Analysis of early postoperative outcomes after pancreatoduodenectomy with Braun entero-enteroanastomosis

Objective. To evaluate early postoperative results after pancreatoduodenectomy with Brown entero–enteroanastomosis. Materials and methods. Collected data of 162 patients who underwent pancreatoduodenectomy from 2015 to 2023. Group 1 was formed retrospectively and contained patients without Braun entero–enterostomy. Prospectivile formed Group 2 contained patients with Braun entero–enterostomy. The comparative analysis of 2 groups was performed. Results. The overall incidence of delayed gastric emptying in both groups was 9.4%. At the same time, the frequency of delayed gastric emptying in the group 2 was significantly lower – 5.9% versus 15% in group 1, although the difference did not reach statistical significance (p=0.896). Conclusion. Braun entero–enteroanastomosis during pancreatoduodenectomy reduced the frequency of delayed emptying, while not increasing the number of other complications.

Pancreaticoduodenectomy (PD) is the main treatment for pancreatic cancer and periampullary tumours.Since the first PDE was reported in the 1930s [1], the mortality rate after this operation was 20-40% over the next 50 years.With the improvement of surgical techniques, instruments and perioperative treatment, the mortality rate after PDE has decreased dramatically to less than 5%, while the complication rate remains high at 30-50% [2] and even reaches 60% [3].The most common complications after a PDE are pancreatic fistula (PF) and delayed gastric evacuation (DGE).According to the definition of The International Study Group of Pancreatic Surgery (ISGPS) [4,5], the incidence of PA ranges from 14 to 60% [6], and GED -from 38 to 57% [7].Therefore, reducing the incidence of complications after DRE, including PU and ESW, remains an urgent issue.
The optimal method of resection and reconstruction that can significantly reduce the incidence of GERD has not been determined.The efficacy of pylorus-preserving PDE or PDE with resection of the pyloric region of the stomach [8], anterior or posterior gastroenteroanastomosis, classical Child reconstruction or gastroenteroanastomosis on the small bowel loop according to Roux [9] is debated.Recently, the formation of an enteroenteroanastomosis according to Brown [10] between the small intestine adductor and abductor loops in addition to the gastroenteroanastomosis has also become popular, which can potentially reduce the incidence of EEE.
This topic has become even more relevant over the past decade after the implementation of the concept of an accelerated recovery programme after PDE into routine clinical practice [11], aimed at reducing the incidence of postoperative complications, including ESRD, and early resumption of oral nutrition.So far, no randomised controlled trials have been conducted on the effectiveness of Brown's enteroenteroanastomosis in reducing the incidence of complications, and only the results of retrospective studies have been published.The effectiveness of this technique has also not been studied in the framework of the accelerated recovery programme after DUI.
The aim of the study was to evaluate the early results after PDE with the formation of a Brown enteroenteroanastomosis, the perioperative management of which corresponded to the accelerated recovery programme, and to compare with the results after PDE without the formation of a Brown enteroenteroanastomosis.

Materials and methods of the study
We studied the results of treatment of 162 patients, 97 (59.9%) men and 65 (40.1%)women aged 34 to 77 years, who underwent PDE for benign and malignant pathology in the period from 2015 to 2023.The perioperative management of patients was in accordance with the accelerated recovery programme adapted and implemented at the National Scientific Centre of Surgery and Transplantation named after A. A. Shalimov.

The Ukrainian Journal of Clinical Surgery
The study included patients who underwent PDE with resection of the pyloric section of the stomach, cutting the stomach immediately behind the pyloric ring [12], with a standard lymphadenectomy according to the 1999 consensus definition [13].The pancreatojejunoanastomosis was formed using the duct-to-mucosa technique, end to end, with tworow Maxon 5-0 and Surgipro 5-0 nodal sutures (Covidien, Dublin, Ireland), the hepatojejunoanastomosis was formed 20 cm below with a single-row Maxon 5-0 nodal suture, and the gastrojejunoanastomosis was formed anteroposteriorly with two-row continuous Maxon 4-0 and Surgipro 4-0 sutures.In 102 patients, an additional 15 cm below the gastroenteroanastomosis, a Brown's enteroenteroanastomosis with a diameter of 1-1.5 cm between the adductor and abductor loops of the small intestine was formed using tworow continuous Maxon 5-0 and Surgipro 5-0 sutures.
The Clavien-Dindo classification and ISGPS definition were used to assess postoperative complications.Statistical analysis was performed using the statistical package SPSS, version 20 (SPSS Inc., Chicago, USA).Continuous variables were compared using a two-sample Student's t-test for independent samples, categorical variables were compared using the test 2 .

Results.
Patients were divided into two groups: group I (retrospective) -60 patients who underwent PDE without the formation of a Brown's enteroenteroanastomosis in the period from 2015 to 2018; group II (prospective) -102 patients who underwent PDE with the formation of a Brown's enteroenteroanastomosis in the period from 2019 to 2023.In group I, there were 35 men (58.3%) and 25 women (41.7%).The average age of patients in group I was (55.7 ± 11.6) years.In group II, there were 62 (60.8%) men and 40 (39.2%)women.The average age of patients in group II was (59.6 ± 9.9) years.

The Ukrainian Journal of Clinical Surgery
The average body mass index (BMI) of patients in group I was (25.4 ± 4.6) kg/m 2 , patients in group II -(26.3 ± 4.0) kg/m 2 .
There was no statistically significant difference between the groups in terms of gender (p=0.758),age (p=0.121) and mean BMI (p=0.446).There were also no statistically significant differences between the groups in the American Society of Anaesthesiology (ASA) score and comorbidities: p=0.788, p=0.356, respectively.The groups were also comparable in terms of the nature of the underlying pathology and the frequency of biliary decompression (p=0.401)(Table 1).
The duration of the operation was slightly shorter in patients of group I: from 240 to 540 minutes, mean -348.1 minutes, than in patients of group II: from 275 to 590 minutes, mean -353.2 minutes, but there was no statistically significant difference in these indicators between the groups (p=0.567).The volume of blood loss in group I was (316 ± 161) ml, in group II -(280 ± 100.1) ml and had no significant differences (p=0.453).There were no significant differences between the groups in other intraoperative parameters (Table 2).
The overall incidence of VEP was 9.4%.However, the incidence of ESI in patients of group II was significantly lower (5.9%)than in patients of group I (15%), although the difference between these figures was not statistically significant (p=0.896).
The groups did not differ in the incidence of other postoperative complications (Table 3).There were no complications directly related to the formation of Brown's enteroenteroanastomosis, such as suture failure or bleeding.In 1 patient of group I, bleeding occurred as a result of grade C PU, which was stopped by conservative methods.In 1 patient of group II, massive intra-abdominal bleeding from the pancreatojejunoanastomosis occurred, which was stopped by relaparotomy.Another 1 patient of this group developed massive bleeding from the pancreatic jejunojejunal anastomosis into the lumen of the digestive tract with regurgitation and massive aspiration of gastric contents on the 7th postoperative day, which resulted in the patient's death.
The length of hospital stay did not differ significantly: group I -13.1 days, group II -12 days (p>0.05).

Discussion
GERD remains one of the most common complications after PDE.Possible causes of GERD include local ischaemia or venous congestion of the pyloric and antrum, gastric atony due to vagal nerve injury [14], lack of motilin secretion [14], and gastric dysrhythmias due to other complications.However, definitive conclusions have not yet been obtained, and the pathogenesis of GERD is currently considered multifactorial.
More than 100 years ago, Brown proposed to form an enteroenteroanastomosis between the small intestine's adductor and abductor loops distal to the gastroenteroanastomosis to reduce the incidence of alkaline reflux gastritis and bile vomiting after gastric surgery.Nowadays, the technique of Brown's enteroenteroanastomosis formation is becoming popular in combination with PDE, and several retrospective studies have described its benefits [14].
Since 2019, we have been routinely forming a Brown enteroenteroanastomosis for PDE in all patients and have seen a positive impact in the form of a decrease in the incidence of VEP, as demonstrated by the results of our study.
Although the duration of the operation without the formation of this anastomosis is somewhat shorter, it is worth noting that its formation requires only about 15 minutes.And as the surgical technique improved over time, this difference was almost levelled, as we observed in the study groups.
Certain limitations of this study, in particular, the retrospective formation of group I, different periods of