Pancreatic injury response is different depending on the method of resecting the parenchyma

How alcohol induces human acute alcoholic pancreatitis - problem solved?

It has been a puzzle why only minority of heavy alcohol drinkers develop acute alcoholic pancreatitis. In this review the sparse data available in published studies were collected and based on them formed a hypothesis. Long-term high alcohol consumption results in lowered cholecystokinin and cholinergic stimulus of the pancreas. Alcohol causes also concentration and acidification of pancreatic juice, predisposing to protein precipitation. Early during the withdrawal period when returning to normal or high fat non-alcoholic diet, there is a relative hyperstimulation of the pancreas, a well-established mechanism to result in experimental acute pancreatitis. Lower, physiological stimulation is enough to start acute pancreatitis, when the precipitations cause temporary obstruction in the duct system - the stimulation against temporary obstruction is also well-known to result in experimental acute pancreatitis. The magnitude of alcohol induced deficits in acinar cell defense mechanisms then finally determines the onset of pancreatitis.

Monopolar electrocautery versus scalpel for pancreatic neck transection during open pancreatoduodenectomy: A retrospective, registry-based study

BACKGROUND

The method of transecting the pancreatic parenchyma during pancreatic resection may influence the rate of complications, including pancreatic fistula and bleeding. The objective of this study was to compare the transection of the pancreatic parenchyma during pancreatoduodenectomy with monopolar electrocautery versus scalpel in terms of postoperative complications.

METHODS

A retrospective analysis of patients with open pancreatoduodenectomy from the German DGAV StuDoQ|Pancreas registry (January 2013 to December 2021) was performed. Transection of the pancreatic parenchyma with a scalpel versus monopolar electrocautery was compared regarding postoperative pancreatic fistula B/C, post-pancreatectomy hemorrhage B/C, and major complications (Clavien-Dindo classification ≥3) rates. Multivariable analysis with adjustment for potential confounders and surgical center cluster effect was performed.

RESULTS

Overall, 6,752 patients were included in the study. In 4,072 (60.3%), transection was performed with a scalpel and, in 2,680 (39.7%), with electrocautery. Transection with electrocautery was associated with higher postoperative pancreatic fistula B/C (15.4% vs 12.8%; P = .003), post-pancreatectomy hemorrhage B/C (11% vs 7.4%; P < .001), and major complications (33.4% vs 29.6%; P = .001) rates. In the multivariable analysis, after adjustment for potential confounders and surgical center, the association of the transection method with postoperative pancreatic fistula B/C (odds ratio = 1.01; 95% CI, 0.79-1.2; P = .962), post-pancreatectomy hemorrhage B/C (odds ratio = 1.23; 95% CI, 0.94-1.6; P = .127), and major complications (odds ratio = 1.09; 95% CI, 0.93-1.27; P = .297) was not significant.

CONCLUSION

The study found no significant association between transection of the pancreatic parenchyma during open pancreatoduodenectomy with a scalpel compared with monopolar electrocautery regarding pancreatic fistula, postoperative bleeding, or overall major complication rates.

Incidence and risk factors of postoperative acute pancreatitis after pancreaticoduodenectomy: a systematic review and meta-analysis

Background

Postoperative acute pancreatitis (POAP) is a specific complication after pancreatectomy. The acute inflammatory response of the residual pancreas may affect the healing of pancreatoenteric anastomoses, leading to postoperative pancreatic fistulas (POPFs), abdominal infections, and even progressive systemic reactions, conditions that negatively affect patients' prognoses and can cause death. However, to the best of our knowledge, no systematic reviews or meta-analytic studies have assessed the incidence and risk factors of POAP after pancreaticoduodenectomy (PD).

Method

We searched PubMed, Web of Science, Embase, and Cochrane Library databases for relevant literature describing the outcomes of POAP after PD until November 25, 2022, and we used the Newcastle-Ottawa Scale to assess the quality of the studies. Next, we pooled the incidence of POAP and the odds ratios (ORs) and 95% confidence intervals (CIs) of the risk factors using a random-effect meta-analysis. I2 tests were used to assess heterogeneity between the studies.

Results

We analyzed data from 7,164 patients after PD from 23 articles that met the inclusion criteria for this study. The subgroup results of the meta-analysis by different POAP diagnostic criteria showed that the incidences of POAP were 15% (95% CI, 5-38) in the International Study Group for Pancreatic Surgery group, 51% (95% CI, 42-60) in the Connor group, 7% (95% CI, 2-24) in the Atlanta group, and 5% (95% CI, 2-14) in the unclear group. Being a woman [OR (1.37, 95% CI, 1.06-1.77)] or having a soft pancreatic texture [OR (2.56, 95% CI, 1.70-3.86)] were risk factors of POAP after PD.

Conclusion

The results showed that POAP was common after PD, and its incidence varied widely according to different definitions. Large-scale reports are still needed, and surgeons should remain aware of this complication.

Systematic Review Registration

identifier: CRD42022375124.

Irreversible electroporation of the pancreas is feasible and safe in a porcine survival model

OBJECTIVES

Use of thermal tumor ablation in the pancreatic parenchyma is limited because of the risk of pancreatitis, pancreatic fistula, or hemorrhage. This study aimed to evaluate the feasibility and safety of irreversible electroporation (IRE) in a porcine model.

METHODS

Ten pigs were divided into 2 study groups. In the first group, animals received IRE of the pancreatic tail and were killed after 60 minutes. In the second group, animals received IRE at the head of the pancreas and were followed up for 7 days. Clinical parameters, computed tomography imaging, laboratory results, and histology were obtained.

RESULTS

All animals survived IRE ablation, and no cardiac adverse effects were noted. Sixty minutes after IRE, a hypodense lesion on computed tomography imaging indicated the ablation zone. None of the animals developed clinical signs of acute pancreatitis. Only small amounts of ascites fluid, with a transient increase in amylase and lipase levels, were observed, indicating that no pancreatic fistula occurred.

CONCLUSIONS

This porcine model shows that IRE is feasible and safe in the pancreatic parenchyma. Computed tomography imaging reveals significant changes at 60 minutes after IRE and therefore might serve as an early indicator of therapeutic success. Clinical studies are needed to evaluate the efficacy of IRE in pancreatic cancer.

Laparoscopic pancreaticoduodenectomy: a systematic literature review

BACKGROUND

Laparoscopic pancreaticoduodenectomy (LPD) is gaining momentum, but there is still uncertainty regarding its safety, reproducibility, and oncologic appropriateness. This review assesses the current status of LPD.

METHODS

Our literature review was conducted in Pubmed. Articles written in English containing five or more LPD were selected.

RESULTS

Twenty-five articles matched the review criteria. Out of a total of 746 LPD, 341 were reported between 1997 and 2011 and 405 (54.2 %) between 2012 and June 1, 2013. Pure laparoscopy (PL) was used in 386 patients (51.7 %), robotic assistance (RA) in 234 (31.3 %), laparoscopic assistance (LA) in 121 (16.2 %), and hand assistance in 5 (0.6 %). PL was associated with shorter operative time, reduced blood loss, and lower rate of pancreatic fistula (vs LA and RA). LA was associated with shorter operative time (vs RA), but with higher blood loss and increased incidence of pancreatic fistula (vs PL and RA). Conversion to open surgery was required in 64 LPD (9.1 %). Operative time averaged 464.3 min (338-710) and estimated blood 320.7 mL (74-642). Cumulative morbidity was 41.2 %, and pancreatic fistula was reported in 22.3 % of patients (4.5-52.3 %). Mean length of hospital stay was 13.6 days (7-23), showing geographic variability (21.9 days in Europe, 13.0 days in Asia, and 9.4 days in the US). Operative mortality was 1.9 %, including one intraoperative death. No difference was noted in conversion rate, incidence of pancreatic fistula, morbidity, and mortality when comparing results from larger (≥30 LPD) and smaller (≤29 LPD) series. Pathology demonstrated ductal adenocarcinoma in 30.6 % of the specimens, other malignant tumors in 51.7 %, and benign tumor/disease in 17.5 %. The mean number of lymph nodes examined was 14.4 (7-32), and the rate of microscopically positive tumor margin was 4.4 %.

CONCLUSIONS

In selected patients, operated on by expert laparoscopic pancreatic surgeons, LPD is feasible and safe.

Difference in Early Activation of NF-κB and MCP-1 in Acinar-Cell-Rich versus Fibrotic Human Pancreas Exposed to Surgical Trauma and Hypoxia

Objectives. Previously we have shown that a pancreas with over 40% acinar cells is exposed to postoperative pancreatitis and other complications after pancreaticoduodenectomy (PD). Our aim was to analyze the expression of NF-κB and MCP-1 in the cut edge of human pancreas after PD in both acinar-cell-rich and fibrotic pancreata. Methods. Several pancreatic samples from six patients, three with acinar-cell-rich and three with fibrotic pancreata, were exposed to surgical trauma in PD, and thereafter to hypoxemia for 15 minutes, 2-2.5 hours, 4 hours, or 6 hours, to mimic postoperative conditions of the pancreatic remnant in a patient. Immunohistochemical analysis of inflammation markers (NF-κB, MCP-1) was performed. Results. In the acinar-cell-rich pancreata, intra-acinar NF-κB and MCP-1 expression increased from mild at 15 minutes to high during the first 4 hours, whereas in ductal cells MCP-1 staining was highly intense at both time points. Acinar cell NF-κB and MCP-1 expression and ductal cell MCP-1 expression were also observed in the fibrotic pancreata, but the activation remained low throughout the 6 hours. Conclusions. In acinar-cell-rich pancreas, an extensive inflammatory cascade begins almost immediately after surgical trauma. Fibrosis may limit the progression of inflammatory process in pancreas.

Pancreaticodigestive anastomosis and the postoperative management strategies to prevent postoperative pancreatic fistula formation after pancreaticoduodenectomy

Over the past 100 years, advances in surgical techniques and perioperative management have reduced the morbidity and mortality after pancreaticoduodenectomy (PD). Many techniques have been proposed for the reconstruction of the pancreaticodigestive anastomosis to prevent the development of a postoperative pancreatic fistula (POPF), but which is the best approach is still highly debated. We carried out a systematic review to determine and compare the effectiveness of various methods of anastomosis after PD. A meta-analysis and most randomized controlled trials (RCTs) showed that the mortality, POPF rate and incidence of other postoperative complications were not statistically different between the pancreaticogastrostomy and pancreaticojejunostomy (PJ) groups. One RCT showed that a binding PJ significantly decreased the risk of POPF and other postoperative complications compared with conventional PJ. External duct stenting reduced the risk of clinically relevant POPF in a meta-analysis and RCTs. The prophylactic use of octreotide after PD does not result in a reduced incidence of POPF. In conclusion, our findings suggest that the successful management of pancreatic anastomoses may depend more on the meticulous surgical technique, surgical volume, and other management parameters than on the type of technique used. However, some new approaches, such as binding PJ, and the use of external stents should be considered in further RCTs.

Ultrasonic dissection versus conventional dissection techniques in pancreatic surgery: a randomized multicentre study

OBJECTIVE

: This prospective randomized multicenter trial was performed to assess the potential benefits of ultrasonic energy dissection compared with conventional dissection techniques in pancreatic surgery.

BACKGROUND

: Surgical procedures for tumors of the pancreatic head involve time-consuming manual dissection. The primary hypothesis was that use of ultrasonic tissue and vessel dissection would lead to substantial saving in operative time during pancreatic resection.

METHODS

: Patients eligible for pancreaticoduodenectomy (PD) or pylorus-preserving PD (PPPD) were randomized to group A (dissection with ultrasonic device) or group B (conventional dissection) from March 2009 to May 2011. The primary endpoint was overall duration of operation time. Secondary endpoints were time to end of resection phase, intraoperative blood loss, number of transfused units of blood, and postoperative morbidity.

RESULTS

: Analysis of primary and secondary endpoints included 101 patients, who received either PD or PPPD. Demographical characteristics and clinical parameters were similar in both groups. The use of an ultrasonic dissection device did not significantly reduce overall operation time (median 316 minutes in group A and 319 minutes in group B, P = 0.95) and did not significantly increase the costs of surgery. Analysis of secondary endpoints revealed no difference in postoperative course.

CONCLUSIONS

: Tissue dissection and vessel closure using an ultrasonic device is equivalent to dissection with conventional techniques in pancreatic surgery.

The risk for immediate postoperative complications after pancreaticoduodenectomy is increased by high frequency of acinar cells and decreased by prevalent fibrosis of the cut edge of pancreas

OBJECTIVES

Soft pancreas is considered as a factor for pancreatitis after pancreaticoduodenectomy, which in turn constitutes a high risk for local complications. The aim was to analyze the proportion of different cell types in the cut edge of pancreas (CEP) in relation to postoperative pancreatitis and other complications after pancreaticoduodenectomy.

METHODS

Data from postoperative follow-up was collected on 40 patients who had undergone pancreaticoduodenectomy. Positive urine trypsinogen-2, an early detector of pancreatitis, was checked on days 1 to 6 after operation. Drain amylase was measured on postoperative day 3. Anastomotic leakages, delayed gastric emptying, and other complications were registered. The areas of different cell types were calculated from the entire hematoxylin-eosin-stained section of CEP.

RESULTS

High frequency of acinar cells in the CEP significantly increased positive urine trypsinogen-2 days, drain amylase values, and delayed gastric emptying. In a subgroup of patients with more than 40% acini in the CEP, there were significantly more postoperative complications. Increased fibrosis correlated with a small number of positive urine trypsinogen-2 days and postoperative complications.

CONCLUSIONS

A large number of acinar cells in the CEP increases, whereas extensive fibrosis in the CEP decreases, the risk for postoperative complications after pancreaticoduodenectomy. These results emphasize the importance of acini in the development of postoperative complications.

Theoretical considerations of tissue electroporation with high-frequency bipolar pulses

This study introduces the use of high-frequency pulsed electric fields for tissue electroporation. Through the development of finite element models and the use of analytical techniques, electroporation with rectangular, bipolar pulses is investigated. The electric field and temperature distribution along with the associated transmembrane potential development are considered in a heterogeneous skin fold geometry. Results indicate that switching polarity on the nanosecond scale near the charging time of plasma membranes can greatly improve treatment outcomes in heterogeneous tissues. Specifically, high-frequency fields ranging from 500 kHz to 1 MHz are best suited to penetrate epithelial layers without inducing significant Joule heating, and cause electroporation in underlying cells.

Theoretical study for the treatment of pancreatic cancer using electric pulses

Through the development of numerical models, this study describes how Non-Thermal Irreversible Electroporation (N-TIRE) of the pancreas presents certain challenges that can be alleviated through the use of non-puncturing plate electrodes and ultra-short electric pulses.