Perioperative acinar cell count method works well in the prediction of postoperative pancreatic fistula and other postoperative complications after pancreaticoduodenectomy.

BACKGROUND: Earlier we have shown that high frequency of acinar cells in the pancreatic transsection line predicts postoperative pancreatic fistula after pancreaticoduodenectomy (PD). Acinar cell count method (ACM) is fast to perform during operation. In this study our aim was to validate the accuracy of ACM to compare it with other published risk prediction methods. METHODS: 87 patients who underwent PD without any trial including perioperative medications were collected from a single hospital. Data on demographics, surgical details, postoperative complications clinically relevant pancreatic fistulae (CR-POPF) and clinically relevant Clavien-Dindo complications (CR-CDC) were registered. Thirteen previously published risk prediction methods were included in the comparison, such as pancreatic duct diameter, palpable texture of pancreas, Braga score (BC), Fistula Risk Score, Modified Fistula Risk Score, Alternative Fistula Risk Score and multiple radiological parameters. ROC-curves were calculated to compare sensitivity and specificity for identifying high risk patients for CR-POPF and CR-CDC. RESULTS: The three most accurate risk prediction methods for CR-POPF were ACM (sensitivity 88.9%, specificity 52.6%; p = 0.043), BC (87.5%, 56.6%; p = 0.039) and visceral fat area to subcutaneous fat area ratio (75.5%, 80.0%; p = 0.032). In predicting CR-CDC the three most accurate methods were ACM (73.9%, 56.2%; p = 0.033), BC (68.4%, 59.5%; p = 0.036) and TPAI (78.3%, 41.7%; p = 0.012). CONCLUSION: ACM was shown to be as good as the more complicated risk scoring methods in the prediction of CR-POPF. It was good also in predicting all clinically relevant complications. ACM is easy to use during operation and can be recommended as a routine risk prediction method.

Wnt/ß-catenin signalling plays diverse functions during the process of fibrotic remodelling in the exocrine pancreas.

BACKGROUND/OBJECTIVES: Wnt/ß-catenin signalling plays vital roles in tissue homeostasis. Dysregulation of the pathway has been implicated in the pathogenesis of cancer and fibroses in numerous tissues, including the pancreas. We studied the effect of microenvironmental changes pertaining to fibrotic tissue remodelling on the expression of selected Wnt/ß-catenin pathway proteins in the human exocrine pancreas. The role of acinar/stellate cross-talk on the expression of the proteins was elucidated in a long-term mouse co-culture system. METHODS: Expression of ß-catenin, Wnt2, Wnt5a and SFRP4 was analysed immunohistochemically in normal and moderately or highly fibrotic human pancreata (n = 8). The effect of humoral interactions on the expression of the proteins was studied by immunocytochemical means in parallel mono- and co-cultures of mouse acinar and stellate cells (PSCs). RESULTS: In human pancreatic tissue, fibrotic microenvironment was associated with redistribution of the proteins in and between epithelial and stromal compartments, compared to acinar-rich tissue. In non-fibrotic and moderately fibrotic tissue the proteins appeared only in acinar cells whereas in highly fibrotic tissue stromal fibroblastoid/stellate cells and macrophages were their predominant locations. Subcellular changes in the expression of ß-catenin and Wnt5a were detected. Our in vitro data suggest potential involvement of acinar cell/PSC cross-talk in mediating the changes observed in tissue specimens. CONCLUSIONS: Wnt/ß-catenin pathway-associated proteins are abundantly expressed in the exocrine pancreas with prominent changes in their cellular and subcellular expression patterns along with increasing levels of fibrosis. Diverse functions for Wnt/ß-catenin signalling during the course of fibrotic remodelling in the exocrine pancreas are suggested.

Perioperative Hydrocortisone Reduces Major Complications After Pancreaticoduodenectomy: A Randomized Controlled Trial.

OBJECTIVES: The aim of this study was to study whether post-pancreaticoduodenectomy complications (PPDC) in high-risk patients can be reduced with hydrocortisone. BACKGROUND: Soft pancreas is a well-known risk factor for PPDC. Previously, we have shown that patients with >40% acini in the pancreatic transection line are most prone to PPDC. Recent studies have demonstrated that surgical trauma leads to inflammation of the pancreatic remnant, which precedes PPDC. METHODS: On the basis of power analysis, randomized controlled trial (RCT) (Clinicaltrials.gov NCT01460615), 155 patients (February 2011-May 2015) scheduled for pancreaticoduodenectomy were randomized to intravenous (i.v.) treatment with hydrocortisone 100 mg or placebo. All patients received the first dose at the induction of anesthesia. During the operation, the percentage of acini was calculated from pancreatic transection line frozen samples by a pathologist. As planned, only the high-risk patients with >40% acini (n = 62) continued in the study to receive in total 8 doses of randomization-based hydrocortisone/placebo every 8 hours. Primary endpoints were urine trypsinogen positive days and overall complications (Clavien-Dindo III-IV). Postoperative pancreatic fistulas (POPFs), postpancreatectomy hemorrhage (PPH), and delayed gastric emptying (DGE) were also graded. RESULTS: Hydrocortisone treatment did not alter trypsinogen release (2 or more positive days 46% vs 50%), but it significantly reduced overall complications compared with placebo in the high-risk patients (18% vs 41%; P < 0.05; Clavien-Dindo III-IV). Also, clinically significant POPF (11% vs 27%), PPH (14% vs 24%), and DGE (29% vs 44%) tended to be lower in the hydrocortisone group. Ninety-day mortality was zero. CONCLUSIONS: This RCT shows that in high-risk patients, overall PPDC can be significantly reduced with hydrocortisone treatment. Inflammation may be an important mediator of PPDC.

Reciprocal stimulation of pancreatic acinar and stellate cells in a novel long-term in vitro co-culture model.

BACKGROUND/OBJECTIVES: Pancreatic stellate cells (PSCs) are the key fibrogenic cells in the pancreas. Acinar cell injury is known to trigger PSC activation. To facilitate the experimental analysis of the crosstalk between acinar cells and PSCs, an in vitro system for their long-term co-cultivation was developed. MATERIALS AND METHODS: PSCs and acinar cells capable of retaining their secretory phenotype in long-term in vitro culture were obtained from mouse pancreata. A dual-chamber co-culture model was built in 24-well format with acinar cells seeded in the wells and PSCs in tissue culture inserts. Acinar cell-3T3 fibroblast co-cultures served as controls. After 4-day maintenance, the acinar compartment was analyzed for cell morphology, secretory capability, necrosis (HMGB1), apoptosis (TUNEL) and inflammation (NFκB). PSCs were analyzed for migratory activity and extracellular matrix (ECM) protein expression. The results were compared to parallel monocultures. RESULTS: Acinar cells in monoculture and in co-culture with fibroblasts exhibited a healthy monolayer arrangement and an ability to respond to 0.1 nM caerulein stimulus by increased amylase release. Co-culture with PSCs caused marked changes in acinar cell morphology and rendered them insensitive to secretagogue stimulus. Activation of NFκB and necrotic changes, but not apoptosis, were identified in co-cultured acinar cells. Co-culture increased the migratory activity and ECM protein expression of PSCs. CONCLUSIONS: Humoral interactions between acinar and PSCs in co-culture were shown to reciprocally affect their cellular functions. With its two separable cell compartments the co-culture system provides a versatile culture setting that allows independent manipulation and analysis of both cell types.

Difference in Early Activation of NF-κB and MCP-1 in Acinar-Cell-Rich versus Fibrotic Human Pancreas Exposed to Surgical Trauma and Hypoxia.

Objectives. Previously we have shown that a pancreas with over 40% acinar cells is exposed to postoperative pancreatitis and other complications after pancreaticoduodenectomy (PD). Our aim was to analyze the expression of NF-κB and MCP-1 in the cut edge of human pancreas after PD in both acinar-cell-rich and fibrotic pancreata. Methods. Several pancreatic samples from six patients, three with acinar-cell-rich and three with fibrotic pancreata, were exposed to surgical trauma in PD, and thereafter to hypoxemia for 15 minutes, 2-2.5 hours, 4 hours, or 6 hours, to mimic postoperative conditions of the pancreatic remnant in a patient. Immunohistochemical analysis of inflammation markers (NF-κB, MCP-1) was performed. Results. In the acinar-cell-rich pancreata, intra-acinar NF-κB and MCP-1 expression increased from mild at 15 minutes to high during the first 4 hours, whereas in ductal cells MCP-1 staining was highly intense at both time points. Acinar cell NF-κB and MCP-1 expression and ductal cell MCP-1 expression were also observed in the fibrotic pancreata, but the activation remained low throughout the 6 hours. Conclusions. In acinar-cell-rich pancreas, an extensive inflammatory cascade begins almost immediately after surgical trauma. Fibrosis may limit the progression of inflammatory process in pancreas.

The risk for immediate postoperative complications after pancreaticoduodenectomy is increased by high frequency of acinar cells and decreased by prevalent fibrosis of the cut edge of pancreas.

OBJECTIVES: Soft pancreas is considered as a factor for pancreatitis after pancreaticoduodenectomy, which in turn constitutes a high risk for local complications. The aim was to analyze the proportion of different cell types in the cut edge of pancreas (CEP) in relation to postoperative pancreatitis and other complications after pancreaticoduodenectomy. METHODS: Data from postoperative follow-up was collected on 40 patients who had undergone pancreaticoduodenectomy. Positive urine trypsinogen-2, an early detector of pancreatitis, was checked on days 1 to 6 after operation. Drain amylase was measured on postoperative day 3. Anastomotic leakages, delayed gastric emptying, and other complications were registered. The areas of different cell types were calculated from the entire hematoxylin-eosin-stained section of CEP. RESULTS: High frequency of acinar cells in the CEP significantly increased positive urine trypsinogen-2 days, drain amylase values, and delayed gastric emptying. In a subgroup of patients with more than 40% acini in the CEP, there were significantly more postoperative complications. Increased fibrosis correlated with a small number of positive urine trypsinogen-2 days and postoperative complications. CONCLUSIONS: A large number of acinar cells in the CEP increases, whereas extensive fibrosis in the CEP decreases, the risk for postoperative complications after pancreaticoduodenectomy. These results emphasize the importance of acini in the development of postoperative complications.