Association between perineural infiltrations and delayed gastric emptying after Whipple procedure for periampullary tumours, and the relationship with other clinicopathological factors and overall survival

Introduction
Pancreaticoduodenectomy is a major procedure. Delayed gastric emptying (DGE) is a frequent postoperative complication that is attributed to several factors.

Aim
To investigate the probable association between perineural infiltrations and DGE, and the effects on overall survival.

Material and methods
A total of 123 patients who underwent pancreaticoduodenectomy were enrolled in the study. Factors like the presence of perineural infiltrations and post-operative DGE along with age, gender, presence of postoperative fistula, and grade of fistula and postoperative haemorrhage were analysed, and survival analyses were conducted.

Results
The presence of perineural infiltrations is statistically associated with DGE occurrence (p = 0.01). Moreover, the occurrence of DGE is statistically associated with male gender (p = 0.001), worse grade of postoperative fistula (p < 0.01), and the presence of postoperative haemorrhage (p = 0.03). There was no statistical association between the presence of perineural infiltrations and the other factors. Cox regression and Kaplan-Meier survival analyses showed that increased overall survival is associated with low age (p = 0.018 and p = 0.028, respectively), absence of perineural infiltrations (p = 0.005 and p = 0.003, respectively), better grade of postoperative fistula (p < 0.001), and absence of postoperative haemorrhage (p < 0.001). Multivariate analysis showed that independent prognostic factors for survival prognosis are perineural infiltrations, age, the presence of postoperative pancreatic fistula, and the presence of postoperative haemorrhage.

Conclusions
This is the first study that proves a statistically significant association between the presence of perineural infiltrations and the occurrence of DGE. Moreover, perineural infiltrations are an important independent prognostic factor for overall survival, along with other clinical factors.