10.1055/a-1070-9168Once upon a time … there was a bleeding visceral artery pseudoaneurysm. This extremely
rare condition, with an incidence of 0.01 % to 0.2 %, usually occurs after vascular
injuries or erosions such as in trauma or inflammation [1]. The leading cause is represented by chronic pancreatitis (CP). Sixty-eight percent
of visceral artery pseudoaneurysms are secondary to pancreatitis and pseudocyst formation,
with up to 17 % of patients with chronic pancreatitis developing pseudoaneurysms.
Although prevalence of a pseudoaneurysm in CP is not high, in three of four cases
it may bleed, either into the gastrointestinal tract or pancreatic duct, simulating
upper gastrointestinal bleeding, or directly into the peritoneal or retroperitoneal
cavity, with potentially catastrophic outcomes. Indeed, in the setting of complicated
chronic pancreatitis, bleeding has high morbidity and mortality. True visceral aneurysms,
in which all three layers are involved, have very low risk of bleeding. False or pseudo-aneurysms
arise from a breach of the inner-wall layers, resulting in bulging of the adventitial
layer, and carry a very high risk of rupture [2]
[3].
For both elective and nonelective therapy to date, open and laparoscopic surgical
approaches, as well as endovascular interventions have been employed for this condition.
In the last 15 years, a few case reports and small case series have appeared in the
literature showing the feasibility of endoscopic ultrasound (EUS)-guided obliteration
of visceral pseudoaneurysm by means of glue or thrombin injection, alone or combined
with coil deployment [4]
[5].
In this issue of the journal, Maharshi et al. described the technical aspect, outcomes
and follow-up of a prospective series of eight patients who underwent EUS-guided thrombin
injection for management of visceral pseudoaneurysms [6]. Patients enrolled were considered not suitable for an endovascular approach due
to technical aspects or economic evaluation. All patients had symptomatic pseudoaneurysms,
that is, pain and bleeding. The majority of patients were suffering from complicated
CP. Technical success was achieved in all but one case, which required an additional
procedure to reach obliteration. No adverse events occurred with a median follow-up
of 3 months.
The results demonstrated in this paper are encouraging. Nevertheless, should we add
this procedure to the ever-growing list of EUS interventional procedures? Are we really
ready for prime time? Despite the lack of specific guidelines, with surgical or endovascular
approaches still equally contemplated, according to European Society Gastrointestinal
Endoscopy guidelines on endoscopic treatment of chronic pancreatitis (latest update
2018), in case of arterial pseudoaneurysm close to a CP-related pseudocyst, arterial
embolization is “strongly” recommended prior to endoscopic drainage, with “low quality
of evidence” [7].
Even if not all pseudoaneurysms arise in the setting of chronic pancreatitis, they
surely represent the most challenging cases, above all for a surgical approach. Moreover,
increasing use of an EUS-guided approach for complications of CP (such as EUS-guided
pancreatic fluid collection drainage) especially with introduction of lumen apposing
metal stents on the market, has led us to face more situations with potential risk
of bleeding from a pseudoaneurysm. EUS-guided obliteration could represent a significant
and fashionable alternative to an endovascular route.
However, there remain many open questions regarding careful evaluation of the pseudoaneurysm’s
characteristics as it relates to increased embolic risk; use of coils, choice of glue
or human thrombin or a combination of more than one. These issues are still not clear
in angioembolization practice. Should an EUS-guided approach be the preferred salvage
procedure in case of early or delayed rebleeding even if an endovascular route is
feasible? Should only false or pseudo-aneurysm be the target or could a true visceral
aneurysm be a target, perhaps outside the setting of chronic pancreatitis or another
abdominal syndrome? Usually, randomized controlled trials are claimed to resolve open
questions in clinical management of controversial entities. In the case of this procedure,
there have been too few papers, and too few patients encountered (the current series
being the largest, counting eight patients). This warrants at least larger retrospective
studies and carefully evaluation before addressing specific and powerful outcomes.
So, ultimately: yes, we may be ready for EUS-guided vascular treatment of visceral
artery pseudoaneurysm, but still with a “low quality of evidence.”
