Critical appraisal of the techniques of pancreatic anastomosis following pancreaticoduodenectomy: A network meta-analysis

Pancreatic anastomosis training models: Current status and future directions

Postoperative pancreatic fistula (POPF) is a major cause of morbidity and mortality after pancreatoduodenectomy (PD), and previous research has focused on patient-related risk factors and comparisons between anastomotic techniques. However, it is recognized that surgeon experience is an important factor in POPF outcomes, and that there is a significant learning curve for the pancreatic anastomosis. The aim of this study was to review the current literature on training models for the pancreatic anastomosis, and to explore areas for future research. It is concluded that research is needed to understand the mechanical properties of the human pancreas in an effort to develop a synthetic model that closely mimics its mechanical properties. Virtual reality (VR) is an attractive alternative to synthetic models for surgical training, and further work is needed to develop a VR pancreatic anastomosis training module that provides both high fidelity and haptic feedback.

Novel invagination procedure for pancreaticojejunostomy using double purse string sutures: A technical note

BACKGROUND

Postoperative pancreatic fistula (POPF) is one of the most serious complications after pancreaticoduodenectomy (PD), and the choice of pancreaticojejunostomy (PJ) is considered a key factor affecting the occurrence of POPF. Numerous anastomotic methods and their modifications have been proposed, and there is no method that can completely avoid the occurrence of POPF. Based on our team's experience in pancreatic surgery and a review of relevant literature, we describe a novel invagination procedure for PJ using double purse string sutures, which has resulted in favourable outcomes.

AIM

To describe the precise procedural steps, technical details and clinical efficacy of the novel invagination procedure for PJ.

METHODS

This study adopted a single-arm retrospective cohort study methodology, involving a total of 65 consecutive patients who underwent PD with the novel invagination procedure for PJ, including the placement of a pancreatic stent, closure of the residual pancreatic end, and two layers of purse-string suturing. Baseline data included age, sex, body mass index (BMI), pancreatic texture, pancreatic duct diameter, operation time, and blood loss. Clinical outcomes included the operation time, blood loss, and incidence of POPF, postoperative haemorrhage, delayed gastric emptying, postoperative pulmonary infection, postoperative abdominal infection, and postoperative pulmonary infection.

RESULTS

The mean age of the patients was 59.12 (± 8.08) years. Forty males and 25 females were included, and the mean BMI was 21.61 kg/m2 (± 2.74). A total of 41.53% of patients had a pancreatic duct diameter of 3 mm or less. The mean operation time was 263.83 min (± 59.46), and the mean blood loss volume was 318.4 mL (± 163.50). Following the surgical intervention, only three patients showed grade B POPF (4.62%), while no patients showed grade C POPF. Five patients (5/65, 7.69%) were diagnosed with postoperative haemorrhage. Six patients (6/65, 9.23%) experienced delayed gastric emptying. Four patients (4/65, 6.15%) developed postoperative pulmonary infection, while an equivalent number (4/65, 6.15%) exhibited postoperative abdominal infection. Additionally, two patients (2/65, 3.08%) experienced postoperative pulmonary infection.

CONCLUSION

The novel invagination technique for PJ is straightforward, yields significant outcomes, and has proven to be safe and feasible for clinical application.

Safety and feasibility of modified duct-to-mucosa pancreaticojejunostomy during pancreatoduodenectomy: A retrospective cohort study

BACKGROUND

Pancreatoduodenectomy (PD) is the most effective surgical procedure to remove a pancreatic tumor, but the prevalent postoperative complications, including postoperative pancreatic fistula (POPF), can be life-threatening. Thus far, there is no consensus about the prevention of POPF.

AIM

To determine possible prognostic factors and investigate the clinical effects of modified duct-to-mucosa pancreaticojejunostomy (PJ) on POPF development.

METHODS

We retrospectively collected and analyzed the data of 215 patients who underwent PD between January 2017 and February 2022 in our surgery center. The risk factors for POPF were analyzed by univariate analysis and multivariate logistic regression analysis. Then, we stratified patients by anastomotic technique (end-to-side invagination PJ vs modified duct-to-mucosa PJ) to conduct a comparative study.

RESULTS

A total of 108 patients received traditional end-to-side invagination PJ, and 107 received modified duct-to-mucosa PJ. Overall, 58.6% of patients had various complications, and 0.9% of patients died after PD. Univariate and multivariate logistic regression analyses showed that anastomotic approaches, main pancreatic duct (MPD) diameter and pancreatic texture were significantly associated with the incidence of POPF. Additionally, the POPF incidence and operation time in patients receiving modified duct-to-mucosa PJ were 11.2% and 283.4 min, respectively, which were significantly lower than those in patients receiving traditional end-to-side invagination PJ (27.8% and 333.2 minutes).

CONCLUSION

Anastomotic approach, MPD diameter and pancreatic texture are major risk factors for POPF development. Compared with traditional end-to-side invagination PJ, modified duct-to-mucosa PJ is a simpler and more efficient technique that results in a lower incidence of POPF. Further studies are needed to validate our findings and explore the clinical applicability of our technique for laparoscopic and robotic PD.

Machine learning versus logistic regression for the prediction of complications after pancreatoduodenectomy

BACKGROUND

Machine learning is increasingly advocated to develop prediction models for postoperative complications. It is, however, unclear if machine learning is superior to logistic regression when using structured clinical data. Postoperative pancreatic fistula and delayed gastric emptying are the two most common complications with the biggest impact on patient condition and length of hospital stay after pancreatoduodenectomy. This study aimed to compare the performance of machine learning and logistic regression in predicting pancreatic fistula and delayed gastric emptying after pancreatoduodenectomy.

METHODS

This retrospective observational study used nationwide data from 16 centers in the Dutch Pancreatic Cancer Audit between January 2014 and January 2021. The area under the curve of a machine learning and logistic regression model for clinically relevant postoperative pancreatic fistula and delayed gastric emptying were compared.

RESULTS

Overall, 799 (16.3%) patients developed a postoperative pancreatic fistula, and 943 developed (19.2%) delayed gastric emptying. For postoperative pancreatic fistula, the area under the curve of the machine learning model was 0.74, and the area under the curve of the logistic regression model was 0.73. For delayed gastric emptying, the area under the curve of the machine learning model and logistic regression was 0.59.

CONCLUSION

Machine learning did not outperform logistic regression modeling in predicting postoperative complications after pancreatoduodenectomy.

Outcomes of Duct-to-Mucosa vs. Invagination Pancreatojejunostomy: Toward a Personalized Approach for Distal Pancreatic Stump Anastomosis in Central Pancreatectomy?

(1) Background: The jejunum is primarily used for distal pancreatic stump anastomoses after central pancreatectomy (CP). The study aimed to compare duct-to-mucosa (WJ) and distal pancreatic invagination into jejunum anastomoses (PJ) after CP. (2) Methods: All patients with CP and jejunal anastomoses (between 1 January 2002 and 31 December 2022) were retrospectively assessed and compared. (3) Results: 29 CP were analyzed: WJ-12 patients (41.4%) and PJ-17 patients (58.6%). The operative time was significantly higher in the WJ vs. PJ group of patients (195 min vs. 140 min, p = 0.012). Statistically higher rates of patients within the high-risk fistula group were observed in the PJ vs. WJ group (52.9% vs. 0%, p = 0.003). However, no differences were observed between the groups regarding the overall, severe, and specific postpancreatectomy morbidity rates (p values ≥ 0.170). (4) Conclusions: The WJ and PJ anastomoses after CP were comparable in terms of morbidity rates. However, a PJ anastomosis appeared to fit better for patients with high-risk fistula scores. Thus, a personalized, patient-adapted technique for the distal pancreatic stump anastomosis with the jejunum after CP should be considered. At the same time, future research should explore gastric anastomoses' emerging role.

Prediction of clinically relevant postoperative pancreatic fistula using radiomic features and preoperative data

Clinically relevant postoperative pancreatic fistula (CR-POPF) can significantly affect the treatment course and outcome in pancreatic cancer patients. Preoperative prediction of CR-POPF can aid the surgical decision-making process and lead to better perioperative management of patients. In this retrospective study of 108 pancreatic head resection patients, we present risk models for the prediction of CR-POPF that use combinations of preoperative computed tomography (CT)-based radiomic features, mesh-based volumes of annotated intra- and peripancreatic structures and preoperative clinical data. The risk signatures were evaluated and analysed in detail by visualising feature expression maps and by comparing significant features to the established CR-POPF risk measures. Out of the risk models that were developed in this study, the combined radiomic and clinical signature performed best with an average area under receiver operating characteristic curve (AUC) of 0.86 and a balanced accuracy score of 0.76 on validation data. The following pre-operative features showed significant correlation with outcome in this signature ([Formula: see text]) - texture and morphology of the healthy pancreatic segment, intensity volume histogram-based feature of the pancreatic duct segment, morphology of the combined segment, and BMI. The predictions of this pre-operative signature showed strong correlation (Spearman correlation co-efficient, [Formula: see text]) with the intraoperative updated alternative fistula risk score (ua-FRS), which is the clinical gold standard for intraoperative CR-POPF risk stratification. These results indicate that the proposed combined radiomic and clinical signature developed solely based on preoperatively available clinical and routine imaging data can perform on par with the current state-of-the-art intraoperative models for CR-POPF risk stratification.

Clinical decisions in pancreatic cancer surgery: a national survey and case-vignette study

Very few surveys have been carried out of oncosurgical decisions made in patients with pancreatic cancer (PC), or of the possible differences in therapeutic approaches between low/medium and high-volume centers. A survey was sent out to centers affiliated to the Spanish Group of Pancreatic Surgery (GECP) asking about their usual pre-, intra- and post-operative management of PC patients and describing five imaginary cases of PC corresponding to common scenarios that surgeons regularly assess in oncosurgical meetings. A consensus was considered to have been reached when 80% of the answers coincided. We received 69 responses from the 72 GECP centers (response rate 96%). Pre-operative management: consensus was obtained on 7/16 questions (43.75%) with no significant differences between low- vs high-volume centers. Intra-operative: consensus was obtained on 11/28 questions (39.3%). D2 lymphadenectomy, biliary culture, intra-operative biliary margin study, pancreatojejunostomy, and two loops were significantly more frequent in high-volume hospitals (p < 0.05). Post-operative: consensus was obtained on 2/8 questions (25%). No significant differences were found between low-/medium- vs high-volume hospitals. Of the 41 questions asked regarding the cases, consensus was reached on 22 (53.7%). No differences in the responses were found according to the type of hospital. Management and cases: consensus was reached in 42/93 questions (45.2%). At GECP centers, consensus was obtained on 45% of the questions. Only 5% of the answers differed between low/medium and high-volume centers (all intra-operative). A more specific assessment of why high-volume centers obtain the best results would require the design of complex prospective studies able to measure the therapeutic decisions made and the effectiveness of their execution. Clinicaltrials.gov identifier: NCT04755036.

Prevention and Treatment of Grade C Postoperative Pancreatic Fistula

Postoperative pancreatic fistula (POPF) is a troublesome complication after pancreatic surgeries, and grade C POPF is the most serious situation among pancreatic fistulas. At present, the incidence of grade C POPF varies from less than 1% to greater than 9%, with an extremely high postoperative mortality rate of 25.7%. The patients with grade C POPF finally undergo surgery with a poor prognosis after various failed conservative treatments. Although various surgical and perioperative attempts have been made to reduce the incidence of grade C POPF, the rates of this costly complication have not been significantly diminished. Hearteningly, several related studies have found that intra-abdominal infection from intestinal flora could promote the development of grade C POPF, which would help physicians to better prevent this complication. In this review, we briefly introduced the definition and relevant risk factors for grade C POPF. Moreover, this review discusses the two main pathways, direct intestinal juice spillover and bacterial translocation, by which intestinal microbes enter the abdominal cavity. Based on the abovementioned theory, we summarize the operation techniques and perioperative management of grade C POPF and discuss novel methods and surgical treatments to reverse this dilemma.

Modified binding pancreaticogastrostomy vs modified Blumgart pancreaticojejunostomy after laparoscopic pancreaticoduodenectomy for pancreatic or periampullary tumors

BACKGROUND

Laparoscopic pancreaticoenteric anastomosis is one of the technically challenging steps of minimally invasive pancreaticoduodenectomy (PD), especially during the learning curve. Despite multiple randomized controlled trials and meta-analyses, the type of pancreatico-enteric anastomosis as a risk factor for post-pancreatectomy complications is debatable. Also, the ideal technique of pancreatic reconstruction during the learning curve of laparoscopic PD has not been well studied.

AIM

To compare the short-term outcomes of modified binding pancreaticogastrostomy (PG) and Blumgart pancreaticojejunostomy (PJ) during learning curve of laparoscopic PD.

METHODS

The first 25 patients with resectable pancreatic or periampullary tumors who underwent laparoscopic PD with modified binding PG or modified Blumgart PJ between January 2015 and May 2020 were retrospectively analyzed to compare perioperative outcomes during the same learning curve. A single layer of the full-thickness purse-string suture was placed around the posterior gastrotomy in the modified binding PG. In the modified Blumgart technique, only a single transpancreatic horizontal mattress suture was placed on either side of the pancreatic duct (total two sutures) to secure the pancreatic parenchyma to the jejunum. Also, on the ventral surface, the knot is tied on the jejunal wall without going through the pancreatic parenchyma. Post pancreatectomy complications are graded as per the International Study Group for Pancreatic Surgery criteria.

RESULTS

During the study period, modified binding PG was performed in 27 patients and modified Blumgart PJ in 29 patients. The demographic and clinical parameters of the first 25 patients included in both groups were comparable. Lower end cholangiocarcinoma and ampullary adenocarcinoma were the primary indications for laparoscopic PD in both groups (32/50, 64%). The median operative time for pancreatic reconstruction was significantly lower in the binding PG group (42 vs 58 min, P = 0.01). The clinically relevant (Grade B/C) postoperative pancreatic fistula (POPF) was significantly more in the modified PJ group (28% vs 4%, P = 0.04). In contrast, intraluminal postpancreatectomy hemorrhage (PPH) was more in the binding PG group (32% vs 4%, P = 0.02). There was no significant difference in the incidence of delayed gastric emptying between the two groups.

CONCLUSION

During the learning curve of laparoscopic PD, modified binding PG reduces POPF but is associated with increased intraluminal PPH compared to PJ using the modified Blumgart technique.

Comparison of early postoperative outcomes between omega-like duct-to-mucosa pancreatojejunostomy and conventional duct-to-mucosa pancreatojejunostomy after pancreaticoduodenectomy

BACKGROUND

Pancreatic fistula is a life-threatening complication of pancreaticoduodenectomy. Omega-like duct-to-mucosa pancreatojejunostomy is a novel technique which helps reduce the risk of fistulation. This study aimed to compare early postoperative outcomes of omega-like and conventional pancreatojejunostomy.

METHODS

A retrospective single-centre cohort study comparing outcomes of adult patients who underwent open pancreatoduodenectomy with conventional (CDMP) or omega-like duct-to-mucosa pancreatojejunostomy (ODMP) between 1 January 2015 and 31 December 2019. The primary outcome measure was the pancreatic fistula rate.

RESULTS

440 patients were included in this study of whom 233 underwent CDMP and 207 ODMP. The rate of clinically relevant pancreatic fistula (grade B/C) was significantly higher after CDMP than ODMP (18.5% vs. 10.6%, P = 0.021). 153 patients in CDMP group and 99 patients in ODMP group developed one or more complications (65.7% vs. 47.8%, P = 0.004). The average hospitalization expenses were numerically decreased in ODMP group, although this was not statistically significant (120,000 ± 42,000 [Chinese Yuan] vs. 100,000 ± 40,000 [Chinese Yuan] or 18,581 ± 6503 [United States Dollar] vs. 15,484 ± 6194 [United States Dollar], P = 0.402).

CONCLUSION

ODMP may reduce the incidence of pancreatic fistula and other early postoperative complications after pancreatoduodenectomy.

Prospective Study Correlating External Biliary Stenting and Pancreatic Fistula Following Pancreaticoduodenectomy

BACKGROUND

Postoperative pancreatic fistula (POPF) is the most common complication of pancreaticoduodenectomy (PD). Sometimes POPF is associated with biliary fistula (BF) or "mixed" fistula. The purpose of this study is to assess whether the severity of the fistulae, when present, is decreased with an external biliary stent in place.

METHODS

In this single-center study, we assessed patients who underwent elective PD from January 2014 to December 2017. Patients were divided into two groups: standard PD (ST-PD) vs. PD with external biliary stent (PD-BS). Demographic, preoperative, intraoperative, and postoperative variables were analyzed, including complications according to the Clavien-Dindo classification, and those specific to pancreatic surgeries, and mortality rates within 90 days of operation.

RESULTS

A total of 128 patients were included (65 in ST-PD group and 63 in PD-BS group). Postoperative complications occurred in 61.7% of patients (32.8%, Clavien-Dindo ≥ III) and were more common among patients in the PD-BS group (44.4% vs. 23.1%; p = 0.03). POPF was also more common among patients in the PD-BS group (39.7% vs. 18.5%; p = 0.008). No statistically significant differences were found for any other complications.

CONCLUSION

Based on the results of our study, placement of a transanastomotic external biliary stent does not reduce the rate of pancreatic or biliary fistulae, or their severity; in fact, POPF is more likely when biliary exteriorization is present.

TRIAL REGISTRATION

NCT04654299.

A novel anastomosis technique facilitates pancreaticojejunostomy in total laparoscopic pancreaticoduodenectomy (with video)

BACKGROUND

While the best technique for pancreatic anastomosis during Whipple's procedure remains controversial, laparoscopic pancreaticoduodenectomy (LPD) has been rapidly increasing in popularity. Because of their feasibility and reliability, new pancreatic anastomosis techniques may have vital roles when adapted for LPD. Here, we describe a new pancreaticojejunostomy (PJ) technique using three sutures (termed the "three sutures" PJ technique), which facilitates pancreatic anastomosis during total LPD.

METHODS

A total of 149 patients who underwent LPD using the "three sutures" PJ technique at three hospitals were included in this study (81 patients at Guangdong Provincial People's Hospital [GDPH], 60 patients at Sun Yat-Sen Memorial Hospital [SMH], and 8 patients at Affiliated Hospital of Guangdong Medical University [AHGMU]). Data on the demographic characteristics, operative outcomes, and postoperative results (pancreatic fistula rate, mortality rate, and length of hospital stay) of these patients were collected and analyzed.

RESULTS

A surgical video showing the details of the "three sutures" PJ method was included. The mean operation times at GDPH, SMH, and AHGMU were 4.08 ± 0.99 h, 4.65 ± 1.53 h, and 4.67 ± 0.64 h, respectively, and the average PJ times were 17.96 ± 3.49 min, 18.19 ± 2.63 min, and 22.5 ± 3.96 min, respectively. The numbers of grade B pancreatic fistulas were 9 (11.11%), 2 (3.33%), and 1 (12.50%), respectively, and two patients had grade C fistulas, one each at GDPH and SMH. The numbers of clinically relevant postoperative pancreatic fistula (CR-POPF) were 10 (12.35%), 3 (5.00%), and 1 (12.50%) in each center, respectively. The overall rate of CR-POPF was 9.40% (14/149) among patients of all three centers. The perioperative mortality rate was 0%.

CONCLUSIONS

The "three sutures" PJ technique for total LPD is a safe and reliable method, with a low risk of pancreatic fistula, short anastomosis time, and steep learning curve.

Modified Technique for Wirsung-Pancreatogastric Anastomosis after Pancreatoduodenectomy: A Single Center Experience and Systematic Review of the Literature

BACKGROUND

The mortality rate following pancreaticoduodenectomy (PD) has been decreasing over the past few years; nonetheless, the morbidity rate remains elevated. The most common complications after PD are post-operative pancreatic fistula (POPF) and delayed gastric emptying (DGE) syndrome. The issue as to which is the best reconstruction method for the treatment of the pancreatic remnant after PD is still a matter of debate. The aim of this study was to retrospectively analyze the morbidity rate in 100 consecutive PD reconstructed with Wirsung-Pancreato-Gastro-Anastomosis (WPGA), performed by a single surgeon applying a personal modification of the pancreatic reconstruction technique.

METHODS

During an 8-year period (May 2012 to March 2020), 100 consecutive patients underwent PD reconstructed with WPGA. The series included 57 males and 43 females (M/F 1.32), with a mean age of 68 (range 41-86) years. The 90-day morbidity and mortality were retrospectively analyzed. Additionally, a systematic review was conducted, comparing our technique with the existing literature on the topic.

RESULTS

We observed eight cases of clinically relevant POPF (8%), three cases of "primary" DGE (3%) and four patients suffering "secondary" DGE. The surgical morbidity and mortality rate were 26% and 6%, respectively. The median hospital stay was 13.6 days. The systematic review of the literature confirmed the originality of our modified technique for Wirsung-Pancreato-Gastro-Anastomosis.

CONCLUSIONS

Our modified double-layer WPGA is associated with a very low incidence of POPF and DGE. Also, the technique avoids the risk of acute hemorrhage of the pancreatic parenchyma.

Intraoperative Perfusion Assessment in Enhanced Reality Using Quantitative Optical Imaging: An Experimental Study in a Pancreatic Partial Ischemia Model

To reduce the risk of pancreatic fistula after pancreatectomy, a satisfactory blood flow at the pancreatic stump is considered crucial. Our group has developed and validated a real-time computational imaging analysis of tissue perfusion, using fluorescence imaging, the fluorescence-based enhanced reality (FLER). Hyperspectral imaging (HSI) is another emerging technology, which provides tissue-specific spectral signatures, allowing for perfusion quantification. Both imaging modalities were employed to estimate perfusion in a porcine model of partial pancreatic ischemia. Perfusion quantification was assessed using the metrics of both imaging modalities (slope of the time to reach maximum fluorescence intensity and tissue oxygen saturation (StO2), for FLER and HSI, respectively). We found that the HSI-StO2 and the FLER slope were statistically correlated using the Spearman analysis (R = 0.697; p = 0.013). Local capillary lactate values were statistically correlated to the HSI-StO2 and to the FLER slope (R = −0.88; p < 0.001 and R = −0.608; p = 0.0074). HSI-based and FLER-based lactate prediction models had statistically similar predictive abilities (p = 0.112). Both modalities are promising to assess real-time pancreatic perfusion. Clinical translation in human pancreatic surgery is currently underway.

The modified Blumgart anastomosis after pancreaticoduodenectomy: a retrospective single center cohort study

Objectives

The postoperative pancreatic fistula (POPF) is a major complication after pancreatic head resection whereby the technique of the anastomosis is a very influencing factor. The literature describes a possible protective role of the Blumgart anastomosis.

Methods

Patients after pancreatic head resection with reconstruction through the modified Blumgart anastomosis (a 2 row pancreatic anastomosis through mattress sutures of the parenchyma and duct to mucosa pancreaticojejunostomy, Blumgart-group) were compared with patients after pancreatic head resection and reconstruction through the conventional pancreatojejunostomy (single suture technique of capsule and parenchyma to seromuscularis, PJ-group). The Data were collected retrospectively. Depending on the propensity score matching in a ratio of 1:2 comparison groups were set up. Blumgart-group (n=29) and PJ-group (n=56). The primary end point was the rate of POPF. Secondary goals were duration of operation, length of hospital stay, length of stay on intermediate care units and hospital mortality.

Results

The rate of POPF (biochemical leak, POPF "grade B" and POPF "grade C") was less in the Blumgart-group, but without statistical relevance (p=0.23). Significantly less was the rate of POPF "grade C" in the Blumgart-group (p=0.03). Regarding the duration of hospital stay, length of stay on intermediate care units and hospital mortality, there was no relevant statistical difference between the groups (p=0.1; p=0.4; p=0.7). The duration of the operation was significantly less in the Blumgart-group (p=0.001).

Conclusions

The modified Blumgart anastomosis technique may have the potential to decrease major postoperative pancreatic fistula.

Blumgart anastomosis reduces the incidence of pancreatic fistula after pancreaticoduodenectomy: a systematic review and meta-analysis

Postoperative pancreatic fistula (POPF) is the most serious complication after pancreaticoduodenectomy (PD). Recently, Blumgart anastomosis (BA) has been found to have some advantages in terms of decreasing POPF compared with other pancreaticojejunostomy (PJ) using either the duct-to-mucosa or invagination approach. Therefore, the aim of this study was to examine the safety and effectiveness of BA versus non-Blumgart anastomosis after PD. The PubMed, EMBASE, Web of Science and the Cochrane Central Library were systematically searched for studies published from January 2000 to March 2020. One RCT and ten retrospective comparative studies were included with 2412 patients, of whom 1155 (47.9%) underwent BA and 1257 (52.1%) underwent non-Blumgart anastomosis. BA was associated with significantly lower rates of grade B/C POPF (OR 0.38, 0.22 to 0.65; P = 0.004) than non-Blumgart anastomosis. Additionally, in the subgroup analysis, the grade B/C POPF was also reduced in BA group than the Kakita anastomosis group. There was no significant difference regarding grade B/C POPF in terms of soft pancreatic texture between the BA and non-Blumgart anastomosis groups. In conclusion, BA after PD was associated with a decreased risk of grade B/C POPF. Therefore, BA seems to be a valuable PJ to reduce POPF comparing with non-Blumgart anastomosis.

Is Invagination Anastomosis More Effective in Reducing Clinically Relevant Pancreatic Fistula for Soft Pancreas After Pancreaticoduodenectomy Under Novel Fistula Criteria: A Systematic Review and Meta-Analysis

Objective: To define the effectiveness of different anastomosis on clinically relevant postoperative fistula in patients with soft pancreas using the newest version of the fistula definition and criteria.

Background: Different criteria of clinically relevant postoperative pancreatic fistula (POPF) result in the optimal anastomosis technique remaining controversial.

Methods: PubMed, Embase, Web of Science, the Cochrane Central Library, and ClinicalTrials.gov were systematically searched up to 20 April 2020, and were evaluated by Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. Randomized controlled trials comparing duct-to-mucosa anastomosis vs. invagination anastomosis in pancreatic surgery were included.

Result: Seven studies involving 1,110 participants were included. Using the postoperative pancreatic fistula definition provided by the International Study Group of Pancreatic Surgery 2016, the incidence rate of grade B/C pancreatic fistula was significantly lower in patients experiencing invagination anastomosis than in those undergoing duct-to-mucosa anastomosis. Four of seven trials comparing invagination with duct-to-mucosa anastomosis in patients with a soft pancreas showed that invagination was significantly better than duct-to-mucosa anastomosis in controlling pancreatic fistula formation, but no significant difference was detected between the two anastomosis techniques in patients with a hard pancreas. No significant difference in the length of hospital stay or postoperative mortality rate was found between the two methods.

Conclusion: This study demonstrated superiority of invagination anastomosis over duct-to-mucosa anastomosis in reducing the risk of Grade B/C postoperative pancreatic fistula using the ISGPS 2016 definition, but it does not significantly reduce the mortality rate or length of hospital stay. The effect of invagination in reducing pancreatic fistula formation is obvious in patients with a soft pancreas, but there is no significant difference between the two anastomosis techniques in patients with a hard pancreas. We found a lower rate of clinically relevant postoperative pancreatic fistula in the invagination group, in patients with a soft pancreas.