Visceral artery pseudoaneurysm (VA-PSA) is an important complication that can occur after pancreatic surgery and in the setting of acute and chronic pancreatitis. “VA-PSA can significantly impact patient outcomes and requires prompt identification and treatment,” explains Thomas K. Maatman, MD. “The prevalence of VA-PSA in necrotizing pancreatitis, its ideal treatment strategy, and its impact on patient outcomes has not been reported in a large cohort of patients.”

While published literature has provided clinical insights on the causes and effects of arterial pseudoaneurysm in patients with pancreatitis, research is lacking on the development of VA-PSA in those with necrotizing pancreatitis. Previous studies have been limited to case reports, small case series, or data collected from only a few participants with necrotizing pancreatitis who were part of mixed cohorts of patient with chronic pancreatitis and those who underwent pancreatic surgery.

For a study published in the Canadian Journal of Surgery, Dr. Maatman and colleagues evaluated the incidence, presentation, treatment, and outcomes associated with VA-PSA in patients with necrotizing pancreatitis. “We wanted to describe the natural history of VA-PSA in necrotizing pancreatitis,” Dr. Maatman says. “We also wanted to outline its clinical presentation and treatment strategy so that physicians can promptly diagnosis and treat these patients.”

Key Findings

The study team analyzed data from 647 patients with necrotizing pancreatitis who were treated between 2005 and 2017 at Indiana University Health University Hospital. “VA-PSA developed in 4% of patients with necrotizing pancreatitis,” says Dr. Maatman. “We also found that VA-PSA could involve practically any visceral artery, with the splenic artery being the most common. The clinical presentation was most commonly bloody drain output or an incidental finding identified on CT imaging. However, the presentation of VA-PSA could also include new or changing abdominal pain, gastrointestinal bleeding, downward trending hemoglobin, or shock.” Notably, patients older than 50 years of age and those with organ failure were more likely to develop VA-PSA (Table).

All participants in the study were treated within 24 hours of their VA-PSA diagnosis and 89% who developed VA-PSA were successfully treated with percutaneous angioembolization. Among patients who developed VA-PSA, the mortality rate before necrotizing pancreatitis resolved was 25%, compared with an approximate 8% rate seen in those who did not develop a VA-PSA. “Overall, VA-PSA was associated with a 4-fold increase in mortality in patients with necrotizing pancreatitis and was best treated by percutaneous angioembolization,” says Dr. Maatman.

Important Implications

Data from the study provide key insights into VA-PSA in the setting of necrotizing pancreatitis. “VA-PSA is a potentially lethal complication for patients with necrotizing pancreatitis,” Dr. Maatman says. “Clinicians should be vigilant about making an early diagnosis because—despite advances in management—the mortality rate for patients with necrotizing pancreatitis is especially high in those who develop VA-PSA.” In addition, the study team recommended that age and risks for organ failure be factored into treatment decisions.

The data also highlight the importance of evaluating the entire visceral arterial tree, including the celiac axis and branches of the superior mesenteric artery, when treating patients. The authors added that the findings on patients presenting with new or changed pain, gastrointestinal bleeding, and catastrophic hemorrhage and shock highlight the diversity of this patient group and illustrate the need for increased awareness of the pathology of VA-PSA in those with necrotizing pancreatitis.

Future Research

Several questions remain on the optimal management strategy for these patients, according to Dr. Maatman. “For example, after treating an identified VA-PSA, it would be helpful if future research explored if peri-pancreatic necrosis should be managed more aggressively to mitigate risks of further VA-PSA development,” he says. “We also need to determine the appropriate timing of necrosis intervention after identifying and treating VA-PSA. Furthermore, studies on the risks of VA-PSA development in at-risk patients who receive an earlier necrosis intervention are warranted. Establishing which necrosis intervention is safest and its impact on rates of developing VA-PSA is also paramount.”

References

Maatman TK, Heimberger MA, Lewellen KA, et al. Visceral artery pseudoaneurysm in necrotizing pancreatitis: incidence and outcomes. Can J Surg. 2020;63(3):E272-E277. Available at: http://canjsurg.ca/wp-content/uploads/2020/05/63-3-E272.pdf.

Zyromski NJ, Vieira C, Stecker M, et al. Improved outcomes in postoperative and pancreatitis-related visceral pseudoaneurysms. J Gastrointest Surg. 2007;11:50-5.

Van Grinsven J, van Brunschot S, Bakker O, et al. Diagnostic strategy and timing of intervention in infected necrotizing pancreatitis: an international expert survey and case vignette study. HPB. 2016; 18:49-56.