Correlation between preoperative imaging and intraoperative risk assessment in the prediction of postoperative pancreatic fistula following pancreatoduodenectomy

Peripancreatic fluid collections following distal pancreatectomy and splenectomy-when is intervention warranted?

BACKGROUND

Peripancreatic fluid collections after distal pancreatectomy and splenectomy are commonly identified on postoperative cross-sectional imaging. This study aimed to determine the incidence, natural history, and indications for intervention.

METHODS

We conducted a retrospective review of patients with peripancreatic fluid collections after distal pancreatectomy with or without splenectomy between 2013 and 2018, approved by our institutional review board. The chi-square test was used for categorical variables, the Mann-Whitney U test for continuous variables, and Fisher's exact test was used for values in which the sample size was less than 5 to compare data.

RESULTS

During the study period, 235 patients underwent distal pancreatectomy with or without splenectomy, and 182 patients with postoperative imaging were included. In the cohort of patients with postoperative imaging, 83 (46%) had peripancreatic fluid collections, of which 46 (55%) were symptomatic fluid collections (SFCs) and 37 (45%) were asymptomatic fluid collections (AFCs). Those with SFC had a higher incidence of postoperative morbidity (46% vs 8%; P = .0002), most commonly postoperative pancreatic fistula (90%). Of patients with SFC, 34 (74%) underwent treatment via percutaneous drainage (n = 26), endoscopic drainage (n = 7), or antibiotics alone (n = 1). AFCs (n = 37) were observed. Collections that were intervened upon resolved significantly faster than those observed, 3.5 months vs 13.2 months (P < .0001), respectively.

CONCLUSION

Asymptomatic patients may be observed with or without serial imaging and the AFC will typically resolve spontaneously with time. Patients who develop symptoms should generally be intervened upon with drainage if deemed feasible, given that this reduces the time to resolution.

Simple Preoperative Imaging Measurements Predict Postoperative Pancreatic Fistula After Pancreatoduodenectomy

OBJECTIVE

Postoperative pancreatic fistula is a potentially devastating complication after pancreatoduodenectomy (PD). The purpose of this study was to identify features on preoperative computed tomography (CT) imaging that correlate with an increased risk of postoperative pancreatic fistula (POPF).

METHODS

Patients who underwent PD at our high-volume pancreatic surgery center from 2019 to 2021 were included if CT imaging was available within 8 weeks of surgical intervention. Pancreatic neck thickness (PNT), abdominal wall thickness (AWT), and intra-abdominal distance from pancreas to peritoneum (PTP) were measured by two board-certified radiologists who were blinded to the clinical outcomes. Radiographic measurements, as well as preoperative patient characteristics and intraoperative data, were assessed with univariate and multivariable analysis (MVA) to determine risk for clinically relevant POPF (CR-POPF, grades B and C).

RESULTS

A total of 204 patients met inclusion criteria. Median PTP was 5.8 cm, AWT 1.9 cm, and PNT 1.3 cm. CR-POPF occurred in 33 of 204 (16.2%) patients. MVA revealed PTP > 5.8 cm (odds ratio [OR] 2.86, p = 0.023), PNT > 1.3 cm (OR 2.43, p = 0.047), soft pancreas consistency (OR 3.47, p = 0.012), and pancreatic duct size ≤ 3.0 mm (OR 4.55, p = 0.01) as independent risk factors for CR-POPF after PD. AWT and obesity were not associated with increased risk of CR-POPF. Patients with PTP > 5.8 cm or PNT > 1.3 cm were significantly more likely to suffer a major complication after PD (39.6% vs. 22.3% and 40% vs. 22.1%, p < 0.008).

CONCLUSIONS

Patients with a thick pancreatic neck and increased intra-abdominal girth have a heightened risk of CR-POPF after pancreatoduodenectomy, and they experience more serious postoperative complications. We defined a simple CT scan-based measurement tool to identify patients at increased risk of CR-POPF.

A Machine Learning Approach to Predict Postoperative Pancreatic Fistula After Pancreaticoduodenectomy Using Only Preoperatively Known Data

BACKGROUND

Clinically-relevant postoperative pancreatic fistula (CR-POPF) following pancreaticoduodenectomy (PD) is a major postoperative complication and the primary determinant of surgical outcomes. However, the majority of current risk calculators utilize intraoperative and postoperative variables, limiting their utility in the preoperative setting. Therefore, we aimed to develop a user-friendly risk calculator to predict CR-POPF following PD using state-of-the-art machine learning (ML) algorithms and only preoperatively known variables.

METHODS

Adult patients undergoing elective PD for non-metastatic pancreatic cancer were identified from the ACS-NSQIP targeted pancreatectomy dataset (2014-2019). The primary endpoint was development of CR-POPF (grade B or C). Secondary endpoints included discharge to facility, 30-day mortality, and a composite of overall and significant complications. Four models (logistic regression, neural network, random forest, and XGBoost) were trained, validated and a user-friendly risk calculator was then developed.

RESULTS

Of the 8666 patients who underwent elective PD, 13% (n = 1160) developed CR-POPF. XGBoost was the best performing model (AUC = 0.72), and the top five preoperative variables associated with CR-POPF were non-adenocarcinoma histology, lack of neoadjuvant chemotherapy, pancreatic duct size less than 3 mm, higher BMI, and higher preoperative serum creatinine. Model performance for 30-day mortality, discharge to a facility, and overall and significant complications ranged from AUC 0.62-0.78.

CONCLUSIONS

In this study, we developed and validated an ML model using only preoperatively known variables to predict CR-POPF following PD. The risk calculator can be used in the preoperative setting to inform clinical decision-making and patient counseling.

Prediction of clinically relevant postoperative pancreatic fistula using radiomic features and preoperative data

Clinically relevant postoperative pancreatic fistula (CR-POPF) can significantly affect the treatment course and outcome in pancreatic cancer patients. Preoperative prediction of CR-POPF can aid the surgical decision-making process and lead to better perioperative management of patients. In this retrospective study of 108 pancreatic head resection patients, we present risk models for the prediction of CR-POPF that use combinations of preoperative computed tomography (CT)-based radiomic features, mesh-based volumes of annotated intra- and peripancreatic structures and preoperative clinical data. The risk signatures were evaluated and analysed in detail by visualising feature expression maps and by comparing significant features to the established CR-POPF risk measures. Out of the risk models that were developed in this study, the combined radiomic and clinical signature performed best with an average area under receiver operating characteristic curve (AUC) of 0.86 and a balanced accuracy score of 0.76 on validation data. The following pre-operative features showed significant correlation with outcome in this signature ([Formula: see text]) - texture and morphology of the healthy pancreatic segment, intensity volume histogram-based feature of the pancreatic duct segment, morphology of the combined segment, and BMI. The predictions of this pre-operative signature showed strong correlation (Spearman correlation co-efficient, [Formula: see text]) with the intraoperative updated alternative fistula risk score (ua-FRS), which is the clinical gold standard for intraoperative CR-POPF risk stratification. These results indicate that the proposed combined radiomic and clinical signature developed solely based on preoperatively available clinical and routine imaging data can perform on par with the current state-of-the-art intraoperative models for CR-POPF risk stratification.

Total pancreatectomy as an alternative to high-risk pancreatojejunostomy after pancreatoduodenectomy: a propensity score analysis on surgical outcome and quality of life

BACKGROUND

Total pancreatectomy (TP) is mentioned as alternative to pancreatoduodenectomy (PD) with high-risk pancreatojejunostomy (PJ) to avoid severe pancreatic fistula-related complications, but its benefit is controversial and comparative studies are scarce.

METHODS

Cross-sectional single-center study among patients after PD with high-risk PJ versus patients after single-stage elective TP for any indication (2015-2017), using propensity scores to evaluate surgical outcomes and long-term quality of life (QoL) in three risk strata. EORTC QLQ-C30 and EQ-5D-5L were used for QoL assessment.

RESULTS

Overall, 77 patients after TP (68.8%) and 102 patients after high-risk PD (34.5%) were included. Major morbidity (29.9% vs. 41.2%; p = 0.119) and 90-day mortality (5.2% vs. 8.8%; p = 0.354) did not differ significantly between TP and high-risk PD. Interventions for intra-abdominal fluid collections (9.1% vs. 23.5%, p = 0.011) and postpancreatectomy haemorrhage (6.5% vs. 18.6%; p = 0.018) were more often required after high-risk PD, but these differences did not remain after stratification. QoL was comparable after TP and high-risk PD (75% vs. 83%; p = 0.720), even after stratification.

CONCLUSIONS

TP seems not to be inferior to high-risk PD regarding surgical outcomes and QoL. TP could be considered as an alternative to a very high-risk PD, but reluctance persists since TP does not appear to reduce mortality.

The effect of atrophied pancreas as shown in the preoperative imaging on the leakage rate after pancreaticoduodenectomy

Backgrounds/Aims

The soft texture of the pancreas parenchyma may influence the incidence of pancreatic leakage after pancreaticoduodenectomy (PD). One possible method to assess pancreatic texture and atrophy, is via computed tomography (CT) scan of the abdomen. The purpose of our study was to evaluate the relation between the preoperative CT scan and the incidence of pancreatic fistula after PD.

Methods

A retrospective single-center study including patients who underwent PD for a benign and malignant tumor of the periampullary region between the years 2000 and 2016. Demographic and imaging data were analysed and a correlation with the post-operative leak was evaluated.

Results

Pancreatic leak was documented in 34 out of 154 (22.1%) patients. All the leakage cases occurred in the preserved pancreas group (33.1% of the total preserved pancreas group alone). No leak was documented in the atrophic pancreas group. This difference between the two groups was found to be statistically significant (p ≤ 0.00001).

Conclusions

Atrophic pancreas in the preoperative CT scan may be protective against leakage after PD. These findings may help the surgeon to risk stratify patients accordingly. In addition, the findings suggest that patients with a preserved pancreas may require more protective methods to prevent leakage.

The image-based preoperative fistula risk score (preFRS) predicts postoperative pancreatic fistula in patients undergoing pancreatic head resection

Clinically relevant postoperative pancreatic fistula (CR-POPF) is a common severe surgical complication after pancreatic surgery. Current risk stratification systems mostly rely on intraoperatively assessed factors like manually determined gland texture or blood loss. We developed a preoperatively available image-based risk score predicting CR-POPF as a complication of pancreatic head resection. Frequency of CR-POPF and occurrence of salvage completion pancreatectomy during the hospital stay were associated with an intraoperative surgical (sFRS) and image-based preoperative CT-based (rFRS) fistula risk score, both considering pancreatic gland texture, pancreatic duct diameter and pathology, in 195 patients undergoing pancreatic head resection. Based on its association with fistula-related outcome, radiologically estimated pancreatic remnant volume was included in a preoperative (preFRS) score for POPF risk stratification. Intraoperatively assessed pancreatic duct diameter (p < 0.001), gland texture (p < 0.001) and high-risk pathology (p < 0.001) as well as radiographically determined pancreatic duct diameter (p < 0.001), gland texture (p < 0.001), high-risk pathology (p = 0.001), and estimated pancreatic remnant volume (p < 0.001) correlated with the risk of CR-POPF development. PreFRS predicted the risk of CR-POPF development (AUC = 0.83) and correlated with the risk of rescue completion pancreatectomy. In summary, preFRS facilitates preoperative POPF risk stratification in patients undergoing pancreatic head resection, enabling individualized therapeutic approaches and optimized perioperative management.

External validation of postoperative pancreatic fistula prediction scores in pancreatoduodenectomy: a systematic review and meta-analysis

BACKGROUND

Multiple risk scores claim to predict the probability of postoperative pancreatic fistula (POPF) after pancreatoduodenectomy. It is unclear which scores have undergone external validation and are the most accurate. The aim of this study was to identify risk scores for POPF, and assess the clinical validity of these scores.

METHODS

Areas under receiving operator characteristic curve (AUROCs) were extracted from studies that performed external validation of POPF risk scores. These were pooled for each risk score, using intercept-only random-effects meta-regression models.

RESULTS

Systematic review identified 34 risk scores, of which six had been subjected to external validation, and so included in the meta-analysis, (Tokyo (N=2 validation studies), Birmingham (N=5), FRS (N=19), a-FRS (N=12), m-FRS (N=3) and ua-FRS (N=3) scores). Overall predictive accuracies were similar for all six scores, with pooled AUROCs of 0.61, 0.70, 0.71, 0.70, 0.70 and 0.72, respectively. Considerably heterogeneity was observed, with I2 statistics ranging from 52.1-88.6%.

CONCLUSION

Most risk scores lack external validation; where this was performed, risk scores were found to have limited predictive accuracy. . Consensus is needed for which score to use in clinical practice. Due to the limited predictive accuracy, future studies to derive a more accurate risk score are warranted.

Preoperative Computed Tomography Imaging of the Pancreas Identifying Predictive Factors for the Progression of Grade A, or Biochemical Leak, to Grade B Postoperative Pancreatic Fistula Following Pancreaticoduodenectomy: A Retrospective Study

Background

This retrospective study aimed to identify the predictive factors for the progression of grade A, or early biochemical leak, to grade B postoperative pancreatic fistula (POPF) following pancreaticoduodenectomy using preoperative computed tomography (CT) imaging of the pancreas.

Material/Methods

A total of 156 patients were analyzed retrospectively. Biochemical leakage occurred in 60 patients, who were divided into POPF progression and non-POPF progression groups. Perioperative parameters were collected. Univariate analysis and multivariate logistic regression analysis were done. For the parameters with statistical significance, the area under the curve (AUC) was calculated if possible and the predictive value was assessed.

Results

Univariate analysis showed that main pancreatic duct diameter, postoperative complications (except POPF), prothrombin time (PT) and serum albumin on postoperative day 3, and pancreatic CT value were risk factors of POPF (P<0.05). Multivariate analysis showed that serum albumin and PT on postoperative day 3 and pancreatic CT value were independent risk factors of POPF (P<0.05). Lower postoperative albumin, lower pancreatic CT value, and longer PT were associated with a higher risk of POPF (P<0.05). The AUC of CT value was 0.808. CT value thresholds of 42.5 Hounsfield units (HU) and 41.5 HU were tied for the highest predictive performance, with Youden indices of 0.486 for both, and sensitivity of 79% and 71%, and specificity of 69% and 78%, respectively.

Conclusions

Preoperative laboratory investigations and CT imaging of the pancreas may identify factors associated with early biochemical leakage progressing to grade B POPF following pancreaticoduodenectomy.

Dynamic prediction for clinically relevant pancreatic fistula: a novel prediction model for laparoscopic pancreaticoduodenectomy

Background

With the recent emerge of dynamic prediction model on the use of diabetes, cardiovascular diseases and renal failure, and its advantage of providing timely predicted results according to the fluctuation of the condition of the patients, we aim to develop a dynamic prediction model with its corresponding risk assessment chart for clinically relevant postoperative pancreatic fistula after laparoscopic pancreaticoduodenectomy by combining baseline factors and postoperative time-relevant drainage fluid amylase level and C-reactive protein-to-albumin ratio.

Methods

We collected data of 251 patients undergoing LPD at West China Hospital of Sichuan University from January 2016 to April 2019. We extracted preoperative and intraoperative baseline factors and time-window of postoperative drainage fluid amylase and C-reactive protein-to-albumin ratio relevant to clinically relevant pancreatic fistula by performing univariate and multivariate analyses, developing a time-relevant logistic model with the evaluation of its discrimination ability. We also established a risk assessment chart in each time-point.

Results

The proportion of the patients who developed clinically relevant postoperative pancreatic fistula after laparoscopic pancreaticoduodenectomy was 7.6% (19/251); preoperative albumin and creatine levels, as well as drainage fluid amylase and C-reactive protein-to-albumin ratio on postoperative days 2, 3, and 5, were the independent risk factors for clinically relevant postoperative pancreatic fistula. The cut-off points of the prediction value of each time-relevant logistic model were 14.0% (sensitivity: 81.9%, specificity: 86.5%), 8.3% (sensitivity: 85.7%, specificity: 79.1%), and 7.4% (sensitivity: 76.9%, specificity: 85.9%) on postoperative days 2, 3, and 5, respectively, the area under the receiver operating characteristic curve was 0.866 (95% CI 0.737–0.996), 0.896 (95% CI 0.814–0.978), and 0.888 (95% CI 0.806–0.971), respectively.

Conclusions

The dynamic prediction model for clinically relevant postoperative pancreatic fistula has a good to very good discriminative ability and predictive accuracy. Patients whose predictive values were above 14.0%, 8.3%, and 7.5% on postoperative days 2, 3, and 5 would be very likely to develop clinically relevant postoperative pancreatic fistula after laparoscopic pancreaticoduodenectomy.

A deep pancreas is a novel predictor of pancreatic fistula after pancreaticoduodenectomy in patients with a nondilated main pancreatic duct

BACKGROUND

We investigated the risk factors for clinically relevant postoperative pancreatic fistula after pancreaticoduodenectomy in patients with a nondilated main pancreatic duct.

METHODS

We investigated a total of 354 patients who underwent pancreaticoduodenectomy. The diameter of the main pancreatic duct, the shortest distance from the body surface to the pancreas (the pancreatic depth), and the computed tomography attenuation index (the difference between the pancreatic and splenic computed tomography attenuation) were measured in preoperative computed tomography.

RESULTS

One hundred eighty-one (51.1%) patients had a nondilated main pancreatic duct, and 50 (27.6%) of the 181 patients with a nondilated main pancreatic duct developed a clinically relevant postoperative pancreatic fistula. Univariate analyses revealed that the calculated body mass index (≥21.8 kg/m²) (P = .004), deep pancreas (pancreatic depth ≥51.2 mm) (P = .001), and low computed tomography attenuation index (≤-3.8 Hounsfield units) (P = .02) were significant risk factors for clinically relevant postoperative pancreatic fistula. The multivariate logistic regression analysis revealed that deep pancreas (odds ratio 2.370; 95% confidence interval 1.0019-5.590; P = .049) was an independent risk factor for clinically relevant postoperative pancreatic fistula. Among patients with a nondilated main pancreatic duct, deep pancreas (in comparison to patients without deep pancreas) was associated with male sex (72.7% vs 54.9%; P = .016), higher body mass index (22.5 kg/m² vs 19.6 kg/m²; P < .001), a history of diabetes mellitus (24.5% vs 8.5%; P = .006), a lower computed tomography attenuation index (-9.6 Hounsfield units vs -4.6 Hounsfield units; P = .007), a longer operative time (454 minutes vs 420 minutes; P = .007), and a higher volume of intraoperative blood loss (723 mL vs 500 mL; P < .001), respectively.

CONCLUSION

Deep pancreas may be an important parameter associated with significant risk factors for clinically relevant postoperative pancreatic fistula after pancreaticoduodenectomy in patients with a nondilated main pancreatic duct.

Measurement of Pancreatic Fat Fraction by CT Histogram Analysis to Predict Pancreatic Fistula after Pancreaticoduodenectomy

Objective

To evaluate the effectiveness of computed tomography (CT) Hounsfield unit histogram analysis (HUHA) in postoperative pancreatic fistula (PF) prediction.

Materials and Methods

Fifty-four patients (33 males and 21 females; mean age, 65.6 years; age range, 37–89 years) who had undergone preoperative CT and pancreaticoduodenectomy were included in this retrospective study. Two radiologists measured mean CT Hounsfield unit (CTHU) values by drawing regions of interest (ROIs) at the level of the pancreaticojejunostomy site on preoperative pre-contrast images. The HUHA values were arbitrarily divided into three categories, comprising HUHA-A ≤ 0 HU, 0 HU < HUHA-B < 30 HU, and HUHA-C ≥ 30 HU. Each HUHA value within the ROI was calculated as a percentage of the entire area using commercial 3-dimensional analysis software. Pancreas texture was evaluated as soft or hard by manual palpation.

Results

Fifteen patients (27.8%) had clinically relevant PFs. The PF group had significantly higher HUHA-A (p < 0.01) and significantly lower mean CTHU (p < 0.01) values than those of the non-PF group. The HUHA-A value had a moderately strong correlation with PF occurrence (r = 0.60, p < 0.01), whereas the mean CTHU had a weak negative correlation with PF occurrence (r = −0.27, p < 0.01). The HUHA-A and mean CTHU areas under the curve (AUCs) for predicting PF occurrence were 0.86 and 0.65, respectively, with significant difference (p < 0.01). The HUHA-A and mean CTHU AUCs for predicting pancreatic softness were 0.86 and 0.64, respectively, with significant difference (p < 0.01).

Conclusion

The HUHA-A values on preoperative pre-contrast CT images demonstrate a strong correlation with PF occurrence.

Pancreatic attenuation on computed tomography predicts pancreatic fistula after pancreaticoduodenectomy

BACKGROUND

Some parameters using preoperative computed tomography (CT) have been evaluated to predict the development of pancreatic fistula (PF) after pancreaticoduodenectomy (PD). The present retrospective study evaluated the predictive value of pancreatic attenuation for PF after PD.

METHODS

A retrospective review was conducted of the patients who underwent PD between January 2010 and December 2014. The pancreatic attenuation was measured in unenhanced preoperative CT images. Pre- and intraoperative variables were analyzed for the risk of PF after PD.

RESULTS

Of the 346 consecutive patients, PF occurred in 116 (34%). The pancreatic attenuation was significantly greater in patients with PF than in those without PF (median, 40.0 vs. 33.3 Hounsfield units [HU], P < 0.001). A multivariate analysis showed that a pancreatic attenuation ≥30.0 HU (odds ratio [OR], 3.72; P < 0.001), a body mass index ≥25.0 kg/m² (OR, 3.67; P < 0.001) and a diameter of the main pancreatic duct <3.0 mm (OR, 1.84; P = 0.034) were independent risk factors for PF after PD.

CONCLUSION

The degree of pancreatic attenuation on preoperative CT images was significantly associated with PF, and a pancreatic attenuation ≥30.0 HU was an independent risk factor of PF after PD.

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.

Remnant pancreatic volume as an indicator of poor prognosis in pancreatic cancer patients after resection

BACKGROUND

Remnant pancreatic volume (RPV) is a well-known marker for short-term outcomes in pancreatic cancer patients after resection. However, in terms of the long-term outcomes, the significance of the RPV value remains unclear. Here, we address whether the RPV value is a predictor of the long-term outcomes in pancreatic cancer patients after resection by comparing various cancer-, patient-, and surgery-related prognostic factors and systemic inflammatory response markers in a retrospective cohort.

METHODS

The RPV was measured on a three-dimensional (3D) image, revealing the actual pancreatic parenchymal remnant volume. Ninety-one patients who underwent pancreaticoduodenectomy were retrospectively enrolled. We divided the cohort into high- and low-RPV groups based on a cut-off value (>31.5 cm³, n = 66 and ≤31.5 cm³, n = 25, respectively). The median survival times (MSTs) were compared between the two groups. Using multivariate analysis, the RPV and other well-known prognostic factors were independently assessed.

RESULTS

The MSTs (days) were significantly different between the two groups (high, 823 vs. low, 482, p = 0.001). Multivariate analysis identified the RPV (≤31.5 cm³) (hazard ratio [HR], 2.015; p = 0.011), lymph node metastasis (HR, 8.415; p = 0.002), lack of adjuvant chemotherapy (HR, 5.352; p < 0.001), stage III/IV disease (HR, 2.352; p = 0.029), and pathological fibrosis (HR, 1.771; p = 0.031) as independent prognostic factors.

CONCLUSIONS

The present study suggests that the RPV value is also useful for predicting long-term outcomes in pancreatic cancer patients after resection.

Power of computed-tomography-defined sarcopenia for prediction of morbidity after pancreaticoduodenectomy

Background

The goal of our study was to evaluate the current approach in prediction of postoperative major complications after pancreaticoduodenectomy (PD), especially symptomatic pancreatic fistula (POPF), using parameters derived from computed tomography (CT).

Methods

Patients after PD were prospectively collected in a database of the local department of surgery and all patients with CT scans available were assessed in this study. CT parameters were measured at the level of the intervertebral disc L3/L4 and consisted of the areas of the visceral adipose tissue (A_VAT), the diameters of the pancreatic parenchyma (DPP) and the pancreatic duct (DPD), the areas of ventral abdominal wall muscle (A_MVEN), psoas muscle (A_MPSO), paraspinal muscle (A_MSPI), total muscle (A_MTOT), as well as the mean muscle attenuation (MA) and skeletal muscle index (SMI). Mann-Whitney-U Test for two independent samples and binary logistic regression were used for statistical analysis.

Results

One hundred thirty-nine patients (55 females, 84 males) were included. DPD was 2.9 mm (Range 0.7–10.7) on median and more narrow in patients with complications equal to or greater stadium IIIb (p < 0.04) and severe POPF (p < 0.01). DPP median value was 17 (6.9–37.9) mm and there was no significant difference regarding major complications or POPF. A_VAT showed a median value of 127.5 (14.5–473.0) cm² and was significantly larger in patients with POPF (p < 0.01), but not in cases of major complications (p < 0.06). A_MPSO, A_MSPI, A_MVEN and A_MTOT showed no significant differences between major complications and POPF. MA was both lower in groups with major complications (p < 0.01) and POPF (p < 0.01). SMI failed to differentiate between patients with or without major complications or POPF.

Conclusion

Besides the known factors visceral obesity and narrowness of the pancreatic duct, the mean muscle attenuation can easily be examined on routine preoperative CT scans and seems to be promising parameter to predict postoperative complications and POPF.

Preoperative risk evaluation for pancreatic fistula after pancreaticoduodenectomy

BACKGROUND

Pancreatic fistula remains common, with limited ability to risk stratify patients preoperatively. The objective of this study was to identify risk factors for clinically-relevant postoperative pancreatic fistula (CR-POPF) that are routinely available in the preoperative setting.

METHODS

Preoperatively available variables for all pancreaticoduodenectomies from 2014-2017 were examined using a national clinical registry. The cohort was separated into risk factor identification and internal validation subgroups.

RESULTS

Among 15 033 pancreaticoduodenectomies, the CR-POPF rate was 16.7%. CR-POPF was more likely in patients that were male (odds ratio [OR], 1.51), obese (body mass index [BMI] > 30, OR, 1.97), had minimal preoperative weight loss (OR, 1.25), had a nondilated pancreatic duct (OR, 1.81), did not have diabetes, (OR, 1.80), did not receive neoadjuvant therapy (OR, 1.78), had no evidence of biliary obstruction (OR, 1.18), or had nonadenocarcinoma pathology (OR, 1.96; all P < 0.01). Patients with three or fewer risk factors had a CR-POPF rate of 7.1%, while those with six or more risk factors had a CR-POPF rate of 26.3% (P < 0.001).

CONCLUSION

Preoperative CR-POPF risk evaluation could be a useful tool in patient counseling and surgical planning, and risk may allow for more well-informed decisions regarding perioperative management, including enhanced recovery protocols and use of somatostatin analogs.

Three-Dimensional Remnant Pancreatic Volumetry Predicts Postoperative Pancreatic Fistula in Pancreatic Cancer Patients after Pancreaticoduodenectomy

Background

Postoperative pancreatic fistula (POPF) is a serious complication that can occur following pancreaticoduodenectomy (PD). Recent studies suggest that remnant pancreatic volume (RPV) values from preoperative multidetector computed tomography (MDCT) are highly predictive of POPF. We performed three-dimensional (3D) surgical simulation of PD including RPV measurements. The aim of this study was to determine whether 3D-measured RPV is predictive of POPF after PD.

Methods

We used the SYNAPSE VINCENT® medical imaging system (Fujifilm Medical Co., Ltd., Tokyo, Japan) to construct 3D images after integrating MDCT and magnetic resonance cholangiopancreatography images. RPV was measured using this 3D image, which simulated actual intraoperative pancreatic parenchymal remnant volume. Ninety-one patients who underwent PD were retrospectively enrolled. Using multivariate analysis, RPV and other well-known POPF risk factors were independently assessed.

Results

Multivariate analysis identified high RPV values (hazard ratio [HR] = 8.41, p = 0.01), pancreatic duct diameter < 3.0 mm (HR = 5.48, p < 0.01), no pathological fibrosis (HR = 3.41, p < 0.01), and body mass index > 25 kg/m² (HR = 1.53, p = 0.02) as independent risk factors for POPF.

Conclusion

The present study indicates that preoperative 3D-measured RPV is predictive of POPF after PD.

Developing and validating a center-specific preoperative prediction calculator for risk of pancreaticoduodenectomy

BACKGROUND

The American College of Surgeons (ACS) Surgical Risk Calculator predicts postoperative risk based on preoperative variables. The ACS model was compared to an institution-specific risk calculator for pancreaticoduodenectomy (PD).

METHODS

Observed outcomes were compared with those predicted by the ACS and institutional models. Receiver operating characteristic (ROC) analysis evaluated the models' predictive ability. Institutional models were evaluated with retrospective and prospective internal validation.

RESULTS

Brier scores indicate equivalent aggregate predictive ability. ROC values for the institutional model (ROC: 0.675-0.881, P < 0.01) indicate superior individual event occurrence prediction (ACS ROC: 0.404-0.749, P < 0.01-0.860). Institutional models' accuracy was upheld in retrospective (ROC: 0.765-0.912) and prospective (ROC: 0.882-0.974) internal validation.

CONCLUSIONS

Identifying higher-risk patients allows for individualized care. While ACS and institutional models accurately predict average complication occurrence, the institutional models are superior at predicting individualized outcomes. Predictive metrics specific to PD center volume may more accurately predict outcomes.

Association Between the Incidence of Pancreatic Fistula After Pancreaticoduodenectomy and the Degree of Pancreatic Fibrosis

OBJECTIVE

The objective of this study is to investigate the association between the incidence of pancreatic fistula after pancreaticoduodenectomy (PD) and the degree of pancreatic fibrosis.

METHOD

Between January 2013 and December 2016, the analysis of the clinical data of 529 cases of pancreaticoduodenectomy patients of our hospital was performed in a retrospective fashion. The univariate analysis and multivariate analysis were done using the Pearson chi-squared test and binary logistic regression analysis model; correlations were analyzed by Spearman rank correlation analysis. The value of the degree of pancreatic fibrosis to predict the incidence of pancreatic fistula after pancreaticoduodenectomy was evaluated by the area under the receiver operating characteristic (ROC) curve.

RESULTS

The total incidence of pancreatic fistula after pancreaticoduodenectomy was 28.5% (151/529). Univariate analysis and multivariate analysis showed that BMI ≥ 25 kg/m², pancreatic duct size ≤ 3 mm, pancreatic CT value< 30, the soft texture of the pancreas (judged during the operation), and the percent of fibrosis of pancreatic lobule ≤ 25% are prognostic factors of pancreatic fistula after pancreaticoduodenectomy (P < 0.05); the pancreatic CT value and the percent of fibrosis of pancreatic lobule in pancreatic fistula group were both lower than those in non-pancreatic fistula group (P < 0.05). Results indicated that there is a negative correlation between the severity of pancreatic fistula and the pancreatic CT value or the percent of fibrosis of pancreatic lobule (r = - 0.297, - 0.342, respectively). The areas under the ROC curve of the percent of fibrosis of pancreatic lobule and the pancreatic CT value were 0.756 and 0.728, respectively.

CONCLUSION

The degree of pancreatic fibrosis is a prognostic factor which can influence the pancreatic texture and the incidence of pancreatic fistula after pancreaticoduodenectomy. The pancreatic CT value can be used as a quantitative index of the degree of pancreatic fibrosis to predict the incidence of pancreatic fistula after pancreaticoduodenectomy.

Risk factors and preventive strategies for post-operative pancreatic fistula after pancreatic surgery: a comprehensive review

BACKGROUND

Pancreas surgery has developed into a fairly safe procedure in terms of mortality, but is still hampered by considerable morbidity. Among the most frequent and dreaded complications are the development of a post-operative pancreatic fistula (POPF). The prediction and prevention of POPF remains an area of debate with several questions yet to be firmly addressed with solid answers.

METHODS

A systematic review of systematic reviews/meta-analyses and randomized trials in the English literature (PubMed/MEDLINE, Cochrane library, EMBASE) covering January 2005 to December 2015 on risk factors and preventive strategies for POPF.

RESULTS

A total of 49 systematic reviews and meta-analyses over the past decade discussed patient, surgeon, pancreatic disease and intraoperative related factors of POPF. Non-modifiable factors (age, BMI, comorbidity) and pathology (histotype, gland texture, duct size) that indicates surgery are associated with POPF risk. Consideration of anastomotic technique and use of somatostatin-analogs may slightly modify the risk of fistula. Sealant products appear to have no effect. Perioperative bleeding and transfusion enhance risk, but is modifiable by focus on technique and training. Drains may not prevent fistulae, but may help in early detection. Early drain-amylase may aid in detection. Predictive scores lack uniform validation, but may have a role in patient information if reliable pre-operative risk factors can be obtained.

CONCLUSIONS

Development of POPF occurs through several demonstrated risk factors. Anastomotic technique and use of somatostatin-analogs may slightly decrease risk. Drains may aid in early detection of leaks, but do not prevent POPF.

Are there still indications for total pancreatectomy?

Total pancreatectomy is associated with short- and long-term high complication rate and without evidence of oncologic advantages. Several metabolic consequences are co-related with the apancreatic state. The unstable diabetes related to the total resection of the pancreas expose the patients to short- and long-term life-threatening complications. Severe hypoglycemia is a short-term dangerous complication that can also cause patients’ death. Chronic complications of severe diabetes (cardiac and vascular diseases, neuropathy, nephropathy, and retinopathy) are also cause of morbidity, mortality and worsening of quality of life. For this reasons the number of total pancreatectomies performed has certainly decreased over time. However, today there are still some indications for this kind of procedures. Chronic pancreatitis untreatable with conventional treatments, surgical treatment of precancerous pancreatic lesions, surgical treatment of locally advanced pancreatic cancer and the management of patients with extraordinary high-risk pancreatic texture after pancreaticoduodenectomy represent possible indications for total pancreatectomy and are analyzed in the present paper.

Comparison of preoperative CT-based imaging parameters to predict postoperative pancreatic fistula

AIM

To review all reported methods of preoperative computed tomography (CT) in one patient cohort and to identify which were the strongest to predict postoperative pancreatic fistula (POPF) after pancreatoduodenectomy.

MATERIALS AND METHODS

Consecutive patients undergoing pancreatoduodenectomy were included if they had unenhanced CT images for review. Eighteen variables and two scores were tested. Receiver operator characteristics (ROC) were explored.

RESULTS

POPF affected 26 of 107 patients (24.3%). Nine variables were significantly related to POPF with pancreatic duct width having the largest area under the ROC curve (AUROC; 0.808, p<0.001). An obese body habitus was associated with POPF with six of nine related variables using data from CT images associated with POPF; of these intra-abdominal wall thickness yielded the largest AUROC (0.713, p=0.001). This corresponded to the finding that body mass index (BMI) was related to POPF (AUROC 0.705, p=0.002). The largest AUROC of all was associated with one of the predictive scores (0.828, p<0.001). Substituting BMI for intra-abdominal wall thickness in this score yielded a non-significant increase to predict POPF (AUROC 0.840, p=0.676). None of the assessments of organ density (in Hounsfield Units) were associated with POPF.

CONCLUSION

Data from preoperative CT imaging provides valuable information regarding a patient's risk of POPF. Obesity as assessed by CT images strongly relates to POPF, but the largest single risk factor for POPF is a narrow pancreatic duct.

Value of preoperative computed tomography for prediction of pancreatic fistula after pancreaticoduodenectomy

AIM: To assess the value of preoperative computed tomography (CT) for prediction of pancreatic fistula after pancreaticoduodenectomy (PD).

METHODS: The clinical and imaging data for 60 patients who received PD from January 2011 to June 2014 at our hospital were retrospectively analyzed. Cases were divided into two groups, those with pancreatic fistula group and those without. Patients with pancreatic fistula were divided into three subgroups based on the grade of pancreatic fistula: A, B and C. The pancreatic CT HU, the CT HU ratio of the pancreas/abdominal aorta, pancreatic duct diameter and pancreatic gland thickness were compared among all groups. Simple linear correlation analysis was performed to analyze the correlation between the results of CT and severity of pancreatic fistula. The area under the receiver operation characteristic (ROC) curve was used to evaluate the value of these results of CT for prediction of pancreatic fistula after PD.

RESULTS: Twelve (20.0%) cases of pancreatic fistula occurred after PD, including 7 cases of grade A, 3 cases of grade B and 2 cases of grade C. The pancreatic CT HU, the CT HU ratio of the pancreas/abdominal aorta, and pancreatic duct diameter were significantly lower in patients with pancreatic fistula than those without, and pancreatic gland thickness was significantly lower in the pancreatic fistula group (P < 0.05). There were significant differences in all results of CT between three grades of pancreatic fistula. The severity of pancreatic fistula was negatively related to the pancreatic CT HU, the CT HU ratio of the pancreas/abdominal aorta, and pancreatic duct diameter, but positively to pancreatic gland thickness. The area under the ROC curve of the pancreatic CT HU, the CT HU ratio of the pancreas/abdominal aorta, pancreatic duct diameter and pancreatic gland thickness was 0.820, 0.794, 0.809 and 0.765, respectively.

CONCLUSION: Preoperative CT imaging has certain value for prediction of pancreatic fistula after PD. The method of anastomosis and perioperative management should be adjusted according to the index to reduce the risk of postoperative pancreatic fistula and improve patients' prognosis.