Walled-off necrosis: safety of watchful waiting

Endoscopic management of pancreatic collections. Endoscopic Ultrasound Group, Spanish Society of Digestive Endoscopy (GSEED-USE) Clinical Guidelines

Acute pancreatitis is associated with significant morbidity and mortality. It can develop complications such as fluid collections and necrosis. Infection of necrosis occurs in about 20-40 % of patients with severe acute pancreatitis, and is associated with organ failure and worse prognosis. In the past few years the treatment of pancreatic collections has shifted from open surgery to minimally invasive techniques such as endoscopic ultrasound-guided drainage. These guidelines from a selection of experts among the Endoscopic Ultrasound Group, Spanish Society of Gastrointestinal Endoscopy (GSEED-USE) are intended to provide advice on the management of pancreatic collections based on a thorough review of the available scientific evidence. It also reflects the experience and clinical practice of the authors, who are advanced endoscopists or clinical pancreatologists with extensive experience in managing patients with acute pancreatitis.

Controversies in endoscopic ultrasonography-guided management of walled-off necrosis

Walled-off necrosis (WON) develops as local complications after acute necrotizing pancreatitis. Although less invasive interventions such as endoscopic ultrasonography (EUS)-guided drainage and endoscopic necrosectomy are selected over surgical interventions, delayed and step-up interventions are still preferred to avoid procedure-related adverse events. However, there is a controversy about the appropriate timing of drainage and subsequent necrosectomy. The advent of large-caliber lumen-apposing metal stents has also brought about potential advantages of proactive interventions, which still needs investigation in future trials. When step-up interventions of necrosectomy and additional drainage are necessary, a structured or protocoled approach for WON has been reported to improve safety and effectiveness of endoscopic and/or percutaneous treatment, but has not been standardized yet. Finally, long-term outcomes such as recurrence of WON, pancreatic endocrine, and exocrine function are increasingly investigated in association with disconnected pancreatic duct syndrome. In this review we discuss current evidence and controversy on EUS-guided management of WON.

Natural History of Asymptomatic Walled-off Necrosis in Patients With Acute Pancreatitis

Background and objectives Studies on the natural history of asymptomatic walled-off necrosis (WON) in acute pancreatitis (AP) are scarce. We conducted a prospective observational study to look for the incidence of infection in WON. Material and methods In this study, we included 30 consecutive AP patients with asymptomatic WON. Their baseline clinical, laboratory, and radiological parameters were recorded and followed up for three months. Mann Whitney U test and unpaired t-tests were used for quantitative data and chi-square and Fisher's exact tests were used for qualitative data analysis. A p-value <0.05 was considered significant. Receiver operating characteristic curve (ROC) analysis was done to identify the appropriate cutoffs for the significant variables. Results Of the 30 patients enrolled, 25 (83.3%) were males. Alcohol was the most common etiology. Eight patients (26.6%) developed an infection on follow-up. All were managed by drainage either percutaneously (n=4, 50%) or endoscopically (n=3, 37.5%). One patient required both. No patient required surgery and there was no mortality. Median baseline C-reactive protein (CRP) was higher in infection group 76 (IQR=34.8) mg/L vs asymptomatic group, 9.5 mg/dl (IQR=13.6), p<0.001. IL-6 and tumor necrosis factor (TNF)-alpha was also higher in the infection group. The size of the largest collection (157.50±33.59 mm vs 81.95±26.22 mm, P<0.001) and CT severity index (CTSI) (9.50±0.93 vs 7.82±1.37, p<0.01) were also higher in infection group as compared to the asymptomatic group. ROC curve analysis of baseline CRP (cutoff 49.5mg/dl), size of WON (cutoff 127mm) and CTSI (cutoff of 9) showed AUROC (area under ROC) of 1, 0.97, and 0.81 respectively for the future development of infection in WON. Conclusion Around one-fourth of asymptomatic WON patients developed an infection during three-months follow-up. Most patients with infected WON can be managed conservatively.

Predicting need for intervention in acute necrotizing pancreatitis following discharge- A single center experience in 525 patients

BACKGROUND AND AIMS

The clinical course of necrotizing pancreatitis (NP) is variable and unpredictable, with some patients managed conservatively, but a significant proportion become symptomatic and needing intervention for drainage and/or necrosectomy. The aim of this study was to identify patients based on baseline clinical and imaging metrics who will likely need intervention and therefore closer follow-up.

METHODS

All NP patients managed in our institution between 2010 and 2019 were identified from a prospective database and those who did not undergo intervention during initial hospitalization were followed longitudinally post discharge until clinical and imaging resolution of necrosis. Patients were categorized into a conservative arm or intervention arm (endoscopic/percutaneous/surgical drainage and/or necrosectomy) for criteria defined according to IAP/APA guidelines. Clinical and imaging characteristics during initial presentation were analyzed between the two groups to identify independent predictors for eventual intervention using multivariable logistic regression. A nomogram was designed based on factors that were significant as defined by P value < 0.05.

RESULTS

Among 525 patients, 340 who did not meet criteria for intervention during initial admission were included for study and followed for an average 7.4 ± 11.3 months. 140 were managed conservatively and 200 needed intervention (168 within 6 months and 32 after 6 months). Independent predictors of need for eventual intervention were white race [OR 3.43 (1.11-10.62)], transferred status [OR 3.37 (1.81-6.27)], and need for TPN [OR 6.86 (1.63-28.9)], necrotic collection greater than 6 cm [OR 8.66 (4.10-18.32)] and necrotic collection with greater than 75% encapsulation [OR 41.3 (8.29-205.5)]. A prediction model incorporating these factors demonstrated an area under the curve of 0.88.

CONCLUSIONS

Majority of NP patients do not need intervention during initial admission but may require drainage/necrosectomy mostly in the first 6 months following discharge. Need for subsequent intervention can be accurately predicted by a combination of clinical and imaging features on index admission.

RWON Study: The Real-World Walled-off Necrosis Study

Background/Aims

The management of walled-off necrosis (WON) has undergone a paradigm shift from surgical to nonsurgical modalities. Real-world data on the management of symptomatic WON are scarce.

Methods

Prospectively collected data of symptomatic WON cases were retrospectively evaluated. The treatment modalities used were medical management alone, percutaneous catheter drainage (PCD) or endoscopic drainage (ED), or a combination of PCD and ED. We compared clinical outcome among these modalities.

Results

A total of 264 patients were evaluated. The most common indications for drainage were pain and fever. Of the patients, 28% was treated with medical therapy alone, 31% with ED, 37% with PCD, and 4% with a combined approach. Technical success and clinical success were achieved in 93% and 91% of patients in the endoscopic arm and in 90% and 81% patients in the PCD arm, respectively (p=0.0004 for clinical success). Lower rates of complications (7% vs. 22%, p=0.005), readmission (20% vs. 34%, p=0.04), and mortality (4% vs. 19%, p=0.0012), and shorter hospital stay (13 days vs. 19 days, p=0.0018) were observed in the endoscopic group than in the PCD group.

Conclusions

ED of WON is better than PCD and is associated with lower mortality, fewer complications, and shorter hospitalization.

Clinical outcome of endoscopic treatment for symptomatic sterile walled-off necrosis

BACKGROUND

The majority of patients with symptomatic sterile walled-off necrosis (WON) can be treated conservatively. Although endoscopic transluminal drainage (ETD) is often performed in cases of persistent symptoms, post-procedural iatrogenic infection may occur. This study aimed to evaluate clinical outcomes after ETD of symptomatic sterile WON.

METHODS

This was a retrospective, multicenter, open-label case series of 56 patients with necrotizing pancreatitis who underwent ETD for symptomatic sterile WON between July 2001 and August 2018 at two tertiary referral hospitals. Primary end point was clinically relevant post-procedural iatrogenic infection, defined as need for endoscopic transluminal necrosectomy. Secondary end points included mortality, total number of interventions, hospital stay, and resolution of symptoms at 1-year follow-up.  RESULTS : ETD of sterile WON was performed in 56 patients (median age 55 years, 57 % male), who presented with abdominal pain (71 %), gastric outlet obstruction (45 %), jaundice (20 %), and failure to thrive (27 %). A total of 41 patients (73 %) developed clinically relevant post-procedural iatrogenic infection, resulting in a median of 3 (interquartile range [IQR] 2 - 4) endoscopic, radiological, and/or surgical interventions. Mortality rate was 2 %. Median total hospital stay was 12 days (IQR 6 - 17). Resolution of symptoms was reported in 40 of 46 patients (87 %) for whom long-term follow-up data were available (median follow-up 13 months, IQR 6 - 29).

CONCLUSIONS

ETD of symptomatic sterile WON resulted in high clinical success. Nonetheless, the majority of patients required additional reinterventions for clinically relevant post-procedural iatrogenic infection.

Open necrosectomy is feasible as a last resort in selected cases with infected pancreatic necrosis: a case series and systematic literature review

BACKGROUND

Acute pancreatitis is a common inflammatory pancreatic disorder, often caused by gallstone disease and frequently requiring hospitalization. In 80% of cases, a rapid and favourable outcome is described, while a necrosis of pancreatic parenchyma or extra-pancreatic tissues is reported in 10-20% of patients. The onset of pancreatic necrosis determines a significant increase of early organ failure rate and death that has higher incidence if infection of pancreatic necrosis (IPN) or extra-pancreatic collections occur. IPN always requires an invasive intervention, and, in the last decade, the advent of minimally invasive techniques has gradually replaced the employment of the open traditional approach. We report a series of three severe cases of IPN managed with primary open necrosectomy (ON) and a systematic review of the literature, in order to understand if emergency surgery still has a role in the current clinical practice.

METHODS

From January 2010 to January 2020, 3 cases of IPN were treated in our Academic Department of General and Emergency Surgery. We performed a PubMed MEDLINE search on the ON of IPN, selecting 20 from 654 articles for review.

RESULTS

The 3 cases were male patients with a mean age of 61.3 years. All patients referred to our service complaining an evolving severe clinical condition evocating a sepsis due to IPN. CT scan was the main diagnostic tool. Patients were initially conservatively managed. In consideration of clinical worsening conditions, and at the failure of conservative and minimal invasive treatment, they were, finally, managed with emergency ON. Patients reported no complications nor procedure-related sequelae in the follow-up period.

CONCLUSION

The ON is confirmed to be the last resort, useful in selected severe cases, with a defined timing and in case of proven non-feasibility and no advantage of other minimally invasive approaches.

Spontaneous regression of asymptomatic walled-off pancreatic necrosis

INTRODUCTION

Asymptomatic walled-off pancreatic necrosis (WOPN) should be treated conservatively, irrespective of the extent and size of the necrosis. The aim of this study was to evaluate the efficacy and safety of a strategy involving the observation of patients with asymptomatic WOPN over a long period of time.

MATERIAL AND METHODS

This study involved the retrospective analysis of 368 patients hospitalized in our department between 2010 and 2016, due to acute pancreatitis and its consequences in the form of pancreatic and peripancreatic fluid collection.

RESULTS

Walled-off pancreatic necrosis was identified in 168/368 (46%) patients. 124/168 (74%) patients with WOPN required interventional treatment due to clinical symptoms arising from the presence of the WOPN. Asymptomatic WOPN was identified in 44/168 (26%) patients. The mean observation time of patients with asymptomatic WOPN was 417.02 days (range: 47-1149 days). Only 1 out of the 44 patients (2%) failed to complete the follow-up. Complete regression of WOPN occurred in 30/44 (68%) patients. The presence of symptoms related to WOPN were identified in 13/44 (30%) patients during the observation. The most frequent indication for interventional treatment of WOPN was infection of the pancreatic necrosis, which was identified in 6/13 patients (46%). Altogether, 137/168 (82%) patients with WOPN required interventional treatment.

CONCLUSIONS

The majority of patients with WOPN required interventional treatment. This study provided evidence to support the view that careful observation of patients with asymptomatic WOPN is an efficient and safe treatment strategy. Long-term observation of such patients showed that most will experience spontaneous regression of asymptomatic WOPN without any other form of interventional treatment.

Natural course of asymptomatic walled off pancreatic necrosis

INTRODUCTION

There is paucity of data on natural course of asymptomatic walled off necrosis (WON).

OBJECTIVE

To study the natural course as well as outcome of conservative management in patients with asymptomatic WON.

METHODS

Retrospective analysis of prospectively maintained data base of patients with asymptomatic WON presenting to us 4-6 weeks after an episode of acute necrotising pancreatitis (ANP).

RESULTS

Forty three patients (37 M; mean age: 38.2 ± 10.4 years) with asymptomatic WON were studied. The size of WON ranged from 5 to 16 cm (mean 8.2 ± 2.2 cm). The site of WON was head, body and tail in 5 (11%), 34 (79%) and 4 (10%) patients respectively. Thirty of 43 patients (70%) patients did not have any complications during the expectant management period of 3 weeks-32 months with 13 (30%) patients having spontaneous resolution within 6.2 ± 3.4 months. Thirteen (30%) patients became symptomatic or developed complication within 3.2 ± 1.3 months. These were refractory pain (n = 7), infection (n = 4), spontaneous rupture into gastrointestinal tract (n = 5; stomach in 3, duodenum in 1 and colon in 1 patient respectively) and bleeding from splenic artery pseudoaneursym in 1 patient.

CONCLUSIONS

Majority of patients with asymptomatic WON have an uneventful clinical course. However, one third patients will develop symptoms/complications requiring interventional treatment.

Management of (Peri)Pancreatic Collections in Acute Pancreatitis

The development of (peri)pancreatic fluid collections are frequent local complications in acute pancreatitis. These collections are classified as early (acute peripancreatic fluid collection or acute necrotic collection) or late (walled-off necrosis or pseudocyst). The majority of pancreatic fluid collections resolve spontaneously and do not require intervention. However, infection may require intervention. Interventions may include endoscopic or percutaneous catheter drainage, or in a next step endoscopic or surgical necrosectomy, minimally invasive or open. The best timing for the first intervention is still under investigation. Whereas some use antibiotics to postpone intervention until the stage of walled-off necrosis, others drain earlier. Endoscopic drainage of (peri)pancreatic fluid collections is now the preferred approach of drainage due to reduced morbidity as compared to surgical or percutaneous drainage. However, each collection must be treated according to a tailored approach. The final treatment should take into consideration anatomic characteristics, patient preference, comorbidity profile of the patient, and physician discretion. This review summarizes the current evidence on the treatment of (peri)pancreatic fluid collections.

Pancreatic Necrosis and Gas in the Retroperitoneum: Treatment with Antibiotics Alone

OBJECTIVE:

To present our experience in the management of patients with infected pancreatic necrosis without drainage.

METHODS:

The records of patients with pancreatic necrosis admitted to our facility from 2011 to 2015 were retrospectively reviewed.

RESULTS:

We identified 61 patients with pancreatic necrosis. Six patients with pancreatic necrosis and gas in the retroperitoneum were treated exclusively with clinical support without any type of drainage. Only 2 patients had an APACHE II score >8. The first computed tomography scan revealed the presence of gas in 5 patients. The Balthazar computed tomography severity index score was >9 in 5 of the 6 patients. All patients were treated with antibiotics for at least 3 weeks. Blood cultures were positive in only 2 patients. Parenteral nutrition was not used in these patients. The length of hospital stay exceeded three weeks for 5 patients; 3 patients had to be readmitted. A cholecystectomy was performed after necrosis was completely resolved; pancreatitis recurred in 2 patients before the operation. No patients died.

CONCLUSIONS:

In selected patients, infected pancreatic necrosis (gas in the retroperitoneum) can be treated without percutaneous drainage or any additional surgical intervention. Intervention procedures should be performed for patients who exhibit clinical and laboratory deterioration.