The safety and efficacy of a new 20-mm lumen apposing metal stent (lams) for the endoscopic treatment of pancreatic and peripancreatic fluid collections: a large international, multicenter study

International Consensus Recommendations for Safe Use of LAMS for On- and Off-Label Indications Using a Modified Delphi Process

INTRODUCTION

The study aimed to develop international consensus recommendations on the safe use of lumen-apposing metal stents (LAMSs) for on- and off-label indications.

METHODS

Based on the available literature, statements were formulated and grouped into the following categories: general safety measures, peripancreatic fluid collections, endoscopic ultrasound (EUS)-biliary drainage, EUS-gallbladder drainage, EUS-gastroenterostomy, and gastric access temporary for endoscopy. The evidence level of each statement was determined using the Grading of Recommendations Assessment, Development, and Evaluation methodology.International LAMS experts were invited to participate in a modified Delphi process. When no 80% consensus was reached, the statement was modified based on expert feedback. Statements were rejected if no consensus was reached after the third Delphi round.

RESULTS

Fifty-six (93.3%) of 60 formulated statements were accepted, of which 35 (58.3%) in the first round. Consensus was reached on the optimal learning path, preprocedural imaging, the need for airway protection and essential safety measures during the procedure, such as the use of Doppler, and measurement of the distance between the gastrointestinal lumen and the target structure. Specific consensus recommendations were generated for the different LAMS indications, covering, among others, careful patient selection, the preferred size of the LAMS, the need for antibiotics, the preferred anatomic location of the LAMS, the need for coaxial pigtail placement, and the appropriate management of LAMS-related adverse events.

DISCUSSION

Through a modified international Delphi process, we developed general and indication-specific experience- and evidence-based recommendations on the safe use of LAMS.

Endoscopic Ultrasound-Guided Drainage of Pancreatic Fluid Collections: Not All Queries Are Already Solved

Pancreatic fluid collections (PFCs) are well-known complications of acute pancreatitis. The overinfection of these collections leads to a worsening of the prognosis with an increase in the morbidity and mortality rate. The primary strategy for managing infected pancreatic necrosis (IPN) or symptomatic PFCs is a minimally invasive step-up approach, with endosonography-guided (EUS-guided) transmural drainage and debridement as the preferred and less invasive method. Different stents are available to drain PFCs: self-expandable metal stents (SEMSs), double pigtail stents (DPPSs), or lumen-apposing metal stents (LAMSs). In particular, LAMSs are useful when direct endoscopic necrosectomy is needed, as they allow easy access to the necrotic cavity; however, the rate of adverse events is not negligible, and to date, the superiority over DPPSs is still debated. Moreover, the timing for necrosectomy, the drainage technique, and the concurrent medical management are still debated. In this review, we focus attention on indications, timing, techniques, complications, and particularly on aspects that remain under debate concerning the EUS-guided drainage of PFCs.

Endoscopic ultrasound-guided drainage of pancreatic collections with dedicated metal stents: A nationwide, multicenter, propensity score-matched comparison

BACKGROUND

The new dedicated stents for endoscopic ultrasound (EUS)-guided transluminal drainage of peri‑pancreatic fluid collections (PFCs) demonstrated optimal efficacy and safety profiles.

AIMS

This study aimed to evaluate the safety, technical and clinical success, and recurrence rate of PFCs drained with Lumen Apposing Metal Stent (LAMS) or Bi-Flanged Metal Stent (BFMS).

METHODS

Data from a multicenter series of PFCs treated with LAMS or BFMS at 30 Italian centers during a 5-year period were retrieved. The rate of adverse events (AEs), technical success, clinical success, PFC recurrence were evaluated. To overcome biases, a 1-to-1 match was created using propensity score analysis.

RESULTS

Out of 476 patients, 386 were treated with LAMS and 90 with BFMS, with a median follow-up of 290 days (95% CI 244 to 361). Using propensity score matching, 84 patients were assigned to each group. The incidence of AEs did not differ between the two stents (13.1% versus 15.5%, p = 0.29), mainly bleeding or recurrence rate (4.7% versus 3.5%, p = 1). Technical and clinical success in the BFMS and LAMS groups were 92% versus 95% (p = 0.36) and 91% versus 94% (p = 0.64), respectively.

CONCLUSION

Our study demonstrates that LAMS and BFMS have comparable safety profiles with similar technical and clinical success rates for EUS-guided PFC drainage.

Safety and efficacy of lumen-apposing metal stents and double-pigtail plastic stents for endoscopic ultrasound-guided drainage of walled-off necrosis; a systematic review and meta-analysis

BACKGROUND

Patients with walled-off necrosis (WON) are still challenging to treat safely and effectively. Recently, double-pigtail plastic stents (DPS), bi-flanged metallic stents (BFMS), and lumen-apposing metal stents (LAMS) have been employed with endoscopic ultrasound-guided (EUS-guided) drainage. However, there is little solid evidence to support the effectiveness and safety of using stents. This study aims to compare the outcomes of the LAMS and the PS.

METHOD

Till July 2022, a thorough database search was done, and studies that met the criteria were chosen. By using the RevMan software, the technical and clinical success and other secondary outcomes were calculated. Subgroup analysis was performed between the LAMS and the BFMS.

RESULTS

Fifteen studies (two randomized controlled trials and thirteen observational) with 687 patients receiving metal stents and 771 patients receiving plastic stents were selected for final analysis. There was no significant risk of bias or publication bias. The odds ratios (OR) for technical and clinical success were 0.36 (95% confidence interval (95% CI) 0.08, 1.52) and 2.26 (95%CI 1.62, 3.15), respectively. The OR for overall adverse events was 0.74 (95% CI 0.41, 1.34). In subgroup analysis, the LAMS and the BFMS showed the same outcomes.

CONCLUSION

Compared to DPS, LAMS had better clinical outcomes and fewer side effects when treating patients with WON.

Endoscopic ultrasound drainage of pancreatic fluid collections: do we know enough about the best approach?

Pancreatic fluid collection often occurs as a local complication of acute pancreatitis, and drainage is indicated in symptomatic patients. The drainage may be surgical, percutaneous, or endoscopic ultrasound (EUS) guided. In symptomatic collections older than 4 weeks and localized in the upper abdomen, EUS-guided drainage is the first choice of treatment. Lumen-apposing metal stents are useful in cases of walled-off necrosis, facilitating access to the cavity; however, they do not reduce the number of necrosectomy sessions required. In most pancreatic pseudocysts requiring drainage, plastic stents remain the first choice of treatment. This review aimed to summarize the principles and techniques of step-up therapy of pancreatic fluid collections, including preprocedural and postprocedural assessment and practical approaches of drainage and necrosectomy, making available evidence more accessible to endoscopists aiming to train for this procedure. Successful and safe EUS drainage connotes early recognition and treatment of complications and the presence of a multidisciplinary team for optimal patient management. However, the best time for necrosectomy, modality of drainage method (lumen-apposing metal stents or plastic stents), and duration of antibiotherapy are still under evaluation.

Lumen-apposing-metal stent misdeployment in endoscopic ultrasound-guided drainages: A systematic review focusing on issues and rescue management

BACKGROUND

The introduction of lumen-apposing metal stents (LAMS) for endoscopic ultrasound (EUS)-guided drainages has marked a turning point in the field of interventional ultrasound and it is gathering worldwide diffusion in different clinical settings. Nevertheless, the procedure may conceal unexpected pitfalls. LAMS misdeployment is the most frequent cause of technical failure and it can be considered a procedure-related adverse event when it hampers the conclusion of the planned procedure or results in significant clinical consequences. Stent misdeployment can be managed successfully by endoscopic rescue maneuvers to allow the completion of the procedure. To date, no standardized indication is available to guide an appropriate rescue strategy depending on the type of procedure or of misdeployment.

AIM

To evaluate the incidence of LAMS misdeployment during EUS-guided choledochoduodenostomy (EUS-CDS), gallbladder drainage (EUS-GBD) and pancreatic fluid collections drainage (EUS-PFC) and to describe the endoscopic rescue strategies adopted under the circumstance.

METHODS

We conducted a systematic review of the literature on PubMed by searching for studies published up to October 2022. The search was carried out using the exploded medical subject heading terms “lumen apposing metal stent”, “LAMS”, “endoscopic ultrasound” and “choledochoduodenostomy” or “gallbladder” or “pancreatic fluid collections”. We included in the review on-label EUS-guided procedures namely EUS-CDS, EUS-GBD and EUS-PFC. Only those publications reporting EUS-guided LAMS positioning were considered. The studies reporting a technical success rate of 100% and other procedure-related adverse events were considered to calculate the overall rate of LAMS misdeployment, while studies not reporting the causes of technical failure were excluded. Case reports were considered only for the extraction of data regarding the issues of misdeployment and rescue techniques. The following data were collected from each study: Author, year of publication, study design, study population, clinical indication, technical success, reported number of misdeployment, stent type and size, flange misdeployed and type of rescue strategy.

RESULTS

The overall technical success rate of EUS-CDS, EUS-GBD and EUS-PFC was 93.7%, 96.1%, and 98.1% respectively. Significant rates of LAMS misdeployment have been reported for EUS-CDS, EUS-GBD and EUS-PFC drainage, respectively 5.8%, 3.4%, and 2.0%. Endoscopic rescue treatment was feasible in 86.8%, 80%, and 96.8% of cases. Non endoscopic rescue strategies were required only in 10.3%, 16% and 3.2% for EUS-CDS, EUS-GBD, and EUS-PFC. The endoscopic rescue techniques described were over-the-wire deployment of a new stent through the created fistula tract in 44.1%, 8% and 64.5% and stent-in-stent in 23.5%, 60%, and 12.9%, respectively for EUS-CDS, EUS-GBD, and EUS-PFC. Further therapeutic option were endoscopic rendezvous in 11.8% of EUS-CDS and repeated procedure of EUS-guided drainage in 16.1% of EUS-PFC.

CONCLUSION

LAMS misdeployment is a relatively common adverse event in EUS-guided drainages. There is no consensus on the best rescue approach in these cases and the choice is often made by the endoscopist relying upon the clinical scenario, anatomical characteristics, and local expertise. In this review, we investigated the misdeployment of LAMS for each of the on-label indications focusing on the rescue therapies used, with the aim of providing useful data for endoscopists and to improve patient outcomes.

Nomogram for prediction of adverse events after lumen-apposing metal stent placement for drainage of pancreatic fluid collections

OBJECTIVES

To generate a prognostic model based on a nomogram for adverse event (AE) prediction after lumen-apposing metal stents (LAMS) placement in patients with pancreatic fluid collections (PFC).

METHODS

Data from a large multicenter series of PFCs treated with LAMS placement were retrieved. AE (overall and excluding mild events) prediction was calculated through a logistic regression model and a nomogram was created and internally validated after bootstrapping. Results were expressed in terms of odds ratio (OR) and 95% confidence interval (CI). Discrimination was assessed by c-statistics and calibrated by comparing deciles of predicted and observed ORs.

RESULTS

Overall, 516 patients were included (males 68%, mean age 61.6 ± 15.2 years). PFCs were predominantly walled-off necrosis (52.1%). Independent predictors of AE occurrence were injury of main pancreatic duct (OR in the case of leak 2.51, 95% CI 1.06-5.97, P = 0.03; OR in the case of complete disruption 2.61, 1.53-4.45, P = 0.01), abnormal vessels (OR in the case of perigastric varices 2.90, 1.31-6.42, P = 0.008; OR in the case of pseudoaneurysm 2.99, 1.75-11.93, P = 0.002), using a multigate technique (OR 3.00, 1.28-5.24; P = 0.05), and need of percutaneous drainage (OR 2.81, 1.03-7.65, P = 0.04). By nomogram, a score beyond 200 points corresponded to a 50% probability of AE occurrence. The model was confirmed even when excluding mild AEs and it showed optimal discrimination (c-index 76.8%, 95% CI 74-79), confirmed after internal validation.

CONCLUSION

Patients with preprocedural evidence of pancreatic duct leak/disruption, vessel alteration, requiring percutaneous drainage or a multigate technique are at higher risk for AE.

Definition of a hospital volume threshold to optimize outcomes after drainage of pancreatic fluid collections with lumen-apposing metal stents: a nationwide cohort study

BACKGROUND AND AIMS

There is increasing interest in expanding the use of lumen-apposing metal stents (LAMSs) in patients with pancreatic fluid collections (PFCs). The aim of this study was to determine whether there is a hospital volume threshold for which patient outcomes could be optimized.

METHODS

Data from a large multicenter series of patients with PFCs treated with LAMSs were retrieved. Rate of adverse events (AEs) was the primary outcome. Multivariable models with restricted cubic splines were used to identify a hospital volume threshold by plotting hospital volume against the log odds ratio (OR) of AE rate. Propensity score matching was applied to obtain 2 well-balanced groups according to hospital volume, and univariate/multivariate logistic regression analysis was performed to identify significant predictors of AEs.

RESULTS

Overall, 516 patients were included. Increasing hospital volume was associated with a reduced AE rate (P = .03), and the likelihood of experiencing an AE declined as hospital volume increased up to 15 cases. After propensity score matching, 175 patients in the high-volume (>15 cases) and 132 in the low-volume hospital group were compared. Overall, 41 AEs were observed (13.3%), of which 14 (8%) and 27 (20.4%) occurred at high-volume and low-volume centers, respectively (P = .001). Severe and fatal events were observed more frequently in low-volume centers (6% vs 1.7% and 2.2% vs 0%, respectively; P = .05). In multivariate analysis, main pancreatic duct injury (OR, 2.62; 95% confidence interval [CI], 1.26-4.67; P = .02), presence of abnormal vessels (OR, 2.93; 95% CI, 1.41-5.02; P = .006), and institutional experience (OR, 2.95; 95% CI, 1.48-5.90; P = .002) were significant predictors of AEs.

CONCLUSIONS

With 15 procedures representing the minimum number of cases associated with the lowest risk for postprocedural AEs, hospital volume is associated with improved outcomes. (Clinical trial registration number: NCT03903523.).

Disconnected pancreatic duct syndrome and outcomes of endoscopic ultrasound-guided treatment of pancreatic fluid collections: Systematic review and meta-analysis

BACKGROUND

Disconnected pancreatic duct syndrome (DPDS) frequently occurs in patients with acute necrotizing pancreatitis and resultant pancreatic fluid collection (PFC). We performed a systematic review and meta-analysis to evaluate outcomes of endoscopic ultrasound-guided treatment of PFCs according to the presence of DPDS.

METHODS

Using PubMed, Embase, and the Cochrane database, we identified clinical studies published until January 2021 with data comparing outcomes of endoscopic ultrasound-guided drainage of PFCs between DPDS and non-DPDS patients. We pooled data on technical and clinical success rates, PFC recurrence, and adverse events using the random-effects model.

RESULTS

We identified five eligible articles including 941 PFC patients treated with endoscopic ultrasound-guided interventions. Clinical success, defined as resolution of the PFC and symptoms, was achieved in a majority of the cases irrespective of DPDS (pooled odds ratio [OR] comparing DPDS to non-DPDS patients, 0.77; 95% confidence interval [CI] 0.33-1.81). Compared to patients without DPDS, patients with DPDS were more likely to undergo PFC recurrence (pooled OR 6.72; 95% CI 2.72-16.6) after clinical resolution of PFC. Prolonged plastic stent placement following the clinical resolution was more frequently performed in DPDS patients than in non-DPDS patients (pooled OR 15.9; 95% CI 2.76-91.9). No statistically significant difference was observed between the groups in terms of the rate of technical success, adverse events, or mortality.

CONCLUSION

Disconnected pancreatic duct syndrome was associated with higher rate of PFC recurrence after successful endoscopic treatment of PFCs. Future studies should evaluate effectiveness and optimal duration of long-term placement of transmural plastic stents for PFCs with DPDS.

Prediction and management of bleeding during endoscopic necrosectomy for pancreatic walled-off necrosis: results of a large retrospective cohort at a tertiary referral center

BACKGROUND AND AIMS

Lumen-apposing metal stents (LAMSs) provide an endoscopic method for management of walled-off necrosis (WON) and a gateway for the performance of endoscopic necrosectomy (EN). However, bleeding may occur in up to 20% of EN procedures. Predictive factors for bleeding in this patient population are unknown, and there is no agreed-on algorithm for the management of bleeding. The aim of this study was to evaluate preprocedural risk factors for bleeding in patients undergoing endoscopic drainage or EN for WON.

METHODS

A retrospective cohort of patients undergoing EN for WON was reviewed. Demographics, comorbidities, concurrent medications, and etiology of pancreatitis were recorded. Pre-, peri-, and postprocedural clinical variables were compared using the χ² test and independent t test.

RESULTS

Between June 2014 and October 2020, 536 ENs were performed in 151 patients. Intraprocedural bleeding occurred during 28 procedures (5.2%) in 18 patients (11.9%). Endoscopic hemostasis was attempted in 8 patients (10 procedures). Eight patients (10 procedures) in total were treated by interventional radiology (IR). Thrombocytopenia (P = .006) and cirrhosis (P = .049) were associated with intraprocedural bleeding, although thrombocytopenia was present in only 1 patient. Identification of a vessel within the cavity endoscopically was also associated with bleeding (P < .001). On multivariate analysis, identification of a vessel within the cavity endoscopically remained a strong predictor of bleeding (P < .001), whereas cirrhosis was no longer significant. Patients who required IR for hemostasis were transfused with significantly more blood before the procedure than patients who did not (3.4 units vs .67 units, P = .002).

CONCLUSIONS

EN for WON was associated with a 5.2% per-procedure risk of bleeding and an 11.9% per-patient bleeding risk. Identification of a vessel within the cavity during endoscopy is predictive of bleeding during EN. Patients who require more transfusions before endoscopy may require earlier intervention by IR.

Endoscopic Transmural Drainage and Necrosectomy in Acute Necrotizing Pancreatitis: A Review

Acute necrotizing pancreatitis occurs in 10%–20% of patients with acute pancreatitis (AP) which is one of the most important acute abdominal diseases that require hospital admission. Pancreatic necrosis is also associated with high mortality and morbidity. In the past 20 years, the treatment of pancreatic necrosis has shifted from open necrosectomy to minimally invasive techniques, such as endoscopic interventions. With the development of endoscopic techniques, the safety and effectiveness of endoscopic interventions have improved, but there exist several unresolved problems. Currently, there is no unified standard approach for endoscopic treatment of pancreatic necrosis that takes into account local expertise, anatomical features of necrosis, patients’ preferences, and comorbidity profile. We reviewed the current status of endoscopic therapy for acute necrotizing pancreatitis, focusing on the new endoscopic drainage technique and necrosectomy protocol.

Direct Endoscopic Necrosectomy: Timing and Technique

Walled-off pancreatic necrosis (WOPN) is one of the local complications of acute pancreatitis (AP). Several interventional techniques have been developed over the last few years. The purpose of this narrative review is to explore such methodologies, with specific focus on endoscopic drainage and direct endoscopic necrosectomy (DEN), through evaluation of their indications and timing for intervention. Findings indicated how, after the introduction of lumen-apposing metal stents (LAMS), DEN is becoming the favorite technique to treat WOPN, especially when large solid debris or infection are present. Additionally, DEN is associated with a lower adverse events rate and hospital stay, and with improved clinical outcome.

Role of endoscopic ultrasonography in the management of peripancreatic collections. Diagnostic and therapeutic approach

Pancreatic fluid collections are surrounded by a wall of granulation tissue and may contain necrotic debris. They occur following a severe acute pancreatitis and most of the cases resolve spontaneously after several weeks. However, their management may lead to a very hardto-treat condition, requiring a multidisciplinary approach. During the last decades we assisted to a change of paradigm involving Endoscopic Ultrasonography, from a pure diagnostic technique to an interventional-therapeutic one, allowing an effective, safe and less invasive approach than other existing treatment standards, historically consisting of surgical and percutaneous drainage. Treatment of pancreatic fluid collections is indicated if they become infected or symptomatic. Over the past years, exponential developments were done in interventional endoscopic approach, making it the first line suggested modality. The use of endoscopic ultrasound allows assessment of the collection, even when it is not directly bulging on gastrointestinal wall, creation of an internal fistulous tract, checking for surrounding vessels with the use of Doppler, and deployment of a stent avoiding the discomfort of external tubes. Several types of stent have been used for endoscopic drainage: plastic double pigtail stents, fully covered self-expanding metal stents and, more recently, lumen apposing metal stents, which are considered revolutionary because of their two-side flanges and wide and short internal channel, a new design that made easier direct endoscopic necrosectomy. This review aims to go through currently available literature on the diagnostic and therapeutic role of Endoscopic Ultrasonography to handle pancreatic fluid collections.

Safety issues in endoscopy ultrasound-guided interventions using lumen apposing metal stents: a review of the literature

Lumen-apposing metal stents (LAMS) are recently introduced devices that allow to create anastomoses. The indications for LAMS placement are increasing and currently these stents can be used in multiple clinical situations such as endoscopic drainage of pancreatic fluid collections (PFCs), endoscopic ultrasound-guided choledocho-duodenostomy (EUS-CDS), endoscopic ultrasound gallbladder drainage (EUS-GBD), endoscopic ultrasound gastrojejunostomy (EUS-GJ). Since their introduction, they have revealed to allow a higher rate of technical and clinical success, and potentially lower risk of adverse events (AEs) compared with previously available devices. Despite ongoing innovation, any advanced intervention carries risks of AEs. These AEs may occur during the deployment or can be delayed because of the consequent effects of the procedure and/or stent itself. This review represents an overview of current indications, technical and clinical results, with an extensive focus on safety issues related to placement and on long-term indwelling related ones.

When Should We Perform Endoscopic Drainage and Necrosectomy for Walled-Off Necrosis?

Endoscopic drainage and necrosectomy are now accepted treatment approaches for patients with symptomatic walled-off pancreatic necrosis (WON). The current recommendations advocate step-up approaches for the treatment of symptomatic WON. Previous recommendations stipulated that endoscopic intervention should be delayed until more than four weeks after the onset. Recent data on early drainage have been increasing and this option might be considered in well-encapsulated cases, but the percutaneous route is preferred if the drainage is performed within two weeks after onset or in nonencapsulated cases. Recently, additional drainage methods, such as the multiple gateway technique and multiple stent placement, have been developed to open up multiple dead spaces in the WON cavity. Endoscopic necrosectomy could be performed via the transluminal route or percutaneous route after failed initial and additional drainage procedures. The use of novel lumen-apposing stents is a promising treatment option that could reduce the number of steps, the procedure time, and the overall number of necrosectomies.

Lumen-apposing metal stents for approved and off-label indications: a single-centre experience

BACKGROUND AND STUDY AIMS

Lumen-apposing stents (LAMS) are approved to treat peripancreatic collections and for gallbladder and bile duct drainage. Over the last years, LAMS have also been used for off-label indications including gastrojejunostomy, gastro-gastrostomy and drainage of postsurgical collections. We aimed to analyze indications, technical/clinical success rates and complications of all LAMS placed over the last 2 years.

PATIENTS AND METHODS

Data from 61 consecutive LAMS (Hot Axios, Boston Scientific) in 57 patients were analyzed. Technical success was defined as successful deployment of the LAMS in the desired position. Clinical success was defined as follows: for pancreatic collections: resolution without the need for non-endoscopic interventions; for choledochoduodenostomy: ≥ 50% drop in baseline serum bilirubin within 2 weeks AND patient can receive chemotherapy if indicated; for gastrojejunostomy: resolution of gastric outlet obstruction and successful re-initiation of oral intake; for gastro-gastrostomy: successful endoscopic access to the excluded stomach; for gallbladder or postsurgical collection drainage: resolution of sepsis.

RESULTS

Indications were drainage of peripancreatic collections in 24 cases (39.3%), choledochoduodenostomy in 13 (21.3%), gastrojejunostomy in 6 (9.8%), gastro-gastrostomy in 13 (21.3%), gallbladder drainage in 1 (1.6%) and postsurgical collection drainage in 4 (6.6%). Overall technical and clinical success rates were high (57/61; 93.4% and 54/61; 88.5%, respectively). Clinical success rate for non-approved indications was 95.6% (22/23 cases). Complications occurred in 13 patients (21.3%, 4 serious).

CONCLUSIONS

LAMS are increasingly used in interventional endoscopy. In our cohort, more than one third of LAMS are placed for off-label indications, with a high success rate and acceptable complication rate.

Guessing the future of endoscopic drainage of walled-off necrosis

The endoscopic treatment of walled-off necrosis is rapidly evolving concurrently with an increasing number of endoscopic techniques, devices, and combined procedures. Thus, there is a growing armamentarium of alternatives for those patients in whom the conventional direct endoscopic necrosectomy is not enough. However, when the patient reaches this point he enters in an unexplored field and choosing the correct option can be challenging. Furthermore, there is no consensus on the number of endoscopic procedures to perform before considering that direct endoscopic necrosectomy has failed and therefore another strategy should be considered.