Prophylactic abdominal drainage after distal pancreatectomy (PANDORINA): an international, multicentre, open-label, randomised controlled, non-inferiority trial

BACKGROUND

Prophylactic passive abdominal drainage is standard practice after distal pancreatectomy. This approach aims to mitigate the consequences of postoperative pancreatic fistula (POPF) but its added value, especially in patients at low risk of POPF, is currently being debated. We aimed to assess the non-inferiority of a no-drain policy in patients after distal pancreatectomy.

METHODS

In this international, multicentre, open-label, randomised controlled, non-inferiority trial, we recruited patients aged 18 years or older undergoing open or minimally invasive elective distal pancreatectomy for all indications in 12 centres in the Netherlands and Italy. We excluded patients with an American Society of Anesthesiology (ASA) physical status of 4-5 or WHO performance status of 3-4, added by amendment following the death of a patient with ASA 4 due to a pre-existing cardiac condition. Patients were randomly assigned (1:1) intraoperatively by permuted blocks (size four to eight) to either no drain or prophylactic passive drain placement, stratified by annual centre volume (<40 or ≥40 distal pancreatectomies) and low risk or high risk of grade B or C POPF. High-risk was defined as a pancreatic duct of more than 3 mm in diameter, a pancreatic thickness at the neck of more than 19 mm, or both, based on the Distal Pancreatectomy Fistula Risk Score. Other patients were considered low-risk. The primary outcome was the rate of major morbidity (Clavien-Dindo score ≥III), and the most relevant secondary outcome was grade B or C POPF, grading per the International Study Group for Pancreatic Surgery. Outcomes were assessed up to 90 days postoperatively and analysed in the intention-to-treat population and per-protocol population, which only included patients who received the allocated treatment. A prespecified non-inferiority margin of 8% was compared with the upper limit of the two-sided 95% CI (Wald) of unadjusted risk difference to assess non-inferiority. This trial is closed and registered in the Netherlands Trial Registry, NL9116.

FINDINGS

Between Oct 3, 2020, and April 28, 2023, 376 patients were screened for eligibility and 282 patients were randomly assigned to the no-drain group (n=138; 75 [54%] women and 63 [46%] men) or the drain group (n=144; 73 [51%] women and 71 [49%] men). Seven patients in the no-drain group received a drain intraoperatively; consequently, the per-protocol population included 131 patients in the no-drain group and 144 patients in the drain group. The rate of major morbidity was non-inferior in the no-drain group compared with the drain group in the intention-to-treat analysis (21 [15%] vs 29 [20%]; risk difference -4·9 percentage points [95% CI -13·8 to 4·0]; pnon-inferiority=0·0022) and the per-protocol analysis (21 [16%] vs 29 [20%]; risk difference -4·1 percentage points [-13·2 to 5·0]; pnon-inferiority=0·0045). Grade B or C POPF was observed in 16 (12%) patients in the no-drain group and in 39 (27%) patients in the drain group (risk difference -15·5 percentage points [95% CI -24·5 to -6·5]; pnon-inferiority<0·0001) in the intention-to-treat analysis. Three patients in the no-drain group died within 90 days; the cause of death in two was not considered related to the trial. The third death was a patient with an ASA score of 4 who died after sepsis and a watershed cerebral infarction at second admission, leading to multiple organ failure. No patients in the drain group died within 90 days.

INTERPRETATION

A no-drain policy is safe in terms of major morbidity and reduced the detection of grade B or C POPF, and should be the new standard approach in eligible patients undergoing distal pancreatectomy.

FUNDING

Ethicon UK (Johnson & Johnson Medical, Edinburgh, UK).

Minimally invasive versus open distal pancreatectomy for resectable pancreatic cancer (DIPLOMA): an international randomised non-inferiority trial

Background

The oncological safety of minimally invasive surgery has been questioned for several abdominal cancers. Concerns also exist regarding the use of minimally invasive distal pancreatectomy (MIDP) in patients with resectable pancreatic cancer as randomised trials are lacking.

Methods

In this international randomised non-inferiority trial, we recruited adults with resectable pancreatic cancer from 35 centres in 12 countries. Patients were randomly assigned to either MIDP (laparoscopic or robotic) or open distal pancreatectomy (ODP). Both patients and pathologists were blinded to the assigned approach. Primary endpoint was radical resection (R0, ≥1 mm free margin) in patients who had ultimately undergone resection. Analyses for the primary endpoint were by modified intention-to-treat, excluding patients with missing data on primary endpoint. The pre-defined non-inferiority margin of -7% was compared with the lower limit of the two-sided 90% confidence interval (CI) of absolute difference in the primary endpoint. This trial is registered with the ISRCTN registry (ISRCTN44897265).

Findings

Between May 8, 2018 and May 7, 2021, 258 patients were randomly assigned to MIDP (131 patients) or ODP (127 patients). Modified intention-to-treat analysis included 114 patients in the MIDP group and 110 patients in the ODP group. An R0 resection occurred in 83 (73%) patients in the MIDP group and in 76 (69%) patients in the ODP group (difference 3.7%, 90% CI -6.2 to 13.6%; p_{non-inferiority} = 0.039). Median lymph node yield was comparable (22.0 [16.0-30.0] vs 23.0 [14.0-32.0] nodes, p = 0.86), as was the rate of intraperitoneal recurrence (41% vs 38%, p = 0.45). Median follow-up was 23.5 (interquartile range 17.0-30.0) months. Other postoperative outcomes were comparable, including median time to functional recovery (5 [95% CI 4.5-5.5] vs 5 [95% CI 4.7-5.3] days; p = 0.22) and overall survival (HR 0.99, 95% CI 0.67-1.46, p = 0.94). Serious adverse events were reported in 23 (18%) of 131 patients in the MIDP group vs 28 (22%) of 127 patients in the ODP group.

Interpretation

This trial provides evidence on the non-inferiority of MIDP compared to ODP regarding radical resection rates in patients with resectable pancreatic cancer. The present findings support the applicability of minimally invasive surgery in patients with resectable left-sided pancreatic cancer.

Funding

Medtronic Covidien AG, Johnson & Johnson Medical Limited, Dutch Gastroenterology Society.

Benchmarking of robotic and laparoscopic spleen-preserving distal pancreatectomy by using two different methods

BACKGROUND

Benchmarking is an important tool for quality comparison and improvement. However, no benchmark values are available for minimally invasive spleen-preserving distal pancreatectomy, either laparoscopically or robotically assisted. The aim of this study was to establish benchmarks for these techniques using two different methods.

METHODS

Data from patients undergoing laparoscopically or robotically assisted spleen-preserving distal pancreatectomy were extracted from a multicentre database (2006-2019). Benchmarks for 10 outcomes were calculated using the Achievable Benchmark of Care (ABC) and best-patient-in-best-centre methods.

RESULTS

Overall, 951 laparoscopically assisted (77.3 per cent) and 279 robotically assisted (22.7 per cent) procedures were included. Using the ABC method, the benchmarks for laparoscopically assisted and robotically assisted spleen-preserving distal pancreatectomy respectively were: 150 and 207 min for duration of operation, 55 and 100 ml for blood loss, 3.5 and 1.7 per cent for conversion, 0 and 1.7 per cent for failure to preserve the spleen, 27.3 and 34.0 per cent for overall morbidity, 5.1 and 3.3 per cent for major morbidity, 3.6 and 7.1 per cent for pancreatic fistula grade B/C, 5 and 6 days for duration of hospital stay, 2.9 and 5.4 per cent for readmissions, and 0 and 0 per cent for 90-day mortality. Best-patient-in-best-centre methodology revealed milder benchmark cut-offs for laparoscopically and robotically assisted procedures, with operating times of 254 and 262.5 min, blood loss of 150 and 195 ml, conversion rates of 5.8 and 8.2 per cent, rates of failure to salvage spleen of 29.9 and 27.3 per cent, overall morbidity rates of 62.7 and 55.7 per cent, major morbidity rates of 20.4 and 14 per cent, POPF B/C rates of 23.8 and 24.2 per cent, duration of hospital stay of 8 and 8 days, readmission rates of 20 and 15.1 per cent, and 90-day mortality rates of 0 and 0 per cent respectively.

CONCLUSION

Two benchmark methods for minimally invasive distal pancreatectomy produced different values, and should be interpreted and applied differently.

Benchmarking of minimally invasive distal pancreatectomy with splenectomy: European multicentre study

Background

Benchmarking is the process to used assess the best achievable results and compare outcomes with that standard. This study aimed to assess best achievable outcomes in minimally invasive distal pancreatectomy with splenectomy (MIDPS).

Methods

This retrospective study included consecutive patients undergoing MIDPS for any indication, between 2003 and 2019, in 31 European centres. Benchmarks of the main clinical outcomes were calculated according to the Achievable Benchmark of Care (ABC™) method. After identifying independent risk factors for severe morbidity and conversion, risk-adjusted ABCs were calculated for each subgroup of patients at risk.

Results

A total of 1595 patients were included. The ABC was 2.5 per cent for conversion and 8.4 per cent for severe morbidity. ABC values were 160 min for duration of operation time, 8.3 per cent for POPF, 1.8 per cent for reoperation, and 0 per cent for mortality. Multivariable analysis showed that conversion was associated with male sex (OR 1.48), BMI exceeding 30 kg/m2 (OR 2.42), multivisceral resection (OR 3.04), and laparoscopy (OR 2.24). Increased risk of severe morbidity was associated with ASA fitness grade above II (OR 1.60), multivisceral resection (OR 1.88), and robotic approach (OR 1.87).

Conclusion

The benchmark values obtained using the ABC method represent optimal outcomes from best achievable care, including low complication rates and zero mortality. These benchmarks should be used to set standards to improve patient outcomes.

Prognostic Factors After Pancreatectomy for Pancreatic Cancer Initially Metastatic to the Liver

Background

Resection of initially oligometastatic pancreatic ductal adenocarcinoma (PDAC) following response to first-line chemotherapy is controversial. We herein updated a previous case series to investigate the oncologic outcomes and preoperative factors that could drive the decision-making process.

Methods

This retrospective analysis was limited to patients with liver-only synchronous metastases who experienced complete regression of the metastatic component and underwent pancreatectomy between October 2008 and July 2020 at two high-volume institutions. Clinical-pathologic variables were captured, and inflammation-based prognostic scores were calculated. Recurrence and survival analyses were performed using standard statistical methods.

Results

Overall, 52 patients were included. FOLFIRINOX was the most employed chemotherapy regimen (63.5%). Post-treatment tumor size, serum carbohydrate antigen (CA) 19-9 and carcinoembryonic antigen (CEA) were significantly decreased relative to baseline evaluation. The median time from diagnosis to pancreatectomy was 10.2 months, while the median time from chemotherapy completion to pancreatectomy was 2 months. Major postoperative complications occurred in 26.9% of patients, while postoperative mortality was nil. The median disease-free survival (DFS) and overall survival (OS) from pancreatectomy were 16.5 and 23.0 months, respectively, and the median OS from diagnosis was 37.2 months. At multivariable analysis, vascular resection, operative time, prognostic nutrition index (PNI) and neutrophil-to-lymphocyte ratio (NLR) were associated with OS. Operative time, platelet × neutrophil/lymphocyte count (SII), and PNI were associated with DFS.

Conclusions

We confirm promising outcomes of selected patients who underwent pancreatectomy following downstaging of liver metastases. The absence of vascular involvement of the primary tumor, good nutritional status, and low inflammatory index scores could be useful to select candidates for resection.

Minimally invasive versus open distal pancreatectomy for pancreatic ductal adenocarcinoma (DIPLOMA): study protocol for a randomized controlled trial

Background

Recently, the first randomized trials comparing minimally invasive distal pancreatectomy (MIDP) with open distal pancreatectomy (ODP) for non-malignant and malignant disease showed a 2-day reduction in time to functional recovery after MIDP. However, for pancreatic ductal adenocarcinoma (PDAC), concerns have been raised regarding the oncologic safety (i.e., radical resection, lymph node retrieval, and survival) of MIDP, as compared to ODP. Therefore, a randomized controlled trial comparing MIDP and ODP in PDAC regarding oncological safety is warranted. We hypothesize that the microscopically radical resection (R0) rate is non-inferior for MIDP, as compared to ODP.

Methods/design

DIPLOMA is an international randomized controlled, patient- and pathologist-blinded, non-inferiority trial performed in 38 pancreatic centers in Europe and the USA. A total of 258 patients with an indication for elective distal pancreatectomy with splenectomy because of proven or highly suspected PDAC of the pancreatic body or tail will be randomly allocated to MIDP (laparoscopic or robot-assisted) or ODP in a 1:1 ratio. The primary outcome is the microscopically radical resection margin (R0, distance tumor to pancreatic transection and posterior margin ≥ 1 mm), which is assessed using a standardized histopathology assessment protocol. The sample size is calculated with the following assumptions: 5% one-sided significance level (α), 80% power (1-β), expected R0 rate in the open group of 58%, expected R0 resection rate in the minimally invasive group of 67%, and a non-inferiority margin of 7%. Secondary outcomes include time to functional recovery, operative outcomes (e.g., blood loss, operative time, and conversion to open surgery), other histopathology findings (e.g., lymph node retrieval, perineural- and lymphovascular invasion), postoperative outcomes (e.g., clinically relevant complications, hospital stay, and administration of adjuvant treatment), time and site of disease recurrence, survival, quality of life, and costs. Follow-up will be performed at the outpatient clinic after 6, 12, 18, 24, and 36 months postoperatively.

Discussion

The DIPLOMA trial is designed to investigate the non-inferiority of MIDP versus ODP regarding the microscopically radical resection rate of PDAC in an international setting.

Trial registration

ISRCTN registry ISRCTN44897265. Prospectively registered on 16 April 2018.

Impact of Neoadjuvant Therapy in Resected Pancreatic Ductal Adenocarcinoma of the Pancreatic Body or Tail on Surgical and Oncological Outcome: A Propensity-Score Matched Multicenter Study

BACKGROUND

Several studies have suggested a survival benefit of neoadjuvant therapy (NAT) for pancreatic ductal adenocarcinoma (PDAC) in the pancreatic head. Data concerning NAT for PDAC located in pancreatic body or tail are lacking.

METHODS

Post hoc analysis of an international multicenter retrospective cohort of distal pancreatectomy for PDAC in 34 centers from 11 countries (2007-2015). Patients who underwent resection after NAT were matched (1:1 ratio), using propensity scores based on baseline characteristics, to patients who underwent upfront resection. Median overall survival was compared using the stratified log-rank test.

RESULTS

Among 1236 patients, 136 (11.0%) received NAT, most frequently FOLFIRINOX (25.7%). In total, 94 patients receiving NAT were matched to 94 patients undergoing upfront resection. NAT was associated with less postoperative major morbidity (Clavien-Dindo ≥ 3a, 10.6% vs. 23.4%, P = 0.020) and pancreatic fistula grade B/C (9.6% vs. 21.3%, P = 0.026). NAT did not improve overall survival [27 (95% CI 14-39) versus 31 months (95% CI 19-42), P = 0.277], as compared with upfront resection. In a sensitivity analysis of 251 patients with radiographic tumor involvement of splenic vessels, NAT (n = 37, 14.7%) was associated with prolonged overall survival [36 (95% CI 18-53) versus 20 months (95% CI 15-24), P = 0.049], as compared with upfront resection.

CONCLUSION

In this international multicenter cohort study, NAT for resected PDAC in pancreatic body or tail was associated with less morbidity and pancreatic fistula but similar overall survival in comparison with upfront resection. Prospective studies should confirm a survival benefit of NAT in patients with PDAC and splenic vessel involvement.

Circulating tumor DNA quantity is related to tumor volume and both predict survival in metastatic pancreatic ductal adenocarcinoma

Circulating tumor DNA (ctDNA) is assumed to reflect tumor burden and has been suggested as a tool for prognostication and follow‐up in patients with metastatic pancreatic ductal adenocarcinoma (mPDAC). However, the prognostic value of ctDNA and its relation with tumor burden has yet to be substantiated, especially in mPDAC. In this retrospective analysis of prospectively collected samples, cell‐free DNA from plasma samples of 58 treatment‐naive mPDAC patients was isolated and sequenced using a custom‐made pancreatobiliary NGS panel. Pathogenic mutations were detected in 26/58 (44.8%) samples. Cross‐check with droplet digital PCR showed good agreement in Bland–Altman analysis (p = 0.217, nonsignificance indicating good agreement). In patients with liver metastases, ctDNA was more frequently detected (24/37, p < 0.001). Tumor volume (3D reconstructions from imaging) and ctDNA variant allele frequency (VAF) were correlated (Spearman's ρ = 0.544, p < 0.001). Median overall survival (OS) was 3.2 (95% confidence interval [CI] 1.6–4.9) versus 8.4 (95% CI 1.6–15.1) months in patients with detectable versus undetectable ctDNA (p = 0.005). Both ctDNA VAF and tumor volume independently predicted OS after adjustment for carbohydrate antigen 19.9 and treatment regimen (hazard ratio [HR] 1.05, 95% CI 1.01–1.09, p = 0.005; HR 1.00, 95% CI 1.01–1.05, p = 0.003). In conclusion, our study showed that ctDNA detection rates are higher in patients with larger tumor volume and liver metastases. Nevertheless, measurements may diverge and, thus, can provide complementary information. Both ctDNA VAF and tumor volume were strong predictors of OS.

What's new?

Circulating tumor DNA (ctDNA) attracts much interest as a possible prognostic tool for cancer. Here, the authors showed that the quantity of ctDNA correlated strongly with tumor volume in metastatic pancreatic ductal adenocarcinoma (mPDAC). They conducted a retrospective analysis using samples collected from 58 untreated mPDAC patients. For this study, the authors designed a pancreatobiliary NGS panel, which they used to test the patients’ cell‐free DNA, along with droplet digital PCR. Both ctDNA variant allele frequency and tumor volume predicted overall survival, they found.

International Validation of the Eighth Edition of the American Joint Committee on Cancer (AJCC) TNM Staging System in Patients With Resected Pancreatic Cancer

Importance

The recently released eighth edition of the American Joint Committee on Cancer TNM staging system for pancreatic cancer seeks to improve prognostic accuracy but lacks international validation.

Objective

To validate the eighth edition of the American Joint Committee on Cancer TNM staging system in an international cohort of patients with resected pancreatic ductal adenocarcinoma.

Design, Setting, and Participants

This international multicenter cohort study took place in 5 tertiary centers in Europe and the United States from 2000 to 2015. Patients who underwent pancreatoduodenectomy for nonmetastatic pancreatic ductal adenocarcinoma were eligible. Data analysis took place from December 2017 to April 2018.

Exposures

Patients were retrospectively staged according to the seventh and eighth editions of the TNM staging system.

Main Outcomes and Measures

Prognostic accuracy on survival rates, assessed by Kaplan-Meier and multivariate Cox proportional hazards analyses and concordance statistics.

Results

A total of 1525 consecutive patients were included (median [IQR] age, 66 (58-72) years; 802 (52.6%) male). Distribution among stages via the seventh edition was stage IA in 41 patients (2.7%), stage IB in 42 (2.8%), stage IIA in 200 (13.1%), stage IIB in 1229 (80.6%), and stage III in 12 (0.8%); this changed with use of the eighth edition to stage IA in 118 patients (7.7%), stage IB in 144 (9.4%), stage IIA in 22 (1.4%), stage IIB in 643 (42.2%), and stage III in 598 (39.2%). With the eighth edition, 774 patients (50.8%) migrated to a different stage; 183 (12.0%) were reclassified to a lower stage and 591 (38.8%) to a higher stage. Median overall survival for the entire cohort was 24.4 months (95% CI, 23.4-26.2 months). On Kaplan-Meier analysis, 5-year survival rates changed from 38.2% for patients in stage IA, 34.7% in IB, 35.3% in IIA, 16.5% in IIB, and 0% in stage III (log-rank P < .001) via classification with the seventh edition to 39.2% for patients in stage IA, 33.9% in IB, 27.6% in IIA, 21.0% in IIB, and 10.8% in stage III (log-rank P < .001) with the eighth edition. For patients who were node negative, the T stage was not associated with prognostication of survival in either edition. In the eighth edition, the N stage was associated with 5-year survival rates of 35.6% in N0, 20.8% in N1, and 10.9% in N2 (log-rank P < .001). The C statistic improved from 0.55 (95% CI, 0.53-0.57) for the seventh edition to 0.57 (95% CI, 0.55-0.60) for the eighth edition.

Conclusions and Relevance

The eighth edition of the TNM staging system demonstrated a more equal distribution among stages and a modestly increased prognostic accuracy in patients with resected pancreatic ductal adenocarcinoma compared with the seventh edition. The revised T stage remains poorly associated with survival, whereas the revised N stage is highly prognostic.

Clinical impact of the updated international postoperative pancreatic fistula definition in distal pancreatectomy

BACKGROUND

Postoperative pancreatic fistula (POPF) remains the most common complication after distal pancreatectomy. The International Study Group on Pancreatic Surgery definition of POPF is used worldwide. Recently, an update of the definition was published. The aim of this study was to determine the clinical impact of the update.

METHODS

An international retrospective validation study, including patients who underwent DP (2005 -2016) in 5 centers was performed. Distribution of complications amongst POPF grades were compared for the old and updated definition.

RESULTS

In total, 1089 patients were included. The incidence of POPF decreased with the updated definition from 47% to 24% (P < 0.01), largely because a downgrade of grade A and grade B into biochemical leak. Comparable morbidity was seen in the old and updated 'no POPF group' (Clavien -Dindo 3 5% vs. 6% P = 0.320 and hospital stay (7 vs. 7 days P = 0.301). The change in definition of POPF grade B resulted in more Clavien -Dindo 3 (38% vs. 51%) P < 0.01) and longer hospital stay (9 [9 -13] vs. 9 days [7 -15] P < 0.01) in the updated `grade B group'.

CONCLUSION

Applying the updated POPF definition showed improved discrimination between grades and should therefore be used to report POPF after DP.