Clinical impact of developing better practices at the institutional level on surgical outcomes after distal pancreatectomy in 1515 patients: Domestic audit of the Japanese Society of Pancreatic Surgery

Utility of fistula risk score in assessing the risk of postoperative pancreatic fistula occurrence and other significant complications after different types of pancreatic neuroendocrine tumor resections

Purpose

This study was performed to evaluate the utility of the fistula risk score (FRS) and its components in predicting the occurrence of postoperative pancreatic fistula and other significant postoperative complications after resections of pancreatic neuroendocrine tumors.

Methods

Retrospective analysis of 131 patients operated on for pancreatic neuroendocrine tumors between 2015 and 2021 was performed. The correlation of the FRS scale with the occurrence of postoperative pancreatic fistulas and postoperative complications according to the Clavien-Dindo classification was analyzed; only in 109 cases of distal resections and pancreatoduodenectomies (PD).

Results

Soft pancreatic texture and intraoperative blood loss of >700 mL are risk factors for clinically significant pancreatic fistula (P = 0.001 and P = 0.001, respectively) and significant postoperative complications (P = 0.016 and P = 0.001, respectively). Wirsung duct diameter (WDD) was associated only with the occurrence of postoperative pancreatic fistula (P = 0.013). FRS scale is associated with the occurrence of pancreatic fistulas and clinically significant postoperative complications in cases of distal resections and PDs (P < 0.001 and P = 0.005, respectively). Postoperative complications are correlated with the occurrence of fistula type B or C (P < 0.001).

Conclusion

Soft pancreatic texture, intraoperative blood loss of >700 mL, and a WDD of ≤3 mm are risk factors for clinically significant postoperative pancreatic fistula. FRS may be applied not only in PDs but also in distal pancreatectomies. Unfortunately, it is not used in total pancreatic resections and enucleations since FRS takes into account the WDD.

Systematic review and meta-analysis of risk factors of postoperative pancreatic fistula after distal pancreatectomy in the era of 2016 International Study Group pancreatic fistula definition

BACKGROUND

Risk factors for the development of clinically relevant POPF (CR-POPF) following distal pancreatectomy (DP) need clarification particularly following the 2016 International Study Group of Pancreatic Fistula (ISGPF) definition.

METHODS

A systemic search of MEDLINE, Pubmed, Scopus, and EMBASE were conducted using the PRISMA framework. Studies were evaluated for risk factors for the development CR-POPF after DP using the 2016 ISGPF definition. Further subgroup analysis was undertaken on studies ≥10 patients in exposed and non-exposed subgroups.

RESULTS

Forty-three studies with 8864 patients were included in the meta-analysis. The weighted rate of CR-POPF was 20.4% (95%-CI: 17.7-23.4%). Smoking (OR 1.29, 95%-CI: 1.08-1.53, p = 0.02) and open DP (OR 1.43, 95%-CI: 1.02-2.01, p = 0.04) were found to be significant risk factors of CR-POPF. Diabetes (OR 0.81, 95%-CI: 0.68-0.95, p = 0.02) was a significant protective factor against CR-POPF. Substantial heterogeneity was observed in the comparisons of pancreatic texture and body mass index. Seventeen risk factors achieved significance in a univariate or multivariate comparison as reported by individual studies in the narrative synthesis, however, they remain difficult to interpret as statistically significant comparisons were not uniform.

CONCLUSION

This meta-analysis found smoking and open DP to be risk factors and diabetes to be protective factor of CR-POPF in the era of 2016 ISGPF definition.

Investigation of factors associated with reduced clinical benefits of personalized peptide vaccination for pancreatic cancer

The aim of the present study was to determine the factors associated with reduced clinical benefits of personalized peptide vaccination (PPV) for pancreatic cancer. Phase II PPV clinical trials comprising 309 (8 non-advanced and 301 advanced-stage) patients with pancreatic cancer were conducted. Two to four peptides were selected among a set of 31 different peptides as vaccine candidates for personalized peptide vaccination based on human leukocyte antigen types and preexisting peptide-specific IgG levels, and subcutaneously injected. The selected peptides were subcutaneously injected. Of the 309 patients, 81 failed to complete the 1st PPV cycle due to rapid disease progression, and their median overall survival [2.1 months; 95% confidence interval (CI), 1.8-2.7] was significantly shorter than that of the remaining 228 patients (8.4 months; 95% CI, 8.4-9.9; P<0.01). ‘Immune boosting’ was defined when IgG levels before vaccination increased more than 2-fold after vaccination. Immune boosting was observed in the majority of patients with PPV irrespective of whether or not they received concomitant chemotherapy. Additionally, patients demonstrating immune boosting exhibited longer survival rates. Although the positive-response rates and peptide-specific IgG levels in pre- and post-vaccination samples differed among the 31 peptides, patients exhibiting immune boosting in response to each of the vaccinated peptides demonstrated longer survival times. Pre-vaccination factors associated with reduced clinical benefits were high c-reactive protein (CRP) levels, high neutrophil counts, lower lymphocyte and red blood cell counts, advanced disease stage and the greater number of chemotherapy courses prior to the PPV treatment. The post-vaccination factors associated with lower clinical benefits were PPV monotherapy and lower levels of immune boosting. In conclusion, pre-vaccination inflammatory signatures, rather than pre- or post-vaccination immunological signatures, were associated with reduced clinical benefits of personalized peptide vaccination (PPV) for pancreatic cancer.