Closure method for thick pancreas stump after distal pancreatectomy: soft coagulation and polyglycolic acid felt with fibrin glue

Dual-layer nanofibrous PCL/gelatin membrane as a sealant barrier to prevent postoperative pancreatic leakage

Post-operative pancreatic leakage is a severe surgical complication that can cause internal bleeding, infections, multiple organ damage, and even death. To prevent pancreatic leakage and enhance the protection of the suture lining and tissue regeneration, a dual-layer nanofibrous membrane composed of synthetic polymer polycaprolactone (PCL) and biopolymer gelatin was developed. The fabrication of this dual-layer (PGI-PGO) membrane was achieved through the electrospinning technique, with the inner layer (PGI) containing 2% PCL (w/v) and 10% gelatin (w/v), and the outer layer (PGO) containing 10% PCL (w/v) and 10% gelatin (w/v) in mixing ratios of 2:1 and 1:1, respectively. Experimental results indicated that a higher gelatin content reduced fiber diameter enhanced the hydrophilicity of the PGI layer compared to the PGO layer, improved the membrane's biodegradability, and increased its adhesive properties. In vitro biocompatibility assessments with L929 fibroblast cells showed enhanced cell proliferation in the PGI-PGO membrane. In vivo studies confirmed that the PGI-PGO membrane effectively protected the suture line without any instances of leakage and promoted wound healing within four weeks post-surgery. In conclusion, the nanofibrous PGI-PGO membrane demonstrates a promising therapeutic potential to prevent postoperative pancreatic leakage.

Multi-functional dual-layer nanofibrous membrane for prevention of postoperative pancreatic leakage

Postoperative pancreatic leakage due to pancreatitis in patients is a life-threatening surgical complication. The majority of commercial barriers are unable to meet the demands for pancreatic leakage due to poor adhesiveness, toxicity, and inability to degrade. In this study, we fabricated mitomycin-c and thrombin-loaded multifunctional dual-layer nanofibrous membrane with a combination of alginate, PCL, and gelatin to resolve the leakage due to suture line disruption, promote hemostasis, wound healing, and prevent postoperative tissue adhesion. Electrospinning was used to fabricate the dual-layer system. The study results demonstrated that high gelatin and alginate content in the inner layer decreased the fiber diameter and water contact angle, and crosslinking allowed the membrane to be more hydrophilic, making it highly biodegradable, and adhering firmly to the tissue surfaces. The results of in vitro biocompatibility and hemostatic assay revealed that the dual-layer had a higher cell proliferation and showed effective hemostatic properties. Moreover, the in vivo studies and in silico molecular simulation indicated that the dual layer was covered at the wound site, prevented suture disruption and leakage, inhibited hemorrhage, and reduced postoperative tissue adhesion. Finally, the study results proved that dual-layer multifunctional nanofibrous membrane has a promising therapeutic potential in preventing postoperative pancreatic leakage.

Assessing Intra-abdominal status for clinically relevant postoperative pancreatic fistula based on postoperative fluid collection and drain amylase levels after distal pancreatectomy

Aim

The aim of this study was to evaluate the intra-abdominal status related to postoperative pancreatic fistula by combining postoperative fluid collection and drain amylase levels.

Methods

We retrospectively reviewed the data of 203 patients who underwent distal pancreatectomy and classified their postoperative abdominal status into four groups based on postoperative fluid collection size and drain amylase levels. We also evaluated the incidence of clinically relevant postoperative pancreatic fistula in each group according to C-reactive protein values.

Results

The incidence of clinically relevant postoperative pancreatic fistula in the entire cohort (n = 203) was 28.1%. Multivariate analysis revealed that postoperative fluid collection, drain amylase levels, and C-reactive protein levels are considerable risk factors for clinically relevant postoperative pancreatic fistula. In the subgroup with large postoperative fluid collection and high drain amylase levels, 65.9% of patients developed clinically relevant postoperative pancreatic fistula. However, no significant difference was observed in C-reactive protein levels between patients with clinically relevant postoperative pancreatic fistula and those without it. In contrast, in the subgroup with a large postoperative fluid collection size or a high amylase level alone, a significant difference was observed in C-reactive protein values between the patients with clinically relevant postoperative pancreatic fistula and those without it.

Conclusion

Postoperative fluid collection status and the C-reactive protein value provide a more precise assessment of intra=abdominal status related to postoperative pancreatic fistula after distal pancreatectomy. This detailed analysis may be a clinically reasonable approach to individual drain management.

The utility of bile juice culture analysis for the management of postoperative infection after pancreaticoduodenectomy

BACKGROUND

Surgical site infections are common after pancreaticoduodenectomy. Our institution routinely performs intraoperative bile culture with pancreaticoduodenectomy. Herein we examined whether antibiotic selection based on bile culture analysis reduced the surgical site infection risk after pancreaticoduodenectomy.

METHODS

A total of 349 patients underwent pancreaticoduodenectomy with intraoperative bile cultures in our institution between 2008 and 2019. Patients were categorized into "group A" (196 patients who underwent pancreaticoduodenectomy between 2008 and 2013) or "group B" (153 patients who underwent pancreaticoduodenectomy between 2018 and 2019). Group A received cefazoline perioperatively and for 2 days postoperatively, whereas group B received piperacillin-tazobactam instead based on the bile culture findings in group A.

RESULTS

In group A, 91 (46.4%) intraoperative bile cultures were positive, and surgical site infections occurred in 61 patients (31.1%). A total of 32 patients had both positive bile culture and surgical site infection, of whom 23 (71.9%) exhibited the same microorganisms in the biliary and surgical site infection cultures. Due to the common finding of cefazoline-resistant Enterococcus spp. and Enterobacter spp. in group A, group B received piperacillin-tazobactam. Surgical site infection incidence in group B was 18.3% (n = 28), which was significantly lower than in group A (P = .006). Cefazoline-resistant Enterococcus spp. and Enterobacter spp., respectively, were cultured in 69.8% and 24.3% of patients with preoperative biliary drainage, compared with 32.2% and 9.7% of patients without preoperative biliary drainage.

CONCLUSION

The perioperative selection of antibiotics based on bile culture findings at pancreaticoduodenectomy can reduce the incidence of surgical site infection.

Efficacy of electrocoagulation hemostasis: a study on the optimal usage of the very-low-voltage mode

BACKGROUND

The very-low-voltage (VLV) mode in electrosurgery can stably and deeply energize tissues even if the local electrical resistance changes with energization. Therefore, in electrosurgical hemostasis, the VLV mode is more reliable than other coagulation modes. In clinical practice, the appropriate use of combined saline drip and blood suction under the VLV mode can further enhance coagulation ability. However, the detailed mechanism is not known. The current study aimed to evaluate the association between electrosurgical activation time (ET) and hemostatic tissue effect (HTE) under the VLV mode. Further, the effect of saline drip and suction on power consumption and HTE was validated.

METHODS

Twelve female pigs weighing 35 kg were included in the experiment. A liver hemorrhage model was established via an open abdominal procedure, and hemostasis in the hemorrhagic lesion was attempted using the VLV mode under different conditions (ET: 3, 6, 9, and 12 s, with/without saline drip and/or continuous suction). Electrical data (such as voltage, current, and resistance) during coagulation were extracted. Then, the vertical/horizontal extent of HTE was assessed, and the hemostasis outcome (successful or failed) was recorded.

RESULTS

The vertical/horizontal HTE, power consumption, and integrated current value were positively correlated with the ET. The coagulation depth deepened with saline drip (p < 0.01). However, it was not affected by continuous suction (p = 0.20). The HTE area increased with saline drip (p < 0.01) and decreased with suction (p < 0.01). The power consumption and integrated current increased with saline drip (p < 0.01) and decreased with suction (p < 0.01). The success rate of hemostasis decreased with saline drip alone (31of 48 trials [success rate = 64.5%] in the saline drip group and 44/48 trials (success rate = 91.7%) in the control group). However, it improved with continuous suction (46/48 trials [success rate = 95.8%]).

CONCLUSION

The electrosurgical activation time was positively correlated with hemostatic tissue effect. Saline drip increased heat transfer efficiency but decreased the success rate of hemostasis. Therefore, the use of continuous suction in addition to saline drip increased hemostatic efficiency.

The clinical impact of modified transpancreatic mattress sutures with polyglactin 910 woven mesh on postoperative pancreatic fistula in distal pancreatectomy

BACKGROUND

We previously reported the stump closure method for the remnant pancreas in distal pancreatectomy, in which soft coagulation and polyglycolic acid felt attached with fibrin glue were utilized. Transpancreatic mattress suture with polyglactin 910 woven mesh was recently reported as a novel stump closure technique. We developed the modified transpancreatic mattress suture with polyglactin 910 woven mesh method, which combined our polyglycolic acid felt method with the transpancreatic mattress suture with polyglactin 910 woven mesh method.

METHODS

The polyglycolic acid felt group included patients undergoing distal pancreatectomy in whom the pancreatic stump was closed with the polyglycolic acid felt method from 2017 to 2018 (n = 54); whereas the modified transpancreatic mattress suture with polyglactin 910 woven mesh group included those whose stump was closed with the modified transpancreatic mattress suture with polyglactin 910 woven mesh method from 2019 to 2020 (n = 51). Perioperative parameters, including grade B/C postoperative pancreatic fistula (clinically relevant postoperative pancreatic fistula), were assessed according to the stump closure method.

RESULTS

The incidence of clinically relevant postoperative pancreatic fistula was significantly lower in the modified transpancreatic mattress suture with polyglactin 910 woven mesh group than in the polyglycolic acid felt group (7.8% vs 22.2%, P = .036). In multivariate analysis, the use of neoadjuvant chemoradiotherapy and the transpancreatic mattress suture with polyglactin 910 woven mesh method were independent factors for preventing clinically relevant postoperative pancreatic fistula (P = .011 and 0.0038, respectively). Moreover, in the modified transpancreatic mattress suture with polyglactin 910 woven mesh group, the incidence of clinically relevant postoperative pancreatic fistula in patients with a thick pancreas (≥13 mm, 6.7%) was comparably as low as that in patients with a thin pancreas (<13 mm, 9.5%).

CONCLUSION

The modified transpancreatic mattress suture with polyglactin 910 woven mesh method is an effective stump closure technique to prevent clinically relevant postoperative pancreatic fistula after distal pancreatectomy. Our results warrant further prospective investigation to evaluate the efficacy of the modified transpancreatic mattress suture with polyglactin 910 woven mesh method compared with other standard closure methods (eg, stapler closure or hand-sewn closure).

Postoperative aggressive diuresis prevents postoperative tissue edema and complications in patients undergoing distal pancreatectomy

PURPOSE

Intraoperative fluid restriction is reported to be associated with reduced postoperative tissue edema and decreased incidence of postoperative pancreatic fistula (POPF) in pancreatic surgery. However, there is limited information regarding the postoperative approach to prevent postoperative tissue edema and reduce POPF.

METHODS

Patients undergoing distal pancreatectomy from 2013 to 2018 in our institute were retrospectively enrolled (n = 128). The patients were classified into the two groups: an early diuresis group (ED group: patients administered diuretic agents on postoperative day 2 or earlier between 2016 and 2018, n = 69) and a conventional diuresis group (CD group: patients administered diuretic agents on postoperative day 3 or later between 2013 and 2015, n = 59). Postoperative tissue edema assessed by CT imaging and the incidence of clinically relevant POPF (CR-PF; grade B or C) were compared.

RESULTS

Postoperative tissue edema was significantly reduced in the ED group (p < 0.0001). The incidence of CR-PF was lower in the ED group (19% vs. 32%, p = 0.082), especially in patients with postoperative diuresis on POD 1 (12%, p = 0.044).

CONCLUSION

Early and aggressive postoperative diuresis potentially reduced postoperative visceral tissue edema. This postoperative approach to prevent tissue edema may reduce the incidence of CR-PF in pancreatic surgery.

Self-assembling peptide hydrogel SPG-178 as a pancreatic fistula-preventing agent

PURPOSE

Pancreatic fistula (PF) is a common and challenging complication after pancreatic surgery. The aim of this study was to investigate the efficacy of a new method for preventing PF utilizing self-assembling peptide hydrogel SPG-178 as a preclinical study.

METHODS

The degradability of SPG-178 was confirmed by mixing it with protease. A PF rat model was then established to investigate the efficacy of SPG-178 at preventing PF. After transecting the pancreatic duct toward the spleen, SPG-178 was attached to both sides of the pancreatic stump. The levels of amylase and lipase in both the serum and ascites were measured and surgical specimens investigated pathologically.

RESULTS

The hardness of SPG-178 did not change when treated with protease over a short period. The ascitic amylase level was significantly lower in rats treated with SPG-178 than rats who were not 3 days after transection of the pancreatic duct toward the spleen. Pathological examination showed fewer inflammatory cells and presence of a structure body on the surface of the pancreatic stump in the SPG-178-treated group. SPG-178 remained on the surface and many cells that covered it formed fibrous tissue or mesothelium.

CONCLUSION

Self-assembling peptide hydrogel SPG-178 has potential as a tool for preventing PF.

Management of the pancreatic transection plane after left (distal) pancreatectomy: Expert consensus guidelines by the International Study Group of Pancreatic Surgery (ISGPS)

BACKGROUND

The aim was to evaluate the various operative techniques and outcomes used to manage the pancreatic transection plane (or stump) during a left (distal) pancreatectomy and to develop expert consensus guidelines.

METHODS

Evidence-based, clinically relevant questions were discussed and then were circulated among members of the International Study Group of Pancreatic Surgery. After agreement on the questions and statements, voting in a 9-point Likert scale was used to gauge the level of objective support for each.

RESULTS

Studies using the International Study Group of Pancreatic Surgery definition of postoperative pancreatic fistula including 16 randomized trials were reviewed to generate a series of statements set into 14 domains. There was strong consensus in the following statements: there was no difference in the postoperative pancreatic fistula rate after left pancreatectomy between the handsewn and stapler techniques; a stapling technique could not be used in all cases of left pancreatectomy; the use of an energy-based tissue sealant or a chemical sealant device or combinations of these did not impact the postoperative pancreatic fistula rate; there was no difference in the postoperative pancreatic fistula rate between the open, laparoscopic, or robotic approaches; and there are 1 or more clinically important, patient-related risk factors associated with the postoperative pancreatic fistula rate. There was weak or conditional agreement on the use of prophylactic somatostatin analogs, stents, stump closure, stump anastomosis, and the role of abdominal drains.

CONCLUSION

Areas of strong consensus suggests a change in clinical practice and priority setting. Eight domains with lower agreement will require novel approaches and large multicenter studies to determine future key areas of practice.

Pancreatic parenchymal injection of ethanol and octreotide to induce focal pancreatic fibrosis in rats: Strategies to eliminate postoperative pancreatic fistula

BACKGROUND

Postoperative pancreatic fistula (POPF) is more likely to occur in a soft pancreas compared to a hard pancreas in which fibrosis has progressed. There is almost no leakage at the anastomosis site or cut surface of a hard pancreas. The aim of this study was to induce localized fibrosis at the cut surface of the pancreas in a rat model.

METHODS

Thirty-six rats were divided into three groups (group S: normal saline group; group E: ethanol group; and group O: octreotide group). Each rat was directly injected with a particular compound at the duodenal lobe of the pancreatic parenchyma. Each group was divided into three subgroups according to the time of post-injection sacrifice (1, 2, or 4 weeks). The hardness, suture holding capacity (SHC), and histological fibrosis grade of each pancreas were measured.

RESULTS

The hardness, SHC, and fibrosis grade of groups E and O were increased at week 1, with greater increases in group E (all P < 0.001). In a subgroup comparison, the hardness, SHC, and fibrosis grade of group E tended to decrease gradually over time, with no regular pattern evident in group O. A comparison between the injected site (duodenal lobe) and non-injected site (splenic lobe) of the pancreas revealed increases in the three parameters of group E only in the duodenal lobe, with increases in group O at both the duodenal and splenic lobes.

CONCLUSIONS

Parenchymal injection of ethanol and octreotide increased pancreatic fibrosis. Unlike octreotide, ethanol provoked localized fibrosis that was maintained over time. It is expected that ethanol injection could eliminate POPF during pancreatic surgery.

Engineered mesenchymal stem-cell-sheets patches prevents postoperative pancreatic leakage in a rat model

Post-operative pancreatic fistula (POPF) following pancreatic resection is a life-threatening surgical complication. Cell sheets were prepared and harvested using temperature-responsive culture dishes and transplanted as patches to seal POPF. Two different mesenchymal stem cell (MSC) sheets were compared in terms of the preventative ability for pancreatic leakage in a rat model. Both rat adipose-derived stem cell (rADSC) and bone marrow-derived stem cell (rBMSC) sheets were transplanted. Those rADSC and rBMSC sheets are created without enzymes and thus maintained their cell-cell junctions and adhesion proteins with intact fibronectin on the basal side, as well as characteristics of MSCs. The rats with post-pancreatectomy rADSC- or rBMSC-sheet patches had significantly decreased abdominal fluid leakage compared with the control group, demonstrated by MR image analysis and measurement of the volume of abdominal fluid. Amylase level was significantly lower in the rats with rADSC-sheet and rBMSC-sheet patches compared with the control groups. The rADSC sheet patches had increased adhesive and immune-cytokine profiles (ICAM-1, L-selectin, TIMP-1), and the rBMSC sheets had reduced immune reactions compared to the control. This is first project looking at the feasibility of tissue engineering therapy using MSC-sheets as tissue patches preventing leakage of abdominal fluid caused by POPF.

C-Reactive Protein/Albumin Ratio and Prognostic Nutritional Index Are Strong Prognostic Indicators of Survival in Resected Pancreatic Ductal Adenocarcinoma

Purpose: We evaluated the clinical importance, such as the occurrence of postoperative pancreatic fistula (POPF) or prognosis, of preoperative serum markers of chronic inflammation, nutrition, and immunity, as well as that of serum tumor markers after curative resection of pancreatic ductal adenocarcinomas (PDACs). Methods: Between 2006 and 2015, 43 patients with PDACs underwent curative resection at Tottori Prefectural Central Hospital. We analyzed which preoperative indicators (i.e., C-reactive protein/albumin ratio [CAR], neutrophil/lymphocyte ratio [NLR], prognostic nutritional index [PNI], carcinoembryonic antigen [CEA], and carbohydrate antigen 19-9 [CA 19-9]) were the most relevant risk factors for occurrence of POPF and poor patient survival. Results: POPF was detected in 8/43 (18.6%) patients. One patient died of pancreatic fistula at 2 months postoperatively. Among nine candidate factors (operative procedure, operation time, tumor stage, preoperative serum amylase, preoperative CAR, NLR, PNI, CEA, and CA 19-9), we did not identify any significant risk factor for the occurrence of POPF. The 5-year overall survival (OS) rate of the 43 patients was 22.4%, and the overall median survival time was 21 months. The multivariate OS analysis demonstrated that high CAR and low PNI were strong preoperative markers of poor prognosis independently of tumor stage. Conclusions: Preoperative CAR and PNI are useful prognostic markers for patients with operable PDACs.

Risk factors of postoperative pancreatic fistula after distal pancreatectomy using a triple-row stapler

PURPOSE

Postoperative pancreatic fistula (POPF) is one of the major complications in patients who undergo distal pancreatectomy (DP). Recently, dividing the pancreas by stapler is a commonly performed technique, however, POPF still occurs. Therefore, the purpose of this study was to investigate the risk factors for POPF after DP using a triple-row stapler.

METHODS

A total of 75 patients underwent DP using a triple-row stapler (Endo GIA™ Reloads with Tri-Staple™ Technology 60 mm; COVIDIEN, North Haven, CT, USA) at Yamanashi University from December 2012 to December 2016. The clinical risk factors for POPF after DP using a triple-row stapler were identified based on univariate and multivariate analyses.

RESULTS

Clinical POPF (ISGPF Grade B and C) was seen in 7 of 75 patients (9.3%). The body mass index (BMI) was significantly higher in the patients with POPF (26.8 ± 0.5 kg/m²) compared with the patients without POPF (21.4 ± 0.4 kg/m²; a cut-off value; 25.7 kg/m²). In addition, the patients with POPF were significantly younger than the patients without POPF (56.4 ± 5.6 vs 67.0 ± 1.5; a cut-off value was 57.0 years old).

CONCLUSIONS

BMI and age were found to be significant risk factors for POPF after DP using a triple-row stapler.

Comparison of surgical outcomes of three different stump closure techniques during distal pancreatectomy

BACKGROUND

To find the appropriate method of pancreatic transection during distal pancreatectomy (DP), we retrospectively compared post-operative complications including postoperative pancreatic fistula (POPF) according to the different types of pancreatic transection.

METHODS

This study included 169 patients who underwent pancreatic transection using an ultrasonic activated device (USAD) with transfixion of the pancreatic duct (DP-TF group, n = 89), USAD followed by pancreaticogastrostomy (DP-PG group, n = 44), and a reinforced linear tristapler (DP-ST, n = 36).

RESULTS

Overall and POPF-related complications in DP-PG group, and delayed gastric emptying (DGE) in DP-ST group were significantly lower than DP-TF group. There were no significant difference in overall complication, length of hospitalization and operative costs between DP-PG and DP-ST groups. Operative time was significantly longer in DP-PG group than others.

CONCLUSION

Both DP-PG and DP-ST are associated with better surgical outcomes. Regarding ease of surgical technique, shorter operative times, and similar medical costs, DP with a reinforced linear tristapler is a good choice during DP.

Risk factors for postoperative pancreatic fistula after laparoscopic distal pancreatectomy using stapler closure technique from one single surgeon

Laparoscopic distal pancreatectomy (LDP) is a safe and reliable treatment for tumors in the body and tail of the pancreas. Postoperative pancreatic fistula (POPF) is a common complication of pancreatic surgery. Despite improvement in mortality, the rate of POPF still remains high and unsolved. To identify risk factors for POPF after laparoscopic distal pancreatectomy, clinicopathological variables on 120 patients who underwent LDP with stapler closure were retrospectively analyzed. Univariate and multivariate analyses were performed to identify risk factors for POPF. The rate of overall and clinically significant POPF was 30.8% and13.3%, respectively. Higher BMI (≥25kg/m²) (p-value = 0.025) and longer operative time (p-value = 0.021) were associated with overall POPF but not clinically significant POPF. Soft parenchymal texture was significantly associated with both overall (p-value = 0.012) and clinically significant POPF (p-value = 0.000). In multivariable analyses, parenchymal texture (OR, 2.933, P-value = 0.011) and operative time (OR, 1.008, P-value = 0.022) were risk factors for overall POPF. Parenchymal texture was an independent predictive factor for clinically significant POPF (OR, 7.400, P-value = 0.001).