Radiofrequency is a secure and effective method for pancreatic transection in laparoscopic distal pancreatectomy: results of a randomized, controlled trial in an experimental model

Radiofrequency-assisted transection of the pancreas versus stapler in distal pancreatectomy: study protocol for a multicentric randomised clinical trial (TRANSPAIRE)

INTRODUCTION

To date, no pancreatic stump closure technique has been shown to be superior to any other in distal pancreatectomy. Although several studies have shown a trend towards better results in transection using a radiofrequency device (radiofrequency-assisted transection (RFT)), no randomised trial for this purpose has been performed to date. Therefore, we designed a randomised clinical trial, with the hypothesis that this technique used in distal pancreatectomies is superior in reducing clinically relevant postoperative pancreatic fistula (CR-POPF) than mechanical closures.

METHODS AND ANALYSIS

TRANSPAIRE is a multicentre randomised controlled trial conducted in seven Spanish pancreatic centres that includes 112 patients undergoing elective distal pancreatectomy for any indication who will be randomly assigned to RFT or classic stapler transections (control group) in a ratio of 1:1. The primary outcome is the CR-POPF percentage. Sample size is calculated with the following assumptions: 5% one-sided significance level (α), 80% power (1-β), expected POPF in control group of 32%, expected POPF in RFT group of 10% and a clinically relevant difference of 22%. Secondary outcomes include postoperative results, complications, radiological evaluation of the pancreatic stump, metabolomic profile of postoperative peritoneal fluid, survival and quality of life. Follow-ups will be carried out in the external consultation at 1, 6 and 12 months postoperatively.

ETHICS AND DISSEMINATION

TRANSPAIRE has been approved by the CEIM-PSMAR Ethics Committee. This project is being carried out in accordance with national and international guidelines, the basic principles of protection of human rights and dignity established in the Declaration of Helsinki (64th General Assembly, Fortaleza, Brazil, October 2013), and in accordance with regulations in studies with biological samples, Law 14/2007 on Biomedical Research will be followed. We have defined a dissemination strategy, whose main objective is the participation of stakeholders and the transfer of knowledge to support the exploitation of activities.

REGISTRATION DETAILS

ClinicalTrials.gov Registry (NCT04402346).

Radiofrequency-assisted transection of the pancreas vs stapler in distal pancreatectomy: a propensity score matched cohort analysis

To demonstrate the efficacy of radiofrequency for pancreatic stump closure in reducing the incidence of postoperative pancreatic fistula (POPF) in distal pancreatectomy (DP) compared with mechanical transection methods. Despite all the different techniques of pancreatic stump closure proposed for DP, best practice for avoiding POPF remains an unresolved issue, with an incidence of up to 30% regardless of center volume or surgical expertise. DP was performed in a cohort of patients by applying radiofrequency to stump closure (RF Group) and compared with mechanical closure (Control Group). A propensity score (PS) matched cohort study was carried out to minimize bias from nonrandomized treatment assignment. Cohorts were matched by PS accounting for factors significantly associated with either undergoing RF transection or mechanical closure through logistic regression analysis. The primary end-point was the incidence of clinically relevant POPF (CR-POPF). Of 89 patients included in the whole cohort, 13 case patients from the RF-Group were 1:1 matched to 13 control patients. In both the first independent analysis of unmatched data and subsequent adjustment to the overall propensity score-matched cohort, a higher rate of CR-POPF in the Control Group compared with the RF-Group was detected (25.4% vs 5.3%, p = 0.049 and 53.8% vs 0%; p = 0.016 respectively). The RF Group showed better outcomes in terms of readmission rate (46.2% vs 0%, p = 0.031). No significant differences were observed in terms of mortality, major complications (30.8% vs 0%, p = 0.063) or length of hospital stay (5.7 vs 5.2 days, p = 0.89). Findings suggest that the RF-assisted technique is more efficacious in reducing CR-POPF than mechanical pancreatic stump closure.

Clinical case report: endoluminal thermal ablation of main pancreatic duct for patients at high risk of postoperative pancreatic fistula after pancreaticoduodenectomy

PURPOSE

Multiple attempts have been made to manage the pancreatic stump and the pancreatic duct in order to reduce the rate of postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy (PD), however radiofrequency-based technologies could help to achieve this goal. Previous encouraging clinical and experimental results support the use of endoluminal thermal ablation (ETHA) of the main pancreatic duct to reduce pancreatic exocrine secretion and hence POPF. We here describe our initial clinical experience with ETHA of the main pancreatic duct in two cases at high risk of POPF.

METHODS

Two cases underwent PD for malignancy with a high risk of POPF (adenocarcinoma, obese patients, surgical difficulties with heavy intraoperative blood loss, soft pancreas or walled-off pancreatitis and a tight small pancreatic main duct). In both cases, ETHA of the main pancreatic duct was conducted intraoperatively just before Blumgart-type pancreatic-jejunal anastomosis using a ClosureFast catheter (Medtronic, Mansfield, MA, USA) normally used for varicose vein treatment (therefore an off-label use).

RESULTS

Although a clear radiological POPF was detected in the second case, the clinical postoperative course in both cases was uneventful. Little pancreatic fluid collected in the abdominal drainage with low levels of amylase enzyme, confirming low exocrine pancreatic function. No other procedure-related complications were detected.

CONCLUSION

Endoluminal thermal ablation of the main pancreatic duct may be a feasible and safe technique to reduce the adverse effects of POPF after PD.

Prevention and treatment of pancreatic fistula after pancreatic body and tail resection: current status and future directions

Postoperative pancreatic fistula (POPF) is the most common and critical complication after pancreatic body and tail resection. How to effectively reduce the occurrence of pancreatic fistula and conduct timely treatment thereafter is an urgent clinical issue to be solved. Recent research standardized the definition of pancreatic fistula and stressed the correlation between POPF classification and patient prognosis. According to the literature, identification of the risk factors for pancreatic fistula contributed to lowering the rate of the complication. Appropriate management of the pancreatic stump and perioperative treatment are of great significance to reduce the rate of POPF in clinical practice. After the occurrence of POPF, the treatment of choice should be determined according to the classification of the pancreatic fistula. However, despite the progress and promising treatment approaches, POPF remains to be a clinical issue that warrants further studies in the future.

Endoluminal radiofrequency ablation of the main pancreatic duct is a secure and effective method to produce pancreatic atrophy and to achieve stump closure

Radiofrequency energy has been used both experimentally and clinically to manage the pancreatic remnant after distal pancreatectomies. Our goal was to determine whether endoluminal radiofrequency (RF) ablation of the main pancreatic duct in large animals would be more efficient than glue occlusion as an exocrine pancreatic atrophy-inducing procedure. Thirty-four Landrace pigs were assigned to either the transpapilar (n = 16) or transection (n = 18) groups. The transection implied the pancreas neck was severed. In each of these groups the remaining distal pancreatic duct was occluded either by RF or by glue. In the transpapilar group complete atrophy was observed in all the RF cases, while atrophy was incomplete in all the members of the glue subgroup. The failure rate of the main pancreatic duct (usually expressed by a pseudocyst) in the transection groups was dramatically higher in the glue subgroup than the RF subgroups (9 out of 9 and 1 out of 9, respectively) and postoperative mortality occurred only in the glue subgroup (3 out of 9). These results show the superiority of endoluminal RF ablation over glue for main pancreatic duct occlusion, as seen by the degree of atrophy and fewer postoperative pancreatic fistulas.

Radiofrequency-induced heating versus mechanical stapler for pancreatic stump closure: in vivo comparative study

PURPOSE

The aim of this study was to assess the capacity of two methods of surgical pancreatic stump closure in terms of reducing the risk of pancreatic fistula formation (POPF): radiofrequency-induced heating versus mechanical stapler.

MATERIALS AND METHODS

Sixteen pigs underwent a laparoscopic transection of the neck of the pancreas. Pancreatic anastomosis was always avoided in order to work with an experimental model prone to POPF. Pancreatic stump closure was conducted either by stapler (ST group, n = 8) or radiofrequency energy (RF group, n = 8). Both groups were compared for incidence of POPF and histopathological alterations of the pancreatic remnant.

RESULTS

Six animals (75%) in the ST group and one (14%) in the RF group were diagnosed with POPF (p = 0.019). One animal in the RF group and three animals in the ST group had a pseudocyst in close contact with both pancreas stumps. On day 30 post-operation (PO), almost complete atrophy of the exocrine distal pancreas was observed when the main pancreatic duct was efficiently sealed.

CONCLUSIONS

Our findings suggest that RF-induced heating is more effective at closing the pancreatic stump than mechanical stapler and leads to the complete atrophy of the distal remnant pancreas.

Long-term evolution of acinar-to-ductal metaplasia and β-cell mass after radiofrequency-assisted transection of the pancreas in a controlled large animal model

BACKGROUND

Pancreatic duct ligation (PDL) has been used as a model of chronic pancreatitis and as a model to increase β-cell mass. However, studies in mice have demonstrated acinar regeneration after PDL, questioning the long-term validity of the model. We aim to elucidate whether RF-assisted transection (RFAT) of the main pancreatic duct is a reliable PDL model, both in short (ST, 1-month) and long-term (LT, 6-months) follow-ups.

METHODS

Eleven pigs were subjected to RFAT. Biochemical (serum/peripancreatic amylase and glucose) and histological changes (including a semiautomatic morphometric study of over 1000 images/pancreas and IHC analysis) were evaluated after ST or LT follow-up and also in fresh pancreas specimens that were used as controls for 1 (n = 4) and 6 months (n = 6).

RESULTS

The distal pancreas in the ST was characterized by areas of acinar-to-ductal metaplasia (56%) which were significantly reduced at LT (21%) by fibrotic replacement and adipose tissue. The endocrine mass showed a normal increase.

CONCLUSION

RFAT in the pig seems to be an appropriate PDL model without restoration of pancreatic drainage or reduction of endocrine mass.

Radiofrequency pancreatic ablation and section of the main pancreatic duct does not lead to necrotizing pancreatitis

OBJECTIVE

The aim of this study was to determine whether radiofrequency ablation (RFA) of the pancreas and subsequent transection of the main pancreatic duct may avoid the risk of both necrotizing pancreatitis and postoperative pancreatic fistula (POPF) formation.

METHODS

Thirty-two rats were subjected to RFA and section of the pancreas over their portal vein. Animals were killed at 3, 7, 15, and 21 days (groups 0-3, respectively). Two additional control groups (sham operation and user manipulation only, respectively) of 15 days of postoperative period were considered. Postoperative complications, histological changes (including morphometric and immunohistochemical analysis), and incidence of POPF were evaluated.

RESULTS

A significant increase in serum amylase levels (P < 0.05) on the third postoperative day, which return to baseline levels in the following weeks, was noted in groups 0 to 3. Those groups showed a rapid atrophy of the distal pancreas by apoptosis with no signs of necrotizing pancreatitis or POPF. The distal pancreas in groups 1 to 3 compared with group 0 and control groups showed a significant increase of small islets (<1000 µm).

CONCLUSIONS

The rapid acinar atrophy of the distal pancreas after RFA and section of the pancreatic ducts in this model does not lead to necrotizing pancreatitis.