreatic resection for IPMN at four centres each in Eastern and Western countries were collected. After excluding patients with missing data for at least one malignancy predictor in the nomogram (main pancreatic duct diameter, cyst size, presence of mural nodule, serum carcinoembryonic antigen and carbohydrate antigen (CA) 19-9 levels, and age). In total, data from 393 patients who fit the criteria were analysed, of whom 265 were from Eastern and 128 from Western institutions. Although mean age, sex, log value of serum CA19-9 level, tumour location, main duct diameter, cyst size and presence of mural nodule differed between the Korean/Japanese, Eastern and Western cohorts, rates of malignancy and invasive cancer did not differ significantly. Areas under the receiver operating characteristic (ROC) curve values for the nomogram predicting malignancy were 0·745 for Eastern, 0·856 for Western and 0·776 for combined cohorts; respective values for the nomogram predicting invasiveness were 0·736, 0·891 and 0·788. External validation of the nomogram showed good performance in predicting cancer in both Eastern and Western patients with IPMN lesions.

Laparoscopic longitudinal pancreatojejunostomy and modified Frey's operation for chronic calcific pancreatitis.

BackgroundChronic pancreatitis is a debilitating disease presenting with pain, diabetes and steatorrhoea. Surgery offers better long‐term pain relief than other interventions, but there is still uncertainty about the optimal surgical procedure and approach and a lack of long‐term follow‐up data in patients with chronic calcific pancreatitis selected for laparoscopic surgical treatment.MethodsThis was an observational cohort study of patients who underwent laparoscopic surgery for chronic calcific pancreatitis between January 2006 and April 2017, and had completed a minimum follow‐up of 1 year at a tertiary‐care teaching institute. Eligibility for the laparoscopic approach was main duct diameter greater than 7 mm, absence of extensive head calcification, size of head less than 3·5 cm, absence of local complications, and ASA grade I or II status. The primary outcome variable was a reduction in pain score by 1 year. Secondary outcomes were hospital stay, complications, pain score at 3 and 5 years, and the development or progression of exocrine and endocrine insufficiency.ResultsSome 57 patients were scheduled to undergo laparoscopic surgery for chronic pancreatitis: longitudinal pancreatojejunostomy (39), modified Frey's procedure (15) and pancreatoduodenectomy for suspicion of malignancy (3). The latter three patients were excluded from the analysis. Conversion to open surgery was needed in ten of the 57 patients (18 per cent). The mean(s.d.) age of the analysed cohort was 34·2(3·7) years and there was a predominance of men (34, 63 per cent). Adequate pain relief was achieved in 91, 89 and 88 per cent of patients at 1, 3 and 5 years of follow‐up respectively.ConclusionLaparoscopic surgical management of chronic calcific pancreatitis with longitudinal pancreatojejunostomy or modified Frey's procedure is feasible, safe and effective in selected patients for the relief of pain.

The Dilemma of the Dilated Main Pancreatic Duct in the Distal Pancreatic Remnant After Proximal Pancreatectomy for IPMN

Objective(s)A dilated main pancreatic duct in the distal remnant after proximal pancreatectomy for intraductal papillary mucinous neoplasms (IPMN) poses a diagnostic dilemma. We sought to determine parameters predictive of remnant main-duct IPMN and malignancy during surveillance. MethodsThree hundred seventeen patients underwent proximal pancreatectomy for IPMN (Indiana University, 1991–2016). Main-duct dilation included those ≥ 5 mm or “dilated” on radiographic reports. Statistics compared groups using Student’s T/Mann-Whitney U tests for continuous variables or chi-square/Fisher’s exact test for categorical variables with P < 0.05 considered significant. ResultsHigh-grade/invasive IPMN or adenocarcinoma at proximal pancreatectomy predicted malignant outcomes (100.0% malignant outcomes; P < 0.001) in remnant surveillance. Low/moderate-grade lesions revealed benign outcomes at last surveillance regardless of duct diameter. Twenty of 21 patients undergoing distal remnant reoperation had a dilated main duct. Seven had main-duct IPMN on remnant pathology; these patients had greater mean maximum main-duct diameter prior to reoperation (9.5 vs 6.2 mm, P = 0.072), but this did not reach statistical significance. Several features showed high sensitivity/specificity for remnant main-duct IPMN. ConclusionsRemnant main-duct dilation after proximal pancreatectomy for IPMN remains a diagnostic dilemma. Several parameters show a promise in accurately diagnosing main-duct IPMN in the remnant.

External validation of a nomogram to predict malignancy risk in patients with intraductal papillary mucinous neoplasms, using Eastern and Western cohorts

Introduction: Intraductal papillary mucinous neoplasm (IPMN) is premalignant pancreatic lesion. International guidelines suggest several treatments and malignancy predictors but offer limited predictors of individual risk. A nomogram to predict individual IPMN malignancy risk was released with good diagnostic performance, based on a cohort of 2258 Korean or Japanese patients with IPMN. This study validated a nomogram to predict malignancy risk and invasiveness of IPMN, using Eastern and Western cohorts. Method: We collected clinicopathological and radiological data of patients who underwent pancreas resection for IPMN at 4 centers each in Eastern and Western countries. After excluding patients with ≥1 missing malignancy predictor in the nomogram (main pancreatic duct diameter, cyst size, presence of mural nodule, serum CEA and CA19-9 levels, and age), we analyzed data of the remaining 393 patients (Eastern: n=265; Western: n=128). Result: Although mean age, sex, log value of serum CA19-9, tumor location, main duct diameter, cyst size and presence of mural nodule differed between the Korea/Japan, Eastern and Western cohorts, rates of malignancy and invasive cancer did not significantly differ. Areas under the receiver operating characteristics curve (AUC) values using the nomogram to predict malignancy were Eastern: 0.745, Western: 0.856, and combined cohorts: 0.776; and to predict invasiveness were Eastern: 0.736, Western: 0.891, and combined cohorts: 0.788. Conclusion: External validation of the nomogram showed good performance in predicting malignancy and invasive cancer in both Eastern and Western IPMN patients. The nomogram could be globally applicable to decide customized treatment options for patients with IPMN.

Distribution and correlation of pancreatic gland size and duct diameters on MRCP in patients without evidence of pancreatic disease.

To use MRCP to investigate age-related changes and gender differences of the pancreas and to correlate pancreatic gland size and duct diameter. In this institutional review, board-approved, HIPAA-compliant study, 280 patients (age 20-88years) without a history of pancreatic or liver disease who had undergone MRI/MRCP from 2004 to 2015 were identified. The anteroposterior size and main duct diameter of the pancreatic head, body, and tail were measured. The pancreatic gland and duct sizes were compared between genders, and among seven age subgroups (20-29, 30-39, 40-49, 50-59, 60-69, 70-79, 80-89). The pancreatic head and body were significantly larger in males than females (head, p < 0.01; body, p = 0.03), while the tail and the duct diameters of the pancreatic head, body, and tail showed no gender difference. As the age of male participants increased, there was an associated increase in size of the pancreatic gland initially (largest at age 50-59 (body) and 60-69 (head)), followed by subsequent decline in size thereafter. Additionally, the pancreatic duct diameter was found to increase gradually. In females, the size of the pancreatic gland decreased, while the diameter of the pancreatic duct increased with age. Moderate positive correlation for gland size and strong positive correlation for duct diameter among different pancreatic regions were found. Weak negative correlation was found between gland size and duct diameter. There are gender differences in the gland size of the pancreatic head and body. The pancreatic gland size increases until the sixth decade in males, with a more continuous decrease in gland size with age in females. Both males and females demonstrate a marked decrease in gland size after the eighth decade. The duct diameter increases with age in both males and females.

Circulating Thrombospondin-2 enhances prediction of malignant intraductal papillary mucinous neoplasm

BackgroundIPMNs are cystic pancreatic lesions with variable malignant potential. Thrombospondin-2 (THBS2)—an endogenous, anti-angiogenic matrix glycoprotein—may modulate tumor progression. We hypothesized that circulating levels of THBS2 could aid in preoperative prediction of malignant IPMN. MethodsPreoperative serum/plasma samples were procured from patients undergoing surgery. Circulating levels of THBS2 were measured (enzyme-linked immunosorbent assay) and compared to surgical pathology IPMN dysplastic grade. Results164 patients underwent THBS2 testing (100 Low/Moderate-IPMN; 64 High-Grade/Invasive-IPMN). Circulating THBS2 (mean ± SD) was greater in High-Grade/Invasive-IPMN than Low/Moderate-grade IPMN (26.6 ± 12.7 ng/mL vs. 20.4 ± 8.2 ng/mL; P < 0.001). THBS2 (AUC = 0.65) out-performed CA19-9 (n = 144; AUC = 0.59) in predicting IPMN grade. The combination of THBS2, CA19-9, radiographic main-duct involvement, main-duct diameter, age, sex, and BMI (AUC 0.82; n = 137) provided a good prediction model for IPMN grade. ConclusionCirculating THBS2 is correlated with IPMN dysplasia grade. THBS2 alone did not strongly predict IPMN grade but rather strengthened prediction models for High-Grade/Invasive IPMN when combined with other clinical/biomarker data.

Secretin-stimulated MRI characterization of pancreatic morphology and function in patients with chronic pancreatitis

Background/ObjectivesChronic pancreatitis (CP) is characterized by abnormal pancreatic morphology and impaired endocrine and exocrine function. However, little is known about the relationship between pancreatic morphology and function, and also the association with the etiology and clinical manifestations of CP. The aim was to explore pancreatic morphology and function with advanced MRI in patients with CP and healthy controls (HC) MethodsEighty-two patients with CP and 22 HC were enrolled in the study. Morphological imaging parameters included pancreatic main duct diameter, gland volume, fat signal fraction and apparent diffusion coefficient (ADC) values. Functional secretin-stimulated MRI (s-MRI) parameters included pancreatic secretion (bowel fluid volume) and changes in pancreatic ADC value before and after secretin stimulation. Patients were classified according to the modified Cambridge and M-ANNHEIM classification system and fecal elastase was collected. ResultsAll imaging parameters differentiated CP patients from HC; however, correlations between morphological and functional parameters in CP were weak. Patients with alcoholic and non-alcoholic etiology had comparable s-MRI findings. Fecal elastase was positively correlated to pancreatic gland volume (r = 0.68, P = 0.0016) and negatively correlated to Cambridge classification (r = −0.35, P < 0.001). Additionally, gland volume was negatively correlated to the duration of CP (r = −0.39, P < 0.001) and baseline ADC (r = −0.35, P = 0.027). When stratified by clinical stage (M-ANNHEIM), the pancreatic gland volume was significantly decreased in the severe stages of CP (P = 0.001). ConclusionsS-MRI provides detailed information about pancreatic morphology and function and represents a promising non-invasive imaging method to characterize pancreatic pathophysiology and may enable monitoring of disease progression in patients with CP.

Investigation of flow characteristics effects on heat transfer in water-cooled cylinder heads

An experimental and theoretical study has been performed to investigate the effect of flow characteristics on heat-transfer in water impingement-cooled cylinder heads. Numerous investigations have been made using a three-dimensional model, which is designed and solved by FLUENT software using both realizable k–e turbulent and heat transfer models. The simulation investigates a fully developed turbulent-water flow in asymmetric heated circular passage cooled by parallel flow or impingement of circular submerged confined liquid jet. The following parameters were investigated for both parallel flow and jet impingement flow: flow velocities (1, 2 and 3 m/s), bulk fluid temperatures (50, 70 and 90 °C), main duct diameters (6, 8, 10 and 12 mm). While the following parameters were investigated for jet impingement flow, jet diameter ratio (0.6, 0.8 and 1) and jet inclination angles as measured from horizontal (45°, 60° and 90°). Experimental results were used to verify the theoretical model. Results indicate that, the normal jet (90°) gives the maximum cooling effect in comparison to other angles while the maximum heat transfer coefficient is found at jet interface position.

Accuracy of 2012 International Consensus Guidelines for the prediction of malignancy of branch-duct intraductal papillary mucinous neoplasms of the pancreas.

To determine accuracy of 2012 International Consensus Guidelines (ICG) predicting malignancy in a surgical cohort of branch-duct intraductal papillary mucinous neoplasms (BD-IPMN). This study included all consecutive patients with final pathological diagnosis of pure BD-IPMN resected between 2006 and 2014 at Beaujon Hospital. Neoplasms were classified as malignant in presence of high-grade dysplasia (HGD) or invasive carcinoma. Medical, pathological, and radiological data were retrospectively recorded. One hundred and twenty patients (65 males, mean age: 57.9 ± 10.8 years) were included. Malignant BD-IPMN accounted for 30% (HGD: 18%, invasive: 12%). Thickened cyst walls (odds ratio (OR): 3.058, 95% confidence interval (CI 95%): 1.102-8.484, p = 0.032), main duct diameter 5-9 mm (OR: 3.395, CI 95%: 1.349-8.543, p = 0.007), and mural nodule (OR: 3.802, CI 95%: 1.156-12.511, p = 0.028) were independently associated with malignancy in multivariate analysis. Among the 89 patients (74%) who underwent surgical resection with ICG criteria, the malignancy rate was 38%, compared with 6% in the 31 ICG-negative group. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for malignancy of having at least one ICG criteria were 94%, 34%, 38%, 94%, and 53%, respectively. Patients with malignant tumors had more ICG criteria than those with benign lesions (2.06 ± 0.98 vs. 0.99 ± 0.95, p < 0.001). 2012 ICG criteria are useful to manage BD-IPMN permitting not to miss a malignant form (NPV of 94%), but frequently point out unnecessary surgery (PPV of 38%). Malignancy rate increases with the number of ICG criteria. In patients with only one criterion, additional criteria would be necessary.

Body Mass Index and Stump Morphology Predict an Increased Incidence of Pancreatic Fistula After Pancreaticoduodenectomy.

A majority of factors associated with the occurrence of clinical relevant postoperative pancreatic fistula (CR-POPF) after pancreaticoduodenectomy (PD) can only be identified intra- or postoperatively. There are no reports for assessing the morphological features of pancreatic stump and analyzing its influence on CR-POPF risk after PD preoperatively. A total of 90 patients underwent PD between April 2012 and May 2014 in our hospital were included. Preoperative computed tomographic (CT) images were imported into the Medical Image Three-Dimensional Visualization System (MI-3DVS) for acquiring the morphological features of pancreatic stump. The demographics, laboratory test and morphological features of pancreatic stump were recorded prospectively. The clinical course was evaluated focusing on the occurrence of pancreatic fistula as defined by the International Study Group on Pancreatic Fistula (ISGPF). Logistic regression analysis was used to identify independent predictors of CR-POPF. CR-POPF occurred in 18 patients (14 grade B, 4 grade C). In univariate analysis, male gender (P=0.026), body mass index (BMI)≥25.3kg/m(2) (P=0.002), main pancreas duct diameter (MPDD)<3.1mm (P=0.005), remnant pancreatic parenchymal volume (RPPV)>27.8mL (P<0.001), and area of cut surface (AOCS)>222.3mm(2) (P<0.001) were associated with an increased risk of CR-POPF. In multivariate analysis, BMI≥25.3kg/m(2) (OR 12.238, 95% CI 1.822-82.215, P=0.010) and RPPV>27.8mL (OR 12.907, 95% CI 1.602-104.004, P=0.016) were the only independent risk factors associated with CR-POPF. A cut-off value of 27.8mL for RPPV established based on the receiver operating characteristic (ROC) curve, which was the strongest single predictive factor for CR-POPF, with a sensitivity and specificity of 77.8 and 86.1%, respectively. The area under the ROC curve of RPPV was 0.770 (95% CI 0.629-0.911, P<0.001). Our study demonstrated that CR-POPF is correlated with BMI and RRPV. MI-3DVS provides us a novel and convenient method for measuring the RPPV. Preoperative acquisition of RPPV and BMI may help the surgeons in fitting postoperative management to patient's individual risk after PD.

Pathologic Evaluation and Reporting of Intraductal Papillary Mucinous Neoplasms of the Pancreas and Other Tumoral Intraepithelial Neoplasms of Pancreatobiliary Tract: Recommendations of Verona Consensus Meeting.

There are no established guidelines for pathologic diagnosis/reporting of intraductal papillary mucinous neoplasms (IPMNs). An international multidisciplinary group, brought together by the Verona Pancreas Group in Italy-2013, was tasked to devise recommendations. (1) Crucial to rule out invasive carcinoma with extensive (if not complete) sampling. (2) Invasive component is to be documented in a full synoptic report including its size, type, grade, and stage. (3) The term "minimally invasive" should be avoided; instead, invasion size with stage and substaging of T1 (1a, b, c; ≤ 0.5, > 0.5-≤ 1, > 1 cm) is to be documented. (4) Largest diameter of the invasion, not the distance from the nearest duct, is to be used. (5) A category of "indeterminate/(suspicious) for invasion" is acceptable for rare cases. (6) The term "malignant" IPMN should be avoided. (7) The highest grade of dysplasia in the non-invasive component is to be documented separately. (8) Lesion size is to be correlated with imaging findings in cysts with rupture. (9) The main duct diameter and, if possible, its involvement are to be documented; however, it is not required to provide main versus branch duct classification in the resected tumor. (10) Subtyping as gastric/intestinal/pancreatobiliary/oncocytic/mixed is of value. (11) Frozen section is to be performed highly selectively, with appreciation of its shortcomings. (12) These principles also apply to other similar tumoral intraepithelial neoplasms (mucinous cystic neoplasms, intra-ampullary, and intra-biliary/cholecystic). These recommendations will ensure proper communication of salient tumor characteristics to the management teams, accurate comparison of data between analyses, and development of more effective management algorithms.