Acinar cell density at the pancreatic resection margin is associated with post-pancreatectomy pancreatitis and the development of postoperative pancreatic fistula

Lipase-to-Amylase Ratio for the Prediction of Clinically Relevant Postoperative Pancreatic Fistula Following Pancreaticoduodenectomy

OBJECTIVE

Postoperative pancreatic fistula (POPF) represents a leading cause of morbidity and mortality following major pancreatic resections. This study aimed to evaluate the use of postoperative drain fluid lipase-to-amylase ratio (LAR) for the prediction of clinically relevant fistulae (CR-POPF).

METHODS

Consecutive patients undergoing pancreaticoduodenectomy between 2017 and 2021 at a tertiary centre were retrospectively reviewed. Univariable and multivariable analyses were performed to identify predictors for CR-POPF (ISGPS grade B/C). Receiver operating characteristic (ROC) curve analyses were conducted to evaluate the performance of LAR and determine optimum prediction thresholds.

RESULTS

Among 130 patients, 28 (21.5%) developed CR-POPF. Variables positively associated with CR-POPF included soft gland texture, acinar cell density, diagnosis other than PDAC or chronic pancreatitis, resection without neoadjuvant therapy, and postoperative drain fluid lipase, amylase, and LAR (all P <0.05). Multivariable regression analysis identified LAR as an independent predictor of CR-POPF ( P <0.05). ROC curve analysis showed that LAR had moderate ability to predict CR-POPF on POD1 (AUC,0.64; 95%CI,0.54-0.74) and excellent ability on POD3 (AUC,0.85; 95%CI,0.78-0.92) and POD 5 (AUC,0.86; 95%CI,0.79-0.92). Optimum thresholds were consistent over PODs 1 to 5 (ratio>2.6) and associated with 92% sensitivity and 46% to 71% specificity.

CONCLUSIONS

Postoperative drain fluid LAR represents a reliable predictor for the development of CR-POPF. With early prognostication, the postoperative care of patients at risk of developing high-grade fistulas may be optimized.

Extracellular volume fraction derived from dual-energy CT: a potential predictor for acute pancreatitis after pancreatoduodenectomy

OBJECTIVES

To investigate the value of extracellular volume (ECV) fraction and fat fraction (FF) derived from dual- energy CT (DECT) for predicting postpancreatectomy acute pancreatitis (PPAP) after pancreatoduodenectomy (PD).

METHODS

This retrospective study included patients who underwent DECT and PD between April 2022 and September 2022. PPAP was determined according to the International Study Group for Pancreatic Surgery (ISGPS) definition. Iodine concentration (IC) and FF of the pancreatic parenchyma were measured on preoperative DECT. The ECV fraction was calculated from iodine map images of the equilibrium phase. The independent predictors for PPAP were assessed by univariate and multivariable logistic regression analysis and receiver operating characteristic (ROC) curve analysis.

RESULTS

Sixty-nine patients were retrospectively enrolled (median age, 60 years; interquartile range, 55-70 years; 47 men). Of these, nine patients (13.0%) developed PPAP. These patients had lower portal venous phase IC, equilibrium phase IC, FF, and ECV fraction, and higher pancreatic parenchymal-to-portal venous phase IC ratio and pancreatic parenchymal-to-equilibrium phase IC ratio, compared with patients without PPAP. After multivariable analysis, ECV fraction was independently associated with PPAP (odd ratio [OR], 0.87; 95% confidence interval [CI]: 0.79, 0.96; p < 0.001), with an area under the curve (AUC) of 0.839 (sensitivity 100.0%, specificity 58.3%).

CONCLUSIONS

A lower ECV fraction is independently associated with the occurrence of PPAP after PD. ECV fraction may serve as a potential predictor for PPAP after PD.

CLINICAL RELEVANCE STATEMENT

DECT-derived ECV fraction of pancreatic parenchyma is a promising biomarker for surgeons to preoperatively identify patients with higher risk for postpancreatectomy acute pancreatitis after PD and offer selective perioperative management.

KEY POINTS

PPAP is a complication of pancreatic surgery, early identification of higher-risk patients allows for risk mitigation. Lower DECT-derived ECV fraction was independently associated with the occurrence of PPAP after PD. DECT aids in preoperative PAPP risk stratification, allowing for appropriate treatment to minimize complications.

Preoperative pancreatic radiologic characteristics predict pancreatic-specific complications before pancreaticoduodenectomy: the pancreatic acinar radiologic score

BACKGROUND

High acinar pancreatic contents are associated with a higher rate of postpancreatectomy acute pancreatitis and pancreatic fistula formation (POPF). Predicting acinar contents preoperatively might identify those at high risk of developing postoperative complications.

METHODS

A multivariable analysis was performed to identify radiological factors associated with high pancreatic acinar content at histology in patients undergoing pancreaticoduodenectomy. Clinical and radiological variables identified were used to build a composite score predicting low, moderate, and high acinar pancreatic contents.

RESULTS

Pancreatic density, wirsung caliber, and pancreatic thickness on preoperative CT-scan predicted acinar contents. These three variables predicted low, moderate, and high acinar content in 94 (26%), 122 (33.6%), and 147 (40.5%) patients, respectively. Patients with high radiological acinar scores compared with patients with intermediate-low risk scores were more frequently male (73.4% vs. 54.1%; p = 0.0003), obese (14% vs. 6%; p = 0.01), and had a statistically significant higher rate of pancreatic-specific complications (23.8% vs. 8.33%; p = 0.01), POPF (12.9% vs. 4.63%; p = 0.005) and pancreaticogastrostomy bleeding (10.8% vs. 4.17%; p = 0.01).

CONCLUSION

A simple radiological score combining pancreatic thickness, density, and wirsung caliber at CT scan preoperatively predicts patients with pancreatic parenchyma that are at higher risk of postoperative pancreatic-specific complications.

Comparing the distal pancreatectomy fistula risk score (D-FRS) and DISPAIR-FRS for predicting pancreatic fistula after distal pancreatectomy

BACKGROUNDS

Distal pancreatectomy fistula risk score (D-FRS) and DISPAIR-FRS has not been widely validated for predicting postoperative pancreatic fistula (POPF) after distal pancreatectomy (DP).

METHODS

We retrospectively analysed 104 patients undergoing DP. The predictive value of the D-FRS and DISPAIR-FRS were compared. Risk factors associated with POPF were investigated by multivariate analysis.

RESULTS

Of the 104 patients, 23 (22.1%) were categorized into the POPF group (all grade B). The areas under the ROC (AUCs) of the D-FRS (preoperative), D-FRS (intraoperative), and DISPAIR-FRS were 0.737, 0.809, and 0.688, respectively. Stratified by the D-FRS (preoperative), the POPF rates in low-risk, intermediate-risk, and high-risk groups were 5%, 22.6%, and 36.4%, respectively. By the D-FRS (intraoperative), the POPF rates in low-risk, intermediate-risk, and high-risk groups were 8.8%, 47.1%, and 47.4%, respectively. By the DISPAIR-FRS, the POPF rates in low-risk, intermediate-risk, and extreme-high-risk groups were 14.8%, 23.8% and 62.5%, respectively. Body mass index and main pancreatic duct diameter were independent risk factors of POPF both in preoperative (P = 0.014 and P = 0.033, respectively) and intraoperative (P = 0.015 and P = 0.039) multivariate analyses.

CONCLUSION

Both the D-FRS (preoperative), D-FRS (intraoperative), and DISPAIR-FRS has good performance in POPF prediction after DP. The risk stratification was not satisfactory in current Asian cohort.

Acinar content at pancreatic resection margin is significantly associated with clinically relevant pancreatic fistula after partial pancreatoduodenectomy

BACKGROUND

This study aimed to evaluate the clinical significance of acinar content at the pancreatic resection margin after partial pancreatoduodenectomy (PD).

METHODS

A total of 228 consecutive patients undergoing PD were included for analysis. Resection margins were assessed for acinar, fibrosis, and fat contents by 2 pathologists blinded to the patients' clinical data. Univariate and multivariable analyses of possible predictors for clinically relevant postoperative pancreatic fistula (cr-POPF) were performed.

RESULTS

The median acinar, fibrosis, and fat contents were 70% (IQR, 25%-82%), 13% (IQR, 5%-40%), and 15% (IQR, 9.25%-25%), respectively. The rates of cr-POPF were significantly higher in patients with an acinar content of >70% than in patients with an acinar content of ≤70% (26.4% vs 5.5%, respectively; P < .001). In addition, the rates of postoperative hyperamylasemia (POH) were significantly higher in patients with an acinar content of ≥70% than in patients with an acinar content of ≤70% (55.2% vs 13.8%, respectively; P < .001). The median fat content did not differ between patients with and without cr-POPF (13.0% [IQR, 7.5%-20.0%] vs 15.0% [IQR, 10.0%-30.0%], respectively; P = .06). An acinar content of >70% at the pancreatic resection margin (odds ratio [OR], 4.85; 95% CI, 1.61-14.58; P = .005) and a soft pancreatic texture (OR, 2.82; 95% CI, 1.02-7.76; P = .046) were independent predictive factors of cr-POPF in the multivariable analysis.

CONCLUSION

An acinar content of ≥70% at the pancreatic resection margin was a significant predictive factor for cr-POPF after PD and was also significantly associated with POH, a precursor of cr-POPF after PD in many cases. Fatty infiltration of the pancreatic resection margin was not associated with cr-POPF.

Either High or Low Risk: The Acinar Score at the Resection Margin Dichotomizes the Risk Spectrum of Pancreas-specific Complications After Pancreatoduodenectomy

BACKGROUND

Pancreatic acinar content (Ac) has been associated with pancreas-specific complications after pancreatoduodenectomy. The aim of this study was to improve the prediction ability of intraoperative risk stratification by integrating the pancreatic acinar score.

METHODS

A training and validation cohort underwent pancreatoduodenectomy with a subsequent histologic assessment of pancreatic section margins for Ac, fibrosis (Fc), and fat. Intraoperative risk stratification (pancreatic texture, duct diameter) and pancreas-specific complications (postoperative hyperamylasemia [POH], postpancreatectomy acute pancreatitis [PPAP], pancreatic fistula [POPF]) were classified according to ISGPS definitions.

RESULTS

In the validation cohort (n= 373), the association of pancreas-specific complications with higher Ac and lower Fc was replicated (all P <0.001). In the entire cohort (n= 761), the ISGPS classification allocated 275 (36%) patients into intermediate-risk classes B (POH 32%/PPAP 3%/POPF 17%) and C (POH 36%/PPAP 9%/POPF 33%). Using the acinar score (Ac ≥60% and/or Fc ≤10%), intermediate-risk patients could be dichotomized into a low-risk (POH 5%/PPAP 1%/POPF 6%) and a high-risk (POH 51%/PPAP 9%/POPF 38%) group (all P <0.001). The acinar score AUC for POPF prediction was 0.70 in the ISGPS intermediate-risk classes. Overall, 239 (31%) patients were relocated into the high-risk group from lower ISGPS risk classes using the acinar score.

CONCLUSIONS

The risk of pancreas-specific complications appears to be dichotomous-either high or low-according to the acinar score, a tool to better target the application of mitigation strategies in cases of intermediate macroscopic features.

Intraoperative Fluorescence Imaging During Robotic Pancreatoduodenectomy to Detect Suture-Induced Hypoperfusion of the Pancreatic Stump as a Predictor of Postoperative Pancreatic Fistula (FLUOPAN): Prospective Proof-of-concept Study

Background

A potential downside of robotic pancreatoduodenectomy (RPD) is the lack of tactile feedback when tying sutures, which could be especially perilous during pancreatic anastomosis. Near-infrared fluorescence imaging with indocyanine green (NIRF-ICG) could detect transpancreatic-suture-induced hypoperfusion of the pancreatic stump during RPD, which may be related to postoperative pancreatic fistula (POPF) grade B/C, but studies are lacking.

Methods

This prospective study included 37 patients undergoing RPD to assess the relation between pancreatic stump hypoperfusion as objectified with NIRF-ICG using Firefly and the rate of POPF grade B/C. In 27 patients, NIRF-ICG was performed after tying down the transpancreatic U-sutures. In 10 'negative control' patients, NIRF-ICG was performed before tying these sutures.

Results

Pancreatic stump hypoperfusion was detected using NIRF-ICG in 9/27 patients (33%) during RPD. Hypoperfusion was associated with POPF grade B/C (67% [6/9 patients] versus 17% [3/18 patients], P = 0.026). No hypoperfusion was objectified in 10 'negative controls'.

Conclusions

Transpancreatic-suture-induced pancreatic stump hypoperfusion can be detected using NIRF-ICG during RPD and was associated with POPF grade B/C. Surgeons could use NIRF-ICG to adapt their suturing approach during robotic pancreatico-jejunostomy. Further larger prospective studies are needed to validate the association between transpancreatic-suture-induced hypoperfusion and POPF.

Postoperative pancreatitis and pancreatic fistulae: a review of current evidence

OBJECTIVES

Postoperative pancreatic fistula (POPF) represents one of the most severe complications following pancreatic surgery. Despite being a leading cause of morbidity and mortality, its pathophysiology is poorly understood. In recent years, there has been growing evidence to support the role of postoperative or post-pancreatectomy acute pancreatitis (PPAP) in the development of POPF. This article reviews the contemporary literature on POPF pathophysiology, risk factors, and prevention strategies.

METHODS

A literature search was conducted using electronic databases, including Ovid Medline, EMBASE, and Cochrane Library, to retrieve relevant literature published between 2005 and 2023. A narrative review was planned from the outset.

RESULTS

A total of 104 studies fulfilled criteria for inclusion. Forty-three studies reported on technical factors predisposing to POPF, including resection and reconstruction technique and adjuncts for anastomotic reinforcement. Thirty-four studies reported on POPF pathophysiology. There is compelling evidence to suggest that PPAP plays a critical role in the development of POPF. The acinar component of the remnant pancreas should be regarded as an intrinsic risk factor; meanwhile, operative stress, remnant hypoperfusion, and inflammation represent common mechanisms for acinar cell injury.

CONCLUSIONS

The evidence base for PPAP and POPF is evolving. Future POPF prevention strategies should look beyond anastomotic reinforcement and target underlying mechanisms of PPAP development.

How i do it: microscope augmented pancreaticojejunostomy

PURPOSE

Post-operative pancreatic fistula (POPF) is perhaps one of most dreaded pancreatoduodenectomy-related complications. Various approaches to mitigate this risk have been explored, with conflicting results and no clear consensus on the comparative superiority of any one technique. We postulate that regardless of technique, the key to reducing POPF is a robust pancreatic anastomosis with careful apposition of tissues, in particular the duct-to-mucosa anastomosis.

METHOD

We describe the fashioning of a pancreatojejunostomy with an external pancreatic stent in the setting of a high-risk anastomosis with help of a 10 × magnification surgical microscope. A technical description with a short, edited video is presented.

Drain fluid biomarkers for the diagnosis of clinically relevant postoperative pancreatic fistula: a diagnostic accuracy systematic review and meta-analysis

BACKGROUND

Pancreatectomy is the only curative treatment available for pancreatic cancer and a necessity for patients with challenging pancreatic pathology. To optimize outcomes, postsurgical complications such as clinically relevant postoperative pancreatic fistula (CR-POPF) should be minimized. Central to this is the ability to predict and diagnose CR-POPF, potentially through drain fluid biomarkers. This study aimed to assess the utility of drain fluid biomarkers for predicting CR-POPF by conducting a diagnostic test accuracy systematic review and meta-analysis.

METHODS

Five databases were searched for relevant and original papers published from January 2000 to December 2021, with citation chaining capturing additional studies. The QUADAS-2 tool was used to assess the risk of bias and concerns regarding applicability of the selected studies.

RESULTS

Seventy-eight papers were included in the meta-analysis, encompassing six drain biomarkers and 30 758 patients with a CR-POPF prevalence of 17.42%. The pooled sensitivity and specificity for 15 cut-offs were determined. Potential triage tests (negative predictive value >90%) were identified for the ruling out of CR-POPF and included postoperative day 1 (POD1) drain amylase in pancreatoduodenectomy (PD) patients (300 U/l) and in mixed surgical cohorts (2500 U/l), POD3 drain amylase in PD patients (1000-1010 U/l) and drain lipase in mixed surgery groups (180 U/l). Notably, drain POD3 lipase had a higher sensitivity than POD3 amylase, while POD3 amylase had a higher specificity than POD1.

CONCLUSIONS

The current findings using the pooled cut-offs will offer options for clinicians seeking to identify patients for quicker recovery. Improving the reporting of future diagnostic test studies will further clarify the diagnostic utility of drain fluid biomarkers, facilitating their inclusion in multivariable risk-stratification models and the improvement of pancreatectomy outcomes.

Postoperative Serum Hyperamylasemia Adds Sequential Value to the Fistula Risk Score in Predicting Pancreatic Fistula after Pancreatoduodenectomy

OBJECTIVE

To evaluate whether postoperative serum hyperamylasemia (POH), with drain fluid amylase (DFA) and C-reactive protein (CRP), improves the Fistula Risk Score (FRS) accuracy in assessing the risk of a postoperative pancreatic fistula (POPF).

SUMMARY BACKGROUND DATA

The FRS predicts POPF occurrence using intraoperative predictors with good accuracy but intrinsic limits.

METHODS

Outcomes of patients who underwent pancreaticoduodenectomies between 2016 and 2021 were evaluated across FRS-risk zones and POH occurrence. POH consists of serum amylase activity greater than the upper limit of normal (52 U/l), persisting within the first 48 hours postoperatively (postoperative day -POD- 1 and 2).

RESULTS

Out of 905 pancreaticoduodenectomies, some FRS elements, namely soft pancreatic texture (odds ratio (OR) 11.6), pancreatic duct diameter (OR 0.80), high-risk pathologic diagnosis (OR 1.54), but not higher blood loss (OR 0.99), were associated with POH. POH was an independent predictor of POPF, which occurred in 46.8% of POH cases ( P <0.001). Once POH occurs, POPF incidence rises from 3.8% to 42.9%, 22.9% to 41.7%, and 48.9% to 59.2% in patients intraoperatively classified at low, moderate and high FRS risk, respectively. The predictive ability of multivariable models adding POD 1 drain fluid amylase, POD 1-2 POH and POD 3 C-reactive protein to the FRS showed progressively and significantly higher accuracy (AUC FRS=0.82, AUC FRS-DFA=0.85, AUC FRS-DFA-POH=0.87, AUC FRS-DFA-POH-CRP=0.90, DeLong always P <0.05).

CONCLUSIONS

POPF risk assessment should follow a dynamic process. The stepwise retrieval of early, postoperative biological markers improves clinical risk stratification by increasing the granularity of POPF risk estimates and affords a possible therapeutic window before the actual morbidity of POPF occurs.

Incidence and risk factors of postoperative acute pancreatitis after pancreaticoduodenectomy: a systematic review and meta-analysis

Background

Postoperative acute pancreatitis (POAP) is a specific complication after pancreatectomy. The acute inflammatory response of the residual pancreas may affect the healing of pancreatoenteric anastomoses, leading to postoperative pancreatic fistulas (POPFs), abdominal infections, and even progressive systemic reactions, conditions that negatively affect patients' prognoses and can cause death. However, to the best of our knowledge, no systematic reviews or meta-analytic studies have assessed the incidence and risk factors of POAP after pancreaticoduodenectomy (PD).

Method

We searched PubMed, Web of Science, Embase, and Cochrane Library databases for relevant literature describing the outcomes of POAP after PD until November 25, 2022, and we used the Newcastle-Ottawa Scale to assess the quality of the studies. Next, we pooled the incidence of POAP and the odds ratios (ORs) and 95% confidence intervals (CIs) of the risk factors using a random-effect meta-analysis. I2 tests were used to assess heterogeneity between the studies.

Results

We analyzed data from 7,164 patients after PD from 23 articles that met the inclusion criteria for this study. The subgroup results of the meta-analysis by different POAP diagnostic criteria showed that the incidences of POAP were 15% (95% CI, 5-38) in the International Study Group for Pancreatic Surgery group, 51% (95% CI, 42-60) in the Connor group, 7% (95% CI, 2-24) in the Atlanta group, and 5% (95% CI, 2-14) in the unclear group. Being a woman [OR (1.37, 95% CI, 1.06-1.77)] or having a soft pancreatic texture [OR (2.56, 95% CI, 1.70-3.86)] were risk factors of POAP after PD.

Conclusion

The results showed that POAP was common after PD, and its incidence varied widely according to different definitions. Large-scale reports are still needed, and surgeons should remain aware of this complication.

Systematic Review Registration

identifier: CRD42022375124.

Clinical validation of the international study group of pancreatic surgery (ISGPS) definition for post-pancreatectomy acute pancreatitis

BACKGROUND

The diagnosis of postoperative or post-pancreatectomy acute pancreatitis (PPAP) is controversial. In 2021, the International Study Group of Pancreatic Surgery (ISGPS) published the first unifying definition and grading system for PPAP. This study sought to validate recent consensus criteria, using a cohort of patients undergoing pancreaticoduodenectomy (PD) in a high-volume pancreaticobiliary specialty unit.

METHODS

All consecutive patients undergoing PD at a tertiary referral centre between January 2016 and December 2021 were retrospectively reviewed. Patients with serum amylase recorded within 48h from surgery were included for analysis. Postoperative data were extracted and evaluated against the ISGPS criteria, including the presence of postoperative hyperamylasaemia, radiologic features consistent with acute pancreatitis, and clinical deterioration.

RESULTS

A total of 82 patients were evaluated. The overall incidence of PPAP was 32% (26/82) in this cohort, of which 3/26 demonstrated postoperative hyperamylasaemia and 23/26 had clinically relevant PPAP (Grade B or C) when correlated radiologic and clinical criteria.

CONCLUSIONS

This study is among the first to apply the recently published consensus criteria for PPAP diagnosis and grading to clinical data. While the results support their utility in establishing PPAP as a distinct post-pancreatectomy complication, there remains a need for future large-scale validation studies.

Impact of pancreatic fat infiltration on postoperative pancreatic fistula occurrence in patients undergoing invagination pancreaticojejunostomy

BACKGROUND

No studies to date have determined the impact of pancreatic fat infiltration on postoperative pancreatic fistula (POPF) occurrence in patients undergoing invagination pancreaticojejunostomy (IV-PJ).

METHODS

The medical records of patients with a soft pancreas who underwent pancreatoduodenectomy followed by IV-PJ were reviewed . The pancreatic fat ratio on computed tomography (CT) images (I-PFR) was determined using preoperative CT and verified by histologic examination. The relationship between the I-PFR and POPF occurrence was determined. Patients were classified into 2 groups based on I-PFR value (fatty and non-fatty pancreas). Postoperative outcomes were compared between the two groups, and specifically among patients who developed POPF.

RESULTS

Of 221 patients, POPF occurred in 67 (30.3%). I-PFR was positively correlated with histologic-calculated fat ratio (ρ = 0.517, p < 0.001). This index was shown to be an independent predictor of POPF. Based on an I-PFR cut-off value of 3.2%, 92 patients were classified in the fatty pancreas group. Subgroup analysis of the patients who developed POPF showed that incidence of abscess formation and hemorrhage tended to be higher in patients with fatty pancreas than in those with non-fatty pancreas.

CONCLUSIONS

Pancreatic fat infiltration is highly associated with POPF and possibly causes subsequent serious complications in patients undergoing IV-PJ.

Drain fluid biomarkers for prediction and diagnosis of clinically relevant postoperative pancreatic fistula: A narrative review

Clinically relevant postoperative pancreatic fistula (CR-POPF) has continued to compromise patient recovery post-pancreatectomy despite decades of research seeking to improve risk prediction and diagnosis. The current diagnostic criteria for CR-POPF requires elevated drain fluid amylase to present alongside POPF-related complications including infection, haemorrhage and organ failure. These worrying sequelae necessitate earlier and easily obtainable biomarkers capable of reflecting evolving CR-POPF. Drain fluid has recently emerged as a promising source of biomarkers as it is derived from the pancreas and hence, capable of reflecting its postoperative condition. The present review aims to summarise the current knowledge of CR-POPF drain fluid biomarkers and identify gaps in the field to invigorate future research in this critical area of clinical need. These findings may provide robust diagnostic alternatives for CR-POPF and hence, to clarify their clinical utility require further reports detailing their diagnostic and/or predictive accuracy.

Pancreatic Apoplexy: Fulminant Necrotizing Pancreatitis Leading to Completion Pancreatectomy Within 3 Days After Partial Pancreaticoduodenectomy

OBJECTIVES

Patient characteristics with postoperative acute necrotizing pancreatitis and completion pancreatectomy (CP) after pancreaticoduodenectomy (PD) remain unclear.

METHODS

Data from all patients who underwent a PD with need for CP (January 2011-December 2019) at a German University Hospital were analyzed regarding the indications and timing of CP, laboratory and histopathological findings, and overall outcome.

RESULTS

Six hundred twelve patients underwent PD, 33 (5.4%) of them needed a CP. Indications were grade C pancreatic fistula with or without biliary leak (46% and 12%), biliary leak (6%), and hemorrhage due to pancreatic fistula (36%). Eight patients (24%) underwent CP within 3 days after PD. These fulminant courses ("pancreatic apoplexy") were accompanied by significantly higher levels of lactate dehydrogenase, C-reactive protein, serum amylase, serum lipase, drain amylase, and drain lipase compared with patients with CP after the third day. Pancreatic apoplexy was histologically associated with higher rates of pancreatic necrosis (P = 0.044) and hemorrhage (P = 0.001). A trend toward higher mortality was observed (75% vs 36%, P = 0.058).

CONCLUSIONS

Pancreatic apoplexy, defined as fulminant necrotizing pancreatitis after PD leading to CP within 3 days, is associated with characteristic laboratory and histopathological findings and a trend to higher mortality.

Risk Factors and Clinical Impacts of Post-Pancreatectomy Acute Pancreatitis After Pancreaticoduodenectomy: A Single-Center Retrospective Analysis of 298 Patients Based on the ISGPS Definition and Grading System

Background

The definition and grading system of post-pancreatectomy acute pancreatitis (PPAP) has recently been proposed by ISGPS. This study aimed to put this definition and classification into practice and investigate the potential risk factors and clinical impacts of PPAP.

Methods

Demographic and perioperative data of consecutive patients who underwent pancreaticoduodenectomy (PD) from January 2019 to July 2021 were collected and analyzed retrospectively. The diagnostic criteria of PPAP published by ISGPS, consisting of biochemical, radiologic, and clinical parameters, were adopted. The risk factors were analyzed by univariate and multivariate analyses.

Results

A total of 298 patients were enrolled in this study, and the total incidence of PPAP was 52.4% (150 patients). Stratified by clinical impacts of PPAP, the incidences of grades B and C PPAP were 48.9% and 3.5%, respectively. PPAP after PD was significantly associated with pancreatic fistula and other unfavorable complications. Soft pancreatic texture (OR 3.0) and CRP ≥ 180 mg/L (OR 3.6) were the independent predictors of PPAP, AUC 0.613. Stratified by the grade of PPAP, soft pancreatic texture (OR 2.7) and CRP ≥ 180 mg/L (OR 3.4) were the independent predictors of grade B PPAP, and soft pancreatic texture (OR 19.3), operation duration >360 min (OR 13.8), and the pancreatic anastomosis by using conventional duct to mucosa methods (OR 10.4) were the independent predictors of grade C PPAP. PPAP complicated with pancreatic fistula significantly increased the severe complications and mortality compared to only PPAP occurrence.

Conclusion

PPAP was not an uncommon complication after PD and was associated with unfavorable clinical outcomes, especially since it was complicated with pancreatic fistula. Soft pancreatic texture and CRP ≥ 180 mg/L were the independent predictors of PPAP. Higher-volume multicenter and prospective studies are strongly needed.

Postpancreatectomy Acute Pancreatitis (PPAP): Definition and Grading From the International Study Group for Pancreatic Surgery (ISGPS)

OBJECTIVE

The ISGPS aimed to develop a universally accepted definition for PPAP for standardized reporting and outcome comparison.

BACKGROUND

PPAP is an increasingly recognized complication after partial pancreatic resections, but its incidence and clinical impact, and even its existence are variable because an internationally accepted consensus definition and grading system are lacking.

METHODS

The ISGPS developed a consensus definition and grading of PPAP with its members after an evidence review and after a series of discussions and multiple revisions from April 2020 to May 2021.

RESULTS

We defined PPAP as an acute inflammatory condition of the pancreatic remnant beginning within the first 3 postoperative days after a partial pancreatic resection. The diagnosis requires (1) a sustained postoperative serum hyperamylasemia (POH) greater than the institutional upper limit of normal for at least the first 48 hours postoperatively, (2) associated with clinically relevant features, and (3) radiologic alterations consistent with PPAP. Three different PPAP grades were defined based on the clinical impact: (1) grade postoperative hyperamylasemia, biochemical changes only; (2) grade B, mild or moderate complications; and (3) grade C, severe life-threatening complications.

DISCUSSIONS

The present definition and grading scale of PPAP, based on biochemical, radiologic, and clinical criteria, are instrumental for a better understanding of PPAP and the spectrum of postoperative complications related to this emerging entity. The current terminology will serve as a reference point for standard assessment and lend itself to developing specific treatments and prevention strategies.

OUP accepted manuscript

Background

Recent studies have suggested postoperative acute pancreatitis (POAP) as a serious complication after pancreaticoduodenectomy (PD) and have speculated on its possible role in the pathogenesis of postoperative pancreatic fistula (POPF). This study aimed to assess the impact of POAP on post-PD outcomes and fistula risk score (FRS) performance in predicting POAP.

Methods

All PDs at Helsinki University Hospital between 2013 and 2020 were analysed. POAP was defined as a plasma amylase activity greater than the normal upper limit on postoperative day (POD) 1 and stratified as clinically relevant (CR)-POAP once C-reactive protein (CRP) reached or exceeded 180 mg/l, and non-CR-POAP once CRP was less than 180 mg/l on POD 2. The Comprehensive Complication Index (CCI) was used to assess total postoperative morbidity. Different FRSs were assessed using receiver operating characteristic curves.

Results

Of the 508 patients included, POAP occurred in 202 (39.8 per cent) patients, of whom 91 (17.9 per cent) had CR-POAP. The incidence of CR-POPF was 12.6 per cent (64 patients). Patients with non-CR-POAP had a similar morbidity to patients with no POAP (median CCI score 24.2 versus 22.6; P = 0.142), while CCI score was significantly higher (37.2) in patients with CR-POAP (P < 0.001). CR-POAP was associated with increased rates of CR-POPF, delayed gastric emptying, haemorrhage, and bile leak, while non-CR-POAP was associated only with CR-POPF. Ninety-day mortality was 1.6 per cent, 0.9 per cent, and 3.3 per cent in patients with no-POAP, non-CR-POAP, and CR-POAP, respectively. Updated alternative FRS showed the best performance in predicting CR-POAP (area under the curve 0.834).

Conclusion

CR-POAP was associated with a higher CCI score, suggesting CR-POAP as a distinct entity from non-CR-POAP. FRSs can be used to assess the risk of CR-POAP.

Pharmacological prevention of post-operative pancreatitis: systematic review and meta-analysis of randomized controlled trials on animal studies

BACKGROUND

Postoperative pancreatic fistula (POPF) remains a significant complication of pancreatic resection with recent evidence showing a strong association between post-operative pancreatitis and subsequent development of POPF. Incidence and severity of pancreatitis following endoscopic therapy has been effectively reduced with indomethacin prophylaxis, however further agents require evaluation. We present a systematic literature review and meta-analysis of the prophylactic treatment with corticosteroids or n-acetyl cysteine (NAC) of induced pancreatitis in rodent models.

METHODS

A systematic literature search was conducted using Pubmed, Medline, Embase and Cochrane library to identify eligible randomized control trials (RCT) involving animal models that examined NAC or corticosteroids. The primary outcome was the subsequent effect on serum amylase and IL-6 and the histopathological markers of severity such as pancreatic oedema and necrosis.

RESULTS

Four RCTs (n = 178) met inclusion criteria examining NAC and eight RCTs (n = 546) examining corticosteroid agents (dexamethasone, hydrocortisone, methylprednisolone). Prophylactic administration of all corticosteroid agents showed a net effect in favour of reducing markers of severity of pancreatitis. NAC showed a significant reduction in severity of amylase and necrosis.

CONCLUSION

The RCTs examined suggest that prophylactic administration of corticosteroid agents and NAC can reduce the severity of pancreatitis as indicated by histopathologic markers, serum amylase and IL-6 levels.

Postoperative acute pancreatitis is a serious but rare complication after distal pancreatectomy

BACKGROUND

The clinical relevance of hyperamylasemia after distal pancreatectomy (DP) remains unclear and no internationally accepted definition of postoperative acute pancreatitis (POAP) exists. The aim of this study was to characterize POAP after DP and to assess the role of serum amylase (SA) in POAP.

METHODS

Outcomes of 641 patients who had undergone DP between 2015 and 2019 were analyzed. Postoperative SA was determined in all patients. POAP was defined based on contrast-enhanced computed tomography (CT) or intraoperative findings during relaparotomy.

RESULTS

An elevation of SA on postoperative day 1 (hyperamylasemia^POD1) was found in 398 patients (62.1%). Twelve patients (1.87%) were identified with POAP. Ten patients demonstrated radiologic criteria for POAP and in two patients POAP was diagnosed during relaparotomy. Outcome of POAP patients was worse than that of patients with hyperamylasemia^POD1 alone and that with normal SA^POD1 without POAP evidence (postoperative pancreatic fistula 50% vs 30.6% vs 18.5%; length of hospital stay 26 days vs 12 vs 11, respectively). The overall 90-day mortality of all 641 patients was 0.6%.

CONCLUSION

POAP is a serious but rare complication after DP. Hyperamylasemia^POD1 is of prognostic relevance after DP, but it seems not sufficient as a single parameter to diagnose POAP.

[Scoring systems to predict pancreatic fistula after Whipple procedure]

Specific complications is an «Achilles heel» of pancreaticoduodenectomy. Postoperative pancreatic fistula (POPF) is the most common specific complication. POPF prediction is an actual problem in pancreatic surgery. Analysis of statistically significant scoring systems to predict POPF is a modern trend in perioperative planning. Several prognostic scales (FRS, a-FRS, ua-FRS, Modified Fistula Risk Score) are recommended for clinical practice.

Fluorescence-based pancreas stump perfusion is associated with postoperative acute pancreatitis after pancreatoduodenectomy a prospective cohort study

BACKGROUND

Postoperative acute pancreatitis (POAP) emerges as a distinct pancreas-specific complication increasing both the risk and the burden of POPF after pancreatoduodenectomy. Among various risk factors, pancreas stump (PS) hypoperfusion might play a role in POAP occurrence but has never been investigated. The current study aimed at evaluating the feasibility of intraoperative fluorescence angiography (IOFA) of the PS using ICG and its association with POAP.

METHODS

Consecutive patients who underwent pancreatoduodenectomy for a periampullary tumor with pancreatojejunostomy and PS perfusion assessment using IOFA between January 2020 and November 2020 were prospectively included. Perioperative management and surgical strategy were standardized. IOFA of the pancreas stump was performed before fashioning pancreatojejunostomy. POAP was defined according to the Connor definition and was confirmed upon radiological blind review. Outcomes between patients with normally perfused and hypoperfused PS were compared. POAP was the primary endpoint.

RESULTS

Among 30 patients, nine patients (30%) developed POAP according to the Connor definition, and six patients (20%) had CT-confirmed POAP. Upon IOFA, six patients (20%) presented PS hypoperfusion; of which one patient underwent extended pancreatectomy further to the left. PS hypoperfusion was statistically associated with the occurrence of POAP (80% vs. 16%; p = 0.011) and CT-confirmed POAP (60% vs. 12%; p = 0.041). Clinically relevant POPF rate was 40% in case of PS hypoperfusion and 4% in case of normal PS perfusion (p = 0.064).

CONCLUSIONS

PS perfusion assessment using IOFA seems safe and reliable to anticipate POAP. PS IOFA could be considered as a potential tool for perioperative assessment of surgical risk after pancreatoduodenectomy.

Estimated functional remnant pancreatic volume predicts nonalcoholic fatty liver disease after pancreaticoduodenectomy: use of computed tomography attenuation value of the pancreas

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a late complication of pancreaticoduodenectomy (PD). However, this complication is difficult to predict preoperatively. This study aimed to assess the association between NAFLD and preoperative computed tomography (CT) findings.

METHODS

Medical records of 112 patients who had undergone PD and had CT scans preoperatively and 6 months postoperatively were retrospectively reviewed. We evaluated several CT findings, including the CT attenuation value of the remnant pancreas, remnant pancreatic volume (RPV), and the estimated functional remnant pancreatic volume (eFRPV) on preoperative CT. The variables, including the CT findings and histopathological findings, were compared between the patients with and without NAFLD after PD.

RESULTS

The NAFLD group included 21 patients (18.8%). The CT attenuation value of the remnant pancreas was correlated with the pancreatic acinar cell density (r = 0.537), and was lower in the NAFLD group than in the non-NAFLD group (p = 0.007). The eFRPV was lower in the NAFLD group than in the non-NAFLD group (p = 0.002). An eFRPV ≤47 mL·HU was an independent predictive factor for NAFLD (p = 0.007; odds ratio: 6.73; 95% confidence interval: 1.70-26.70).

CONCLUSION

The eFRPV can be used to preoperatively predict NAFLD after PD.

The role of acinar content at pancreatic resection margin in the development of postoperative pancreatic fistula and acute pancreatitis after pancreaticoduodenectomy

BACKGROUND

A fatty infiltration of the pancreas has been traditionally regarded as the main histological risk factor for postoperative pancreatic fistula, whereas the role of the secreting acinar compartment has been poorly investigated. The aim of this study was to evaluate the role of acinar content at pancreatic resection margin in the development of clinically relevant postoperative pancreatic fistula and clinically relevant postoperative acute pancreatitis after pancreaticoduodenectomy.

METHODS

Data from 388 consecutive patients who underwent pancreaticoduodenectomy (2018-2019) were analyzed. Pancreatic section margins were histologically assessed for acinar, fibrosis, and fat content. Acinar content was categorized using median and third quartile as cut-offs. Univariate and multivariable analysis of possible predictors of clinically relevant postoperative pancreatic fistula and clinically relevant postoperative acute pancreatitis were performed.

RESULTS

Acinar content was <60% in 166 patients (42.8%), ≥60% and ≤80% in 156 patients (40.2%), and >80% in 66 patients (17.0%). The rate of clinically relevant postoperative pancreatic fistula and clinically relevant postoperative acute pancreatitis was significantly higher in patients with acinar content >80% (39.4% and 33.3%, respectively) as well as in those with acinar content ≥60% and ≤80% (36.5% and 35.3%, respectively), compared with patients with acinar content <60% (10.2% and 5.4%, respectively) (P < .001). Acinar content was identified as an independent predictor of clinically relevant postoperative pancreatic fistula (≥60% and ≤80%, odds ratio 2.51, P = .008; >80%, odds ratio 2.93, P = .010) and clinically relevant postoperative acute pancreatitis (≥60% and ≤80%, odds ratio 9.42, P < .001; >80%, odds ratio 10.16, P < .001).

CONCLUSION

An acinar content at pancreatic resection margin ≥60% is associated to an increased risk of clinically relevant postoperative pancreatic fistula and clinically relevant postoperative acute pancreatitis. Fat content was associated neither with clinically relevant postoperative pancreatic fistula nor with clinically relevant postoperative acute pancreatitis.

Optimal stapler cartridge selection to reduce post-operative pancreatic fistula according to the pancreatic characteristics in stapler closure distal pancreatectomy

BACKGROUND

Postoperative pancreatic fistula (POPF) is associated with potentially fatal complications, but there is lack of data on relationship between pancreas thickness, and stapler size and the POPF rate. This study aimed to suggest optimal stapler that reduces POPF rate according to the pancreas thickness.

METHODS

This retrospective cohort study was conducted in two tertiary high-volume pancreas centers. 599 patients who underwent distal pancreatectomy were assessed for stump reinforcement methods, pathology findings, pancreas thickness, and cartridge used. The cartridges were grouped as I, II, III according to the closed height ≤1.5 mm, 1.8 mm, and ≥2.0 mm, respectively.

RESULTS

The POPF rate increased according to the thickness. The stapler Groups I, II, and III had an overall POPF rate of 66.4% vs. 61.7% vs. 57.8%, but Group II stapler cartridge showed a significant reduction in the POPF rate than other cartridges in pancreas with thickness <13 mm (53.5% vs. 21.7% vs. 36.0%, p = 0.031). There was no significant difference between the POPF rate according to stapler groups when the pancreas was thicker than 13 mm.

CONCLUSION

Thickness is the strongest risk factor in predicting POPF. Use of Group II stapler cartridge for pancreas with a thickness of <13 mm can help reduce POPF.

Increased postoperative pancreatic fistula rate after distal pancreatectomy compared with pancreatoduodenectomy is attributable to a difference in acinar scores

BACKGROUND

Postoperative pancreatic fistula (POPF) is a potentially lethal complication of pancreatic surgery. POPF rate is consistently higher after distal pancreatectomy (DP) compared with pancreatoduodenectomy (PD). The acinar score of the remnant pancreas is associated with postoperative pancreatitis and POPF. This study aimed to: (i) confirm the difference in POPF rate after DP vs PD; (ii) confirm the association between acinar score and POPF; and (iii) evaluate the difference in acinar scores between DP and PD.

METHODS

Patients undergoing DP or PD at a single institution from 2011 to 2017 were included. Hematoxylin and eosin-stained slides of the pancreatic resection margin were evaluated for all patients and scored for acinar cell density. Clinicopathological data were retrieved from a prospectively maintained database.

RESULTS

Two hundred and ninety-four patients were included in the analysis (206 PD, 88 DP). The POPF rate was significantly higher after DP than PD (20.4% vs 11.2%, P = .043). Acinar score >50 was independently associated with the development of POPF (OR 6.457, P = .003). DP was associated with a higher median acinar score than PD (65 vs 50, P < .001).

CONCLUSION

The POPF rate is significantly higher after DP compared with PD and is attributable to a higher acinar score of the pancreatic resection margin.

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.

Implications of increased serum amylase after pancreaticoduodenectomy: toward a better definition of clinically relevant postoperative acute pancreatitis

BACKGROUND

Postoperative acute pancreatitis (POAP) can be a possible cause of postoperative pancreatic fistula (POPF). The present study aimed to evaluate the role of clinically-relevant POAP (CR-POAP), defined according to different cut-offs of postoperative amylase (AMS) values and C-reactive protein (CRP), in the development of clinically relevant POPF (CR-POPF) after pancreaticoduodenectomy (PD).

METHODS

Data from 610 patients who underwent PD (2015-2018) were analyzed. Patients were divided according to the upper limit (100 U/l) and 3-fold the upper limit (300 U/l) of serum POD1 AMS. Univariate and multivariable analysis of possible predictors of CR-POPF were performed.

RESULTS

Overall, 360 patients (59%) had POD1 serum AMS ≤100 U/l, 142 patients (23%) had POD1 serum AMS >100 U/l and ≤300 U/l, and 108 patients (18%) had POD1 serum AMS >300 U/l. Patients with POD1 serum AMS >300 had a higher frequency of soft pancreatic texture, complications, main pancreatic duct diameter ≤3 mm, and CR-POPF. POD1 serum AMS >100 U/l associated to POD2 CRP ≥180 mg/l (OR: 4.3, p < 0.001) was an independent predictor of CR-POPF.

CONCLUSION

These results confirm that CR-POAP, defined as POD1 serum AMS >100 U/l and POD2 CRP ≥ 180 mg/l, is associated with an increased risk of CR-POPF.

Neoadjuvant therapy for pancreatic cancer changes the composition of the pancreatic parenchyma

BACKGROUND

Postoperative pancreatic fistula (POPF) remains a prominent complication following pancreatic cancer resections. The primary aim of this study was to evaluate the histological changes that occur in the pancreas due to neoadjuvant therapy (NAT) by comparing the acinar, collagen and fat scores in resected PDAC specimens of patients who did and did not receive NAT. Secondary aims included (1) the difference in rates of POPF in PDAC patients who received NAT versus upfront resection; and (2) the association between acinar/collagen/fat scores and the development of POPF.

METHODS

Consecutive patients who underwent pancreaticoduodenectomy for PDAC, with and without NAT were included for analysis. Acinar, collagen and fat scores were determined from histology slides of the pancreatic resection margin.

RESULTS

One hundred and thirty-four patients were included. There was a significant decrease in the median acinar score (48 vs 23, p = 0.003) and increase in the collagen score (28 vs 50, p = 0.011) for patients who received NAT and a significant correlation with the number of cycles of NAT. This study found no statistical difference between NAT and the development of POPF.

CONCLUSION

The use of NAT in the treatment of PDAC changes the composition of the pancreas.

Characterization of postoperative acute pancreatitis (POAP) after distal pancreatectomy

BACKGROUND

Postoperative acute pancreatitis has recently been reported as a specific complication after pancreatoduodenectomy. The aim of this study was to characterize postoperative acute pancreatitis after distal pancreatectomy.

METHODS

We analyzed the outcomes retrospectively of 368 patients who underwent distal pancreatectomies during the period January 2016 to December 2019. Postoperative acute pancreatitis was defined as an increase of serum amylase activity greater than our laboratory normal upper limit on postoperative days 0 to 2. We assessed the incidence of postoperative acute pancreatitis after distal pancreatectomy and examined possible predictors of postoperative acute pancreatitis and relationships of postoperative acute pancreatitis with postoperative pancreatic fistula.

RESULTS

The rates of postoperative acute pancreatitis and postoperative pancreatic fistula after distal pancreatectomy were 67.9% and 28.8%, respectively. Patients who developed postoperative acute pancreatitis experienced an increased rate of severe morbidity (18.4 vs 9.3%; P = .030). Neoadjuvant therapy (odds ratio 0.28, 0.09-0.85; P = .025), age ≥ 65 y (odds ratio 0.34, 0.13-0.85; P = .020), duct size (odds ratio 0.02, 0.002-0.47; P = .013), pancreatic thickness (odds ratio 3.4, 1.29-8.9; P = .013), resection at the body-tail level (odds ratio 4.3, 1.15-23.19; P = .041), and neuroendocrine histology (odds ratio 1.14, 1.06-3.90; P = .013) were independent predictors of postoperative acute pancreatitis. Furthermore, postoperative acute pancreatitis was an independent predictor of postoperative pancreatic fistula (odds ratio 5.8, 2.27-15.20; P < .001). Postoperative pancreatic fistula occurred in 37% of patients who developed postoperative acute pancreatitis. Patients developing postoperative acute pancreatitis alone demonstrated a statistically significantly increased rate of biochemical leakage and bacterial contamination in the peripancreatic drainage fluid.

CONCLUSION

Postoperative acute pancreatitis is a frequent event after distal pancreatectomy and, despite its close association with postoperative pancreatic fistula, evidently represents a separate phenomenon. A universally accepted definition of postoperative acute pancreatitis that applies to all types of pancreatic resections is needed, because it may identify patients at greater risk for additional morbidity immediately after pancreatic resections.

Postoperative hyperamylasemia (POH) and acute pancreatitis after pancreatoduodenectomy (POAP): State of the art and systematic review

BACKGROUND

Postoperative hyperamylasemia is a frequent finding after pancreatoduodenectomy, but its incidence and clinical implications have not yet been analyzed systematically. The aim of this review is to reappraise the concept of postoperative hyperamylasemia with postoperative acute pancreatitis, including its definition, interpretation, and correlation.

METHODS

Online databases were used to search all available relevant literature published through June 2019. The following search terms were used: "pancreaticoduodenectomy," "amylase," and "pancreatitis." Surgical series reporting data on postoperative hyperamylasemia or postoperative acute pancreatitis were selected and screened.

RESULTS

Among 379 screened studies, 39 papers were included and comprised data from a total of 9,220 patients. Postoperative hyperamylasemia was rarely defined in most of these series, and serum amylase values were measured at different cutoff levels and reported on different postoperative days. The actual levels of serum amylase activity and the representative cutoff levels required to reach a diagnosis of postoperative acute pancreatitis were markedly greater on the first postoperative days and tended to decrease over time. Most studies analyzing postoperative hyperamylasemia focused on its correlation with postoperative pancreatic fistula and other postoperative morbidities. The incidence of postoperative acute pancreatitis varied markedly between studies, with its definition completely lacking in 40% of the analyzed papers. A soft pancreatic parenchyma, a small pancreatic duct, and pathology differing from cancer or chronic pancreatitis were all predisposing factors to the development of postoperative hyperamylasemia.

CONCLUSION

Postoperative hyperamylasemia has been proposed as the biochemical expression of pancreatic parenchymal injury related to localized ischemia and inflammation of the pancreatic stump. Such phenomena, analogous to those associated with acute pancreatitis, could perhaps be renamed as postoperative acute pancreatitis from a clinical standpoint. Patients with postoperative acute pancreatitis experienced an increased rate of all postoperative complications, particularly postoperative pancreatic fistula. Taken together, the discrepancies among previous studies of postoperative hyperamylasemia and postoperative acute pancreatitis outlined in the present review may provide a basis for stronger evidence necessary for the development of universally accepted definitions for postoperative hyperamylasemia and postoperative acute pancreatitis.

Pre-, peri- and post-operative factors for the development of pancreatic fistula after pancreatic surgery

BACKGROUND

The most hazardous complication to pancreatic surgery is the development of a post-operative pancreatic fistula (POPF). Appropriate understanding of the underlying pathophysiology, risk factors and perioperative mechanisms may allow for better management and use of preventive measures.

METHODS

Systematic literature search using the English PubMed literature up to April 2019, with emphasis on the past 5 years.

RESULTS

Several risk scores have been developed but none are perfect in predicting POPF risk. A conceptual framework of factors that contribute to the pathophysiology of pancreatic fistulae is still developing but incomplete. Recognized factors include those related to the patient, the pathology and the perioperative care. Interventions such as use of drains, stents and various drugs to mediate risk is still debated. Emerging data suggest that both the microbiome and the inflammation in the post-operative phase may play important roles in risk for POPF. Available risk scores allow for stratification of risk and mitigation strategies tailored to reduce this. However, accurate estimation of risk remains a challenge and mechanisms are only partially understood.

CONCLUSIONS

The pathophysiology of POPF remains poorly understood. Current models only partially explain risks or associated mechanisms. Novel areas of investigation need to be explored for better prediction.

Density and enhancement of the pancreatic tail on computer tomography predicts acinar score and pancreatic fistula after pancreatoduodenectomy

BACKGROUND

Acinar score calculated at the pancreatic resection margin is associated with postoperative pancreatic fistula (POPF) after pancreatoduodenectomy (PD). The present study evaluates the association between (i) computed tomography (CT) density of the pancreas and the acinar score of the pancreatic resection margin, and (ii) CT density of the pancreas and POPF after PD.

METHODS

Consecutive patients who underwent PD were included for analysis. CT densities of the pancreatic head, neck, body and tail were measured in non-contrast (NC), arterial (ART) and portal venous (PV) phases. Histologic slides of the pancreatic resection margin were scored for acinar cell density.

RESULTS

Ninety patients were included for analysis. Non-contrast density of the pancreatic tail was a good predictor of POPF (AUROC 0.704, p = 0.036), and a cut-off value of >40 Hounsfield units predicted POPF with 70.0% sensitivity and 73.4% specificity. The ratio of densities between PV and NC phases in the pancreatic tail was also a good predictor of POPF (AUROC 0.712, p = 0.030), and a cut-off value of <2.29 predicted POPF with 70.9% sensitivity and 80% specificity.

CONCLUSION

Non-contrast CT density of the pancreatic tail correlates with acinar cell density of the pancreatic resection margin and predicts the development of POPF after PD.

A Predictive Risk Scoring System for Clinically Relevant Pancreatic Fistula After Pancreaticoduodenectomy

Background

Postoperative pancreatic fistula remains a challenge after pancreaticoduodenectomy (PD). This study aimed to establish a scoring system to predict clinically relevant postoperative pancreatic fistula (CR-POPF) after PD.

Material/Methods

The clinical records of 361 consecutive patients who underwent PD between 2009 and 2017 were reviewed retrospectively. Patients were divided into a study group (225 patients) and a validation group (136 patients). CR-POPF was defined and classified based on the 2016 ISGPS definition and classification system. Univariate and multivariate logistic regression analyses were performed and we thus developed a scoring system based on the regression coefficient of the multivariate logistic regression model. The predictive value was determined using the receiver operating characteristic (ROC) curve.

Results

A predictive scoring system with a maximum of 6 points for CR-POPF was established using the following 4 factors: 1 point for soft pancreatic texture (OR 2.09, 95%CI 1.10–3.98, P=0.025), 1.5 points for main pancreatic duct diameter ≤2.5 mm (OR 2.72, 95%CI 1.23–5.99, P=0.013), 0.5 points for extended lymphadenectomy (OR 1.57, 95%CI 1.13–2.18, P=0.007), 0.5 points for a 25–30 g/L postoperative day 1 serum albumin (OR 1.43, 95%CI 1.02–2.00, P=0.037), and 3 points for postoperative day 1 serum albumin ≤25 g/L (OR 5.12, 95%CI 1.82–14.41, P=0.002). The ROC curve showed that this scoring system was highly predictive for CR-POPF in the validation group (AUC=0.806, 95%CI: 0.735–0.878).

Conclusions

This 6-point risk scoring system will be useful for perioperative risk management of CR-POPF.

Postoperative pancreatic fistula: a review of traditional and emerging concepts

Postoperative pancreatic fistula (POPF) remains the major cause of morbidity after pancreatic resection, affecting up to 41% of cases. With the recent development of a consensus definition of POPF, there has been a large number of reports examining various risk factors, prediction models, and mitigation strategies for this costly complication. Despite these strategies, the rates of POPF have not significantly diminished. Here, we review the literature and evidence regarding both traditional and emerging concepts in POPF prediction, prevention, and management. In particular, we review the evidence for the association between postoperative pancreatitis and POPF, and present a novel proposed mechanism for the development of POPF.