Intra-arterial bolus octreotide administration during Whipple procedure in patients with fragile pancreas: A novel technique for safer pancreaticojejunostomy

Focal change of the pancreatic texture using a direct injection mixture of N-butyl cyanoacrylate and lipiodol in the pig model: a strategy for preventing pancreatic leakage during pancreatic surgery

Purpose

A soft texture of the pancreas is one of the most important predisposing factors for a pancreatic fistula. Thus, in a porcine model, we investigated a method to harden the pancreas locally by directly injecting an artificial material.

Methods

During the laparotomy, 51 samples from 17 pigs, including 13 survival models, were randomly divided into 3 groups and either received a direct injection into the pancreas of MHL (1:4 mixture of histoacryl [n-butyl cyanoacrylate] and lipiodol) (group E) or saline (group C) or only received a pinprick into the pancreas without injecting a substance (sham). We measured the change in the pancreatic hardness after the injection using a durometer and examined the histological change of the pancreas using the fibrosis grade in the survival model.

Results

The postinjection hardness of the pancreas was significantly increased in group E compared to group C and the sham group (P < 0.001). Pathologically, all cases in group E showed a severe fibrotic change, whereas the other groups demonstrated mild to no fibrosis (P < 0.001). The fibrosis in group E was localized to the area of the injection, while the surrounding areas were preserved.

Conclusion

The direct injection of MHL could induce focal hardening and fibrotic changes in the pancreas of the porcine model.

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.

Developing Risk Prediction Models for Postoperative Pancreatic Fistula: a Systematic Review of Methodology and Reporting Quality

Postoperative pancreatic fistula is still a major complication after pancreatic surgery, despite improvements of surgical technique and perioperative management. We sought to systematically review and critically access the conduct and reporting of methods used to develop risk prediction models for predicting postoperative pancreatic fistula. We conducted a systematic search of PubMed and EMBASE databases to identify articles published before January 1, 2015, which described the development of models to predict the risk of postoperative pancreatic fistula. We extracted information of developing a prediction model including study design, sample size and number of events, definition of postoperative pancreatic fistula, risk predictor selection, missing data, model-building strategies, and model performance. Seven studies of developing seven risk prediction models were included. In three studies (42 %), the number of events per variable was less than 10. The number of candidate risk predictors ranged from 9 to 32. Five studies (71 %) reported using univariate screening, which was not recommended in building a multivariate model, to reduce the number of risk predictors. Six risk prediction models (86 %) were developed by categorizing all continuous risk predictors. The treatment and handling of missing data were not mentioned in all studies. We found use of inappropriate methods that could endanger the development of model, including univariate pre-screening of variables, categorization of continuous risk predictors, and model validation. The use of inappropriate methods affects the reliability and the accuracy of the probability estimates of predicting postoperative pancreatic fistula.

Effects of intra-arterial octreotide on pancreatic texture: a randomized controlled trial

BACKGROUND AND AIMS

Octreotide is suggested to harden the pancreas, thus facilitating the construction of a pancreatic anastomosis and lowering the risk of postoperative fistula. We tested the hypothesis that intra-arterial application of octreotide in the gastroduodenal artery during pancreatectomy may increase pancreatic hardness.

MATERIAL AND METHODS

A single-center, prospective, double-blinded, randomized controlled trial with parallel assignment was conducted. Patients planned for a pancreatoduodenectomy or a total pancreatectomy, who had a palpatory and durometer proven (<40 Shore units) soft pancreas, were assigned to receive intraoperatively either 5 mL 500µg octreotide or 5 mL 0.9% saline solution as a bolus injection in the gastroduodenal artery. Pancreatic hardness was measured before, early, and late after intervention. The investigator performing the durometer measurements and pathologist were masked to group assignment. The primary outcome was increased pancreatic hardness. Analysis was by intention to treat. This trial is registered at http://www.clinicaltrials.gov (ID NCT01400100).

RESULTS

A total of 12 patients received octreotide and 13 received saline solution. Pancreatic hardness marginally increased in the octreotide group: 0.67 ± 2.3 Shore units, whereas it decreased in the control group: -2.15 ± 2.7 Shore units. The difference was statistically significant, p = 0.029 (95% confidence interval = -4.87 to -0.77). Histology did not find any correlate for this clinically irrelevant hardening effect.

CONCLUSIONS

A single bolus application of octreotide did not deliver a clinically relevant increase in pancreatic hardness. Future studies on the hardening effect of octreotide should employ repeated or continuous preoperative administration of this drug.

Histomorphological features of the pancreatic remnant as independent risk factors for postoperative pancreatic fistula: a matched-pairs analysis

BACKGROUND/AIMS

Postoperative pancreatic fistula (POPF) is a major complication after resective pancreatic surgery. This study aimed to identify histomorphological features of the pancreatic remnant as independent determinants for the development of POPF.

METHODS

Twenty-five patients, 3.6% of 696 resections over a period of 5 years, who developed POPF were matched for age, gender, diagnosis, comorbidities, surgeon and procedure with 25 controls without POPF. Pancreatic duct size and index, fibrosis grade, fat content, edema, and signs of chronic and acute inflammation were measured in frozen sections of the resection margin and were then compared.

RESULTS

The POPF rate was 12.2 and 2.6% after distal pancreatectomy and pancreatoduodenectomy, respectively. The POPF group was characterized by a longer ICU and total postoperative stay, higher rate of reoperations and complications. Their pancreata were softer at palpation (88 vs. 56%). Their pancreatic duct was smaller (2.5 vs. 3.2 mm) and their pancreatic fat content higher (16 vs. 8%). High inter- and intralobular fat content, small duct size, low interlobular fibrosis grade and lack of signs of chronic pancreatitis were predictors of POPF development. A score including these parameters identified high-risk patients with a sensitivity of 92% and a specificity of 84%.

CONCLUSION

Histomorphological features of the pancreatic remnant play an independent role as risk factors for the development of POPF. A simple histological score based on the frozen sections may already intraoperatively predict the risk of POPF development.

A simple scoring system based on clinical factors related to pancreatic texture predicts postoperative pancreatic fistula preoperatively

BACKGROUND

Postoperative pancreatic fistula (POPF) is regarded as the most serious complication of pancreatic surgery. The preoperative risk stratification of patients by simple means is of interest in perioperative clinical management.

METHODS

Based on prospective data, we performed a risk factor analysis for POPF after pancreatoduodenectomy in 62 patients operated between 2006 and 2008 with special focus on clinical parameters that might serve to predict POPF. A predictive score was developed and validated in an independent second dataset of 279 patients operated between 2001 and 2010.

RESULTS

Several pre- and intraoperative factors, as well as underlying pathology, showed significant univariate correlation with rate of POPF. Multivariate analysis (binary logistic regression) disclosed soft pancreatic texture (odds ratio [OR] 10.80, 95% confidence interval [CI] 1.80-62.20) and history of weight loss (OR 0.15, 95% CI 0.04-0.66) to be the only independent preoperative clinical factors influencing POPF rate. The subjective assessment of pancreatic hardness by the surgeon correlated highly with objective assessment of pancreatic fibrosis by the pathologist (r = -0.68, P < 0.001, two-tailed Spearman's rank correlation). A simple risk score based on preoperatively available clinical parameters was able to stratify patients correctly into three risk groups and was independently validated.

CONCLUSIONS

Preoperative stratification of patients regarding risk for POPF by simple clinical parameters is feasible. Pancreatic texture, as evaluated intraoperatively by the surgeon, is the strongest single predictive factor of POPF. The findings of the study may have important implications for perioperative risk assessment and patient care, as well as for the choice of anastomotic techniques.

Assessment of pancreatic hardness-surgeon versus durometer

BACKGROUND

This study reports the first results of durometrically measured hardness of human pancreas and investigates its correlation to palpatory determined hardness, grade of pancreatic fibrosis, and preoperatively determined radiodensity.

METHODS

Fifty-two patients with pancreatic resections were prospectively recruited. Hardness of samples from pancreatic cancer, chronic pancreatitis, and normal pancreas was measured using a durometer on a 0-100 Shore units (SU) scale. Three pancreatic surgeons palpated the pancreas and reported their assessment of hardness on a subjective 0-100 "Bochum units" (BU) scale. Radiodensity and fibrosis of pancreatic tissue were used for comparison.

RESULTS

Pancreatic hardness differed significantly in normal pancreas, chronic pancreatitis, and pancreatic cancer; 30 SU, 51 SU, and 65.8 SU, respectively. Palpatory hardness of normal pancreas was 20 BU and of pancreatitis 60 BU. It correlated well to durometric readings: r(2)=0.56, P<0.00001. Fibrosis grade and radiodensity correlated neither to durometry nor to palpation. Pancreatic leak developed 4/20 (20%) patients with normal pancreas vs. 1/32 (3.1%) with chronic pancreatitis in the resection margin, P<0.05.

CONCLUSIONS

Palpatory assessment of pancreatic hardness performed by experienced surgeons correlated well to durometric measurements and remains the method of choice for intraoperative decision making. Durometry was more precise and should be considered in studies on pancreatic texture and for teaching purposes. Hardness and fibrosis grade appeared to be independent characteristics of pancreatic texture.

Selective Administration of Prophylactic Octreotide During Pancreaticoduodenectomy: A Clinical and Cost-Benefit Analysis in Low- and High-Risk Glands

BACKGROUND

The efficacy of prophylactic octreotide after pancreaticoduodenectomy has been rigorously scrutinized, yet few studies have specifically illustrated its impact in patients at high risk for pancreatic fistula. Applying a previously validated clinical classification scheme (International Study Group on Pancreatic Fistula) for postoperative pancreatic fistula severity, we examined whether prophylactic octreotide could effectuate a clinical or fiscal benefit, or both, after pancreatic resection.

STUDY DESIGN

There were 227 consecutive patients who underwent pancreaticoduodenectomy from October 2001 to January 2007. At the surgeon's discretion, prophylactic octreotide was administered intraoperatively and continued postoperatively. Clinically relevant fistulas, requiring therapeutic interventions or resulting in severe clinical sequelae, were identified, as were other complications. Through multivariate analysis, risk factors for fistula were defined as soft gland texture; small duct size; ampullary, duodenal, cystic, or islet cell pathology; and increased blood loss. Beyond a traditional review of clinical outcomes, a novel economic cost-benefit analysis of octreotide prophylaxis was performed, with concentration of impact on high-risk glands (one or more risk factors).

RESULTS

Overall, 55% of patients had at least one risk factor. Clinically relevant fistulas were present in 14.9% of all patients. High-risk glands resulted in significantly worse clinical and economic outcomes compared with low-risk glands (no risk factors present). Prophylactic octreotide in low-risk glands was neither clinically effective nor cost efficient after pancreaticoduodenectomy, contributing to $781 in overspending per patient--approximately equivalent to a 7-day postoperative course of octreotide. But in patients with high-risk glands, octreotide prophylaxis was associated with a decreased incidence (20% versus 35%) and morbidity of clinically relevant fistulas. These improved clinical outcomes were associated with reduced resource use, translating to considerable cost savings ($11,849) per high-risk patient.

CONCLUSIONS

Octreotide prophylaxis is an effective approach to mitigate the negative impact of pancreatic fistulas, but to obtain maximal clinical value and cost benefit, octreotide should be administered exclusively to patients with high-risk glands.

Therapeutic strategies for the management of delayed gastric emptying after pancreatic resection

BACKGROUND

Delayed gastric emptying (DGE) is one of the most troublesome postoperative complications following pancreatic resection. Not only does it contribute considerably to prolonged hospitalization, but it is also associated with increased postoperative morbidity and mortality.

METHODS

We performed an electronic and manual search of the international literature for studies dealing with the treatment of DGE following pancreatic resection using the Medline database. The search items used were "delayed gastric emptying," "pancreaticoduodenectomy," "Whipple procedure," "pylorus-preserving pancreaticoduodenectomy," and "complications following pancreatic resection" in various combinations.

RESULTS

A number of studies were identified regarding possible therapeutic alternatives for the treatment of DGE. From the class of prokinetic regimens, most studies seem to support the use of erythromycin. However, its use has not gained wide acceptance. Regarding the operative technique, both standard Whipple and pylorus-preserving pancreatic resection carry similar rates of DGE. Billroth II type-like gastrointestinal reconstruction is the most widely accepted method and is associated with lower rates of DGE. Reoperations for managing severe DGE were very rarely reported.

CONCLUSIONS

The incidence of DGE in high-volume centers specialized in pancreatic surgery is well below 20%, thus following the improved rates that have been reported in the last decade regarding mortality and length of hospital stay after pancreatic surgery. DGE mandates a uniform definition and method of evaluation to achieve homogeneity among studies. Standardization of the operative technique, as well as "centralizing" pancreatic resections in high-volume centers, should aid to improve the occurrence of this bothersome postoperative complication.

Risk factors for pancreatic anastomotic leakage: the significance of preoperative dynamic magnetic resonance imaging of the pancreas as a predictor of leakage

BACKGROUND

The histologic degree of pancreatic fibrosis can be assessed preoperatively by using the time-signal intensity curve (TIC) of the pancreas obtained from dynamic magnetic resonance imaging.

STUDY DESIGN

To identify risk factors for postoperative pancreatic anastomotic leakage and to assess the impact of pancreatic TIC on this complication, 89 patients who underwent a pancreatic head resection with an end-to-side pancreaticojejunostomy between December 1998 and August 2005 were retrospectively reviewed. The pancreatic TIC profiles were classified into 3 types: type I, indicating a normal pancreas without fibrosis; and types II and III indicating fibrotic pancreas.

RESULTS

Pancreaticojejunal anastomotic leakage occurred in 14 patients (16%). In a univariate analysis, pancreatic texture (hard, 3% versus intermediate, 20% versus soft, 23%; p = 0.046), pancreatic duct size (> 3 mm, 8% versus <or= 3 mm, 25%; p = 0.037), and pancreatic TIC (types II, III, 3% versus type I, 25%; p = 0.006) were notably associated with pancreatic anastomotic leakage. In a multivariable analysis, pancreatic TIC (odds ratio [OR], 9.58; 95% CI, 1.1 to 91.7) was the only marked independent predictor of postoperative pancreatic leakage. A subanalysis of 52 patients with type I pancreatic TIC demonstrated hemoglobin A1c (odds ratio, 9.81; 95% CI, 1.2 to 127.9) to be a notable predictor of leakage and pancreatic leakage developed in diabetic patients with a high hemoglobin A1c concentration (> 6.0%) than in those with a normal hemoglobin A1c level.

CONCLUSIONS

Pancreatic TIC from dynamic MRI provides reliable information for predicting risk of pancreatic anastomotic leakage after pancreatic head resection. Especially in patients with type I pancreatic TIC, the presence of uncontrolled diabetes is considered a primary risk factor for postoperative pancreatic leakage.

Octreotide hardens the pancreas

BACKGROUND AND AIMS

Leakage from pancreaticojejunostomy and development of pancreatic fistulas are the major postoperative complications in patients undergoing duodenopancreatectomy. The risk of developing these complications is higher when surgery is performed on a soft pancreas. A recent report suggests that octreotide hardens the pancreas when given intraoperatively. The present study aims at verifying this observation by measuring tissue hardness of the pancreas by a commercially available durometer in pigs with and without octreotide pretreatment.

METHODS

Three groups of pigs were investigated: Group 1 (n=6) received no treatment; group 2 (n=6) was treated with 3x100 microg octreotide for 1 day; group 3 (n=6) for 5 days. Thereafter, animals were killed and the pancreas was harvested for performing measurements: Tissue hardness was assessed by a commercially available durometer, and a suture holding test was performed using a Newton dynamometer.

RESULTS

There was a significant increase in tissue hardness between untreated control animals [26.3+/-2.5 S.U. (shore units)] and animals with 1 day octreotide pretreatment (29.8+/-2.6 S.U.; p=0.04) as well as between the groups treated for 1 and 5 days (34.8+/-2.8 S.U.; p=0.01). Suture holding capacity was higher in animals treated for 5 days.

CONCLUSION

The present study agrees with a recent report suggesting that octreotide hardens the pancreas. Octreotide pretreatment may therefore be an advantage when performing surgery on a soft pancreas, i.e., in patients scheduled for duodenopancreatectomy for ampullary carcinomas or circumscript pancreatic tumors not associated with chronic pancreatitis.

Increased plasma levels of IL-6 and IL-8 are associated with surgical site infection after pancreaticoduodenectomy

OBJECTIVES

Cytokines and chemokines potentially modulate postoperative immune response. Association of circulating cytokines and chemokines with postoperative infectious complications after pancreaticoduodenectomy was evaluated.

METHODS

Plasma concentrations of interleukin (IL) 6, IL-10, IL-8, macrophage chemoattractant protein 1, heat shock protein 70, and amylase, as well as amylase levels in peritoneal exudative fluid, were measured perioperatively in 60 consecutive patients who underwent pancreaticoduodenectomy.

RESULTS

Of the 60 patients, 27 patients had surgical site infection (SSI), including peritoneal infection in all, intra-abdominal abscess in 14, and radiologically visualized pancreatic leakage in 6. Postoperative plasma levels of IL-6, IL-8, and macrophage chemoattractant protein 1, as well as peritoneal amylase levels, were significantly higher in patients with SSI than in those without SSI (P < 0.05). Nonpancreatic cancer as a histopathologic diagnosis, high pancreatic juice flow, and increased levels of IL-6 and IL-8 were independently associated with SSI (P < 0.05) in multiple logistic regression analysis. Plasma levels of IL-6 and IL-10 among patients with SSI were significantly higher in those with pancreatic leakage than in those without leakage.

CONCLUSIONS

These results suggest that, in addition to pancreatic exocrine function, IL-6 and IL-8 are associated with postoperative SSI, including pancreatic leakage after pancreaticoduodenectomy.