External pancreatic duct stent reduces pancreatic fistula: a meta-analysis and systematic review

Modulating pancreatic cancer microenvironment: The efficacy of Huachansu in mouse models via TGF-β/Smad pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Huachansu (HCS) is a traditional Chinese medicine obtained from the dried skin glands of Bufo gargarizans and clinical uses of HCS have been approved in China to treat malignant tumors. The traditional Chinese medicine theory states that HCS relieves patients with cancer by promoting blood circulation to remove blood stasis. Clinical observation found that local injection of HCS given to pancreatic cancer patients can significantly inhibit tumor progression and assist in enhancing the efficacy of chemotherapy. However, the material basis and underlying mechanism have not yet been elucidated.

AIM OF THE STUDY

To investigate the therapeutic potential of HCS for the treatment of pancreatic cancer in in situ transplanted tumor nude mouse model. Furthermore, this study sought to elucidate the molecular mechanisms underlying its efficacy and assess the impact of HCS on the microenvironment of pancreatic cancer. To identify the antitumor effect of HCS in in situ transplanted tumor nude mouse model and determine the Chemopreventive mechanism of HCS on tumor microenvironment (TME).

METHODS

Using the orthotopic transplantation nude mouse model with fluorescently labeled pancreatic cancer cell lines SW1990 and pancreatic stellate cells (PSCs), we examined the effect of HCS on the pancreatic ductal adenocarcinoma (PDAC) microenvironment based on the transforming growth factor β (TGF-β)/Smad pathway. The expression of TGF-β, smad2, smad3, smad4, collagen type-1 genes and proteins in nude mouse model were detected by qRT-PCR and Western blot.

RESULTS

HCS significantly reduced tumor growth rate, increased the survival rate, and ameliorated the histopathological changes in the pancreas. It was found that HCS concentration-dependently reduced the expression of TGF-β1 and collagen type-1 genes and proteins, decreased the expression of Smad2 and Smad3 genes, and downregulated the phosphorylation level of Smad2/3. Additionally, the gene and protein expression of Smad4 were promoted by HCS. Further, the promoting effect gradually enhanced with the rise of HCS concentration.

CONCLUSIONS

The results demonstrated HCS could regulate the activity of the TGF-β/Smad pathway in PDAC, improved the microenvironment of PDAC and delayed tumor progression. This study not only indicated that the protective mechanism of HCS on PDAC might be attributed partly to the inhibition of cytokine production and the TGF-β/Smad pathway, but also provided evidence for HCS as a potential medicine for PDAC treatment.

Gradient inflammation in the pancreatic stump after pancreaticoduodenectomy: Two case reports and review of literature

BACKGROUND

Postoperative pancreatic fistula (POPF) contributes significantly to morbidity and mortality after pancreaticoduodenectomy (PD). However, the underlying mechanisms remain unclear. This study explored this pathology in the pancreatic stumps and elucidated the mechanisms of POPF following PD.

CASE SUMMARY

Pathological analysis and 16S rRNA gene sequencing were performed on specimens obtained from two patients who underwent complete pancreatectomy for grade C POPF after PD. Gradient inflammation is present in the pancreatic stump. The apoptosis was lower than that in the normal pancreas. Moreover, neutrophil-dominated inflammatory cells are concentrated in the ductal system. Notably, neutrophils migrated through the ductal wall in acinar duct metaplasia-formed ducts. Additionally, evidence indicates that gut microbes migrate from the digestive tract. Gradient inflammation occurs in pancreatic stumps after PD.

CONCLUSION

The mechanisms underlying POPF include high biochemical activity in the pancreas, mechanical injury, and digestive reflux. To prevent POPF and address pancreatic inflammation and reflux, breaking the link with anastomotic dehiscence is practical.

Application of split pancreatic duct stent in laparoscopic pancreaticoduodenectomy

Laparoscopic pancreaticoduodenectomy (LPD) is a classic surgical method for diseases, such as tumors at the lower end of the common bile duct, pancreatic head, and benign and malignant tumors of the duodenum. Postoperative pancreatic fistula (POPF) is one of the most serious complications of LPD. To reduce the incidence of grade B or C POPF and other complications after LPD, we applied a split pancreatic duct stent combined with the characteristics of internal and external stent drainage. Between September 2020 and September 2022,12 patients underwent placement of the Split pancreatic duct stent during LPD. Data on basic characteristics of patients, surgical related indicators and postoperative POPF incidence were collected and analyzed. The results showed that the average operation time was 294.2 ± 36 minutes, average time for pancreaticojejunostomy was 35.9 ± 4.1 minutes, and average estimated blood loss was 204.2 ± 58.2 mL. Biochemical leakage occurred in 2 patients (16.7%), whereas no grade B or C POPF, 1 case (8.3%) had postoperative bleeding, and no death occurred within 30 days after the operation. Preliminary experience shows that the split pancreatic duct stent can effectively reduce the incidence of complications after LPD, especially grade B or C POPF.

Early and Sustained Elevation in Serum Pancreatic Amylase Activity: A Novel Predictor of Morbidity After Pancreatic Surgery

OBJECTIVE

To characterize early postoperative serum pancreatic amylase (spAMY) trends after pancreatic resections.

SUMMARY BACKGROUND DATA

A postoperative spAMY elevation is a common finding but uncertainties remain about its meaning and prognostic implications.

METHODS

Analysis of patients who consecutively underwent pancreatectomy from 2016 to 2019. spAMY activity was assessed from postoperative day (POD) 0 to 3. Different patterns of spAMY have been identified based on the spAMY standard range (10-52 U/l).

RESULTS

Three patterns were identified: (#1) spAMY values always < the lower limit of normal/within the reference range /a single increase in spAMY > upper limit of normal at any POD; (#2) Sustained increase in spAMY activity on POD 0 + 1; (#3) Sustained increase in spAMY activity including POD 1 + 2. Shifting through spAMY patterns was associated with increase morbidity (21% in #1 to 68% in #3 at POD 7; log rank < 0.001). Almost all severe complications (at least Clavien-Dindo ≥3) occurred in patients with pattern #3 (15% vs 3% vs 5% in #1 and #2 at POD 7, P = 0.006), without difference considering >3-times or >the spAMY normal limit ( P = 0.85). POPF (9% in #1 vs 48% in #3, P < 0.001) progressively increased across patterns. Pre-operative diabetes (OR 0.19), neoadjuvant therapy (OR 0.22), pancreatic texture (OR 8.8), duct size (OR 0.78), and final histology (OR 2.2) were independent predictors of pattern #3.

CONCLUSIONS

A sustained increase in spAMY activity including POD 1 + 2 (#3) represents an early postoperative predictor of overall and severe early morbidity. An early and dynamic evaluation of spAMY could crucially impact the subsequent clinical course with relevant prognostic implications.

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.

Pancreatic duct stents

Pancreatic duct stenting using endoscopy or surgery is widely used for the management of benign and malignant pancreatic diseases. Endoscopic pancreatic stents are mainly used to relieve pain caused by chronic pancreatitis and pancreas divisum, and to treat pancreatic duct disruption and stenotic pancreaticointestinal anastomosis after surgery. They are also used to prevent postendoscopic retrograde cholangiopancreatography pancreatitis and postoperative pancreatic fistula, treat pancreatic cancer, and locate radiolucent stones. Recent advances in endoscopic techniques, such as endoscopic ultrasonography and balloon enteroscopy, and newly designed stents have broadened the indications for pancreatic duct stenting. In this review we outlined the types, insertion procedures, efficacy, and complications of endoscopic pancreatic duct stent placement, and summarized the applications of pancreatic duct stents in surgery.

USE of Biodegradable STENTS in Pancreaticoduodenectomy: Initial Experience

Background. Plastic stents have been used to avoid postoperative pancreatic fistula (POPF) following Whipple's Pancreaticoduodenectomy (WPD), but they may cause some stent-related complications. Biodegradable stents have been recently introduced and might be a safe alternative. Here we present our initial experience with their use. Methods. Between March 1, 2020, and September 30, 2020, ten (10) consecutive patients underwent WPD. They all had conventional two-layer pancreaticojejunostomy with the placement of an internal biodegradable stent. They were assessed for technical feasibility, pancreatic leak, and stent-related complications. Results. The use of biodegradable stents was technically feasible in all patients, despite some difficulties in insertion due to stent stiffness and design. After a median follow-up period of 124 days, none of the patients suffered POPF. One patient had a biochemical pancreatic leak with no clinical significance. The median hospital stay was 7 days, and there were no stent-related complications. Conclusion. Biodegradable stents are technically feasible and safe in WPD with good short-term outcomes. They might provide a better alternative to plastic stents and their potential complications. Larger long-term studies are needed to validate efficacy and safety. Few modifications of the stent's design might be needed to facilitate use in open surgery.

Drain use in pancreatic surgery: Results from an international survey among experts in the field

BACKGROUND

Drain use in pancreatic surgery remains controversial. This survey sought to evaluate habits, experiences, and opinions of experts in the field on the use of drains to provide interesting insights for pancreatic surgeons worldwide.

METHODS

An online survey designed via Google Forms was sent in December 2020 to experienced surgeons of the International Study Group for Pancreatic Surgery.

RESULTS

Forty-two surgeons (42/63, 67%) completed the survey. During their career, 74% (31/42) performed personally >500 pancreatic resections; of these, 9 (21%) >1,500. Sixty-nine percent of the respondents (29/42) declared to always use drains during pancreatic resections and 17% (7/42) in >50% of the operations. For these participants, the use of drains does not increase but reduces the risk of pancreatic fistula and other complications, and more importantly, helps to detect them earlier and manage them better. By contrast, 2 surgeons (5%) declared to never apply drains, whereas other 4 (10%) use drains only in selective cases, deeming that drains increase the risk of infection and other complications. When applied, drains are managed very heterogeneously as for the type of drains, enzyme testing, and removal schedules. Four participants declared to practice continuous irrigation. Twenty-two surgeons (55%) remove drains routinely within the third postoperative day, other 11 (27.5%) only in selected cases, whereas 7 (17.5%) normally keep drains longer.

CONCLUSION

Despite plenty of publications on this topic, drain management in pancreatic surgery remains very heterogeneous. Safety and the surgeon´s personal experience seem to play a determining role.

Incidence of postoperative pancreatic fistula after using a defined pancreaticojejunostomy technique for laparoscopic pancreaticoduodenectomy: A prospective multicenter study on 1033 patients

OBJECTIVE

This prospective multicenter study aimed to study the incidence of postoperative pancreatice fistula using a defined technique of pancreaticojejunostomy (PJ) in laparoscopic pancreaticoduodenectomy (LPD).

BACKGROUND

PJ is a technically challenging and time-consuming procedure in LPD. Up to now, only a few small sample size studies have been reported on various PJ techniques in LPD, none of which has widely been accepted by surgeons.

METHODS

This prospective study enrolled consecutive patients who underwent LPD using a defined technique of PJ at four institutions in China between January 2017 and December 2020.

RESULTS

Of 1045 patients, after excluding 12 patients (1.2%) due to conversion to open surgery, 1033 patients were analysed. The males comprised of 57.12% (590/1033), and females 42.88% (443/1033), with a mean age of 59.00 years. The mean ± s.d. operation time was (270.2 ± 101.8) min. The median time for PJ was 24min (IQR = 20.0-30.0). The overall incidence of postoperative pancreatic fistula was 12.6%, including 67 patients (6.5%) with Grade A biochemical leak, 50 patients (4.8%) with Grade B, and 13 patients (1.3%) with Grade C pancreatic fistulas. The overall incidence of major complications (Clavien-Dindo score ≥3) was 6.3% and the 30-day mortality was 2.8%.

CONCLUSION

The pancreaticojejunostomy technique for LPD was safe, simple and reproduceable with favorable clinical outcomes. However, further validations using high-quality RCTs are still required to confirm the findings of this study.

Pancreatic adenocarcinoma: A review of recent paradigms and advances in epidemiology, clinical diagnosis and management

Pancreatic cancer is one of the dreaded malignancies for both the patient and the clinician. The five-year survival rate of pancreatic adenocarcinoma (PDA) is as low as 2% despite multimodality treatment even in the best hands. As per the Global Cancer Observatory of the International Agency for Research in Cancer estimates of pancreatic cancer, by 2040, a 61.7% increase is expected in the total number of cases globally. With the widespread availability of next-generation sequencing, the entire genome of the tumors is being sequenced regularly, providing insight into their pathogenesis. As invasive PDA arises from pancreatic intraepithelial neoplasia and mucinous neoplasm and intraductal papillary neoplasm, screening for them can be beneficial as the disease is curable with resection at an early stage. Routine preoperative biliary drainage has no role in patients suffering from PDA with obstructive jaundice. If performed, metallic stents are preferred over plastic ones. Minimally invasive procedures are preferred to open procedures as they have less morbidity. The duct-to-mucosa technique for pancreaticojejunostomy is presently widely practiced. The role of intraperitoneal drains after surgery for PDA is controversial. Neoadjuvant chemoradiotherapy has been proven to have a significant role both in locally advanced as well as in resectable PDA. Many new regimens and drugs have been added in the arsenal of chemoradiotherapy for metastatic disease. The roles of immunotherapy and gene therapy in PDA are being investigated. This review article is intended to improve the understanding of the readers with respect to the latest updates of PDA, which may help to trigger new research ideas and make better management decisions.

Pancreaticoduodenectomy and external Wirsung stenting: Our outcomes in 80 cases

INTRODUCTION

There is controversy regarding the ideal pancreaticojejunostomy technique after pancreaticoduodenectomy. Many authors consider the external Wirsung stenting technique to be associated with a low incidence of fistula, morbidity and mortality. We analyse our experience with this technique.

PATIENTS AND METHODS

A retrospective analysis of the morbidity and mortality of a series of 80 consecutive patients who had been treated surgically over a 6.5-year period for pancreatic head or periampullary tumors, performing pancreaticoduodenectomy and pancreaticojejunostomy with external Wirsung duct stenting.

RESULTS

Mean patient age was 68.3 ± 9 years, and the resectability rate was 78%. The texture of the pancreas was soft in 51.2% of patients and hard in 48.8%. Pylorus-preserving resection was performed in 43.8%. Adenocarcinoma was the most frequent tumor (68.8%), and R0 was confirmed in 70% of patients. Biochemical fistula was observed in 11.2%, pancreatic fistula grade B in 12.5% and C in 2.5%, whereas the abdominal reoperation rate was 10%. Median postoperative hospital stay was 16 days, and postoperative and 90-day mortality was 2.5%. Delayed gastric emptying was observed in 36.3% of patients, de novo diabetes in 12.5%, and exocrine insufficiency in 3. Patient survival rates after 1, 3 and 5 years were 80.2%, 53.6% and 19.2%, respectively.

CONCLUSIONS

Although our low rates of postoperative complications and mortality using external Wirsung duct stenting coincides with other more numerous recent series, it is necessary to perform a comparative analysis with other techniques, including more cases, to choose the best reconstruction technique after pancreaticoduodenectomy.

Clinical Impact of Portal Vein Distance on Computed Tomography for Postoperative Pancreatic Fistula after Pancreatoduodenectomy

BACKGROUND

Pancreatic fistulas remain a significant concern after pancreatectomy owing to the associated high risk of mortality and high costs. It is not possible to perform preoperative risk stratification for all patients. This study aimed to evaluate the usefulness of the measurement of portal vein (PV) distance as a predictive indicator of pancreatic fistula development after pancreatoduodenectomy and compare it with the usefulness of other indicators such as body mass index (BMI), and abdominal fat area.

METHODS

Patient characteristics, preoperative laboratory data, radiographic findings, and their association with pancreatic fistula development after pancreatoduodenectomy were analyzed for 157 patients who underwent resection during 2011-2017. Clinically relevant postoperative pancreatic fistulas (CR-POPF) were defined as Grade B or C fistulas based on the International Study Group of Pancreatic Surgery (ISGPS) 2016 consensus.

RESULTS

CR-POPF developed in 38 patients (24.2%). Multivariate logistic regression indicated that PV distance and BMI were potential candidates for predictive models for pancreatic fistula development, and small pancreatic duct diameter, diabetes mellitus development, and pathology of non-pancreatic cancers were independent factors for CR-POPF. When comparing the two risk models (PV distance- and BMI-based models), the PV distance-derived risk model was compatible to the BMI-based stratification models (area under the curve 0.831 vs. 0.830).

CONCLUSIONS

PV distance was confirmed to be a useful risk predictor for CR-POPF. This research highlighted the efficacy of abdominal thickness measurement, which is simple and easily applicable in the clinical setting.

Pancreaticoduodenectomy and external Wirsung stenting: our outcomes in 80 cases

INTRODUCTION

There is controversy regarding the ideal pancreaticojejunostomy technique after pancreaticoduodenectomy. Many authors consider the external Wirsung stenting technique to be associated with a low incidence of fistula, morbidity and mortality. We analyse our experience with this technique.

PATIENTS AND METHODS

A retrospective analysis of the morbidity and mortality of a series of 80 consecutive patients who had been treated surgically over a 6.5-year period for pancreatic head or periampullary tumors, performing pancreaticoduodenectomy and pancreaticojejunostomy with external Wirsung duct stenting.

RESULTS

Mean patient age was 68.3 ± 9 years, and the resectability rate was 78%. The texture of the pancreas was soft in 51.2% of patients and hard in 48.8%. Pylorus-preserving resection was performed in 43.8%. Adenocarcinoma was the most frequent tumor (68.8%), and R0 was confirmed in 70% of patients. Biochemical fistula was observed in 11.2%, pancreatic fistula grade B in 12.5% and C in 2.5%, whereas the abdominal reoperation rate was 10%. Median postoperative hospital stay was 16 days, and postoperative and 90-day mortality was 2.5%. Delayed gastric emptying was observed in 36.3% of patients, de novo diabetes in 12.5%, and exocrine insufficiency in 3. Patient survival rates after 1, 3 and 5 years were 80.2, 53.6 and 19.2%, respectively.

CONCLUSIONS

Although our low rates of postoperative complications and mortality using external Wirsung duct stenting coincides with other more numerous recent series, it is necessary to perform a comparative analysis with other techniques, including more cases, to choose the best reconstruction technique after pancreaticoduodenectomy.

Achilles'heel of laparoscopic pancreatectomy: reconstruction of the remnant pancreas

INTRODUCTION

Laparoscopic pancreatic reconstruction is a challenging procedure and is considered the Achilles' heel of laparoscopic pancreatectomy. Multiple techniques of laparoscopic pancreatic reconstruction have been reported, but the optimal technique remains unclear.

AREAS COVERED

This paper provides a brief introduction to the developmental status and major related complications of laparoscopic pancreatic reconstruction. We reviewed all published literature on the technology of laparoscopic pancreatic reconstruction within the last 5 years and herein discuss the advantages and disadvantages of different reconstruction methods. We also discuss several details of different reconstruction techniques in terms of their significance to the operation and complications.

EXPERT OPINION

No individual method of laparoscopic pancreatic reconstruction is considered optimal for all conditions. The reconstruction strategy should be based on the surgeon's proficiency with laparoscopic technology and the patient's individual risk factors. Personalized methods of pancreatic reconstruction may more effectively reduce morbidity and mortality.

Propensity score-matched analysis of internal stent vs external stent for pancreatojejunostomy during pancreaticoduodenectomy: Japanese-Korean cooperative project

BACKGROUND

Several studies comparing internal and external stents have been conducted with the aim of reducing pancreatic fistula after PD. There is still no consensus, however, on the appropriate use of pancreatic stents for prevention of pancreatic fistula. This multicenter large cohort study aims to evaluate whether internal or external pancreatic stents are more effective in reduction of clinically relevant pancreatic fistula after pancreaticoduodenectomy (PD).

METHODS

We reviewed 3149 patients (internal stent n = 1,311, external stent n = 1838) who underwent PD at 20 institutions in Japan and Korea between 2007 and 2013. Propensity score matched analysis was used to minimize bias from nonrandomized treatment assignment. The primary endpoint was the incidence of clinically relevant pancreatic fistula. This study was registered on the UMIN Clinical Trials Registry (UMIN000032402).

RESULTS

After propensity score matched analysis, clinically relevant pancreatic fistula occurred in more patients in the external stents group (280 patients, 28.7%) than in patients in the internal stents group (126 patients, 12.9%) (OR 2.713 [95% CI, 2.139-3.455]; P < 0.001). In subset analysis of a high-risk group with soft pancreas and no dilatation of the pancreatic duct, clinically relevant pancreatic fistula occurred in 90 patients (18.8%) in internal stents group and 183 patients (35.4%) in external stents group. External stents were significantly associated with increased risk for clinically relevant pancreatic fistula (OR 2.366 [95% CI, 1.753-3.209]; P < 0.001).

CONCLUSION

Propensity score matched analysis showed that, regarding clinically relevant pancreatic fistula after PD, internal stents are safer than external stents for pancreaticojejunostomy.

Pancreatic fistula rates after internal and external stenting of the pancreatojejunostomy anastomosis following pancreatoduodenectomy

Background: This retrospective comparative case series study aims to analyze the pancreatic fistula rates of internal and external stenting of the pancreatojejunostomy (PJ) anastomosis in patients who underwent pancreatoduodenectomy (PD) for periampullary tumors.Methods: Ninety-eight patients with periampullary tumors who were operated between 2010 and 2017 were enrolled in this study. A classic open PD with Roux-en-Y PJ reconstruction was performed in all cases.Results: The PJ anastomosis of 53 patients (54%) were stented internally whereas in 45 patients (46%) external stenting was preferred. Pancreatic fistula was observed in 29 patients (29.6%). Internal stenting and soft pancreatic tissue were found to be related to higher pancreatic fistula rates with odds ratios of 3.27 (p = .024) and 3.4 (p = .017), respectively. When only grade B and grade C fistulas were taken into account, the type of stenting has lost its significance but the texture of the remnant pancreas was still associated with 'clinically important' pancreatic fistula.Conclusions: We concluded that the external stenting of the PJ anastomosis may be considered as an effective approach for reducing postoperative pancreatic leaks in PD-planned patients for periampullary tumors. Although our study was retrospectively designed, we used standard charts to gather patient data and compared two stenting methods among homogeneous patient groups.

Pancreatic reconstruction techniques after pancreaticoduodenectomy: a review of the literature

Introduction: Postoperative pancreatic fistula is the most troublesome complication after pancreaticoduodenectomy, and is an on-going area of concern for pancreatic surgeons. The specific pancreatic reconstruction technique is an important factor influencing the development of postoperative pancreatic fistula after pancreaticoduodenectomy. Areas covered: In this paper, we briefly introduced the definition and relevant influencing factors of postoperative pancreatic fistula. We performed a search of all meta-analyses published in the last 5 years and all published randomized controlled trials comparing different pancreatic anastomotic techniques, and we evaluated the advantages and disadvantages of different techniques. Expert opinion: No individual anastomotic method can completely avoid postoperative pancreatic fistula. Selecting specific techniques tailored to the patient's situation intraoperatively may be key to reducing the incidence of postoperative pancreatic fistula.

Surgical techniques and postoperative management to prevent postoperative pancreatic fistula after pancreatic surgery

Postoperative pancreatic fistula (POPF) is one of the most severe complications after pancreatic surgeries. POPF develops as a consequence of pancreatic juice leakage from a surgically exfoliated surface and/or anastomotic stump, which sometimes cause intraperitoneal abscesses and subsequent lethal hemorrhage. In recent years, various surgical and perioperative attempts have been examined to reduce the incidence of POPF. We reviewed several well-designed studies addressing POPF-related factors, such as reconstruction methods, anastomotic techniques, stent usage, prophylactic intra-abdominal drainage, and somatostatin analogs, after pancreaticoduodenectomy and distal pancreatectomy, and we assessed the current status of POPF. In addition, we also discussed the current status of POPF in minimally invasive surgeries, laparoscopic surgeries, and robotic surgeries.

Proposal for a Safe and Functional Pancreaticojejunostomy Technique from a Histopathological Perspective

BACKGROUND

To prevent leakage of pancreatic juice from the main pancreatic duct (MPD), complete external drainage appears to be the most effective technique. However, because this requires a pancreatic stent tube to be ligated with MPD, duct-to-mucosa pancreaticojejunostomy (PJ) is difficult. From our histopathological examination, a large amount of pancreatic juice is drained from the ducts other than MPD. This study aimed to evaluate our new conceptual technique of PJ after pancreaticoduodenectomy (PD).

METHODS

We considered it important to drain pancreatic juice from the branch pancreatic ducts to the intestinal tract and to perform duct-to-mucosa PJ, while pancreatic juice from MPD is completely drained out of the body. We designed a technique that could simultaneously achieve these points. In our technique, which is based on conventional "two-row" anastomosis, a stent tube is fixed with MPD and its surrounding tissue by purse-string suture at the cut surface of the pancreas, and duct-to-mucosa PJ is concomitantly performed.

RESULTS

Of 45 patients undergoing PD, 12 of soft pancreas underwent surgery with this technique. According to the classification of the International Study Group on Pancreatic Fistula, a Grade A PF was observed in four patients, whereas no patient had a Grade B or C PF.

CONCLUSIONS

We propose our anastomotic technique that could simultaneously prevent PF and keep the pancreatic duct patent.

Implantation of amniotic membrane over pancreatic anastomosis after pancreaticoduodenectomy: report of the first case

The amniotic membrane (AM) has an increasing role as a scaffold for tissue repair due to its unique biological properties. The implantation of AM on pancreatic anastomosis after pancreaticoduodenectomy might improve the anastomotic healing and strengthen its structure, however has never been used in pancreatic surgery. We present the first application of AM after a pancreaticoduodenectomy was performed for a malignant tumor of the pancreatic head. After completing the pancreatic anastomosis, the AM was placed around the pancreatic anastomosis and fixed to it with single stiches. The AM, due to its physical characteristics, could be easily manipulated and adapted to the pancreatic anastomosis. This interesting and unique case shows that covering a pancreatic anastomosis with the AM is safe and technically feasible. The AM has no adverse effects while it may eventually provide a beneficial impact over the anastomotic healing.

Strategies for pancreatic anastomosis after pancreaticoduodenectomy: What really matters?

BACKGROUND

The postoperative pancreatic fistula rate remains approximately 10-20% even in institutions treating a high-volume of pancreatic cases. The best strategy to restore the continuity between the pancreatic remnant and the digestive tract is still in debate.

DATA SOURCES

Studies were identified by searching PubMed for studies published between January 1934 (when pancreaticogastrostomy was technically feasible) and December 2016. The following search terms were used: "duct-to-mucosa", "invagination", "pancreaticojejunostomy", "pancreaticogastrostomy," and "pancreaticoduodenectomy". The search was limited to English publications.

RESULTS

Many technical methods have been developed and optimized to restore pancreaticoenteric continuity, including pancreaticojejunostomy, pancreaticogastrostomy, and stented drainage of the pancreatic duct, among other modifications. Researchers have also attempted to decrease the postoperative pancreatic fistula after pancreaticoduodenectomy by using fibrin glue and somatostatin analogues. However, no significant decrease in postoperative pancreatic fistula has been observed in most of these studies, and only an external pancreatic duct stent has been found to decrease the leakage rate of pancreatic anastomosis after pancreaticojejunostomy.

CONCLUSION

Pancreatic surgeons should choose a suitable technique according to the characteristics of individual cases.

Comparison of patient outcomes with and without stenting tube in pancreaticoduodenectomy

Objective To evaluate the clinical effect of different pancreaticojejunostomy techniques in the treatment of pancreaticoduodenectomy and investigate the applicability of pancreaticojejunostomy without pancreatic duct stenting. Methods From January 2012 to December 2015, 87 patients who underwent pancreaticoduodenectomy were randomly assigned to either Group A (duct-to-mucosa anastomosis with pancreatic duct stenting, n = 43) or Group B (pancreas-jejunum end-to-side anastomosis without stenting (n = 44). The operative duration of pancreaticojejunostomy, postoperative hospital stay, and incidence of postoperative complications were compared between the two methods. Results The operative duration of pancreaticojejunostomy without use of the pancreatic duct stent was significantly shorter in Group B than in Group A (t = 7.137). The postoperative hospital stay was significantly shorter in Group B than in Group A (t = 2.408). The differences in the incidence of postoperative complications such as pancreatic fistula, abdominal bleeding, abdominal infection and delayed gastric emptying were not significantly different between the two groups (χ²= 0.181, 0.322, 0.603, and 0.001, respectively). Conclusion Pancreaticoduodenectomy without pancreatic duct stenting is safe and reliable and can reduce the operative time and hospital stay. No significant differences were observed in the incidence of postoperative complications.

Pancreatoduodenectomy (PD) and postoperative pancreatic fistula (POPF): A systematic review and analysis of the POPF-related mortality rate in 60,739 patients retrieved from the English literature published between 1990 and 2015

BACKGROUND

Pancreatoduodenectomy (PD) is one of the most technically demanding operations challenging surgeons, and a postoperative pancreatic fistula (POPF) can complicate an otherwise uneventful postoperative (PO) course. This review examined the methods and procedures used to prevent postoperative pancreatic fistula (POPF) after pancreatoduodenectomy (PD).

METHODS

A comprehensive systematic search of the literature was performed using PubMed (Medline), Embase, Web of science, and the Cochrane databases for studies published between January 1, 1990 and December 31, 2015. English language articles involving at least 100 patients undergoing PDs carried out in centers performing at least 10 PDs/y were screened for data regarding the Grade of any POPFs according to the definition of the International Study Group on Pancreatic Fistula (ISGPF) and the overall rate of PO mortality related to POPF.

RESULTS

We reviewed 7119 references through the major databases, and an additional 841 studies were identified by cross-checking the bibliographies of the full-text articles retrieved. After excluding 7379 out of 7960 studies, because they did not meet the eligibility criteria, the full texts of 581 articles were examined; 96 studies were excluded at this point, because they concerned partially or totally duplicate data that had already been reported. The remaining 485 articles were screened carefully for POPF-related mortality and POPF Grades as defined by the ISGPF. Of the 485 articles, 208 reported the POPF-related PO mortality rate and 162 the Grades (A, B, and C) of POPFs in 60,739 and 54,232 patients, respectively. The POPF-related mortality rates after pancreatojejunostomy and pancreatogastrostomy were similar but were less (0.5% vs. 1%; P = .014) when an externally draining, trans-anastomotic stent was placed intraoperatively. The incidence of the different Grades of POPF Grade was quite variable, but Grade C POPFs were associated with a PO mortality rate of 25.7% (range 0-100%).

CONCLUSIONS

The POPF-related mortality rate has remained at approximately 1% over the past 25 years. Only externally draining, trans-anastomotic stents decreased the POPF-related mortality rate. However, adequately designed venting drains were never tested in randomized controlled trials (RCTs).

Risk factors and preventive strategies for post-operative pancreatic fistula after pancreatic surgery: a comprehensive review

BACKGROUND

Pancreas surgery has developed into a fairly safe procedure in terms of mortality, but is still hampered by considerable morbidity. Among the most frequent and dreaded complications are the development of a post-operative pancreatic fistula (POPF). The prediction and prevention of POPF remains an area of debate with several questions yet to be firmly addressed with solid answers.

METHODS

A systematic review of systematic reviews/meta-analyses and randomized trials in the English literature (PubMed/MEDLINE, Cochrane library, EMBASE) covering January 2005 to December 2015 on risk factors and preventive strategies for POPF.

RESULTS

A total of 49 systematic reviews and meta-analyses over the past decade discussed patient, surgeon, pancreatic disease and intraoperative related factors of POPF. Non-modifiable factors (age, BMI, comorbidity) and pathology (histotype, gland texture, duct size) that indicates surgery are associated with POPF risk. Consideration of anastomotic technique and use of somatostatin-analogs may slightly modify the risk of fistula. Sealant products appear to have no effect. Perioperative bleeding and transfusion enhance risk, but is modifiable by focus on technique and training. Drains may not prevent fistulae, but may help in early detection. Early drain-amylase may aid in detection. Predictive scores lack uniform validation, but may have a role in patient information if reliable pre-operative risk factors can be obtained.

CONCLUSIONS

Development of POPF occurs through several demonstrated risk factors. Anastomotic technique and use of somatostatin-analogs may slightly decrease risk. Drains may aid in early detection of leaks, but do not prevent POPF.

Shen's Whole-Layer Tightly Appressed Anastomosis Technique for Duct-to-Mucosa Pancreaticojejunostomy in Pancreaticoduodenectomy

BACKGROUND Postoperative pancreatic fistulas (POPFs) due to anastomotic leaks are always closely related to significant morbidity and mortality following pancreaticoduodenectomy (PD). A series of modified anastomotic methods have been proposed. The object of our study was to provide a novel anastomotic method for operations involving the Child technique, termed the "whole-layer tightly appressed anastomosis technique". MATERIAL AND METHODS An improved pancreatic whole-layer suture technique was used when we performed the duct-to-mucosa pancreaticojejunostomies; this method ensured the tight joining of the pancreatic stump and jejunum and decreased the pinholes in the pancreatic stump. This new method was used in 41 patients, and was compared with the traditional duct-to-mucosa anastomosis technique that was used in 50 patients as controls. RESULTS The POPF rate was much lower in the new method group than in the control group (6, 14.63% and 20, 40.00%, respectively, P=0.010). There were 5 grade A POPF patients and 1 grade B POPF patient in the study group. In the control group there were 12 grade A POPFs patients, 7 grade B POPFs patients, and 1 grade C POPF patient. The study group exhibited a lower morbidity rate (7, 17.07% vs. 16, 32.00%, P=0.022) and a reduced hospital stay (17.16 d vs. 22.92 d, P=0.001). CONCLUSIONS The whole-layer tightly appressed anastomosis technique presented in our study is a safer anastomotic method than the traditional duct-to-mucosa pancreaticojejunostomy technique. This new technique effectively reduced the incidence of POPF after PD and decreased the postoperative morbidity.

Comparison of postoperative complications between internal and external pancreatic duct stenting during pancreaticoduodenectomy: a meta-analysis

BACKGROUND

Two types of pancreatic duct stents are used to improve postoperative outcomes of pancreatic anastomosis. The aim of this meta-analysis was to evaluate and compare the postoperative outcomes of patients with internal or external stenting during pancreaticoduodenectomy (PD).

METHODS

We searched PubMed, EMBASE, the Cochrane Library and Web of Science databases until the end of December, 2014. Studies comparing outcomes of external vs. internal stent placement in PD were eligible for inclusion. Included literature was extracted and assessed by two independent reviewers.

RESULTS

Seven articles were identified for inclusion: three randomized controlled trials (RCTs) and four observational clinical studies (OCS). The meta-analyses revealed that use of external stents had advantage on reducing the incidences of pancreatic fistula (PF) in total [odds ratio (OR) =0.69; 95% confidence interval (CI), 0.48-0.99; P=0.04], PF in soft pancreas (OR =0.30; 95% CI, 0.16-0.56; P=0.0002) and delayed gastric emptying (DGE) (OR =0.58; 95% CI, 0.38-0.89; P=0.01) compared with internal stents. There were no significant differences in other postoperative outcomes between two stenting methods, including postoperative morbidity (OR =0.93; 95% CI, 0.39-2.23; P=0.88), overall mortality (OR =0.70; 95% CI, 0.22-2.25; P=0.55), and intra-abdominal collections (OR =0.67; 95% CI, 0.26-1.71; P=0.40).

CONCLUSIONS

Based upon this meta-analysis, the use of external pancreatic stents might have potential benefit in reducing the incidence of PF and DGE. Due to the limited number of original studies, more RCTs are needed to further support our result and clarify the issue.