Drainage fluid and serum amylase levels accurately predict development of postoperative pancreatic fistula

Cross-sectional imaging of pancreatic leak: a pictorial review

Pancreatic leaks occur when a disruption in the pancreatic ductal system results in the leakage of pancreatic enzymes such as amylase, lipase, and proteases into the abdominal cavity. While often associated with pancreatic surgical procedures, trauma and necrotizing pancreatitis are also common culprits. Cross-sectional imaging, particularly computed tomography, plays a crucial role in assessing postoperative conditions and identifying both early and late complications, including pancreatic leaks. The presence of fluid accumulation or hemorrhage near an anastomotic site strongly indicates a pancreatic fistula, particularly if the fluid is connected to the pancreatic duct or anastomotic suture line. Pancreatic fistulas are a type of pancreatic leak that carries a high morbidity rate. Early diagnosis and assessment of pancreatic leaks require vigilance and an understanding of its imaging hallmarks to facilitate prompt treatment and improve patient outcomes. Radiologists must maintain vigilance and understand the imaging patterns of pancreatic leaks to enhance diagnostic accuracy. Ongoing improvements in surgical techniques and diagnostic approaches are promising for minimizing the prevalence and adverse effects of pancreatic fistulas. In this pictorial review, our aim is to facilitate for radiologists the comprehension of pancreatic leaks and their essential imaging patterns.

Predictive value of drain fluid amylase level on postoperative day one after pancreatic resection for predicting postoperative pancreatic fistula

Objectives

The aim of this study was to evaluate the predictive value of the first postoperative day (POD1) drain fluid amylase in predicting pancreatic fistula formation following pancreaticoduodenectomy (PD).

Material and Methods

One-hundred and eighty-five prospective patients undergoing PD between April 2014 and April 2018 were studied retrospectively. Cut-off point to predict the development of POPF was determined by median values for drain fluid amylase of 1883 U/L. Patients were classified into two groups according to POD1 drain fluid amylase values: <1883 U/L (Group 1) and ≥1883 U/L (Group 2). Differences between the groups with clinically relevant POPF and without POPF were evaluated.

Results

The incidence of POPF was 17.2%. POD1 amylase level was the strongest predictor of POPF, with levels of higher than 1883 U/L demonstrating the best accuracy (87.5%), sensitivity (78.1%), specificity (89.5%), positive predictive value (60.9%), and negative predictive value (95.1%). One-hundred and forty-four patients (77.8%) had a POD1 drain amylase level of less than 1883 U/L, and POPF developed in only seven (3.7%) cases, whereas in patients with POD1 drain amylase level of 1883 U/L or higher (n= 41), the POPF rate was 31.4% [OR: 22.24, 95% CI (7.930-62.396), p<0.001].

Conclusion

The cut-off point of POD1 drain fluid amylase level (1883 U/L) might predict the clinically relevant POPF with adequate sensitivity and specificity rates in patients undergoing pancreatic resection.

The risk of clinically-relevant pancreatic fistula after pancreaticoduodenectomy is better predicted by a postoperative trend in drain fluid amylase compared to day 1 values in isolation

BACKGROUND

Recent studies support early drain removal after pancreaticoduodenectomy in patients with a drain fluid amylase on postoperative day 1 (DFA1) level of ≤5,000. The use of DFA1 to guide drain management is increasingly common among pancreatic surgeons; however, the benefit of checking additional drain fluid amylases beyond DFA1 is less known. We sought to determine whether a change in drain fluid amylase (ΔDFA) is a more reliable predictor of clinically relevant postoperative fistula than DFA1 alone.

METHODS

Using the American College of Surgeons National Surgical Quality Improvement Plan, pancreaticoduodenectomy patients with intraoperative drain placement, known DFA1, highest recorded drain fluid amylase value on postoperative day 2 to 5 (DFA2nd), day of drain removal, and clinically relevant postoperative fistula status were reviewed. Logistic models compared the predictive performance of DFA1 alone versus DFA1 + ΔDFA.

RESULTS

A total of 2,417 patients with an overall clinically relevant postoperative fistula rate of 12.6% were analyzed. On multivariable regression, clinical predictors for clinically relevant postoperative fistula included body mass index, steroid use, operative time, and gland texture. These variables were used to develop model 1 (DFA1 alone) and model 2 (DFA1 + ΔDFA). Model 2 outperformed model 1 in predicting the risk of clinically relevant postoperative fistula. According to model 2 predictions, the risk of clinically relevant postoperative fistula increased with any rise in drain fluid amylase, regardless of whether the DFA1 was above or below 5,000 U/L. The risk of clinically relevant postoperative fistula significantly decreased with any drop in drain fluid amylase, with an odds reduction of approximately 50% corresponding with a 70% decrease in drain fluid amylase (P < .001). A risk calculator was developed using DFA1 and a secondary DFA value in conjunction with other clinical predictors for clinically relevant postoperative fistula.

CONCLUSION

Clinically relevant postoperative fistula after pancreaticoduodenectomy is more accurately predicted by DFA1 and ΔDFA versus DFA1 in isolation. We developed a novel risk calculator to provide an individualized approach to drain management after pancreaticoduodenectomy.

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.

A Simple Classification of Pancreatic Duct Size and Texture Predicts Postoperative Pancreatic Fistula: A classification of the International Study Group of Pancreatic Surgery

OBJECTIVE

The aim of this study was to develop a classification system for pancreas-associated risk factors in pancreatoduodenectomy (PD).

SUMMARY BACKGROUND DATA

Postoperative pancreatic fistula (POPF) is the most relevant PD-associated complication. A simple standardized surgical reporting system based on pancreas-associated risk factors is lacking.

METHODS

A systematic literature search was conducted to identify studies investigating clinically relevant (CR) POPF (CR-POPF) and pancreas-associated risk factors after PD. A meta-analysis of CR-POPF rate for texture of the pancreas (soft vs not-soft) and main pancreatic duct (MPD) diameter was performed using the Mantel-Haenszel method. Based on the results, the International Study Group of Pancreatic Surgery (ISGPS) proposes the following classification: A, not-soft (hard) texture and MPD >3 mm; B, not-soft (hard) texture and MPD ≤3 mm; C, soft texture and MPD >3 mm; D, soft texture and MPD ≤3 mm. The classification was evaluated in a multi-institutional, international cohort.

RESULTS

Of the 2917 articles identified, 108 studies were included in the analyses. Soft pancreatic texture was significantly associated with the development of CR-POPF [odds ratio (OR) 4.24, 95% confidence interval (CI) 3.67-4.89, P < 0.01) following PD. Similarly, MPD diameter ≤3 mm significantly increased CR-POPF risk compared with >3 mm diameter MPDs (OR 3.66, 95% CI 2.62-5.12, P < 0.01). The proposed 4-stage system was confirmed in an independent cohort of 5533 patients with CR-POPF rates of 3.5%, 6.2%, 16.6%, and 23.2% for type A-D, respectively ( P < 0.001).

CONCLUSION

For future pancreatic surgical outcomes studies, the ISGPS recommends reporting these risk factors according to the proposed classification system for better comparability of results.

Drain Placement After Pancreatic Resection: Friend or Foe For Surgical Site Infections?

BACKGROUND

Despite multiple studies and randomized trials, there remains controversy over whether drains should be placed, and if so for how long, after pancreas resection. The aim was to determine if post-pancreatectomy drain placement and timing of drain removal were associated with differences in infectious outcomes and, if so, which specific procedures and infectious sites were most at risk.

METHODS

The ACS-NSQIP targeted pancreatectomy database was utilized to identify patients who underwent pancreatectomies between 2015 and 2020 with postoperative drain placement for retrospective cohort analysis. A propensity score matching analyses was conducted to determine associations between drain placement and surgical site infections (SSI).

RESULTS

Of 39,057 pancreatic resections, 66.4% were proximal pancreatectomies, and 33.6% were distal pancreatectomies. After propensity score matching, drain placement was not associated with significantly lower rates of superficial SSI (7% vs 9%, p = 0.755) or organ/space SSI (17% vs 16%, p = 0.647) after proximal pancreatectomy. After distal pancreatectomy, drain placement was associated with higher rates of organ/space SSI (12% vs 9%, p = 0.010). Drain removal on or after postoperative day 3 was significantly associated with higher rates of SSI in both proximal and distal pancreatectomy.

CONCLUSIONS

Drain placement is associated with an increased rate of organ/space SSI after distal pancreatectomy and not after pancreaticoduodenectomy. When drains are utilized, early removal is associated with a reduction of SSI after all types of pancreatectomy. In surgical units where post-pancreatectomy SSI is a concern, selective drain placement for high-risk glands or after distal pancreatectomy, combined with early drain removal, may be considered.

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.

Diagnosis and treatment of pancreatic duct disruption or disconnection: an international expert survey and case vignette study

BACKGROUND

Pancreatic duct disruption or disconnection is a potentially severe complication of necrotizing pancreatitis. With no existing treatment guidelines, it is unclear whether there is any consensus among experts in clinical practice. We evaluated current expert opinion regarding the diagnosis and treatment of pancreatic duct disruption and disconnection in an international case vignette study.

METHODS

An online case vignette survey was sent to 110 international expert pancreatologists. Expert selection was based on publications in the last 5 years and/or participation in development of IAP/APA and ESGE guidelines on acute pancreatitis. Consensus was defined as agreement by at least 75% of the experts.

RESULTS

The response rate was 51% (n = 56). Forty-four experts (79%) obtained a MRI/MRCP and 52 experts (93%) measured amylase levels in percutaneous drain fluid to evaluate pancreatic duct integrity. The majority of experts favored endoscopic transluminal drainage for infected (peri)pancreatic necrosis and pancreatic duct disruption (84%, n = 45) or disconnection (88%, n = 43). Consensus was lacking regarding the treatment of patients with persistent percutaneous drain production, and with persistent sterile necrosis.

CONCLUSION

This international survey of experts demonstrates that there are many areas for which no consensus existed, providing clear focus for future investigation.

The value of serum amylase and drain fluid amylase to predict postoperative pancreatic fistula after pancreatoduodenectomy: a retrospective cohort study

Purpose

Serum and drain amylase have been identified as important predictors of postoperative pancreatic fistula (POPF) and might be useful to guide postoperative drain management after pancreatoduodenectomy. We aimed to determine and compare the value of serum amylase and drain fluid amylase to predict postoperative pancreatic fistula after pancreatoduodenectomy.

Methods

This retrospective cohort study included patients after pancreatoduodenectomy from 2012 to 2019. The primary endpoint of our study was grade B/C POPF. Serum amylase on postoperative day 1 (SA-1) and drain fluid amylase on postoperative day 2 (DFA-2) were analyzed.

Results

A total of 92 of 437 patients (21.1%) developed a grade B/C POPF. SA-1 was higher in patients who developed a grade B/C POPF (336 U/L vs. 97 U/L, p<0.001). Similarly, DFA-2 was higher in patients who developed a grade B/C POPF (1764 U/L vs. 78 U/L, p<0.001). SA-1 and DFA-2 had similar predictive accuracy (AUC: 0.82 vs. 0.85, respectively, p=0.329). Patients with SA-1<100 U/L (n=178) had a risk of 2.2% of developing grade B/C POPF, compared to 38.2% in patients with SA-1 >100 U/L (n=207). Patients with DFA-2<100 U/L (n=141) had a risk of 0% of developing grade B/C POPF, compared to 36.2% in patients with DFA-2>100 U/L (n=196). SA-1 and DFA-2 were strongly associated at a cut-off of 100 U/L (p<0.001, 89% concordance rate).

Conclusion

Postoperative serum and drain amylase values below 100 U/L both effectively rule out POPF after pancreatoduodenectomy. The advantage of serum amylase measurement is that it can be used in patients who are managed without surgical drains.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00423-021-02192-y.

Various Modalities Accurate in Diagnosing a Disrupted or Disconnected Pancreatic Duct in Acute Pancreatitis: A Systematic Review

BACKGROUND

Severe pancreatitis may result in a disrupted pancreatic duct, which is associated with a complicated clinical course. Diagnosis of a disrupted pancreatic duct is not standardized in clinical practice or international guidelines. We performed a systematic review of the literature on imaging modalities for diagnosing a disrupted pancreatic duct in patients with acute pancreatitis.

METHODS

A systematic search was performed in PubMed, Embase and Cochrane library databases to identify all studies evaluating diagnostic modalities for the diagnosis of a disrupted pancreatic duct in acute pancreatitis. All data regarding diagnostic accuracy were extracted.

RESULTS

We included 8 studies, evaluating five different diagnostic modalities in 142 patients with severe acute pancreatitis. Study quality was assessed, with proportionally divided high and low risk of bias and low applicability concerns in 75% of the studies. A sensitivity of 100% was reported for endoscopic ultrasound and endoscopic retrograde cholangiopancreatography. The sensitivity of magnetic resonance cholangiopancreatography with or without secretin was 83%. A sensitivity of 92% was demonstrated for a combined cohort of secretin-magnetic resonance cholangiopancreatography and magnetic resonance cholangiopancreatography. A sensitivity of 100% and specificity of 50% was found for amylase measurements in drain fluid compared with ERCP.

CONCLUSIONS

This review suggests that various diagnostic modalities are accurate in diagnosing a disrupted pancreatic duct in patients with acute pancreatitis. Amylase measurement in drain fluid should be standardized. Given the invasive nature of other modalities, secretin-magnetic resonance cholangiopancreatography or magnetic resonance cholangiopancreatography would be recommended as first diagnostic modality. Further prospective studies, however, are needed.

Lack of Association between Postoperative Pancreatitis and Other Postoperative Complications Following Pancreaticoduodenectomy

Background: Prediction of post-pancreaticoduodenectomy (PD) morbidity is difficult, especially in the early postoperative period when CT (Computed Tomography) scans are not available. Elevated serum amylase and lipase in postoperative day 0 or 1 may be used to define postoperative acute pancreatitis (POAP), but the existing literature does not agree on whether POAP is significantly associated with postoperative pancreatic fistula (POPF). Methods: We analyzed the data obtained from a previously published randomized controlled trial. POAP was defined as elevations in serum amylase above 110 U/L on postoperative day 0 or 1. Clinically relevant POAP (CR-POAP) was defined as elevations in C-reactive protein level (CRP) on postoperative day 2 in those with POAP. Postoperative complications including severe complications (Clavien–Dindo ≥ IIIa), POPF, and clinically relevant POPF (CR-POPF) were analyzed. Results: In 246 patients, POAP did not show significant associations with total postoperative complications (odds ratio (OR) 0.697; 95% CI, 0.360–1.313; p = 0.271), severe complications (OR 0.647; 95% CI, 0.258–1.747; p = 0.367), and CR-POPF (OR 0.998; 95% CI, 0.310–3.886; p = 0.998) in multivariable analysis. Conclusions: In patients undergoing PD, POAP was not significantly associated with postoperative complications including POPF. Caution should be taken when using POAP as a predictor of POPF.

Amylase level after pancreaticoduodenectomy in predicting postoperative pancreatic fistula

BACKGROUND

It is new clinical interest higher serum amylase level with pancreatitis after pancreaticoduodenectomy (PD) correlates with postoperative pancreatic fistula (POPF). Nevertheless, its evidence and study were scarce. We aimed to investigate correlation of serum amylase level immediate after PD and POPF occurrence.

METHODS

Of 163 patients who underwent PD at between January 2009 and December 2019, retrospective analysis was conducted to identify risk factors including serum amylase level immediate after PD for POPF occurrence.

RESULTS

Overall incidence of POPF (25/163) was 15.3%. The patients occurred a POPF had significantly higher level of serum amylase on POD0 compared to in whom without a POPF (414 vs 253, p < 0.001). In univariate analysis, ASA classification, post pancreatectomy acute pancreatitis (POAP, serum amylase on POD0 >285IU/L) and Fistula Risk Grade were correlated with POPF occurrence. In multivariable analysis, Fistula risk grade and POAP were significantly associated with developing POPF.

CONCLUSION

In patients with higher serum amylase (>285IU/L) on POD0 with higher fistula risk grade, comprehensive management to achieve mitigation of POPF is important.

Systematic review and meta-analysis of factors associated with post-operative pancreatic fistula following pancreatoduodenectomy

BACKGROUND

Many studies have explored factors relating to post-operative pancreatic fistula (POPF); however, the original definition (All-POPF) was revised to include only 'clinically relevant' (CR) POPF. This study identified variables associated with the two International Study Group on Pancreatic Surgery definitions to identify which variables are more strongly associated with CR-POPF.

METHODS

A systematic review identified all studies reporting risk factors for POPF (using both International Study Group on Pancreatic Fistula definitions) following pancreatoduodenectomy. The primary outcome was factors associated with CR-POPF. Meta-analyses (random effects models) of pre-, intra- and post-operative factors associated with POPF in more than two studies were included.

RESULTS

Among 52 774 patients All-POPF (n = 69 studies) and CR-POPF (n = 53 studies) affected 27% (95% confidence interval (CI_95% ) 23-30) and 19% (CI_95% 17-22), respectively. Of the 176 factors, 24 and 17 were associated with All- and CR-POPF, respectively. Absence of pre-operative pancreatitis, presence of renal disease, no pre-operative neoadjuvant therapy, use of post-operative somatostatin analogues, absence of associated venous or arterial resection were associated with CR-POPF but not All-POPF.

CONCLUSION

In conclusion this study demonstrates wide variation in reported rates of POPF and that several risk factors associated with CR-POPF are not used within risk prediction models. Data from this study can be used to shape future studies, research and audit across ethnic and geographic boundaries in POPF following pancreatoduodenectomy.

Serum amylase elevation following pancreatoduodenectomy with pancreatogastrostomy is strongly associated with major complications

BACKGROUND

Recent reports suggest that, following pancreatic resection, serum amylase elevation (SAE) may be a surrogate indicator of post-operative acute pancreatitis (PAP) and predict post-operative pancreatic fistula (POPF). However, POPF may not account for the majority of complications when pancreatoenteric continuity is restored by pancreatogastrostomy. We aimed to evaluate, among patients undergoing pancreatoduodenectomy with pancreatogastrostomy, the correlation between SAE, radiological changes consistent with PAP and types of post-operative complications overall and specific for pancreatic surgery.

METHODS

Perioperative data from 102 patients who underwent pancreatoduodenectomy with pancreatogastrostomy at two Italian hospitals (January 2015-January 2017) were retrospectively analysed. SAE was defined as serum amylase more than three times the normal concentration at post-operative day 1. Post-operative abdominal computed tomography scan was routinely performed and retrospectively and blindly re-assessed for findings consistent with PAP.

RESULTS

Among 102 study patients, overall and major complications and mortality occurred in 68% and 24% and 3% of cases, respectively. POPF and post-pancreatectomy haemorrhage (PPH) occurred in 12% and 21%, respectively. In 75% of patients developing PPH, it occurred in the absence of POPF. SAE occurred in 36 patients who, compared to 66 non-SAE patients, more frequently showed computed tomography scan findings consistent with pancreatic stump inflammation (P = 0.002), confirming association between SAE and PAP. SAE was independently associated with the occurrence of major complications, POPF and PPH (hazard ratio (HR) 3.27, P = 0.032; HR 3.94, P = 0.012; HR 12.26, P = 0.002).

CONCLUSION

SAE can be considered a valid surrogate of PAP and is strongly associated with a higher rate of post-operative major complications, both overall and specific for pancreatic resection.

Risk factors and preventive measures for postoperative pancreatic fistula after pancreaticoduodenectomy

Postoperative pancreatic fistula (POPF) is the most serious complication after pancreaticoduodenectomy (PD), which can lead to slow recovery, deterioration, and even reoperation and death. At present, the mortality rate after PD has decreased, but the incidence of POPF is still high. Therefore, exploring the risk factors and prevention strategies for pancreatic fistula has become a hot research topic in pancreatic surgery. This paper summarizes the nature, risk factors, and preventive measures for POPF.

Combined prognostic nutritional index ratio and serum amylase level during the early postoperative period predicts pancreatic fistula following pancreaticoduodenectomy

BACKGROUND

The aim of this study was to investigate the usefulness of the range of change in prognostic nutritional index (PNI) during the early postoperative period as a predictor of postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy.

METHODS

Data were retrospectively analyzed for 192 patients who underwent pancreaticoduodenectomy. Univariate and multivariate logistic regression analyses were used to evaluate perioperative variables. PNI^P3-Pre ratio represented the range of change in PNI from before surgery to postoperative day (POD) 3, PNI^P1-Pre ratio represented the range of change in PNI from before surgery to POD 1, and PNI^P3-P1 ratio represented the range of change in PNI from POD 1 to POD 3.

RESULTS

The area under the curve (AUC) for PNI^P3-P1 for prediction of POPF following pancreaticoduodenectomy was 0.683 (P <  0.001), which was highest among PNI ratios and higher than PNI on POD 3. The AUC for serum amylase level on POD 1 was 0.704 (P <  0.001), which was superior to the corresponding AUC on POD 3. The AUC for the combination of PNI^P3-P1 ratio and serum amylase level on POD 1 for prediction of POPF was higher than the AUC of either indicator alone (0.743, P <  0.001). The combination of PNI^P3-P1 ratio and serum amylase level on POD 1 was an independent predictor of POPF following pancreaticoduodenectomy (P = 0.018).

CONCLUSIONS

The combination of the range of change in PNI from POD 1 to POD 3 and serum amylase levels on POD 1 may be useful for prediction of POPF following pancreaticoduodenectomy.

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.

Impaired immune reaction and increased lactate and C-reactive protein for early prediction of severe morbidity and pancreatic fistula after pancreatoduodenectomy

BACKGROUND

Prediction of complications after pancreatoduodenectomy (PD) remains of interest. Blood parameters and biomarkers during first and second postoperative days (POD1, POD2) may be early indicators of complications.

METHODS

This case-control study included 50 patients. Baseline, POD1 and POD2 values of leukocytes, neutrophils, lymphocytes, platelets, hemoglobin, C-reactive protein (CRP), procalcitonin and arterial lactate were compared between individuals presenting Clavien ≥ III morbidity, pancreatic fistula (PF) or clinically relevant PF (CRPF) and those without these morbidities. Common variables reaching significance were further analyzed in order to calculate a predictive score.

RESULTS

Severe morbidity, PF and CRPF rates were 28.0%, 26.0% and 14.0%, respectively. Patients with severe morbidity had lower leukocytes on POD2 (P = 0.04). Patients with PF presented higher CRP on POD2 (P = 0.001), higher lactate on POD1 (P = 0.007) and POD2 (P = 0.008), and lower lymphocytes on POD1 (P = 0.007) and POD2 (P = 0.008). Patients with CRPF had lower leukocytes and neutrophils on POD1 (P = 0.048, P = 0.038), lower lymphocytes on POD1 (P = 0.001) and POD2 (P = 0.003), and higher CRP on POD2 (P = 0.001). Baseline parameters and procalcitonin obtained no statistical associations. Score was defined according to lymphocytes on POD1 < 650/µL and CRP on POD2 ≥ 250 mg/L allocating patients in 3 risk categories. PF and CRPF rates were statistically higher as risk category increased (P<0.001). Receiver operating characteristic curves and Hosmer-Lemeshow tests showed a good accuracy.

CONCLUSIONS

Impaired immunological reaction during early postoperative period (lower leukocytes and, particularly, lymphocytes) in response to surgical aggression would favor complications after PD. Likewise, acidosis (higher arterial lactate) could behave as risk factor of PF. An elevated CRP on POD2 is also an early biomarker of PF. Our novel score based on postoperative lymphocyte count and CRP seems reliable for early prediction of PF.