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.

Risk of conversion to open surgery during robotic and laparoscopic pancreatoduodenectomy and effect on outcomes: international propensity score-matched comparison study

BACKGROUND

Minimally invasive pancreatoduodenectomy (MIPD) is increasingly being performed because of perceived patient benefits. Whether conversion of MIPD to open pancreatoduodenectomy worsens outcome, and which risk factors are associated with conversion, is unclear.

METHODS

This was a post hoc analysis of a European multicentre retrospective cohort study of patients undergoing MIPD (2012-2017) in ten medium-volume (10-19 MIPDs annually) and four high-volume (at least 20 MIPDs annually) centres. Propensity score matching (1 : 1) was used to compare outcomes of converted and non-converted MIPD procedures. Multivariable logistic regression analysis was performed to identify risk factors for conversion, with results presented as odds ratios (ORs) with 95 per cent confidence intervals (c.i).

RESULTS

Overall, 65 of 709 MIPDs were converted (9.2 per cent) and the overall 30-day mortality rate was 3.8 per cent. Risk factors for conversion were tumour size larger than 40 mm (OR 2.7, 95 per cent c.i.1.0 to 6.8; P = 0.041), pancreatobiliary tumours (OR 2.2, 1.0 to 4.8; P = 0.039), age at least 75 years (OR 2.0, 1.0 to 4.1; P = 0.043), and laparoscopic pancreatoduodenectomy (OR 5.2, 2.5 to 10.7; P < 0.001). Medium-volume centres had a higher risk of conversion than high-volume centres (15.2 versus 4.1 per cent, P < 0.001; OR 4.1, 2.3 to 7.4, P < 0.001). After propensity score matching (56 converted MIPDs and 56 completed MIPDs) including risk factors, rates of complications with a Clavien-Dindo grade of III or higher (32 versus 34 per cent; P = 0.841) and 30-day mortality (12 versus 6 per cent; P = 0.274) did not differ between converted and non-converted MIPDs.

CONCLUSION

Risk factors for conversion during MIPD include age, large tumour size, tumour location, laparoscopic approach, and surgery in medium-volume centres. Although conversion during MIPD itself was not associated with worse outcomes, the outcome in these patients was poor in general which should be taken into account during patient selection for MIPD.