Intraoperative Bile Culture in Pancreaticoduodenectomy: Teaching Old Dogma New Tricks

INTRODUCTION

Biliary stents increase surgical site infections (SSIs) following pancreaticoduodenectomy due to bactibilia and contaminated intraoperative bile spillage. Intraoperative bile culture (IOBC) is performed to guide empiric therapy for SSIs; however, its utility is poorly studied. We sought to evaluate IOBC and the interplay between stenting, bactibilia, and SSI following pancreaticoduodenectomy.

METHODS

Patients undergoing pancreaticoduodenectomy from January 2008 to April 2020 were identified through our institutional National Surgical Quality Improvement Project (NSQIP) database; patients without IOBC were excluded. Odds of SSI were analyzed with multivariable logistic regression.

RESULTS

Four-hundred-eighty-three patients were identified. One-hundred-eighty-nine (39%) patients had plastic stents and 154 (32%) had metal stents. Three-hundred-twenty-nine (96%) patients with stents had bactibilia versus 18 (13%) without stents (P < 0.001). The biliary microbiome and antibiotic resistance patterns in patients with metal and plastic stents were nearly identical. Of 159 NSQIP-defined SSIs, most were incisional (n = 92, 58%). Bactibilia and stent presence were associated with incisional (OR 3.69 and 3.39, both P < 0.001) but not organ space SSI (P > 0.1); however, stent type was not (P > 0.5). Of the 73 speciated SSI cultures, an IOBC-identified organism was present in 42 (58%), while at least one organism not found in the IOBC was present in 49 (67%).

CONCLUSION

Bactibilia is associated with incisional but not organ space SSI following pancreaticoduodenectomy and is strongly associated with stent presence. Stent type does not independently influence the biliary microbiome or SSI risk. IOBC has a poor ability to predict causative organisms in SSIs following pancreaticoduodenectomy and is not recommended for routine use.

Self-expanding metal ureteral stent for ureteral stricture: Experience of a large-scale prospective study from a high-volume center - Cross-sectional study

BACKGROUND

The management of ureteral stricture is still a challenge for urologists. The aim of this prospective study was to assess the safety and effectiveness of self-expanding metal ureteral stents (URS) in ureteral strictures.

METHODS

We performed URS placement procedures for ureteral stricture from Jan 2019 to July 2020, and prospectively collect various data before and after the operation. A paired T test was used to compare continuous variables before and after surgery, binary logistic regression analysis was used to identify the independent risk predictors of surgical failure.

RESULTS

A total of 147 patients with 157 renal units received successful placement of URS. The mean operative time was 70.0 min. After a median follow-up time of 15 months, 73.2% (115/157) of stents were kept in situ. The most common complication was hematuria (13, 8.8%), followed by urinary tract infection (11, 7.5%) and pain (8, 5.4%). The volume of hydronephrosis (67.9 ± 34.9 VS 34.9 ± 51.1 cm³, P = 0.0001), serum creatinine level (103.0 ± 54.5 VS 93.8 ± 45.1 μmol/L, P = 0.034) and blood urea nitrogen level (6.6 ± 6.7 VS 5.4 ± 2.4 mmol/L, P = 0.032) decreased significantly at last follow up when compared with baseline. Stricture of the distal ureter was an independent risk factor for stent failure (HR 1.77, 95% CI 1.15, 2.73, P = 0.009).

CONCLUSIONS

URS was found to be safe and effective for ureteral strictures with a limited complications and good long-term results. For those who are not suitable for surgical reconstruction, the URS is an alternative management.

Comparative study of renal drainage with different ureteral stents subject to extrinsic ureteral obstruction using an in vitro ureter-stent model

BACKGROUND

To compare the efficacy of different ureteral stents subject to extrinsic ureteral obstruction (EUO), in a controlled in vitro stented ureter experiment.

METHODS

We employ an in vitro ureter-stent experimental set-up, with latex tubing simulating flexible ureters attached to vessels simulating renal units and bladders. The flow behavior of five ureteral stents-polymeric 8F, tandem 6F, tandem 7F, endopyelotomy and metal-was tested under a ureteral deformation configuration of 40°, with 2000 g external force over a 3.5 cm length of the ureter. A constant fluid flow was applied through the ureter-stent configurations, and pressure fluctuations in the renal unit were monitored. We considered a renal unit pressure of 10 cmH₂O or flow discontinuation in the bladder as stent failure. Urine containing debris was mimicked by use of a colloidal solution.

RESULTS

Of all assessed ureteral stents, under EUO conditions, only the single 8F stents remained patent throughout the length of the experiment. All other stents-tandem 6F and 7F, single 7F, metal and endopyelotomy-displayed limitations.

CONCLUSIONS

Tandem and metal stents show no superiority over large luminal polymeric stents for EUO treatment in this in vitro model. Larger luminal stents offer excellent resistance to external pressure and allow adequate colloidal flow. The need for frequent exchange and bladder irritation should also be considered in the choice of stent configuration for treatment of kidney drainage under EUO.

Recent advances in treatment of pancreatic pseudocyst with endoscopic ultrasonography guided lumen-apposing metal stents

Endoscopic pancreatic pseudocyst (PPC) drainage has become one of the most important methods for the treatment of PPC. With the continuous application of the new lumen-apposing metal stent (LAMS), it has shown better efficacy and clinical practical value. This paper focuses on the current situation of endoscopic PPC drainage, especially the therapeutic effect, complications, and countermeasures with endoscopic ultrasound-guided LAMS.

Should a fully covered self-expandable biliary metal stent be anchored with a double-pigtail plastic stent? A retrospective study

BACKGROUND

The migration rate of fully covered self-expandable metal stents (FCSEMSs) has been reported to be between 14% to 37%. Anchoring of FCSEMSs using a double-pigtail plastic stent (DPS) may decrease migration.

AIM

To compare stent migration rates between patients who received FCSEMS alone and those who received both an FCSEMS and anchoring DPS.

METHODS

We conducted a retrospective analysis of endoscopy reporting system and medical records of 1366 patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) with FCSEMS placement at the University of Kentucky health care. Between July 2015 and April 2017, 203 patients with FCSEMS insertion for the treatment of malignant biliary stricture, benign biliary stricture, post-sphincterotomy bleeding, bile leak, and cholangitis drainage were identified. The review and analysis were conducted through our endoscopy reporting system (ProVation^® MD) and medical records. Categorical data were analyzed using Chi-Square and Fischer exact test and continuous data using non-parametric tests. A regression analysis was performed to identify factors independently associated with increased risk of stent migration. We determined an FCSEMS migration endoscopically if the stent was no longer visible in the major papilla.

RESULTS

1366 patients had undergone ERCP by three advanced endoscopists over 21-mo period; among these, 203 patients had FCSEMSs placed. 65 patients had FCSEMSs with DPS, and 138 had FCSEMSs alone. 65 patients had FCSEMSs with DPS, and 138 had FCSEMSs alone. 95 patients had a malignant stricture, 82 patients had a benign stricture, 12 patients had bile leak, 12 patients had cholangitis, and nine patients had post-sphincterotomy bleeding. The migration rate in patients with anchored FCSEMSs with DPS was 6%, and those without anchoring DPS was 10% (P = 0.35). Overall, migration was reported in 18 patients with FCSEMSs placement out of 203 patients with an overall migration rate of 9.7%. There was no significant association between anchoring the FCSEMSs with DPS and the risk of stent migration. Only patients with the previous sphincterotomy and begin biliary stricture were found to have a statistically significant difference in the migration rate between patients who had FCSEMS with DPS and FCSEMS alone (P = 0.01).

CONCLUSION

The risk of migration of biliary FCSEMS was 9.7 %. Anchoring an FCSEMS with DPS does not decrease the risk of stent migration.

A systematic review and meta-analysis of metal versus plastic stents for drainage of pancreatic fluid collections: metal stents are advantageous

BACKGROUND

The use of fully covered metal stents (FCSEMS) and specifically designed lumen apposing metal stents for transmural drainage of pancreatic fluid collections has become widespread. A systematic review published in 2015 did not support the routine use of metal stents for drainage of pancreatic fluid collections. However, recent studies have shown conflicting data; therefore a systematic review and meta-analysis was performed.

METHOD

We conducted a database search for original comparative studies between plastic and metal stents. The random effects model was used to calculate pooled risk ratios (RR) with 95% confidence intervals (CI). Outcomes analysed were clinical success, adverse events and requirement of further intervention.

RESULTS

The search identified 936 studies, 7 studies with 681 (340 metal, 341 plastic) patients met inclusion criteria and were included in the meta-analysis. Clinical success was achieved in 93.8% versus 86.2% in the metal and plastic groups, respectively, RR 1.08 [95% CI 1.02-1.14]; p = 0.009. Adverse events were reduced for metal stents when compared with plastic (10.2% vs. 25.0%), RR 0.42 [95% CI 0.22-0.81]; p = 0.010. Metal stent usage reduced bleeding (2.8% vs. 7.9%), RR 0.37; [95% CI 0.18-0.75]; p = 0.006. Further intervention was required in 12.4% of patients in the metal stent group versus 26.7% for plastic stents, RR 0.54; [95% CI 0.22-1.29]; p = 0.165.

CONCLUSIONS

The use of metal stents for drainage of pancreatic fluid collections is associated with improved clinical success, fewer adverse events and reduced bleeding compared to plastic stents.

Palliation With Endoscopic Metal Stents May Be Preferable to Surgical Intervention for Patients With Obstructive Pancreatic Head Adenocarcinoma

The aim of this study was to evaluate the efficacy of endoscopically placed metal stents in comparison with operative procedures, in patients with obstructive pancreatic head cancer. Endoscopic stenting techniques and materials for gastrointestinal malignancies are constantly improving. Despite this evolution, many still consider operative procedures to be the gold standard for palliation in patients with unresectable obstructive pancreatic head cancer. This is a retrospective study of 52 patients who were diagnosed with obstructive (biliary, duodenal, or both) adenocarcinoma of the pancreatic head. Twenty-nine patients (endoscopy group) underwent endoscopic stenting. Eleven patients (bypass group) underwent biliodigestive bypass. Twelve patients (Whipple group) underwent Whipple operation with curative intent; however, histopathology revealed R1 resection (palliative Whipple). T4 disease was identified in 13 (44.8%), 7 (63.6%), and 3 (25%) patients in the endoscopy, bypass, and Whipple groups, respectively. Metastatic disease was present only in the endoscopy group (n = 12; 41.3%). There was no intervention-related mortality. Median survival was 280 days [95% confidence interval (95% CI), 103, 456 days], 157 days (95% CI, 0, 411 days), and 647 days (95% CI, 300, 993 days) for the endoscopy, bypass, and Whipple groups, respectively (P = 0.111). In patients with obstructive pancreatic head cancer, endoscopic stenting may offer equally good palliation compared with surgical double bypass. The numerically (not statistically) better survival after palliative Whipple might be explained by the smaller tumor burden in this subgroup of patients and not by the superior efficacy of this operation.

Pancreatic Endotherapy for Chronic Pancreatitis

Extracorporeal shock wave lithotripsy is recommended as the first-line therapy for large (>5-mm) obstructive pancreatic ductal stones. Dominant pancreatic duct strictures should be initially managed with a wide-bore single plastic stent with 3 monthly exchanges for a year, even in asymptomatic patients. Recent studies have evaluated multiple plastic and self-expanding covered metal stents for refractory pancreatic ductal stricture. Pancreatic pseudocysts should be treated endoscopically with or without endoscopic ultrasound guidance.

A Phase I study of high-dose-rate intraluminal brachytherapy as palliative treatment in extrahepatic biliary tract cancer

PURPOSE

To determine the recommended dose of endoscopically assisted high-dose-rate intraluminal brachytherapy (HDR-192Ir-ILBT) as a palliative treatment of extrahepatic biliary tract cancer.

METHODS AND MATERIALS

Patients with non-metastatic extrahepatic biliary cancer with age <80 years, unsuitable for surgical resection or radiochemotherapy for comorbidities or Eastern Cooperative Oncology Group (ECOG) ≥2 or patients with age ≥80 years were included. They were undergone to implantation of metal stents by endoscopic retrograde cholangiopancreatography followed by HDR-192Ir-ILBT. The initial dose of HDR-192-Ir-ILBT was 15 Gy. Three levels of dose were planned. At each dose level almost three patients were treated, and if no Grade 3-4 toxicity (considering as dose-limiting toxicity) was recorded, dose escalation was applied with 5 Gy increments until the maximum tolerated dose was established. A high dose Iridium-192 after loading system was used (Nucletron Microselectron HDR).

RESULTS

From May 2007 to January 2010, 18 patients underwent HDR-192Ir-ILBT, with one catheter in 12 patients and two catheters in six patients. Three levels of dose were planned: 15 Gy in three patients, 20 Gy in nine patients, and 25 Gy in six patients with daily dose of 500 cGy per fraction. One patient at Dose Level II experienced acute toxicity (cholangitis) related to brachytherapy procedure, so the cohort was expanded. No patient of Level III had a dose-limiting toxicity and we stopped at this dose level waiting to assess the late toxicity that has not yet appeared at the time of the analysis. Six months and 1 year overall survival was 77% and 59%, respectively, with a median of 12 months.

CONCLUSIONS

The recommended dose was defined as 25 Gy in five fractions. It will be used in a Phase II study to better evaluate tumor and symptom control in patients with extrahepatic biliary tract cancer.

Bilateral metallic stenting in malignant hilar obstruction

Endoscopic palliative biliary drainage is considered as a gold standard treatment in advanced or inoperable hilar cholangiocarcinoma. Also, metal stents are preferred over plastic stents in patients with >3 months life expectancy. However, the endoscopic intervention of advanced hilar obstruction is often more challenging and complex than that of distal malignant biliary obstructions. In this literature review, we describe the issues commonly encountered during endoscopic unilateral (single) versus bilateral (multiple) biliary stenting for malignant hilar obstruction. Also, we provide technical guidance to improve the technical success rates and patient outcomes, focusing on bilateral metallic stenting techniques such as stent-in-stent or side-by-side deployment.

Metal versus Plastic Stent for Transmural Drainage of Pancreatic Fluid Collections

The conventional management of pancreatic fluid collections (PFCs) involves surgery or percutaneous drainage. While surgery is associated with significant complications and mortality, percutaneous drainage is associated with prolonged hospitalization and oftentimes the need for other adjunctive treatment measures. Therefore, the use of endoscopy to drain PFCs is becoming increasingly popular. Randomized trials have demonstrated that endoscopic ultrasound-guided drainage is superior to conventional endoscopy in terms of technical success and potentially decreases the rates of procedural complications. While transmural drainage is usually undertaken by deployment of plastic endoprosthesis, of late, fully covered self-expandable metal stents are being placed with increasing frequency. However, the benefits of this approach are unclear and require further validation in prospective trials.